Galaxy groups and clusters are the largest known gravitationally bound objects to have arisen thus far in the process of cosmic structure formation. They form the densest part of the large-scale structure of the Universe. In models for the gravitational formation of structure with cold dark matter, the smallest structures collapse first and build the largest structures, clusters of galaxies. Clusters are formed recently between 10 billion years ago and now. Groups and clusters may contain ten to thousands of individual galaxies; the clusters themselves are associated with larger, non-gravitationally bound, groups called superclusters. Groups of galaxies are the smallest aggregates of galaxies, they contain no more than 50 galaxies in a diameter of 1 to 2 megaparsecs. Their mass is 1013 solar masses; the spread of velocities for the individual galaxies is about 150 km/s. However, this definition should be used as a guide only, as larger and more massive galaxy systems are sometimes classified as galaxy groups.

Groups are the most common structures of galaxies in the universe, comprising at least 50% of the galaxies in the local universe. Groups have a mass range between those of the large elliptical galaxies and clusters of galaxies. Our own Galaxy, the Milky Way, is contained in the Local Group of more than 54 galaxies. In July 2017 S. Paul, R. S. John et al. defined clear distinguishing parameters for classifying galaxy aggregations as ‘galaxy groups’ and ‘clusters’ on the basis of scaling laws that they followed. According to this paper, galaxy aggregations less massive than 8 × 1013 solar masses are classified as Galaxy groups. Clusters are larger than groups; when observed visually, clusters appear to be collections of galaxies held together by mutual gravitational attraction. However, their velocities are too large for them to remain gravitationally bound by their mutual attractions, implying the presence of either an additional invisible mass component, or an additional attractive force besides gravity.

X-ray studies have revealed the presence of large amounts of intergalactic gas known as the intracluster medium. This gas is hot, between 107K and 108K, hence emits X-rays in the form of bremsstrahlung and atomic line emission; the total mass of the gas is greater than that of the galaxies by a factor of two. However, this is still not enough mass to keep the galaxies in the cluster. Since this gas is in approximate hydrostatic equilibrium with the overall cluster gravitational field, the total mass distribution can be determined, it turns out the total mass deduced from this measurement is six times larger than the mass of the galaxies or the hot gas. The missing component is known as dark matter and its nature is unknown. In a typical cluster only 5% of the total mass is in the form of galaxies, maybe 10% in the form of hot X-ray emitting gas and the remainder is dark matter. Brownstein and Moffat use a theory of modified gravity to explain X-ray cluster masses without dark matter. Observations of the Bullet Cluster are the strongest evidence for the existence of dark matter.

Clusters of galaxies have been found in surveys by a number of observational techniques and have been studied in detail using many methods: Optical or infrared: The individual galaxies of clusters can be studied through optical or infrared imaging and spectroscopy. Galaxy clusters are found by optical or infrared telescopes by searching for overdensities, confirmed by finding several galaxies at a similar redshift. Infrared searches are more useful for finding more distant clusters. X-ray: The hot plasma emits X-rays that can be detected by X-ray telescopes; the cluster gas can be studied using both X-ray X-ray spectroscopy. Clusters are quite prominent in X-ray surveys and along with AGN are the brightest X-ray emitting extragalactic objects. Radio: A number of diffuse structures emitting at radio frequencies have been found in clusters. Groups of radio sources have been used as tracers of cluster location. At high redshift imaging around individual radio sources has been used to detect proto-clusters.

Sunyaev-Zel'dovich effect: The hot electrons in the intracluster medium scatter radiation from the cosmic microwave background through inverse Compton scattering. This produces a "shadow" in the observed cosmic microwave background at some radio frequencies. Gravitational lensing: Clusters of galaxies contain enough matter to distort the observed orientations of galaxies behind them; the observed distortions can be used to model the distribution of dark matter in the cluster. Clusters of galaxies are the most recent and most massive objects to have arisen in the hierarchical structure formation of the Universe and the study of clusters tells one about the way galaxies form and evolve. Clusters have two important properties: their masses are large enough to retain any energetic gas ejected from member galaxies and the thermal energy of the gas within the cluster is observable within the X-Ray bandpass; the observed state of gas within a cluster is determined by a combination of shock heating during accretion, radiative cooling, thermal feedback triggered by that cooling.

The density and substructure of the intracluster X-Ray gas therefore represents the entire thermal history of cluster formation. To better understand this thermal history one needs to study the entropy of the gas because entropy is the quantity most directly ch

A certified teacher is an educator who has earned credentials from an authoritative source, such as the government, a higher education institution or a private body or source. This teacher qualification gives a teacher authorization to teach and grade in pre-schools, primary or secondary education in countries, content areas or curricula where authorization is required. While many authorizing entities require student teaching experience before earning teacher certification, routes vary from country to country. A teaching qualification is one of a number of academic and professional degrees that enables a person to become a registered teacher. Examples of teaching qualifications in different jurisdictions include the Postgraduate Certificate in Education, the Professional Graduate Diploma in Education, Level 5 Diploma in Education and Training and the Bachelor of Education. Though teacher certifications are most provided by governments and higher education institutions, there are a few private bodies providing teacher certifications.

The Australian education system is regulated on a state-by-state basis with each state having its own requirements for teacher registration. Publicly funded schools are funded from the state level whereas private schools are funded with federal per student grants as well as smaller grants from state governments and private fees. Private schools are free to hire teachers regardless of their level of qualification although in practice most teachers in Australia have a relevant tertiary qualification such as a graduate diploma, bachelor's degree or master's degree. There are moves on both sides of politics in Australia towards a national curriculum which may or may not involve a national system of teacher registration. Four years are required to be a certified teacher. In Canada provinces have jurisdiction over education. In some provinces certification is handled through a provincial government department while in others a provincial College of Teachers has responsibility; the requirements are for an undergraduate university degree plus a one- or two-year Bachelor of Education or equivalent.

For general overviews, the governing departments or Colleges have dedicated websites, accessible here: http://www.edu.gov.mb.ca/k12/profcert/province.html In Manitoba, for example, the responsibility for teacher certification lies with the Department of Education and Youth - Professional Certification and Records Branch. Teachers need a Bachelor's degree in Education on top of another recognized bachelor's degree; this adds two more years to a university education. To earn a degree in secondary education, teachers must have a certain number of university credits in their subject field; this number varies from province to province, in some provinces it varies from school to school. Most employers of teachers require that successful applicants complete criminal record checks, as well as verification that an employee is not listed in the Child Abuse Registry; these same requirements are, in addition to being a sound part of the hiring practice, a requirement of most provincial education legislation.

Other requirements such as a tuberculosis test, level of experience criteria may be required. Many provinces require prospective teachers to obtain a criminal record check prior to hire. In extreme circumstances, such as a lack of any suitable certifiable candidates for a specific teaching position, an employer may apply for temporary certification of a non-certified person; this temporary certification is valid for one calendar year after ministry approval, but must be requested by the school, not by a non-certified applicant for a teaching position. Education system in Finland is globally exceptional as teachers need a Master's degree in Education to be qualified for teaching on primary or secondary education, it has been seen that success in Finland's high OECD PISA scores is influenced by the high education level of teachers. In France, teachers are civil servants, recruited by competitive examination, they must have gained college education and receive professional education in IUFMs. They were replaced by the Ecoles Supérieures du Professorat et de l'Education in 2013.

MAs in Education were created in 2013. Since 2010, one has to hold a master's degree to become a teacher. There are six corps of teachers in France's public service: Professeurs des écoles: Primary education teachers, they pass the CRPE competitive exam. Professeurs certifiés: high school junior high, teachers, they hold the CAPES or the CAPET. Professeurs de l'enseignement privé: private schools teachers, they hold the CAFEP. Professeurs de lycées professionnels: vocational high schools teachers, they hold the CAPLP. Professeurs de l'enseignement physique et sportif: sport teachers, they hold the CAPEPS. Professeurs agrégés: high school teachers who may teach in post-high school programs, they pass the Agrégation competitive exam

Several politico-constitutional arrangements use reserved political positions when endeavoring to ensure the rights of minorities or preserving a political balance of power. These arrangements can distort the democratic principle of one person - one vote in order to address special circumstances; the Constitution of Afghanistan guarantees at least 64 delegates to be female in the lower house of the bicameral National Assembly, while Kochi nomads elect 10 representatives through a single national constituency. Moreover, "one third of the members shall be appointed by the President, for a five-year term, from amongst experts and experienced personalities, including two members from amongst the impaired and handicapped, as well as two from nomads; the President shall appoint fifty percent of these individuals from amongst women." The Argentine Constitution requires for a 30% quota for female candidates for Congress. Since the 2015 Armenian constitutional referendum, electoral law requires that four seats for ethnic minorities are allocated in the National Assembly.

50 seats out of 350 in the Parliament are reserved for women. The Parliament of the Brussels-Capital Region in Belgium includes 17 reserved seats for the Flemish minority, on a total of 89, but there are no separate electorates. China's National People's Congress includes special delegations for the military of China and Taiwan. 55 minority ethnic groups are recognized in China and each has as at least one delegate, though they belong to normal region delegations. Additionally, from 1954–1974, the NPC included a special delegation for Overseas Chinese who returned to China. Hong Kong and Macau provide for constituencies which represent professional or special interest groups rather than geographical locations. Voters for the members representing these constituencies include both natural persons as well as non-human local entities, including organizations and corporations. Under the 2016 peace agreement brokered between the Colombian government and the FARC rebel group, five seats in the Senate and five seats in the House of Representatives are reserved for former FARC combatants.

Croatia reserves eight seats from the minorities and five for citizens living abroad in its parliament. There are three seats for Serbs, one for Italians, a few more for other ethnic groups, where a single representative represents more than one group; the Republic of Cyprus is full of reserved political positions. Due to its nature as a bi-communal republic, certain posts are always appropriated among Greek Cypriots and Turkish Cypriots. For example, the president is chosen from the Greek Cypriot community by using separate electoral rolls, whereas the vice president is chosen by the Turkish Cypriot community, using their own separate electoral rolls. 70% of the parliament are chosen from Greek Cypriots whereas 30% are chosen by and from Turkish Cypriots. In the Supreme Court, there should be One Turkish and one neutral foreign judge. 10 seats out of 105 seats in Parliament are reserved for women. Fiji used to provide for the election of specific numbers of Members of Parliament on the basis of three racially defined constituencies: the indigenous Fijians, the Fijian Indians and the "General" electorate.

India has seats in the Parliament of the country, State Assemblies, Local Municipal Bodies and Village level institutions reserved for untouchable castes called Dalits or Scheduled Castes and Scheduled Tribes. The election of Untouchables and Tribes candidates is by a Joint or mixed electorate, which includes all castes. Out of 543 constituencies in India's parliament, a total of 131 seats are Reserved or blocked for Representatives from Scheduled Castes and Scheduled Tribes only; this is different from separate electorate practiced in other countries. Many Indian states, like Kerala and Bihar, have parliamentary reserved seats for the Anglo-Indian community, as does the Lok Sabha. Iran reserves a fixed number of seats in the Majlis for certain recognized non-Muslim ethnoreligious groups. To wit, two seats are reserved for the Christian Armenian community, one seat each is reserved for the Assyrian and Chaldean Catholic and Zoroastrian communities. Jordan has reserved seats for women, Circassians and Bedouins.

Lebanon specifies the religious affiliation of several of its high officers, such as the President, the Prime Minister and the Parliament's Speaker. Every electoral district for the parliamentary elections includes a fixed number of the various religious communities. There are seven New Zealand Parliament constituencies – known as the Māori electorates – that are reserved for representatives of the Māori people. Māori electorates have undergone several changes since then. Māori may enrol either on the general roll, but not both. Since 1967 there has not been any specific requirement for candidates in Māori electorates to be Māori themselves, anyone on either the Māori roll or the General roll can stand as a candidate. Technically, these seats should not be described as "reserved" as there is no legal or constitutional guarantee that the successful candidate will themselves be of Māori descent

Harlond Benton "Darkie" Clift was a Major League Baseball third baseman for the St. Louis Browns and the Washington Senators, he was an All-Star for the American League in 1937. Clift was born in Oklahoma, he sustained an unusual injury during the tryout. While reaching to field a ball, Clift stepped on his own glove, which caused him to trip and roll forward, he broke his collarbone in the fall. Nonetheless, the Browns signed Clift and he made his major-league debut in 1934, he scored 145 runs in the second highest total in the American League behind Lou Gehrig. In the 1937 season, he set single-season records of 50 double plays and 405 assists that stood until 1971. Clift was traded to the Washington Senators in 1943. A serious case of the mumps and a horse-riding injury hampered Clift's play late in his career. In 12 seasons, Clift played in 1,582 games, had 1,558 hits in 5,730 at bats for a.272 batting average. Clift was one of the first power-hitting third basemen, posting his offensive numbers at a time when players at that position were more valued for their fielding.

However, Clift was regarded as a superb fielder. Clift's nickname, "Darkie", has what Bill James referred to as "a rather unpleasant derviation": One of his Browns teammates, Alan Strange, misheard Clift's first name and thought that it was Harlem, a predominantly black area in New York. Clift died in Yakima, Washington, at the age of 79. List of Major League Baseball career runs scored leaders Career statistics and player information from MLB, or ESPN, or Baseball-Reference, or Fangraphs, or Baseball-Reference Harlond Clift at Find a Grave

Carola Höhn was a German stage and movie actress. Derrick – Season 4, Episode 2: "Hals in der Schlinge" Derrick – Season 5, Episode 9: "Lissas Vater" Derrick – Season 6, Episode 10: "Das dritte Opfer" Derrick – Season 7, Episode 11: "Pricker" 1989 Bavarian Film Awards 1990 Deutscher Filmpreis 1999 Federal Cross of Merit on Ribbon Höhn, Carola. Fange nie an aufzuhören.... Koblenz ISBN 3-934639-00-3 Carola Höhn @ filmportal.de Carola Höhn on IMDb Carola Höhn at the Deutschen SynchronkarteiCarola Höhn in the German National Library catalogue

William Henderson Packwood was an American politician who served at the Oregon Constitutional Convention in 1857. A United States Army veteran from the state of Illinois, he was a school superintendent and acquaintance of President Abraham Lincoln, he was an early resident of Baker City in Eastern Oregon. William Packwood was born near the community of Mount Vernon, Illinois, to Larkin Canada Packwood and Elizabeth Cathcart on October 23, 1832. Packwood received two years of formal education and moved to Springfield, Illinois where he knew future United States President Abraham Lincoln. In 1848 he enlisted in the U. S. Army with Company B of the U. S. Mounted Rifles; the following year Packwood and the company were sent to the newly created Oregon Territory and stationed at Fort Vancouver. Packwood went to California when gold was discovered there, returning to Oregon in 1851 where he was transferred to Port Orford, Oregon to fight Native American uprisings. In 1853 he became a gold miner for several years.

In 1854, he served. In that role, he helped lead a massacre of the Nasomah band of the Coquille Indian Tribe; the Volunteers attacked while the Nasomah people were sleeping, killing between 21 people. In 1855, Packwood served as captain of the Coquille Guards during the Rogue River Wars against Native Americans in Southern Oregon. In 1857, he represented Curry County in southwestern Oregon at the Oregon Constitutional Convention that met in Salem during August and September, framed a constitution in anticipation of Oregon becoming a state, he was the youngest of the delegates at the convention. Packwood moved east of the Cascade Mountains to Eastern Oregon where he was involved with establishing the town of Auburn in 1862. Auburn was a gold-mining boomtown, the county seat of Baker County, Packwood helped plat the town. There he served as the first school superintendent of Baker County in 1862. During the 1864 presidential election he campaigned for Abraham Lincoln in that county. Soon after, he was responsible for another Baker County town receiving the name of Sparta.

In that town he and his family built and operated a boarding house until 1867. In years Packwood mined, was an assistant postmaster, clerk for Baker City, a police judge before retiring in 1910. In 1862, Packwood married Johanna A. O'Brien, he is the great-grandfather of former United States Senator Robert Packwood. William Henderson Packwood died on September 21, 1917, in Baker City with interment at Mount Hope Cemetery, he was the last living member of the constitutional convention at his death. Photograph of Sparta, Oregon Biographical Sketch of William Packwood at Oregon State Archives Lockley, Fred. "Reminiscences of William H. Packwood"; the Quarterly of the Oregon Historical Society. 16. Retrieved 12 April 2013