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Q’anjob’al Language
Q'anjob'al (also Kanjobal) is a Mayan language spoken primarily in Guatemala and part of Mexico. According to 1998 estimates compiled by SIL International in Ethnologue, there were approximately 77,700 native speakers, primarily in the Huehuetenango Department of Guatemala. Municipalities where the Q'anjob'al language is spoken include San Juan Ixcoy (Yich K'ox), San Pedro Soloma (Tz'uluma' ), Santa Eulalia (Jolom Konob' ), Santa Cruz Barillas (Yalmotx), San Rafael La Independencia, and San Miguel Acatán (Pedro Mateo Pedro 2010). Q'anjob'al is taught in public schools through Guatemala's intercultural bilingual education programs.
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  • 06 Oct 2022
Topic Review
Global 200
The Global 200 is the list of ecoregions identified by WWF, the global conservation organization, as priorities for conservation. According to WWF, an ecoregion is defined as a "relatively large unit of land or water containing a characteristic set of natural communities that share a large majority of their species dynamics, and environmental conditions". So, for example, based on their levels of endemism, Madagascar gets multiple listings, ancient Lake Baikal gets one, and the North American Great Lakes get none. The WWF assigns a conservation status to each ecoregion in the Global 200: critical or endangered; vulnerable; and relatively stable or intact. Over half of the ecoregions in the Global 200 are rated endangered.
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  • 06 Oct 2022
Topic Review
Start School Later Movement
The movement to start school later consists of efforts by health care professionals, sleep scientists, educators, economists, legislators, parents, students, and other concerned citizens to restore a later start to the school day. Based on a growing body of evidence that starting middle and high schools too early in the morning is unhealthy, counterproductive, and incompatible with adolescent sleep needs and patterns. During the second half of the 20th century, many public schools in the United States began shifting instructional time earlier than the more conventional bell time, thought to be about 9 a.m. Today it is common for American schools to begin the instructional day in the 7 a.m. hour and end about seven hours later, around 2 p.m. Most sleep research suggests that morning classes should begin no earlier than 8:30 a.m. for middle and high school students. Advocates of a return to later school start times argue that sleep and school hours should be viewed as a public health issue, citing evidence linking early school start times to widespread sleep deprivation among teenagers as well as a wide array of acute and chronic physical, psychological, and educational problems. Not only do students consistently get significantly more sleep on school nights when their schools move to later start times, but later school hours have been consistently linked with improved school performance, reduced impulsiveness, and greater motivation, as well as with lower rates of depression, tardiness, truancy, and morning automobile accidents. Recent (2011) studies suggest that early school start times disproportionately hurt economically disadvantaged students and may even negatively impact future earning potential of students, offsetting any financial savings to the school system attributed to earlier hours.
  • 4.7K
  • 06 Oct 2022
Topic Review
Duality (Mathematics)
In mathematics, a duality translates concepts, theorems or mathematical structures into other concepts, theorems or structures, in a one-to-one fashion, often (but not always) by means of an involution operation: if the dual of A is B, then the dual of B is A. Such involutions sometimes have fixed points, so that the dual of A is A itself. For example, Desargues' theorem is self-dual in this sense under the standard duality in projective geometry. In mathematical contexts, duality has numerous meanings. It has been described as "a very pervasive and important concept in (modern) mathematics" and "an important general theme that has manifestations in almost every area of mathematics". Many mathematical dualities between objects of two types correspond to pairings, bilinear functions from an object of one type and another object of the second type to some family of scalars. For instance, linear algebra duality corresponds in this way to bilinear maps from pairs of vector spaces to scalars, the duality between distributions and the associated test functions corresponds to the pairing in which one integrates a distribution against a test function, and Poincaré duality corresponds similarly to intersection number, viewed as a pairing between submanifolds of a given manifold. From a category theory viewpoint, duality can also be seen as a functor, at least in the realm of vector spaces. This functor assigns to each space its dual space, and the pullback construction assigns to each arrow f: V → W its dual f∗: W∗ → V∗.
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  • 06 Oct 2022
Topic Review
Clustal
Clustal is a series of widely used computer programs used in bioinformatics for multiple sequence alignment. There have been many versions of Clustal over the development of the algorithm that are listed below. The analysis of each tool and its algorithm are also detailed in their respective categories. Available operating systems listed in the sidebar are a combination of the software availability and may not be supported for every current version of the Clustal tools. Clustal Omega has the widest variety of operating systems out of all the Clustal tools.
  • 3.3K
  • 06 Oct 2022
Topic Review
McGill Picture Anomaly Test
The McGill Picture Anomaly Test (MPAT) is a scientific test that was created by Donald O. Hebb of McGill University and N.W. Morton that assists in testing visual intelligence as well as understanding human behavior. The test includes a series of pictures that each show a typical situation but have something out of place in the photo and provides evidence that supports the idea that the right temporal lobe is involved in visual recognition. When patients with lesions to the right temporal lobe were given the MPAT, they were unable to point to the absurdity in the photo and perceived that nothing was out of place. The test is used to measure a cultural comprehension which allows for a basis to then estimate an individual's intelligence. However, this test alone is not enough to accurately give a single score or representation of a person's overall intelligence. The MPAT is not meant to be used across a variety of populations due to the fact that the social norms of varied populations can be tremendously different, causing the results of the test to be indeterminate.
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  • 06 Oct 2022
Topic Review
Substrate
In chemistry, a substrate is typically the chemical species being observed in a chemical reaction, which reacts with a reagent to generate a product. It can also refer to a surface on which other chemical reactions are performed, or play a supporting role in a variety of spectroscopic and microscopic techniques. In synthetic and organic chemistry, the substrate is the chemical of interest that is being modified. In biochemistry, an enzyme substrate is the material upon which an enzyme acts. When referring to Le Chatelier's principle, the substrate is the reagent whose concentration is changed. The term substrate is highly context-dependent.
  • 2.9K
  • 06 Oct 2022
Topic Review
Standard Electrode Potential
In electrochemistry, standard electrode potential [math]\displaystyle{ E^\ominus }[/math], or [math]\displaystyle{ E^\ominus_{red} }[/math], is a measure of the reducing power of any element or compound. The IUPAC "Gold Book" defines it as: "the value of the standard emf (electromotive force) of a cell in which molecular hydrogen under standard pressure is oxidized to solvated protons at the left-hand electrode".
  • 2.5K
  • 06 Oct 2022
Topic Review
Chlamydia Infection
Chlamydia infection, often simply known as chlamydia, is a sexually transmitted infection caused by the bacterium Chlamydia trachomatis. Most people who are infected have no symptoms. When symptoms do develop this can take a few weeks following infection to occur. Symptoms in women may include vaginal discharge or burning with urination. Symptoms in men may include discharge from the penis, burning with urination, or pain and swelling of one or both testicles. The infection can spread to the upper genital tract in women causing pelvic inflammatory disease which may result in future infertility or ectopic pregnancy. Repeated infections of the eyes that go without treatment can result in trachoma, a common cause of blindness in the developing world. Chlamydia can be spread during vaginal, anal, or oral sex, and can be passed from an infected mother to her baby during childbirth. The eye infections may also be spread by personal contact, flies, and contaminated towels in areas with poor sanitation. Chlamydia trachomatis only occurs in humans. Diagnosis is often by screening which is recommended yearly in sexually active women under the age of twenty five, others at higher risk, and at the first prenatal visit. Testing can be done on the urine or a swab of the cervix, vagina, or urethra. Rectal or mouth swabs are required to diagnose infections in those areas. Prevention is by not having sex, the use of condoms, or having sex with only one other person, who is not infected. Chlamydia can be cured by antibiotics with typically either azithromycin or doxycycline being used. Erythromycin or azithromycin is recommended in babies and during pregnancy. Sexual partners should also be treated and the infected people advised not to have sex for seven days and until symptom free. Gonorrhea, syphilis, and HIV should be tested for in those who have been infected. Following treatment people should be tested again after three months. Chlamydia is one of the most common sexually transmitted infections, affecting about 4.2% of women and 2.7% of men worldwide. In 2015 about 61 million new cases occurred globally. In the United States about 1.4 million cases were reported in 2014. Infections are most common among those between the ages of 15 and 25 and are more common in women than men. In 2015 infections resulted in about 200 deaths. The word "chlamydia" is from the Greek, χλαμύδα meaning "cloak".
  • 2.2K
  • 06 Oct 2022
Topic Review
PhyloCode
The International Code of Phylogenetic Nomenclature, known as the PhyloCode for short, is a developing draft for a formal set of rules governing phylogenetic nomenclature. Its current version is specifically designed to regulate the naming of clades, leaving the governance of species names up to the rank-based Nomenclature codes (ICN, ICZN, ICNB, ICTV). The PhyloCode is associated with the International Society for Phylogenetic Nomenclature (ISPN). The PhyloCode proposes to regulate phylogenetic nomenclature by providing rules for how to decide which associations of names and definitions will be considered established, which of those will be considered homonyms or synonyms, and which one of a set of synonyms or homonyms will be considered accepted (generally the one registered first; see below). The PhyloCode will only allow the naming of clades, not of paraphyletic or polyphyletic groups, and will only allow the use of specimens, species, and apomorphies as specifiers (anchors).
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  • 06 Oct 2022
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