Are farm animals naturally patient with kid goats, or is it a trained behavior?

Question: Youtube is awash with videos of young and adolescent goats climbing on things, including other farm animals. Obviously temperament will come with an individual animal, but the videos the creater the goat is climbing on never really seems to mind. I'm probably a victim of a limited sample size, but is this typical behavior in farm animals, or is it (goat climbing tolerance) something you have to train for?
Comment: Something playing into it may be baby schema (https://en.wikipedia.org/wiki/Cuteness). It has been shown to work between different species (apes caring for kittens and the like).
Comment: @skymningen That's kind of what I was guessing, but I'd be curious if anyone knew firsthand.
Answer: Goats are obnoxious about climbing on things.  If you google horse bucking goats you will find several videos where the horse is not happy about it.
What happens is the annoy goat tries to climb on the horse (or cow, or car, or tree, etc) and it either works or not.  If not the goat tries again and again and again... At some point the horse (etc, all) either gets tired of bucking goat off, and just lets it happen, or the goat gives up, goats do not give up easily.
So the answer to your question is this "something you have to train for?" = When left together the goats train the farm animals. The only people interaction is leaving goats unsupervised in with horses, cows, etc.
If goats and horses or cows should be left alone together is a different question, with lots of variables, and no, one right answer.


Growth rates and log-transformation of variables

Question: In my model I include the variables deposits, first at levels but after I transform them to growth rates, using $DGR=\frac{DL_2-DL_1}{DL_1}$. I have also included the exchange rate, which I have log-transformed using logarithm.
Is this logic presentation of the variables? What does the log-transformed exchanged rate present? Or should I also log-transform the level of the deposits, instead of using growth rates?
Answer: By taking the natural log of x, exchange rates, and do not log-transform y, deposits, the beta coefficient resulting from this regression indicates that a 1% change in x leads to a (beta/100) change in y. If you take the natural log of both x and y, then the beta coefficient in the regression becomes an elasticity where a 1% change in x drives a corresponding % change in y as a function of the value of beta.
Do you have other information, features or variables to include as explanatory factors in the model? For instance, if this information has been gathered over time, then including temporal factors would adjust the betas for temporal variability. What about other components such as cross-sections, e.g., countries, etc.? Then, your model would become a type of panel data model where information is pooled across the cross-sections and time, resulting in smaller errors.


Announcements Tiles display limit

Question: This seems like it should be a silly-easy question but for some reason it has me stumped. I have a page with an Announcement Tiles web part on it, and have several items added to it. But the web part only displays one announcement at a time and makes you click to scroll through the rest. I just want it to display them all in a row, preferably bounded by the zone (though a defined number would be fine), but that setting is nowhere to be found in the web part properties, and the only view of the list has a 30-item limit which obviously isn't affecting this. What is limiting this web part to only displaying one tile at a time?
Comment: Anyone find a solution to this?
Answer: Search Results & Content Query web part settings has a limit. Try these:

Announcements Tiles display limit


When did the word "guys" become popular as a gender-neutral word?

Question: It's normal nowadays to walk into a room (men and women, boys and girls etc) and go, "Hey guys!". Has this always been the case, or what?
Comment: It has not always been the case. It was originally an eponym for Guy Fawkes. Later, it was used to describe someone dressed up in an unsettling costume. By in the middle of the 19th century, it began to be used to refer to males. Sometime during the 20th century, it began to see use as a gender-neutral term, but only in the plural. You may remember "Hey you guys!" on the Electric Company. This article was the best I could find on the subject: http://www.slate.com/blogs/lexicon_valley/2016/02/10/the_gender_neutral_use_of_guys_is_on_the_rise_but_it_s_a_slow_rise.html
Comment: First I would like to give a related link to a question, [which regards *if* it is acceptable](https://english.stackexchange.com/questions/11816/is-guy-gender-neutral), however while doing so I would also like to note that this question asks *when* it became acceptable, which is a matter that is as of yet unaddressed in the other question, so I am also of the opinion that the related question is not a duplicate. I am mostly just doing this so we can sort which answers should go where properly.
Comment: 1. Is it really 'normal' ? 2. Is it really 'popular' ? 3. Is it really 'gender-neutral' ? 4. When did 'nowadays' start ? I think some facts are needed.
Comment: Some relevant background: [What is a feminine version of guys?](https://english.stackexchange.com/questions/19074/what-is-a-feminine-version-of-guys)
Comment: The word guy by definition is not gender neutral. The definition of guy is male. It is offensive to address women as guy, even in a mixed gender group. For years many tried to say men was gender inclusive. But it is not. Using guys to address anyone and everyone shows lack of respect. It is an informal address that refers to men. Knowing the origins of the word makes it offensive to men also.
Answer: It has not always been the case. The term "guy" first referred to "an effigy of Guy Fawkes traditionally burnt on the evening of November the Fifth, usually with a display of fireworks" according to the OED; this sense is first attested in 1806.
The word first began to refer to a man or group of men in 1876, also according to the OED's examples.
Unfortunately, the OED is not clear on when it began to be gender neutral. However, I did find some other sources that try to answer that question.

"Denotatively, this is an established use of 'guys' to mean 'people' — that use goes back a while, probably to the mid-1900s," said Kory Stamper, a lexicographer and editor at Merriam-Webster.
An unnecessarily long and surprisingly fascinating history of 'guys'

Macquarie Dictionary senior editor Victoria Morgan said in Australia, teenagers started using "guys" as a gender neutral term in the '80s and it has been since been used to refer to groups of people of both gender. She added the word "guys" was not a term that carried an inherently sexist connotation and came into usage without any power struggle between the genders.
Hey guys: Oxford, Macquarie dictionary experts say using 'guys' is not sexist

It is important to note that "gender neutral guys" is used in other dialects of English, notably mine (as this graph shows, pretty much everywhere in America uses it except for the south).
Answer: The Southern American translation of "Hey, you guys!" is "Hey, y'all!", which suggests that the informal second person plural guys addressing a mixed gender group is 1) the same inclusive/generic masculine that's been around for centuries, but 2) is perceived by those using the form to be gender neutral, and 3) the source of other plural uses in the third person that may seem gender neutral or not depending on circumstance and audience.
Wiktionary has the following usage note:

In plural, guys is not completely gender-neutral but it may refer to people of either sex in some circumstances and forms; the greeting "Hey guys" can generally refer to people of either gender. This usage is not always seen as accurate or correct. Referring to a group as "guys" usually means a group of men or a mixed-gender group, since describing a group of women as guys, as in "The Pussycat Dolls are a bunch of guys", suggests that they are male, and is generally viewed as incorrect or inaccurate in that usage. In contrast, the all-male band Green Day could accurately be described as "a bunch of guys" in slang. The usage of the plural guys in the phrase "some guys chased them away" would generally be assumed to mean men rather than women.
  When used of animals, guy usually refers to either a male or one whose gender is not known; it is rarely if ever used of an animal that is known to be female.
  In some varieties of US and Canadian English, you guys revives the distinction between a singular and plural you, much like y'all in other varieties; in this sense, guys is gender-neutral.

You can also read there how the etymology really goes back to Guy Fawkes and that in earlier centuries, a woman dressed like a guy most likely wasn't in a flannel shirt, jeans, and workboots.
Comment: Hi KarlG. I don't really think this answer addresses the specific question being asked here. Are trying to imply that it was always acceptable, or if not, could you please try to give us a date of when it happened? I surmise that Jane is most particularly interested in when sense 3 transitioned into sense 4 in particular.
Comment: The answer to the question "Has this always been the case, or what?" is not the same as asking when something happened, although that would be an interesting factoid, I suppose. On the other hand, the expression seems to have survived intact the demand for "mail carrier" vs. "postman" since the 1980s — most likely because it fills the lexical gap of second person plural outside of the South.


How do tell my family not to got dargah (shrine)?

Question: Assalamualaikum, I am actually a 14 year old boy, my family goes to dargah (shrine of a dead person) and I don't know exactly what they do but I think they might have committed shirk, I realised this all is haram and I repented from it, only Allah knows whether my repentance would be accepted or not and I am sure the next time I go to a dargah, I would try to avoid it but if I can't, I'll don't do anything there or just do acting, but my family does it, I am the youngest In my family so they may not listen to what I am saying. How can I get my family to not go to dargah?
Comment: You say that you don't know what they are doing there - but that's an important detail. It would only be shirk if they worship the dead; some other actions may be haram. You may accompany them without taking part and then ask what they were doing. Then you can ask whether that is acceptable (halal) or not.
Comment: Visiting the Grave, Shrine, etc. of any believer is not at all Shirk, however, If you see your family do acts that are Shirk, maybe doing Sujood towards the grave then stop them with Qur'an and Hadith while being kind and definitely don't indulge in such Haram.
Answer: You don't need to try to stop them from visiting the grave of a believer. In fact, visiting the cemetery has many benefits, such as increasing remembrance of death, and can even be a recommendable practice.
You do not know whether your family has committed shirk (ie. treating anything other than Allah as being a partner of His or independent of Him). Don't rush to assume that they have; it is better to hold a good opinion of fellow believers and make excuses for them before jumping to the conclusion that they have sinned.
It's good that you care for your family; you must love them a lot. It's also clear that you really want to worship Allah exclusively and sincerely. Focus on being kind and respectful to your family, and make them happy with you, as Allah has commanded. In doing so, you will both be obedient to Allah as well as caring for the ones you love.


Eclipse CDT build error: make not in path

Question: I just recently(actually today) started using Eclipse CDT for windows. Created a project, a test C file(Hello World) added to project. Build the project, I got error as below.
Error: Program make is not found in Path -

So then I read that Eclipse CDT needs Mingw/MSYS, which I did install. Now i See that there is make.exe in
C:\MinGW\msys\1.0\bin

But Since I dont have administrator privileges, I could not add this folder containing make to the Path system variable on Windows. (I am not likely to get administrator privileges)
Now how do I work around this error to build and use CDT on windows? Any Project settings for Eclipse CDT which if added the path to make could help resolve this?
Answer: Was able to get a fix around this problem.
Added the correct paths for two exes - make and gcc/g++ (installed by Mingw/Ansys) to the User environment variable Path (Was not allowed to edit System variable Path).
But adding these paths to User environment variable Path also helped to resolve this. Now Eclipse CDT built and executed the code fine.
Answer:
check environment variable path has c:/cygwin/bin or c:/mingw/bin or wherever u installed it
if makefile name is mingw32-make.exe or something else , make a copy and rename that to make.exe
Answer: The problem is simply that your IDE need to know  where is  the place of GNU Binary Utilities so  how to deal with that simple go to
Windows -> preference -> C/C++ -> new c++ project wizerd   -> makefile

then chose what are u instal for example I use MinGW  so now I will chose GUN elf parse  and now I need the location  for c++ filt  :D

you will go to place where u install minGW in default it will be C:\MinGW

and search for  c++ filt.exe :D and  now u done :D
and you can install minGW from
http://www.mingw.org/
Answer: Also after adding C:\MinGW\bin to PATH variable. Make sure your new project is created with MinGW GCC toolchain as shown below.


Can HTTPS webserver host an HTML page that uses JS to connect with secured web socket protocol multiplayer game just like node js?

Question: Can HTTPS webserver host an HTML page that uses JS to connect with secured web socket protocol multiplayer game just like node js?
If so point me in the correct direction to read more.
Answer: You can create a client websocket in browser-based JavaScript like this. Note the protocol wss:// before the URL of the server. wss is to ws like https is to http - it's websocket via TLS.
var socket = new WebSocket("wss://example.com/yourgameserver");
socket.onerror = errorHandler;
socket.onopen = openHandler;
socket.onmessage = messageHandler;

function errorHandler(error) {
     // your code to handle connection errors
}

function openHandler(event) {
     // your code to handle a successful connection.
     // event.data might already contain the first data from the server
}

function messageHandler(event) {
     // your code to handle messages received from the server.
     // event.data will contain the message payload
}

After the connection is established, you can send data to the server with:
socket.send(data);

where data can be a String, ArrayBuffer, ArrayBufferView or Blob.
Check the documentation of the WebSocket API for further details.
But keep in mind that the websocket protocol won't allow you to connect to any multiplayer game. The WebSocket protocol isn't raw TCP/IP. The data is wrapped in a framing protocol. In order to allow a websocket connection, the server needs to understand that protocol.
Further, many websocket-based servers check the Origin header of incomming websocket requests to avoid connections from JS applications hosted on unauthorized websites. This header contains the URL of the website on which the script is running. So if you are trying to create an own client for a websocket server controlled by someone else, that server can easily refuse the connection.


Why is Sodium acetate called a salt of weak acid and strong base, when Acetic acid acts as a strong acid in Sodium hydroxide soln.?

Question: Why is Sodium acetate called a salt of weak acid and strong base, when Acetic acid behaves as a strong acid (i.e. it shows almost cent percent dissociation) in Sodium hydroxide solution ?
Comment: Strength and weakness are relative terms, of course when we compare acetic acid and sodium hydroxide in terms of acidity it is considered as strong acid, but this is not the case when this compare acetic acid and sulfuric acid in the same terms. In other words sodium hydroxide is very much weak acid to a degree that is considered as a strong base.
Comment: @M.Ibrahim Please add that as an answer. Thanks! :)
Comment: @M.Ibrahim you got my question wrong. Acetic acid acts as a strong acid in sodium hydroxide soln., doesn't it ? and sodium acetate is formed when acetic acid reacts with sodium hydroxide, so doesn't  it behave as strong acid then ?
Comment: do you mean the strength of sodium acetate salt ? It is for sure a weaker acid than the parent acetic acid.
Comment: @M.Ibrahim I did not mean the acidic strength of sodium acetate salt.
Comment: So, What did you mean ?
Answer: Your definition of strong acid is wrong.
Simplistically speaking, it is defined with respect to dissociation in water, not in NaOH.
Acetic acid only dissociates partially in water, so it is a weak acid. It doesn't matter whether it dissociates completely in NaOH or not. That's irrelevant.
Comment: The dissociation is affected by the PH of the medium, water is more acidic than NaOH. It is not necessary to use the standard definition to compare these characteristics especially qualitatively as here.
Comment: No, sorry to be blunt, you don't understand the question at all.
Answer: Good question.
You are right. In sodium hydroxide solution, you should not call sodium acetate a salt of strong base and weak acid. If so then the pH should be even more greater than what we expect. However, the pH should be less than expected, though not appreciable. It is because the ionization of NaOH will compete with the ionization of sodium acetate as well as with the hydrolysis of acetate ion.
However, defining of strong or weak acids or bases is done in water not in sodium hydroxide solution.
Ref: www.adichemistry.com
Comment: Yeah, that's exactly what I meant to say, but unfortunately very few people understood that, and what is more surprising is that the ones who understood the least spoke out the most !!


Skyrim A Night to Remember

Question: I have now played the A Night To Remember questions twice. My follower (I also married him for the convenience factor) Marcurio. I am playing on PS4. First time through, Marcurio followed me into the Grove and when I was teleported back, he was gone. I picked him up at The Bee and Barb, so naturally I checked to see if he was there. Nope. Then went to Solitude where our house is with our two kids. Nope, not there either. I waited 3 days in each location. Nothing. So I went back, reloaded, and the second time around, I told him to wait in my house in Riften. I flew through the quest a second time, came back to Honeyside. Nope. He's gone. Checked The Bee and Barb (again), nope. Went to Solitude again, kids were there, dad no where to be found. How can I complete this quest without looking my follower/hubs?
Comment: What does Marcurio have to do with the quest? At the moment, it sounds like a generic "Lost follower" problem, not linked to the quest.

I also found this [here](http://elderscrolls.wikia.com/wiki/Marcurio)
"After marrying him, choosing to live with Marcurio involves living at the Bee and Barb"
Answer: They do come back to The Bee and Barb, but it can be a random amount of time, sadly. You just have to wait.
See here for the answer:
https://www.reddit.com/r/skyrim/comments/18epcl/marcurio_has_vanished_how_can_i_get_him_back/
Comment: You should incorporate information from the link rather than just posting the link - emphasize important information etc.
Comment: like the information I posted above it. Some people are looking to criticise everything on this site. It's a shame.
Comment: I'm not trying to criticize, just trying to encourage you to provide more information because there is other information on that link, and not everyone wants to open new pages.. if you can provide more useful information, why not do so

Skyrim A Night to Remember


Creating a filter in Google Analytics

Question: I have a website, www.example.com. I have a subdomain, subdomain.example.com/ that contains all my website's landing pages. Do I have to add subdomain.example.com as a new property in Google Analytics to see my landing pages, or is there a filter I can create under the www.example.com property that will allow me to see the subdomain landing pages (i.e. subdomain.example.com/landing-page)?
Comment: Have a look at this answer:  http://webmasters.stackexchange.com/questions/52424/tracking-subdomains-in-google-analytics/52441#52441
Answer: I would create a new View under the same Property and apply a Filter to only include that sub domain.
In your Google Analytics Account:
1) Click on Admin button - Make sure that the right property is selected
2) Click Create New View - Third column on the right.
3) Create your View
4) With the sub domain view selected click on Filters
5) Enter Filter Name - Filter Type [Predefined]
 - [Include Only] - [traffic to the hostname] - [that contains]
6) Hostname [sub.domain.tld]
In Classic you also need to go to Tracking info and turn on the sub domain tracking option and then update your tracking code. It will add a line that looks like this:
<code>_gaq.push(['_setDomainName', 'example.com']);
</code>
Comment: If it's possible, how would I go about setting up the filter?
Comment: I updated the answer with details
Comment: Do you know how I would accomplish this in Classic Analytics? I entered the Filter name, predefined filter, include only, traffic to hostname, that contains, "subdomain.example.com."

When I click verify, I see the subdomain I'm looking for in the column labeled "Before Filter applied." In the column labeled "After filter applied," it only shows www.exmaple.com.
Comment: Ahh... there is one extra step. I added that part to my answer.
Comment: So, going into Tracking Info, I'm not seeing dub domain tracking options. I have to assume that it's turned on and working because I can see my subdomains, I just can't filter by them for some reason. I'm also using Google Tag Manager.

Creating a filter in Google Analytics


Probability and permutations involving tests

Question: Thirty-five students in algebra 2 class took a test. 9 received A's, 18 received B's, and 8 received C's. If the teacher randomly chooses 3 tests, what is the probability that the teacher chose tests with grades A, B, and C in that order?
Answer: Basic approach. There are $35$ tests in all.  There are $35$ ways to select the first test, $x$ ways to select the second test (once the first selection has already removed that test from the pile), and $y$ ways to select the third test.  Determine what $x$ and $y$ are.  Then the total number of ways to select three tests, maintaining sequence, is $35 \times x \times y$.
Of those ways, only some satisfy the given condition.  How many ways are there to do that?  There are $9$ ways to select the first test appropriately (because there are $9$ tests that received an A), $z$ ways to select the second test appropriately (from the tests that received a B), and $w$ ways to select the third test appropriately.  Thus, the total number of ways to select three tests that satisfy the condition, is $9 \times z \times w$.
The probability you want is then the number of satisfactory selections, divided by the number of total selections (satisfactory or otherwise), or
$$
\frac{35 \times x \times y}{9 \times z \times w}
$$
Comment: This completely makes sense, but wouldn't there be greater than a 3.3% chance of selecting an A, then a B, and then a C? Just seems low
Comment: @Ldoe: It's essentially in the neighborhood of a one in four chance, followed by a one in two chance, followed by another one in four chance.  Individually, they don't seem that unlikely, but they combine to about a one in $32$ chance.


Combining outcome measures for meta-analysis

Question: I have to conduct a meta-analysis. Following problem occured: a single study have measured Quality of Life and therefore, used two questionnaires. Now is my question whether I have two choose one of the instrument to include in meta-analysis or is there a possibility to combine the means of the two scales to provide one standard mean difference in the meta-analysis?
THANK YOU!!!!
Answer: At least 3 different approaches are possible:

You compute two standardized mean differences for this study and include both of these values in the meta-analysis.
Since the two effects were computed based on the same sample, they are not independent. Therefore, you have to account for and incorporate the degree of dependence between the two estimates in the analysis. This means that you will have to calculate the covariance between the two estimates, which requires knowing the size of the correlation of the raw scores for the two instruments. This is typically not reported, so at that point, you would have to 'guestimate' a reasonable value for the correlation and then conduct a sensitivity analysis in the end (by varying the guestimated value within a reasonable range and then checking whether the conclusions remain unchanged).
The equation for the covariance can be found in:
Gleser, L. J., & Olkin, I. (2009). Stochastically dependent effect sizes. In H. Cooper, L. V. Hedges, & J. C. Valentine (Eds.), The handbook of research synthesis and meta-analysis (2nd ed., pp. 357–376). New York: Russell Sage Foundation.
The model required for the analysis is also a bit more complex. If you are using R, you could take a look at: http://www.metafor-project.org/doku.php/analyses:gleser2009#multiple-endpoint_studies where I actually describe this type of analysis based on the Gleser & Olkin (2009) chapter (although in practice, one may consider adding random effects to the model to model heterogeneity).
While this approach maximizes the amount of information extracted from the studies, it comes with a lot of additional complexities that are hardly worth it if you only have one or two studies like that.
You compute two standardized mean differences for this study and average them.
This is in fact a common practice in meta-analysis. From a purely statistical perspective, this approach is not quite right. The average itself is fine, but the sampling variance of the average is typically not computed in the right way. Computing this correctly again requires knowing the correlation of the raw scores. So, while this approach avoids the additional complexities of having to use a model that accommodates multiple effects for the same study, if you want to do this in the correct way, you still need information that is not typically reported and extra steps to check for the sensitivity of the conclusions to the 'guestimated' size of the correlation.
You set up a hierarchy of 'preferred instruments' and then only include the SMD computed based on the instrument highest on that list.
This is another common practice and actually the easiest. So, for example, if instrument X is used, we calculate the SMD based on that; if X is not reported but Y is, then we use that; and if that is not reported, then we use Z; and so on.
It's important to set up the hierarchy a priori and not let the size of the observed effects guide your selection. Then it's a perfectly defensible approach that avoids all of the complexities described above.
Comment: Thanks, its very helpful. Can I ask you another question? A study in my meta-analysis examined quality of life. They used two instruments in a sample of adolescents and young adults. One instrument for participants up to 18 years and the other instrument for older participants. Can I combine these two? Or can I include both because the samples are somewhat different?
Comment: If I understand you correctly, you have two SMDs for this study, one based on a group of adolescents and one based on a group of adults. Since the two samples are independent (i.e., no overlap between the two groups), the two SMDs are also independent. So, you could include them both. However, one may still want to account for the multilevel structure of the data (SMDs nested within studies), which again requires more elaborate models. See, for example, this paper: http://onlinelibrary.wiley.com/doi/10.1002/jrsm.35/abstract
Comment: Yes,thats right. Its an overall sample of n=371; 11 filled out questionnaire A and n=360 answered questionnaire B, both questionnaires assessed quality of life. And I would compute two effect sizes (Hedges'g) and display them in a forest plot. Can I do that?
Comment: Yes, but if you plan on conducting an actual meta-analysis with these values, then again I would recommend reading the paper that I linked to.


What is meant by "Institutional Purchase" in App Store Connect?

Question: I've recently discovered unusual spikes in the downloads of my app. I could trace them back to the source type "Institutional Purchase". What does this mean?
The other source types are more or less clear.
Answer: Institutional Purchase is indicating the copies of your app bought under Apple's Volume Purchase Program. Any app sold on the App Store automatically become available under the Volume Purchase Program:

https://developer.apple.com/support/volume-purchase-and-custom-apps/

All apps on the App Store are automatically available for volume purchase for the same price in Apple Business Manager and Apple School Manager, which is where businesses and educational institutions download apps for volume distribution.

However, if you sell a paid app on the App Store, you can alternatively offer them at a reduced price for educational institutes.
Comment: I have a single free app in App Store, that has a very limited audience (people who own a particular piece of my company's equipment, less than 3000 sold).  An institutional purchase of 5000 appeared this month.  Previous months also show institutional purchases, but much less. Can an institution really purchase free apps? Could someone be gaming the system?
Comment: I see the same spikes for my app. It is free to download in the App Store and offers subscriptions as in-app-purchase. I assume a company can download it in Apple Business Manager and it will be rolled out to all enrolled devices, however the subscription mechanisms are still in place so they can only use the free version. As far as I know subscriptions are not supported in Apple's Volume Purchase Program (at least this was the case a few years ago).


Wedding invitation card riddle

Question: I'm looking for a riddle to put on my wedding invitation card. Ideally it's short (3 lines max) and not english-specific, as my guests are arabic - speakers. Any suggestions?
Comment: (Not related to the question, but...) Congratulations on getting married!
Comment: Do you have a desired solution/subject matter?
Comment: Not really, but it'd be nice if it were related to the wedding.
Answer: How about

We are a symbol of unity, of love that's bloomed
  Up the aisle, through the room
  There's two of us, but we're not bride or groom

  What am I?

To which the answer would be

A wedding ring

Unites two people who have fallen in love
Brought up the aisle as everyone watches the ceremony
Two rings, one for bride one for groom, yet they aren't either

To save you the trouble here it is in arabic:

نحن رمزا للوحدة، من الحب الذي هو أزهرت
  حتى في الممر، من خلال غرفة
  هناك اثنين منا، لكننا لا العروس أو العريس
ما أنا؟

Quite nice as it rhymes as well as being related to a wedding, and is 3 lines long (excluding the 'What am I?')
Comment: I see great minds think alike here! :)
Comment: Thank you for the riddle and the initiative of translating it nicely into arabic :)
Answer: This is an adaptation of a riddle I discovered online here:
True love's quest will end with me
Yet I am crafted endlessly
I'm seen on hands and feet and heads
And every hour my name is said
What am I?
Answer:

 I am a ring.

 Wedding rings are used to symbolize and finalize marriage;
 Yet a ring has no end in its shape;
 They are worn on toes, fingers, and ears (as well as other places on the face and body);
 And every hour, the church bell rings to indicate the time.
Comment: Thank you for your riddle. There is no "right" or "wrong" answer to my post, so I just chose the answer I got chronologically first. :)
Comment: Same answer as mine :) Just a note: '3 lines max'
Comment: Well, you could combine lines 1&2 and lines 3&4 very easily. I separated them just for clarity. :)

Wedding invitation card riddle


Is there a way to use a custom control in the designer and avoid the GAC?

Question: There is a great library I found here.  It's AeroWizard done in Windows Forms, and it handles Aero Basic elegantly.  What is awesome is it's supposed to have designer support.  When I attempt to open any of the WizardPages in the sample in the Form Designer, I get this error:
Could not find type 'Aero.Controls.MainInstructionsLabel'. Please make sure that the assembly that contains this type is referenced. If this type is a part of your development project, make sure that the project has been successfully built using settings for your current platform or Any CPU.
The library is referenced in my project under Aero.Controls and Aero.Wizard, so I'm not really sure what's going wrong.
Do I need to GAC register an assembly to have designer support?
Edit:
I just checked with reflector, here are the references
Aero.Controls
mscorlib
System
System.Drawing
System.Windows.Forms
user32.dll
Aero.Wizard
mscorlib
System
System.Drawing
System.Windows.Forms
dwmapi.dll
gdi32.dll
user32.dll
uxtheme.dll
Nothing besides the native Dlls concerns me, but I don't see how those would prevent the Form from rendering in the Designer.
Here is a screen-shot from the designer:
alt text http://www.ceasetopanic.com/wp-content/uploads/2010/02/compile-error.jpg
Answer: Visual Studio should have no problem finding the control and loading it as long as the project that is using it has referenced the DLL. You might want to try building the project then closing and re-opening Visual Studio. There is no need for the assembly to be in the GAC.
You might also try opening the assembly in Reflector to see if it references other assemblies that you don't have. If Aero.Controls references another assembly that you haven't referenced and Visual Studio can't find it when probing for it, you will see that kind of error and GAC'ing the assemblies mentioned above would not fix that.
Comment: This sounds like an issue with another referenced assembly not being found.
Comment: Turns out the assembly was signed, the "snk" file was missing from my lib folder, I copied from the source, and now the designer loads jsut fine.
Answer: Visual studio needs to be able to find them. Usually this means the GAC, however you can use the trick I use here on my blog to fool an application to looking elsewhere. I've used it to fool outlook to find our dlls when writing addins. Personally I think the GAC may be less of a headache in terms of maintenance.


Do fresh noodles need a hashgacha?

Question: I saw this video earlier today and it got me thinking: nothing in the recipe for fresh ramen noodles (as opposed to instant ramen) requires a hechsher on its own, as the ingredients are: flour, water, kansui (an alum-rich water, traditionally sourced from lakes in Mongolia) and [sometimes] egg. They are packed while moist, rather than being dried in oil. Consequently: as they are also uncooked, should fresh, Asian-style noodles, require a hechsher?
Comment: The video says explicitly that they also add extra gluten, vitamins, colorings.
Comment: @DanF nonkosher birds? Or any other issues mentioned in the laws of eggs. We are actually not allowed to buy cracked open / beaten  eggs from them. But it's just indicative of the bigger issue. 'Plain' noodles are nothing like plain coffee beans.
Comment: A few concerns that I can think of - If in a factory, what else do they produce that may be non-kosher that could have been in contact with the noodle ingredients? Were the eggs checked for blood? Chicken eggs? (Asians tend to use many animals that Americans wouldn't think of eating. Could be ostrich eggs for all you know.) Was the flour checked for bugs? BTW - have you found a brand of kosher fresh ramen noodles available in U.S.?
Comment: He also says they may add egg white
Comment: @user6591 Other than what I mentioned about blood spots on eggs, what would be the kashrut problem with egg whites?
Comment: Utensils. Offhand, I don't see a bishul akum problem as there doesn't seem to be any bishul (cooking), here.
Answer: I am not certain about Asia, but I can say that in some South American countries (e.g. Peru), flour is legally required to be enriched with vitamins and minerals -- which is most often from a "non-kosher source".

Unlike the U.S., where major flour brands are certified kosher, Peru's
  two-year-old flour enrichment program has left kosher observant Jews
  searching for options. Vitamins and minerals added to the flour have a
  "non kosher source," said Rabbi Blumenfeld. While a solution is
  sought, a friendly flourmill owner sets aside a monthly allotment of
  some 500 kilos of flour without additives for Chabad.
Comment: Ariel, the company used in the link is actually based in the US. In general, food items from certain countries which might not normally require certification do necessitate them (eg. anything from China).

Do fresh noodles need a hashgacha?


A Mikveh used alternatively by men and women

Question: In a situation where a mikva is used at different times by both men and women, is there a need to change the mikva water between uses?
Comment: Possible duplicate https://judaism.stackexchange.com/q/13075/759
Comment: I thought your question was about the artificial insemination as the Gemmorah's story (Chagigah 15 - באמבטי עיברה).
Comment: My question was based on the concerns of AI which feature in the opinion of Shmuel in Chagiga as referenced by Al Berko. I recall the Maharil (or perhaps) others referring to Ben Sira as being conceived via the mikva. My question is, are these sources and AI issues relevant on a practical level to change the immersion water?
Answer: In order to keep Mikvaos functioning the whole year round, the Mikveh water that is used for dunking is not the same water that is used for the Mikva itself.  What is done is two processes called hoshoka (Kissing).  The mayim shoevim (non mikva water) is made to connect to the Mikvah water.  Once that happens, then all the waters become kosher for immersion.
In general, a Men's mikva, they often just do one hoshoka.  In a women's mikvah they do things l'chumra (stringently) and do hoshoka in both ways.  A men's mikvah is only because of takanas Ezra (the edict of Ezra) and so is Middos Chassidus (a better thing to do if you can).  Women's mikvah is for Tahora for Tahras Mishpacha - an issue of D'oraissa (Torah prohibition), and so we're more machmir (stringent).  It would seem therefore that a women's mikvah can also be used for a men's mikvah but not vice-versa.
As regards the actual change of water of the place of dunking.  It would probably be a matter of practicality and cleanliness.  Mikvah water can get dirty and murky easily, unless of course, they didn't do a proper neshika. (see here).
So the water would have to be changed for women.  Since we want women to do the mitzvah, we make sure that everything is setup accordingly for her benefit.
The Iggros Moshe writes that given that it would be uncomfortable for women to use the same mikvah as men, it would be better to move the men's mikvah away (See Iggros Moshe, Yoreh Deah 2, 90). Thus, we see that any discomfort on the part of a woman is enough to stop the men's mikvah entirely.  There would be an implied necessity to change the water after the men's mikvah.
Comment: This answer could do with a good deal less jargon.
Comment: It is called השקה *hashoko* -- not *neshika* - but the root is the same.
Comment: @RibbisRabbiAndMore how would you translate it literally?
Comment: +1 but i do not think " the waters become **Tahor** " they just become kosher
Comment: Link for the igros moshe http://www.hebrewbooks.org/pdfpager.aspx?req=919&st=&pgnum=156&hilite=


What would the position vs. time graph look like if the velocity vs. time graph was a curve?

Question: In my physics class we are learning about velocity vs. time graphs and position vs. time graphs for an object.  We have learned that if the object is moving with constant velocity (this would be a diagonal line on the position vs. time graph) that the velocity vs. time graph would be a horizontal line.  We have also learned that if the object is accelerating and is not moving with constant velocity (a curved position vs. time graph) that the velocity vs. time graph would be a diagonal line.  However, what would the graph of the Position vs. Time graph look like if the Velocity vs. Time graph was a curve?
Comment: @Craig That seems like an answer, rather than a comment.
Comment: @Craig  I know how to find the integral but not any details like that
Answer: Let's say the speed was described by a curve that is itself described by some function of time $v = f(t)$. If you know what the initial position $x_0$ is, then the curve of position vs. time would be described by
$$x(t) =x_0 +\int_0^t f(t')dt'$$
From a conceptual standpoint, you are calculating the total area below the curve $f(t)$ between the point where time is zero and some point $t$, adding the value of the initial position, and jotting down that value as the position of the system at time $t$. Doing this for all points in time give you the position curve. (Remember to count the areas below the speed equals zero axis as negative!)
Answer: For simplicity assume one dimensional motion and a relatively simple curve for the velocity against time graph.
The displacement $s$ between time $t= t_1$ and $t=t_2$  is the area under a velocity against time graph $  s = \int^{t_2}_{t_1}v \: dt$ as shown below.

The reverse process is that the gradient of a displacement against time graph $\frac{ds}{dt}$ is equal to the velocity $v$.


Lipo powered earphone amp

Question: Requirements: I would like to design a circuit that uses an in-amp, and it needs dual supply (+/- 3V at least). I want it to use two lipo cells so it can be recharged. The output from the circuit is a headphone (earphone). I can have 32 ohm headphones, but that is the max. (There are 600 ohm phones out there but they are too expensive for this project.) This is an educational project for myself, and I would like to build the output stage using discrete components, or maybe simple opamps. My problem is with the output stage. The 32 ohm speaker at 3.7V would have about 100mA peak current, which is too much for a headphone. I could add a 330 ohm resistor in series, or lower the gain of the amp, but then most of the output power becomes heat - not a very good design for a battery operated device. Using a class D amp would probably solve the problem, but I don't think I capable of designing a class d amp. How others do this?
Comment: Why not use 2 9V battery with 4556 to learn first?
Comment: There are single chip D-Class amplifiers available.  From what I have seen of them, they are simple to use.  I've never built one, though, so I can't tell if they are as simple to use as the datasheets make it appear.  The ones I've seen were about the size of an opamp.
Comment: Actually, NJM4556 can be driven from +-2V, and it is more common and much cheaper than LM4880. 70mA into 150Ohm load is not bad at all! Thanks for the tip!
Answer: Let's consider the headphones.

Earbuds. No need for a dedicated amp since earbuds audio quality is terrible anyway.
In-ear rubber-nipple thingies. I picked a random one off the net: Sennheiser CX300 is 18 ohms and delivers a whooping 118dB for 1V RMS.
Real headphones. OK, let's pick some not too expensive ones... HD4.20 again 18 ohms and 118dB for 1V RMS.
Some cheaper ones HD2.10 26 ohms and 110dB/1VRMS

Sooo... if you use the latter ones, listen to an average level of 80dB which is already loud, with peaks around 100dB (if your music is not too compressed), then:

RMS voltage will be -30dBV, ie 31mV RMS
Peak voltage around -10...-3 dBV (like half a volt)
Peak current won't be huge either, like 30mA.

Now, let's look for an opamp.
The "maximum output current" specification is useless here. What we want is an opamp that can output the required current with the least amount of performance degradation. An opamp picked at random may have good distortion figures, but when driving relatively high currents (for an opamp) with low headroom, it's an entirely different story.
For example, TL072 isn't so bad with a 10kOhm load, but if asked to drive any kind of actual current, its performance simply ceases to exist.

The 32 ohm speaker at 3.7V would have about 100mA peak current, which is too much for a headphone.

You will go deaf before the voice coil burns.
The resistor which everyone puts at the output of headphone amps actually degrades performance, but it has a rather important purpose: protect the output stage when the output is shorted.
...and every time you insert a 3.5mm jack into the connector, the output will short during insertion. This is a "feature" of this connector, you gotta live with it. If the connector is mis-inserted, the short can be permanent. You must select an opamp that will survive this, so you can get rid of the resistor for better sound.
(Explanation: headphone impedance varies with frequency like every loudspeaker. With a resistor in series you got a voltage divider. Voltage on headphone thus depends on its impedance at the frequency of interest. So you get bumps and dips in the frequency response).
You mention a discrete amp. With such a low supply voltage, discrete design is very complicated. An opamp would offer much better performance.
For example,
OPA1688 is a nice opamp with high output current and rail to rail output; it is specified to drive headphones. Beware the input is not really rail to rail, it should not go above Vcc-2V, but this should be OK.
If you wanna go real fancy, you can use a nested feedback with OPA1652 as frontent, and a beefy fast opamp as the output driver.
Comment: Well I forgot to mention that this is not for listening to music, and sound quality is of less importance. But your comments about the series resistor got me thinking. Is it true that, if I'm willing to burn most of the power on a huge series resistor, then I can make the frequency response close to ideal? E.g. put a 10k resistor in series with the phone, so the frequency response becomes much more flat. (I know this is not closely related to the question.)
Comment: Higher resistor will make the amplifier look more like a current source. Since transducers are optimized for a voltage source amplifier, higher output impedance will give you worse frequency response...
Comment: Very interesting! Thanks, it makes sense this way. Is there a graph where I can see the SPL vs voltage and SPL vs current, and compare them (for an "average" transducer). I guess the graph would not be a line, but I never understood the exact correlation.
Comment: If you have frequency response and impedance data, you can take the transducer frequency response, which was taken at constant RMS voltage, and multiply this by its impedance at each frequency... you'll get the response in constant RMS current mode.
Answer: With a combined rail of 6 volts and (say) 1 volt dropped in the transistor driver stage when producing a high or a low output, the maximum voltage across your load will be about 4 Vp-p. For a sinewave this is an RMS voltage of 1.414 volts and the power into a 32 ohm load will be 62.5 mW.
If you think this is too high you can use a step down transformer to efficiently drop the output voltage. From looking at headphone specs, about 20 mW is around typical max power so I would use a series 33 ohm resistor to approximately quarter the power into the headphones. Power wastage is significant as a percentage but how significant compared to the watt hours deliverable by the batteries?
Also worth factoring in is the type of sound you are listening to. For instance, if music, then although the peak power may appear high, the average power will be ten times lower or more. A peak of 15 mW can easily be an average power of less than 2 mW. Put it into context is my advice.
If I were building this I would use a single battery and an LM4880 amplifier like this: -

It'll work down to 2.7 volts.
Comment: Yes, 62mW is way too much for a headphone. Dual power supply was a requirement, bu I can use just one half of it for the outut stage.
Answer:
How others do this?

by first trying to figure out what your goals are. For example, are you trying to design a balanced-in/balanced-out headphone driver for a low or high sensitivity phone....
the best (ac/sound) quality would come from CFB opamps. you will find them cheap in used modems - they were widely used as xdsl drivers. no amp, diy or otherwise, will come even close to those little beasts.
as to output attenuation, I would put a 110R resistor on the output to protect for shorts.
if you need additional attenuation, put it on the input. unless you have some low-sensitivity / high-impedance phones (very rare), those amps should just be followers.

Lipo powered earphone amp


Failed to load resource (file not found) Electron js cannot import or export

Question: Failed to load resource: net::ERR_FILE_NOT_FOUND
I am using latest version of npm, node.js and electron.
My html file calls upon a terrautils.js:

My terrautils.js file has first line as:
import { LCDClient, Coin } from './node_modules/@terra-money/terra.js';

Which is the link to an npm module that I want to use, and I have it installed and have confirmed that the folder is really there using file explorer. I also know the module works perfectly file, because this issue only happens when I run using npm start but when I run using node terrautils.js and swap from using import to using require, it works perfectly fine.
This is something to do with electron I think, and not sure what to do. My main.js has createWindow function like:
function createWindow (site) {
  var win = new BrowserWindow({
    width: 700,
    height: 600,
    webPreferences: {
      preload: path.join(__dirname, 'preload.js'),
      nodeIntegration: true,
      contextIsolation: true,
      devTools: true,
    }
  })

  win.loadFile(site)
}

I do not care about security, I just want this to work. Thank you.
Comment: When you install a node module, you should not give the folder path, but just specify its name. For example : `import { LCDClient, Coin } from '@terra-money/terra.js'` (as mentionned in the [@terra-money/terra.js package](https://www.npmjs.com/package/@terra-money/terra.js).
Comment: This still does not solve the problem @Dony
Answer: Solution:
Change html invoking of the js file to this instead:

dont know how it works, but it does.


Feature Activation Routing Workflows - SharePoint 2010 (en-US)

Question: We get an error message: "the feature with the ID {3bc0c1e1-b7d5-4e82-afd7-9f7e59b60409} must be activated."
Does somebody know how to activate this feature. I can't find it in central administration or in site actions.
I think it's an hidden feature, but i no idea how to activate it.
Answer: It is Routing Workflows - SharePoint 2010 (en-US) feature which needs to be activated at Site collection level.It is a hidden feature.
You can activate it using powershell:
<code>Enable-SPFeature -identity {3bc0c1e1-b7d5-4e82-afd7-9f7e59b60409} -URL http://yoursite
</code>


How can I control things without using delay?

Question: I have always hated that you couldn't do other things while you used the delay(); function. However, I want to blink a LED or do whatever while using serial, but how does this work? How do I do this without using the delay function?
Comment: isn't there a separate Arduino area? Find it strange to see Programming-related stuff in Electrical Engineering area (apart from the question involving a LED that is)
Comment: @GeorgeBirbilis This question is almost three years old, long before there was an Arduino stackexchange.
Comment: @pipe thing is I came here from the same question at Arduino stackexchange and there was a comment there that it had been copied here too or something like that
Answer: Interrupts are a common way to get things done while something else is going on.  In the example below, the LED is blinking without using delay().  Whenever Timer1 fires, the interrupt service routine (ISR) isrBlinker() is called.  It switches the LED on/off.
To show that other things can simultaneously happen, loop() repeatedly writes foo/bar to the serial port independent of the LED blinking.
#include "TimerOne.h"

int led = 13;

void isrBlinker()
{
  static bool on = false;
  digitalWrite( led, on ? HIGH : LOW );
  on = !on;
}

void setup() {
  Serial.begin(9600);
  Serial.flush();
  Serial.println("Serial initialized");

  pinMode(led, OUTPUT);

  // initialize the ISR blinker
  Timer1.initialize(1000000);
  Timer1.attachInterrupt( isrBlinker );
}

void loop() {
  Serial.println("foo");
  delay(1000);
  Serial.println("bar");
  delay(1000);
}

This is a very simple demo.  ISRs can be much more complex and can be triggered by timers and external events (pins).  Many of the common libraries are implemented using ISRs.
Answer: Here is an example on Arduino:
const int ledPin =  13;      // the number of the LED pin

int ledState = LOW;             // ledState used to set the LED
long previousMillis = 0;        // will store last time LED was updated

// the follow variables is a long because the time, measured in miliseconds,
// will quickly become a bigger number than can be stored in an int.
long interval = 1000;           // interval at which to blink (milliseconds)

void setup() {
  // set the digital pin as output:
  pinMode(ledPin, OUTPUT);
}

void loop()
{
  // here is where you'd put code that needs to be running all the time.
  unsigned long currentMillis = millis();

  if(currentMillis - previousMillis > interval) {
    // save the last time you blinked the LED
    previousMillis = currentMillis;

    // if the LED is off turn it on and vice-versa:
    if (ledState == LOW)
      ledState = HIGH;
    else
      ledState = LOW;

    // set the LED with the ledState of the variable:
    digitalWrite(ledPin, ledState);
  }
}

This records when it will need to change and waits until it is that time.

Of course, this function (millis();) will reset after about 50 days when it becomes too large to store, but if you don't keep it on for more than about 40 days, you should be good. You could prevent this by finding out how large this value can be and do a if statement for when it nears the top to stop for a minute or so. You would have trouble adding to the milliseconds when it gets that high, but I don't know how to solve that, but this will work for a small project.


Comparing chars in Java

Question: I want to check a char variable is one of 21 specific chars, what is the shortest way I can do this?
For example:
if(symbol == ('A'|'B'|'C')){}

Doesn't seem to be working. Do I need to write it like:
if(symbol == 'A' || symbol == 'B' etc.)

Comment: Yes, that's one way. Take a look at [regex](http://download.oracle.com/javase/tutorial/essential/regex/)
Answer: If your input is a character and the characters you are checking against are mostly consecutive you could try this:
if ((symbol >= 'A' && symbol <= 'Z') || symbol == '?') {
    // ...
}

However if your input is a string a more compact approach (but slower) is to use a regular expression with a character class:
if (symbol.matches("[A-Z?]")) {
    // ...
}

If you have a character you'll first need to convert it to a string before you can use a regular expression:
if (Character.toString(symbol).matches("[A-Z?]")) {
    // ...
}

Comment: +1 this is how I would do it if for the most part the 21 symbols are consecutive.
Comment: Thanks Mark, I've used regex before but never with Java, wasn't even aware you could!
Comment: Oracle doc pretty much summarizes the answer and provides flaws to the above answer so take a look.  https://docs.oracle.com/javase/tutorial/i18n/text/charintro.html.
Answer: If you know all your 21 characters in advance you can write them all as one String and then check it like this:
char wanted = 'x';
String candidates = "abcdefghij...";
boolean hit = candidates.indexOf(wanted) >= 0;

I think this is the shortest way.
Comment: Very ellegant solution. Congrats.
Answer: you can use this:
if ("ABCDEFGHIJKLMNOPQRSTUVWXYZ".contains(String.valueOf(yourChar)))

note that you do not need to create a separate String with the letters A-Z.
Answer: The first statement you have is probably not what you want... 'A'|'B'|'C' is actually doing bitwise operation :)
Your second statement is correct, but you will have 21 ORs.
If the 21 characters are "consecutive" the above solutions is fine.
If not you can pre-compute a hash set of valid characters and do something like
if (validCharHashSet.contains(symbol))...

Answer: It might be clearer written as a switch statement with fall through e.g.
switch (symbol){
    case 'A':
    case 'B':
      // Do stuff
      break;
     default:
}

Answer: Using Guava:
if (CharMatcher.anyOf("ABC...").matches(symbol)) { ... }

Or if many of those characters are a range, such as "A" to "U" but some aren't:
CharMatcher.inRange('A', 'U').or(CharMatcher.anyOf("1379"))

You can also declare this as a static final field so the matcher doesn't have to be created each time.
private static final CharMatcher MATCHER = CharMatcher.anyOf("ABC...");

Answer: If you have specific chars should be:
Collection<Character> specificChars = Arrays.asList('A', 'D', 'E');  // more chars
char symbol = 'Y';
System.out.println(specificChars.contains(symbol));   // false
symbol = 'A';
System.out.println(specificChars.contains(symbol));   // true

Comment: +1 for perfectly good alternative approach, which may be better for lots of characters.
Answer: Option 2 will work.  You could also use a Set<Character> or
char[] myCharSet = new char[] {'A', 'B', 'C', ...};
Arrays.sort(myCharSet);
if (Arrays.binarySearch(myCharSet, symbol) >= 0) { ... }

Answer: You can solve this easily by using the String.indexOf(char) method which returns -1 if the char is not in the String.
String candidates = "ABCDEFGHIJK";
if(candidates.indexOf(symbol) != -1){
    //character in list of candidates
}

Answer: Yes, you need to write it like your second line.  Java doesn't have the python style syntactic sugar of your first line.
Alternatively you could put your valid values into an array and check for the existence of symbol in the array.
Answer: pseudocode as I haven't got a java sdk on me:
Char candidates = new Char[] { 'A', 'B', ... 'G' };

foreach(Char c in candidates)
{
    if (symbol == c) { return true; }
}
return false;

Answer: You can just write your chars as Strings and use the equals method.
For Example:
String firstChar = "A";
String secondChar = "B";
String thirdChar = "C";

if (firstChar.equalsIgnoreCase(secondChar) ||
        (firstChar.equalsIgnoreCase(thirdChar))) // As many equals as you want
{
    System.out.println(firstChar + " is the same as " + secondChar);
} else {
    System.out.println(firstChar + " is different than " + secondChar);
}

Answer: One way to do it using a List<Character> constructed using overloaded convenience factory methods in java9 is as :
if(List.of('A','B','C','D','E').contains(symbol) {
    // do something
}

Comparing chars in Java


toilet basin rattling valve

Question: our toilet water basin valve makes a terrible rattling noise when filling up with water. It's the left side tube making that. Any idea about possible solutions beyond calling a plumber and replacing the valve?
Answer: Replacing the toilet fill valve is an easy DIY project.  You can buy a new one for less then $20.00.
I found this YouTube video that is a good tutorial.
I am not affiliated with them.
You only need minimal tools and to know how to turn off water supply valve.
There is a valve just under your toilet on the side with the flush lever. Turn the valve handle clockwise until it stops. Flush the toilet to drain the water out, there should not be any water coming out of the tube if the valve is shut completely.
I like to take a big sponge and soak up the remaining water in the tank but you can use a bucket to catch the extra water that comes out when you remove the fill valve.
Use a pair of adjustable pliers to loosen the nut of the top of the supply hose that connects to the fill valve on the bottom of the tank (basin). Once the supply line is disconnected  there is a plastic nut that holds the fill valve in place on the bottom of the tank, use the pliers to loosen this and then remove by hand, remove the rubber gasket as well. Now you can pull the valve out of the tank. ( if there is any extra water in the tank it will run out of the hole so have your bucket under the hole. )
Now you just reverse the process with the new valve and follow the instructions to adjust the fill level, ( the shut off point that tells the valve when to stop filling )
Yes even you can do it. ;).

toilet basin rattling valve


Scapula placement of flying hexapedal primates?

Question: I am designing a 'fairy' that is a relative of primates (essentially a sapient flying monkey). It has a skeleton similar to that of a spider monkey, but with a larger ribcage and shorter limbs. It will have a third pair of limbs in the form of wings just behind the forelimbs.The wings will neither be feathered or furred, but be similar to bat wings. They are comprised of membrane tissue webbed between "fingers", and the first and last two fingers will be fused so that the fairy's wings each have three sections (thumb, first two fingers, and last two fingers). ** Where should I place the secondary scapula for these wings? And how should they attach to the clavicle (if at all)?**
Answer: Google for "Anatomy of angel wings" in google images. You will find some interesting anatomical diagrams where people analyze musculature and skeletal systems for "wings and arms"-type creatures.  Wings are anatomically a variant of arms and hands.
Based on my research, there are effectively four variants you will find:

it's magical, so just trust me, it works. This is a viable solution.
wings/arms stack on top of each other as if the creature has two shoulders. This is anatomically insanely difficult to imagine, though aesthetically looks cool.
wings/arms stack front-to-back. - viable, though would make for a massive musculature more appropriate for creatures rather than humanoids or "slight" creatures like monkey-fairies.
mid-back wings - scapula is essentially a fusion of some ribs behind the lungs. This is probably the most "acceptable" placement and easiest to explain to science-minded readers.
Comment: I always really like the pictures but these are the magic kind. The musculature for folding and unfolding the wings are there but there is no skeletal structure or pectoralis musculature to actually flap the wings. This is why to me the only working one's are those that basically place the wings as romboideus muscles between the scapula and use the rotatorcuff to pull on the wings. Even those dont add the extended sternum that would be necessary to fly.
Answer: The wings usually dont have much scapula. Take a look at this chicken skeleton for example:
https://www.google.com/search?q=chicken+skeleton&oq=chicken+skeleton&aqs=chrome..69i57j0l3.5790j0j7&client=ms-android-samsung&sourceid=chrome-mobile&ie=UTF-8#imgrc=iJmnJbQ1lX4P9M:
It just gets in the way of flying to have much scapula. But as I have remarked in other questions about 4 limbs plus 2 wing creatures it is easier to use kinematic chains.
Having wings below the arm scapula means that they are supported by the floating ribs (if you want to leave room for the arm scapula to rotate and translate downwards) and the musculature of the lumbar region with no real connection to the clavicule. To generate enough lift to push the spidermonkey in the air the muscles at the stomach and back have to generate a force larger than the monkey's weight, without a skeleton to support that properly you would either have to painfully smash the intestines, kidney and lower Aorta each time you flap the wings, connect the muscles to the hips and sternum causing a bending motion with each flap or add skeleton structure that severely hampers the bending capability of the monkey.
This leaves putting the wings on top/between the arm scapula. You already mention the chest would be larger, which I hope means larger sternum like the overlarge sternum seen in the chicken picture. Here the kinematic chain comes into effect. Muscles can stretch over multiple joints which allows forces to be transferred from one joint to another. For example if the knee is bent but you counter the force with the quadriceps then your hips are pulled forwards. This is what you can use with sit-ups when someone sits on your feet. A similar kinematic chain can be used for the wings. It does mean the wings and arms will not move independently when flying and have limited independent movement from the arms when not flying.
Comment: What if the wings had a notarium, like birds do?
Comment: @IchthysKing You would have the same problems. I assumed the entire wing, Notarium and all, would be there and functional, otherwise what would be the point of having the wings at all? You would be severely hampered in steering without one and taking off+flying would require a specific position of the body rather than repositioning the wings for a moment.


How can I obtain the component if I know the ID of the DOM element?

Question: I just inherit an ExtJS application that has a lot of pages.  This application allows user to paste from MS Word.  In MS Word 2003, the single quotes and double quotes are not normal ASCII characters.  When the data is stored in the database, they got converted into square box or inverted question mark because our database column does not handle Unicode, and we do not want to convert the columns to handle Unicode (the data is only supposed to be ASCII, except for these quotes).  I found a JavaScript function online that would remove these quotes from a given string.
I've test this function by adding:
enableKeyEvents: true,
listeners: {
    keyup: function(c,e) { ... }
}

This works fine for one element / component.  But I have about 100 components, and with this application, it is not easy to find these components.  So what I decide to do is to listen for the keyup event on body element using jQuery:
jQuery('body').keyup(function(e) {
    var keyCode = e.which;
    if ((keyCode == 86) && (e.ctrlKey)) {
        var domEl = e.target;
        var domId = domEl.getAttribute('id');
    }
}

This application use grid components and other non-grid components as well.  To reliably get and set the value, I want to obtain the component and use its getValue() and setValue() method.  So, knowing the ID of the DOM element, is there a way to obtain the component?
Comment: Does anyone have any idea on how I can obtain the component from the ID of the element, or any suggestions on how I can solve my problem?
Answer: if you have domId try with
var objComp = Ext.getCmp(domId);

if you are using any layout try
var objComp = Ext.getCmp('center-region').getComponent(domId)


Notice: Undefined index: value in noverwrite_civicrm_buildForm()

Question: I have the no overwrite extension installed latest version.
Civi 5.2.2
I get the message on bringing up a profile form
Answer: the message gives a notice, that is a low level message that does not signify a "real" problem, rather that the program should do an additional check to make sure it meets the syntax rules.
So although the notice can be fixed, I would recommend you log the issue on the actual extension repository (https://github.com/TechToThePeople/noverwrite/issues) and rest assured that the notice does not present an urgent problem that needs fixing immediately.
Comment: logged issue on github


How to completely remove the top section with the menu?

Question: I am using a child of Pixova Lite 2.0.4 on Wordpress 5.1.1 running on local machine to make a landing page. I want my header image to start from the very top of the page with no top menu section over it. How do I get rid of the top section with the menu?
Answer: If there is no option to disable that sticky header, u can use css.. inspect its div, then hide it with display : none;
Comment: Thanks a lot!  It worked. It might have been s simple answer for you,  but for a novice like me it meant the world!!!


How can a get OSM data in QGIS in a way that shows the direction of a road as it would in JOSM?

Question: I am trying to download OSM data into QGIS in a way that is as close as possible to what it looks like in JOSM. I am doing a visual comparison between OSM data and satellite images. One of the things I am looking at is comparing if one-ways are mapped correctly. How can I get the OSM data in QGIS in a way that shows the direction of a road as it would in JOSM?
Comment: If you use OSM tile server, i think you can't do it. What about to download OSM vector data and add style? (http://www.geofabrik.de/)
Answer: You can get OSM data into QGIS with the QuickOSM plugin.
Under Web -> QuickOSM -> QuickOSM, go to the OSM file section. Look for the path to the osmconf.ini file, search it with your explorer, and open it with a good text editor like notepad++.
In the [lines] section, go to the attributes line, and add ,oneway at the end.
Save the file and close it.
Back in the QuickOSM panel, go to the  Quick query tab and enter highway in the key field. Using the Openlayers plugin, navigate to your place of interest, and run the query.
You can remove the node and multipolygon layers, and save the temporary lines layer to a shapefile on disk.
Now you need a special style for the oneways.
Rightclick on the lines layer, Properties..., go to the Styles tab, and change the style from Single Symbol to Categorized on column oneway. Click on Classifyand see what values you get.
In the line with yes, double-click on the symbol, and add a new line with the green +. Select the added line, change the symbol layer type from Simple line to Marker line. select the Simple Markerline, and select >as the symbol.
If you have oneways with -1 or value, you have to rotate the symbol by 180°.
You might have a look at http://wiki.openstreetmap.org/wiki/Key:oneway#Implied_oneway_restriction too.
You can style the highways with empty oneway field different, and you will get this result:

If you don't want to see footways etc, you can filter the dataset with
NOT ("highway"  = 'bridleway'  OR "highway" = 'cycleway' OR "highway" = 'footway' OR "highway" = 'path' OR "highway" = 'steps' OR "highway" = 'track')

Comment: Thank you so much! I really deeply appreciate the help! Very useful.
Comment: How can I show the nodes that are at the intersection of two roads? This is useful, because how will I know by just looking at the downloaded data from OSM into QGIS that the crossing of the two roads are an intersection or a bridge? In OSM a node shows that there is an intersection and that a car can turn from the one road onto the other, if the node is not there a car cannot turn, this is the case with a bridge.
Comment: This can be determined by the `layer` tag. But on this site there should be one question per topic, so you better open up a new one.


Can multiple users edit a node to create several different revisions without being able to publish them?

Question: I want to create a Wiki style website where many users can edit a document but can not publish their edits. Imagine having four users -- an administrator and three normal users. The three users can't publish anything they create or edit. So... one user creates a node. The administrator publishes the node after reviewing it. Then a second user edits the node and it's saved to a draft and after the third user edits the node and it's saved to a different draft. Now there is a published node and two different drafts of the node from two different users waiting for the administrator to publish one of them. Is there a clean Drupal solution for this?
Answer: The Workbench module with Workbench Moderation seems to do what you require. Users create drafts, which can then be markled for review. Once an admin reviews the content he can choose to publish it, update it or send it back to the user for further work. Each user has their own drafts, so different users can have drafts of the same document.
You can have as many stages and transitions as you want, so you could have a reviewer role who reviews content and sends it off to a publisher role to be published.
Workbench is Drupal 7 only, but Workflow seems to do similar things for Drupal 6, although I've got no experience with it personally.
Answer: Drupal supports revisions natively, but does not allow for very sophisticated "revision-play". However, as it is the case for almost anything with Drupal, you can use a module that allows more advanced revisioning options. Its name is - guess what - Revisioning.
Notice, that if you want to create a complete wiki, you will probably have to use some wiki-specific modules that provide most of the wiki functionality without any hassle. An example of such a module is Wikitools.
Finally, if you do not have enough time and you prefer to click-and-play you can check the Wiki Installation Profile.


Strange way to offer a job

Question: I was offered a job in IT department at a public school system. Had 2 interviews and they called me on the phone the next day to say they wanted to offer me the job. The guy basically said "we want to offer this job at this pay rate, do you accept?"  I asked if they could send it to me in writing and he said they don't do that. The rate was less than they advertised in their job posting and less than I need to take the job. I stupidly said I accepted but was thinking I could negotiate. They then said that I needed to send them an email stating that I accepted the job at the offered rate. I again stupidly followed their request. I felt pressured to respond and did not want to lose the position. They then said I should hear from their HR in a few days. That has been over a week ago and have not heard anything. After thinking about it, the rate will be insufficient for me plus this whole deal is setting off alarms in my head. I think it is reasonable to get their offer in writing and asked for it again in me acceptance email. They have not responded to that email. My question is, since I sent the email stating I would take the job at the low rate, is there any way to try and negotiate at this point since they have not been very good at handling this with me in my opinion. HR seems borderline incompetent, and I am not sure this place is somewhere I want to work since they seem so weird about giving me an offer in writing.
Comment: The verbal agreement may have been weak enough to push back for renegotiation.  For example  "Ya I think I could work with that" allows for "I agreed in principal to taking the job but did not agree on the details as I felt negotiation would come later" whereas "Yes I agree to work X position for $Y per year" is pretty black and white.  The email is likely to be treated as a finalized negotiation.  You wouldn't consider it acceptable if a company coming back to you for further negotiation after they sent an email offer.
Comment: In the future ***never*** say you agree to anything which you wouldn't sign. In other words don't verbally agree to $X, if you wouldn't sign the contract saying you're being paid $X. If you would have immediately said: ***"I'd like to accept, but the amount you're quoting me is lower than what the job description stated. Could we negotiate a higher wage?"*** then - based on the reply - you would know whether you should keep looking or not. Instead you're now in a situation where you're not even sure if you're hired, and most likely won't be anyway once they hear you want more money.
Comment: If you don't have a signed agreement, you don't have a job. The fact that you don't have a signed agreement, however, allows you to renegotiate as much as you want.
Comment: Iron rule: You _never_ accept less than was offered, and you _never_ accept less than you need to live.
Answer:
My question is, since I sent the email stating I would take the job at
  the low rate, is there any way to try and negotiate at this point
  since they have not been very good at handling this with me in my
  opinion. HR seems borderline incompetent, and I am not sure this place
  is somewhere I want to work since they seem so weird about giving me
  an offer in writing.

Certainly you can decide to go back on your word for any reason and attempt to negotiate a better offer.
While it seems very unlikely to succeed, it doesn't sound like you care much anyway, so you have nothing to lose.
(As an aside, you can blame them for being "borderline incompetent" but you were the one who accepted both verbally and via email.)
Comment: exactly - if OP doesn't care if the job is taken or not, just say "oh i got a new job offer at , can you match? I wouldn't normally ask but you've taken 1+ weeks"
Comment: On the other hand, the slowness of HR may be work to OP's luck. If they fail to follow up, he might be able to send a mail to ask whether the discussed offer is still valid, and, if no response, renege a week later by another mail without losing face. But, IANAL, and different rules may apply.

Strange way to offer a job


Is it okay to use source code from another paper in thesis?

Question: I am currently writing my Master's thesis in Math and part of my results involves using running simulations to test for certain types of algebraic properties of parameterised equations. The theoretical basis for these simulations were derived from a paper, in which the authors published their code online. I wish to copy this code and put it in the appendix. My reason for doing this is that I don't trust the link to always be available and the interested readers of my thesis will always be able to view said code which makes it easier to reader the thesis, as opposed to looking it up.
Comment: As an alternative, you could host a copy of the code yourself online and reference the original link and your mirror, assuming that license is attributable.
Answer: It depends on the licensing terms of their code. If it's under an open source license, then you might probably be able to use the same by giving due credits to the authors of the same. It would also be better if you could try to contact the author of the paper and ask their permission before using the same if you're not able to find any specific licensing terms.
Comment: This addresses copyright, but I suspect plagiarism is more of a concern.
Answer: You will of course be citing this paper in your body text. But in the appendix, you would need to be absolutely clear that the code is reproduced from the paper. If instead you have based your own code on the code in the paper, be clear about which bits are yours and which are from the paper, as well as to what extent your work is derived from the literature.


Can I change company's name in quote from before the name was legally changed?

Question: So in one of my reports I am quoting an executive who talks about the company "Company X" at a time when it was still called "Company X." This was a few months ago, and the company's name has since been changed to "Company Z." Can I change the company name to the current name in the executive's quoted sentence?
Comment: Is the name of Company X all that changed? Is it literally the  same company with a different name.  You'd probably want to go with the original name, because the executive was speaking  as executive of Company X. Company Z might not literally bet he same legal entity.
Comment: You might want to make it unambiguous that the executive worked at the old company too.
Answer: The usual practice if it is necessary to make a change to a quote is to put the change in square brackets. Example:

Jones wrote "In all my years working at Company X [now named Company Y] I've never heard of such a thing."


Yahoo Search has hijacked all my internet browsers (Safari, Firefox). How to remove the adware/malware?

Question: Today I installed a program that I'm familiar with and that I have used before called Filezilla using SourceForge. I've never had a problem with it before, and I only uninstalled it because I had no need for it. So I moved to install it again and thought it was strange it kept asking for key permission (so I said no). All the sudden my fireox browser disappeared I had some crapware installed I had no interest in, plus another unpleasant surprise: whenever I load firefox OR Safari Yahoo search comes up even though my default for Safari is google search. How do I fix this? I'm trying to delete the program it came from but it says that it's 'in use', but when I pull up the task manager all that shows up are finder and Microsoft Word. Any word on how I can delete the covert adware/malware?
Comment: Do you know the name?
Comment: if it is running use cmd+alt+esc then kill it from there.
Comment: Nowadays it's much, much harder to install crapware on macOS, and it's much easier to remove as well. As long as you don't install anything from a suspicious website with your password, you will be fine. It's both a blessing (for security) and a curse (for customization).
Answer: So after downloading Vuze a while back, I wound up with api.mybrowserbar redirects and a bunch of stuff pointing at some thing called Spigot, deterministically finger banging my bandwidth and internet experience in general.
Sorry, this assumes some knowledge of the command line and file structures.
The solution, grep is your friend.
Open Terminal and navigate to /Users/YOUR_COMPUTER_USERNAME/Library/Application Support/Google/Chrome
YOUR_COMPUTER_USERNAME must of course be replaced with your computer username, you can retrieve it by running the whoami command in your terminal.
grep -rnw '.' -e 'spigot'
and
grep -rnw '.' -e 'api.mybrowserbar'
get in there and remove that shit.
In the most annoying case, their genius software made itself the default restart page for whenever chrome unexpectedly crashes. This little tidbit is located deep inside a sort of huge JSON blob at
/Users/YOUR_COMPUTER_USERNAME/Library/Application Support/Google/Chrome/Default/Preferences
Answer: This response IS for a Mac user, specifically, OS X 10.11(El Capitan).
That said, I set all my machines up with the exact same programs (again Mac machines only), and even version specific (browsers, etc.), see why this is relevant here-->. Of the units that reach out to the web, the Mac Pro, Mac Mini, or MacBook Pro 17, has NOT been affected. *Not going to give hardware specs as I'd be on here all day. This has only affected a MacBook Pro 15(2013 model) via Google Chrome.
Part of my job is finding and ending problems such as this, so I've done a bit of research on the issue and this is what I have come up with, I certainly hope it helps someone:
In this case, certain Chrome 'Extensions' appear to worm there way into the Extensions list. Heres a small list of extensions that install without user consent: "Amazon Shopping Assistant by Spigot", "Domain Error Assistant", "Ebay Shopping Assistant by Spigot" and "Slick Savings." In my case, I narrowing my logs down to an extension called "domain error assistant" being the first installed without user consent. The yahoo search engine appeared relentlessly even after all browser cache was deleted.
My Fix? Save bookmarks, etc. Trash ALL extensions, Remove Chrome, reinstall Chrome. Its been good for over a month now.
Good Luck!
Comment: Thanks! The problem I had was with Firefox and Safari, however. The problem was fixed suing the Terminal.
Answer: I had the same problem in Safari using Mac OS, and I found the problem was caused an extension called Any Search that got installed in the browser when installing some other app. I removed it, and it solved the problem.
Answer: I had a similar issue and it was resolved once I removed the "Emoji keyboard" Chrome extension.
(My problem was limited to Chrome, I think)
Answer: Go to Activity Monitor, and you'll see a list of all the tasks your computer is running. Find the program that the adware came from, select it,  and click the Quit button in the top left corner of Activity Monitor's toolbar (the button with an octagon with an X in it, not the red "close window" button). That should stop the program so you can delete it.
Answer: Check your extensions for anything by Spigot and either run AdwareMedic or follow the instructions on the site that hosts AdwareMedic. Or use Apple's plagiarized article.
Comment: What is "Apple's plagiarized article"?
Comment: HT203987 Remove Unwanted Adware Long Winded Title
Answer: I'm aware that this thread is a little bit old, but I just faced the same problem after having installed Vuze.
What I did was delete an extension called "Quick Browse", and now everything seems to be back to normal.
I hope this helps!
Answer: I have had the same problem and I discovered a program that had piggybacked into my system called Yahoo Search Set.  Uninstalling that program, restarting the computer, and then manually removing the Yahoo Search URL from my homepage setting did the trick.  I have found references to another software called "Spigot" that may do the same thing.  Go to "Uninstall Programs" in your control panel and look the list over.  If you see either of these listed, uninstall them.  If they are not there, look for any other program listed that you are not familiar with.  Check those programs out by doing search on "what is" plus the program name and you should find information about whether the program is legitimate.  If it is not something you want or need and not something that is part of another function like printer function software, consider uninstalling it. That is how I found and decided to uninstall Yahoo Search Set which cured my problem.
Comment: Ask Different is specific to OS X.
Answer: I ended up using the terminal to delete it, and whatever it is, hopefully is gone (it no longer hijacks my browsers).
EDIT: I used the commands rm -rf to delete the original file.
Comment: Do you know what it was called. not goldernboy per chance?
Comment: I have no idea unfortunately. I think it was part of the download itself, because once I deleted that it wasn't working anymore.
Comment: This isn't a very useful answer. Yes you used the terminal, but how did you delete it? What commands did you run? If you followed another answer's recommendation, then you should have marked that as being the solution.
Comment: Didn't realize my answer was so unpopular haha. I believe that I googled the question and eventually found the answer. What I did was that I used the commands rm -rf to delete the undeletable file. I found it by searching the name for the file using the terminal and then using the above command to delete what I needed. I restarted the browser and there, problem solved. Does that answer your question?


Differences and conversion between encoding techniques (NRZI, Manchester, MLT3)

Question: I'm currently reading a lot about different encoding techniques for data transmission, in particular ethernet, fiber (and usb). 10Base Tx ethernet uses Manchester encoding for data transmission. But it is not used for 100Base Tx or 100Base Fx. Instead MLT3 or NRZI encoding is used. I read that this has something to do with the speed (frequency?) limitations of the techniques. But where does this limitation come from? Is it dependent on the media (fiber, copper), the distance between the transmit and the receive side or is it somehow inherent to the applied technique?
Could I maybe use Manchester encoding for a high speed (100 mbps) optical data link over air or for a cable link if the distance between both sides is only some centimeters?
Related to this question: Is there a way to convert encoded data from e.g. MLT3 to Manchester or NRZI encoding? Most ethernet chips for 100 mbps use MLT3 encoding but for my application I probably need Manchester encoded data as input.
Comment: you can try using digital signal processors, program them accordingly to change the encoding.
Answer: Multi-level codings allow you to send more bits in a given frequency, with the trade-off of needing more complexity to generate and detect the multiple levels.
At the time the 100mbps Ethernet copper standard was being developed, this obviously felt like the right compromise of interface complexity vs demands for cabling of a particular quality.
Standards like Ethernet are an immensely complex balancing act of backwards compatibility, politics, vested interests and attempts to predict future demand.  You can't really pick one of umpteen overlapping engineering decisions and say 'why did they do that?', because the answer is always at least in part 'because they did all the other stuff'.
In answer to your specific question about recoding stuff, then yes, you can always do that, because if you can decode one format and generate another, then you can put those circuits back-to-back.
Comment: "with the trade-off of needing more complexity to generate and detect the multiple levels" -- and also needing a better signal to noise ratio to correctly decode.


IGCSE to apply for Australian visa

Question: Can I use my I IGCSE to apply for my work and holiday Australian visa?
Or should I take a TOEFL or IELTS?
Comment: @MarkMayo no, TOEFL "is a test of an individual's ability to use and understand English in an academic setting" while TEFL "refers to teaching English to students whose first language is not English". IELTS is similar to TOEFL
Comment: TOEFL = "Test of English as a Foreign Language" usually required of foreign students applying to US universities.  Not sure what the rest of the alphabet soup means.
Comment: What country are you from? This determines the 'Work and Holiday' visa requirements... that said, I imagine if an English test is required it'll be standard across the board...
Comment: @Karlson IGCSEs are the international equivalent of the UK GCSE program sat many 16 yr olds who follow British curriculum outside the UK. The main difference between them & standard GCSEs is that they contain no coursework element (as such are becoming increasing popular with schools within the UK also). People who then continue there education post 16, then may progress to A levels in preparation for university entrance (alternatives to A levels include Pre U & International Baccalaureate (IB).
Comment: Also, I think IGCSE is International GCSE (GCSE being the U.K. general set of qualifications achieved in your 3rd or 4th year of secondary education).
Comment: IELTS is a comparable English-as-a-foreign-language test. IGCSE is the international version of a U.K high school qualification. I used to teach the former, for my sins.
Comment: Based on what I can see IGCSE is a colledge qualification exams in multiple subjects.  So if part of that program you have passed an equivalent you might check with Australian Consulate if they will accept it.  If not you will need to take one of the tests mentioned.
Comment: It is not college qualification level. It is for 14-16 year olds, and each subject has its own IGCSE. See http://www.cie.org.uk/qualifications/academic/middlesec/igcse/overview
Answer: One of the following is required (from the Work and Holiday visa page of Australian immigration). The criteria in bold is likely where the IGCSE fits in.

Achieved an IELTS average band score of at least 4.5 based on the four test components of speaking, reading, writing and listening in a test conducted no more than two years before lodging the visa application. For visa purposes you only need to sit the General Training Module.
Achieved a TOEFL score of 133 on a computer based test, or 450 on a paper based test or 45-46 on an internet-based test, no more than two years before lodging the visa application.
Passed the Occupational English Test no more than two years before lodging the visa application.
Completed all years of primary education and at least three years of secondary education at an educational institution in which all instruction was in English.
Completed at least five years of secondary education (high school) at an educational institution in which all instruction was in English.
Completed a post-secondary qualification that required at least two years of full-time study or training, in which all tuition was in English.
Successfully completed, in Australia, at least one year of full-time study or equivalent part-time study towards a degree, higher degree, diploma or associate diploma at an institution or institutions where all the instruction was in English.

However, I assume that passing the IGCSE isn't enough - at least 5 years of your secondary / high school education, in all subjects, must have been in English.
There are also additional education requirements that must be met based on your home country. You can find these from the page above by selecting your country.
Comment: There are 'Working Holiday' visas, and 'Work and Holiday' visas. Looks like 'Work and Holiday' needs at least 'diploma level' qualifications, whilst 'Working Holiday' does not. Which you can apply for depends on your country. See http://www.immi.gov.au/visitors/working-holiday/visa-options.htm.
Comment: You need qualifications to get a working holiday visa to my country??? I thought you just had to be from one of certain countries and be below the cutoff age. I'm a bit shocked. Or is this something different?
Comment: This, of course, in addition to age requirements etc.
Answer: This what is accepted (one being something from Cambridge):
https://www.border.gov.au/Lega/Lega/Form/Immi-FAQs/aelt
However, the visa applications are never decided based on one criteria. If your country has low chance of getting visa you better have everything right. It is also likely they will require you to do the tests if they dont like your English certificate. However, I would suggest not taking the risk and just do the test.

IGCSE to apply for Australian visa


Is the energy used to manufacture and install solar panels in proper balance with the energy output from them?

Question: From mining/harvesting materials to altering them into useful manufacturing materials to making actual products, and then packaging them and shipping them to retail stores, or directly to customers, and then the time and energy it takes to mount them (especially on larger scales eg. fields), do they really put out enough energy to outweigh all that?
Comment: Annoying, can't mark it as a duplicate because there's no an answer (yet). Although this is a simpler question, a valid answer is "yes" :)
Comment: I think this is effectively a duplicate of [this](http://sustainability.stackexchange.com/q/1013/48) - an answer there, would answer the question here.
Answer: I asked my late father (an electrical engineer) this very question years ago and he said that essentially, the entire cost of a solar panel is the cost of the energy to make it. You dig dirt out of the ground and apply energy to turn that into metal, glass, etc, then you use energy to ship parts around and to assemble them into a panel and ship the panel, etc. The cost of the true raw material is very low indeed and the cost of the factory is again the cost of the energy to make the factory, and so on down the line. The possible exception may be a retail markup and a labour cost when you finally acquire and install it.
Now, consider that solar panels "pay for themselves" in the end. You pay $X for a panel and after some number of years, you have saved $X in energy bills. It therefore follows that it has generated at least as much energy as it cost to make it. This logic would only fail if you pay a wildly different cost for energy than everyone before you in the chain. Aluminum smelters do locate near dams to get cheap power, but I don't think you'll find that cheap means "1/10th the price" or even "1/2 the price" so the logic holds. Any panel that is economically worthwhile has produced more power than it took to smelt and refine its materials and to make it, as measured in dollars.
Comment: For some actual numbers on this, see this question on Skeptics: http://skeptics.stackexchange.com/q/27394
Comment: @NeilTyson Generally is probably too general. In NZ (not vastly different to US) a case may be made for a sensible PV installation. IOt is possible to pay too much and get too little but paybacks inside system lifetime using proper rate of return calculations are possible.
Comment: Actually wholesale prices for electricity can be 1/10 of the retail price or lower. Tiwai Point aluminium smelter [pays about 1/4 retail](http://en.wikipedia.org/wiki/New_Zealand_Aluminium_Smelters#Electricity), for example.
Comment: Panels are generally not economically worthwhile without subsidy