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Jack Sepkoski
Joseph John Sepkoski Jr. (July 26, 1948 – May 1, 1999) was a University of Chicago paleontologist. Sepkoski studied the fossil record and the diversity of life on Earth. Sepkoski and David Raup contributed to the knowledge of extinction events. They suggested that the extinction of dinosaurs 66 mya was part of a cycle of mass extinctions that may have occurred every 26 million years. Life and work Sepkoski was born in Presque Isle, Maine. In 1970, Sepkoski received a B.S. degree, magna cum laude, from the University of Notre Dame. Under Stephen Jay Gould he earned a Ph.D. in geological sciences from Harvard University in 1977. His Ph.D. was on the field geology and paleontology of the Black Hills of South Dakota. From 1974 to 1978, Sepkoski taught at the University of Rochester. In 1978 he joined the University of Chicago and became a professor in 1986. Sepkoski was also a research associate at the Field Museum of Natural History in Chicago. He died of heart failure relat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Chicago
The University of Chicago (UChicago, Chicago, U of C, or UChi) is a private research university in Chicago, Illinois. Its main campus is located in Chicago's Hyde Park neighborhood. The University of Chicago is consistently ranked among the best universities in the world and it is among the most selective in the United States. The university is composed of an undergraduate college and five graduate research divisions, which contain all of the university's graduate programs and interdisciplinary committees. Chicago has eight professional schools: the Law School, the Booth School of Business, the Pritzker School of Medicine, the Crown Family School of Social Work, Policy, and Practice, the Harris School of Public Policy, the Divinity School, the Graham School of Continuing Liberal and Professional Studies, and the Pritzker School of Molecular Engineering. The university has additional campuses and centers in London, Paris, Beijing, Delhi, and Hong Kong, as well as in downtown ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Logistic Function
A logistic function or logistic curve is a common S-shaped curve (sigmoid curve) with equation f(x) = \frac, where For values of x in the domain of real numbers from -\infty to +\infty, the S-curve shown on the right is obtained, with the graph of f approaching L as x approaches +\infty and approaching zero as x approaches -\infty. The logistic function finds applications in a range of fields, including biology (especially ecology), biomathematics, chemistry, demography, economics, geoscience, mathematical psychology, probability, sociology, political science, linguistics, statistics, and artificial neural networks. A generalization of the logistic function is the hyperbolastic function of type I. The standard logistic function, where L=1,k=1,x_0=0, is sometimes simply called ''the sigmoid''. It is also sometimes called the ''expit'', being the inverse of the logit. History The logistic function was introduced in a series of three papers by Pierre François Verhulst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Near Earth Object
A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). If a NEO's orbit crosses the Earth's orbit, and the object is larger than across, it is considered a potentially hazardous object (PHO). Most known PHOs and NEOs are asteroids, but a small fraction are comets. There are over 30,503 known near-Earth asteroids (NEAs) and over a hundred known short-period near-Earth comets (NECs). A number of solar-orbiting meteoroids were large enough to be tracked in space before striking the Earth. It is now widely accepted that collisions in the past have had a significant role in shaping the geological and biological history of the Earth. Asteroids as small as in diameter can cause significant damage to the local environment and human populations. Larger asteroids penetrate the atmosphere to the surf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Paleontology
The ''Journal of Paleontology'' is a peer-reviewed scientific journal covering the field of paleontology. It is published by the Paleontological Society. Indexing The ''Journal of Paleontology'' is indexed in: *BIOSIS Previews *Science Citation Index *The Zoological Record *GeoRef __NOTOC__ The GeoRef database is a bibliographic database that indexes scientific literature in the geosciences, including geology. Coverage ranges from 1666 to the present for North American literature, and 1933 to the present for the rest of t ... References Paleontology journals Publications established in 1927 Academic journals published by learned and professional societies Cambridge University Press academic journals Bimonthly journals Paleontological Society {{paleo-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American National Biography
The ''American National Biography'' (ANB) is a 24-volume biographical encyclopedia set that contains about 17,400 entries and 20 million words, first published in 1999 by Oxford University Press under the auspices of the American Council of Learned Societies. Background A 400-entry supplement appeared in 2002. Additional funding came from the Rockefeller Foundation, the Andrew W. Mellon Foundation and the National Endowment for the Humanities. The ''ANB'' bills itself as the successor of the ''Dictionary of American Biography'', which was first published between 1926 and 1937. It is not, however, a strict superset of this older publication; the selection of topics was made anew. It is commonly available in the reference sections of United States libraries, and is available online by subscription (see external links). Awards and reception In 1999, the American Library Association awarded the ''American National Biography'' its Dartmouth Medal as a reference work of outstand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleontological Research Institution
The Paleontological Research Institution, or PRI, is a paleontological organization in Ithaca, New York, with a mission including both research and education. PRI is affiliated with Cornell University, houses one of the largest fossil collections in North America, and publishes, among other things, the oldest journal of paleontology in the western hemisphere, ''Bulletins of American Paleontology''. PRI's facilities include the Museum of the Earth, a natural history museum that houses some of PRI's collections for public viewing and educates visitors on the history of life on Earth, and, since 2013, the Cayuga Nature Center, an educational venue with a focus on outdoor and environmental education. History PRI was founded in 1932 by Gilbert Harris, a professor of geology at Cornell University from 1894 to 1934. Frustrated by the university's lack of assurance for the safety and perpetuation of his fossil collections and printing enterprise, ''Bulletins of American Paleontology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulletins Of American Paleontology
''Bulletins of American Paleontology'' is a peer-reviewed scientific journal published by the Paleontological Research Institution and issued biannually that features monographs and dissertations in the field of paleontology and other related subjects. Founded by Gilbert Harris in 1895, it is the oldest continuously-published paleontological periodical in the Western Hemisphere, and one of the oldest in the world. History In 1895, Gilbert Harris, a professor of geology at Cornell University, established ''Bulletins of American Paleontology'' in order to publish his research on Paleocene and Eocene mollusk fossils. Printing originally took place at Harris's own printing enterprise at McGraw Hall, Cornell. Publication of ''Bulletins'' was transferred to the Paleontological Research Institution The Paleontological Research Institution, or PRI, is a paleontological organization in Ithaca, New York, with a mission including both research and education. PRI is affiliated with Cor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proceedings Of The National Academy Of Sciences Of The United States Of America
''Proceedings of the National Academy of Sciences of the United States of America'' (often abbreviated ''PNAS'' or ''PNAS USA'') is a peer-reviewed multidisciplinary scientific journal. It is the official journal of the National Academy of Sciences, published since 1915, and publishes original research, scientific reviews, commentaries, and letters. According to ''Journal Citation Reports'', the journal has a 2021 impact factor of 12.779. ''PNAS'' is the second most cited scientific journal, with more than 1.9 million cumulative citations from 2008 to 2018. In the mass media, ''PNAS'' has been described variously as "prestigious", "sedate", "renowned" and "high impact". ''PNAS'' is a delayed open access journal, with an embargo period of six months that can be bypassed for an author fee ( hybrid open access). Since September 2017, open access articles are published under a Creative Commons license. Since January 2019, ''PNAS'' has been online-only, although print issues are ava ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science (journal)
''Science'', also widely referred to as ''Science Magazine'', is the peer-reviewed academic journal of the American Association for the Advancement of Science (AAAS) and one of the world's top academic journals. It was first published in 1880, is currently circulated weekly and has a subscriber base of around 130,000. Because institutional subscriptions and online access serve a larger audience, its estimated readership is over 400,000 people. ''Science'' is based in Washington, D.C., United States, with a second office in Cambridge, UK. Contents The major focus of the journal is publishing important original scientific research and research reviews, but ''Science'' also publishes science-related news, opinions on science policy and other matters of interest to scientists and others who are concerned with the wide implications of science and technology. Unlike most scientific journals, which focus on a specific field, ''Science'' and its rival ''Nature (journal), Nature'' c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleobiology (journal)
Paleobiology is a scientific journal promoting the integration of biology and conventional paleontology Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ..., with emphasis placed on biological or paleobiological processes and patterns. It attracts papers of interest to more than one discipline, and occasionally publishes research on recent organisms when this is of interest to paleontologists. Paleontology journals Academic journals published by learned and professional societies Publications established in 1975 Quarterly journals English-language journals Paleobiology Cambridge University Press academic journals {{paleontology-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polish Academy Of Sciences
The Polish Academy of Sciences ( pl, Polska Akademia Nauk, PAN) is a Polish state-sponsored institution of higher learning. Headquartered in Warsaw, it is responsible for spearheading the development of science across the country by a society of distinguished scholars and a network of research institutes. It was established in 1951, during the early period of the Polish People's Republic following World War II. History The Polish Academy of Sciences is a Polish state-sponsored institution of higher learning, headquartered in Warsaw, that was established by the merger of earlier science societies, including the Polish Academy of Learning (''Polska Akademia Umiejętności'', abbreviated ''PAU''), with its seat in Kraków, and the Warsaw Society of Friends of Learning (Science), which had been founded in the late 18th century. The Polish Academy of Sciences functions as a learned society acting through an elected assembly of leading scholars and research institutions. The Academy h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleontological Society
The Paleontological Society, formerly the Paleontological Society of America, is an international organisation devoted to the promotion of paleontology. The Society was founded in 1908 in Baltimore, Maryland, and was incorporated in April 1968 in the District of Columbia. The Society publishes the bi-monthly ''Journal of Paleontology'' and the quarterly ''Paleobiology'', holds an annual meeting in the autumn in conjunction with the Geological Society of America, sponsors conferences and lectures, and provides grants and scholarships. The Society has five geographic sections—Pacific Coast (founded March 1911), North-Central (founded May 1974), Northeastern (founded March 1977), Southeastern (founded November 1979), Rocky Mountain (founded October 1985), and South-Central (founded November 1988). Medals and awards The Society recognizes distinguished accomplishments through three awards, one recognized by a medal, the other two by inscribed plaques normally presented annually: *T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
