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Ralph Erskine Cleland
Ralph Erskine Cleland (20 October 1892 – 11 June 1971) was an American botanist. In 1947, he was the President of the Botanical Society of America. He was also a professor at the Department of Botany at Indiana University. Cleland's most seminal field of research concerned the genetics of the plant genus '' Oenothera''. He discovered the structures of linked rings of meiotic chromosomes (not to be confused with ring chromosomes)Dunn, E.W. Dobzhansky, Th. Sinnott, L.C. Principles of Genetics. Publisher: McGraw-Hill 1957 ASIN: B0000CK0MJ that, by their interference with functions such as chromosomal crossover explained the unusual genetics and reproduction of plants in the genus ''Oenothera''. He was elected to the American Philosophical Society in 1932 and both the United States National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oenothera
''Oenothera'' is a genus of about 145 species of herbaceous flowering plants native to the Americas. It is the type genus of the family Onagraceae. Common names include evening primrose, suncups, and sundrops. They are not closely related to the true primroses (genus ''Primula''). Description The species vary in size from small alpine plants 10 centimeters tall, such as ''O. acaulis'' from Chile, to vigorous lowland species growing to 3 meters, such as ''O. stubbei'' from Mexico. The leaves form a basal rosette at ground level and spiral up to the flowering stems. The blades are dentate or deeply lobed (pinnatifid). The flowers of many species open in the evening, hence the name "evening primrose". They may open in under a minute. Most species have yellow flowers, but some have white, purple, pink, or red. Most native desert species are white. ''Oenothera caespitosa'', a species of western North America, produces white flowers that turn pink with age. One of the most distincti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Academy Of Sciences
The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the National Academy of Medicine (NAM). As a national academy, new members of the organization are elected annually by current members, based on their distinguished and continuing achievements in original research. Election to the National Academy is one of the highest honors in the scientific field. Members of the National Academy of Sciences serve '' pro bono'' as "advisers to the nation" on science, engineering, and medicine. The group holds a congressional charter under Title 36 of the United States Code. Founded in 1863 as a result of an Act of Congress that was approved by Abraham Lincoln, the NAS is charged with "providing independent, objective advice to the nation on matters related to science and technology. ... to provide scien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Members Of The United States National Academy Of Sciences
Member may refer to: * Military jury, referred to as "Members" in military jargon * Element (mathematics), an object that belongs to a mathematical set * In object-oriented programming, a member of a class ** Field (computer science), entries in a database ** Member variable, a variable that is associated with a specific object * Limb (anatomy), an appendage of the human or animal body ** Euphemism for penis * Structural component of a truss, connected by nodes * User (computing), a person making use of a computing service, especially on the Internet * Member (geology), a component of a geological formation * Member of parliament * The Members, a British punk rock band * Meronymy, a semantic relationship in linguistics * Church membership, belonging to a local Christian congregation, a Christian denomination and the universal Church * Member, a participant in a club or learned society A learned society (; also learned academy, scholarly society, or academic association) is an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indiana University Faculty
Indiana () is a U.S. state in the Midwestern United States. It is the 38th-largest by area and the 17th-most populous of the 50 States. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th state on December 11, 1816. It is bordered by Lake Michigan to the northwest, Michigan to the north, Ohio to the east, the Ohio River and Kentucky to the south and southeast, and the Wabash River and Illinois to the west. Various indigenous peoples inhabited what would become Indiana for thousands of years, some of whom the U.S. government expelled between 1800 and 1836. Indiana received its name because the state was largely possessed by native tribes even after it was granted statehood. Since then, settlement patterns in Indiana have reflected regional cultural segmentation present in the Eastern United States; the state's northernmost tier was settled primarily by people from New England and New York, Central Indiana by migrants from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1971 Deaths
* The year 1971 had three partial solar eclipses (February 25, July 22 and August 20) and two total lunar eclipses (February 10, and August 6). The world population increased by 2.1% this year, the highest increase in history. Events January * January 2 – 66 people are killed and over 200 injured during a crush in Glasgow, Scotland. * January 5 – The first ever One Day International cricket match is played between Australia and England at the Melbourne Cricket Ground. * January 8 – Tupamaros kidnap Geoffrey Jackson, British ambassador to Uruguay, in Montevideo, keeping him captive until September. * January 9 – Uruguayan president Jorge Pacheco Areco demands emergency powers for 90 days due to kidnappings, and receives them the next day. * January 12 – The landmark United States television sitcom ''All in the Family'', starring Carroll O'Connor as Archie Bunker, debuts on CBS. * January 14 – Seventy Brazilian political prisoners are rel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1892 Births
Year 189 ( CLXXXIX) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Silanus and Silanus (or, less frequently, year 942 ''Ab urbe condita''). The denomination 189 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * Plague (possibly smallpox) kills as many as 2,000 people per day in Rome. Farmers are unable to harvest their crops, and food shortages bring riots in the city. China * Liu Bian succeeds Emperor Ling, as Chinese emperor of the Han Dynasty. * Dong Zhuo has Liu Bian deposed, and installs Emperor Xian as emperor. * Two thousand eunuchs in the palace are slaughtered in a violent purge in Luoyang, the capital of Han. By topic Arts and sciences * Galen publishes his ''"Treatise on the various temperaments"'' (aka ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Academy Of Arts And Sciences
The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, and other Founding Fathers of the United States. It is headquartered in Cambridge, Massachusetts. Membership in the academy is achieved through a thorough petition, review, and election process. The academy's quarterly journal, ''Dædalus'', is published by MIT Press on behalf of the academy. The academy also conducts multidisciplinary public policy research. History The Academy was established by the Massachusetts legislature on May 4, 1780, charted in order "to cultivate every art and science which may tend to advance the interest, honor, dignity, and happiness of a free, independent, and virtuous people." The sixty-two incorporating fellows represented varying interests and high standing in the political, professional, and commercial secto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Philosophical Society
The American Philosophical Society (APS), founded in 1743 in Philadelphia, is a scholarly organization that promotes knowledge in the sciences and humanities through research, professional meetings, publications, library resources, and community outreach. Considered the first learned society in the United States, it has about 1,000 elected members, and by April 2020 had had only 5,710 members since its creation. Through research grants, published journals, the American Philosophical Society Museum, an extensive library, and regular meetings, the society supports a variety of disciplines in the humanities and the sciences. Philosophical Hall, now a museum, is just east of Independence Hall in Independence National Historical Park; it was designated a National Historic Landmark in 1965. History The Philosophical Society, as it was originally called, was founded in 1743 by Benjamin Franklin, James Alexander (lawyer), James Alexander, Francis Hopkinson, John Bartram, Philip Syn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indiana University
Indiana University (IU) is a system of public universities in the U.S. state of Indiana. Campuses Indiana University has two core campuses, five regional campuses, and two regional centers under the administration of IUPUI. *Indiana University Bloomington (IU Bloomington) is the flagship campus of Indiana University. The Bloomington campus is home to numerous premier Indiana University schools, including the College of Arts and Sciences, the Jacobs School of Music, an extension of the Indiana University School of Medicine, the School of Informatics, Computing, and Engineering, which includes the former School of Library and Information Science (now Department of Library and Information Science), School of Optometry, the O'Neil School of Public and Environmental Affairs, the Maurer School of Law, the School of Education, and the Kelley School of Business. *Indiana University–Purdue University Indianapolis (IUPUI), a partnership between Indiana University and Purdue Universi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosomal Crossover
Chromosomal crossover, or crossing over, is the exchange of genetic material during sexual reproduction between two homologous chromosomes' non-sister chromatids that results in recombinant chromosomes. It is one of the final phases of genetic recombination, which occurs in the ''pachytene'' stage of prophase I of meiosis during a process called synapsis. Synapsis begins before the synaptonemal complex develops and is not completed until near the end of prophase I. Crossover usually occurs when matching regions on matching chromosomes break and then reconnect to the other chromosome. Crossing over was described, in theory, by Thomas Hunt Morgan. He relied on the discovery of Frans Alfons Janssens who described the phenomenon in 1909 and had called it "chiasmatypie". The term '' chiasma'' is linked, if not identical, to chromosomal crossover. Morgan immediately saw the great importance of Janssens' cytological interpretation of chiasmata to the experimental results of hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ring Chromosome
A ring chromosome is an aberrant chromosome whose ends have fused together to form a ring. Ring chromosomes were first discovered by Lilian Vaughan Morgan in 1926. A ring chromosome is denoted by the symbol ''r'' in human genetics and ''R'' in ''Drosophila'' genetics. Ring chromosomes may form in cells following genetic damage by mutagens like radiation, but they may also arise spontaneously during development. Formation In order for a chromosome to form a ring, both ends of the chromosome are usually missing, enabling the broken ends to fuse together. In rare cases, the telomeres at the ends of a chromosome fuse without any loss of genetic material, which results in a normal phenotype. Complex rearrangements, including segmental microdeletions and microduplications, have been seen in numerous ring chromosomes, providing important clues regarding the mechanisms of their formation. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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