|
Tikvah Alper
Tikvah Alper (22 January 1909 – 2 February 1995) trained as a physicist and became a distinguished radiobiologist. Among many other initiatives and discoveries, she was among the first to find evidence indicating that the infectious agent in Scrapie does not contain nucleic acid: a finding that was instrumental in understanding the development of the Prion theory. She was director of the MRC Experimental Radiopathology Unit, Hammersmith Hospital, London, UK, 1962–1974. She married Max Sterne but never adopted his name. Early life and career Tikvah Alper was born in South Africa, the youngest of four daughters in a family of Jewish refugees from Russia. As a schoolgirl at Durban Girls' High School, she was described as "the most intellectually distinguished girl ever to attend the school", and matriculated with distinction a year early. She graduated with distinction in physics from University of Cape Town in 1929, and then studied in Berlin with the nuclear physicist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wynberg, Cape Town
Wynberg () is a southern suburb of the City of Cape Town in Western Cape, South Africa. It is situated between Plumstead, Cape Town, Plumstead and Kenilworth, Cape Town, Kenilworth, and is a main transport hub for the Southern Suburbs, Cape Town, Southern Suburbs of Cape Town. History In the 1650s, Jan van Riebeeck's farm Boscheuvel, where he planted the Cape's first vineyards and was the first to produce History of South African wine, wine in the Cape, was located in the greater Wynberg area close to the slopes of Table Mountain. In 1683 land along the Liesbeek River was granted to Herman Weeckens by Simon van der Stel. The farm was named De Oude Wijnbergh (Old Wine Mountain). The Cape's rough seas in the winter months led to a formal winter anchorage in 1743 where ships would dock at Simons' Baai (present day Simon's Town). A wagon route linking Cape Town to Simon's Town went over the hill adjacent to De Oude Wjinbergh estate. When the British took control of the Cape sett ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Particles
Alpha particles, also called alpha rays or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. They are generally produced in the process of alpha decay, but may also be produced in other ways. Alpha particles are named after the first letter in the Greek alphabet, α. The symbol for the alpha particle is α or α2+. Because they are identical to helium nuclei, they are also sometimes written as or indicating a helium ion with a +2 charge (missing its two electrons). Once the ion gains electrons from its environment, the alpha particle becomes a normal (electrically neutral) helium atom . Alpha particles have a net spin of zero. Due to the mechanism of their production in standard alpha radioactive decay, alpha particles generally have a kinetic energy of about 5 MeV, and a velocity in the vicinity of 4% of the speed of light. (See discussion below for the limits of these figures in alpha decay.) T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1995 Deaths
File:1995 Events Collage V2.png, From left, clockwise: O.J. Simpson is acquitted of the murders of Nicole Brown Simpson and Ronald Goldman from the year prior in "The Trial of the Century" in the United States; The Great Hanshin earthquake strikes Kobe, Japan, killing 5,000-6,000 people; The Unabomber Manifesto is published in several U.S. newspapers; Gravestones mark the victims of the Srebrenica massacre near the end of the Bosnian War; Windows 95 is launched by Microsoft for PC; The first exoplanet, 51 Pegasi b, is discovered; Space Shuttle Atlantis docks with the Space station Mir in a display of U.S.-Russian cooperation; The Alfred P. Murrah Federal Building in Oklahoma City is bombed by domestic terrorists, killing 168., 300x300px, thumb rect 0 0 200 200 O. J. Simpson murder case rect 200 0 400 200 Kobe earthquake rect 400 0 600 200 Unabomber Manifesto rect 0 200 300 400 Oklahoma City bombing rect 300 200 600 400 Srebrenica massacre rect 0 400 200 600 Space Shuttle Atlant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1909 Births
Nineteen or 19 may refer to: * 19 (number), the natural number following 18 and preceding 20 * one of the years 19 BC, AD 19, 1919, 2019 Films * ''19'' (film), a 2001 Japanese film * ''Nineteen'' (film), a 1987 science fiction film Music * 19 (band), a Japanese pop music duo Albums * ''19'' (Adele album), 2008 * ''19'', a 2003 album by Alsou * ''19'', a 2006 album by Evan Yo * ''19'', a 2018 album by MHD * ''19'', one half of the double album ''63/19'' by Kool A.D. * ''Number Nineteen'', a 1971 album by American jazz pianist Mal Waldron * ''XIX'' (EP), a 2019 EP by 1the9 Songs * "19" (song), a 1985 song by British musician Paul Hardcastle. * "Nineteen", a song by Bad4Good from the 1992 album '' Refugee'' * "Nineteen", a song by Karma to Burn from the 2001 album ''Almost Heathen''. * "Nineteen" (song), a 2007 song by American singer Billy Ray Cyrus. * "Nineteen", a song by Tegan and Sara from the 2007 album '' The Con''. * "XIX" (song), a 2014 song by Slipk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timeline Of Women In Science
This is a timeline of women in science, spanning from ancient history up to the 21st century. While the timeline primarily focuses on women involved with natural sciences such as astronomy, biology, chemistry and physics, it also includes women from the social sciences (e.g. sociology, psychology) and the formal sciences (e.g. mathematics, computer science), as well as notable science educators and medical scientists. The chronological events listed in the timeline relate to both scientific achievements and gender equality within the sciences. Ancient history * 1900 BCE: Aganice, also known as Athyrta, was an Egyptian princess during the Middle Kingdom (about 2000–1700 BCE) working on astronomy and natural philosophy. *c. 1500 BCE: Hatshepsut, also known as the Queen Doctor, promoted a botanical expedition searching for officinal plants. * 1200 BCE: The Mesopotamian perfume-maker Tapputi-Belatekallim was referenced in the text of a cuneiform tablet. She is often consi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FEMS Microbiology Letters
''FEMS Microbiology Letters'' is a peer-reviewed scientific journal covering all aspects of microbiology, including virology. The journal was established in 1977 and is published by Oxford University Press on behalf of the Federation of European Microbiological Societies. The Editor-in-Chief has been Dr Rich Boden of the University of Plymouth since 2014. Former Editors-in-Chief include Prof Jeff Cole from 2002-2014 (University of Birmingham), Prof Fergus 'Gus' Priest from 1997-2002 (1948-2019, Heriot-Watt University) and Dr David W Tempest (Free University of Amsterdam). The journal gave rise to separate titles over the years but retained the subject areas of ecology and medical microbiology and indeed review articles as part of its scope nonetheless: *'' FEMS Microbiology Immunology'' (1988), which was retitled ''FEMS Immunology and Medical Microbiology'' (1993) and is now ''Pathogens and Disease'' (2013). *''FEMS Microbiology Reviews'' (1985) *''FEMS Microbiology Ecology'' (19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prion
Prions are misfolded proteins that have the ability to transmit their misfolded shape onto normal variants of the same protein. They characterize several fatal and transmissible neurodegenerative diseases in humans and many other animals. It is not known what causes a normal protein to misfold, but the resulting abnormal three-dimensional structure confers infectious properties by collapsing nearby protein molecules into the same shape. The word ''prion'' is derived from the term, "proteinaceous infectious particle". In comparison to all other known infectious agents such as viroids, viruses, bacteria, fungi, and parasites, all of which contain nucleic acids ( DNA, RNA, or both), the hypothesized role of a protein as an infectious agent stands in contrast. Prion isoforms of the prion protein (PrP), whose specific function is uncertain, are hypothesized as the cause of transmissible spongiform encephalopathies (TSEs), including scrapie in sheep, chronic wasting disease (CWD) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Dogma Of Molecular Biology
The central dogma of molecular biology is an explanation of the flow of genetic information within a biological system. It is often stated as "DNA makes RNA, and RNA makes protein", although this is not its original meaning. It was first stated by Francis Crick in 1957, then published in 1958: He re-stated it in a ''Nature'' paper published in 1970: "The central dogma of molecular biology deals with the detailed residue-by-residue transfer of sequential information. It states that such information cannot be transferred back from protein to either protein or nucleic acid." A second version of the central dogma is popular but incorrect. This is the simplistic DNA → RNA → protein pathway published by James Watson in the first edition of ''The Molecular Biology of the Gene'' (1965). Watson's version differs from Crick's because Watson describes a two-step (DNA → RNA and RNA → protein) process as the central dogma. While the dogma, as originally stated by Crick, remains ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmissible Spongiform Encephalopathy
Transmissible spongiform encephalopathies (TSEs) are a group of progressive and fatal conditions that are associated with prions and affect the brain and nervous system of many animals, including humans, cattle, and sheep. According to the most widespread hypothesis, they are transmitted by prions, though some other data suggest an involvement of a ''Spiroplasma'' infection. Mental and physical abilities deteriorate and many tiny holes appear in the cortex causing it to appear like a sponge when brain tissue obtained at autopsy is examined under a microscope. The disorders cause impairment of brain function, including memory changes, personality changes and problems with movement that worsen chronically. TSEs of humans include Creutzfeldt–Jakob disease, Gerstmann–Sträussler–Scheinker syndrome, fatal familial insomnia, and kuru, as well as the recently discovered variably protease-sensitive prionopathy and familial spongiform encephalopathy. Creutzfeldt-Jakob disease itsel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louis Harold Gray
Louis Harold Gray FRS (10 November 1905 – 9 July 1965) was an English physicist who worked mainly on the effects of radiation on biological systems. He was one of the earliest contributors of the field of radiobiology. A summary of his work is given below. Amongst many other achievements, he defined a unit of radiation dosage which was later named after him as an SI unit, the gray. Career * 1933 - Hospital physicist at Mount Vernon Hospital, London * 1936 - Developed the Bragg–Gray equation, the basis for the cavity ionization method of measuring gamma-ray energy absorption by materials * 1937 - Built an early neutron generator at Mount Vernon Hospital * 1938 - Studied biological effects of neutrons using the generator * 1940 - Developed concept of RBE (Relative Biological Effectiveness) of doses of neutrons * 1952 - Initiated research into cells in hypoxic tumors and hyperbaric oxygen * 1953 - Established the British Empire Cancer Campaign Research Unit in Radiobiolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apartheid
Apartheid (, especially South African English: , ; , "aparthood") was a system of institutionalised racial segregation that existed in South Africa and South West Africa (now Namibia) from 1948 to the early 1990s. Apartheid was characterised by an authoritarian political culture based on ''baasskap'' (boss-hood or boss-ship), which ensured that South Africa was dominated politically, socially, and economically by the nation's minority white population. According to this system of social stratification, white citizens had the highest status, followed by Indians and Coloureds, then black Africans. The economic legacy and social effects of apartheid continue to the present day. Broadly speaking, apartheid was delineated into ''petty apartheid'', which entailed the segregation of public facilities and social events, and ''grand apartheid'', which dictated housing and employment opportunities by race. The first apartheid law was the Prohibition of Mixed Marriages ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
