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1950 In Science
The year 1950 in science and technology included some significant events. Astronomy and space sciences * Dutch astronomer Jan Oort postulates the existence of an orbiting cloud of planets (the Oort cloud) at the outermost edge of the Solar System. * Enrico Fermi discusses the Fermi paradox. Biology * Melvin Calvin, James Bassham, and Andrew Benson at the University of California, Berkeley, discover the Calvin cycle in photosynthesis. * Entomologist Willi Hennig publishes ''Grundzüge einer Theorie der phylogenetischen Systematik'' in East Germany, pioneering the study of cladistics. * Full-scale release of myxomatosis Myxomatosis is a disease caused by '' Myxoma virus'', a poxvirus in the genus '' Leporipoxvirus''. The natural hosts are tapeti (''Sylvilagus brasiliensis'') in South and Central America, and brush rabbits (''Sylvilagus bachmani'') in North ... for control of the Australian rabbit population. Chemistry * February 9 – Californium, a Radioactive de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Bassham
James Alan Bassham (November 26, 1922 – November 19, 2012) was an American scientist known for his work on photosynthesis. He received a B.S. degree in chemistry in 1945 from the University of California, Berkeley, earning his Ph.D. degree from Berkeley in 1949. His graduate studies were on the subject of carbon reduction during photosynthesis, working with Melvin Calvin in the Bio-Organic Chemistry Group of the Lawrence Radiation Laboratory at the University of California. He discovered, with Melvin Calvin and Andrew Benson, the Calvin-Benson-Bassham cycle. He continued his work as Associate Director of this group. Besides his work on the basic carbon reduction cycle of photosynthesis, Bassham conducted research on the biosynthetic paths leading from the cycle to the thermodynamics Thermodynamics is a branch of physics that deals with heat, Work (thermodynamics), work, and temperature, and their relation to energy, entropy, and the physical properties of matte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Californium
Californium is a synthetic chemical element; it has symbol Cf and atomic number 98. It was first synthesized in 1950 at Lawrence Berkeley National Laboratory (then the University of California Radiation Laboratory) by bombarding curium with alpha particles (helium-4 ions). It is an actinide element, the sixth transuranium element to be synthesized, and has the second-highest atomic mass of all elements that have been produced in amounts large enough to see with the naked eye (after einsteinium). It was named after the university and the U.S. state of California. Two crystalline forms exist at normal pressure: one above and one below . A third form exists at high pressure. Californium slowly tarnishes in air at room temperature. Californium compounds are dominated by the +3 oxidation state. The most stable of californium's twenty known isotopes is californium-251, with a half-life of 898 years. This short half-life means the element is not found in significant quantities in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rabbit
Rabbits are small mammals in the family Leporidae (which also includes the hares), which is in the order Lagomorpha (which also includes pikas). They are familiar throughout the world as a small herbivore, a prey animal, a domesticated form of livestock, and a pet, having a widespread effect on ecologies and cultures. The most widespread rabbit genera are '' Oryctolagus'' and '' Sylvilagus''. The former, ''Oryctolagus'', includes the European rabbit, ''Oryctolagus cuniculus'', which is the ancestor of the hundreds of breeds of domestic rabbit and has been introduced on every continent except Antarctica. The latter, ''Sylvilagus'', includes over 13 wild rabbit species, among them the cottontails and tapetis. Wild rabbits not included in ''Oryctolagus'' and ''Sylvilagus'' include several species of limited distribution, including the pygmy rabbit, volcano rabbit, and Sumatran striped rabbit. Rabbits are a paraphyletic grouping, and do not constitute a clade, as ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australia
Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller islands. It has a total area of , making it the list of countries and dependencies by area, sixth-largest country in the world and the largest in Oceania. Australia is the world's flattest and driest inhabited continent. It is a megadiverse countries, megadiverse country, and its size gives it a wide variety of landscapes and Climate of Australia, climates including deserts of Australia, deserts in the Outback, interior and forests of Australia, tropical rainforests along the Eastern states of Australia, coast. The ancestors of Aboriginal Australians began arriving from south-east Asia 50,000 to 65,000 years ago, during the Last Glacial Period, last glacial period. By the time of British settlement, Aboriginal Australians spoke 250 distinct l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myxomatosis
Myxomatosis is a disease caused by '' Myxoma virus'', a poxvirus in the genus '' Leporipoxvirus''. The natural hosts are tapeti (''Sylvilagus brasiliensis'') in South and Central America, and brush rabbits (''Sylvilagus bachmani'') in North America. The myxoma virus causes only a mild disease in these species, but causes a severe and usually fatal disease in European rabbits (''Oryctolagus cuniculus''), the species of rabbit commonly raised for companionship and as a food source. Myxomatosis is an example of what occurs when a virus jumps from a species adapted to the virus to a naive host, and has been extensively studied for this reason. The virus was intentionally introduced in Australia, France, and Chile in the 1950s to control wild European rabbit populations. Cause ''Myxoma virus'' is in the genus '' Leporipoxvirus'' (family ''Poxviridae''; subfamily ''Chordopoxvirinae''). Like other poxviruses, myxoma viruses are large DNA viruses with linear double-stranded DNA. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladistics
Cladistics ( ; from Ancient Greek 'branch') is an approach to Taxonomy (biology), biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived (phylogenetics), derived characteristics (synapomorphies) that are not present in more distant groups and ancestors. However, from an empirical perspective, common ancestors are inferences based on a cladistic hypothesis of relationships of taxa whose Phenotypic trait, character states can be observed. Theoretically, a last common ancestor and all its descendants constitute a (minimal) clade. Importantly, all descendants stay in their overarching ancestral clade. For example, if the terms ''worms'' or ''fishes'' were used within a ''strict'' cladistic framework, these terms would include humans. Many of these terms are normally used Paraphyly, paraphyletically, outside of cladistics, e.g. as a 'E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
East Germany
East Germany, officially known as the German Democratic Republic (GDR), was a country in Central Europe from Foundation of East Germany, its formation on 7 October 1949 until German reunification, its reunification with West Germany (FRG) on 3 October 1990. Until 1989, it was generally viewed as a communist state and described itself as a Socialist state, socialist "workers' and peasants' state". The Economy of East Germany, economy of the country was Central planning, centrally planned and government-owned corporation, state-owned. Although the GDR had to pay substantial war reparations to the Soviets, its economy became the most successful in the Eastern Bloc. Before its establishment, the country's territory was administered and occupied by Soviet forces following the Berlin Declaration (1945), Berlin Declaration abolishing German sovereignty in World War II. The Potsdam Agreement established the Soviet occupation zone in Germany, Soviet-occupied zone, bounded on the east b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Willi Hennig
Emil Hans Willi Hennig (20 April 1913 – 5 November 1976) was a German biologist and zoologist who is considered the founder of phylogenetic systematics, otherwise known as cladistics. In 1945 as a prisoner of war, Hennig began work on his theory of cladistics, which he published in German in 1950, with a substantially revised English translation published in 1966. With his works on evolution and systematics he revolutionised the view of the natural order of beings. As a taxonomist, he specialised in dipterans (true flies). Hennig coined the key terms synapomorphy, symplesiomorphy, and paraphyly. He also asserted, in his "auxiliary principle", that "the presence of apomorphous characters in different species 'is always reason for suspecting kinship .e., that species belong to a monophyletic group and that their origin by convergence should not be presumed a priori' (Hennig, 1953). This was based on the conviction that 'phylogenetic systematics would lose all ground on which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entomologist
Entomology (from Ancient Greek ἔντομον (''éntomon''), meaning "insect", and -logy from λόγος (''lógos''), meaning "study") is the branch of zoology that focuses on insects. Those who study entomology are known as entomologists. In the past, the term ''insect'' was less specific, and historically the definition of entomology would also include the study of animals in other arthropod groups, such as arachnids, myriapods, and crustaceans. The field is also referred to as insectology in American English, while in British English insectology implies the study of the relationships between insects and humans. Over 1.3million insect species have been described by entomology. History Entomology is rooted in nearly all human cultures from prehistoric times, primarily in the context of agriculture (especially biological control and beekeeping). The natural Roman philosopher Pliny the Elder (23–79 CE) wrote a book on the kinds of insects, while the scientist of Kufa, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Biological Chemistry
The ''Journal of Biological Chemistry'' (''JBC'') is a weekly peer-reviewed scientific journal that was established in 1905., jbc.org Since 1925, it is published by the American Society for Biochemistry and Molecular Biology. It covers research in areas of biochemistry and molecular biology. The editor is Alex Toker. the journal is fully open access. In press articles are available free on its website immediately after acceptance. Editors The following individuals have served as editors of the journal: * 1906–1909: John Jacob Abel and Christian Archibald Herter * 1909–1910: Christian Archibald Herter * 1910–1914: Alfred Newton Richards * 1914–1925: Donald D. Van Slyke * 1925–1936: Stanley R. Benedict. After Benedict died, John T. Edsall served as temporary editor until the next editor was appointed. * 1937–1958: Rudolph J. Anderson * 1958–1967: John T. Edsall * 1968–1971: William Howard Stein * 1971–2011: Herbert Tabor * 2011–2015: Martha Fedor * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosynthesis
Photosynthesis ( ) is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their metabolism. ''Photosynthesis'' usually refers to oxygenic photosynthesis, a process that produces oxygen. Photosynthetic organisms store the chemical energy so produced within intracellular organic compounds (compounds containing carbon) like sugars, glycogen, cellulose and starches. To use this stored chemical energy, an organism's cells metabolize the organic compounds through cellular respiration. Photosynthesis plays a critical role in producing and maintaining the oxygen content of the Earth's atmosphere, and it supplies most of the biological energy necessary for complex life on Earth. Some bacteria also perform anoxygenic photosynthesis, which uses bacteriochlorophyll to split hydrogen sulfide as a reductant instead of water, p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
