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70,864,232 | https://en.wikipedia.org/wiki/Daramba | Daramba is a Visayan term referring to paddling and fighting platforms mounted directly on the outriggers (katig) of traditional large trimaran warships (balangay) of the Philippines. They accommodated one or more rows on each side of commoner warriors (horo-han) with large leaf-shaped paddles (bugsay) during travel, naval warfare, and seasonal coastal raids (mangayaw). The paddlers were kept in rhythm by various chants and songs. The platforms for the horo-han are distinguished from the side-mounted fighting platforms (pagguray) of the warrior-nobility (the timawa and tumao), which were also built on the outriggers, in that the daramba was mounted on or near the water surface, while the pagguray was mounted above, closer to the hull.
See also
Outrigger boat
Lashed-lug boat
Balangay
Karakoa
Lanong
Bangka (boat)
References
Shipbuilding
Multihulls
Outrigger canoes
Visayan culture
Visayan history
Austronesian culture
Indigenous ships of the Philippines | Daramba | [
"Engineering"
] | 230 | [
"Shipbuilding",
"Marine engineering"
] |
70,864,519 | https://en.wikipedia.org/wiki/Aderemi%20Kuku | Aderemi Oluyomi Kuku (20 March 1941 – 13 February 2022) was a Nigerian mathematician and academic, known for his contributions to the fields of algebraic K-theory and non-commutative geometry. Born in Ijebu-Ode, Ogun State, Nigeria, Kuku began his academic journey at Makerere University College and the University of Ibadan, where he earned his B.Sc. in Mathematics, followed by his M.Sc. and Ph.D. under Joshua Leslie and Hyman Bass. His doctoral research focused on the Whitehead group of p-adic integral group-rings of finite p-groups. Kuku held positions as a lecturer and professor at various Nigerian universities, including the University of Ife and the University of Ibadan, where he served as Head of the Department of Mathematics and Dean of the Postgraduate School. His research involved developing methods for computing higher K-theory of non-commutative rings and articulating higher algebraic K-theory in the language of Mackey functors. His work on equivariant higher algebraic K-theory and its generalisations impacted the field.
During his career, Kuku was elected a Fellow of the African Academy of Sciences, the Nigerian Academy of Science, and the American Mathematical Society. He also received the Nigerian National Order of Merit and the Officer of the Order of the Niger. He served as president of the African Mathematical Union, where he worked to promote mathematics across Africa. Kuku's work extended beyond research, encompassing education and mentorship. He authored several books and articles, supervised graduate students, and fostered international collaborations.
Early life and education
Aderemi Oluyomi Kuku was born on 20 March 1941, in Ijebu-Ode, Ogun State, Nigeria. His father Busari Adeoye Kuku was a photographer, and mother Abusatu Oriaran Baruwa was a trader. Aderemi was the third of four brothers, all of whom pursued professional careers. Kuku began his education at Bishop Oluwole Memorial School in Agege, Lagos State, and continued at St James School Anglican primary school in Oke-Odan, Ogun State. He came first in the first school leaving certificate which led to his admission to Eko Boys' High School in Lagos, Nigeria, where he served as Head Boy in his final year, 1959.
After completing his secondary education, Kuku moved to Abeokuta Grammar School to pursue his Higher School Certificate, focusing on Mathematics, Further Mathematics, and Physics. His performance earned him a scholarship from the African Scholarship Program of American Universities, administered by the United States Agency for International Development. However, he chose to attend Makerere University College in Kampala, Uganda, for his undergraduate studies.
At Makerere University College, then part of the University of East Africa and an external college of the University of London, Kuku supplemented his coursework with self-study. He graduated in 1965 with a B.Sc. in Mathematics. Upon graduation, Kuku returned to Nigeria, where he was appointed as an Assistant Lecturer at the University of Ife in Ile-Ife, Osun State. Despite his lecturing duties, he registered at the University of Ibadan to pursue a Master's Degree.
The University of Ibadan, established in 1948 as a College of the University of London and becoming an independent university in 1962, provided Kuku with the opportunity to delve deeper into his mathematical interests. Under the supervision of Joshua Leslie and with the external examination by Hyman Bass, Kuku submitted his M.Sc. thesis titled A survey of Algebraic K-theory, and bagged an M.Sc. in 1968.
Academic career
Aderemi Kuku pursued an academic career after earning his M.Sc. from the University of Ibadan. He was appointed as a Lecturer II at the University of Ife, where he began his teaching career. His dedication to education and research led to his promotion within the university in 1967. In 1968, Kuku transitioned to the University of Ibadan as a Lecturer II in Mathematics, succeeding Joshua Leslie. During this period, he married Felicia Osifunke Kalesanwo.
Kuku's tenure at the University of Ibadan was marked by a focus on his research interests. He accepted an invitation from Hyman Bass to conduct research at Columbia University in New York City. This opportunity allowed him to spend the year 1970–71 at Columbia University, where he worked with Bass and submitted his thesis On the Whitehead group of p-adic integral group-rings of finite p-groups, earning his Ph.D. in 1971. Upon his return to Nigeria, Kuku was promoted to Senior Lecturer in Mathematics in 1976, to Reader in Mathematics in 1980, and to Professor of Mathematics at the University of Ibadan in 1982.
Throughout the 1980s and 1990s, Kuku served as President of the African Mathematical Union, where he worked to establish commissions and networks to promote mathematics across the continent. He also organised the fourth Pan-African Congress of Mathematicians in Morocco in 1995, where he delivered a plenary lecture. Kuku's academic work extended beyond Nigeria. He held visiting professorships and research positions at various universities and research institutes. His international experience contributed to global mathematical discourse.
Research contributions
Kuku's work in mathematics, specifically algebraic K-theory and non-commutative geometry, has linked various mathematical disciplines, aiding in the understanding of algebraic structures and their applications. His research intersects algebra, number theory, and geometry, using K-theory and cyclic homology methodologies. He formulated higher algebraic K-theory using representation theory, specifically Mackey functors. This led to the development of equivariant higher algebraic K-theory and its relative generalisations in exact and Waldhausen categories.
Kuku developed methods for computing higher K-theory of non-commutative rings, including non-commutative orders and group-rings, twisted polynomials, and Laurent series rings over orders. These methods are used in the calculations of higher K-theory of virtually infinite cyclic groups within the Farrell–Jones conjecture's context. In non-commutative geometry, Kuku's research includes entire/periodic cyclic homology and K-theory of involutive Banach algebras, C*-algebras, group C*-algebras, Hopf algebras, and quantum groups. He studied the connections between K-theory and cyclic homology of these structures.
In collaboration with M. Mahdavi-Hezavehi, Kuku studied the algebraic structure of subgroups in the group of units of a non-commutative local ring. His work with N.Q. Tho and D.N. Diep on compact Lie group C*-algebras and compact quantum groups resulted in the construction and study of non-commutative Chern characters from K-theory to entire/periodic cyclic homology. Kuku's research includes the Baum–Connes conjecture in non-commutative geometry. He formulated this conjecture for the action of quantum groups and confirmed it in specific cases, such as for quantum SU2. In addition to theoretical work, Kuku has contributed to the computational aspects of algebraic K-theory, focusing on the computation of K-groups, periodic cyclic homology, and Chern characters of various non-commutative structures.
His research has implications for other fields such as mathematical physics, dynamical systems, econometrics, and control theory, fostering collaborations across different research areas. Kuku has authored research articles, books, and monographs throughout his career. He has mentored M.Sc., M.Phil., and Ph.D. candidates, and guided postdoctoral researchers and mathematicians globally. His book Abstract Algebra, is used as a textbook for undergraduate and beginning graduate students. His advanced texts, such as "Representation Theory and Higher Algebraic K-theory," serve as resources for researchers and graduate students.
Awards and honours
Kuku has received various recognition for his works and contributions. He was the recipient of the Ogun State Special Merit Award in 1987, the Officer of the Order of the Niger in 2008, and the Nigerian National Order of Merit Award in 2009. Kuku has been a fellow of different academic institutions including the African Academy of Sciences, and a member of European Academy of Arts Science and Humanities in 1986, the Nigerian Academy of Science and The World Academy of Sciences in 1989, the Mongolian Academy of Sciences in 2005, and the American Mathematical Society in 2012.
In 2011 during his 70th birthday, Kuku was honoured with an International Conference on Algebraic K-theory at Nanjing University in China. As the President of the African Mathematical Union, Kuku played a role in the establishment of networks to promote mathematics across the continent.
Death and legacy
Kuku died on 13 February 2022. His work in algebraic K-theory and non-commutative geometry has influenced mathematical sciences. His research has resulted in practical tools and methodologies for future research. Kuku has focused on education and has mentored mathematicians, particularly in Africa. He has helped establish networks that support students and researchers across the continent. Kuku has guided many students academically. The Ph.D. students and postdoctoral researchers he mentored have contributed to mathematics.
Kuku's work has been recognised in conferences and special journal issues. Kuku has advocated for the application of mathematics to solve real-world problems. Kuku has written numerous publications and articles, which are often cited and used as references in mathematical research. Kuku's efforts to advance mathematics in Africa have impacted the continent's academic landscape. His work has raised the profile of African mathematics and encouraged international collaboration and recognition. Kuku's legacy includes his academic work, his role as a mentor and educator, and his influence on the development of mathematical sciences in Africa and beyond.
Selected publications
References
Citations
Bibliography
Academic administrators
Academic staff of the University of Ibadan
1941 births
2022 deaths
Fellows of the African Academy of Sciences
Fellows of the Nigerian Academy of Science
Fellows of the American Mathematical Society
People from Ogun State
Makerere University alumni
University of Ibadan alumni
Columbia University alumni
Officers of the Order of the Niger
Nigerian expatriate academics in the United States
Nigerian expatriates in Uganda
20th-century Nigerian mathematicians
21st-century Nigerian mathematicians
Algebraists
Mathematical analysts
Recipients of the Nigerian National Order of Merit Award | Aderemi Kuku | [
"Mathematics"
] | 2,121 | [
"Algebra",
"Mathematical analysis",
"Mathematical analysts",
"Algebraists"
] |
70,864,805 | https://en.wikipedia.org/wiki/Tau%20Octantis | Tau Octantis, Latinized from τ Octantis, is a solitary star in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.50, allowing it to be faintly seen with the naked eye. The object is located at a distance of 480 light years but is receding with a heliocentric radial velocity of .
Tau Octantis has a stellar classification of K2 III, indicating that the object is a red giant. It has 114% the mass of the Sun but is 223 times as luminous. However, an enlarged radius of yields an effective temperature of 4,422 K, giving it an orange glow. Tau Octantis has an iron abundance 132% that of the Sun and is believed to be a member of the old disk population. Currently, it spins with a projected rotational velocity less than .
References
Octans
K-type giants
Octantis, Tau
Octantis, 81
219765
115836
8862
PD-88 204 | Tau Octantis | [
"Astronomy"
] | 204 | [
"Octans",
"Constellations"
] |
70,864,908 | https://en.wikipedia.org/wiki/Phosphate%20sulfate | The phosphate sulfates are mixed anion compounds containing both phosphate and sulfate ions.
Related compounds include the arsenate sulfates, phosphate selenates, and arsenate selenates.
Some hydrogen phosphate sulfates are superprotonic conductors.
List
Artificial
Organic derivatives
A catenated sulfophosphate has the sulfur and phosphorus joined by an oxygen atom. In biochemistry, metabolism of sulfate may use such a group, for example with adenosine-5'-phosphosulfate.
References
Phosphates
Mixed anion compounds
Sulfates | Phosphate sulfate | [
"Physics",
"Chemistry"
] | 112 | [
"Matter",
"Mixed anion compounds",
"Sulfates",
"Salts",
"Phosphates",
"Ions"
] |
70,865,048 | https://en.wikipedia.org/wiki/Abequose | Abequose is a hexose and a 3,6-dideoxysugar. It is a constituent of the in O-specific chains in lipopolysaccharides that occur in certain serotypes of Salmonella and Citrobacter bacteria. It is the enantiomer of colitose.
References
External links
Hexoses
Deoxy sugars | Abequose | [
"Chemistry"
] | 81 | [
"Carbohydrates",
"Deoxy sugars",
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
70,865,508 | https://en.wikipedia.org/wiki/Dibrospidium%20chloride | Dibrospidium chloride, also known as spirobromin, is a drug being investigated to treat bone cancer. It has potential anti-inflammatory and anti-neoplastic properties. It is an alkylating antineoplastic agent.
Dibrospidium chloride and related compounds were developed in Russia in the 1980s. It is currently used in Russia as a cytostatic antitumor chemotherapeutic drug.
References
Experimental cancer drugs
Alkylating antineoplastic agents
Quaternary ammonium compounds
Spiro compounds
Nitrogen heterocycles
Organobromides
Chlorides
Amides | Dibrospidium chloride | [
"Chemistry"
] | 125 | [
"Chlorides",
"Inorganic compounds",
"Functional groups",
"Salts",
"Organic compounds",
"Amides",
"Spiro compounds"
] |
58,464,262 | https://en.wikipedia.org/wiki/Bette%20Korber | Bette Korber is an American computational biologist focusing on the molecular biology and population genetics of the HIV virus that causes infection and eventually AIDS. She has contributed heavily to efforts to obtain an effective HIV vaccine. She created a database at Los Alamos National Laboratory that has enabled her to design novel mosaic HIV vaccines, one of which is currently in human testing in Africa. The database contains thousands of HIV genome sequences and related data.
Korber is a scientist in theoretical biology and biophysics at Los Alamos National Laboratory. She has received the Ernest Orlando Lawrence Award, the Department of Energy's highest award for scientific achievement. She has also received several other awards including the Elizabeth Glaser Award for pediatric AIDS research and the Richard Feynman Award for Innovation.
Early life and education
Bette Korber grew up in Southern California. She earned her B.S. in chemistry in 1981 from California State University, Long Beach, where her father was a sociology professor, her mother graduated in nursing, and her sister graduated in journalism. From 1981 to 1988, she was in the graduate program at the California Institute of Technology (Caltech), where she worked with Iwona Stroynowski in Leroy Hood's laboratory, receiving her PhD in chemistry in 1988. Her work focused on regulation of the expression of major histocompatibility complex type 1 genes, producing cell surface proteins that participate in the rejection of tissue transplants, by interferon induced by viral infections.
She then became a postdoctoral fellow with Myron Essex, working on the molecular epidemiology of the AIDS/HIV virus and HTLV-1, the human leukemia virus, at the Harvard School of Public Health until 1990. There, Korber used polymerase chain reaction (PCR) to show both complete and deleted versions of viral genomes in leukemic cells. Her work on these viral partial and complete genomes was influential and widely cited. She became a visiting faculty member at the Santa Fe Institute in 1991, continuing in that position until 2011.
Research
Korber conducts her research at Los Alamos National Laboratory, where she began in 1990. Her approach involves applying computational biology to the design of a vaccine against the HIV/AIDS virus. She first became interested in HIV when a close friend of hers and her fiancé's at Caltech contracted one of the first cases of AIDS in Pasadena, California. She said, "We learned a lot about HIV while he was sick. But there was no treatment for him and he died in 1991. I decided when I graduated from my PhD program that I wanted to work on HIV." Several years later, looking back on this event, she described its effects: "I hate HIV ... I lost a couple friends to it. HIV kills in horrible ways. I think of what the epidemic has done to Africa and it motivates me."
HIV database
Korber oversees the HIV Database and Analysis Project at Los Alamos. She and her team have built a global HIV database of more than 840,000 sequences from publications of the viral genome. In addition, the database focuses on the small regions (called epitopes) within the virus that can be recognized by antibodies, and evaluates the evidence for the strength of each epitope in eliciting immune responses. There is also data on the immunological profiles of individuals resistant to HIV. Korber and many other researchers have applied the data to devise possible treatments and vaccines against HIV. Her work has resulted in design of vaccines now being tested in clinical trials.
HIV vaccine design
Creating a vaccine against HIV has been challenging because the virus mutates rapidly, creating multiple variants that may not be recognized by immune system components specific to the original infecting virus. The most variable region is the surface of the virus, but there is also some variation of the internal proteins involved in virus replication, which may be attacked by the cellular immunity system or T cell responses. A recent approach that Korber and collaborators have taken is to design mosaic antigens. Korber developed a novel mosaic HIV vaccine that may slow or prevent HIV infection; this is currently in human testing in Africa. The goal of the mosaic antigen vaccine is to protect the vaccinated person against the great variety of HIV variants encountered.
Since the proteins of HIV vary so greatly, mosaic test proteins are designed to represent the most common forms of HIV-1 virus that can be recognized by antibodies or cellular immune responses (epitopes). In 2009, Korber described the process: "I create sort of little Frankenstein proteins that look and feel like HIV proteins but they don't exist in nature."
Several of the major variations are included in each molecule of protein, thus producing a variant protein antigen that probably does not exist in the wild virus population but should cross-react with variants that do exist. Korber has taken two different approaches to designing such antigens. Her group has developed a computer algorithm to choose epitopes to combine into a mosaic molecule for the mosaic antigens. In 2009, she described a designed mosaic protein this way: "People didn't know if it would fold properly, if it would be antigenic, or if it would have the same sites that recognized by killer T cells". They found that the newly designed antigens did fold properly and acted as a strong antigen, and were recognized by the cytotoxic T cells (killer cells). Also, Korber and her collaborators have developed a graphical analysis called Epigraph that can generate promising antigens with a mixture of epitopes. Korber explains that the approach of designing a protein via computer, combining bits of known proteins that provoke immune responses, had never been tried. She says, "Even after it worked, it was hard to convince people that this novel thing could be a vaccine because it hadn't been done before".
In collaboration with Dan Barouch, a professor at Harvard Medical School, some of these antigens have been tested in monkeys as possible vaccines. With one series of tests, Barouch checked a number of possible ways to deliver the virus genes and chose to use the common cold virus as a vehicle. The tested mosaic vaccine routinely slowed monkey infection with the closely related Simian Immunodeficiency Virus (SIV), and for 66 percent of monkeys exposed multiple times, no infection resulted. Next, in collaboration with the National Institutes of Health, Janssen Pharmaceutical Companies (a division of Johnson & Johnson), and the Bill and Melinda Gates Foundation, the researchers tested a mosaic vaccine for safety in human subjects; it passed that test too. In 2017, the group of collaborators announced a human efficiency test with that same mosaic protein preparation, vaccinating 2,600 women in Sub Saharan Africa, who will be examined for several years to show how efficiently, if at all, the virus interferes with infection. Korber cautioned that effectiveness of this strategy in monkeys is not a guarantee that a human vaccine will work.
In recognition of her research, Korber received the 2018 Feynman Award for Innovation, the first woman at Los Alamos National Laboratory to receive one. She recalled that at Caltech when few women were there, she took a class with physicist Richard Feynman and became friends with him. She said, "At a time when kindness seemed rare, I really appreciated his generous spirit and encouragement. I think he would have been pleased about this award".
Dating the HIV-1 virus
In the history of HIV/AIDS virus with regard to when and where HIV originated, Edward Hooper had postulated in a best-selling book called The River: A Journey to the Source of HIV and AIDS in 1999 that HIV could have jumped from chimpanzees to humans because of an accidental contamination by chimpanzee SIV of the oral polio vaccine (CHAT) used in Africa in the 1950s. Korber and her colleagues employed the Los Alamos National Laboratory database's genomic data to calculate when the HIV sequence evolution began, using a model of evolution based on the mutation rate of HIV strains and assuming that variable was the same on all branches of the evolutionary tree. In 2000 they published an estimate of approximately 1930 for the origin of the human immunodeficiency virus. Their research was covered widely as establishing a new date for the origin of the human virus, discrediting the oral polio virus theory, and therefore refuting concerns about using oral polio vaccine (OPV). These two concepts of the origin of this virus plus other related theories continued to compete for scientific credibility.
In 2008, Worobey and collaborators used a computer modeling approach similar to Korber's but with a relaxed evolutionary model and two older samples, collected earlier than any genomes included in Korber's study, and found an origin date for HIV of approximately 1900.
COVID-19
As the COVID-19 pandemic unfolded, Korber and her Los Alamos colleagues devised computational strategies that look for evolutionary changes in genes that encode the Spike proteins that stud the SARS-CoV-2 coronavirus and give it its crown-like appearance. Her strategies can examine millions of global genomes stored by GISAID, and it flags mutations that vary from the original Wuhan sequence by at least a minimum specified threshold amount. Using this strategy, she and colleagues identified a particular Spike mutation, Aspartic acid (Asp) to Glycine (Gly) at position 614 (D614G), that was gaining prevalence across the globe since February 2020. This finding, which was controversial at first, was validated by multiple other groups who showed that the D614G mutation was shown to improve the efficiency of replication and transmission of SARS-CoV-2, and this mutation, as of June 2020, has become part of all globally prevalent SARS-CoV-2 strains. As of September 28, 2021, she and her group continue to analyze GISAID data for novel variants, and she continues to be an active member of the NIH TRACE Working Group, whose objective is to "provide actionable intelligence on SARS-CoV-2 variants through genomic surveillance, data sharing and curation, and standardized in vitro assessments of therapeutics against novel strains."
Personal life
Korber married James Theiler in 1988. They have two sons.
Out of her concern for the impact of AIDS on those with few financial resources, Korber contributed $50,000 from her EO Lawrence Award to help establish, along with family and friends, an AIDS orphanage in South Africa, working through Nurturing Orphans of AIDS for Humanity (NOAH). She has joined the Board of NOAH. She also contributed to the distribution of Earth Boxes of maintenance-free portable gardens to orphanages, clinics, and schools in Africa.
Awards and honors
2021: Los Alamos Medal, for changing the course of science
2019: Inventor of the Year, Battelle, 2019, Award given in Columbus, Ohio
2018: R&D Magazine Scientist of the Year
2018: Richard Feynman Award for Innovation
2014: Selected to Thomson Reuters Corporation's 100 Most Influential Minds of the Decade
2004: Ernest Orlando Lawrence Award
2002: Los Alamos National Laboratory Fellow
2001: Distinguished Alumna of CSULB
1997: Elizabeth Glaser Scientist, for work on pediatric AIDS, presented by Hillary Clinton
Other work
In 2019, Korber led a series of lectures called Frontiers in Science that focused on her work designing a vaccine against HIV.
Selected publications
Keele, Brandon F.; Giorgi, Elena E.; Salazar-Gonzalez, Jesus F.; Decker, Julie M.; Pham, Kimmy T.; Salazar, Maria G.; Sun, Chuanxi; Grayson, Truman; Wang, Shuyi; Li, Hui; Wei, Xiping (2008-05-27). "Identification and characterization of transmitted and early founder virus envelopes in primary HIV-1 infection". Proceedings of the National Academy of Sciences. 105 (21): 7552–7557. doi:10.1073/pnas.0802203105. ISSN 0027-8424. PMID 18490657.
References
Living people
Computational chemistry
Computational biology
American women molecular biologists
American molecular biologists
American virologists
California Institute of Technology alumni
Los Alamos National Laboratory personnel
Year of birth missing (living people) | Bette Korber | [
"Chemistry",
"Biology"
] | 2,528 | [
"Theoretical chemistry",
"Computational chemistry",
"Computational biology"
] |
58,465,306 | https://en.wikipedia.org/wiki/Aspergillus%20clavatonanicus | Aspergillus clavatonanicus is a species of fungus in the genus Aspergillus. It is from the Clavati section. The species was first described in 1955. A. clavatonanicus has been reported to produce antafumicins, glyanthrypine, kotanins, tryptoquivalines, and tryptoquivalones.
References
clavatonanicus
Fungi described in 1955
Fungus species | Aspergillus clavatonanicus | [
"Biology"
] | 97 | [
"Fungi",
"Fungus species"
] |
58,465,322 | https://en.wikipedia.org/wiki/Aspergillus%20longivesica | Aspergillus longivesica is a species of fungus in the genus Aspergillus. It is from the Clavati section. The species was first described in 1971. A. longivesica has been reported to produce patulin, tryptoquivalones, tryptoquivalines, antafumicins, and pyripyropen.
Growth and morphology
A. longivesica has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
longivesica
Fungi described in 1971
Fungus species | Aspergillus longivesica | [
"Biology"
] | 144 | [
"Fungi",
"Fungus species"
] |
58,465,394 | https://en.wikipedia.org/wiki/Aspergillus%20rhizopodus | Aspergillus rhizopodus is a species of fungus in the genus Aspergillus. It is from the Clavati section. The species was first described in 1975. A. rhizopodus has been reported to produce pseurotins, dehydrocarolic acid, tryptoquivalines, tryptoquivalones, kotanins, and cytochalasins.
Growth and morphology
A. rhizopodus has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid® (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
rhizopodus
Fungi described in 1975
Fungus species | Aspergillus rhizopodus | [
"Biology"
] | 160 | [
"Fungi",
"Fungus species"
] |
58,465,487 | https://en.wikipedia.org/wiki/Aspergillus%20arxii | Aspergillus arxii (also referred to as Cristaspora arxii) is a species of fungus in the genus Aspergillus. It is from the Cremei section. The species was first described in 1984.
Growth and morphology
A. arxii has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid® (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
arxii
Fungi described in 1984
Fungus species | Aspergillus arxii | [
"Biology"
] | 118 | [
"Fungi",
"Fungus species"
] |
58,465,509 | https://en.wikipedia.org/wiki/Aspergillus%20chrysellus | Aspergillus chrysellus is a species of fungus in the genus Aspergillus. It is from the Cremei section. The species was first described in 1965.
Growth and morphology
A. chrysellus has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid® (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
chrysellus
Fungi described in 1965
Fungus species | Aspergillus chrysellus | [
"Biology"
] | 108 | [
"Fungi",
"Fungus species"
] |
58,465,514 | https://en.wikipedia.org/wiki/L2%20Syntactic%20Complexity%20Analyzer | L2 Syntactical Complexity Analyzer (L2SCA) developed by Xiaofei Lu at the Pennsylvania State University, is a computational tool which produces syntactic complexity indices of written English language texts. Along with Coh-Metrix, the L2SCA is one of the most extensively used computational tool to compute indices of second language writing development. The L2SCA is also widely utilised in the field of corpus linguistics. The L2SCA is available in a single and a batch mode. The first provides the possibility of analyzing a single written text for 14 syntactic complexity indices. The latter allows the user to analyze 30 written texts simultaneously.
Usage
Second language writing development
The L2SCA has been used in numerous studies in the field of second language writing development to compute indices of syntactic complexity.
Corpus linguistics
The L2SCA has also been used in various studies in the field of corpus linguistics.
Indices
Notes
Note 1: Abbreviation
See also
Coh-Metrix
References
External links
Computational linguistics
Applied linguistics
Second language writing | L2 Syntactic Complexity Analyzer | [
"Technology"
] | 211 | [
"Natural language and computing",
"Computational linguistics"
] |
58,465,560 | https://en.wikipedia.org/wiki/Aspergillus%20neoflavipes | Aspergillus neoflavipes is a species of fungus in the genus Aspergillus. It is from the Flavipedes section. The species was first described in 2015.
Growth and morphology
A. neoflavipes has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
neoflavipes
Fungi described in 2015
Fungus species | Aspergillus neoflavipes | [
"Biology"
] | 108 | [
"Fungi",
"Fungus species"
] |
58,465,579 | https://en.wikipedia.org/wiki/Aspergillus%20frequens | Aspergillus frequens is a species of fungus in the genus Aspergillus. It is from the Flavipedes section. The species was first described in 2015.
Growth and morphology
A. frequens has been cultivated on both Czapek Yeast Extract Agar (CYA) plates and Malt Extract Agar Oxoid (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
frequens
Fungi described in 2015
Fungus species | Aspergillus frequens | [
"Biology"
] | 108 | [
"Fungi",
"Fungus species"
] |
58,465,610 | https://en.wikipedia.org/wiki/Aspergillus%20capensis | Aspergillus capensis is a species of fungus in the genus Aspergillus. It is from the Flavipedes section. The species was first described in 2014.
Growth and morphology
A. capensis has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid® (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
capensis
Fungi described in 2014
Fungus species | Aspergillus capensis | [
"Biology"
] | 103 | [
"Fungi",
"Fungus species"
] |
58,465,640 | https://en.wikipedia.org/wiki/Aspergillus%20flavipes | Aspergillus flavipes is a species of fungus in the genus Aspergillus. It is from the Flavipedes section. The species was first described in 1926. It has been reported to produce sterigmatocystin, citrinin, and lovastatin.
Growth and morphology
A. flavipes has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid® (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
flavipes
Fungi described in 1926
Fungus species | Aspergillus flavipes | [
"Biology"
] | 130 | [
"Fungi",
"Fungus species"
] |
58,465,686 | https://en.wikipedia.org/wiki/Aspergillus%20nishimurae | Aspergillus nishimurae is a species of fungus in the genus Aspergillus. It is from the Fumigati section. The species was first described in 2001.
Growth and morphology
A. nishimurae has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid® (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
nishimurae
Fungi described in 2001
Fungus species | Aspergillus nishimurae | [
"Biology"
] | 109 | [
"Fungi",
"Fungus species"
] |
58,465,787 | https://en.wikipedia.org/wiki/Aspergillus%20duricaulis | Aspergillus duricaulis is a species of fungus in the genus Aspergillus. It is from the Fumigati section. The species was first described in 1965. It has been reported to produce pseurotin A, fumagillin, asperpentyn, duricaulic acid, asperdurin, phthalides, chromanols, cyclopaldic acid, and 3-O-methylcyclopolic acid.
Growth and morphology
A. duricaulis has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid® (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
duricaulis
Fungi described in 1965
Fungus species | Aspergillus duricaulis | [
"Biology"
] | 170 | [
"Fungi",
"Fungus species"
] |
58,465,803 | https://en.wikipedia.org/wiki/Aspergillus%20fumigatiaffinis | Aspergillus fumigatiaffinis is a species of fungus in the genus Aspergillus. It is from the Fumigati section. The species was first described in 2005. It has been reported to produce auranthine, cycloechinuline, fumigaclavines, helvolic acid, neosartorin, palitantin, , , , , tryptoquivaline, and tryptoquivalone.
References
fumigatiaffinis
Fungi described in 2005
Fungus species | Aspergillus fumigatiaffinis | [
"Biology"
] | 114 | [
"Fungi",
"Fungus species"
] |
58,465,819 | https://en.wikipedia.org/wiki/Aspergillus%20thermomutatus | Aspergillus thermomutatus (also called Neosartorya pseudofischeri) is a species of fungus in the genus Aspergillus. It is from the Fumigati section. The species was first described in 1992. It has been reported to produce asperfuran, cytochalasin-like compounds, fiscalin-like compounds, pyripyropens, and gliotoxin.
Growth and morphology
A. thermomutatus has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid® (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
thermomutatus
Fungi described in 1992
Fungus species | Aspergillus thermomutatus | [
"Biology"
] | 163 | [
"Fungi",
"Fungus species"
] |
58,465,846 | https://en.wikipedia.org/wiki/Aspergillus%20fumisynnematus | Aspergillus fumisynnematus is a species of fungus in the genus Aspergillus. It is from the Fumigati section. The species was first described in 1993. It has been reported to produce neosartorin, pyripyropens, and fumimycin.
Growth and morphology
A. fumisynnematus has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid® (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
fumisynnematus
Fungi described in 1993
Fungus species | Aspergillus fumisynnematus | [
"Biology"
] | 136 | [
"Fungi",
"Fungus species"
] |
58,465,857 | https://en.wikipedia.org/wiki/Aspergillus%20botucatensis | Aspergillus botucatensis (also known as Neosartorya spinosa) is a species of fungus in the genus Aspergillus. It is from the Fumigati section. The species was first described in 1995. It has been reported to produce aszonalenins, 2-pyrovoylaminobenzamide, and pseurotin.
Growth and morphology
A. botucatensis has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid® (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
botucatensis
Fungi described in 1995
Fungus species | Aspergillus botucatensis | [
"Biology"
] | 149 | [
"Fungi",
"Fungus species"
] |
58,465,926 | https://en.wikipedia.org/wiki/Aspergillus%20turcosus | Aspergillus turcosus is a species of fungus in the genus Aspergillus. It is from the Fumigati section. The species was first described in 2008. It has been reported to produce kotanins.
Growth and morphology
A. turcosus has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid® (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
turcosus
Fungi described in 2008
Fungus species | Aspergillus turcosus | [
"Biology"
] | 116 | [
"Fungi",
"Fungus species"
] |
58,465,978 | https://en.wikipedia.org/wiki/Aspergillus%20igneus | Aspergillus igneus (also known as Neosartorya aurata) is a species of fungus in the genus Aspergillus. It is from the Fumigati section. The species was first described in 1989. It has been reported to produce helvolic acid.
Growth and morphology
A. igneus has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid® (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
igneus
Fungi described in 1989
Fungus species | Aspergillus igneus | [
"Biology"
] | 126 | [
"Fungi",
"Fungus species"
] |
58,465,995 | https://en.wikipedia.org/wiki/Aspergillus%20aureoluteus | Aspergillus aureoluteus (also known as Neosartorya aureola) is a species of fungus in the genus Aspergillus. It is from the Fumigati section. The species was first described in 1985. It has been reported to produce fumagillin, tryptoquivaline, tryptoquivalone, pseurotin A, and viriditoxin.
Growth and morphology
A. aureoluteus has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid® (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
aureoluteus
Fungi described in 1985
Fungus species | Aspergillus aureoluteus | [
"Biology"
] | 161 | [
"Fungi",
"Fungus species"
] |
58,466,006 | https://en.wikipedia.org/wiki/Aspergillus%20ferenczii | Aspergillus ferenczii is a species of fungus in the genus Aspergillus. It is from the Fumigati section. The species was first described in 2014. It has been reported to produce asperfuran, aszonalenin, fumigaclavine, viridicatumtoxin, and fumigatins.
Growth and morphology
A. ferenczii has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid® (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
ferenczii
Fungi described in 2014
Fungus species | Aspergillus ferenczii | [
"Biology"
] | 145 | [
"Fungi",
"Fungus species"
] |
58,466,176 | https://en.wikipedia.org/wiki/Protein%20tandem%20repeats | An array of protein tandem repeats is defined as several (at least two) adjacent copies having the same or similar sequence motifs. These periodic sequences are generated by internal duplications in both coding and non-coding genomic sequences. Repetitive units of protein tandem repeats are considerably diverse, ranging from the repetition of a single amino acid to domains of 100 or more residues.
"Repeats" in proteins
In proteins, a "repeat" is any sequence block that returns more than one time in the sequence, either in an identical or a highly similar form. The degree of similarity can be highly variable, with some repeats maintaining only a few conserved amino acid positions and a characteristic length. Highly degenerate repeats can be very difficult to detect from sequence alone. Structural similarity can help to identify repetitive patterns in sequence.
Structure
Repetitiveness does not in itself indicate anything about the structure of the protein. As a "rule of thumb", short repetitive sequences (e.g. those below the length of 10 amino acids) may be intrinsically disordered, and not part of any folded protein domains. Repeats that are at least 30 to 40 amino acids long are far more likely to be folded as part of a domain. Such long repeats are frequently indicative of the presence of a solenoid domain in the protein.
Approximately half of the tandem repeat regions have intrinsically disordered conformation being naturally unfolded. Examples of disordered repetitive sequences include the 7-mer peptide repeats found in the RPB1 subunit of RNA polymerase II, or the tandem beta-catenin or axin binding linear motifs in APC (adenomatous polyposis coli). The other half of the regions with the stable 3D structure has a plethora of shapes and functions. Examples of short repeats exhibiting ordered structures include the three-residue collagen repeat or the five-residue pentapeptide repeat that forms a beta helix structure.
Classification
Depending on the length of the repetitive units, their protein structures can be subdivided into five classes:
crystalline aggregates formed by regions with 1 or 2 residue long repeats, archetypical low complexity regions
fibrous structures stabilized by inter-chain interactions with 3-7 residue repeats
elongated structures with repeats of 5–40 residues dominated by solenoid proteins
closed (not elongated) structures with repeats of 30-60 residues as toroid repeats
beads on a string structures with typical size of repeats over 50 residues, which are already large enough to fold independently into stable domains.
Function
Some well-known examples of proteins with tandem repeats are collagen, which plays a key role in the arrangement of the extracellular matrix; alpha-helical coiled coils having structural and oligomerization functions; leucine-rich repeat proteins, which specifically bind some globular proteins by their concave surfaces; and zinc-finger proteins, which regulate the expression of genes by binding DNA.
Tandem repeat proteins frequently function as protein-protein interaction modules. The WD40 repeat is a prime example of this function.
Distribution in proteomes
Tandem repeats are ubiquitous in proteomes and occur in at least 14% of all proteins. For example, they are present in almost every third human protein and even in every second protein from Plasmodium falciparum or Dictyostelium discoideum. Tandem repeats with short repetitive units (especially homorepeats) are more frequent than others.
Annotation methods
Protein tandem repeats can be either detected from sequence or annotated from structure. Specialized methods were built for the identification of repeat proteins.
Sequence-based strategies, based on homology search or domain assignment, mostly underestimate TRs due to the presence of highly degenerate repeat units. A recent study to understand and improve Pfam coverage of the human proteome showed that five of the ten largest sequence clusters not annotated with Pfam are repeat regions. Alternatively, methods requiring no prior knowledge for the detection of repeated substrings can be based on self-comparison, clustering or hidden Markov models. Some others rely on complexity measurements or take advantage of meta searches to combine outputs from different sources.
Structure-based methods instead take advantage of the modularity of available PDB structures to recognize repetitive elements.
References
External links
RepeatsDB: a database of annotated tandem repeat protein structures
Protein tandem repeats
Protein domains | Protein tandem repeats | [
"Biology"
] | 892 | [
"Protein tandem repeats",
"Protein domains",
"Protein classification"
] |
58,466,180 | https://en.wikipedia.org/wiki/Aspergillus%20hiratsukae | Aspergillus hiratsukae is a species of fungus in the genus Aspergillus. It is from the Fumigati section. The species was first described in 1991. It has been reported to produce avenaciolide.
Growth and morphology
A. hiratsukae has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid® (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
hiratsukae
Fungi described in 1991
Fungus species | Aspergillus hiratsukae | [
"Biology"
] | 120 | [
"Fungi",
"Fungus species"
] |
58,466,189 | https://en.wikipedia.org/wiki/Aspergillus%20laciniosus | Aspergillus laciniosus (also named Neosartorya laciniosa) is a species of fungus in the genus Aspergillus. It is from the Fumigati section. The species was first described in 2006. It has been reported to produce aszonalenins, tryptoquivaline, and tryptoquivalone.
Growth and morphology
A. laciniosus has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid® (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
laciniosus
Fungi described in 2006
Fungus species | Aspergillus laciniosus | [
"Biology"
] | 147 | [
"Fungi",
"Fungus species"
] |
58,466,212 | https://en.wikipedia.org/wiki/Aspergillus%20paleaceus | Aspergillus paleaceus (also named Neosartorya stramenia) is a species of fungus in the genus Aspergillus. It is from the Fumigati section. The species was first described in 1985. It has been reported to produce quinolactacin and avenaciolide.
Growth and morphology
A. paleaceus has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid® (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
paleaceus
Fungi described in 1985
Fungus species | Aspergillus paleaceus | [
"Biology"
] | 134 | [
"Fungi",
"Fungus species"
] |
58,467,542 | https://en.wikipedia.org/wiki/Capped%20trigonal%20prismatic%20molecular%20geometry | In chemistry, the capped trigonal prismatic molecular geometry describes the shape of compounds where seven atoms or groups of atoms or ligands are arranged around a central atom defining the vertices of an augmented triangular prism. This shape has C2v symmetry and is one of the three common shapes for heptacoordinate transition metal complexes, along with the pentagonal bipyramid and the capped octahedron.
Examples of the capped trigonal prismatic molecular geometry are the heptafluorotantalate () and the heptafluoroniobate () ions.
References
Stereochemistry
Molecular geometry | Capped trigonal prismatic molecular geometry | [
"Physics",
"Chemistry"
] | 124 | [
"Molecules",
"Molecular geometry",
"Stereochemistry",
"Space",
"Stereochemistry stubs",
"nan",
"Spacetime",
"Matter"
] |
58,467,706 | https://en.wikipedia.org/wiki/Dodecahedral%20molecular%20geometry | In chemistry, the dodecahedral molecular geometry describes the shape of compounds where eight atoms or groups of atoms or ligands are arranged around a central atom defining the vertices of a snub disphenoid (also known as a trigonal dodecahedron). This shape has D2d symmetry and is one of the three common shapes for octacoordinate transition metal complexes, along with the square antiprism and the bicapped trigonal prism.
One example of the dodecahedral molecular geometry is the ion.
References
Stereochemistry
Molecular geometry | Dodecahedral molecular geometry | [
"Physics",
"Chemistry"
] | 115 | [
"Molecular geometry",
"Molecules",
"Stereochemistry",
"Space",
"Stereochemistry stubs",
"nan",
"Spacetime",
"Matter"
] |
58,467,746 | https://en.wikipedia.org/wiki/Schl%C3%BCsselger%C3%A4t%2039 | The Schlüsselgerät 39 (SG-39) was an electrically operated rotor cipher machine, invented by the German Fritz Menzer during World War II. The device was the evolution of the Enigma rotors coupled with three Hagelin pin wheels to provide variable stepping of the rotors. All three wheels stepped once with each encipherment. Rotors stepped according to normal Enigma rules, except that an active pin at the reading station for a pin wheel prevented the coupled rotor from stepping. The cycle for a normal Enigma was 17,576 characters. When the Schlüsselgerät 39 was correctly configured, its cycle length was characters, which was more than 15,000 times longer than a standard Enigma. The Schlüsselgerät 39 was fully automatic, in that when a key was pressed, the plain and cipher letters were printed on separate paper tapes, divided into five-digit groups. The Schlüsselgerät 39 was abandoned by German forces in favour of the Schlüsselgerät 41.
Technical description
Note: Otto Buggisch gave the technical description of the cipher unit as part of TICOM homework.
Gerät 39 is an electrically operated cipher machine. The cipher technique is derived from the Enigma cipher machine. A direct current passes through 3 or 4 wheels, with 26 positions, I, II, II, a reflector wheel U, and the again through the 3 wheels in reverse order, III II and I. Unlike the Enigma, the wheels here do not control their own movement: this is done through 3 independent pin-wheels N1 N2 and N3 with periods 21,23 and 25. The figures were distributed among N1 N2 and N2 in possibly two different configurations.
The pin wheels have a uniform motion, i.e. they move one position for every letter keyed. As for the movement of the key wheels and other details, the machine passed through different stages of development in the course of time, for which there were no specific names and which will be denoted here by a, b, c and d.
Each of three wheels moves on one place when there is an active pin at the sensing point of the relevant pin-wheel, and it only moves then. The wheels have no moveable rings on the body of the wheel, with the result that, unlike the Enigma, the initial position of the body of the wheel is determine absolutely, at the same time as the clear message setting. The reflector wheel is pluggable like the reflector wheel D on the Enigma; it can be quickly exchanged for the second reflector wheel with prepared reflector plugging.
Wheels I, I and III, whose wiring now correspond exactly to those of the Enigma, have adjustable rings; they can be moved around the body of the wheels and have a fixed pin, which, by analogy with the Enigma, is to be called the turn-over notch, although mechanically it is not so made. Opposite the wheels I and II are two sensing points which pick up the turn-over notch as it passes. U is pluggable as in a). In addition there is between the point of input and I, a stecker S like the Enigma stecker. The following two methods of working are possible:
Working on own wiring: N1 N2 and N3 are given a certain pin arrangements, there being, it is true, certain limitations to the number of activating pins. Wheel I moves as under a) above. For wheel II there are the following 3 causes of movement:
An active pin at the sensing point of N2 causes II to move on one place as in a) above
When the turn-over notch on the ring of I comes to the sensing point, II is caused to move on when the next letter is keyed (as with Enigma).
When the turn-over notch comes to the sensing point of II, II turns on one place when the next letter is keyed (at the same time as III, as with the double step on Enigma)
If any of these three causes of movement take effect simultaneously on II, it nevertheless only moves on one place. There are three causes of movement for wheel III.
An active pin at the sensing-point of N3 causes III to move to one place, as in the first a) above,
When the turn-over notch on the ring of II comes to the sensing point, III moves on one place when the next letter is keyed.
Just as in the case of II, if the two causes of the movement for III operation simultaneously the combine to produce one stop.
Working on Enigma wiring. All the pins of N1 are set at active, the pins of N2 and N3 all remaining inactive. Then the movements identical with that of the Enigma. As all other factors also agree with the corresponding ones on the Enigma interchangeable working between both machines is possible.
A sensing-point is also provided opposite wheel III. If the turn-over notch on the ring of III is touched by it, then I turns on one place when the next letter is keyed. If this movement coincides with the step caused by N1, this again results in the single step. Thus the possibility of interchangeable working with the Enigma remains. In addition, the machine now gets a fourth wheel, which is placed between III and U and does not move on when a key is touched. It corresponds to the fourth wheel on the Naval Enigma and is used for interchangeable working with this machine.
In the summer of 1944, Karl Stein of OKW/Chi told Buggisch that the reciprocal influencing of the wheels was to be altered in some way. Buggisch could not remember the details but nothing fundamental on the principle of the machine described under c) was changed. Interchangeable working with army and naval Enigma remained possible.
Investigations in Periodicity
In the case of model first a) above, the question of periodicity is elementary, there are 262=676 pure periods of the length
21 x 23 x 25 x 26 = 313, 950
as long as the number of active pins on each of the pin wheels is prime to 2 and 13. This last condition should be laid down in the cipher regulations; otherwise the 676 periods would be further broken in a manner easily seen.
Things are much more complicated in the case of Model b). Investigations into this problem in the winter of 1942/1943 were only partly successful; above all it was not possible exactly to calculate the lengths of the pure periods and the pre-periods. Estimates which were quite adequate for practical purposes were however given. Buggisch could not remember the details of these somewhat investigations. The extraordinary length of many pre-periods (lengths of some thousands were not uncommon) and the complication of their branches were remarkable. The general type can be illustrated by the following diagram:
In this circle represents the pure period and the straight lines the pre-periods. There were usually several pure periods, each one of them having a complicated system of pre-periods branching into it. Several separate figures of the above type side by side are then necessary to give a graphic representation of the periodicities. A lower limit for the lengths of the pure periods was, as far as I remember: 252 x 21 x 23 x 25 = 8,162,700.
The questions of periodicities in the case of model c) was still more involved. It was just not possible to calculate the lengths of the pure periods and pre-periods, let alone give the lower limits which are themselves not inconsiderable.
Cipher Security
The principal weaknesses of the Enigma were as follows:
Wheel I moved uniformly
Wheel II and above all, wheel III moved too infrequently.
The period of was comparatively small, so that when there was a large amount of traffic on one day, on one key, one had to reckon with the concurrence of critical depths (this applies at least to the Army Enigma; the naval machine had a fourth wheel, so that a days traffic on one key was spread out over 26 periods).
The reflector wheel was not plugable and had remained unchanged for years (and because of (5), the enemy could easily establish by Hollerith methods for example, all of the substitution alphabets of the unplugged machines.
The number of possible wheel combinations was only 60, since the set of wheels belonging to the machine, at least in the case of the Army Enigma, only consisted of 5 different wheels.
Faults 1 to 4 had already been eliminated on model a) of Schlüsselgerät 39, 5. then no longer appears vital. On the other hand, however, the giving up of the adjustable rings and of the stecker gave rise to weaknesses which the Enigma did not have. In fact, the absence of stecker S cannot be compensated for by making the reflector wheel U pluggable; investigations into Enigma had shown that it was considerably more difficult to find out the steckering S than the reflectoring wheel U.
In detail, the results of the investigations were as follows:
If the inner wiring and the clear message setting of wheels I, II and II are known, the wiring of the reflector wheel and the pin arrangement of N1 N2 N3 can be found out from a crib of 25 letters, this was a fairly laborious process.
If the inner wiring of wheels I, I and II and of the reflector wheel U is known, it is likewise possible to find out the clear message-setting and the pin-arrangement of N1 N2 and N3 from a crib of 25 letters; this too is a laborious process.
The above-mentioned weakness of model a) were eliminated by the introduction of steckering and adjustable rings of model b), although this had been done primarily for quite a different reason, namely to make interchangeable working with Enigma possible. It was not now thought that there was any longer a serious possibility of a break-in. As however the system of I and N1 still had a relatively small period of 21 x 26 it appeared desirable to destroy this too. This was done on model c) by making III react to I, and presented no technical difficulties.
Finally in model c), the total number of periods was multiplied by 26 compared with a) and b), but the introduction of a fourth wheel; it was not, it is true, intended primarily for this purpose but was added to carry out interchangeable working with the Naval Enigma.
History of Gerät 39
Model a) had been developed as early as the year 1939 or 1940 at Wa Pruef 7 at the Waffenamt. In the summer of 1942, a prototype was available at Dr. Pupp's laboratory at Wa Pruef 7, and was made by the firm Telefonbau und Normalzeit (literally 'Telephone and Standard Time', later called Tenovis). A noteworthy feature was that when the clear-text letter was keyed, the corresponding cipher letter could be sent out simultaneously by the transmitter as a Morse character. This from a technical point of view, a fairly complicated operation. The machine thus was like a cipher teleprinter except that instead of the 5-element alphabet the ordinary Morse alphabet was used. The maximum keying speed was also the same as on a current (1940s) cipher teleprinter. It could not however be made use of when working on direct transmission, because reception at the other end was not automatic as in the case of a cipher teleprinter, but had to be done aurally by the operator. That was one of the many reasons why the automatic transmission part of the machine was omitted in later models. This was done when Oberst Kahn, the director of the Pruef 7 department of the Waffenamt, left, he having especially advocated this strange principle. The second model actually constructed was like the model designated with c) in the [See 2.1.1] section above. It only printed clear text and cipher text on 2 separate strips. Buggisch saw it in January 1944 when I was visiting Wa Pruef 7 Section II at Planken.
The change from cipher-technical a) to b) and also c) was made at the end of 1942. It was made at the instigation of the Kriegsmarine who laid down the principle that any newly introduced cipher machine for higher HQs should permit interchangeable working with the Enigma. The Army (Heer and Wehrmacht) also adopted this standpoint: In the first instance only the highest authorities were to be issued with the new machine, e.g. OKW, OKH and the Army groups, and only gradually, as production permitted, was the Enigma machine to be replaced by the 39 at Armies, and finally perhaps at Army Corps. There were, during 1943 and 1944 between the various HQs interested, many and lengthy discussions and arguments for and against the introduction of the 39 machine. Special wishes of the Navy had to be taken into account. The industrial firm complained of lack of material and labour. Owing to these and similar difficulties, development stopped altogether at one time, and it was resumed however. At any rate the vagueness of the decisive authorities was, in addition to difficulties of production, the chief reason why the machine was never completed.
Citations
References
Bibliography
Cryptographic hardware
Encryption devices
History of telecommunications in Germany
Military communications of Germany
World War II military equipment of Germany
Signals intelligence of World War II
Rotor machines | Schlüsselgerät 39 | [
"Physics",
"Technology"
] | 2,752 | [
"Physical systems",
"Machines",
"Rotor machines"
] |
58,468,005 | https://en.wikipedia.org/wiki/IPhone%20XR | The iPhone XR (stylized and marketed as iPhone Xʀ; Roman numeral "X" pronounced as "ten") is a smartphone developed and marketed by Apple Inc. It is part of the twelfth generation of the iPhone, alongside the higher-end iPhone XS/XS Max models. Pre-orders began on October 19, 2018, with the official release on October 26, 2018. The iPhone XR was the least expensive device in Apple's twelfth generation of iPhones, which also includes the iPhone XS and XS Max, and was therefore considered an "affordable flagship" or "budget flagship" phone at its release.
The XR shares key internal hardware but with features removed or downgraded to reduce the price. The XR features the same processor as the XS and XS Max, the Apple A12 Bionic chip built with a 7 nanometer process, which Apple claimed to be the "smartest and most powerful chip" ever put into a smartphone. Instead of the OLED screen on the XS, the XR has a 6.1-inch Liquid Retina LED-backlit LCD IPS panel display, which Apple advertised as the "most advanced LCD in the industry." According to Apple, the full charge of the XR battery lasts up to one-and-a-half hours longer than that of its direct predecessor, the iPhone 8 Plus.
The iPhone XR was available in six colors: black, white, blue, yellow, coral (a shade of pink and orange), and Product Red. It is the second iPhone to be released in white, yellow and blue, the first being the iPhone 5c in 2013. Internationally, the phone supports dual SIMs through a Nano-SIM and an eSIM. In mainland China, Hong Kong, and Macau, dual Nano-SIM (in a single tray) is offered instead. The iPhone XR was available in three storage capacities: 64 GB, 128 GB, and 256 GB. The 256 GB version was discontinued with the release of the iPhone 11 and 11 Pro; while the iPhone XS was discontinued and replaced by the iPhone 11 Pro, the iPhone XR continued on sale at a lower price point with the iPhone 11 succeeding as the "affordable flagship".
The iPhone XR was Apple's best selling 2018 model. It also became the top-selling and the most popular smartphone globally in Q3 2019. As of September 2020, the iPhone XR has sold 77.4 million units worldwide, making it the eighth best-selling smartphone of all time.
In 2019, Apple started assembling the iPhone XR in India. The iPhone XR as well as the iPhone 12 Pro with its Max variant were discontinued and removed from Apple's website after the announcement of the iPhone 13 and iPhone 13 Pro on September 14, 2021, but is still available through third party retailers today.
History
The iPhone XR was announced by Phil Schiller on September 12, 2018, at the Steve Jobs Theater in the Apple Park campus, alongside the higher-priced iPhone XS and XS Max, where all three products were showcased to the public.
Design
Hardware
The XR has a similar design to the iPhone X and iPhone XS. However, the XR has slightly larger bezels, a bigger screen, an aluminum frame, and is available in a wide variety of colors. Similar to other X-branded iPhones, all models come with a black front. The XR has an IP67 rating for dust and water resistance, which means it can be immersed in 1-metre deep water for up to 30 minutes.
Released as part of the same twelfth generation, the XR has similar hardware to the XS, but with a few features removed or downgraded to reduce the price. The XR features the same system-on-chip (SoC) as the XS and XS Max, the Apple A12 Bionic chip built with a 7 nanometer process.
The XR has an LCD display known as "Liquid Retina" instead of the OLED screen used on the X, XS, and XS Max. The display on the XR has a resolution of 1792 × 828 pixels and a pixel density of 326 ppi, compared with 458 ppi on other X-branded iPhones. However, it has 120 Hz Touch Sample Rate which is the same as the XS and XS Max. Instead of 3D Touch, the XR comes with Haptic Touch where the user long-presses until they feel a vibration from the Taptic Engine. The screen-to-body ratio of the XR is 79.3%, much higher than the 67.5% of the iPhone 8 Plus but is still lower than most other phones in its price category.
Unlike other phones in the X-series, the XR ships with a single camera on the rear on the phone, featuring exactly the same main camera sensor as on the XS and XS Max, utilizing a 1/2.55" sensor size and 1.4μm pixel size. Unlike the XS, it does not have optical zoom because of the single camera. DxOMark gave the camera on the iPhone XR a rating of 101, giving the title "Top-ranked single-lens phone". Despite the rear single-camera setup, a modified version of Portrait Mode is included. It works unaltered while using the TrueDepth front camera, but with the rear camera, it attempts to calculate the depth of field using a combination of the focus pixels on the image sensor and AI, resulting in more limitations including lower resolution depth data and subjects not being close enough due to the wide-angle lens being used instead of the missing telephoto lens. Just like the iPhone XS and XS Max, the iPhone XR also offers an adjustable depth of field through software, allowing the user to adjust the background bokeh effect after taking a photo.
Software
The iPhone XR shipped with iOS 12 installed out of the box and is compatible with every update of iOS, including most recently iOS 18, which was released on September 16, 2024.
Controversy
Display
Some online media outlets criticized the iPhone XR's display for having a low resolution and a low pixel per inch density, relative to other phones on the market at the time of h release at the price point. However, other online media outlets ignored these concerns, saying that under normal use, users should not be able to discern the pixels.
Power adapter and EarPods
Apple, as part of an environmental initiative, removed the EarPods and power adapter from all new iPhone boxes starting in October 2020, including the iPhone XR. It is claimed that removing these items will reduce e-waste and permit a smaller iPhone box, allowing more devices to be shipped simultaneously to decrease carbon footprint. Apple only included a USB-C to Lightning cable, which was compatible with increasingly prevalent USB-C charging sources, but incompatible with the previous (and then more common) USB-A power adapter that Apple included with its devices, leading to Apple recommending users who don't have a USB-C based charging source to use existing USB-A to Lightning cables or buying a USB-C power adapter separately.
Notes
See also
List of iPhone models
History of iPhone
List of best-selling mobile phones
Timeline of iPhone models
References
External links
– official site
Computer-related introductions in 2018
Mobile phones introduced in 2018
Mobile phones with 4K video recording
Discontinued flagship smartphones | IPhone XR | [
"Technology"
] | 1,535 | [
"Discontinued flagship smartphones",
"Flagship smartphones"
] |
58,468,054 | https://en.wikipedia.org/wiki/Penicillium%20spinulosum | Penicillium spinulosum (spinulosus means with small spines in Latin) is a non-branched, fast-growing fungus with a swelling at the terminal of the stipe (vesiculate) in the genus Penicillium. P. spinulosum is able to grow and reproduce in environment with low temperature and low water availability, and is known to be acidotolerant. P. spinulosum is ubiquitously distributed, and can often be isolated from soil. Each individual strain of P. spinulosum differs from others in their colony morphology, including colony texture, amount of sporulation and roughness of conidia and conidiophores.
History and taxonomy
Penicillium spinulosum was first discovered in 1910 by Dr. Charles Thom as a contaminant in another Penicillium culture sent to him by the German mycologist, Dr. Carl Wehmer. Classification and identification of the genus Penicillium were solely based on morphological traits before DNA sequencing was discovered. Key characteristics that are commonly involved in the grouping of P. spinulosm include vesiculate, rapid growth, spherical rough conidia and long conidiophores that projected from tangled mass of aerial hyphae. In 1949, Raper & Thom classified P. spinulosum as a member of the Penicillium section Monovertcillata due to its simple conidiospores branching pattern. In 1980 , Pitt modified their classification by only including species with conidiospore stipes that are strictly or predominantly monovertcillate in the subgenus Aspergilloides, and P. spinulosm was placed under one of his newly introduced sections called Aspergilloides due to the presence of an apical swelling on the conidiophore resembling members of the genus, Aspergillus.
As classification based on morphology can be problematic, the taxonomy was repeatedly studied. P. spinulosm is phenotypically similar to P. glabrum and the related species P. purpurescens and P. montanense. Their categorization was studied by the international commission on Penicillium and Aspergillus in 1900, and the study indicated that the identification could be achieved based on width of the phialides, the conidial wall texture and the colony diameters, 4 out of the 15 strains, however, were still indistinguishable. The problem of phenotype-based identification was later solved by Peterson (2000) by using nuclear ribosomal RNA gene sequences.
Growth and morphology
Penicillium spinulosum has round, spiny or irregularly rough-walled conidia produced in loose columns. The diameter of a conidium ranges from 3.0 to 3.5 μm. Penicillium spinulosum has thin-walled conidia with smooth or finely roughened texture terminating in a vesicle, the stipes of conidiospores generally range from 100 to 300 μm long, occasionally the length can be shorter than that. The conidiophores of P. spinulosum can arise from submerged or aerial hyphae. For conidiophores arising from aerial hyphae, the size of the stipes is shorter, e.g., 25–30 μm in length. The apex of conidiophores is inflated with simple (or monoverticilate) branching pattern. The conidiophores of P. spinulosum are terminated in 6 to 9 flask or bottom- shaped structure called phialides, these are not very abundant, and the length of individual phialide ranges from 2.5 to 3 μm. Subdivision of the genus Penicillium into subgenera and sections has traditionally been based on the branching pattern of the conidiophore. The conidiophores of P. spinulosum do not branch and is described as monoverticillate. However, modern phylogenetic studies of the genus Penicillium have revealed that these morphological patterns can arise independently, and thus do not reliably predict evolutionary relationships.
Growing colonies of P. spinulosum have broad white edges consist of white mycelium. Young colonies appears blue-green or grey-green and white to cream or faintly pink on the reverse. As the colonies mature, the colour becomes grey. The growth of P. spinulosum on czapek dox agar (CZ), malt extract agar (MEA) and Yeast Extract with Supplements (YES) occur rapidly. On CZ or MEA, colonies can spread broadly, reaching 20–30 mm in a week at 25 °C with light or moderate sporulation. The texture of the colony when grown on CZ is velutinous to floccose, which means that conidiophores can either arise like short velvet with little aerial mycelium or from a mass of tangled aerial hyphae.
Physiology
Penicillium spinulosum is psychrophilic, meaning that it is able to grow and reproduce at low temperature, and xerophile as it can germinate in decreased water activity environment (down to 0.8 Aw) by producing compatible solutes using enzyme systems. In vitro, P. spinulosum does not grow at 37 °C. Jussila stated that no mycotoxin production by P. spinulosum have been reported, however, based on the work of Overy and colleagues, a mixed culture of P. glabrum and P. spinulosum was involved in chestnuts spoilage and mycotoxin production.
Colonies growth and germination of Penicillium spinulosum were extremely sensitive to several different disinfectants and preservatives, among them, potassium sorbate and Suma Bac imposed the strongest inhibition effect. Compare to the two other Penicillium species that isolated from baked products with P. spinulosm together (P. expansum and P. verruculosum), P. spinulosm shows better resistant to benzoic acid but more susceptible to sodium lactate during spore germination. P. spinulosm is able to survive in acidic environment although growth will be impeded. When grow in a chemically defined glucose or sucrose medium, can produce large amount of fat that is non-toxic to rats.
Habitat and ecology
Penicillium spinulosum is found world-wide, and is most commonly isolated from soil. P. spinulosum has also been isolated from dextrin paste, distilled water containers, cotton yarn, walnut kernels, chrome tanned leather, vinyl wall covering, paracetamol tablet, diesel fuel and emulsion paint treated with chromate. P. spinulosumis highly resistant to heavy metals, tannins and acids, and can be isolated from substrata contaminated by those materials.
Pathogenicity
The pathogenicity of P. spinulosum remains controversial. In vitro, spores produced by P. spinulosum were reported to cause toxic and inflammatory responses in mouse macrophages. However, according to an experiment done by Jussila, this fungus can induce inflammation due to the production of moderate pro-inflammatory cytokines. The response of which is dose- and time- dependent and not cytotoxic even at high spore dose, so it is not likely to cause acute respiratory inflammations. Respiratory tract infection due to P. spinulosm was reported by Delore et al. in 1955, but the isolate they described had smooth conidia and restricted growth; by contrast, P. spinulosm typically has conidia with small spines and its growth is rapid. P. spinulosm is thought to be unlikely to cause human infection due to its inability to grow at 37 °C.
References
spinulosum
Fungi described in 1910
Taxa named by Charles Thom
Fungus species | Penicillium spinulosum | [
"Biology"
] | 1,629 | [
"Fungi",
"Fungus species"
] |
58,468,085 | https://en.wikipedia.org/wiki/Cladosporium%20oxysporum | Cladosporium oxysporum is an airborne fungus that is commonly found outdoors and is distributed throughout the tropical and subtropical region, it is mostly located In Asia and Africa. It spreads through airborne spores and is often extremely abundant in outdoor air during the spring and summer seasons. It mainly feeds on decomposing organic matter in warmer climates, but can also be parasitic and feed on living plants. The airborne spores can occasionally cause cutaneous infections in humans, and the high prevalence of C. oxysporum in outdoor air during warm seasons contributes to its importance as an etiological agent of allergic disease and possibly human cutaneous phaeohyphomycosis in tropical regions.
Taxonomy
This species was described by Reverend Miles Joseph Berkeley and Moses Ashley Curtis in 1868 in the Botanical Journal of the Linnean Society.
Growth and morphology
Cladosporium oxysporum expands moderately, often floccose at the center of the fungus that consists of woolly tufts, and it can grow up to 650 μm long and 4-5 μm wide. The colony is colored olive to olive-green on top with velvety surface, and greenish black at the bottom. The conidiophores are either straight or slightly bent, and the conidia range from oval to lemon-shaped. C. oxysporum produces conidia in unbranched or branched chains arising from cylindrical base cells. After the first spores have formed on the conidiophore, they bud apically to form secondary spores. They have pores connected in very fragile chains that can fall apart at the slightest movement of air, the spores are wind-dispersed and often extremely abundant in outdoor air under warm temperature.
Habitat and ecology
Cladosporium oxysporum is mostly located Asia and Africa, but it can also be found distributed throughout tropical and the subtropical regions. The fungus is commonly found on dead herbaceous and woody plants in the tropics as they are saprotrophs in warmer climates. In general, most Cladosporium species are widely distributed throughout the world In tropical and subtropical regions, and growing In soil or on organic matters. In a study conducted by Guan Et al., C. oxysporum was found to produce extracellular xylanase when grown on decaying agricultural waste. Production of extracellular xylanase was enhanced by elevated levels of Mg2+ ion in the soil or the surrounding environment, but inhibited by the high levels of Cu2+ ion. In the wild, C. oxysporum grows on hosts like Alnus, Bambusa, Citrus, Helianthus, and Pseudotsuga.
Physiology
Cladosporium oxysporum is a saprobic secondary invader in warmer climates, meaning they invade and feed on organisms that are weakened or already dead. It breaks down cellulose from dead herbaceous or plants, which is then further turned into glucose to Be used by the fungi themselves, and it uses NH4Cl as a nitrogen source. In a study by Oxenbøll et al., C. oxysporum catalyzed glucose oxidation by producing glucose oxidase, which it is mentioned in another study conducted by Viswanathan et al. that the glucose oxidase helped protect against bacterial infection on the surface of fungi. The organism is also proven to be very osmotolerant in a laboratory environment, meaning it can tolerate extreme changes in water availability. C. oxysporum can be easily grown on agar media containing 10% glucose or 12 – 17% NaCl, they rarely grow on media containing 24% NaCl or 50% glucose and never isolated from media containing 32% NaCl or greater. C. oxysporum exhibits high metal tolerance, allowing it to survive well in contaminated soil.
Pathogenicity
Effects on humans
Cladosporium oxysporum is a low-risk microbe that usually poses little to No threat of infection In healthy adults As it has a Biosafety level of 1(BSL-1). However, there have been rare reports of this fungus causing infection in humans. Only a handful of other species in the Cladosporium genera contributed to human infections, including C. cladosporioides, C. herbarum, C. sphaerospermum, and C. elatum. Although it is a rare cause of disease in humans, C. oxysporum has been reported as a cause of keratitis and cutaneous infections. A study by Forster et al. reported on 16 cases of keratitis caused by C. oxysporum in which 9 patients were healed by the use of Natamycin (Pimaricin), suggesting that the damage caused by this fungus was reversible. It is also reported that C. oxysporum can also cause occasional cutaneous phaeohyphomycosis and invasion of the neck lymph nodes in humans. Several genera of fungi are found to cause phaeohyphomycosis, but it is a rare case caused by C. oxysporum. In a 2006 case report, a 30-year-old farmer in India was affected by phaeohyphomycosis due to the infection of C. oxysporum which caused large areas of lesion on the skin. It was also tested that phaeohyphomycosis occurred after implanting the fungus from the environment to exposed tissue. The patient was responded positively after receiving a treatment of saturated solution of potassium iodide (SSKI), showing dramatic regression of lesions within 3 weeks of the onset of therapy.
Effects on insects
In a study conducted by Samways Et al. In South Africa in 1986, C. oxysporum was observed to cause mortality In certain species of homoptera, suggesting that it can be used as a potential targeted insecticide. The pathogen was grown in submerged culture and then applied to 4 species of insects: Planococcus citri, Pseudococcus longispinus, Pulvinaria aethiopica and Trioza erytreae. C. oxysporum successfully caused mortality and hyphal growth In all four species. Field applications of the fungus had a considerable initial impact on the insect populations, which made it a potential biocontrol agent.
Effects on mice
In an experiment conducted in India in 1992 by Singh et al., an in vivo experiment was conducted on mice to determine the pathogenicity of C. oxysporum. No mortality occurred during the four-week period of the experiment, but the concentration of the microorganism inside of the body increased tremendously. The lungs were the most commonly infected organ As they presented with multiple nodules that had extensively invaded the endothelium of the bronchioles, and the surrounding tissues were heavily infiltrated with polymorphonuclear leucocytes.
Effects on plants
It is also found in multiple studies suggesting that C. oxysporum is pathogenic to many vegetables and fruits. A study performed by Lamboy et al. studied the pathogenic effects of C. oxysporum to tomatoes. The fungus creates dark brown, angular lesions on the tomato foliage known as "leaf spots", ultimately reducing the ability for the plant to survive. The study also describes C. oxysporum as a causal agent of a leaf spot disease of pepper and also a storage disease of ripe tomato fruit. Due to the high prevalence of this fungi in warm climax, they reproduce extremely well in a green house setting, which they were able to spread to healthy tomato plants in vicinity within three weeks. Other studies also provided insight on the pathogenic effect of C. oxysporum on other vegetation; it causes the formation of scabs on the surface of passion-fruits, and it also causes severe leaf blight in Prunus napaulensis, especially affecting the seedlings.
Treatment
In a study performed by Raj et al., the fungal metabolite, taxol, extracted from Cladosporium oxysporum induced apoptosis in T47D human breast cancer cell line, which suggested that the extract may exert its anti-proliferative effect on human breast cancer cell line by suppressing growth, and down-regulating the expression of NF-B, Bcl-2 and Bcl-XL and up-regulation of pro-apoptotic proteins like Bax, cyt-C and caspase-3. This discovery allowed the medical field to test a new substance to study the ongoing battle with cancer. In another study, fungal taxol extracted from C. oxysporum can Be used against human pathogenic bacteria and human colon cancer cell line HCT 15. The taxol extracted could suppress the growth of the cancer cells As well as effectively combating both gram positive and gram negative bacteria.
Uses
It is proposed that C. oxysporum has a potential function in textile processes or paper/feed industries due to the xylanase resistance to most of tested neutral and alkaline proteases, meaning that xylanase would not be broken down by other protease, which allows it to continuously break down fiber into paper-making materials. C. oxysporum can also be used to make tempeh; traditional soy product originating from Indonesia. In multiple studies, C. oxysporum has been used in bioremediation. water bioremediation by targeting endosulfan and it exhibits metal tolerance and an ability to synthesize gold nanoparticles with superior catalytic activity for degradation of rhodamine B.
References
oxysporum
Fungi described in 1868
Fungi of Africa
Fungi of Asia
Taxa named by Miles Joseph Berkeley
Taxa named by Moses Ashley Curtis
Fungus species
] | Cladosporium oxysporum | [
"Biology"
] | 2,016 | [
"Fungi",
"Fungus species"
] |
58,468,200 | https://en.wikipedia.org/wiki/Biting | Biting is an action involving a set of teeth closing down on an object. It is a common zoological behavior, being found in toothed animals such as mammals, reptiles, amphibians, fish, and arthropods. Biting is also an action humans participate in, most commonly when chewing food. Myocytic contraction of the muscles of mastication is responsible for generating the force that initiates the preparatory jaw abduction (opening), then rapidly adducts (closes) the jaw and moves the top and bottom teeth towards each other, resulting in the forceful action of a bite. Biting is one of the main functions in the lives of larger organisms, providing them the ability to forage, hunt, eat, build, play, fight, protect, and much more. Biting may be a form of physical aggression due to predatory or territorial intentions. In animals, biting can also be a normal activity, being used for eating, scratching, carrying objects, preparing food for young, removing ectoparasites or irritating foreign objects, and social grooming. Humans can have the tendency to bite each other whether they are children or adults.
Bites often result in serious puncture wounds, avulsion injuries, fractures, hemorrhages, infections, envenomation, and death. In modern human societies, dog bites are the most common type of bite, with children being the most common victims and faces being the most common target. Some other species that may bite humans include urban animals such as feral cats, spiders, and snakes. Other common bites to humans are inflicted by hematophagous insects and arthropods, such as mosquitoes, fleas, lice, bedbugs, and ticks (whose "bites" are actually a form of stinging rather than true biting).
Types of teeth
The types of teeth that organisms use to bite vary throughout the animal kingdom. Different types of teeth are seen in herbivores, carnivores, and omnivores as they are adapted over many years to better fit their diets. Carnivores possess canine, carnassial, and molar teeth, while herbivores are equipped with incisor teeth and wide-back molars. In general, tooth shape has traditionally been used to predict dieting habits. Carnivores have long, extremely sharp teeth for both gripping prey and cutting meat into chunks. They lack flat chewing teeth because they swallow food in chunks. An example of this is shown by the broad, serrated teeth of great white sharks which prey on large marine animals. On the other hand, herbivores have rows of wide, flat teeth to bite and chew grass and other plants. Cows spend up to eleven hours a day biting off grass and grinding it with their molars. Omnivores consume both meat and plants, so they possess a mixture of flat teeth and sharp teeth.
Carrying mechanism
Biting can serve as a carrying mechanism for species such as beavers and ants, the raw power of their species-specific teeth allowing them to carry large objects. Beavers have a large tooth adapted for gnawing wood. Their jaw muscles are tuned to power through big trees and carry them back to their dam. Ants use their powerful jaws to lift material back to the colony. They can carry several thousand times their weight due to their bite and are adapted to use this to forage for their colonies. Fire ants use their strong bite to get a grip on prey, then inject a toxin via their stinger and carry the prey back to their territory.
Dangers
Some organisms have dangerous bites that inject venom. Many snakes carry a venomous saliva containing at least one of the major groups of toxins, which include cytotoxins, hemotoxins, myotoxins, and neurotoxins. Spider venom polypeptides target specific ion channels, which excites components of the peripheral, central and autonomic nervous systems, causing hyperactive neurotransmitter release and subsequently refractory paralysis. Spider bites, or arachnidism, are mainly a form of predation, but also means of self-defense — when trapped or accidentally tampered with by humans, spiders retaliate by biting. The recluse spider and widow species have neurotoxins and necrotizing agents that paralyze and digest prey.
Humans biting each other can cause a number of diseases with streptococci, staphylococci, and anaerobic organisms being very severe causing infections. These bites are typically deep cutting into the skin where the infection forms.
There are several creatures with non-lethal bites that may cause discomfort or diseases. Mosquito bites may cause allergic wheals that are itchy and may last a few days; in some areas, they can spread blood-borne diseases (e.g. malaria and West Nile fever) via transmission of protozoic or viral pathogens. Similarly, tick bites spread diseases endemic to their location, most famously Lyme disease, but ticks also serve as disease vectors for Colorado tick fever, African tick bite fever, Tick-borne encephalitis, etc.
In humans
Young children who bite others do so out of play or aggression whereas adults bite others out of aggression. Bites that occur from adults fighting are usually on the hands and the skeletal section. Infections are a result of bacteria from the mouth spread to another human and are the third common types of bites that require a hospital visit. Biting in children is common however, it may be prevented by methods including redirection, change in the environment and responding to biting by talking about appropriate ways to express anger and frustration. School-age children, those older than 30 months, who habitually bite may require professional intervention. Some discussion of human biting appears in The Kinsey Report on Sexual Behavior in the Human Female. Biting may also occur in physical fights or in self-defense.
Criminally, Forensic Dentistry is involved in bite-mark analysis. Because bite-marks change significantly over time, investigators must call for an expert as soon as possible. Bites are then analyzed to determine whether the biter was human, self-inflicted or not, and whether DNA was left behind from the biter. All measurements must be extremely precise, as small errors in measurement can lead to large errors in legal judgment.
Human bites have historically been viewed superstitiously, particularly in the American South where there was once a common belief that the bite of a "blue-gum negro" (i.e., a Black person with darkly pigmented gums) was lethally poisonous.
See also
Chewing
Bite force quotient
Animal bite
References
External links
Ethology | Biting | [
"Biology"
] | 1,366 | [
"Behavioural sciences",
"Ethology",
"Behavior"
] |
58,468,292 | https://en.wikipedia.org/wiki/Aspergillus%20wentii | Aspergillus wentii is an asexual, filamentous, endosymbiotic fungus belonging to the mold genus, Aspergillus. It is a common soil fungus with a cosmopolitan distribution, although it is primarily found in subtropical regions. Found on a variety of organic materials, A. wentii is known to colonize corn, cereals, moist grains, peanuts and other ground nut crops. It is also used in the manufacture of biodiesel from lipids and is known for its ability to produce enzymes used in the food industry.
History and taxonomy
Aspergillus wentii was first described by German mycologist Carl Friedrich Wilhelm Wehmer in 1896. Following a morphology-based classification scheme he created in 1901, Wehmer grouped A. wentii under a category of large Aspergilli that he called the "Macroaspergilli" due to its large fruiting body structure (the conidial head). The taxonomic position of A. wentii remained unclear within the genus as A. wentii Wehmer synonyms (A. archaeoflavus Blochwitz and Aspergillus wentii var. minimus) were presented by Drs. Charles Thom and Kenneth Raper as possible variations or strains. The first A. wentii group was proposed by Drs. Thom and Raper in 1945. This original A. wentii group was classified under the Circumdati subgenus of the genus Aspergillus and included 4 fungal species currently known as A. avenaceus Smith, A. panamensis Raper and Thom, A. alliaceus Thom and Church, and A. wentii Wehmer. Presently, Aspergillus wentii Wehmer is the only remaining fungus of the four fungi that originally made up the "A. wentii group". The 3 former members of the A. wentii group (A. avenaceus, A. panamensis, and A. alliaceus) have since been reassigned to different Aspergillus subgenera (A. flavus group, A. ustus group, and A. ocheaceus group) respectively. Drs. Charles Thom and Dorothy Fennell revised the A. wentii group in 1965 to include Aspergillus thomii Smith and A. terricola Marchal along with A. wentii Wehmer. However, Aspergillus group classifications within subgenera became obsolete in the 1980s being replaced by sections.
The new Aspergilli sections adapted and revised previously established morphological and physiological characteristics of Aspergillli groups and incorporated DNA sequencing analyses to confirm phylogenetic relationships among related Aspergilli. Many species were reassigned to new Aspergilli sections as phylogenetic relationships were confirmed by DNA and genome sequencing experiments. As a result, A. wentii and A. dimorphicus, previously described as synonyms within the A. wentii section, were later confirmed to be distinct species.
Growth and morphology
Aspergillus wentii produces single-celled, globose, conidia (singular conidium) in unbranched, filamentous chains. Young asexual conidia (also called spores) start off smooth, colourless, and ellipsoidal before maturing into rough, globose spores approximately 4.5–5 μm in diameter. Aspergillus wentii conidia can appear anywhere from darker yellow to brown in colour when mature and have a single wall, unlike related species Aspergillus tamarii whose conidia have a double wall membrane. The elongating chains of conidia are dispersed through slightly pigmented, vase-shaped structures known as phialides that are around 6–8 μm. The phialides sit on top of almond-shaped structures known as metulae that are about 10–20 μm in length and also slightly pigmented. Together, these metulae and phialides structures radiate outward from a spheroid structure known as the vesicle, layering around its entire surface area. The vesicle can grow to a diameter of 80 μm, with a completely fertile spheroid surface area. Collectively, this large globose complex made up of the vesicle at the centre with metulae and phialides radiating outward is called the conidial head. The conidial head can vary from tan-yellow to darker coffee-coloured brown and grow as big as 500–800 μm in diameter. The conidial head is affixed atop of a thick, aseptate stalk known as a stipe. Aspergillus wentii stipes are notable for being interspersed and longer than average Aspergillus stalks. The stipe and conidial head together form a translucent, rod-shaped structure collectively known as the conidiophore that in turn, extends from the hyphal tip. The conidiophore can grow anywhere between 3 and 5 millimeters in length, has a glassy appearance (described as hyaline) and typically have a smooth texture, although granular conidiophores have been observed. Aspergillus wentii produces aerial hyphae, white or sometimes yellow in colour that can grow to a few millimeters in length. Aspergillus wentii foot cells have dense walls and are branched.
Overall, Aspergillus wentii colonies appear dense, floccose (fluffy) to cottony, and are white in colour. Colonies can grow up to 2–3.5 cm in diameter on Czapek agar when grown under controlled conditions for a span of 7 days. Optimal growth of Aspergillus wentii in culture occurs on glucose media at pH 6.0 at a temperature of 30°C for a duration of 7 days.
Dr. Wehmer originally described seeing cleistothecia; however, there have been no reports of such structures on Aspergillus wentii since. According to subsequent authors, it is believed that Wehmer misinterpreted densely packed masses of hyphae for cleistothecia which are structurally similar.
Reproduction
Aspergillus wentii is an asexual fungus with no known sexual state. Although Aspergillus wentii is currently a mitotic fungus, vestigial remnants found in the hyphae of A. wentii are evidence that ancestral Aspergilli once had the ability to sexually reproduce by meiosis. Morphological similarities observed between hyphal masses in Aspergillus wentii and young sexual structures (cleistothecia) found in Chaetosartorya chrysella are further vestigial evidence of meiotic ability in ancestral Aspergilli. Phylogenetic analysis of DNA sequences revealed a strong phylogenetic relation between the obligate asexual species Aspergillus wentii and meiotic (sexual) species Chaetosartorya chrysella, suggesting that the two species are close relatives, having recently diverged from the same sexually-reproducing ancestor.
Physiology
Aspergillus wentii is a filamentous fungus. In culture, optimal growth of Aspergillus wentii occurs on glucose media at pH 6.0 at a temperature of 30 °C. Aspergillus wentii grows well on carbon-based media supplemented with mannitol, fructose, galactose, sucrose, lactose, or maltose. Generally, Aspergillus wentii exhibits the highest growth rates in carbon-based media, although it can be grown on nitrogen-based media with lower growth yields. Aspergillus wentii does not grow well on creatine sucrose agar (CREA) and produces sterile hyphae on malt extract agar.
Aspergillus wentii is moderately xerophile, able to tolerate very dry conditions with low water activity (with an aW of 0.73–0.79 for growth and germination). In its natural environment, Aspergillus wentii is aerobic, able to grow, replicate, and produce metabolites optimally in an oxygen-rich environment. Under light exposure, Aspergillus wentii cultures have been observed to produce white aerial mycelium (at times expressing a pink hue) in large masses that can often expand to fit entire volumes of test tubes or culture plates. Aspergillus wentii mycelia have an 8-9 % glucosamine content and have an average doubling time of 4–8 hours in liquid culture.
Like many Aspergillus fungi, Aspergillus wentii is resistant to amphotericin B and itraconazole. Thermal death time for Aspergillus wentii occurs after 25 minutes at a temperature of 63 °C. Conditions of 100% oxygen pressurized at 10 atm will also cease A. wentii fungal growth.
Metabolism
Aspergillus wentii is able to produce a wide range of metabolites characteristic of mold fungi including kojic acid, 2-hydroxymethylfuran-5-carboxylic acid, and citric acid. Aspergillus wentii Wehmer is also capable of producing the plant-growth inhibitor metabolite 1-amino-2-nitrocyclopentane-1-carboxylic acid (ANPCA), known for its ability to stunt growth and cause deformation in plants such as Chrysanthemum, pea plants, and Nicotiana (tobacco) plants.
Aspergillus wentii strains produce numerous enzymes such as pectinases (in food sources), dextranase, lipases, cellulases, amylase, β-glucosidase and other common mold enzymes. Aspergillus wentii is a fungus capable of producing high quantities of lipase. Ideal lipase growth conditions in Aspergillus wentii (100% lipase activity) occur under media supplemented with glucose of pH 6.0 at a temperature of 30 °C. Aspergillus wentii grown in mannitol media produces the second largest lipase yield (with 84% lipase activity). Lipase activity for Aspergillus wentii grown on fructose media produces just under 50% lipase activity while media supplemented with galactose, sucrose, lactose or maltose all yielded moderate lipase activity (20–37%).
Aspergillus wentii strain NRRL 2001 spores were found to naturally produce glucose from hydrolyzing soluble starch. Of all Aspergilli, A. wentii was found to produce the best yields of glucose, able to convert approximately 20-40% of original starch, with almost zero maltose conversions. Optimal glucose production from Aspergillus wentii NRRL 2001's starch degradation occurred from younger spores (glucose production decrease with spore age), in the presence of Iodoacetate (a compound that blocks glucose breakdown pathways), and at a pH 3.0 or higher.
Toxins such as aflatoxin B1, aflatoxin B2 (in small traces), emodin and wentilacton are all made by Aspergillus wentii. Aspergillus wentii toxins are commonly found on plant, animal, or food sources. One intracellular metabolite secreted by Aspergillus wentii is toxic to mice as well as chicken embryos. Aspergillus wentii chloroform extracts of mycelium, moldy corn, and moldy rice all produce varying levels of toxicity when introduced to chicken embryos on yeast-extract sucrose (YES) medium. While moldy corn with Aspergillus wentii was unable to kill mice in one study, YES extracts of corn and mycelium were shown to be deadly to mice, with YES mycelium extract being the most potent to both chicken and mice.
One Aspergillus wentii strain, Ras101, is known for its ability to produce biodiesel from the transesterification of lipids. Optimal yield of biodiesel from Aspergillus wentii is dependent upon factors such as the optimization of lipid production, pH, incubation time, temperature, and the medium composition. Under ideal conditions, Aspergillus wentii can optimize 31.65% biomass of biodiesel in 30 minutes of lipid transesterification at 70 °C.
Habitat and ecology
Aspergilli are collectively classified as indoor mold fungi. Aspergillus wentii is typically found as mold on various decomposing vegetable and organic material and is notorious for causing food spoilage in corns, cereals, ground nuts and peanuts. Aspergillus wentii can also be isolated from tobacco. As a common soil fungus and endosymbiont, Aspergillus wentii often lives in symbiosis with species in rhizospheres (an area of soil populated with roots and home to many microorganisms). Within these rhizospheres, Aspergillus wentii can be found amongst cottonseed, olives, barley, rice, pineapple, oats, Brazil nuts, pecans, groundnuts, wheat, fir tree leaf matter, and more. Not only limited to plant and vegetative sources, A. wentii has also been associated with bird and gerbil nests.
Distributed in many different parts of the world, Aspergillus wentii has been found in countries such as China, Peru, Argentina, Japan, South Africa, France, Pakistan, Guyana, Turkey, India, Spain, Italy, Israel, the Bahamas, the United States and more. Aspergillus wentii is most commonly found in warm, subtropical areas such as South America.
Aspergillus wentii has a tendency to colonize dry soils, especially in deserts and warm climates. However, A. wentii has been isolated from a variety of cultivated and uncultivated soil types including grassland soils, forest soils, clay isolated from caves and even alkaline soils. It is also common to find Aspergillus wentii near water sources such as in seawater, sediments of estuaries (partially enclosed coastal bodies), peat bogs, waste stabilization ponds, water treatment plants and in fresh water sources. In Hawaii, one study found that Aspergillus wentii only colonized roots of pineapple plants in regions with higher rainfall and lower soil pH. In addition to moist environments, Aspergillus wentii was also found to colonize dry plant stems of Coptis japonicus in soil. As an aerobic organism, Aspergillus wentii was cited as a rare, trivial component of spora found in the air in Europe.
Disease
Until recently, Aspergillus wentii was not known to be pathogenic in humans. The first case of a human disease caused by Aspergillus wentii was reported in 2009. This disease was described as Necrotising external otitis (also known as NEO), a fungal infection characterized by severe ear pains. Prior to this report, NEO was known to be primarily caused by the bacteria Pseudomonas aeruginosa, although cases of other fungal-origin NEO infections were previously described. In both Pseudomonas and Aspergillus wentii NEO, immunocompromised patients are more susceptible to disease. However, unlike classical NEO caused by P. aeruginosa, that is commonly found in diabetic elderly, NEO of Aspergillus wentii origin can infect diabetic or non-diabetic adults anywhere between the ages of 20 and 85 years old. In more severe cases of NEO, paralysis symptoms in cranial nerve VII appear uniquely in cases of fungal infection, including NEO of Aspergillus wentii origin. Generally, amphotericin B and itraconazole are used as treatment of Aspergillus wentii infection.
Uses
Widely used in the food industry, Aspergillus wentii is exploited for its ability to make enzymes (such as lipase) that create flavour byproducts in foods when degrading lipids. Aspergillus wentii is primarily used in Asian cuisines, often combined with other Aspergilli (such as Aspergillus oryzae and A. flavus) to create soy products through production of kojic acid and fermentation processes. Enzymes such as pectinase are also produced by Aspergillus wentii in several food sources such as salted fish, Chinese chestnuts, and popcorn. Like Aspergillus oryzae, A. tamarii and A. flavus, Aspergillus wentii can produce a wide range of mold enzymes. Proteolytic (protein degrading) enzymes, such as amylase, were also found to be produced by Aspergillus wentii when fermenting on cocoa beans.
Aspergillus wentii fungal strain, Aspergillus wentii Ras101, is known for its ability to produce biodiesel through a transesterification process. As a fungus that produces lipids in high quantities, Aspergillus wentii was proposed as a favourable microorganism to produce large yields of biodiesel product. Optimal yield of biodiesel from Aspergillus wentii is dependent upon factors such as the optimization of lipid production, pH, incubation time, temperature, and the medium composition. Under ideal conditions, Aspergillus wentii can optimize 31.65% biomass of biodiesel in 30 minutes of lipid transesterification at 70 °C. Physiological properties of Aspergillus wentii biodiesel (density, water content, calorific value, and viscosity) are comparable to standards of ordinary biodiesel and fossil fuel requirements as an alternative fuel source, making this strain a potential feedstock for producing biodiesel as a renewable, alternative fuel source in the industrial sector.
References
wentii
Fungi described in 1896
Fungus species | Aspergillus wentii | [
"Biology"
] | 3,740 | [
"Fungi",
"Fungus species"
] |
58,468,325 | https://en.wikipedia.org/wiki/Bicapped%20trigonal%20prismatic%20molecular%20geometry | In chemistry, the bicapped trigonal prismatic molecular geometry describes the shape of compounds where eight atoms or groups of atoms or ligands are arranged around a central atom defining the vertices of a biaugmented triangular prism. This shape has C2v symmetry and is one of the three common shapes for octacoordinate transition metal complexes, along with the square antiprism and the dodecahedron.
It is very similar to the square antiprismatic molecular geometry, and there is some dispute over the specific geometry exhibited by certain molecules. One example of the bicapped trigonal prismatic molecular geometry is the ion.
The bicapped trigonal prismatic coordination geometry is found in the plutonium(III) bromide crystal structure type, which is adopted by many of the bromides and iodides of the lanthanides and actinides.
References
Stereochemistry
Molecular geometry | Bicapped trigonal prismatic molecular geometry | [
"Physics",
"Chemistry"
] | 184 | [
"Molecular geometry",
"Molecules",
"Stereochemistry",
"Space",
"Stereochemistry stubs",
"nan",
"Spacetime",
"Matter"
] |
58,468,854 | https://en.wikipedia.org/wiki/Cladosporium%20herbarum | Cladosporium herbarum is a common fungus found worldwide in organic and inorganic matter. It is efficiently distributed in the air, where it exists as the most frequently occurring fungal species. It can grow over a wide range of temperatures including very cold environments, giving it the ability to grow on refrigerated meat and form "black spots". Its high prevalence in the air and production of allergens makes C. herbarum an important exacerbant of asthma and hay fever.
Prevalence
Cladosporium herbarum is the type species of the genus Cladosporium. Its spores are highly prevalent in the air; the genus Cladosporium is the dominant genus of spores found in the air, with the C. herbarum species contributing the highest percentage to this group. These airborne spores are more common during the summer and fall seasons; in the summer there can be as many as 15,000 spores per m3 air of C. herbarum. Cladosporium herbarum is also found all over the world on dead organic material, in the soil, and sometimes appears as a plant parasite. It is also a common fungus found in indoor environments.
Growth
In young cultures, newly-formed spores show growth by budding into a large, multi-branched mycelium. It has an optimal growth temperature between and , with a maximum growth temperature between and . It has been shown to grow at temperatures as low as , and ; allowing it to grow actively (albeit slowly) on frozen materials. Cladosporium herbarum can also grow in dry environments (xerophile). C. herbarum grows optimally at pH 6 but tolerates environments with a pH as low as 4.4. Conidium production is higher in wet than dry conditions. The production of spores is inhibited by rubratoxin B and aflatoxin. Its growth is inhibited in atmospheres of reduced oxygen and increased carbon dioxide. Mycosphaerella tassiana is the sexual reproductive stage (teleomorph) of C. herbarum.
Morphology
Spores produced by C. herbarum can be lemon-shaped or cone-shaped, often composed of 2-4 cells (3-23 mm). One-celled conidia (5.5-13 x 3.8-6 μm) also exist. In culture, newly-formed spores appear mostly 1-celled, later forming tree-like colonies with multiple branches. The stalks which produce C. herbarum spores are 250 μm long and 3-6 μm wide. They appear swollen at the tip and in between cells, and have irregularly bent branches. Under microscopy, these stalks appear pale or dark brown in color and have smooth or rough walls. When submerged in fluid, they become brittle and break up completely into spores and rod-like fragments. Colonies grown on Czapek yeast extract agar (CYA) and malt extract agar (MEA) appear velvety or fluffy, with smooth or slightly wrinkled walls, and are green or brown in color. The reverse side of the colony appears a darker green or grey/black. Colonies can appear both sparse or densely grown. At , colonies are 1-2 mm in diameter.
Habitat and ecology
This species is distributed worldwide, inhabiting polar, temperate, mediterranean, subtropical, tropical, forest, grassland, and arable soil regions. It is found frequently in wood exposed to soil, deep soil depths, and the highly nutritious soil directly surrounding the roots of plants (rhizosphere). It is one of the early colonizers on dying and dead plants (saprobe), especially the leaves and stems of both aquatic and desert plant species (for example ferns and mosses). It is the most common fungal species found on living leaves (given suitable conditions) and dead plant material in very moist environments. It also has an adaptation to high salt concentrations (has been found in high salinity sediments) and extremely dry areas (xerophilic).
Cladosporium herbarum causes spoilage of fresh fruits and vegetables including yams, peaches, nectarines, apricots, plums, cherries, tomatoes, and melons. Its common occurrence on fresh apples can lead to contamination of apple juice and fruit based products. It has also been found in eggs, hazelnuts, cereals, chickpeas, soybeans, and frozen fruit pastries. Cladosporium herbarum can also spoil cheese and pasteurized soft cheese, causing problems during its manufacturing. Being able to survive at temperatures below freezing, C. herbarum can cause "black spot" spoilage of meat in cold storage (between and ). It has been isolated from fresh, frozen, and processed meats.
Cladosporium herbarum has been isolated from caterpillars, nests, feathers, pellets of free-living birds, nests of gerbils, bee honeycombs, internal organs of frogs, and earthworms. It has also been found indoors on walls, wallpaper, textiles, rubber strips of window-frames, and bathrooms. Increased release of C. herbarum spores is correlated with increasing temperatures, daylight, and declining humidity. This species appears more frequently during the summer than the winter with peak concentrations of airborne spores found during the afternoon of a 24 hour cycle. The spores are easily carried through the air and can be transported long distances including over oceans.
Pathogenicity
This fungus is non-pathogenic, but its ability to freely produce spores that are easily dispersed in air currents adds to its effect as a fungal airway allergen; it is one of the main fungal causes of asthma and hay fever in the Western Hemisphere. More than 60 antigens derived from C. herbarum have been detected, and 36 of these have immunoglobulin E (IgE) binding properties. Most of these antigens are proteins found inside cells, and eight of these antigens are members of the World Health Organization's official allergen list. There is variation in allergen content between different strains of C. herbarum .
Toxic effects of C. herbarum on warm-blood animals have been reported when they were fed with heavily infected wheat. It can produce a toxin causing mucosal damage in horses, and mycelium extracts are shown to have low-level toxicity in chicken embryos.
C. herbarum is also fungal plant pathogen. Its hosts include Bryum, Buxbaumia, Gyroweissia, Tortula, and Dicranella. It can cause Cladosporium ear rot on corn.
Molecular genetics
Most often, C. herbarum conidia have 1 nucleus, but some can have 2 nuclei. During mitosis, 5 to 8 dot-like chromosomes have been observed. Based on DNA analysis, they have a guanine-cytosine content (GC-content) of 55%.
Using molecular diagnostics, C. herbarum internal transcribed spacer (ITS) sequences have been found to be identical to those of Cyphellophora laciniata.
References
herbarum
Fungal plant pathogens and diseases
Fungi described in 1815
Taxa named by Christiaan Hendrik Persoon
Fungus species | Cladosporium herbarum | [
"Biology"
] | 1,503 | [
"Fungi",
"Fungus species"
] |
58,469,254 | https://en.wikipedia.org/wiki/CLEVER%20score | The CLEVER (Cross Lipschitz Extreme Value for nEtwork Robustness) score is a way of measuring the robustness of an artificial neural network towards adversarial attacks.
It was developed by a team at the MIT-IBM Watson AI Lab in IBM Research and first presented at the 2018 International Conference on Learning Representations. It was mentioned and reviewed by Ian Goodfellow as well. It was adopted into an educational game Fool The Bank by Narendra Nath Joshi, Abhishek Bhandwaldar and Casey Dugan
References
Deep learning
AI safety | CLEVER score | [
"Technology",
"Engineering"
] | 114 | [
"Safety engineering",
"AI safety",
"Computer science stubs",
"Computer science",
"Computing stubs"
] |
58,469,853 | https://en.wikipedia.org/wiki/Visual%20temporal%20attention | Visual temporal attention is a special case of visual attention that involves directing attention to specific instant of time. Similar to its spatial counterpart visual spatial attention, these attention modules have been widely implemented in video analytics in computer vision to provide enhanced performance and human interpretable explanation of deep learning models.
As visual spatial attention mechanism allows human and/or computer vision systems to focus more on semantically more substantial regions in space, visual temporal attention modules enable machine learning algorithms to emphasize more on critical video frames in video analytics tasks, such as human action recognition. In convolutional neural network-based systems, the prioritization introduced by the attention mechanism is regularly implemented as a linear weighting layer with parameters determined by labeled training data.
Application in Action Recognition
Recent video segmentation algorithms often exploits both spatial and temporal attention mechanisms. Research in human action recognition has accelerated significantly since the introduction of powerful tools such as Convolutional Neural Networks (CNNs). However, effective methods for incorporation of temporal information into CNNs are still being actively explored. Motivated by the popular recurrent attention models in natural language processing, the Attention-aware Temporal Weighted CNN (ATW CNN) is proposed in videos, which embeds a visual attention model into a temporal weighted multi-stream CNN. This attention model is implemented as temporal weighting and it effectively boosts the recognition performance of video representations. Besides, each stream in the proposed ATW CNN framework is capable of end-to-end training, with both network parameters and temporal weights optimized by stochastic gradient descent (SGD) with back-propagation. Experimental results show that the ATW CNN attention mechanism contributes substantially to the performance gains with the more discriminative snippets by focusing on more relevant video segments.
Literature
Seibold VC, Balke J and Rolke B (2023): Temporal attention. Front. Cognit. 2:1168320. doi: 10.3389/fcogn.2023.1168320.
See also
Attention
Visual spatial attention
Action Recognition
Video content analysis
Convolutional neural network
Computer vision
References
Attention
Computer vision
Machine vision
Applications of computer vision
Applied machine learning
Film and video technology
Cognition
Cognitive neuroscience
Neuropsychology | Visual temporal attention | [
"Engineering"
] | 458 | [
"Robotics engineering",
"Packaging machinery",
"Machine vision",
"Artificial intelligence engineering",
"Computer vision"
] |
58,470,588 | https://en.wikipedia.org/wiki/NGC%203981 | NGC 3981 is an unbarred spiral galaxy located 65 million light-years away in the constellation of Crater. It was discovered on February 7, 1785, by William Herschel.
NGC 3981 is a member of the NGC 4038 Group which is part of the Virgo Supercluster.
See also
Galaxy
References
External links
NGC 3981 on SIMBAD
3981
NGC 4038 Group
Crater (constellation)
Unbarred spiral galaxies
037496
UGCA objects
289
Astronomical objects discovered in 1785
Discoveries by William Herschel | NGC 3981 | [
"Astronomy"
] | 113 | [
"Crater (constellation)",
"Constellations"
] |
58,470,726 | https://en.wikipedia.org/wiki/Pharmacy%20management%20system | The pharmacy management system, also known as the pharmacy information system, is a system that stores data and enables functionality that organizes and maintains the medication use process within pharmacies.
These systems may be an independent technology for the pharmacy's use only, or in a hospital setting, pharmacies may be integrated within an inpatient hospital computer physician order entry (CPOE) system.
Necessary actions for a basic, functioning pharmacy management system include a user interface, data entry and retention, and security limits to protect patient health information. Pharmacy computer software is usually purchased ready-made or provided by a drug wholesaler as part of their service. Various pharmacy software operating systems are common place throughout the many practice settings.
Purpose
The pharmacy management system serves many purposes, including the safe and effective dispensing of pharmaceutical drugs. During the dispensing process, the system will prompt the pharmacist to verify the medication they have is for the correct patient and has the correct quantity, dosage, and information on the prescription label. Advanced pharmacy management systems offer clinical decision support and may be configured to alert the pharmacist to perform clinical interventions, such as an opportunity to offer verbal counseling if the patient's prescription requires additional education in the pharmacy.
Pharmacy management systems should also serve the pharmacist throughout the Pharmacists’ Patient Care Process, a cycle developed by the Joint Commission of Pharmacy Practitioners (JCPP). The process details the steps pharmacists take to practice tangible, proven care to their patients.
Pharmacist patient care process
The JCPP's pharmacist patient care process consists of five steps: collect, assess, plan, implement, and follow-up. Ideally, the pharmacy management system assists with each of these practices. The pharmacy system should Collect data at intake and continue to store and organize information as the pharmacist learns more about the patient's medications, their history, goals, and other factors that may affect their health. The technology within the pharmacy information system should allow the pharmacists to Assess the collected information to form a Plan and Implement creative strategies that address the patient's issues. After implementing a plan, the pharmacist should routinely Follow-Up with the patient and make adjustments as needed to further progress.
Vendors
Outpatient software vendors
Outpatient pharmacies typically are retail pharmacies that offer patient care services outside of hospitals and treatment facilities. Outpatient pharmacies, also known as community pharmacies or independent pharmacies, offer care in the form of medication therapy management (MTM), patient education, and clinical services.
Rx30
Developed in Florida in 1980, Rx30 is a multi-platform software that offers automated pharmacy processes, vendor integrations, and compounding functionality. The Core Services include Accounts Receivable, Point of Sale, and Virtual Pharmacist, a feature that automates the refill process. On October 6, 2016, Rx30 announced its merger with Computer-Rx.
Inpatient software vendors
Inpatient pharmacies operate within hospitals and dispense medications to admitted patients receiving treatment. Inpatient pharmacists manage patient health alongside doctors and nurses, and the pharmacy management system must integrate with the various systems operating throughout the hospital to maintain accurate Electronic Medical or Health Records (EMR, EHR).
Epic Willow
Epic, named for the long-form poems chronicling hero's lives, began in 1979 by founder Judith R. Faulkner. Epic software currently manages over 200 million patient electronic records. The Willow Inpatient Pharmacy System, when combined with other Epic systems, allows pharmacies access to medical administration records (MAR) and links all aspects of the ordering and dispensing process to simplify collaboration amongst all parties involved in patient care management.
Cerner PharmNet: Medication Manager
Cerner Corporation has provided health information technology (HIT) to hospitals and healthcare systems since 1979. Cerner PharmNet enables pharmacists to automate their workflow processes and center care around the patient, not the encounter. This software allows pharmacists and doctors to manage prescriptions and verification from the same order in order to streamline medication management.
Datascan: Winpharm
Datascan was started back in 1981 by Alex Minassian focused on providing pharmacy management software to independently owned community pharmacies. Initially, Datascan modified the code it had purchased and began selling its DOS based version of the software. In the early 2000's Winpharm was written and released as an updated Windows version of the software, which continued the ability to quickly fill prescriptions using only the keyboard as part of the fill screen. Back in 2009, Kevin Minassian stepped in to purchase Datascan. Today, over 40 years later, Datascan continues to serve the needs of independent pharmacies nationwide with a focus on technology and support.
See also
Health information technology
Pharmacoinformatics
References
Pharmacy
Health informatics | Pharmacy management system | [
"Chemistry",
"Biology"
] | 1,010 | [
"Pharmacology",
"Medical technology",
"Health informatics",
"Pharmacy"
] |
58,470,933 | https://en.wikipedia.org/wiki/Water%20supply%20in%20Sudan | Sudan is a country that is half desert and much of the population suffers from a shortage of clean drinking water as well as a reliable source of water for agriculture. With the Nile river in the east of the country, parts of Sudan have substantial water resources, but those in the west have to rely on wadis, seasonal wells which often dry up. These imbalances in water availability are a source of hardship, as well as a source of conflict. While storage facilities are limited, many local communities have constructed makeshift dams and reservoirs, weirs, which help in stabilizing farming communities. Farmers also utilize hafirs to store rain water which falls in the rainy season, but groundwater remains a vital source of water for over 80% of Sudanese people.
For decades, political instability has led to terrible conditions and thwarted many projects and relief efforts, but aid is making its way through. Several water infrastructure projects have been enacted in recent years, with both domestic and international sources of funding. Funding from the UN has provided 9,550 local farmers with better access to water and fertile soils. A project which also plans to replant forest cover in the wadi to reverse desertification.
Darfur is located in an arid region, in the western part of Sudan, where water scarcity is common. Due to recent population growth, there is an increased pressure on urban water supply sources and infrastructure. Now there is a greater difficulty accessing water—especially for cattle farmers. Many women and children, mostly girls, spend countless hours walking to a clean water supply a year preventing time taking care of children and schooling. Collecting water from ponds, marshes, ditches, or hand-dug wells, often contaminated with disease-causing parasites and bacteria. Experience dry and wet seasons. Wet seasons are plentiful with rainfall and crops; however, dry seasons force families to make mile treks for water and some relocated during the dry seasons.
Water resources
The Nile River flows through the eastern part of the country and provides a large portion of those living nearby with ample water for drinking and agriculture. Wetlands flanking the Nile cover almost 10% of the country, and support diverse riparian ecosystems. Others living in the more arid western region rely on wells or seasonal wadi to obtain their daily water. These wadis are dry stream beds for large portions of the year, but people are able to access the groundwater that accumulates underneath by digging well holes. Water storage infrastructure is limited throughout the western part of the country, but many local communities have constructed makeshift dams and reservoirs called weirs which can store water for future use and play big parts in stabilizing farming communities. Farmers also utilize hairs to store rainwater during the rainy season, but groundwater remains a vital source of water for over 80% of Sudanese people. The Nubian Sandstone Aquifer System, the largest aquifer in the country, provides most of Sudan's drinking water,
Quality
Another concern within Sudan is the quality of the water people have access to. In eastern Sudan, a study was conducted in the cities of Wad Madani and Al Khartoum that revealed 86% of water in public taps was meeting both Sudanese and international quality levels. In Darfur, water scarcity is more prevalent with many people regularly being exposed to drought and famine conditions. Most of the western part of Sudan lacks year round access to quality water, as the wadi are dry for much of the year unless heavy rains fall. Due to instability in much of this part of the county, water quality dramatically decreases when compared to the more water-secure east. The capital of Sudan, Khartoum, will benefit greatly from the Grand Ethiopian Renaissance Dam and looks to be in a much better position with regards to accessing quality sanitary water in the near future. Many of the communities living nearby the border of Chad are exposed to chronic water shortages with no solution in sight until the conflicts are fully resolved.
Water Treatment
United Nations Office for Project Services (UNOPS), rehabilitated an unused water treatment plant in El Fasher, Darfur’s state capital, installing a chlorination unit ensuring water quality. This unit now produces enough water for 37,500 people a day.
Fecal contamination of drinking water supplies is the main cause of diseases found in water. Proper disposal, waste removal, of fecal matter are rare and often difficult without a proper plumbing infrastructure. Consequently, child stunting rate increases with high levels of open defecation and limited access to improved water sources. Poor sanitation conditions cause about 700,000 children deaths a year and prevent full mental and physical development.
Plans for improvement
An organization called United Nations Office for Project Services (UNOPS) had done chlorination plant projects in Darfur's capital city of El Fasher with major funding from Japan. The organization rehabilitated a water treatment plant in 2010, then installed a chlorination plant to improve the quality for over 37,500 people. In the city of El Daein, UNOPS had done projects rehabilitating water treatment facilities, helping over 50,000 with access to clean water. Japan has played a huge part by providing funding and expertise in projects to develop rural Sudan and its access to clean water. UNOPS had completed projects that now help over 250,000 people with access to a potable water source.
The Grand Ethiopian Renaissance Dam is already under construction on the Nile river just nine miles upstream of the border of Sudan and has the potential for a multitude of positive effects for the country. More reliable river levels would allow large-scale irrigation and agricultural production that was not possible due to the annual change of the Nile within Sudan being over 8 m Hydro-electric power produced from the dam would exceed the amount needed by Ethiopia, so Sudan will stand to benefit greatly by being able to purchase this extra power. Another benefit from this dam will be creation of jobs, as the infrastructure to distribute the electricity efficiently does not exist yet and will have to be built.
Grassroots organizations have seen success in the Darfur region, an example being the Wadi El Ku Catchment Forum, which was founded to help the 81,000 residents in the Wadi El Ku area provide more water for their crops. The local group consists of 50 representatives from 34 villages in the area, and these men and women decided the construction of weirs would be both cost-efficient and help the most people. Their efforts to build three weirs with funding from the UN provided 9,550 local farmers with better access to water and fertile soils. This project also plans to replant forest cover in the wadi to accommodate pastoral farmers and reverse climate change from previous desertification.
See also
History of irrigation in Sudan
References
Economy of Sudan
Water supply | Water supply in Sudan | [
"Chemistry",
"Engineering",
"Environmental_science"
] | 1,351 | [
"Hydrology",
"Water supply",
"Environmental engineering"
] |
58,471,140 | https://en.wikipedia.org/wiki/Donald%20R.%20Davis%20%28entomologist%29 | Donald Ray Davis (March 28, 1934 – October 12, 2024) was an American entomologist, specializing in Lepidoptera.
Life and career
Davis was born in Oklahoma City on March 28, 1934. In 1956, he earned his bachelor's degree in Entomology at the University of Kansas. He received his Ph.D. at Cornell University in 1962.
From 1961 to 2015, Davis was a research entomologist in microlepidoptera for the Smithsonian Institution. Don’s research specialized on the biology, biogeography, and phylogeny of early diverging lineages of Lepidoptera (moths), and he served as official curator for 41 Lepidoptera families while on the Smithsonian staff. Don published more than 200 peer-reviewed research papers and described many hundreds of new moth species during his 54-years long career at the Smithsonian. He conducted fieldwork over much of the United States and in 40 countries, focused on the biology of plant-mining Lepidoptera, that resulted in the addition of many new specimens to NMNH Entomology's collections. Don continued his research at the Smithsonian after his retirement until shortly before his death.
The Lepidopterists' Society awarded him its Karl Jordan Medal in 1977 for his work on the Prodoxidae.
Davis died on October 12, 2024, at the age of 90.
References
External links
Tree of Life Web Project
1934 births
2024 deaths
American lepidopterists
Taxon authorities
21st-century American biologists
21st-century American zoologists
Smithsonian Institution people
University of Kansas alumni
Cornell University alumni
Smithsonian Institution affiliates
People from Oklahoma City | Donald R. Davis (entomologist) | [
"Biology"
] | 332 | [
"Taxon authorities",
"Taxonomy (biology)"
] |
58,471,381 | https://en.wikipedia.org/wiki/Curvularia%20pallescens | Curvularia pallescens is a soil fungus, that commonly grows on crops found in tropical regions. The conidia of the fungus are distinguishable from those of related species due to their lack of curvature. C. pallescens has been reported to cause infection in plants, and in immunocompetent individuals. This species is the anamorph of Cochliobolus pallescens.
Morphology
The colonies of C. pallescens differ in morphology depending on the growth medium used. On Czapek Yeast Extract Agar (CYA), colonies of C. pallescens are 50-65mm in diameter. On Malt Extract Agar (MEA), the colonies are fuzzy in texture, and pale grey to grey in colour. On the reverse side, they appear brown to dark brown. The colonies rapidly cover the entire Petri dish. On G25N, the colonies of C. pallescens are 3–6 mm in diameter, and appear grey and brown in colour. On Dichloran Chloramphenicol Malt Agar (DCMA), the colonies are 50–65 mm in diameter, and pale brownish-grey in colour. Lastly, colonies of C. pallescens grown on Phenylethyl Alcohol Agar (PEA) appear woolly at the centre. The conidiophores of C. pallescens are rarely branched, and are brown in colour. They can appear slightly bent at the apices, but otherwise they are predominately straight. The dimensions of the conidiophore vary, especially concerning its length. They can be up to 6μm wide. The conidia of C. pallescens are rugby or gridiron football- to bean-shaped, and are less curved than those of related species. They appear smooth in texture, and pale-brown to brown in colour. The three septa within each conidium give rise to four cells. The third cell from the base appears swollen in comparison to the surrounding cells. The dimensions of the conidia are 18-25 x 9-12 μm.
Cochliobolus pallescens is the teleomorphic form of Curvularia pallescens. It produces spherical ascomata that are black in colour. On the surface of the ascomata, there are protruding colourless necks from which the ascospores emerge. Ascospores are produced within cylindrical asci. The ascospores are colourless, and are either straight or slightly curved. Each ascospore contains 6-13 septa.
Ecology and growth
Curvularia pallescens is commonly found in tropical regions, such as India. They usually grow on unharvested crops (i.e., crops that have not been dried or stored), such as grass, rice, wheat, maize, and sorghum. Optimal growth occurs at 25-30 °C, and at an aw of 0.976. The minimum aw for growth is 0.89. Germination occurs at 0.855 aw but does not result in the establishment of colonies. Sulphur and phosphorus are macronutrients involved in the production of DNA, RNA and proteins in fungal species. It has been reported that C. pallescens is able to grow and sporulate in the absence of both. Magnesium sulphide and tripotassium phosphate support the growth and sporulation of C. pallescens whereas, ammonium sulphate and ammonium phosphate do not.
Physiology
Curvularia pallescens acts as a biological reducing agent of AgNO3, resulting in the production of silver nanoparticles (Ag NPs). This is considered a green method of Ag NP synthesis, unlike other methods that use chemical agents. Silver nanoparticles have widespread applications in industries such as healthcare, environmental health and drug-gene delivery. Curvularia pallescens has been reported to produce several secondary metabolites—particularly, isolates from spirostaphylotrichines and curvupallides. These two groups of secondary metabolites are structurally similar. Isolates of spirostaphylotrichines (i.e., C and D) were found to be phytotoxins whereas, the curvupallide isolates showed no phytotoxic activity. Despite the limited genome sequencing of this fungus, C. pallescens has been found to produce several enzymes with differing immunological and physiological functions in humans. These enzymes include BRN-1, vacuolar protease, fructose-bisphosphate aldolase, mannitol-1-phosphate 5-dehydrogenase, formate dehydrogenase, pyruvate decarboxylase, transketolase, peroxidase, catalase, phosphogluconate dehydrogenase and 14-3-3 protein. These proteins give C. pallescens its allergenic potential in humans. They have also been reported as allergens of other fungal species, and of species outside the kingdom Fungi.
Infection and disease
Curvularia pallescens has been reported to cause subcutaneous, pulmonary, and cerebral lesions, in immunocompetent individuals. It is thought that lesions arise as the result of inhalation of soils containing C. pallescens. The human pathogenic potential of C. pallescens stems from its viability and functionality at the normal human body temperature (37 °C), and its ability to disseminate. In addition to human infection, there have been multiple reported cases of leaf spots caused by C. pallescens, in crops. In particular, infections have occurred in bamboos (such as Bambusa vulgaris, Dendrocalamus longispathus and Thyrsostachys oliveri), sugarcanes, and grasses (such as Imperata arundinacea and Eleusine coracana). The severity of disease and the appearance of the spots differ between species. In B. vulgaris, the leaf spots appear circular or irregular in shape with a greyish-black centre and yellow perimeter. In sugarcane, the leaf spots appear elliptical in shape and light brown in colour. In I. arundinacea and E. coracana, the leaf spots appear irregular in shape and brown to black in colour. Curvularia pallescens invades the host organism via the stomata or proceeding damage. Infection arises as the result of the propagation of hyphae within the host, causing the host cell to rupture. This results in the spotty appearance on the leaf. Over time, the spots combine to form necrotic zones at the leaf tips causing dehydration in those areas. The leaf spots can be controlled by fungicide sprays, such as Mancozeb (0.1%). In addition to leaf spots, infection can result in: the hindrance of germination, inhibited growth of seedlings and mature crops of lesser quality (e.g., fewer grains produced, and the grains that are produced are damaged).
References
Pleosporaceae
Fungi described in 1933
Taxa named by Karel Bernard Boedijn
Fungus species | Curvularia pallescens | [
"Biology"
] | 1,509 | [
"Fungi",
"Fungus species"
] |
58,471,517 | https://en.wikipedia.org/wiki/Mariannaea%20elegans | Mariannaea elegans an anamorphic fungus (i.e., it reproduces exclusively asexually). It is mainly found on rotting wood and soil. M. elegans is not pathogenic to humans, animals, or plants.
History and taxonomy
Czech mycologist August Carl Joseph Corda named this species Penicillium elegans in 1838. This species was transferred to the genus Paecilomyces in 1951. Later, in 1952, French mycologist, Gabriel Arnaud named the species Mariannaea elegans although he failed to provide a Latin description, which was a requirement for valid publication at the time. Arnaud noted that the genus Mariannaea shared many characteristics with genus Paecilomyces but was distinguished by the divergent nature of the conidial chains of Mariannaea. This conclusion was supported by Dutch mycologist, Robert Archibald Samson, who in 1974 validated the names of the genus and species by providing Latin diagnoses. The genus Mariannaea currently consists of eight species. Two varieties of M. elegans exist: M. elegans var. elegans and M. elegans var. punicea.
Growth and morphology
Mariannaea elegans is an anamorphic fungus (i.e., it reproduces asexually). When M. elegans is grown on a Petri dish in 2% MEA (Malt Extract Agar; medium used in a Petri dish) and PDA (potato-dextrose agar) at the growth and morphological characteristics listed below are observed. The colonies of M. elegans grows better in MEA than in PDA. On average colonies of M. elegans can be observed with the naked eye having a diameter of 2.5–6 cm after 10 days of growth. They appear thin and velvety (i.e. smooth) or floccose (i.e. woolly) or matted (i.e. powdery) and are odourless. Sometimes the colonies make a ring shaped pattern as might be seen on a jawbreaker candy. Specimens isolated from wood possess brown colonies whose brown pigment fuses into the surrounding agar. However, specimens isolated from soil possess reddish-purple colonies whose pigmentation does not diffuse in to the agar surrounding the colonies of M. elegans. Colonies are white to cinnamon buff (peanut butter colour) and possess either smooth or rough walls. The mycelium is either smooth-walled or rough-walled, white to olivaceous (the green colour of the mould on blue cheese) or pink.
Conidiophores are arise from mycelia immersed in the agar. They are light brown, with a smooth or verrucose (i.e., bumpy) surface and grow to a maximum of 1000 μm long and reach a maximum of 10 μm in width at the base. Conidiophores can also arise from aerial hyphae. These conidiophores grow to 250 μm in length and 7 μm in width. Additionally, they can grow to reach a maximum of 1400 μm in length and 23 μm in width at their base. The tops narrow to 3-4 μm. Alternatively, conidiophores can grow laterally from ascending mycelium (i.e., the mycelium is not immersed in the agar) or hyphal ropes. On average these conidiophores are smaller than the ones that grow from hypha immersed in agar. They are smooth-walled or rough-walled, hyaline to pale yellowish. Bearing up to 4 diverging branches that are 9-22 μm long and 3-5 μm wide. They may bear secondary branches. Phialides are observed at the apex of the conidiophores and their branches. They are hyaline in colour and possesses a smooth surface and ellipsoidal (i.e. shaped like a football) to fusiform (i.e. spindle) in shape. They are 8-22 x 2.2-3.5 μm in width and they gradually become thinner reaching 0.8-1.4 μm in width at their apex. Growing obliquely form the apex of a phialide are long chains of conidia (singular conidium). Like phialides, they have a smooth surface and are ellipsoidal to fusiform in shape. Their apex is sharply pointed and round at the base, on average 5.3 x 2.7 μm and reaches a maximum of 9.0 x 4.0 μm in width.
The two varieties of Mariannaea elegans, M. elegans var. elegans and M. elegans var. punicea, are highly morphologically similar. Colonies of M. elegans var. elegans grow more slowly than those of M. elegans var. punicea. Colonies of the former also tend to develop a brownish colour and ringed pattern whereas those of the latter tend to develop a reddish-purple pigmentation and lacking a ringed pattern. M. elegans var. elegans is most commonly isolated from rotting wood whereas M. elegans var. punicea is only known from soil. The genus Mariannaea is closely related to Clonastachys and Gliocladium. They differ from Mariannaea because their conidiophores are clustered tightly together. M. elegans is often misidentified as a member of the genus Paecilomyces because of its morphological similarity. However, the phialides of Mariannaea are flask shaped (thick at the base gradually narrow towards the apex, in cross-section like a canoe paddle) whereas those of Paecilomyces tend to be shorter and stouter (in cross-section like a tennis racquet).
Physiology
This fungus is not known to be a pathogen of humans, animals, or plants. A study carried out in 2007 revealed anti-M. elegans cutaneous bacterial communities that live on the skin of amphibians. The presence of these bacteria inhibits the growth of M. elegans on amphibians. The species grows optimally at a pH of 7.0; however, it tolerates a pH range of 5.5-8.0. The sporulation phase of M. elegans is sensitive to pH. It sporulates best at a pH range of 6.0-6.5 and below a pH of 5.0 sporulation is reduced. The optimal temperature that it grows in is . However, trances of M. elegans can be founds thriving at . M. elegans produces amylase, beta-glucosidase, cellulase, and protease. It is able to degrade cellulose. When M. elegans is grown in vitro in the presence of different sugars (e.g., glucose, galactose, sucrose, mannose, fructose, and lactose) at for 2 days in PDA distinct cell morphology is observed. Growth in 2% of glucose, galactose, or sucrose leads to the formation of many small fungal cells. Whereas the opposite is observed in 2% of mannose, fructose, or lactose, which lead to the formation of a few large fungal cells. Sugar appears to be an important factor in the growth of M.elegans because in the absence of sugar it experiences a delay in growth.
Habitat and ecology
Mariannaea elegans grows on decaying coniferous bark or wood, forest soil, house dust, prairie and grassland soils, calcareous soil, running water that has little pollution, waste stabilization ponds, acid mine drainage stream, fields treated with digested sewage sludge, in arable soils, and on pine chips.
Mariannaea elegans has been isolated from various regions in Canada: Quebec, Ontario, Manitoba, Saskatchewan, and British Columbia. Both varieties have both been recorded in Germany, the Netherlands, the United States, and Canada. However, only M. elegans var. elegans has also be found in France, the British Isles, Italy, Poland, and South Africa, whereas, M. elegans var. punicea has exclusively be found in Democratic Republic of the Congo.
The ecological role of this species is not well known. It is involved in wood biodeterioration either through the formation of soft rot cavities or through cell wall erosion. It may also influence the growth of other fungi. For example, at it inhibits mycelial growth in the mushroom, Pholiota microspora; but at it enhances mycelial growth of P. microspora. It is capable of preventing sapstain (a blue to greyish-black colour) formation on wood treated with M. elegans. This is important in the lumber industry because discoloured wood is less versatile and can not be used for some applications. M. elegans has potential implication in humans. A study carried out in 2001 concluded that mariannaeaprone, a fungal metabolite made by M. elegans induces the aggregation of human platelet cells. M. elegans may also be consumed by amoebae.
References
Nectriaceae
Fungi described in 1838
Fungus species
Taxa named by August Carl Joseph Corda | Mariannaea elegans | [
"Biology"
] | 1,979 | [
"Fungi",
"Fungus species"
] |
58,471,769 | https://en.wikipedia.org/wiki/Exophiala%20pisciphila | Exophiala pisciphila is a mesophilic black yeast and member of the dark septate endophytes. This saprotrophic fungus is found commonly in marine and soil environments. It is abundant in harsh environments like soil contaminated with heavy metals. E. pisciphila forms symbiotic relationships with various plants by colonizing on roots, conferring resistance to drought and heavy metal stress. It is an opportunistic pathogen that commonly causes infections in captive fish and amphibians, while rarely causing disease in humans. Secondary metabolites produced by this species have potential clinical antibiotic and antiretroviral applications.
History and taxonomy
In 1969, Nikola Fijan first described a systemic mycosis outbreak in channel catfish from a pond in Alabama and identified it as Exophiala salmonis. In 1974, Michael McGinnis and Libero Ajello reevaluated the fungus and identified it as a new species Exophiala pisciphila. The specific epithet pisciphila is a linguistic barbarism, combining the Latin word piscis meaning "fish" with the Greek suffix -philos (φίλος) meaning "loving".
Habitat and ecology
Exophiala pisciphila is commonly found in soil, plants and water in North America, Netherlands, United Kingdom, and Australia. E. pisciphila occurs as a colonist or pathogen in cold-blooded vertebrates such as various commercially cultivated fish and amphibians. It has low host specificity. Captive fish are especially susceptible due to the confined space of aquariums and accumulation of fungal particles. Decorative pieces, stones or contaminated food in aquariums can all be reservoirs of E. pisciphila. This fungus has a high tolerance to certain metals ions and has been encountered in harsh environments such as heavy metal polluted soils. When this fungus colonizes plant roots, it enhances plant tolerance to heavy metal ions. Symbiotic relationships with host plants also allow for improved growth performance and plant survival rate in drought conditions.
Growth and morphology
Exophiala pisciphila is an exclusively asexual fungus that exhibits both filamentous and yeast-like growth. Due to its variable growth forms and the dark pigmentation of its cell walls, it is considered a member of the descriptive grouping of similar fungi known as the black yeasts. E. pisciphila forms slow growing colonies approximately in size which is similar to other species in the genus, E. salmonis and E. brunnea. The texture of the colony is dry and fluffy due to the formation on aerial hyphae in mature colonies. The upper surface is grey to green black in colour while the reverse surface tends to be black.
Growth occurs on various media including malt extract agar (MA), oatmeal agar (OA), Sabourand's dextrose agar (SA), corn meal agar (CMA), Czapeck's solution agar, potato dextrose agar (PDA) and nutrient agar (NA). Optimal growth occurs on PDA and MA with the most aerial hyphae forming dome shaped colonies. Media interpreted to be associated with less optimal growth result in the formation of flat colonies. A distinguishing feature of this fungus from others in the genus is its ability to grow on L-arabinitol.
Ideal growth conditions for E. pisciphila occur between , where maximum growth occurs at . This differentiates it from E. jeanselmei which has similar physiology otherwise.
Reproduction for this species occurs asexually by conidiation which was observed to occur through various means in developing colonies. The conidia are produced either by (1) pre-existing conidia, (2) mature hyphae or (3) the differentiation of the cell into a specialized conidium-producing cell called an annellide. E. pisciphila have smooth-walled conidia with yellow-brown walls that characteristically differentiate into annelides. Annelides are bottle-shaped cells that give rise to conidia from a point at the tip of the bottle-neck, as it were. In this way, annelides are similar to phialides but differ in that their necks incrementally elongate as each successive conidium is borne. The cell walls of this species contain the brown pigment melanin which is both a pathogenicity factor and a mechanism of enhancing cell survival during periods of stress. The developing colonies also produce aerial hyphae that appear as hyphal strands that intertwine in a rope-like fashion. The formation of aerial hyphae has been suggested as a means of enhancing survival during harsh growth conditions. E. salmonis has single-celled conidia that are smaller than those of the otherwise morphologically the similar species, E. brunnea.
Pathology
Unlike closely related species such as E. jeanselmei and E. dermatitidis, E. pisciphila rarely causes disease in humans primarily due to its inability to tolerate human body temperature. One case of human disease was reported in Brazil where a person undergoing immunosuppressive therapy for a liver transplant developed a skin infection. The infection did not disseminate and resolved with therapy within a month. Uncontrolled asthmatics may manifest hypersensitivity to E. pisciphila antigens. This fungus is pathogenic to an array of aquatic animals most notably freshwater and seawater fish in which infection is associated with the development of skin lesions and nodules on visceral organs. It can cause deadly infections in Atlantic salmon where the hyphae invade the brain causing chronic inflammation. These infections are associated with abnormal swimming behaviours, depression and darkening of skin. Non-salmonid fish such as smooth dogfish, channel catfish, American sole, Cardinal tetra, cod, triggerfish, Japanese flounder, King George whiting, American plaice are also susceptible. Systemic, lethal infections have been described in captive sharks including the zebra, bonnethead and hammerhead sharks. Infections of sharks, rays and skates are typically associated with severe tissue damage especially necrosis of the spleen and gills. Other cold-blooded animals such as turtles, crabs, sea horses and frogs can be affected. E. pisciphila has been implicated as a minor egg pathogen due to its ability to infect a small number of nematode larvae. Isolates have been identified from tongue ulcers of various terrestrial animals such as horses and dogs.
Uses
E. pisciphila produces Exophilin A, a secondary metabolite identified as a new antibiotic against Gram-positive bacteria. Another secondary metabolite produced by this species is a newly discovered polyketide compound 1-(3,5-dihydroxyphenyl)-4-hydroxypentan-2-one which may have antimicrobial activity. A novel fungal metabolite, Exophilic acid, has been isolated which acts as an inhibitor of HIV-1 integrase, an enzyme critical for replication and spread of HIV virus. This demonstrates its potential to be used for antiretroviral therapy.
References
Eurotiomycetes
Fungi described in 1974
Fungus species | Exophiala pisciphila | [
"Biology"
] | 1,506 | [
"Fungi",
"Fungus species"
] |
58,471,833 | https://en.wikipedia.org/wiki/Chaetomium%20elatum | Chaetomium elatum is a very common and widely distributed saprotrophic fungus of the Chaetomiaceae family of molds which has been found to grow on many different substances all over the world. It was first established by Gustav Kunze after he observed it growing on dead leaves. Its defining features that distinguish it from other Chaetomium species are its extremely coarse terminal hairs and the lemon-shaped morphology of its ascospores. It produces many metabolites with potential biotechnology uses including one with promise against the rice blast disease fungus, Magnaporthe grisea. It shows very little pathogenic ability causing confirmed disease in only a few plant species.
History and taxonomy
Gustav Kunze established the genus Chaetomium in 1817 after discovering a new species of fungus in dead stalks and leaves which he named C. globosum. In 1818, when observing the dead leaves of Typha and Sparganium in Germany, Kunze recognized a new fungus that looked like C. globosum but was darker in pigmentation, and after characterizing it named it Ch. elatum. In addition to Kunze's identification and characterization of the species (in which he failed to discern asci), Robert Greville created illustrations in 1826 to show the morphology of the species. Despite this, C. elatum has been confused by other mycologists many times and thus has been re-described more than any other Chaetomium species, leading to many obligate synonyms. It was during the creation of one of these synonyms, C. lageniforme, by August Corda in 1837 that asci were first recognized, thus identifying the defining feature that placed this fungus in the fungal division, Ascomycota.
Growth and morphology
Chaetomium elatum produces darkly-coloured oval perithecia covered with stiff, black hairs. The perithecia are typically attached firmly to the substratum by dark/black rhizoids. In laboratory colonies C. elatum generally grows 5–6 mm per day, but can show different growth rates and colour characteristics depending on the growth medium. Under certain growth conditions, colonies of some strains of C. elatum may develop coloured guttation droplets of liquid on their surfaces whose function and composition are unknown. C. elatum has a homothallic mating system.
The perithecia are superficial, usually mature in 13 to 20 days, and are 280–440 μm high with a diameter of 255–380 μm. They may appear greenish in color under reflected light with a round/oval-like shape and have an ostiole that is sparsely covered in white/buff aerial hyphae. The perithecial wall is made of brown interwoven hyphae or tightly packed pseudoparenchyma. Morphology of the black/dark perithecium hairs varies depending on their location. Terminal hairs are extremely coarse, branched at right to straight angles, have irregular projections, blunt spines, and dwindle off to thin translucent tips. Lateral hairs are thin, long, unbranched, coarsely roughened by irregular projections and dwindle into translucent smooth tips that are vaguely separate. The difference between the terminal hair of C. elatum and C. globosum is a distinguishing factor between the two taxa.
The asci of C. elatum are generally club-shaped and contain 8 round ascospores. The ascospores are translucent/light olive when young and become brown with pointed tips when they mature giving them lemon-like shape when viewed in profile. The ascospores also have a thick wall with a small pore on the outer wall of their apex. Morphology of the ascospores is a distinguishing factor when compared to other Chaetomium species with which it might be confused like C. indicum, C. funicolum, and C. virgecephalum.
The asexual morph of C. elatum has acremonium-like growth, with its conidia being borne on phialidic conidiophogeous cells that form on aerial aseptate hyphae and are 6–24.5 μm long with a diameter of 1.5–3.5 μm at the base. Conidium dimensions are 2.5–5.5 μm × 1.5–2.5 μm and they form towards the base of the conidiophore in chains, are translucent, smooth, and oval-shaped with a rounded apex and short base.
rhizo
Habitat and ecology
Chaetomium elatum is a very common and widely distributed species of Chaetomium, with it being found all over the world. The species has been found in many areas of the United States, Canada, England, France, Russia, Switzerland, Germany, Scotland, the Galapagos Islands and many other localities.
It is the most common species of fungi that grows on damp rotting straw, but has also been found and isolated from a variety of materials like rope, burlap, wood, paper, cellulose products, animal dung, seeds, barrel hoops, old brooms, Hordeum vulgare L, Triticum aestivum and the dead leaves of Typha and Sparganium. In general this species of Chaetomium mainly colonizes cereal, Alkali seepweed, True grasses, has been found to interact with Japanese yew, Alkali seepweed, European rabbit, Bread wheat, True grasses, Corn. It has also been associated with the mycobiota of Sugarcane as well as is known as a root-colonizing fungus in the avocado plant where it serves as both a rhizoplane and rhizosphere.
Biotechnology uses
Chaetomium elatum has been isolated from different materials and its metabolic properties with potential biotechnology uses have been explored. In the presence of nitrocellulose (a very important cellulose derivative).C. elatum can break down nitrocellulose in liquid culture. Investigations into the types of metabolites produced by this fungus have found that it produces benzoquinone derivatives, tetra-S-methyl derivatives, anthraquinone-chromanone, orsellinic acid, globosumones, sterols Chaetoglobsins, Cochliodones 1–3 (azaphilone derivatives), azaphilones, chlorinated phenolic glycosides, and xanthoquinodins. Xanthoquinodins are fungal metabolites that have been found to have antibacterial, antifungal, anticoccidial, antiplasmodial, and cytotoxic activities. Azaphilones have antimicrobial, antifungal, antiviral, antioxidant, cytotoxic, nematicidal and anti-inflammatory properties, and the three metabolized by C. elatum have also been found to inhibit Caspase 3 which is involved in cell death. Phenolic compounds have shown to possess antimicrobial properties. Chaetoglobosins has been found to have anticancer activity, and benzoquinone derivatives have antibacterial properties. Nnanoparticles harvested from crude extracts of the C. elatum exhibit antimicrobial activity against Magnaporthe grisea, the plant pathogen that causes rice blast disease.
Plant pathogenicity
Chaetomium elatum is a known pathogen of the common grape vine. In 2007, an investigation to determine its pathogenicity on avocado plants found that it opportunistically colonizes the plant roots and only becomes pathogenic when resources are very limited and intraspecific competition is high.
References
elatum
Fungi described in 1818
Fungus species | Chaetomium elatum | [
"Biology"
] | 1,631 | [
"Fungi",
"Fungus species"
] |
58,472,484 | https://en.wikipedia.org/wiki/Collariella%20bostrychodes | Collariella bostrychodes is a fungal decomposer of lignin and carbohydrate in the family Chaetomiaceae commonly found in soil and dung. The fungus is distinguished by a darkened collar-like ostiole around the ostiolar pore, giving the fungus its name. The fungus is highly variable in shape and form, giving raise to the belief that there are two subclades in the species. The ascospores range from lemon-shaped to nearly spherical with slightly pointed ends. It can grow to be pale green and later turn pale bluish grey or olivaceous with age. The fungus produces the toxic secondary metabolite, chaetochromin.
History and taxonomy
In 1877, the fungus was originally described by Friedrich Wilhelm Zopf in the Verhandlungen des Botanischen Vereins der Provinz Brandenburg for the Botanischer Verein der Provinz Brandenburg. He described the fungus as part of the genus Chaetomium and initially being named as Chaetomium bostrychodes. C. bostrychodes was originally described to have ellipsoid ascomata by Pier Andrea Saccardo in 1882, but later in 1963, Ames re-examined and described the species to have subglobose to ovoid ascomata instead. The fungus was noted as being unable to produce functional antheridia, which suggested it wasn't part of the heterothallic species of Chaetomium. The fungus was described as unique in the genus Chaetomium for possessing banded spores that are characteristic of no species of Chaetomium described in 1937.
The fungus was believed to have two subclades designated C. bostrychodes and C. bostrychodes (A), which were considered to be macroscopically indistinguishable but closely related enough to each other that both subclades were kept as the same species. The two subclades were previously suggested both to be either aberrant physiological or nearly related forms. Using phylogenetic analyses, combined with morphological comparisons to related genera and species, Wang and Samson determined C. bostrychodes to have morphological diversity specific to indoor Chaetomiaceae that required creating a new genus. The genus, Collariella, was created to include for this diversity, its name refers to the dark collar-like apex that occurs around the ostiolar pore of the ascomata. C. bostrychodes was then transferred to the new genus and renamed Collariella bostrychodes, with the two subclades then grouped together and placed under this name.
Morphology and phylogeny
Colonies of C. bostrychodes can grow 2.5 to 3.5 mm daily, usually without developing aerial mycelium. It can sometimes grow with pale green exudates and a green or uncoloured reverse. When young, C. bostrychodes appears as colourless and dextrinoid, but upon maturity, turns pale bluish grey or olivaceous with an apical germ pore . C. bostrychodes often are darkened around the 25 to 35 μm wide ostiolar pore, giving the genus its name of Collariella. Chaetomium convolutum can have a disposition to develop into some forms of C. bostrychodes, developing narrowly ellipsoidal or narrowly ovoidal perithecia restricted just below the darkened periostiolar collar. Similarly, C. bostrychodes appears similar morphologically to Collariella hilkhuijsenii, but C. bostrychodes can be distinguished via their larger ascospores and thicker terminal ascomatal hairs compared to those of C. hilkhuijsenii. The ascomatal walls are brown or ochraceous and composed of angular 5 to 12 μm cells. These tend to fracture underneath the terminal hairs, which then break away as a unit. Brown ascomatal hairs grow mainly from the apical disc, usually appearing as helically coiled in the apical region with little branching. The hairs are either verrucose or warty, which are about 4.5 to 6.5 μm thick with occasionally coiled branches. Lateral seta-like hairs are often also present and have tapered or clavate terminal ends with septate. These hairs break away at maturity with no aerial mycelium. C. bostrychodes develops perithecia late and possesses tightly coiled black terminal setae. The terminal hairs are branched, forming one spiral on another. The ascospores are considerably larger on average than those of C. robustum.
The asci are often surrounded by paraphyses-like, broad, evanescent filaments with a long, evanescent stalk that is 8 spored and 11 to 14 μm wide. The ascomata matures in 10 to 17 days, taking on a silvery appearance when young but then turns dark grey to black when mature. The apically flattened ascomata can be obovate, turbinate, ampulliform or cylindrical with its width ranging from 140 to 250 μm wide and ranging from 200 to 400 μm high. The fungus is recorded having touter, subglobose or ovoidal, ascomata but it is also recorded having slender, narrowly ellipsoid ascomata with 1 to 2 rows of textura prismatica. The breakdown of asci begins within the perithecia, and ascospores are later ejected in a slime consisting of the freed ascospores. The filaments grow upward and inward to exert pressure against each other to create a central cavity which asci push their way up. The asci deliquesce and then oozes out of the perithecial neck and are not violently discharged. C. bostrychodes fruits in the spring and early summer.
The two subclades are divided by phylogenetic and morphological evidence, but high statistical support was found to suggest they share a recent common ancestor and are closely related. The two subclades differ in setae, variability in length and color of terminal hairs, variety in ascospores' shape, with extreme variability between the two in the species. C. bostrychodes can vary in shape, such as possessing mostly ellipsoidal or broadly ellipsoid perithecia. However, both subclades have a specific banding of the spores that appears which is characteristic of C. bostrychodes only. There are differences on what the two subclades will reproduce on, with C. bostrychodes (A) being able to reproduce on asparagin and alcohol-glucose cultures, whereas C. bostrychodes can reproduce on blood fibrin, starch, phenol red, eosin methylene blue, and dextrine-FeClh instead. In C. bostrychodes (A), anastomoses of the terminal hairs are common, but not found in C. bostrychodes.
Habitat and ecology
Collariella bostrychodes is considered a lignin, lignocellose, and carbohydrate decomposer but shows a significant preference for lignin, with a high frequency of occurrence in the fermentation layers of the forest. It can be isolated from soil, dung, decaying stems, roots, and seeds, but very rarely in woody materials. It has been isolated and found to be saprobic both in and on dung or excretions of dung of Oryctolagus cuniculu. C. bostrychodes is not limited to forest ecosystems. While not a marine fungi, it has been isolated in the ocean and sediments in the marine muds, which suggests that the fungus can be wind-carried. C. bostrychodes has been rarely isolated from food products, but it has been isolated in contaminated oat grains, okra, pea seeds and pepper. When C. bostrychodes is found in food products, it is typically a result of simple contamination.
Health significance
A toxic pigment, chaetochromin, has now been proven to be widely associated with Chaetomium fungi., including C. bostrychodes. Oral and intraperitoneal administration of chaetochromin to mice may result in pronounced toxicity, which can lead to potential detrimental effects like selective inhibition of haematopoiesis. C. bostrychodes has been isolated from industrially polluted soils of the Kola Peninsula in ecosystems, specifically in ground cover and in areas of pine forests that have associations of moss shrubs and lichens shrubs, it believed to potentially cause diseases like Onychomycosis, skin infections, and peritonitis. However, such cases are rare and therefore not well studied.
References
Sordariales
Fungi described in 1877
Fungus species | Collariella bostrychodes | [
"Biology"
] | 1,876 | [
"Fungi",
"Fungus species"
] |
58,472,531 | https://en.wikipedia.org/wiki/Maximum-entropy%20random%20graph%20model | Maximum-entropy random graph models are random graph models used to study complex networks subject to the principle of maximum entropy under a set of structural constraints, which may be global, distributional, or local.
Overview
Any random graph model (at a fixed set of parameter values) results in a probability distribution on graphs, and those that are maximum entropy within the considered class of distributions have the special property of being maximally unbiased null models for network inference (e.g. biological network inference). Each model defines a family of probability distributions on the set of graphs of size (for each for some finite ), parameterized by a collection of constraints on observables defined for each graph (such as fixed expected average degree, degree distribution of a particular form, or specific degree sequence), enforced in the graph distribution alongside entropy maximization by the method of Lagrange multipliers. Note that in this context "maximum entropy" refers not to the entropy of a single graph, but rather the entropy of the whole probabilistic ensemble of random graphs.
Several commonly studied random network models are in fact maximum entropy, for example the ER graphs and (which each have one global constraint on the number of edges), as well as the configuration model (CM). and soft configuration model (SCM) (which each have local constraints, one for each nodewise degree-value). In the two pairs of models mentioned above, an important distinction is in whether the constraint is sharp (i.e. satisfied by every element of the set of size- graphs with nonzero probability in the ensemble), or soft (i.e. satisfied on average across the whole ensemble). The former (sharp) case corresponds to a microcanonical ensemble, the condition of maximum entropy yielding all graphs satisfying as equiprobable; the latter (soft) case is canonical, producing an exponential random graph model (ERGM).
Canonical ensemble of graphs (general framework)
Suppose we are building a random graph model consisting of a probability distribution on the set of simple graphs with vertices. The Gibbs entropy of this ensemble will be given by
We would like the ensemble-averaged values of observables (such as average degree, average clustering, or average shortest path length) to be tunable, so we impose "soft" constraints on the graph distribution:
where label the constraints. Application of the method of Lagrange multipliers to determine the distribution that maximizes while satisfying , and the normalization condition results in the following:
where is a normalizing constant (the partition function) and are parameters (Lagrange multipliers) coupled to the correspondingly indexed graph observables, which may be tuned to yield graph samples with desired values of those properties, on average; the result is an exponential family and canonical ensemble; specifically yielding an ERGM.
The Erdős–Rényi model
In the canonical framework above, constraints were imposed on ensemble-averaged quantities . Although these properties will on average take on values specifiable by appropriate setting of , each specific instance may have , which may be undesirable. Instead, we may impose a much stricter condition: every graph with nonzero probability must satisfy exactly. Under these "sharp" constraints, the maximum-entropy distribution is determined. We exemplify this with the Erdős–Rényi model .
The sharp constraint in is that of a fixed number of edges , that is , for all graphs drawn from the ensemble (instantiated with a probability denoted ). This restricts the sample space from (all graphs on vertices) to the subset . This is in direct analogy to the microcanonical ensemble in classical statistical mechanics, wherein the system is restricted to a thin manifold in the phase space of all states of a particular energy value.
Upon restricting our sample space to , we have no external constraints (besides normalization) to satisfy, and thus we'll select to maximize without making use of Lagrange multipliers. It is well known that the entropy-maximizing distribution in the absence of external constraints is the uniform distribution over the sample space (see maximum entropy probability distribution), from which we obtain:
where the last expression in terms of binomial coefficients is the number of ways to place edges among possible edges, and thus is the cardinality of .
Generalizations
A variety of maximum-entropy ensembles have been studied on generalizations of simple graphs. These include, for example, ensembles of simplicial complexes, and weighted random graphs with a given expected degree sequence
See also
Principle of maximum entropy
Maximum entropy probability distribution
Method of Lagrange multipliers
Null model
Random graph
Exponential random graph model
Canonical ensemble
Microcanonical ensemble
References
Random graphs | Maximum-entropy random graph model | [
"Mathematics"
] | 962 | [
"Mathematical relations",
"Graph theory",
"Random graphs"
] |
58,472,618 | https://en.wikipedia.org/wiki/Jiugong%20Tunnel | The Jiugong Tunnel () or Siwei Tunnel () is a tunnel in Lieyu Township, Kinmen County, Taiwan. It was used during the 1958 Second Taiwan Strait Crisis, when the island was heavily shelled by People's Republic of China. Supplies and equipment from larger ocean going ships were brought in to shore by smaller vessels. They were unloaded in the tunnel safe from the bombardments.
Geology
The tunnel is located on a coastal area at the southeast of Lieyu Island. It is located in a reef of granite mountain.
Architecture
The tunnel was constructed in a twin T-shape with four exits. It spans over a length of 790 meters and a height of 11.5 meters.
See also
List of tourist attractions in Taiwan
References
Lieyu Township
Military history of Taiwan
Tunnels in Kinmen County
Tunnel warfare | Jiugong Tunnel | [
"Engineering"
] | 168 | [
"Military engineering",
"Tunnel warfare"
] |
58,472,849 | https://en.wikipedia.org/wiki/Curve%20of%20growth | In astronomy, the curve of growth describes the equivalent width of a spectral line as a function of the column density of the material from which the spectral line is observed.
Shape
The curve of growth describes the dependence of the equivalent width , which is an effective measure of the strength of a feature in a emission or absorption spectrum, on the column density .
Because the spectrum of a single spectral line has a characteristic shape, being broadened by various processes from a pure line, by increasing the optical depth of a medium that either absorbs or emits light, the strength of the feature develops non-trivially.
In the case of the combined natural line width, collisional broadening and thermal Doppler broadening, the spectrum can be described by a Voigt profile and the curve of growth exhibits the approximate dependencies depicted on the right.
For low optical depth corresponding to low , increasing the thickness of the medium leads to a linear increase of absorption and the equivalent line width grows linearly . Once the central Gaussian part of the profile saturates, and the Gaussian tails will lead to a less effective growth of . Eventually, the growth will be dominated by the Lorentzian tails of the profile, which decays as , producing a dependence of .
References
Spectroscopy | Curve of growth | [
"Physics",
"Chemistry",
"Astronomy"
] | 259 | [
"Molecular physics",
"Spectrum (physical sciences)",
"Instrumental analysis",
"Astronomy stubs",
"Spectroscopy"
] |
58,472,865 | https://en.wikipedia.org/wiki/Phosphaethynolate | The phosphaethynolate anion, also referred to as PCO, is the phosphorus-containing analogue of the cyanate anion with the chemical formula or . The anion has a linear geometry and is commonly isolated as a salt. When used as a ligand, the phosphaethynolate anion is ambidentate in nature meaning it forms complexes by coordinating via either the phosphorus or oxygen atoms. This versatile character of the anion has allowed it to be incorporated into many transition metal and actinide complexes but now the focus of the research around phosphaethynolate has turned to utilising the anion as a synthetic building block to organophosphanes.
Synthesis
The first reported synthesis and characterisation of phosphaethynolate came from Becker et al. in 1992. They were able to isolate the anion as a lithium salt (in 87% yield) by reacting lithium bis(trimethylsilyl)phosphide with dimethyl carbonate . The x-ray crystallographic analysis of the anion determined the bond length to be (indicative of a phosphorus-carbon triple bond) and the bond length to be . Similar studies were performed on derivatives of this structure and the results indicated that dimerisation to form a four-membered Li ring is favoured by this molecule.
Ten years later, in 2002, Westerhausen et al. published the use of Becker's method to make a family of alkaline earth metal salts of PCO ; this work involved the synthesis of the magnesium, calcium, strontium and barium bis-phosphaethynolates. Like the salts previously reported by Becker, the alkali-earth metal analogues were unstable to moisture and air and thus were required to be stored at low temperatures (around ) in dimethoxyethane solutions.
It was not until 2011 that the first stable salt of the phosphaethynolate anion was reported by Grutzmacher and co-workers . They managed to isolate the compound as a brown solid in 28% yield. The structure of the stable sodium salt, formed by carbonylation of sodium phosphide, contains bridging PCO units in contrast to the terminal anions found in the previously reported structures. The authors noted that this sodium salt could be handled in air as well as water without major decomposition; this emphasises the significance of the accompanying counter cation in stabilisation of PCO.
Direct carbonylation was a method also employed by Goicoechea in 2013 in order to synthesis a phosphaethynolate anion stabilised by a potassium cation sequestered in 18-crown-6 . This method required the carbonylation of solutions of at and produced by-products that were readily separated during aqueous work ups. The use of aqueous work ups reflects the high stability of the salt in water. This method afforded the PCO anion in reasonable yields around 43%. Characterisation of the compound involved infra-red spectroscopy; the band indicative of the triple bond stretch was observed at .
Ambidentate nature of the anion
The phosphaethynolate anion is the heavier isoelectronic congener of the cyanate anion. It has been shown that it behaves in a similar way to its lighter analogue, as an ambidentate nucleophile. This ambidentate character of the anion means that it is able to bind via both the phosphorus and oxygen atoms depending on the nature of the centre being coordinated.
Computational studies carried out on the anion such as Natural Bond Orbital (NBO) and Natural Resonance Theory (NRT) analyses can go part way to explain why PCO can react in such a manner . The two dominant resonance forms of the phosphaethynolate anion localise negative charge on either the phosphorus or oxygen atoms meaning both are sites of nucleophilicity. The same applies for the cyanate anion hence why PCO is observed to have similar pseudo-halogenic behaviour.
Attack by oxygen
Coordination via the oxygen atom is favoured by hard, highly electropositive centres. This is due to the fact that oxygen is a more electronegative atom and thus prefers to bind via more ionic interactions. Examples of this type of coordination were presented in the work of Arnold et al. from 2015. The group found that actinide complexes of PCO involving uranium and thorium both coordinated through the oxygen. This is the result of the contracted nature of the actinide orbitals which makes the metal centres more 'core-like' thus favouring ionic interactions.
Attack by phosphorus
On the other hand, softer, more polarisable centres prefer to coordinate in a more covalent manner through the phosphorus atom. Examples of this include complexes accommodating a neutral or sparsely charged transition metal centre. The first example of this nature of PCO binding was published by Grutzmacher and co-workers in 2012. The group's studies used a Re(I) complex and the analysis of its bonding parameters and electronic structure showed that the phosphaethynolate anion coordinated in a bent fashion. This suggested the Re(I) – P bond possessed a highly covalent character thus the complex would be best described as a metallaphosphaketene. It wasn't until four years later that a second example of this coordination nature of PCO was identified. This time it came in the form of a W(0) pentacarbonyl complex produced by the Goicoechea group.
Rearrangement of coordination character
There is one particular reaction studied by Grutzmacher et al. that exhibits the rearrangement of coordination character of PCO. Initially when reacting the anion with triorganyl silicon compounds, it binds via the oxygen forming the kinetic oxyphosphaalkyne product. The thermodynamic silyl phosphaketene product is generated when the kinetic product rearranges to allow PCO to coordinate through phosphorus.
The formation of the kinetic product is charged controlled and thus explains why it is formed by oxygen coordination. The oxygen atom favours a larger degree of ionic interactions as a result of its greater electronegativity. Contrastingly, the thermodynamic product of the reaction is generated under orbital control. This comes in the form of phosphorus coordination as the largest contribution in the HOMO of the anion resides on the phosphorus atom; this is clearly visible in Figure 3.
Reactivity of the anion
Extensive studies involving the phosphaethynolate anion have shown that it can react in a variety of ways. It has documented use in cycloadditions, as a phosphorus transfer agent, a synthetic building block and as pseudo halide ligands (as described above).
Phosphorus transfer agents
In these types of reactions, CO is released as the phosphaethynolate anion acts as either a mild nucleophilic source of phosphorus or a Brønsted base. Examples of these types of reactions involving PCO include work conducted by Grutzmacher and Goicoechea.
In 2014, Grutzmacher et al. reported that an imidazolium salt would react with the phosphaethynolate anion to produce a phosphinidine carbene adduct. Computational mechanistic studies were conducted on this reaction using density functional theory at the B3LYP/6-31+G* level. The results of these investigations suggested that the lowest energy and therefore most likely pathway involves PCO acting as a Brønsted base initially deprotonating the acidic imidazolium cation to generate the intermediate phosphaketene, HPCO. The highly unstable protonated PCO remains hydrogen bonded to the newly produced N-heterocylic carbene prior to rearrangement and formation of the observed product. In this case, PCO does not act as a mild nucleophile due to the augmented stability of the starting imidazolium cation.
On the other hand, in the work published by Goicoechea and co-workers in 2015, the phosphaethynolate anion can be seen to act as a source of nucleophilic phosphide (). The anion was seen to add across the double bond of cyclotrisilene thus introducing a phosphorus vertex into its scaffold (after undergoing decarbonylation).
Cycloaddition Reagents
After synthesising the potassium salt of the phosphaethynolate anion in 2013, Goicoechea et al. began to look into the potential of PCO towards cycloadditions. They found that the anion could react in a [2+2] fashion with a diphenyl ketene to produce the first isolatable example of a four-membered monoanionic phosphorus containing heterocycle. They employed the same method to test other unsaturated substrates such as carbodiimides and found that the likelihood of cyclisation heavily relies on the nature of the substituents on the unsaturated substrate.
Cycloaddition reactions involving the phosphaethynolate anion have also been shown by Grutzmacher and co-workers to be a viable synthetic route to other heterocycles. One simple example is the reaction between the NaPCO and an α-pyrone. This reaction yields the sodium phosphinin-2-olate salt which is stable to both air and moisture.
Synthetic building blocks
A large part of the research involving PCO is now looking into utilising the anion as a synthetic building block to derive phosphorus containing analogues of small molecules.
The first major breakthrough in this area came from Goicoechea et al. in 2013; they published the reaction between the PCO anion and ammonium salts which yielded the phosphorus containing analogue of urea in which phosphorus replaces a nitrogen atom. The group predict that this heavier congener could have applications in new materials, anion sensing and coordination chemistry.
Goicoechea and co-workers were also able to isolate the heavily sought after phosphorus containing analogue of isocyanic acid, HPCO, in 2017. This molecule is thought to be a crucial intermediate in a lot of reactions involving PCO (including P-transfer to an imidazolium cation).
Moreover, the most recent addition to this class of small molecules is the phosphorus containing analogue of N,N-dimethylformamide. This work in which the phosphorus again replaces a nitrogen atom was published in 2018 by Stephan and co-workers. Generating acylphosphines in this manner is considered a much milder route than other current strategies that require multi-step syntheses involving toxic, volatile and pyrophoric reagents.
Other analogues
The other analogues of the phosphaethynolate anion all obey the general formulae E-C-X and are made by varying E and X. When changing either atom, unique trends amongst the different analogues become apparent.
Varying E
As 'E' is varied by descending group 15, there is a clear shift in the weights of the resonance structures towards the phosphaketene analogue . This reflects the decrease in effective orbital overlap between E and C which in turn disfavours multiple bond formation. This increasing tendency to form double and not triple E-C bonds is also reflected in calculated E-C bond lengths . The data from Table 1 is evidence of E-C bond elongation which correlates with the change from triple to double bond.
In addition, NBO analysis highlights that the greatest electron delocalisation within the anions stems from the donation of an oxygen lone pair into the E−C π antibonding orbital. The energy value associated with this donation is seen to increase down the group . This explains the increasing resonance weight towards the ketene like isomer as populating antibonding orbitals usually suggests the breaking of a bond.
The shift towards the ketene isomer will also cause an increase in charge density on the elemental 'E' atom; this makes the elemental atom an increasing source of nucleophilicity .
Varying X
The simplest analogue that can be formed as 'X' is varied is . This anion was first isolated by Becker et al. by reacting the phosphaethynolate anion with carbon disulphide. Unlike PCO, PCS shows ambidentate nucleophilic tendencies towards the W(0) complex mentioned above.
This is the result of a reduced difference in electronegativity between E and X thus neither atom offers a substantial advantage over the other in terms of providing ionic contributions to bonding. As a result, the average electron density in PCS is spread over the entire anion whereas in PCO, most electron density is localised on the phosphorus atom as this is the atom which bonds to form the thermodynamically favourable product.
References
Anions
Organophosphorus compounds
Physical organic chemistry
Substances discovered in the 1990s | Phosphaethynolate | [
"Physics",
"Chemistry"
] | 2,720 | [
"Matter",
"Anions",
"Functional groups",
"Organic compounds",
"Organophosphorus compounds",
"Physical organic chemistry",
"Ions"
] |
58,473,010 | https://en.wikipedia.org/wiki/Alternaria%20brassicicola | Alternaria brassicicola is a fungal necrotrophic plant pathogen that causes black spot disease on a wide range of hosts, particularly in the genus of Brassica, including a number of economically important crops such as cabbage, Chinese cabbage, cauliflower, oilseeds, broccoli and canola. Although mainly known as a significant plant pathogen, it also contributes to various respiratory allergic conditions such as asthma and rhinoconjunctivitis. Despite the presence of mating genes, no sexual reproductive stage has been reported for this fungus. In terms of geography, it is most likely to be found in tropical and sub-tropical regions, but also in places with high rain and humidity such as Poland. It has also been found in Taiwan and Israel. Its main mode of propagation is vegetative. The resulting conidia reside in the soil, air and water. These spores are extremely resilient and can overwinter on crop debris and overwintering herbaceous plants.
Growth and morphology
The conidia of A. brassicicola are abundant in the outdoor environment from the months of May to late October in the northern hemisphere, peaking in June and again in October. The conidia are dark brown and smooth-walled, up to 60 x 14μm. The conidia are cylindrical to oblong in shape and are muriform and produced in chains of 8-10 spores. They are firmly attached to conidiophores that are olive-brown, septate, and growing to an upper range of 100-200 μm, although this overall length may vary. Conidia are borne in continuous, chain-like structure, but branching at the base has also been observed. Although conidia can be spread by rain, the most common means of spread is through the air. The fungus grows on epidermal leaf wax of plants, particularly those in the Brassicaceae, and prefers an environment with high humidity and temperature range of . Macroscopically, the mycelium exhibits a range of colour: unpigmented when young, to olive-grey, grey-black at maturity. Colonies of A. brassicicola tend to be dark brown or black in colour.
Research history
Historically, much of the early research concerning the fungus was based on plant defense mechanisms. However, once its genome was sequenced, efforts shifted to identifying the genes involved in host-parasite interaction. One of the pioneers for genetic research into Alternaria brassicicola was the Lawrence group at Virginia Bioinformatics Institute and the Genome Center at Washington University. The most common media used for A. brassicicola growth are PDA (potato dextrose agar) and V8 juice-agar. In vitro and under optimal conditions, colonies grow rapidly and appear dark green or white-grey. Spontaneous sporulation occurs at 25°C in darkness on PDA medium.
Growth cycle
Hours after inoculation:
2h: Conidia swells
3h: Germ tube formation observed at the apical or middle cells of conidia
8h: Vesicle of dissolved contents moves from conidial cell to germ tube
20h: Infection of the host cell
48h: Mycelial network develops on the surface
72h: Many chains of conidia can be seen
Pathogenesis and infection
There are three main sources of infection: nearby infected seeds, spores from plant debris in the topsoil and Brassica weeds, and spores moved by wind and air from farther away. Infected leaves can spread their spores up to a diameter of 1800m. There are also three major entry points to the host cell: epidermal penetration, stomatal penetration and penetration through an insect. Contact with the host cell triggers the release of various cell wall degrading enzymes which allow the fungus to attach itself to the plant and begin degradation. The suggested mode of attack is through host-specific toxins, primarily AB toxins, that induce cell death by apoptosis. This results in what look like dents and lesions in the host plant. These are brown, concentric circles with a yellow tinge at the circumference, usually about 0.5-2.5cm in diameter. Necrosis can generally be observed within 48 hours of infection. The spores can reside on the external seed coat of infected seeds, but the mycelium can also penetrate under the seed coat, where it has the ability to remain viable for several years. Occasionally, it can even penetrate the embryo tissue. The primary mode of transmission is through contaminated seed. Also, the infection is not limited to specific areas of the host plant; it can spread all over and even cause damping off of the seedlings at a relatively early stage. It also affects the host species at various developmental stages. As mentioned above, seedlings exhibit dark stem lesions followed by damping off. Velvety, black spots, resembling soot, can be observed on older plants. Pathogenesis is affected by factors such as: temperature, humidity, pH, reactive oxidation species, host defense molecules.
Genes
Out of the 10,688 predicted genes from the A. brassicicola genome, 139 encode small secretion proteins that may be involved in pathogenesis, 76 encode lipases and 249 encode glycosyl hydrolases that are important for polysaccharide digestion, potentially damaging host cells. In contrast, mutations in genes such as AbHog1, AbNPS2, and AbSlt2 affect cell wall integrity and make the fungus more susceptible to host defenses. Currently, research is being done to identify the gene(s) responsible for encoding a transcription factor, Bdtf1, important for the detoxification of host metabolites.
Biochemistry
The most common toxin studied for A. brassicicola is the AB toxin, said to be connected to the virulence, pathogenicity and host range for the fungus. It is most likely produced during conidial germination and probably linked to the ability of the fungus to infect and colonize Brassica leaves However, recent studies have explored new potential metabolites. For example, this fungus also produces histone deacetylase inhibitors, but these do not have a significant impact on lesion size. Some studies show only a 10% reduction in virulence. Furthermore, alternariol and tenuazonic acid seem to affect mitochondrial-mediated apoptosis pathways and protein synthesis respectively (in the host cell), but again, not to a significant degree. Some cytokines have been linked with the discolouration associated with A. brassicicola infection. Cell wall degrading enzymes like lipases and cutinases are also linked to its pathogenicity, but more evidence of their efficacy is required. One important transcription factor is AbPf2. It regulates 6 of the 139 genes encoding small secretion proteins and may have a role in pathogenesis, specifically cellulose digestion.
Treatments
In order to protect their crops, many individuals pre-treat their seeds with fungicides. The most widespread active ingredients in these fungicides are Iprodione and Strobilurins. In 1995, it was reported that Iprodione most likely acts by mutating two histidine residues in the target site of enzymes. Ultimately, it inhibits germ tube growth. However, the ubiquitous use of fungicides has resulted in the fungus growing increasingly resistant. Thus, different, non-chemical approaches have been explored. People have tried to develop resistant Brassicaceae crops through breeding. However, this has proved challenging due to the difficulty of transferring genes from wild-type to cultivated strains, resulting in genetic bottlenecks. It is further complicated by the probability that resistance seems to be a polygenic trait. There are also some Brassica plants that have developed resistance to the pathogen naturally. High phenolase activity, high leaf sugar, and thicker wax layers reduce water-borne spore germination. It has been shown that the presence of camalexin in the host plant helps it to disrupt pathogen development. For example, an Arabidopsis mutant in the pad-3 gene that does not produce camalexin is more susceptible to infection. Varying levels show differing levels of resistance. Another suggestion put forth is crop debris management. The aim is to minimize exposure of the crop plants to spores present in the soil by using crop rotation and weed control.
Biological approaches have also been studied. One approach has been to use antagonistic fungi such as Aureobasidium pullulans & Epicoccum nigrum to subdue the effect of A. brassicicola. The plants C. fenestratum and Piper betle also show potent fungicidal activity towards A. brassicicola both in vitro and under greenhouse conditions. These levels are comparable to Iprodione. The active compound, berberine, affects cell wall integrity and ergosterol biosynthesis. Ethanol extracts from the dried roots of Solanum nigrum (black nightshade), traditionally used as herbal remedies in places ranging from the Far East to India and Mexico, show promising anti-fungal activity as well. They seem to suppress conidial germination, possibly by interfering with the AB toxin.
Economic impact
As mentioned previously, Alternaria brassicicola causes severe black spot diseases in a number of ecologically important crops. Often, it occurs in conjunction with Alternaria brassicae. However, it is the more dominant invasive species. These infections lead to a significant loss in viable seeds and produce. The resulting lesions greatly reduce available photosynthetic area, leading to wilt and plant death. Crops like infected cabbages do not last long during storage or transportation. In some cases, yield reductions can be as high as 20-50%. The lack of ability to use fungicides makes it challenging to sustain organic crops in a cost-effective way.
References
brassicicola
Fungal plant pathogens and diseases
Eudicot diseases
Fungi described in 1947
Fungus species | Alternaria brassicicola | [
"Biology"
] | 2,045 | [
"Fungi",
"Fungus species"
] |
58,474,050 | https://en.wikipedia.org/wiki/List%20of%20fireworks%20accidents%20and%20incidents%20in%20Sivakasi | Sivakasi is a town in Virudhunagar District in the Indian state of Tamil Nadu. The town is known for its firecracker, matchbox and printing industries. The industries in Sivakasi employ over 250,000 people with an estimated turn over of . The major issues in the fireworks industry in Sivakasi are child labour and frequent accidents.
Background
The economy of Sivakasi is dependent on three major industries: firecrackers, matchbox manufacturing, and printing. The town has 520 registered printing industries, 53 match factories, 32 chemical factories, seven soda factories, four flour mills and two rice and oil mills. The town is the nodal center for firecracker manufacturing at the national level. In 2011, the industry employed over 25,000 people and some of the private enterprises had an annual turnover of . In 2011, the combined estimated turnover of the firecracker, matchbox making and printing industry in the town was around . Approximately 70% of the firecrackers and matches produced in India are from Sivakasi. The hot and dry climate of the town is conducive to the firecracker and matchbox making industries. The raw materials for these industries were procured from Sattur earlier but were discontinued due to the high power and production cost. The source of raw materials is Kerala and Andaman. The paper for the printing industry is procured from various states. The town is a major producer of diaries, contributing to 30% of the total diaries produced in India. Printing industry in the town was initially utilized for printing labels for the firecrackers and later evolved with modern machinery to grow as a printing hub. In 2012, all the industries suffered 15–20% production loss due to power shortage and escalating labor cost.
The major issues in the fireworks industry in Sivakasi is child labour and frequent accidents. In a blast in 1991 in a factory, 39 people were killed and 65 others were injured.
In July 2009, more than 40 people were killed in a fire accident in a firecracker unit. The police traced out unregistered units and irregularities that led to the accident. In a fire accident in August 2011, seven people were killed and five were seriously injured. A similar fire accident and blast in a private unit in September 2012 killed 40 people and injured 38 others. The common reasons cited for the accidents are inadequate training of workers and supervisors involved in different stages of production and marketing of firecracker items. Other reasons are found to be overstocking of explosives, raw material and finished goods, and employment of workers in excess of the permitted strength.
Fireworks accidents and explosions
Sri Krishna Fireworks – Namaskarithanpatti – 20.07.2009
Anil Fireworks - Keezha Tiruthangal - 28.07.2009
Classic Fireworks - Meenampatti – 03.08.2009
Om Sakthi Fire works – Mudhalaipatti – 05.09.2012
Meenakshi Fireworks - Kichanayakkanpatti – 15.05.2013
Chidambaram Fireworks – Vilampatty – 22.08.2013
Jonal Fireworks – Chokkalingapuram – 25.02.2016
Krishnasamy Fireworks – Maraneri – 09.06.2016
Whole Sale Shop - Raghavendra Agency – Sivakasi – 20.10.2016
Nagamalli Fireworks - Vetrilai Oorani - 11.03.2017
ARV fireworks – Ramuthevanpatti – 06.04.2018
SKS fireworks – Kakkivadanpatti – 06.04.2018
Factory belonging to Krishnasamy Industries - Kakkivadanpatti - 08.09.2018
References
Virudhunagar district
-Sivakasi
Lists of fires
Lists of explosions
Lists of disasters in India
Tamil Nadu-related lists | List of fireworks accidents and incidents in Sivakasi | [
"Chemistry"
] | 790 | [
"Lists of explosions",
"Explosions"
] |
58,474,192 | https://en.wikipedia.org/wiki/Jincheng%20Civil%20Defense%20Tunnel | The Jincheng Civil Defense Tunnel () is a tunnel in Jincheng Township, Kinmen County, Taiwan.
History
After the first and second Taiwan Strait Crisis, the government decided to construct an underground civilian tunnels for protection. The construction of the tunnel started in March 1968 and completed in June 1969 for 15 months of works. It was then used to connect various public buildings in the island.
Architecture
The tunnel has a total combined length of 2,315 meters. It is equipped with air raid shelters, ammunition depots and pillboxes.
See also
List of tourist attractions in Taiwan
References
1969 establishments in Taiwan
Civil defense
Jincheng Township
Military history of Taiwan
Tunnels completed in 1969
Tunnels in Kinmen County
Tunnel warfare | Jincheng Civil Defense Tunnel | [
"Engineering"
] | 142 | [
"Military engineering",
"Tunnel warfare"
] |
58,475,316 | https://en.wikipedia.org/wiki/HD%20143183 | HD 143183 is a red supergiant variable star of spectral type M3Ia in constellation Norma. It is a member of the Norma OB1 association, at a distance of about 2 kiloparsecs. It is one of the most luminous red supergiants with a luminosity over 250,000 times greater than the Sun (), and is as well one of the largest stars with a radius more than a thousand times that of the Sun (). Older studies frequently calculated higher luminosities and radii. It has an estimated mass loss rate of per year and has been once described as a cool hypergiant. It is surrounded by a dozen early-type stars and a circumstellar nebula which extends .
HD 143183 is catalogued with the variable star designation V558 Normae as its brightness varies irregularly between apparent magnitudes 7.3 and 8.6.
It is possible that HD 143183 is a spectroscopic binary with an OB+ companion but this is considered doubtful. HD 143183 lies approximately 1' from the 10th-magnitude O-class bright giant CD-53 6363, the second-brightest star in the cluster.
References
Norma (constellation)
M-type supergiants
M-type hypergiants
143183
J16013621-5408356
IRAS catalogue objects
CD-53 6947
Slow irregular variables
Normae, V558
Population I stars | HD 143183 | [
"Astronomy"
] | 300 | [
"Norma (constellation)",
"Constellations"
] |
61,462,133 | https://en.wikipedia.org/wiki/SWAPGS%20%28security%20vulnerability%29 | SWAPGS, also known as Spectre variant 1, is a computer security vulnerability that utilizes the branch prediction used in modern microprocessors. Most processors use a form of speculative execution, this feature allows the processors to make educated guesses about the instructions that will most likely need to be executed in the near future. This speculation can leave traces in the cache, which attackers use to extract data using a timing attack, similar to side-channel exploitation of Spectre.
The Common Vulnerabilities and Exposures ID issued to this vulnerability is .
History
SWAPGS is closely related to the Spectre-V1 vulnerability, which used similar side-channel vulnerabilities to access privileged cache memory in an operating system. The vulnerability was discovered by Andrei Vlad Lutas of Bitdefender and was reported to Intel. Intel coordinated with industry partners to address the issue on a software level. The first patches for SWAPGS were released on 9 July 2019 as part of the Microsoft Patch Tuesday. However, details regarding the vulnerability were not disclosed until 6 August 2019.
SWAPGS itself is an instruction to swap the GSBase register with a value stored in MSR. This is typically used to store kernel data.
Affected systems
Any Intel-based processor that support SWAPGS and WRGSBASE instructions is affected. This includes every Intel processor starting from the Intel Ivy Bridge CPUs up to the most recent Intel processors.
Devices equipped with AMD processors are not affected, according to the company's product security update.
Mitigation
For Windows operating system-based devices, Microsoft's security advisory lists the patches released in July 2019, which fix the vulnerability.
For Linux distributions, it is advised to check whether there are SWAPGS-specific patches that need to be applied. The kernel documentation describes the nature of the attacks and the in-kernel mitigations.
Bitdefender mentions in its original report that Apple devices are unlikely to be at risk.
See also
Foreshadow (security vulnerability)
Microarchitectural Data Sampling − another set of vulnerabilities, including ZombieLoad, that can leak data in Intel microprocessors
Rogue System Register Read (RSRR) – a related vulnerability, also known as Variant 3a
Transient execution CPU vulnerabilities
References
Transient execution CPU vulnerabilities
2019 in computing
X86 memory management | SWAPGS (security vulnerability) | [
"Technology"
] | 476 | [
"Transient execution CPU vulnerabilities",
"Computer security exploits"
] |
61,463,857 | https://en.wikipedia.org/wiki/C21H19F2N3O3 | {{DISPLAYTITLE:C21H19F2N3O3}}
The molecular formula C21H19F2N3O3 (molar mass: 399.39 g/mol) may refer to:
Difloxacin
RWJ-51204
Molecular formulas | C21H19F2N3O3 | [
"Physics",
"Chemistry"
] | 65 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,464,897 | https://en.wikipedia.org/wiki/PK-4%20%28ISS%20experiment%29 | The PK-4 or (Plasmakristall-4) laboratory is a joint Russian-European laboratory for the investigation of dusty/complex plasmas on board the International Space Station (ISS), with the principal investigators at the Institute of Materials Science at the German Aerospace Center (DLR) and the Russian Institute for High Energy Densities of the Russian Academy of Sciences. It is the third laboratory on board the ISS to study complex plasmas, after the PKE Nefedov and PK-3 Plus experiments. In contrast to the previous setups, the geometry was significantly changed and is more suited to study flowing complex plasmas.
Technical description
The heart of the PK-4 laboratory consists of a direct current (DC) discharge tube. A plasma is generated by applying an electric field between an anode and a cathode. Microparticles are then injected into the plasma and move through the tube into the working area where their motion is recorded with two cameras, the images of which are joined for analysis. The movement of the microparticles inside the fields of view of the cameras is followed by experimenters. The polarity of this electric field can be switched at a high frequency, so that the microparticles can be trapped in the working area.
A variety of manipulation techniques are available, for instance a manipulation laser that can produce shear flow, and a thermal manipulator which can trap microparticles with a thermal gradient. The optical observation of the microparticles is complemented by other diagnostics methods: a spectrometer and a glow camera that records the plasma glow in several spectral lines.
Scientific goals
As its predecessors, PK-4 Plus studies complex plasmas, which are low temperature plasmas that contain highly charged microparticles. The microparticles interact with each other and with the plasma and can be used to study a variety of topics, for instance waves, the influence of microparticles on the plasma, string formation, and shear flow.
External links
Forschungsgruppe komplexe Plasmen - DLR Oberpfaffenhofen
References
Plasma physics facilities
Science facilities on the International Space Station
International Space Station experiments | PK-4 (ISS experiment) | [
"Physics"
] | 452 | [
"Plasma physics facilities",
"Plasma physics"
] |
61,465,449 | https://en.wikipedia.org/wiki/Vaccine%20cooler | Many vaccines require refrigeration to remain active, and the lack of infrastructure to maintain the cool chain to reliably bring vaccines into more remote areas of developing countries poses a serious challenge to national immunization programs. Portable vaccine cooler units have been proposed by several technologists. The WHO Performance, Quality and Safety (PQS) programme is a driver of the technology.
Technology development
In 2005 Ian Tansley of Sure Chill designed an ice-chest vaccine cooler regulated by the density of water. Since water has greatest density at around 4 °C, putting the vaccine chamber at the bottom of a thermo-syphon regulates the temperature at between 2 °C and 8 °C, as long as there is ice and the heat-exchange capacity is not overloaded. Sure Chill claimed to be WHO approved and in use for vaccine storage in 46 countries.
A refrigeration device was shown for this purpose by Adam Grosser at a TED Talk in 2007, but had not been produced commercially as of 2020. Grosser's proposed device uses exposure to a cooking fire for 30 minutes to store heat. After a cooling period of an hour, the device is placed into a 15-litre container, which contains the vaccine. His concept calls for a 24-hour re-cycle period.
It was revealed in March 2008 that another class of long-term Vaccine Cooler is based around an Ice Box with separate Ice and Vaccine chambers. Using ice as the energy storage device allows the Vaccine Cooler to operate for long periods without power: separating the vaccine chamber from the ice chamber allows temperature regulation while avoiding the need for special packing and conditioning of the cold packs. Suggestions have included the use of a regulated heat pipe to connect the vaccine chamber and the ice chamber.
In September 2008 it was reported that Malcolm McCulloch of Oxford University was heading a three-year project to develop more robust appliances that could be used in locales lacking electricity, and that his team had completed a prototype of his renewal of the Einstein refrigerator. He was quoted as saying that improving the design and changing the types of gases used might allow the design's efficiency to be quadrupled. The three working fluids in this design are water, ammonia and butane.
The Free Piston Stirling Cooler, a type of mechanical refrigerator, was brought to market before 2010 by Twinbird Corporation of Japan. In 2016 Will Broadway won the James Dyson Award for a vaccine cooler based on a miniaturisation of the bi-fluid Icyball technology. Broadway's design uses electricity or propane as the heat source. As of August 2019, Broadway claimed an 88-hour cool-life under WHO PQS test conditions, whereas competitor products could only meet a nine-hour cool-life.
References
Vaccination
Cooling technology
Heating, ventilation, and air conditioning
Gas technologies | Vaccine cooler | [
"Biology"
] | 569 | [
"Vaccination"
] |
61,467,119 | https://en.wikipedia.org/wiki/4-Hydroxyphenylacetaldehyde | 4-Hydroxyphenylacetaldehyde, also known as p-hydroxyphenylacetaldehyde, is a natural product with the formula HOC6H4CH2CHO.
It is a derivative of phenylacetaldehyde and occurs as a white solid at room temperature.
Synthesis
4-Hydroxyphenylacetaldehyde can be synthesized from (L-tyrosine) via a parsley tyrosine decarboxylase.
Occurrence
4-Hydroxyphenylacetaldehyde is produced from the metabolism of tyramine by monoamine oxidase (MAO) enzymes in humans and the tyramine oxidase (tynA) enzyme in Escherichia coli. In both species, it is subsequently metabolized into 4-hydroxyphenylacetate by aldehyde dehydrogenase (ALDH) enzymes in humans and the phenylacetaldehyde dehydrogenase (feaB) enzyme in E. coli.
The condensation of 4-hydroxyphenylacetaldehyde and dopamine is a key step in the biosynthesis of benzylisoquinoline alkaloids. These natural products include berberine and morphine.
References
4-Hydroxyphenyl compounds
Aldehydes
Phenolic human metabolites | 4-Hydroxyphenylacetaldehyde | [
"Chemistry"
] | 284 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
61,467,609 | https://en.wikipedia.org/wiki/Warshipping | In computer network security, warshipping is using a physical package delivery service to deliver an attack vector to a target. This concept was first described in 2008 at the DEF CON hacking convention by Robert Graham and David Maynor as part of a talk entitled “Bringing Sexy Back: Breaking in with Style”, that included various penetration testing methods. In their implementation, an iPhone box was modified to include a larger battery, which powered a jailbroken iPhone. A first-generation iPhone was chosen for this attack based on the reported run-time of 5 days when coupled with an external battery, whereas newer 3G iPhones of the era would reportedly run for 1½ days. A social engineering pretext was described that would trick the recipient into believing they had won an iPhone, in order to explain the shipment.
The advancement of low-power electronics, thanks in part to maker culture, has greatly increased the effectiveness of this methodology as a credible method of attacking networks. In 2019, IBM X-Force Red coined the name “Warshipping” and described an attack platform that included several low-cost components that could be combined, shipped to targets, and controlled remotely for 2–3 weeks. A solar component was also described to allow the devices to run indefinitely.
Aspects of a modern warshipping attack include the following:
Devices that are hidden from the recipient, potentially inside objects or inside the packaging material or box structure itself.
Command and Control (C2) capability via a dependable communication medium. Most commonly this is provided via cellular modems.
A power management strategy that allows the device to operate for weeks. Solar panels may be utilized to lengthen the run-time of the device.
One or more devices used for the operational attack. These can include radios that are built for protocols such as Bluetooth, Wireless LAN, Near Field Communication (NFC), and software-defined radio (SDR) devices for capturing multiple types of protocols. Microphones, cameras, and other capture devices could be included as well.
Satellite navigation (GNSS) technology for reporting on the location of the device, allowing the activation of certain capabilities upon delivery to its target.
Passive triangulation to get around GPS signal issues
The increasing use of large, online retailers contributes to the relevancy of this attack. In 2019, the United States Postal Service reports that they deliver 484.8 million mailpieces per day. The name is by analogy with wardriving and wardialling.
References
Computer security exploits
Wireless networking | Warshipping | [
"Technology",
"Engineering"
] | 503 | [
"Wireless networking",
"Computer networks engineering",
"Computer security exploits"
] |
61,468,534 | https://en.wikipedia.org/wiki/Synapse.org | Synapse.org is an open source platform for collaborative scientific data analysis. It can store data, code, results, and descriptions research work. It is operated by nonprofit organization Sage Bionetworks.
The Synapse web portal is an online registry of research projects that allows data scientists to discover and share data, models, and analysis methods.
References
Open science
Collaborative projects
Computing websites
Cross-platform software
Project hosting websites | Synapse.org | [
"Technology"
] | 86 | [
"Computing websites"
] |
61,469,969 | https://en.wikipedia.org/wiki/Interruption%20%28map%20projection%29 | In map projections, an interruption is any place where the globe has been split. All map projections are interrupted at at least one point. Typical world maps are interrupted along an entire meridian. In that typical case, the interruption forms an east/west boundary, even though the globe has no boundaries.
Most map projections can be interrupted beyond what is required by the projection mathematics. The reason for doing so is to improve distortion within the map by sacrificing proximity—that is, by separating places on the globe that ought to be adjacent. Effectively, this means that the resulting map is actually an amalgam of several partial map projections of smaller regions. Because the regions are smaller, they cover less of the globe, are closer to flat, and therefore accrue less inevitable distortion. These extra interruptions do not create a new projection. Rather, the result is an "arrangement" of an existing projection.
In casual parlance, interrupted projection usually means a projection that has been interrupted beyond mathematical necessity. In this casual sense, the usual east/west interruption of a pseudocylindric map is ignored as an interruption to focus on the elective interruptions. An archetypical example is the Goode homolosine projection. In 1916, John Paul Goode experimented by interrupting the Mollweide projection. Satisfied with the interruption scheme, he then devised a new projection as a composite of the Mollweide and the sinusoidal projection and applied the same interruption scheme to the new projection, which he dubbed "homolosine".
Because pseudocylindric projections map parallels as straight lines, and meridians to have constant spacing, they are easy to interrupt. This is normally done to optimize either for continental areas or for oceanic areas, as explored by Goode.
Many interruption schemes that are much more elaborate have been developed. Since antiquity, for example, globe gores have been developed in order to paste map sections onto model globes. These are regular interruption either along the equator, or in polar form as "rosettes". The Cahill butterfly projection divides the world into octahedral sections. More generally, any mapping onto polyhedral faces becomes an interrupted map when laid flat. Buckminster Fuller proposed his "dymaxion" map in 1943, using a modified icosahedral interruption scheme to divide the oceans up in a way that shows the continents in a nearly continuous mass as "one island". The most elaborate interruptions schemes include those of Athelstan Spilhaus along continental boundaries, and JJ Wijk's myriahedral projections.
References
Map projections | Interruption (map projection) | [
"Mathematics"
] | 530 | [
"Map projections",
"Coordinate systems"
] |
61,471,625 | https://en.wikipedia.org/wiki/7-Methyl-1%2C5%2C7-triazabicyclo%284.4.0%29dec-5-ene | 7-Methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (mTBD) is a bicyclic strong guanidine base (pKa = 25.43 in CH3CN and pKa = 17.9 in THF). mTBD, like 1,5,7-triazabicyclo[4.4.0]dec-5-ene and other guanidine super bases, can be used as a catalyst in a variety of chemical reactions. It also reacts with CO2, which could make it useful for carbon capture and storage.
When brought into contact with some acids, mTBD reacts to form an ionic liquid. Some of these ionic liquids can dissolve cellulose.
References
Catalysts
Guanidines
Pyrimidopyrimidines
Amines
Reagents for organic chemistry
Superbases | 7-Methyl-1,5,7-triazabicyclo(4.4.0)dec-5-ene | [
"Chemistry"
] | 195 | [
"Catalysis",
"Catalysts",
"Superbases",
"Guanidines",
"Functional groups",
"Reagents for organic chemistry",
"Amines",
"Bases (chemistry)",
"Chemical kinetics"
] |
61,473,187 | https://en.wikipedia.org/wiki/Eave%20return | An eave return (also a cornice return) is an element in Neoclassical architecture where the line of roof eave on a gable end comes down to a point, then doubles back briefly. There is a classical version and simpler substitutes.
An eve (or cornice) return is in contrast to a full pediment, which spans the full width of the gable.
Among the types are: boxed return, boxed gable return, gable end return (or full gable return) or simply gable return are variations, or synonyms.
See also
Cornice return
References
Architectural elements | Eave return | [
"Technology",
"Engineering"
] | 113 | [
"Building engineering",
"Architectural elements",
"Architecture stubs",
"Components",
"Architecture"
] |
73,797,518 | https://en.wikipedia.org/wiki/82%20Virginis | 82 Virginis, also known as m Virginis, is a star in the constellation Virgo. It is located from Earth based on a parallax of from Gaia DR2. It is a red giant, based on its spectral type of M1III. Its apparent magnitude is 5.01.
Characteristics
82 Virginis is a red giant star, based on its spectral type of M1III, where M means that it is an M-type star and III is the luminosity class, meaning it is a giant star. The star is 70.8 times larger than the Sun and 890 times more voluminous. The effective temperature of the star is 3675K, which is 2197 degrees colder than the solar temperature of 5772 K. Its rotational velocity is 2.3 km/s. The angular diameter of the star, as measured from the CHARM survey, is of . At the current distance, this would lead to a radius of , which is similar to the radius derived by Gaia DR2.
The parallax of the star is measured at from Gaia DR2, translating to a distance of from Earth. The star is moving towards Earth at a velocity of 36.6 km/s. Its apparent magnitude is 5.01, making it visible to the naked eye.
Notes
References
M-type giants
Virgo (constellation)
Durchmusterung objects
Flamsteed objects
Henry Draper Catalogue objects
Hipparcos objects
Bright Star Catalogue objects
2MASS objects
Bayer objects | 82 Virginis | [
"Astronomy"
] | 307 | [
"Virgo (constellation)",
"Constellations"
] |
73,797,791 | https://en.wikipedia.org/wiki/Kishibe%20Tile%20Kiln%20Site | is an archaeological site consisting of the remains of Heian period kilns located in what is now the Kishibe-kita neighborhood of the city of Suita, Osaka Prefecture in the Kansai region of Japan. It has been protected by the central government as a National Historic Site since 1971.
Overview
The Kishibe tile kiln ruins are located halfway up the southern slope of Shikinzan hills, which extends from the Senri Hills to the right bank of the Yodo River and is part of the precincts of Kishibe Shrine. The site consists of nine flat kilns and three climbing kilns arranged in two tiers, the upper tier being the climbing kilns and the lower tier being the flat kilns. The flat kilns have a semi-underground structure with a total length of about five meters, and both the combustion and firing sections are well preserved. The climbing kiln has a total length of about six meters and a width of about three meters, and the floor is covered with flat tiles. On the south side of the tile kiln, was the remains of a building with pillars, a well, a rotary table, and a clay mining site.
Green-glazed eaves tiles from the early to late Heian period were unearthed here, and green-glazed pottery was also found in the climbing kiln, indicating that the kiln was both a pottery and a tile-making kiln. The green-glazed roof tiles were fired in the flat kiln for the first firing and the second firing for the glazing stage in the climbing kiln. Among the excavated tiles, there are tiles that is considered to be identical to the roof tiles used in the construction of the early Heian Palace.
The site is maintained as "Shikinzan Park" and is about a 20-minute walk from Kishibe Station on the JR West Tokaido Main Line.
See also
List of Historic Sites of Japan (Osaka)
References
External links
Osaka Prefectural Government home page
Suita
Heian period
Japanese pottery kiln sites
History of Osaka Prefecture
Historic Sites of Japan
Settsu Province | Kishibe Tile Kiln Site | [
"Chemistry",
"Engineering"
] | 433 | [
"Kilns",
"Japanese pottery kiln sites"
] |
73,799,297 | https://en.wikipedia.org/wiki/Ri%20plasmid | The root inducing (Ri) -plasmid of Rhizobium rhizogenes (formerly Agrobacterium rhizogenes) is a plasmid capable of undergoing horizontal gene transfer of its transfer DNA (T-DNA), upon contact with a plant host. The T-DNA of the Ri-plasmid affects the plant host in such a way, that gene expression is altered, especially in regard to phytohormonal balances, metabolism and certain phenotypical characteristics.
The Ri-plasmid is generally classified based on the type of opines produced, and four have been described so far: the agropine, cucumopine, mannopine, and mikinopine types. While all types of Ri-plasmid contain T-DNA, the agropine plasmid contains both a TL and a TR-domain (left and right, resp.). The TL-DNA is reminiscent of the T-DNA of the other strain types, containing a virulence region with a set of virulence (vir) genes, opine synthesis genes, root oncogenic loci (rol) genes (rolA, rolB, rolC and rolD) and a number of other genes with unidentified functions (open reading frames (ORFs)). The TR-DNA resembles the T-DNA of the Ti-plasmid (pTi) found in Agrobacterium tumefaciens, and carries two codes for auxin biosynthesis genes (aux1 and aux2), homologous to the pTi tms1 and tms2 regions.
The Ri-phenotype
Upon infection with R. rhizogenes and subsequent integration of the Ri-plasmid, the host plant displays phenotypical characteristics aptly named the hairy root disease with the so-called Ri-phenotype. The phenotypical changes include but are not limited to increased, agravitropic root growth and root hair growth, shortened internodes, wrinkled leaves and reduced apical dominance, dwarfism and early flowering. Several of these physical traits are of interest in the commercial breeding of horticultural and agricultural plants.
The different rol genes have been shown to have different effects on their host plant, both when incorporated into the plant genome separately and in combination with one another; for example, rolA has been shown to exhibit inhibitory effects on the rolB and rolC domains, and rolC is by now essentially known to induce dwarfism in its plant host.
References
Plasmids | Ri plasmid | [
"Biology"
] | 546 | [
"Plasmids",
"Bacteria"
] |
73,800,460 | https://en.wikipedia.org/wiki/Definitions%20of%20intersex | Various criteria have been offered for the definition of intersex, including ambiguous genitalia, atypical genitalia, and differential sexual development. Ambiguous genitalia occurs in roughly 0.05% of all births, usually caused by masculinization or feminization during pregnancy, these conditions range from full androgen insensitivity syndrome to ovotesticular syndrome.
1.7% of people are born with a disorder of sexual development (DSD) as defined by the DSD consortium, such as those with Klinefelter's syndrome. The DSD was specifically made to be as inclusive to all atypical sexual development; not all conditions within the DSD affect individuals to the same extent.
Most intersex activism is based around the end of unnecessary medical interventions on intersex youth which attempt to assign an arbitrary sex and gender binary, often causing physical harm with no input from the child. Intersex conditions are usually expanded to include the DSD more generally. 0.05% of births are medically treated or considered to have ambiguous genitalia.
There can also be a stricter definition, specifically for ambiguous DSD. This definition is restricted to those conditions in which typical chromosomal categorization patterns is inconsistent with phenotypic sex, or in which the phenotype is not easily classifiable as either male or female," with the prevalence of about 0.018%.
The exact cut-off point between male and female in an intersex context is largely arbitrary. Likewise, the definition of biological sex is also sometimes considered to be arbitrary; as an example, some individuals with XY female (SRY inactivation) may have a uterus, ovaries, and normal menstruation, and be able to achieve pregnancy. These individuals would be declared to be biologically female but karyotypically male. Likewise, many intersex individuals are born completely sterile, although medical interventions have been known to remove potentially fertile gonads, which makes sex determination often arbitrary. Individuals with XX male develop male genitalia but are entirely infertile due to a lack of SRY gene expression and develop a generally feminine body. This range of possibilities is further expanded by conditions which effect genital development but not hormonal or sex gene expression. Generally, most intersex advocates, as well as parts of the medical community, advocate for broadening the definitions of sexual development and the definition of intersex.
Causes of intersex development
The overall causes of intersex conditions are complex, and are caused primarily by sexual development during pregnancy. Certain individuals may have a masculinized clitoris or a feminized penis, however this might change after pregnancy. The exact differentiation of ovotestis of intersex people are often ambiguous. Other cases of intersex conditions can occur when hormones are taken during pregnancy such as estrogens or androgens, which can lead to atypical sexual development. Commonly intersex people are defined as those who are born with ambiguous genitalia, usually within the context of the OGR, or individuals with substantial atypical sexual development such as those with XX male.
Most conditions under the DSD are not apparent at birth, and most are not medicalized. Certain definitions declare the need for atypical masculinization or feminization during fetal development to declare an intersex condition. Under this definition, cloacal exstrophy a rare condition which is caused by the stomach internal organs developing incorrectly would not be intersex. Individuals with cloacal exstrophy who are born with XY do not develop a penis and are usually castrated and assigned female at birth. These people are medicalized like other people with intersex conditions and the OGR model. Due to this individuals with cloacal exstrophy are often considered intersex. InterACT the leading organization of intersex rights in the US, states that 1.5% of children are born with an intersex condition (DSD), and 0.05% are born with full ambiguous genitalia.
Assigned sex
There is a high bias to assign intersex people with ambiguous genitalia as female at birth, as it was generally thought that it was easier to create a girl than a boy. Likewise as puberty would result in general feminization for most intersex children as well as a low libido, it was thought that they should be assigned female. This was also motivated by the fact that vaginoplasty was far more developed than phalloplasty.
This system was known as the optimum gender of rearing model (OGR model) which attempted to define a binary for intersex children. Some individuals who did not have any intersex conditions were raised under the OGR model, such as David Reimer who suffered a botched circumcision and was assigned female at seven months. The primary goal of the OGR was to stop gender incongruence, and to assign a gender binary for "proper" sex socialization. The model often specifically involved the falsification of medical history, such as the karyotype falsification or that internal testis were ovaries and needed to be removed for "cancer," despite no physical complications existing from their presence.
Intersex advocates used a feminist perspective for criticism of the OGR as inherently sexist and cruel. The OGR modeled girls as passive and the receivers of penetration, and boys as the givers of penetration. As most intersex conditions cause vagina-like development and no phallus, medical staff were biased towards assigning female at birth. Transfeminists and queer liberationists particularly criticized the OGR model for not allowing children deviate from gender binary or expression. Likewise, feminists view bodily autonomy as a fundamental human right, which led to criticisms of the OGR taking away the bodily autonomy of intersex people.
Intersex and medical definitions
The OGR stated that gender non-conformity was a physiological threat which affected an individual's ability to function in normal society. Most research has found this to be false and that the medical procedures practiced against intersex individuals generally leads to isolation, physiological stress and physical complications throughout life. The definition of intersex is closely linked to the specific medical interventions on intersex people. According to the ISNA 1.92% of the population will have some variation in sexual development throughout their lives, (0.42% excluding LOCAH). 1% of people have bodies that "differ from standard male or female," and 0.1-0.2% of births are considered for intersex genital surgeries.
The DSD as a model was advocated for by intersex advocates to include all variation of atypical sexual development. Specifically the DSD exists as replacement for the OGR which was the standard model for individuals with atypical sexual development. This model stated goal was to assign a gender binary, usually female via non-consensual medicalization, often via the falsification of medical records. After the publication of individuals who had undergone the OGR model and had gone through serious physiological distress, the model was discredited. The term "disorders of sexual development" was chosen to reflect the variation of sexual development over differences which effects all individuals, this however has been controversial, with many instead opting for "differentiation" or "variation."
The DSD has generally superseded the OGR in the US, although no official medical precautions exist against intersex genital mutilation in the US. Another point of contention is intersex conditions and karyotype, while many intersex individuals have atypical gene expression, many intersex individuals are born due to hormonal changes in pregnancy, either natural or induced. As an example, a case of a woman who had a virilized clitoris which was surgically altered during her birth, brought up the point that she was intersex, which was stated to be "false" by a doctor as her mother had gone on progesterone, instead of natural virilization which induced biological change. Generally those who have undergone the OGR model, or have ambiguous genitalia are considered intersex. The DSD consortium was specifically made to remedy this, and was advocated for by intersex activists by including all differentiation in sexual development.
The definitions of intersex genitalia are difficult as different medical practices exist in different regions for what a "normal" penis or vagina should look like.
Spectrum approach
Many intersex activists have advocated for a spectrum based approach for intersex conditions, which would differentiate various intersex conditions, including hormonal differences. Intersex conditions, even the same conditions such as ovotesticular syndrome, can vary wildly in terms of organs, genetic expression, phenotype, genotype, and karyotype. Under this model intersex conditions would be described via their own individualized effects described as effecting individuals on a spectrum. The DSD generally describes this by the description of individualized care for people with atypical sexual development, making the distinction between different conditions.
See also
Yogyakarta Principles
Genetic diagnosis of intersex
History of intersex surgery
Intersex human rights
Disorders of sex development
Androgen insensitivity syndrome
References
Intersex topics
Sex differences in humans
Intersex healthcare
Intersex rights
External links
Intersex people OHCHR and the human rights of LGBTI people
Intersex Definitions, InterACT | Definitions of intersex | [
"Biology"
] | 1,984 | [
"Intersex topics",
"Sex"
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73,800,544 | https://en.wikipedia.org/wiki/Mitra%2015 | The Mitra 15 is a minicomputer made by the French company CII under Plan Calcul, along with the Iris 50 and Iris 80 mainframe computers. It was marketed from 1971 to 1985 and could function in conjunction with large systems. CII manufactured a thousand Mitra 15 machines until 1975 in its Toulouse factory, then in Crolles in the suburbs of Grenoble. A total of 7,929 units were built, most of them for the French market, with a small number sold in Australia, Indonesia, and in other European countries.
History
The Mitra 15 is the successor to the CII 10010, also called Iris 10, a 16-bit minicomputer released in July 1967. At the time, CII also produced another 16-bit minicomputer, the CII 10020 (actually a licensed Sigma 3 from SDS) and wanted to replace them both with a new, more powerful design compatible with the latest offering of the company. The Mitra 15 was designed from the outset to complement and network with the most powerful French computer of the time, the CII Iris 80, with which it was compatible. Its name is an acronym of , meaning “Mini-machine for Real-Time and Automatic Computing”. The first versions featured a main memory of lithium ferrite cores organized in 16-bit words. It was designed and developed by a team led by Alice Recoque.
The first Mitra 15 was delivered on May 10, 1971, and produced in Crolles then Échirolles.
Intended for command and control of industrial processes such as scientific computing, the Mitra 15 was designed to be adaptable to very diverse fields of application, thanks to an innovative microprogramming system and a good price/performance ratio. Variants of this computer have also been produced according to the needs of CII's customers. The Mitra 15 was also developed into a militarized version, the Mitra 15M. Microprograms use firmware stored in a ROM, the execution of which causes a simple computer (the micromachine) to always execute the same algorithm, for the instructions of another computer: the macromachine, or simply the machine, which is what is visible to the programmer.
Only the first version is incompatible with the CII Iris computers of the time, the Iris 50. The Mitra 15 was widely used as the front-end for the CII Iris 80 (MCR-2) computer. Initially, it was produced as a simple stand-alone module with external cabinetry. It was succeeded by the Mitra 15–20, Mitra 15–30, and Mitra 15–35, produced from 1972. The Mitra 15-30 and Mitra 15-35 which have an external chassis cabinet with extended configuration and modular drawers are intended in particular for customers in the telecommunications industry; they were priced from the dollars. Later, the low-end Mitra 15M/05 was produced in 1975.
Competition and innovation
The first commercially-successful minicomputer, the 12-bit DEC PDP-8 was introduced in 1965, and sold for . In 1969, Data General, founded by ex-DEC engineers introduced the 16-bit Nova, which sold for . The Hewlett-Packard HP2000 series appeared in the late 1960s and early 1970s.
The main French competitor to the Mitra 15 were the Télémécanique T1600 [fr], introduced in 1971, and its successor, the Solar 16 [fr] in 1975, which sold in about 16 000 units.
According to Le Monde, by 1974 the Mitra 15 had achieved revenue of 150 million francs; one eighth of the total sales of the CII, of which "30% was for remote processing" and "around 20%" for export.
Users
Cyclades packet-switching network
Cyclades was an early packet-switching network developed by Louis Pouzin in the early 1970s, which played a significant role in the development of the Internet. It used a decentralized approach where Mitra 15 minicomputers acted as routers and allowed for the transmission of data in small packets. Cyclades was a forerunner of the Transmission Control Protocol (TCP).
French nuclear program
The Mitra 15 was used to monitor the deployment of the use of the new generation of electric generators from , during the French nuclear program. In particular, it was used as part of the transmission network automation master plan, launched in 1973.
The Mitra 15 gradually equipped all of the network's control sites – about a hundred in France – to ensure and manage data exchanges between the remote control equipment of the sites ordered and the regional nodes which control the control of the electricity network. In 1975, EDF 's Mitra 15s were systematically fitted with monitors and printers.
PTT telecom network
Within the French PTT telecom network, the Mitra 15 was used with CII Iris 80s, due to its ability to handle a large number of interrupts.
Telecom switches
The Mitra 15 equipped the telephone switches of the E10N4 between 1972 and 1976, sold by CIT-Alcatel to the PTT. After 1976, because of the lowering of component prices, a fully electronic 2nd generation global telephone switch system, based on new integrated circuits, became affordable.
Experimental computer science in secondary education
As part of Plan Calcul, tt was then decided to install computers, on an experimental basis, in 58 high schools. Two minicomputers were selected for the pilot: The Télémécanique T1600 and the Mitra 15.Although the performance of the Mitra was three or four times better than the T1600, the delivery of the Mitra lagged by two months, so it was decided to install more T1600s than Mitras.
The Ariane rocket
In Kourou, at the Guiana Space Center, the Ariane 1 control console was built around two Mitra 15s: one for managing electrical systems, the other for fluid systems. The Ariane 4 consoles also used two Mitra 15-30 computers and peripherals for command controls. One in the preparation area (CCD) Dock Command Control, the other in the launch area (CCE) Electrical Command Control. The peripherals have evolved during the launch campaigns and in particular the DRI magnetic head disks which have been replaced by RAM memory disks whose speed of access times has required software reorganizations.
On the launch pad, the Mitra 15, associated with an Intel Frontal Table Image (FTI), controlled, among other functions, the ignition sequence. A sustainability study of these computers and all the control consoles enabled them to be used until 2003, the date of the last Ariane 4 V159 flight.
Political decisions in 1976
CII was handicapped by its 1974-1976 merger with Honeywell-Bull, who were more centered on traditional business computing, and by the abandonment of Unidata, which caused the termination of orders from Siemens. Sales of the Mitra 15 were tied by CII with that of the big computer, the Iris 80, to the point that Le Monde asked if CII would not be forced to launch into this market and manufacture its own equipment. The Mitra 15 mini-computer, a mainstay since 1971 of its distributed computing strategy, was then sold to its shareholder Thomson, who had been opposed for more than a year to the merger of CII with Honeywell-Bull, despite a special mediation mission.
Mitra 15 successors
The Mitra 125, sometimes called "Mitra 15M/125" succeeded the Mitra 15 in 1975. It introduced a memory management unit, with extended addressing capabilities, protected memory and paging support, allowing it to address up to 32 pages of 64 kB for a total of 512 kB. It also added three I/O microcoded processors, and up to sixteen units could be interconnected for distributed computing. A version specially designed for the Spacelab, a modular space laboratory used during some of the missions of the American Space Shuttle, was also developed: the Mitra 125 MS.
Its immediate successor, the Mitra 225 was a powerful version built from 1975 around the AMD 2901 bit-slice microprocessors and MOS memory. This family of processors, easier to program than those of Intel, was also introduced in 1975 by Advanced Micro Devices.
From 1976, Mitra minicomputers were grouped, together in the European Society for Minicomputing and Systems, formed for civilian applications, with the mini-computers T1600 and Solar of Télémécanique (24%) and 9% of IDI.
The Mitra 525 ratifies, in a three-bus architecture, the possibilities of extension of the Mitra 225 with which it remains compatible. The 1982 Mitra 625 will only bring detail changes, allowing up to 25% more power. Finally, the 1984 Mitra 725 was produced at a time when SEMS was transferred to Bull, which "didn't deal much with this SEMS, having to deal with Honeywell's Level 6 as well as the heavy financial losses of the period, 1982-1984.
The Mitra 525, 625, and 725 used the ECL MC10800 and MC10802 circuits, introduced by Motorola in 1975, while Intel's 3002 lost its advantage over competitors.
References
External links
Mitra 15 Reference Manual
Technical summary at the Fédération des Equipes Bull
Minicomputers
History of computing in France
Computers designed in France
16-bit computers | Mitra 15 | [
"Technology"
] | 1,954 | [
"History of computing",
"History of computing in France"
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73,801,836 | https://en.wikipedia.org/wiki/Nanao%20Tile%20Kiln%20Site | is an archaeological site consisting of the remains of Asuka period kilns located in what is now the Kishibe-kita neighborhood of the city of Suita, Osaka Prefecture in the Kansai region of Japan. It has been protected by the central government as a National Historic Site since 1980.
Overview
The Nanao kiln ruins are located on the northwest slope of Shikinzan hills, which extends from the Senri Hills to the right bank of the Yodo River. Nearby was the Shakagaike branch of the Senri kilns, where Sue ware was fired during the Kofun period, and 300 meters to the east is the Kishibe Shrine, which is the site of the Heian period Kishibe Tile Kiln Site, which has a separate National Historic Site designation. The slope of the hill has an ash layer containing tile fragments, and it was recognized from around 1964 that this was the location of an ancient kiln: however, archaeological excavations did not occur until 1979, when there was a plan to develop residential land in this area. A large amount of roof tiles have been excavated from the kiln site. The soil and techniques of these tiles match those of the tiles used in the Naniwa Palace, which Emperor Shōmu started constructing in 726 AD.
The 1979 excavation confirmed the remains of seven kilns. There are six kilns on the northern slope of the hill that stretches from southwest to northeast, all of which are ascending kilns At the eastern end of the hill, 25 meters southeast of Kiln No. 1, was the remnants of a flat kiln in a poor state of preservation. Of the six ascending kilns, Kiln No.3 was the largest, at 5.4 meters in length and 1.75 meters in width, and both the firing section and the combustion section with seven steps in good preserved. Large sun-dried bricks were used for the side walls. The slope of the floor is gentler than that of No.2 kiln, averaging 17 degrees. The risers of the stairs are lined with large pillars, and the upper surface is covered with round and flat tiles. At this kiln site, unfired tiles were found in the state they were in when they were packed into the kiln. For some reason, it seems that the use was stopped without firing, and it is a rare case.
Kiln No. 2 had been partially leveled, but the total length of the existing part is 4.5 meters, and the width of the underground firing section is 2 meters. The slope of the floor surface is 40 degrees on average. The risers of the stairs are lined with large pillars, and the upper surface is covered with round tiles and half-cut flat tiles. Kiln No. 4 has a boat-shaped plan, with a total length of 6.3 meters, firing section maximum width of 2.2 meters. Kiln No.5 and Kiln No.6 had lengths of 5.5 meters and 5.8 meters respectively, and share the same vestibule. No. 1 kiln has not been investigated. The coexistence and simultaneous operation of different types of kilns is a characteristic of this site.
Follow on excavations were conducted in 1983, 1984-1985 and 1990. It is believed that there was a tile-making workshop on the north side of the kiln site, the location of which has yet to be discovered.
The site is about 20 minutes on foot from Kishibe Station on the JR West Tokaido Main Line.
See also
List of Historic Sites of Japan (Osaka)
References
External links
Osaka Prefectural Government home page
Suita
Asuka period
Japanese pottery kiln sites
History of Osaka Prefecture
Historic Sites of Japan
Settsu Province | Nanao Tile Kiln Site | [
"Chemistry",
"Engineering"
] | 774 | [
"Kilns",
"Japanese pottery kiln sites"
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73,802,483 | https://en.wikipedia.org/wiki/Underground%20House%20Las%20Vegas | The Underground House in Las Vegas, Nevada, is a Cold War-era subterranean dwelling. This structure was built in the wake of the Cuban Missile Crisis.The house was completed in the 1978.
History
In 1969, the Avon Products executive Girard B. Henderson relocated to Las Vegas, Nevada, and embarked on the construction of the Dawson buildings on Spencer Street and an underground house across the street, which took from 1974 to 1978 to build. Oswald Gutsche, the president of Alexander Dawson Inc., oversaw the building of a new underground residence. This dwelling was inspired by the designs of Jay Swayze and served as a model. He enlisted Frank Zupancic, a private contractor who had previously constructed Oswald Gutsche's home, to undertake the construction. Henderson and his wife chose to reside in this subterranean abode, located on 3970 Spencer Street.
To access the underground home, a stairwell or a elevator descent takes people below ground level, opening into the entry of the residence. The underground property consists of several key features, including the home centered in the space.
After Henderson died on November 16, 1983, his wife Mary lived in the underground house for a short while. Following her death on October 1, 1988, businessman Thomas "Tex" Edmonson (1908–2003) acquired the underground property. As the second husband of Lucy Henderson, Tex Edmonson purchased the property under the Tex-Tex Corporation, becoming the new owner of the underground dwelling.
An article appeared in The New Yorker magazine, which talked about Susan Roy, a magazine editor and architecture historian, who saw images of family fallout shelters including this one back in 2003, in Nest magazine (published from 1997 to 2004). The experience resulted in a book she wrote, Bamboozled: How the U.S. Government Misled Itself and Its People into Believing They Could Survive a Nuclear Attack.
Design
The Ranch-style house is underground and has brick veneer siding but is enclosed in a waterproof concrete shell measuring approximately and covered with a compacted earth berm. The Clark County, Nevada Records show that the Underground House is on . The main house itself encompasses three bedrooms and three bathrooms, and includes a small guest quarters. The home, designed to sustain life for approximately one year, was equipped with an underground generator and fuel tank."
The interior design of this home serves as a reflection of the Cold War era during which it was constructed. The prevailing atmosphere at the time, particularly in the aftermath of the Cuban Missile Crisis, was one of heightened concern among Americans regarding the looming threat of nuclear war. The homeowner held a firm conviction that the United States and the Soviet Union might continue to intensify their conflict, ultimately leading to a catastrophic nuclear confrontation.
The underground area has been designed to imitate an above-ground setting, including grass-looking carpet as an imitation lawn, artificial trees and wall to wall, floor to ceiling scenery. A fireplace chimney channeled smoke through a "trunk and branches" of a fake tree on the surface. The house was lit with nearly 1,000 fluorescent lights. These lights, in four colors, enabled the night sky to simulate a sunrise.
The muralist Jewel Smith painted the Trompe-l'œil murals to depict Henderson's sheep ranch in Cecil Peak Station, New Zealand, the ranch he owned in Colorado, a view of Los Angeles from Beverly Hills, and a depiction of his childhood home in Suffern, New York.
Current state
The underground property has changed hands over the years. The property sold in 1990 for $1.3 million after Henderson passed away, and again in 2005 for $2 million. The current owners bought it in 2014 for $1,150,000. In 2019 it was again on the market for $18 million, then in 2024 reduced to $5.9 million. The purchasers, under the name "Society for the Preservation of Near Extinct Species," made the decision to maintain their anonymity while acquiring the property, which is now recognized as the Stasis Foundation.
See also
1964 New York World's Fair
Earth shelter
Underground World Home
Underground living
References
External links
New York World's Fair, Underground World Home Brochure
World's Weirdest Homes
Mark Voelker Interview on the Underground House of Las Vegas
1978 introductions
Air raid shelters in the United States
Cold War sites
Nuclear fallout
Radiation protection
Survivalism | Underground House Las Vegas | [
"Chemistry",
"Technology"
] | 890 | [
"Nuclear fallout",
"Environmental impact of nuclear power",
"Radioactive contamination"
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73,803,054 | https://en.wikipedia.org/wiki/EdgeUno | EdgeUno is a technology company established in 2018. It provides services related to cloud computing, edge computing, and connectivity. The company was founded by Mehmet Akcin, who has previously held positions at Microsoft, Yahoo, and ICANN. EdgeUno's services are primarily targeted towards the Latin American market.
Services
EdgeUno provides a range of services including managed hosting, managed cloud, content delivery network (CDN), and Internet exchange point (IXP).
Expansion
As of 2023, EdgeUno operates 50 data centers in Latin America and has plans to increase this number by the end of the year. The company is also considering expansion into four additional Latin American countries.
Network
EdgeUno's network has a capacity of 300 Tbps and includes over 50 data centers. The company has direct peering arrangements with more than 3000 networks across Latin America.
Sports sponsorship
EdgeUno sponsors the Fortaleza football club, a professional football team based in Bogotá, Colombia.
References
External links
Internet service providers of the United States
Telecommunications companies of South America
Internet service providers
Cloud computing providers
Internet technology companies
Data centers
Web hosting | EdgeUno | [
"Technology"
] | 224 | [
"Data centers",
"Computers"
] |
73,803,388 | https://en.wikipedia.org/wiki/Tetraoxidane | Tetraoxidane is an inorganic compound of hydrogen and oxygen with the chemical formula . This is one of the unstable hydrogen polyoxides.
Synthesis
The compound is prepared by a chemical reaction between hydroperoxyl radicals () at low temperatures:
Physical properties
This is the fourth member of the polyoxidanes. The first three are water [(mon)oxidane], hydrogen peroxide (dioxidane), and trioxidane. Tetraoxidane is more unstable than the previous compounds. The term "tetraoxidane" extends beyond the parent compound to several daughter compounds of the general formula , where R can be hydrogen, halogen atoms, or various inorganic and organic monovalent radicals. The two Rs together can be replaced by a divalent radical, so heterocyclic tetraoxidanes also exist.
Ionization
Tetraoxidane autoionizes when in liquid form:
References
Inorganic compounds
Oxides
Polyoxides
Oxoacids | Tetraoxidane | [
"Chemistry"
] | 205 | [
"Inorganic compounds",
"Oxides",
"Salts"
] |
73,804,695 | https://en.wikipedia.org/wiki/James%20J.%20H.%20Gregory | James John Howard Gregory (November 7, 1827 – February 20, 1910) was an American educator, horticultural businessman, writer, politician, and philanthropist from Marblehead, Massachusetts. Gregory started his career as a public school teacher and later served as a principal. In 1854, he founded a successful seed company, introduced innovations like seed catalogs and developed notable varieties such as the Hubbard squash and cherry tomato. Due to the success of his business, he was known as the "Seed King of Marblehead". Gregory also served as a Massachusetts State Senator (1876–1877) and Marblehead Selectman, advocating for local development and education. A prolific author, he wrote practical gardening guides and supported African American education through the Marblehead Libraries program and school donations.
Biography
Early life
James John Howard Gregory was born in Marblehead, Massachusetts, on November 7, 1827, to James Adams and Ruth Gregory (née Roundey). His father worked as a Justice of the Peace and customs officer in Marblehead.
Education and teaching career
Gregory received his education in the public schools of Marblehead and spent two years studying at Middlebury College. Following this, he worked as a teacher at Marblehead Academy and the Farm School before graduating from Amherst College in 1850. After graduation, Gregory taught in Marblehead and Lunenberg. From 1851 to 1854, Gregory worked as the principal of Derby Academy in Hingham.
Business career
In 1854, Gregory began his seed business, James J. H. Gregory & Son, initially operating from his home.
According to legend, Gregory responded to an advertisement in the New England Farmer magazine looking for a good squash seed. Gregory sent the magazine some seeds his father had received from their neighbor Elizabeth "Marm" Hubbard. Dubbing it the Hubbard Squash, the seeds became extremely popular.
Gregory was innovative for his time, becoming an early adopter of seed catalogs for his business. He used paper envelopes to package and transport his seeds, featuring illustrations on the envelopes to indicate the type of seeds they contained.
According to the Victory Horticultural Library, Gregory developed the first cherry tomato and was a key distributor of the Danvers onion. He also developed several other vegetable and plant varieties. He grew various vegetables and was one of the leading seed sellers in the United States. His success led to him being known as the "Seed King of Marblehead".
As his business expanded, Gregory took a fish-drying house from Gerry Island to 59 Elm Street in Marblehead for use as a seed drying warehouse. Dubbed the "Squash House", it still exists today.
Writing career
Gregory authored practical guides on vegetable gardening. His works, such as Squashes: How to Grow Them (1867) and Cabbages and Cauliflowers: How to Grow Them (1908) provided detailed instructions for growing and marketing crops. Gregory wrote about fertilizers and soil productivity in Fertilizers: Where the Materials Come From (1886). Additionally, Gregory wrote for horticultural magazines.
Political career
Gregory was active in both local and state politics. He was elected to the Board of Selectmen in Marblehead in 1861 and 1868. Gregory was a Republican and served as a Massachusetts State Senator from 1876 to 1877, representing 2nd Essex district. He was elected by the joint vote of the Republican and Prohibition parties.
Philanthropy
As Gregory's wealth grew, he came to believe that keeping a significant portion of it was unjust while others endured hardships. He decided to cap his annual personal expenses at $300, donating the rest to help those in need. In 1907, he retired and dedicated his life to helping others.
Gregory actively engaged in philanthropic efforts both in Marblehead and in communities across the United States. He donated art to local schools and churches, provided the land that became Fountain Park, and supplied the bell and clock for Abbot Hall when it was designated as Marblehead's town hall.
In 1880, Gregory anonymously donated funds under the name "Howard" to build a predominantly Black Congregational church in Wilmington, North Carolina, inspired by his support for the American Missionary Association and the needs of newly freed slaves. Though initially anonymous, his identity was revealed during the church's 1881 dedication ceremony. Originally named "Christ's Congregational Church", it became known as Gregory Congregational Church by the early 1900s.
Gregory was particularly passionate about education for African Americans. In 1883, Gregory made a substantial contribution to the Wilmington Normal School, a high school for African Americans in Wilmington. Due to his contribution, the school was renamed the Gregory Normal School.
Marblehead Libraries
In 1910, Gregory created a traveling library service, called the Marblehead Libraries, that operated in over 50 African-American schools and colleges across the South. The service continued for 20 years, sustained by the funds donated by Gregory. That same year, Gregory funded a librarian apprentice program operating out of Louisville Free Public Library in Louisville, Kentucky, which operated until 1929.
Personal life and death
Gregory married three times but never had children of his own. He married his first wife, Eliza Candler Bubier on December 30, 1863. With Eliza, he adopted his first three children; James, Edgar, and Annie from a South Boston orphanage. Following Eliza's death, he adopted his second daughter, Laura. In 1878, Gregory married Harried Roundey, who died in 1894. In 1895, Gregory married his third wife, Sarah Lydia Caswell (died 1922).
Gregory was an occasional poet. Some of his poems were published in the Essex Antiquarian. His poem "Ode to Evelyn" was composed in remembrance of his granddaughter, Evelyn Burroughs. Gregory also collected Native American artifacts and authored an article based on his collection for the Essex Antiquarian.
Gregory constructed an elegant coastal residence on Peach's Point, Marblehead. He extended an invitation to President Garfield to use the home during the summer of 1881, but the president, though appreciative, politely declined.
Gregory died on February 20, 1910. He was buried in the Waterside Cemetery in Marblehead, Massachusetts. In his will, Gregory established a fund in Marblehead that would provide payment to new mothers of twins born within the year. Gregory Street, which stretches along the Townside Harbor Front in Marblehead, was named to commemorate him.
Selected publications
Onion Raising: What Kinds to Raise, and the Way to Raise Them (Boston: A. Williams & Company, 1865)
Squashes: How to Grow Them (New York: Orange Judd Company, )
Pamphlets on Vegetable Gardening (Marblehead, Mass: Messenger Steam Printing House, 1867–1883)
Cabbages: How to Grow Them (New York: Orange Judd Company, )
Carrots, Mangold Wurtzels and Sugar Beets (Marblehead, Mass: N.A. Lindsey & Co., )
Fertilizers (Boston: Rand, Avery & Company, 1885)
Cabbages and Cauliflowers: How to Grow Them (Boston: S. J. Parkhill & Co., 1908)
References
Further reading
External links
Works by James J. H. Gregory at the Internet Archive
Works by James J. H. Gregory at the Biodiversity Heritage Library
1827 births
1910 deaths
19th-century American businesspeople
19th-century American educators
19th-century American male writers
19th-century American non-fiction writers
19th-century American philanthropists
20th-century American businesspeople
20th-century American male writers
20th-century American non-fiction writers
20th-century American philanthropists
Activists from Massachusetts
American education activists
American garden writers
American horticulture businesspeople
American horticulturists
American male non-fiction writers
American school principals
Amherst College alumni
Businesspeople from Massachusetts
Middlebury College alumni
People from Marblehead, Massachusetts
Politicians from Essex County, Massachusetts
Philanthropists from Massachusetts
Plant breeding
Schoolteachers from Massachusetts
Seed companies
Republican Party Massachusetts state senators
Writers from Massachusetts
19th-century members of the Massachusetts General Court | James J. H. Gregory | [
"Chemistry"
] | 1,595 | [
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73,805,220 | https://en.wikipedia.org/wiki/Horst%20D.%20Simon | Horst D. Simon (born August 8, 1953) is a computer scientist known for his contributions to high-performance computing (HPC) and computational science. He is director of ADIA Lab in Abu Dhabi, UAE and editor of TOP500.
Early life and education
Simon was born on August 8, 1953, in Stadtsteinach, Germany. From 1963 to 1972, he attended a high school in Germany, Markgraf-Georg-Friedrich Gymnasium Kulmbach. He completed his undergraduate studies at Technische Universität Berlin from 1973 to 1976. Simon joined University of California, Berkeley in 1976 from where he studied Masters of Mathematics from 1976 to 1977 and graduated with PhD in Mathematics in 1982.
Career
Horst Simon is an expert in the development of parallel computational methods for the solution of scientific problems. His research interests include development of sparse matrix algorithms, algorithms for large-scale eigenvalue problems, and domain decomposition algorithms.
Early in his career he has served as a senior manager for Silicon Graphics from 1994 to 1996. Horst Simon has been an assistant professor of Applied Mathematics at the State University of New York from 1982 to 1983.
Boeing (1983 – 1987)
Simon has worked at Boeing Computer Services from 1983 to 1989. He was part of a team at Boeing that improved the stability and efficiency of the Lanczos method, which was implemented in the BCSLIB library and used by MSC Nastran, a commercial software package for structural analysis. The block-shifted and inverted Lanczos solver incorporated the research of five PhD theses and involved collaboration between academia and industry Some of the key innovations that Simon and his colleagues introduced were block algorithms, selective reorthogonalization, shifting techniques, and a smart algorithm for choosing shifts These enhancements increased the computational performance and robustness of the Lanczos method for solving large and complex eigenvalue problems.
NASA Ames (1987 – 1995)
From 1989 to 1994, Simon has worked at NASA Ames Research Center in Moffett Field, CA while serving as head of Applied Research Department for Computer Sciences Corporation. He developed the Conjugate Gradient benchmark, one of the NAS Parallel Benchmarks, a set of programs that measure the performance of parallel supercomputers. His benchmark has been widely used to evaluate and optimize parallel computing technologies, and has contributed to the establishment of standards and metrics for high-performance computing.
TOP500 (1996 – current)
In 1996 Simon joined the TOP500 project, that was founded by Erich Strohmaier, Hans Meuer, and Jack Dongarra in 1993.
Lawrence Berkeley National Laboratory (1996-2022)
Simon joined Lawrence Berkeley National Laboratory in 1996 as director of the newly formed NERSC Division. In 2004, Simon was appointed Associate Laboratory Director (ALD) for Computing Sciences at Berkeley Lab. In 2007, Simon was appointed adjunct professor in the Department of Electrical Engineering and Computer Science (EECS) at UC Berkeley.
In 2010, Simon was appointed Deputy Laboratory Director and Chief Research Officer (CRO) of LBNL. In collaboration with the senior laboratory scientific leadership, he develops, funds, and monitors the progress of the multidisciplinary laboratory research initiatives. In 2018 these include water-energy research, machine learning for science, microbiome research for environmental application, quantum information science, advanced microelectronics beyond Moore’s law, and biogenic materials and chemistry.
From 2012 to 2014 Simon had assumed the leadership role in the development of the “second campus” at LBNL, a project to create a new site for the expanding programs at LBNL in biosciences and the environment. From 2014 onnward, Simon focused his activities on developing the strategic thrust of “Energy Innovation” at Berkeley Lab. Since 2016 Simon is leading the Diversity and Inclusion in Science working group at LBNL, exploring new structures to recruit and retain a more diverse workforce.
ADIA Lab (2022-present)
Simon was appointed in 2022 as the founding director of ADIA Lab, an independent research centre for data and computational sciences based in Abu Dhabi, United Arab Emirates.
Selected publications
Articles
Books
Awards and nominations
1998 — Gordon Bell Prize (jointly with group from Cray and Boeing) in recognition of his efforts in parallel processing research.
1995 — H. Julian Allen Award (jointly with the NAS Parallel Benchmarks Team) for notable scientific papers written by authors at NASA Ames Research Center, for the NAS Parallel Benchmarks.
2009 — Gordon Bell Prize (in collaboration with IBM researchers) for the second time for the development of innovative techniques that produce new levels of performance on a real application.
2012 — Gordon Bell Prize Finalist (jointly with group from Intel and LBNL) for development of best price performance application.
2015 — Test of Time Award (ACM), for the long term impact (citations) of the paper “NAS Parallel Benchmarks” (jointly with the NAS Parallel Benchmarks team).
2016 — Society for Industrial and Applied Mathematics - Supercomputing Career Award.
References
External links
1953 births
Living people
Computer scientists
German computer scientists
Technische Universität Berlin alumni | Horst D. Simon | [
"Technology"
] | 1,039 | [
"Computer science",
"Computer scientists"
] |
73,805,271 | https://en.wikipedia.org/wiki/Hue-heat%20hypothesis | The hue-heat hypothesis is the hypothesis that an environment with warm colors (red, orange yellow hues) will feel warmer in terms of temperature and comfort, while an environment with cold colors (blue, green hues) will feel cooler.
The idea is both investigated scientifically and ingrained in popular culture in the terms warm and cold colors.
See also
Color temperature
References
Lighting
Color
Perception | Hue-heat hypothesis | [
"Engineering"
] | 80 | [
"Design stubs",
"Design"
] |
73,805,306 | https://en.wikipedia.org/wiki/Exobiology%20Extant%20Life%20Surveyor | Exobiology Extant Life Surveyor, (also called EELS) is a snakebot vehicle originally designed to explore the surface and the oceans of Enceladus, a moon of Saturn. The JPL has also referred to the possibility of using EELS to explore locations such as lunar lava tubes, Mars's polar caps, and Earth's ice sheets.
It uses multiple segments containing actuation, propulsion, power and, communication electronics. The segments use corkscrews to move across the ground.
These corkscrews can act as propellers while underwater.
, the current version (1.0) weighs approximately , and is or 10 segments long. EELS has no scientific instruments, uses stereo cameras and Lidar, and it uses a tether for power and communications.
References
Robotic sensing
Lidar
Planetary rovers
Jet Propulsion Laboratory | Exobiology Extant Life Surveyor | [
"Astronomy"
] | 167 | [
"Astronomy stubs",
"Spacecraft stubs"
] |
73,805,427 | https://en.wikipedia.org/wiki/Satureja%20gilliesii | The scientific name Satureja gilliesii has been used for two different species of plants:
Satureja gilliesii (Graham) Briq., basionym Gardoquia gilliesii Graham, a synonym of Clinopodium chilense (Benth.) Govaerts
Satureja gilliesii (Benth.) Briq., nom. illeg., basionym Micromeria gilliesii Benth., a synonym of Clinopodium gilliesii (Benth.) Kuntze
It should not be confused with Satureja gillesii, a name associated with Calamintha gillesii Sennen, a synonym of Clinopodium nepeta subsp. nepeta.
References | Satureja gilliesii | [
"Biology"
] | 157 | [
"Set index articles on plants",
"Set index articles on organisms",
"Plants"
] |
73,805,564 | https://en.wikipedia.org/wiki/Mendix | Mendix is a cloud-based low-code application development platform that provides tools for organizations to build web and mobile applications using visual drag-and-drop elements. Mendix was founded in 2005 in Rotterdam, the Netherlands. Its US headquarters are located in Boston. Since 2018, Mendix has been a Siemens subsidiary.
History
Mendix was founded in Rotterdam, the Netherlands, by Roald Kruit, Derek Roos, and Derckjan Kruit. Roald, a freelance software developer at the time, noticed a communication disconnect between software developers and end users, which often led to dissatisfaction with the developed applications. Using a visual development language, Mendix's founders wanted to create a platform that would enable better collaboration and understanding between developers and business users.
In October 2011, Mendix raised $13 million with its first round of venture capital funding.
In August 2018, the company's co-founder and CEO announced its acquisition by Siemens for $730 million in cash. The deal was finalized later that year. It was reported that Mendix would continue to operate as an independent entity. Siemens customers can use Mendix to extend functionality of Siemens software and create their own applications on top of it, such as connecting various IT systems or tracking the production of products in various facilities.
In February 2024, Raymond Kok was appointed as Mendix's new CEO.
Features
Mendix aims to support the entire software development lifecycle (SDLC) with an integrated development environment (IDE) with tools for businesses to build, test, iterate, and deploy applications driven by a visual programming language. Organizations can use their own or Mendix's servers to host their applications. According to Roos, the platform should not replace professional programmers instead of promoting collaboration with them, as "[p]rofessional IT people supply the technical, low-coder the logistics theme".
In 2014, Mendix introduced a free community edition of the platform without the private server deployment, app monitoring, backup, resource management, and enterprise support features.
The system is built on Java now, and starting from version Mendix 10.18, it will be based on React.
At CES 2024 in January 2024, Siemens and AWS announced they were integrating Mendix with Amazon Bedrock, a machine learning platform used to build generative artificial intelligence applications on AWS cloud computing platform.
References
2005 establishments
Enterprise architecture
Software development
Companies based in Boston
Low Code Application Platform | Mendix | [
"Technology",
"Engineering"
] | 517 | [
"Software engineering",
"Computer occupations",
"Software development"
] |
73,805,874 | https://en.wikipedia.org/wiki/Sustainable%20employability | Sustainable employability generally refers to employees’ capacities to function in work and on the labor market throughout their working lives. The topic emerged in response to population aging and the pressure that puts on retirement systems. This pressure requires the maximization of participation in paid work to be able to maintain valued retirement systems and other societally valued institutions (e.g., high quality healthcare). Consequently, research in this topic area focuses on identifying aspects of an employment situation (i.e., the work, work context, and individuals themselves, that prevent harm to individuals' ability to function at work and on the labor market. The purpose of this research is to ultimately develop interventions, in organizations that enable individuals to work in ways that are beneficial - or at least not harmful - to both themselves and the organizations they may be employed in. Much of the initial research has concentrated on older workers as this specific group was considered to need the most immediate attention. However, later work questions whether age really place such an important role in sustainable employability.
Most definitions of sustainable employability incorporate several domains of functioning at work. As workplace functioning is a multifaceted concept, aspects like employability, work ability, work engagement (sometimes referred to as 'vitality' in the context of sustainable employability) are included. However, several definitions have been forwarded in the scientific literature that differ in nuanced ways and that emphasize different aspects of functioning. Other approaches particularly propose defining sustainable employability as a form of an enduring fit between a person and their work. Such approaches show a strong connection to previous thinking on Person-Job fit and Person-Environment fit, with the extension that such a fit should be good and be sustained over time.
A commonly cited definition of sustainable employability is based on Amartya Sen's concept of capabilities. Within this capability approach to sustainable employability, individuals are considered to be sustainably employable when they have the capabilities to achieve things they value in their work and are enabled by their work to do so. Specifically, within this approach, seven capabilities that people are thought to generally value and hope to achieve via their work are a) using their knowledge and skills; b) developing their knowledge and skills; c) being involved in important decisions regarding their work; d) building meaningful relationships in work; e) setting their own goals in work; f) earning a good income via work; and g) contributing to creating something valuable in work. Importantly, this approach recognizes that work environments are crucial in facilitating people to work. However, the approach has received some criticism, as capabilities constitute both characteristics of individuals and their employment context, which complicates separating cause and effect.
Most recent approaches to sustainable employability integrate the above ideas and resolve their limitations. They do so by recognizing sustainable employability as an integrative concept that consists of several aspects of functioning, emphasizing the long term component of sustainability and the need for longitudinal research, and positioning sustainable employability as an outcome of interacting work, work contextual and individual characteristics.
As the field of sustainable employability research matures, research increasingly considers sustainable employability of specific groups of workers or segments of the labor market. Additionally, this initially Northern European topic is now increasingly studied in other parts of the world and particularly those that face similar labor market or social security systems issues.
References
Employment
Organizational behavior
Labor studies | Sustainable employability | [
"Biology"
] | 680 | [
"Behavior",
"Organizational behavior",
"Human behavior"
] |
73,806,366 | https://en.wikipedia.org/wiki/Paleobiota%20of%20the%20Klondike%20Mountain%20Formation | The Paleobiota of the Klondike Mountain Formation comprises a diverse suite of Early Eocene plants and animals recovered in North Central Washington State from the Klondike Mountain Formation. The formation outcrops in locations across the north western area of Ferry County, with major sites in Republic, north west of Curlew Lake, and on the Toroda Creek area. The formation is the southern most of the Eocene Okanagan Highlands, sharing much of the paleoflora and paleofauna with site across Central and southern British Columbia.
Plants
Bryophytes
Dillhoff et al. (2013) reference undescribed moss specimens known from the Klondike Mountain Formation known from vegetative gametophytes and they noted them to be similar to undescribed specimens from the Allenby Formation and Horsefly shales.
Lycophytes
Rare specimens of Selaginella fossils were noted by Wehr (1998), with no species level description.
Pteridophytes
Gymnosperms
Three major groups of gymnosperms are present in the Klondike Mountain Formation, with the most speciose being the pinophytes. The ginkgophytes are represented by two species of Ginkgo, while an undescribed Zamiaceae member is the sole cycadophyte.
Cycadophytes
Gingkophytes
Pinophytes
Flowering plants
Angiosperms, commonly called flowering plants belong to a single plant clade which diverged from other plants during the prior to the Cretaceous, and began to rapidly evolve and radiate by the Middle Cretaceous. Angiosperm diversification during the Cretaceous and Paleocene resulted in eight recognized clades that are segregated into two groups the Basal angiosperms and Core angiosperms. Present in the Klondike Mountain Formation are four of the eight groups, Nymphaeales representing Basal Angiosperms, plus Magnoliids, Monocots, and Eudicots all in the Core angiosperms.
Nymphaeales
The Basal Angiosperms are represented by a single Nymphaeales water-lily species Nuphar carlquistii, though a second member, Allenbya collinsonae, has been described from the Princeton Chert. Wehr (1995) illustrated two fossils that were tentatively identified as fruits of the banana genus Ensete and the extinct myrtle genus Paleomyrtinaea respectively, however further fossil finds resulted in the re-identification of the first as a N. carlquistii rhizome section, and the second is a seed mass from the same water-lily.
Magnoliids
Under the APG IV system of flowering plant classification, the magnoliids are divided into four orders Canellales, Laurales, Magnoliales, and Piperales. Member species and undescribed taxa placed confidently in the Laurales and Magnoliales are present in the formation. The laurales are the most diverse magnoliid order of the formation with one described species Sassafras hesperia plus three tentatively identified genera which have not been described. Of the magnoliales, only an undescribed Magnolia, having possible affinity with Magnolia subg. Talauma, is found in the formation, while Liriodendroxylon princetonensis has described from permineralized wood in the Princeton Chert. The extinct angiosperm genus Dillhoffia has noted similarities to the piperalean family Aristolochiaceae, but was left incertae sedis as to family by Manchester and Pigg (2008) due to a lack of confident morphological characters for placement. Piperales are known from the Princeton chert, with Saururus tuckerae representing the oldest confident Saururaceae species in the fossil record.
Monocots
The second largest clade of flowering plants, monocots are divided into eleven separate orders and of those, the Alismatales, Asparagales, Liliales, and Poales are found in the Klondike Mountain Formation, each represented by a single taxon. The Alismatales are represented by the Araceae species Orontium wolfei, which is considered similar to the modern golden clubs of eastern North America, while the extinct Paleoallium belongs to the Liliales. Asparagales and Poales are both present as undescribed species associated with the genera Smilax and Typha respectively. Extinct genera of monocots are also represented in the Princeton chert by the arecalean palm Uhlia, the alismatalean genus Heleophyton, the alismatalean Keratosperma, the asparagalean pollen morphogenus Pararisteapollis, the lilialean genus Soleredera, and the poalean genus Ethela,
Eudicots
Over a dozen different Rosaceae genera, both extant and extinct, have been identified in the formation providing some of the oldest reliable macrofossil records (excluding fossil pollen) for the family. Benedict et al. (2011) described first fossils for the prunoid genus Oemleria along with the oldest Prunus flowers. The Prunus flowers are complemented by leaf fossils representing five to six distinct morphotypes. Spiraea is known from an inflorescence with multiple flowers and leaves that are either from the genus or a closely related extinct type. The leaves frequently are preserved with a persistent stipule, a feature not found in modern Spiraea species. The firethorn genus Pyracantha and the South American genus Hesperomeles have been tentatively identified from leaves while Maloidea leaves belonging to either Malus or Pyrus have been found. Two distinct species of the Asian endemic genus Photinia are known, however only one of them Photinia pagae had been described as of 2007. The rosaceous genus Physocarpus had been reported by Hopkins and Wehr (1994) as also occurring in the formation, however subsequent examination of the fossils by Oh & Potter (2005) failed to find stellate trichomes which are a distinct feature of the genus. They noted the fossils might be stem Neillieae, the rose tribe containing both Physocarpus and Neillia, or possibly Rubus, Crataegus, or Ribes.
Fossils of both Sorbus and Rhus species leaves showing evidence of being interspecies hybrids have been noted from the formation and Flynn, DeVore and Pigg (2019) described four species of sumac which formed multiple hybrids. Between three and four Trochodendraceae species that have been described from the Klondike Mountain Formation. Broadly circumscribed four species in three genera have been identified at Republic, Paraconcavistylon wehrii, Pentacentron sternhartae, Tetracentron hopkinsii, and Trochodendron nastae. Additionally the species Trochodendron drachukii is known from related Kamloops group shales at the McAbee Fossil Beds near Cache Creek, British Columbia. Manchester et al. 2018 noted that Tr. drachukii is likely the fruits of Tr. nastae, while Pe. sternhartae are likely the fruits of Te. hopkinsii. If fossils of the fruits and foliage in attachment are found, that would bring the species count down to three whole plant taxa. Additionally, the extinct genus Nordenskioldia is also known from the formation. The placement of Nordenskioldia is debated, with some treatments placing it into Trochodendraceae, while a 2020 analysis placed it outside of the crown-group Trochodendaceae. Wesley Wehr in 1994 reported Bignoniaceae seeds along with a single Rubiaceae fruit and an isolated Fabaceae leaf. An update of the floral list by Wehr and Manchester published in 1996 added an additional fifteen taxa identified from reproductive structures such as flowers fruits or seeds.
Pigg, Manchester, and Wehr (2003) noted in during the description of Corylus johnsonii and Carpinus perryae that they were the oldest confirmed hazelnut and hornbeam fossils. That status was affirmed by Forest et al. (2005) who used both as fossil calibration points for phylogenetic analysis of Betulaceae. Within the family Bignoniaceae, the fossil seeds and fruits are noted by Ze-Long Nie et al (2006) as the oldest confirmed for the family.
Animals
Arthropods
The insect fauna of the Klondike Mountain Formation includes representatives from over 13 orders, based on a 1992 estimate, including immature though adult specimens and both terrestrial and aquatic taxa. The most prevalent orders are Diptera and Hemiptera, each making up approximately 30% of the fossil insects known in 1992.
Blattodea
Coleoptera
A list of Coleopteran families identified by 1992 included Carabidae, Cerambycidae, Chrysomelidae, Curculionidae, Dytiscidae, Elateridae and Lucanidae, but the beetle fauna has not been described in depth yet, with only two weevil species having been fully described. A third beetle group belonging to the bean beetle tribe Pachymerini has been identified as palm beetles of the Caryobruchus–Speciomerus genus group.
Dermaptera
The order Dermaptera was first reported in 1992 and is known from a series of isolated partial specimens, mostly abdominal sections with the distinct anal forceps attached. Based on the forceps structuring the specimens were tentatively assigned to the modern family Forficulidae, as the oldest North American representatives of the family known at that time.
Diptera
Ephemeroptera
Lewis (1992) listed one species of Heptageniidae and three specimens that he did not place to family. The next year Lewis and Wehr (1993) gave a slightly more detailed description of the specimens again identifying one to Heptageniidae, possibly in the genera Heptagenia or Stenonema. The specimens were later examined by Nina D. Sinitchenkova (1999) who described one as a squaregill mayfly and the oldest member of the genus Neoephemera, confirmed the Heptageniidae
identification but that it was unidentifiable to genus. The last specimen she confirmed as an ephemeropteran, but unidentifiable below order level.
Hemiptera
Hymenoptera
A review of the Okanagan highlands hymenoptera published in 2018 identified four "Symphyta" families in the formation Cimbicidae, Pamphiliidae, Siricidae, and Tenthredinidae. Of the "Apocrita" families thirteen are represented, the "Parasitica" families are Braconidae, Diapriidae Ichneumonidae, Proctotrupidae, and Roproniidae while the Vespoidea families are Formicidae, Pompilidae, Scoliidae and Vespidae. Within Apoidea the "Spheciformes" families include Angarosphecidae and Sphecidae while Halictidae is the sole "Apiformes" family known from body fossils. Prunus and Ulmus leaves have been found having damage that is consistent with the damage pattern left by Megachilidae species bees when they remove sections of tissue for nest lining. There are several additional Apoidea fossils that were left as incertae sedis in the group based on the similarity between them and Paleorhopalosoma menatensis, a Paleocene species described from the Menat Formation Auvergne, France. The placement of P. menatensis is uncertain, having been initially described as a member of Rhopalosomatidae, but is possibly an Angarosphecidae or closely related taxon, based on the wing and body morphology.
Lepidoptera
A solitary lepidopteran body fossil has been recovered, but no full descriptive work has been made on the specimen, aside from a single PhD dissertation. Early examination placed the moth in the family Geometridae, but later work has identified it as the oldest member of the tiger moth subfamily Arctiinae. Trace fossil evidence from leaf fossil herbivory indicates at least four other possible lepidopteran families were present in the formation.
Mecoptera
A number of mecopteran species belonging to the families Cimbrophlebiidae, Dinopanorpidae, Eorpidae, and Panorpidae are also known.
Neuroptera
The neuropteran insects (lacewings and their allies) identified as of 2014 include species from the families Berothidae, Chrysopidae, Hemerobiidae, Ithonidae (including Polystoechotidae), Nymphidae, Osmylidae, and Psychopsidae.
Odonata
Orthoptera
Phasmatodea
Fossil wings first described in 2015 were identified as being from Susumanioidea stick-insects, a group that had previously been known from the Jurassic to the Paleocene only. Archibald and Bradler (2015) did not place Eoprephasma into Susumaniidae family, maintaining that known characters of the describe specimens did not match taxa in the family, they instead kept the genus as Susumanioidea incertae sedis. Phylogenetic analysis of Susumanioidea published by Yang et al. (2021) resulted in placement of Eoprephasma as the sister group to Renphasma deep within the Susumaniidae subfamily Susumaniinae. The phylogeny produced by Yang et al. indicated a sister group state with the Cretaceous genus Renphasma of China, and placed both as the most derived of the Susumaniinae taxa.
Raphidioptera
Trichoptera
Trichopterans are known mainly from laraval cases and occasional isolated wings.
Vertebrates
Five species of fish have been identified from the formation, four of which are known from skeletal elements, while the fifth is only known from isolated scales. Of the five species, two are unique to the formation, Hiodon woodruffi and Libotonius pearsoni were both described by paleoichthyologist Mark V. H. Wilson in 1978 and 1979 respectively. The other three species, "Amia" hesperia, Amyzon aggregatum, and Eosalmo driftwoodensis, were first described from Okanagan Highlands formations in British Columbia and subsequently also identified from Ferry County fossils. The first notation of fish fossils in the Republic area was by Joseph Umpleby in his 1910 visit to the area, who collected fish near the Tom Thumb Mine, and sent them to the National Museum of Natural History. After examining the fossils, Charles R. Eastman listed the specimens as belonging to the extinct species Amyzon brevipinne in his Fossil fishes in the collection of the United States National Museum. Research tapered off until a series of fish were collected in the Toroda Creek Graben northwest of Republic by Robert Carl Pearson during his early 1960's field mapping for the Geologic map of the Bodie Mountain quadrangle, Ferry and Okanogan Counties, Washington. The fossils were tentatively identified by paleoichthyologist David Dunkle in 1962 and 1965 as members of the genera Amyzon, Tricophanes, Erismatopterus and an undefined salmonid. Pearson sent almost all of the specimens collected to the Smithsonian, but the fossils were never accessioned into the collections and are now considered lost. He did retain one fossil from the initial collection which was later donated to the USGS collections. The largest single work on the fish of the Okanagan Highlands was published by Mark Wilson in 1977 and covered fossils collected from the known British Columbian Okanagan Highlands fossil sites of the time. While not covering the Washington State fossils, Wilson named two of the species that are currently recognized from the Klondike Mountain Formation Amyzon aggregatum and Eosalmo driftwoodensis. Additionally scales attributed to the genus Amia were discussed and the genus Libotonius was named from fossils in the Allenby Formation. In the late 1960s a collection of fish from near the Tom Thumb Mine in Republic was compiled by resident R. Woodward. During the summers of 1976 and 1977 the University of Alberta conducted field collecting in both the Republic and Toroda Creek areas, along with the donation of the Woodward collection, yielded a number of fossil catostomids, along with a single percopsid, a salmonid, a hiodontid, and an Amia scale. The hiodontids were subsequently described as the species Eohiodon woodruffi in 1978 based on differences between the Tom thumb Tuff fossils and those found in British Columbian sites. A year later the percopsid fossils were also described as Libotonius pearsoni, extending the range of the genus south from the Allenby Formation.
Bird fossils are limited to mostly isolated feathers that are preserved in the finer grained strata of the lake bed, though one partial bird skeleton has also been recovered.
References
Klondike Mountain Formation
Klondike Mountain
Klondike Mountain Formation
Klondike Mountain Formation | Paleobiota of the Klondike Mountain Formation | [
"Biology"
] | 3,557 | [
"Cenozoic paleobiotas",
"Prehistoric biotas"
] |
73,806,646 | https://en.wikipedia.org/wiki/No%20Filter%3A%20The%20Inside%20Story%20of%20Instagram | No Filter: The Inside Story of Instagram is a non-fiction book written by American journalist and author Sarah Frier. Published by Simon & Schuster in 2020, the book presents an in-depth look into the history and inner workings of the popular social media platform, Instagram.
Overview
No Filter: The Inside Story of Instagram offers an exhaustive account of Instagram's journey from a small start-up to one of the world's most influential social media platforms. Frier draws on interviews with Instagram's founders, Kevin Systrom and Mike Krieger, as well as employees, competitors, and users to tell the story of Instagram's creation, growth, and acquisition by Facebook.
The book delves into Instagram's distinct ethos of crafting beautiful images, which set it apart from other social media platforms. It also explores the influence Instagram has had on global trends in areas such as food, fashion, and travel, and how it has reshaped the nature of celebrity and advertising.
Frier also investigates the tensions that arose after Facebook's acquisition of Instagram in 2012. The book chronicles the struggles for autonomy within the corporate structure of Facebook and the eventual departure of Systrom and Krieger from the company.
Reception
No Filter received a positive review from The Hindu for its comprehensive and insightful look into the evolution of Instagram. It was praised for its detailed reporting and analysis of the impact of Instagram on society and culture.
The book won the 2020 Financial Times and McKinsey Business Book of the Year Award. In their citation, the judges described "No Filter" as "a compelling saga" filled with "vivid reporting" and "sharp analysis".
References
2020 non-fiction books
Books about the media
Books about companies
Instagram
Social media
Simon & Schuster books | No Filter: The Inside Story of Instagram | [
"Technology"
] | 371 | [
"Computing and society",
"Social media"
] |
73,807,818 | https://en.wikipedia.org/wiki/Nuria%20Llombart | Nuria Llombart Juan is an electrical engineer who studies quasioptics, antennas for terahertz radiation, and their applications including 3D imaging and submillimeter astronomy. Educated in Spain and Germany, she works in the Netherlands as a professor in the Department of Microelectronics at the Delft University of Technology.
Education and career
Llombart earned a master's degree in 2002 and a Ph.D. in 2006 from the Technical University of Valencia, including study as a visiting student at the University of Erlangen–Nuremberg.
During her doctoral studies, she worked in the Security and Safety Institute of the Netherlands Organisation for Applied Scientific Research in The Hague. After postdoctoral research at the California Institute of Technology from 2007 until 2010, and as a Ramón y Cajal fellow in optics at the Complutense University of Madrid from 2010 until 2012, she returned to the Netherlands in 2012, taking a position at the Technical University of Delft. She became a full professor there in 2018.
Recognition
Llombart was the recipient of the 2014 IEEE Antenna and Propagation Society Lot Shafai Mid-Career Distinguished Achievement Award, "for her original contributions to terahertz antennas and quasi-optical systems, academic leadership, and proven role model for women in antenna engineering". She was named an IEEE Fellow, in the 2020 class of fellows, "for contributions to millimeter and submillimeter wave quasi-optical antennas".
References
External links
Terahertz Sensing group, TU Delft
Year of birth missing (living people)
Living people
Electrical engineers
Women electrical engineers
Technical University of Valencia alumni
Academic staff of the Delft University of Technology
Fellows of the IEEE | Nuria Llombart | [
"Engineering"
] | 339 | [
"Electrical engineering",
"Electrical engineers"
] |
73,812,406 | https://en.wikipedia.org/wiki/Kolmogorov%20Prize | The Kolmogorov Prize is a mathematical prize awarded by the Russian Academy of Sciences for outstanding results in the field of mathematics. It bears the name of the mathematician Andrey Kolmogorov.
The award was established by a Decree of the Presidium of the Russian Academy of Sciences on February 23, 1993. As a rule, it is awarded every three years.
Awarded Scientists
The following scientists have won the award:
1994 — Albert Shiryaev
1997 — Nikolay Nekhoroshev
2000 — Sergey Nikolsky
2003 — Anatoli Vitushkin
2006 — Alexei Semenov
2006 — Andrey Muchnik
2009 — Boris Gurevich
2009 — Valeriy Oseledets
2009 — Anatoly Styopin
2012 — Boris Kashin
2015 — Aleksandr Borovkov
2015 — Anatoly Mogulsky
2018 — Vladimir Bogachev
2018 — Stanislav Shaposhnikov
2018 — Andrey Kirillov
2021 — Alexander Bulinsky
References
Academic awards
Mathematics awards
Awards established in 1993 | Kolmogorov Prize | [
"Technology"
] | 203 | [
"Science and technology awards",
"Mathematics awards"
] |
73,813,252 | https://en.wikipedia.org/wiki/Pentaoxidane | Pentaoxidane is an inorganic compound of hydrogen and oxygen with the chemical formula . This is one of the most unstable hydrogen polyoxides.
Synthesis
The compound is prepared as a byproduct of trioxidane production.
has also been synthesized by reaction among peroxy radicals at low temperature.
References
Inorganic compounds
Oxides
Polyoxides
Oxoacids | Pentaoxidane | [
"Chemistry"
] | 77 | [
"Inorganic compounds",
"Oxides",
"Salts"
] |
73,813,366 | https://en.wikipedia.org/wiki/Ecohydraulics | Ecohydraulics is an interdisciplinary science studying the hydrodynamic factors that affect the survival and reproduction of aquatic organisms and the activities of aquatic organisms that affect hydraulics and water quality. Considerations include habitat maintenance or development, habitat-flow interactions, and organism responses. Ecohydraulics assesses the magnitude and timing of flows necessary to maintain a river ecosystem and provides tools to characterize the relation between flow discharge, flow field, and the availability of habitat within a river ecosystem. Based on this relation and insights into the hydraulic conditions optimal for different species or communities, ecohydraulics-modeling predicts how hydraulic conditions in a river change, under different development scenarios, the aquatic habitat of species or ecological communities. Similar considerations also apply to coastal, lake, and marine eco-systems.
In the past century, hydraulic engineers have been challenged by habitat modeling, complicated by lack of knowledge regarding ecohydraulics. Since the 1990s, especially after the first International Symposium on Ecohydraulics in 1994, ecohydraulics has developed rapidly, mainly to assess the impacts of human-induced changes of water flow and sediment conditions in river ecosystems...
Ecohydraulics analyzes, models, and seeks to mitigate the adverse impacts of changes in hydraulic characteristics caused by dam construction and other human activities, on the suitability of habitat for organisms, such as fish and invertebrates, and to predict changes in biological communities and biodiversity. Many articles report research findings about fluvial ecohydraulics. For example, the International Association for Hydro-Environment Engineering and Research (IAHR) and Taylor & Francis have been publishing the Journal of Ecohydraulics since 2016. The journal spans all topics in natural and applied ecohydraulics in all environmental settings.
Key Concepts
An aquatic ecosystem is defined as a community of aquatic organisms, with the species dependent on each other and on their physical-chemical environment and linked through flows of energy and materials. The distribution patterns of species are affected by the spatial and temporal characteristics of water flow.
Flow velocity affects the delivery of food and nutrients to organisms. It can also dislodge organisms and prevent them from remaining at a site. Some vertebrates and invertebrates, such as the shellfish Corbicula fluminea, filter their food through flowing water. Flow velocity and turbulence are critical to the life activities of many species. For example, some fish migrate and some fish spawn when they detect high flows. However, extremely high flow velocity, or high intensities of turbulence, created by hydraulic engineering infrastructure can exert pressure on most fish and invertebrates and even kill them. When the flow velocity is below 0.1 m/s, the biological community in a river is similar to that in a lake. Usually, in rivers, flow velocity between 0.1–1 m/s is most suitable for major-stream fish species.
High flow velocity and turbulence are cues for timing migration and spawning of some fish. Asian carp lay floating eggs when they sense increasing discharge resulting from a spring flood flow. The settling velocity of the eggs varies in the range of 0.7-1.5 cm/s. Once a carp egg settles on the riverbed, the egg cannot hatch. Only if flow velocity exceeds the settling velocity can an egg remain in suspension and complete incubation within 24–40 hours.
Golden mussels (Limnoperna fortune) are an invasive filter-feeding macro-invertebrate species. Dense attachment of the species to the boundaries of water-transfer tunnels and pipelines results in biofouling, causing high resistance to water flow and damage to pipeline walls. This consequence, along with the decay of dead mussels, harm water quality. Golden mussel larvae can be killed by high-frequency turbulence and increased flow velocity. Experiments show that the larvae can be killed in a flow field with velocities in excess of 0.08-0.15 m/s and a turbulence frequency higher than 30 Hz. Preliminary results have shown that the higher the turbulence intensity the higher the mortality of golden mussel larvae. On the other hand, low vertical mixing or turbulence is a key factor in favoring the development of harmful algal blooms.
Reservoirs are operated according to the requirements of power generation, water supply, navigation, and, in recent decades, environmental flows. Thus, the time and magnitude of peak discharge of floods may change, which thereby affect the life cycle and habitat of aquatic bio-communities. Most faunal species in a river cannot adapt to the non-natural change of flow and disappear from the reach downstream of the dam. Fish stranding caused by reservoir operation has occurred downstream of hydropower stations in many countries. A hydro-power dam, such as Fengshuba Dam on the East River, China, releases water suddenly during daytime and shuts off at night to meet an unsteady power demand. The instantaneous fluctuation in flow discharge and velocity kills most species except for those (e.g., the small shrimp, Palaemonidae) that can hide in crevices in riverbed sediment.
Water depth is crucial for large fauna. The habitats created by shallow rapids of small rivers in mountainous areas typically suit invertebrates and small vertebrates. Only mountain streams with many deep pools can have medium-sized creatures such as rainbow trout. White-flag dolphin, Chinese sturgeon, and finless porpoise require the water depths associated with the middle and lower reaches of the Yangtze River, where there is sufficient water depth for them to grow and hide. On the other hand, few animals can live in the lower layers of deep lakes and reservoirs, because of low dissolved-oxygen (DO) concentration.
Temperature is an important factor for many species. Salmon can only survive in cold water rivers. The Mississippi and Yangtze rivers are not suitable for salmon due to high temperatures. However, aquatic insects grow and develop more rapidly in tropical and subtropical rivers than in temperate rivers. Some species may complete two or more generations per year at warmer sites yet only one or fewer at cooler sites. Some dragonfly species on the Tibetan Plateau live for more than ten years in cold water before attaining sexual maturity and eclosion.
Variability of hydraulic characteristics is essential for biodiversity. A wide variety of flow velocities, water depths, and temperatures, both spatial and temporal, are needed to maintain high levels of biodiversity in aquatic ecosystems.
Eutrophication refers to the enrichment of a water body by nutrients to a level that results in algal blooms, deterioration in water quality, and undesirable disruption to the balance of an aquatic ecosystem. Eutrophication and algal blooms occur in rivers, lakes, estuaries, coastal, and marine waters. Algal blooms in lakes and coastal waters may lead to massive fish kills. The onset and the risk of algal blooms are closely related to the hydraulic flow and vertical turbulent mixing processes. This relationship has been shown by a real-time forecasting and warning system established to monitor algal and DO dynamics. Monitoring shows that diurnal DO fluctuations mirror the algal biomass. Algae of high density can increase fluid viscosity by more than 100%. Real-time monitoring and early warning systems can help with adaptive management to mitigate the harmful effects of massive algal blooms.
Emergent vegetation (e.g., reeds and bulrushes) on floodplains and riparian wetlands imposes significant resistance to overbank flow. The resistance of emergent vegetation is so great that the resistance coefficient in the equations of hydraulics requires adjustment. For instance, the Manning's n increases tenfold as flow depth increases from 0.03 to 0.5 m, mainly due to emergent vegetation. Emergent and submerged vegetation change the turbulence structure and sediment transportation, and may cause these quantities to vary with flow velocity over a floodplain.
Aquatic animals may change flow and sediment transportation. Initiation of motion for sediment and transportation are affected by salmonid spawning. Clustering of bed gravel is important to embryo survival of the species. The spawning fish move the riverbed pebbles and bury their eggs underneath and the egg burial depth tends to be just deeper than the observed scour depth. The species has adapted its egg placement strategy to the process of flood scouring. Beavers may construct wood dams across small streams and the beaver dams alter the hydrological process and hydraulic characteristics of a stream. Invasion of Zebra mussels and Golden mussels into pipelines, such as the cooling water pipeline of a hydro-power plant, can block pipelines and hamper power generation.
Habitat is an area where plants or animals normally live, grow, feed, reproduce, and otherwise exist for any portion of their life cycle. Because each species responds differently to environmental and biotic conditions, the term habitat is specific to a species, and in more general terms, specific to guilds of species; for example, 'fish habitat' is specific to fish. Hydraulic attributes are considered to be the most important features of habitat for almost all organisms in rivers. The biological diversity and species abundance in streams depend on the diversity of available habitat. The slope, planform, confinement, and cross-sectional shape and dimensions of a stream, and the grain-size distribution of bed sediment affect aquatic habitat. Under less disturbed situations, a narrow, steep-walled cross section provides less physical area for habitat than does a wide cross section. A steep, confined stream is a high-energy environment that may limit the occurrence, diversity, and stability of habitat.
Substrate is a general term that refers to all material that constitutes a riverbed or stream bed, which in most cases mainly comprise sediment. Stream-bed and bank erosion, sediment transportation, and deposition are among the most important factors that affect aquatic habitat. Stable streams are streams with a stable channel bed, which normally features energy-dissipation structures and little bed-load motion (transport of particles from a bed). Such streams have the best habitat for fish and benthic invertebrates. Incised streams are streams experiencing channel bed erosion, which provide the second-best habitat. Streams with intensive bed-load motion and sedimentation provide bad habitat for organisms. The taxa richness or biodiversity of these different types of rivers varies extremely because of different magnitudes of erosion, sedimentation, and sediment transportation. A uniform sand bed in a stream provides less potential habitat diversity than a bed with a step-pool system, boulder cascades, rapids, pool-riffle sequences, or other types of "bed structures" because of the resting places such feature provide.
Hyporheic zone is a layer of substrate on the riverbed in which benthic animals normally live or exist for any portion of their life cycle. Animals in the hyporheic zone usually are protected from severe washouts and temperature extremes. Other species prefer the stream bed surface for its higher DO concentration, direct contact with flowing water, and high food availability. Macro-invertebrates inhabit a sediment bed layer with a thickness of about 40–55 cm in gravel beds, 60 cm in cobble beds, 10–30 cm in coarse sand beds, and 5–10 cm in fine sand beds. The thickness of the zone in clay and silt beds is about 30 cm because the bed is relatively soft; some macro-invertebrates can move within the fluid mud layer.
Environmental Flows are defined as the quantity, timing, and quality of freshwater flows and levels necessary to sustain aquatic ecosystems which, in turn, support human cultures, economies, sustainable livelihoods, and well-being. The natural flow regime plays a critical role in sustaining native biodiversity and ecosystem integrity in rivers. The concepts and terminology vary across countries，such as minimum flow, environmental flow regime, environmental water, ecological flows. In the 2010s, the assessments of environmental flows at the basin scale have greatly evolved with the application of habitat-based methods or holistic methods, to balance the environmental flows and water uses, e.g. agriculture and hydropower, in the water planning at the watershed or river basin scale. In addition, some methodologies of water planning evaluate performance in river systems including stress tests, which consider the uncertainty associated with climate and global change, and evaluate the feasibility of balancing environmental flows and other water uses. For instance, several irrigation schemes were being considered for development of the Kilombero River Basin, Tanzania. It was determined what quantity of water could be abstracted from the river without degrading the ecological condition.
Basic Principles and Models
High habitat diversity supports high biodiversity. Or stated alternatively, biodiversity depends on habitat diversity, which is defined as the diversity of habitat types suitable for different bio-communities. The physical conditions of stream habitats depend mainly on the following factors: 1) substrate; 2) water depth; and 3) flow velocity. Different physical conditions support different bio-communities, so diversified physical conditions may support diversified bio-communities. Habitats with flow velocity less than 0.3 m/s are suitable for species that swim slowly. Habitats with flow velocity higher than 1 m/s are suitable for species that like high flow velocities. Fish species diversity and richness are strongly related to the combination of the effects of substrate, velocity, and depth, which can be represented by the Habitat Diversity Index. Field investigations have shown that a stream with different substrates is suitable for a large variety of invertebrate species and has a high biodiversity. The species richness, or number of species, S, is proportional to the habitat diversity index.
Cut-off of connections of habitats impairs ecology. Connections of habitats are essential for complex bio-communities and high biodiversity. Cut-off of the connections with artificial dams or locks reduces biodiversity and undermines the bio-communities. Some projects are intended to restore the connections of habitats.
The Yangtze River once connected thousands of riparian lakes in its middle and lower reaches, thereby forming a complex habitat system. Water flowed from the river to the lakes during the rising stage of floods and vice versa during the recession stage of floods. The river had high biodiversity and was home to 400 species of fish, 3 species of whales, and numerous species of amphibians, reptiles, birds, and invertebrates. The connection between the upper reaches and the middle and lower reaches, and the connections between the river and riparian lakes have been cut-off to reduce the cost of levee construction and to promote fish farming, resulting in the fragmentation of the complex habitats. Investigations have shown that cutting the connections has reduced the numbers of macroinvertebrate species by 60% and fish species by 40-50% in the lakes. There are 101 fish species in Poyang Lake, which remains connected to the Yangtze River, but only 57 and 47 fish species in Honghu Lake and Zhangdu Lake, respectively, which have been cut off from the river. Experiments have shown that a substantial reduction in the number of species and the abundance of macro-invertebrates occurs within 4 months after a riparian wetland is isolated from the river.
Resilience refers to an ecosystem's stability and capability to tolerate disturbances and restore itself. The resilience of an eco-system involves both the process and the outcome of successfully adapting to ecological stresses, and the ability to maintain its normal patterns of biomass production after being subjected to damage. If a disturbance were of sufficient magnitude or duration, a threshold may be reached where the ecosystem undergoes a regime shift, possibly permanently. Ecological projects, in some sense, are designed to enhance the resilience of ecosystems, reduce the time required for the ecosystem to return to an equilibrium, and increase the ecosystem's capacity to absorb disturbances and reorganize. A new paradigm in river and coastal management is evolving ecological enhancement, recreation, and aesthetics, as well as complying with strict environmental protection legislation. These complex projects require extensive data and simulation tools to assist decision makers and communities in selecting management strategies which offer the maximum benefits, whilst preserving and enhancing the ecological integrity of the river system.
Models, especially numerical models often are needed. A common approach to habitat studies is to apply numerical hydraulic modeling with the models included in PHABSIM. This approach is based on a one‑dimensional hydraulic characterization of a limited river reach under steady flow conditions. The model was tested to assess its capability to evaluate suitable habitat for Pacific and Atlantic salmon spawning and the results showed that the model works well for this lifestage, as spawning involves adult fish and is tightly coupled with hydrogeomorphology.
Vegetation affects the turbulence intensity and turbulence structure. Modeling of the dynamic process of vegetative succession describes the relation between the hydraulic characteristics of flood disturbances and the colonization and succession processes of vegetation on sediment bars and floodplains. The model is composed of modules for hydraulic, wood, and herbaceous plants, and soil nutrients. The model's hydraulic module simulates the processes of flood inundation, flushing, and sedimentation. The timing and locations of plant recruitment use the characteristics of a flood. The mortality of plants at each location during a flood is estimated from surface erosion rates obtained from a hydrodynamic model.
The gap between the existing model technology and the requirements of modeling the whole aquatic ecosystem on a wide range of spatial and temporal scales requires investigation. Physical habitat models are particularly useful for assessing the impact of hydropower projects, analyzing the effects of water abstraction on river ecology, and determining the minimum flow requirements of aquatic populations.
As mentioned above, hydraulic variables profoundly affect habitat utilization by biota. Fluvial habitat suitability curves have been developed for forty years. Also, habitat suitability models are applied to evaluate the ability of a habitat to support a particular species. Fish behavior has been analyzed in designing microhabitat in a meter-resolution two-dimensional (2D) microhabitat modeling.
Suitability indices are the core for habitat modeling, which may be illustrated for the Chinese sturgeon. The life cycle of the Chinese sturgeon in the Yangtze River mainly comprises spawning, hatching, and maturation. Brood fish seek suitable spawning sites and adhere fertilized eggs to stones, which hatch after about 120 to 150 h. Juvenile sturgeon swim to the East China Sea and stay there until they reach maturity. Ten aquatic eco-factors influence the habitat suitability of the Chinese sturgeon: 1) water temperatures for adults and juveniles (V1, °C); 2) water depth for adults (V2, m); 3) substrate for adults (V3); 4) water temperature for spawning (V4, °C); 5) water depth for spawning (V5, m); 6) substrate for spawning and hatching (V6); 7) water temperature during hatching (V7, °C); 8) flow velocity during spawning (V8, m/s); 9) suspended sediment concentration during spawning (V9, mg/L); and 10) the ratio of estimated brood sturgeon to eggs-predatory fish (V10). The ratio, V10, is important because 90% of eggs suffer predation. The Habitat Suitability Index (HSI) is given by as
Figure 1 shows suitability curves for the ten eco-factors. Using these curves, the Habitat Suitability Index (HSI) was calculated, in which the velocity, depth, temperature, and substrate were estimated using a two-dimensional model of hydraulics and sediment movement. The habitat suitability HSI ranges from 0 (unsuitable) to 1 (optimal). Yi et al. indicated that the space and time suitable for spawning were reduced after the completion of the Three Gorges Dam in 2003. The model proved that reservoir operation revised to mimic the natural flow regime would enhance habitat suitability.
Applications
Construction of dams has caused insurmountable obstacles to migratory fish. At least 1/5 of the world's 9000 species of freshwater fish have disappeared due to dams. This proportion is even higher in rivers with more dams, which is 2/5 in the United States and 3/4 in Germany. More than 130 dams have been built on the Columbia River and its tributaries, blocking salmon spawning upstream, resulting in a fishery loss of $6.5 billion between 1960 and 1980.
A fish ladder is designed to help the migrating fish and brood fish to cross a dam to the upstream spawning ground, and a fish pass helps the juvenile fish to cross the dam to the downstream and the sea. Fish ladders and passes can be designed separately or can be combined into one channel. The main concept of fish ladder design is to create extremely high resistance, letting the water from upstream to downstream of the dam flow at a low velocity while maintaining a large depth. The design of the inlet and outlet of the fish ladder is critical. If the downstream outlet velocity is too high, fish cannot swim into the fish ladder. If the outlet flow velocity is too low, the fish cannot determine whether it leads to the upstream spawning ground. Also important is turbulence along a ladder or pass.
The earliest fish ladder was constructed by Denil in 1909. The ladder consists of a series of baffles positioned on the walls and floor of a channel all of which enable the upstream moving brood fish, specifically Atlantic salmon, to bypass weirs and small dams. Generally, a fish ladder maximizes energy dissipation and reduces flow velocity, the shape and position of the baffles create a secondary outward circulation of flow, producing a momentum transfer from the central portion of the channel towards the walls.
Research has been done regarding Denil's fish ladder, focusing mainly on refining the baffles. Additionally, research concentrates on understanding organism response to the hydrodynamics (flow velocity and turbulence) under experimental settings. Attention has been paid to the turbulence intensity, eddy size, and hydrodynamic drag in fishways. On the other hand, fish biologists have worked closely with hydraulic engineers to understand how fish respond to complex fluid dynamics. Humans have created a variety of fish ladders, such as the submerged jet from a vertical gap type, which is suitable for large fish; step-pool type and submerged window type, which is suitable for medium fish; and overflow weir type, which is suitable for small fish (Figure 2).
Figure 2 Various types of fish ladder
In 2004, a fish ladder was built for the brood fish to bypass the Itaipu Dam on the Parana River, and for juvenile fish to pass down the river. The maximum flow velocity was less than 3 m/s. At the initial stage, the flow discharge used for trapping fish was 20 m3/s, and when the fish were swimming into the passage channel, the flow discharge dropped to 11.4 m3/s.
The most successful fish passages in the world are the fish ladders and fish passes bypassing the eight dams on the Columbia River. The U.S. government legislates that dams on the Columbia River must be built with a fishway. Bonneville Dam is the most downstream dam on the river, with a height of 60 m. The fish ladder was designed as a series of "cabins" using vertical gap jet diffusion and energy dissipation. Since the 1930s, a yearly average of 721,000 brood fish have crossed the dam and entered an upstream spawning ground.
Reservoir operation: Since 2010, the Three Gorges Reservoir has been operated to promote spawning of the Asian carp. In June 2011, the discharge from the reservoir increased by 2,000 m3/s every day, and the flow velocity and turbulence intensity increased continuously for 5 days. Stimulating flood flow, brood fish gathered downstream and spawned. In 2022, the reservoir increased the discharge from 12,800 m3/s on June 3 to 22,400 m3/s on June 8. The number of drifting eggs spawned by the carps in the Yichang-Yidu section increased by more than 400 million.
Artificial step-pools: In the past decades, artificial step-pools have been applied in mountain rivers to increase the habitat diversity, and thereby improve river ecology in Germany, Italy, the United States, Canada, Switzerland, Austria, and other countries. An experiment done in the Diaoga River in Yunnan, China, proved that artificial step-pools may create stable and diverse habitat with low velocity and deep-water pools and high velocity waterfalls. Thus, different species can find suitable habitat for survival and reproduction. Myriophyllum and Periphyton (forms of algae) grew on the riverbed, and the original white gravel bed was covered with green aquatic plants. The number of species of invertebrates doubled, and the number of individuals per unit area increased by 10 to 85 times. The artificial step-pool system created great resistance to flow and reduced debris-flow problems.
Elsewhere, step-pool systems are used. For example, Germany invested 400,000 Euros to build an artificial step-pool system on the Mangfall River, a tributary of the Inn River. Italy imitated a step-pool system and constructed a group of small dams with boulders, achieving significant results in stabilizing streams and restoring river ecology in northern mountain rivers. Artificial step-pool system constructed on the Kleinschmidt River in Montana and on the Little Snake River in Wyoming restored salmon and rainbow trout habitats.
Wetland restoration: Channelization of the Kissimmee River in central Florida destroyed or degraded most of the fish and wildlife habitat once provided by the river and its floodplain wetlands. A subsequent project restored the river's biological resources from 1984 to 1989. The straight channel was re-meandered, flow velocity was reduced, and water-stage increased. Reintroduction of flow through remnant river channels increased habitat diversity and led to favorable responses by fish and invertebrate communities. The habitat was restored forming a shallow and wide "River of Grass" which flowed slowly across everglades sawgrass toward mangrove estuaries in the Gulf of Mexico
Restoration of habitat connectivity: Restoration of connectivity between habitats that became fragments mainly involves dredging and excavating channels to connect lakes, wetlands, and rivers and creating ecological corridors for aquatic animals. In 2012, the city of Wuhan, China, connected 20 lakes on the left bank of the Yangtze River. A channel with a maximum width of 60 m and a depth of 1.5 m was dug between the lakes. The city built the ecological network of the Great East Lake on the right bank of the Yangtze River, reconnecting six lakes to the river. During the project, pump stations were used to exchange water between the lakes and the river to improve the water quality. The reconnection of the fragmented habitat repaired the damaged ecosystem.
Case Studies
Many examples can be given. A few ensue.
Ecohydraulics for land development: Sand Motor (Netherlands)-Ecohydraulics is increasingly used in the quest for nature-based solutions for sustainable development. A landmark example of building with nature, the "sand motor", was first implemented in the Netherlands in 2011 as a pilot project to provide an alternative solution for depositing a large amount of sand along the shore to nourish the coast and safeguard the hinterland from being eroded. A hook-shaped peninsula of about 21.5 million m3 of sand was constructed to protrude 1 km into the sea and cover about 2 km alongshore (Figure 3). By making use of natural processes such as waves, wind and tide to redistribute the sand, this innovative approach succeeded in limiting the disturbance of local ecosystems, while also providing new areas for nature and more types of recreation
Figure 3 Creating land by natural processes to minimize ecosystem disruption: The Sand Motor after completion in July 2011 (left) and 5 years later in January 2016 (right)
Ecohydraulics for restoring habitat of migratory birds (South Korea)- Nakdong River estuary is regulated by a 2,400-meter-long dam built in 1987 to control the inflow of seawater into farmland and secure drinking and agricultural water for nearby regions, including Busan, Ulsan and South Gyeongsang Province (Figure 4). However, the biodiversity of the river had been diminished since the establishment of the barrage; the stoppage of upstream sea water intrusion limited the supply of brackish water to the rice paddy fields which provided a natural habitat for migratory birds. A controlled partial gate-opening project was started in 2019 to restore and protect the biodiversity of the estuary, and by its third opening in July 2020, improvement was confirmed as the estuary's eco-species, including eels and anchovies, were found again in the waters upstream of the gates. A tidal flat was formed towards the seaside where the sand and mud carried over along the river accumulates provides fertile soil, rendering the area agriculturally rich and the habitat for migratory birds restored.
Other examples of eco-hydraulics can also be found in the IAHR Media Library.
Figure 4 The Nakdong Estuary Dam traps freshwater and prevents salt water from flowing upstream, affecting the rice paddy habitat of migratory birds. Ecological restoration involves opening a small part of the dam using modern eco-hydraulics (Courtesy of K-water)
References
External links
International Association for Hydro-Environment Engineering and Research (IAHR)
IAHR Media Library
Hydrology
Ecosystems | Ecohydraulics | [
"Chemistry",
"Engineering",
"Biology",
"Environmental_science"
] | 5,950 | [
"Hydrology",
"Symbiosis",
"Ecosystems",
"Environmental engineering"
] |
73,814,302 | https://en.wikipedia.org/wiki/HOPO%2014-1 | HOPO 14-1 is an investigational drug product for removing radioactive contaminants from the body. It is an oral capsule designed to act as a defence against radioactive threats such as nuclear power plant accidents or dirty bomb attacks. The active ingredient is the hydroxypyridinone ligand 3,4,3-LI(1,2-HOPO), which is a powerful chelating agent. HOPO 14-1 works by selectively binding to heavy metals in the body and forming a complex that the body can naturally excrete. The drug is also being studied as a treatment for other forms of heavy metal toxicity, including lead poisoning and exposure to gadolinium from MRI contrast agents. HOPO 14-1 was developed at Lawrence Berkeley National Laboratory by actinide chemist Rebecca Abergel. Abergel and former postdoc Julian Avery Rees co-founded HOPO Therapeutics, a company commercializing HOPO 14-1 and other treatments for heavy metal poisoning.
References
See also
Diethylenetriamine pentaacetate
Experimental drugs
Chelating agents used as drugs
Pyridines
Carboxamides | HOPO 14-1 | [
"Chemistry"
] | 232 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
66,448,918 | https://en.wikipedia.org/wiki/Technetium%28IV%29%20bromide | Technetium(IV) bromide is an inorganic compound with the formula TcBr4. A brown solid, it is moderately soluble in water.
Preparation
Technetium tetrabromide is produced by combining the elements at elevated temperatures:
Tc + 2Br2 → TcBr4
Structure
As verified by X-ray crystallography, the compound is an inorganic polymer consisting of interconnected TcBr6 octahedra. Platinum(IV) bromide and osmium(IV) bromide adopt similar structures.
References
Technetium compounds | Technetium(IV) bromide | [
"Chemistry"
] | 111 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
66,449,406 | https://en.wikipedia.org/wiki/HAT-P-41 | HAT-P-41 is a binary star system. Its primary is a F-type main-sequence star. Its surface temperature is 6390 K. compared to the Sun, HAT-P-41 is enriched in heavy elements, with a metallicity Fe/H index of 0.21, but is much younger at an age of 2.2 billion years.
The candidate stellar companion was detected simultaneously with the planet discovery in 2012. A multiplicity survey in 2015 did confirm a dim stellar companion of later-K to early-M spectral class, with the probability of being a background star of 14%. By 2020, it was concluded the candidate companion star is probably gravitationally bound.
Planetary system
In 2012, one planet, named HAT-P-41b, was discovered on a tight, circular orbit around the primary star.
The planetary orbit is mildly misaligned with the equatorial plane of the star, misalignment angle equal to −22.1 degrees.
The transmission spectrum of HAT-P-41b taken in 2020 has resulted in contradictory interpretations. One team has concluded the planetary atmosphere is metal-rich, with clear water signatures and absorption bands from sodium, aluminum, titanium and vanadium compounds. Another team has interpreted the results as arising from a dense hydrogen atmosphere without detectable heavy elements, but with significant ionization. The atmosphere also appears to contain significant cloud and hazes. Neither heavy element compounds nor H− ion opacity were found in 2022 study.
The planetary equilibrium temperature is within 1700-1950 K, and the dayside temperature has been measured at 1622 K.
References
Binary stars
Aquila (constellation)
Planetary transit variables
F-type main-sequence stars
Planetary systems with one confirmed planet
J19491743+0440207 | HAT-P-41 | [
"Astronomy"
] | 362 | [
"Aquila (constellation)",
"Constellations"
] |
66,451,435 | https://en.wikipedia.org/wiki/Amphiprora | Amphiprora is a genus of diatoms belonging to the family Amphipleuraceae.
The genus was first described by C. G. Ehrenberg in 1843.
The genus has cosmopolitan distribution.
Species:
Amphiprora alata
Amphiprora ornata
Amphiprora paludosa
References
Diatoms
Diatom genera | Amphiprora | [
"Biology"
] | 74 | [
"Diatoms",
"Algae"
] |
66,451,641 | https://en.wikipedia.org/wiki/P%C3%A5l%20Stenmark | Pål Stenmark (born 14 April 1976) is a Swedish biochemist and structural biologist. He was appointed professor of Structural Biochemistry at Lund University in 2019 and was appointed professor in Neurochemistry at Stockholm University in 2021.
Stenmark's research focus on two different areas:
The Botulinum and Tetanus Neurotoxins.
Enzymes in nucleotide metabolism and DNA repair.
Stenmark is among other things known for his discovery of several novel neurotoxins, including a neurotoxin that specifically kills Malaria mosquitos.
Awards and honours
The Lindbomska prize 2021 awarded by the Royal Swedish Academy of Sciences.
The Sven and Ebba-Christina Hagberg prize, 2017.
Ingvar Carlsson Award from the Swedish Foundation for Strategic Research, 2009.
Selected for the Wenner-Gren Fellow program, 2007
References
1976 births
Living people
Swedish biochemists
Structural biologists
Academic staff of Lund University
Academic staff of Stockholm University
Crystallographers | Pål Stenmark | [
"Chemistry",
"Materials_science"
] | 204 | [
"Crystallography",
"Structural biologists",
"Structural biology",
"Crystallographers"
] |
66,451,982 | https://en.wikipedia.org/wiki/Vytenis%20Vasyliunas | Vytenis M. Vasyliunas (born 25 September 1939) is a Lithuanian space scientist who was director of Germany's Max Planck Institute for Solar System Research from 1977 to 2007.
Life and work
Vasyliunas was born as son of the Lithuanian violinist Izidorius Vasyliūnas in 1939. He studied at Harvard College and received a degree in 1962. At the Massachusetts Institute of Technology he received his Ph.D. in 1966. In the following years he was Sloan Fellow and received the Macelwane Award in 1975.
From 1977 to 2007 he was one of the directors of Germany's Max Planck Institute for Solar System Research.
References
Lithuanian astronomers
Massachusetts Institute of Technology alumni
Harvard College alumni
Lithuanian organists
Living people
1939 births
Max Planck Institute directors | Vytenis Vasyliunas | [
"Astronomy"
] | 158 | [
"Astronomers",
"Astronomer stubs",
"Astronomy stubs"
] |
66,452,088 | https://en.wikipedia.org/wiki/Chemical%20graph%20generator | A chemical graph generator is a software package to generate computer representations of chemical structures adhering to certain boundary conditions. The development of such software packages is a research topic of cheminformatics. Chemical graph generators are used in areas such as virtual library generation in drug design, in molecular design with specified properties, called inverse QSAR/QSPR, as well as in organic synthesis design, retrosynthesis or in systems for computer-assisted structure elucidation (CASE). CASE systems again have regained interest for the structure elucidation of unknowns in computational metabolomics, a current area of computational biology.
History
Molecular structure generation is a branch of graph generation problems. Molecular structures are graphs with chemical constraints such as valences, bond multiplicity and fragments. These generators are the core of CASE systems. In a generator, the molecular formula is the basic input. If fragments are obtained from the experimental data, they can also be used as inputs to accelerate structure generation. The first structure generators were versions of graph generators modified for chemical purposes. One of the first structure generators was CONGEN, originally developed for the DENDRAL project, the first artificial intelligence project in organic chemistry. DENDRAL was developed as a part of the Mariner program launched by the NASA to search for life on Mars. CONGEN dealt well with overlaps in substructures. The overlaps among substructures rather than atoms were used as the building blocks. For the case of stereoisomers, symmetry group calculations were performed for duplicate detection.
After DENDRAL, another mathematical method, MASS, a tool for mathematical synthesis and analysis of molecular structures, was reported. As with CONGEN, the MASS algorithm worked as an adjacency matrix generator. Many mathematical generators are descendants of efficient branch-and-bound methods from Igor Faradjev and Ronald C. Read's orderly generation method. Although their reports are from the 1970s, these studies are still the fundamental references for structure generators. In the orderly generation method, specific order-check functions are performed on graph representatives, such as vectors. For example, MOLGEN performs a descending order check while filling rows of adjacency matrices. This descending order check is based on an input valence distribution. The literature classifies generators into two major types: structure assembly and structure reduction. The algorithmic complexity and the run time are the criteria used for comparison.
Structure assembly
The generation process starts with a set of atoms from the molecular formula. In structure assembly, atoms are combinatorically connected to consider all possible extensions. If substructures are obtained from the experimental data, the generation starts with these substructures. These substructures provide known bonds in the molecule. One of the earliest attempts was made by Hidetsugu Abe in 1975 using a pattern recognition-based structure generator. The algorithm had two steps: first, the prediction of the substructure from low-resolution spectral data; second, the assembly of these substructures based on a set of construction rules. Hidetsugu Abe and the other contributors published the first paper on CHEMICS, which is a CASE tool comprising several structure generation methods. The program relies on a predefined non-overlapping fragment library. CHEMICS generates different types of component sets ranked from primary to tertiary based on component complexity. The primary set contains atoms, i.e., C, N, O and S, with their hybridization. The secondary and tertiary component sets are built layer-by-layer starting with these primary components. These component sets are represented as vectors and are used as building blocks in the process.
Substantial contributions were made by Craig Shelley and Morton Munk, who published a large number of CASE papers in this field. The first of these papers reported a structure generator, ASSEMBLE. The algorithm is considered one of the earliest assembly methods in the field. As the name indicates, the algorithm assembles substructures with overlaps to construct structures. ASSEMBLE overcomes overlapping by including a “neighbouring atom tag”. The generator is purely mathematical and does not involve the interpretation of any spectral data. Spectral data are used for structure scoring and substructure information. Based on the molecular formula, the generator forms bonds between pairs of atoms, and all the extensions are checked against the given constraints. If the process is considered as a tree, the first node of the tree is an atom set with substructures if any are provided by the spectral data. By extending the molecule with a bond, an intermediate structure is built. Each intermediate structure can be represented by a node in the generation tree. ASSEMBLE was developed with a user-friendly interface to facilitate use. The second version of ASSEMBLE was released in 2000. Another assembly method is GENOA. Compared to ASSEMBLE and many other generators, GENOA is a constructive substructure search-based algorithm, and it assembles different substructures by also considering the overlaps.
The efficiency and exhaustivity of generators are also related to the data structures. Unlike previous methods, AEGIS was a list-processing generator. Compared to adjacency matrices, list data requires less memory. As no spectral data was interpreted in this system, the user needed to provide substructures as inputs. Structure generators can also vary based on the type of data used, such as HMBC, HSQC and other NMR data. LUCY is an open-source structure elucidation method based on the HMBC data of unknown molecules, and involves an exhaustive 2-step structure generation process where first all combinations of interpretations of HMBC signals are implemented in a connectivity matrix, which is then completed by a deterministic generator filling in missing bond information. This platform could generate structures with any arbitrary size of molecules; however, molecular formulas with more than 30 heavy atoms are too time consuming for practical applications. This limitation highlighted the need for a new CASE system. SENECA was developed to eliminate the shortcomings of LUCY. To overcome the limitations of the exhaustive approach, SENECA was developed as a stochastic method to find optimal solutions. The systems comprise two stochastic methods: simulated annealing and genetic algorithms. First, a random structure is generated; then, its energy is calculated to evaluate the structure and its spectral properties. By transforming this structure into another structure, the process continues until the optimum energy is reached. In the generation, this transformation relies on equations based on Jean-Loup Faulon's rules. LSD (Logic for Structure Determination) is an important contribution from French scientists. The tool uses spectral data information such as HMBC and COSY data to generate all possible structures. LSD is an open source structure generator released under the General Public License (GPL). A well-known commercial CASE system, StrucEluc, also features a NMR based generator. This tool is from ACD Labs and, notably, one of the developers of MASS, Mikhail Elyashberg. COCON is another NMR based structure generator, relying on theoretical data sets for structure generation. Except J-HMBC and J-COSY, all NMR types can be used as inputs.
In 1994, Hu and Xu reported an integer partition-based structure generator. The decomposition of the molecular formula into fragments, components and segments was performed as an application of integer partitioning. These fragments were then used as building blocks in the structure generator. This structure generator was part of a CASE system, ESESOC.
A series of stochastic generators was reported by Jean-Loup Faulon. The software, MOLSIG, was integrated into this stochastic generator for canonical labelling and duplicate checks. As for many other generators, the tree approach is the skeleton of Jean-Loup Faulon's structure generators. However, considering all possible extensions leads to a combinatorial explosion. Orderly generation is performed to cope with this exhaustivity. Many assembly algorithms, such as OMG, MOLGEN and Jean-Loup Faulon's structure generator, are orderly generation methods. Jean-Loup Faulon's structure generator relies on equivalence classes over atoms. Atoms with the same interaction type and element are grouped in the same equivalence class. Rather than extending all atoms in a molecule, one atom from each class is connected with other atoms. Similar to the former generator, Julio Peironcely's structure generator, OMG, takes atoms and substructures as inputs and extends the structures using a breadth-first search method. This tree extension terminates when all the branches reach saturated structures.
OMG generates structures based on the canonical augmentation method from Brendan McKay's NAUTY package. The algorithm calculates canonical labelling and then extends structures by adding one bond. To keep the extension canonical, canonical bonds are added. Although NAUTY is an efficient tool for graph canonical labelling, OMG is approximately 2000 times slower than MOLGEN. The problem is the storage of all the intermediate structures. OMG has since been parallelized, and the developers released PMG (Parallel Molecule Generator). MOLGEN outperforms PMG using only 1 core; however, PMG outperforms MOLGEN by increasing the number of cores to 10.
A constructive search algorithm is a branch-and-bound method, such as Igor Faradjev's algorithm, and an additional solution to memory problems. Branch-and-bound methods are matrix generation algorithms. In contrast to previous methods, these methods build all the connectivity matrices without building intermediate structures. In these algorithms, canonicity criteria and isomorphism checks are based on automorphism groups from mathematical group theory. MASS, SMOG and Ivan Bangov's algorithm are good examples in the literature. MASS is a method of mathematical synthesis. First, it builds all incidence matrices for a given molecular formula. The atom valences are then used as the input for matrix generation. The matrices are generated by considering all the possible interactions among atoms with respect to the constraints and valences. The benefit of constructive search algorithms is their low memory usage. SMOG is a successor of MASS.
Unlike previous methods, MOLGEN is the only maintained efficient generic structure generator, developed as a closed-source platform by a group of mathematicians as an application of computational group theory. MOLGEN is an orderly generation method. Many different versions of MOLGEN have been developed, and they provide various functions. Based on the users' needs, different types of inputs can be used. For example, MOLGEN-MS allows users to input mass spectrometry data of an unknown molecule. Compared to many other generators, MOLGEN approaches the problem from different angles. The key feature of MOLGEN is generating structures without building all the intermediate structures and without generating duplicates.
In the field, the studies recent to 2021 are from Kimito Funatsu's research group. As a type of assembly method, building blocks, such as ring systems and atom fragments, are used in the structure generation. Every intermediate structure is extended by adding building blocks in all possible ways. To reduce the number of duplicates, Brendan McKay's canonical path augmentation method is used. To overcome the combinatorial explosion in the generation, applicability domain and ring systems are detected based on inverse QSPR/QSAR analysis. The applicability domain, or target area, is described based on given biological as well as pharmaceutical activity information from QSPR/QSAR. In that study, monotonically changed descriptors (MCD) are used to describe applicability domains. For every extension in intermediate structures, the MCDs are updated. The usage of MCDs reduces the search space in the generation process. In the QSPR/QSAR based structure generation, there is the lack of synthesizability of the generated structures. Usage of retrosynthesis paths in the generation makes the generation process more efficient. For example, a well-known tool called RetroPath is used for molecular structure enumeration and virtual screening based on the given reaction rules. Its core algorithm is a breadth-first method, generating structures by applying reaction rules to each source compound. Structure generation and enumeration are performed based on Brendan McKay's canonical augmentation method. RetroPath 2.0 provides a variety of workflows such as isomer transformation, enumeration, QSAR and metabolomics.
Besides these mathematical structure generation methods, the implementations of neural networks, such as generative autoencoder models, are the novel directions of the field.
Structure reduction
Unlike these assembly methods, reduction methods make all the bonds between atom pairs, generating a hypergraph. Then, the size of the graph is reduced with respect to the constraints. First, the existence of substructures in the hypergraph is checked. Unlike assembly methods, the generation tree starts with the hypergraph, and the structures decrease in size at each step. Bonds are deleted based on the substructures. If a substructure is no longer in the hypergraph, the substructure is removed from the constraints. Overlaps in the substructures were also considered due to the hypergraphs. The earliest reduction-based structure generator is COCOA, an exhaustive and recursive bond-removal method. Generated fragments are described as atom-centred fragments to optimize storage, comparable to circular fingerprints and atom signatures. Rather than storing structures, only the list of first neighbours of each atom is stored. The main disadvantage of reduction methods is the massive size of the hypergraphs. Indeed, for molecules with unknown structures, the size of the hyper structure becomes extremely large, resulting in a proportional increase in the run time.
The structure generator GEN by Simona Bohanec combines two tasks: structure assembly and structure reduction. Like COCOA, the initial state of the problem is a hyper structure. Both assembly and reduction methods have advantages and disadvantages, and the GEN tool avoids these disadvantages in the generation step. In other words, structure reduction is efficient when structural constraints are provided, and structure assembly is faster without constraints. First, the useless connections are eliminated, and then the substructures are assembled to build structures. Thus, GEN copes with the constraints in a more efficient way by combining these methods. GEN removes the connections creating the forbidden structures, and then the connection matrices are filled based on substructure information. The method does not accept overlaps among substructures. Once the structure is built in the matrix representation, the saturated molecule is stored in the output list. The COCOA method was further improved and a new generator was built, HOUDINI. It relies on two data structures: a square matrix of compounds representing all bonds in a hyper structure is constructed, and second, substructure representation is used to list atom-centred fragments. In the structure generation, HOUDINI maps all the atom-centred fragments onto the hyper structure.
Mathematical basis
Chemical graphs
In a graph representing a chemical structure, the vertices and edges represent atoms and bonds, respectively. The bond order corresponds to the edge multiplicity, and as a result, chemical graphs are vertex and edge-labelled graphs. A vertex and edge-labelled graph is described as a chemical graph where is the set of vertices, i.e., atoms, and is the set of edges, which represents the bonds.
In graph theory, the degree of a vertex is its number of connections. In a chemical graph, the maximum degree of an atom is its valence, and the maximum number of bonds a chemical element can make. For example, carbon's valence is 4. In a chemical graph, an atom is saturated if it reaches its valence. A graph is connected if there is at least one path between each pair of vertices. Although chemical mixtures are one of the main interests of many chemists, due to the computational explosion, many structure generators output only connected chemical graphs. Thus, the connectivity check is one of the mandatory intermediate steps in structure generation because the aim is to generate fully saturated molecules. A molecule is saturated if all its atoms are saturated.
Symmetry groups for molecular graphs
For a set of elements, a permutation is a rearrangement of these elements. An example is given below:
The second line of this table shows a permutation of the first line. The multiplication of permutations, and , is defined as a function composition, as shown below.
The combination of two permutations is also a permutation. A group, , is a set of elements together with an associative binary operation defined on such that the following are true:
There is an element in satisfying , for all elements of .
For each element of G, there is an element such that is equal to the identity element.
The order of a group is the number of elements in the group. Let us assume is a set of integers. Under the function composition operation, is a symmetry group, the set of all permutations over X. If the size of is , then the order of is . Set systems consist of a finite set and its subsets, called blocks of the set. The set of permutations preserving the set system is used to build the automorphisms of the graph. An automorphism permutes the vertices of a graph; in other words, it maps a graph onto itself. This action is edge-vertex preserving. If is an edge of the graph, , and is a permutation of , then
A permutation of is an automorphism of the graph if
The automorphism group of a graph , denoted , is the set of all automorphisms on . In molecular graphs, canonical labelling and molecular symmetry detection are implementations of automorphism groups. Although there are well known canonical labelling methods in the field, such as InChI and ALATIS, NAUTY is a commonly used software package for automorphism group calculations and canonical labelling.
List of available structure generators
The available software packages and their links are listed below.
See also
Simplified molecular-input line-entry system
References
External links
Cheminformatics | Chemical graph generator | [
"Chemistry"
] | 3,725 | [
"Computational chemistry",
"nan",
"Cheminformatics"
] |
66,452,527 | https://en.wikipedia.org/wiki/Relief%20Therapeutics | Relief Therapeutics is a Swiss biopharmaceutical company based in Geneva. The company focuses on developing drugs for serious diseases with few or no existing treatment options. Its lead compound, RLF-100, is a synthetic form of a natural peptide that protects the lung. The company was incorporated as Relief Therapeutics Holdings AG (RFLB.S) and listed on the SIX Swiss Exchange in 2016.
History
Relief Therapeutics was founded in 2013 by Gael Hédou with the aim of developing new treatments for diseases with high unmet needs. The company today considers itself the successor to Mondobiotech, which was founded in 2000 by Fabio Cavalli and Dorian Bevec. Mondobiotech began research into Vasoactive intestinal peptide (VIP), a naturally occurring substance in humans that was first identified in the 1970s. They were granted US and European patents for a synthetic version of VIP known as aviptadil in 2006.
On June 23, 2013, Mondobiotech merged with Italian pharmaceutical company Pierrel Research International to form a new Contract research organization known as Therametrics. On July 14, 2016, Therametrics merged with Relief Therapeutics to form Relief Therapeutics Holdings AG, which inherited all patents related to aviptadil.
COVID-19 research
Aviptadil
In the wake of the COVID-19 pandemic, scientists at Relief conducted initial studies into the efficacy of RLF-100 in treating severe COVID-19 patients. In June 2020, the U.S. Food and Drug Administration granted fast-track designation to RLF-100 for treatment of respiratory distress in COVID-19. In September 2020, Relief partnered with US-Israeli firm NRX Pharmaceuticals (formerly NeuroRx Inc) for the co-development of the drug and the co-ordination of US trials. In April 2021, a reformulated version of aviptadil, known as Zyesami, was included in a National Institutes of Health (NIH) sponsored Phase 3 trial with the aim of testing aviptadil against remdesivir. In May 2021, NRX submitted a request for an Emergency Use Authorization (EUA) to the US FDA for aviptadil's use in patients in intensive care. On 7 October 2021 Relief Therapeutics filed a lawsuit against NRX Pharmaceuticals and its CEO Dr. Jonathan Javitt in the Supreme Court of the State of New York, citing multiple alleged breaches of the collaboration agreement signed by the two companies for the co-development of aviptadil.
On 4 November 2021 the FDA declined EUA for the drug, but committed to working with NRX to further develop it. On 29 November 2021, NRX announced that data analysis from the NIH-sponsored Phase 3 trial showed a fourfold increase in survival at 60 days for patients administered with Zyesami (Aviptadil) vs those who received placebo.
Sentinox
On 27 October 2021, Applied Pharma Research (APR), a wholly-owned subsidiary of Relief, announced positive interim data from its clinical trial of Sentinox, a nasal spray aimed at reducing the viral load of patients with COVID-19, in-turn reducing the transmissibility of the virus.
Other research
In October 2021, Relief announced that its collaboration partner, Texas-based Acer Therapeutics, had successfully filed for a New Drug Application with US FDA for their drug ACER-001, for the treatment of Urea Cycle Disorders (UCDs) and Maple syrup urine disease.
In September 2021, APR launched a chewable tablet for the treatment of Phenylketonuria, called PKU GOLIKE KRUNCH, in Germany and Italy. APR are also developing Nexodyn, a drug which aids in the management of hard-to-heal ulcers requiring long periods of treatment.
Relief is actively developing RLF-100 for non-COVID-19 related acute and chronic lung diseases, such as Pulmonary sarcoidosis.
Acquisitions
In July 2016, Relief acquired FirstString Research, a clinical-stage biotech firm based in Charleston, South Carolina, US.
In January 2021, Relief acquired German-based firm AdVita in a €25 million agreement to further their research into inhaled treatments for Acute respiratory distress syndrome.
In May 2021, Relief acquired Swiss biotech firm Applied Pharma Research (APR), including its existing portfolio and all pipeline products, for CHF 72 million ($79 million).
References
2016 initial public offerings
Biotechnology companies established in 2013
Pharmaceutical companies established in 2013
Swiss companies established in 2013
Biotechnology companies of Switzerland
Companies listed on the SIX Swiss Exchange
Companies based in Geneva
Biopharmaceutical companies
Pharmaceutical companies of Switzerland
Life sciences industry | Relief Therapeutics | [
"Biology"
] | 969 | [
"Life sciences industry"
] |
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