score
float64 4
5.34
| text
stringlengths 256
572k
| url
stringlengths 15
373
|
|---|---|---|
4.125 | Through this post I am going to explain How Linear Regression works? Let us start with what is regression and how it works? Regression is widely used for prediction and forecasting in field of machine learning. Focus of regression is on the relationship between dependent and one or more independent variables. The “dependent variable” represents the output or effect, or is tested to see if it is the effect. The “independent variables” represent the inputs or causes, or are tested to see if they are the cause. Regression analysis helps to understand how the value of the dependent variable changes when any one of the independent variables is varied, while the other independent variables are kept unchanged. In the regression, dependent variable is estimated as function of independent variables which is called regression function. Regression model involves following variables.
- Independent variables X.
- Dependent variable Y
- Unknown parameter θ
In the regression model Y is function of (X,θ). There are many techniques for regression analysis, but here we will consider linear regression.
In the Linear regression, dependent variable(Y) is the linear combination of the independent variables(X). Here regression function is known as hypothesis which is defined as below.
hθ(X) = f(X,θ)
Suppose we have only one independent variable(x), then our hypothesis is defined as below.
The goal is to find some values of θ(known as coefficients), so we can minimize the difference between real and predicted values of dependent variable(y). If we take the values of all θ are zeros, then our predicted value will be zero. Cost function is used as measurement factor of linear regression model and it calculates average squared error for m observations. Cost function is denoted by J(θ) and defined as below.
As we can see from the above formula, if cost is large then, predicted value is far from the real value and if cost is small then, predicted value is nearer to real value. Therefor, we have to minimize cost to meet more accurate prediction.
Linear regression in R
R is language and environment for statistical computing. R has powerful and comprehensive features for fitting regression models. We will discuss about how linear regression works in R. In R, basic function for fitting linear model is lm(). The format is
fit <- lm(formula, data)
where formula describes model(in our case linear model) and data describes which data are used to fit model. The resulting object(fit in this case) is a list that contains information about the fitted model. The formula typically written as
Y ~ x1 + x2 + … + xk
where ~ separates the dependent variable(y) on the left from independent variables(x1, x2, ….. , xk) from right, and the independent variables are separated by + signs. let’s see simple regression example(example is from book R in action). We have the dataset women which contains height and weight for a set of 15 women ages 30 to 39. we want to predict weight from height. R code to fit this model is as below.
>fit <-lm(weight ~ height, data=women) >summary(fit)
Output of the summary function gives information about the object fit. Output is as below
Call: lm(formula = weight ~ height, data = women) Residuals: Min 1Q Median 3Q Max -1.7333 -1.1333 -0.3833 0.7417 3.1167 Coefficients: Estimate Std. Error t value Pr(>|t|) (Intercept) -87.51667 5.93694 -14.74 1.71e-09 *** height 3.45000 0.09114 37.85 1.09e-14 *** --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 Residual standard error: 1.525 on 13 degrees of freedom Multiple R-squared: 0.991, Adjusted R-squared: 0.9903 F-statistic: 1433 on 1 and 13 DF, p-value: 1.091e-14
Let’s understand the output. Values of coefficients(θs) are -87.51667 and 3.45000, hence prediction equation for model is as below
Weight = -87.52 + 3.45*height
In the output, residual standard error is cost which is 1.525. Now, we will look at real values of weight of 15 women first and then will look at predicted values. Actual values of weight of 15 women are as below
Output 115 117 120 123 126 129 132 135 139 142 146 150 154 159 164
Predicted values of 15 women are as below
Output 1 2 3 4 5 6 7 8 9 112.5833 116.0333 119.4833 122.9333 126.3833 129.8333 133.2833 136.7333 140.1833 10 11 12 13 14 15 143.6333 147.0833 150.5333 153.9833 157.4333 160.8833
We can see that predicted values are nearer to the actual values.Finally, we understand what is regression, how it works and regression in R.
Here, I want to beware you from the misunderstanding about correlation and causation. In the regression, dependent variable is correlated with the independent variable. This means, as the value of the independent variable changes, value of the dependent variable also changes. But, this does not mean that independent variable cause to change the value of dependent variable. Causation implies correlation , but reverse is not true. For example, smoking causes the lung cancer and smoking is correlated with alcoholism. Many discussions are there on this topic. if we go deep into than one blog is not enough to explain this.But, we will keep in mind that we will consider correlation between dependent variable and independent variable in regression.
In the next blog, I will discuss about the real world business problem and how to use regression into it.
Liked this? Get more by Signing up for our free newsletter!
Would you like to understand the value of predictive analysis when applied on web analytics data to help improve your understanding relationship between different variables? So register now for our Upcoming Webinar: How to perform predictive analysis on your web analytics tool data. Get More Info & Book Your Seat Now! | http://www.tatvic.com/blog/linear-regression-using-r/ |
4.25 | You can use the teaching and learning outcomes in each phase to support your unit planning and help you plan for the children's learning across the unit.
The teaching sequences model good practice. You will need to tailor and develop this unit to match the needs of your pupils and the curriculum of your school.
- Phase 1: Familiarisation
Around four days
Prior to teaching the unit, whole-class collections of fantasy or science fiction texts are established to support independent reading for pleasure. Texts could include films, comics, picture books, television programmes and written texts. One particular text could be chosen as the whole-class novel for children to experience how a narrative builds over a period of time.
- As a whole class, read, share and discuss different fantasy or science fiction texts. Investigate the themes of the narratives and identify the key elements of the narrative structure using an interactive whiteboard (IWB) to create a framework for a story skeleton plan. The framework can be printed out as a template plan for children later in the unit.
- Compare and contrast settings from the texts. Display the text using the IWB and use the IWB tools to highlight how the author created mood and atmosphere. Note the findings on the IWB setting and atmosphere comparison grid.
- Children read descriptions of other fantasy settings to identify and discuss the atmosphere evoked. Children compare the settings to find common techniques for creating different atmospheres and highlight evidence in the text.
- During the plenary, collate children's findings on the IWB grid to decide which atmospheres are most commonly associated with which settings.
- In shared reading, return to the IWB comparison grid. Explain that, for children's writing to be successful, the atmosphere of the setting influence the characters' reactions. Different characters may react in different ways. Revisit the texts from previous sessions and model how to highlight evidence that illustrates how the author has communicated to the reader the thinking and feelings of different characters, for example, descriptions of their facial expressions, body posture, speech and behaviour.
- Divide children into groups. Each group focuses on one of the texts used in the previous sessions. Ask each child in a group to focus on one particular character, for example, the main character or the main character's best friend. Children locate and highlight evidence in the texts that demonstrates how the author has shown what a character is thinking and feeling in response to a setting.
- During the plenary, explore the range of responses displayed by characters, using the emotional response scale on the IWB. Identify the range of reactions displayed by characters in response to a setting and record the findings on the comparison grid.
Children can express opinions about an author's intended impact on a reader.
- Phase 2: Capturing ideas and planning
Around seven days
A range of photographs is needed to create children's fantasy settings using photo editing software. Children could source the images on the Internet or take their own digital photographs using the local environment.
- Remind children about the need to have settings that create a particular atmosphere. Explain that children are going to use the filters and cutting tool in photo editing software to create their own fantasy settings to support their writing. Model how to add filters to a photograph of a landscape. Experiment with the filters and discuss how, for example, changing the colour saturation can make the image appear warm and welcoming or cold and hostile. Save the different examples of enhanced images in a central folder for children to access later.
- Arrange children into pairs. Ask them to take four of the images they have sourced and alter the images using the software program. Children keep notes of the filters or effects they have used to create particular atmospheres so that the process can be repeated at a later date or shared with peers. Ask children to save the images in a central folder using an appropriate word to describe the atmosphere of the image.
- During the plenary, ask each group to choose one image to share with the rest of the class. From their notes the group describe which filters were used and what atmosphere these are intended to communicate to a reader. Other members of the class can provide feedback on the effectiveness of the filters used. Time will be needed to enable children to make adjustments to their images in response to the feedback.
- In the shared session, project one of the images made in the previous session onto the IWB. Ask children to refer back to the notes made during reading about characters' responses to settings. Discuss how the image could make the characters feel and decide on appropriate facial gestures and body postures to reflect their inner thoughts. Freeze-frame children in front of the images showing various responses to the settings. Take digital photographs of the freeze-frames to record the ideas and for later use to support children's writing.
- Return to the story skeleton plan on the IWB created in phase 1. Insert onto the page the four altered images of fantasy settings made in phase 2 and discuss which of the four settings would be most suitable at different stages in the story. Experiment with the order of the images, alternating threatening environments with calmer places of safety. Explain to children how alternating the setting in this way gives the reader a period of rest and increases the impact of the next dramatic encounter.
- Each group repeats the ordering process with their own images. Encourage children to copy and paste the images into different orders so that the different alternatives can be kept for future reference and to enable discussion and comparison.
- Encourage the children to critically reflect on the different order of their images to assess which sequence of settings would have the most impact on a reader, creating the feeling of tension followed by a breathing space.
- Use modelled and shared teaching approaches to demonstrate how to use the planner and the image sequences as a support for telling an oral version of a fantasy narrative. Small-world role-play figures could be used to provide a stimulus for the main characters. Remind children that each box on the story planner will be equivalent to one paragraph of their final narrative.
- Children follow the example set in the shared session and work in pairs or small groups to re-tell their narratives. Encourage children to use appropriate language to describe the characters' reactions to the settings and to develop the narrative in paragraphs using the boxes as a support to structure their ideas.
- Ask children to add brief notes to their paragraph planner to remind them of ideas gained from the oral storytelling.
- To extend the use of adverbs and conjunctions within paragraphs, use the original text examples and identify key words and phrases used by the authors. Use the IWB to create a word bank. Drag and drop words onto the planner and model how to include the words in a second oral draft of the narrative. Keep the word bank on display to support children in adding appropriate adverbs and conjunctions to their own plans. Children then perform their second oral draft with their peer, making sure that they have included the cohesive words and phrases.
- Encourage children to add notes of the vocabulary used in the session onto their planner.
Children can tell a story orally based on their role-play using the organisational and language features of the text type.
- Phase 3: Writing
Around seven to nine days
- Use modelled, shared and supported composition to write a first draft of the narrative. Refer back to the word bank, plans and oral versions of the narrative to model, drawing on a range of sources to support the writing process. Make explicit reference to organising the ideas from each box on the paragraph planner into written paragraphs. Using supported composition, children suggest different options for connecting the ideas within a paragraph using their oral storytelling and the word bank created in previous sessions.
- Extend the writing process over an appropriate number of days to suit the pace and confidence of the children. Assess the progress of the writing against the success criteria of the text type at appropriate intervals in the writing process. Provide time for children to revise and adapt their drafts based on the assessments against the success criteria.
- Review the use of adverbs and conjunctions to create cohesion within a paragraph. Use supported composition to re-draft the whole-class narrative on the IWB ensuring that the ideas flow naturally for the reader.
- Ask children, working in pairs in the shared session, to review their work and revise the cohesive devices that link the ideas together within and across the paragraphs.
- During the plenary, ask children to identify three successful cohesive devices they have used and one area of the narrative that needs a stronger link between ideas. Share the top three ideas from the children as a class and provide time for children to use the ideas to alter the area they identified as a possible weakness.
- Publish the work in an appropriate format. Children's narratives could be word processed with the images created as part of the planning and inserted as illustrations. Additional illustrations of the main characters could be created and added by scanning in children's drawings or using photo editing software.
Children can write a narrative using paragraphs to organise ideas maintaining cohesion within and between paragraphs. | http://webarchive.nationalarchives.gov.uk/20110809091832/http:/www.teachingandlearningresources.org.uk/node/2937 |
4 | Factory Method Pattern
An important facet of system design is the manner in which objects are created. One of the most widely used creational patterns is the Factory Method Pattern.
Creational patterns describe object-creation mechanisms that enable greater levels of reuse in evolving systems
Let’s consider that, the client is an object that requires an instance of another object (the product) for some purpose. Rather than creating the product instance directly, the client delegates this responsibility to the factory. Once invoked, the factory creates a new instance of the product, passing it back to the client. Put simply, the client uses the factory to create an instance of the product.
CLIENT ---uses----> FACTORY (Creator) ----create---->PRODUCT
The Factory completely abstracts the creation and initialization of the Product from the Client, which helps client to focus on its discrete role. As the product implementation changes in future, the client remains unchanged.
“Factory Method Pattern defines an interface for creating an object but let’s subclass decide which class to instantiate”
Most implementations of the Factory method pattern use two abstract classes, Factory and Product.
Consider the following example for Factory Method Pattern.
Let consider AbstractProduct.java class as abstract product class which return the cost of the product. This abstract product class is extended and two concrete classes are created i.e. ProductSubClass_One.java and ProductSubClass_Sec.java
ProductSubClass_One.java-This class extends AbstractProduct class and provide first concrete implementation of getProductCost() method.
ProductSubClass_Sec.java-This class extends AbstractProduct class and provide second concrete implementation of getProductCost() method.
Next consider the Factory (Creator) class AbstractCreator.java is an abstract class which contains one method createProduct(String) method for creating the Product.
Now we will create a concrete class of the Factory (creator) i.e. ConcreteCreator.java which override the createProduct (String) method to return object of the concrete Product Sub Class based on the type.
Till now we have created Factory and Product related classes, now we will create a Client class which in turn uses Factory (creator) class to obtain a Product object.
Here in this class we are creating a Factory (creator) object and using this factory object to obtain the product based on “type” which passed as argument in createProduct (String) method.
When we run the Client.java class we will get object of ProductSubClass_One class which gives following output.
Factory method pattern should be used,
- When the object creation depends upon the user data or some event;
- When object which is getting created is abstracted from the user;
- When the type of object created is to be decided at runtime. | http://technical-tutorials.blogspot.com/ |
4 | Pre-Algebra, Algebra 1, and Algebra 2 all require you to master new math skills. Do you find solving equations and word problems difficult in Algebra class? Are the exponents, proportions, and variables of Algebra keeping you up at night? Intercepts, functions, and expressions can be confusing to most Algebra students, but a qualified tutor can clear it all up! Our Algebra tutors are experts in math and specialize in helping students like you understand Algebra. If you are worried about an upcoming Algebra test or fear not passing your Algebra class for the term, getting an Algebra tutor will make all the difference.
Pre-algebra - The goal of Pre-algebra is to develop fluency with rational numbers and proportional relationships. Students will: extend their elementary skills and begin to learn algebra concepts that serve as a transition into formal Algebra and Geometry; learn to think flexibly about relationships among fractions, decimals, and percents; learn to recognize and generate equivalent expressions and solve single-variable equations and inequalities; investigate and explore mathematical ideas and develop multiple strategies for analyzing complex situations; analyze situations verbally, numerically, graphically, and symbolically; and apply mathematical skills and make meaningful connections to life's experiences.
Algebra I - The main goal of Algebra is to develop fluency in working with linear equations. Students will: extend their experiences with tables, graphs, and equations and solve linear equations and inequalities and systems of linear equations and inequalities; extend their knowledge of the number system to include irrational numbers; generate equivalent expressions and use formulas; simplify polynomials and begin to study quadratic relationships; and use technology and models to investigate and explore mathematical ideas and relationships and develop multiple strategies for analyzing complex situations.
Algebra II - A primary goal of Algebra II is for students to conceptualize, analyze, and identify relationships among functions. Students will: develop proficiency in analyzing and solving quadratic functions using complex numbers; investigate and make conjectures about absolute value, radical, exponential, logarithmic and sine and cosine functions algebraically, numerically, and graphically, with and without technology; extend their algebraic skills to compute with rational expressions and rational exponents; work with and build an understanding of complex numbers and systems of equations and inequalities; analyze statistical data and apply concepts of probability using permutations and combinations; and use technology such as graphing calculators.
College Algebra – Topics for this course include basic concepts of algebra; linear, quadratic, rational, radical, logarithmic, exponential, and absolute value equations; equations reducible to quadratic form; linear, polynomial, rational, and absolute value inequalities, and complex number system; graphs of linear, polynomial, exponential, logarithmic, rational, and absolute value functions; conic sections; inverse functions; operations and compositions of functions; systems of equations; sequences and series; and the binomial theorem.
No matter the level of the algebra course that the student is taking, we have expert tutors available and ready to help. All of our algebra tutors have a degree in mathematics, science, or a related field (like accounting). We are so confident in our algebra tutors that you can meet with them for free. Just ask your tutoring coordinator about our Meet and Greet program.
Our Tutoring Service
We offer our clients choice when searching for a tutor, and we work with you all the way through the selection process. When you choose to work with one of our tutors, expect quality, professionalism, and experience. We will never offer you a tutor that is not qualified in the specific subject area you request. We will provide you with the degrees, credentials, and certifications each selected tutor holds so that you have the same confidence in them that we do. And for your peace of mind, we conduct a nation-wide criminal background check, sexual predator check and social security verification on every single tutor we offer you. We will find you the right tutor so that you can find success! | http://www.advancedlearners.com/albuquerque/algebra/tutor/find.aspx |
4 | An introduction to the basics of Unicode, distilled from several earlier posts. In the interests of presenting the big picture, I have painted with a broad brush — large areas are summarized; nits are not picked; hairs are not split; wind resistance is ignored.
Unicode = one character set, plus several encodings
Unicode is actually not one thing, but two separate and distinct things. The first is a character set and the second is a set of encodings.
- The first — the idea of a character set — has absolutely nothing to do with computers.
- The second — the idea of encodings for the Unicode character set — has everything to do with computers.
The idea of a character set has nothing to do with computers. So let’s suppose that you’re a British linguist living in, say, 1750. The British Empire is expanding and Europeans are discovering many new languages, both living and dead. You’ve known about Chinese characters for a long time, and you’ve just discovered Sumerian cuneiform characters from the Middle East and Sanskrit characters from India.
Trying to deal with this huge mass of different characters, you get a brilliant idea — you will make a numbered list of every character in every language that ever existed.
You start your list with your own familiar set of English characters — the upper- and lower-case letters, the numeric digits, and the various punctuation marks like period (full stop), comma, exclamation mark, and so on. And the space character, of course.
01 a 02 b 03 c ... 26 z 27 A 28 B ... 52 Z 53 0 54 1 55 2 ... 62 9 63 (space) 64 ? (question mark) 65 , (comma) ... and so on ...
Then you add the Spanish, French and German characters with tildes, accents, and umlauts. You add characters from other living languages — Greek, Japanese, Chinese, Korean, Sanscrit, Arabic, Hebrew, and so on. You add characters from dead alphabets — Assyrian cuneiform — and so on, until finally you have a very long list of characters.
- What you have created — a numbered list of characters — is known as a character set.
- The numbers in the list — the numeric identifiers of the characters in the character set — are called code points.
- And because your list is meant to include every character that ever existed, you call your character set the Universal Character Set.
Congratulations! You’ve just invented (something similar to) the the first half of Unicode — the Universal Character Set or UCS.
Now suppose you jump into your time machine and zip forward to the present. Everybody is using computers. You have a brilliant idea. You will devise a way for computers to handle UCS.
You know that computers think in ones and zeros — bits — and collections of 8 bits — bytes. So you look at the biggest number in your UCS and ask yourself: How many bytes will I need to store a number that big? The answer you come up with is 4 bytes, 32 bits. So you decide on a simple and straight-forward digital implementation of UCS — each number will be stored in 4 bytes. That is, you choose a fixed-length encoding in which every UCS character (code point) can be represented, or encoded, in exactly 4 bytes, or 32 bits.
UTF-8 and variable-length encodings
UCS-4 is simple and straight-forward… but inefficient. Computers send a lot of strings back and forth, and many of those strings use only ASCII characters — characters from the old ASCII character set. One byte — eight bits — is more than enough to store such characters. It is grossly inefficient to use 4 bytes to store an ASCII character.
The key to the solution is to remember that a code point is nothing but a number (an integer). It may be a short number or a long number, but it is only a number. We need just one byte to store the shorter numbers of the Universal Character Set, and we need more bytes only when the numbers get longer. So the solution to our problem is a variable-length encoding.
Specifically, Unicode’s UTF-8 (Unicode Transformation Format, 8 bit) is a variable-length encoding in which each UCS code point is encoded using 1, 2, 3, or 4 bytes, as necessary.
In UTF-8, if the first bit of a byte is a “0″, then the remaining 7 bits of the byte contain one of the 128 original 7-bit ASCII characters. If the first bit of the byte is a “1″ then the byte is the first of multiple bytes used to represent the code point, and other bits of the byte carry other information, such as the total number of bytes — 2, or 3, or 4 bytes — that are being used to represent the code point. (For a quick overview of how this works at the bit level, see How does UTF-8 “variable-width encoding” work?)
Just use UTF-8
UTF-8 is a great technology, which is why it has become the de facto standard for encoding Unicode text, and is the most widely-used text encoding in the world. Text strings that use only ASCII characters can be encoded in UTF-8 using only one byte per character, which is very efficient. And if characters — Chinese or Japanese characters, for instance — require multiple bytes, well, UTF-8 can do that, too.
Byte Order Mark
Unicode fixed-length multi-byte encodings such as UTF-16 and UTF-32 store UCS code points (integers) in multi-byte chunks — 2-byte chunks in the case of UTF-16 and 4-byte chunks in the case of UTF-32.
Unfortunately, different computer architectures — basically, different processor chips — use different techniques for storing such multi-byte integers. In “little-endian” computers, the “little” (least significant) byte of a multi-byte integer is stored leftmost. “Big-endian” computers do the reverse; the “big” (most significant) byte is stored leftmost.
- Intel computers are little-endian.
- Motorola computers are big-endian.
- Microsoft Windows was designed around a little-endian architecture — it runs only on little-endian computers or computers running in little-endian mode — which is why Intel hardware and Microsoft software fit together like hand and glove.
Differences in endian-ness can create data-exchange issues between computers. Specifically, the possibility of differences in endian-ness means that if two computers need to exchange a string of text data, and that string is encoded in a Unicode fixed-length multi-byte encoding such as UTF-16 or UTF-32, the string should begin with a Byte Order Mark (or BOM) — a special character at the beginning of the string that indicates the endian-ness of the string.
Strings encoded in UTF-8 don’t require a BOM, so the BOM is basically a non-issue for programmers who use only UTF-8.
- Ned Batchelder’s Pragmatic Unicode. Highly recommended.
- The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!) (2003) by Joel Spolsky is good, and widely read, but now a bit dated. I think it is rather misleading in the prominence it gives to the BOM. | http://pythonconquerstheuniverse.wordpress.com/2012/03/16/unicode-the-basics/?like=1&_wpnonce=401286028f |
4.1875 | Brazilian and British scientists have been examining the heavy smoke plumes from wildfires in the Amazon, gathering data, to understand how the burning of biomass in South America is affecting the local weather and air quality. This might help close crucial gaps in climate models about how the process changes the Earth’s radiation balance.
The South American Biomass Burning Analysis (SAMBBA) mission uses a jet carrying a suite of sensor instruments to take measurements up to 12 km above the jungle’s canopy. Previous campaigns used smaller planes and flew lower, and were unable to observe some crucial processes. The Amazon is dominated by high-altitude convection clouds, and scientists aren’t sure how they process energy and how fire interferes with them, making weather predictions moot.
The scientists are using a LiDAR, which is a laser that measures how much light is being blocked by aerosol particles of smoke at various altitudes. This local dimming of the atmosphere can hamper photosynthesis, possibly drastically. Local measurements have shown a decrease of plant productivity of around 30%. There is no estimate for the Amazon in its entirety.
Aerosols might also produce a cooling effect at the surface, as well as warming mid-altitudes. Current climate models cannot account for such complex interactions, and therefore can’t predict how increasing carbon dioxide concentrations and burning biomass will affect the radiation balance of the Amazon.
Information on these aerosols is also important for global weather forecasts. SAMBBA will also allow scientists to measure the air quality in Amazonian cities. Concentrations of nitrogen oxides and other compounds that react to form polluting ozone at low altitudes are higher during the burning season in the Amazon than in heavily polluted areas of São Paulo. However, ozone-forming compounds have never been measured across the whole Amazon. | http://scitechdaily.com/amazon-fire-analysis-might-close-gaps-in-climate-models/ |
4.03125 | |Albania Table of Contents
Political chaos engulfed Albania after the outbreak of World War I. Surrounded in by insurgents Durrės, Prince Wilhelm departed the country in September 1914, just six months after arriving, and subsequently joined the German army and served on the Eastern Front. The Albanian people split along religious and tribal lines after the prince's departure. Muslims demanded a Muslim prince and looked to Turkey as the protector of the privileges they had enjoyed. Other Albanians became little more than agents of Italy and Serbia. Still others, including many beys and clan chiefs, recognized no superior authority. In late 1914, Greece occupied southern Albania, including Korēė and Gjirokastėr. Italy occupied Vlorė, and Serbia and Montenegro occupied parts of northern Albania until a Central Powers offensive scattered the Serbian army, which was evacuated by the French to Thessaloniki. Austro-Hungarian and Bulgarian forces then occupied about two-thirds of the country.
Under the secret Treaty of London signed in April 1915, the Triple Entente powers promised Italy that it would gain Vlorė and nearby lands and a protectorate over Albania in exchange for entering the war against Austria-Hungary. Serbia and Montenegro were promised much of northern Albania, and Greece was promised much of the country's southern half. The treaty left a tiny Albanian state that would be represented by Italy in its relations with the other major powers. In September 1918, Entente forces broke through the Central Powers' lines north of Thessaloniki, and within days Austro-Hungarian forces began to withdraw from Albania. When the war ended on November 11, 1918, Italy's army had occupied most of Albania; Serbia held much of the country's northern mountains; Greece occupied a sliver of land within Albania's 1913 borders; and French forces occupied Korēė and Shkodėr as well as other with sizable Albanian populations, regions such as Kosovo, which were later handed over to Serbia.
Source: U.S. Library of Congress | http://countrystudies.us/albania/23.htm |
4.15625 | Not Just Black and White
Not Just Black and White is a science project that teaches kids about color and light. Different colors will appear when you and your kids view spinning black-and-white circles.
What You'll Need:
- White paper
- Black paper
- Black marker
- Knitting needle
- Paper plate
Learn About Not Just Black and White:Step 1: Draw and cut out 3 circles of white paper that are each 5-1/2 inches in diameter. Put a small hole in the center of each circle.
Step 2: Draw and cut out a circle of black paper that is 5-1/2 inches in diameter. Cut the black circle in half. Cut 1 of the halves in half.
Step 3: Use these materials to make several different disks. Glue a black half-circle onto a white circle so that the disk is 1/2 black and 1/2 white. Glue a black quarter-circle onto a white circle so that the disk is 1/4 black and 3/4 white.
Step 4: Using a black marker, divide 1 white disk into 8 pie-wedge shapes. Color some of the pie wedges black, leaving others white.
Step 5: Wrap some tape around the middle of a knitting needle. Put the knitting needle through the middle of a 6-inch paper plate, and push the plate down to rest on the tape.
Step 6: Spin the plate. Be sure it spins smoothly and doesn't wobble. Use this as your spinner. Poke the knitting needle through the hole in the center of 1 disk, and let the disk rest on the paper plate.
Step 7: Spin the plate, and look at the disk as it spins. What colors do you see? Do you see different colors when the disk is spinning quickly or slowly? Spin the other disks to see what colors they produce.
Colors at a Distance is a science project that teaches kids about visual perception. Learn about Colors at a Distance on the next page of science projects for kids: spectrum of colors. | http://tlc.howstuffworks.com/family/science-projects-for-kids-spectrum-of-colors1.htm |
4 | An elaborate system of leads spreads across our hearts. These leads – the heart's electrical system – control our pulse and coordinate contraction of the heart chambers. While the structure of the human heart has been known for a long time, the evolutionary origin of our conduction system has nevertheless remained a mystery. Researchers have finally succeeded in showing that the spongy tissue in reptile hearts is the forerunner of the complex hearts of both birds and mammals. The new knowledge provides a deeper understanding of the complex conductive tissue of the human heart, which is of key importance in many heart conditions.
"The heart of a bird or a mammal – for example a human – pumps frequently and rapidly. This is only possible because it has electrically conductive tissue that controls the heart. Until now, however, we haven't been able to find conductive tissue in our common reptilian ancestors, which means we haven't been able to understand how this enormously important system emerged," says Bjarke Jensen, Department of Bioscience, Aarhus University. Along with Danish colleagues and colleagues from the University of Amsterdam, he can now reveal that the genetic building blocks for highly developed conductive tissue are actually hidden behind the thin wall in the spongy hearts of reptiles. The new results have just been published in the journal PLoS ONE.
"We studied the hearts of cold-blooded animals like lizards, frogs and zebrafish, and we investigated the gene that determines which parts of the heart are responsible for conducting the activating current. By comparing adult hearts from reptiles with embryonic hearts from birds and mammals, we discovered a common molecular structure that's hidden by the anatomical differences," explains Dr Jensen.
Since the early 1900s, scientists have been wondering how birds and mammals could have developed almost identical conduction systems independently of each other when their common ancestor was a cold-blooded reptile with a sponge-like inner heart that has virtually no conduction bundles.
The studies show that it is simply the spongy inner tissue in the foetal heart that gets stretched out to become a fine network of conductive tissue in adult birds and mammals. And this knowledge can be put to use in the future.
"Our knowledge about the reptilian heart and the evolutionary background to our conductive tissue can provide us with a better understanding of how the heart works in the early months of foetal life in humans, when many women miscarry, and where heart disorders are thought to be the leading cause of spontaneous abortion," says Professor Tobias Wang.
Explore further: Potato may help feed Ethiopia in era of climate change
More information: www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0044231 | http://phys.org/news/2012-09-reptile-hearts.html |
4.03125 | The Missouri Indians first came to the attention of Europeans through the account left from the Louis Jolliet and Father Jacques Marquette expedition in 1673. On the Marquette map, they are referred to as the "Oumessourit." This is the Illinois name for them, and can be translated as the "people of the dugout canoes." It is not what the Missouri called themselves, but the name would remain.
The Missouri were not newcomers to the area. While the Osage and Illinois had been pushed westward from the east after Europeans started settling the East Coast, the Missouri had been here for centuries. The earliest Oneota (ancestral Missouri) site in the area dates from A.D. 1250, and the Missouri Indian village (the Utz site) dates from as early as A.D. 1450.
The Missouri were typical prairie dwellers. They lived in large rush mat-covered houses with from 15-25 people in each. These longhouses were fairly widely spaced across the village, which contained approximately 5,000 people at first European contact. The people grew corn, beans and squash in small agricultural plots, probably in the bottomlands. The crops were planted in the spring, and the people stayed in the village through the early stages of the crops. In June, they left on the summer hunt, principally seeking bison. In August, they returned to harvest the crops. While most remained for the rest of the year, the men often left on other hunting trips through the winter.
The Old Fort, an irregular, double-ditched earthwork located in the park, was built by the ancestral Missouri Indians (Oneota). Archaeological investigations have not yet revealed the nature and purpose of this interesting man-made feature of the landscape.
Because the Missouri were the first group encountered on the Missouri River, they were visited early by the French. Probably the first direct contact with Europeans came in 1680 or 1681 when two traders were captured by the Missouri and taken to their village. The first recorded encounter was in 1682 when French explorer Sieur de La Salle, Robert Cavelier, was on his way south to the mouth of the Mississippi River. His party came upon a group of Tamaroa (Illinois Indians) and some Missouri on their way to conduct a raid on the Osage Indians.
About 1715, the Little Osage Indians moved from western Missouri and established a village near the Missouri to have greater access to fur traders. The Missouri often stopped traders from going upriver to obtain guns, lead and other items from them. Following the Big Osage and Little Osage, the Missouri contributed significantly to the fur trade in St. Louis.
There are a number of accounts from the early part of the 18th century, with many centering around the construction of Fort Orleans by Etienne Veniard de Bourgmond across the river from the Missouri Indian village in 1721. De Bourgmond's account of his visit to the Kansa Indians the following year illustrates that the Missouri Indians had already been heavily affected by European diseases. When de Bourgmond came down with a fever, most of the people with him fled the expedition. Fort Orleans was abandoned in 1728, and it appears that shortly thereafter, the remaining Missouri moved to the Late Missouri Indian village near the Little Osage Indians.
Disease and warfare with other tribes took their toll on the population. By 1758, there were only about 750 Missouri remaining. Warfare with the Sac and Fox and Ioway in the late 18th century forced the Little Osage and Missouri to abandon the area. Most of the surviving Missouri joined with the Otoes in Nebraska.
In 1804, the Meriwether Lewis and William Clark Expedition passed the area and noted the location of the Late Missouri Indian village and the village of the Little Osage. Farther upriver, the first Indians they met were the remainder of the Missouri living with the Otoes. They estimated that there were 300 Missouri there at that time. By 1829, there were only 80 Missouri alive; 40 in 1882; and the last full-blooded Missouri Indian died about 1908. However, some members of the Otoe-Missouria Nation of Oklahoma continue to count their linage as Missouri. | http://mostateparks.com/page/55157/homeland-missouri-indians |
4.09375 | 3.8 Related Rates
Two variables, perhaps x and y, are both functions of a third variable, time, t, and x and y are related by an equation.
Example A fire has started in a dry, open field and spreads in the form of a circle. The radius of the circle increases at a rate of 6 ft/min. Find the rate at which the fire area is increasing when the radius is 150 ft.
Strategy: Draw and label picture. What are we finding? Name variables and equations involved. (Substitute) and differentiate, then "plug-in" values.
Implicitly differentiate with respect to t. Note: The area and radius are both functions of t.
Given: ft/min and r = 150
Example: A ladder 26 ft long leans against a vertical wall. The foot of the ladder is drawn away from the wall at a rate of 4 ft/s. How fast is the top of the ladder sliding down the wall, when the foot of the ladder is 10 ft from the wall?
Strategy: Draw and label pictures. What are we finding? Name variables and equations involved. (Substitute) and differentiate, then "plug-in" values.
Differentiate implicitly with respect to the variable t. Note: x and y are both functions of t.
Given: Must find y using
Example: Water runs into a conical tank shown at a constant rate of 2 ft3 per minute. The dimensions of the tank are altitude of 12ft and base radius of 6 ft. How fast is the water level rising when the water is 6 feet deep?
Draw a picture. Need both the volume of a cone and similar triangle proportions.
Find: Volume of cone = Similar Triangle:
Example: A spherical balloon is inflated with gas at the rate of 100 ft3/min. Assuming the gas pressure remains constant, how fast is the radius of the balloon increasing when the radius is 3 ft?
Find: Volume of Sphere =
Given: r = 3 Know:
Example: A man 6 ft tall walks at the rate of 5 ft/sec. toward a street light that is 16 ft. above the ground. At what rate is the tip of his shadow moving?
Find: Similar Triangles
Assignment 3.8 pg 186; 1-11 odd, 12 [ans:-1/(20π)], 13,15, 16 [ans: 0.6 m/s]19, 20 [ans: ] 21, 27, 29, 30 [ans: -1/8 rad/s], 31 | http://homepages.ius.edu/MEHRINGE/M215/Fall%2007%20Notesr/Section3.8.htm |
4.15625 | Russian, early 20th century
The Tsar, the Priest, and the Kulak. 1918
Lithograph printed in two colors on paper
Purchased with the Elizabeth Halsey Dock, class of 1933, Fund
Photograph by Stephen Petegorsky
The earliest antireligious posters needed to be instantly legible to a wide audience. Often, they paired an image of the Tsar with a religious figure and stereotypical “rich man” (a kulak is a rich person of the peasant class), recognizable by his girth and a black top hat or bowler. By allying religious figures with Tsarist and class oppression, the Communists sought to convince the peasantry that religious leaders were actively working against the well-being of the common man.
Among those peasants who could read, the printed word was generally accepted to be “true.” Often the only people who could read in a village were the clergy, and the only books were religious, so peasants developed a sense that the written word was some how “holy.” The Communists exploited this connection by translating posters such as this (which is in Estonian) into many languages to appeal directly to the wide range of ethnicities represented in the lands they sought to control. The religious figure, here a Catholic priest, and the kulak were also customized according to regional stereotypes. This poster was also issued in Russian, Ukrainian, Belarusian, Polish, Tatar, Hebrew, Chuvash, Latvian, Lithuanian, Moldovan, and Mari.
Estonia had been a part of the Russian empire since 1721, but was declared an independent republic in 1920. The country was placed under Russian influence as part of the Nazi-Soviet Non-Aggression Pact of 1939, and the territory was reabsorbed by the Soviet Union following World War II. Estonia officially regained independence in 1991. | http://www.smith.edu/artmuseum2/archived_exhibitions/godlesscommunists/tsar_priest_kulak.htm |
4.375 | Children are best encouraged to engage in an activity when they
see others participating in it. This is why it is important for
educators of young children to model the writing process.
Outlined below are a few ways in which this can be
1. Many teachers like to begin each class with writing a short
morning message. This message outlines what activities are
planned for the day. As the teacher is writing she models the
writing process. She might focus on how words make a sentence,
stretching sounds to determine how they are spelled or the use
of capitals and periods. This modeling is a very important
component in a child's learning process as it demonstrates to
them that writing is an important means of communication.
2. Within a learning environment should be a safe and encouraging
place where the children can develop this skill which would be the
"Writing Center". The "Writing Center" would consist of a table,
chairs, paper, envelopes, pencils, crayons, felts, tracers, rulers,
whiteboard, chalkboard and clipboard. The alphabet, in upper and
lower case letters should be posted nearby at the child's level.
Plenty of print should be displayed within the classroom for the
children to use as models for reading and writing. As a member
of the Kinderplans website you will have access to hundreds of
picture cards related to specific themes. Each of the cards have
the words printed on them. These were designed to use for this
3. Writing develops at different rates. For many children in the
younger years they draw pictures to convey their ideas. This
begins with scribbling to something that resembles a picture.
The educator (teacher) may ask the child to dictate what the
picture conveys and print this in words and read it back to the
child. This is another means of modeling the writing process.
4. Large classroom books can be made for the children to read.
These books were designed around each child's conveyed message.
for example, if you are working on a "Colors Theme", each child
would dictate a sentence telling what their favorite color is.
After, they would would draw a picture displaying the color. The
teacher would include the printed text of what each child said
below the picture drawn. This would be bound together to make a
It is important to understand that writing is a process and each
child develops at their own pace. The more support and
encouragement provided the greater the success!
In the link below you will find some suggested craft/writing
activities that can be done together as a class.
Preschool-Kindergarten Writing Activities | http://kinderplans.blogspot.com/2011/02/preschool-kindergarten-writing.html |
4.375 | Eye vision enables us to see clearly the objects in our surroundings at different distances and under numerous conditions of lights.
How Eye sees?
Eye works by changing the curvature of the lens to bring the image to a focus from any light from a single point of a distant object and/or a near object called as eyesight or eye vision.
The eyes are the windows to the world; it allows us to see objects both far and near.
Light reflects off an object enters the eye. The light enters the eye through the front window of the eye, called the cornea. A clear covering helps to focus the light. Other sides of the cornea are clearer, watery fluid is the aqueous humor.
After light passes through the aqueous humor, it passes through the pupil, the central circular opening in the colored part of the eye called the iris. Depending on the amount of light available, the iris can contract or dilate, limiting or increasing the amount of light needed that gets deeper into the eye. The light then goes through the lens, which focuses the light (Just like the lens of a camera). The suspended lens changes shape with the help of ciliary muscle to focus on light reflecting from near or distant objects. Lens focuses the light on the retina at the back of the eye.
The retina is a thin layer of tissue at the back of the eye that contains millions of tiny light sensing nerve cells called rods and cones, which are naming for their distinct shapes. Cones are concentrated in the center of the retina; an area called the macula. In bright light conditions, cones provide clear, sharp central vision and detect colors and fine-details. Rods are located outside the macula and extend all the way to the outer edge of the retina. They provide peripheral or side vision. Rods also allow the eyes to detect motion and help us see in dim light and at night. These cells in the retina convert the light into electrical impulses. The optic nerve sends these impulses to the brain where it produces an image.
Visual information as impulses from the retina is transfers from the eye to the brain via the optic nerve. Because both eyes seeing from slightly different position and got different images, the brain has the ability to mix properly these two images in such a way to receive a complete clear actual picture.
Sometimes eyeball shape makes it difficult for the cornea, lens, and retina to work properly as a team. When this happens, the person eye sees will be out of focus. In addition, they need to wear eyeglasses to focus images correctly on to the retina and allow them to see clearly. | http://healthy-ojas.com/eye/eyesight.html |
4.15625 | Dec. 8, 2010 Thirteen billion years ago our universe was dark. There were neither stars nor galaxies; there was only hydrogen gas left over after the Big Bang. Eventually that mysterious time came to an end as the first stars ignited and their radiation transformed the nearby gas atoms into ions. This phase of the universe's history is called the Epoch of Reionization (EoR), and it is intimately linked to many fundamental questions in cosmology. But looking back so far in time presents numerous observational challenges.
Arizona State University's Judd Bowman and Alan Rogers of Massachusetts Institute of Technology have developed a small-scale radio astronomy experiment designed to detect a never-before-seen signal from the early universe during this period of time, a development that has the potential to revolutionize the understanding of how the first galaxies formed and evolved.
"Our goal is to detect a signal from the time of the Epoch of Reionization. We want to pin down when the first galaxies formed and then understand what types of stars existed in them and how they affected their environments," says Bowman, an assistant professor at the School of Earth and Space Exploration in ASU's College of Liberal Arts and Sciences.
Bowman and Rogers deployed a custom-built radio spectrometer called EDGES to the Murchison Radio-astronomy Observatory in Western Australia to measure the radio spectrum between 100 and 200 MHz. Though simple in design -- consisting of just an antenna, an amplifier, some calibration circuits, and a computer, all connected to a solar-powered energy source -- its task is highly complex. Instead of looking for early galaxies themselves, the experiment looks for the hydrogen gas that existed between the galaxies. Though an extremely difficult observation to make, it isn't impossible, as Bowman and Rogers have demonstrated in their paper published in Nature on Dec. 9.
"This gas would have emitted a radio line at a wavelength of 21 cm -- stretched to about 2 meters by the time we see it today, which is about the size of a person," explains Bowman. "As galaxies formed, they would have ionized the primordial hydrogen around them and caused the radio line to disappear. Therefore, by constraining when the line was present or not present, we can learn indirectly about the first galaxies and how they evolved in the early universe." Because the amount of stretching, or redshifting, of the 21 cm line increases for earlier times in the Universe's history, the disappearance of the inter-galactic hydrogen gas should produce a step-like feature in the radio spectrum that Bowman and Rogers measured with their experiment.
Radio measurements of the redshifted 21 cm line are anticipated to be an extremely powerful probe of the reionization history, but they are very challenging. The experiment ran for three months, a rather lengthy observation time, but a necessity given the faintness of the signal compared to the other sources of emission from the sky.
"We carefully designed and built this simple instrument and took it out to observe the radio spectrum and we saw all kinds of astronomical emission but it was 10,000 times stronger than the theoretical expectation for the signal we are looking for," explains Bowman. "That didn't surprise us because we knew that going into it, but it means it's very hard to see the signal we want to see."
The low frequency radio sky is dominated by intense emission from our own galaxy that is many times brighter than the cosmological signal. Add to that the interference from television, FM radio, low earth orbit satellites, and other telecommunications radio transmitters (present even in remote areas like Australia's Outback) and it is a real challenge. Filtering out or subtracting these troublesome foreground signals is a principal focus of instrument design and data analysis techniques. Fortunately, many of the strongest foregrounds have spectral properties that make them possible to separate from the expected EoR signals.
After careful analysis of their observations, Bowman and Rogers were able to show that the gas between galaxies could not have been ionized extremely rapidly. This marks the first time that radio observations have directly probed the properties of primordial gas during the EoR and paves the way for future studies. "We're breaking down barriers to open an entirely new window into the early universe," Bowman says.
The next generation of large radio telescopes is under construction right now to attempt much more sophisticated measurements of the 21 cm line from the EoR. Bowman is the project scientist for one of the telescopes called the Murchison Widefield Array. According to him, the most likely physical picture for the EoR looked like a lot of bubbles that started percolating out from galaxies and then grew together -- but that idea needs to be tested. If lots of galaxies all put out a little bit of radiation, then there would be many little bubbles everywhere and those would grow and eventually merge like a really fizzy and frothy foam. On the other hand, if there were just a few big galaxies that each emitted a lot of radiation then there would have been only a few big bubbles that grew together.
"Our goal, eventually, is to make radio maps of the sky showing how and when reionization occurred. Since we can't make those maps yet, we are starting with these simple experiments to begin to constrain the basic properties of the gas and how long it took for galaxies to change it," explains Bowman. "This will improve our understanding of the large-scale evolution of the universe."
Other social bookmarking and sharing tools:
- Judd D. Bowman, Alan E. E. Rogers. A lower limit of Δz > 0.06 for the duration of the reionization epoch. Nature, 2010; 468 (7325): 796 DOI: 10.1038/nature09601
Note: If no author is given, the source is cited instead. | http://www.sciencedaily.com/releases/2010/12/101208132210.htm |
4.15625 | Planets are in equilibrium with their surroundings: they are neither getting hotter nor colder. All planets absorb incident radiation from the Sun (this heats them up); to maintain equilibrium, they must radiate away the same amount of energy. The temperature of a planet can be approximated by assuming that it is a black body.
You determine the temperature by equating the planetary luminosity (proportional to its temperature raised to the fourth power, T4) to the solar irradiance (L/D2, where L is the solar luminosity and D is the distance to the Sun). The distance at which a planet is at temperature T is proportional to 1/T2. Merely plug in the values of the upper and lower temperature to get the radii of the inner and outer radii of the habitable zone.
To do this correctly, you need to take into account a number of effects:
The likelihood of finding a planet in the habitable zone depends on the area in the habitable zone. This is proportional to Do2 - Di2, where Do and Di are the outer and inner boundaries of the zone, respectively. Since D2 is proportional to the stellar luminosity, the area of the habitable zone, and the likelihood of finding planets in it, is largest for the massive O, B, and A stars on the upper main sequence. In the figure at left, the habitable zone (yellow) is plotted as a function of spectral type for main sequence stars. The planets of our solar system are indicated. Planets inside the "tidal lock radius" are tidally locked to the star, i.e., they rotate once per year, or a fractional number of times per year. Mercury rotates three times every two Mercurian years. (The Moon is tidally-locked to the Earth, and rotates once per month).
(These illustration are downloaded from http://www.astro.psu.edu/users/williams) | http://www.astro.sunysb.edu/fwalter/AST101/habzone.html |
4.28125 | Plants In Arches National Park
Photograph by brewbooksFlikr
Desert plants, since they are rooted in place, must cope with extremes in temperature, water availability and solar radiation physiologically rather than behaviorally. In fact, surface temperatures in direct sunlight are commonly 25 to 50 degrees F warmer than the air temperature six feet above. Most desert plant adaptations seem to be geared towards minimizing water loss: a difficult task since plants must "breathe" (collecting Carbon Dioxide from the air) in order to photosynthesize, losing body water to the atmosphere in the process.
Drought escapers are plants that make use of favorable growing conditions when they exist. These plants are usually annuals and complete their life cycles in a matter of days or weeks when water is plentiful enough for them to do so. Seeds may lie dormant for years if conditions are not favorable. Most grasses are "escapers," as are the spring wildflowers that sometimes bloom during April and May.
Drought resistors are typically perennials. Many perennials have small, spiny leaves which reduce the impact of solar radiation; others may drop their leaves when water is unavailable. Spines and hairs on leaves act as a buffer against warm air currents, limiting the amount of water lost to evaporation. Plants also use "solar tracking" to regulate their exposure to the sun. Cacti store water within their bodies and have extensive, shallow root systems that are able to soak up rainwater quickly. Yucca have extensive tap roots that are able to use water beyond the reach of other plants. Moss, a plant not commonly associated with deserts, thrives because it can tolerate complete dehydration: when rains finally return, the plant greens up almost immediately. Another extreme adaptation can be found in the utah juniper tree, one of the most common plants in the southwest. During a drought, junipers can self-prune, shutting off water flow to one or more their branches in order to conserve enough water for the rest of the tree to survive.
Drought evaders take advantage of wetter "micro climates" found in the desert. Monkey flower, columbine, easter flower, and ferns are found in well-shaded alcoves near seeps or dripping springs. Cottonwood, willow and cattail all require lots of water, and only grow in riparian areas where their roots can reach the water table easily.
Did you like this page? Did you find it helpful? Please consider sharing. | http://www.travelwest.net/canyonlands-plants |
4.03125 | Thursday, November 18, 2010
By Aaron Dicks
In the photovoltaic process solar cells are used to covert light into electricity. Solar cells are made up of semiconductor materials such as: silicon, gallium, cadmium telluride and copper indium diselenide. One of the most common materials used in solar cells is silicon.
In the case of crystalline silicon solar cells, substantially pure silicon with high crystal quality is needed to make strong usable solar cells. In the outer shell of a silicon atom it comprises of 4 bonding electrons. In order to form a stable electron configuration, in the crystal lattice two electrons of neighbouring atoms from an electron pair bond. By forming a stable bond with 4 neighbouring electrons silicon achieves its noble gas configuration with 8 out electrons. This electron bond can be broken by light or heat, which enables the electron to move freely and as a result it leaves a hole in the crystal lattice. This is known as intrinsic conductivity.
Intrinsic conductivity cannot be used to produce electricity. The silicon can only produce electricity when impurities (known as doping atoms) are introduced into the crystal lattice. These atoms have one electron more (phosphorous) or one electron less (boron) than silicon in their outer shell. The phosphorous doping method is known as negative doping (n-doping) and the boron doping method is known as positive doping (p-doping).
In the case of n-doping the electron can move about freely in the crystal and as a result can transport electrical charge. On the other hand p-doping has a missing bonding electron for every bonding born atom in the crystal lattice. This enables electrons from silicon atoms to fill the hole caused by the missing bonding electron, creating a new hole elsewhere. The conduction method based on these doping atoms is known impurity conduction.
If both the p and n-doped semiconductor layers are brought together a p-n junction is made. This junction allows surplus electrons from the n-semiconductor to diffuse into the p-semiconductor layer, thus creating an area known as the space charge region. Positively charged doping atoms remain in the n-region of the transition and negatively charged doping atoms remain in the p-region of the transition. An electrical field is then created that is opposed to the movement of the charge carriers, with the result that diffusion does not continue indefinitely. This p-n semiconductor is what is known as a solar cell. Once the solar cell is exposed to light photons are absorbed by the electrons. This contribution of energy breaks electron bonds. The released electrons are pulled through the electrical field into the n-region. The holes that are formed migrate in the opposite direction, into the p-region. This process is what is known as the photovoltaic effect - turning light into electricity.
Copyright (c) 2010 Aaron Dicks
EvoEnergy design and install Solar PV Solar systems can benefit investments of any size through the Government Clean Energy Cashback scheme, also called the Feed-In Tariffs. | http://www.solarpowerbuzzmedia.com/2010/11/crystalline-silicon-solar-cells.html |
4.0625 | Fishing is a topic that provides many opportunities for comparing present-day practices with the past. For example, how would a young person today become a fisherman or lobsterman? Perhaps there are local fishermen in the area who could provide information to the class. What skills, knowledge, and abilities would help someone become a good fisherman? How has technology changed the skill requirements? What do fishermen do to conserve marine resources?
In addition to writing opportunities of all types, learning about fisheries provides topics for easy research for younger students. Even a trip to a market with a fresh fish counter can be a research opportunity: what kinds of fish and shellfish are available? Where did they come from? Compare to canned or frozen fish and shellfish products. Calculate price comparisons: which costs more, canned or fresh salmon? Visit a lobster pound or seafood restaurant. Make observations about the lobsters in the tanks.
Other math opportunities include: ordering fish by length and weight; working with numbers of lobster traps and lobstermen; collecting data on fish found in the grocery store; measuring with gauges used by lobstermen; classifying fish by where they live, what they eat; fresh vs. salt water, etc.
These concepts lead to science activities as well: students can draw pictures of the life cycle of the lobster or other fish, describe characteristics of marine animals, and learn about the food chain. Locally, there may be opportunities to visit the shoreline and look for shells and evidence of marine animals and plants. Learn more about efforts to conserve fish and other marine resources in Maine.
The history of trying to keep fish fresh and lobster alive for markets led to use of specific kinds of boats (smacks) and later to the use of ice and then refrigeration. What other methods have been used to preserve fish? What were the hazards of canning? How do people can products today in their homes? What precautions have to be observed?
Compare similar shellfish: clams, oysters, and mussels. What similarities and differences are there? Are students willing to taste samples?
Industrial development and overfishing have affected fish and shellfish populations. Industrial effluent from lumber mills and paper mills, along with untreated sewage, has negatively impacted fish and shellfish populations along Maine’s coast. The construction of dams across rivers has kept salmon and other anadromous fish from spawning. What has been done to clean up Maine’s waters and improve fish habitats?
Lobstermen had certain assumptions about the habits and life cycle of the lobster, based on their observations. What do we know about lobster migration? About egg-bearing females? How does recent scientific investigation differ from traditional folk belief? Are there any traditional Native American legends or stories about fish or shellfish?
Students, themselves, may go fishing, or know friends or relatives who fish. They might share, orally or in writing, stories about first-hand experiences. These stories may lend themselves to map-making, research into kinds of sport fish, etc.
Cooking activities are always fun. Find some menus from seafood restaurants. Read recipes. | http://penobscotmarinemuseum.org/pbho-1/fisheries/k-2-activities |
4.09375 | and Whole Language Learning
Balanced Approach to Beginning Reading
Association for the Education of Young Children
Children cannot learn to read
without an understanding of phonics. All children must know their ABCs and the
sounds that letters make in order to communicate verbally. The question in
early childhood programs is not whether to teach "phonics" or
"whole language learning," but how to teach phonics in
context--rather than in isolation--so that children make connections between
letters, sounds, and meaning.
Phonics should not be taught as a
separate "subject" with emphasis on drills and rote memorization. The
key is a balanced approach and attention to each child's individual needs. Many
children's understanding of phonics will arise from their interest, knowledge,
and ideas. Others will benefit from more formal instruction. There are many
opportunities to teach the sound a letter makes when children have reason to
know. For example, the first letter a child learns typically is the first
letter of her name.
worry that encouraging children to learn through experience and invent their
own spellings will not provide them with adequate language skills. But literacy
is not so much a skill as a complex activity that involves reading, writing and
oral language. Ideally, children should develop literacy through real life
settings as they read together with parents or other caring adults. Children
begin to make connections between printed words and their representations in
Adults should keep in mind that
children may learn to read at different paces during kindergarten and first
grade. This is true for all children, including those with special needs and
those from linguistically and culturally diverse backgrounds. If parents andteachers work together
and demonstrate mutual respect, children's learning will be reinforced at home
and in the classroom.
Parents Can Help
- Talk, read, and sing to infants--they learn from
everything they see and hear even in the first stages of life.
- Take your baby to the park, zoo, and the store with
you. Bring her attention to objects, signs, and people.
- Always make books a part of your baby's toy selection,
even if he enjoys handling books more than being read to. As your child
grows, point out pictures of objects and offer their names. Eventually,
your child will be able to name the pictures, too.
- Encourage associations between symbols and their
meaning--as they get closer to toddlerhood, children may begin to
recognize familiar signs for products and logos for cereal or fast food
- Help toddlers make the transition from baby talk to
adult language by repeating their words and expressions correctly without
- Let toddlers "read" their favorite picture
books by themselves while you remain close by to comment. Or, pause before
a familiar word as you read to your toddler, and let her fill in the
missing word. This works especially well with rhymes or repeated refrains.
- Provide magnetic and block letters to introduce a
toddler to the spelling of his name.
- Before you take your toddler on a new type of outing,
read about the events you are about to witness. Talk with your child about
the experience, and follow up with further reading to reinforce learning.
- Add new books to your childs collection, but keep reading old
favorites. Your preschooler may know them by heart now--this represents an
important step in learning about reading.
- Continue to take children shopping with you, and let
them help identify products with coupons. Let preschool children join in
as you follow a recipe.
- Take books on long trips with you to encourage reading
- Continue to read to your child, even if she has learned
to read already. Take turns reading pages of your favorite books.
- Encourage story writing by listening to the stories
- Play word games like Scrabble or Boggle with children
and introduce them to crossword puzzles.
Chapman, M.L. 1996. The development
of phonemic awareness in young children: Some insights from a case study of a first-grade writers. Young
Children 51 (2). Washington, DC: NAEYC.
Schickedanz, J.A. 1986. More than the ABCs: The early stages of
reading and writing. Washington, DC: NAEYC #204/$6.
1998. Raising a Reader, Raising a Writer: How Parents Can Help.
Washington, DC: NAEYC #530. For a free copy of this brochure, send SASE to
NAEYC, Box 530, 1509 16th St., NW, Washington, DC
Publication Release: July 26, 2007 | http://www.readinguniverse.com/articles.php?id=23 |
4.09375 | Welcome to the study guide for King Lear. In it you will find information about the play and the historical context in which it was written, along with that in which this production is set. In order to prepare your class to see the performance, David Dean has supplied background information on Shakespeare and the time in which King Lear was written. Suzanne Keeptwo has provided in-depth research on relations between the First Nations of Canada and the British Colonial powers of the 17th century as well as character interpretations with a First Nations’ point of view. Janet Irwin has provided pre- show and post- show discussion questions and exercises that are intended to engage students and prompt them to think creatively about both the form and content of the play.
King Lear from a First Nations’ Point of View
In Peter Hinton’s revisioning of Shakespeare’s King Lear, we see Lear, an aging First Nations chief, in the early days of the long history of treaty-making between his people and the British colonial powers. As the play opens, he has just signed a treaty with the Crown, and is regretting the decision. The resulting loss of ancestral lands, and the erosion of Lear’s sense of self, fuels his decision to cast off the responsibilities of leadership (while retaining the privileges) and turn to his inheriting daughters for comfort and support. A sense of tension and impending dissent colour the startling opening scene where Lear demands avowals of love from his daughters in exchange for portions of the land. When Cordelia fails to say what he wants to hear, he disowns her and casts her out of the family.
The decision we don’t see – the treaty signing - and the ramifications of the colonial presence and power on traditional lands, plus his sense that he has betrayed his people, feed Lear’s irrational behaviour, and descent into madness.
Study guide written by Suzanne Keeptwo with additional content by David Dean and Janet Irwin. | http://nac-cna.ca/en/englishtheatre/studyguide/king-lear |
4.3125 | Prepositions and Prepositional Phrases: Lesson plans and teaching resources
Commas: Introductory Prepositional Phrases
Interactive practice with punctuation of long introductory phrases. Appropriate for elementary students and older.
Finding Prepositional Phrases
Students find the prepositional phrases in the sentences given.
Kinds (Function) of Prepositional Phrase Recognition Practice
An explanation, 10 practice sentences, and answers.
Filling in the Blanks: Using Modifiers to Provide Detail
Students develop voice and style by adding details to their writing.
Phrase/Clause Recognition Practice
An explanation of the difference, examples, and 15 practice items. Answers available.
Playing with Prepositions through Poetry
Students play with words as they explore how prepositions work in Ruth Heller's picture book Behind the Mask. They first explore the use of language in the text and identify how prepositions are used. They then read and identify prepositions used in a poem. Finally, students compose their own original prepositional poems, which they publish in a multimodal format modeled on Heller's text.
This slide presentation is a good review activity for independent work by individual students or small groups.
The Preposition Song
Students memorize a list of prepositions sung to "Yankee Doodle."
Prepositional Phrase Identification
Interactive practice identifying prepositional phrases, appropriate for elementary students and older. Follow links on the left for additional exercises.
Prepositional Phrase Recognition Practice
This page offers a definition, examples, a list of prepositions, and 10 sentences for students to practice with. Students can check their responses by clicking on "answers."
A collection of teacher-tested activities for teaching prepositions to elementary students.
Third graders read Find the Puppy by Felicity Brooks and identify the prepositions. After practicing prepositions by completing worksheets (not included), students write their own preposition books.
Students complete a variety of activities including identifying prepositions, expanding sentences using prepositional phrases, and distinguishing prepositions and adverbs. In cooperative groups the students will analyze the last three lines of the Gettysburg Address by Abraham Lincoln as well as write prepositional phrase poetry. Designed for grades 6-8.
Rosie's Walk by Pat Hutchins
Four activities to develop literacy skills, including one that helps students learn prepositions. Print this card and send it home with students to work on with parents. | http://www.webenglishteacher.com/prepositions.html |
4 | Hosted by The Math Forum
The diagram shows a circle of radius 1, with the boundary of the shaded (gray) portion consisting of three circular arcs of radius 1 whose centers are equally spaced on the ambient circle. Dissect the unshaded (yellow) portion of the circle's interior into pieces that can be reassembled to form a rectangle.
To get the diagram: Start with a unit circle with center O and inscribe an equilateral triangle ABC. Then draw arcs through O centered at A, B, and C, respectively, and consider only the part of the arcs lying inside the circle. The propeller-like region they form is the shaded region referred to.
See Jeff Erickson's solution
© Copyright 1996 Stan Wagon. Reproduced with permission.
Home || The Math Library || Quick Reference || Search || Help | http://mathforum.org/wagon/fall95/p794.html |
4 | - Explain how the following elements and terms affect the quality
of a picture:
- Light-natural light/ambient, flash
- Exposure-aperture (f-stops), shutter speed, depth of field
- Composition-rule of thirds, leading lines, framing, depth
- Angle of view
- Stopping action
- Explain the basic parts and operation of a film camera or digital camera. Explain how an exposure is made when you take a picture.
- Discuss with your counselor the differences between a film camera and a digital camera. List at least five advantages and five disadvantages of using a digital camera versus using a film camera.
- Do ONE of the following:
- Produce a picture story using the photojournalistic technique of documenting an event. Share your plan with your counselor and get your counselor's input and approval before you proceed. Then, using either a film camera or a digital camera, produce your approved picture story. Process your images and select eight to 12 images that best tell your story. Arrange your images in order, then mount the prints on a poster board. If you are using digital images, you may create a slide show on your computer or produce printouts for your poster board. Share your picture story with your counselor.
- Choose a topic that interests you to photograph for an exhibit or display. Get your counselor's approval, then photograph (digital or film) your topic. Process your images. Choose 20 of your favorite images and mount them on poster board. Share your display with your counselor. If you are using digital images, you may create a slide show on your computer or produce printouts for your poster board.
- Discuss with your counselor the career opportunities in photography. Pick one that interests you and explain how to prepare for such a career. Discuss with your counselor the education and training such a career would require.
BSA Advancement ID#:
Requirements last updated in: 2006
Pamphlet Publication Number: 33340A or 35930
Pamphlet Stock (SKU) Number: 35930
Pamphlet Revision Date: 2005
Page updated on: May 02, 2013 | http://usscouts.org/usscouts/mb/old/mb083-06.asp |
4.125 | What is Asperger Syndrome?
Asperger Syndrome or (Asperger's Disorder) is a neurobiological disorder that lies on the Autistic Spectrum and affects more boys than it does girls.
The O.A.S.I.S. organization describes Asperger's as the following:
“Individuals with AS can exhibit a variety of characteristics and the disorder can range from mild to severe. Persons with AS show marked deficiencies in social skills, have difficulties with transitions or changes and prefer sameness. They often have obsessive routines and may be preoccupied with a particular subject of interest. They have a great deal of difficulty reading nonverbal cues (body language) and very often the individual with AS has difficulty determining proper body space. Often overly sensitive to sounds, tastes, smells, and sights, the person with AS may prefer soft clothing, certain foods, and be bothered by sounds or lights no one else seems to hear or see. It's important to remember that the person with AS perceives the world very differently. Therefore, many behaviors that seem odd or unusual are due to those neurological differences and not the result of intentional rudeness.”
All accommodations are made for students on an individual basis.
- Admission to Cook Dining Hall and Kletz Snack Bar
- Single room accommodations
- Academic support
- Writing Lab
- Counseling Center
- Support Group
- Life Coaching | http://hope.edu/student/development/disabled/asperger_syndrome.htm |
4.0625 | A part of the vast Central Lowlands of North America, the Osage Plains incorporate western Missouri, southeastern Kansas, central Oklahoma, and north-central Texas. The area is sometimes called the Lower Plains, North Central Plains, and the Rolling Plains. In Oklahoma the Osage Plains is divided into subregions, broad bands that stretch north-south from Kansas to Texas. The west-central subregion, lying generally west of Interstate 35, is the Red Bed Plains. West of this, in western Oklahoma, is the subregion called the Gypsum Hills (often combined with the Red Bed Plains into a larger area called the Western Red Prairies). Lying generally east of Interstate 35 is the Flint Hills/Sandstone Hills subregion. To the east of that, the Eastern Lowlands region is often included in the Osage Plains.
The topography of the Osage Plains began forming during the Cretaceous Period when an epeiric (shallow continental) sea covered the region, depositing carbonate rocks. Pulses of siliciclastic rocks were laid down due to tectonic activity to the south. More sediments washed into the region from the Rocky Mountains during the Tertiary. Soils are Pennsylvanian-age mollisols, alfisols, usfosols, and inceptisols. Tectonic activity played little role since the Cretaceous, and the region remained one of relatively flat plains to gently rolling hills. The average relief is between three hundred and five hundred feet. Oklahoma's three main river systems, the Salt Fork of the Arkansas, the Canadian, and the Red, traverse the broad region, flowing generally from west to east as the elevation of the plains gently declines in that direction.
The Osage Plains lie within the Prairie Parkland (Temperate) ecological province. Winters are cold, and summers are hot. The mean annual temperature is 60° F. This provides an average 235-day growing season. Natural vegetation varies across the Osage Plains. The overall aspect is one of tallgrass prairie that grades into savannah, woodlands, and mixed grasses. A broad band of the Cross Timbers extends as far west as Seiling, as far east as the Ozark Plateau, and from Kansas to Texas. Native grasses grow over the region's rolling hills and plains. Tallgrasses were the area's predominant vegetation until the late nineteenth century, when white settlers began clearing land for agriculture and wood. Among the tallgrasses that survived the settlement era include big bluestem (Andropogen gerardii), little bluestem (Schizachyrium scoparium), Indian grass (Sorghastrum nutans), and switchgrass (Panicum virgatum). These grasses can still be observed at the Tallgrass Prairie Preserve in Osage County, Oklahoma. Early territorial farmers introduced the Osage orange tree (also known as bois d'arc), named for the Osage people, into the Osage Plains as a living fence. The living fence was accomplished by planting many young trees in a line and pruning for thick, bushy growth. After barbed wire was introduced, the Osage orange primarily served as fence posts.
Pre-dating the first European settlers in the Osage Plains were American Indians. Tribes such as the Kaw, Omaha, Quapaw, Ponca, Kiowa, Comanche, and Osage lived in the territory. Many Osage migrated from Missouri around 1802, when the tribe split into factions. A large group followed Cashesgra, or "Big Track," relocating along the Three Forks area, where the Arkansas, Verdigris, and Grand Rivers merged, in present Oklahoma. On July 15, 1870, the U.S. government moved the tribe to present Osage County. In the twentieth century the Osage Nation acquired wealth from oil and gas extraction.
The Osage Plains lay in both Indian Territory (eastern Oklahoma) and Oklahoma Territory (western Oklahoma). After land openings and tribal land allotment took place, by the beginning of the twenty-first century towns and cities dotted the Osage Plains. Farming, ranching, and petroleum production have been the dominant economic activities. However, in some domains there are vegetation and wildlife reserves. Among the wildlife protected in these reserves are birds, including the prairie chicken, and bison. The Tallgrass Prairie Preserve in Osage County protects the remaining regional tallgrasses.
BIBLIOGRAPHY: James M. Goodman, "Physical Environments of Oklahoma," in Geography of Oklahoma, ed. John W. Morris (Oklahoma City, Okla.: Oklahoma Historical Society, 1977). Kenneth S. Johnson, "Mountains, Streams, and Lakes of Oklahoma," Oklahoma Geological Survey Informational Series No. 1 (Norman: Oklahoma Geological Survey, 1998). Kenneth S. Johnson, et al., Geology and Earth Resources of Oklahoma: An Atlas of Maps and Cross Sections (Norman: Oklahoma Geological Survey, 1972). John W. Morris, Oklahoma Geography (Oklahoma City-Chattanooga: Harlow Publishing Corporation, 1954). John W. Morris, Charles R. Goins, and Edwin C. McReynolds, Historical Atlas of Oklahoma (Norman: University of Oklahoma Press, 1986).
Melanie L. McPhail and Richard A. Marston
© Oklahoma Historical Society | http://digital.library.okstate.edu/encyclopedia/entries/O/OS007.html |
4.125 | The definition of cyber-bullying is "when the Internet, cell phones or other devices are used to send or post text or images intended to hurt or embarrass another person." StopCyberbullying.org, an expert organisation dedicated to Internet safety, security and privacy, defines cyber-bullying as: "a situation when a child, tween or teen is repeatedly 'tormented, threatened, harassed, humiliated, embarrassed or otherwise targeted' by another child or teenager using text messaging, email, instant messaging or any other type of digital technology." Other researchers use similar language to describe the phenomenon.
Cyber-bullying can be as simple as continuing to send e-mail to someone who has said they want no further contact with the sender, but it may also include threats, sexual remarks, pejorative labels (i.e., hate speech), ganging up on victims by making them the subject of ridicule in forums, and posting false statements as fact aimed at humiliation.
Cyber-bullies may disclose victims' personal data (e.g. real name, address, or workplace/schools) at websites or forums or may pose as the identity of a victim for the purpose of publishing material in their name that defames or ridicules them. Some cyber-bullies may also send threatening and harassing emails and instant messages to the victims, while other post rumors or gossip and instigate others to dislike and gang up on the target. | http://clc2.uniservity.com/GroupHomepage.asp?GroupID=20222617 |
4.15625 | Archaeologists led by the University of Cincinnati have revealed new details about sustainable water and land management among the ancient Maya, including the discovery of the largest ancient dam in Central America.
Recent excavations, sediment coring and mapping at the pre-Columbian city of Tikal have identified new landscaping and engineering feats, including the largest ancient dam built by the Maya of Central America.
That dam – constructed from cut stone, rubble and earth – stretched more than 260 feet in length, stood about 33 feet high and held about 20 million gallons of water in a man-made reservoir. These findings on ancient Maya water and land-use systems at Tikal in northern Guatemala are published in the Proceedings of the National Academy of Sciences .
The study sheds new light on how the Maya conserved and used their natural resources to support a populous, highly complex society for over 1,500 years despite environmental challenges, including periodic drought.
Starting in 2009, the archaeologists were the first North American group permitted to work at the Tikal site core in more than 40 years.
“The overall goal of the research is to better understand how the ancient Maya supported a population at Tikal of perhaps 60,000 to 80,000 inhabitants and an estimated population of five million in the overall Maya lowlands by AD 700,” said lead author Vernon Scarborough, a professor of anthropology at the University of Cincinnati.
“That is a much higher number than is supported by the current environment. So, they managed to sustain a populous, highly complex society for well over 1,500 years in a tropical ecology. Their resource needs were great, but they used only stone-age tools and technology to develop a sophisticated, long-lasting management system in order to thrive.”
Water collection and storage were critical in the environment where rainfall is seasonal and extended droughts not uncommon. And so, the Maya carefully integrated the built environment – expansive plazas, roadways, buildings and canals – into a water-collection and management system. At Tikal, they collected literally all the water that fell onto these paved and/or plastered surfaces and sluiced it into man-made reservoirs.
In fact, by the Classic Period (AD 250-800), the dam, called the Palace Dam, identified by the team was constructed to contain the waters that were now directed from the many sealed plaster surfaces in the central precinct. It was this dam on which the team focused its latest work, completed in 2010. This gravity dam presents the largest hydraulic architectural feature known in the Maya area. In terms of greater Mesoamerica, it is second in size only to the huge Purron Dam built in Mexico’s Tehuacan Valley sometime between AD 250-400.
“We also termed the Palace Dam at Tikal the Causeway Dam, as the top of the structure served as a roadway linking one part of the city to another. For a long time, it was considered primarily a causeway, one that tourists coming to the site still use today. However, our research now shows that it did double duty and was used as an important reservoir dam as well as a causeway,” Prof Scarborough said.
The team also discovered that to help purify water as it sluiced into the reservoir tanks via catchment runoff and canals, the Maya employed deliberately positioned “sand boxes” that served to filter the water as it entered into the reservoirs.
“These filtration beds consisted of quartz sand, which is not naturally found in the greater Tikal area. The Maya of Tikal traveled at least 20 miles (about 30 km) to obtain the quartz sand to create their water filters. It was a fairly laborious transportation effort. That speaks to the value they placed on water and water management,” said co-author Nicholas Dunning, a professor of geography at the University of Cincinnati.
Bibliographic information: Scarborough VL et al. 2012. Water and sustainable land use at the ancient tropical city of Tikal, Guatemala. PNAS, published online before print July 16, 2012; doi: 10.1073/pnas.1202881109 | http://www.sci-news.com/archaeology/article00470.html |
4.375 | Solution to Additional Practice
Unit 1: Analyzing Lines on a Graph
In the graph below, the straight line
S is given by the equation y = c + dx. If the line
shifts from this initial position S0 to a new position of
what must have changed in the equation?
- In this graph, the line has changed
in steepness, which means the slope must have changed.
- In the equation y = c + dx, "d"
is the slope of the line. Since the slope must have
changed, the constant "d"
must have changed. Since S1 is steeper than S0 , "d" must
have increased. and "c" is the y-intercept.
- In the equation y = c + dx,
"c" is the y-intercept. In the
graph, the lines have not been extended
to where they intercept the y-axis, so it is hard to tell
if "c" changed or not. Unless you extend
the lines to the y-axis and can be certain the two lines
both intercept the y-axis in the same place, it is hard to tell if "c" changed
or not, but we can be certain that
"d" did change.
- If you do extend both lines through
the y-axis, you will find they have the same y-intercept,
which means "c" does not change.
If you feel comfortable with this material, move on to the
If you still do not understand this practice, you may need more
review than is offered by this book. You may wish to review Book
I of this series before moving on. | http://cstl.syr.edu/fipse/graphb/unit6/SolnT2Full.html |
4.40625 | In 152 Ways to Keep Students in School: Effective, Easy-to-Implement Tips for Teachers, author Franklin P. Schargel provides practical tips for teachers that can be read quickly and easily implemented in order to improve student learning.
Involved Students Learn Faster!
Children should be active participants in their education and enjoy being involved in the learning process. Moreover, students who do so actually learn faster.
Examples of how to involve students in the learning process include:
• Have students write the end to stories in English classes.
• Give students a choice of books to read in English and social studies.
• Ask students “What if...?” questions. For example, in history class, “What if Germany had won WWII?” Construct similar questions for music, art, math, and English: “What if Beethoven had never lost his hearing?” “What if Monet had not pioneered impressionism?” “What if Pythagoras had never discovered and proved the Pythagorean Theorem?” “What if J.D. Salinger had never written Catcher in the Rye?”
• Bring an object into school and have the students identify it.
• Bring an object into school and have the students make a story up about the object.
Although these tips can be and have been used at all grade levels with all types of students, these strategies prove to be especially successful with nontraditional students. Purposefully written so that each tip can be read quickly and easily implemented, these learning techniques provide concise snapshots of what educators can do to keep students from dropping out. | http://www.eyeoneducation.com/Blog/articleType/ArticleView/articleId/1504/Involved-Students-Learn-Faster |
4.1875 | Halifax was founded by the English in 1748 to counteract the French military presence at Louisbourg. To build Halifax the English cut down forests and infringed on Micmac lands. This brought them into greater conflict with the native people who were friends and allies of the Acadians. Micmac raids that resulted from the founding of Halifax became another factor in English distrust of the Acadians which culminated with their expulsion.
As well as establishing a military fort there, the English encouraged more Protestant immigrants to come to add weight against the larger numbers of Catholic Acadians and their converted Micmac allies. (Chief Membertou of the Micmac tribe was one of the first native chiefs to be converted to Catholicism back in 1610.)
As part of this Protestant immigration a number of German Protestants arrived later in the 1700s and established a settlement around Lunenburg, just down the coast from Halifax. | http://www.canadahistoryproject.ca/1755/1755-05-founding-halifax.html |
4.34375 | - Learn how to identify the main verb in a sentence. Verbs express what someone or something does. Look for the verb that express the 'action' of the sentence.
- Decide on when the action takes place. Does it take place in the present, the past or the future?
- Once you have discovered the general time, find out the specific time. Is the action happening at the moment? Does the action happen every day? Has the action happened up to a point in the past, present or future?
- If the action happens regularly or is a habit, use the present simple verb form: For example: He doesn't work on Saturdays. They play football after school. etc.
- If the action happens once in the past at a specific point in time, use the past simple. For example: They went to school when they were young. Did Mary visit you last week?
- If the action happens up to a point in time use a perfect form: present perfect, past perfect, or future perfect. For example: She has worked her for many years. They had finished lunch by the time he arrived. Mary will have finished the report by five pm.
- If the action is happening at a specific moment in time use a continuous form: present continuous, past continuous or future continuous.
For example: She is working at the moment. They will be playing tennis at 5 pm. Tom was eating when she arrived.
- Now that you know WHEN the action happens, and in what time frame, learn your helping verbs. Present simple or past - do, perfect forms - have, continuous forms - be.
- Learn to conjugate the helping verbs: I, you, we, they do / she, he it does | I am / you, we, they are | I, you, we have / he, she it has
- Learn which form the main verb takes for each form. Simple forms = verb without 'to' (i.e. play, walk, eat, work, etc.). Continuous forms = verb + ing (playing, walking, eating, working, etc.) Perfect forms = past participle (verb in the third form, i.e. bought, understood, played, etc.)
- Conjugate the verb. Here is the thinking process: 1) What's the general time? - past 2) What's the specific time? - at a specific moment 3) Aha! continuous in the past OR past continuous 4) conjugate the helping verb - She was 5) Use the continuous form of the main verb: doing 6) Conjugate the verb: She was doing
- Remember these simple steps: Time? Action Happening? Simple, Continuous or Perfect? Auxiliary verb? Main Verb? Conjugate
- Example 1: Time? > Present
Action Happening? > Up to the present
Simple, Continuous or Perfect? > Perfect
Auxiliary verb? > have
Main Verb? > live
Verb Form? > lived
Conjugate > We have lived here for ten years.
- Example 2: Time? > Future
Action Happening? > happening at a specific moment
Simple, Continuous or Perfect? > continuous
Auxiliary verb? > be
Main Verb? watch
Verb Form? > watchingConjugate > She will be watching TV at nine.
- Example 3: Time? Past
Action Happening? > one day in past
Simple, Continuous or Perfect? > simple
Auxiliary verb? > did
Main Verb? > play
Verb Form? > playConjugate > Did you play the piano yesterday?
- Be patient with yourself when learning how to conjugate verbs.
- Remember that the present simple and past simple do NOT take auxiliary verbs in positive forms.
- Changes occur in the auxiliary verb, not in the main verb EXCEPT for the present simple.
What You Need
- A clear head to concentrate
- A dictionary
- A pencil
- Some paper | http://esl.about.com/od/tense-review/ht/How-To-Conjugate-Verbs.htm |
4.28125 | A condition that exists during the winter time in the Antarctic, in which the air moves in a ringing, circular motion, allowing little air to come in or out. This is one of the factors resulting in the low stratospheric temperature during the polar night, which are a prerequisite for the ozone hole. When the vortex dissipates during ozone-deprived air can spread over other parts of the globe, leading to excess UV radiation.
A semi-isolated area of cyclonic circulation formed each winter in the polar stratosphere. The southern polar vortex is stronger than the northern one. The vortex increases ozone depletion by trapping very cold air containing aerosols on which ozone- depleting reactions can take place.
A low depression system caused by strong westerly winds that remains stationary over the south pole.
wind region around the North or South pole. The southern vortex is a well formed circular to oblong mass of extremely cold, stagnant air, held in place by the ocean surrounding the Antarctic land mass and a strong westerly circulation pattern produced by the coriolis effect. The northern vortex is not as distinct because the Arctic is a frozen ocean surrounded by rugged land masses, which cause the circulating winds to encounter a variety of temperatures.
A distinct column of cold air contained over the poles (esp. South) by meterological effects. Develops during the polar winter when the polar regions are in polar night (sunlight does not reach the poles). Wind speeds around the vortex may reach 100 metres per second. The vortex establishes itself in the middle to lower stratosphere. It's important because it isolates the very cold air within it.
Field measurements in and theoretical studies of the Antarctic stratosphere have demonstrated that processes that occur in the wintertime engender chemical transformations that lead to the formation of the springtime ozone hole over the Antarctic continent.
A circumpolar wind circulation which isolates the Antarctic continent during the cold Southern Hemisphere winter, heightening ozone depletion.
In the stratosphere, a strong belt of winds that encircles the South Pole at mean latitudes of approximately 60°S to 70°S. A weaker and considerably more variable belt of stratospheric winds also encircles the North Pole at high latitudes during the colder months of the year.
High pressure system located in the upper atmosphere at the polar regions. In this system, air in the upper troposphere moves into the vortex center and then descends to the Earth's surface to create the polar highs.
large-scale cyclonic circulation in the middle and upper troposphere centered generally in the polar regions; it is often called circumpolar vortex.
The polar vortex is a persistent, large-scale cyclone located near the Earth's poles, in the middle and upper troposphere and the stratosphere. It surrounds the polar highs and is part of the polar front The vortex is most powerful in the hemisphere's winter, when the temperature gradient is steepest, and diminishes or can disappear in the summer. The Antarctic polar vortex is more pronounced and persistent than the Arctic one; this is because the distribution of land masses at high latitudes in the northern hemisphere gives rise to Rossby waves which contribute to the breakdown of the vortex, whereas in the southern hemisphere the vortex remains more undisturbed. | http://www.metaglossary.com/meanings/955499/ |
4.0625 | ENGLISH AND LANGUAGE ARTS
Sixth Graders review parts of speech and verb tenses and write detailed reports and compositions. Grammar emphasis is on clauses, phrases and the formulation of good sentences and paragraphs. Oral presentations of reports and research are given with an artistic component. Students practice lengthy recitation of epic poems such as “Horatio at the Bridge” or “Hiawatha.” Class plays usually come from Roman or Medieval history. Biographies are assigned for reports, and readers include: The Bronze Bow, King Arthur legends, and Otto of the Silver Hand.
The seventh grade grammar lessons emphasize different styles of writing, use of an outline, paragraph format, self-editing, organization of compositions, note taking and the development of compound and complex sentences. Creative writing is practiced in the Wish, Wonder and Surprise block. For the first time in an English block, the students are graded on quizzes, tests, essays, artwork, class participation, and timeliness. Poetry continues to be spoken daily, and oral reports are given to the class. The class play is usually placed in the Renaissance or late medieval times. Independent reading with regular book reports gives the students an opportunity to explore different literature. Often choices include The Giver, Education of Little Tree, Midwives Apprentice, Wrinkle in Time and Robin Hood.
Eighth Graders learn to edit their writing, summarize written work, and solidify their grammar skills (passive and active verbs, direct and indirect objects, clauses and phrases, pronouns). The spoken work continues with more oral reports including biographies, modern history and geography. Poetry continues to be a lively part of the main lesson. The class play is often Shakespeare or a modern play with rich use of language. Each individual now begins to understand a point of view and the dramatic themes used in acting. Eighth grade continues with some assigned reading, book reports and short stories such as Dragon Wings, The Master Puppeteer, and Johnny Tremain.
MATHEMATICSThe sixth grade Math curriculum is based on an intense review of previously taught material. This review is done in such a way that there is always something new. A continual theme through the year is the sense of number and the interrelationship between division, fractions, decimals, and percents, with fractions playing the central role. Another theme in sixth grade math is developing good work habits. Weekly homework assignments, organization skills, and keeping a good notebook are emphasized. Percents, business math, and algebraic formulas are introduced in sixth grade as well as drawing geometric figures exactly with Euclidean tools: the compass and the straight edge.
The seventh graders’ introduction to algebra (done in one three-week Main Lesson block) is an important milestone in development of the students’ abstract thinking. This serves as a crucial foundation for studying mathematics in high school. Another central theme for the seventh grade year is ratios, through which p and irrational numbers are introduced. The study of geometry continues with the Euclidean constructions that were introduced in sixth grade, and then moves on to theorems and proofs, culminating in the Pythagorean theorem. The year often ends with the students learning how to calculate the square roots of numbers by hand.
Instead of devoting a large portion of the eighth grade year to algebra in order to get the students “ahead,” the bulk of the material found in a traditional Algebra I course is kept for ninth grade, the year that we feel most students are ripe for algebra. Much of our eighth grade year is dedicated to non-traditional topics, such as number bases, in order to develop abstract thinking, and stereometry (the study of three-dimensional solids) and loci (the study of two-dimensional curves such as the conic sections), in order to develop the capacity of “exact” imagination. The traditional topics covered in eighth grade include volumes, proportions, dimensional analysis, percents and exponential growth.
Middle School Science
In the next three grades, the study of science turns to the lawfulness that comes from cause-and-effect relationships in the physical world. The focus now shifts to a threefold approach to the phenomena: observation, evaluation, and conceptualization. There is an emphasis on the hands-on and visual approaches in the middle school, by doing experiments that speak to the kinesthetic learners and drawings on the board that serve the visual.
In sixth grade, the threefold approach is now applied to electricity, magnetism, optics, acoustics, and heat in physics. Geography expands again, spiraling out to include either Europe (paralleling the study of Rome in history) or South America (as an extension of the North American studies in fifth grade). The polarity between the heights and the depths is explored in the complementary studies of Astronomy and Mineralogy.
In seventh grade, a mathematical approach is applied for the first time to physics content in mechanics, acoustics, electricity, heat and optics. In mechanics, for example, fulcrums are studied by first approaching the phenomena with seesaws and weights, and by identifying levers all around them in their homes and lives, then developing a rule or law. The students then use the rule to predict leverage and mechanical advantage for new arrangements. In chemistry, combustion, the lime cycle, and acids and bases form the content. The transformation of a substance through burning is an important highlight in this course. Nutrition, as well as Physiology, is taught in Main Lesson. In Geography, Africa is studied, continuing the expansion outward from the local to the farther extents of the world.
In eighth grade, Geography either focuses on a study of Asia, or of world religions. In physics, students learn how certain concepts are applied to technology or natural systems. The content areas (heat, light, electricity, acoustics, and mechanics) manifest as convection systems, refraction and lenses, the electric motor, musical instruments, and fluid mechanics and hydraulics. Fats, carbohydrates and proteins are studied in chemistry both in terms of what is happening in their own metabolisms and what can be achieved externally, such as by making personal care products (lip balm, soap, lotion, etc.). In biology, the human anatomy is studied, for example the musculoskeletal and nervous systems, to complement and complete the work done in seventh grade. Eight Graders also study Meteorology.
SOCIAL STUDIES AND HISTORY
Sixth grade history often begins with the life and conquests of Alexander the Great. In two three-week blocks, important highlights of life in the Roman Empire are studied, including the rise of the Empire, the emperors, the Republic, conquests, government, building and construction, barbarian incursions and the fall of the empire. Also included, are the life of Jesus of Nazareth and the influence of Christianity on the Empire. The Sixth Grader is left with a strong impression of all we have inherited from ancient Rome.
Later in the year, a three-week block delves into the life of medieval Europe. This includes, but is not limited to feudalism, peasant life, knighthood and the life of the monasteries. The life of Mohammed and the rise of Islam as a counterforce to Christianity are studied. This naturally brings in the Crusades. Parallels to modern life become evident in this block. The geography of Latin America is the focus this year. Each country is handled much like the states in our study of the U.S., but in one three-week block. Each student will write a report on one of the countries in this region.
Some of the books that may be read during this year to further support these studies may include, The Sword and the Circle, by Rosemary Sutcliff, The Bronze Bow, by Elizabeth George Spear, Otto of the Silver Hand, by Howard Pyle, and Secret of the Andes, by Ann Nolan Clark.
In seventh grade the students study European history from the late Middle Ages through the Renaissance. There are usually three, three or four week Main Lesson blocks. Key biographies of either people who were forerunners of the times or individuals who particularly exemplified a character type from that time are studied in depth. In the Late Middle Ages, Marco Polo, Eleanor of Aquitaine, and Joan of Arc are typical biographies. As the curriculum moves towards the Reformation, the role of the Roman Catholic Church is explored with emphasis on the developments that took place within the church that contributed to the turbulence of the times. Martin Luther is typical of a key biography for this time period. Not only are the changes that took place in the religious/political life studied, but also the explorers in science, art, and world travel. Copernicus, Galileo, Columbus, Magellan, de Vinci, and Michelangelo are some of the fascinating biographies that tell the story of the times. The students deeply immerse themselves in the art of the times through their own reproductions of the work of “the renaissance masters.” The geography of Africa and Europe are covered in seventh grade. Typically, students write a report related to some aspect of a particular country. Some of the books related to history that are read in seventh grade include: Robin Hood, Adam of the Road, and Young Joan.
The eighth grade History curriculum spans the time from Elizabethan England through the modern times, with particular emphasis on the founding of America. First, the social, political, and economic climates in Europe set a stage for the mass migration to the American continent. The Revolutionary War, the Declaration of Independence, and the Constitution of the U.S. are studied in depth through biographies, art, literature, and pertinent readings. The settling of America, including the interaction of the settlers with the Native American people, is explored. Biographies of great Americans, such as, Abraham Lincoln lead the students into the Civil War and the Industrial Revolution. Rockefeller and Carnegie are two major biographies juxtaposed to the life of the common factory worker or miner. Through student presentations on the inventions of the 1900’s, the class is introduced to the genius of the modern world. The students are led through history to the two World Wars as well as the Civil Rights Movement and the biography of Martin Luther King Jr. Geography focuses on the Asian continent. Students continue to write reports on a country or on some aspect of world geography related to commerce. A wide variety of readers can be used in eighth grade depending on the focus of the teacher. Some examples related to history and geography may include: Johnny Tremain, Dragonwings, The Master Puppeteer, and My Brother Sam is Dead.
Studying music gives children an inspiring aesthetic experience while it develops focus, discipline, and social skills. Both singing and playing in ensembles strengthens students’ ability to work as individuals within a group. Middle school students become aware of their individual responsibility to the group as they work together to create a meaningful musical experience. They have many opportunities to perform in concerts, assemblies, and festivals throughout the school year.
Sixth grade students continue to develop their musical skills in choir, band and orchestra. They begin to explore how music developed throughout history by studying and performing music of different styles and eras.
Students continue to participate in choir, band and orchestra classes, bringing musical concepts and skill acquisition together in rehearsing and performing. Seventh graders are introduced to music related to the historical and geographical eras they study—such as the Renaissance and Africa.
In their ongoing musical education, eighth grade students benefit from the opportunity to experience more intense and varied emotions through the music they create together. Study and performance of good music of various styles enhances their aesthetic development and helps them begin to develop musical judgment and an understanding of the profound effects music can have on human beings.
WORLD LANGUAGESMWS offers German and Spanish in Grades 1-12. Grades 1-7 have three lessons each week in blocks. At the end of a block, students switch to the alternate language. In Grade 8 students choose between Spanish and German and continue with this selection in the High School. Beginning in Grade 9 each student has four World Language classes per week. The World Language teachers strive to integrate Morning Lesson topics into the World Language lessons in support of our interdisciplinary approach to teaching.
By Grade 6, writing and reading has become a focal point. Beginning elements of grammar are taught. The language teacher uses dialogues, storytelling, verses, songs, tongue twisters, and small plays during instruction. Throughout these years, the students’ vocabulary comprehension increases,and they are able to say simple descriptive sentences, perform dialogues, and retell simple stories. In Grade 6 German, students use Zusammen Lesen by Roswitha Garff. In Spanish, they use an easy reader called Piratas del Caribe.
In Grades 7 and 8 teachers emphasize the languages’ phonetic structure so that students can read and write correctly. Teachers also place emphasis on listening comprehension and oral competence.
EURYTHMYThe sixth grader has changed physically from the well-proportioned fifth grader into the developing adolescent, often with limbs akimbo. The eurythmy curriculum for this grade is designed to meet the physical and emotional changes that accompany this challenging developmental time. One way to work with these changes is to introduce the orderly forms of geometry, with their accompanying laws such as: the five-pointed star, hexagon, square, and figure eight.. The students use a capacity they are just beginning to develop, cause and effect thinking.
Students learn to listen to and identify the major intervals. They then learned to form the eurythmy gestures for these intervals, forming the gestures for the tonic to the octave, where they must reach upwards, out of the narrow confines of themselves.
Some of the eurythmy elements include the vowel and consonant forms, and mirroring. Copper rod exercises continue, including: the seven-fold, waterfall, spiral, spinning, and tossing. Copper rod exercises help improve the students’ posture, as well as enhance their spatial orientation.
The seventh grade eurythmy curriculum is full of the dark and light aspects in movement that reflect the turbulent emotional climate of the developing adolescent. Humor and drama are key elements in expressing this range. Head and foot gestures are learned as a kind of punctuation to enhance the understanding of poetry and music. The work with the copper rods becomes more challenging. Forms learned in years past become more complicated in their execution, e.g., the figure-eight form and the seven-pointed star.
The 8th grade year reviews forms learned in previous years, but now taken up in new ways, with the students beginning to apply their own understanding in the creation of the forms. They learn the deeper meaning of the gestures for the sounds of the alphabet and create their own poetry to move to. They often perform a story set to eurythmy for the younger students.
HANDWORK AND PRACTICAL ARTSFollowing the lower school years, in Middle School students expand on their skills with increasingly sophisticated and complex projects. Sixth grade brings the opportunity to design and hand-sew an animal. Seventh grade progresses to hand-sewn dolls and doll clothing. In the eighth grade, while students are studying the Industrial Age, the Handwork curriculum involves sewing clothes on a treadle sewing machine.
Middle school students are combined weekly for a double period of Practical Arts. During these classes, mixed-age groups of students rotate through a variety of project-based classes. This provides an opportunity for our middle school students to learn and work together, and encourages greater familiarity among the grades. Through performing, fine and practical arts students deepen and transform experience. Every creation bears the stamp of individuality and expresses the student’s response to the world. The student uses imagination, cognition, and skill to bring each artistic or practical task to fruition. Experiencing this process repeatedly builds confidence for setting and implementing goals later in adult life.
Middle School Practical Arts activities include: watercolor painting in both veil and wet-on-wet technique, needle and wet felting, baking/cooking, batik, pastel drawing, charcoal drawing, figure drawing, mosaics, stained glass, folk dancing, basketry, bead work, metal work, printmaking, pottery, gymnastics, geometric string art, clay work, mountain biking, figure drawing and print making, and Outdoor education skills (gardening, earth-based skills and Winter skills). | http://shiningmountainwaldorf.org/our-program/middle-school/main-lesson-and-subject-classes/ |
4.125 | Play is vital for providing opportunities to develop language, thinking, motor skills and social skills. Children participate in different types of play and their skills change and develop over time. Providing children with opportunities to develop these skills helps lay the foundation for strong skills in communicating, socialising and learning.
Some of the types of play that children experience include:
Sensory and locomotor play: This develops motor skills as well as strength and coordination and also provides excercise. It includes tasks such as puzzles, threading and craft actvities as well as running, skipping, climbing and exploring playground equipment.
Object or construction play: This inlcudes construction activities such as blocks and also objects such as doll and car play which develops into pretend play.
Language play: Children vocalise and chat to themselves.
Pretend play: Otherwise called symbolic play or fantasy play. Children pretend that an object or action is something else, such as a doll being a baby, or climbing a tree is exploring a jungle.
Socio-dramatic play: Pretend play with others. This play is particularly important for developing social skills, higher level language and thinking skills. It might include playing "families" or "schools" or acting out roles such as pirates or princesses.
The development of play skills:
Babies up to 10 months of age use play to explore the world around them. This includes touching, holding, shaking, throwing, banging, moving and mouthing objects. They tend to explore one thing at a time and though they enjoy common items they don't use them in the typical way, for example they may use keys for shaking and enjoy the noise they make but not try to open things with them.
Toddlers of 10 to 18 months begin to show an understanding of how objects are used and copy the actions they see others do. They may use a brush to try to brush their hair or try to put a key into a door. They may combine two objects together such as pushing blocks over with a car.
Older toddlers of 18 months to 2 years begin to show simple pretending. They may pretend to drink form a toy cup even though it is empty or pretend to eat from a spoon. They begin with actions directed at themselves, such as eating from a spoon and later begin to direct actions to others such as feeding mum with a spoon or putting teddy to bed.
Two year olds begin to do true pretending where they imagine that things are "real" such as eating pretend food. They also begin to pretend that an object is something else such as pushing a block along, making car noises and pretending that the block is a car. They can "imagine" objects that are not there such as putting a pretend hat on a doll. They can also pretend that they are something else, such as "being" a character such as a pirate or an animal such as a tiger.
Three to four year olds begin to combine actions and objects to act out scenes. They use a mixture of people, real objects
and imaginary objects to act out sequences of actions and whole scenes such as a tea party, caring for babies or going to the petrol station. Play scenes may be
based on things that the child has experienced or on things they have seen but not experienced such as stories and movies.
To help develop your child's play skills:
- Offer a range of age appropriate toys and activities
- Allow time for your child to play every day
- Watch and follow your child's lead in the play
- Encourage younger children to imitate actions with objects
- Expland your child's actions by copying them then adding an extra action to the sequence
- Gradually add new objects to your child's play to expand opportunities such as adding plastic animals to blocks.
- Introduce new themes to expand your child's interests, for example if they like cars, try some boats or trucks.
- Talk about your child's play by acting as a narrator. "Look teddy is eating his tea, he likes that food, now he is getting full".
- Introduce a challenge or problem to the play to encourage thinking skills. "Oh no teddy is thirsty now, what can he do?"
- Provide opportunities to play with children of a similar age to develop cooperative play.
If you are concerned about your child's development, social or language skills check the Talking Matters website for more information. Watch out for future blogs on developing play for different ages. Why not follow so you don't miss out.
This blog is based on information from a workshop by Alison Winkworth "Creative pretend play in language intervention" (2012) presented by Speech Pathology Australia and includes information from Paiget (1951), McClune (1995) and Nicolich (1977).
Talking Matters Team | http://blog.talkingmatters.com.au/developing-play/ |
4.03125 | Here's a very simple GNU Make function: it takes three arguments and makes a
'date' out of them by inserting / between the first and second and second and third arguments:
make_date = $1/$2/$3
The first thing to notice is that make_date is defined just like any other GNU Make macro (you must use = and not := for reasons we'll see below).
To use make_date we $(call) it like this:
today = $(call make_date,19,12,2007)
That will result in today containing 19/12/2007.
The macro uses special macros $1, $2, and $3. These macros contain the argument specified in the $(call). $1 is the first argument, $2 the second and so on.
There's no maximum number of arguments, but if you go above 10 then you need parens: you can't write $10 instead of $(10). There's also no minimum number. Arguments that are missing are just undefined and will typically be treated as an empty string.
The special argument $0 contains the name of the function. In the example above $0 is make_date.
Since functions are just macros with some special automatic macros filled in (if you use the $(origin) function on any of the argument macros ($1 etc.) you'll find that they are classed as automatic just like $@), you can use GNU Make built in functions to build up complex functions.
Here's a function that turns every / into a \ in a path"
unix_to_dos = $(subst /,\,$1)
using the $(subst). Don't be worried about the use of / and \ there. GNU Make does very
little escaping and a literal \ is most of the time just a \.
Some argument handling gotchas
When GNU Make is processing a $(call) it starts by splitting the argument list on commas to set $1 etc. The arguments are expanded so that $1 etc. are completely expanded before they are ever referenced (it's as if GNU Make used := to set them). This means that if an argument has a side-effect (such as calling $(shell)) then that side-effect will always occur as soon as the $(call) is executed, even if the argument was never actually used by the function.
One common problem is that if an argument contains a comma the splitting of
arguments can go wrong. For example, here's a simple function that swaps its two arguments:
swap = $2 $1
If you do $(call swap,first,argument,second) GNU Make doesn't have any way to know that the first argument was meant to be first,argument and swap ends up returning argument first instead of second first,argument.
There are two ways around this. You could simply hide the first argument inside a macro. Since GNU Make doesn't expand the arguments until after splitting a comma inside a macro will not cause any confusion:
FIRST := first,argument
SWAPPED := $(call swap,$(FIRST),second)
The other way to do this is to create a simple macro that just contains a comma and use that instead:
c := ,
SWAPPED := $(call swap,first$cargument,second)
Or even call that macro , and use it (with parens):
, := ,
SWAPPED := $(call swap,first$(,)argument,second)
Calling built-in functions
It's possible to use the $(call) syntax with built in GNU Make functions. For example, you could call $(warning) like this:
This is useful because it means that you can pass any function name as an argument to a user-defined function and $(call) it without needing to know if it's built-in or not.
This gives you the ability to created functions that act on functions. The classic functional programming map function (which applies a function to every member of a list returning the resulting list) can be created | http://www.agileconnection.com/article/gnu-make-user-defined-functions |
4 | Electrical elementAn electric circuit, or electrical network, consists of electrical elements or components connected by conductors. Elements include devices (such as an inductor, resistor, capacitor, conductor, line, or cathode ray tube) with terminals at which it may be connected directly with other devices. It can also mean a antenna radiator (either parasitic or active). In circuitry, it can be used to specify a portion of a integrated circuit that contributes directly to the IC's operation.
The elements alter the way that electric current flows through the conductors. The concept of electrical elements is used in the analysis of electrical networks. Each element represents one of the fundamental aspects of the electrical network.
The elements are:
- Current source, measured in amperes - produces a current in a wire.
- Voltage source, measured in volts - produces a potential difference across two points.
- Resistance, measured in ohms - produces a voltage proportional to the current flowing through it.
- Capacitance, measured in farads - produces a current proportional to the rate of change of voltage across it.
- Inductance, measured in henries - produces a voltage proportional to the rate of change of current through it.
Elements and Components
A battery provides electromotive force (emf), or voltage, in a circuit. It contains layers of chemicals that cause electrons to move in a certain direction, from its negative pole to its positive pole. It is marked with a rating of how much voltage there is across the two poles, and a (-) for the negative pole and a (+) for the positive pole. Batteries may also be marked with an ampere hour (Ah) rating, indicating total charge capacity.
An ideal battery can thus be represented as a voltage source. In practice, a battery also has an internal resistance that is represented as a resistance in series with the voltage source.
If a wire is used to connect the two poles of a battery, electrons flow through the wire from the negative end to the positive end. (The wire will also get hot because it isn't a perfect conductor, and the battery will quickly exhaust all its power.) Thus a wire can be represented as a low-value resistor.
Current sources are often absent from basic electric circuits, and are more likely to be found in electronic circuits containing semiconductors.
A resistor is a component whose function is to regulate the current in the circuit. One common kind is a little cylinder of graphite with metal wires coming out of either end. These are painted with colored stripes that indicate the resistance, in ohms, and the tolerance, in percent. This system is called the resistor color code.
Another kind of resistor is a filament, which is a coil of metal wire that can withstand high temperature but has a finite resistance. When a current is passed through a filament, it heats up because of this resistance. Filaments are commonly used in light bulbs and heaters. They are marked with the voltage that should be applied to them, and the power, in watts, that they will then give off as light and heat. Due to the effect of heating, a filament's resistance is higher when it is hot than when it is cold.
An electric charge can be stored and then quickly released by a component called a capacitor. A common type of capacitor consists of two pieces of metal foil (or plates) with an insulator (the dielectric) such as waxed paper between them.
If an electric charge is placed on the plates of a capacitor, it will stay there because it can't cross the insulator to the other plate. If a wire is then connected between the two plates, the charge will flow through the wire to balance the charges on the opposite plates--the capacitor is then said to be discharged.
Some capacitors look like a cylinder or blob with two wires coming out one end, and are marked to indicate their capacitance (the charge that they store per volt) in microfarads (μF), nanofarads (nF) or picofarads (pF).
Inductance in a circuit is provided by components called inductors, which are almost always built from coils of wire. Large values of inductance are obtained by forming the coil around a magnetic core, such as a lump of iron or ferrite. Inductance is also present in the windings of electric motors and generatorss, and to a lesser extent in any piece of wire.
A longer list of electronic components can be found in the electronics article. | http://www.encyclopedia4u.com/e/electrical-element.html |
4.0625 | Of the over 620 species and subspecies of carnivorous plants currently recognised in the world, New Zealand has but relatively few. Although many of our native carnivores are small in stature they are both beautiful and deadly; masters of their boggy realm.
Carnivorous plants occur on every continent throughout the world except Antarctica. They live in almost every conceivable environment except deserts and saline environments. They are plants of fresh-water habitats that are wet for at least part of the year and where the soils are low in nutrients and often acidic. Their carnivorous nature offsets the lack of nutrients available in the poor soils of their habitats and allows them to grow where other plants cannot. Their carnivorous processes also require a high light level in order to function properly so they are commonly found in open places such as bogs, lakes and various other types of barren land.
New Zealand's Carnivorous Plants -
Of the 16 genera of carnivorous plants found worldwide, New Zealand only has representatives from two and they are also the two most common genera. From these two genera there are 12 species in total thought to be native. They are Drosera, or the sundews, with 7 species and Utricularia, or the bladderworts, with 5 species. This paucity of carnivorous plants is probably due to New Zealand's long period of geological isolation.
New Zealand's carnivorous plants live in a wide range of habitats including coastal bogs, clay banks, roadside drains, seepages, peatlands, lakes, and alpine cushion bogs high in the mountains from the tip of the North Island southwards to our subantarctic islands and eastwards to the Chatham Islands. | http://www.nzcps.co.nz/NZCPSNativeCPs.html |
4.375 | Whether your students' families came to America ten days ago, ten months ago, ten years ago, or much longer than that, they, like most Americans, are either immigrants or descendants of immigrants. Have your students do an oral-history project that explores each one's immigrant background. Develop questions such as:
Who in your family immigrated to America?
What countries were the original homelands?
When did they come to the U.S.A.?
Why did they come?
How did they get here? Was the journey anything like the one in How Many Days to America?
What language did they originally speak? Is that language still spoken in the home?
What songs, customs, or traditional clothing can they tell about?
Your students should interview and tape-record, if possible, their parents and grandparents, as well as write and talk about their own personal experiences. Keep a world map in the room, and as the reports come, flag countries of origin.
On the day the histories are presented to the class, invite parents and conclude the presentations with an International Food Day.
Understands that culture and experience influence our perceptions of places and regions
Understands the patterns of human settlement and their causes
Obtains information about a topic using a variety of oral sources, such as conversations and interviews
Makes basic oral presentations to class
Organizes ideas for oral presentations | http://www.hmhbooks.com/readers_guides/bunting/america.shtml |
4.3125 | Children, Moms and Dads – or maybe Grans and Granddads – Enjoy!
Would be authors – would you like to see your stories published here?
Writing Short Stories for Children.
- Choose a narrative point of view . You can write your children’s short story like one of the characters (first person), as an individual narrator presents the thoughts and observations of a character (in the third person ), or as an individual narrator who presents the thoughts and observations of several characters. A story from the point of view of the first person refers to the protagonist as “I” instead of “he” or “she.”
- Create a protagonist or main character . This must be the most developed character and usually the friendliest in this short story for children .
- Create a problem or conflict, for the protagonist . The conflict of the tale usually has one of the five basic forms: person versus person, person versus self, person against nature, person against society, or of the person in front of God or fate. If you choose conflict from person to person, develop an antagonist to serve as the person to whom the protagonist must face.
- Set believable characters and scenes in the story , with vivid descriptions and dialogue, to create a children’s story that will fascinate readers.
- Build the narrative tension of the story making the protagonist have several failed attempts to try to solve or overcome the problem or conflict in the story. (You may want to skip this step for shorter stories.)
- Describe a crisis to serve as the last opportunity for the protagonist as he/she solves the problem or conflict of the story.
- Resolving the tension narrative making the protagonist triumph through his/her own intelligence, creativity, courage or other positive attributes. This is usually called, the climax of the short story.
- Extend this resolution phase , if you wish, to reflect on the action of the story and what it means for the characters in today’s society. | http://www.mclkids.org/ |
4.25 | dogs descended from the gray wolf. But dogs are so different from wolves that
it seems difficult to imagine how one species led to another. How an organism
evolves has to do with the selective pressures it is exposed to in its
environment. In this activity, see what happens to two different populations of
wolves as different selective pressures are applied.
Cut apart the 24 cards from your "Wolf Deck" student handouts.
Appoint one member of your group to be the scorekeeper. The scorekeeper will
record the total value of each student's hand of six cards before the game
begins and after each round. The scorekeeper should also calculate the deck
average by summing all 24 cards before the game begins, and after the
5th, 10th, and 20th round.
Have the scorekeeper calculate the initial value of the deck and record
below. This represents the initial temperament of your wolf population.
Deal six cards. Each hand represents the collection of genes that contribute
to the temperament for one wolf. A hand with low value represents an aggressive
wolf while a hand with higher value represents a tamer animal.
Calculate the total of each hand. Follow the instructions below for your
Wolf Group A
to selective pressures, the wolves with the most aggressive genes do not
survive. To simulate this, the players who have the two lowest hand totals will
remark their cards with numbers on the cards of the other two players. Twelve
cards will be remarked.
Wolf Group B
to selective pressures, the wolves with the most aggressive and most tame genes
do not survive. To simulate this, the players who have the highest and lowest
hand totals will remark their cards with numbers on the cards of the other two
players. Twelve cards will be remarked.
Shuffle all 24 cards together. This represents the mating of the wolves. As
in nature, some of the offspring from this mating have random genetic mutations
of their temperament genes. To simulate this, draw two random cards, keeping
track of where they came from in the deck. Throw a die for each card you have
removed and then change the value on the card (write the new number directly on
the card) according to the following table:
Return the cards back to their original place in the deck.
Deal six cards to each player. Repeat steps 5-7.
Play a total of 20 hands, recording the entire deck average after hands 5,
10, and 20.
When you have finished the game, answer the questions listed on your
"Examining the Game" student handout. | http://www.pbs.org/wgbh/nova/education/activities/3103_dogs_01.html |
4.3125 | Strides are continuing to be made in the world of quantum computing. The most advanced quantum computer contains about 12 quibits… meaning it can hold 4096 pieces of data simultaneously. So how does quantum computing work? With normal computers, a bit may be represented by a group of electrons. In a quantum computer, information is stored by a single particle, maybe just a single electron. Because the rules of quantum mechanics dictate that a single particle can be in two places at once, that single particle can store two pieces of information. Information is exchanged by hitting these particles with microwaves. Because they can hold twice as much information, quantum computers can perform calculations much faster. As a result, quantum computing will wind up pushing the current limits of computing power. | http://community.mis.temple.edu/richm3538/2011/11/07/what-is-quantum-computing/ |
4.03125 | Sometimes you can see that certain parts of clouds show iridescent colours. In most cases this iridescence appears in clouds which form rapidly (e.g. altocumulus lenticularis). Especially the rims of these clouds have purple red, blue and green colours. This phenomenon is closely related to the coronae. Here the colours are also caused by the diffraction of light. The water droplets that cause the iridescence are very small. Small droplets generate very big coronae with wide rings of the same colour. This is the reason why great parts of the cloud have the same colour. The other colours in the iridescent cloud are less due to the changing distance from the sun, but to different sizes of the droplets. Different droplet sizes generate different coronae, what makes the colour differ despite the equal distance from the sun.
As the results of continuous observations of atmospheric phenomena show, about 12% of the cloud iridescence observed were visible in cirrocumulus clouds. The greatest part of these clouds consists of ice crystals while freezing water droplets make only a sma1l part of them. Even in cirrocumulus clouds iridescence is often observed more than 30° away from the sun, a fact that almost excludes the diffraction of light as a reason for the formation of the iridescence. So the latest theories assume that the colours are caused by interfering rays of light being reflected from the front or rear side of very thin plateshaped ice crystals or by interfering rays a part of which directly passes the cloud layer while the other rays are reflected once or several times inside the cloud layer. | http://www.meteoros.de/iris/irise.htm |
4.3125 | Architecture played a very important role for the church in Medieval England. The more splendid the architecture, the more the church believed it was praising God. The church in Medieval England poured vast sums of money into the creation of grandiose architectural projects that peaked in the cathedrals at Canterbury and York.
Medieval churches and cathedrals were superbly built. No peasant wattle and daub homes exist anymore as they were so crudely made. But the vast sums accrued by the church (primarily from the poorer classes) gave it the opportunity to spend on large building projects. Many of the churches and cathedrals that survive from medieval times have also had additions to them. Therefore, we can identify different building styles in the same complete building.
For example, York Minster contains sections that can be traced to 1080 to 1100, 1170, major expansion work between 1220 to 1253, further expansion from 1291 to 1360 and the completion of the Central Tower which took from 1407 to 1465. Over the near 400 years of development, different styles would have developed and give historians an in-depth look at changes in church architectural styles.
The cathedrals started in the reign of William the Conqueror were the largest buildings seen in England up to that time. With the exception of Worcester Cathedral, William appointed Norman bishops to these cathedrals. Therefore, these men would have been heavily influenced by the architecture used in Normandy and this style came to dominate the architecture of the cathedrals built under William. Norman architecture is also referred to as Romanesque because it was influenced in turn by the Ancient Romans.
Norman architecture tends to be dominated by a round shape style. In Medieval England, the Normans used barely skilled Saxons as labourers and the tools they used were limited – axes, chisels etc. The churches and cathedrals built by the Normans tended to use large stones. This was because cutting stone to certain measurements was a skilled art and it is assumed that the Normans reckoned that the Saxons who worked on the stone would not be able to master such a skill.
Norman walls and pillars had faced stone on the outer surfaces but rubble was put into the hollow between the cut stone. Hence, the effect would be wall, rubble and wall. Pillars were effectively hollow until the central core was filled with rubble. This method of building was not particularly strong. To get round this and strengthen them, the Normans made their walls much thicker than later styles of building which relied on specifically cut stone that fitted together with the blocks surrounding it thus creating its own strength.
Norman doorways into a church or cathedral tended to be highly decorated with concentric arches that receded into the thickness of the wall. Windows were built in a similar way but they remained small and let in little light. This was because the Normans realised that their walls with large window spaces would not have been able to hold up the weight of the roofs.
To assist in the support of the roofs, the Normans used large pillars. These allowed the weight of the roof to be dispersed into the foundations via the pillars – once again saving the walls from taking all of the weight of the roof.
Pillars supporting the roof at Battle Abbey
The ceilings of Norman churches and cathedrals were vaulted. These vaults allowed the weight of the roof to be evenly distributed throughout the pillars and walls as the main points of the vaults rested on the tops of the pillars. The Normans used three styles of vaulting: barrel, rib and cross.
Rib vaulting at Battle Abbey
The architecture used by the Normans must have been successful as so many of their churches and cathedrals still exist – even if they have been built onto.
The main architectural style that was used after the Normans was the Gothic style. | http://www.historylearningsite.co.uk/medieval_church_architecture.htm |
4 | Logic is the skill of correct thinking and conceptual development. It is the thinking through of similarities, comparisons, and differences in order to induce the correct general conclusions. Studying logic and practicing logical thinking prepares students for the development of wisdom. Unfortunately, logic is all but forgotten in modern schools.
During the Logic Stage (Grades 6-8), students study the various types of logic including informal logic, categorical logic and symbolic logic. Logic has a central place in our Logic Stage curriculum in that it is a subject and skill that is applied and used in virtually every other class. For example, students in history, literature or science classes are required to think logically about the content they study and to respectfully expose any fallacies they detect in texts, presentations, or discussions. Their writing in these classes is assessed for logical sharpness, and examinations presuppose and exercise logical skill. These skills in logic are also foundational for more extensive studies in the Rhetoric Stage (Grades 9-12). | http://covenantclassicalschool.org/pages/page.asp?page_id=104572 |
4.03125 | As our closest neighbor in space, a time-capsule of planetary evolution and the only world outside of Earth that humans have stepped foot on, the Moon is an obvious and ever-present location for future exploration by humans. The research that can be done on the Moon as well as from it will be invaluable to science. But the only times humans have visited the Moon were during quick, dusty jaunts on its surface, lasting only 2-3 days each before departing. Long-term human exposure to the lunar environment has never been studied in depth, and its quite possible that in addition to the many inherent dangers of living and working in space the Moon itself may be toxic to humans.
An international team of researchers has attempted to quantify the health dangers of the Moon or at least its dust-filled regolith. In a paper titled Toxicity of Lunar Dust (D. Linnarsson et al.) the health hazards of the Moons fine, powdery dust which plagued Apollo astronauts both in and out of their suits are investigated in detail (or as best as they can be without actually being on the Moon with the ability to collect pristine samples.)
Within their research the team, which included physiologists, pharmacologists, radiologists and toxicologists from 5 countries, investigated some of the following potential health hazards of lunar dust:
Inhalation. By far the most harmful effects of lunar dust would come from inhalation of the particulates. Even though lunar explorers would be wearing protective gear, suit-bound dust can easily make its way back into living and working areas as Apollo astronauts quickly discovered. Once inside the lungs the super-fine, sharp-edged lunar dust could cause a slew of health issues, affecting the respiratory and cardiovascular system and causing anything from airway inflammation to increased risks of various cancers. Like pollutants encountered on Earth, such as asbestos and volcanic ash, lunar dust particles are small enough to penetrate deep within lung tissues, and may be made even more dangerous by their long-term exposure to proton and UV radiation. In addition, the research suggests a microgravity environment may only serve to ease the transportation of dust particles throughout the lungs.
Skin Damage. Lunar regolith has been found to be very sharp-edged, mainly because it hasnt undergone the same kind of erosive processes that soil on Earth has. Lunar soil particles are sometimes even coated in a glassy shell, the result of rock vaporization by meteorite impacts. Even the finer particles of dust which constitute about 20% of returned lunar soil samples are rather sharp, and as such pose a risk of skin irritation in instances of exposure. Of particular note by the research team is abrasive damage to the outer layer of skin at sites of anatomical prominence, i.e., fingers, knuckles, elbows, knees, etc.
The dust was so abrasive that it actually wore through three layers of Kevlar-like material on Jack [Schmitt's] boot, said Professor Larry Taylor, Director of the Planetary Geosciences Institute, University of Tennessee (2008).
Eye Damage. Needless to say, if particles can pose abrasive damage to human skin, similar danger to the eyes is also a concern. Whether lunar dust makes its way into the eye via airborne movement (again, much more of a concern in microgravity) or through direct contact from fingers or another dust-coated object, the result is the same: danger of abrasion. Having a scratched cornea is no fun, but if youre busy working on the Moon at the time it could turn into a real emergency.
While the research behind the paper used data about airborne pollutants known to exist on Earth and simulated lunar dust particles, actual lunar dust is harder to test. The samples returned by the Apollo missions have not been kept in a true lunar-like environment being removed from exposure to radiation and not stored in a vacuum, for instance and as such may not accurately exhibit the properties of actual dust as it would be encountered on the Moon. The researchers conclude that only studies conducted on-site will fill the gaps in our knowledge of lunar dust toxicity. Still, the research is a step in the right direction as it looks to ensure a safe environment for future explorers on the Moon, our familiar yet still alien satellite world.
Read the teams paper in full here.
The Apollo astronauts reported undesirable effects affecting the skin, eyes and airways that could be related to exposure to the dust that had adhered to their space suits during their extravehicular activities and was subsequently brought into their spacecraft," said Dag Linnarsson, lead author, Toxicity of Lunar Dust.
Explore further: NASA's IRIS mission readies for a new challenge | http://phys.org/news/2012-07-moon-toxic.html |
4.09375 | In this math worksheet, your child will get practice with place value by writing each number as a sum of 10s and 1s.
This coloring math worksheet lets your child practice counting sets of animals' legs, which lays a foundation for understanding multiplication.
Help the kids share the food equally! This coloring math worksheet helps your child build a visual foundation for understanding division.
Which item is least likely to be picked? This math worksheet introduces your child to probability and interpreting data.
A line of symmetry divides each of these images. This coloring math worksheet asks your child to draw the other half of each image to make both sides match.
This coloring math worksheet introduces your child to skip counting by 2, 5, and 10 and asks your child to color in the next numbers in each series.
Your child will connect the spaceships and rockets to the planets and stars with 1 or 10 more or less in this coloring math worksheet.
In this math worksheet, your child gets to practice number sequencing by putting sets of 4 numbers in order in ascending and descending order. Other math skills include understanding smaller and larger numbers and writing numbers up to 100.
Ready for fractions? This coloring math worksheet introduces children to fractional parts by asking them to color in 1/3 of familiar shapes.
This money math worksheet gives your child practice drawing and adding up coins to find money values. | http://www.greatschools.org/articles/?p=6&grades=201&outcomes=209&language=EN |
4 | Science Fair Project Encyclopedia
This global, interconnected body of salt water, called the World Ocean, is divided by the continents and archipelagos into the following five bodies, from the largest to the smallest: the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, the Southern Ocean, and the Arctic Ocean. Official boundaries are defined by the International Hydrographic Organization; the Southern Ocean, though long recognized in maritime tradition, was officially sanctioned only in 2000, and is unique in being defined only by a line of latitude with no landmass boundaries.
Oceanographers, however, may recoginize only four oceans, treating the Arctic Ocean (or the Arctic Sea) as a part of the Atlantic Ocean.
The area of the World Ocean is 361 million km≤, its volume is 1370 million km≥, and its average depth is 3790 m. This does not include seas not connected to the World Ocean, such as the Caspian Sea.
The total mass of the hydrosphere is about 1.4 × 1021 kg, ca. 0.023 % of the Earth's total mass.
Travel on the surface of the ocean through the use of boats dates back to prehistoric times, but only in modern times has extensive underwater travel become possible.
The deepest point in the ocean is the Mariana Trench located in the Pacific Ocean near the Northern Mariana Islands. It has a maximum depth of 10,923 m (35,838 ft) . It was fully surveyed in 1951 by the British navy vessel, "Challenger II" which gave its name to the deepest part of the trench, the "Challenger Deep".
Much of the bottom of the world's oceans is unexplored and unmapped. A global image of many underwater features larger than 10 km was created in 1995 based on gravitational distortions of the nearby sea surface.
One of the most dramatic forms of weather occurs over the oceans: tropical cyclones (also called "typhoons" and "hurricanes" depending upon where the system forms). Ocean currents greatly affect Earth's climate by transferring warm or cold air and precipitation to coastal regions, where they may be carried inland by winds. The Antarctic Circumpolar Current encircles that continent, influencing the area's climate and connecting currents in several oceans.
The oceans are home to many forms of life, such as:
- cetacea such as whales, dolphins and porpoises,
- cephalopods such as the octopus
- crustaceans such as lobsters and shrimp
- marine worms
The oceans are essential to transportation: a huge portion of the world's goods are moved by ship between the world's seaports. Important ship canals include the Saint Lawrence Seaway, Panama Canal, and Suez Canal.
Earth is the only planet known with liquid water on its surface, and is certainly the only such in our own solar system. However, liquid water is thought to be present under the surface of several natural satellites, particularly the Galilean moons of Europa, and, with less certainty, its fellows Callisto and Ganymede. Other icy moons may have once had internal oceans that have now frozen, such as Triton. The planets Uranus and Neptune may also possess large oceans of liquid water under their thick atmospheres, though their internal structure is not well understood at this time.
There is currently much debate over whether Mars once had an ocean of water in its northern hemisphere, and over what happened to it if it did; recent findings by the Mars Exploration Rover mission indicate that it had some long-term standing water in at least one location, but its extent is not known.
Liquid hydrocarbons are thought to be present on the surface of Titan, though it may be more accurate to describe them as "lakes" rather than an "ocean". The distribution of these liquid regions will hopefully be better known after the full analysis of data from the Huygens probe of the Cassini-Huygens space mission, which dropped onto Titan's surface in January 2005. Titan is also thought likely to have a subterranean water ocean under the mix of ice and hydrocarbons that forms its outer crust.
- Science taps into ocean secrets
- Why is the ocean salty?
- Official IHO boundaries of Oceans and Seas
- The Hydrogen Expedition The first circumnavigation of the globe in a hydrogen fuel cell powered boat
- NOPP - The National Oceanographic Partnership Program
The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details | http://all-science-fair-projects.com/science_fair_projects_encyclopedia/Ocean |
4.03125 | The monument maintains an Air Quality Station which tracks visibility, particulates, ozone, nitrates, sulfides, dioxins, and rainwater deposition. This data is analyzed and used to determine overall air quality, and factors or events that may be having detrimental effects on the air. This information can help managers decide what future actions may be necessary to maintain the current level of air quality, or to make improvements. The monument's close proximity to Mexico makes it a prime candidate for monitoring the effect of Mexico's pollution on air quality in the United States. Smelting, manufacturing and power plants on the other side of the border produce pollutants that can be carried into the monument. That, along with plans to build an additional incinerator and power plants within 50 miles of the monument, makes it even more critical that baseline air quality data be collected.
Air quality data from 48 Class 1 NPS sites and others can be viewed on the Internet. See the links below.
Did You Know?
The rock formations at Chiricahua National Monument were carved by ice and water from layers of rhyolite, which was originally ash blown out during the Turkey Creek Volcano eruption 27 million years ago. | http://www.nps.gov/chir/naturescience/airquality.htm |
4.25 | Brain: The Inside Story
Brain: The Inside Story explores how neurons communicate; how the brain processes sensory information, emotions, and behaviors; how the organ evolved in vertebrates; and what makes each human brain unique. This comprehensive guide will help you explore the exhibition with your students.
Use these free online resources to further explore themes presented in Brain: The Inside Story exhibition.
You don't have to speak the same language, or even speak, to understand when someone is happy or sad. Explore how and why our brains have evolved to read facial expressions.
Neurons can send more than 100 signals a second at speeds up to 250 miles an hour. Create a life-sized drawing to learn more about your body's speedy message carriers.
Reading by touch instead of sight forms new and different neuron connections. Discover firsthand how your brain can learn to read Braille with your fingertips.
It's not just the taste buds in your mouth that let you taste sweet, bitter, salty, sour, and other flavors. Take the Jellybean Test to find out how your nose helps you taste.
In a game like dodge ball, how is it that your brain is able to tell you to raise your arm and block an incoming ball with your elbow? Find out with this simple experiment.
The Museum's Brain: The Inside Story exhibition takes an in-depth look at the remarkable organ that's sometimes described as the world's most complex structure. This comprehensive guide will help you explore the exhibit with your students. It includes: | http://www.amnh.org/exhibitions/past-exhibitions/brain-the-inside-story/brain-promos/for-educators |
4.03125 | Least common multiple
In arithmetic and number theory, the least common multiple (also called the lowest common multiple or smallest common multiple) of two integers a and b, usually denoted by LCM(a, b), is the smallest positive integer that is divisible by both a and b. If either a or b is 0, LCM(a, b) is defined to be zero.
The LCM of more than two integers is also well-defined: it is the smallest integer that is divisible by each of them.
A multiple of a number is the product of that number and an integer. For example, 10 is a multiple of 5 because 5 × 2 = 10, so 10 is divisible by 5 and 2. Because 10 is the smallest positive integer that is divisible by both 5 and 2, it is the least common multiple of 5 and 2. By the same principle, 10 is the least common multiple of −5 and 2 as well.
What is the LCM of 4 and 6?
Multiples of 4 are:
- 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72, 76, ...
and the multiples of 6 are:
- 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, ...
Common multiples of 4 and 6 are simply the numbers that are in both lists:
- 12, 24, 36, 48, 60, 72, ....
So, from this list of the first few common multiples of the numbers 4 and 6, their least common multiple is 12.
When adding, subtracting, or comparing vulgar fractions, it is useful to find the least common multiple of the denominators, often called the lowest common denominator, because each of the fractions can be expressed as a fraction with this denominator. For instance,
where the denominator 42 was used because it is the least common multiple of 21 and 6.
Computing the least common multiple
Reduction by the greatest common divisor
Many school age children are taught the term greatest common factor (GCF) instead of the greatest common divisor(GCD); therefore, for those familiar with the concept of GCF, substitute GCF when GCD is used below.
The following formula reduces the problem of computing the least common multiple to the problem of computing the greatest common divisor (GCD):
This formula is also valid when exactly one of a and b is 0, since gcd(a, 0) = |a|.
Because gcd(a, b) is a divisor of both a and b, it's more efficient to compute the LCM by dividing before multiplying:
This reduces the size of one input for both the division and the multiplication, and reduces the required storage needed for intermediate results (overflow in the a×b computation). Because gcd(a, b) is a divisor of both a and b, the division is guaranteed to yield an integer, so the intermediate result can be stored in an integer. Done this way, the previous example becomes:
Finding least common multiples by prime factorization
The unique factorization theorem says that every positive integer greater than 1 can be written in only one way as a product of prime numbers. The prime numbers can be considered as the atomic elements which, when combined together, make up a composite number.
Here we have the composite number 90 made up of one atom of the prime number 2, two atoms of the prime number 3 and one atom of the prime number 5.
This knowledge can be used to find the LCM of a set of numbers.
Example: Find the value of lcm(8,9,21).
First, factor out each number and express it as a product of prime number powers.
The lcm will be the product of multiplying the highest power of each prime number together. The highest power of the three prime numbers 2, 3, and 7 is 23, 32, and 71, respectively. Thus,
This method is not as efficient as reducing to the greatest common divisor, since there is no known general efficient algorithm for integer factorization, but is useful for illustrating concepts.
This method can be illustrated using a Venn diagram as follows. Find the prime factorization of each of the two numbers. Put the prime factors into a Venn diagram with one circle for each of the two numbers, and all factors they share in common in the intersection. To find the LCM, just multiply all of the prime numbers in the diagram.
Here is an example:
- 48 = 2 × 2 × 2 × 2 × 3,
- 180 = 2 × 2 × 3 × 3 × 5,
and what they share in common is two "2"s and a "3":
- Least common multiple = 2 × 2 × 2 × 2 × 3 × 3 × 5 = 720
- Greatest common divisor = 2 × 2 × 3 = 12
This also works for the greatest common divisor (GCD), except that instead of multiplying all of the numbers in the Venn diagram, one multiplies only the prime factors that are in the intersection. Thus the GCD of 48 and 180 is 2 × 2 × 3 = 12.
A simple algorithm
This method works as easily for finding the LCM of several integers.
Let there be a finite sequence of positive integers X = (x1, x2, ..., xn), n > 1. The algorithm proceeds in steps as follows: on each step m it examines and updates the sequence X(m) = (x1(m), x2(m), ..., xn(m)), X(1) = X. The purpose of the examination is to pick up the least (perhaps, one of many) element of the sequence X(m). Assuming xk0(m) is the selected element, the sequence X(m+1) is defined as
- xk(m+1) = xk(m), k ≠ k0
- xk0(m+1) = xk0(m) + xk0.
In other words, the least element is increased by the corresponding x whereas the rest of the elements pass from X(m) to X(m+1) unchanged.
The algorithm stops when all elements in sequence X(m) are equal. Their common value L is exactly LCM(X). (For a proof and an interactive simulation see reference below, Algorithm for Computing the LCM.)
A method using a table
This method works for any number of factors. One begins by listing all of the numbers vertically in a table (in this example 4, 7, 12, 21, and 42):
The process begins by dividing all of the factors by 2. If any of them divides evenly, write 2 at the top of the table and the result of division by 2 of each factor in the space to the right of each factor and below the 2. If a number does not divide evenly, just rewrite the number again. If 2 does not divide evenly into any of the numbers, try 3.
Now, check if 2 divides again:
Once 2 no longer divides, divide by 3. If 3 no longer divides, try 5 and 7. Keep going until all of the numbers have been reduced to 1.
Now, multiply the numbers on the top and you have the LCM. In this case, it is 2 × 2 × 3 × 7 = 84. You will get to the LCM the quickest if you use prime numbers and start from the lowest prime, 2.
Fundamental theorem of arithmetic
where the exponents n2, n3, ... are non-negative integers; for example, 84 = 22 31 50 71 110 130 ...
Given two integers and their least common multiple and greatest common divisor are given by the formulas
In fact, any rational number can be written uniquely as the product of primes if negative exponents are allowed. When this is done, the above formulas remain valid. Using the same examples as above:
The positive integers may be partially ordered by divisibility: if a divides b (i.e. if b is an integer multiple of a) write a ≤ b (or equivalently, b ≥ a). (Forget the usual magnitude-based definition of ≤ in this section - it isn't used.)
Under this ordering, the positive integers become a lattice with meet given by the gcd and join given by the lcm. The proof is straightforward, if a bit tedious; it amounts to checking that lcm and gcd satisfy the axioms for meet and join. Putting the lcm and gcd into this more general context establishes a duality between them:
- If a formula involving integer variables, gcd, lcm, ≤ and ≥ is true, then the formula obtained by switching gcd with lcm and switching ≥ with ≤ is also true. (Remember ≤ is defined as divides).
The following pairs of dual formulas are special cases of general lattice-theoretic identities.
This identity is self-dual:
Let D be the product of ω(D) distinct prime numbers (i.e. D is squarefree).
where the absolute bars || denote the cardinality of a set.
The LCM in commutative rings
The least common multiple can be defined generally over commutative rings as follows: Let a and b be elements of a commutative ring R. A common multiple of a and b is an element m of R such that both a and b divide m (i.e. there exist elements x and y of R such that ax = m and by = m). A least common multiple of a and b is a common multiple that is minimal in the sense that for any other common multiple n of a and b, m divides n.
In general, two elements in a commutative ring can have no least common multiple or more than one. However, any two least common multiples of the same pair of elements are associates. In a unique factorization domain, any two elements have a least common multiple. In a principal ideal domain, the least common multiple of a and b can be characterised as a generator of the intersection of the ideals generated by a and b (the intersection of a collection of ideals is always an ideal). In principal ideal domains, one can even talk about the least common multiple of arbitrary collections of elements: it is a generator of the intersection of the ideals generated by the elements of the collection.
See also
- Crandall, Richard; Pomerance, Carl (2001), Prime Numbers: A Computational Perspective, New York: Springer, ISBN 0-387-94777-9
- Hardy, G. H.; Wright, E. M. (1979), An Introduction to the Theory of Numbers (Fifth edition), Oxford: Oxford University Press, ISBN 978-0-19-853171-5
- Landau, Edmund (1966), Elementary Number Theory, New York: Chelsea
- Long, Calvin T. (1972), Elementary Introduction to Number Theory (2nd ed.), Lexington: D. C. Heath and Company, LCCN 77-171950
- Pettofrezzo, Anthony J.; Byrkit, Donald R. (1970), Elements of Number Theory, Englewood Cliffs: Prentice Hall, LCCN 77-81766 | http://en.wikipedia.org/wiki/Least_common_multiple |
4.125 | Learning the Swahili Articles is very important because its structure is used in every day conversation. The more you practice the subject, the closer you get to mastering the Swahili language. But first we need to know what the role of Articles is in the structure of the grammar in Swahili.
Swahili articles are words that combine with a noun to indicate the type of reference being made by the noun. Generally articles specify the grammatical definiteness of the noun. Examples are "the, a, and an".
UnlikeEnglish, which has only one definite article “the", Swahili has no definite and indefinite articles articlesand does not differentiate things/words according to gender.
For example:Mtu (Person) can either be a man or a woman, Mtoto( child) can be male orfemale.
When we say-Mtu mmoja amekuja( one person has come)- it can be either a man or a woman.
However,there are also specific names for men and women
mwanamme(man)mwanamke(woman), mvulana(boy) msichana(girl)
For thethings, there are not labeled according to gender
Kitabu(book)nyumba( house) – plural Vitabu(books) Nyumba(houses)
You noticethat these are in another class as discussed in the section of nouns. Kitabu (book)is in the class of KI-VI and nyumba is in the class of I-ZI.
So we say:
kitabuni kizuri (a (the) book is good) and in plural vitabu ni vizuri(the books are good)
Nyumba imejengwa(a(the)house has been built) and in plural nyumba zimejengwa( the houses havebeen built)
You notice that in the second example the noun does not change but you can see the pluralin the sentence construction.
Here are some examples:
|English Articles||Swahili Articles|
|the||not normally used|
|a||not normally used|
|one book||kitabu kimoja|
|some books||baadhi ya vitabu|
|few books||vitabu vichache|
As you can see from the example above, the structure of the Articles in Swahili has a logical pattern. Locate the Articles above and see how it works with the rest of the sentence in Kiswahili.
List of Articles in Swahili
Below is a list of vocabulary where you can use the Definite and Indefinite Articles in Swahili. Try to practice but also memorizing this table will help you add very useful and important words to your Swahili vocabulary.
|English Vocabulary||Swahili Vocabulary|
|dinner||chakula cha jioni|
|ice cream||ice cream|
|lunch||chakula cha mchana|
|salad||mchanganyiko wa mboga/matunda|
Definite and Indefinite Articles have a very important role in Swahili, therefore they need very special attention. Once you're done with the Kiswahili Articles, you might want to check the rest of our Swahili lessons here: Learn Swahili. Don't forget to bookmark this page. | http://www.mylanguages.org/swahili_articles.php |
4.09375 | Arctic sea ice
In recent years, the area covered by Arctic sea ice, particularly the minimum extent in summer, has rapidly shrunk. This is thought to result from a combination of factors: over the past several decades surface air temperatures in the Arctic have been warming at about twice the global rate, and the ocean has been warming. Other possible factors may be changes to ocean and atmospheric circulation patterns, which play a role in flushing ice out of the Arctic Basin. Once melting is initiated, the lower ALBEDO of water compared to ice also provides a reinforcing feedback mechanism that accelerates further melting, because the open water is able to absorb more heat from the sun.
Arctic sea ice extent changes since the mid-1970s
Source: UK Department of Environment, Food and Rural Affairs, Met Office Hadley Centre, Climate change and the greenhouse effect—a briefing from the Hadley Centre, December 2005, p. 35. © British Crown Copyright 2005, the Met Office.
Modelling suggests that under several of the IPCC's emissions scenarios, ice in the month of September (when it is at its minimum extent in the annual cycle) will have almost completely disappeared on average by 2100. However, the recent rapid decrease in Arctic sea ice is occurring faster than predicted by IPCC's Fourth Assessment Report. A new summer minimum was set in 2007 which is around 30 years ahead of a range of simulation model forecasts (see the Climate Institute’s Evidence of Accelerated Climate Change). An ice-free Arctic Ocean might be achieved well ahead of the timeframe indicated by IPCC modelling; if so, this suggests that the Arctic is even more sensitive to greenhouse warming than suspected to date. An animation of possible Arctic ice loss to 2100 can be viewed at http://www.metoffice.gov.uk/climatechange/science/projections/
Present day and projected Arctic sea ice fractional concentration
At the opposite end of the globe, the Antarctic Peninsula also appears to be warming. The collapse of the Larsen B ice shelf in 2002 was the largest single event in a series of retreats by ice shelves in the Peninsula during the last 30 years. The rate of warming in this region is approximately 0.5°C per decade, compared to the global rate of about 0.2°C per decade. The warming is indicated by increased summer snowmelt, loss of ice shelves and the retreat of marine and tidewater glacial fronts. Flow rate measurements for Antarctic Peninsula glaciers indicate accelerating trends. The Southern Ocean is also warming more rapidly than the global ocean. These changes are impacting the flora and fauna of the Peninsula: sea-ice adapted Adelie penguins are being replaced by the more open-water oriented Chinstrap penguins, and there has been increasing plant cover.
However, surface temperatures over the rest of Antarctica have remained approximately stable, and the amount of snow falling in Antarctica appears to be increasing. Although regional snowfall is not easy to measure there (partly because the snow can blow considerable distances and accumulate) the number of days of precipitation has increased. Antarctica is the world's driest continent, but global warming—by increasing global evaporation—is likely on theoretical grounds to increase precipitation in many areas.
The total average area of Antarctic sea ice has more or less stayed the same over the last three decades. In contrast, the mass of ice in the two large ice sheets over the continent, and associated ice shelves that represent the extension of the ice sheets over the ocean, may be changing. Antarctica contains most of the current global ice mass—enough to cause a sea level rise of about 60 metres if the ice sheets disappeared completely. However, large scale melting and dynamical loss of the Antarctic ice sheets is thought to be unlikely in the next century. Most at risk is the smaller West Antarctic ice sheet, which has the potential to contribute about 6 metres to sea level rise if it were lost completely. Current evidence suggests that the West Antarctic ice sheet is losing mass, which is partially offset by smaller gains in the East Antarctic ice sheet.
There is considerable uncertainty over the influence of atmospheric and ocean circulation patterns on Antarctic temperatures, snowfall distribution and amount and how these patterns may change with global warming, which complicates efforts to predict changes in the continent's ice mass balance. Models are in general agreement in predicting that for the next century enhanced snowfall on the continent of Antarctica should exceed warming-induced ice losses, and this increased accumulation of ice should offset some of the sea level rise that would otherwise occur.
Greenland ice sheet
The Greenland ice sheet contains the equivalent of about 7 metres of sea level rise. Recent studies suggest that the ice sheet has been experiencing a net loss (losses due to melting and ice flow discharge are exceeding gains due to snow accumulation), and that the rate of loss is increasing. Ice mass loss from the Greenland ice sheet is thought to have contributed to a sea level rise of 0.05 millimetres per year from 1961 to 2003, with the rate increasing to 0.21 millimetres per year from 1993 to 2003. There is a high degree of year-to-year variability in the ice mass balance, driven largely by variability in the amount of summer melting, as well as variability in the rate of discharge via glaciers.
Models predict that the Greenland ice sheet may shrink substantially over the next few hundred years in response to global warming. Results also suggest the ice sheet could disappear completely if temperatures rise above a critical threshold, and that this threshold could be crossed this century. The melting process would occur slowly, raising global sea level by about 7 metres over more than 1000 years, as shown in model simulation below. It is uncertain whether melting of the ice sheet could be reversed once the process was substantially underway, as the absence of ice would change the albedo to allow more of the sun's heat to be absorbed, and surface temperatures would also be enhanced by an overall lowering of surface elevation.
Simulated melting of the Greenland ice sheet under atmospheric CO2 concentrations stabilised at 4x pre-industrial levels
Evolution of the Greenland surface elevation and ice sheet volume versus time in the experiment of Ridley et al. (J. Climate, vol. 17, p. 3409, 2005) with the UKMO–HadCM3 AOGCM coupled to the Greenland Ice Sheet model of Huybrechts and De Wolde (1999) under a climate of constant quadrupled pre-industrial atmospheric CO2.
Source: Intergovernmental Panel on Climate Change, Fourth Assessment Report, Working Group I report—the physical science basis, Chapter 10 Global climate projections, Figure 10.38, p. 830.
Outlet glaciers of the Greenland and West Antarctic ice sheets provide one of the mechanisms of ice loss from these large ice sheets. This dynamic drainage of ice can account for most of the observed Antarctic net ice mass loss, and about half of the Greenland mass loss (the remainder being due to melting of the ice sheet in excess of replenishing snowfall). Recent evidence suggests that the flow rate of these outlet glaciers is increasing, thereby enhancing the rate of mass loss from the ice sheets. This may foreshadow a more rapid rise in sea level that could have a potentially dramatic effect on coastal regions worldwide.
Crucial to the survival of a glacier is its mass balance, the difference between accumulation and ablation (melting and sublimation). Climate change may cause variations in both temperature and snowfall, causing changes in mass balance. A glacier with a sustained negative balance is out of equilibrium and will retreat. A glacier with sustained positive balance is also out of equilibrium, and will advance to re-establish equilibrium. Currently, there are a few advancing glaciers, although their modest growth rates suggest that they are not far from equilibrium.
As a general rule, the world's glaciers have been retreating since the 1850s. Mid-latitude mountain ranges such as the Himalayas, European Alps, Rocky Mountains, Cascade Range, and the southern Andes, as well as isolated tropical summits such as Mount Kilimanjaro in Africa, are showing some of the largest proportionate glacial loss. The rate of retreat of most glaciers has increased since 1990. The observed decline in mass balance of glaciers and ice caps (excluding those surrounding the Greenland and West Antarctic ice sheets) can be translated to an equivalent sea level rise of about 0.3 millimetres per year from 1960 to 1990; with the rate doubling to about 0.6 millimetres per year of equivalent sea level rise from 1990 to 2004.
Retreat of the world’s glaciers
Large-scale regional mean length variations of glacier tongues. The raw data are all constrained to pass through zero in 1950. The curves shown are smoothed with the Stineman method and approximate this. Glaciers are grouped into the following regional classes: SH (tropics, New Zealand, Patagonia), northwest North America (mainly Canadian Rockies), Atlantic (South Greenland, Iceland, Jan Mayen, Svalbard, Scandinavia), European Alps and Asia (Caucasus and central Asia).
Source: Intergovernmental Panel on Climate Change, Fourth Assessment Report, Working Group I Report—the physical science basis, Chapter 4 Observations—changes in snow, ice and frozen ground, Figure 4.13, p. 357.
There is much information supporting the retreat of glaciers. Perhaps the most striking evidence relates to the retreat of European glaciers. The World Glacier Monitoring Service monitors changes in the mass, length, volume and area of glaciers worldwide. Between 1995 and 2000, 103 of 110 glaciers examined in Switzerland, 95 of 99 glaciers in Austria, all 69 glaciers in Italy, and all 6 glaciers in France were in retreat. As an example, since 1870 the Argentière and Mont Blanc Glacier have receded by 1150 metres and 1400 metres respectively. The rate of retreat appears to be increasing: the Trift Glacier in Switzerland retreated over 500 metres or 10 per cent of its total length in the three years 2003–2005. Closer to home, in both Papua New Guinea and New Zealand glaciers have retreated rapidly over the last 60 years, coinciding with warming over this period.
Glaciers stockpile rock and soil that has been carved from mountainsides at their terminal end. These debris piles often form dams that impound water behind them and form glacial lakes as the glaciers melt and retreat from their maximum extents. These are commonly unstable and have been known to burst if overfilled or displaced by earthquakes, landslides or avalanches. So-called 'glacial lake outbursts' have occurred in every region of the world where glaciers are located. Continued glacier retreat is expected to create and expand glacial lakes, increasing the risk to infrastructure, property and life relating to glacial lake failures.
Intergovernmental Panel on Climate Change, Working Group I Contribution to the Fourth Assessment Report, Climate Change 2007: The Physical Science Basis, Chapter 4 Observations—changes in snow, ice and frozen ground. | http://www.aph.gov.au/About_Parliament/Parliamentary_Departments/Parliamentary_Library/Browse_by_Topic/ClimateChange/theClimate/glaciers |
End of preview. Expand
in Dataset Viewer.
- Downloads last month
- 60