title: Westchester County Airport

text: In 2013, Delta Air Lines announced that they would begin seasonal service to Orlando starting in December of that year. Delta ceased operation of the route, leaving JetBlue as the only airline that currently serves it.


title: Westchester County Airport

text: In December 2015, Tradewind Aviation began service to the Morrisville–Stowe Airport in northern Vermont.


title: Westchester County Airport

text: In August 2016, American Airlines announced nonstop service to Miami via its American Eagle subsidiary with 2 round-trip flights daily on board their Embraer E175 aircraft operated by Republic Airways. Service commenced on December 15, 2016, only to cease in late 2017. On September 6, 2022, American announced they would relaunch this route on January 10, 2023, with 1 daily round-trip E175 flight lasting until May 3, 2022. Envoy Air will operate this flight as American Eagle.


title: Westchester County Airport

text: Between December 2 and 20, 2017, Delta Air Lines upgauged 1–2 flights on select days to Boeing 717-200 aircraft to test increased payload feasibility to HPN. This was necessitated by the airport's limit of 240 arriving and departing passengers per half-hour; operators who exceed this cap are fined. As of the present time, Delta uses this equipment for flights on the HPN-ATL route on a full-time basis along with the Bombardier CRJ900.


title: Westchester County Airport

text: On November 13, 2018, JetBlue announced that they would be offering service to Nantucket from HPN on a seasonal and 5x round-trip flight per week basis on board the Embraer E190 stating in June 2019. JetBlue didn't operate this route in 2020 due to the COVID-19 pandemic. It currently operates this route 1x daily but still on a seasonal basis.


title: Westchester County Airport

text: On April 27, 2020, the airport was closed to general aviation traffic for one week and commercial airlines for about a month so Runway 16/34 could be repaved, a project originally scheduled to span four months with construction only occurring from midnight to 6 AM. This decision was made in the midst of COVID-19 pandemic-related air travel cuts, which drastically reduced commercial airline service to the airport. Some operators were forced to ferry their aircraft to nearby airports where they could continue flights. This was the first total shutdown of a U.S. commercial airport for reasons relating to the COVID-19 pandemic.


title: Westchester County Airport

text: On April 20, 2022, Breeze Airways announced several new routes from the airport, including the airport's first-ever commercial transcontinental service, with flights to Las Vegas (dropped after October 2, 2022), Los Angeles, and San Francisco (cancelled), on board the airline's Airbus A220-300. Other new service that was announced from the airport included flights to Charleston (SC), Jacksonville (FL), Norfolk, and Savannah.


title: Westchester County Airport

text: On August 8, 2022, Delta began selling flights to Boston, with the first flight taking-off on October 6, 2022. This route operates twice round-trip on Mondays-Wednesdays and 3x round-trip on Thursdays and Fridays, with slightly altered schedules on and around holidays, on board their Embraer E170 or E175 operated by Republic Airways.


title: Westchester County Airport

text: On August 10, 2022, according to their website, Breeze cancelled planned service from HPN to San Francisco and also dropped planned service to Las Vegas after October 2, 2022 (HPN-LAS only operated on Sundays and Thursdays from 9/8/22 to 10/2/22). New service also appeared, including flights to Nashville and Sarasota. The former route commenced on November 4, 2022 but will end just under 2 months later on January 2, 2023. The latter route commenced on November 2, 2022. Both routes use the airline’s Embraer E195.


title: Westchester County Airport

text: On October 18, 2022, Breeze began selling flights to Vero Beach, which begin on February 3, 2023. The route will operate on Sundays, Thursdays, and Saturdays starting on February 16, 2023, using the airline’s Embraer E195. To make room for this route, Breeze dropped all flights to Nashville after January 2, 2023. The Nashville flights started on November 4, 2022, meaning that they’ll only last for just under 2 months. Between January 2 and February 3, 2023, HPN-SRQ will see increased frequency.


title: Westchester County Airport

text: Several capital projects are planned, including a new US Customs and Border Protection facility and a new ARFF Station.


title: Westchester County Airport

text: In its effort to mitigate aircraft noise pollution into neighboring communities, HPN maintains six major noise abatement programs that are in effect daily.


title: Westchester County Airport

text: One of them is its Voluntary Restraint from Flying Program (VRFF), sometimes referred to as a voluntary curfew, that helps assuage anti-airport complainants by requesting—not mandating—that operators refrain from flying into the airport between midnight and 6:30 AM. Those that breach the VRFF are reminded of the initiative and notified of any noise complaints that may have resulted from their operations.


title: Westchester County Airport

text: The airport's Airport Noise and Operations Monitoring System (ANOMS) collects noise data from remote noise-monitoring terminals, and both registered aircraft and community noise levels are published in the Airport Monitor. This system works in conjunction with the High Range Noise Event (HRNE) Program; ANOMS staff can identity any operator who causes a maximum noise level event of 90.0 decibels or higher at any of its remote noise monitor terminals and advise them in order to prevent future noise level transgressions. As of September 2020, there are no fines, penalties, or aircraft restrictions associated with this program.


title: Westchester County Airport

text: Additionally, HPN prohibits intersection takeoffs from its runways and restricts maintenance runups and use of reverse thrust. It also employs Advanced Authorization for operations.


title: Westchester County Airport

text: Following several renovations and discussions about the airport's viability, HPN is currently served by 5 airlines with flights to 19 destinations throughout the United States. Although there has long been controversy over the airport and its proposed expansions, concerns have also arisen regarding travelers seeking relief from long delays at the other New York metropolitan area airports, such as John F. Kennedy International Airport (JFK) and LaGuardia Airport (LGA).


title: Westchester County Airport

text: More recently, these concerns pertain to flight paths and vehicular congestion. The latter has been addressed by the County of Westchester with Bee-Line Bus System (bus #12 from downtown White Plains) service to the airport and the encouragement of travelers to share rides to the airport.


title: Westchester County Airport

text: The airport's environmental management performance is monitored through its ISO 14001 certified Airport Environmental Management System (AEMS). This enables operators to report the airport's impacts on surface water, groundwater, and noise. Airport-wide environmental management practices are also continually revised with this technology, and annual objectives and targets are determined to avoid or mitigate adverse environmental impacts. In addition, airport employees receive environmental training. In 2004, HPN was the third airport in the U.S. to achieve this level of environmental performance.


title: Westchester County Airport

text: In May 2011, the New York State Department of Transportation published the "New York Statewide Airport Economic Impact Study," highlighting the economic impacts of public-use airports in New York state for fiscal year 2009. The study noted that HPN was one of only three airports in the state that increased its enplanements, surpassing the U.S. benchmark. It also noted that the cumulative economic activity for the airport was approximately $736 million.


title: Westchester County Airport

text: The airport can be accessed from I-684's Exit 2 onto New York State Route 120. More directly, the terminals are accessed by NY Route 135.


title: Westchester County Airport

text: The IATA code for Westchester County Airport is HPN. The origins of this code are in dispute. Some believe it is derived from the name of the city, White Plains (IATA codes normally do not begin with W because those are reserved for radio signals), while others maintain the IATA code represents the first letter of the airport's three neighboring communities, Harrison, Purchase, and North Castle. The full ICAO code for Westchester County Airport is KHPN.


title: Westchester County Airport

text: Westchester County Airport covers 702 acres (284 ha) at an elevation of 439 feet (134 m) above mean sea level. It has two asphalt paved runways: 16/34 is 6,549 by 150 feet (1,996 x 46 m) and 11/29 is 4,451 by 150 feet (1,357 x 46 m). Runway 29's threshold is displaced 1,297 feet (395 m) due to trees obstructing the approach path. The trees (in Connecticut) are 37 ft (11 m) tall and 370 ft (113 m) from the end of the runway.


title: Westchester County Airport

text: Westchester County Airport has several fixed-base operators (FBOs), including Signature Flight Support East and West, Ross Aviation East and West, NetJets, and Million Air. Although varied in services offered, the FBOs at Westchester County Airport provide Jet A and 100LL fueling services, repairs and maintenance, aircraft tiedowns, de-icing, United States Customs, and other aircraft services. Some of the FBOs are particularly luxurious, providing limousine transportation services and deluxe surroundings.


title: Westchester County Airport

text: There are three flight schools. Performance Flight operates out of the Million Air at Hangar M, while Academy of Aviation operates out of Ross Aviation West at Hangar T. Wings Air offers helicopter flight training out of Hangar T. Additionally, the Westchester Flying Club, a private organization of pilots, is based at the airport as well as the Westchester Aviation Association, a not-for-profit organization that promotes aviation education and understanding on the part of government authorities and the public.


title: Westchester County Airport

text: Westchester County Airport is also the home of the New York Wing Civil Air Patrol headquarters, the Lt. Anthony L. Willsea Cadet Squadron (NY-422).


title: Westchester County Airport

text: Aircraft Rescue Fire Fighting (ARFF) is provided by Airport Operations Crews. The airport owns three ARFF apparatuses (three Oshkosh Striker 1500s), two of which are in service full-time. The ARFF Crews only respond to aircraft emergencies. All structure-related fire and rescue calls are deferred to the local fire departments. The Purchase Fire Department, for example, handles all structure calls on the southern part of the airfield, the Armonk Fire Department handles calls on the northern part and the Rye Brook/Port Chester Fire Department handle all calls on the east end, including the main terminal. EMS calls are handled by Port Chester-Rye-Rye Brook EMS, Harrison EMS and Armonk Fire/EMS depending on location of call.


title: Westchester County Airport

text: In 2010, the airport had 191,017 total aircraft operations, an average of 523 per day: 23% commercial aviation, 48% heavy general aviation, and 29% light general aviation. 316 aircraft, including helicopters, are based out of this airport.


title: Westchester County Airport

text: An aircraft must have a maximum gross weight of 120,000 pounds or less, or permission from the manager, to land at the airport.


title: Westchester County Airport

text: Westchester County Airport has one small, three-level terminal with six gates, of which only four can be used simultaneously because only four aircraft can be scheduled to use the terminal's ramp at any given time. The $35 million terminal was built in 1995 and designed by Lothrop Associates. Gates A, B, C, and F have jetways. The terminal also has a luggage carousel, a baggage reclaim office and two Transportation Security Administration (TSA) screening lanes. Passenger amenities include a gift shop, departure lounge, and food concessions such as a Dunkin' Donuts.


title: Westchester County Airport

text: In November 2015, the airport began a $30 million construction project to expand the terminal and ramp areas. The project will expand the terminal by 20% and include additional check-in, screening and passenger waiting areas. The expansion will also include the addition of four new jet bridges. A separate terminal with "lodge-like ambiance" to serve passengers of private jets opened in 2019.


title: Westchester County Airport

text: ^PSA Airlines operates American Eagle flights to Charlotte, NC and Washington–National, D.C. while SkyWest operates American Eagle flights to Chicago–O’Hare, IL.


title: Westchester County Airport

text: ^^Endeavor Air operates Delta Connection flights to Atlanta, GA while SkyWest operates Delta Connection flights to both Atlanta, GA and Detroit, MI.


title: Westchester County Airport

text: Expansion of the airport has raised concerns over adverse environmental impacts by numerous community advocacy groups and area residents. The facility lies between the Blind Brook watershed and the Rye Lake watershed/Kensico Reservoir. The Citizens for a Responsible County Airport, which count the Sierra Club Lower Hudson and Federated Conservationists of Westchester as supporters, has raised safety concerns about the stormwater runoff directed towards Westchester and New York City's drinking water supply. They are especially alarmed about PFAS discovered in groundwater tests between the Airport and the Kensico watershed.


title: Amy Manson

text: Amy Manson (born 9 September 1985) is a Scottish actress. She has portrayed Alice Guppy in "Torchwood", Abby Evans in "Casualty", Lizzie Siddal in "Desperate Romantics", Daisy Hannigan-Spiteri in "Being Human", Medea in "Atlantis", and Merida in the fifth season of the ABC fairy tale drama series "Once Upon a Time".


title: Amy Manson

text: Born and brought up in Aberdeenshire, Scotland, Manson has one sister, Ailsa Manson and one brother, James Manson, all of Sept Manson of Clan Gunn. She attended Stage Coach, a Saturday drama school, before leaving home for London at the age of seventeen. She trained at the Central School of Speech and Drama, leaving early to film "" in Romania. She lives in North London.


title: Amy Manson

text: Manson made her film debut in "", and has also appeared in the horror film "Blood Monkey" and the short film "Smile Emily".


title: Amy Manson

text: Manson has lent her voice to the radio dramas "Lost in Plain Sight", "The Summer Walking" and "The Dead Hour".


title: Amy Manson

text: On television, she played Alice Guppy in two episodes of "Torchwood", and appeared as Abby Evans in nine episodes of "Casualty". She has guest-starred in episodes of "Doctors", "The Bill" and "My Family".


title: Amy Manson

text: Manson played Lizzie Siddal, muse, wife and lover of Dante Gabriel Rossetti, in the BBC Two period drama "Desperate Romantics". She appeared as the vampire Daisy Hannigan-Spiteri in series two of "Being Human", alongside "Desperate Romantics" co-star Aidan Turner.


title: Amy Manson

text: Manson played Ginger Corrigan in the 2010 adaptation of "Agatha Christie's Marple": "The Pale Horse", and also played Fleur Morgan in "Outcasts", an eight-part series by Kudos for BBC One.


title: Amy Manson

text: In 2011, Manson portrayed Leah in the third series of "Misfits" and Emma "Whirly" Tyson in the BBC drama "Young James Herriot".


title: Amy Manson

text: Manson won Best Performance (Female) at the 2008 Critics' Awards for Theatre in Scotland, for playing Stepdaughter in the National Theatre of Scotland production of "Six Characters in Search of an Author".


title: Instrumental variables estimation

text: In statistics, econometrics, epidemiology and related disciplines, the method of instrumental variables (IV) is used to estimate causal relationships when controlled experiments are not feasible or when a treatment is not successfully delivered to every unit in a randomized experiment. Intuitively, IVs are used when an explanatory variable of interest is correlated with the error term, in which case ordinary least squares and ANOVA give biased results. A valid instrument induces changes in the explanatory variable but has no independent effect on the dependent variable, allowing a researcher to uncover the causal effect of the explanatory variable on the dependent variable.


title: Instrumental variables estimation

text: Instrumental variable methods allow for consistent estimation when the explanatory variables (covariates) are correlated with the error terms in a regression model. Such correlation may occur when:


title: Instrumental variables estimation

text: Explanatory variables that suffer from one or more of these issues in the context of a regression are sometimes referred to as endogenous. In this situation, ordinary least squares produces biased and inconsistent estimates. However, if an "instrument" is available, consistent estimates may still be obtained. An instrument is a variable that does not itself belong in the explanatory equation but is correlated with the endogenous explanatory variables, conditionally on the value of other covariates.


title: Instrumental variables estimation

text: First use of an instrument variable occurred in a 1928 book by Philip G. Wright, best known for his excellent description of the production, transport and sale of vegetable and animal oils in the early 1900s in the United States, while in 1945, Olav Reiersøl applied the same approach in the context of errors-in-variables models in his dissertation, giving the method its name.


title: Instrumental variables estimation

text: Wright attempted to determine the supply and demand for butter using panel data on prices and quantities sold in the United States. The idea was that a regression analysis could produce a demand or supply curve because they are formed by the path between prices and quantities demanded or supplied. The problem was that the observational data did not form a demand or supply curve as such, but rather a cloud of point observations that took different shapes under varying market conditions. It seemed that making deductions from the data remained elusive.


title: Instrumental variables estimation

text: The problem was that price affected both supply and demand so that a function describing only one of the two could not be constructed directly from the observational data. Wright correctly concluded that he needed a variable that correlated with either demand or supply but not both – that is, an instrumental variable.


title: Instrumental variables estimation

text: After much deliberation, Wright decided to use regional rainfall as his instrumental variable: he concluded that rainfall affected grass production and hence milk production and ultimately butter supply, but not butter demand. In this way he was able to construct a regression equation with only the instrumental variable of price and supply.


title: Instrumental variables estimation

text: While the ideas behind IV extend to a broad class of models, a very common context for IV is in linear regression. Traditionally, an instrumental variable is defined


title: Instrumental variables estimation

text: as a variable "Z" that is correlated with the independent variable "X" and uncorrelated with the "error term" U in the linear equation


title: Instrumental variables estimation

text: formula_2 is a vector. formula_3 is a matrix, usually with a column of ones and perhaps with additional columns for other covariates. Consider how an instrument allows formula_4 to be recovered. Recall that OLS solves for formula_5 such that formula_6 (when we minimize the sum of squared errors, formula_7, the first-order condition is exactly formula_8.) If the true model is believed to have formula_9 due to any of the reasons listed above—for example, if there is an omitted variable which affects both formula_3 and formula_2 separately—then this OLS procedure will "not" yield the causal impact of formula_3 on formula_2. OLS will simply pick the parameter that makes the resulting errors appear uncorrelated with formula_3.


title: Instrumental variables estimation

text: Consider for simplicity the single-variable case. Suppose we are considering a regression with one variable and a constant (perhaps no other covariates are necessary, or perhaps we have partialed out any other relevant covariates):


title: Instrumental variables estimation

text: In this case, the coefficient on the regressor of interest is given by formula_16. Substituting for formula_17 gives


title: Instrumental variables estimation

text: where formula_19 is what the estimated coefficient vector would be if "x" were not correlated with "u". In this case, it can be shown that formula_19 is an unbiased estimator of formula_21 If formula_22 in the underlying model that we believe, then OLS gives a coefficient which does "not" reflect the underlying causal effect of interest. IV helps to fix this problem by identifying the parameters formula_23 not based on whether formula_24 is uncorrelated with formula_25, but based on whether another variable formula_26 is uncorrelated with formula_25. If theory suggests that formula_26 is related to formula_24 (the first stage) but uncorrelated with formula_25 (the exclusion restriction), then IV may identify the causal parameter of interest where OLS fails. Because there are multiple specific ways of using and deriving IV estimators even in just the linear case (IV, 2SLS, GMM), we save further discussion for the Estimation section below.


title: Instrumental variables estimation

text: Informally, in attempting to estimate the causal effect of some variable "X" on another "Y", an instrument is a third variable "Z" which affects "Y" only through its effect on "X". For example, suppose a researcher wishes to estimate the causal effect of smoking on general health. Correlation between health and smoking does not imply that smoking causes poor health because other variables, such as depression, may affect both health and smoking, or because health may affect smoking. It is at best difficult and expensive to conduct controlled experiments on smoking status in the general population. The researcher may attempt to estimate the causal effect of smoking on health from observational data by using the tax rate for tobacco products as an instrument for smoking. The tax rate for tobacco products is a reasonable choice for an instrument because the researcher assumes that it can only be correlated with health through its effect on smoking. If the researcher then finds tobacco taxes and state of health to be correlated, this may be viewed as evidence that smoking causes changes in health.


title: Instrumental variables estimation

text: Angrist and Krueger (2001) present a survey of the history and uses of instrumental variable techniques.


title: Instrumental variables estimation

text: Of course, IV techniques have been developed among a much broader class of non-linear models. General definitions of instrumental variables, using counterfactual and graphical formalism, were given by Pearl (2000; p. 248). The graphical definition requires that "Z" satisfy the following conditions:


title: Instrumental variables estimation

text: where formula_32 stands for "d"-separation and formula_33 stands for the graph in which all arrows entering "X" are cut off.


title: Instrumental variables estimation

text: where "Y" stands for the value that "Y" would attain had "X" been "x" and formula_32 stands for independence.


title: Instrumental variables estimation

text: If there are additional covariates "W" then the above definitions are modified so that "Z" qualifies as an instrument if the given criteria hold conditional on "W".


title: Instrumental variables estimation

text: used, if it satisfies conditions 1–5. The exclusion restriction (condition 4) is redundant; it follows from conditions 2 and 3.


title: Instrumental variables estimation

text: Since "U" is unobserved, the requirement that "Z" be independent of "U" cannot be inferred from data and must instead be determined from the model structure, i.e., the data-generating process. Causal graphs are a representation of this structure, and the graphical definition given above can be used to quickly determine whether a variable "Z" qualifies as an instrumental variable given a set of covariates "W". To see how, consider the following example.


title: Instrumental variables estimation

text: Suppose that we wish to estimate the effect of a university tutoring program on grade point average (GPA). The relationship between attending the tutoring program and GPA may be confounded by a number of factors. Students who attend the tutoring program may care more about their grades or may be struggling with their work. This confounding is depicted in the Figures 1–3 on the right through the bidirected arc between Tutoring Program and GPA. If students are assigned to dormitories at random, the proximity of the student's dorm to the tutoring program is a natural candidate for being an instrumental variable.


title: Instrumental variables estimation

text: However, what if the tutoring program is located in the college library? In that case, Proximity may also cause students to spend more time at the library, which in turn improves their GPA (see Figure 1). Using the causal graph depicted in the Figure 2, we see that Proximity does not qualify as an instrumental variable because it is connected to GPA through the path Proximity formula_36 Library Hours formula_36 GPA in formula_33. However, if we control for Library Hours by adding it as a covariate then Proximity becomes an instrumental variable, since Proximity is separated from GPA given Library Hours in formula_33.


title: Instrumental variables estimation

text: Now, suppose that we notice that a student's "natural ability" affects his or her number of hours in the library as well as his or her GPA, as in Figure 3. Using the causal graph, we see that Library Hours is a collider and conditioning on it opens the path Proximity formula_40 Library Hours formula_41 GPA. As a result, Proximity cannot be used as an instrumental variable.


title: Instrumental variables estimation

text: Finally, suppose that Library Hours does not actually affect GPA because students who do not study in the library simply study elsewhere, as in Figure 4. In this case, controlling for Library Hours still opens a spurious path from Proximity to GPA. However, if we do not control for Library Hours and remove it as a covariate then Proximity can again be used an instrumental variable.


title: Instrumental variables estimation

text: We now revisit and expand upon the mechanics of IV in greater detail. Suppose the data are generated by a process of the form


title: Instrumental variables estimation

text: The parameter vector formula_4 is the causal effect on formula_43 of a one unit change in each element of formula_44, holding all other causes of formula_43 constant. The econometric goal is to estimate formula_4. For simplicity's sake assume the draws of "e" are uncorrelated and that they are drawn from distributions with the same variance (that is, that the errors are serially uncorrelated and homoskedastic).


title: Instrumental variables estimation

text: Suppose also that a regression model of nominally the same form is proposed. Given a random sample of "T" observations from this process, the ordinary least squares estimator is


title: Instrumental variables estimation

text: where "X", "y" and "e" denote column vectors of length "T". This equation is similar to the equation involving formula_55 in the introduction (this is the matrix version of that equation). When "X" and "e" are uncorrelated, under certain regularity conditions the second term has an expected value conditional on "X" of zero and converges to zero in the limit, so the estimator is unbiased and consistent. When "X" and the other unmeasured, causal variables collapsed into the "e" term are correlated, however, the OLS estimator is generally biased and inconsistent for "β". In this case, it is valid to use the estimates to predict values of "y" given values of "X", but the estimate does not recover the causal effect of "X" on "y".


title: Instrumental variables estimation

text: To recover the underlying parameter formula_56, we introduce a set of variables "Z" that is highly correlated with each endogenous component of "X" but (in our underlying model) is not correlated with "e". For simplicity, one might consider "X" to be a "T" × 2 matrix composed of a column of constants and one endogenous variable, and "Z" to be a "T" × 2 consisting of a column of constants and one instrumental variable. However, this technique generalizes to "X" being a matrix of a constant and, say, 5 endogenous variables, with "Z" being a matrix composed of a constant and 5 instruments. In the discussion that follows, we will assume that "X" is a "T" × "K" matrix and leave this value "K" unspecified. An estimator in which "X" and "Z" are both "T" × "K" matrices is referred to as just-identified .


title: Instrumental variables estimation

text: This specification approaches the true parameter as the sample gets large, so long as formula_59 in the true model:


title: Instrumental variables estimation

text: As long as formula_59 in the underlying process which generates the data, the appropriate use of the IV estimator will identify this parameter. This works because IV solves for the unique parameter that satisfies formula_59, and therefore hones in on the true underlying parameter as the sample size grows.


title: Instrumental variables estimation

text: Now an extension: suppose that there are more instruments than there are covariates in the equation of interest, so that "Z" is a "T × M" matrix with "M > K". This is often called the over-identified case. In this case, the generalized method of moments (GMM) can be used. The GMM IV estimator is


title: Instrumental variables estimation

text: This expression collapses to the first when the number of instruments is equal to the number of covariates in the equation of interest. The over-identified IV is therefore a generalization of the just-identified IV.


title: Instrumental variables estimation

text: In the just-identified case, we have as many instruments as covariates, so that the dimension of "X" is the same as that of "Z". Hence, formula_68 and formula_69 are all squared matrices of the same dimension. We can expand the inverse, using the fact that, for any invertible "n"-by-"n" matrices A and B, (AB) = BA (see Invertible matrix#Properties):


title: Instrumental variables estimation

text: There is an equivalent under-identified estimator for the case where "m < k". Since the parameters are the solutions to a set of linear equations, an under-identified model using the set of equations formula_71 does not have a unique solution.


title: Instrumental variables estimation

text: One computational method which can be used to calculate IV estimates is two-stage least squares (2SLS or TSLS). In the first stage, each explanatory variable that is an endogenous covariate in the equation of interest is regressed on all of the exogenous variables in the model, including both exogenous covariates in the equation of interest and the excluded instruments. The predicted values from these regressions are obtained:


title: Instrumental variables estimation

text: In the second stage, the regression of interest is estimated as usual, except that in this stage each endogenous covariate is replaced with the predicted values from the first stage:


title: Instrumental variables estimation

text: This method is only valid in linear models. For categorical endogenous covariates, one might be tempted to use a different first stage than ordinary least squares, such as a probit model for the first stage followed by OLS for the second. This is commonly known in the econometric literature as the "forbidden regression", because second-stage IV parameter estimates are consistent only in special cases.


title: Instrumental variables estimation

text: Replacing formula_78 and noting that formula_79 is a symmetric and idempotent matrix, so that formula_80


title: Instrumental variables estimation

text: The resulting estimator of formula_4 is numerically identical to the expression displayed above. A small correction must be made to the sum-of-squared residuals in the second-stage fitted model in order that the covariance matrix of formula_4 is calculated correctly.


title: Instrumental variables estimation

text: When the form of the structural equations is unknown, an instrumental variable formula_84 can still be defined through the equations:


title: Instrumental variables estimation

text: where formula_87 and formula_88 are two arbitrary functions and formula_84 is independent of formula_90. Unlike linear models, however, measurements of formula_91 and formula_2 do not allow for the identification of the average causal effect of formula_3 on formula_2, denoted ACE


title: Instrumental variables estimation

text: Balke and Pearl [1997] derived tight bounds on ACE and showed that these can provide valuable information on the sign and size of ACE.


title: Instrumental variables estimation

text: In linear analysis, there is no test to falsify the assumption the formula_84 is instrumental relative to the pair formula_97. This is not the case when formula_3 is discrete. Pearl (2000) has shown that, for all formula_87 and formula_88, the following constraint, called "Instrumental Inequality" must hold whenever formula_84 satisfies the two equations above:


title: Instrumental variables estimation

text: The exposition above assumes that the causal effect of interest does not vary across observations, that is, that formula_4 is a constant. Generally, different subjects will respond in different ways to changes in the "treatment" "x". When this possibility is recognized, the average effect in the population of a change in "x" on "y" may differ from the effect in a given subpopulation. For example, the average effect of a job training program may substantially differ across the group of people who actually receive the training and the group which chooses not to receive training. For these reasons, IV methods invoke implicit assumptions on behavioral response, or more generally assumptions over the correlation between the response to treatment and propensity to receive treatment.


title: Instrumental variables estimation

text: The standard IV estimator can recover local average treatment effects (LATE) rather than average treatment effects (ATE). Imbens and Angrist (1994) demonstrate that the linear IV estimate can be interpreted under weak conditions as a weighted average of local average treatment effects, where the weights depend on the elasticity of the endogenous regressor to changes in the instrumental variables. Roughly, that means that the effect of a variable is only revealed for the subpopulations affected by the observed changes in the instruments, and that subpopulations which respond most to changes in the instruments will have the largest effects on the magnitude of the IV estimate.


title: Instrumental variables estimation

text: For example, if a researcher uses presence of a land-grant college as an instrument for college education in an earnings regression, she identifies the effect of college on earnings in the subpopulation which would obtain a college degree if a college is present but which would not obtain a degree if a college is not present. This empirical approach does not, without further assumptions, tell the researcher anything about the effect of college among people who would either always or never get a college degree regardless of whether a local college exists.


title: Instrumental variables estimation

text: As Bound, Jaeger, and Baker (1995) note, a problem is caused by the selection of "weak" instruments, instruments that are poor predictors of the endogenous question predictor in the first-stage equation. In this case, the prediction of the question predictor by the instrument will be poor and the predicted values will have very little variation. Consequently, they are unlikely to have much success in predicting the ultimate outcome when they are used to replace the question predictor in the second-stage equation.


title: Instrumental variables estimation

text: In the context of the smoking and health example discussed above, tobacco taxes are weak instruments for smoking if smoking status is largely unresponsive to changes in taxes. If higher taxes do not induce people to quit smoking (or not start smoking), then variation in tax rates tells us nothing about the effect of smoking on health. If taxes affect health through channels other than through their effect on smoking, then the instruments are invalid and the instrumental variables approach may yield misleading results. For example, places and times with relatively health-conscious populations may both implement high tobacco taxes and exhibit better health even holding smoking rates constant, so we would observe a correlation between health and tobacco taxes even if it were the case that smoking has no effect on health. In this case, we would be mistaken to infer a causal effect of smoking on health from the observed correlation between tobacco taxes and health.


title: Instrumental variables estimation

text: The strength of the instruments can be directly assessed because both the endogenous covariates and the instruments are observable. A common rule of thumb for models with one endogenous regressor is: the F-statistic against the null that the excluded instruments are irrelevant in the first-stage regression should be larger than 10.


title: Instrumental variables estimation

text: When the covariates are exogenous, the small-sample properties of the OLS estimator can be derived in a straightforward manner by calculating moments of the estimator conditional on "X". When some of the covariates are endogenous so that instrumental variables estimation is implemented, simple expressions for the moments of the estimator cannot be so obtained. Generally, instrumental variables estimators only have desirable asymptotic, not finite sample, properties, and inference is based on asymptotic approximations to the sampling distribution of the estimator. Even when the instruments are uncorrelated with the error in the equation of interest and when the instruments are not weak, the finite sample properties of the instrumental variables estimator may be poor. For example, exactly identified models produce finite sample estimators with no moments, so the estimator can be said to be neither biased nor unbiased, the nominal size of test statistics may be substantially distorted, and the estimates may commonly be far away from the true value of the parameter.


title: Instrumental variables estimation

text: The assumption that the instruments are not correlated with the error term in the equation of interest is not testable in exactly identified models. If the model is overidentified, there is information available which may be used to test this assumption. The most common test of these "overidentifying restrictions", called the Sargan–Hansen test, is based on the observation that the residuals should be uncorrelated with the set of exogenous variables if the instruments are truly exogenous. The Sargan–Hansen test statistic can be calculated as formula_104 (the number of observations multiplied by the coefficient of determination) from the OLS regression of the residuals onto the set of exogenous variables. This statistic will be asymptotically chi-squared with "m" − "k" degrees of freedom under the null that the error term is uncorrelated with the instruments.


title: Brake fluid

text: Brake fluid is a type of hydraulic fluid used in hydraulic brake and hydraulic clutch applications in automobiles, motorcycles, light trucks, and some bicycles. It is used to transfer force into pressure, and to amplify braking force. It works because liquids are not appreciably compressible.


title: Brake fluid

text: Most brake fluids used today are glycol-ether based, but mineral oil ("Citroën/Rolls-Royce liquide hydraulique minéral" (LHM)) and silicone-based (DOT 5) fluids are also available.


title: Brake fluid

text: Most Brake fluids are manufactured to meet standards set by international, national, or local organizations or government agencies.


title: Brake fluid

text: The International Standards Organisation has published its standard ISO 4925, defining classes 3, 4, and 5, as well as class 5.1, class 6 and class 7 reflecting progressively higher performance for brake fluids.


title: Brake fluid

text: The Society of Automotive Engineers SAE has published standards J1703, J1704, and J1705, reflecting progressively higher performance for brake fluids. These have counterparts in the international standard, ISO 4925.


title: Brake fluid

text: The Federal Motor Vehicle Safety Standards (FMVSS) under FMVSS Standard No. 116 defines grades DOT 3, DOT 4, DOT 5 and DOT 5.1, where DOT refers to the U.S. Department of Transportation. These are widely used in other countries. Their classifications broadly reflect the SAE's specifications, DOT 3 is equivalent to SAE J1703 and ISO class 3, DOT 4 to SAE J1704 and ISO class 4, etc.


title: Brake fluid

text: All DOT compliant fluids must be colorless or amber, except for DOT 5 silicone, which must be purple. FMVSS Standard No. 116's scope is limited to fluid 'for use'. Brake fluid 'in use', or not labeled DOT compliant, is found any color.


title: Brake fluid

text: While a vehicle that uses DOT 3 may also use DOT 4 or 5.1 (a temperature upgrade) if the elastomers in the system accept the borate compounds that raise the boiling point, a vehicle that requires DOT 4 might boil the brake fluid if a DOT 3 (a temperature downgrade) is used. Additionally, these polyglycol-ether-based fluids cannot be mixed with DOT 5.0, which is silicone based.


title: Brake fluid

text: DOT 5 is a silicone-based fluid and is separate from the series of DOT 2, 3, 4, 5.1. It is immiscible with water, and with other brake fluids, and must not be mixed with them. Systems can change fluid only after a complete system changeover, such as a total restoration.


title: Brake fluid

text: It contains at least 70% by weight of a diorgano polysiloxane. Unlike polyethylene glycol based fluids, DOT 5 is hydrophobic. An advantage over other forms of brake fluid is that silicone has a more stable viscosity index over a wider temperature range. Another property is that it does not damage paint.


title: Brake fluid

text: DOT 5 brake fluid is not compatible with anti-lock braking systems. DOT 5 fluid can aerate when the anti-lock brake system is activated. DOT 5 brake fluid absorbs a small amount of air requiring care when bleeding the system of air.


title: Brake fluid

text: Lack of acceptance of silicone-based fluids led to the development of DOT 5.1, a fluid giving the performance advantages of silicone, whilst retaining some familiarity and compatibility with the glycol ether fluids. DOT 5.1 is the non-silicone version of DOT 5, defined by FMVSS 116 as being less than 70% silicone. Above that threshold makes it DOT 5.


title: Brake fluid

text: In the 1950s, Citroën introduced a hydropneumatic suspension system, powered by an engine-driven pump and also used to operate the braking system. This used a Citroën-specific hydraulic fluid. The first fluids were of variable chemistry, and available from various suppliers. Shell Donax D, Lockheed HD19, Castrol HF were some of them. Citroën then attempted to improve and standardise the fluid in 1962 with LHS (), a vegetable/synthetic based fluid. In 1964 this was improved with the fully synthetic LHS2. In 1966 Citroën introduced LHM (), a mineral fluid. LHS was hygroscopic and gave problems with internal corrosion. Although the two fluids are incompatible, LHM has been universal since 1967, and some older cars have been converted to use it.


title: Brake fluid

text: Hydragas and Hydrolastic suspension were a widely used form of hydropneumatic suspension, designed by Alex Moulton, and used on British Leyland cars from the 1960s. This system was not engine-driven and did not involve the braking system.


title: Brake fluid

text: Brake fluids must have certain characteristics and meet certain quality standards for the braking system to work properly.


title: Brake fluid

text: For reliable, consistent brake system operation, brake fluid must maintain a constant viscosity under a wide range of temperatures, including extreme cold. This is especially important in systems with an anti-lock braking system (ABS), traction control, and stability control (ESP), as these systems often use micro-valves and require very rapid activation. DOT 5.1 fluids are specified with low viscosity over a wide range of temperatures, although not all cars fitted with ABS or ESP specify DOT 5.1 brake fluid.


title: Brake fluid

text: For a faster reaction of the ABS and ESP systems, DOT 4 and DOT 5.1 brake fluids exist with low viscosity meeting the maximum 750 /s viscosity at -40 °C°F requirement of ISO 4925 class 6. These are often named DOT 4+ or Super DOT 4 and DOT 5.1 ESP.


title: Brake fluid

text: Brake fluid is subjected to very high temperatures, especially in the wheel cylinders of drum brakes and disk brake calipers. It must have a high boiling point to avoid vaporizing in the lines. This vaporization creates a problem because vapor is highly compressible relative to liquid, and therefore negates the hydraulic transfer of braking force - so the brakes will fail to stop the vehicle.


title: Brake fluid

text: Quality standards refer to a brake fluid's "dry" and "wet" boiling points. The wet boiling point, which is usually much lower (although above most normal service temperatures), refers to the fluid's boiling point after absorbing a certain amount of moisture. This is several (single digit) percent, varying from formulation to formulation. Glycol-ether (DOT 3, 4, and 5.1) brake fluids are hygroscopic (water absorbing), which means they absorb moisture from the atmosphere under normal humidity levels. Non-hygroscopic fluids (e.g. silicone/DOT 5 and mineral oil based formulations), are hydrophobic, and can maintain an acceptable boiling point over the fluid's service life.


title: Brake fluid

text: Silicone based fluid is more compressible than glycol based fluid, leading to brakes with a "spongy" feeling. It can potentially suffer phase separation/water pooling and freezing/boiling in the system over time - the main reason single phase hygroscopic fluids are used.


title: Brake fluid

text: Brake fluids must not corrode the metals used inside components such as calipers, wheel cylinders, master cylinders and ABS control valves. They must also protect against corrosion as moisture enters the system. Additives (corrosion inhibitors) are added to the base fluid to accomplish this. Silicone is less corrosive to paintwork unlike glycol-ether based DOT fluids.


title: Brake fluid

text: The advantage of the Citroën LHM mineral oil based brake fluid is the absence of corrosion. Seals may wear out at high mileages but otherwise these systems have exceptional longevity. It cannot be used as a substitute without changing seals due to incompatibility with the rubber.


title: Brake fluid

text: Brake fluids must maintain a low level of compressibility, even with varying temperatures to accommodate different environmental conditions. This is important to ensure consistent brake pedal feel. As compressibility increases, more brake pedal travel is necessary for the same amount of brake caliper piston force.


title: Brake fluid

text: Glycol-ether (DOT 3, 4, and 5.1) brake fluids are hygroscopic (water absorbing), which means they absorb moisture from the atmosphere under normal humidity levels. Non-hygroscopic fluids (e.g. silicone/DOT 5 and mineral oil based formulations), are hydrophobic, and can maintain an acceptable boiling point over the fluid's service life. Ideally, silicone fluid should be used only to fill non-ABS systems that have not been previously filled with glycol based fluid. Any system that has used glycol-based fluid (DOT 3/4/5.1) will contain moisture; glycol fluid disperses the moisture throughout the system and contains corrosion inhibitors. Silicone fluid does not allow moisture to enter the system, but does not disperse any that is already there, either. A system filled from dry with silicone fluid does not require the fluid to be changed at intervals, only when the system has been disturbed for a component repair or renewal. The United States armed forces have standardised on silicone brake fluid since the 1990s. Silicone fluid is used extensively in cold climates, particularly in Russia and Finland.


title: Brake fluid

text: Brake fluids with different DOT ratings can not always be mixed. DOT 5 should not be mixed with any of the others as mixing of glycol with silicone fluid may cause corrosion because of trapped moisture. DOT 2 should not be mixed with any of the others. DOT 3, DOT 4, and DOT 5.1 are all based on glycol esters and can be mixed, although it is preferable to completely replace existing fluids with fresh to obtain the specified performance.


title: The Story of Minglan

text: The Story of Minglan () is a 2018 Chinese television series adapted from an eponymous novel written under the pseudonym "Guanxin Zeluan". It stars Zhao Liying, Feng Shaofeng and Zhu Yilong. The series premiered on December 25, 2018, on Hunan TV.


title: The Story of Minglan

text: Set in the Northern Song dynasty, the story revolves around Sheng Minglan, the unfavored sixth daughter of an official. After being mistreated by her legal mother and bullied by her half-sisters, Minglan learns to hide her skills and true intentions. She meets Gu Tingye as a child, although she initially has feelings for Qi Heng, the only son of the Duke of Qi. Eventually, Gu Tingye and Minglan fall in love with each other after experiencing many personal trials and tribulations. After Gu Tingye becomes a powerful official, he successfully makes Minglan his wife. As his wife, Minglan helps guard against his unpleasant relatives, purges the court of corrupt ministers and ultimately succeeds in avenging her biological mother's death. The couple eventually earned their happily-ever-after, and Minglan rose to prominence as an influential figure of the Sheng family.


title: The Story of Minglan

text: Sheng Hong, a fifth rank official, is head of the Sheng household, and he has one official wife, two concubines, and six children. His official wife is Wang Ruofu, a bad tempered but kind lady who is always at odds with Sheng Hong's favorite concubine, Lin Qinshuang. Lin Qinshuang, a former servant, pretends to act weak and sympathetic, gaining the pity and attention of Sheng Hong, to Wang Ruofu's dismay. Sheng Hong also has a step mother, Old Mrs. Sheng, who is the only daughter of the Marquis of Yongyi and is respected by her fellow nobles. However, her relationship with Sheng Hong is strained because she dislikes how Sheng Hong isn't able to control Lin Qinshuang's tactics.


title: The Story of Minglan

text: Sheng Minglan is the sixth daughter of Sheng Hong and was born to his second concubine, Wei Shuyi. Although she is bright and intelligent, she hid her talents after witnessing her pregnant mother die as a result of Minglan standing up for her. She was raised by Old Mrs. Sheng, who dotes and loves her dearly. She has five other siblings, Hualan, Changbai, Changfeng, Molan, and Rulan. Hualan, Changbai, and Rulan are the children of Wang Ruofu and Changfeng and Molan are the children of Lin Qinshuang, and the children inherited their mother's personalities and dislikes. Hualan is the respected eldest daughter but is domineered by her mother in law. Changbai is a wise scholar and is Gu Tingye's close friend. Changfeng is carefree and wants a higher social standing. Rulan is short tempered but easy-going while Molan is scheming and wants to improve her social status through marriage. The children study and grow up together along with Qi Heng, Gu Tingye, and Yu Yanran.


title: The Story of Minglan

text: Meanwhile, Molan is desperate to marry into a rich household to suppress her feelings of inferiority as the daughter of a concubine. Lin Qinshuang helps her daughter, and Molan flirts with Liang Han, the son of the Count of Yongchang. Liang Han's mother, Lady Wu, prefers Minglan as a daughter in law and despises Molan. Molan eventually uses an underhanded method to marry into the Liang household, to the shame of her father, her siblings, and her grandmother. As a result, Lin Qinshuang is beaten and reveals that she didn't have feelings for Sheng Hong. She is sent away, and Minglan reveals to Lin Qinshuang that Molan's marriage was revenge for Wei Shuyi's death. Molan eventually suffers in her marriage as Liang Han has a lot of concubines, especially favoring his maid Chun Ke. Rulan is simple and only wishes to find true happiness. She shares the characteristics of her mother and despises Molan and Lin Qinshuang. She has an amiable relationship with Minglan. Her mother Wang Ruofu wants her to marry into a noble family to compete with Lin Qinshuang. Rulan instead falls in love with her father's student, who also happens to be Molan's fiancee until the Liang Han incident. She eventually marries the scholar, who also loves her back and treats her well.


title: The Story of Minglan

text: On the other hand, Qi Heng develops feelings for Minglan. Qi Heng is the only son of the Duke of Qi and the Princess of Pingning. He is well respected coming from an affluent family, and is considered a suitable husband by many households. Molan and the Princess of Jiacheng are interested in marrying him, but he only likes Minglan. She also develops feelings for him, but Qi Heng never understands her feelings through his idealized view of her. Qi Heng is eventually forced to marry the Princess of Jiacheng. However, their marriage doesn't last long because of a rebellion against the Emperor. His wife and her family is executed, and his mother the Princess of Pingning witnesses the tragedy and becomes mentally ill. Gu Tingye is rewarded for saving the Emperor, and he returns to the Gu Household with honors. He is the son of the Marquis of Ningyuan, but he has a poor relationship with his father and his stepmother Lady Qin despises him. His father was forced by his family to marry his mother Lady Bai for her wealth, and Lady Bai died of grief after finding out the truth. Gu Tingye also has a horrible reputation, fathering two children with his mistress Zhu Manniang. Zhu Manniang eventually leaves him when she believes he's of no worth, and Gu Tingye also has to deal with the constant scheming of Lady Qin. Lady Qin wants her son Tingwei to be the next Marquis, although Tingwei clearly objects.


title: The Story of Minglan

text: Gu Tingye proposes to Sheng Minglan after being impressed by her, and although she refuses at first, she agrees after realizing he's changed his old habits. Minglan becomes the lady of the Gu household, and she has to deal with the schemes of Lady Qin, Gu relatives, Wang Ruoyu (Wang Ruofu's older sister and lady of the Kang household), Zhu Manniang, and the imperial household (Emperor, Empress Dowager, Consorts). She strengthens her relationship with her siblings, father, and stepmother Wang Ruofu, and helps other nobles find success in their respective families. She helps Gu Tingye win back the trust of the emperor and they gradually realize their feelings and trust for each other.


title: The Story of Minglan

text: In the novel, the protagonist is a 21st century woman who died and whose consciousness entered the body of a fever-ridden, five year old Minglan. She uses almost none of her knowledge from the 21st century though and strives to not stand out, so the actual events which take place aren't really affected.


title: The Story of Minglan

text: Rulan is haughty and arrogant. Once she grows up, she has a reasonably amicable relationship with Minglan, but only because Minglan goes out of her way to be accommodating. Minglan does not actually like Rulan's company all that much.


title: The Story of Minglan

text: Minglan's father is vacillating when it comes to settling the competition between his wife and his favorite concubine, but he is reasonable and fair towards his children. Minglan's premarital life is mostly peaceful and she does not suffer much bullying.


title: The Story of Minglan

text: There is no love triangle with Qi Heng. He did want to marry Minglan but he tells almost no-one, and ends up marrying a princess at the urging of his family. Neither Minglan nor the public knew of his intentions, and the matter is almost never brought up again, after Minglan is betrothed to her childhood acquaintance, and then married to Tingye.


title: The Story of Minglan

text: Gu Tingye initially sought to marry Minglan's friend, but Minglan interfered with this matter and Gu Tingye eventually married Minglan's friend's sister who was born from a concubine. At that time, he was already in a relationship with, and had children with, Zhu Manniang. Minglan warns Gu Tingye that Manniang is a power hungry gold digger putting on an act, points out some flaws in her reasoning, and predicts a series of events which all come true. Following the death of Minglan's friend's sister, Gu Tingye performs an investigation and eventually decides to expel Manniang. She and her children are sent away and never heard from again.


title: The Story of Minglan

text: Gu Tingye uses a scheme to marry Minglan and is the mastermind behind that series of events. He fell for Minglan after numerous interactions with her and slightly seeing through her facade of being an ordinary, obedient girl. However, he doesn't ask her parents for her hand in marriage because he knows Old Madam Sheng will definitely object, as she wants Minglan to have a happy marriage and does not care if Minglan's marital family lacks high power and status. Instead, he proposes a marriage to the Sheng house after finding out Rulan was in love with a scholar. Since he was of extremely high status, Minglan's family readily agrees to marry "One of the Sheng daughters" to him. He then makes a show of discovering Rulan's relationship with the scholar, making Minglan the only "Sheng daughter" who can be married to him. Even then, he still has to meet with Minglan in private to convince her to convince her grandma to allow the marriage to go ahead instead of defaulting on the agreement. Minglan does not believe she will be as happy married to Tingye as she will be if married to her original intended partner, but she believes it will be tolerable and makes the sacrifice for the sake of her family.


title: The Story of Minglan

text: Gu Tingye keeps his word and basically gives Minglan a free pass to break all social norms and be as rude as she likes to Gu Tingye's relatives and to be as tyrannical as she wants to her servants. Minglan, however, chooses to maintain the image of an virtuous, traditional wife who manages things using the proper methods.


title: The Story of Minglan

text: Minglan's opponents in the novel are not nearly as violent or confrontational in general. Many of them are leeches trying to obtain benefits from Minglan, either directly or through her proximity to Gu Tingye, and Minglan carefully thwarts their attempts while maintaining social etiquette and decorum. Very few directly attack Minglan's reputation directly, and none of them attempt to use means like murder and such.


title: The Story of Minglan

text: The series is produced by Hou Hong Liang and Daylight Entertainment, who has produced several hit television series like "Nirvana in Fire" and "Ode to Joy". It is directed by Zhang Kaizhou of "Love Me If You Dare" and "Ode to Joy 2". The screenplay of the series is written by Zeng Lu and Wu Tong, who were both co-writers of "Battle of Changsha".


title: The Story of Minglan

text: Pre-production started in April 2017. On May 8, 2017, Zhao Liying was announced to play the leading role of Sheng Minglan. Feng Shaofeng was unveiled as the male lead on June 20, 2017. The rest of the supporting cast was announced in August 2017. Filming began in September 2017 at Hengdian World Studios. The series wrapped up filming in April 2018.


title: The Story of Minglan

text: The show has an 8.1 out of 10 on Douban and received mainly positive reviews. It has become a major trending topic on social media, with related hashtags being viewed hundreds of millions of times. Many netizens have praised the television series for revealing problems and contradictions in real life, such as traditional Chinese families' preference for boys over girls (), NEET (), and generational conflicts when it comes to providing care for the elderly ().


title: Firecracker

text: A firecracker (cracker, noise maker, banger) is a small explosive device primarily designed to produce a large amount of noise, especially in the form of a loud bang, usually for celebration or entertainment; any visual effect is incidental to this goal. They have fuses, and are wrapped in a heavy paper casing to contain the explosive compound. Firecrackers, along with fireworks, originated in China.


title: Firecracker

text: The predecessor of the firecracker was a type of heated bamboo, used as early as 200 BCE, that exploded when heated continuously. The Chinese name for firecrackers, 爆竹("baozhu"), literally means "exploding bamboo." After the invention of gunpowder, gunpowder firecrackers had a shape that resembled bamboo and produced a similar sound, so the name "exploding bamboo" was retained. In traditional Chinese culture, firecrackers were used to scare off enemies or evil spirits.


title: Firecracker

text: Firecrackers are generally made of cardboard or plastic, with flash powder, cordite, smokeless powder, or black powder as the propellant. This is not always the case, however. Anything from match heads to kerosene and lighter fluid has been used successfully in making firecrackers.The key to loud firecrackers, however, although in part lying in the propellant substance, is pressure. The entire firecracker must be very tightly packed in order for it to work best. Flash powder, however, does not need to be packed tightly, and should not be.


title: Firecracker

text: James Dyer Ball, in his book "Things Chinese," has a detailed description about the process and material used for making firecrackers at the end of the 19th century. At that time, firecrackers were made by women and children workers, using straw paper to make the body of the firecracker, while the fuse was made of paper imported from Japan made from the inner lining of the bamboo plant, or rice paper, stiffened with buckwheat paste. The bamboo paper was cut into strips of long and wide, laid on a table; a string of gunpowder was placed at the center with a hollow tube, then twisted up to make a piece of fuse. The firecracker tubes were made from pieces of straw paper wrapped around iron rods of various diameters and then tightened with a special tool. 200 to 300 firecrackers were tied up in a bunch, then red clay was spread at the bottom of the bunch and forced into each end of the firecracker with a punch; gunpowder was poured in, then the other end was sealed with an awl by turning the tube inward, and a fuse inserted.


title: Firecracker

text: After India's National Green Tribunal (NGT) enacted a ban on the sale and use of crackers on Diwali festival in 2020, the Council for Scientific and Industrial Research (CSIR) developed green crackers made from cleaner raw materials which reduce emissions by suppressing the production of dust; their emissions are 30% lower but are also are of reduced loudness at 110-125 decibels instead of the more than 160 decibels of traditional firecrackers. However, green crackers still contain harmful pollutants such as aluminium, barium, potassium nitrate and carbon.


title: Firecracker

text: Early (pre-1920s) Chinese firecrackers (also known as "Mandarin firecrackers") were typically long, and approximately in diameter, and were charged with black powder. Mandarin crackers produced a less loud, duller thud compared to modern flash-light crackers (which utilize a different explosive known as flash powder). Mandarin crackers produced a dimmer, less brilliant flash when they exploded also. Individual Mandarin crackers were most often braided into "strings" of varying lengths, which, when ignited, exploded in rapid sequence. Generally, the strings (sometimes containing as many as several thousand crackers) would be hung from an overhead line before ignition. Most Mandarin crackers were colored all red and did not generally have designs or logos decorating their exterior surface (or "shell wraps"). Occasionally a few yellow and green colored Mandarin crackers were created and would be braided into the predominantly all-red strings to symbolize the emperor and the ruling class, while the numerous red crackers symbolized the common man.


title: Firecracker

text: Once flash powder, which produces a significantly sharper and brighter bang, replaced black powder as a firecracker's explosive charge (circa 1924), manufacturers began competing to gain loyalty of typical consumers (that is, mainly boys 8 to 16 years old). Thousands of brands were created during the flash-light cracker's heyday from the 1920s through the early 1970s. Only a small percentage of brands lasted more than a year or two. Collectors now seek the various labels from the era.


title: Firecracker

text: Until the mid-1980s, firecracker production was low-tech. They were handmade, beginning with rolling tubes. Once the firecracker tubes were rolled by hand (commonly from newspaper) and labelled, and then filled with powder, their ends were crimped and fuses inserted, all by hand. These finished firecrackers were usually braided into "strings" and sold in packs which came in many sizes, from the very small ("penny packs" containing as few as four to six firecrackers) to the most common size packs (containing 16 and 20 crackers per pack), to larger packs (containing 24, 30, 32, 40, 50, 60, 72, 90, 100, and 120 firecrackers), to huge "belts" and "rolls" (packages containing strings of several hundred to several thousand crackers—Phantom Fireworks sells rolls as large as 16,000 firecrackers). Firecracker packages were wrapped in colourful and translucent glassine paper, as well as clear cellophane, with glassine the most popular.


title: Firecracker

text: The final operation involved applying a branded label on each pack, then bundling finished packs into wholesale lots called "bricks" which contained an average of 80 packs each (varying according to the size of the packs being bundled; for example, packs of 32 crackers might have 40 packs per brick, compared to packs of 16 or 20 with 80 packs per brick).


title: Firecracker

text: Firecrackers, as well as other types of explosives, are subject to various laws in many countries, although firecrackers themselves are not usually considered illegal contraband material. It is usually the manufacture, sale, storage, and use of firecrackers that are subject to laws including safety requirements for manufacture, the requirement of a permit to sell or store, or restrictions on the use of firecrackers.


title: Firecracker

text: Firecrackers are commonly used in celebration of holidays or festivals, such as Halloween, Independence Day (also known as the Fourth of July) in the United States, Diwali in India, Eid al-Fitr in Southeast Asia, Tihar in Nepal, Day of Ashura in Morocco, Guy Fawkes Night or Bonfire Night in the United Kingdom, Halloween in Ireland, Bastille Day in France, Spanish Fallas, in almost every cultural festival of Sri Lanka (e.g. Sri Lankan New Year), New Year's Eve and New Year's Day, and in the celebration of Chinese New Year by Chinese communities around the world.


title: Firecracker

text: The use of firecrackers, although a traditional part of the celebration, has over the years led to many injuries and deaths. There have been incidents every year of users being blinded, losing body parts, or suffering other injuries, especially during festivities that customarily involve firecrackers such as Chinese New Year season. Hence, many governments and authorities have enacted laws completely banning the sale or use of firecrackers, or banning the use of firecrackers in the street, primarily because of safety or environmental reasons.


title: Firecracker

text: These rules also require a permit from the local government, as well as any relevant local bodies such as maritime or aviation authorities (as relevant to the types of fireworks being used) and hospitals, schools, etc., within a certain range.


title: Firecracker

text: In most states and territories, firecrackers are illegal without a permit and part of a display by a licensed pyrotechnician. Tasmania, ACT and Northern Territory allow consumer use with a permit (dependent on calendar date). Northern Territory is the only part of Australia where a consumer does not require a permit, but this only applies on 1 July for Territory Day.


title: Firecracker

text: Firecrackers are not authorized under the Explosives Act, thus making importation, possession, transportation, storage, or manufacturing illegal in Canada. Canada banned firecrackers on 27 September 1972, after two children were killed and three others severely burned when some older children threw some firecrackers inside their tent. While it is rumoured that the children inside the tent had been smoking, this is unsubstantiated and makes no sense considering the firework ban by authorities. Fireworks are still legal to buy for anyone 18 years of age or over.


title: Firecracker

text: The use of firecrackers is regulated by the "Law on Explosive Substances and the Production and Trading of Weapons" (). According to the Law, firecrackers (including other pyrotechnic articles) are divided into three classes: "Class 1 Pyrotechnics" - pyrotechnic articles for fireworks which represent a very low risk, have negligible noise level and are intended for use in restricted areas, including fireworks intended for use within residential buildings; "Class 2 and 3 Pyrotechnics" - pyrotechnic articles for fireworks which represent low to medium risk, have medium to high noise level and are intended for outdoor use in restricted areas and large open areas. Class 1 Pyrotechnics can be sold all year round to people over the age of 14 in general stores and newsstands, while Class 2 and 3 Pyrotechnics can only be sold between 15 December and 1 January each year at gun shops and stores with special permits to the people over the age of 14 (class 2) or over the age of 18 (class 3). Use of Class 2 and 3 Pyrotechnics is allowed only in the period between 27 December and 1 January. Each year since 1993, between 15 December and 8 January, the police carries out the "Peace and good" action with the aim of prevention of people from getting hurt and violating public order. The penalties for unauthorized use of pyrotechnic articles range between 1,000 and 15,000 kunas (€135 - €2,035) for people, and between 10,000 and 80,000 kunas (€1,355 - €10,850) for companies. For a legal guardian of a child under the age of 14 who have used pyrotechnic articles, fine ranges between 1,000 and 3,000 kunas (€135 - €405).


title: Firecracker

text: As of 2008, most urban areas in mainland China permit firecrackers. In the first three days of the traditional New Year, it is a tradition that people compete with each other by playing with firecrackers. However, many urban areas banned them in the 1990s. For example, they were banned in Beijing's urban districts from 1993 to 2005. In 2004, 37 people were killed in a stampede when four million people gathered for a rumored Lantern Festival firework display in nearby Miyun. Since the ban was lifted, the firecracker barrage has been tremendous. An unusual feature is that many residents in major cities look down on street-level fireworks from their tower blocks. Bans are rare in rural areas.


title: Firecracker

text: Firecrackers are legal in the Czech Republic. They can have up to 5g of flash powder and can be bought by anyone older than 21 years. For stronger firecrackers (up to 100g) a permit is required.


title: Firecracker

text: Fireworks are classified. Some fireworks are restricted to adults (18 years), may be sold to private persons only on three days before New Year's Eve and may be used only on New Year's Eve or New Year (special permits can be obtained to use these on other days of the year). Other fireworks have no such restrictions, however, they are not recommended for children below 12 years and guidance by adults is advised. Certain fireworks are available only to professionals.


title: Firecracker

text: Firecrackers sold to consumers are restricted to 0.95 grams of black powder. The ban on larger firecrackers went into effect in 1996. Before, mid-size "kiinanpommi" or "kiinari" ("Chinese bomb") and "tykinlaukaus" and large "tykäri" ("artillery shot") had become cheap and common products that were often used by children after the celebration, leading to accidents.


title: Firecracker

text: Fireworks are banned for security reasons, as some speculate a connection between firework use and the 1967 Leftist Riot. However, the government stages a fireworks display in Victoria Harbour for New Year countdown and the second day of the Chinese New Year.


title: Firecracker

text: Firecrackers are banned in Hungary since 2005. However, they are legal in Slovakia and people smuggle them.


title: Firecracker

text: Firecrackers are easily available in India and are used to mark a celebratory event. They are legal, and anyone 18 and over can buy them without a licence.


title: Firecracker

text: Diwali fireworks are a family event in many parts of India. People light up fireworks near their homes and in streets. Additionally, cities and communities have community fireworks.


title: Firecracker

text: This custom may have begun on the Indian subcontinent after 1400 CE when gunpowder started being utilised in Indian warfare.


title: Firecracker

text: In October and November, farmers from Punjab and Haryana burn agricultural waste and the weather tends not to be windy, so Delhi's air pollution usually increases, which has been a major environmental problem since 2002. Firecrackers for the Diwali holiday can worsen this pollution. In October 2017, the Supreme Court banned firecrackers in Delhi, as a result of which the industry said it faced losses of Rs 1,000-crore and consequently layoffs.


title: Firecracker

text: After India's National Green Tribunal (NGT) ordered a ban in the NCR region on the sale and use of crackers in 2020, the Council for Scientific and Industrial Research (CSIR) developed "green crackers" that used less polluting raw materials. Several states in India have either banned firecrackers or limited the time, noise level and type (mandatory use of less polluting firecrackers) that can be used. Nonetheless, many firecrackers were used to celebrate the Diwali holiday in 2020, immediately after which Delhi's air pollution was over 9 times the level that the World Health Organization considers safe.


title: Firecracker

text: Aaratrika Bhaumik writing for the website "livelaw.in" mentions the ban put in place by the Calcutta High Court on firecrackers (green firecrackers included) throughout the state of West Bengal for the 2021 Diwali and Kali Puja festivities. The ban extends to all remaining festivals in the year, such as, Chhath Puja, Guru Nanak Jayanti, Christmas and New Year's.


title: Firecracker

text: Firecrackers and fireworks are generally forbidden in public during the Chinese New Year, especially in areas with significant non-Chinese populations, to avoid conflict between the two. However, there are some exceptions. The usage of firecrackers is legal in some metropolitan areas such as Jakarta and Medan, where the degree of racial and cultural tolerance is higher.


title: Firecracker

text: Fireworks and firecrackers are not permitted in the Republic of Ireland; however, many people smuggle them from Northern Ireland, where they are legal. They are most common around Halloween. Irish anti-firecracker laws are considered among the strictest in the world, equal to Chile's.


title: Firecracker

text: Private citizens are banned from using fireworks in the Minor Offences Act 1955 and Explosives Act 1957. However, many Malaysians smuggle them from Thailand and the Philippines. The ban on fireworks is poorly enforced. Many Malaysians set off fireworks during the festive season although it is illegal to do so.


title: Firecracker

text: The government only allows fireworks for public events, and some authorised events held by businesses and other groups with a permit.


title: Firecracker

text: Fireworks and firecrackers are widely available throughout the Philippines and both Republic Act 7183 and Executive Order 28 were enacted to regulate and to control the sale, distribution, manufacture and use of firecrackers for public safety. Under Republic Act 7183, there are certain firecrackers that are legal such as Judas' belt and the prohibition of a certain firecracker and pyrotechnic devices shall be determined by the Director-General of the Philippine National Police. Although, there are cities in the Philippines banning all kinds of firecrackers and those cities are Muntinlupa (since 2013), Olongapo (since 2008) and Davao City (since 2001). Injuries involving the use or ingestion of "Piccolo" sticks account for the majority of firecracker-related incidents in the country. However, in December 2020, firecrackers were banned in some areas of Metro Manila to prevent injuries and avoid mass gatherings in the region due to the COVID-19 pandemic. For example, Mayor Joy Belmonte of Quezon City said that fireworks and firecracker use is strictly prohibited in basketball courts, streets and public spaces, and can only be used in designated firecracker zones. Some provinces and municipalities outside of Metro Manila also imposed a firecracker ban to make sure that minimum health protocols will be observed during the new year celebration.


title: Firecracker

text: A partial ban on firecrackers was imposed in March 1970 after a fire killed six people and injured 68. This was extended to a total ban in August 1972, after an explosion that killed two people. and an attack on two police officers attempting to stop a group from letting off firecrackers in February 1972. However, in 2003, the government allowed firecrackers to be set off during the festive season. At the Chinese New Year light-up in Chinatown, at the stroke of midnight on the first day of the Lunar New Year, firecrackers are set off under controlled conditions by the Singapore Tourism Board. Other occasions where firecrackers are allowed to be set off are determined by the tourism board or other government organizations. However, their sale is not allowed.


title: Firecracker

text: Only rocket-type fireworks are allowed in Sweden. The ban of firecrackers was effectuated by the EU Parliament and Swedish government effective 1 December 2001, but in 2006 the EU Parliament changed the laws, allowing smaller types of firecrackers. By 2008, the law had to be in effect in all EU member countries, including Sweden.


title: Firecracker

text: Firecrackers have been banned in urban areas of Taiwan since 2008, but are still allowed in rural areas.


title: Firecracker

text: In 2007, New York City lifted its decade-old ban on firecrackers, allowing a display of 300,000 firecrackers to be set off in Chinatown's Chatham Square. Under the supervision of the fire and police departments, Los Angeles regularly lights firecrackers every New Year's Eve, mostly at temples and the shrines of benevolent associations. The San Francisco Chinese New Year Parade, the largest outside China, is accompanied by numerous firecrackers, both officially sanctioned and illicit.


title: Firecracker

text: In 1994, the Government of Vietnam decided to ban firecrackers nationwide. Only fireworks displays produced and performed by the government are permitted.


title: Emmer

text: Emmer wheat or hulled wheat is a type of awned wheat. Emmer is a tetraploid (4"n" = 4"x" = 28 chromosomes). The domesticated types are "Triticum turgidum" subsp. "dicoccum" and "Triticum turgidum "conv." durum". The wild plant is called "Triticum turgidum" subsp. "dicoccoides". The principal difference between the wild and the domestic is that the ripened seed head of the wild plant shatters and scatters the seed onto the ground, while in the domesticated emmer the seed head remains intact, thus making it easier for humans to harvest the grain.


title: Emmer

text: Along with einkorn wheat, emmer was one of the first crops domesticated in the Near East. It was widely cultivated in the ancient world, but is now a relict crop in mountainous regions of Europe and Asia.


title: Emmer

text: Strong similarities in morphology and genetics show that wild emmer ("Triticum dicoccoides" ) is the wild ancestor and a crop wild relative of domesticated emmer. Because wild and domesticated emmer are interfertile with other tetraploid wheats, some taxonomists consider all tetraploid wheats to belong to one species, "T. turgidum". Under this scheme, the two forms are recognized at subspecies level, thus "T. turgidum" subsp. "dicoccoides" and "T. turgidum" subsp. "dicoccum". Either naming system is equally valid; the latter lays more emphasis on genetic similarities.


title: Emmer

text: Wild emmer grows wild in the Near East. It is a tetraploid wheat formed by the hybridization of two diploid wild grasses, "Triticum urartu", closely related to wild einkorn ("T. boeoticum"), and an as yet unidentified "Aegilops" species related to "A. searsii" or "A. speltoides".


title: Emmer

text: Botanists Körnicke and Aaronsohn in the late 19th-century were the first to describe the wild emmer ("Triticum dicoccoides") native to Land of Israel and adjacent countries. Earlier, in 1864, the Austrian botanist Kotschy had collected specimens of the same wild emmer, without signifying where he had collected them.


title: Emmer

text: Although cultivated in ancient Egypt, its cultivation for human consumption in Israel in recent history is not known, perhaps owing to the difficulty with which the chaff is separated from the seed kernels, formerly requiring the spikes to be pounded with mortar and pestle.


title: Emmer

text: The wild emmer is distinguished from "Triticum vulgare", with its tougher ear rhachis and the beards releasing the grains easily, by their ear rhachis that are brittle when ripe and their firmly fitting beards. The wild emmer grows to a height of , and bears an elongated spike measuring , with long, protruding awns extending upwards.


title: Emmer

text: Like einkorn and spelt wheats, emmer is a hulled wheat, meaning it has strong glumes (husks) that enclose the grains, and a semibrittle rachis. On threshing, a hulled wheat spike breaks up into spikelets. These require milling or pounding to release the grains from the glumes.


title: Emmer

text: Wild emmer wheat spikelets effectively self-cultivate by propelling themselves mechanically into soils with their awns. During a period of increased humidity during the night, the awns of the spikelet become erect and draw together, and in the process push the grain into the soil. During the daytime, the humidity drops and the awns slacken back again; however, fine silica hairs on the awns act as hooks in the soil and prevent the spikelets from backing out. During the course of alternating stages of daytime drying and nighttime humidity, the awns' pumping movements, which resemble a swimming frog kick, will drill the spikelet or more into the soil.


title: Emmer

text: Wild emmer is native to the Fertile Crescent of the Middle East, growing in the grass and woodland of hill country from modern-day Israel to Iran. The origin of wild emmer has been suggested, without universal agreement among scholars, to be the Karaca Dağ mountain region of southeastern Turkey. In 1906, Aaron Aaronsohn's discovery of wild emmer wheat growing in Rosh Pinna (Israel) created a stir in the botanical world. Emmer wheat has been found in archaeological excavations and ancient tombs. Emmer was collected from the wild and eaten by hunter gatherers for thousands of years before its domestication. Grains of wild emmer discovered at Ohalo II had a radiocarbon dating of 17,000 BC and at the Pre-Pottery Neolithic A (PPNA) site of Netiv Hagdud are 10,000–9,400 years old.


title: Emmer

text: The location of the earliest site of emmer domestication is still unclear and under debate. Some of the earliest sites with possible indirect evidence for emmer domestication during the Early Pre-Pottery Neolithic B include Tell Aswad, Çayönü, Cafer Höyük, Aşıklı Höyük, and Shillourokambos. Definitive evidence for the full domestication of emmer wheat is not found until the Middle Pre-Pottery Neolithic B (10,200 to 9,500 BP), at sites such as Beidha, Tell Ghoraifé, Tell es-Sultan (Jericho), Abu Hureyra, Tell Halula, Tell Aswad and Cafer Höyük.


title: Emmer

text: Emmer is found in a large number of Neolithic sites scattered around the fertile crescent. From its earliest days of cultivation, emmer was a more prominent crop than its cereal contemporaries and competitors, einkorn wheat and barley. Small quantities of emmer are present during Period 1 at Mehrgharh on the Indian subcontinent, showing that emmer was already cultivated there by 7000–5000 BC.


title: Emmer

text: In the Near East, in southern Mesopotamia in particular, cultivation of emmer wheat began to decline in the Early Bronze Age, from about 3000 BC, and barley became the standard cereal crop. This has been related to increased salinization of irrigated alluvial soils, of which barley is more tolerant, although this study has been challenged. Emmer had a special place in ancient Egypt, where it was the main wheat cultivated in Pharaonic times, although cultivated einkorn wheat was grown in great abundance during the Third Dynasty, and large quantities of it were found preserved, along with cultivated emmer wheat and barleys, in the subterranean chambers beneath the Step Pyramid at Saqqara. Neighbouring countries also cultivated einkorn, durum and common wheat. In the absence of any obvious functional explanation, the greater prevalence of emmer wheat in the diet of ancient Egypt may simply reflect a marked culinary or cultural preference, or may reflect growing conditions having changed after the Third Dynasty. Emmer and barley were the primary ingredients in ancient Egyptian bread and beer. Emmer recovered from the Phoenician settlement at Volubilis (in present-day Morocco) has been dated to the middle of the first millennium BC.


title: Emmer

text: Emmer wheat may be one of the five species of grain which have a special status in Judaism. One of these species, referred to as (Aramaic) or (), may be either emmer or spelt (emmer and spelt are easily confused with each other). However, it is fairly certain that spelt did not grow in ancient Israel, and emmer was probably a significant crop until the end of the Iron Age. References to emmer in Greek and Latin texts are traditionally translated as "spelt", even though spelt was not common in the Classical world until very late in its history.


title: Emmer

text: In northeastern Europe, emmer (in addition to einkorn and barley) was one of the most important cereal species and this importance can be seen to increase from 3400 BC onward. Pliny the Elder notes that although emmer was called in his time formerly it was called (or 'glory'), providing an etymology explaining that emmer had been held in glory ("N.H." 18.3), and later in the same book he describes its role in sacrifices.


title: Emmer

text: Today emmer is primarily a relict crop in mountainous areas. Its value lies in its ability to give good yields on poor soils, and its resistance to fungal diseases such as stem rust that are prevalent in wet areas. Emmer is grown in Armenia, Morocco, Spain (Asturias), the Carpathian mountains on the border of Czechia and Slovakia, Albania, Turkey, Switzerland, Germany, Greece and Italy. It is also grown in the U.S. as a specialty product. A traditional food plant in Ethiopia, this relatively little-known grain has potential to improve nutrition, boost food security, foster rural development and support sustainable landcare.


title: Emmer

text: In Italy, uniquely, emmer cultivation is well established and even expanding. In the mountainous Garfagnana area of Tuscany emmer (known as farro) is grown by farmers as an IGP (Indicazione Geografica Protetta) product, with its geographic identity protected by law. Production is certified by a co-operative body, the Consorzio Produttori Farro della Garfagnana. IGP-certified farro is widely available in health food shops across Europe, and even in some British supermarkets. The demand for Italian farro has led to competition from non-certified farro, grown in lowland areas and often consisting of a different wheat species, spelt ("Triticum spelta").


title: Emmer

text: Emmer's main use is as a human food, though it is also used for animal feed. Ethnographic evidence from Turkey and other emmer-growing areas suggests that emmer makes good bread (judged by the taste and texture standards of traditional bread), and this is supported by evidence of its widespread consumption as bread in ancient Egypt. Emmer bread is available in Switzerland and the Netherlands. The largest Dutch supermarket chain in the Netherlands, Albert Heijn, sells emmer bread as part of their luxury bread line.


title: Emmer

text: In Armenian cuisine, emmer pilaf is cooked in sunflower oil. The pre-cooked emmer is fried in oil and then the sautéed onions are added. In the second version, boiled water and emmer are added to the sautéed onion and then cooked until tender.


title: Emmer

text: In Armenia, emmer porridge with lamb called "kashovi" is widespread in the Shirak region, while lean kashovi is known in all regions of Armenia. Chopped lamb is added to cold water then boiled for 10 minutes, emmer and sautéed onion are added and cooked over a low heat until tender.


title: Emmer

text: In Italy, whole emmer grains can be easily found in most supermarkets and groceries, emmer bread ("pane di farro") can be found in bakeries in some areas, while in Tuscany emmer has traditionally been consumed as whole grains in soup. Emmer has also been used in beer production.


title: Emmer

text: In parts of India, emmer wheat (in Maharashtra called खपली गहू, transcription "khapalī gahū", meaning "crusty wheat") is grown as a drought- and stress-resistant wheat variety with some work ongoing to improve yields, as a result of increased interest in this variety due to possible value for diabetics.


title: Emmer

text: As with all varieties and hybrids of wheat, emmer is unsuitable for people with gluten-related disorders, such as celiac disease, non-celiac gluten sensitivity and wheat allergy sufferers, among others.


title: Root directory

text: In a computer file system, and primarily used in the Unix and Unix-like operating systems, the root directory is the first or top-most directory in a hierarchy. It can be likened to the trunk of a tree, as the starting point where all branches originate from. The root file system is the file system contained on the same disk partition on which the root directory is located; it is the filesystem on top of which all other file systems are mounted as the system boots up.


title: Root directory

text: Unix abstracts the nature of this tree hierarchy entirely and in Unix and Unix-like systems the root directory is denoted by the codice_1 (slash) sign. Though the root directory is conventionally referred to as codice_1, the directory entry itself has no name its path is the "empty" part before the initial directory separator character (codice_1). All file system entries, including mounted file systems are "branches" of this root.


title: Root directory

text: In UNIX-like operating systems, each process has its own idea of what the root directory is. For most processes this is the same as the system's actual root directory, but it can be changed by calling the system call. This is typically done to create a secluded environment to run software that requires legacy libraries and sometimes to simplify software installation and debugging. Chroot is not meant to be used for enhanced security as the processes inside can break out.


title: Root directory

text: Some Unix systems support a directory below the root directory. Normally, "/.." points back to the same inode as "/", however, under , this can be changed to point to a super-root directory, where remote trees can be mounted. If, for example, two workstations "pcs2a" and "pcs2b" were connected via "connectnodes" and "uunite" startup script, "/../pcs2b" could be used to access the root directory of "pcs2b" from "pcs2a".


title: Root directory

text: On many Unixes, there is also a directory named (pronounced "slash root"). This is the home directory of the 'root' superuser. On many Macintosh and iOS systems this superuser home directory is .


title: Boystown (website)

text: As of May 2021, the website was considered the largest international darknet platform to host child pornography. The website had 400,000 registered users. The website was found to have what prosecutors considered some of the most severe sexual abuse images of toddlers.


title: Boystown (website)

text: The website featured various forums and chats for communication. The illegal images and videos were posted on the forums and the chats where members were able to communicate with one another. There were two chat services provided, one called "Lolipub" and the other was known as "BOYSPUB". The child abuse materials exchanged between users were of young children and toddlers, most of which were boys, from around the world. The child pornographic content had various categories including "Art", "hardcore", "kindergarten", and "toddler".


title: Boystown (website)

text: The website was investigated by a German police task force with cooperation from Europol and international law enforcement agencies. The platforms administrators and users were under investigation for months.


title: Boystown (website)

text: There were three primary suspects that were discovered and identified during the investigation: a 40-year-old man from Paderborn, a 49-year-old man from Munich and a 58-year-old man from Northern Germany who was living in Paraguay. The suspects allegedly acted as administrators for the website and gave advice to its users on how to evade law enforcement while using the platform. Another suspect was a 64-year-old man from Hamburg who was accused of being one of the most active users uploading over 3,500 posts.


title: Backsword

text: A backsword is a type of sword characterised by having a single-edged blade and a hilt with a single-handed grip. It is so called because the triangular cross section gives a flat back edge opposite the cutting edge. Later examples often have a "false edge" on the back near the tip, which was in many cases sharpened to make an actual edge and facilitate thrusting attacks. From around the early 14th century, the backsword became the first type of European sword to be fitted with a knuckle guard.


title: Backsword

text: The term "backsword" can also refer to the singlestick, which is used to train for fighting with the backsword, or to the sport or art of fighting in this fashion. Backswording was an alternative term for singlesticking tournaments in England.


title: Backsword

text: Being easier and cheaper to make than double-edged swords, backswords became the favored sidearm of common infantry, including irregulars such as the Highland Scots, which in Scottish Gaelic were called the "claidheamh cuil" (back sword), after one of several terms for the distinct types of weapons they used. Backswords were often the secondary weapons of European cavalrymen beginning in the 17th century.


title: 4+1 architectural view model

text: 4+1 is a view model used for "describing the architecture of software-intensive systems, based on the use of multiple, concurrent views". The views are used to describe the system from the viewpoint of different stakeholders, such as end-users, developers, system engineers, and project managers. The four views of the model are logical, development, process and physical view. In addition, selected use cases or scenarios are used to illustrate the architecture serving as the 'plus one' view. Hence, the model contains 4+1 views:


title: 4+1 architectural view model

text: The 4+1 view model is generic and is not restricted to any notation, tool or design method. Quoting Kruchten,


title: Jersey barrier

text: A Jersey barrier, Jersey wall, or Jersey bump is a modular concrete or plastic barrier employed to separate lanes of traffic. It is designed to minimize vehicle damage in cases of incidental contact while still preventing vehicle crossovers resulting in a likely head-on collision. Jersey barriers are also used to reroute traffic and protect pedestrians and workers during highway construction. They are named after the U.S. state of New Jersey which first started using the barriers as separators between lanes of a highway in the 1950s.


title: Jersey barrier

text: The barriers are also known as a K-rail, a term stipulated in the California Department of Transportation specification for temporary concrete traffic barriers which first started using concrete median barriers in the mid-1940s.


title: Jersey barrier

text: Over time, different variants were created. Taller variants, such as the Ontario Tall Wall, proved more effective at stopping vehicles and had the added advantage of blocking most oncoming headlights. More modular variants, including plastic water-filled barriers, have been created.