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Matrix (mathematics)
In mathematics, a matrix (plural matrices) is a rectangular array or table of numbers, symbols, or expressions, arranged in rows and columns, which is used to represent a mathematical object or a property of such an object. For example, \begin1 & 9 & -13 \\20 & 5 & -6 \end is a matrix with two rows and three columns. This is often referred to as a "two by three matrix", a "-matrix", or a matrix of dimension . Without further specifications, matrices represent linear maps, and allow explicit computations in linear algebra. Therefore, the study of matrices is a large part of linear algebra, and most properties and operations of abstract linear algebra can be expressed in terms of matrices. For example, matrix multiplication represents composition of linear maps. Not all matrices are related to linear algebra. This is, in particular, the case in graph theory, of incidence matrices, and adjacency matrices. ''This article focuses on matrices related to linear algebra, and, unle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roman Numeral
Roman numerals are a numeral system that originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. Numbers are written with combinations of letters from the Latin alphabet, each letter with a fixed integer value, modern style uses only these seven: The use of Roman numerals continued long after the decline of the Roman Empire. From the 14th century on, Roman numerals began to be replaced by Arabic numerals; however, this process was gradual, and the use of Roman numerals persists in some applications to this day. One place they are often seen is on clock faces. For instance, on the clock of Big Ben (designed in 1852), the hours from 1 to 12 are written as: The notations and can be read as "one less than five" (4) and "one less than ten" (9), although there is a tradition favouring representation of "4" as "" on Roman numeral clocks. Other common uses include year numbers on monuments and buildings and c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplogroup I (Y-DNA)
Haplogroup I (M170) is a Y-chromosome DNA haplogroup. It is a subgroup of haplogroup IJ, which itself is a derivative of the haplogroup IJK. Subclades I1 and I2 can be found in most present-day European populations, with peaks in some Northern European and Southeastern European countries. Haplogroup I appears to have arisen in Europe, so far being found in Palaeolithic sites throughout Europe (Fu 2016), but not outside it. It diverged from common ancestor IJ* about 43,000 years B.P. (Karafet 2008). Early evidence for haplogroup J has been found in the Caucasus and Iran (Jones 2015, Fu 2016). In addition, living examples of the precursor Haplogroup IJ* have been found only in Iran, among the Mazandarani and ethnic Persians from Fars. This may indicate that IJ originated in South West Asia. Haplogroup I has been found in multiple individuals belonging to the Gravettian culture. The Gravettians expanded westwards from the far corner of Eastern Europe, likely Russia, to Centr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple Inc
Apple Inc. is an American multinational technology company headquartered in Cupertino, California, United States. Apple is the largest technology company by revenue (totaling in 2021) and, as of June 2022, is the world's biggest company by market capitalization, the fourth-largest personal computer vendor by unit sales and second-largest mobile phone manufacturer. It is one of the Big Five American information technology companies, alongside Alphabet, Amazon, Meta, and Microsoft. Apple was founded as Apple Computer Company on April 1, 1976, by Steve Wozniak, Steve Jobs and Ronald Wayne to develop and sell Wozniak's Apple I personal computer. It was incorporated by Jobs and Wozniak as Apple Computer, Inc. in 1977 and the company's next computer, the Apple II, became a best seller and one of the first mass-produced microcomputers. Apple went public in 1980 to instant financial success. The company developed computers featuring innovative graphical user inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplogroup I (mtDNA)
Haplogroup I is a human mitochondrial DNA (mtDNA) haplogroup. It is believed to have originated about 21,000 years ago, during the Last Glacial Maximum (LGM) period in West Asia (; ; ). The haplogroup is unusual in that it is now widely distributed geographically, but is common in only a few small areas of East Africa, West Asia and Europe. It is especially common among the El Molo and Rendille peoples of Kenya, various regions of Iran, the Lemko people of Slovakia, Poland and Ukraine, the island of Krk in Croatia, the department of Finistère in France and some parts of Scotland and Ireland. Origin Haplogroup I is a descendant (subclade) of haplogroup N1a1b and sibling of haplogroup N1a1b1 . It is believed to have arisen somewhere in West Asia between 17,263 and 24,451 years before present (BP) , with coalescence age of 20.1 thousand years ago . It has been suggested that its origin may be in Iran or more generally the Near East . It has diverged to at least seven distinct clad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionic Strength
The ionic strength of a solution is a measure of the concentration of ions in that solution. Ionic compounds, when dissolved in water, dissociate into ions. The total electrolyte concentration in solution will affect important properties such as the dissociation constant or the solubility of different salts. One of the main characteristics of a solution with dissolved ions is the ionic strength. Ionic strength can be molar (mol/L solution) or molal (mol/kg solvent) and to avoid confusion the units should be stated explicitly. The concept of ionic strength was first introduced by Lewis and Randall in 1921 while describing the activity coefficients of strong electrolytes. Quantifying ionic strength The molar ionic strength, ''I'', of a solution is a function of the concentration of ''all'' ions present in that solution. :I = \begin\frac\end\sum_^ c_i z_i^ where one half is because we are including both cations and anions, ''c''i is the molar concentration of ion i (M, mol/L), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iodine
Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , and boils to a violet gas at . The element was discovered by the French chemist Bernard Courtois in 1811 and was named two years later by Joseph Louis Gay-Lussac, after the Ancient Greek 'violet-coloured'. Iodine occurs in many oxidation states, including iodide (I−), iodate (), and the various periodate anions. It is the least abundant of the stable halogens, being the sixty-first most abundant element. As the heaviest essential mineral nutrient, iodine is required for the synthesis of thyroid hormones. Iodine deficiency affects about two billion people and is the leading preventable cause of intellectual disabilities. The dominant producers of iodine today are Chile and Japan. Due to its high atomic number and ease of attachment to organic compound ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
I (kana)
I (い in hiragana or イ in katakana) is one of the Japanese kana each of which represents one mora. い is based on the sōsho style of the kanji character 以, and イ is from the radical (left part) of the kanji character 伊. In the modern Japanese system of sound order, it occupies the second position of the syllable chart, between あ and う. Additionally, it is the first letter in Iroha, before ろ. Both represent the sound . In the Ainu language, katakana イ is written as ''y'' in their Latin-based syllable chart, and a small ィ after another katakana represents a diphthong. Variant forms Like other vowels, scaled-down versions of the kana (ぃ, ィ) are used to express sounds foreign to the Japanese language, such as フィ (fi). In some Okinawan writing systems, a small ぃ is also combined with the kana く (''ku'') and ふ to form the digraphs くぃ ''kwi'' and ふぃ ''hwi'' respectively, although the Ryukyu University system uses the kana ゐ/ヰ inste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Troponin I
Troponin I is a cardiac and skeletal muscle protein family. It is a part of the troponin protein complex, where it binds to actin in thin myofilaments to hold the actin-tropomyosin complex in place. Troponin I prevents myosin from binding to actin in relaxed muscle. When calcium binds to the troponin C, it causes conformational changes which lead to dislocation of troponin I. Afterwards, tropomyosin leaves the binding site for myosin on actin leading to contraction of muscle. The letter ''I'' is given due to its inhibitory character. It is a useful marker in the laboratory diagnosis of heart attack. It occurs in different plasma concentration but the same circumstances as troponin T - either test can be performed for confirmation of cardiac muscle damage and laboratories usually offer one test or the other. Three paralogs with unique tissue-specific expression patterns are expressed in humans, listed below with their locations and OMIM accessions: * Slow-twitch skeletal muscle i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vietnamese Pot-bellied
Vietnamese Pot-bellied is the exonym for the Lon I ( vi, Lợn Ỉ, italic=no) or I pig, an endangered traditional Vietnamese breed of small domestic pig. The I is uniformly black and has short legs and a low-hanging belly, from which the name derives. It is reared for meat; it is slow-growing, but the pork has good flavour. The I was depicted in the traditional Đông Hồ paintings of Bắc Ninh province as a symbol of happiness, satiety and wealth. History The I is a traditional Vietnamese breed. It is thought to have originated in Nam Định province of Vietnam, in the Red River Delta. It was the dominant local pig breed in most provinces of the delta, and was widely distributed in Nam Định province and the neighbouring provinces of Hà Nam, Ninh Bình and Thái Bình, as well as in the province of Thanh Hóa immediately to the south, in the North Central Coast region. Until the 1970s the I was probably the most numerous pig breed in northern Vietnam, with numbers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
I (pronoun)
In Modern English, ''I'' is the singular, first-person pronoun. Morphology In Standard Modern English, ''I'' has five distinct word forms: * ''I'': the nominative (subjective) form **''I'' is the only pronoun form that is always capitalized in English. This practice became established in the late 15th century, though lowercase ''i'' was sometimes found as late as the 17th century. * ''me'': the accusative (objective) forms (The accusative case is also called the 'oblique'.) * ''my:'' the dependent genitive (possessive) form * ''mine'': the independent genitive * ''myself'': the reflexive form History Old English had a first person pronoun that inflected for four cases and three numbers. ''I'' originates from Old English (OE) ''ic'', which had in turn originated from the continuation of Proto-Germanic *''ik'', and ''ek''; The asterisk denotes an unattested form, but ''ek'' was attested in the Elder Futhark inscriptions (in some cases notably showing the variant ''eka''; see ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Troponin
image:Troponin Ribbon Diagram.png, 400px, Ribbon representation of the human cardiac troponin core complex (52 kDa core) in the calcium-saturated form. Blue = troponin C; green = troponin I; magenta = troponin T.; ; rendered with PyMOL Troponin, or the troponin complex, is a complex of three regulatory proteins (troponin C, troponin I, and troponin T) that are integral to muscle contraction in skeletal muscle and cardiac muscle, but not smooth muscle. Measurements of cardiac-specific troponins I and T are extensively used as diagnostic and prognostic indicators in the management of myocardial infarction and acute coronary syndrome. Blood troponin levels may be used as a diagnostic marker for stroke or other myocardial injury that is ongoing, although the sensitivity of this measurement is low. Function Troponin is attached to the protein tropomyosin and lies within the groove between actin filaments in muscle tissue. In a relaxed muscle, tropomyosin blocks the attachment site fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
