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https://en.wikipedia.org/wiki/Erwin%20Hahn
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Erwin Louis Hahn (June 9, 1921 – September 20, 2016) was an American physicist, best known for his work on nuclear magnetic resonance (NMR). In 1950 he discovered the spin echo.
Education
He grew up in Sewickley, Pennsylvania. He received his B.S. in Physics from Juniata College and his M.S. and Doctor of Philosophy from the University of Illinois at Urbana–Champaign. He served as an enlisted sailor in the United States Navy and was an instructor on radar and sonar.
Career and research
He was professor of physics, from 1955 to 1991, and subsequently, Professor Emeritus at the University of California, Berkeley. Hahn was elected a Fellow of the American Academy of Arts and Sciences in 1971. In 1993 he was awarded the Comstock Prize in Physics from the National Academy of Sciences. In 2013, Sir Peter Mansfield said in his autobiography that Hahn was "the person who really missed out" the Nobel Prize for his contribution to the principles of spin echoes. He also received the 2016 Gold Medal from the International Society for Magnetic Resonance in Medicine (ISMRM). The award, ISMRM's highest honor, was given to Hahn for his creation of pulsed magnetic resonance and processes of signal refocusing which are essential to modern day MRI. He died at the age of 95 in 2016.
See also
References
External links
Oral History interview transcript with Erwin L. Hahn on 21 August 1986, American Institute of Physics, Niels Bohr Library and Archives
Alexander Pines and Dmitry Budker, "E
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https://en.wikipedia.org/wiki/Martin%20Karplus
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Martin Karplus (; born March 15, 1930) is an Austrian and American theoretical chemist. He is the Director of the Biophysical Chemistry Laboratory, a joint laboratory between the French National Center for Scientific Research and the University of Strasbourg, France. He is also the Theodore William Richards Professor of Chemistry, emeritus at Harvard University. Karplus received the 2013 Nobel Prize in Chemistry, together with Michael Levitt and Arieh Warshel, for "the development of multiscale models for complex chemical systems".
Early life
Martin Karplus was born in Vienna, Austria. He was a child when his family fled from the Nazi-occupation in Austria a few days after the Anschluss in March 1938, spending several months in Zürich, Switzerland and La Baule, France before immigrating to the United States. Prior to their immigration to the United States, the family was known for being "an intellectual and successful secular Jewish family" in Vienna. His grandfather, Johann Paul Karplus (1866–1936) was a highly acclaimed professor of psychiatry at the University of Vienna. His great-aunt, Eugenie Goldstern, was an ethnologist who was killed during the Holocaust. He is the nephew, by marriage, of the sociologist, philosopher and musicologist Theodor W. Adorno and grandnephew of the physicist Robert von Lieben. His brother, Robert Karplus, was an internationally recognized physicist and educator at University of California, Berkeley. Continuing with the academic family theme
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https://en.wikipedia.org/wiki/Joseph%20Keller
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Joseph Bishop Keller (July 31, 1923 – September 7, 2016) was an American mathematician who specialized in applied mathematics. He was best known for his work on the "geometrical theory of diffraction" (GTD).
Early life and education
Born in Paterson, New Jersey on July 31, 1923, Keller attended Eastside High School, where he was a member of the math team. After earning his undergraduate degree in 1943 at New York University, Keller obtained his PhD in 1948 from NYU under the supervision of Richard Courant. He was a professor of mathematics in the Courant Institute at New York University until 1979. Then he was Professor of Mathematics and Mechanical Engineering at Stanford University until 1993, when he became professor emeritus.
Research
Keller worked on the application of mathematics to problems in science and engineering, such as wave propagation. He contributed to the Einstein–Brillouin–Keller method for computing eigenvalues in quantum mechanical systems.
Awards and honors
Keller was awarded a Lester R. Ford Award (shared with David W. McLaughlin) in 1976 and (not shared) in 1977. In 1988 he was awarded the U.S. National Medal of Science, and in 1997 he was awarded the Wolf Prize by the Israel-based Wolf Foundation. In 1996, he was awarded the Nemmers Prize in Mathematics. In 1999 he was awarded the Ig Nobel Prize for calculating how to make a teapot spout that does not drip. With Patrick B. Warren, Robin C. Ball and Raymond E. Goldstein, Keller was awarded an
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https://en.wikipedia.org/wiki/Elliot%20Meyerowitz
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Elliot Meyerowitz (born May 22, 1951) is an American biologist.
Career
Meyerowitz did his undergraduate work at Columbia University (A.B. in biology, 1973), where he worked part-time in the laboratory of Cyrus Levinthal on combined microscopic and computational methods for tracing axons and dendritic trees in the nervous systems of fish. His graduate work was in the Department of Biology at Yale University (Ph.D. 1977), where he worked in the laboratory of Douglas Kankel on the interaction of eye and brain development in Drosophila, by use of genetic mosaics. From 1977 to 1979 he was a postdoctoral fellow in the laboratory of David Hogness in the Biochemistry Department at the Stanford University School of Medicine, developing and using methods for the molecular cloning of genes in the early days of gene cloning and genomics. Since 1980 he has been a faculty member in the Division of Biology at the California Institute of Technology, where he served as division chair from 2000 to 2010, and where he is now George W. Beadle Professor of Biology. Between 2011 and 2013, he was appointed as inaugural director of the Sainsbury Laboratory at the University of Cambridge and elected into a professorship in the university, and a professorial fellow at Trinity College, while on leave from the California Institute of Technology.
Meyerowitz was a Drosophila melanogaster expert before he became a pioneer of Arabidopsis thaliana research. Dr. Meyerowitz is well known for his contributions
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https://en.wikipedia.org/wiki/Gilbert%20Stork
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Gilbert Stork (December 31, 1921 – October 21, 2017) was an organic chemist. For a quarter of a century he was the Eugene Higgins Professor of Chemistry Emeritus at Columbia University. He is known for making significant contributions to the total synthesis of natural products, including a lifelong fascination with the synthesis of quinine. In so doing he also made a number of contributions to mechanistic understanding of reactions, and performed pioneering work on enamine chemistry, leading to development of the Stork enamine alkylation.
It is believed he was responsible for the first planned stereocontrolled synthesis as well as the first natural product to be synthesised with high stereoselectivity.
Stork was also an accomplished mentor of young chemists and many of his students have gone on to make significant contributions in their own right.
Early years
Gilbert Stork was born in the Ixelles municipality of Brussels, Belgium on December 31, 1921. The oldest of 3 children, his middle brother, Michel, died in infancy, but he remained close with his younger sister Monique his whole life. His family had Jewish origins, although Gilbert himself didn't recall them being religiously active. The family moved to Nice when Gilbert was about 14 (circa. 1935) and remained there until 1939. During this period, Gilbert completed his lycée studies, distinguishing himself in French literature and writing. Characterizing himself during those years as "not terribly self-confident," an
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https://en.wikipedia.org/wiki/Valentine%20Telegdi
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Valentine Louis Telegdi (Hungarian: Telegdi Bálint; 11 January 1922 – April 8, 2006) was a Hungarian-born American physicist. He was the Enrico Fermi Distinguished Service Professor of Physics at the University of Chicago before he moved to ETH Zürich.
After retiring from ETH he divided his time between CERN and the California Institute of Technology. Telegdi chaired CERN's scientific policy committee from 1981 to 1983.
According to György Marx he was one of The Martians.
Awards and honours
In 1991 he shared the Wolf Prize in Physics with Maurice Goldhaber. He was elected a Foreign Member of the Royal Society (ForMemRS) in 2003.
See also
The Martians (scientists)
References
1922 births
2006 deaths
20th-century American physicists
People associated with CERN
Academic staff of ETH Zurich
20th-century Hungarian physicists
Particle physicists
Jewish American scientists
Jewish physicists
Hungarian Jews
Foreign Members of the Royal Society
Foreign Members of the Russian Academy of Sciences
Members of the Hungarian Academy of Sciences
Members of the French Academy of Sciences
Members of the United States National Academy of Sciences
Wolf Prize in Physics laureates
Hungarian emigrants to the United States
20th-century American Jews
21st-century American Jews
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https://en.wikipedia.org/wiki/Charles%20Weissmann
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Charles Weissmann (born 14 October 1931) is a Hungarian-Swiss molecular biologist. Weissmann is particularly known for the first cloning and expression of interferon and his contributions to the unraveling of the molecular genetics of neurogenerative prion diseases such as scrapie, Creutzfeldt–Jakob disease and "mad cow disease".
Weissmann went to University of Zurich and obtained his MD in 1956 and Ph.D. in Organic Chemistry in 1961. In 1978, Weissmann co-founded the biotech company Biogen in Geneva. Biogen is considered one of the pioneers of the biotechnology industries. Weissmann was director of the Institute for Molecular Biology in Zurich, President of the Roche Research Foundation and co-founder and Member of the Scientific Council of Biogen. He was Chairman of the Department of Infectology, Scripps Florida until 2011.
Weissmann won several awards, including the Otto Warburg Medal (1980) and the Scheele Award (1982). A member of the American Society of Biological Chemistry and the Deutsche Akademie der Naturforscher Leopoldina he is also a Foreign Associate of the U.S. National Academy of Sciences, the Royal Society (UK) and the Pour le Mérite (Germany). On May 16, 2011 Weissmann became Doctor of Science Honoris Causa at New York University.
Awards
Sir Hans Krebs Medal (1974).
Otto Warburg Medal (1980).
Scheele Award (1982).
Wilhelm Exner Medal (1996).
Max Delbrück Medal (1997)
Mendel Medal (1998)
References
External links
Profile at The Scripps Research Institu
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https://en.wikipedia.org/wiki/Frank%20Westheimer
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Frank Henry Westheimer NAS ForMemRS APS (January 15, 1912 – April 14, 2007) was an American chemist. He taught at the University of Chicago from 1936 to 1954, and at Harvard University from 1953 to 1983, becoming the Morris Loeb Professor of Chemistry in 1960, and Professor Emeritus in 1983. The Westheimer medal was established in his honor in 2002.
Westheimer did pioneering work in physical organic chemistry,
applying techniques from physical to organic chemistry and integrating the two fields.
He explored the mechanisms of chemical and enzymatic reactions,
and made fundamental theoretical advances.
Westheimer worked with John Gamble Kirkwood on the Bjerrum electrostatic analysis of carboxylic acids;
with Joseph Edward Mayer on the calculation of molecular mechanics;
explored the mechanisms of enzyme catalysis with Birgit Vennesland
and determined the mechanisms of chromic acid oxidations and kinetic isotope effects.
He received the National Medal of Science in 1986 "For his series of extraordinary, original and penetrating investigations of the mechanisms of organic and enzymic reactions, which have played an unequaled role in the advancement of our knowledge of the ways in which chemical and biochemical processes proceed."
Early life and education
Frank Henry Westheimer was born on January 15, 1912, to Henry F. Westheimer (1870–1960) and Carrie C (Burgunder) Westheimer (1887–1972) of Baltimore, Maryland.
He graduated from Dartmouth College in 1932. He went on to
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https://en.wikipedia.org/wiki/Richard%20Zare
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Richard Neil Zare (born November 19, 1939, in Cleveland, Ohio) is the Marguerite Blake Wilbur Professor in Natural Science and a Professor of Chemistry at Stanford University. Throughout his career, Zare has made a considerable impact in physical chemistry and analytical chemistry, particularly through the development of laser-induced fluorescence (LIF) and the study of chemical reactions at the molecular and nanoscale level. LIF is an extremely sensitive technique with applications ranging from analytical chemistry and molecular biology to astrophysics. One of its applications was the sequencing of the human genome.
Zare is known for his enthusiasm for science and his exploration of new areas of research. He has mentored over 150 PhD students and postdoctoral researchers, of whom more than 49 are women or members of minorities. Zare is a strong advocate for women in science, and a fellow of the Association for Women in Science (AWIS) as of 2008.
Education
Zare earned his BA in chemistry and physics in 1961 and his PhD in 1964 in physical and analytical chemistry at Harvard University. As an undergraduate he worked with William Klemperer. Zare moved to the University of California, Berkeley to do PhD work with Dudley Herschbach, then returned 2 years later when Herschbach accepted a position at Harvard. Zare completed his PhD thesis, a theoretical analysis of Molecular fluorescence and photodissociation, with Herschbach at Harvard in 1964.
Career
Zare joined Massachusett
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https://en.wikipedia.org/wiki/Moscow%20School%20of%20Mathematics%20and%20Navigation
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Moscow School of Mathematics and Navigation () was a Russian educational institution founded by Peter the Great in 1701. Situated in the Sukharev Tower, it provided Russians with technical education for the first time and much of its curriculum was devoted to producing sailors, engineers, cartographers and bombardiers to support Peter's expanding navy and army. It is the forerunner of the modern system of technical education of Russia. In 1712, Artillery classes and Engineering classes were moved to Saint Petersburg to found the Engineering school and Artillery school. Abram Petrovich Gannibal was the first chief of engineering school. In 1715 Navigator classes were moved to Saint Petersburg to found the Marine academy. The school closed in 1752.
Sources
Schools in Russia
Schools in Moscow
1701 establishments in Russia
1752 disestablishments
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https://en.wikipedia.org/wiki/Bengt%20Gustafsson%20%28astronomer%29
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Bengt Gustafsson (born 18 July 1943) is a Swedish astronomer and emeritus professor in theoretical astrophysics at Uppsala University.
He is known for his work in uniting cosmic science with culture and theology, and questioning space science from a humanistic point of view. Gustafsson received an honorary doctorate from the Faculty of Theology at Uppsala University in 2000. In 2002, Gustafsson was awarded the grand prize of the Royal Institute of Technology, and has also been awarded the grand prize of Längmanska kulturfonden. At one point during his career, he was a counselor working for the government of Sweden.
He is a member of the Norwegian Academy of Science and Letters.
References
External links
Bengt Gustafsson
Members of the Norwegian Academy of Science and Letters
20th-century Swedish astronomers
21st-century Swedish astronomers
Academic staff of Uppsala University
1943 births
Living people
Members of the Royal Swedish Academy of Sciences
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https://en.wikipedia.org/wiki/Lateral%20inhibition
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In neurobiology, lateral inhibition is the capacity of an excited neuron to reduce the activity of its neighbors. Lateral inhibition disables the spreading of action potentials from excited neurons to neighboring neurons in the lateral direction. This creates a contrast in stimulation that allows increased sensory perception. It is also referred to as lateral antagonism and occurs primarily in visual processes, but also in tactile, auditory, and even olfactory processing. Cells that utilize lateral inhibition appear primarily in the cerebral cortex and thalamus and make up lateral inhibitory networks (LINs). Artificial lateral inhibition has been incorporated into artificial sensory systems, such as vision chips, hearing systems, and optical mice. An often under-appreciated point is that although lateral inhibition is visualised in a spatial sense, it is also thought to exist in what is known as "lateral inhibition across abstract dimensions." This refers to lateral inhibition between neurons that are not adjacent in a spatial sense, but in terms of modality of stimulus. This phenomenon is thought to aid in colour discrimination.
History
The concept of neural inhibition (in motor systems) was well known to Descartes and his contemporaries.
Sensory inhibition in vision was inferred by Ernst Mach in 1865 as depicted in his mach band.
Inhibition in single sensory neurons was discovered and investigated starting in 1949 by Haldan K. Hartline when he used logarithms to expr
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https://en.wikipedia.org/wiki/Abudefduf
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Abudefduf, also known as the sergeant-majors, is a genus of fish in the family Pomacentridae.
The name is from Arabic abu, "the one with"; and def, "side", and the intensive plural ending -duf. The name thus means "the one with prominent sides".
General biology
The approximately 20 species of Abudefduf may be divided into planktivores and benthivores and three broadly pantropical clades. Two of the Abudefduf clades are primarily benthivorous and a third clade is composed of planktivores and is the most species-rich. Most diversification has occurred in the last 10 million years within this genus across all clades.
Species
The following 21 species are recognized in the genus Abudefduf:
Abudefduf abdominalis (Quoy & Gaimard, 1825) (Green damselfish)
Abudefduf bengalensis (Bloch, 1787) (Bengal sergeant)
Abudefduf caudobimaculatus Okada & Ikeda, 1939 (Okinawa sergeant)
Abudefduf concolor (T. N. Gill, 1862)
Abudefduf conformis J. E. Randall & Earle, 1999
Abudefduf declivifrons (T. N. Gill, 1862) (Mexican nightsergeant)
Abudefduf hoefleri (Steindachner, 1881) (African sergeant)
Abudefduf lorenzi Hensley & G. R. Allen, 1977 (Black-tail sergeant)
Abudefduf margariteus (G. Cuvier, 1830) (Pearly sergeant)
Abudefduf natalensis Hensley & J. E. Randall, 1983 (Natal sergeant)
Abudefduf nigrimargo Wibowo, Koeda, Muto & Motomura, 2018 (Black margined-scale sergeant)
Abudefduf notatus (F. Day, 1870) (Yellowtail sergeant)
Abudefduf saxatilis (Linnaeus, 17
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https://en.wikipedia.org/wiki/SMO
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SMO or Smo may refer to:
War
Special military operation, the Russian government's name for the 2022 Invasion of Ukraine
Biology
Smoothened, a gene that encodes a protein of the same name
Spermine oxidase, an enzyme
Styrene monooxygenase, an enzyme
Computing and technology
Sequential minimal optimization, an algorithm for training support vector machines
Social media optimization
Solar Monitoring Observatory, on the International Space Station
SQL Server Management Objects for Microsoft SQL Server
Organizations
Sabhal Mòr Ostaig, a Scottish Gaelic-medium public college on the Isle of Skye
Slovak Youth Orchestra
Transport
SMO, IATA airport code for Santa Monica Airport, USA
SMO, National Rail station code for South Merton railway station, London
Other uses
SMO, ITU country code for Samoa
smo, ISO 639-3 code for the Samoan language
Smo, former stage name of Sara Forsberg (born 1994), Finnish singer
SMO, a character first appeared in the episode "Be More" of the animated series Adventure Time
Senior Medical Officer, a rank in the British Royal Army Medical Corps
Singapore Mathematical Olympiad, a mathematics competition
Site management organization, a provider of services to an organization holding a clinical trial
Social movement organization, a formal organization within a social movement
Special military operation, particularly by Russia in Ukraine
Super Mario Odyssey, a video game released for the Nintendo Switch
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https://en.wikipedia.org/wiki/Session%20hijacking
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In computer science, session hijacking, sometimes also known as cookie hijacking, is the exploitation of a valid computer session—sometimes also called a session key—to gain unauthorized access to information or services in a computer system. In particular, it is used to refer to the theft of a magic cookie used to authenticate a user to a remote server. It has particular relevance to web developers, as the HTTP cookies used to maintain a session on many websites can be easily stolen by an attacker using an intermediary computer or with access to the saved cookies on the victim's computer (see HTTP cookie theft). After successfully stealing appropriate session cookies an adversary might use the Pass the Cookie technique to perform session hijacking. Cookie hijacking is commonly used against client authentication on the internet. Modern web browsers use cookie protection mechanisms to protect the web from being attacked.
A popular method is using source-routed IP packets. This allows an attacker at point B on the network to participate in a conversation between A and C by encouraging the IP packets to pass through B's machine.
If source-routing is turned off, the attacker can use "blind" hijacking, whereby it guesses the responses of the two machines. Thus, the attacker can send a command, but can never see the response. However, a common command would be to set a password allowing access from elsewhere on the net.
An attacker can also be "inline" between A and C using a sn
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https://en.wikipedia.org/wiki/Kohn%E2%80%93Sham%20equations
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The Kohn-Sham equations are a set of mathematical equations used in quantum mechanics to simplify the complex problem of understanding how electrons behave in atoms and molecules. They introduce fictitious non-interacting electrons and use them to find the most stable arrangement of electrons, which helps scientists understand and predict the properties of matter at the atomic and molecular scale.
Description
In physics and quantum chemistry, specifically density functional theory, the Kohn–Sham equation is the non-interacting Schrödinger equation (more clearly, Schrödinger-like equation) of a fictitious system (the "Kohn–Sham system") of non-interacting particles (typically electrons) that generate the same density as any given system of interacting particles.
In the Kohn–Sham theory the introduction of the noninteracting kinetic energy functional Ts into the energy expression leads, upon functional differentiation, to a collection of one-particle equations whose solutions are the Kohn–Sham orbitals.
The Kohn–Sham equation is defined by a local effective (fictitious) external potential in which the non-interacting particles move, typically denoted as vs(r) or veff(r), called the Kohn–Sham potential. If the particles in the Kohn–Sham system are non-interacting fermions (non-fermion Density Functional Theory has been researched), the Kohn–Sham wavefunction is a single Slater determinant constructed from a set of orbitals that are the lowest-energy solutions to
This e
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https://en.wikipedia.org/wiki/De%20Furtivis%20Literarum%20Notis
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De Furtivis Literarum Notis (On the Secret Symbols of Letters) is a 1563 book on cryptography written by Giambattista della Porta.
The book includes three sets of cypher discs for coding and decoding messages and a substitution cipher improving on the work of Al-Qalqashandi.
References
1563 books
Cryptography books
Non-fiction books
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https://en.wikipedia.org/wiki/Harry%20Gunning
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Harry Emmet Gunning, (December 16, 1916 – November 24, 2002) was a Canadian scientist and administrator.
Born in Toronto, Ontario, he received a Bachelor of Arts degree, a Master of Arts degree, and a Ph.D. in physical chemistry in 1942 from the University of Toronto.
In 1957, he was appointed Professor and Chairman of the Department of Chemistry at the University of Alberta. From 1974 to 1979, he was the President as well.
In 1979, he was made an Officer of the Order of Canada as a "scientist and educator, who has achieved an international reputation for chemical research".
Career
Gunning attended the University of Toronto, and there he earned three degrees in physical chemistry; a BA Honors, an MA, and a PhD. He finished his schooling in 1942, when he earned his PhD. Next, he did post-doctoral studies at Harvard. After that, Gunning returned to Canada and became a research chemist in Dr. Edgar Steacie's laboratory in Ottawa. He also did research for the National Research council at the time. In 1946, he became a professor at the University of Rochester and then at the Illinois Institute of Technology. In 1957, he returned to Canada again and became Professor and Chair of the Department of Chemistry at the University of Alberta. He was very passionate about building up the department to much higher standards. In the next ten years, Gunning's work achieved the University's chemistry department international recognition and it became a rapidly evolving center for chemi
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https://en.wikipedia.org/wiki/Guido%20Beck
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Guido Beck (29 August 1903 in Liberec – 21 October 1988 in Rio de Janeiro) was an Argentinian physicist of German Bohemian origin.
Biography
Beck studied physics in Vienna and received his doctorate in 1925, under Hans Thirring. He worked in Leipzig in 1928 as an assistant to Werner Heisenberg. A combination of the troubled political climate of Europe in the 1930s, his own restlessness, and the Nazi persecutions in Germany, made the Jewish-born Beck a traveler in those years. Until 1935 he worked in Cambridge with Ernest Rutherford, Copenhagen, Prague, United States and Japan.
In 1935, Beck was invited to work in the Soviet Union by Head of the Institute of Physics, Odessa University Yelpidifor Anempodistovich Kirillov. At the Odessa University Beck was head of the Department of Theoretical Physics and gave a course of theoretical physics in German; his lectures were simultaneously translated into Ukrainian by his assistant Yu.G. Vekshtein. In 1936–1937 Beck was head of the department of theoretical mechanics at the Institute of Water Transport Engineers in Odessa. Four of his Odessa students – VV Malyarov, MM Alperin, GV Skrotskii and PE Nemirovsky – became professors in Odessa and Moscow.
In 1937, Guido Beck moved to France, where he was imprisoned when World War II broke out. In 1941, he fled to Portugal. From 1942 to 1943 he was a guest professor at the University of Coimbra and the University of Oporto. In 1943 he emigrated to Argentina.
In Argentina, he was instrum
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https://en.wikipedia.org/wiki/Kappa%20Epsilon
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Kappa Epsilon () is an American professional women's pharmacy fraternity founded in Iowa in 1921. Today, KE has 43 collegiate chapters and ten alumni chapters. Over 20,000 women and men have been initiated into ΚΕ since its founding.
History
Kappa Epsilon was established on May 13, 1921, in the Hall of Pharmacy and Chemistry at the University of Iowa. Its founders were professor Zada M. Cooper and members of women's pharmacy clubs at the University of Iowa, the University of Minnesota, and the University of Nebraska. The fraternity was founded to unite female pharmacy students in an era when women were a minority in the profession. Its name was taken from the pharmacy club at the University of Minnesota, the oldest of the three clubs.
In 1942, the fraternity published an official songbook that included original compositions such as the "Kappa Epsilon Pledging Song." The songbook was revised in the 1960s. To encourage women to become pharmacists, Kappa Epsilon published several books, including Women in Pharmacy in 1950, She Is a Pharmacist in 1958, and Pharmacy-Career for the Modern Girl in 1970.
The fraternity was incorporated in January 1960 in Minnesota. Every two years, the fraternity holds a convention where national officers are elected and collegiate and alumni members can network. At the 15th convention in April 1947, the fraternity updated its policies to allow Jews to be admitted. At its 31st convention in 1977, Kappa Epsilon voted to allow men to join as full m
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https://en.wikipedia.org/wiki/Polar%20effect
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The polar effect or electronic effect in chemistry is the effect exerted by a substituent on modifying electrostatic forces operating on a nearby reaction center. The main contributors to the polar effect are the inductive effect, mesomeric effect and the through-space electronic field effect.
An electron-withdrawing group (EWG) draws electrons away from a reaction center. When this center is an electron rich carbanion or an alkoxide anion, the presence of the electron-withdrawing substituent has a stabilizing effect.
Examples of electron withdrawing groups are
halogens (F, Cl);
nitriles CN;
carbonyls RCOR';
nitro groups NO2.
An electron-releasing group (ERG) or electron-donating group (EDG) releases electrons into a reaction center and as such stabilizes electron deficient carbocations.
Examples of electron releasing groups are
alkyl groups;
alcohol groups;
amino groups.
The total substituent effect is the combination of the polar effect and the combined steric effects.
In electrophilic aromatic substitution and nucleophilic aromatic substitution substituents are divided into activating groups and deactivating groups where the direction of activation or deactivation is also taken into account.
References
External links
Polar effect definition by the IUPAC Gold Book
Physical organic chemistry
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https://en.wikipedia.org/wiki/S-function
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In mathematics, S-function may refer to:
sigmoid function
Schur polynomials
A function in the Laplace transformed 's-domain'
In computer science,
It may be member of a series of graph parameters, see
In physics, it may refer to:
action functional
In MATLAB, it may refer to:
A type of dynamically linked subroutine for Simulink.
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https://en.wikipedia.org/wiki/Joseph%20Winlock
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Joseph Winlock (February 6, 1826 – June 11, 1875) was an American astronomer and mathematician.
Biography
He was born in Shelby County, Kentucky, the grandson of General Joseph Winlock (1758–1831). After graduating from Shelby College in Kentucky in 1845, he was appointed professor of mathematics and astronomy at that institution.
From 1852 until 1857 he worked as a computer for the American Ephemeris and Nautical Almanac, and relocated to Cambridge, Massachusetts. He briefly served as head of the department of mathematics at the United States Naval Academy, but returned as superintendent of the Almanac office. He was elected a Fellow of the American Academy of Arts and Sciences in 1853.
He married Isabella Washington in Shelbyville, Kentucky on December 10, 1856, and they had six children.
In 1863 he was one of the fifty charter members of the National Academy of Sciences. Three year later in 1866 he became director of the Harvard College Observatory, succeeding George Bond, and making many improvements in the facility. He was also appointed professor of astronomy at Harvard. He remained at the university, eventually becoming professor of geodesy until his sudden death in Cambridge on June 11, 1875.
Much of his astronomical work included measurements with the meridian circle, a catalogue of double stars and stellar photometry investigations. He also led solar eclipse expeditions to Kentucky in 1860 and Spain in 1870.
The crater Winlock on the Moon is named after him.
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https://en.wikipedia.org/wiki/Pixie%20%28renderer%29
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Pixie is a free (open source), photorealistic raytracing renderer for generating photorealistic images, developed by Okan Arikan in the Department of Computer Science at The University of Texas At Austin. It is RenderMan-compliant (meaning it reads conformant RIB, and supports full SL shading language shaders) and is based on the Reyes rendering architecture, but also support raytracing for hidden surface determination.
Like the proprietary BMRT, Pixie is popular with students learning the RenderMan Interface, and is a suitable replacement for it.
Contributions to Pixie are facilitated by SourceForge and the Internet where it can also be downloaded free of charge as source code or precompiled. It compiles for Windows (using Visual Studio 2005), Linux and on Mac OS X (using Xcode or Unix-style configure script).
Key features include:
64-bit Capable
Fast multi-threaded execution.
Possibility to distribute the rendering process to several machines.
Motion blur and depth of field.
Programmable shading (using RenderMan Shading Language) including full displacement support.
Scalable, multi-resolution raytracing using ray differentials.
Global illumination.
Support for conditional RIB.
Point cloud baking and 3D textures.
Pixie is developed by Okan Arikan and George Harker.
External links
Home page
Pixie Wiki
Blender - Open Source 3D Creator
Rib Mosaic - Blender Rib Export
Free 3D graphics software
3D rendering software for Linux
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https://en.wikipedia.org/wiki/Geometric%20topology%20%28object%29
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In mathematics, the geometric topology is a topology one can put on the set H of hyperbolic 3-manifolds of finite volume.
Use
Convergence in this topology is a crucial ingredient of hyperbolic Dehn surgery, a fundamental tool in the theory of hyperbolic 3-manifolds.
Definition
The following is a definition due to Troels Jorgensen:
A sequence in H converges to M in H if there are
a sequence of positive real numbers converging to 0, and
a sequence of -bi-Lipschitz diffeomorphisms
where the domains and ranges of the maps are the -thick parts of either the 's or M.
Alternate definition
There is an alternate definition due to Mikhail Gromov. Gromov's topology utilizes the Gromov-Hausdorff metric and is defined on pointed hyperbolic 3-manifolds. One essentially considers better and better bi-Lipschitz homeomorphisms on larger and larger balls. This results in the same notion of convergence as above as the thick part is always connected; thus, a large ball will eventually encompass all of the thick part.
On framed manifolds
As a further refinement, Gromov's metric can also be defined on framed hyperbolic 3-manifolds. This gives nothing new but this space can be explicitly identified with torsion-free Kleinian groups with the Chabauty topology.
See also
Algebraic topology (object)
References
William Thurston, The geometry and topology of 3-manifolds, Princeton lecture notes (1978-1981).
Canary, R. D.; Epstein, D. B. A.; Green, P., Notes on notes of Thurston. A
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https://en.wikipedia.org/wiki/SBML
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The Systems Biology Markup Language (SBML) is a representation format, based on XML, for communicating and storing computational models of biological processes. It is a free and open standard with widespread software support and a community of users and developers. SBML can represent many different classes of biological phenomena, including metabolic networks, cell signaling pathways, regulatory networks, infectious diseases, and many others. It has been proposed as a standard for representing computational models in systems biology today.
History
Late in the year 1999 through early 2000, with funding from the Japan Science and Technology Corporation (JST), Hiroaki Kitano and John C. Doyle assembled a small team of researchers to work on developing better software infrastructure for computational modeling in systems biology. Hamid Bolouri was the leader of the development team, which consisted of Andrew Finney, Herbert Sauro, and Michael Hucka. Bolouri identified the need for a framework to enable interoperability and sharing between the different simulation software systems for biology in existence during the late 1990s, and he organized an informal workshop in December 1999 at the California Institute of Technology to discuss the matter. In attendance at that workshop were the groups responsible for the development of DBSolve, E-Cell, Gepasi, Jarnac, StochSim, and The Virtual Cell. Separately, earlier in 1999, some members of these groups also had discussed the creation
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https://en.wikipedia.org/wiki/Cuntz%20algebra
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In mathematics, the Cuntz algebra , named after Joachim Cuntz, is the universal C*-algebra generated by isometries of an infinite-dimensional Hilbert space satisfying certain relations. These algebras were introduced as the first concrete examples of a separable infinite simple C*-algebra, meaning as a Hilbert space, is isometric to the sequence space
and it has no nontrivial closed ideals. These algebras are fundamental to the study of simple infinite C*-algebras since any such algebra contains, for any given n, a subalgebra that has as quotient.
Definitions
Let n ≥ 2 and be a separable Hilbert space. Consider the C*-algebra generated by a set
of isometries (i.e. ) acting on satisfying
This universal C*-algebra is called the Cuntz algebra, denoted by .
A simple C*-algebra is said to be purely infinite if every hereditary C*-subalgebra of it is infinite. is a separable, simple, purely infinite C*-algebra. Any simple infinite C*-algebra contains a subalgebra that has as a quotient.
Properties
Classification
The Cuntz algebras are pairwise non-isomorphic, i.e. and are non-isomorphic for n ≠ m. The K0 group of is , the cyclic group of order n − 1. Since K0 is a functor, and are non-isomorphic.
Relation between concrete C*-algebras and the universal C*-algebra
Theorem. The concrete C*-algebra is isomorphic to the universal C*-algebra generated by n generators s1... sn subject to relations si*si = 1 for all i and ∑ sisi* = 1.
The proof of the theorem h
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https://en.wikipedia.org/wiki/Gas%20kinetics
|
Gas kinetics is a science in the branch of fluid dynamics, concerned with the study of motion of gases and its effects on physical systems. Based on the principles of fluid mechanics and thermodynamics, gas dynamics arises from the studies of gas flows in transonic and supersonic flights. To distinguish itself from other sciences in fluid dynamics, the studies in gas dynamics are often defined with gases flowing around or within physical objects at speeds comparable to or exceeding the speed of sound and causing a significant change in temperature and pressure. Some examples of these studies include but are not limited to: choked flows in nozzles and valves, shock waves around jets, aerodynamic heating on atmospheric reentry vehicles and flows of gas fuel within a jet engine. At the molecular level, gas dynamics is a study of the kinetic theory of gases, often leading to the study of gas diffusion, statistical mechanics, chemical thermodynamics and non-equilibrium thermodynamics. Gas dynamics is synonymous with aerodynamics when the gas field is air and the subject of study is flight. It is highly relevant in the design of aircraft and spacecraft and their respective propulsion systems.
History
Progress in gas dynamics coincides with the developments of transonic and supersonic flights. As aircraft began to travel faster, the density of air began to change, considerably increasing the air resistance as the air speed approached the speed of sound. The phenomenon was l
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https://en.wikipedia.org/wiki/Paul%20W.%20K.%20Rothemund
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Paul Wilhelm Karl Rothemund is a research professor at the Computation and Neural Systems department at Caltech. He has become known in the fields of DNA nanotechnology and synthetic biology for his pioneering work with DNA origami. He shared both categories of the 2006 Feynman Prize in Nanotechnology with Erik Winfree for their work in creating DNA nanotubes, algorithmic molecular self-assembly of DNA tile structures, and their theoretical work on DNA computing. Rothemund is also a 2007 recipient of the MacArthur Fellowship.
Life
Rothemund graduated from Laconia High School, New Hampshire, in 1990. He was the team captain of the championship Laconia team for the television quiz show Granite State Challenge. After graduating, Rothemund studied as an undergraduate at Caltech from 1990–1994, where he was a resident and member of Ricketts House. He attained his Ph.D. from the University of Southern California in 2001.
As a research fellow at Caltech, Rothemund has developed a technique to manipulate and fold strands of DNA known as DNA origami.
Eventually, Rothemund hopes that self-assembly techniques could be used to create a "programming language for molecules, just as we have programming languages for computers."
His work on large-scale sculptures of his DNA origami was exhibited at the Museum of Modern Art in New York from February 24 to May 12, 2008.
His grandfather, Paul Rothemund, was a chemist as well.
References
External links
Paul Rothemund's home page
Mar
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https://en.wikipedia.org/wiki/Multiplicity%20of%20infection
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In microbiology, the multiplicity of infection or MOI is the ratio of agents (e.g. phage or more generally virus, bacteria) to infection targets (e.g. cell). For example, when referring to a group of cells inoculated with virus particles, the MOI is the ratio of the number of virus particles to the number of target cells present in a defined space.
Interpretation
The actual number of viruses or bacteria that will enter any given cell is a stochastic process: some cells may absorb more than one infectious agent, while others may not absorb any. Before determining the multiplicity of infection, it's absolutely necessary to have a well-isolated agent, as crude agents may not produce reliable and reproducible results. The probability that a cell will absorb virus particles or bacteria when inoculated with an MOI of can be calculated for a given population using a Poisson distribution. This application of Poisson's distribution was applied and described by Ellis and Delbrück.
where is the multiplicity of infection or MOI, is the number of infectious agents that enter the infection target, and is the probability that an infection target (a cell) will get infected by infectious agents.
In fact, the infectivity of the virus or bacteria in question will alter this relationship. One way around this is to use a functional definition of infectious particles rather than a strict count, such as a plaque forming unit for viruses.
For example, when an MOI of 1 (1 infectious viral p
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https://en.wikipedia.org/wiki/Self-limiting
|
Self-limiting may refer to:
Self-limiting (biology), an organism or colony of organisms which limits its own growth
Governor (device), used to control the speed of mechanical equipment to prevent it from operating at unsafe speeds
Electronic speed limiter, a system set by a manufacturer or by a driver to limit the maximum speed which can be reached by a road vehicle
See also
Self-regulation (disambiguation)
|
https://en.wikipedia.org/wiki/John%20Ross%20%28chemist%29
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John Ross (October 2, 1926 – February 18, 2017) was a scientist in physical chemistry and the Camille and Henry Dreyfus Professor of Chemistry at Stanford University.
Unraveling the mechanisms of complex chemical reactions, Ross opened new avenues in physical chemistry through the development of groundbreaking methods to study complex reactions within intact systems. His theoretical and experimental studies in statistical mechanics and chemical kinetics proved new means to reveal details of biochemical reactions taking place far from equilibrium and involving many chemical species.
Education and career
Born in Vienna in 1926, Ross left Austria with his parents only days before the outbreak of World War II. They settled in New York, where he studied chemistry at Queens College (B.S. 1948), with a two-year interruption to serve in the Army from 1944 to 1946. After completing his degree, he went on to perform doctoral research in physical chemistry, studying gas transport properties under the guidance of Isador Amdur at the Massachusetts Institute of Technology (Ph.D. 1951). This led to postdoctoral work in gas thermometry and the statistical mechanical theory of irreversible processes with physical chemist John Kirkwood at Yale. Ross began his faculty career as assistant professor in chemistry at Brown University in 1953. There, he launched a program to test the viscosity of liquids as a function of temperature and pressure with unprecedented precision. Two years later, he an
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https://en.wikipedia.org/wiki/Stephen%20B.%20Streater
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Stephen Bernard Streater (born 1965) is a British technology entrepreneur.
Career
Streater was born in Boston Lying-In Hospital, Massachusetts, United States. He achieved a degree in mathematics from Trinity College, Cambridge and then began a PhD on artificial pattern recognition in the physics department at King's College London.
In 1990, he co-founded Eidos, a company specialising in video compression and non-linear editing systems, particularly for computers running the RISC OS operating system. He later sold and left Eidos, which had moved into the computer games market, and founded Blackbird in 2000, where he was the company's R&D Director.
On 21 July 2011, Streater was honoured by the University of Bedfordshire with a Doctor of Science degree in recognition of "outstanding contribution to the development of computer technologies."
Personal life
Streater is married to Victoria Jane (née Fantl) and has three daughters (Sophie, Juliette and Emily). He has a sister (Catherine) and a brother (Alexander). His hobbies include playing classical chamber and orchestral music, Go, new technology, and making videos. Streater's father, Ray Streater, is a professor of mathematics at King's College London.
References
External links
Blackbird plc
Stephen Bernard Streater, inventor – from his father's website
1965 births
Alumni of Trinity College, Cambridge
Alumni of King's College London
English businesspeople
Living people
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https://en.wikipedia.org/wiki/Exchange%20interaction
|
In chemistry and physics, the exchange interaction or exchange splitting (with an exchange energy and exchange term) is a quantum mechanical effect that only occurs between identical particles. Despite sometimes being called an exchange force in an analogy to classical force, it is not a true force as it lacks a force carrier.
The effect is due to the wave function of indistinguishable particles being subject to exchange symmetry, that is, either remaining unchanged (symmetric) or changing sign (antisymmetric) when two particles are exchanged. Both bosons and fermions can experience the exchange interaction. For fermions, this interaction is sometimes called Pauli repulsion and is related to the Pauli exclusion principle. For bosons, the exchange interaction takes the form of an effective attraction that causes identical particles to be found closer together, as in Bose–Einstein condensation.
The exchange interaction alters the expectation value of the distance when the wave functions of two or more indistinguishable particles overlap. This interaction increases (for fermions) or decreases (for bosons) the expectation value of the distance between identical particles (compared to distinguishable particles). Among other consequences, the exchange interaction is responsible for ferromagnetism and the volume of matter. It has no classical analogue.
Exchange interaction effects were discovered independently by physicists Werner Heisenberg and Paul Dirac in 1926.
"Force" descr
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https://en.wikipedia.org/wiki/Nominal%20type%20system
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In computer science, a type system is nominal (also called nominative or name-based) if compatibility and equivalence of data types is determined by explicit declarations and/or the name of the types. Nominal systems are used to determine if types are equivalent, as well as if a type is a subtype of another. Nominal type systems contrast with structural systems, where comparisons are based on the structure of the types in question and do not require explicit declarations.
Nominal typing
Nominal typing means that two variables are type-compatible if and only if their declarations name the same type. For example, in C, two struct types with different names in the same translation unit are never considered compatible, even if they have identical field declarations.
However, C also allows a typedef declaration, which introduces an alias for an existing type. These are merely syntactical and do not differentiate the type from its alias for the purpose of type checking. This feature, present in many languages, can result in a loss of type safety when (for example) the same primitive integer type is used in two semantically distinct ways. Haskell provides the C-style syntactic alias in the form of the type declaration, as well as the newtype declaration that does introduce a new, distinct type, isomorphic to an existing type.
Nominal subtyping
In a similar fashion, nominal subtyping means that one type is a subtype of another if and only if it is explicitly declared to be so
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https://en.wikipedia.org/wiki/Morgan%20Prize%20%28disambiguation%29
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The Morgan Prize in Mathematics may refer to:
Frank and Brennie Morgan Prize for Outstanding Research in Mathematics by an Undergraduate Student awarded jointly by the American Mathematical Society, Mathematical Association of America and Society for Industrial and Applied Mathematics
De Morgan Medal awarded by the London Mathematical Society
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https://en.wikipedia.org/wiki/Broca%27s%20Brain
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Broca's Brain: Reflections on the Romance of Science is a 1979 book by the astrophysicist Carl Sagan. Its chapters were originally articles published between 1974 and 1979 in various magazines, including The Atlantic Monthly, The New Republic, Physics Today, Playboy, and Scientific American. In the introduction, Sagan wrote:
Title
The title essay is named in honor of the French physician, anatomist and anthropologist Paul Broca (1824–1880). He is best known for his discovery that different functions are assigned to different parts of the brain. He believed that by studying the brains of cadavers and correlating the known experiences of the former owners of the organs, human behavior could eventually be discovered and understood. To that end, he saved hundreds of human brains in jars of formalin; among the collection is his own brain. When Sagan finds it in the Musée de l'Homme, he poses questions that challenge some core ideas of human existence such as "How much of that man known as Paul Broca can still be found in this jar?"—a question that evokes both religious and scientific argument.
Contents
A major part of the book is devoted to debunking "paradoxers" who either live at the edge of science or are outright charlatans. An example of this is the controversy surrounding Immanuel Velikovsky's ideas presented in the book Worlds in Collision. Another large part of the book discusses naming conventions for the members of our solar system and their physical features. Sagan a
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https://en.wikipedia.org/wiki/Calogero%20conjecture
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The Calogero conjecture is a minority interpretation of quantum mechanics. It is a quantization explanation involving quantum mechanics, originally stipulated in 1997 and further republished in 2004 by Francesco Calogero that suggests the classical stochastic background field to which Edward Nelson attributes quantum mechanical behavior in his theory of stochastic quantization is a fluctuating space-time, and that there are further mathematical relations between the involved quantities.
The hypothesis itself suggests that if the angular momentum associated with a stochastic tremor with spatial coherence provides an action purported by that motion within the order of magnitude of Planck's constant then the order of magnitude of the associated angular momentum has the same value. Calogero himself suggests that these findings, originally based on the simplified model of the universe "are affected (and essentially, unaffected) by the possible presence in the mass of the Universe of a large component made up of particles much lighter than nucleons".
Essentially, the relation explained by Calogero can be expressed with the formulas:
Furthermore:
Const G,m
Where:
represents the gravitational constant
represents the mass of a hydrogen atom.
represents the radius of the universe accessible by gravitational interactions in time, t.
is a dimensional constant.
Despite its common description, it has been noted that the conjecture is not entirely defined within the realms of Nels
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https://en.wikipedia.org/wiki/Irvington%20High%20School%20%28New%20York%29
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Irvington High School (IHS) is a public high school in Irvington, New York, United States. It is part of the Irvington Union Free School District in Westchester County.
Academics
In 2021, Irvington High School's graduation rate was 98%. Of the school body, 96% are proficient in reading, and 95% are proficient in mathematics. Of seniors, 84% had taken at least one Advanced Placement exam, and 75% had passed at least one Advanced Placement exam.
Student body
In 2021, 71% of the student body was white, 11% was Asian, 7% was black, 7% was Hispanic, 4% was multiracial, and 1% was Native American.
Rankings
In 2015, U.S. News & World Report rated IHS as #32 in New York State, making it the ninth-best in Westchester.
The next year it was ranked as #198 in the United States, and #35 in New York – which was the 10th best in Westchester – with a college readiness index of 70.3, and a student-teacher ratio of 12:1. Earlier that same year, 2016, Niche.com, a rating and ranking website, listed IHS as the #83 high school in New York, and the 595th high school in the country.
In 2017, U.S. News & World Report ranked the high school as #45 in New York state, and #377 in the country, which earned it a gold medal for being in the top 500 nationally.
In 2021, U.S. News & World Report ranked Irvington High School #304 nationally and #35 in New York State.
History
The Irvington Union Free School District originally had three schools, the Main Street School, which accommodated all student
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https://en.wikipedia.org/wiki/Nucleofuge
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In chemistry, a nucleofuge () is a leaving group which retains the lone pair of electrons from its previous bond with another species. For example, in the SN2 mechanism, a nucleophile attacks an organic compound containing the nucleofuge (the bromo group) which simultaneously breaks the bond with the nucleofuge.
After a reaction nucleofuges may contain either a negative or a neutral charge; this is governed by the nature of the specific reaction.
The word 'nucleofuge' is commonly found in older literature, but its use is less common in current literature in which the term leaving group dominates.
See also
Electrofuge
Nucleophile
Electrophile
References
Organic chemistry
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https://en.wikipedia.org/wiki/Electrofuge
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In chemistry, an electrofuge is a leaving group which does not retain the lone pair of electrons from its previous bond with another species (in contrast to a nucleofuge, which does). It can result from the heterolytic breaking of covalent bonds.
After this reaction an electrofuge may possess either a positive or a neutral charge; this is governed by the nature of the specific reaction.
An example would be the loss of from a molecule of benzene during nitration.
The word 'electrofuge' is commonly found in older literature, but its use in contemporary organic chemistry is now uncommon.
See also
Nucleofuge
Nucleophile
Electrophile
References
.
Organic chemistry
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https://en.wikipedia.org/wiki/Klaus%20Biemann
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Klaus Biemann (November 2, 1926 – June 2, 2016) was an Austrian-American professor of chemistry at the Massachusetts Institute of Technology. His work centered on structural analysis in organic and biochemistry. He has been called the "father of organic mass spectrometry" but was particularly noted for his role in advancing protein sequencing with tandem mass spectrometry following pioneering work conducted in this area by Michael Barber.
Career and research
Biemann was born in Innsbruck, Austria in 1926. Following in the footsteps of his father, he studied pharmacy at the University of Innsbruck where he graduated in 1948. He was drafted into the Wehrmacht during the final months of World War II and was sent to aid the divisions retreating before the Soviet Army on the Eastern Front. Fearing capture, he deserted with a friend to travel back to Innsbruck. He received his PhD at the University of Innsbruck supervised by Hermann Bretschneider in 1951. He started his work on his habilitation, but instead moved to the MIT in 1955 to work as a postdoctoral fellow in the group of George Büchi. Two years later with the assistance of Büchi, he was offered a faculty position at MIT in the analytical chemistry division where he turned his focus to peptide analysis and sequencing. Before embarking on his new research, however, Biemann decided to buy a mass spectrometer and use it to study peptides instead. He used his background in organic chemistry to modify peptides so that they beco
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https://en.wikipedia.org/wiki/Joel%20Primack
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Joel R. Primack (born July 14, 1945) is a professor of physics and astrophysics at the University of California, Santa Cruz and is a member of the Santa Cruz Institute for Particle Physics.
Primack received his A.B. from Princeton University in 1966 and his Ph.D. from Stanford University in 1970. His fields of study are relativistic quantum field theory, cosmology, and particle astrophysics. He is also involved in supercomputer simulations of dark matter models. He directs the University of California High-Performance AstroComputing Center (UC-HiPACC). Primack is best known for his co-authorship with George Blumenthal, Sandra Moore Faber, and Martin Rees of the theory of cold dark matter (CDM) in 1984. He co-authored two books with Nancy Abrams, The View from the Center of the Universe (2006) and The New Universe and the Human Future (2011). He played main roles in starting the Congressional Science and Technology Fellowship program, the Forum on Physics and Society of the American Physical Society, and the Science and Human Rights program of the American Association for the Advancement of Science in 1970-1973. He is a fellow of the American Physical Society and the American Association for the Advancement of Science.
References
External links
The Terry Lectures 2009 - Yale University - first of four lectures on cosmology by Joel Primack and Nancy Abrams.
American astronomers
Lick Observatory
University of California, Santa Cruz faculty
Stanford University alumni
Living
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https://en.wikipedia.org/wiki/Duhamel%27s%20principle
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In mathematics, and more specifically in partial differential equations, Duhamel's principle is a general method for obtaining solutions to inhomogeneous linear evolution equations like the heat equation, wave equation, and vibrating plate equation. It is named after Jean-Marie Duhamel who first applied the principle to the inhomogeneous heat equation that models, for instance, the distribution of heat in a thin plate which is heated from beneath. For linear evolution equations without spatial dependency, such as a harmonic oscillator, Duhamel's principle reduces to the method of variation of parameters technique for solving linear inhomogeneous ordinary differential equations. It is also an indispensable tool in the study of nonlinear partial differential equations such as the Navier–Stokes equations and nonlinear Schrödinger equation where one treats the nonlinearity as an inhomogeneity.
The philosophy underlying Duhamel's principle is that it is possible to go from solutions of the Cauchy problem (or initial value problem) to solutions of the inhomogeneous problem. Consider, for instance, the example of the heat equation modeling the distribution of heat energy in . Indicating by the time derivative of , the initial value problem is
where g is the initial heat distribution. By contrast, the inhomogeneous problem for the heat equation,
corresponds to adding an external heat energy at each point. Intuitively, one can think of the inhomogeneous problem as a set of homog
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https://en.wikipedia.org/wiki/MPE
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MPE may refer to:
Malignant pleural effusion
Markov perfect equilibrium, in game theory
Max Planck Institute for Extraterrestrial Physics, a German research institute
Maximum permissible exposure, the highest power of a light source that is considered safe
Mean Percentage Error, in statistics
Media Processing Engine, short MPE, is an image/video processor
Methidiumpropyl-EDTA, a chemical that can intercalate and cleave DNA
MIDI Polyphonic Expression, a MIDI specification to provide more expressive qualities for performing music
Minimum polynomial extrapolation, a sequence transformation algorithm used for convergence acceleration of vector sequences
Miss Philippines Earth
Molecular Pathological Epidemiology, an interdisciplinary integration of molecular pathology and epidemiologylect
Mors Principium Est, a Finnish melodic death metal band
Multi-Programming Executive, a business-oriented minicomputer operating system made by Hewlett-Packard
Multiprotocol Encapsulation, a Data link layer protocol
Mumbai-Pune Expressway, an Indian motorway
MyPhoneExplorer, a software application of Sony Ericsson and Android mobile phones
Myxopapillary ependymoma, a tumor of the central nervous system
Phaswane Mpe (1970-2004), South African author
The IATA airport code for the defunct Griswold Airport in Madison, Connecticut
The Federal Aviation Administration Location identifier for Philadelphia Municipal Airport, an airport located in Philadelphia, Mississippi
.MPE, alterna
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https://en.wikipedia.org/wiki/D%27Alembert%27s%20formula
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In mathematics, and specifically partial differential equations, d´Alembert's formula is the general solution to the one-dimensional wave equation:
for
It is named after the mathematician Jean le Rond d'Alembert, who derived it in 1747 as a solution to the problem of a vibrating string.
Details
The characteristics of the PDE are (where sign states the two solutions to quadratic equation), so we can use the change of variables (for the positive solution) and (for the negative solution) to transform the PDE to . The general solution of this PDE is where and are functions. Back in coordinates,
is if and are .
This solution can be interpreted as two waves with constant velocity moving in opposite directions along the x-axis.
Now consider this solution with the Cauchy data .
Using we get .
Using we get .
We can integrate the last equation to get
Now we can solve this system of equations to get
Now, using
d'Alembert's formula becomes:
Generalization for inhomogeneous canonical hyperbolic differential equations
The general form of an inhomogeneous canonical hyperbolic type differential equation takes the form of:
for .
All second order differential equations with constant coefficients can be transformed into their respective canonic forms. This equation is one of these three cases: Elliptic partial differential equation, Parabolic partial differential equation and Hyperbolic partial differential equation.
The only difference between a homogeneou
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https://en.wikipedia.org/wiki/PDAG
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PDAG may refer to:
Propositional directed acyclic graph, a data structure in computer science
Mixed graph or partially directed acyclic graph
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https://en.wikipedia.org/wiki/PSW
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PSW may refer to:
PSW Science, the oldest scientific society in Washington, D.C.
Personal Support Worker, Canada
PlayStation World, a UK magazine
Program status word, a control register in IBM mainframe computers
Baillie–PSW primality test in mathematics
Part Submission Warrant in production part approval process
Post Study Work Visa, UK
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https://en.wikipedia.org/wiki/Andreas%20Krieger
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Andreas Krieger (born 20 July 1965 in East Berlin) is a German former shot putter who competed on the women's East German athletics team at SC Dynamo Berlin as Heidi Krieger.
He was systematically and unknowingly doped with anabolic steroids for years by East German officials, which caused body chemistry issues. Being a trans man, Krieger subsequently underwent gender affirmation surgery. Krieger says that, while he did experience gender dysphoria before being doped, he regretted not being able to transition without the doping abuses.
Athletics career
At the 1986 European Championships in Athletics, Krieger won the gold medal in the shot put event after putting the shot at 21.10 m (69 ft 3 in). Krieger retired in 1991.
Doping
Krieger was systematically doped with steroids from the age of 16 onward. According to Werner Franke and Brigitte Berendonk's 1991 book, Doping: From Research to Deceit, Krieger took almost 2,600 milligrams of steroids in 1986; nearly 1,000 milligrams more than Ben Johnson took during the 1988 Summer Olympics.
As early as the age of 18, Krieger began developing visibly male characteristics. Eventually, years of doping left him with many masculine traits. By 1997, at the age of 31, Krieger underwent sex reassignment surgery and changed his name to Andreas. Krieger had "felt out of place and longed in some vague way to be a boy", and said in a 2004 interview in The New York Times that he was "glad that he became a man". However, he felt that receiving
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https://en.wikipedia.org/wiki/Reactome
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Reactome is a free online database of biological pathways. There are several Reactomes that concentrate on specific organisms, the largest of these is focused on human biology, the following description concentrates on the human Reactome. It is authored by biologists, in collaboration with Reactome editorial staff. The content is cross-referenced to many bioinformatics databases. The rationale behind Reactome is to visually represent biological pathways in full mechanistic detail, while making the source data available in a computationally accessible format.
The website can be used to browse pathways and submit data to a suite of data analysis tools. The underlying data is fully downloadable in a number of standard formats including PDF, SBML and BioPAX. Pathway diagrams use a Systems Biology Graphical Notation (SBGN)-based style.
The core unit of the Reactome data model is the reaction. Entities (nucleic acids, proteins, complexes and small molecules) participating in reactions form a network of biological interactions and are grouped into pathways. Examples of biological pathways in Reactome include signaling, innate and acquired immune function, transcriptional regulation, translation, apoptosis and classical intermediary metabolism.
The pathways represented in Reactome are species-specific, with each pathway step supported by literature citations that contain an experimental verification of the process represented. If no experimental verification using human reagents e
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https://en.wikipedia.org/wiki/Smith%20conjecture
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In mathematics, the Smith conjecture states that if f is a diffeomorphism of the 3-sphere of finite order, then the fixed point set of f cannot be a nontrivial knot.
showed that a non-trivial orientation-preserving diffeomorphism of finite order with fixed points must have a fixed point set equal to a circle, and asked in if the fixed point set could be knotted. proved the Smith conjecture for the special case of diffeomorphisms of order 2 (and hence any even order). The proof of the general case was described by and depended on several major advances in 3-manifold theory, In particular the work of William Thurston on hyperbolic structures on 3-manifolds, and results by William Meeks and Shing-Tung Yau on minimal surfaces in 3-manifolds, with some additional help from Bass, Cameron Gordon, Peter Shalen, and Rick Litherland.
gave an example of a continuous involution of the 3-sphere whose fixed point set is a wildly embedded circle, so the Smith conjecture is false in the topological (rather than the smooth or PL) category. showed that the analogue of the Smith conjecture in higher dimensions is false: the fixed point set of a periodic diffeomorphism of a sphere of dimension at least 4 can be a knotted sphere of codimension 2.
See also
Hilbert–Smith conjecture
References
3-manifolds
Conjectures
Diffeomorphisms
Theorems in topology
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https://en.wikipedia.org/wiki/Lydia%20Makhubu
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Lydia Phindile Makhubu (1 July 1937 - July 2021) was a Swazi chemist and former professor of chemistry, dean and vice-chancellor of the University of Swaziland (now the University of Eswatini).
Life
She was born at the Usuthu Mission in Swaziland. Her parents were teachers, but her father also worked as an orderly in health clinics. Her early exposure to medicine had a great influence on her choice of career; she initially wanted to become a doctor, but then switched to chemistry.
Makhubu graduated from Pius XII College (now the National University of Lesotho) in Lesotho with a B.Sc. in 1963. With a Canadian Commonwealth scholarship, she obtained an M.Sc. in organic chemistry from the University of Alberta in 1967, followed by a Ph.D. in medicinal chemistry from the University of Toronto in 1973, becoming the first Swazi woman to earn a doctorate.
She returned to her homeland and joined the faculty of the University of Swaziland, becoming a lecturer in the chemistry department in 1973, the dean of science from 1976 to 1980, a senior lecturer in 1979, a full professor the following year, and vice-chancellor from 1988 to 2003. Her research focused on the medical effects of plants used by traditional Swazi healers.
From its inception in 1993 until 2005, Makhubu was the President of the Third World Organization for Women in Science, which provides fellowships for postgraduate study. She was the first woman chairperson of the executive committee of the Association of Commonwe
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https://en.wikipedia.org/wiki/Intracule
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An intracule is a quantum mechanical mathematical function for the two electron density which depends not upon the absolute values of position or momentum but rather upon their relative values. Its use is leading to new methods in physics and computational chemistry to investigate the electronic structure of molecules and solids. These methods are a development of Density functional theory (DFT), but with the two electron density replacing the one electron density.
References
P. M. W. Gill, D. L. Crittenden, D. P. O'Neill and N. A. Besley, A family of intracules, a conjecture and the electron correlation problem, Physical Chemistry Chemical Physics, 2006, 8, 15 - 25.
Computational chemistry
Theoretical chemistry
Computational physics
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https://en.wikipedia.org/wiki/Accelerated%20Math
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Accelerated Math is a daily, progress-monitoring software tool that monitors and manages mathematics skills practice, from preschool math through calculus. It is primarily used by primary and secondary schools, and it is published by Renaissance Learning, Inc. Currently, there are five versions: a desktop version and a web-based version in Renaissance Place, the company's web software for Accelerated Math and a number of other software products (e.g. Accelerated Reader). In Australia and the United Kingdom, the software is referred to as "Accelerated Maths".
Research
Below is a sample of some of the most current research on Accelerated Math.
Sadusky and Brem (2002) studied the impact of first-year implementation of Accelerated Math in a K-6 urban elementary school during the 2001–2002 school year. The researchers found that teachers were able to immediately use data to make decisions about instruction in the classroom. The students in classrooms using Accelerated Math had twice the percentile gains when tested as compared to the control classrooms that did not use Accelerated Math.
Ysseldkyke and Tardrew (2003) studied 2,202 students in 125 classrooms encompassing 24 states. The results showed that when students using Accelerated Math were compared to a control group, those students using the software made a significant gains on the STAR Math test. Students in grades 3 through 10 that were using Accelerated Math had more than twice the percentile gains on these tests than
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https://en.wikipedia.org/wiki/Curtis%20Priem
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Curtis R. Priem is an American electrical engineer.
He received a B.S. degree in electrical engineering from Rensselaer Polytechnic Institute in 1982. He designed the first graphics processor for the PC, the IBM Professional Graphics Adapter.
From 1986 to 1993, he was a senior staff engineer at Sun Microsystems, where he developed the GX graphics chip.
He cofounded NVIDIA with Jen-Hsun Huang and Chris Malachowsky and was its Chief Technical Officer from 1993 to 2003. He retired from NVIDIA in 2003.
In 2000, RPI named him Entrepreneur of the Year. From 2003 to 2007 he was a trustee of Rensselaer. In 2004 he announced that he would donate an unrestricted gift of $40 million to the Institute. Rensselaer subsequently created the Curtis R. Priem Experimental Media and Performing Arts Center, named in his honor and usually referred to as "EMPAC" for short.
He is also president of the Priem Family Foundation, which he established with his wife Veronica in September, 1999. The foundation is non-operating (i.e., has no office or staff, and therefore, no overhead) and exists only to give money to other foundations or charities.
References
Nvidia people
Rensselaer Polytechnic Institute alumni
Year of birth missing (living people)
Living people
American technology company founders
American electrical engineers
American chief technology officers
American philanthropists
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https://en.wikipedia.org/wiki/HashClash
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HashClash was a volunteer computing project running on the Berkeley Open Infrastructure for Network Computing (BOINC) software platform to find collisions in the MD5 hash algorithm. It was based at Department of Mathematics and Computer Science at the Eindhoven University of Technology, and Marc Stevens initiated the project as part of his master's degree thesis.
The project ended after Stevens defended his M.Sc. thesis in June 2007. However SHA1 was added later, and the code repository was ported to git in 2017.
The project was used to create a rogue certificate authority certificate in 2009.
See also
Berkeley Open Infrastructure for Network Computing (BOINC)
List of volunteer computing projects
References
External links
HashClash
HashClash at Stevens' home page
Create your own MD5 collisions on AWS, Nat McHugh's blog
Science in society
Free science software
Volunteer computing projects
Cryptography
Cryptanalytic software
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https://en.wikipedia.org/wiki/Triphenylmethyl%20radical
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The triphenylmethyl radical (often shorted to trityl radical) is an organic compound with the formula (C6H5)3C. It is a persistent radical. It was the first radical ever to be described in organic chemistry. Because of its accessibility, the trityl radical has been heavily exploited.
Preparation and properties
It can be prepared by homolysis of triphenylmethyl chloride 1 by a metal like silver or zinc in benzene or diethyl ether. The radical 2 forms a chemical equilibrium with the quinoid-type dimer 3 (Gomberg's dimer). In benzene the concentration of the radical is 2%.
Solutions containing the radical are yellow; when the temperature of the solution is raised, the yellow color becomes more intense as the equilibrium is shifted in favor of the radical (in accordance with Le Chatelier's principle).
When exposed to air, the radical rapidly oxidizes to the peroxide, and the color of the solution changes from yellow to colorless. Likewise, the radical reacts with iodine to triphenylmethyl iodide.
While the trityl radical forms a quinoid dimer, derivatives thereof with the appropriate substitution pattern do form dimers with a hexaphenylethane structure. X-ray studies give a bond length of 1.67 Å for hexakis(3,5-di-t-butylphenyl)ethane. Theoretical calculations on a very high level of theory indicate that van der Waals attraction between the tert-butyl groups create a potential minimum that is absent in the unsubstituted molecule. Other derivatives have been reported as the
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https://en.wikipedia.org/wiki/1%2C2-Bis%28diphenylphosphino%29ethane
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1,2-Bis(diphenylphosphino)ethane (dppe) is an organophosphorus compound with the formula (PhPCH) (Ph = phenyl). It is a commonly used bidentate ligand in coordination chemistry. It is a white solid that is soluble in organic solvents.
Preparation
The preparation of dppe is by the alkylation of NaPPh:
P(CH) + 2 Na → NaP(CH) + NaCH
NaP(CH), which is readily air-oxidized, is treated with 1,2-dichloroethane (ClCHCHCl) to give dppe:
2 NaP(CH) + ClCHCHCl → (CH)PCHCHP(CH) + 2 NaCl
Reactions
The reduction of dppe by lithium to give PhHP(CH)PHPh has been reported.
PhP(CH)PPh + 4 Li → PhLiP(CH)PLiPh + 2 PhLi
Hydrolysis gives the bis(secondary phosphine):
PhLiP(CH)PLiPh + 2 PhLi + 4HO → PhHP(CH)PHPh + 4 LiOH + 2 CH
Treatment of dppe with conventional oxidants such as hydrogen peroxide (HO), aqueous bromine (Br), etc., produces dppeO in low yield (e.g., 13%) as a result of non-selective oxidation. Selective mono-oxidation of dppe can be achieved by reaction with PhCHBr to give dppeO.
Hydrogenation of dppe gives the ligand bis(dicyclohexylphosphino)ethane.
Coordination complexes
Many coordination complexes of dppe are known, and some are used as homogeneous catalysts. Dppe is almost invariably chelating, although there are examples of monodentate (e.g., W(CO)(dppe)) and of bridging behavior. The natural bite angle is 86°.
Related compounds
1,2-Bis(dimethylphosphino)ethane
Bis(diphenylphosphino)methane
References
Chelating agents
Diphosphines
Phenyl compounds
1,2-Ethanediyl compo
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https://en.wikipedia.org/wiki/Hans-Hermann%20Hupfeld
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Gustav Theodor Hans Hermann Hupfeld (November 28, 1905 – November 11, 1942 in Mecklenburg, Germany) was a German physicist known for his work on the scattering of gamma rays.
Early career
Hans-Hermann Hupfeld was born on his parents' farm in Klein-Varchow, Mecklenburg, Germany. He obtained a degree in physics and worked at the Kaiser Wilhelm Institut, Berlin Dahlem, from 1929 until 1932 with Prof. Otto Hahn and Prof. Lise Meitner. His research during that time resulted in the discovery of the so-called Meitner–Hupfeld effect.
The Meitner-Hupfeld effect is an anomalously large scattering of Gamma rays by heavy elements. Later on, the Meitner–Hupfeld effect was explained by a broad theory from which evolved the Standard Model, a theory for explaining the structure of the atomic nucleus. The anomalous gamma-ray behavior was eventually ascribed to electron–positron pair production and annihilation.
Although Professor Meitner was recognized for her work, Hupfeld is usually ignored, and little or no account of his life exists. His name is misspelled as Heinz Hupfeld, instead of Hans-Hermann Hupfeld in publications from the early '30s.
Later career
Disgruntled by lack of recognition, Hupfeld left the Kaiser Wilhelm Institut in 1932 (now known as the Max Planck Society) in Berlin and went, because of Germany's bad economic situation at that time, to help in the construction of buildings using a sustainable earthen technology known as the "Dunne loam loaf" technique, pioneered in
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https://en.wikipedia.org/wiki/Liam%20Gillick
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Liam Gillick (born 1964, Aylesbury, Buckinghamshire) is a British artist who lives and works in New York City. Gillick deploys multiple forms to make visible the aesthetics of the constructed world and examine the ideological control systems that have emerged along with globalization and neoliberalism. He utilizes materials that resemble everyday built environments, transforming them into minimalist abstractions that deliver commentaries on social constructs, while also exploring notions of modernism.
Life and career
Liam Gillick graduated from Goldsmiths College in 1987 with a degree in fine art. In 1989 he mounted his first solo gallery exhibition, 84 Diagrams, through Karsten Schubert in London. Gillick has exhibited in galleries and institutions in Europe and the United States, many of which have been collaborative projects with other artists, architects, designers and writers.
In 1991, together with art collector, and co-publisher of Art Monthly, Jack Wendler, Gillick founded the limited editions and publishing company G-W Press. The company produced limited editions by artists including Jeremy Deller and Anya Gallaccio.
In the early 1990s Gillick was a member of the band Soho and is credited with providing samples during their live performances.
Together with Damien Hirst, Sarah Lucas, Angela Bulloch and Henry Bond, he was "the earliest of the YBAs" — the Young British Artists who dominated British art during the 1990s.
Gillick was included in the 1996 exhibition
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https://en.wikipedia.org/wiki/Robert%20Kirshner
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Robert P. Kirshner (born August 15, 1949) is an American astronomer, Chief Program Officer for Science for the Gordon and Betty Moore Foundation, and the Clownes Research Professor of Science at Harvard University. Kirshner has worked in several areas of astronomy including the physics of supernovae, supernova remnants, the large-scale structure of the cosmos, and the use of supernovae to measure the expansion of the universe.
Career
Kirshner received his A.B. magna cum laude in Astronomy from Harvard College in 1970, where he also won a Bowdoin Prize for Useful and Polite Literature. He earned his Ph.D., also in Astronomy, from Caltech in 1975.
He then worked as a postdoc at the Kitt Peak National Observatory, before joining the faculty at the University of Michigan, where he rose to become Professor and Chairman of the Astronomy Department and helped to build the 2.4 meter Hiltner Telescope. Whilst at Michigan, he received an Alfred P. Sloan Fellowship and won the Henry Russel Award.
In 1985, he moved to the Harvard Astronomy Department as Professor of Astronomy (1985–2016), where he served as Chairman of the Department from 1990-1997 and as the head of the Optical and Infrared Division of the Center for Astrophysics Harvard & Smithsonian. from 1997-2003. He was appointed Clownes Professor of Science in 2001, Master of Quincy House, one of Harvard’s undergraduate residences, from 2001-2007 and Harvard College Professor (2004–2009). He helped Harvard join the Magellan Ob
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https://en.wikipedia.org/wiki/Standard%20model%20%28cryptography%29
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In cryptography the standard model is the model of computation in which the adversary is only limited by the amount of time and computational power available. Other names used are bare model and plain model.
Cryptographic schemes are usually based on complexity assumptions, which state that some problems, such as factorization, cannot be solved in polynomial time. Schemes that can be proven secure using only complexity assumptions are said to be secure in the standard model. Security proofs are notoriously difficult to achieve in the standard model, so in many proofs, cryptographic primitives are replaced by idealized versions. The most common example of this technique, known as the random oracle model, involves replacing a cryptographic hash function with a genuinely random function. Another example is the generic group model, where the adversary is given access to a randomly chosen encoding of a group, instead of the finite field or elliptic curve groups used in practice.
Other models used invoke trusted third parties to perform some task without cheating; for example, the public key infrastructure (PKI) model requires a certificate authority, which if it were dishonest, could produce fake certificates and use them to forge signatures, or mount a man in the middle attack to read encrypted messages. Other examples of this type are the common random string model, where it is assumed that all parties have access to some string chosen uniformly at random, and its generalizati
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https://en.wikipedia.org/wiki/Roman%20pot
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The Roman pot is the name of a technique (and of the relevant device) used in accelerator physics. Named after its implementation by the CERN-Rome collaboration in the early 1970s, it is an important tool to measure the total cross section of two particle beams in a collider. They are called pots because the detectors are housed in cylindrical vessels. The first generation of Roman pots was purpose-built by the CERN Central Workshops and used in the measurement of the total cross-section of proton-proton inter-actions in the ISR.
Roman pots are located as close to the beamline as possible, to capture the accelerated particles which scatter by very small angles.
Roman pots used at the Large Hadron Collider (LHC)
Roman pots were first used in the TOTEM experiment and later by the ATLAS and the CMS collaborations at the LHC. The figure below shows a detector used on the beamline near IP5 (interaction point 5), the location of the CMS detector. Three of these are used per Roman pot unit. Each is shoved into place to within 10 microns of the beamline. Two detectors are placed above and below the beamline, and a third to the side. These detectors will record any protons that are not travelling precisely along the beamline, and thus record the elastic scattering of the protons. This is used to measure the total elastic cross-section, including Coulomb scattering as well as diffractive scattering (i.e. diffraction because the protons are not point particles, and have an internal st
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https://en.wikipedia.org/wiki/George%20Gessert
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George Gessert is one of the best-known artists in the contemporary art movement known as bio-art a/k/a BioArt. Gessert began his career as a painter and printmaker, and began breeding plants as an art form in the late 1970s. Beginning in the 1980s, Gessert's work focused on the overlap between art and genetics, and he has exhibited a series of installations of hybrids and documentation of breeding projects.
Early life
George Gessert was born in 1944 in Milwaukee, Wisconsin. He has a BA in English from the University of California at Berkeley 1966 and an MA in Fine Arts from the University of Wisconsin-Madison in 1969.
Technique
Gessert creates his artistic irises by hybridizing wild varieties and discarding undesirable results. He is especially interested in plant aesthetics and ways that human aesthetic preferences affect evolution. Gessert calls his practice "genetic folk art," and his work points to the way nature is interpreted—even authored—by humans. Gessert's work mainly focuses on irises and other ornamental flowers.
Awards
Gessert's awards include the Leonardo Award for Excellence and the Pushcart prize for his essay, "Notes on Uranium Weapons and Kitsch." His article, "An Orgy of Power" was included in Best American Essays 2007. Gessert is also an Editorial Board Member of Leonardo Journal published by MIT Press for Leonardo/ISAST, the International Society for the Arts, Sciences and Technology.
See also
Leonardo/The International Society for the Arts, S
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https://en.wikipedia.org/wiki/First%20quantization
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A first quantization of a physical system is a possibly semiclassical treatment of quantum mechanics, in which particles or physical objects are treated using quantum wave functions but the surrounding environment (for example a potential well or a bulk electromagnetic field or gravitational field) is treated classically.
However, this need not be the case. In particular, a fully quantum version of the theory can be created by interpreting the interacting fields and their associated potentials as operators of multiplication, provided the potential is written in the canonical coordinates that are compatible with the Euclidean coordinates of standard classical mechanics. First quantization is appropriate for studying a single quantum-mechanical system (not to be confused with a single particle system, since a single quantum wave function describes the state of a single quantum system, which may have arbitrarily many complicated constituent parts, and whose evolution is given by just one uncoupled Schrödinger equation) being controlled by laboratory apparatuses that are governed by classical mechanics, for example an old fashion voltmeter (one devoid of modern semiconductor devices, which rely on quantum theory—however though this is sufficient, it is not necessary), a simple thermometer, a magnetic field generator, and so on.
History
Published in 1901, Max Planck deduced the existence and value of the constant now bearing his name from considering only Wien's displacement l
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https://en.wikipedia.org/wiki/Load%20profile
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In electrical engineering, a load profile is a graph of the variation in the electrical load versus time. A load profile will vary according to customer type (typical examples include residential, commercial and industrial), temperature and holiday seasons. Power producers use this information to plan how much electricity they will need to make available at any given time. Teletraffic engineering uses a similar load curve.
Power generation
In a power system, a load curve or load profile is a chart illustrating the variation in demand/electrical load over a specific time. Generation companies use this information to plan how much power they will need to generate at any given time. A load duration curve is similar to a load curve. The information is the same but is presented in a different form. These curves are useful in the selection of generator units for supplying electricity.
Electricity distribution
In an electricity distribution grid, the load profile of electricity usage is important to the efficiency and reliability of power transmission. The power transformer or battery-to-grid are critical aspects of power distribution and sizing and modelling of batteries or transformers depends on the load profile. The factory specification of transformers for the optimization of load losses versus no-load losses is dependent directly on the characteristics of the load profile that the transformer is expected to be subjected to. This includes such characteristics as average
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https://en.wikipedia.org/wiki/Logarithmic%20mean
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In mathematics, the logarithmic mean is a function of two non-negative numbers which is equal to their difference divided by the logarithm of their quotient.
This calculation is applicable in engineering problems involving heat and mass transfer.
Definition
The logarithmic mean is defined as:
for the positive numbers .
Inequalities
The logarithmic mean of two numbers is smaller than the arithmetic mean and the generalized mean with exponent one-third but larger than the geometric mean, unless the numbers are the same, in which case all three means are equal to the numbers.
Toyesh Prakash Sharma generalizes the arithmetic logarithmic geometric mean inequality for any belongs to the whole number as
Now, for :
This is the arithmetic logarithmic geometric mean inequality. similarly, one can also obtain results by putting different values of as below
For :
for the proof go through the bibliography.
Derivation
Mean value theorem of differential calculus
From the mean value theorem, there exists a value in the interval between and where the derivative equals the slope of the secant line:
The logarithmic mean is obtained as the value of by substituting for and similarly for its corresponding derivative:
and solving for :
Integration
The logarithmic mean can also be interpreted as the area under an exponential curve.
The area interpretation allows the easy derivation of some basic properties of the logarithmic mean. Since the exponential function is mon
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https://en.wikipedia.org/wiki/Bregman%20divergence
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In mathematics, specifically statistics and information geometry, a Bregman divergence or Bregman distance is a measure of difference between two points, defined in terms of a strictly convex function; they form an important class of divergences. When the points are interpreted as probability distributions – notably as either values of the parameter of a parametric model or as a data set of observed values – the resulting distance is a statistical distance. The most basic Bregman divergence is the squared Euclidean distance.
Bregman divergences are similar to metrics, but satisfy neither the triangle inequality (ever) nor symmetry (in general). However, they satisfy a generalization of the Pythagorean theorem, and in information geometry the corresponding statistical manifold is interpreted as a (dually) flat manifold. This allows many techniques of optimization theory to be generalized to Bregman divergences, geometrically as generalizations of least squares.
Bregman divergences are named after Russian mathematician Lev M. Bregman, who introduced the concept in 1967.
Definition
Let be a continuously-differentiable, strictly convex function defined on a convex set .
The Bregman distance associated with F for points is the difference between the value of F at point p and the value of the first-order Taylor expansion of F around point q evaluated at point p:
Properties
Non-negativity: for all , . This is a consequence of the convexity of .
Positivity: When is str
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https://en.wikipedia.org/wiki/O-Matrix
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O-Matrix is a matrix programming language for mathematics, engineering, science, and financial analysis, marketed by Harmonic Software. The language is designed for use in high-performance computing.
O-Matrix provides an integrated development environment and a matrix-based scripting language. The environment includes mathematical, statistical, engineering and visualization functions. The set of analysis functions is designed for development of complex, computationally intensive scientific, mathematical and engineering applications.
The integrated environment provides a mode that is largely compatible with version 4 of the MATLAB language in the commercial product from MathWorks. Certain features of MATLAB, such as non-numeric data types (structures, cell arrays and objects), error handling with try/catch, and nested and anonymous functions, are missing in O-Matrix.
The O-Matrix environment includes a virtual machine of the O-Matrix language to enable re-distribution of applications.
External links
Array programming languages
Numerical programming languages
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https://en.wikipedia.org/wiki/Inside%E2%80%93outside%20algorithm
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For parsing algorithms in computer science, the inside–outside algorithm is a way of re-estimating production probabilities in a probabilistic context-free grammar. It was introduced by James K. Baker in 1979 as a generalization of the forward–backward algorithm for parameter estimation on hidden Markov models to stochastic context-free grammars. It is used to compute expectations, for example as part of the expectation–maximization algorithm (an unsupervised learning algorithm).
Inside and outside probabilities
The inside probability is the total probability of generating words , given the root nonterminal and a grammar :
The outside probability is the total probability of beginning with the start symbol and generating the nonterminal and all the words outside , given a grammar :
Computing inside probabilities
Base Case:
General case:
Suppose there is a rule in the grammar, then the probability of generating starting with a subtree rooted at is:
The inside probability is just the sum over all such possible rules:
Computing outside probabilities
Base Case:
Here the start symbol is .
General case:
Suppose there is a rule in the grammar that generates .
Then the left contribution of that rule to the outside probability is:
Now suppose there is a rule in the grammar. Then the right
contribution of that rule to the outside probability is:
The outside probability is the sum of the left and right
contributions over all such rules:
References
J. Baker (1
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https://en.wikipedia.org/wiki/Barton%27s%20pendulums
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First demonstrated by Prof Edwin Henry Barton FRS FRSE (1858–1925), Professor of Physics at University College, Nottingham, who had a particular interest in the movement and behavior of spherical bodies, the Barton's pendulums experiment demonstrates the physical phenomenon of resonance and the response of pendulums to vibration at, below and above their resonant frequencies. In its simplest construction, approximately 10 different pendulums are hung from one common string. This system vibrates at the resonance frequency of a driver pendulum, causing the target pendulum to swing with the maximum amplitude. The other pendulums to the side do not move as well, thus demonstrating how torquing a pendulum at its resonance frequency is most efficient.
The driver may be a very heavy pendulum also attached to this common string; the driver is set to swing and move the whole system.
References
External links
YouTube video of Barton's Pendulums experiment
Physics experiments
Pendulums
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https://en.wikipedia.org/wiki/Al-Khwarizmi%20%28disambiguation%29
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Al-Khwarizmi or Muḥammad ibn Mūsā al-Khwārizmī (c. 780 – c. 850) was a Persian scholar who produced works in mathematics, astronomy, and geography.
Al-Khwarizmi may also refer to:
People
Muhammad ibn Ahmad al-Khwarizmi, 10th-century encyclopedist who wrote Mafātīḥ al-ʿulūm ("Key to the Sciences")
Abū Bakr Muḥammad b. al-ʿAbbās al-Khwarizmi, Arabic poet and writer (934-93)
Al-Khwarizmi al-Khati, 11th-century alchemist
Shuja al-Khwarazmi (d. 861) was the mother of Abbasid caliph Ja'far al-Mutawakkil
Places
Al-Khwarizmi (crater), a crater on the far-side of the Moon named after Muhammad ibn Musa al-Khwarizmi
Khwarizmi International Award, a research award for achievements in science and technology research
See also
Khwarezmian (disambiguation)
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https://en.wikipedia.org/wiki/Reproductive%20value%20%28population%20genetics%29
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Reproductive value is a concept in demography and population genetics that represents the discounted number of future female children that will be born to a female of a specific age. Ronald Fisher first defined reproductive value in his 1930 book The Genetical Theory of Natural Selection where he proposed that future offspring be discounted at the rate of growth of the population; this implies that sexually reproductive value measures the contribution of an individual of a given age to the future growth of the population.
Definition
Consider a species with a life history table with survival and reproductive parameters given by and , where
= probability of surviving from age 0 to age
and
= average number of offspring produced by an individual of age
In a population with a discrete set of age classes, Fisher's reproductive value is calculated as
where is the long-term population growth rate given by the dominant eigenvalue of the Leslie matrix. When age classes are continuous,
where is the intrinsic rate of increase or Malthusian growth rate.
See also
Population dynamics
Euler–Lotka equation
Leslie matrix
Senescence
Notes
Fisher, R. A. 1930. The Genetical Theory of Natural Selection. Oxford University Press, Oxford.
Keyfitz, N. and Caswell, H. 2005. Applied Mathematical Demography. Springer, New York. 3rd edition. doi:10.1007/b139042
References
Population genetics
Senescence
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https://en.wikipedia.org/wiki/Clinton%20Ballou
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Clinton Edward Ballou (June 18, 1923 – March 8, 2021) was an American academic who was a professor of biochemistry at the University of California, Berkeley. His research focused on the metabolism of carbohydrates and the structures of microbial cell walls. He joined the United States National Academy of Sciences in 1975.
Ballou was born in King Hill, Idaho in June 1923, to William Clinton Ballou and "Mollie" Ballou. He attended Boise Junior College, and graduated from Oregon State College, and the University of Wisconsin. He served in the U. S. Navy from 1944 to 1946.
He held a postdoctoral fellowship with E. L. Hirst in Chemistry at the University of Edinburgh. Ballou became a professor of biochemistry at the University of California, Berkeley in 1955, and became a professor emeritus in 1991.
Ballou served on the editorial board of the Journal of Biological Chemistry. He died in March 2021 at the age of 97.
Awards
1975 National Academy of Sciences
1981 American Chemical Society's Claude Hudson Award in Carbohydrate Chemistry
1972 Welch Foundation Lectureship
1976 University of Notre Dame Reilly Lectureship
1977 Duke University Belfort Lectureship
1961 National Science Foundation Senior Fellowship
References
External links
Clinton Ballou on the University of California, Berkeley website
1923 births
2021 deaths
Alumni of the University of Edinburgh
American biochemists
Members of the United States National Academy of Sciences
People from Elmore County, Idaho
Uni
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https://en.wikipedia.org/wiki/Elkan%20Blout
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Elkan Rogers Blout (July 2, 1919 – December 20, 2006) was a biochemist at Polaroid Corporation, Boston Children's Hospital, and the Edward S. Harkness Professor of Biological Chemistry, emeritus at Harvard University.
Blout received his BA in chemistry in 1939 from Princeton University, and his Ph.D. in 1942 from Columbia University.
Blout was elected to the United States National Academy of Sciences in 1969. In 1990, he was awarded the National Medal of Science “for his pioneering studies of protein conformation and devotion to the scientific enterprise of the Nation.”
Blout died in December 2006, in Boston.
References
External links
1919 births
2006 deaths
American biochemists
Members of the United States National Academy of Sciences
Foreign Members of the USSR Academy of Sciences
Foreign Members of the Russian Academy of Sciences
National Medal of Science laureates
Harvard Medical School faculty
Scientists from Cambridge, Massachusetts
People from Cuttyhunk Island
Princeton University alumni
Columbia University alumni
Phillips Exeter Academy alumni
Members of the National Academy of Medicine
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https://en.wikipedia.org/wiki/Daniele%20Barbaro
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Daniele Matteo Alvise Barbaro (also Barbarus) (8 February 1514 – 13 April 1570) was an Italian cleric and diplomat. He was also an architect, writer on architecture, and translator of, and commentator on, Vitruvius.
Barbaro's fame is chiefly due to his vast output in the arts, letters, and mathematics. A cultured humanist, he was a friend and admirer of Torquato Tasso, a patron of Andrea Palladio, and a student of Pietro Bembo. Francesco Sansovino considered Daniele to be one of the three best Venetian architects, along with Palladio and Francesco's father Jacopo.
Biography
He was born in Venice, the son of Francesco di Daniele Barbaro and Elena Pisani, daughter of the banker Alvise Pisani and Cecilia Giustinian. Barbaro studied philosophy, mathematics, and optics at the University of Padua. He has been credited with the design of the university's botanical garden.
Barbaro served the Republic of Venice as ambassador to the court of Edward VI in London and as representative at the Council of Trent. In 1561 Pope Pius IV appointed him a cardinal in pectore, that is, secretly, to avoid causing diplomatic complications, but since Pius never made the appointment public Barbaro was never a cardinal. In 1550 he was elected Patriarch of Aquileia, an ecclesiastical appointment that required the approval of the Venetian Senate.
On the death of his father, he inherited a country estate with his brother Marcantonio Barbaro. They commissioned Palladio to design their shared country
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https://en.wikipedia.org/wiki/Non-Euclidean%20crystallographic%20group
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In mathematics, a non-Euclidean crystallographic group, NEC group or N.E.C. group is a discrete group of isometries of the hyperbolic plane. These symmetry groups correspond to the wallpaper groups in euclidean geometry. A NEC group which contains only orientation-preserving elements is called a Fuchsian group, and any non-Fuchsian NEC group has an index 2 Fuchsian subgroup of orientation-preserving elements.
The hyperbolic triangle groups are notable NEC groups. Others are listed in Orbifold notation.
See also
Non-Euclidean geometry
Isometry group
Fuchsian group
Uniform tilings in hyperbolic plane
References
.
.
.
Non-Euclidean geometry
Hyperbolic geometry
Symmetry
Discrete groups
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https://en.wikipedia.org/wiki/Spirapril
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Spirapril, sold under the brand name Renormax among others, is an ACE inhibitor antihypertensive drug used to treat hypertension. It belongs to dicarboxy group of ACE inhibitors.
It was patented in 1980 and approved for medical use in 1995.
Chemistry
Like many ACE inhibitors, this prodrug is converted to the active metabolite spiraprilat following oral administration. Unlike other members of the group, it is eliminated both by renal and hepatic routes, which may allow for greater use in patients with renal impairment.
However, data on its effect upon the renal function are conflicting.
References
External links
ACE inhibitors
Carboxamides
Enantiopure drugs
Ethyl esters
Nitrogen heterocycles
Prodrugs
Spiro compounds
Dithiolanes
Carboxylic acids
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https://en.wikipedia.org/wiki/Order%20type
|
In mathematics, especially in set theory, two ordered sets and are said to have the same order type if they are order isomorphic, that is, if there exists a bijection (each element pairs with exactly one in the other set) such that both and its inverse are monotonic (preserving orders of elements).
In the special case when is totally ordered, monotonicity of already implies monotonicity of its inverse.
One and the same set may be equipped with different orders. Since order-equivalence is an equivalence relation, it partitions the class of all ordered sets into equivalence classes.
Notation
If a set has order type denoted , the order type of the reversed order, the dual of , is denoted .
The order type of a well-ordered set is sometimes expressed as .
Examples
The order type of the integers and rationals is usually denoted and , respectively. The set of integers and the set of even integers have the same order type, because the mapping is a bijection that preserves the order. But the set of integers and the set of rational numbers (with the standard ordering) do not have the same order type, because even though the sets are of the same size (they are both countably infinite), there is no order-preserving bijective mapping between them. The open interval of rationals is order isomorphic to the rationals, since, for example, is a strictly increasing bijection from the former to the latter. Relevant theorems of this sort are expanded upon below.
More examples c
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https://en.wikipedia.org/wiki/Corona%20theorem
|
In mathematics, the corona theorem is a result about the spectrum of the bounded holomorphic functions on the open unit disc, conjectured by and proved by .
The commutative Banach algebra and Hardy space H∞ consists of the bounded holomorphic functions on the open unit disc D. Its spectrum S (the closed maximal ideals) contains D as an open subspace because for each z in D there is a maximal ideal consisting of functions f with
f(z) = 0.
The subspace D cannot make up the entire spectrum S, essentially because the spectrum is a compact space and D is not. The complement of the closure of D in S was called the corona by , and the corona theorem states that the corona is empty, or in other words the open unit disc D is dense in the spectrum. A more elementary formulation is that elements f1,...,fn generate the unit ideal of H∞ if and only if there is some δ>0 such that
everywhere in the unit ball.
Newman showed that the corona theorem can be reduced to an interpolation problem, which was then proved by Carleson.
In 1979 Thomas Wolff gave a simplified (but unpublished) proof of the corona theorem, described in and .
Cole later showed that this result cannot be extended to all open Riemann surfaces .
As a by-product, of Carleson's work, the Carleson measure was invented which itself is a very useful tool in modern function theory. It remains an open question whether there are versions of the corona theorem for every planar domain or for higher-dimensional domains.
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https://en.wikipedia.org/wiki/Eugenie%20Clark
|
Eugenie Clark (May 4, 1922 – February 25, 2015), popularly known as The Shark Lady, was an American ichthyologist known for both her research on shark behavior and her study of fish in the order Tetraodontiformes. Clark was a pioneer in the field of scuba diving for research purposes. In addition to being regarded as an authority in marine biology, Clark was popularly recognized and used her fame to promote marine conservation.
Early life and education
Eugenie Clark was born and raised in New York City. Her father, Charles Clark, died when Eugenie was almost two years old, and her mother, Yumico Motomi, later married Japanese restaurant owner Masatomo Nobu.
Clark attended elementary school in Woodside, Queens, and graduated from Bryant High School in Queens, New York. She was the only student of Japanese descent in her schools.
From an early age, Clark was passionate about marine science, with many of her school reports covering topics in marine biology. An initial visit to the New York Aquarium at Battery Park inspired Clark to return to the aquarium every Saturday thereafter, fascinated by marine animals. The work of naturalist William Beebe further inspired Clark to become an oceanographer.
Academic and scientific life
Eugenie Clark received a Bachelor of Arts in zoology from Hunter College (1942). During summers, she studied at the University of Michigan Biological Station, and prior to graduate school, she worked for Celanese Corporation as a chemist. Eugenie initial
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https://en.wikipedia.org/wiki/Algebraic%20manifold
|
__notoc__
In mathematics, an algebraic manifold is an algebraic variety which is also a manifold. As such, algebraic manifolds are a generalisation of the concept of smooth curves and surfaces defined by polynomials. An example is the sphere, which can be defined as the zero set of the polynomial and hence is an algebraic variety.
For an algebraic manifold, the ground field will be the real numbers or complex numbers; in the case of the real numbers, the manifold of real points is sometimes called a Nash manifold.
Every sufficiently small local patch of an algebraic manifold is isomorphic to km where k is the ground field. Equivalently the variety is smooth (free from singular points). The Riemann sphere is one example of a complex algebraic manifold, since it is the complex projective line.
Examples
Elliptic curves
Grassmannian
See also
Algebraic geometry and analytic geometry
References
(See also Proc. Internat. Congr. Math., 1950, (AMS, 1952), pp. 516–517.)
External links
K-Algebraic manifold at PlanetMath
Algebraic manifold at Mathworld
Lecture notes on algebraic manifolds
Lecture notes on algebraic manifolds
Algebraic varieties
Manifolds
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https://en.wikipedia.org/wiki/Adduct
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In chemistry, an adduct (; alternatively, a contraction of "addition product") is a product of a direct addition of two or more distinct molecules, resulting in a single reaction product containing all atoms of all components. The resultant is considered a distinct molecular species. Examples include the addition of sodium bisulfite to an aldehyde to give a sulfonate. It can be considered as a single product resulting from the direct combination of different molecules which comprises all atoms of the reactant molecules.
Adducts often form between Lewis acids and Lewis bases. A good example is the formation of adducts between the Lewis acid borane and the oxygen atom in the Lewis bases, tetrahydrofuran (THF): or diethyl ether: . Many Lewis acids and Lewis bases reacting in the gas phase or in non-aqueous solvents to form adducts have been examined in the ECW model. Trimethylboron, trimethyltin chloride and bis(hexafluoroacetylacetonato)copper(II) are examples of Lewis acids that form adducts which exhibit steric effects. For example: trimethyltin chloride, when reacting with diethyl ether, exhibits steric repulsion between the methyl groups on the tin and the ethyl groups on oxygen. But when the Lewis base is tetrahydrofuran, steric repulsion is reduced. The ECW model can provide a measure of these steric effects.
Compounds or mixtures that cannot form an adduct because of steric hindrance are called frustrated Lewis pairs.
Adducts are not necessarily molecular in nature
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https://en.wikipedia.org/wiki/Minkowski%20plane
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In mathematics, a Minkowski plane (named after Hermann Minkowski) is one of the Benz planes (the others being Möbius plane and Laguerre plane).
Classical real Minkowski plane
Applying the pseudo-euclidean distance on two points (instead of the euclidean distance) we get the geometry of hyperbolas, because a pseudo-euclidean circle is a hyperbola with midpoint .
By a transformation of coordinates , , the pseudo-euclidean distance can be rewritten as . The hyperbolas then have asymptotes parallel to the non-primed coordinate axes.
The following completion (see Möbius and Laguerre planes) homogenizes the geometry of hyperbolas:
the set of points:
the set of cycles
The incidence structure is called the classical real Minkowski plane.
The set of points consists of , two copies of and the point .
Any line is completed by point , any hyperbola by the two points (see figure).
Two points can not be connected by a cycle if and only if or .
We define:
Two points are (+)-parallel () if and (−)-parallel () if .
Both these relations are equivalence relations on the set of points.
Two points are called parallel () if
or .
From the definition above we find:
Lemma:
For any pair of non parallel points there is exactly one point with .
For any point and any cycle there are exactly two points with .
For any three points , , , pairwise non parallel, there is exactly one cycle that contains .
For any cycle , any point and any point and there exists exactl
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https://en.wikipedia.org/wiki/PHYLIP
|
PHYLogeny Inference Package (PHYLIP) is a free computational phylogenetics package of programs for inferring evolutionary trees (phylogenies). It consists of 65 portable programs, i.e., the source code is written in the programming language C. As of version 3.696, it is licensed as open-source software; versions 3.695 and older were proprietary software freeware. Releases occur as source code, and as precompiled executables for many operating systems including Windows (95, 98, ME, NT, 2000, XP, Vista), Mac OS 8, Mac OS 9, OS X, Linux (Debian, Red Hat); and FreeBSD from FreeBSD.org.
Full documentation is written for all the programs in the package and is included therein. The programs in the phylip package were written by Professor Joseph Felsenstein, of the Department of Genome Sciences and the Department of Biology, University of Washington, Seattle.
Methods (implemented by each program) that are available in the package include parsimony, distance matrix, and likelihood methods, including bootstrapping and consensus trees. Data types that can be handled include molecular sequences, gene frequencies, restriction sites and fragments, distance matrices, and discrete characters.
Each program is controlled through a menu, which asks users which options they want to set, and allows them to start the computation. The data is read into the program from a text file, which the user can prepare using any word processor or text editor (but this text file cannot be in the special form
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https://en.wikipedia.org/wiki/Integer%20matrix
|
In mathematics, an integer matrix is a matrix whose entries are all integers. Examples include binary matrices, the zero matrix, the matrix of ones, the identity matrix, and the adjacency matrices used in graph theory, amongst many others. Integer matrices find frequent application in combinatorics.
Examples
and
are both examples of integer matrices.
Properties
Invertibility of integer matrices is in general more numerically stable than that of non-integer matrices. The determinant of an integer matrix is itself an integer, thus the numerically smallest possible magnitude of the determinant of an invertible integer matrix is one, hence where inverses exist they do not become excessively large (see condition number). Theorems from matrix theory that infer properties from determinants thus avoid the traps induced by ill conditioned (nearly zero determinant) real or floating point valued matrices.
The inverse of an integer matrix is again an integer matrix if and only if the determinant of equals or . Integer matrices of determinant form the group , which has far-reaching applications in arithmetic and geometry. For , it is closely related to the modular group.
The intersection of the integer matrices with the orthogonal group is the group of signed permutation matrices.
The characteristic polynomial of an integer matrix has integer coefficients. Since the eigenvalues of a matrix are the roots of this polynomial, the eigenvalues of an integer matrix are algebr
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https://en.wikipedia.org/wiki/Stress%20granule
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In cellular biology, stress granules are biomolecular condensates in the cytosol composed of proteins and RNAs that assemble into 0.1–2 μm membraneless organelles when the cell is under stress. The mRNA molecules found in stress granules are stalled translation pre-initiation complexes associated with 40S ribosomal subunits, translation initiation factors, poly(A)+ mRNAs and RNA-binding proteins (RBPs). While they are membraneless organelles, stress granules have been proposed to be associated with the endoplasmatic reticulum. There are also nuclear stress granules. This article is about the cytosolic variety.
Proposed functions
The function of stress granules remains largely unknown. Stress granules have long been proposed to have a function to protect RNAs from harmful conditions, thus their appearance under stress. The accumulation of RNAs into dense globules could keep them from reacting with harmful chemicals and safeguard the information coded in their RNA sequence.
Stress granules might also function as a decision point for untranslated mRNAs. Molecules can go down one of three paths: further storage, degradation, or re-initiation of translation. Conversely, it has also been argued that stress granules are not important sites for mRNA storage nor do they serve as an intermediate location for mRNAs in transit between a state of storage and a state of degradation.
Efforts to identify all RNAs within stress granules (the stress granule transcriptome) in an unbiased w
|
https://en.wikipedia.org/wiki/Maker%20Faire
|
Maker Faire is a convention of do it yourself (DIY) enthusiasts established by Make magazine in 2006. Participants come from a wide variety of interests, such as robotics, 3D printing, computers, arts and crafts, and hacker culture.
History
In 2005, Dale Dougherty founded Make: magazine as a quarterly publication with Tim O’Reilly. The first Make: magazine was published in 2005 and the first Maker Faire took place in 2006 in San Mateo, Over the next 13 years, this inaugural maker faire expanded to more than 200 licensed Maker Faires in more than 40 countries.
Dale Dougherty convened the first Maker Faire in 2006 in San Mateo, Calif., drawing a crowd of 20,000.
Maker Media Inc. went out of business in June 2019, and Dale Dougherty rebranded as Make Community.
Maker Faires in the US
Flagship Maker Faires
Flagship Maker Faires are held in San Mateo, California and New York City.
The last Bay Area Maker Faire was held in 2019. The Maker Faire Bay Area was not held in 2020. This was due to the potential impact of coronavirus as well as the 2019 transition of Maker Media to Make: Community.
A revived Bay Area Maker Faire was held in October 2023 at the Mare Island Naval Shipyard in Vallejo, California.
The New York Maker Faire is also known as the "World Maker Faire". Maker Faire has most recently happened in New York in 2018.
However, the New York City Faire was cancelled in 2019 due to financial difficulties.
White House Maker Faire
On June 18, 2014, President Obama
|
https://en.wikipedia.org/wiki/Frame%20%28linear%20algebra%29
|
In linear algebra, a frame of an inner product space is a generalization of a basis of a vector space to sets that may be linearly dependent. In the terminology of signal processing, a frame provides a redundant, stable way of representing a signal. Frames are used in error detection and correction and the design and analysis of filter banks and more generally in applied mathematics, computer science, and engineering.
Definition and motivation
Motivating example: computing a basis from a linearly dependent set
Suppose we have a set of vectors in the vector space V and we want to express an arbitrary element as a linear combination of the vectors , that is, we want to find coefficients such that
If the set does not span , then such coefficients do not exist for every such . If spans and also is linearly independent, this set forms a basis of , and the coefficients are uniquely determined by . If, however, spans but is not linearly independent, the question of how to determine the coefficients becomes less apparent, in particular if is of infinite dimension.
Given that spans and is linearly dependent, one strategy is to remove vectors from the set until it becomes linearly independent and forms a basis. There are some problems with this plan:
Removing arbitrary vectors from the set may cause it to be unable to span before it becomes linearly independent.
Even if it is possible to devise a specific way to remove vectors from the set until it becomes a bas
|
https://en.wikipedia.org/wiki/Thomas%20Heath
|
Thomas Heath may refer to:
Thomas Heath (classicist) (1861–1940), British civil servant, and historian of ancient Greek mathematics
Thomas Heath (cricketer) (1806–1872), cricketer
Thomas Kurton Heath (1853–1938), vaudeville actor
Tommy Heath (born 1947), musician
Tommy Heath (baseball) (1913–1967), American catcher, scout and baseball manager
Thomas Heath Haviland Sr. (1795-1867), Canadian land owner and banker
Thomas Heath Haviland (1822–1895), Canadian lawyer and politician
Thomas Heath Robinson (1869–1954), English illustrator
Thomas Heth (or Heath) (fl. 1583), English mathematician
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https://en.wikipedia.org/wiki/Trigger%20%28particle%20physics%29
|
In particle physics, a trigger is a system that uses criteria to rapidly decide which events in a particle detector to keep when only a small fraction of the total can be recorded. Trigger systems are necessary due to real-world limitations in computing power, data storage capacity and rates. Since experiments are typically searching for "interesting" events (such as decays of rare particles) that occur at a relatively low rate, trigger systems are used to identify the events that should be recorded for later analysis. Current accelerators have event rates greater than 1 MHz and trigger rates that can be below 10 Hz. The ratio of the trigger rate to the event rate is referred to as the selectivity of the trigger. For example, the Large Hadron Collider (LHC) has an event rate of 40 MHz (4·107 Hz), and the Higgs boson is expected to be produced there at a rate of roughly 1 Hz. The LHC detectors can manage to permanently store about one thousand events per second. Therefore, the minimum selectivity required is 10−5, with much stricter requirements for the data analysis afterwards.
See also
ATLAS trigger system
CMS trigger
References
Experimental particle physics
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https://en.wikipedia.org/wiki/Downwards%20zigzag%20arrow
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The symbol ↯ () is a Unicode character. It may refer to:
a contradiction (the relationship between incompatible propositions) in mathematical logic
electrolysis (the process of using an electrical current to separate molecules) in chemistry
See also
Arrow (disambiguation)
→ (disambiguation)
↑ (disambiguation)
↓ (disambiguation)
← (disambiguation)
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https://en.wikipedia.org/wiki/Roscoe%20Brady
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Roscoe Owen Brady (October 11, 1923 – 13 June 2016) was an American biochemist.
He attended the Pennsylvania State University and obtained his M.D. degree from Harvard Medical School in 1947. He interned at the Hospital of the University of Pennsylvania. From 1948 to 1952 he was a post-doctoral fellow in the department of physiological chemistry at the University of Pennsylvania School of Medicine and fellow in clinical medicine in the department of medicine. In collaboration with Samuel Gurin at the University of Pennsylvania, Brady discovered the enzyme system for the biosynthesis of long chain fatty acids, and later discovered the role of malonate coenzyme A in this process. After two and one-half years on active duty in the U.S. Naval Medical Corps, he joined the National Institutes of Health in 1954. He was Chief of the Developmental and Metabolic Neurology Branch in the National Institute of Neurological Disorders and Stroke from 1972 to 2006. Dr. Brady and his colleagues identified the enzymatic defects in Gaucher's disease, Niemann–Pick disease, Fabry disease and the specific metabolic abnormality in Tay–Sachs disease. He and his associates developed diagnostic, carrier detection, prenatal tests for these conditions, and effective enzyme replacement therapy for patients with Gaucher disease and Fabry disease. These were the first-ever enzyme replacement therapy (ERT) treatments for lysosomal diseases, and directly led to great advances in the development of enzyme r
|
https://en.wikipedia.org/wiki/Patrick%20O.%20Brown
|
Patrick O'Reilly Brown (born 1954) is an American scientist and businessman who is the founder of Impossible Foods Inc. and professor emeritus in the department of biochemistry at Stanford University. Brown is co-founder of the Public Library of Science, inventor of the DNA microarray, and a former investigator at Howard Hughes Medical Institute.
Education
Brown received each of his degrees from The University of Chicago, including his B.S. in 1976 and M.D. in 1982. His Ph.D., granted in 1980 while under the guidance of Nicholas R. Cozzarelli, involved the study of DNA topoisomerases.
Academic career
After getting his medical degree in 1982, Brown completed a 3-year pediatric residency at Children's Memorial Hospital in Chicago but decided he could have a greater impact through basic research. In 1985, Brown took a 3-year postdoctoral fellowship at the University of California, San Francisco with J. Michael Bishop and Harold Varmus (who shared the 1989 Nobel Prize in Medicine for their discoveries about how genes can ignite cancerous tumors). At UCSF, Brown and colleagues defined the mechanism by which retroviruses, such as the HIV virus, integrate their genes into the genome of the cells they infect, which helped lead to development of new drugs to fight the disease.
In 1988, Brown became an investigator of the Howard Hughes Medical Institute and an assistant professor in the department of biochemistry at Stanford University School of Medicine, where he continued to inves
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https://en.wikipedia.org/wiki/John%20Buchanan%20%28biologist%29
|
John Machlin Buchanan (September 29, 1917 – June 25, 2007) was an American professor of biochemistry at the Massachusetts Institute of Technology. He arrived at MIT in 1953 and retired in 1988 after a distinguished career in which he was elected a fellow of the American Academy of Arts and Sciences and the National Academy of Sciences. He played a key role in the development of MIT's Department of Biology as a major force in biochemistry research and was himself a prominent researcher of purine biosynthesis. He died in 2007 at age 89.
Early life and education
Buchanan was born in Winamac, Indiana, in 1917. He became interested in a career in science during a high school chemistry course. He attended DePauw University as an undergraduate, where he gained his first scientific research experience, and from which he graduated with a bachelor's degree in chemistry in 1938. He received his M.S. from the University of Michigan, Ann Arbor in 1939, and later identified the head of its chemistry department, Howard B. Lewis, as a key influence in his research career. Buchanan received his Ph.D. from Harvard University in 1943 under the supervision of Albert Baird Hastings.
Academic career
Buchanan arrived at MIT in 1953 after reaching the rank of full professor at the University of Pennsylvania Medical School. He had been heavily recruited by the head of what was then called the Department of Molecular Biology, Francis O. Schmitt. He became the head of the Division of Biochemistry an
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https://en.wikipedia.org/wiki/Paul%20Flaherty
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Paul Andrew Flaherty (March 14, 1964 – March 16, 2006) was an American computer scientist. He was a renowned specialist in Internet protocols and the inventor of the AltaVista search engine.
Biography
Flaherty was born in Milwaukee, Wisconsin. He received his bachelor's degree in electrical engineering and mathematics from Marquette University, and his master's degree and PhD in electrical engineering from Stanford University.
He joined Digital Equipment Corporation in 1994 and, as the Associated Press wrote:
He held an amateur radio Extra class license with the call sign N9FZX. Was President, W6YX, Stanford Amateur Radio Club, 1986-1990.
Station Engineer, W6YX, Stanford Amateur Radio Club, 1990-1994.
Started the VHF+ mailing list in 1989.
Married to his Stanford University sweetheart N6YBV (this number refers to her amateur radio call sign).
An avid railfan photographer and past Assistant General Manager of the Niles Canyon Railway.
Member of the Marquette chapter of Triangle Fraternity as an undergrad, where he served as chapter President. He exercised his duties with honor and was well liked within the fraternity.
Member of the Sunnyvale Rod and Gun Club where he enjoyed target shooting and trap shooting.
While a grad student drove a 1979 Z28 Camaro with T-tops.
At age 42, Flaherty died of a heart attack at his home in Belmont, California.
References
1964 births
2006 deaths
Scientists from Milwaukee
Amateur radio people
Marquette University alumni
Stanford Univers
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https://en.wikipedia.org/wiki/John%20Carbon
|
John A. Carbon is a professor emeritus of molecular and cellular biology at the University of California, Santa Barbara.
Biography
He earned his B.S. degree in chemistry in 1952 at the University of Illinois, and his Ph.D. degree in biochemistry in 1955 from Northwestern University. He did basic research developing new anticancer drugs at Abbott Laboratories (North Chicago, IL) for 12 years (1956-1968). He joined the faculty of the University of California, Santa Barbara in 1968, and became professor emeritus in 1999. His research contributions include elucidation of the mechanism of genetic missense suppression in bacteria, the development of techniques to make genomic libraries using recombinant DNA, techniques for using yeast for DNA cloning, characterization of centromere DNA, and construction of the first artificial chromosomes. Many of his later research contributions were carried out in collaboration with his wife, Professor Louise B. Clarke. He was elected to membership in the United States National Academy of Sciences and the American Academy of Arts and Sciences in 1986. Carbon was among the founding scientific advisors of the Amgen Corporation. An endowed chair in Biochemistry and Molecular Biology at UC Santa Barbara was named for Carbon. The chair is currently held by Jamey Marth.
Carbon and Louise Clarke, his wife, published the Carbon-Clarke equation in 1976, used for calculating the number of clones required when constructing a clone library to ensure
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https://en.wikipedia.org/wiki/Fred%20Espenak
|
Fred Espenak is a retired emeritus American astrophysicist. He worked at the Goddard Space Flight Center. He is best known for his work on eclipse predictions.
He became interested in astronomy when he was 7–8 years old, and had his first telescope when he was around 9–10 years old. Espenak earned a bachelor's degree in physics from Wagner College, Staten Island, where he worked in the planetarium. His master's degree is from the University of Toledo, based on studies he did at Kitt Peak Observatory of eruptive and flare stars among red dwarfs.
He was employed at Goddard Space Flight Center, where he used infrared spectrometers to measure the atmospheres of planets in the Solar System. He provided NASA's eclipse bulletins since 1978. He is the author of several canonical works on eclipse predictions, such as the Fifty Year Canon of Solar Eclipses: 1986–2035 and Fifty Year Canon of Lunar Eclipses: 1986–2035, both of which are standard references on eclipses. The first eclipse he saw was the solar eclipse of March 7, 1970, which sparked his interest in eclipses, and he has since seen over 20 eclipses.
Together with Jean Meeus, he published the Five Millennium Canon of Solar Eclipses in 2006, which covers all types of solar eclipses (partial, total, annular, or hybrid) from 2000 BCE to AD 3000, and the Five Millennium Canon of Lunar Eclipses in 2009, which lists all lunar eclipses (penumbral, partial, or total) in that time span. Later, he published the more compact Thousand
|
https://en.wikipedia.org/wiki/Institut%20Agro%20Dijon
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The Institut Agro Dijon is a French grande école located in Dijon, France. The institute specialises in agriculture, food science and environmental science.
History
The school traces its back to the 1960s. In 2009, the National Higher Institute of Agronomic, Food and Environmental Sciences (AgroSup Dijon) was created by the merger of National Higher School of Biology Applied to Nutrition and Food (ENSBANA) and National Establishment of Higher Agronomic Education of Dijon (ENESAD).
In 2022, the AgroSup Dijon was renamed the Institut Agro Dijon. It is a part of the , along with Institut Agro Rennes-Angers and Institut agro Montpellier.
Curriculum
Chemistry, Biochemistry
Food Technology and Food Processing
Sensory Analysis
Nutrition
Microbiology and Biotechnology
Food Safety, Hygiene, Toxicology and Quality Assurance
Applied Mathematics, Economics, Foreign Languages
External links
Institut Agro Dijon
Association des Ingénieurs de l'ENS.BANA
Conférence des Grandes Ecoles
Dijon
Educational institutions established in 1967
1967 establishments in France
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https://en.wikipedia.org/wiki/Agent%20architecture
|
Agent architecture in computer science is a blueprint for software agents and intelligent control systems, depicting the arrangement of components. The architectures implemented by intelligent agents are referred to as cognitive architectures. The term agent is a conceptual idea, but not defined precisely. It consists of facts, set of goals and sometimes a plan library.
Types
Reactive architectures
Subsumption
Deliberative reasoning architectures
Procedural reasoning system (PRS)
Layered/hybrid architectures
3T
AuRA
Brahms
GAIuS
GRL
ICARUS
InteRRaP
TinyCog
TouringMachines
Cognitive architectures
ASMO
Soar
ACT-R
Brahms
LIDA
PreAct
Cougaar
PRODIGY
FORR
See also
Action selection
Cognitive architecture
Real-time Control System
References
Software architecture
Robot architectures
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