id int64 39 79M | url stringlengths 31 227 | text stringlengths 6 334k | source stringlengths 1 150 ⌀ | categories listlengths 1 6 | token_count int64 3 71.8k | subcategories listlengths 0 30 |
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61,514,597 | https://en.wikipedia.org/wiki/C19H28O6S | {{DISPLAYTITLE:C19H28O6S}}
The molecular formula C19H28O6S (molar mass: 384.487 g/mol, exact mass: 384.1607 u) may refer to:
15α-Hydroxy-DHEA sulfate
16α-Hydroxy-DHEA sulfate
Molecular formulas | C19H28O6S | [
"Physics",
"Chemistry"
] | 76 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,515,200 | https://en.wikipedia.org/wiki/C18H20INO4 | {{DISPLAYTITLE:C18H20INO4}}
The molecular formula C18H20INO4 (molar mass: 441.260 g/mol, exact mass: 441.0437 u) may refer to:
25I-NB34MD (NB34MD-2C-I)
25I-NBMD
Molecular formulas | C18H20INO4 | [
"Physics",
"Chemistry"
] | 77 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,515,551 | https://en.wikipedia.org/wiki/C11H11NO2 | {{DISPLAYTITLE:C11H11NO2}}
The molecular formula C11H11NO2 (molar mass: 189.211 g/mol) may refer to:
3-Indolepropionic acid (IPA), or indole-3-propionic acid
Phensuximide
Molecular formulas | C11H11NO2 | [
"Physics",
"Chemistry"
] | 71 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,515,664 | https://en.wikipedia.org/wiki/C860H1353N227O255S9 | {{DISPLAYTITLE:C860H1353N227O255S9}}
The molecular formula C860H1353N227O255S9 (molar mass: 19240.898 g/mol) may refer to:
Interferon alfacon-1
Peginterferon alfa-2a
Molecular formulas | C860H1353N227O255S9 | [
"Physics",
"Chemistry"
] | 77 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,515,687 | https://en.wikipedia.org/wiki/C20H28I3N3O9 | {{DISPLAYTITLE:C20H28I3N3O9}}
The molecular formula C20H28I3N3O9 (molar mass: 835.164 g/mol) may refer to:
Iobitridol
Iopentol
Molecular formulas | C20H28I3N3O9 | [
"Physics",
"Chemistry"
] | 61 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,515,705 | https://en.wikipedia.org/wiki/C12H11I3N2O4 | {{DISPLAYTITLE:C12H11I3N2O4}}
The molecular formula C12H11I3N2O4 (molar mass: 627.940 g/mol) may refer to:
Iodamide
Metrizoic acid
Molecular formulas | C12H11I3N2O4 | [
"Physics",
"Chemistry"
] | 61 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,515,898 | https://en.wikipedia.org/wiki/C17H22I3N3O8 | {{DISPLAYTITLE:C17H22I3N3O8}}
The molecular formula C17H22I3N3O8 (molar mass: 777.085 g/mol) may refer to:
Iomeprol
Iopamidol
Molecular formulas | C17H22I3N3O8 | [
"Physics",
"Chemistry"
] | 63 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,515,921 | https://en.wikipedia.org/wiki/C18H24I3N3O8 | {{DISPLAYTITLE:C18H24I3N3O8}}
The molecular formula C18H24I3N3O8 (molar mass: 791.112 g/mol, exact mass: 790.8698 u) may refer to:
Iopromide
Ioxilan | C18H24I3N3O8 | [
"Chemistry"
] | 68 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
61,516,900 | https://en.wikipedia.org/wiki/Gurzhi%20effect | The Gurzhi effect was theoretically predicted by Radii Gurzhi in 1963, and it consists of decreasing of electric resistance of a finite size conductor with increasing of its temperature (i.e. the situation for some temperature interval). Gurzhi effect usually being considered as the evidence of electron hydrodynamic transport in conducting media. The mechanism of Gurzhi effect is the following. The value of the resistance of the conductor is inverse to the — a mean free path corresponding to the momentum loss from the electrons+phonons systemwhere is the average distance which electron pass between two consecutive interactions with a boundary, and is a mean free path corresponding to other possibilities of momentum loss. The electron reflection from the boundary is assumed to be diffusive.
When temperature is low we have ballistic transport with , , where is a width of the conductor, is a mean free path corresponding to effective normal electron-electron collisions (i.e. collisions without total electrons+phonons momentum loss). For low temperatures phonon emitted by electron quickly interacts with another electron without loss of total electron+phonons momentum and , where is a mean free path corresponding to the electron-phonon collisions. Also we assume . Thus the resistance for lowest temperatures is a constant (see the picture). The Gurzhi effect appears when the temperature is increased to have . In this regime the electron diffusive length between two consecutive interactions with the boundary can be considered as momentum loss free path: , and the resistance is proportional to , and thus we have a negative derivative . Therefore, Gurzhi effect can be observed when .
Gurzhi effect corresponds to unusual situation when electrical resistance depends on a frequency of normal collisions. As one can see this effect appears due to the presence of a boundaries with finite characteristic size . Later Gurzhi's group discovered a special role of electron hydrodynamics in a spin transport. In such a case magnetic inhomogeneity plays role of a "boundary" with spin-diffusion length as a characteristic size instead of as before. This magnetic inhomogeneity stops electrons of the one spin component which becomes an effective scatterers for electrons of another spin component. In this case magnetoresistance of a conductor depends on the frequency of normal electron-electron collisions as well as in the Gurzhi effect.
References
Electric current | Gurzhi effect | [
"Physics"
] | 490 | [
"Electric current",
"Wikipedia categories named after physical quantities",
"Physical quantities"
] |
61,518,155 | https://en.wikipedia.org/wiki/Aenictus%20hilli | Aenictus hilli is a species of light brown army ant found in Australia, the only specimen collected in Malanda, Queensland.
References
Dorylinae
Hymenoptera of Australia
Insects described in 1928
Species known from a single specimen | Aenictus hilli | [
"Biology"
] | 50 | [
"Individual organisms",
"Species known from a single specimen"
] |
61,518,581 | https://en.wikipedia.org/wiki/Betty%20Lise%20Anderson | Betty Lise Anderson is an American electrical engineer, working in the field of photonics. She has been a professor at the Ohio State University since 1990. She is a Fellow of SPIE, and a Senior Member of the Optical Society of America and of the Institute of Electrical and Electronics Engineers.
Education
1978 - Bachelors of Science in Electrical Engineering (Syracuse University)
1988 - Masters in Science (University of Vermont)
1990 - Ph.D. in Materials Science and Electrical Engineering (University of Vermont)
Early career
Anderson began her career as a teacher at an experimental elementary school, where she worked for two years. After leaving teaching, she worked in industry for nine years at Tektronix, Inc., C.S. Draper Labs, and GTE Laboratories.
Later career
After going back to and graduating with her Ph.D., Anderson has been part of The Ohio State University, where she has held various positions, including Assistant Professor, and currently Professor, since 2004. Anderson's impact extends beyond traditional academics, as evidenced by her roles as Associate Chair and Director of Outreach, where she has spearheaded initiatives such as the K12 Engineering Outreach program.
Research interests
Anderson's research interests include laser diodes, interferometry, optoelectronic devices, fiber sensing, optical interconnection, and optical multiplexing.
Publications
Betty Lise Anderson's owns co-authorship of "Fundamentals of Semiconductor Devices," which has seen both first and second editions published by McGraw-Hill in 2005 and 2017. Anderson has made contributions to peer-reviewed journals in areas such as optical delay devices, photonic switches, and spatial coherence measurements. Some publications include her work on optical true-time delay devices, demonstrated through her papers in prestigious journals like the Journal of Lightwave Technology and Applied Optics. Anderson's research has also delved into practical applications, as seen in her investigations into laser diode effects under gamma radiation and spatial coherence modulation for free space communication. Anderson has also done work on microbend fiber optic sensors and vertical cavity ring lasers.
Awards and recognition
2022 - National Science Board Public Service Award
2015 - Fellow of SPIE
2015 - University Outreach and Engagement Award (Ohio State University)
2015 - Distinguished Community Engagement Award (Ohio State University)
2014 - Women in Engineering Faculty Award for Outreach and Engagement (Ohio State University)
2012 - Faculty Diversity Award (Ohio State University)
2007 - Innovators Award (Ohio State University)
2006 - Outstanding Woman in Technology: Top Contributor to the Advancement of Technology Award (TechColumbus, now Rev1 Ventures)
2005 - Outstanding Woman of the Year
2000 - Annual Research Accomplishment Award (Ohio State University)
Outreach
Anderson leads 'Engineering Outreach', a program within the College of Engineering at the Ohio State University. Her program focuses on going out to schools, after-school camps, and STEM clubs in and around Columbus, Ohio, to building interest in STEM subjects from female and minority students.
Bibliography
Anderson co-wrote a book with Richard Anderson entitled 'Fundamentals in Semiconductor Devices', published by McGraw-Hill in 2005.
References
Living people
American electrical engineers
Syracuse University alumni
20th-century American women engineers
20th-century American engineers
20th-century American women writers
20th-century American non-fiction writers
University of Vermont alumni
Year of birth missing (living people)
American optical engineers
Laser researchers
Ohio State University faculty
American women non-fiction writers
Women in optics
American materials scientists
Women materials scientists and engineers
21st-century American women academics
21st-century American academics
21st-century American non-fiction writers
21st-century American women engineers
21st-century American engineers
21st-century American women writers | Betty Lise Anderson | [
"Materials_science",
"Technology"
] | 739 | [
"Women materials scientists and engineers",
"Materials scientists and engineers",
"Women in science and technology"
] |
61,518,918 | https://en.wikipedia.org/wiki/Cross-wing | A cross-wing is an addition to a house, at right angles to the original block of a house, usually with a gable. A cross-wing plan is an architectural plan reflecting this; cross-wing architecture describes the style.
James Stevens Curl, in A Dictionary of Architecture and Landscape Architecture, defines it as a "Wing attached to the hall-range of a medieval house, its axis at right angles to the hall-range, and often gabled."
Cross-wing plans have been used in other eras. For example, during the settlement period in Utah in the late 1800s, original small hall-and-parlor plan houses, often built in vernacular Classical Revival style, were sometimes extended by the addition of a Victorian-style cross-wing.
References
Architectural elements | Cross-wing | [
"Technology",
"Engineering"
] | 156 | [
"Building engineering",
"Architectural elements",
"Components",
"Architecture"
] |
61,519,107 | https://en.wikipedia.org/wiki/The%20Case%20Against%20Education | The Case Against Education: Why the Education System Is a Waste of Time and Money is a book written by libertarian economist Bryan Caplan and published in 2018 by Princeton University Press. Drawing on the economic concept of job market signaling and research in educational psychology, the book argues that much of higher education is very inefficient and has only a small effect in improving human capital, contrary to the conventional consensus in labor economics.
Caplan argues that the primary function of education is not to enhance students' skills but to certify their intelligence, conscientiousness, and conformity—attributes that are valued by employers. He ultimately estimates that approximately 80% of individuals' return to education is the result of signaling, with the remainder due to human capital accumulation.
Summary
Human capital model
The foundation of the drive to increase educational attainment across the board is the human capital model of education, which began with the research of Gary Becker. The model suggests that increasing educational attainment causes increased prosperity by endowing students with increased skills. As a consequence, subsidies to education are seen as a positive investment that increases economic growth and creates spillover effects by improving civic engagement, happiness, health, etc.
Caplan argues against the model due to several contradictions, though he does not dispute that higher educational attainment is strongly correlated with increased individual income. He highlights how most adults rarely remember much of what they were taught in school not related to their career besides English and math, and even the latter two are inadequate. He also analyzes the sheepskin effect, where the largest increases in income from higher educational attainment occur after attaining an academic degree, but not for those who dropped out of college despite usually having completed some courses. He finally criticizes educational inflation, the increasing educational requirements for occupations that do not require them, as indicating educational attainment is relative and not nearly as beneficial for society as portrayed.
Present value of learning, adjusted for forgetting
The simple human capital model tends to assume that knowledge is retained indefinitely, while a ubiquitous theme in educational interventions is that "fadeout" (i.e., forgetting) reliably occurs. To take a simple example, we may compute the present value of a marginal fact that increases a person's productivity by as:where is the discount rate used to compute the present value. If is $100 and is 5%, then the present value of learning is $2,000. But this is at odds with the concept of fadeout. To correct for this, assume that the probability density function for retaining follows an exponential distribution—with the corresponding survival function . Then the present value of learning , accounting for fadeout, is given by:Since the expected value of an exponential distribution is , we may tune this parameter based on assumptions about how long is retained. Below is a table showing what the present value is based on and the expected retention time of the fact:
Regardless of the retention time assumption, the present value of learning is significantly reduced.
Signaling model
The main alternative to the human capital model of education is the signaling model of education. The idea of job market signaling through educational attainment goes back to the work of Michael Spence. The model Spence developed suggested that, even if a student did not gain any skills through an educational program, the program can still be useful so long as the signal from completing the program is correlated with traits that predict job performance.
Throughout the book, Caplan details a series of observations that suggest a significant role for signaling in the return to education:
Intelligence and conscientiousness are known predictors of educational and occupational success, and are relatively stable throughout a person's life
International estimates of the effect of an additional year of education on national income are much lower than those estimating the impact of an additional year of education on personal income (p. 114-118)
Many students forget material over the summer and after the end of a class (p. 39-40)
Adults tend to forget much of the information they learned in school (p. 39-50). This builds on Caplan's earlier book The Myth of the Rational Voter.
Students look to take courses that offer easy As, instead of more difficult courses
The sheepskin effect seems to be fairly large (p. 97-102)
Transfer of learning to other disciplines appears to be low or nonexistent (p. 50-59)
Given the above signs of signaling, Caplan argues in ch. 5–6 that the selfish return to education is greater than the social return to education, suggesting that greater educational attainment creates a negative externality (p. 198). In other words, status is zero-sum; skill is not (p. 229).
Cost-benefit analysis of going to college
For many students, Caplan argues that most of the negative social return to pursuing further education comes from the incursion of student debt and lost employment opportunities for students who are unlikely to complete college (p. 210-211, ch. 8). He suggests that these students would be better served by vocational education.
Policy recommendations
Caplan advocates two major policy responses to the problem of signaling in education:
Educational austerity
Increased vocational education
The first recommendation is that government needs to sharply cut education funding, since public education spending in the United States across all levels tops $1 trillion annually. The second recommendation is to encourage greater vocational education, because students who are unlikely to succeed in college should develop practical skills to function in the labor market. Caplan argues for an increased emphasis on vocational education that is similar in nature to the systems in Germany and Switzerland.
Reviews
Positive
Robin Hanson at Overcoming Bias
Naomi Schaefer Riley in The Wall Street Journal
Gene Epstein in City Journal
Mixed
Stephen L. Carter in Bloomberg Opinion
"I'm not sure he's right, especially about education being almost entirely for the purpose of signaling, but goodness does he make a strong case. Agree with him or not, you'll never look at the schools and colleges in quite the same way."
Tyler Cowen in Marginal Revolution
Ilya Somin at Reason
Negative
Sarah Carr in The Washington Post
Sean Illing at Vox
Joshua Kim at Inside Higher Ed
See also
Big Five personality traits
Credential inflation
Grade inflation
Education economics
Intelligence
Labor economics
References
Further reading
Becker, Gary S. (1964). Human Capital: A Theoretical and Empirical Analysis, with Special Reference to Education (3rd ed.). Chicago, IL: University of Chicago Press. .
Bolton, Patrick; Dewatripont, Mathias (2005). Contract Theory. Cambridge, MA: The MIT Press. pp. 99–127. .
Cahuc, Pierre; Carcillo, Stéphane; Zylberberg, André (2014). Labor Economics (2nd ed.). Cambridge, MA: The MIT Press. pp. 191–245. .
Bahrick, Harry P.; Hall, Lynda K. (1991). "Lifetime Maintenance of High School Mathematics Content". Journal of Experimental Psychology: General, 120 (1): 20–33.
External links
Noah Blaylock's Study Guide to The Case Against Education
Asymmetric information
Economics books
Education economics
Labour economics
Books about education | The Case Against Education | [
"Physics"
] | 1,457 | [
"Asymmetric information",
"Symmetry",
"Asymmetry"
] |
61,519,463 | https://en.wikipedia.org/wiki/Holyoke%20Machine%20Company | The Holyoke Machine Company was an American manufacturer of industrial machinery, best known for its work in paper manufacturing equipment and water turbines.
History
The company, formed in 1863, was founded by Nathan H. Whitten, T.C. Page, T. B. Flanders, Richard Pattee, and S. S. Chase, after the Holyoke Water Power Company's machine shop had been sold off. Stephen Holman, the company's treasurer, president, and largest shareholder during different times in its first decade, is credited as its founder, though the nature of his early involvement is not well documented. Holman would purchase the company's foundry works in Worcester in April 1873, a second manufacturing branch which remained open for several decades.
The best known among turbines manufactured by the company was the Hercules turbine; a design developed by engineer John B. McCormick, who improved upon the Francis turbine, it was the first true mixed flow turbine of a high efficiency. With a maximum efficiency of 87%, a considerable improvement over previous designs of the era, the turbine would become ubiquitous in mills in the United States, as well as Europe.
The central location of the company, and its design improvements for various papermaking machinery such as Fourdrinier machines, contributed to the paper making and textile economy of Massachusetts and more specifically the paper industry of the Berkshires, granting ready-access to machinery that often had to be shipped great distances from other manufacturers. In addition to turbines and papermaking machinery, the company was also known to have produced a wide variety of cast parts and custom orders. Among those known were Thomas Edison's personal elevator at his Orange, New Jersey laboratory, as well as doors for the US Capitol Building.
Dissolution
With a changing market steering away from 19th century water-turbine factories, the business went into decline and entered bankruptcy in 1948, when it was bought by Irwin Sagalyn, who closed its foundry and changed the business's focus. At the end of 1950 the company auctioned off all of its remaining tools for the purposes of manufacturing turbines, papermaking tools and other mechanical machinery, choosing to focus entirely on its precision roll and filter business in the paper and textile industries. Citing the shrinking of an American industrial base, changes in technology and its specialization in those industries, Irwin's son, owner James Sagalyn, dissolved the company in August 2017, leaving one competitor working on the same technology, Badger Roll and Machine of Green Bay, Wisconsin to handle remaining customers, many in the Greater Springfield area.
References
External links
Trade catalogs from Holyoke Machine Co. National Museum of American History
Patent Assignee- Holyoke Machine Company Google Patents
Wood Crusher Machine - Biomass Wood Particle Production
Industrial machine manufacturers
1863 establishments in Massachusetts
Manufacturing companies established in 1863
Manufacturing companies disestablished in 2017
Companies based in Holyoke, Massachusetts
Companies based in Worcester, Massachusetts
Defunct manufacturing companies based in Massachusetts | Holyoke Machine Company | [
"Engineering"
] | 585 | [
"Industrial machine manufacturers",
"Industrial machinery"
] |
61,519,578 | https://en.wikipedia.org/wiki/AptarGroup | AptarGroup, Inc., also known as Aptar, is a United States–based global manufacturer of consumer dispensing packaging and drug delivery devices. The group has manufacturing operations in 18 countries.
History
The company began as Werner Die & Stamping in Cary, Illinois, in 1946 and later incorporated as AptarGroup in 1992. Aptar originally developed spray valves and pumps for consumer and household products. The company later began producing nasal administration and pulmonary drug delivery devices such as nasal spray systems and metered-dose inhaler valves. Biotech and pharmaceutical companies use Aptar's different Unidose and Bidose devices for the single or two-shot intranasal delivery of different medicines.
In 2016, Aptar announced that it provided the delivery system for Adapt Pharma's Narcan. Narcan is a naloxone hydrochloride nasal spray used as an emergency treatment for opioid overdoses. Aptar's liquid spray drug delivery technology platform works as a ready-to-use, single-shot, unit-dose system for Narcan. It was the first FDA approved nasally administered, ready-to-use medication used to reverse the effects of an opioid overdose. Narcan does not require any assembly, medical training, or needle injection.
In 2016, Aptar entered into an agreement with Becton Dickinson & Company to develop new self-injection devices.
Aptar entered into an agreement in 2016 with Propeller Health Partners to develop a digitally connected medication inhaler. The company made an investment in Propeller Health Partners (now part of Resmed) in 2018.
In July 2019, the FDA-approved Aptar Pharma's Unidose Powder System as the first intranasally-delivered, needle-free rescue treatment for severe hypoglycemia.
In 2020, during the COVID-19 pandemic, Aptar invested in new tools to accelerate its molding equipment and assembly machines for pumps, but it still wasn't enough to keep up with demand.
Acquisitions
In 2012, Aptar acquired Stelmi, a manufacturer of elastomer primary packaging components. In 2016, Aptar acquired Mega Airless, a manufacturer of airless packaging solutions. In 2018, Aptar acquired CSP Technologies, a material science company that manufactures active packaging solutions.
In June 2019, Aptar acquired two companies, Nanopharm and Gateway Analytical. In November 2019, the company acquired Noble International, which specializes in training devices and patient onboarding. In February 2020, Aptar acquired FusionPKG, a makeup packaging company.
In November 2020, the company acquired the digital respiratory health company Cohero Health.
In July 2021 Aptar acquired the digital therapeutics company, Voluntis (ENXTPA: ALVTX), and 80% of the equity interests of Weihai Hengyu Medical Products Co., Ltd., a Chinese manufacturer of elastomeric and plastic components used in injectable drug delivery.
Sustainability
Aptar was named to Barron's list of the Top 100 Most Sustainable U.S. Companies in 2019, 2020, 2021, and 2022. At the end of 2020, 85% of the company’s global electricity use came from renewable sources. It was also named by Newsweek as one of America's Most Responsible Companies in 2021, 2022, and 2023 and received an A score for climate change from the Climate Disclosure Project.
In September 2019, the company announced a partnership with Loop, a shopping platform from TerraCycle that delivers products in reusable containers. The company made the Forbes Green Growth 50 List in 2021.
References
1992 establishments in Illinois
Drug delivery devices
Packaging companies
Manufacturing
Pumps
Sustainable communities
Companies listed on the New York Stock Exchange
Packaging companies of the United States
Manufacturing companies established in 1992
Companies listed on the Nasdaq
Companies in the S&P 400 | AptarGroup | [
"Physics",
"Chemistry",
"Engineering"
] | 796 | [
"Pumps",
"Pharmacology",
"Turbomachinery",
"Drug delivery devices",
"Manufacturing",
"Physical systems",
"Hydraulics",
"Mechanical engineering"
] |
66,493,584 | https://en.wikipedia.org/wiki/Americium%28II%29%20chloride | Americium(II) chloride, also known as dichloroamericium, is the chemical compound composed of americium and chloride with the formula AmCl2.
References
Americium compounds
Chlorides
Actinide halides | Americium(II) chloride | [
"Chemistry"
] | 50 | [
"Salts",
"Chlorides",
"Inorganic compounds",
"Inorganic compound stubs"
] |
66,493,645 | https://en.wikipedia.org/wiki/Potassium%20perbromate | Potassium perbromate is the chemical compound composed of the potassium ion and the perbromate ion, with the chemical formula KBrO4.
Preparation
Potassium perbromate can be prepared by reacting perbromic acid with potassium hydroxide:
References
Potassium compounds
Perbromates | Potassium perbromate | [
"Chemistry"
] | 55 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
66,493,683 | https://en.wikipedia.org/wiki/Sodium%20perbromate | Sodium perbromate is the chemical compound composed of the sodium ion and the perbromate ion, with the chemical formula NaBrO4.
Preparation
Sodium perbromate can be prepared by reacting sodium bromate with fluorine and sodium hydroxide:
References
Sodium compounds
Perbromates | Sodium perbromate | [
"Chemistry"
] | 58 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
66,494,075 | https://en.wikipedia.org/wiki/Ammonium%20tetrafluoroborate | Ammonium tetrafluoroborate (or ammonium fluoroborate) is an inorganic salt composed of the ammonium cation and the tetrafluoroborate anion, with the chemical formula NH4BF4. When heated to decomposition, ammonium tetrafluoroborate releases toxic fumes of hydrogen fluoride, nitrogen oxides, and ammonia.
Preparation
Ammonium tetrafluoroborate can be prepared by reacting ammonium fluoride with boric and sulfuric acid:
8 NH4F + 2 H3BO3 + 3 H2SO4 → 2 NH4BF4 + 3 (NH4)2SO4 + 6 H2O
References
Ammonium compounds
Tetrafluoroborates | Ammonium tetrafluoroborate | [
"Chemistry"
] | 158 | [
"Ammonium compounds",
"Salts"
] |
66,494,088 | https://en.wikipedia.org/wiki/Glossary%20of%20power%20electronics | This glossary of power electronics is a list of definitions of terms and concepts related to power electronics in general and power electronic capacitors in particular. For more definitions in electric engineering, see Glossary of electrical and electronics engineering. For terms related to engineering in general, see Glossary of engineering.
The glossary terms fit in the following categories in power electronics:
Electronic power converters; converters, rectifiers, inverters, filters.
Electronic power switches and electronic AC power converters; switches and controllers.
Essential components of electric power equipment; device, stack, assembly, reactor, capacitor, transformer, AC filter, DC filter, snubber circuit.
Circuits and circuit elements of power electronic equipment; arms and connections.
Operations within power electronic equipment; commutations, quenchings, controls, angles, factors, states, directions, intervals, periods, frequencies, voltages, breakthroughs and failures, breakdowns, blocking and flows.
Properties of power electronic equipment
Characteristic curves of power electronic equipment
Power supplies
A
B
C
D
E
F
H
I
J
L
M
N
O
P
Q
R
S
T
U
V
Overview of electronic power converters
See also
Glossary of engineering
Glossary of civil engineering
Glossary of mechanical engineering
Glossary of structural engineering
Notes
References
Attribution
External links
Websites
Online Electrotechnical Vocabulary
A Glossary of Electrical Terms
Electronic Terminology
Electronics Glossary
Glossary / Dictionary of Electronics Terms
PDFs
Pictorial Glossary
Electrical Engineering Dictionary
Electrical engineering
Electronic engineering
Power electronics
Power electronics
Power electronics
Wikipedia glossaries using description lists | Glossary of power electronics | [
"Technology",
"Engineering"
] | 314 | [
"Electrical engineering",
"Electronic engineering",
"Computer engineering",
"Power electronics"
] |
66,494,479 | https://en.wikipedia.org/wiki/Lactarius%20mammosus | Lactarius mammosus is a species of fungus belonging to the family Russulaceae. The English vernacular name is Pap Milkcap
It is native to Europe and Northern America.
References
mammosus
Fungus species | Lactarius mammosus | [
"Biology"
] | 47 | [
"Fungi",
"Fungus species"
] |
66,494,527 | https://en.wikipedia.org/wiki/Holopogon%20pekinensis | Holopogon pekinensis is a kind of saprotrophic nutrition orchid. In 2017 it was found in Beijing. It grows under a wooded forest in a ravine at an altitude of 1000m in a mountainous area. , Plants of the World Online regarded the genus Holopogon as a synonym of Neottia, and the species Holopogon pekinensis as "unplaced".
Discovery
Mu Xianyun (沐先运) at Beijing Forestry University discovered the rare orchid species in the Yanqing Mountains during a long-term follow-up survey of another rare orchid in Beijing, Cypripedium shanxiense. The new species was officially announced after minor structural analysis, literature inquiries, communication with Russian experts and confirmation by domestic orchid experts.
In 2020, researchers at Beijing Forestry University found it again during a survey of wild plants in the jungle at an altitude of 1,100 meters in the Wulingshan Nature Reserve in Miyun District.
Description
Plant height 18 to 25 cm, root stem multi-meat, cluster growth. Stem upright, light green, no green leaves; flower sequence green, under the white membrane 2 to 3 pieces, each length 2 to 4 cm, the top piece is sliver-shaped; flower sequence axis length 4 to 8 cm, with 5 to 20 flowers, flower sequence axis is light green soft hair; flower flakes shawl pin-shaped, membrane quality, length 6 to 8 mm back slightly hairy; flower upright, radiation symmetry, green, when flowering the tepals are all expanded; flower stalk length 4 to 8 mm, slim, soft hair; sliver near upright, narrow bar, length 3 to 4 mm, width 1 to 1.2 mm, there is a medium vein, the outer side is slightly hairy; the petals have a distinct middle vein, the lip petals do not crack, 3 to 4 mm long, 0.8 to 1 mm wide; the column is upright, 2 to 3 mm long, the flower wire is short, the anther is nearly egg-shaped, 0.4 to 0.5 mm long, the pollen is oval, the ovary is oval, about 5 mm long, is hairy; florescence is in August, fruit period is in September.
This type of flower features are very primitive, the lip petals are not significantly differentiated, and the petals and slivers are similar, the morphological relative species is Holopogon ussuriensis (a synonym of Neottia ussuriensis).
Holopogon is closely related to the genus Neottia, which some sources treat as synonyms, but studies have also shown that it may be close to the Cephalanthera and should be independent (Chen et al., 2016).
References
Endemic flora of China
Orchids of China
pekinensis
Unplaced names | Holopogon pekinensis | [
"Biology"
] | 580 | [
"Biological hypotheses",
"Controversial taxa",
"Unplaced names"
] |
66,494,684 | https://en.wikipedia.org/wiki/Lasiosphaeria%20ovina | Lasiosphaeria ovina is a species of fungus belonging to the family Lasiosphaeriaceae.
References
Lasiosphaeriaceae
Fungus species | Lasiosphaeria ovina | [
"Biology"
] | 31 | [
"Fungi",
"Fungus species"
] |
66,494,849 | https://en.wikipedia.org/wiki/Pliofilm | Pliofilm was a plastic wrap made by the Goodyear Tire and Rubber Company at plants in the US state of Ohio. Invented in the early 1930s, it was made by dissolving rubber in a benzene solvent and treating it with gaseous hydrochloric acid. Pliofilm was more stable in a range of humidities than earlier cellulose-based wraps and became popular as a food wrap. Its manufacture exposed workers to carcinogenic benzene and, when an additive was used to improve durability, caused dermatitis.
Production of Pliofilm was hampered during World War II because the Japanese occupation of much of Southeast Asia cut off much of the rubber supply. During the war years production was given over entirely to military purposes, with Pliofilm being used to wrap machinery and to waterproof firearms. After the war a plant was opened in Wolverhampton, England, and commercial production continued until the late 1980s.
Manufacture
Pliofilm is a transparent film made of rubber hydrochloride. It is impermeable to water and water vapour and non-flammable.
Pliofilm was manufactured by dissolving natural rubber in the solvent benzene. The solution was kept in a tank at around and treated with gaseous hydrochloric acid. The material was then neutralised with an alkali. The product was cast as a sheet on an endless belt which passed through a dryer that drove off the solvent. The finished product was around 30% chlorine. It could be made thinner by stretching whilst being heated and thicknesses of were sold. Thicker sheets could be produced by laminating the product, combining several sheets with the use of rubber cement.
History and uses
Pliofilm was invented by Harold J. Osterhof at the Goodyear Tire and Rubber Company in the early 1930s and first marketed in 1934. The product found early use as a food wrap, its very low oxygen permeability helping to keep foods fresh. Its clinginess and better stability at a range of humidities was an advantage over the cellulose wrapping films used previously; Pliofilm became about as popular as Cellophane by 1937 and had supplanted cellulose films by 1942. Pliofilm could also function as a shrink wrap and was marketed as a means to reseal bottles (it was advised to place the Pliofilm over an embroidery hoop and to heat it while twisting the bottle).
The material was also used to manufacture aprons and protective sleeves to protect factory workers from hazardous substances. Pliofilm saw widespread use during World War II as a means of protecting tools and engines during shipping. For aviation parts a modified product was produced; a chemical known as RMF was added in quantities of 1–5% to make the product less susceptible to deterioration by ultra-violet light. RMF led to dermatitis in workers who had contact with it. The United States Public Health Service investigated the factories involved and recommended that workers wear protective sleeves made from ordinary Pliofilm. The manufacturing process also caused workers to become exposed to benzene. A study of Pliofilm workers at Goodyear's Akron and St. Marys, Ohio, plants between 1936 and 1976 was used as the basis for determining the cancer slope factor and occupational exposure standards for benzene.
The United States Armed Forces used Pliofilm to waterproof firearms during World War II amphibious landings. Sleeves were produced in three sizes to suit pistols, rifles, and sub-machine guns and were sealed by tying a knot in the sleeve or with an elastic band. It was intended that soldiers would tear off the sleeve after landing, though some troops kept them on inland due to fields having been flooded by the Germans as a defensive measure. The Pliofilm usually trapped enough air to keep the firearm buoyant if dropped in water. Because the sleeve prevented use of the weapon's regular sling some troops fashioned ad-hoc slings from rope that could be used over the Pliofilm. The Houston Chronicle series "D-Day In Color" noted that Pliofilm wrapped around weaponry is evident in an image of United States Army infantry at the Normandy landings.
Pliofilm manufacture was hindered by the Japanese occupation of rubber-producing countries in Southeast Asia. Commercial outputs were stopped and the entire production given over to military uses, leading to a large commercial demand and a backlog of orders after the war's end. In the post-war years Pliofilm saw use as a food wrap, to package drugs and textiles, and as a means of laminating paper. It was also marketed as Vitafilm. Production was extended abroad to the Goodyear factory in Wolverhampton, England, in the late 1940s. The United States Mint switched its packaging for mint set coins from Cellophane to Pliofilm in 1955. The American Chemical Society awarded Harold J. Osterhof the 1971 Charles Goodyear Medal for inventing Pliofilm. It remained commercially available in 1987.
References
Packaging materials
Food storage
Transparent materials
Organic polymers
Rubber | Pliofilm | [
"Physics",
"Chemistry"
] | 1,021 | [
"Physical phenomena",
"Organic polymers",
"Optical phenomena",
"Organic compounds",
"Materials",
"Transparent materials",
"Matter"
] |
66,494,896 | https://en.wikipedia.org/wiki/Leccinum%20melaneum | Leccinum melaneum is a species of fungus belonging to the family Boletaceae.
It is native to Europe and Northern America.
References
melaneum
Fungus species | Leccinum melaneum | [
"Biology"
] | 36 | [
"Fungi",
"Fungus species"
] |
66,494,982 | https://en.wikipedia.org/wiki/Flat%20band%20potential | In semiconductor physics, the flat band potential of a semiconductor defines the potential at which there is no depletion layer at the junction between a semiconductor and an electrolyte or p-n-junction. This is a consequence of the condition that the redox Fermi level of the electrolyte must be equal to the Fermi level of the semiconductor and therefore preventing any band bending of the conduction and valence band. An application of the flat band potential can be found in the determining the width of the space charge region in a semiconductor-electrolyte junction. Furthermore, it is used in the Mott-Schottky equation to determine the capacitance of the semiconductor-electrolyte junction and plays a role in the photocurrent of a photoelectrochemical cell. The value of the flat band potential depends on many factors, such as the material, pH and crystal structure of the material
Background semiconductor physics
In semiconductors, valence electrons are located in energy bands. According to band theory, the electrons are either located in the valence band (lower energy) or the conduction band (higher energy), which are separated by an energy gap. In general, electrons will occupy different energy levels following the Fermi-Dirac distribution; for energy levels higher than the Fermi energy Ef, the occupation will be minimal. Electrons in lower levels can be excited into the higher levels through thermal or photoelectric excitations, leaving a positively-charged hole in the band they left. Due to conservation of net charge, the concentration of electrons (n) and of protons or holes (p) in a (pure) semiconductor must always be equal. Semiconductors can be doped to increase these concentrations: n-doping increases the concentration of electrons while p-doping increases the concentration of holes. This also affects the Fermi energy of the electrons: n-doped means a higher Fermi energy, while p-doped means a lower energy. At the interface between a n-doped and p-doped region in a semiconductor, band bending will occur. Due to the different charge distributions in the regions, an electric field will be induced, creating a so-called depletion region at the interface. Similar interfaces also appear at junctions between (doped) semiconductors and other materials, such as metals/electrolytes. A way to counteract this band bending is by applying a potential to the system. This potential would have to be the flat band potential and is defined to be the applied potential at which the conduction and valence bands become flat
References
Electronic band structures
Semiconductors | Flat band potential | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 538 | [
"Electron",
"Matter",
"Physical quantities",
"Semiconductors",
"Electronic band structures",
"Materials",
"Electronic engineering",
"Condensed matter physics",
"Solid state engineering",
"Electrical resistance and conductance"
] |
66,495,214 | https://en.wikipedia.org/wiki/Appery.io | Appery.io is a cloud-based HTML5, Ionic, jQuery Mobile, and hybrid app-building platform for developing mobile apps, web apps, and PWAs. Appery.io is a browser-based drag-and-drop visual builder tool that supports Android and iOS with integrated Apache Cordova/PhoneGap output. The platform is used by DIYers to create apps for their customers.
History
Appery.io is a product of Exadel and was launched in 2012 under the name Tiggzi.
In 2013, at the TechCrunch Disrupt event in New York City, the platform formally relaunched as Appery.io. After the relaunch, Appery.io continued focusing on enterprise and business apps and began to support Salesforce and other similar enterprise systems.
In 2013, Appery.io partnered with Heroku (a Salesforce.com subsidiary) to allow developers to use Heroku’s approach to provision their apps directly in the cloud. The integrated Appery.io features were meant to ease rapid development within Salesforce's back end and allowed customers with less extensive technical backgrounds to build mobile apps.
In 2014, Appery.io upgraded the platform and introduced new features: a new visual builder UI, an event-oriented mapping editor, and updates to the REST service editor.
Over the course of 2015:
Appery.io introduced an Automatic App Update feature for publishing apps in app stores. Appery.io also updated its API Express, removing steps necessary to integrate enterprise systems, and increased application security with LDAP.
Appery.io partnered with MetaCert, adding new security features to apps built with the platform; the integration of MetaCert security API via a plug-in checks the security of web links in real-time.
Appery.io acquired Verivo software and integrated Verivo’s enterprise connectivity and security capabilities.
Appery.io integrated Ionic into the platform, which lets developers build HTML5/hybrid apps on a single code base with native UX across all platforms.
New features were added to the platform to simplify the way users log in to and test mobile applications on devices: Lightweight Directory Access Protocol (LDAP), social network identity support, and on-device app sharing without app stores.
In 2021, Appery.io added Ionic 5 support to the platform, which supports JavaScript frameworks (Angular, React, and Vue.js). The platform started to support the development of Progressive Web Applications (PWA).
In 2021, Appery.io won the 2021 Devies Award in the "Best Innovation in Mobile Development" category. The award is given annually as a part of the DeveloperWeek trade show.
Platform
The platform comprises an app builder, back-end services, API Express, and plug-ins. The app builder provides cross-platform development with a common API running across iOS and Android. UX is built with Ionic, jQuery Mobile and HTML5 components by using drag-and-drop functionality. The Appery.io back-end services provide hosting, a MongoDB NoSQL database, push notifications, JavaScript server code, and a secure proxy. API Express helps sync Appery.io apps with back-end systems. The plug-ins connect the app to prepackaged REST API services, pages, and data binding.
References
External links
Appery.io Official Website
Software_frameworks
Computing_platforms
Web_frameworks
Mobile_software_programming_tools | Appery.io | [
"Technology"
] | 718 | [
"Computing platforms"
] |
66,495,223 | https://en.wikipedia.org/wiki/Absidia%20glauca | Absidia glauca is a species of fungus belonging to the family Cunninghamellaceae.
It has cosmopolitan distribution.
References
Mucoraceae
Fungus species | Absidia glauca | [
"Biology"
] | 31 | [
"Fungus stubs",
"Fungi",
"Fungus species"
] |
66,496,637 | https://en.wikipedia.org/wiki/MACS%202129-1 | MACS 2129-1 is an early universe so-called 'dead' disk galaxy discovered in 2017 by the Hubble Space Telescope from NASA. It lies approximately 10 billion light-years away from Earth (current distance 18 billion light years) . MACS 2129-1 has been described as 'dead' as it has ceased making new stars.
See also
List of galaxies
References
Galaxies
Aquarius (constellation)
Discoveries by the Hubble Space Telescope | MACS 2129-1 | [
"Astronomy"
] | 92 | [
"Galaxy stubs",
"Galaxies",
"Astronomy stubs",
"Constellations",
"Aquarius (constellation)",
"Astronomical objects"
] |
66,497,042 | https://en.wikipedia.org/wiki/Bruceanol%20A | Bruceanol A is a cytotoxic quassinoid isolated from Brucea antidysenterica with potential antitumor and antileukemic properties.
See also
Bruceanol
References
Quassinoids | Bruceanol A | [
"Chemistry"
] | 48 | [
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
66,497,133 | https://en.wikipedia.org/wiki/Bruceanol%20B | Bruceanol B is a cytotoxic quassinoid isolated from Brucea antidysenterica with potential antitumor and antileukemic properties.
See also
Bruceanol
References
Quassinoids | Bruceanol B | [
"Chemistry"
] | 48 | [
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
66,497,591 | https://en.wikipedia.org/wiki/Bruceanol%20C | Bruceanol C is a cytotoxic quassinoid isolated from Brucea antidysenterica with potential antitumor and antileukemic properties.
See also
Bruceanol
References
Quassinoids | Bruceanol C | [
"Chemistry"
] | 48 | [
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
66,497,650 | https://en.wikipedia.org/wiki/Bruceanol%20D | Bruceanol D is a cytotoxic quassinoid isolated from Brucea antidysenterica with potential antitumor and antileukemic properties.
See also
Bruceanol
References
Quassinoids
Heterocyclic compounds with 5 rings
Methyl esters | Bruceanol D | [
"Chemistry"
] | 60 | [] |
66,497,708 | https://en.wikipedia.org/wiki/Bruceanol%20E | Bruceanol E is a cytotoxic quassinoid isolated from Brucea antidysenterica with potential antitumor and antileukemic properties.
See also
Bruceanol
References
Quassinoids
Heterocyclic compounds with 5 rings
Methyl esters | Bruceanol E | [
"Chemistry"
] | 60 | [] |
66,497,741 | https://en.wikipedia.org/wiki/Bruceanol%20F | Bruceanol F is a cytotoxic quassinoid isolated from Brucea antidysenterica with potential antitumor and antileukemic properties.
See also
Bruceanol
References
Quassinoids | Bruceanol F | [
"Chemistry"
] | 48 | [
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
66,497,761 | https://en.wikipedia.org/wiki/Bruceanol%20G | Bruceanol G is a cytotoxic quassinoid isolated from Brucea antidysenterica with potential antitumor and antileukemic properties.
See also
Bruceanol
References
Quassinoids | Bruceanol G | [
"Chemistry"
] | 48 | [
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
66,497,786 | https://en.wikipedia.org/wiki/Bruceanol%20H | Bruceanol H is a cytotoxic quassinoid isolated from Brucea antidysenterica with potential antitumor and antileukemic properties.
See also
Bruceanol
References
Quassinoids
Heterocyclic compounds with 5 rings
Lactones
Methyl esters
Triols | Bruceanol H | [
"Chemistry"
] | 64 | [] |
66,498,245 | https://en.wikipedia.org/wiki/Rudder%20angle%20indicator | A rudder angle indicator is a device used to indicate the present position of the rudder blade, usually fitted near the Ship's wheel on the bridge and in the engine control room.
See also
Ship's wheel
References
Measuring instruments
Navigational equipment
Watercraft components | Rudder angle indicator | [
"Technology",
"Engineering"
] | 53 | [
"Measuring instruments"
] |
66,501,922 | https://en.wikipedia.org/wiki/Minimal%20polynomial%20of%202cos%282pi/n%29 | In number theory, the real parts of the roots of unity are related to one-another by means of the minimal polynomial of The roots of the minimal polynomial are twice the real part of the roots of unity, where the real part of a root of unity is just with coprime with
Formal definition
For an integer , the minimal polynomial of is the non-zero monic polynomial of smallest degree for which .
For every , the polynomial is monic, has integer coefficients, and is irreducible over the integers and the rational numbers. All its roots are real; they are the real numbers with coprime with and either or These roots are twice the real parts of the primitive th roots of unity. The number of integers relatively prime to is given by Euler's totient function it follows that the degree of is for and for
The first two polynomials are and
The polynomials are typical examples of irreducible polynomials whose roots are all real and which have a cyclic Galois group.
Examples
The first few polynomials are
Explicit form if n is odd
If is an odd prime, the polynomial can be written in terms of binomial coefficients following a "zigzag path" through Pascal's triangle:
Putting and
then we have for primes .
If is odd but not a prime, the same polynomial , as can be expected, is reducible and, corresponding to the structure of the cyclotomic polynomials reflected by the formula , turns out to be just the product of all for the divisors of , including itself:
This means that the are exactly the irreducible factors of , which allows to easily obtain for any odd , knowing its degree . For example,
Explicit form if n is even
From the below formula in terms of Chebyshev polynomials and the product formula for odd above, we can derive for even
Independently of this, if is an even prime power, we have for the recursion (see )
,
starting with .
Roots
The roots of are given by , where and . Since is monic, we have
Combining this result with the fact that the function is even, we find that is an algebraic integer for any positive integer and any integer .
Relation to the cyclotomic polynomials
For a positive integer , let , a primitive -th root of unity. Then the minimal polynomial of is given by the -th cyclotomic polynomial . Since , the relation between and is given by . This relation can be exhibited in the following identity proved by Lehmer, which holds for any non-zero complex number :
Relation to Chebyshev polynomials
In 1993, Watkins and Zeitlin established the following relation between and Chebyshev polynomials of the first kind.
If is odd, then
and if is even, then
If is a power of , we have moreover directly
Absolute value of the constant coefficient
The absolute value of the constant coefficient of can be determined as follows:
Generated algebraic number field
The algebraic number field is the maximal real subfield of a cyclotomic field . If denotes the ring of integers of , then . In other words, the set is an integral basis of . In view of this, the discriminant of the algebraic number field is equal to the discriminant of the polynomial , that is
References
Number theory
Polynomials
Trigonometry | Minimal polynomial of 2cos(2pi/n) | [
"Mathematics"
] | 671 | [
"Algebra",
"Discrete mathematics",
"Number theory",
"Polynomials"
] |
66,504,202 | https://en.wikipedia.org/wiki/Dan%20Burghelea | Dan Burghelea (born July 30, 1943) is a Romanian-American mathematician, academic, and researcher. He is an Emeritus Professor of Mathematics at Ohio State University.
Burghelea has contributed to a number of mathematical domains such as geometric and algebraic topology (including differential topology, algebraic K-theory, cyclic homology), global and geometric analysis (including topology of infinite dimensional manifolds, spectral geometry, dynamical systems), and applied topology (including computational topology).
Early life and education
Burghelea was born in Râmnicu Vâlcea, Romania, in 1943, where he attended Alexandru Lahovari National College (at that time lyceum Nicolae Bălcescu). He attended the University of Bucharest and graduated in mathematics in 1965, with a diploma-thesis in algebraic topology. He obtained his Ph.D. in 1968 from the Institute of Mathematics of the Romanian Academy (IMAR) with a thesis on Hilbert manifolds.
In 1972, Burghelea was awarded the title of Doctor Docent in sciences by the University of Bucharest, making him the youngest recipient of the highest academic degree in Romania.
Career
After a brief military service, Burghelea started his career in 1966 as a junior researcher at IMAR. He was promoted to Researcher in 1968, and to Senior Researcher in 1970. After the dissolution of IMAR, he was employed by the Institute of Nuclear Physics (IFA-Bucharest) and National Institute for Scientific Creation (INCREST) from 1975 until 1977. Burghelea left Romania for the United States in 1977, and in 1979 he joined the Ohio State University as a professor of mathematics. He retired in 2015, and remains associated with this university as an Emeritus Professor.
During his career he has been a visiting professor at numerous universities from Europe and the United States, including the University of Paris, the University of Bonn, ETH Zurich, the University of Chicago, and research institutions including the Institute for Advanced Study, Institut des Hautes Études Scientifiques, Max Planck Institute for Mathematics, Mathematical Sciences Research Institute; and invited speaker to many conferences in Europe, North and South America, and Asia and organized/co-organized workshops and conferences in Topology and Applications in Europe and the United States. He has significantly influenced the orientation of the geometry-topology research in Romania.
Research
Burghelea has worked in algebraic, differential, geometrical topology, differential and complex geometry, commutative algebra, global and geometric analysis, and applied topology.
His most significant contributions are on Topology of infinite dimensional manifolds; Homotopy type of the space of homeomorphisms and diffeomorphisms of compact smooth manifolds; Algebraic K-theory and cyclic homology of topological spaces, groups (including simplicial groups) and commutative algebras (including differential graded commutative algebras); Zeta-regularized determinants of elliptic operators and implications to torsion invariants for Riemannian manifolds.
Burghelea has also proposed and studied a computer friendly alternative to Morse–Novikov theory which makes the results of Morse–Novikov theory a powerful tool in topology, applicable outside topology in situations of interest in fields like physics and data analysis. He was the first to generate concepts of semisimple degree of symmetry and BFK-gluing formula.
He has authored several books including Groups of Automorphisms of Manifolds and New Topological Invariants for Real- and Angle-valued Maps: An Alternative to Morse-Novikov Theory.
He has advised several Ph.D. students.
Awards and honors
1966 – Simion Stoilow Prize, the Romanian Academy
1995 – Doctor Honoris-Causa, West University of Timișoara
2003 – National Order of Faithful Service, Commander rank
2005 – Honorary membership, IMAR, Romania
2009 – Distinction Academic Merit, Romanian Academy of Sciences
2019 – Medal of Honor, the Romanian Mathematical Society
Personal life
Dan Burghelea married Ana Burghelea, in 1965. They have a daughter, Gabriela Tomescu.
Bibliography
Burghelea's books include:
The concordance-homotopy groups of geometric automorphism groups (1971)
Introducere în topologia diferențială (1973)
New Topological Invariants For Real- And Angle-valued Maps: An Alternative To Morse-Novikov Theory, World Scientific (2017)
References
External links
Living people
1943 births
People from Râmnicu Vâlcea
Romanian emigrants to the United States
University of Bucharest alumni
Ohio State University faculty
Topologists
20th-century Romanian mathematicians
21st-century Romanian mathematicians
20th-century American mathematicians
21st-century American mathematicians
Recipients of the National Order of Faithful Service
Institute for Advanced Study visiting scholars | Dan Burghelea | [
"Mathematics"
] | 961 | [
"Topologists",
"Topology"
] |
66,504,377 | https://en.wikipedia.org/wiki/Old-age-security%20hypothesis | The old-age-security hypothesis is an economic hypothesis according to which parents view their children as a source of income and personal services in old age. Within the framework of this hypothesis, the demand for children is considered as the need to ensure a safe old age. As a consequence, increasing the profitability of alternative assets or introducing a universal public pension system reduces the demand for children.
Description
According to this hypothesis, the presence of a state pension system reduces the overall birth rate and hinders investment in the human capital of children, which in the long term leads to a decrease in the size of the working-age population and affects their overall income growth. On the contrary, the absence of alternative assets or state pension provision makes it necessary to have children.
This hypothesis is based on two basic assumptions: people control the number of children born and people in their actions are guided by selfish motives (that is, proceeding only from their own consumption throughout life). According to this hypothesis, payments from children to support their elderly parents are seen as a return on loans that parents spent to provide for their children in childhood.
Alternative hypotheses explaining the birth rate are intergenerational altruism and various hypotheses related to the labor market.
The earliest mention of the inverse relationship between the birth rate and the level of the population's pension is found in Leibenstein in 1957. Van Groezen, Leers and Meijdam in 2003, Sinn in 2007, Cigno and Werding in 2007, Ehrlich and Kim in 2007, Van Groezen and Meijdam in 2008, Gahvari in 2009, Cigno in 2010, expressed the opinion about the decline in the birth rate as a consequence of the introduction of the pension system. Fenge and von Weizsäcker in 2010, Regös in 2014, Boldrin, De Nardi and Jones in 2015. Guinnane in 2011, based on empirical evidence of declining fertility in historical time, considered the introduction of social protection as one of the reasons for the first demographic transition. Cigno and Rosati in 1992, Cigno in 2003, Billari and Galasso in 2009 examined this hypothesis at the level of specific countries and individual pension systems. Cigno and Werding in 2007 gave an overview of work on the relationship between pensions and fertility in the modern period. According to these studies, a smaller pension coverage leads to a higher birth rate.
Alessandro Cigno
According to Alessandro Cigno, ensuring old age is an incentive for raising children and a dominant factor in increasing the birth rate. Cigno also believes that it has been proven that the coverage of the population by the pension system reduces the birth rate, although it increases household savings. In his opinion, the state pension system prevents parents from investing in the human capital of their children. Considering the rapidly aging population and the imbalance between the number of recipients of pensions and those who pay pension contributions as the reason for the deficit of the pension fund and the decrease in the income of pensioners, Alessandro Cigno proposes to pay the pension to parents directly from the pension contributions of their children.
Robert Fenge and Beatrice Scheubel
In 2017, Robert Fenge and Beatrice Scheubel published an article Pensions and fertility: back to the roots, where they studied the relationship between the development of the state pension system, or rather the dynamics of the share of people participating in pension insurance programs and the dynamics of fertility, using the example of the German Empire at the end of 19 and beginning 20th century. In addition to pensions, the multivariate analysis took into account those factors that scientists usually cite as the cause of the first demographic transition. Together with pensions, the impact of factors such as literacy and urbanization was analyzed. According to Robert Fenge and Beatrice Scheubel, the introduction of pensions in Germany at the turn of the 19th and 20th centuries explains up to 15% of the decline in the birth rate in 1895–1907.
UN Conference on the World Population in Bucharest, 1974
A meeting dedicated to the reduction of the world population was held in Bucharest from August 19 to 30. Participants: more than 1.4 thousand delegates from 136 countries (at that time there were 138 countries in the UN, family planning is already being promoted in 59 countries). Initiator: The USA and the UN.
The plan was written in advance, it was mainly developed by the American side, initially contained quantitative target indicators for the CPR (Controlled Population Reduction) for individual countries, but as a result of the protests they had to be removed. It was the first official international document in the field of demography and fertility reduction.
The Conference is proud for the first time in history, setting the goal of "curbing population growth" for the peoples. And also worked out specific ways to achieve this Goal. Among them is the introduction of benefits and pensions.
"Recognizing the diversity of social, cultural, political and economic conditions, everyone agrees that the following development goals will lead to a moderate birth rate: reduction of infant and child mortality, full involvement of women in the development process (education, economics, politics), promotion of social justice, accessibility of education, eradication of child labor and abuse with children, the introduction of social security and old-age pensions, the establishment of a minimum age for marriage."
By this time, demographic policy and "family planning" programs had been successfully applied in Asian countries, in particular in India, Japan, Pakistan and Sri Lanka. In 1974, teaching staff worked in 39 countries, in which about 80% of the population of the "developing world" lived.
Barbara Entwistle
Here is how the author explains the purpose of his work: In 1974, a meeting took place in Bucharest, which resulted in the adoption of an Action Plan for the World Population. It is strongly recommended to introduce everywhere school education and pensions in order to benefit the population, as well as to reduce its number.
Because in America it was already generally accepted that pensions and education lower fertility. And to check the correctness of this opinion, its effectiveness (degree of impact) and applicability to different countries, as well as the predictions made earlier, Barbara just carried out this huge work.
About previous studies. On page 258, the author mentions previous studies of the dependence of fertility on pensions and education, these are: McGreevy and Birdsall (1974), and the Triangle Research Institute (1971), as well as Kirk (1971), Kasarda (1971), Adelman (1963), Friedlander and Silver (1967) and Beaver (1975). and others, at least 15. They showed very different results, from zero correlation to significant (higher than the statistical error). Light was shed by the study of Friedlander and Silver (1967), where they first explored the whole world, but then developed and developing countries separately, and it turned out that the negative impact of education on fertility is indeed significant in developing countries, but practically zero in developed countries.
These studies used different criteria for education (for example: literacy, school enrollment, circulation of newspapers, etc.), included a different number of variables (i.e., a unified method for calculating dependence has not yet been developed), and Barbara comes to the conclusion that correlation becomes significant when the study includes 4–5 variables, in other words, when education is complemented by something else. (p. 261)
Beaver (1975) finds that the effect of education on fertility is more pronounced in TFR but not OCD because TFR is an age-standardized unit of measure. But the difference in results is still small. The same is indicated by the studies of Adelman (1963) and Janowitz (1971). Another interesting finding from Beaver is that education has an effect on OCD with a lag of 12.5 years, but not 7.5 years. (This conclusion of Beaver is not supported by Barbara's own research, she found no dependence on lags of 5, 10 and 15 years.) (P. 262)
Opportunities for education have skyrocketed around the world since World War II, says Barbara. Other studies of the dependence of fertility on education, using, like Beaver, data for the 1950s - early 1960s (for example, Ekanem, 1972), found no relationship between them. (p. 263)
So the question of the dependence of fertility on education remains unclear, although it has been comprehensively and in detail discussed. On this, with education, Barbara ends and moves on to pensions.
Friedlander and Silver (1967) were the first to introduce pensions into country comparisons. They found a significant influence of this factor (pensions), both for developed and developing (especially developing) countries, which was not found according to earlier data from 1960. (pp. 263–264). Holm (1975), in contrast to Friedlander and Silver, already finds a significant negative correlation between fertility and pension coverage, possibly due to the fact that more recent data from the mid-1960s are used. The size of the pension has very little effect on the birth rate. (p. 264).
Kelly, Cutwright, and Hittle (1976) criticized Holm (1975) for not taking into account the so-called. modernization, they argued that the drop in the birth rate does not actually correlate with pensions, but with modernization, and with the introduction of the modernization coefficient they created, the impact of pensions was already insignificant. (p. 265)
Holm responded with a paper (1976), where he analyzed the correlation of fertility and another indicator, the percentage of government spending on pensions from the GDP of that state, and on a larger sample of countries. She confirmed the pension hypothesis (that pensions reduce the birth rate), even with the inclusion of this modernization index. (These results are consistent with those of Barbara's dissertation in Chapters 5 and 6.) Again, Holm's work shows a stronger negative effect of pensions on fertility in developing countries, especially in the early 1960s (p. 265).
Barbara mentions 4 more studies, which gave the same result as hers, but her work is more detailed, because it shows that pensions affect not only the birth rate, but also the rate at which it declines, that pensions have a delayed effect, and that this effect increased during the 1960s. Initially, the effect (of lower fertility due to pensions) was more pronounced in developing countries, but the difference faded as they developed over a 10-year period. (p. 266)
According to Barbara, the creation of comparative analysis models across countries (in terms of the dependence of fertility on economic indicators) began, according to Barbara, in Weintraub's (1962) rather simple model of the dependence of OCD on economic development indices. (p. 267) Since then, the models have become more complex, including more and more variables, including education and pensions, as well as population density, urbanization index, working women, family planning programs, and others (Leibenstein, 1975, Adelman, 1963, Ekanem, 1972). It is curious that many studies (Ekanem, 1972, Gregory and Campbell, 1976, Moldin et al., 1978) show a positive, albeit small, impact of urbanization, like this thesis, and a clear negative impact of urbanization on fertility - Beaver (1975). Moldin et al. (1978) showed a significant impact of family planning programs in developed countries 1965-1975, but did not take into account pensions.
A study by Moldin (1978) showed that family planning programs (introduced mainly in the 1960s) in developing countries have mitigated the effect of economic inequality on fertility, i.e. the poor, whose fertility is usually higher, have lowered this rate. (p. 267) In the 1970s, the delayed effects of family planning programs were expected to affect developed countries (which started earlier) than developing countries, but Moldin did not find significant differences between these groups of countries in the rate of decline in fertility in the 1970s. ... This may indicate that some other factor influenced. p. 268
Research became more complex, Heer (1966), Kirk (1971), Gregory et al. (1971), Beaver (1975), Gregory and Campbell (1976), examined a variety of relationships on a variety of variables. (p. 269) Attention is paid to threshold values, for example, Moldin (1978) estimates the threshold of female literacy from 55 to 85%, from that moment it begins to influence fertility.
The same threshold should apply to pensions, Barbara notes, but there is no research yet that defines this threshold.
Pages 271-276 are devoted to some controversial issues of methodology, for example, the author is a supporter of the so-called. homogeneity, i.e. claims that different nations under the same conditions will behave in the same way. "Heterogeneous women" let them prove it, she says. Or the question of how best to group nations for analysis? or the issue of the influence of time on the results (at different points in time, the reaction to variables (the same pensions and education) may be different, or the issue of converting one unit of fertility measurement to another, the issue of data accuracy, etc.)
Barbara notes that there is interdependence, but she would view education and pensions as causes, and fertility as a consequence. In the chapter "Pension and education programs as a policy of fertility," Barbara notes that these programs are essentially equal to the political decision of the state to reduce the birth rate and curb the growth of its population, and the choice is up to the state. (p. 287). Thus, Tsul and Baugh (1978, p. 33) conclude that the trends of recent years are encouraging because rid the world of the darkest prospects of overpopulation, famine and world war, outlined, according to the Malthusians, by the year 2000. Has a remedy been found for overpopulation? It's premature to think so, says Barbara. In 1975, the birth rate was 4,688 births per 1,000 women in 24 Latin American countries, 6,264 in 40 African countries, 6,009 in 16 countries in the Middle East, 4,572 in 25 Asian countries - the danger has not yet passed. By 1978 (according to Tsula and Baugh's report), the situation had not changed, and 2/3 of developing countries have this figure above 5,000, and more than half of them are more than 6,000, that is, the countries of the Third World double their numbers per generation. Tsul and Baugh are pinning their hopes on family planning programs that world leaders must implement. (p. 288) But these programs only reduce the number of children to what is desired, which is still quite high in developing countries, says Arnold et al. (1975), examining 4 countries.
The policy of reducing the birth rate must continue, Barbara insists.
Barbara Entwistle, in her 1981 dissertation, proposes a "child role hypothesis" based on the thesis that mass education and pension programs are linked to fertility by feedback. (pp. 39, 277) Barbara notes that this thesis was put forward by scientists and before her, mentions four previous studies of the relationship between pensions and fertility, two of which (Friedlander and Silver, 1967, and Kelly and others, 1976) did not find a connection. one revealed a very weak dependence, on the verge of statistical error (Hom, 1975), and the last (Hom, 1976) showed a strong dependence.
Barbara conducted a comprehensive analysis for 146 ethnic populations (countries), of which 120 had complete data, and for 1960, 1965 and 1970. (p. 145) It turned out that 1970 showed a more pronounced dependence than 1965, and 1965, in turn, showed a more pronounced dependence than 1960, in other words, earlier work examined earlier data, where the dependence is small.
Barbara names two explanations for this negative dependence (fertility on pensions), accepted in American demography: economic, where children are breadwinners in old age, and pensions reduce this role, and generally accepted that pensions change the structure of the family. Both of them lead to the same result - a decrease in the birth rate, so Barbara does not distinguish between them, i.e. does not introduce indices measuring the value of children, nor the strength of bonds between children and parents (p. 203). Although she herself is leaning towards the generally accepted explanation, rather than the explanation of "cost and benefit", because, in her opinion, this explains the delayed effect of pensions. Parents-to-be must learn about pensions and the opportunities they provide, and this takes some time. This generally accepted explanation (the destruction of the family structure) is also supported by the fact that the effect of pensions increases over time (p. 204), which, in her opinion, would not have been the case with the "prices and benefits" mechanism.
Pensions have been found to have a deferred effect, i.e. their action slows down.
But Barbara did not find the dependence of fertility on educational programs, or very weak, on the verge of a statistical error, which "disappointed" her (p. 204), which again, in her opinion, does not confirm the hypothesis of "prices and benefits," according to which The "price" of children is greatly increased precisely from education, because parents are forced to spend many years on school bags and notebooks, instead of sending the child to work and carrying a penny into the house. (pp. 204, 278, 281-282) Another confirmation of the hypothesis of the influence of pensions precisely through the weakening of family ties, Barbara considers the fact that pensions initially had a stronger effect on developing countries, because in developed family ties were already weakened.
Barbara notes two studies (Müller, 1972, and Arnold et al., 1975) that introduced indices of family ties, and showed that fertility changes in accordance with them, as predicted. She emphasizes the importance of developing such indices, and so that they include not only the content of parents, but also cohabitation (which is not in the Hypothesis of the role of children), there are no such indicators yet, and most of the countries cannot be evaluated by this indicator. (Although Barbara's own preliminary research did not show fertility as a function of cohabitation indices and the number of adults in the household, therefore she did not include these indices in the main study.)
Caldwell (1976,1977) put forward a similar hypothesis that Westernization (the Western way of life, namely education and pensions) rather than industrialization reduces fertility, based on African countries where industrialization was in its infancy, but something already influenced fertility - and this, according to the author, is Westernization. In other words, the prospect of receiving a pension in the future already influenced (i.e., the future parent considered himself as having already worked at the factory and a recipient of the pension, although the factory was not yet open), and not an example of ancestors (who did not work in factories ). Although such a claim needs more proof, adds Barbara.
But pensions just fit into the Hypothesis of the role of children, because liberate children from the need to feed their parents, thereby weakening family ties, reducing family and the desire to have their own children, and the fertility predictions made on this basis came true.
On pages 205 (also 283, 289), Barbara sums up that pensions are extremely promising for reducing the birth rate, and advises all Third World countries to introduce pensions (including funded ones) for this purpose. Training programs for such a reduction are not useful, says Barbara, except in terms of spreading knowledge about contraception, activities outside the family, etc. among future parents. And even such education, firstly, will take time, and secondly, it will have little effect.
Cites article 20 of the Universal Declaration of Human Rights (1948), which says that "everyone has the right to social security (cited by Savi, 1972, p. 2), and notes that the Plan of Action on World Population (1974) supports this thesis precisely from the goal of reducing the population, as well as ensuring human rights.
Barbara finds it useful not only to make a comparative analysis across countries, but also for individual communities that differ in terms of pension coverage and education, up to the study of individual families (for example, such studies could clarify the role of "son preference" by examining the role of education of boys and girls in -separability), the hypothesis of the role of children is very promising, because predictions come true. (p. 285) Conclusions: the nuclear family is weaker than the "long" family (which includes many relatives, is less able to pay the "price" of children, because it does not receive adequate support from relatives, although it fits better into the modern industrial society, and the nuclear family accompanies lower fertility.
Also, Barbara calls into question the thesis adopted before her that all nations react to the same innovations in the same way. The results of her work do not confirm either the assumption of homogeneity (that all nations react in the same way) or heterogeneity. For example, in developed countries, the decline in fertility due to the introduction of pensions turned out to be less than the forecast showed. The greatest influence of pensions had on the developing countries and the countries of Latin America, and of the studied 1960, 1965 and 1970, the effect was most pronounced in 1970.
Borisov Vladimir Al.
In his book Prospects of fertility [6], back in 1976, Borisov, among the reasons for having few children, along with the separation of children from family production (in a peasant family), the termination of communal land ownership, also calls social insurance systems, i.e. pensions, as well as developed medicine, which reduce the dependence of the elderly on their children and makes children "unnecessary" for these purposes. Borisov saw the reason for the decline in the birth rate in the reduction of the need for children, and argued that no improvements in living conditions and child allowances will increase the birth rate if there is no socio-cultural need for children-the so-called behavioral approach.
For his views on the demographic situation, the threat of depopulation in the country and the demographic policy adopted at that time, Borisov was dismissed from the university and deprived of the right to teach until 1991, A. I. Antonov reports in his article "80 years since the birth of Vladimir Alexandrovich Borisov" [7]. The reason was his speech at a student conference at Moscow State University. The Leninsky District Committee of the CPSU of Moscow declared him an " apolitical scientist"
At that time, it was customary to make ironic remarks about the "threat of depopulation", and some reviewers generally believed that such a thing was impossible in the next 500 years. In 1982, Borisov was demoted to just a researcher. The reason is again "careless performance" (the words of Borisov himself, from his autobiography). This harassment continued in the post-Soviet period, when in 1994 a meeting on the defense of his doctoral dissertation was disrupted.
Borisov considered the birth rate indicator to be the main one in demography, and the decline in the birth rate was the global problem No. 1. He saw the reason for the lack of children in the lack of motivation, intergenerational ties (the need for children). He also believed that this process (the so-called Demographic Transition) is reversible, provided that such a need is returned. Benefits and living conditions alone will not increase the birth rate-if there is no need for children, Borisov believed.
(Also, in his article, Antonov noted that the phenomenon of low birth rate has not been sufficiently studied).
Borisov was once a student of Urlanis, and if Borisov wrote his landmark work Birth Rate Prospects in 1976, then Urlanis wrote "Problems of Population Dynamics of the USSR" in 1974, from which the forecasts of demographic processes for 2000 were removed by censorship. The future will show that they were correct.
Borisov is also the author of a GMER model of a hypothetical minimum of natural fertility. Antonov defines the essence of this model as "behavioral"
References
Bibliography
The long-term determinants of marital fertility in the developed world (19th and 20th centuries): The role of welfare policies Jesús J. Sánchez-Barricarte
EDUCATION, PENSION PROGRAMS, AND FERTILITY: A CROSS-NATIONAL INVESTIGATION, WITH SPECIAL REFERENCE TO THE POTENTIAL HELD BY EDUCATION AND PENSION PROGRAMS AS FERTILITY REDUCTION POLICIES
Entwisle, Barbara (M.A.: Sociology, 1978) Title: The effect of pension programs on fertility : a replicative study Advisor: Kobrin, Frances E.
Barbara Entwisle, Albert I. Hermalin, William M. Mason Socioeconomic Determinants of Fertility Behavior in Developing Nations: Theory and Initial Results
The Effect of Old-Age Pensions on Fertility: Evidence from a Natural Experiment in Brazil
The impact of pension systems on fertility rate: a lesson for developing countries
Influence of women's workforce participation and pensions on total fertility rate: a theoretical and econometric study
Pension, Fertility, and Education
Fertility and Pension Programs in LDCs: A Model of Mutual Reinforcement
Fertility and education investment incentive with a pay-as-you-go pension
The effects of child-related benefits and pensions on fertility by birth order: a test on Hungarian data
Pensions with endogenous and stochastic fertility
The fertility effects of public pension: Evidence from the new rural pension scheme in China
Sociocultural evolution theory
Demographic economics
Human geography | Old-age-security hypothesis | [
"Environmental_science"
] | 5,295 | [
"Environmental social science",
"Human geography"
] |
66,504,810 | https://en.wikipedia.org/wiki/Opha%20Pauline%20Dube | Opha Pauline Dube (born 1960) is a Botswanan environmental scientist and Associate Professor in the Department of Environmental Science at the University of Botswana. She co-authored the IPCC's Special Report on Global Warming of 1.5 °C. She is one of fifteen scientists creating the 2023 Global Sustainable Development Report for the United Nations.
Education
Dube was awarded her MPhil in Applied Remote Sensing at the Cranfield Institute of Technology in the UK in 1989. She graduated with a PhD from the University of Queensland in 2000. She earned her doctorate due to a collaboration between the University of Botswana and the University of Queensland arranged by the Commonwealth Scientific and Industrial Research Organisation. The work involved investigating whether remote sensing-based methods used on Australian ranges could be applied to monitor land degradation in Botswana.
Career and research
Dube is an Associate Professor in the Department of Environmental Science at the University of Botswana. Her research and teaching focuses on the social and biophysical aspects of global environmental change. In 2012, she held a research fellowship at the Australian National Climate Change Adaptation Research Facility (NCCARF) at Griffith University and had a similar position at the Environmental Change Institute at the University of Oxford in 2018.
Dube was Co-Vice Chair of the International Geosphere-Biosphere Programme (IGBP) between 2010 and 2015 and the Deputy Chair of Botswana National Climate Change Committee between 2017 and 2019. Dube is currently serving as the Co-Chair of the Scientific Advisory Committee of the Climate Research for Development in Africa (CR4D)-UNECA and the Vice Chair of the World Meteorological Organisation (WMO) Scientific Advisory Panel.
She is one of the Editors-in-Chief of the Elsevier Current Opinion in Environmental Sustainability academic journal and an associate editor of the CSIRO Rangeland Journal. In 2019, Dube was listed in the top 100 of "The World's Most Influential People in Climate Policy" and in October 2020, she was appointed by the UN Secretary General to be one of fifteen scientists creating the 2023 Global Sustainable Development Report for the United Nations.
Dube has served as part of the Intergovernmental Panel on Climate Change (IPCC) Working Group II since the Third Assessment Report. This group "assesses the vulnerability of socio-economic and natural systems to climate change, negative and positive consequences of climate change and options for adapting to it". She has contributed to the IPCC's Third, Fourth and Fifth Assessment Reports, acting as both an author and a review editor. Her work on the Climate Change 2007: Impacts, Adaptation, and Vulnerability (AR4 WG2) report, as part of the Fourth Assessment Report, led to Dube being awarded an International Nobel Peace Prize Certificate in 2007. She was also coordinating lead author for two of the IPCC's Special Reports: Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX) and Global Warming of 1.5 °C (SR15).
Dube worked as a review editor for the upcoming IPCC Sixth Assessment Report, on the chapter titled "Food, fibre, and other ecosystem products."
Awards and honours
2007: Co-recipient of the International Nobel Peace Prize Certification
2018: "International Alumni of the Year" in the University of Queensland's annual Alumni Awards
2019: Listed in the top 100 "World's Most Influential People in Climate Policy"
Selected publications
Allen, M.R., O.P. Dube, W. Solecki, F. Aragón-Durand, W. Cramer, S. Humphreys, M. Kainuma, J. Kala, N. Mahowald, Y. Mulugetta, R. Perez, M.Wairiu, and K. Zickfeld, 2018. Framing and Context. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte, V. et al. (eds.)]. In Press.
Maru, Y.T., M.S. Smith, A. Sparrow, P.F. Pinho, O.P. Dube, 2014. A linked vulnerability and resilience framework for adaptation pathways in remote disadvantaged communities. Global Environmental Change, 28, 337–350. doi:10.1016/j.gloenvcha.2013.12.007
Dube, O.P., 2009. Linking fire and climate: interactions with land use, vegetation, and soil. Current Opinion in Environmental Sustainability, 1 (2), 161-169. doi.org/10.1016/j.cosust.2009.10.008
Fischlin, A., G.F. Midgley, J.T. Price, R. Leemans, B. Gopal, C. Turley, M.D.A. Rounsevell, O.P. Dube, J. Tarazona, A.A. Velichko, 2007. Ecosystems, their properties, goods, and services. In: Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, [Parry, M.L. et al. eds.]. Cambridge University Press, Cambridge, pp. 211-272.
External links
References
1960 births
Living people
Botswana educators
Climate change in Australia
Climate change in Botswana
African environmentalists
Environmental scientists
Climate change mitigation researchers
Alumni of Cranfield University
University of Queensland alumni | Opha Pauline Dube | [
"Engineering",
"Environmental_science"
] | 1,171 | [
"Geoengineering",
"Environmental scientists",
"Climate change mitigation researchers"
] |
66,506,057 | https://en.wikipedia.org/wiki/French%20Group%20for%20the%20Study%20of%20Polymers%20and%20their%20Application | The French group for the study of polymers and their application, also called more simply French polymer group (GFP) is a French nonprofit organization and learned society, which aims to promote polymer chemistry, physics, and material science in French industry and institutes of higher learning.
History
Creation of the GFP
The GFP was created in 1970 by the polymer physicist André Kovacs and the chemist Georges Champetier, one of the first researchers in France to study polymer science.
The statutes of the GFP set out the following goals:
the advancement and dissemination of studies on macromolecular substances,
the grouping of researchers studying polymers in order to promote exchanges of ideas and facilitate knowledge of scientific and technical progress in this field,
the development of relationships between basic research and its applications.
The GFP is based in Strasbourg, where in 1954 the physicist Charles Sadron founded the first CNRS laboratory dedicated to polymer science, which became the Institut Charles Sadron in 1985. Its first general meeting was held on November 26–27, 1970 in Paris. Its first committee comprised Georges Champetier (President), Charles Sadron and René Riou (Vice-presidents), André Kovacs (Secretary general) and Constant Wippler (Treasurer). Since its founding, the presidency of the GFP has alternated between researchers based in academia and industry, while the secretary has always been a member of the Institut Charles Sadron (originally the CRM).
Sister societies and federations
In May 1990, the GFP reached an agreement with the Société chimique de France, becoming its Division of "Polymeric materials and elastomers". In 2001 this agreement was modified to create a "Polymer and Materials Chemistry" Division that was common to the two societies. In 2002, a similar agreement with the Société française de physique created a common "Polymer" Division between the two organizations. The GFP is a founding member of the Fédération française des matériaux (French Materials Federation), and a member of the European Polymer Federation, whose first conference was organized by the GFP in Lyon in 1986. In 2020, the GFP signed a Memorandum of Understanding with the Society of Polymer Science Japan.
Activities
Conferences and Workshops
The GFP organizes numerous national and regional conferences and workshops. Its flagship event is the Colloque national du GFP, held each November in a different French city, with a typical attendance of 180-250 participants. In addition, the JEPO is an annual conference aimed at students and early career researchers, while the RNJP targets newly established researchers in permanent positions. Finally the GFP organizes regular workshops and training sessions on more specialized subjects.
Regional sections
The GFP comprises 7 regional sections, covering different geographical areas of France (Grand Ouest, Nord, Ile de France, Est, Rhône-Alpes-Auvergne, Méditerranée, Sud Ouest). Each section elects a president who participates in the Administrative Council of the GFP. Organisation of national events (the Colloque national and JEPO) rotates between the sections, while each section organises local events.
Publications
The GFP publishes a newsletter "Actualités du GFP", 2-3 times per year. Additionally, its Education Commission periodically releases books on different aspects of polymers and their applications. In 2004, the GFP joined forces with the International Union for Pure and Applied Chemistry to promote education in polymer science in French-speaking countries.
Awards and distinctions
The GFP bestows several annual or biennial awards, alone or jointly with the SCF or the SFP:
Polymer Thesis Award of the Education Commission of the GFP (annual)
Polymer Division Award, jointly awarded with the SCF, recognizing an early career scientist (less than 40 years old) for significant scientific results or original techniques in polymer chemistry (biennial, since 1992)
Polymer Division Award, jointly awarded with the SFP, recognizing an early career scientist (less than 40 years old) for significant scientific results or original techniques in polymer physics (biennial, since 2004)
Grand Prix of the GFP, recognizing the career or the complete works of a French or international researcher in polymer science (biennial, since 2003)
Prix d'Honneur of the GFP, recognizing a scientific career dedicated to polymer science (annual, since 2017)
Presidents and secretaries general
Notes and references
External links
Chemical industry in France
Learned societies of France
Scientific organizations based in France
Chemistry societies
Chemistry education | French Group for the Study of Polymers and their Application | [
"Chemistry"
] | 896 | [
"Chemistry societies",
"nan"
] |
63,707,904 | https://en.wikipedia.org/wiki/Genome%20informatics | Genome Informatics (also genoinformatics or genetic information processing) is a scientific study of information processing in genomes.
Introduction
Information processing and information flow occur in the course of an organism's development and throughout its lifespan. The essence of computation is information processing, and the essence of biological information processing is control of the molecular events inside a cell. Genome informatics introduces computational techniques and applies them to derive information from genome sequences. Genome informatics includes methods to analyze DNA sequence information and to predict protein sequence and structure. Methods of studying a large genomic data include variant-calling, transcriptomic analysis, and variant interpretation. Genome informatics can analyze DNA sequence information and to predict protein sequence and structure. Genome informatics dealing with microbial and metagenomics, sequencing algorithms, variant discovery and genome assembly, evolution, complex traits and phylogenetics, personal and medical genomics, transcriptomics, genome structure and function. Genoinformatics refers to genome and chromosome dynamics, quantitative biology and modeling, molecular and cellular pathologies. Genome informatics also includes the field of genome design. There still a lot more we can do and develop in Genome Informatics. Find a potential disease, searching a solution for a disease, or proving why people get sick for no reason. For genomic informatics there are several main applications for it, including:
genome information analysis
computational modelling of gene regulatory networks
models for complex eukaryotic regulatory DNA sequences
an algorithm for Ab Initio DNA Motif Detection
Applications
Biomolecular systems that can process information are sought for computational applications, because of their potential for parallelism and miniaturization and because their biocompatibility also makes them suitable for future biomedical applications. DNA has been used to design machines, motors, finite automata, logic gates, reaction networks and logic programs, amongst many other structures and dynamic behaviours.
See also
cellular computing
References
Academic disciplines
Bioinformatics
Genetic mapping | Genome informatics | [
"Technology",
"Engineering",
"Biology"
] | 390 | [
"Biological engineering",
"Computer science stubs",
"Bioinformatics",
"Computer science",
"Computing stubs"
] |
63,708,160 | https://en.wikipedia.org/wiki/Ramularia%20rubella | Ramularia rubella is a plant pathogen in Ascomycota that infects Rumex species. Infection produces reddish spots on leaves. The red color is caused by the production of rubellin, a photodynamic anthraquinone-derived phytotoxin. R. rubella was originally described from Rumex aquaticus in Germany; it has a wide geographic range on Rumex species. It is being investigated as a biological control agent of Rumex obtusifolius.
References
rubella
Fungal plant pathogens and diseases
Taxa named by Hermann Friedrich Bonorden
Fungus species | Ramularia rubella | [
"Biology"
] | 123 | [
"Fungi",
"Fungus species"
] |
63,709,093 | https://en.wikipedia.org/wiki/Sulfate%20chloride | The sulfate chlorides are double salts containing both sulfate (SO42–) and chloride (Cl–) anions. They are distinct from the chlorosulfates, which have a chlorine atom attached to the sulfur as the ClSO3− anion.
Many minerals in this family exist. Many are found associated with volcanoes and fumaroles. As minerals they are included in the Nickel-Strunz classification group 7.DG.
The book Hey's Chemical Index of Minerals groups these in subgroup 12.2.
List
Artificial
Some "chloride sulfates" are sold as solutions in water and used for water treatment. these include ferric chloride sulfate and polyaluminium sulfate chloride. The solutions may also be called "chlorosulfates" even though they do not contain a chlorosulfate group.
References
Sulfates
Chlorides
Double salts
Mixed anion compounds | Sulfate chloride | [
"Physics",
"Chemistry"
] | 184 | [
"Matter",
"Chlorides",
"Inorganic compounds",
"Mixed anion compounds",
"Sulfates",
"Double salts",
"Salts",
"Ions"
] |
63,709,536 | https://en.wikipedia.org/wiki/Vladimir%20Petviashvili | Vladimir Iosifovich Petviashvili (Петвиашвили Владимир Иосифович; September 12, 1936 – July 21, 1993) was a Soviet physicist from Georgia. Petviashvili graduated from Tbilisi State University in 1959, where he also completed his doctoral studies. In 1963–1965, he was research assistant at the Institute of Physics of the Andronikashvili Academy of Sciences of the Georgian SSR. Since 1965 he worked at the Kurchatov Institute (Institute of Atomic Energy named after I.V. Kurchatov) and at the Moscow Institute of Physics and Technology. In 1992, Petviashvili received the I. Tamm Prize for a series of works on Turbulence and eddy current structures in plasma.
Biography
Petviashvili was born in Tbilisi to a family of scientists in 1936. In 1959, he graduated from Tbilisi State University. After defending his doctoral dissertation in March 1979, Petviashvili expanded his research interests to nonlinear drift waves and drift turbulence, which were critical in the development of the theory of plasmas. Petviashvili showed that drift turbulence can have some regularities in its chaotic structure and consists of structural elements— two-dimensional soliton vortices. He investigated possible mechanisms for the self-generation of these structures and suggested diffusion and heat-conductivity processes involving the mixing of plasma and solitons inside these structures. Seeking extensive applications for his results, Petviashvili put forward the idea of modeling drift turbulence in rapidly rotating shallow waters. He laid the foundations for laboratory experiments employing this idea in his paper 'The Red Spot of Jupiter and Drift Solitons in a Plasma". These experiments have been successfully conducted at the Kurchatov Institute and other scientific research centers around the world.
Notable work
Candidate dissertation (1963) - "Some questions of the theory of weakly turbulent plasma."
Boris B. Kadomtsev and V. I. Petviashvili (as well as Vladimir E. Zakharov) obtained and studied integrable nonlinear equations for two-dimensional and three-dimensional waves in plasma containing soliton solutions, known as the Kadomtsev-Petviashvili equation (1970).
Doctoral dissertation (1978) - "The theory of strongly nonlinear waves and solitons in plasma."
V. I. Petviashvili and O. A. Pokhotelov (1992) - "Solitary waves in plasma and atmosphere", Gordon & Breach Science Publishers, Reading, ISBN 978-2881247873
References
External links
Plasma physicists
Physicists from Georgia (country)
Tbilisi State University alumni
Soviet physicists
1936 births
1993 deaths | Vladimir Petviashvili | [
"Physics"
] | 557 | [
"Plasma physicists",
"Plasma physics"
] |
63,709,771 | https://en.wikipedia.org/wiki/Scytalidium%20ganodermophthorum | Scytalidium ganodermophthorum is an anthroconidial ascomycete fungus in the Scytalidium genus. It is also known by its teleomorph name Xylogone ganodermophthora. It is the cause of yellow rot in lingzhi mushrooms and it is used in spalting as a pigmenting fungi.
Taxonomy
Scytalidium ganodermophthorum was first identified in Korea as yellow rot, a disease affecting Ganoderma lucidum. In 1996, Jong-Kyu Lee et al. identified it as a fungal pathogen and categorized it as Xylogone sphaerospora. However, in 1998, Se-Jong Oh and researchers at Kangwon National University recategorized the fungus as Arthrographis cuboidea based on morphological characteristics. Researchers returned to the topic in 2010 and reclassified the fungus as Xylogone ganodermophthora. It is most frequently referred to by its anamorph name, S. ganodermophthorum. DNA analysis suggests that S. ganodermophthorum is part of a clade that includes X. sphaerospora, A. cuboidea and Scytalidium lignicola within Scytalidium, but the position of the clade within Leotiomycetes is unknown.
Description
The fungus is a saprobe and opportunistic fungal pathogen found in wood and soil. Infected wood exhibits a greenish-yellow color with brown border lines. Eventually, infected wood turns black and disintegrates as S. ganodermophthorum consumes it. Fungal colonies range from pale yellow to yellow green on agar plates.
This species reproduces sexually and asexually. In sexual reproduction, it produces small yellow fruiting bodies known as ascocarps. These ascomata are 45-95 μm spheres with dark, thick walls. Within the ascomata are many asci; these asci are thin-walled and disintegrate easily. The ascospores contained in the asci are smooth, refractive spheres with a glassy appearance, about 3.6-4.3 μm in diameter. Most ascospores produced by the ascomata are not viable. In asexual reproduction, the fungus forms conidiophores through mitosis. Conidiophores are septate and break into cylindrical arthrospores 3-6 μm long and 3-4 μm wide. Both sexual and asexual spores are disseminated through soil and wood.
Pathogenicity
Yellow rot first emerged in Korean lingzhi cultivation beds the late 1980s. It rapidly spread through established growing facilities; Chulwon cultivation areas experienced a 61% incidence of the disease and Kanghwa areas experienced a 94% incidence rate. The Shintanjin growing site was also impacted, although the extent of infection was not reported. Newer growing sites in Moonkyung and Hongsung were not infected as of 1998. By 2003, 17 growing sites all over Korea had reported yellow rot. S. ganodermophthorum contamination causes severe yield and profit losses, is difficult to eliminate, and can prevent future use of cultivation spaces. So far, yellow rot has only been reported in Korean cultivation houses.
Diseased G. lucidum display the yellow-green color of S. ganodermophthorum at the base of the mushroom and pilei are malformed. The change in color is due to the accumulation of S. ganodermophthorum mycelia. S. ganodermophthorum mycelia destroys the lingzhi mushroom. Inoculation of S. ganodermophthorum and G. lucidum on agar plates results in the arrest of G. lucidum growth and eventual death. Non-volatile compounds secreted by the pathogen are inhibitory of the crop mushroom's growth by themselves.
Uses
Research into S. ganodermophthorum beyond its status as a fungal pathogen began in the 2000s. The Applied Mycology Lab at Oregon State University is currently researching applications of S. ganodermophthorum for spalting. This species produces a water-insoluble yellow pigment. The structure and components of this pigment are still unidentified. Due to its properties as an insoluble pigment, this fungal pigment is being examined as a naturally-derived aniline dye replacement. There are several methods of pigmenting wood with this fungus. In the cut-wood inoculation method, at 12 weeks, the yellow pigment completely saturated the wood samples. According to the woodchip-agar/chemical solvent extraction method created by Robinson, dichloromethane is the best solvent for extracting this pigment. The fungus can also be grown in a liquid culture and extracted with dichloromethane. Beyond woodworking, this pigment is also being investigated for its potential as a fabric and paint dye. On fabric, this pigment shows greater colorfastness for both light and washing compared to contemporary commercial dyes. Mordanting increases the colorfastness of the yellow pigment under UV radiation. Natural oils (such as linseed oil) can be used as nontoxic alternative carriers compared with dichloromethane, but the pigment is not stable in such carriers.
See also
Spalting
Scytalidium (genus)
Mushroom dye
References
Helotiales
Fungus species | Scytalidium ganodermophthorum | [
"Biology"
] | 1,129 | [
"Fungi",
"Fungus species"
] |
63,711,218 | https://en.wikipedia.org/wiki/European%20Bank%20for%20induced%20pluripotent%20Stem%20Cells | The European Bank for induced pluripotent Stem Cells (EBiSC) is a non-profit induced pluripotent stem cell (iPSC) biorepository and service provider with central facilities in Germany and the United Kingdom.
EBiSC was set up between 2014 and 2017 by a consortium that represented researchers, clinicians and industry stakeholders. A second phase of the project runs between 2019 and 2022 with the aim of consolidating EBiSC as a not-for-profit, self-sustainable iPSC bank and service provider. The initiative is funded by the European Commission and the European Federation of Pharmaceutical Industries and Associations under the Innovative Medicines Initiative.
The European Bank for induced pluripotent Stem Cells performs collection, banking, quality control and distribution of iPSC lines for research purposes. EBiSC's stated goal is to supply academic, non-profit and commercial researchers with quality-controlled, disease-relevant iPSC lines, data and other services. It also seeks to promote the international standardisation of iPSC banking practices and to act as a central hub that ensures the sustainability and accessibility of iPSC lines generated by different research organisations. IPSC lines generated externally can be deposited into EBiSC for storage, banking, quality control and distribution.
Catalogue and facilities
In February 2020, the EBiSC catalogue contained iPSC lines representing diseases and conditions such as Alzheimer's disease, Frontotemporal Dementia, Parkinson's disease, Huntington's disease, Dravet syndrome, Bardet-Biedl syndrome, depression and pain, diabetes mellitus, eye diseases and heart disease. These iPSC lines have been deposited into EBiSC by academic institutions and non-profit and commercial organisations internationally. This includes lines generated within research projects such as StemBANCC, HipSci, IMI-ADAPTED, CRACK IT BadIPS and CRACK IT UnTangle.
The EBiSC Bank is run by two central facilities: the main distributor of EBiSC cell lines, the European Collection of Authenticated Cell Cultures in the UK, and the 'mirror bank' storing duplicates of all deposited lines long-term, established by the Fraunhofer Institute for Biomedical Engineering (IBMT) in Germany.
All EBiSC lines are distributed by the European Collection of Authenticated Cell Cultures operated by Public Health England.
References
Stem cell research
South Cambridgeshire District
Science and technology in Cambridgeshire
Wellcome Trust
Biorepositories | European Bank for induced pluripotent Stem Cells | [
"Chemistry",
"Biology"
] | 500 | [
"Stem cell research",
"Bioinformatics",
"Translational medicine",
"Tissue engineering",
"Biorepositories"
] |
63,711,571 | https://en.wikipedia.org/wiki/Japanese%20Navy%20Signal%20Flags | The Japanese Navy Signal Flags are a set of maritime signal flags for conveying messages in the Japanese language. The system generally uses the standard International Signal Flags, assigning both the letter, number and repeater flags to various kana, roughly following Iroha order for the standard letter flags. It also has several unique flags for some kana, as well as for conveying non-alphabetic messages.
Maritime flags
Maritime signalling
Nonverbal communication
Optical communications
Signal flags
Encodings of Japanese | Japanese Navy Signal Flags | [
"Engineering"
] | 100 | [
"Optical communications",
"Telecommunications engineering"
] |
63,711,954 | https://en.wikipedia.org/wiki/Dixmier%E2%80%93Ng%20theorem | In functional analysis, the Dixmier–Ng theorem is a characterization of when a normed space is in fact a dual Banach space. It was proven by Kung-fu Ng, who called it a variant of a theorem proven earlier by Jacques Dixmier.
Dixmier-Ng theorem. Let be a normed space. The following are equivalent:
There exists a Hausdorff locally convex topology on so that the closed unit ball, , of is -compact.
There exists a Banach space so that is isometrically isomorphic to the dual of .
That 2. implies 1. is an application of the Banach–Alaoglu theorem, setting to the Weak-* topology. That 1. implies 2. is an application of the Bipolar theorem.
Applications
Let be a pointed metric space with distinguished point denoted . The Dixmier-Ng Theorem is applied to show that the Lipschitz space of all real-valued Lipschitz functions from to that vanish at (endowed with the Lipschitz constant as norm) is a dual Banach space.
References
Theorems in functional analysis | Dixmier–Ng theorem | [
"Mathematics"
] | 229 | [
"Theorems in mathematical analysis",
"Theorems in functional analysis"
] |
63,712,852 | https://en.wikipedia.org/wiki/Gymnogongrus%20griffithsiae | Gymnogongrus griffithsiae is a small uncommon seaweed.
Description
This small alga grows to 5 cm long from a small disc. The fronds are erect, stiff and branch dichotomously in 1 plane, the tips a little flattened. In colour it is dark purplish brown. The structure is multiaxial with elongated cells surrounded cortical cells.
Reproduction
Male spermatangia are unknown. Carpotetasporangial outgrowths, that is sporangia containing four spores, by a carposporophyte outgrowth which develops during the year.
Distribution
Found in Great Britain and Ireland with a southern range, as far north as Lough Swilly. In the north Atlantic in the Azores in Europe to Massachusetts to Virginia in North America.
Habitat
The plants grow in rock pools of the lower littoral and in the upper sublittoral.
Possible confusion
This species is similar to Ahnfeltia plicata which usually has wiry irregular branching.
References
Further reading
Phyllophoraceae
Seaweeds | Gymnogongrus griffithsiae | [
"Biology"
] | 216 | [
"Seaweeds",
"Algae"
] |
63,713,707 | https://en.wikipedia.org/wiki/Environment-wide%20association%20study | An environment-wide association study, also known as an environmental-wide association study (abbreviated EWAS), is a type of epidemiological study analogous to the genome-wide association study, or GWAS. The EWAS systematically examines the association between a complex disease and multiple individual environmental factors, controlling for multiple hypothesis testing.
References
Epidemiology | Environment-wide association study | [
"Environmental_science"
] | 74 | [
"Epidemiology",
"Environmental social science"
] |
63,716,011 | https://en.wikipedia.org/wiki/Compassionate%20conservation | Compassionate conservation is a discipline combining the fields of conservation and animal welfare. Historically, these two fields have been considered separate and sometimes contradictory to each other. The proposed ethical principles of compassionate conservation are: "first do no harm, individuals matter, inclusivity, and peaceful coexistence".
Compassionate conservationists argue that the conservation movement uses the preservation of species, populations and ecosystems as a measure of success, without explicit concern given to the welfare and intrinsic value of individual animals. They argue instead, that compassion for all sentient beings should be what guides conservation actions and claim that the killing of animals in the name of conservation goals is unnecessary, as these same objectives can be achieved without killing.
Compassionate conservation has been a subject of criticism by some conservationists, who consider the discipline to be harmful to the goals of conservation.
History
The international wildlife charity Born Free Foundation, which advocates for the well-being of individual wild animals, used the phrase "compassionate conservation" as the name for a Oxford-based symposium it hosted in 2010. The Centre for Compassionate Conservation was created, in 2013, at the University of Technology, Sydney. Ignoring Nature No More: The Case for Compassionate Conservation, a collection of essays edited by compassionate conservation advocate Marc Bekoff, was published in the same year.
In the years since, further conferences have been held on the topic and advocates have published multiple articles in conservation journals.
Criticism
Compassionate conservation has been called "seriously flawed" by certain conservationists, who argue that its implementation is impractical and could lead to negative outcomes for wildlife, ecosystems, humans, and native biodiversity. Others argue that the "do no harm" approach goes "too far" and that put into practice, it would not necessarily lead to positive outcomes for the welfare of individual animals. Andrea S. Griffin et al. argue that compassionate conservation's focus on empathy "is subject to significant biases and that inflexible adherence to moral rules can result in a 'do nothing' approach".
Several conservation management approaches supported by compassionate conservation as an alternative to lethal control have been scrutinised experimentally or observationally. For example, trap–neuter–return management of feral cat populations is proposed as an alternative to lethal methods such as shooting or baiting. However, research has not found TNR to be an effective means of controlling feral cat populations.
Similarly, the use of wildlife contraceptives has been proposed as a non-lethal method for managing overpopulation in native wildlife species. However, attempts to apply this approach—such as the control of overabundant Koala populations on Kangaroo Island in South Australia—have not been successful due to logistical and cost-effectiveness barriers. Alternative compassionate approaches such as wildlife fertility control were also unsuccessful. As with trap–neuter–return programs, nonlethal reproductive management of a subset of a population often results in compensatory increases in reproductive success among untreated individuals. Translocation to lower-abundance habitats was also not successful because the translocated individuals often died, negating any "compassionate" benefits of the approach.
See also
Conservation welfare
Opposition to hunting
Relationship between animal ethics and environmental ethics
Wild animal suffering
Wildlife management
References
Further reading
External links
Compassionate Conservation (archived 21 January 2020)
Centre for Compassionate Conservation
Animal welfare
Environmental conservation
Environmental ethics | Compassionate conservation | [
"Environmental_science"
] | 670 | [
"Environmental ethics"
] |
63,717,070 | https://en.wikipedia.org/wiki/Ministry%20of%20Energy%20%28Kazakhstan%29 | The Ministry of Energy of the Republic of Kazakhstan (ME RK, , ҚР ЭМ; , МЭ РК) is an executive body of the Government of Kazakhstan, which carries out state administration in the field of energy. The Ministry was created during the reorganization of the government on 6 August 2014. The Ministry's functions and powers was from the Ministry of Oil and Gas, Ministry of Industry and New Technologies and the Ministry of Environment and Water.
Background
In 2014, Kazakhstan's energy sector turned to the country's Prime Minister Karim Massimov with a request to create a Ministry of Energy, as the situation in the republic with a lack of coordination in the activities of various government bodies in the electric power industry has developed. Prior to the creation of the ministry, various departments dealt with energy issues, which could not cope with their duties.
Structure
Departments
Department of Strategic and Information Development;
Department of Subsoil Use;
Department of Oil Industry Development;
Department of Gas and Oil;
Department of State Control in the Spheres of Hydrocarbons and Subsoil Use;
Department of Public Policy in the field of electric power industry;
Department of Atomic Energy and Industry;
Department of Renewable Energy Sources;
Department of Environmental Policy and Sustainable Development;
Department of Climate Policy and Green Technologies;
Department of Public Policy in Waste Management;
Department of Internal Audit;
Department of Budget and Financial Procedures;
Department of International Cooperation;
Department of Legal Service;
Department of Administrative Work;
Department of Digitalization and Informatization.
Administrations
Administration of Staff Development;
Administration of Mobilization Preparation and Civil Defense;
Administration of Protection of Public Secrets;
Administration of Information Security.
Committees
Committee of Atomic and Energy Supervision and Control of the Ministry of Energy of the Republic of Kazakhstan;
Committee of Environmental Regulation and Control of the Ministry of Energy of the Republic of Kazakhstan (transferred to the new ministry).
Interregional Department of State Inspection
Western Interregional State Inspection in the oil and gas complex;
Southern Interregional Office of the State Inspection in the oil and gas complex.
References
Energy
Kazakhstan
2014 establishments in Kazakhstan
Ministries established in 2014 | Ministry of Energy (Kazakhstan) | [
"Engineering"
] | 419 | [
"Energy organizations",
"Energy ministries"
] |
63,718,197 | https://en.wikipedia.org/wiki/Intrinsic%20motivation%20%28artificial%20intelligence%29 | Intrinsic motivation in the study of artificial intelligence and any robotics is a mechanism for enabling artificial agents (including robots) to exhibit inherently rewarding behaviours such as exploration and curiosity, grouped under the same term in the study of psychology. Psychologists consider intrinsic motivation in humans to be the drive to perform an activity for inherent satisfaction – just for the fun or challenge of it.
Definition
An intelligent agent is intrinsically motivated to act if the information content alone, or the experience resulting from the action, is the motivating factor.
Information content in this context is measured in the information-theoretic sense of quantifying uncertainty. A typical intrinsic motivation is to search for unusual, surprising situations (exploration), in contrast to a typical extrinsic motivation such as the search for food (homeostasis). Extrinsic motivations are typically described in artificial intelligence as task-dependent or goal-directed.
Origins in psychology
The study of intrinsic motivation in psychology and neuroscience began in the 1950s with some psychologists explaining exploration through drives to manipulate and explore, however, this homeostatic view was criticised by White. An alternative explanation from Berlyne in 1960 was the pursuit of an optimal balance between novelty and familiarity. Festinger described the difference between internal and external view of the world as dissonance that organisms are motivated to reduce. A similar view was expressed in the '70s by Kagan as the desire to reduce the incompatibility between cognitive structure and experience. In contrast to the idea of optimal incongruity, Deci and Ryan identified in the mid 80's an intrinsic motivation based on competence and self-determination.
Computational models
An influential early computational approach to implement artificial curiosity in the early 1990s by Schmidhuber, has since been developed into a "Formal theory of creativity, fun, and intrinsic motivation”.
Intrinsic motivation is often studied in the framework of computational reinforcement learning (introduced by Sutton and Barto), where the rewards that drive agent behaviour are intrinsically derived rather than externally imposed and must be learnt from the environment. Reinforcement learning is agnostic to how the reward is generated - an agent will learn a policy (action strategy) from the distribution of rewards afforded by actions and the environment. Each approach to intrinsic motivation in this scheme is essentially a different way of generating the reward function for the agent.
Curiosity vs. exploration
Intrinsically motivated artificial agents exhibit behaviour that resembles curiosity or exploration. Exploration in artificial intelligence and robotics has been extensively studied in reinforcement learning models, usually by encouraging the agent to explore as much of the environment as possible, to reduce uncertainty about the dynamics of the environment (learning the transition function) and how best to achieve its goals (learning the reward function). Intrinsic motivation, in contrast, encourages the agent to first explore aspects of the environment that confer more information, to seek out novelty. Recent work unifying state visit count exploration and intrinsic motivation has shown faster learning in a video game setting.
Types of models
Ouedeyer and Kaplan have made a substantial contribution to the study of intrinsic motivation. They define intrinsic motivation based on Berlyne's theory, and divide approaches to the implementation of intrinsic motivation into three categories that broadly follow the roots in psychology: "knowledge-based models", "competence-based models" and "morphological models". Knowledge-based models are further subdivided into "information-theoretic" and "predictive". Baldassare and Mirolli present a similar typology, differentiating knowledge-based models between prediction-based and novelty-based.
Information-theoretic intrinsic motivation
The quantification of prediction and novelty to drive behaviour is generally enabled through the application of information-theoretic models, where agent state and strategy (policy) over time are represented by probability distributions describing a markov decision process and the cycle of perception and action treated as an information channel. These approaches claim biological feasibility as part of a family of bayesian approaches to brain function. The main criticism and difficulty of these models is the intractability of computing probability distributions over large discrete or continuous state spaces. Nonetheless, a considerable body of work has built up modelling the flow of information around the sensorimotor cycle, leading to de facto reward functions derived from the reduction of uncertainty, including most notably active inference, but also infotaxis, predictive information, and empowerment.
Competence-based models
Steels' autotelic principle is an attempt to formalise flow (psychology).
Achievement, affiliation and power models
Other intrinsic motives that have been modelled computationally include achievement, affiliation and power motivation. These motives can be implemented as functions of probability of success or incentive. Populations of agents can include individuals with different profiles of achievement, affiliation and power motivation, modelling population diversity and explaining why different individuals take different actions when faced with the same situation.
Beyond achievement, affiliation and power
A more recent computational theory of intrinsic motivation attempts to explain a large variety of psychological findings based on such motives. Notably this model of intrinsic motivation goes beyond just achievement, affiliation and power, by taking into consideration other important human motives. Empirical data from psychology were computationally simulated and accounted for using this model.
Intrinsically Motivated Learning
Intrinsically motivated (or curiosity-driven) learning is an emerging research topic in artificial intelligence and developmental robotics that aims to develop agents that can learn general skills or behaviours, that can be deployed to improve performance in extrinsic tasks, such as acquiring resources. Intrinsically motivated learning has been studied as an approach to autonomous lifelong learning in machines and open-ended learning in computer game characters. In particular, when the agent learns a meaningful abstract representation, a notion of distance between two representations can be used to gauge novelty, hence allowing for an efficient exploration of its environment. Despite the impressive success of deep learning in specific domains (e.g. AlphaGo), many in the field (e.g. Gary Marcus) have pointed out that the ability to generalise remains a fundamental challenge in artificial intelligence. Intrinsically motivated learning, although promising in terms of being able to generate goals from the structure of the environment without externally imposed tasks, faces the same challenge of generalisation – how to reuse policies or action sequences, how to compress and represent continuous or complex state spaces and retain and reuse the salient features that have been learnt.
See also
Reinforcement Learning
Markov decision process
Motivation
Predictive coding
Perceptual control theory
References
Artificial intelligence
Cognitive science
Robotics engineering | Intrinsic motivation (artificial intelligence) | [
"Technology",
"Engineering"
] | 1,305 | [
"Computer engineering",
"Robotics engineering"
] |
63,718,743 | https://en.wikipedia.org/wiki/Crystal%20Watson | Crystal Watson (née Boddie, born April 9, 1983) is a senior scholar at the Johns Hopkins Center for Health Security and an associate professor in the Department of Environmental Health and Engineering. She is an expert in health security, biodefense, and risk assessment and preparedness for emerging infectious diseases. She is currently working on the public health response to the COVID-19 pandemic.
Education
Watson was born and raised in Littleton, Colorado. She attended University of Colorado Boulder, where she received her Bachelor of Arts degree in molecular, cellular, and developmental biology in 2004. She then joined the Johns Hopkins Center for Health Security in 2004. During her tenure, she has received her Master of Public Health degree from Johns Hopkins Bloomberg School of Public Health in 2009 and her Doctor of Public Health degree in 2017 under the mentorship of Mary A. Fox. Her thesis, entitled Risk-Based Decision Making During Public Health Emergencies Involving Environmental Contamination, centered on developing a framework to guide decision makers as they respond to contamination emergencies.
Research
Since joining the Johns Hopkins Center for Health Security in 2004, Watson has focused her work on public health risk assessment, biodefense, and emerging infectious diseases preparedness and response. Early in her career, she worked on evaluating medical care in the wake of disasters. Following Hurricane Katrina, she analyzed the medical response and proposing policy changes to improve the capacity of the healthcare system to respond to mass casualty events. She has since analyzed the public health response to a number of other outbreaks and health emergencies, including Dengue fever, Zika fever, and Ebola virus disease.
From 2012 to 2013, she served with the United States Department of Homeland Security, where she worked as a program manager for the Integrated Terrorism Risk Assessment (ITRA) program. She also worked to assess the Strategic National Stockpile, the United States' repository of antibiotics, vaccines, and other critical supplies needed to address chemical and biological threats.
Federal Budget for Health Security Analysis
Watson is also a budget expert, analyzing the impact of proposed Federal budgets on public health preparedness and health security capacity. She has been critical of proposed Presidential budgets that have reduced the ability of public health officials to effectively respond to health emergencies. In 2012, she noted a proposed $47 million cut to the Strategic National Stockpile, which would critically limit the nation's capability of combatting infectious disease threats. In 2017, she noted Donald Trump's proposed 2018 budget would make the United States vulnerable to bioterrorism with cuts to the Centers for Disease Control and Prevention' (CDC) preparedness and response capability and the elimination of the DHS's National Biodefense Analysis and Countermeasures Center, a national biodefense research laboratory.
COVID-19 Work
Early in the COVID-19 pandemic in the United States, Watson warned that the downward trend of federal funding for state and local officials to prepare and respond to health emergencies would strain the healthcare system as the outbreak progressed. In February 2020, she flagged a number of funding cuts to public health preparedness programs that would help the country combat the COVID-19 pandemic. Among the funding cuts, she noted a $25 million reduction to the CDC's public health preparedness and response programs, as well as an $18 million reduction in funding for the Hospital Preparedness Program, which grants support for public health emergencies, such as the COVID-19 pandemic.
In March 2020, she co-authored a policy proposal through the American Enterprise Institute—along with former FDA commissioners Scott Gottlieb and Mark McClellan, former FDA Chief of Staff Lauren Silvis, and epidemiologist Caitlin Rivers—with a step-by-step timeline on how to safely ease restrictions in the wake of the COVID-19 pandemic. The plan outlines a phased reopening of the country that would mitigate the spread of the disease without having to lock down the country. She has cautioned against easing social distancing measures too early, as those who have been infected may remain asymptomatic while still shedding infectious virus.
Watson was also a lead author on an April 2020 report from Johns Hopkins Bloomberg School of Public Health and Association of State and Territorial Health Officials that outlined a national plan to enable comprehensive contact tracing to identify COVID-19 cases and their close contacts. She has suggested training those who were recently unemployed to become contact tracers and contribute to the mass effort. She has also noted that contact tracing efforts can leverage technologies like Bluetooth that can identify close contact with those infected with COVID-19 while still preserving privacy.
Selected publications
References
1983 births
Living people
University of Colorado Boulder alumni
Johns Hopkins Bloomberg School of Public Health alumni
Johns Hopkins Bloomberg School of Public Health faculty
COVID-19 researchers
Biosecurity
Public health researchers
American women scientists
21st-century American women | Crystal Watson | [
"Environmental_science"
] | 989 | [
"Toxicology",
"Biosecurity"
] |
63,719,093 | https://en.wikipedia.org/wiki/Bachelier%20model | The Bachelier model is a model of an asset price under Brownian motion presented by Louis Bachelier on his PhD thesis The Theory of Speculation (Théorie de la spéculation, published 1900). It is also called "Normal Model" equivalently (as opposed to "Log-Normal Model" or "Black-Scholes Model"). One early criticism of the Bachelier model is that the probability distribution which he chose to use to describe stock prices allowed for negative prices. (His doctoral dissertation was graded down because of that feature.) The (much) later Black-Scholes-(Merton) Model addresses that issue by positing stock prices as following a log-normal distribution which does not allow negative values. This in turn, implies that returns follow a normal distribution.
On April 8, 2020, the CME Group posted the note CME Clearing Plan to Address the Potential of a Negative Underlying in Certain Energy Options Contracts, saying that after a threshold on price, it would change its standard energy options model from one based on Geometric Brownian Motion and the Black–Scholes model to the Bachelier model. On April 20, 2020, oil futures reached negative values for the first time in history, where Bachelier model took an important role in option pricing and risk management.
The European analytic formula for this model based on a risk neutral argument is derived in Analytic Formula for the European Normal Black Scholes Formula (Kazuhiro Iwasawa, New York University, December 2, 2001).
The implied volatility under the Bachelier model can be obtained by an accurate numerical approximation.
For an extensive review of the Bachelier model, see the review paper, A Black-Scholes User's Guide to the Bachelier Model , which summarizes the results on volatility conversion, risk management, stochastic volatility, and barrier options pricing to facilitate the model transition. The paper also connects the Black-Scholes and Bachelier models by using the displaced Black-Scholes model as a model family.
References
Energy economics
Finance theories
Financial models
Options (finance) | Bachelier model | [
"Environmental_science"
] | 433 | [
"Energy economics",
"Environmental social science"
] |
63,721,045 | https://en.wikipedia.org/wiki/Poly-clip%20System | Poly-clip System is a German family-owned company based in Hattersheim near Frankfurt am Main. Poly-clip System is the largest provider of clip closure systems worldwide and the world market leader and hidden champion in this sector of the food industry and packaging industry.
History
The founding of the Oswald Niedecker Metallwarenfabrik oHG in Frankfurt/Main dates back to 1 March 1922. The company initially manufactured tools for the processing and forming of sheet metal. From 1932 onwards, Niedecker has been a successful lead seal manufacturer in Germany and has already gained experience with closure systems; the basis of today's clip closure. In 1948, after the death of her husband, Elisabeth Niedecker took over the management of the company.
From 1950, punched and formed parts, mainly parts for brakes for the automotive industry are produced. In 1952, Herbert Niedecker, the son of the founder, takes charge of the company and its 50 employees. During an exhibition in 1957, the idea of closing sausages with metal clips was born.
The trademark poly-clip was registered in 1958. The parent company of today's Poly-clip System, Niedecker Verschlußtechnik GmbH (NVT), was then founded in 1959. In 1962, the company participated for the first time in the industry's leading exhibition IFFA in Frankfurt. For reasons of capacity, the production of clips was moved to Gedern in 1970. In 1972, the registered trade mark poly-clip was announced worldwide.
In 1990, Frank Niedecker takes over the management and pushes the internationalization of the company. From 1991, the company appears under the brand name Poly-clip System. In 2003, Joachim Meyrahn was appointed President/CEO. In 2011, the company moved to its new headquarters in Hattersheim am Main. On May 1, 2023, Poly-clip System was able to recruit Dr. Alexander Giehl as the new Managing Director and the long-standing Managing Director Dr. Joachim Mehran was given his retirement after 20 years.
Patents
In 1933, Oswald Niedecker received the Patent for his security seal. () This closure can be applied without the use of tools and is tamper-proof, as the seal is destroyed when opened.
In 1957, the reel clip (R-clip) was developed for closing sausage and similar products. () This was followed by the development of a machine that enables the clean stripping of the sausage ends by means of a voiding separator () and the simultaneous closing of the two ends of a sausage () Both processes combined in one automatic clipper revolutionized the worldwide production of sausages to the automatic production of portioned sausages as early as 1967 with the FCA 3401 automatic filling clipping machine.
In 1999, the patent for a safety coating for clips was granted. () This SAFE-COAT safety coating ensures that the consumables clips are food safe on the customer's product. In 2007 the new generation of reel clips, the R-ID clip, followed, which enables bacteria-proof clip closures. () The R-ID generation also includes the clip spool with transponder (RFID)() and the clipping machines with RFID technology, which recognize clip and closing tools and thus ensure overall safety in the production process.()
The company has a total of more than 800 patents.
Products
The product and service range consists of clipping machines, packaging machines and their automation, consumables and services. The SGS Institut Fresenius certifies consumables, which are awarded the SGS Institut Fresenius quality seal. The core of the certification is the testing of the products for food safety (SAFE-COAT, ISO 22000, Halal).
Applications
Originally developed for the meat processing industry and the butcher's trade, the system is used in both the food and non-food sectors, and in other industries that process or pack paste products. In addition to tubular bags which are closed with a clip at each end, bags are also closed with a clip, e.g. for packaging whole poultry.
Locations
The machines and consumables are produced at three locations in Germany and Brazil. Poly-clip System belongs to a group of companies with over 1000 employees worldwide. The group of companies has 31 distribution companies internationally and sales partners in almost all countries of the world.
References
Sources
Bundesanzeiger: Consolidated financial statements for the financial year from 01.01.2021 to 31.12.2021
External links
German brands
Food technology
Meat packing industry
Mechanical engineering
Engineering companies of Germany
Construction equipment manufacturers of Germany
Privately held companies of Germany
Holding companies of Germany
Packaging companies of Germany
Manufacturing companies established in 1922
Companies based in Hesse
Main-Taunus-Kreis | Poly-clip System | [
"Physics",
"Engineering"
] | 984 | [
"Applied and interdisciplinary physics",
"Mechanical engineering"
] |
63,722,403 | https://en.wikipedia.org/wiki/Latent%20period%20%28epidemiology%29 | In epidemiology, particularly in the discussion of infectious disease dynamics (modeling), the latent period (also known as the latency period or the pre-infectious period) is the time interval between when an individual or host is infected by a pathogen and when that individual becomes infectious, i.e. capable of transmitting pathogens to other susceptible individuals.
Relationship with related concepts in infectious disease dynamics
To understand the spreading dynamics of an infectious disease or an epidemic, three important time periods should be carefully distinguished: incubation period, pre-infectious or latent period and infectious period. Two other relevant and important time period concepts are generation time and serial interval.
The infection of a disease begins when a pathogenic (disease-causing) infectious agent, or a pathogen, is successfully transmitted from one host to another. Pathogens leave the body of one host through a portal of exit, are carried by some mode of transmission and after coming into contact (exposure) with a new susceptible host, they enter the host's body through an appropriate portal of entry. Upon entering the new host, they take a period of time to overcome or evade the immune response of the body and to multiply or replicate after having traveled to their favored sites within the host’s body (tissue invasion and tropism). When the pathogens become sufficiently numerous and toxic to cause damage to the body, the host begins to display symptoms of a clinical disease (i.e. the host becomes symptomatic).
Incubation period
The time interval from the time of invasion by an infectious pathogen to the time of onset (first appearance) of symptoms of the disease in question is called the incubation period. After the incubation period is over, the host enters the symptomatic period. Moreover, at a certain point in time after infection, the host becomes capable of transmitting pathogens to others, i.e. they become infectious or communicable. Depending on the disease, the host individual may or may not be infectious during the incubation period. The incubation period is important in the dynamics of disease transmission because it determines the time of case detection relative to the time of infection. This helps in the evaluation of the outcomes of control measures based on symptomatic surveillance. The incubation period is also useful to count the number of infected people.
The period from the time of infection to the time of becoming infectious is called the pre-infectious period or the latent period. During the pre-infectious or latent period, a host may or may not show symptoms (i.e. the incubation period may or may not be over), but in both cases, the host is not capable of infecting other hosts i.e. transmitting pathogens to other hosts. The latent period, rather than the incubation period, has more influence on the spreading dynamics of an infectious disease or epidemic.
Infectious period
The time interval during which the host is infectious, i.e. the pathogens can be transmitted directly or indirectly from the infected host to another individual, is called the infectious period (or the period of communicability), defined as the period from the end of the pre-infectious period or the latent period until the time when the host can no longer transmit the infection to other individuals. During the infectious period, a host may or may not show symptoms, but they are capable of infecting other individuals. The duration of the infectious period depends on the ability of the infected host individual to mount an immune response.
Latent period
In some cases, the pre-infectious or latent period and the incubation period coincide and are mostly of the same duration. In this case, the infected individual becomes infectious at around the same time they start showing symptoms. In certain other infectious diseases such as smallpox or SARS, the host becomes infectious after the onset of symptoms. In this case, the latent period is longer than the incubation period. In these two cases, the disease can be effectively controlled using symptomatic surveillance. A related term is the duration of shedding or the shedding period, which is defined as the time duration during which a host or patient excretes pathogens through saliva, urine, feces or other bodily fluids.
However, for some infectious diseases, the symptoms of the clinical disease may appear after the host becomes infectious. In this case, the pre-infectious or latent period has a shorter duration than the incubation period, the infectious period begins before the end of the incubation period and the host can infect others for some time without showing any noticeable symptoms. This early or mild stage of infection whose symptoms stay below the level of clinical detection is called subclinical infection and the individual concerned is called an asymptomatic carrier of the disease. For example, in HIV/AIDS, the incubation period lasts years longer than the latent period. So an HIV infected individual can show no symptoms and unwittingly infect other susceptible individuals for many years. In COVID-19, the infectious period begins approximately 2 days before the onset of symptoms and 44% of the secondary infections may happen during this pre-symptomatic stage. In these kinds of cases with a significant number of pre-symptomatic (asymptomatic) transmissions, symptomatic surveillance-based disease control measures (such as isolation, contact tracing, enhanced hygiene, etc.) are likely to have their effectiveness reduced, because a significant portion of the transmission may take place before the onset of symptoms and this has to be taken into account when designing control measures.
The infectious period is a very important element in the infectious disease spreading dynamics. If the infectious period is long, then the measure of secondary infections (represented by the basic reproduction number, R0) will generally be larger, regardless of the infectiousness of the disease. For example, even though HIV/AIDS has a very low transmission potential per sexual act, its basic reproduction number is still very high because of its unusually long infectious period spanning many years. From the viewpoint of controlling an epidemic, the goal is to reduce the effective infectious period either by treatment or by isolating the patient from the community. Sometimes a treatment can paradoxically increase the effective infectious period by preventing death through supportive care and thereby increasing the probability of infection of other individuals.
Generation time
The generation time (or generation interval) of an infectious disease is the time interval between the beginning of infection in an individual (infector) to the time that person transmits to another individual (infectee). The generation time specifies how fast infections are spreading in the community with the passing of each generation. In contrast, the effective reproductive number determines in what number the infections are spreading in the community with the passing of each generation. The latent period and the infectious period helps determine the generation time of an infection. The mean generation time is equal to the sum of the mean latent period and one-half of the mean infectious period, given that infectiousness is evenly distributed across the infectious period.
Since the precise moment of infection is very difficult and almost impossible to detect, the generation time is not properly observable for two successive hosts. Generally, in infectious disease statistics, the onset of clinical symptoms for all the hosts are reported. For two successive generations (or cases or hosts) in a chain of infection, the serial interval is defined as the period of time between the onset of clinical symptoms in the first host (infector) and the onset of analogous clinical symptoms in the second host (infectee). Just like the generation time, the length of the serial interval depends on the lengths of the latent period, the infectious period and the incubation period. Therefore the serial interval is often used as a proxy measure to estimate the generation time.
Usage of the term outside epidemiology
Outside the confines of epidemiology, the term "latent period" may be defined in some general-purpose dictionaries (e.g. the Collins English Dictionary or Merriam-Webster Online Dictionary) as being the time interval between infection by a pathogen and the onset of symptoms, i.e., as a synonymous term for the epidemiologically different concept of "incubation period".
In the discussion of cancers (a non-infectious disease), the term "latency period" is used to indicate the time that passes between being exposed to something that can cause disease (such as radiation or a virus) and having symptoms. Doctors and medical journals may speak of "latent" tumors, which are present but not active or causing symptoms.
In the discussion of syphilis (a sexually transmitted infectious disease), the term "latent" refers to asymptomatic periods with different degrees of infectiousness.
See also
Incubation period
Infectious period
Viral shedding
Generation time
Serial interval
Basic reproduction number
Asymptomatic carrier
References
Epidemiology
Infectious diseases | Latent period (epidemiology) | [
"Environmental_science"
] | 1,842 | [
"Epidemiology",
"Environmental social science"
] |
61,519,996 | https://en.wikipedia.org/wiki/C22H17F2N5OS | {{DISPLAYTITLE:C22H17F2N5OS}}
The molecular formula C22H17F2N5OS (molar mass: 437.465 g/mol, exact mass: 437.1122 u) may refer to:
Isavuconazonium
Ravuconazole
Molecular formulas | C22H17F2N5OS | [
"Physics",
"Chemistry"
] | 72 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,521,050 | https://en.wikipedia.org/wiki/C27H39NO7 | {{DISPLAYTITLE:C27H39NO7}}
The molecular formula C27H39NO7 (molar mass: 489.60 g/mol, exact mass: 489.2727 u) may refer to:
Isomigrastatin
Migrastatin | C27H39NO7 | [
"Chemistry"
] | 62 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
61,521,146 | https://en.wikipedia.org/wiki/C3H7Cl | {{DISPLAYTITLE:C3H7Cl}}
The molecular formula C3H7Cl (molar mass: 78.54 g/mol, exact mass: 78.0236 u) may refer to:
Isopropyl chloride
n-Propyl chloride, also known as 1-propyl chloride or 1-chloropropane | C3H7Cl | [
"Chemistry"
] | 76 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
61,521,149 | https://en.wikipedia.org/wiki/C3H7I | {{DISPLAYTITLE:C3H7I}}
The molecular formula C3H7I (molar mass: 169.99 g/mol, exact mass: 169.9592 u) may refer to:
Isopropyl iodide
n-Propyl iodide (also 1-propyl iodide or 1-iodopropane) | C3H7I | [
"Chemistry"
] | 82 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
61,521,167 | https://en.wikipedia.org/wiki/C26H44N7O17P3S | {{DISPLAYTITLE:C26H44N7O17P3S}}
The molecular formula C26H44N7O17P3S (molar mass: 851.65 g/mol, exact mass: 851.1727 u) may refer to:
Isovaleryl-CoA
2-Methylbutyryl-CoA | C26H44N7O17P3S | [
"Chemistry"
] | 75 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
61,521,172 | https://en.wikipedia.org/wiki/C18H12O8 | {{DISPLAYTITLE:C18H12O8}}
The molecular formula C18H12O8 (molar mass: 356.28 g/mol, exact mass: 356.0532 u) may refer to:
Isoxerocomic acid
Xerocomic acid
Molecular formulas | C18H12O8 | [
"Physics",
"Chemistry"
] | 64 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,522,806 | https://en.wikipedia.org/wiki/Silvana%20Cardoso | Silvana Cardoso is a Portuguese fluid dynamicist working in Britain. She is professor of Fluid Mechanics and the Environment at the University of Cambridge and a fellow of Pembroke College, Cambridge. She leads the Fluids and the Environment research group at the Department of Chemical Engineering and Biotechnology.
Her research focuses on fluid mechanics and environmental science, in particular the interaction of natural convection and chemical kinetics including
turbulent plumes and thermals in the environment, such as the BP oil disaster in the Gulf of Mexico, the 2010 eruptions of Eyjafjallajökull in Iceland, the Fukushima Daiichi nuclear disaster in Japan and oceanic methane releases.
flow and reaction in porous media, e.g., the spreading of carbon dioxide in geological storage at Sleipner gas field in the North Sea.
cool flames and thermo-kinetic explosions, as occurred in the crash of TWA flight 800.
self-assembling porous precipitate structures, such as chemical gardens and submarine hydrothermal vents.
She is on the International Advisory Panel of the journal Chemical Engineering Science and the Editorial Board of Chemical Engineering Journal.
In 2016 she was awarded the Davidson medal of the Institution of Chemical Engineers (IChemE).
Recent press interest in her work has included pieces on whether
natural geochemical reactions can delay or prevent the spreading of carbon dioxide in subsurface aquifers used for carbon capture and storage, the possible melting of oceanic methane hydrate deposits owing to climate change, and the importance to astrobiology of brinicles on Jupiter's moon, Europa.
References
External links
Page at Cambridge Fluids Network regarding fluid mechanics research at Cambridge
Page at the Department of Chemical Engineering and Biotechnology
Page at Pembroke College
Page at University of Cambridge
Living people
British women academics
Academics of the University of Cambridge
British chemical engineers
Fellows of Pembroke College, Cambridge
People from Porto
21st-century Portuguese scientists
Portuguese engineers
Fluid dynamicists
University of Porto alumni
Portuguese women scientists
21st-century British women scientists
Portuguese chemical engineers
Year of birth missing (living people) | Silvana Cardoso | [
"Chemistry"
] | 408 | [
"Fluid dynamicists",
"Fluid dynamics"
] |
61,523,241 | https://en.wikipedia.org/wiki/Tomka%20gas%20test%20site | Tomka gas test site () was a secret chemical weapons testing facility near a place codenamed Volsk-18 (Wolsk, in German literature), 20 km off Volsk, now Shikhany, Saratov Oblast, Russia created within the framework of German-Soviet military cooperation to circumvent the demilitarization provisions of the post-World War I Treaty of Versailles. It was co-directed by Yakov Moiseevich Fishman (начальник военно-химического управления Красной Армии), and German chemists Alexander von Grundherr and Ludwig von Sicherer. It operated (according to an agreement undersigned by fictitious joint stock companies) during 1926-1933.
After 1933 the area was used by the Red Army and expanded under the name "Volsk-18" or "Schichany-2" to Russia's most important center for the development of chemical warfare agents and protective measures against NBC weapons.
Another chemical site was established by the settlement of Ukhtomsky, Moscow Region.
See also
Kama tank school
Lipetsk fighter-pilot school
References
Reichswehr
Military history of the Soviet Union
Military history of Germany
1926 establishments in the Soviet Union
Secret military programs
Germany–Soviet Union relations
Military education and training in the Soviet Union
Chemical warfare facilities
Soviet chemical weapons program | Tomka gas test site | [
"Chemistry",
"Engineering"
] | 309 | [
"Military projects",
"Chemical warfare facilities",
"Secret military programs"
] |
61,524,280 | https://en.wikipedia.org/wiki/4-Methoxybenzylthiol | 4-Methoxybenzylthiol is an organosulfur compound with the formula CH3OC6H4CH2SH. A colorless, odiferous oil, it is a reagent used as a protected thiol.
References
Thiols
Benzyl compounds
Foul-smelling chemicals | 4-Methoxybenzylthiol | [
"Chemistry"
] | 64 | [
"Organic compounds",
"Thiols"
] |
61,524,531 | https://en.wikipedia.org/wiki/C59H84N16O12 | {{DISPLAYTITLE:C59H84N16O12}}
The molecular formula C59H84N16O12 (molar mass: 1209.40 g/mol, exact mass: 1208.6455 u) may refer to:
Lecirelin
Leuprorelin, or leuprolide
Molecular formulas | C59H84N16O12 | [
"Physics",
"Chemistry"
] | 75 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,524,550 | https://en.wikipedia.org/wiki/C18H20FN3O4 | {{DISPLAYTITLE:C18H20FN3O4}}
The molecular formula C18H20FN3O4 (molar mass: 361.368 g/mol, exact mass: 361.1438 u) may refer to:
Levofloxacin
Ofloxacin
Zimlovisertib
Molecular formulas | C18H20FN3O4 | [
"Physics",
"Chemistry"
] | 77 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,524,954 | https://en.wikipedia.org/wiki/Janelle%20Shane | Janelle Shane is an optics research scientist and artificial intelligence researcher, writer and public speaker. She keeps a popular science blog called AI Weirdness, where she documents various machine learning algorithms, both ones submitted by readers and ones she personally creates. Shane's first book You Look Like A Thing And I Love You: How AI Works And Why It's Making The World A Weirder Place was published in November 2019 covering many of the topics from her AI Weirdness blog for a general audience.
Early life and education
Shane studied electrical engineering at Michigan State University and graduated in 2007. She started out in a research group that worked on genetic algorithms, and then worked with Marcos Dantus on genetic algorithms for femtosecond lasers. She earned her master's degree in physics at the University of St Andrews, where she worked with Kishan Dholakia on pulse shaping and dispersion compensation. In 2008, Shane joined University of California, San Diego as a graduate student, where she worked on ultra-fast nanoscale optics.
Career
Shane works at Boulder Nonlinear Systems, an organisation who are developing holographic optical trapping modules for the International Space Station. She is also working on low size, weight and power (SWaP) 3D wind sensor technologies for unmanned aerial vehicles. The optical trapping systems (tweezers) use focused laser beams to trap transparent microparticles, and the holographic optical trapping uses liquid crystal spatial light modulators that can convert a single beam into separate steerable beams. This system allows Shane to position trapped particles in arrays. The technologies include liquid polarisation gratings for airborne Doppler lidar systems.
Shane came across a list of neural network cookbook recipes written by Tom Brewe. AI Weirdness, Shane's blog on Artificial Intelligence, features everyday neural networks and algorithms. Shane writes for Fast Company and O'Reilly Media. She has collaborated with CNN, The Guardian, The New York Times Magazine and The New York Times. Shane delivered a talk at TED 2019, where she spoke about the realities of artificial intelligence. She argued that while artificial intelligence is celebrated as a gift to society, in reality it often doesn't live up to the hype. Her book You Look Like a Thing and I Love You: How Artificial Intelligence Works and Why It's Making the World a Weirder Place was released in November 2019.
Selected publications
References
External links
AI Weirdness blog
Artificial intelligence researchers
University of California, San Diego alumni
Alumni of the University of St Andrews
Michigan State University alumni
American women non-fiction writers
Women science writers
Optical engineers
Women in optics
American electrical engineers
American women engineers
21st-century women engineers
American women bloggers
American bloggers
Science bloggers
21st-century science writers
21st-century American women | Janelle Shane | [
"Technology"
] | 558 | [
"Women science writers",
"Women in science and technology"
] |
61,525,015 | https://en.wikipedia.org/wiki/Nyonoksa%20radiation%20accident | The Nyonoksa radiation accident, Arkhangelsk explosion or Nyonoksa explosion () occurred on 8 August 2019 near Nyonoksa, a village under the administrative jurisdiction of Severodvinsk, Arkhangelsk Oblast, Russian Federation. Five military and civilian specialists were killed and three (or six, depending on the source) were injured.
Background
Between November 2017 and 26 February 2018, Russia conducted four tests of the 9M730 Burevestnik nuclear-powered cruise missile, launched from other test sites. According to the United States intelligence community, only the flight test in November 2017 from Pankovo test site was moderately successful with all of the others ending in failure. According to Russia, none of the tests ended in failure. During recovery efforts later in 2018, Russia used three ships, one capable of handling radioactive material from the weapon nuclear core, to bring the missile tested in November 2017 from the seabed of Barents Sea back to the surface. Based on satellite images, the Nyonoksa test site copies those at Kapustin Yar and Pankovo, where 9M730 Burevestnik was tested.
Accident
The accident occurred at the State Central Navy Testing Range () which is the main rocket launching site of the Russian Navy and is also called Nyonoksa. According to the version presented by Russian officials, it was a result of a failed test of an "isotope power source for a liquid-fuelled rocket engine". Nonproliferation expert Jeffrey Lewis and Federation of American Scientists fellow Ankit Panda suspect the incident resulted from a Burevestnik cruise missile test. However, other arms control experts disputed the assertions: Ian Williams of the Center for Strategic and International Studies and James Acton of the Carnegie Endowment for International Peace expressed skepticism over Moscow's financial and technical capabilities to field the weapon, while Michael Kofman of the Wilson Center concluded that the explosion was probably not related to Burevestnik but instead to the testing of another military platform. According to CNBC, the Russians were trying to recover a missile from the seabed which was lost during a previously failed test. No NOTAMs were filed prior to the explosion to warn pilots of a possible missile test. In the past, the residents of Nyonoksa had been warned and evacuated prior to the missile tests. Also, two Russian special purpose ships were at the Nyonoksa test range when the explosion occurred: the Serebryanka (Rosatom Flot vessel used for handling nuclear waste from nuclear reactors) and the Zvezdochka (used for underwater salvage operations and is equipped with two heavy lift sea cranes and two remotely operated vehicles).
An event of explosive nature was registered on 8 August at 06:00 UTC (local time 09:00) at the infrasound station in Bardufoss (Troms, Norway). As the event was also registered on seismic data, it must have been coupled to the ground, meaning that it took place either at the ground or in contact with it; for example on water. The timing and location of the event coincides with the reported accident in Archangelsk. Several fishermen stated on sanatatur.ru that they witnessed the accident: one saw a 100-meter column of water rise into the air after the explosion and another saw a large hole in the side of a ship which had been at the site of the explosion.
Aftermath
In the aftermath of the explosion, three of the victims were treated at the Semashko Medical Center in Arkhangelsk, which had radiation treatment expertise and employed the use of hazmat suits, while three others were taken to the Arkhangelsk Regional Clinical Hospital, arriving at 4:35 p.m. on 8 August, where the hospital staff were not warned of the radiation exposure. Several Arkhangelsk Regional Hospital staff were later flown to Moscow for radiation testing. One doctor was found to test positive for Cesium-137, though the levels remain unknown, as the medical staff involved were forced to sign non-disclosure agreements.
According to an unnamed medical worker, two injured by the explosion died of radiation sickness en route from Arkhangelsk Regional Clinical Hospital (AOKB) () to treatment in Moscow. Their bodies were sent to Moscow's Burnazyan Federal Medical and Biophysical Center (FMBC) (). Six persons with severe injuries from the explosion and radiation exposure were delivered to Burnazyan by two medevac flights and ambulances with special plastic seals, with paramedics wearing chemical protective suits, and, because an operating room apron was highly contaminated after an operation, all Arkhangelsk Regional Hospital doctors, nurses, and staff who came into contact with the injured were sent to Burnazyan, too. The rooms at the Arkangelsk hospital, where injured victims had been treated, were sealed after treatment but none of the hospital workers and staff had worn anti-contamination clothing.
Five immediate deaths
On Monday 12 August 2019, flags in Sarov were lowered to half-mast during the viewing of five coffins in Sarov's main square. These were the bodies of five Rosatom (RFNC-VNIIEF) workers who were killed during and immediately following the 8 August 2019 explosion. Later, on 12 August 2019, their bodies were buried in Sarov's main cemetery. On 21 November 2019, they were posthumously awarded the Order of Courage.
Radiation levels
Yuri Peshkov from the Roshidromet, the Russian meteorology service, stated that background radiation levels peaked at 4–16 times normal levels at six of its eight stations in Severodvinsk, to the east, reaching 1.78 microsieverts per hour shortly after the explosion, but returned to normal levels 2.5 hours after the explosion. The administration in Severodvinsk reported elevated radiation levels for 40 minutes leading to a rush on medical iodine. In the days following the event several monitoring stations in Russia stopped sending data to the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), a data network for radiation monitoring made of 80 stations around the world.
According to the information posted by Roshydromet on radiation situation in Severodvinsk in the hours following the accident, a number of short-lived isotopes were discovered: strontium-91, barium-139, barium-140 and lanthanum-140. Norwegian nuclear safety expert Nils Bøhmer stated that such isotope composition proves a nuclear reactor was involved in the accident.
On 2 September, Belomorkanal news agency published a video showcasing two abandoned pontoons near the mouth of where the Nyonoksa River empties into the Dvina Bay only 4 km from the center of Nyonoksa, with one of them carrying an array of heavily damaged testing equipment. According to Nyonoksa residents, the first pontoon "PP PP Plant No. 2" () with two blue containers washed ashore on 9 August and the heavily damaged second pontoon with a damaged crane, a blue container and a yellow container similar to a Siempelkamp container for highly radioactive materials was towed by tugboats to a site near the first pontoon about five days after the explosion. The video by Severodvinsk journalist Nikolai Karneyevich () demonstrates gamma radiation levels at from the abandoned vessels on the White Sea shore close to Nyonoksa with the reading reaching 186 μR/hour - 15 times higher than natural. Nyonoksa residents said that just days prior to the 31 August measurements, the gamma ray radiation levels were 750 μR/hour at the same location. Alpha and beta radiation levels have not been measured. , the site has been neither enclosed nor guarded and no radiation warning signs have been observed.
Over away, tiny amounts of radioactive iodine, which were collected from 9–12 August, were detected at an air filter station in Svanhovd by Norway's nuclear safety authority. The agency could not determine if the detection was linked to the accident, and, according to Reuters, such iodine measurements were not unusual as monitoring stations in Norway detected radioactive iodine about six to eight times a year and also were usually unable to determine the source of the isotope.
Evacuation of population
According to the local press, it was announced that about 450 inhabitants of the Nyonoksa village had to be evacuated by train for two hours on 14 August then this evacuation would have been canceled. According to The Moscow Times quoting RIA Novosti, residents of Nyonoksa will be evacuated each month by special train for two hours (early Wednesday morning) for planned military activities in the city; evacuation that according to a villager already exists: it is expected, everyone is taken from the village about once a month, even if some remained behind. But now, after the last events, I think everyone will leave. The governor of the Arkhangelsk region (Igor Orlov) denied that the evacuation was an emergency, saying it was a routine measure, already "planned".
Reactions
: Although initially denied, involvement of radioactive materials in the accident was later confirmed by Russian officials. On 13 August, the authorities initiated evacuation of the village of Nyonoksa. On 14 August the evacuation was cancelled. On 26 August, Aleksei Karpov, Russia's envoy to international organizations in Vienna, stated that the accident was linked to the development of weapons which Russia had to begin creating as "one of the tit-for-tat measures in the wake of the United States’ withdrawal from the Anti-Ballistic Missile Treaty". On 21 November, at the ceremony of presentation of posthumous awards to the dead men's families, Vladimir Putin stated that the scientists killed in the August 8th explosion had been testing an “unparalleled” weapon: “We are talking about the most advanced and unparalleled technical ideas and solutions about weapons design to ensure Russia’s sovereignty and security for decades to come". He also noted that the "weapon is to be perfected regardless of anything". On 22 November 2019, Dmitry Peskov, Putin's Press Secretary, stated that the investigation into the explosion will not be made public.
: On 12 August a tweet from US president Donald Trump suggested that the accident was a failed Burevestnik test. In the tweet Burevestnik was referred to by its NATO reporting name "Skyfall". On 10 October, Thomas DiNanno, member of the United States delegation to the United Nations General Assembly First Committee, stated that the "August 8th 'Skyfall' incident [...] was the result of a nuclear reaction that occurred during the recovery of a Russian nuclear-powered cruise missile", which "remained on the bed of the White Sea since its failed test early last year". On 14 October, three United States diplomats were removed from the Nyonoksa-Severodvinsk train; Russia accused the diplomats of attempting to enter the closed city of Severodvinsk without the official permission, stating the diplomats had told Russia they were visiting Arkhangelsk, which wasn't within a restricted zone, but then traveled to the closed area next to the test site. The US Embassy in Russia and the State Department confirmed the incident, stating the diplomats were on official travel and had informed Russian authorities of their travel in advance.
See also
List of military nuclear accidents
Nuclear and radiation accidents and incidents
Andreev Bay nuclear accident
Kramatorsk radiological accident
Kyshtym disaster
Notes
References
External links
August 2019 events in Russia
Explosions in 2019
2019 in military history
2019 health disasters
Nuclear accidents and incidents
2019 disasters in Russia
21st-century military history of Russia
Industrial fires and explosions in Russia
2019 industrial disasters | Nyonoksa radiation accident | [
"Chemistry"
] | 2,413 | [
"Nuclear accidents and incidents",
"Radioactivity"
] |
76,828,449 | https://en.wikipedia.org/wiki/Cristina%20Dalle%20Ore | Cristina Morea Dalle Ore (born 1958) is a hyperspectral imaging and remote sensing expert, originally from Italy. After many years as an astronomer and planetary scientist, she has shifted her interests to Earth-based agricultural applications of remote sensing, as Head of Remote Science and Geospatial Intelligence for Bayer Crop Science. Her work in astronomy studied the chemical composition of objects in the far reaches of the Solar System, with a special focus on tholins, and included the discovery of ammonia on Pluto, suggesting the possibility of liquid water there as well.
Education and career
Dalle Ore is originally from Treviso; astronomy was a shared interest with her father, heart surgeon Mario Morea. She earned a laurea in astronomy, the Italian equivalent of a master's degree, from the University of Padua, in 1983. Next, she began graduate studies with Sandra Faber at the University of California, Santa Cruz, but was pulled away to Boston by her new husband's job there. After spending nine years raising three children and studying spectroscopy at Harvard University, she returned to UC Santa Cruz to complete her Ph.D. Her 1993 dissertation, A critical examination of stellar atmosphere theory for metal-poor K-giant stars, was supervised by Faber.
Despite her early research focus on stars, a chance social connection with planetary scientist Dale Cruikshank led her to a position studying the Solar System as a research scientist for the SETI Institute and NASA Ames Research Center. She worked there beginning in 1996, with a stint as a lecturer at UC Santa Cruz from 2007 to 2008, until taking her present position at Bayer Crop Science.
Recognition
Minor planets 25945 Moreadalleore and 151351 Dalleore are named for Dalle Ore.
References
External links
1958 births
Living people
Italian astronomers
American astronomers
Women astronomers
Planetary scientists
Women planetary scientists
University of Padua alumni
University of California, Santa Cruz alumni | Cristina Dalle Ore | [
"Astronomy"
] | 383 | [
"Women astronomers",
"Astronomers"
] |
76,830,852 | https://en.wikipedia.org/wiki/IC%205145 | IC 5145 is a type Sab spiral galaxy located in the constellation Pegasus. It is located 356 million light-years from the Solar System and was discovered by Edward Emerson Barnard, although the year he discovered it is unknown.
The luminosity class of IC 5145 is I-II and it has a broad H II region. Its dimensions measure 1.60 x 0.9 arcmin.
Supernovae
Six supernovae have been discovered in IC 5145 so far: SN 2002dn, SN 2003hy, SN 2010iq, PSN J21542359+1509224, SN 2020pkj, and SN 2022lfa.
SN 2002dn
SN 2002dn was discovered in IC 5145 by astronomer W. D. Li from University of California at Berkeley via unfiltered KAIT CCD images taken on June 15 and June 17, 2002. It was located 8".8 west and 18".3 north of the nucleus. A further inspection done by A. V. Filippenko, R. Chornock and R. J. Foley, using the Shane 3-m reflector at Lick Observatory confirmed SN 2002dn was a Type Ic supernova which resembled SN 1987m.
SN 2003hy
SN 2003hy was discovered by British amateur astronomer, Tom Boles from Coddenham, England on September 14, through unfiltered CCD images using a 0.35-m reflector as part of the course done by U.K. Nova/Supernova Patrol. Surprising, SN 2003hy was also discovered by another amateur astronomer, Mark Armstrong who saw it on the same unfiltered CCD images and via a 0.35m reflector. It had a magnitude of 16.6 and was located 5".5 west and 12".5 north of the nucleus. The supernova was Type IIn.
A 14-minute exposure of SN 2003hy taken on December 28, 2003, shows it is much dimmer than 19.4 magnitude, which the dimmest stars are magnitude 20.
SN 2010iq
Lick Observatory Supernova Search discovered SN 2010iq on October 11, 2010. It was reported by A. Narla, S. B. Cenko, W. Li and A. V. Filippenko from University of California, Berkeley through unfiltered CCD images. It was located 2".8 east and 4".4 south of the nucleus with a magnitude of 18.2. This supernova was Type Ic.
PSN J21542359+1509224
PSN J21542359+1509224 was discovered on 13 May 2014 by Bin Wang and Xing Gao. It was located 5".3 east and 0".9 south of the nucleus with a magnitude of 18.3. This supernova had an unknown type.
SN 2020pkj
SN 2020pkj (type Ia, mag. 19.2) was discovered on 15 July 2020 by ZTF.
SN 2022lfa
SN 2022lfa was discovered on May 28, 2022, by Zwicky Transient Facility (ZTF) through Palomar 1.2m Oschin telescope on the behalf of K. De from Caltech. On June 28, 2022, astronomers confirmed that SN 2022lfa is a Type Ic supernova via a spectrum obtained on MJD 59755.43 using the 3-m Shane telescope at Lick Observatory.
References
5145
Spiral galaxies
Pegasus (constellation)
Discoveries by Edward Emerson Barnard
11844
067619
2MASS objects
SDSS objects
067619
+02-55-028 | IC 5145 | [
"Astronomy"
] | 775 | [
"Pegasus (constellation)",
"Constellations"
] |
76,831,877 | https://en.wikipedia.org/wiki/NGC%203978 | NGC 3978 is a large intermediate spiral galaxy with a bar located in the constellation of Ursa Major. It is located 460 million light-years away from the Solar System and was discovered by William Herschel on March 19, 1790, but also observed by John Herschel on April 14, 1831.
NGC 3978 has a luminosity class of II-III and it has a broad H II region which contains regions of ionized hydrogen. In addition, it is categorized as a LINER galaxy by SIMBAD, meaning its nucleus presents an emission spectrum which is characterized by broad lines of weakly ionized atoms.
According to Vaucouleurs and Corwin, NGC 3978 and NGC 3975 form a galaxy pair with each other.
Supernovae
Two supernovae were discovered in NGC 3978: SN 2003cq and SN 2008l.
SN 2003cq
SN 2003cq was discovered on March 30, 2003, by British astronomer Ron Arbour. It was located 32".0 east and 2".3 south of the nucleus with a magnitude of 17.1. This supernova was Type Ia.
SN 2008I
SN 2008I was discovered by astronomers P. Thrasher, W. Li, and A. V. Filippenko as part of Lick Observatory Supernova Search (LOSS) on January 2, 2008. It was located 3".7 west and 10."4 north of the nucleus with magnitude of 19.1. The supernova was Type II which possibly resulted from a collapse of a massive star.
References
3978
Intermediate spiral galaxies
Ursa Major
037502
037502
06910
Astronomical objects discovered in 1790
Discoveries by William Herschel
2MASS objects
SDSS objects
IRAS catalogue objects | NGC 3978 | [
"Astronomy"
] | 366 | [
"Ursa Major",
"Constellations"
] |
76,832,355 | https://en.wikipedia.org/wiki/NGC%207222 | NGC 7222 is a large barred spiral galaxy with a ring structure, located in the constellation Aquarius. It is located 570 million light-years away from the Solar System and was discovered by German astronomer, Albert Marth on August 11, 1864.
NGC 7222 has a luminosity class of II and it has a broad H I line which contains regions of ionized hydrogen. NGC 7222 also has a surface brightness of 14.20 mag/am, which means it is considered a low surface brightness galaxy (LSB). LSBs are diffuse galaxies that have surface brightness one magnitude lower compared to the ambient night sky.
Supernova
One supernova has been discovered in NGC 7222 so far: SN 2008dr.
SN 2008dr
SN 2008dr was discovered by a team of astronomers; J. Leja, D. Madison, W. Li, and A. V. Filippenko from University of California, Berkeley as part of Lick Observatory Supernova Search (LOSS). It had a magnitude of 16.8 and was located 1".3 west and 8".1 north of the nucleus. SN 2008dr was confirmed to be a Type Ia.
Companion galaxy
NGC 7222 has a companion which is a spiral galaxy, PGC 68229, also known as CGCG 377-036. The galaxy is located west of NGC 7222 at close proximity and is 579 million light-years distant. It is possible both galaxies together make up a galactic pair.
References
7222
Barred spiral galaxies
Aquarius (constellation)
Astronomical objects discovered in 1864
Discoveries by Albert Marth
11934
068224
068224
SDSS objects
+00-56-012
2MASS objects | NGC 7222 | [
"Astronomy"
] | 355 | [
"Constellations",
"Aquarius (constellation)"
] |
76,832,553 | https://en.wikipedia.org/wiki/Lantheus%20Holdings | Lantheus, headquartered in Billerica, Massachusetts, is a company in the radiopharmaceuticals business. It has strategic partnerships with Bayer, Novartis, Regeneron as well as GE Healthcare and Siemens Healthineers.
Lantheus Holding, which became a NASDAQ company in 2015, is the parent company of Lantheus Medical Imaging, Inc. (formerly BMS Medical Imaging), Progenics Pharmaceuticals (acquired 2020), Inc. and EXINI Diagnostics AB (est. 1999, acquired 2020). Lantheus has offices in Massachusetts, New Jersey, Canada and Sweden.
References
External links
Radiopharmaceuticals
Companies listed on the Nasdaq
Companies based in Billerica, Massachusetts | Lantheus Holdings | [
"Chemistry"
] | 155 | [
"Chemicals in medicine",
"Radiopharmaceuticals",
"Medicinal radiochemistry"
] |
76,832,856 | https://en.wikipedia.org/wiki/IC%202498 | IC 2498 known as PGC 27668, is a type Sb barred spiral galaxy located in constellation Leo. It is located 469 million light-years away from the Solar System and was discovered by Stephane Javelle on April 30, 1896.
Supernova
One supernova has been discovered in IC 2498 so far: SN 2022eaf.
SN 2022eaf
SN 2022eaf was discovered on March 2, 2022 by a team of astronomers, J. Tonry, L. Dennau, H. Weiland from University of Hawaii, A. Heinze, B. Stalder from LSST, A. Rest from STScl, C, Stubbs from Harvard University along with other colleagues from Queen's University Belfast, Stockholm and ESO, on the behalf of ATLAS program (Asteroid Terrestrial-Impact Last Alert System). SN 2022eaf had a magnitude of 19.1, and a right ascension of (09h 41m 21s.597) with declination of (28 degrees 06' 38".24). The supernova had a redshift of 0.033006 and was classified as Type Ia.
References
2498
Barred spiral galaxies
Leo (constellation)
Astronomical objects discovered in 1896
027668
027668
SDSS objects
2MASS objects | IC 2498 | [
"Astronomy"
] | 280 | [
"Leo (constellation)",
"Constellations"
] |
76,842,616 | https://en.wikipedia.org/wiki/HD%2039118 | HD 39118 (HD 39119, HR 2024) is a spectroscopic binary star in the constellation Orion, close to the celestial equator. It is made up from three stars: a cool primary (a K-type giant star) and a hot secondary, which is a binary star formed from a B-type main-sequence star and an A-type main-sequence star. A 2021 estimate derive a distance of to HD 39118, and it is moving away from Earth at a speed of 4.24 km/s. The apparent magnitude is 5.976, making it visible to the naked eye only from dark skies.
Characteristics
HR 2024 is a spectroscopic binary (more precisely a single-lined spectroscopic binary) made up of a cool primary and a hot secondary, which is also a binary star. The designations “cold” and “hot” refer to the effective temperature of the components. They are separated by , and complete an orbit around each other every . The orbital eccentricity is equivalent to 0.3.
HD 39118 can be seen in the northern celestial hemisphere, close to the celestial equator, at a distance of in the constellation Orion. It has an apparent magnitude of 5.976. At this magnitude, it is visible to the naked eye only in dark skies, being close to the limiting magnitude to naked-eye vision of 6.5. The absolute magnitude, i.e. its brightness if it was seen at a distance or , is –2.53. It is moving away from Earth at a velocity of 4.24km/s.
It was double cataloged in the Henry Draper Catalogue, receiving the designations HD 39118 and HD 39119.
Primary star
The primary has an spectral classification of K0II, meaning that it is a K-type star that has left the main sequence, being now a bright giant star. Currently, it is in the red giant branch of evolution. It is 3.28 times more massive has expanded to 25 times the Sun's size. It emitts a luminosity 535 times the solar luminosity from its photosphere at an effective temperature of 4,550 K, which is around 1,200K cooler than the Sun. It has a subsolar metallicity, having an abundance of iron on its surface equivalent to 46% that of the Sun. The age of the primary is estimated at 263 million years, much younger than the Sun (4.6 billion years) despite its advanced evolutionary stage. It rotates under its own axis at a velocity of 4.19 km/s. The B-V index is of 1.12, giving it the typical orange hue of a K-type star.
Hot companion
The hot companion is made up of two other stars, one is a late B-type main-sequence star (spectral type B7V/B8V) and the other is an early A-type main-sequence star (spectral type A0V). It has an absolute magnitude about 1.55 magnitudes fainter than the primary companion. The B-type star has an effective temperature of 11,300 K. The B-V index of the hot companion is of –0.09, meaning that it has a typical hue of a B-type star.
Notes
References
Spectroscopic binaries
Orion (constellation)
2024
039118 | HD 39118 | [
"Astronomy"
] | 699 | [
"Constellations",
"Orion (constellation)"
] |
76,842,634 | https://en.wikipedia.org/wiki/Phenotypic%20disparity | Phenotypic disparity, also known as morphological diversity, morphological variety, morphological disparity, morphodisparity or simply disparity, refers to the variation of observable characteristics within biological groups. It was originally proposed in paleontology, and has also been introduced into the study of extant organisms. Some biologists view phenotypic disparity as an important aspect of biodiversity, while others believe that they are two different concepts.
History
Biologists' interest in phenotypic disparity predates the formal concept. Douglas Erwin argued that it had been central to the organismal biology since Georges Cuvier, who utilized it as a criterion for animal classification. However, prior to the development of quantitative methods for measuring disparity, the disparity recognized within the Linnaean taxonomy faced criticism for being unnatural.
This concept was first proposed in the 1980s, utilized to explore the evolutionary patterns of variation in anatomy, function, and ecology. It arose from the efforts by paleobiologists to define the evolutionary origins of the body plans of animals and by comparative developmental biologists to offer causal explanations for the emergence of these body plans. In 1989, Stephen Jay Gould published Wonderful Life, in which he used the fossils from the Middle Cambrian Burgess Shale to contend that the ancient arthropods at this site has a greater phenotypic disparity than all living arthropods. This concept has been introduced into the study of extant organisms.
Initially, phenotypic disparity was considered a sub-concept of biodiversity, referred to as "morphological diversity", subsequently it acquired its own name "disparity", also known as "phenotypic disparity", "morphological disparity", "morphological variety" or "morphodisparity".
Summary
In the narrower sense, the currently widely accepted concept of biodiversity meant only the taxonomic diversity, or the species richness. However, some groups have a large number of species, while all of them are very similar in morphology; other groups have very few species, while they are highly heterogeneous. For example, there are nearly twice as many species of birds as there are of mammals, indicating greater species richness, but birds are more consistent in morphology, reproductive biology, and developmental biology. The range of their body plans is relatively narrow, with outliers like ratites (e.g. ostriches) and penguins, while mammals include such diverse forms as apes, armadillos, bats, giraffes, marsupials, moles, the platypus and whales. Therefore, relying only on species richness to represent biodiversity is less comprehensive.
The disparity is defined as the phenotypic differentiation within groups. "Groups" usually refers to the taxonomic groups, including species or higher taxa. Some biologists believe that the concept of disparity should also be applied to other groups, including sexes, ages, biomorphs and the castes of social insects.
Disparity has changed at different rates and independently of species richness in the evolutionary history. There are two main patterns in how disparity develops over time. Some groups have developed high disparity early on in their evolution (called "early-disparity"), while others take longer to reach their maximum disparity (called "later-disparity"). The early-disparity boom may happen because species quickly explore new habitats or take advantage of new ecological niches. On the other hand, later-disparity groups may have developed new morphological forms slowly, resulting in a delay in reaching their maximum disparity.
Measuring disparity
Initially, there was no consensus on how to measure disparity. In the 1980s, taxonomic metrics was an early approach of measuring disparity among groups. It involved counting how many different families or genera there were to measuring the diversity and disparity of a taxon. It was based on the assumption that higher-ranked taxa could represent specific morphological innovations. Although this approach was criticized as it relied on artificial and non-monophyletic taxa, it provided valuable insights into the evolution of disparity. Some conclusions have been confirmed by subsequent quantitative metrics.
Currently, disparity is usually quantified using the morphospace, which is a multidimensional space covering the morphological variation within a taxon. Due to the use of different mathematical tools, morphospaces may have different geometric structures and mathematical meanings.
The initial step involves selecting multiple phenotypic descriptors (characteristics described in appropriate ways) that vary among different taxa. All phenotypic characteristics can be used to evaluate the disparity of a group, but the morphological characteristics are mostly used, because they are more accessible than others. Secondly, use the selected descriptors to construct a morphospace. Then, use standard statistical dispersion indicators, such as total range or total variance, to describe the dispersion and distribution of groups in morphospace. The morphospace is a multidimensional space, which is almost impossible to visualize, so the dimensionality of the morphospace should be reduced using principal component analysis, principal coordinate analysis, nonmetric multidimensional scaling, or other mathematical methods. Therefore, it could be projected onto a two-dimensional space to visualize it.
References
Biology theories
Biodiversity
Evolutionary biology concepts
Paleontological concepts and hypotheses | Phenotypic disparity | [
"Biology"
] | 1,126 | [
"Biodiversity",
"Evolutionary biology concepts",
"Biology theories"
] |
76,844,678 | https://en.wikipedia.org/wiki/UGC%209684 | UGC 9684 is a barred spiral galaxy with a ring structure in the Boötes constellation. It is located 250 million light-years from the Solar System and has an approximate diameter of 90,000 light-years.
The luminosity class of UGC 9684 is I-II and it is classified as an active star-forming galaxy according to a study published in 2022, in which produces one solar mass of stars every few years, with levels of stellar formation.
Studying of star formation rate for UGC 9684
Scientists who studied UGC 9684, have longed to find out the star-formation rate for UGC 9684. To do this, they used a Fitting and Assessment of Synthetic Templates code. The scientists used further observations via ultraviolet, both optical and near-infrared and from the luminosity measurements from different databases from GALEX, SDSS and from the final release of the MASS extended source catalog by Jarrett et al. 2000, with all the data retrieved from NASA/IPAC Extragalactic Database.
As for the star formation, they employed a decreasing function of (SFR ∝ e−t ) and also a delayed function (SFR ∝ t × e−t ) as well as the stellar population libraries written from Bruzual & Charlot and Convoy et al. Several metallicity estimates, published by Prieto et al. 2008, Kelly & Kirshner from 2012, whom the majority agreed, it is slightly above solar oxygen abundance 12+ log(O/H) ≈ 9.0 which corresponds to ~2 Z⊙.
Scientists therefore found that the star-formation rate of UGC 9684 is 0.25–0.39 M⊙ yr−1. Apart from that, they found the total stellar mass for the galaxy is M⋆ = (2.0–3.5) × 1010 M⊙ which is a current specific of SFR sSFR ≈ 0.01 Gyr−1. This is higher compared to literature but compatible to large number of recent events in UGC 9684.
Supernovae
Three supernovae and one astronomical transient have been discovered in UGC 9684: SN 2006ed, SN 2012ib, AT 2017cgh, and SN 2020pni. This makes it as one of the most active supernova-producing galaxies.
SN 2006ed
SN 2006ed was discovered on September 18, 2006, via unfiltered CCD images, by N. Joubert, D. R. Madison, R. Mostardi, H. Khandrika and W. Li from University of California, Berkeley on behalf of Lick Observatory Supernova Search program (LOSS). SN 2006ed had a magnitude on 19.0. It was located 1".8 east and 7".2 south of the nucleus. This supernova was Type II.
SN 2012ib
SN 2012ib was discovered on December 20, 2012, by amateur astronomer, V. Shumkov from Sternberg Astronomical Institute (SAI), on four 60-sec unfiltered images from the MASTER-Amur robotic telescope via a 0.40-m f/2.5 reflector. The supernova was located at 48".7 east and 0".4 south of the nucleus, which it had a magnitude of 18.9. The supernova was Type Ib/c.
AT 2017cgh
AT 2017cgh was discovered on March 15, 2017, by Pan-STARRS1 Science consortium. It was located 0".0 east and 0".0 north of the nucleus with a magnitude of 17.7. This astronomical transient had an unknown type, and was never officially classified as a supernova.
SN 2020pni
SN 2020pni was discovered on July 16, 2020, by a team of astronomers on behalf of the ALeRCE broker via r-ZTF filters which was taken by a Palomar 1.2m Oachin telescope. It was located 5".7 west and 5".0 south of the nucleus with a magnitude of 17.0. The supernova was Type II in which its progenitor, a massive star, was enriched in helium and nitrogen in relative abundances in mass fractions of 0.30–0.40 and 8.2 × 10−3, respectively.
A first study shows 1 day after the discovery, there is a significant He II emission which has strong flash features. Another study shows during the 4 days after, there was an increase in velocity of hydrogen lines (from ~250 to ~1000 km/s) suggesting complex circumstellar medium (CSM). A presence of dense and confined CSM as well as its inhomogeneous structure, indicates a phrase of enhanced mass loss of the SN 2020pni progenitor a year before the explosion. As of 2023, the supernova has since faded from view.
References
9684
Boötes
053758
053758
Barred spiral galaxies
SDSS objects
2MASS objects
IRAS catalogue objects
Starburst galaxies
+07-31-024 | UGC 9684 | [
"Astronomy"
] | 1,046 | [
"Boötes",
"Constellations"
] |
76,844,760 | https://en.wikipedia.org/wiki/Neopyrenochaeta%20annellidica | Neopyrenochaeta annellidica is a species of saprobic, hyaline-spored coelomycetes found on submerged decaying wood in freshwater habitats.
Taxonomy
The species was first described in 2020 in a study revising coelomycete classification based on morphology and phylogeny.
Description
The sexual morph of N. annellidica is undetermined.
The asexual morph features conidiomata, the fruiting structures of coelomycetes. The conidiomata are black when dry, dark brown when moist, and feature a white conidial mass surrounding the ostiole. The primary identifying feature of N. annellidica is the presence of pycnidial ("flask-like") conidiomata. The setae are pale brown to black, unbranched, and septate.
PDA cultures range from white to pale gray with white, undulate margins, with a dark brown center and white margins on the reverse side.
Distribution
N. annellidica has been described in Thailand, Vietnam and Spain.
Etymology
The species epithet, "annelidica", refers to its annellidic conidiogenous cells, which are a type of blastic condidiogenesis cells in mycology.
References
Fungi described in 2020
Pleosporales
Fungus species | Neopyrenochaeta annellidica | [
"Biology"
] | 282 | [
"Fungi",
"Fungus species"
] |
76,845,211 | https://en.wikipedia.org/wiki/1DD-LSD | 1DD-LSD (N1-dodecanoyl-lysergic acid diethylamide, SYN-L-004) is an acylated derivative of lysergic acid diethylamide (LSD). In animal studies it produces a weak head-twitch response but with 27x lower potency than LSD itself. It is being researched as a potential slow-onset, long lasting prodrug for LSD which is expected to have reduced psychoactive effects.
See also
1B-LSD
1H-LSD
1P-LSD
1V-LSD
References
Designer drugs
Lysergamides
Prodrugs
Serotonin receptor agonists | 1DD-LSD | [
"Chemistry"
] | 146 | [
"Pharmacology",
"Prodrugs",
"Medicinal chemistry stubs",
"Chemicals in medicine",
"Pharmacology stubs"
] |
76,845,999 | https://en.wikipedia.org/wiki/William%20R.%20Young%20%28oceanographer%29 | William Roy Young (also referred to as Bill Young) is an Australian-American oceanograoher and a professor at the Scripps Institution of Oceanography at the University of California San Diego.
Education and career
William Young graduated from Australian National University with a bachelor's degree in theoretical physics in 1977 and a master's degree in applied mathematics in 1978. He completed his Phd in 1981 under the supervision of Peter B. Rhines that was awarded by a joint PhD program offered by Massachusetts Institute of Technology and Woods Hole Oceanographic Institution. He then worked as a postdoctoral researcher at the Scripps Institution of Oceanography from 1981 to 1984.
He joined the faculty of Massachusetts Institute of Technology in 1985 and worked there till 1987. He returned to the Scripps Institution of Oceanography in 1988 where he still remains.
Awards and honours
He was elected as a fellow of American Geophysical Union in 1989, of American Meteorological Society in 2008 and of the National Academy of Sciences in 2012.
References
External links
1955 births
Living people
Fluid dynamicists
Massachusetts Institute of Technology alumni
University of California, San Diego faculty | William R. Young (oceanographer) | [
"Chemistry"
] | 222 | [
"Fluid dynamicists",
"Fluid dynamics"
] |
76,846,501 | https://en.wikipedia.org/wiki/HD%2085945 | HD 85945 (HR 3922) is a star in the constellation Ursa Major. It is a yellow giant star with a spectral type of G6III:Fe-0.5. Based on information from Gaia DR3, it is located from Earth and is moving towards Earth at a velocity of 47 km/s. It has an apparent magnitude of 5.96, which makes it faintly visible to the naked eye.
Characteristics
It is an evolved G-type giant star, based on its spectral type of G6III:Fe-0.5, which also indicates that is has a [Fe/H] metallicity of -0.5. HD 85945 is 2.5 times more massive than the Sun and has expanded to 10.28 times the Sun's size. It is emitting 78 times the solar luminosity from its photosphere at an effective temperature of 5,281 K. Currently, the star is located in the horizontal branch stage of evolution. The age of HD 85945 is estimated at 660 million years, and it rotates under its axis at a speed of 7.53 km/s. It is slightly metal-poor compared to the Sun, with an abundance of iron equivalent to 40% of the solar abundance.
HD 85945 is located within the Ursa Major constellation, based on its celestial coordinates. The distance to HD 85945 is of , based on spectra from Gaia DR3. The apparent magnitude of the star is of 5.96, which is brighter than the limiting magnitude for naked-eye vision (6.5m), making it faintly visible to the naked eye. The absolute magnitude, i.e. the brightness of the star if it was seen at a distance of , is 0.32. At the current distance, its brightness is diminished by 0.03 magnitudes due to interstellar extinction between Earth and the star. HD 85945 is moving away from Earth at a velocity of 46.55 km/s. It has a high proper motion in the sky.
Notes
References
G-type giants
Ursa Major
Bright Star Catalogue objects
Henry Draper Catalogue objects
Horizontal-branch stars
TIC objects
Hipparcos objects | HD 85945 | [
"Astronomy"
] | 451 | [
"Ursa Major",
"Constellations"
] |
76,846,528 | https://en.wikipedia.org/wiki/Polarization%20%28cosmology%29 | According to the standard Big Bang theory, the early universe was sufficiently hot for all the matter in it to be fully ionised. Under these conditions, electromagnetic radiation was scattered very efficiently by matter, and this scattering kept the early universe in a state of thermal equilibrium.
In physical cosmology, following the quark epoch (when the fundamental interactions of gravitation, electromagnetism, the strong interaction and the weak interaction had taken their present forms, but the temperature of the universe was still too high to allow quarks to bind together to form hadrons) was the hadron epoch in which most of the hadrons and anti-hadrons were eliminated in annihilation reactions, leaving a small residue of hadrons and a Universe dominated by photons, neutrinos and electron-positron pairs called the lepton epoch during which the neutrino decoupling took place. Thereafter the Big Bang nucleosynthesis epoch followed, overlapping with the photon epoch where once recombination was virtually complete, photons ceased to scatter at all and began to propagate freely through the Universe, suffering only the effects of the cosmological redshift.
These two verified instances of decoupling since the Big Bang - namely, neutrino decoupling and photon decoupling led to the cosmic neutrino background and cosmic microwave background respectively, in that sequence. However, the neutrinos from neutrino decoupling event have a very low energy, around 10−10 times smaller than is possible with present-day direct detection. Hence, Neutrino decoupling#Indirect evidence from phase changes to the Cosmic Microwave Background (CMB) theorises that the decoupled neutrinos should have had a very slight effect on the phase of the various CMB fluctuations.
Cosmic Background Radiation Polarization
With a standard optical telescope, the background space between stars and galaxies is almost completely dark. However, a sufficiently sensitive radio telescope detects a faint background glow that is almost uniform and is not associated with any star, galaxy, or other object. This glow is strongest in the microwave region of the radio spectrum.
E and B modes are two types of polarization patterns of radiation observed in sky.
The launch of the IXPE telescope in late 2021 made polarization measurements in the 2–8 KeV band also a reality (more than 40 years after the pioneering observations of the OSO-8 satellite) and its polarimetric observations confirmed theoretical predictions, according to which X-ray radiation from magnetar sources is also highly polarized, up to ≈ 80%, the highest value detected so far. Photons propagating in a strongly magnetized environment are expected to be linearly polarized in two normal modes called the ordinary (O) and the extraordinary (X) one, parallel or perpendicular to the plane of the local magnetic field and the photon propagation direction, respectively. In the 2–10 keV band (which is the one accessible to current instrumentation), radiation emitted from the bare, condensed surface of magnestars is expected to be only mildly polarized (≲30%), with either O- or X-mode dominating, depending on both the photon energy and propagation direction with respect to the star magnetic field. Magnetar emission can be reasonably expected to be mostly polarized in the X-mode.
In plasma physics, in an unmagnetized plasma, the Electromagnetic electron wave is simply a light wave modified by the plasma. In a magnetized plasma, the two modes perpendicular to the field are the O and X modes, and two modes parallel to the field are the R and L waves. The O wave is the "ordinary" wave in the sense that its dispersion relation is the same as that in an unmagnetized plasma. It is plane polarized with E1 || B0. It has a cut-off at the plasma frequency. The X wave is the "extraordinary" wave because it has a more complicated dispersion relation: It is partly transverse (with E1⊥B0) and partly longitudinal.
Cosmic infrared background (CIB) has also been observed to be polarised. This CIB emission from dust surrounding star-forming regions in distant galaxies shows both the CIB E and B modes.
Gamma-ray Bursts are also being studied using gamma-ray (GRB) polarimeters and polarization-sensitive Compton telescopes. A future GRB polarimeter, POLAR-2, is under development for launch in 2024, and COSI has been selected by NASA for launch in 2025. Meanwhile, studies of data from POLAR combined with data from Fermi Gamma-ray Burst Monitor (Fermi-GBM) and Neil Gehrels Swift Observatory has pointed to lower gamma-ray burst polarization. But the authors have also stated that those could be possible artifacts of averaging of the changing polarization signal over time which maybe washing out an actual moderate gamma-ray burst polarization. Hence, the authors have cautioned against over-interpretation of current results and wait for more detailed polarization measurements from future missions such as POLAR-2 and LEAP.
Till date (as of 2021), all GRB polarization measurements performed have made use of Compton scattering in the detector.
B-mode polarization can also be used as an indirect probe into the cosmic neutrino background because unlike E-mode polarization, it is possible to generate the B-mode by Compton scattering in case of tensor mode of metric perturbation but not in the case of scalar mode of metric perturbation.
Properties
There are two directions in a polarization pattern - its orientation and its amplitude. If the polarization orientation is parallel or perpendicular to its amplitude direction, it is called an E-mode polarization. If it is crossed at 45-degree angles, it is called a B-mode polarization.
Plane waves fluctuations (like density or scalar perturbations in the early universe) produce polarization patterns of a particular type, known as E mode. This polarization pattern is highly symmetrical with the observed orientation being independent of observation location while the observed magnitude is independent of longitude (for a fixed latitude of observation).
Gravitational wave can cause an anisotropic stretching of space, and this asymmetry causes a "handedness" to the pattern of polarization. Changing the viewing location, changes the observed orientation and magnitude of polarization (the pattern across all latitudes and longitudes becomes asymmetric). This polarization pattern is known as B mode.
Plane wave (density perturbations) just generate parallel polarization and so generate only E-mode polarization. Gravitational waves generate both and so have a component of B-mode polarization also.
B-modes retain their special nature that they can possess a handedness that distinguishes left from right. If reflected across a line going through the center the E-patterns are unchanged, while the positive and negative B-patterns get interchanged.
Measurement
Planck, BICEP, etc. detect electromagnetic radiation and "E-modes" and "B-modes" refer to polarization characteristics of this radiation, not the actual electric and magnetic fields. The names derive from an analogy to the decomposition of a vector field into curl-less (here "E" for electric or "G" for gradient) and divergence-less ("B" for magnetic or "C" for curl) components.
For measurements, the first step is the measurement of standard Stokes parameters Q and U. In general, the polarization of monochromatic light is completely described via four Stokes parameters, which form a (non-orthonormal) vector space when the various waves are incoherent. For light propagating in the z direction, with electric field:
In cosmology, no circular polarization is expected, so V is not considered. In addition, normalization of Q and U is traditionally with respect to the mean temperature T0 instead of intensity I.
The definitions of Q and U imply that they transform under a rotation 𝝰 around the z-axis according to:
These parameters transform, not like a vector, but like a two-dimensional, second rank symmetric trace-free (STF) polarization tensor P. In spherical polar coordinates (θ, ɸ), the metric tensor g and polarization tensor are:
This matrix is symmetric and trace-free.
Just as a scalar function can be expanded in terms of spherical harmonics Y, the polarization tensor (with its two independent parameters Q and U) can be expanded in terms of two sets of orthonormal tensor harmonics:
The "G" ("E") basis tensors are "like" gradients, and the "C" ("B") like curls.
It appears that cosmological perturbations are either scalar (e.g. energy density perturbations) or tensor (gravitational waves). Crucially, scalar perturbations produce only E-mode (G-type) polarization, so evidence of a cosmological B-mode is evidence of gravitational waves. However, the Milky-Way "dust" polarization (the "foreground" to cosmologists) can produce B-modes, so it must be well-understood and subtracted to obtain the cosmological signal.
Importance
Decoupling freezes the distribution of relativistic particles at the time of decoupling in the radiation dominated phase of early universe when non-relativistic particles are negligible contributors. The number density of the decoupled particles will be comparable to the number density of photons at any given time. In particular, any such decoupled species will continue to exist in our universe today as a relic background with number densities comparable to the number density of photons (but with energy densities proportionate to respective mass).
Infact, the neutrons and protons contained in the present day universe must have existed at temperatures ~ 10^12 K as well since these particles could not have been produced at lesser temperature. The ratio between the number density of baryons and the number density of photons remains approximately constant from temperatures ~ 10^12 K till today.
At the time of decoupling, the photons, neutrinos and the rest of the matter had the same temperature. The interaction rate of neutrinos becomes lower than the expansion rate of the universe when the temperature drops below ~ 1MeV. At lower temperatures, the neutrinos are completely decoupled from the rest of the matter. Since the neutrinos are taken to be almost massless, they are relativistic at the time of decoupling and the present day universe should contain a relic background of these neutrinos.
At the time of decoupling, the distribution function of all species (other than the decoupled particle) will be still with a common temperature. Hence, when the neutrinos have decoupled with their entropy is separately conserved, the photons are in equilibrium with electrons and positrons. When the temperature of the universe becomes lower than the electron rest mass (~0.5MeV which corresponds to a temperature of approx 6 x 10^9 K), then the mean energy of the photons will fall below the energy required to create electron-positron pairs. Thus the backward reaction of photons creating electron-positron pairs will be severely suppressed. The forward reaction of electron-positron pairs annihilation to create photons will continue to occur resulting in the disappearance of the electron-positron pairs.
When the electron-positron pairs annihilation is complete, the only relativistic specie left is the photon.
Observation of these primordial photons is meant to reveal the two polarization patterns E and B modes which help to understand the physics of the early universe and its late-time evolution. Unfortunately, galactic nuclei and dust emit very strongly in the wavelength < 3 x 10^-2 cm, completely swamping the primordial signal.
Understanding decoupling of matter and radiation
In the early universe, several processes keep the radiation and matter tightly coupled until a temperature of about a few eV due to sufficient number of free charged particles.
At temperatures below 0.1MeV (the temperature at which the actual synthesis of the first four light nuclei takes place - even though the binding energies of these nuclei suggest that these could be formed when the temperature of the universe is in the range of 1-30MeV - but then is delayed due to reasons of high entropy of the universe, i.e. the high value for the photon-to-baryon ratio), at this temperature the main constituents of the universe will be the hydrogen nucleus (i.e. proton), helium-4 nucleus, electrons, photons and decoupled neutrinos. Since electron rest mass ~ 0.5Mev, the ions and electrons may be considered non-relativistic. These constituents interact amongst themselves and with the photons through various electromagnetic processes, like Bremsstrahlung, Compton (and Thomson) scattering, recombination reaction () and Coulomb scattering between charged particles.
When the recombination reaction rate falls below the expansion rate of the universe, the formation of neutral atoms ceases. The remaining electrons and protons have negligible probability for combining with each other. Thus, a small fraction (~10 ^-5) of electrons and protons will remain free in the universe.
The formation of atoms affects the photons, which were in thermal equilibrium with the rest of the matter through various scattering processes. The timescales for Compton scattering and free-free absorption become much larger than the expansion timescale when the fraction of charged particles which have not combined to form atoms drops to its residual value. The only scattering which is still somewhat operational is the Thomson scattering, which merely changes the direction of the photon without any energy exchange. When the number density of charged particles decreases, even this interaction rate of the photons drops and eventually becomes lower than the expansion rate of the universe. Thereafter the photons are decoupled from the rest of the matter.
For radiation temperature T <= 0.2eV, the neutral matter and photons evolve as uncoupled systems. The parameter T characterising the Planck spectrum continues to fall because of the redshift of the photons. The neutral matter behaves as a gaseous mixture of hydrogen and helium. The photon mean-free-path becomes larger than expansion rate, thus decoupling radiation from matter.
After decoupling, the temperature of the neutral atoms falls faster than that of radiation. As the fraction of charged particles which have not combined to form atoms drops, the relaxation time for matter increases and the energy transfer from the radiation to the matter becomes less and less effective. The adiabatic cooling makes the matter temperature fall faster than the radiation temperature. A small fraction of ionized matter continues to be affected by the photons. The electron mean-free-path which governs this process is much smaller than the photon mean-free-path. Thus, the free electrons are tied to the radiation till a redshift of 20 or so. In other words, the small number of electrons have many collisions with a small number of photons, though most of the photons are unaffected. This interaction has very little effect on the photons because of the small number of charged particles present.
References
Physical cosmology
Polarization (waves) | Polarization (cosmology) | [
"Physics",
"Astronomy"
] | 3,197 | [
"Theoretical physics",
"Astrophysics",
"Physical cosmology",
"Polarization (waves)",
"Astronomical sub-disciplines"
] |
76,847,003 | https://en.wikipedia.org/wiki/Apple%20M4 | Apple M4 is a series of ARM-based system on a chip (SoC) designed by Apple Inc., part of the Apple silicon series, including a central processing unit (CPU), a graphics processing unit (GPU), a neural processing unit (NPU), and a digital signal processor (DSP). The M4 chip was introduced in May 2024 for the iPad Pro (7th generation), and is the fourth generation of the M series Apple silicon architecture, succeeding the Apple M3. It was followed by the professional-focused M4 Pro and M4 Max in October 2024.
The M4 series is built upon TSMC's second-generation 3-nanometer process and contains 28 billion transistors.
Design
The base M4 features a 10-core design made up of four performance cores and six efficiency cores (with one performance core disabled on binned models). The SoC also includes a 10-core GPU (with hardware-accelerated ray tracing, dynamic caching, and mesh shading introduced with the M3), as well as a 16-core NPU.
The M4 Neural Engine has been significantly improved compared to its predecessor, with the advertised capability to perform up to 38 trillion operations per second, claimed to be more than double the advertised performance of the M3. The M4 NPU performs over 60× faster than the A11 Bionic, and is approximately 3× faster than the original M1.
The M4 is packaged with LPDDR5X unified memory, supporting 120GB/sec of memory bandwidth. The SoC is currently offered in 8GB,16GB, 24GB, and 32GB configurations. It is also Apple's first SoC to use the ARMv9 CPU architecture (specifically ARMv9.2-A).
M4 Pro
The M4 Pro features an up to 14-core CPU, with 10 performance cores and 4 efficiency cores, along with up to a 20-core GPU that Apple claims is twice as powerful as that in the M4 when used in the corresponding MacBook Pro. The M4 Pro is available with up to 64GB unified memory (Mac Mini) with a theoretical maximum bandwidth of 273GB/sec.
M4 Max
The M4 Max chip comes with up to 16 CPU cores, 40 GPU cores, and 16 Neural Engine cores, addressing up to 128GB unified memory with over half a terabyte per second (546GB/sec) of memory bandwidth.
Performance
Apple claims up to 50% more CPU performance and 4× more GPU performance on the M4 compared to the M2. The M4 competes for the highest-scoring consumer SoC for single-core benchmarks according to various sources such as the Geekbench benchmarking suite and Passmark Software's CPU benchmarks. Compared to other modern CPUs, the M4 does not outperform the M3 Pro in multi-core performance but it does in single-core performance and competes with AMD's Ryzen 7 9700X and Intel's Core i9-14900K. In multithreaded performance, the M4 performs similarly to the 12-core M3 Pro.
Additional features
The M4 is the first iPad SoC to support hardware-accelerated AV1 decoding, as well as hardware-accelerated mesh shading and ray tracing introduced to MacBooks in the M3. A new display controller has also been implemented to support the iPad Pro (7th generation)'s Tandem OLED display.
Products that use the Apple M4 series
M4
iPad Pro (7th generation)
iMac (2024)
Mac Mini (2024)
MacBook Pro (14-inch, 2024)
M4 Pro
Mac Mini (2024)
MacBook Pro (14-inch and 16-inch, 2024)
M4 Max
MacBook Pro (14-inch and 16-inch, 2024)
Comparison with other SoCs
The table below shows comparable SoCs
Notes
References
Apple silicon
Computer-related introductions in 2024 | Apple M4 | [
"Technology",
"Engineering"
] | 817 | [] |
76,847,120 | https://en.wikipedia.org/wiki/Mau%C3%A1%20Wall | Mauá Wall () is a flood wall in the Historic Center of Porto Alegre, Rio Grande do Sul.
The reinforced concrete wall is located between Mauá Wharf and Mauá Avenue. It is 2,647 meters long, three meters high and it has a three-meter-deep anchored wall foundation, to help prevent underground percolation. It is part of a flood protection system consisting of 68 km of external and internal dikes, 14 metal gates and 19 pumping stations. The wall represents only 4% of the protective dikes' width and is located along the Navegantes Canal, a part of the Jacuí River Delta. The wall was finished in 1974.
The system was built in order to avoid catastrophe similar to the flood of 1941. The coupures had to be closed at various times after their construction.
As an alternative to the permanent wall, a modular stoplog system based on bleachers has been proposed.
Flood protection system
In addition to the wall, the system has macro-drainage channels (such as Arroio Dilúvio and Arroio Cavalhada streams) and dikes set up under Beira-Rio (to the south) and Presidente Castello Branco avenues (to the north). The pump houses (with 83 pumps capable of pumping 159,000 L/s) are located at specific points in the city to move flood water to Guaíba Lake and Gravataí River.
References
External links
Flood control
Porto Alegre | Mauá Wall | [
"Chemistry",
"Engineering"
] | 304 | [
"Flood control",
"Environmental engineering"
] |
76,847,280 | https://en.wikipedia.org/wiki/64%20Ceti | 64 Ceti is a star located located in the constellation Cetus. Based on its spectral type of G0IV, it is a G-type star that has left the main sequence and evolved into a subgiant. It is located away, based on a parallax measured by Gaia DR3, and it is moving towards Earth at a velocity of 19km/s. The apparent magnitude of 64 Ceti is 5.62, which makes it visible to the naked eye only in dark skies, far away from light pollution.
Characteristics
64 Ceti is a G-type star that has left the main sequence and now evolved into a subgiant, based on its spectral type of G0IV. It has about 1.53 times the Sun's mass and has expanded to 2.53 times the Sun's diameter. It is emitting 8.13 times the solar luminosity from its photosphere at an effective temperature of 6,066 K. The age of 64 Ceti is estimated at 2.63 billion years, about 58% of the Solar System's age, and it rotates under its axis at a speed of 8.96 km/s, translating into a rotation period of 15 days. The B-V index of the star is 0.52, corresponding to a yellow-white hue of a late G/early F star.
It is located in the constellation Cetus, based on its celestial coordinates. Gaia DR3 measured a parallax of 23.8 milliarcseconds for this star, translating into a distance of . The apparent magnitude of 64 Ceti is 5.62, which means that it is a faint star, visible to the naked eye only from locations with dark skies. The absolute magnitude, i.e. its brightness if it was seen at a distance of , is 2.49. The star is moving towards Earth at a velocity of 19 km/s. It has a high proper motion across the sky and belongs to the thin disk population, being located above the galactic plane.
Notes
References
Cetus
Ceti, 64
G-type subgiants
013421
010212
0635
WISE objects | 64 Ceti | [
"Astronomy"
] | 448 | [
"Cetus",
"Constellations"
] |
76,850,085 | https://en.wikipedia.org/wiki/AT2018hyz | AT2018hyz is a tidal disruption event (TDE) that was discovered in 2018 by the All Sky Automated Survey for SuperNovae (ASASS-SN).
History
In 2022, astronomers announced the discovery of radio emission from AT2018hyz using the Very Large Array (VLA), MeerKAT, and the Australia Telescope Compact Array (ATCA), despite no radio emission detected earlier. The emission is still rising rapidly, and has been interpreted as an outflow of material that was "burped" several years after the initial TDE from the accretion disk of the supermassive black hole, traveling at up to half the speed of light. Alternately, it has been proposed that the delayed radio emission from AT2018hyz could be due to an off-axis astrophysical jet, which launched promptly when the black hole was consumed (similar to the TDE Swift J1644+57), and emission only became visible later when it entered our line of sight.
Host galaxy
The host galaxy for AT2018hyz is 2MASS J10065085+0141342, known as LEDA 3119592 or 2dFGRS TGN421Z052, located at redshift z = 0.04573. It is classified as a dormant post starburst galaxy or a type E+A galaxy. Based on studies, the host galaxy's redshift has a g-band visual magnitude of -20.2, with the galaxy containing a low-mass black hole measuring 106 M⊙.
See also
AT2019qiz
RX J1242-11
References
Tidal disruption events
black holes
Sextans | AT2018hyz | [
"Physics",
"Astronomy"
] | 351 | [
"Black holes",
"Physical phenomena",
"Tidal disruption events",
"Physical quantities",
"Concepts in astronomy",
"Astronomical events",
"Sextans",
"Unsolved problems in physics",
"Astrophysics",
"Constellations",
"Density",
"Stellar phenomena",
"Astronomical objects"
] |
76,850,695 | https://en.wikipedia.org/wiki/Michael%20Zeilik | Michael Zeilik (1946–2022) was a professor of astronomy at the University of New Mexico. His main research interests were the study of H II regions at different wavelengths; the light curves of RS Canum Venaticorum variables; and the ethnoastronomy of the Puebloans. He also wrote astronomy textbooks which were the best-selling in the world for a period. These included:
Astronomy: The Evolving Universe
Conceptual Astronomy
Introduction to Astronomy & Astrophysics
References
1946 births
2022 deaths
American astronomers
People from Bridgeport, Connecticut | Michael Zeilik | [
"Astronomy"
] | 112 | [
"Astronomers",
"Astronomer stubs",
"Astronomy stubs"
] |
58,518,670 | https://en.wikipedia.org/wiki/Mortierella%20polycephala | Mortierella polycephala is a saprotrophic fungus with a wide geographical distribution occurring in many different habitats from soil and plants to salt marshes and slate slopes. It is the type species of the genus Mortierella, and was first described in 1863 by Henri Coemans. A characteristic feature of the fungus is the presence of stylospores, which are aerial, spiny resting spores (chlamydospores).
History and taxonomy
Mortierella polycephala was the first species described in the genus Mortierella of the phylum Zygomycota. It has been observed on feces of bats and rodents, such as mice and rats, and it was first described by Coemans on the Bulletin de l'Académie Royale des Sciences de Belgique in 1863. Coemans isolated it from wood rot polypore fungi in the genera Daedalea and Polyporus, however he did not study the mycelium or the chlamydospores. The study of the previous characteristics was done by Van Tieghem who described the sporangia, chlamydospores and stylospores. The species is characterized by the presence of many stylospores (aerial chlamydospores) and sporangiospores arising from aerial hyphae. Jean Dauphin, a professor at The University of Paris dedicated 28 pages to the description, study and experimentation on M. polycephala in his publication Contribution à l'Étude des Mortierellées (1908). In his paper, this species was the only one in which external factors were assessed to determine their role in stimulating the production of zygospores. M. indohii has been proposed as a closely related species to M. polycephala by several studies based on the production of stylospores by both species. Based on phylogenetic analyses where the complete ITS region, and LSU and SSU genes were assessed, close relationship between the two species has been proposed.
Growth and morphology
Colonies are white with a spider web-like texture and sparse growth; they have a garlic-like aroma and can measure up to 7.5 cm in diameter after 5 days at 20 °C on malt extract agar. Sporangiophores in this species measure 300–500 μm long: they are 12.5–20 μm wide at the base, being reduced to 3.5–5 μm at the tip. They can be single or come in clusters; primary branches are present mostly in the upper part of the sporangiophore and they may give rise to secondary and tertiary branches of 12–90 μm long. Sporangia are brown, round (globose), with a diameter of 37–75 μm and they can contain 4–20 spores. M. polycephala''' sporangia can grow well between 10 °C and 25 °C, with an optimum temperature of about 17 °C. Sporangiospores are hyaline, they measure 5.5–13.2 μm long and have an oval to irregular shape. The optimum germination temperature is 27 °C. Zygospores can be up to 1 mm in diameter andare produced by both homothallic and heterothallic mechanisms; they are well formed between 15 °C and 22 °C. Stylospores can be aerial or submerged, they are hyaline and can be found alone or in groups. Their diameter is around 20 μm.
Physiology Mortierella polycephala is able to decompose chitin, liquify gelatin, and produce ethanol, oxalic acid and acetic acid if grown on a glucose medium. Minimal growth is observed at 4 °C; 17 °C is optimal for growth, and growth is not observed above 27 °C. In his experiments Dauphin exposed the fungus to extremely low temperature using liquid air. He observed that at , the spores of M. polycephala did not germinate but were not killed and germinated once returned to ambient temperature. At 4 °C, the chlamydospores and spores could germinate after 3 days and the mycelium was not abundant, yielding this as the minimum temperature at which M. polycephala could grow. At 15 °C germination was the best for M. polycephala: it took 2 days and the mycelium was abundant, but not too crowded. From 22–27 °C mycelium generation started to occur too fast and too crowded; and at 32 °C conditions started to get unhealthy for germination. Finally at 45 °C and higher temperatures, the spores died and germination was not possible. Dauphin also discussed the effects of the lack of oxygen in the fungus growth and concluded it was not a determining factor affecting germination.
Growth of M. polycephala' occurs best in natural or artificial light, and is reduced when colonies are grown in darkness; although no difference in size or morphology of fructifications is seen between colonies developed under differing lighting conditions. M. polycephala grows more slowly under thermal radiation than under longer wavelengths (violet, ultraviolet, blue light) where germination is accelerated. M. polycephala shows a tolerance to short-duration X-ray exposure. Longer periods of x-ray exposure result in slowed germination or death. Dauphin used a radium tube given to him by Professor Pierre Curie to assess the tolerance of M. polycephala to ionizing radiation. He placed the fungus on a Petri dish, and situated the aperture of the radium source towards the centre of the dish. He found that at the borders of the dish, where radiation was more distant, germination was not affected: it was more abundant than normal; however, towards the centre of the dish growth became reduced. He also compared fungal growth exposed to radium with growth under normal conditions using duplicate cultures of the same strain of M. polycephala. The control yielded normal growth and development, but the radium-exposed culture manifested double or triple the normal growth rate in some filaments while others developed cysts.
Habitat and ecologyMortierella polycephala has been reported on decaying polypores, arable and desert soil, trees such as beech and spruce, flowering plants like Calluna, alfalfa roots, wheat, tomato and cabbage; and other ecosystems like salt marshes and slate slopes. It is a saprotroph fungi, extensively distributed in Europe: Belgium, France, The Netherlands, United Kingdom, Ukraine, Germany and Switzerland; Asia: China, Japan, India and Indonesia; and America: Brazil and Mexico. Its spores are transmitted via air or water movement. Although several articles and books report M. polycephala as a cause of pulmonary infections for cattle and abortion in cattle, a primary source that confirms this statement has not been found and no other sources have reproduced the findings. A single report of animal infection attributed M. polycephala may represent a misidentified strain of M. wolfii''.
References
Zygomycota
Fungi described in 1863
Fungus species | Mortierella polycephala | [
"Biology"
] | 1,486 | [
"Fungi",
"Fungus species"
] |
58,519,634 | https://en.wikipedia.org/wiki/Schwarzschild%27s%20equation%20for%20radiative%20transfer | In the study of heat transfer, Schwarzschild's equation is used to calculate radiative transfer (energy transfer via electromagnetic radiation) through a medium in local thermodynamic equilibrium that both absorbs and emits radiation.
The incremental change in spectral intensity, (, [W/sr/m2/μm]) at a given wavelength as radiation travels an incremental distance () through a non-scattering medium is given by:
where
is the number density of absorbing/emitting molecules (units: molecules/volume)
is their absorption cross-section at wavelength (units: area)
is the Planck function for temperature and wavelength (units: power/area/solid angle/wavelength - e.g. watts/cm2/sr/cm)
is the spectral intensity of the radiation entering the increment with the same units as
This equation and various equivalent expressions are known as Schwarzschild's equation. The second term describes absorption of radiation by the molecules in a short segment of the radiation's path () and the first term describes emission by those same molecules. In a non-homogeneous medium, these parameters can vary with altitude and location along the path, formally making these terms , , , and . Additional terms are added when scattering is important. Integrating the change in spectral intensity [W/sr/m2/μm] over all relevant wavelengths gives the change in intensity [W/sr/m2]. Integrating over a hemisphere then affords the flux perpendicular to a plane (, [W/m2]).
Schwarzschild's equation is the formula by which you may calculate the intensity of any flux of electromagnetic energy after passage through a non-scattering medium when all variables are fixed, provided we know the temperature, pressure, and composition of the medium.
History
The Schwarzschild equation first appeared in Karl Schwarzschild's 1906 paper “Ueber das Gleichgewicht der Sonnenatmosphäre” (On the equilibrium of the solar atmosphere).
Background
Radiative transfer refers to energy transfer through an atmosphere or other medium by means of electromagnetic waves or (equivalently) photons. The simplest form of radiative transfer involves a collinear beam of radiation traveling through a sample to a detector. That flux can be reduced by absorption, scattering or reflection, resulting in energy transmission over a path of less than 100%. The concept of radiative transfer extends beyond simple laboratory phenomena to include thermal emission of radiation by the medium - which can result in more photons arriving at the end of a path than entering it. It also deals with radiation arriving at a detector from a large source - such as the surface of the Earth or the sky. Since emission can occur in all directions, atmospheric radiative transfer (like Planck's Law) requires units involving a solid angle, such as W/sr/m2.
At the most fundamental level, the absorption and emission of radiation are controlled by the Einstein coefficients for absorption, emission and stimulated emission of a photon (, and ) and the density of molecules in the ground and excited states ( and ). However, in the simplest physical situation – blackbody radiation – radiation and the medium through which it is passing are in thermodynamic equilibrium, and the rate of absorption and emission are equal. The spectral intensity [W/sr/m2/μm] and intensity [W/sr/m2] of blackbody radiation are given by the Planck function and the Stefan–Boltzmann law. These expressions are independent of Einstein coefficients. Absorption and emission often reach equilibrium inside dense, non-transparent materials, so such materials often emit thermal infrared of nearly blackbody intensity. Some of that radiation is internally reflected or scattered at a surface, producing emissivity less than 1. The same phenomena makes the absorptivity of incoming radiation less than 1 and equal to emissivity (Kirchhoff's law).
When radiation has not passed far enough through a homogeneous medium for emission and absorption to reach thermodynamic equilibrium or when the medium changes with distance, Planck's Law and the Stefan-Boltzmann equation do not apply. This is often the case when dealing with atmospheres. If a medium is in Local Thermodynamic Equilibrium (LTE), then Schwarzschild's equation can be used to calculate how radiation changes as it travels through the medium. A medium is in LTE when the fraction of molecules in an excited state is determined by the Boltzmann distribution. LTE exists when collisional excitation and collisional relaxation of any excited state occur much faster than absorption and emission. (LTE does not require the rates of absorption and emission to be equal.) The vibrational and rotational excited states of greenhouse gases that emit thermal infrared radiation are in LTE up to about 60 km. Radiative transfer calculations show negligible change (0.2%) due to absorption and emission above about 50 km. Schwarzschild's equation therefore is appropriate for most problems involving thermal infrared in the Earth's atmosphere. The absorption cross-sections () used in Schwarzschild's equation arise from Einstein coefficients and processes that broaden absorption lines. In practice, these quantities have been measured in the laboratory; not derived from theory.
When radiation is scattered (the phenomena that makes the sky appear blue) or when the fraction of molecules in an excited state is not determined by the Boltzmann distribution (and LTE doesn't exist), more complicated equations are required. For example, scattering from clear skies reflects about 32 W/m2 (about 13%) of incoming solar radiation back to space. Visible light is also reflected and scattered by aerosol particles and water droplets (clouds). Neither of these phenomena have a significant impact on the flux of thermal infrared through clear skies.
Schwarzschild's equation can not be used without first specifying the temperature, pressure, and composition of the medium through which radiation is traveling. When these parameters are first measured with a radiosonde, the observed spectrum of the downward flux of thermal infrared (DLR) agrees closely with calculations and varies dramatically with location. Where dI is negative, absorption is greater than emission, and net effect is to locally warm the atmosphere. Where dI is positive, the net effect is "radiative cooling". By repeated approximation, Schwarzschild's equation can be used to calculate the equilibrium temperature change caused by an increase in GHGs, but only in the upper atmosphere where heat transport by convection is unimportant.
Derivation
Schwarzschild's equation can be derived from Kirchhoff's law of thermal radiation, which states that absorptivity must equal emissivity at a given wavelength. (Like Schwarzschild's equation, Kirchhoff's law only applies to media in LTE.) Given a thin slab of atmosphere of incremental thickness , by definition its absorptivity is where is the incident radiation and is radiation absorbed by the slab. According to Beer's Law:
Also by definition, emissivity is equal to where is the radiation emitted by the slab and is the maximum radiation any object in LTE can emit. Setting absorptivity equal to emissivity affords:
The total change in radiation, , passing through the slab is given by:
Schwarzschild's equation has also been derived from Einstein coefficients by assuming a Maxwell–Boltzmann distribution of energy between a ground and excited state (LTE). The oscillator strength for any transition between ground and excited state depends on these coefficients. The absorption cross-section () is empirically determined from this oscillator strength and the broadening of the absorption/emission line by collisions, the Doppler effect and the uncertainty principle.
Equivalent equations
Schwarzschild's equation has been expressed in different forms and symbols by different authors. The quantity is known as the absorption coefficient (), a measure of attenuation with units of [cm−1]. The absorption coefficient is fundamentally the product of a quantity of absorbers per unit volume, [cm−3], times an efficiency of absorption (area/absorber, [cm2]). Several sources replace with , where is the absorption coefficient per unit density and is the density of the gas. The absorption coefficient for spectral flux (a beam of radiation with a single wavelength, [W/m2/μm]) differs from the absorption coefficient for spectral intensity [W/sr/m2/μm] used in Schwarzschild's equation.
Integration of an absorption coefficient over a path from and affords the optical thickness () of that path, a dimensionless quantity that is used in some variants of the Schwarzschild equation. When emission is ignored, the incoming radiation is reduced by a factor for when transmitted over a path with an optical thickness of 1.
When expressed in terms of optical thickness, Schwarzschild's equation becomes:
After integrating between a sensor located at and an arbitrary starting point in the medium, , the spectral intensity of the radiation reaching the sensor, , is:
where {{math|I(τ''')}} is the spectral intensity of the radiation at the beginning of the path, is the transmittance along the path, and the final term is the sum of all of the emission along the path attenuated by absorption along the path yet to be traveled.
Relationship to Planck's and Beer's laws
Both Beer's Law and Planck's Law can be derived from Schwarzschild's equation. In a sense, they are corollaries of Schwarzschild's equation.
When the spectral intensity of radiation is not changing as it passes through a medium, . In that situation, Schwarzschild's equation simplifies to Planck's law:
When , is negative and when , is positive. As a consequence, the intensity of radiation traveling through any medium is always approaching the blackbody intensity given by Planck's law and the local temperature. The rate of approach depends on the density of absorbing/emitting molecules () and their absorption cross-section ().
When the intensity of the incoming radiation, , is much greater than the intensity of blackbody radiation, , the emission term can be neglected. This is usually the case when working with a laboratory spectrophotometer, where the sample is near 300 K and the light source is a filament at several thousand K.
If the medium is homogeneous, doesn't vary with location. Integration over a path of length affords the form of Beer's Law used most often in the laboratory experiments:
Application to Climate Science
'If no other fluxes change, the law of conservation of energy demands that the Earth warm (from one steady state to another) until balance is restored between inward and outward fluxes. Schwarzschild's equation alone says nothing about how much warming would be required to restore balance. When meteorologists and climate scientists refer to "radiative transfer calculations" or "radiative transfer equations" (RTE), the phenomena of emission and absorption are handled by numerical integration of Schwarzschild's equation over a path through the atmosphere. Weather forecasting models and climate models use versions of Schwarzschild's equation optimized to minimize computation time. Online programs are available that perform computations using Schwarzschild's equation.
Schwarzschild's equation is used to calculate the outward radiative flux from the Earth (measured in W/m2 perpendicular to the surface) at any altitude, especially the "top of the atmosphere" or TOA. This flux originates at the surface () for clear skies or cloud tops. increments are calculated for layers thin enough to be effectively homogeneous in composition and flux (). These increments are numerically integrated from the surface to the TOA to give the flux of thermal infrared to space, commonly referred to as outgoing long-wavelength radiation (OLR). OLR is the only mechanism by which the Earth gets rid of the heat delivered continuously by the sun. The net downward radiative flux of thermal IR (DLR) produced by emission from GHGs in the atmosphere is obtained by integrating dI from the TOA (where I0 is zero) to the surface. DLR adds to the energy from the sun. Emission from each layer adds equally to the upward and downward fluxes. In contrast, different amounts of radiation are absorbed, because the upward flux entering any layer is usually greater than the downward flux.
In "line-by-line" methods, the change in spectral intensity (, W/sr/m2/μm) is numerically integrated using a wavelength increment small enough (less than 1 nm) to accurately describe the shape of each absorption line. The HITRAN database contains the parameters needed to describe 7.4 million absorption lines for 47 GHGs and 120 isotopologues. A variety of programs or radiative transfer codes can be used to process this data, including an online facility, SpectralCalc. To reduce the computational demand, weather forecast and climate models use broad-band methods that handle many lines as a single "band". MODTRAN is a broad-band method available online with a simple interface that anyone can use.
To convert intensity [W/sr/m2] to flux [W/m2], calculations usually invoke the "two-stream" and "plane parallel" approximations. The radiative flux is decomposed into three components, upward (+z), downward (-z), and parallel to the surface. This third component contributes nothing to heating or cooling the planet. , where is the zenith angle (away from vertical). Then the upward and downward intensities are integrated over a forward hemisphere, a process that can be simplified by using a "diffusivity factor" or "average effective zenith angle" of 53°. Alternatively, one can integrate over all possible paths from the entire surface to a sensor positioned a specified height above surface for OLR, or over all possible paths from the TOA to a sensor on the surface for DLR.
Greenhouse Effect
Schwarzschild's equation provides a simple explanation for the existence of the greenhouse effect and demonstrates that it requires a non-zero lapse rate. Rising air in the atmosphere expands and cools as the pressure on it falls, producing a negative temperature gradient in the Earth's troposphere. When radiation travels upward through falling temperature, the incoming radiation, I, (emitted by the warmer surface or by GHGs at lower altitudes) is more intense than that emitted locally by . is generally less than zero throughout the troposphere, and the intensity of outward radiation decreases as it travels upward. According to Schwarzschild's equation, the rate of fall in outward intensity is proportional to the density of GHGs () in the atmosphere and their absorption cross-sections (). Any anthropogenic increase in GHGs will slow down the rate of radiative cooling to space, i.e. produce a radiative forcing until a saturation point is reached.
At steady state, incoming and outgoing radiation at the top of the atmosphere (TOA) must be equal. When the presence of GHGs in the atmosphere causes outward radiation to decrease with altitude, then the surface must be warmer than it would be without GHGs - assuming nothing else changed. Some scientists quantify the greenhouse effect as the 150 W/m2 difference between the average outward flux of thermal IR from the surface (390 W/m2) and the average outward flux at the TOA.
If the Earth had an isothermal atmosphere, Schwarzschild's equation predicts that there would be no greenhouse effect or no enhancement of the greenhouse effect by rising GHGs. In fact, the troposphere over the Antarctic plateau is nearly isothermal. Both observations and calculations show a slight "negative greenhouse effect" – more radiation emitted from the TOA than the surface. Although records are limited, the central Antarctic Plateau has seen little or no warming.
Saturation
In the absence of thermal emission, wavelengths that are strongly absorbed by GHGs can be significantly attenuated within 10 m in the lower atmosphere. Those same wavelengths, however, are the ones where emission is also strongest. In an extreme case, roughly 90% of 667.5 cm−1 photons are absorbed within 1 meter by 400 ppm of CO2 at surface density, but they are replaced by emission of an equal number of 667.5 cm−1 photons. The radiation field thereby maintains the blackbody intensity appropriate for the local temperature. At equilibrium, and therefore even when the density of the GHG (n) increases.
This has led some to falsely believe that Schwarzschild's equation predicts no radiative forcing at wavelengths where absorption is "saturated". However, such reasoning reflects what some refer to as the surface budget fallacy. This fallacy involves reaching erroneous conclusions by focusing on energy exchange near the planetary surface rather than at the top of the atmosphere (TOA). At wavelengths where absorption is saturated, increasing the concentration of a greenhouse gas does not change thermal radiation levels at low altitudes, but there are still important differences at high altitudes where the air is thinner.
As density decreases with altitude, even the strongest absorption bands eventually become semi-transparent. Once that happens, radiation can travel far enough that the local emission, , can differ from the absorption of incoming . The altitude where the transition to semi-transparency occurs is referred to as the "effective emission altitude" or "effective radiating level." Thermal radiation from this altitude is able to escape to space. Consequently, the temperature at this level sets the intensity of outgoing longwave radiation. This altitude varies depending on the particular wavelength involved.
Increasing concentration increases the "effective emission altitude" at which emitted thermal radiation is able to escape to space. The lapse rate (change in temperature with altitude) at the effective radiating level determines how a change in concentration will affect outgoing emissions to space. For most wavelengths, this level is in the troposphere, where temperatures decrease with increasing altitude. This means that increasing concentrations of greenhouse gas lead to decreasing emissions to space (a positive incremental greenhouse effect), creating an energy imbalance that makes the planet warmer than it would be otherwise. Thus, the presence or absence of absorption saturation at low altitudes does not necessarily indicate that absence of radiative forcing in response to increased concentrations.
The radiative forcing from doubling carbon dioxide occurs mostly on the flanks of the strongest absorption band.
Temperature rises with altitude in the lower stratosphere, and increasing there increases radiative cooling to space and is predicted by some to cause cooling above 14–20 km.
References
Radiometry | Schwarzschild's equation for radiative transfer | [
"Engineering"
] | 3,884 | [
"Telecommunications engineering",
"Radiometry"
] |
58,520,089 | https://en.wikipedia.org/wiki/Vivo%20NEX | The Vivo NEX (also known as the Vivo NEX S) is an Android smartphone that features a different design from traditional smartphones, as it has a mechanical pop-up camera.
References
Android (operating system) devices
NEX
Chinese brands
Mobile phones introduced in 2018
Phablets
Mobile phones with multiple rear cameras
Mobile phones with 4K video recording
Discontinued smartphones | Vivo NEX | [
"Technology"
] | 75 | [
"Crossover devices",
"Mobile technology stubs",
"Phablets",
"Mobile phone stubs"
] |
58,520,836 | https://en.wikipedia.org/wiki/Cylinder%20Head%20Temperature%20gauge | A Cylinder Head Temperature gauge (CHT) measures the cylinder head temperature of an engine. Commonly used on air-cooled engines, the head temperature gauge displays the work that the engine is performing more quickly than an oil or water temperature gauge. As the engine works at high speed or uphill, head temperature will increase quickly. The meter can be digital or analog.
An air-cooled engine requires a steady flow of air for cooling. Most air-cooled engines have thermostats controlling air doors or flaps to help the engine reach operating temperature as quickly as possible. Any failure of the cooling system will cause engine failure via scuffed piston skirts. Air-cooled engines are used in aircraft engine control and other air-cooled engines as in cars and air-cooled motorcycles.
The CHT sender usually has a K-type thermocouple that is mounted under the spark plug. The K-type thermocouple is a pair of two dissimilar metals that produce a small voltage signal when heated. The metal closest to the spark plug is called the hot junction and the other, closest to the head, the cold junction. The ring under the spark plug is used to transfer the heat from the plug to the thermocouple. The gauge and cold junction are usually calibrated at room temperature, . Because the thermocouple is calibrated for room temperature, the gauge readings will only be 100% accurate at that engine compartment temperature. If the engine compartment temperature is colder, the CHT temperature will display higher. If the engine compartment temperature is higher, the reading will be lower. The error can be corrected with a cold-junction compensating thermistor, which measures the temperature at the cold junction so the gauge can adjust the reading. Low budget gauges do not have this compensating thermistor.
See also
Timeline of motor and engine technology
Timeline of heat engine technology
Engine cooling
References
P V Lamarque, "The design of cooling fins for Motor-Cycle Engines". Report of the Automobile Research Committee, Institution of Automobile Engineers Magazine, March 1943 issue, and also in "The Institution of Automobile Engineers. Proceedings XXXVII, Session 1942-1943, pp 99-134 and 309-312.
Julius Mackerle, "Air-cooled Automotive Engines", Charles Griffin & Company Ltd., London 1972.
P V Lamarque, "The design of cooling fins for Motor-Cycle Engines". Report of the Automobile Research Committee, Institution of Automobile Engineers Magazine, March 1943 issue, and also in "The Institution of Automobile Engineers. Proceedings XXXVII, Session 1942-1943, pp 99-134 and 309-312.
Julius Mackerle, "Air-cooled Automotive Engines", Charles Griffin & Company Ltd., London 1972.
Engine technology
Engine sensors | Cylinder Head Temperature gauge | [
"Technology"
] | 579 | [
"Engine technology",
"Engines"
] |
58,520,946 | https://en.wikipedia.org/wiki/Theory%20of%20Computing%20Systems | Theory of Computing Systems is a peer-reviewed scientific journal published by Springer Verlag.
Published since 1967 as Mathematical Systems Theory and since volume 30 in 1997 under its current title, it is devoted to publishing original research from all areas of theoretical computer science, such as computational complexity, algorithms and data structures, or parallel and distributed algorithms and architectures. It is published 8 times per year since 2018, although the frequency varied in the past.
References
External links
Computer science journals
Theoretical computer science
Springer Science+Business Media academic journals
8 times per year journals | Theory of Computing Systems | [
"Mathematics"
] | 109 | [
"Theoretical computer science",
"Applied mathematics"
] |
58,522,731 | https://en.wikipedia.org/wiki/Technical%20and%20Industrial%20Cultural%20Heritage%20in%20Norway | Technical and Industrial Cultural Heritage in Norway encompasses discontinued industrial and other facilities with great historical and architectural value. It is one of the ten conservation programs for the Norwegian Directorate for Cultural Heritage, which seeks to refurbish and preserve a representative range of facilities linked to Norway's most important industrial routes, which has had a significant impact on local business history.
Directorate for Cultural Heritage priority list
The Norwegian Directorate for Cultural Heritage list of priority technical and industrial cultural heritage comprises 15 facilities:
Atlungstad Distillery
Bredalsholmen Shipyards
Bratteklev Shipyard
Fetsund Booms
Folldal Mines
Halden Canal
Kistefos Wood Pulp Mill
Klevfos Cellulose and Paper Factory
Neptune Herring Oil Factory
Næs Ironworks
Odda Smelting Plant
Rjukan Line
Salhus Knitting Mill
Sjølingstad Woolen Mill
Spillum Sawmill and Planing
Tyssedal Hydroelectric Power Station
References
External links
Protection Program for Technical and Industrial Cultural Heritage at the Norwegian Directorate for Cultural Heritage website
Technical and Industrial Cultural Heritage at the Norwegian Environment Agency website
Cultural heritage of Norway
History of technology | Technical and Industrial Cultural Heritage in Norway | [
"Technology"
] | 221 | [
"Science and technology studies",
"History of science and technology",
"History of technology"
] |
58,522,784 | https://en.wikipedia.org/wiki/History%20of%20computing%20in%20South%20America | Computing started in south America in 1957, when the first digital computer arrived in Chile. 1979, the Centro Latinoamericano de Estudios en Informática was established in Caracas, Venezuela. During the 1980s, most Latin American universities incorporated computer programs. By the 1990s the research output in computing began to be significant.
20th century
In 1957, the first digital computer arrived in Chile after the CCU purchased a Univac to be delivered to Valparaiso. The machine was one of the first documented cases in the history of computer science in South America. Among the first computers in Latin America was also the system installed in the Venezuelan offices of the Creole Petroleum Corporation, the initiative becoming a launching pad for computer development in the nation state.
In 1972 Brazil implemented a policy innovation strategy to encourage the economic development of the Brazilian computer industry. This policy project served as a blueprint for policy initiatives across the Latin American continent. The Brazilian government established the CAPRE (Comissao de Coordenacao das Atividades de processamento Eletronico) as division of the planning ministry to review the use of all electronic resources by the government. In 1974 CAPRE was constituted as a regulator so that all imports of computers and electronic components were restrained or approved. In the first ten years this strategy showed remarkable success. In 1982 about 67 percent of installed computers in Brazil had been manufactured locally. Brazil's domestic computer industry was able to take significant shares of the local market from IBM, the Burroughs Corporation, and Hewlett-Packard. In 1986 the government of Argentina signed an integration treaty with the government of Brazil, were informatics was a paramount branch of cooperation.
Also in the early 1970s, the short-lived administration of Salvador Allende implemented Project Cybersyn in Chile. Cybersyn consisted of a Cybernet, which was a network of 500 telex machines and planned to connect every factory in the nationalized socialist economy. At the heart of Cybersyn were two computers, a IBM System/360 Model 50 and a Burroughs B3500, on which the program Cyberstride was running. Today Project Cybersyn is remembered for its unique implementation of socialism and the futuristic industrial design.
21st century
The Free Software Foundation Latin America exists to promote the use of free software in Latin America. In 2009, FSF founder Richard Stallman visited Buenos Aires during the concurrent Wikimania 2009 conference in order to promote free software. Stallman regularly gives speeches in Spanish and has visited Latin America multiples times since 2009.
In 2005, the Chilean government alongside the private IT sector started a program called "Mi Primer PC", with the idea of bringing low-cost PC to the general population. The program was heavily criticized at the time, mainly due to the fact that the computers offered were severely limited due to the usage of Windows XP Starter Edition. This program is not related to the similarly called "Yo Elijo Mi PC" program, put in place during the presidency of Michelle Bachelet which aims to bring computers to primary school students in lower socio-economical classes.
Since February 2014 Venezuela and Argentina are cooperating to develop their respective Linux operating systems. The Huayra GNU/Linux operating system was launched by Argentina in 2014 to be used on laptops that are distributed to schools. The Canaima operating system runs on 51% of government workstations in Venezuela.
In 2015, Google announced that they would invest US$1 million in computer science in Latin America.Amazon has major telescopes in Chile.
See also
History of computing hardware
History of South America
References | History of computing in South America | [
"Technology"
] | 724 | [
"History of computing in South America",
"History of computing"
] |
58,522,924 | https://en.wikipedia.org/wiki/List%20of%20oldest%20minarets | This article lists some but by no means all of the oldest known minaret towers in the world.
The oldest minaret still surviving is that of the Great Mosque of Kairouan in Tunisia. It was constructed in 836 AD and is considered as the prototype for all the square shaped minarets built in the Western Muslim World.
Most ancient, surviving minarets were constructed adjacent to a mosque, for the Muslim call to prayer (Adhan) five times each day by a muezzin (crier). A few minarets were built as watchtowers, landmarks or symbols of victory or glory of a Muslim Khanate or empire. In some instances, like the Minaret of Jam only the minaret tower survives today while the adjoining mosques and other structures were destroyed over time by nature and invaders.
List of oldest minarets
This list ranks the oldest surviving minarets in the world. Only minarets built before 1900 AD. are included.
See also
Minaret
List of tallest minarets
List of tallest mosques
List of the oldest mosques
References
Religion-related lists of superlatives
Mosques, oldest
Mosques, oldest
minarets | List of oldest minarets | [
"Engineering"
] | 235 | [
"Structural engineering",
"Towers"
] |
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