text
stringlengths 2
132k
| source
dict |
|---|---|
Maria Dornelas FRSE is a researcher in biodiversity and professor of biology based at St. Andrew's University. She was made a Fellow of the Royal Society of Edinburgh in 2021. Her research into biodiversity change has challenged previous views, on the growth and decline of coral reefs to understanding global biodiversity with data analysis on how species or ecosystems are changing in the Anthropocene. == Education and career == Maria Ana Azeredo de Dornelas completed her BSc at the University of Lisbon, graduating in 2000, and then a doctorate in the School of Marine Biology, studying 'biodiversity patterns in the context of neutral theory at James Cook University in Queensland, Australia in 2006. Her research challenged the orthodoxy of how coral reefs developed and died off. It was published in Nature and called ' a paper that will turn our attention in a completely new direction' by Dr John Pandolfi of the University of Queensland. After her postdoctoral fellowship, in 2012 she became a Lecturer, then Reader, now Professor, in the Centre for Biological Diversity of the School of Biology at University of St Andrews. She was external examiner for University College London on 'Predicting population trends under environmental change: comparing methods against observed data'. She is a visiting professor in the School of Geosciences at the University of Edinburgh. Her interest in the ecology of the tropical areas, and coral in particular grew during her undergraduate honours project in Mozambique. Her fellowship included working with the University of Aveiro and the ARC Centre of Excellence Coral Reef Studies on 'morphological and life history diversity of corals' (2008-9). When not focused on biodiversity change, macroecology or reef ecology, her research also looked into Trinidadian guppies, in considering polyandry in fish. == Selected publications == Dornelas's key published works are listed
|
{
"page_id": 68686049,
"source": null,
"title": "Maria Dornelas"
}
|
by the University of St Andrews. She compiled and standardised a database of publicly available timeseries, which is the basis of the BioTIME project. Her funded project from the Leverhulme Trust (2019-2029) is generating datasets, and cross-discipline collaborations. Citations can be found in Google Scholar == Biodiversity debates == Dornelas has engaged in a number of public outreach events such as talking to the British Ecological Society on 'Is biodiversity declining?' She was a member of the Young Academy of Scotland, and was positively debating the future of higher education and its resilience in 2020 during the COVID-19 pandemic. In 2020 Dornelas contributed to the World Economic Forum discussion on How forest loss has changed biodiversity across the globe over the last 150 years. And her collaborative work, published in Nature in 2020 has contributed to debate on vertebrate species decline, for example in a Living Planet Report, showing that average declines in populations do not reflect some rapidly declining species at risk. She has been made a Fellow of the Royal Society of Edinburgh in 2021. == References == == External links == Maria Dornelas publications indexed by Google Scholar
|
{
"page_id": 68686049,
"source": null,
"title": "Maria Dornelas"
}
|
In biology, the canopy is the aboveground portion of a plant cropping or crop, formed by the collection of individual plant crowns. In forest ecology, the canopy is the upper layer or habitat zone, formed by mature tree crowns and including other biological organisms (epiphytes, lianas, arboreal animals, etc.). The communities that inhabit the canopy layer are thought to be involved in maintaining forest diversity, resilience, and functioning. Shade trees normally have a dense canopy that blocks light from lower growing plants. Early observations of canopies were made from the ground using binoculars or by examining fallen material. Researchers would sometimes erroneously rely on extrapolation by using more reachable samples taken from the understory. In some cases, they would use unconventional methods such as chairs suspended on vines or hot-air dirigibles, among others. Modern technology, including adapted mountaineering gear, has made canopy observation significantly easier and more accurate, allowed for longer and more collaborative work, and broaddened the scope of canopy study. == Structure == Canopy structure is the organization or spatial arrangement (three-dimensional geometry) of a plant canopy. Leaf area index, leaf area per unit ground area, is a key measure used to understand and compare plant canopies. The canopy is taller than the understory layer. The canopy holds 90% of the animals in the rainforest. Canopies can cover vast distances and appear to be unbroken when observed from an airplane. However, despite overlapping tree branches, rainforest canopy trees rarely touch each other. Rather, they are usually separated by a few feet. Dominant and co-dominant canopy trees form the uneven canopy layer. Canopy trees are able to photosynthesize relatively rapidly with abundant light, so it supports the majority of primary productivity in forests. The canopy layer provides protection from strong winds and storms while also intercepting sunlight and precipitation,
|
{
"page_id": 2953441,
"source": null,
"title": "Canopy (biology)"
}
|
leading to a relatively sparsely vegetated understory layer. Forest canopies are home to unique flora and fauna not found in other layers of forests. The highest terrestrial biodiversity resides in the canopies of tropical rainforests. Many rainforest animals have evolved to live solely in the canopy and never touch the ground. The canopy of a rainforest is typically about 10 m thick, and intercepts around 95% of sunlight. The canopy is below the emergent layer, a sparse layer of very tall trees, typically one or two per hectare. With an abundance of water and a near ideal temperature in rainforests, light and nutrients are two factors that limit tree growth from the understory to the canopy. In the permaculture and forest gardening community, the canopy is the highest of seven layers. == Ecology == Forest canopies have unique structural and ecological complexities and are important for the forest ecosystem. They are involved in critical functions such as rainfall interception, light absorption, nutrient and energy cycling, gas exchange, and providing habitat for diverse wildlife. The canopy also plays a role in modifying the internal environment of the forest by acting as a buffer for incoming light, wind, and temperature fluctuations. The forest canopy layer supports a diverse range of flora and fauna. It has been dubbed "the last biotic frontier" as it provides a habitat that has allowed for the evolution of countless species of plants, microorganisms, invertebrates (e.g., insects), and vertebrates (e.g., birds and mammals) that are unique to the upper layer of forests. Forest canopies are arguably considered some of the most species-rich environments on the planet. It is believed that the communities found within the canopy layer play an essential role in the functioning of the forest, as well as maintaining diversity and ecological resilience. === Climate regulation
|
{
"page_id": 2953441,
"source": null,
"title": "Canopy (biology)"
}
|
=== Forest canopies are significantly involved in maintaining the stability of the global climate. They are responsible for at least half of the global carbon dioxide exchange between terrestrial ecosystems and the atmosphere. Forest canopies act as carbon sinks, reducing the increase of atmospheric CO2 caused by human activity. The destruction of forest canopies would lead to the release of carbon dioxide, resulting in an increased concentration of atmospheric CO2. This would then contribute to the greenhouse effect, thereby causing the planet to become warmer. === Canopy interception === == See also == == References == == Further reading == Lowman, Margaret D.; Nadkarni, Nalini M., eds. (1995). Forest Canopies (First ed.). Academic Press. ISBN 978-0124576506. LCCN 94041251. Moffett, Mark W. (1994). The High Frontier: Exploring the Tropical Rainforest Canopy. Harvard University Press. ISBN 978-0674390386. LCCN 93016935. Russell, Graham; Marshall, Bruce; Jarvis, PaulG., eds. (1989). Plant Canopies: Their Growth, Form and Function. Cambridge University Press. doi:10.1017/CBO9780511752308.002. ISBN 978-0-521-39563-2. LCCN 87032902. Jucker, Tommaso; et al. (23 September 2018). "Canopy structure and topography jointly constrain the microclimate of human‐modified tropical landscapes". Global Change Biology. 24 (11): 5243–5258. Bibcode:2018GCBio..24.5243J. doi:10.1111/gcb.14415. hdl:10044/1/63016. PMID 30246358. == External links == International Canopy Access Network
|
{
"page_id": 2953441,
"source": null,
"title": "Canopy (biology)"
}
|
The octet rule is a chemical rule of thumb that reflects the theory that main-group elements tend to bond in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas. The rule is especially applicable to carbon, nitrogen, oxygen, and the halogens; although more generally the rule is applicable for the s-block and p-block of the periodic table. Other rules exist for other elements, such as the duplet rule for hydrogen and helium, and the 18-electron rule for transition metals. The valence electrons in molecules like carbon dioxide (CO₂) can be visualized using a Lewis electron dot diagram. In covalent bonds, electrons shared between two atoms are counted toward the octet of both atoms. In carbon dioxide each oxygen shares four electrons with the central carbon, two (shown in red) from the oxygen itself and two (shown in black) from the carbon. All four of these electrons are counted in both the carbon octet and the oxygen octet, so that both atoms are considered to obey the octet rule. == Example: sodium chloride (NaCl) == The octet rule is simplest in the case of ionic bonding between two atoms, one a metal of low electronegativity and the other a nonmetal of high electronegativity. For example, sodium metal and chlorine gas combine to form sodium chloride, a crystal lattice composed of alternating sodium and chlorine nuclei. Electron density inside this lattice forms clumps at the atomic scale, as follows. An isolated chlorine atom (Cl) has two and eight electrons in its first and second electron shells, located near the nucleus. However, it has only seven electrons in the third and outermost electron shell. One additional electron would completely fill the outer electron shell with eight electrons, a situation
|
{
"page_id": 266466,
"source": null,
"title": "Octet rule"
}
|
the octet rule commends. Indeed, adding an electron to the produce the chloride ion (Cl−) releases 3.62 eV of energy. Conversely, another surplus electron cannot fit in the same shell, instead beginning the fourth electron shell around the nucleus. Thus the octet rule proscribes formation of a hypothetical Cl2− ion, and indeed the latter has only been observed as a plasma under extreme conditions. A sodium atom (Na) has a single electron in its outermost electron shell, the first and second shells again being full with two and eight electrons respectively. The octet rule favors removal of this outermost electron to form the Na+ ion, which has the exact same electron configuration as Cl−. Indeed, sodium is observed to transfer one electron to chlorine during the formation of sodium chloride, such that the resulting lattice is best considered as a periodic array of Na+ and Cl− ions. To remove the outermost Na electron and return to an "octet-approved" state requires a small amount of energy: 5.14 eV. This energy is provided from the 3.62 eV released during chloride formation, and the electrostatic attraction between positively-charged Na+ and negatively-charged Cl− ions, which releases a 8.12 eV lattice energy. By contrast, any further electrons removed from Na would reside in the deeper second electron shell, and produce an octet-violating Na2+ ion. Consequently, the second ionization energy required for the next removal is much larger — 47.28 eV — and the corresponding ion is only observed under extreme conditions. == History == In 1864, the English chemist John Newlands classified the sixty-two known elements into eight groups, based on their physical properties. In the late 19th century, it was known that coordination compounds (formerly called "molecular compounds") were formed by the combination of atoms or molecules in such a manner that the valencies
|
{
"page_id": 266466,
"source": null,
"title": "Octet rule"
}
|
of the atoms involved apparently became satisfied. In 1893, Alfred Werner showed that the number of atoms or groups associated with a central atom (the "coordination number") is often 4 or 6; other coordination numbers up to a maximum of 8 were known, but less frequent. In 1904, Richard Abegg was one of the first to extend the concept of coordination number to a concept of valence in which he distinguished atoms as electron donors or acceptors, leading to positive and negative valence states that greatly resemble the modern concept of oxidation states. Abegg noted that the difference between the maximum positive and negative valences of an element under his model is frequently eight. In 1916, Gilbert N. Lewis referred to this insight as Abegg's rule and used it to help formulate his cubical atom model and the "rule of eight", which began to distinguish between valence and valence electrons. In 1919, Irving Langmuir refined these concepts further and renamed them the "cubical octet atom" and "octet theory". The "octet theory" evolved into what is now known as the "octet rule". Walther Kossel and Gilbert N. Lewis saw that noble gases did not have the tendency of taking part in chemical reactions under ordinary conditions. On the basis of this observation, they concluded that atoms of noble gases are stable and on the basis of this conclusion they proposed a theory of valency known as "electronic theory of valency" in 1916: During the formation of a chemical bond, atoms combine together by gaining, losing or sharing electrons in such a way that they acquire nearest noble gas configuration. == Explanation in quantum theory == The quantum theory of the atom explains the eight electrons as a closed shell with an s2p6 electron configuration. A closed-shell configuration is one in which
|
{
"page_id": 266466,
"source": null,
"title": "Octet rule"
}
|
low-lying energy levels are full and higher energy levels are empty. For example, the neon atom ground state has a full n = 2 shell (2s22p6) and an empty n = 3 shell. According to the octet rule, the atoms immediately before and after neon in the periodic table (i.e. C, N, O, F, Na, Mg and Al), tend to attain a similar configuration by gaining, losing, or sharing electrons. The argon atom has an analogous 3s23p6 configuration. There is also an empty 3d level, but it is at considerably higher energy than 3s and 3p (unlike in the hydrogen atom), so that 3s23p6 is still considered a closed shell for chemical purposes. The atoms immediately before and after argon tend to attain this configuration in compounds. There are, however, some hypervalent molecules in which the 3d level may play a part in the bonding, although this is controversial (see below). For helium there is no 1p level according to the quantum theory, so that 1s2 is a closed shell with no p electrons. The atoms before and after helium (H and Li) follow a duet rule and tend to have the same 1s2 configuration as helium. == Exceptions == Many reactive intermediates do not obey the octet rule. Most are unstable, although some can be isolated. Typically, octet rule violations occur in either low-dimensional coordination geometries or in radical species. Although hypervalent molecules are commonly taught to violate the octet rule, ab initio calculations show that almost all known examples obey the octet rule. The compounds form many fractional bonds through resonance (see § Hypervalent molecules below). === Low-dimensional geometries === In the trigonal planar coordination geometry, one p orbital points out of the bonding plane, and can only overlap with nearby atomic orbitals in a π bond. If
|
{
"page_id": 266466,
"source": null,
"title": "Octet rule"
}
|
that p orbital would be empty in an isolated atom, it may be filled through an intramolecular dative bond, as with aminoboranes. However, in some cases (e.g. boron trichloride and various boranes, triphenylmethanium), no nearby filled orbital can profitably overlap with the empty p orbital. In such cases, the orbital remains empty, and the compound obeys a "sextet rule". Likewise, linear compounds, such as dimethylzinc, have two p orbitals perpendicular to the bonding axis, and may obey a "quartet rule". In either case, the empty unshielded orbitals tend to attract adducts. === Radicals === Radicals satisfy the octet rule in one spin orientation, with four spin-up electrons in the valence shell, and almost satisfy it in the opposite spin orientation. Thus, for example, the methyl radical (CH3), which has an unpaired electron in a non-bonding orbital on the carbon atom and no electron of opposite spin in the same orbital. Another example is the radical chlorine monoxide (ClO•) which is involved in ozone depletion. Stable radicals tend to adopt states in which the unpaired electron can delocalize through resonance. In such cases, the octet rule can be restored through the formalism of a 1- or 3-electron bond. Species such as carbenes can be interpreted two different ways, depending on their spin state. Triplet carbenes are best thought of as two radicals localized on the same atom, and obey the octet rule in those radicals' shared spin-up orientation. Singlet carbenes tend to adopt a planar configuration, and are best thought of as obeying the planar sextet rule. == Hypervalent molecules == Main-group elements in the third and later rows of the periodic table can form hypercoordinate or hypervalent molecules in which the central main-group atom is bonded to more than four other atoms, such as phosphorus pentafluoride, PF5, and sulfur hexafluoride,
|
{
"page_id": 266466,
"source": null,
"title": "Octet rule"
}
|
SF6. For example, in PF5, if it is supposed that there are five true covalent bonds in which five distinct electron pairs are shared, then the phosphorus would be surrounded by 10 valence electrons in violation of the octet rule. In the early days of quantum mechanics, Pauling proposed that third-row atoms can form five bonds by using one s, three p and one d orbitals, or six bonds by using one s, three p and two d orbitals. To form five bonds, the one s, three p and one d orbitals combine to form five sp3d hybrid orbitals which each share an electron pair with a halogen atom, for a total of 10 shared electrons, two more than the octet rule predicts. Similarly to form six bonds, the six sp3d2 hybrid orbitals form six bonds with 12 shared electrons. In this model the availability of empty d orbitals is used to explain the fact that third-row atoms such as phosphorus and sulfur can form more than four covalent bonds, whereas second-row atoms such as nitrogen and oxygen are strictly limited by the octet rule. However other models describe the bonding using only s and p orbitals in agreement with the octet rule. A valence bond description of PF5 uses resonance between different PF4+ F− structures, so that each F is bonded by a covalent bond in four structures and an ionic bond in one structure. Each resonance structure has eight valence electrons on P. A molecular orbital theory description considers the highest occupied molecular orbital to be a non-bonding orbital localized on the five fluorine atoms, in addition to four occupied bonding orbitals, so again there are only eight valence electrons on the phosphorus. The validity of the octet rule for hypervalent molecules is further supported by ab initio
|
{
"page_id": 266466,
"source": null,
"title": "Octet rule"
}
|
molecular orbital calculations, which show that the contribution of d functions to the bonding orbitals is small. Nevertheless, for historical reasons, structures implying more than eight electrons around elements like P, S, Se, or I are still common in textbooks and research articles. In spite of the unimportance of d shell expansion in chemical bonding, this practice allows structures to be shown without using a large number of formal charges or using partial bonds and is recommended by the IUPAC as a convenient formalism in preference to depictions that better reflect the bonding. On the other hand, showing more than eight electrons around Be, B, C, N, O, or F (or more than two around H, He, or Li) is considered an error by most authorities. == Other rules == The octet rule is only applicable to main-group elements. Other elements follow other electron counting rules as their valence electron configurations are different from main-group elements. These other rules are shown below: The duet rule or duplet rule of the first shell applies to H, He and Li—the noble gas helium has two electrons in its outer shell, which is very stable. (Since there is no 1p subshell, 1s is followed immediately by 2s, and thus shell 1 can only have at most 2 valence electrons). Hydrogen only needs one additional electron to attain this stable configuration, while lithium needs to lose one. For transition metals, molecules tend to obey the 18-electron rule which corresponds to the utilization of valence d, s and p orbitals to form bonding and non-bonding orbitals. However, unlike the octet rule for main-group elements, transition metals do not strictly obey the 18-electron rule and the valence electron count can vary between 12 and 18. == See also == Lewis structure Electron counting == References ==
|
{
"page_id": 266466,
"source": null,
"title": "Octet rule"
}
|
Llinás's law, or law of no interchangeability of neurons, is a statement in neuroscience made by Rodolfo Llinás in 1989, during his Luigi Galvani Award Lecture at the Fidia Research Foundation Neuroscience Award Lectures. A neuron of a given kind (e.g. a thalamic cell) cannot be functionally replaced by one of another type (e.g. an inferior ollivary cell) even if their synaptic connectivity and the type of neurotransmitter outputs are identical. (The difference is that the intrinsic electrophysiological properties of thalamic cells are extraordinarily different from those of inferior olivary neurons). The statement of this law is a consequence of an article written by Rodolfo Llinas himself in 1988 and published in Science with the title "The Intrinsic Electrophysiological Properties of Mammalian Neurons: Insights into Central Nervous System Function", which is considered a watershed due to its more than 2000 citations in the scientific literature, marking a major shift in viewpoint in neuroscience around the functional aspect. Until then, the prevailing belief in neuroscience was that just the connections and neurotransmitters released by neurons was enough to determine their function. Research by Llinás and colleagues during the 80's with vertebrates revealed this previously held dogma was wrong. == References ==
|
{
"page_id": 29167845,
"source": null,
"title": "Llinás's law"
}
|
Martha (Stone) Palmer is an American computer scientist. She is best known for her work on verb semantics, and for the creation of ontological resources such as PropBank and VerbNet. == Education == Palmer received a Master of Arts in Computer Science from University of Texas at Austin in 1976, advised by Robert Simmons. She received her PhD from the University of Edinburgh in 1985. Her thesis was titled "Driving semantics for a limited domain", and was advised by Alan Bundy. == Career == Palmer is currently a professor of computer science and linguistics at the University of Colorado Boulder. She was previously on the faculty of the University of Pennsylvania. === Awards and honors === Palmer served as president of the Association for Computational Linguistics in 2005 and was named an ACL Fellow in 2014 "for significant contributions to computational semantics and the development of semantic corpora". In 2017, she was awarded the Helen & Hubert Croft Professorship by the University of Colorado. In the same year, the university named her a "Professor of Distinction", a title reserved for professors who have received international recognition for their research. She was elected an AAAI Fellow in 2020 "for significant contributions to natural language processing and knowledge representation, including widely-used corpora of annotated structures in several languages". In 2023, she was awarded the ACL Lifetime achievement award, the highest distinction by the Association for Computational Linguistics, for her lifetime work on verb semantics. == References == == External links == Martha Palmer's home page
|
{
"page_id": 60231910,
"source": null,
"title": "Martha Palmer"
}
|
This is a list of organizations involved in genetics research. == Africa == === Kenya === International Livestock Research Institute (ILRI), Nairobi === Namibia === The Life Technologies Conservation Genetics Laboratory (Cheetah Conservation Fund), Otjiwarongo == Asia == === Malaysia === Malaysian Genomics Resource Centre (MGRC) Genetics & Regenerative Medicine Research Centre (GRMRC) Malaysia Genome and Vaccine Institute (MGVI) Medical Genetics Unit, Universiti Putra Malaysia === Pakistan === IBGE Institute of Biomedical and Genetic Engineering === China === BGI Group Chinese National Human Genome Center === India === Institute of Genomics and Integrative Biology DNA Labs India National Institute of Biomedical Genomics === Iran === Royan Institute === Philippines === Philippine Genome Center International Rice Research Institute === Singapore === Genome Institute of Singapore Institute of Molecular and Cell Biology === Taiwan === National Health Research Institutes === Japan === National Institute of Genetics Okinawa Institute of Science and Technology RIKEN === United Arab Emirates === DNA Labs UAE == Europe == === Germany === Max Planck Institute for Molecular Genetics === Italy === Bioversity International === Sweden === Science for Life Laboratory === United Kingdom === The Genome Analysis Centre Wellcome Sanger Institute Wellcome Centre for Human Genetics (University of Oxford) === Russia === Research Centre for Medical Genetics (RCMG), Moscow == North America == === Canada === The Centre for Applied Genomics (University of Toronto) === United States === Arizona Translational Genomics Research Institute California Arc Institute Clear Labs Genetic Information Research Institute Joint Genome Institute (U.S. Department of Energy) Salk Institute for Biological Studies Illinois Carl R. Woese Institute for Genomic Biology (University of Illinois, Urbana-Champaign) Maine The Jackson Laboratory Maryland Howard Hughes Medical Institute J. Craig Venter Institute Kennedy Krieger Institute National Human Genome Research Institute USC Institute Of Translational Genomics Massachusetts Broad Institute (Massachusetts Institute
|
{
"page_id": 987369,
"source": null,
"title": "List of genetics research organizations"
}
|
of Technology and Harvard University) Dana–Farber Cancer Institute Whitehead Institute for Biomedical Research (Massachusetts Institute of Technology) Missouri McDonnell Genome Institute (Washington University in St. Louis) New Mexico National Center for Genome Resources New York Cold Spring Harbor Laboratory Icahn Institute for Genomics and Multiscale Biology (Icahn School of Medicine) New York Genome Center International Society for Transgenic Technologies North Carolina Metabolon, Inc South Carolina Clemson Center for Human Genetics Greenwood Genetic Center Texas Human Genome Sequencing Center (Baylor College of Medicine) Utah ARUP Laboratories (University of Utah) Washington NW Genomics Center (University of Washington) == Oceania == === Australia === Australian Genomics Health Alliance Commonwealth Scientific and Industrial Research Organisation Garvan Institute of Medical Research == South America == === Brazil === Human Genome and Stem Cell Research Center (HUG-CELL), São Paulo == Genetic research watchdog organizations == GeneWatch, UK Council for Responsible Genetics, US Sunshine Project, Hamburg, Germany, and Austin, Texas
|
{
"page_id": 987369,
"source": null,
"title": "List of genetics research organizations"
}
|
Plant transformation vectors are plasmids that have been specifically designed to facilitate the generation of transgenic plants. The most commonly used plant transformation vectors are T-DNA binary vectors and are often replicated in both E. coli, a common lab bacterium, and Agrobacterium tumefaciens, a plant-virulent bacterium used to insert the recombinant DNA into plants. Plant transformation vectors contain three key elements: Plasmids Selection (creating a custom circular strand of DNA) Plasmids Replication (so that it can be easily worked with) Transfer DNA (T-DNA) region (inserting the DNA into the agrobacteria) == Steps in plant transformation == A custom DNA plasmid sequence can be created and replicated in various ways, but generally, all methods share the following processes: Plant transformation using plasmids begins with the propagation of the binary vector in E. coli. When the bacterial culture reaches the appropriate density, the binary vector is isolated and purified. Then, a foreign gene can be introduced. The engineered binary vector, including the foreign gene, is re-introduced in E. coli for amplification. The engineered binary factor is isolated from E. coli and is introduced into Agrobacteria containing a modified (relatively small) Ti plasmid. This engineered Agrobacteria can be used to infect plant cells. The T-DNA, which contains the foreign gene, becomes integrated into the plant cell genome. In each infected cell, the T-DNA is integrated at a different site in the genome. The entire plant will regenerate from a single transformed cell, resulting in an organism with the transformed DNA integrated identically across all cells. === Consequences of the insertion === Foreign DNA inserted Insertional mutagenesis (but not lethal for the plant cell – as the organism is diploid) Transformation DNA fed to rodents ends up in their phagocytes and rarely in other cells. Specifically, this refers to bacterial and M13 DNA. (This
|
{
"page_id": 12128493,
"source": null,
"title": "Plant transformation vector"
}
|
preferential accumulation in phagocytes is thought to be real and not a detection artefact since these DNA sequences are thought to provoke phagocytosis.) However, no gene expression is known to have resulted, and this is not thought to be possible. == Plasmid selection == A selector gene can be used to distinguish successfully genetically modified cells from unmodified ones. The selector gene is integrated into the plasmid along with the desired target gene, providing the cells with resistance to an antibiotic, such as kanamycin, ampicillin, spectinomycin or tetracycline. The desired cells, along with any other organisms growing within the culture, can be treated with an antibiotic, allowing only the modified cells to survive. The antibiotic gene is not usually transferred to the plant cell but instead remains within the bacterial cell. == Plasmids replication == Plasmids replicate to produce many plasmid molecules in each host bacterial cell. The number of copies of each plasmid in a bacterial cell is determined by the replication origin, which is the position within the plasmid molecule where DNA replication is initiated. Most binary vectors have a higher number of plasmid copies when they replicate in E. coli; however, the plasmid copy-number is usually lower when the plasmid is resident within Agrobacterium tumefaciens. Plasmids can also be replicated using the polymerase chain reaction (PCR). == T-DNA region == T-DNA contains two types of genes: the oncogenic genes, encoding for enzymes involved in the synthesis of auxins and cytokinins and responsible for tumor formation, and the genes encoding for the synthesis of opines. These compounds, produced by the condensation between amino acids and sugars, are synthesized and excreted by the crown gall cells, and they are consumed by A. tumefaciens as carbon and nitrogen sources. The genes involved in opine catabolism, T-DNA transfer from the bacterium
|
{
"page_id": 12128493,
"source": null,
"title": "Plant transformation vector"
}
|
to the plant cell and bacterium-bacterium plasmid conjugative transfer are located outside the T-DNA. The T-DNA fragment is flanked by 25-bp direct repeats, which act as a cis-element signal for the transfer apparatus. The process of T-DNA transfer is mediated by the cooperative action of proteins encoded by genes determined in the Ti plasmid virulence region (vir genes) and in the bacterial chromosome. The Ti plasmid also contains the genes for opine catabolism produced by the crown gall cells and regions for conjugative transfer and for its own integrity and stability. The 30 kb virulence (vir) region is a regulon organized in six operons essential for the T-DNA transfer (virA, virB, virD, and virG) or for the increasing of transfer efficiency (virC and virE). Several chromosomal-determined genetic elements have shown their functional role in the attachment of A. tumefaciens to the plant cell and bacterial colonization. The loci chvA and chvB are involved in the synthesis and excretion of the b -1,2 glucan, the chvE required for the sugar enhancement of vir genes induction and bacterial chemotaxis. The cell locus is responsible for the synthesis of cellulose fibrils. The pscA (exoC) locus is involved in the synthesis of both cyclic glucan and acid succinoglycan. The att locus is involved in the cell surface proteins. == References == Technical Focus:a guide to Agrobacterium binary Ti vectors Trends in Plant Science 5(10): 446-451 2000
|
{
"page_id": 12128493,
"source": null,
"title": "Plant transformation vector"
}
|
Amata cerbera, the heady maiden, is a moth of the subfamily Arctiinae. It was described by Carl Linnaeus in 1764. It has an extensive range in sub-Saharan Africa. == Range == It is found in Angola, the DRC, Gabon, Ghana, Guinea, Guinea-Bissau, Kenya, Malawi, Nigeria, Senegal, Sierra Leone, South Africa, Tanzania and Uganda. == Food plants == The larvae feed on Rumex, Corylus, Plantago and Rubus species, but have also been recorded feeding on various grasses (including Festuca and Anthoxanthum) as well as Thapsia, Taraxacum, Urtica and Sonchus species, and even hay and paper. == Description == Upperside: Antennae and head black. Thorax and abdomen shining blueish green; the latter having on the middle three rings of scarlet extending from side to side, but not meeting underneath. Anterior wings dark green, with six transparent spots like glass on them; the smallest, near the base, is round; three others, placed next the external margin, are oblong; the other two, which are in the middle, are oval and triangular. Posterior wings dark green, with two transparent spots; the largest next the shoulders; the other, which is round and small, beyond the middle. Underside: Breast, abdomen, and legs shining mazarine blue, inclining to green; on the former is a small red spot, close to the shoulders of the superior wings. The hinder legs have one joint white. Wings of the same colour as on the upper side. == Subspecies == Amata cerbera cerbera Amata cerbera hanningtoni (Seitz, 1926) – DRC, Malawi, Tanzania == References == == External links == Pitkin, Brian & Jenkins, Paul. "Search results Family: Arctiidae". Butterflies and Moths of the World. Natural History Museum, London. Bode, J. (2011). Amata cerbera mating, video of A. cerbera mating habits, taken near Darling, West Coast of South Africa, YouTube
|
{
"page_id": 41947383,
"source": null,
"title": "Amata cerbera"
}
|
In cell biology, a lymphokine-activated killer cell (also known as a LAK cell) is a white blood cell, consisting mostly of natural killer, natural killer T, and T cells that has been stimulated to kill tumor cells, but because of the function in which they activate, and the cells they can successfully target, they are classified as different than the classical natural killer and T lymphocyte systems. == Mechanism == It has been shown that when Peripheral blood leukocytes (PBL) are cultured in the presence of Interleukin 2, it results in the development of effector cells, which are cytotoxic and are seen to localize to tumor sites and are capable of lysing fresh, non-cultured cancer cells, both primary and metastatic. LAK cells respond to these lymphokines, particularly IL-2, by developing into effector cells capable of lysing tumor cells that are known to be resistant to NK cell activity. After stimulated by IL-2, LAK cells can target and kill tumor cells in the early innate response. The mechanism of LAK cells is distinctive from that of natural killer cell because they can lyse cells that an NK cell cannot. LAK cells are also capable of acting against cells that do not display the major histocompatibility complex, as has been shown by the ability to cause lysis in non-immunogenic, allogeneic and syngeneic tumors. LAK cells function in the same way as NK cells in the peripheral blood but are more sensitive to and can target tumor cells. == Cancer Treatment == The use of LAK cells has been found to be helpful in treating human cells with different cancers in vitro. LAK cell therapy is a method that uses interleukin 2 (IL-2) to enhance the number of lymphocytes in an in vitro setting, and it has formed the foundation of many immunotherapy
|
{
"page_id": 9900287,
"source": null,
"title": "Lymphokine-activated killer cell"
}
|
assays that are now in use. LAK cells have shown potential as a cellular agent for cancer therapy and have been utilized therapeutically in association with IL-2 for the treatment of various cancers. LAK cells have anticancer efficacy against homologous carcinoma cells and can grow ex vivo in the presence of IL-2. In melanoma and gastric cancer cells, intercellular adhesion molecule 1 (ICAM-1) antibody can significantly inhibit in vitro LAK-induced lysis of cancer cells. A study has shown that ICAM1 in lung cancer cells increases LAK cell-mediated tumor cell death as a new anti-tumor mechanism. One study uses a 4 hour chromium release assay, which is an assay used to measure the cytotoxicity of T cells and natural killer cells, to measure lysis of the fresh solid tumor cells from 10 cancer patients and found that in all 10 cancer patients the fresh autologous tumor cells were resistant to lysis by PBL with natural killer cells, but were lysed by the LAK cells. == Treatment Possible Side Effects == LAK cells, along with the administration of IL-2 have been experimentally used to treat cancer in mice and humans, but there is very high toxicity with this treatment - Severe fluid retention was the major side effect of therapy, although all side effects resolved after interleukin-2 administration was stopped. Treatment of IL-2 cells by themselves to treat cancers are more dangerous than treatment with the combination of IL-2 and LAK cells. == Notes and references == == External links == Lymphokine-Activated+Killer+Cells at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
|
{
"page_id": 9900287,
"source": null,
"title": "Lymphokine-activated killer cell"
}
|
The Trolox equivalent antioxidant capacity (TEAC) assay measures the antioxidant capacity of a given substance, as compared to the standard, Trolox. Most commonly, antioxidant capacity is measured using the ABTS Decolorization Assay. Other antioxidant capacity assays which use Trolox as a standard include the diphenylpicrylhydrazyl (DPPH), oxygen radical absorbance capacity (ORAC) and ferric reducing ability of plasma (FRAP) assays. The TEAC assay is often used to measure the antioxidant capacity of foods, beverages and nutritional supplements. == References ==
|
{
"page_id": 21827841,
"source": null,
"title": "Trolox equivalent antioxidant capacity"
}
|
The molecular formula C7H12 (molar mass: 96.17 g/mol, exact mass: 96.0939 u) may refer to: Cycloheptene Heptyne Methylcyclohexenes 1-Methylcyclohexene 3-Methylcyclohexene 4-Methylcyclohexene Methylenecyclohexane Norbornane Norcarane Vinylcyclopentane
|
{
"page_id": 23662851,
"source": null,
"title": "C7H12"
}
|
Biological warfare, also known as germ warfare, is the use of biological toxins or infectious agents such as bacteria, viruses, insects, and fungi with the intent to kill, harm or incapacitate humans, animals or plants as an act of war. Biological weapons (often termed "bio-weapons", "biological threat agents", or "bio-agents") are living organisms or replicating entities (i.e. viruses, which are not universally considered "alive"). Entomological (insect) warfare is a subtype of biological warfare. Biological warfare is subject to a forceful normative prohibition. Offensive biological warfare in international armed conflicts is a war crime under the 1925 Geneva Protocol and several international humanitarian law treaties. In particular, the 1972 Biological Weapons Convention (BWC) bans the development, production, acquisition, transfer, stockpiling and use of biological weapons. In contrast, defensive biological research for prophylactic, protective or other peaceful purposes is not prohibited by the BWC. Biological warfare is distinct from warfare involving other types of weapons of mass destruction (WMD), including nuclear warfare, chemical warfare, and radiological warfare. None of these are considered conventional weapons, which are deployed primarily for their explosive, kinetic, or incendiary potential. Biological weapons may be employed in various ways to gain a strategic or tactical advantage over the enemy, either by threats or by actual deployments. Like some chemical weapons, biological weapons may also be useful as area denial weapons. These agents may be lethal or non-lethal, and may be targeted against a single individual, a group of people, or even an entire population. They may be developed, acquired, stockpiled or deployed by nation states or by non-national groups. In the latter case, or if a nation-state uses it clandestinely, it may also be considered bioterrorism. Biological warfare and chemical warfare overlap to an extent, as the use of toxins produced by some living organisms is considered under
|
{
"page_id": 4361,
"source": null,
"title": "Biological warfare"
}
|
the provisions of both the BWC and the Chemical Weapons Convention. Toxins and psychochemical weapons are often referred to as midspectrum agents. Unlike bioweapons, these midspectrum agents do not reproduce in their host and are typically characterized by shorter incubation periods. == Overview == A biological attack could conceivably result in large numbers of civilian casualties and cause severe disruption to economic and societal infrastructure. A nation or group that can pose a credible threat of mass casualty has the ability to alter the terms under which other nations or groups interact with it. When indexed to weapon mass and cost of development and storage, biological weapons possess destructive potential and loss of life far in excess of nuclear, chemical or conventional weapons. Accordingly, biological agents are potentially useful as strategic deterrents, in addition to their utility as offensive weapons on the battlefield. As a tactical weapon for military use, a significant problem with biological warfare is that it would take days to be effective, and therefore might not immediately stop an opposing force. Some biological agents (smallpox, pneumonic plague) have the capability of person-to-person transmission via aerosolized respiratory droplets. This feature can be undesirable, as the agent(s) may be transmitted by this mechanism to unintended populations, including neutral or even friendly forces. Worse still, such a weapon could "escape" the laboratory where it was developed, even if there was no intent to use it – for example by infecting a researcher who then transmits it to the outside world before realizing that they were infected. Several cases are known of researchers becoming infected and dying of Ebola, which they had been working with in the lab (though nobody else was infected in those cases) – while there is no evidence that their work was directed towards biological warfare, it
|
{
"page_id": 4361,
"source": null,
"title": "Biological warfare"
}
|
demonstrates the potential for accidental infection even of careful researchers fully aware of the dangers. While containment of biological warfare is less of a concern for certain criminal or terrorist organizations, it remains a significant concern for the military and civilian populations of virtually all nations. == History == === Antiquity and Middle Ages === Rudimentary forms of biological warfare have been practiced since antiquity. The earliest documented incident of the intention to use biological weapons is recorded in Hittite texts of 1500–1200 BC, in which victims of an unknown plague (possibly tularemia) were driven into enemy lands, causing an epidemic. The Assyrians poisoned enemy wells with the fungus ergot, though with unknown results. Scythian archers dipped their arrows and Roman soldiers their swords into excrements and cadavers – victims were commonly infected by tetanus as result. In 1346, the bodies of Mongol warriors of the Golden Horde who had died of plague were thrown over the walls of the besieged Crimean city of Kaffa. Specialists disagree about whether this operation was responsible for the spread of the Black Death into Europe, Near East and North Africa, resulting in the deaths of approximately 25 million Europeans. Biological agents were extensively used in many parts of Africa from the sixteenth century AD, most of the time in the form of poisoned arrows, or powder spread on the war front as well as poisoning of horses and water supply of the enemy forces. In Borgu, there were specific mixtures to kill, hypnotize, make the enemy bold, and to act as an antidote against the poison of the enemy as well. The creation of biologicals was reserved for a specific and professional class of medicine-men. === 18th to 19th century === During the French and Indian War, in June 1763 a group of
|
{
"page_id": 4361,
"source": null,
"title": "Biological warfare"
}
|
Native Americans laid siege to British-held Fort Pitt. Following instructions of his superior, Colonel Henry Bouquet, the commander of Fort Pitt, Swiss-born Captain Simeon Ecuyer, ordered his men to take smallpox-infested blankets from the infirmary and give it to a Lenape delegation during the siege. A reported outbreak that began the spring before left as many as one hundred Native Americans dead in Ohio Country from 1763 to 1764. It is not clear whether the smallpox was a result of the Fort Pitt incident or the virus was already present among the Delaware people as outbreaks happened on their own every dozen or so years and the delegates were met again later and seemingly had not contracted smallpox. During the American Revolutionary War, Continental Army officer George Washington mentioned to the Continental Congress that he had heard a rumor from a sailor that his opponent during the Siege of Boston, General William Howe, had deliberately sent civilians out of the city in the hopes of spreading the ongoing smallpox epidemic to American lines; Washington, remaining unconvinced, wrote that he "could hardly give credit to" the claim. Washington had already inoculated his soldiers, diminishing the effect of the epidemic. Some historians have claimed that a detachment of the Corps of Royal Marines stationed in New South Wales, Australia, deliberately used smallpox there in 1789. Dr Seth Carus states: "Ultimately, we have a strong circumstantial case supporting the theory that someone deliberately introduced smallpox in the Aboriginal population." === World War I === By 1900 the germ theory and advances in bacteriology brought a new level of sophistication to the techniques for possible use of bio-agents in war. Biological sabotage in the form of anthrax and glanders was undertaken on behalf of the Imperial German government during World War I (1914–1918), with
|
{
"page_id": 4361,
"source": null,
"title": "Biological warfare"
}
|
indifferent results. The Geneva Protocol of 1925 prohibited the first use of chemical and biological weapons against enemy nationals in international armed conflicts. === World War II === With the onset of World War II, the Ministry of Supply in the United Kingdom established a biological warfare program at Porton Down, headed by the microbiologist Paul Fildes. The research was championed by Winston Churchill and soon tularemia, anthrax, brucellosis, and botulism toxins had been effectively weaponized. In particular, Gruinard Island in Scotland, was contaminated with anthrax during a series of extensive tests for the next 56 years. Although the UK never offensively used the biological weapons it developed, its program was the first to successfully weaponize a variety of deadly pathogens and bring them into industrial production. Other nations, notably France and Japan, had begun their own biological weapons programs. When the United States entered the war, Allied resources were pooled at the request of the British. The US then established a large research program and industrial complex at Fort Detrick, Maryland, in 1942 under the direction of George W. Merck. The biological and chemical weapons developed during that period were tested at the Dugway Proving Grounds in Utah. Soon there were facilities for the mass production of anthrax spores, brucellosis, and botulism toxins, although the war was over before these weapons could be of much operational use. The most notorious program of the period was run by the secret Imperial Japanese Army Unit 731 during the war, based at Pingfan in Manchuria and commanded by Lieutenant General Shirō Ishii. This biological warfare research unit conducted often fatal human experiments on prisoners, and produced biological weapons for combat use. Although the Japanese effort lacked the technological sophistication of the American or British programs, it far outstripped them in its widespread
|
{
"page_id": 4361,
"source": null,
"title": "Biological warfare"
}
|
application and indiscriminate brutality. Biological weapons were used against Chinese soldiers and civilians in several military campaigns. In 1940, the Japanese Army Air Force bombed Ningbo with ceramic bombs full of fleas carrying the bubonic plague. Many of these operations were ineffective due to inefficient delivery systems, although up to 200,000 people may have died. During the Zhejiang-Jiangxi Campaign in 1942, around 1,700 Japanese troops died out of a total 10,000 Japanese soldiers who fell ill with disease when their own biological weapons attack rebounded on their own forces. During the final months of World War II, Japan planned to use plague as a biological weapon against US civilians in San Diego, California, during Operation Cherry Blossoms at Night. The plan was set to launch on 22 September 1945, but it was not executed because of Japan's surrender on 15 August 1945. === 1948 Arab–Israeli War === According to historians Benny Morris and Benjamin Kedar, Israel conducted a biological warfare operation codenamed Operation Cast Thy Bread during the 1948 Arab–Israeli War. The Haganah initially used typhoid bacteria to contaminate water wells in newly cleared Arab villages to prevent the population including militiamen from returning. Later, the biological warfare campaign expanded to include Jewish settlements that were in imminent danger of being captured by Arab troops and inhabited Arab towns not slated for capture. There was also plans to expand the biological warfare campaign into other Arab states including Egypt, Lebanon and Syria, but they were not carried out. Some British soldiers were also poisoned: causing the event to gain international attention. === Cold War === In Britain, the 1950s saw the weaponization of plague, brucellosis, tularemia and later equine encephalomyelitis and vaccinia viruses, but the programme was unilaterally cancelled in 1956. The United States Army Biological Warfare Laboratories weaponized anthrax,
|
{
"page_id": 4361,
"source": null,
"title": "Biological warfare"
}
|
tularemia, brucellosis, Q-fever and others. In 1969, US President Richard Nixon decided to unilaterally terminate the offensive biological weapons program of the US, allowing only scientific research for defensive measures. This decision increased the momentum of the negotiations for a ban on biological warfare, which took place from 1969 to 1972 in the United Nation's Conference of the Committee on Disarmament in Geneva. These negotiations resulted in the Biological Weapons Convention, which was opened for signature on 10 April 1972 and entered into force on 26 March 1975 after its ratification by 22 states. Despite being a party and depositary to the BWC, the Soviet Union continued and expanded its massive offensive biological weapons program, under the leadership of the allegedly civilian institution Biopreparat. The Soviet Union attracted international suspicion after the 1979 Sverdlovsk anthrax leak killed approximately 65 to 100 people. == International law == International restrictions on biological warfare began with the 1925 Geneva Protocol, which prohibits the use but not the possession or development of biological and chemical weapons in international armed conflicts. Upon ratification of the Geneva Protocol, several countries made reservations regarding its applicability and use in retaliation. Due to these reservations, it was in practice a "no-first-use" agreement only. The 1972 Biological Weapons Convention (BWC) supplements the Geneva Protocol by prohibiting the development, production, acquisition, transfer, stockpiling and use of biological weapons. Having entered into force on 26 March 1975, the BWC was the first multilateral disarmament treaty to ban the production of an entire category of weapons of mass destruction. As of March 2021, 183 states have become party to the treaty. The BWC is considered to have established a strong global norm against biological weapons, which is reflected in the treaty's preamble, stating that the use of biological weapons would be "repugnant
|
{
"page_id": 4361,
"source": null,
"title": "Biological warfare"
}
|
to the conscience of mankind". The BWC's effectiveness has been limited due to insufficient institutional support and the absence of any formal verification regime to monitor compliance. In 1985, the Australia Group was established, a multilateral export control regime of 43 countries aiming to prevent the proliferation of chemical and biological weapons. In 2004, the United Nations Security Council passed Resolution 1540, which obligates all UN Member States to develop and enforce appropriate legal and regulatory measures against the proliferation of chemical, biological, radiological, and nuclear weapons and their means of delivery, in particular, to prevent the spread of weapons of mass destruction to non-state actors. == Bioterrorism == Biological weapons are difficult to detect, economical and easy to use, making them appealing to terrorists. The cost of a biological weapon is estimated to be about 0.05 percent the cost of a conventional weapon in order to produce similar numbers of mass casualties per kilometer square. Moreover, their production is very easy as common technology can be used to produce biological warfare agents, like that used in production of vaccines, foods, spray devices, beverages and antibiotics. A major factor in biological warfare that attracts terrorists is that they can easily escape before the government agencies or secret agencies have even started their investigation. This is because the potential organism has an incubation period of 3 to 7 days, after which the results begin to appear, thereby giving terrorists a lead. A technique called Clustered, Regularly Interspaced, Short Palindromic Repeat (CRISPR-Cas9) is now so cheap and widely available that scientists fear that amateurs will start experimenting with them. In this technique, a DNA sequence is cut off and replaced with a new sequence, e.g. one that codes for a particular protein, with the intent of modifying an organism's traits. Concerns have
|
{
"page_id": 4361,
"source": null,
"title": "Biological warfare"
}
|
emerged regarding do-it-yourself biology research organizations due to their associated risk that a rogue amateur DIY researcher could attempt to develop dangerous bioweapons using genome editing technology. In 2002, when CNN went through Al-Qaeda's (AQ's) experiments with crude poisons, they found out that AQ had begun planning ricin and cyanide attacks with the help of a loose association of terrorist cells. The associates had infiltrated many countries like Turkey, Italy, Spain, France and others. In 2015, to combat the threat of bioterrorism, a National Blueprint for Biodefense was issued by the Blue-Ribbon Study Panel on Biodefense. Also, 233 potential exposures of select biological agents outside of the primary barriers of the biocontainment in the US were described by the annual report of the Federal Select Agent Program. Though a verification system can reduce bioterrorism, an employee, or a lone terrorist having adequate knowledge of a bio-technology company's facilities, can cause potential danger by using, without proper oversight and supervision, that company's resources. Moreover, it has been found that about 95% of accidents that have occurred due to low security have been done by employees or those who had a security clearance. == Entomology == Entomological warfare (EW) is a type of biological warfare that uses insects to attack the enemy. The concept has existed for centuries and research and development have continued into the modern era. EW has been used in battle by Japan and several other nations have developed and been accused of using an entomological warfare program. EW may employ insects in a direct attack or as vectors to deliver a biological agent, such as plague. Essentially, EW exists in three varieties. One type of EW involves infecting insects with a pathogen and then dispersing the insects over target areas. The insects then act as a vector, infecting
|
{
"page_id": 4361,
"source": null,
"title": "Biological warfare"
}
|
any person or animal they might bite. Another type of EW is a direct insect attack against crops; the insect may not be infected with any pathogen but instead represents a threat to agriculture. The final method uses uninfected insects, such as bees or wasps, to directly attack the enemy. == Genetics == Theoretically, novel approaches in biotechnology, such as synthetic biology could be used in the future to design novel types of biological warfare agents. Would demonstrate how to render a vaccine ineffective; Would confer resistance to therapeutically useful antibiotics or antiviral agents; Would enhance the virulence of a pathogen or render a nonpathogen virulent; Would increase the transmissibility of a pathogen; Would alter the host range of a pathogen; Would enable the evasion of diagnostic/detection tools; Would enable the weaponization of a biological agent or toxin. Most of the biosecurity concerns in synthetic biology are focused on the role of DNA synthesis and the risk of producing genetic material of lethal viruses (e.g. 1918 Spanish flu, polio) in the lab. Recently, the CRISPR/Cas system has emerged as a promising technique for gene editing. It was hailed by The Washington Post as "the most important innovation in the synthetic biology space in nearly 30 years." While other methods take months or years to edit gene sequences, CRISPR speeds that time up to weeks. Due to its ease of use and accessibility, it has raised a number of ethical concerns, especially surrounding its use in the biohacking space. == By target == === Anti-personnel === Ideal characteristics of a biological agent to be used as a weapon against humans are high infectivity, high virulence, non-availability of vaccines and availability of an effective and efficient delivery system. Stability of the weaponized agent (the ability of the agent to retain its infectivity
|
{
"page_id": 4361,
"source": null,
"title": "Biological warfare"
}
|
and virulence after a prolonged period of storage) may also be desirable, particularly for military applications, and the ease of creating one is often considered. Control of the spread of the agent may be another desired characteristic. The primary difficulty is not the production of the biological agent, as many biological agents used in weapons can be manufactured relatively quickly, cheaply and easily. Rather, it is the weaponization, storage, and delivery in an effective vehicle to a vulnerable target that pose significant problems. For example, Bacillus anthracis is considered an effective agent for several reasons. First, it forms hardy spores, perfect for dispersal aerosols. Second, this organism is not considered transmissible from person to person, and thus rarely if ever causes secondary infections. A pulmonary anthrax infection starts with ordinary influenza-like symptoms and progresses to a lethal hemorrhagic mediastinitis within 3–7 days, with a fatality rate that is 90% or higher in untreated patients. Finally, friendly personnel and civilians can be protected with suitable antibiotics. Agents considered for weaponization, or known to be weaponized, include bacteria such as Bacillus anthracis, Brucella spp., Burkholderia mallei, Burkholderia pseudomallei, Chlamydophila psittaci, Coxiella burnetii, Francisella tularensis, some of the Rickettsiaceae (especially Rickettsia prowazekii and Rickettsia rickettsii), Shigella spp., Vibrio cholerae, and Yersinia pestis. Many viral agents have been studied and weaponized, including some of the Bunyaviridae (especially Rift Valley fever virus), Ebolavirus, many of the Flaviviridae (especially Japanese encephalitis virus), Machupo virus, Coronaviruses, Marburg virus, Variola virus, and yellow fever virus. Fungal agents that have been studied include Coccidioides spp. Toxins that can be used as weapons include ricin, staphylococcal enterotoxin B, botulinum toxin, saxitoxin, and many mycotoxins. These toxins and the organisms that produce them are sometimes referred to as select agents. In the United States, their possession, use, and transfer are regulated
|
{
"page_id": 4361,
"source": null,
"title": "Biological warfare"
}
|
by the Centers for Disease Control and Prevention's Select Agent Program. The former US biological warfare program categorized its weaponized anti-personnel bio-agents as either Lethal Agents (Bacillus anthracis, Francisella tularensis, Botulinum toxin) or Incapacitating Agents (Brucella suis, Coxiella burnetii, Venezuelan equine encephalitis virus, Staphylococcal enterotoxin B). === Anti-agriculture === ==== Anti-crop/anti-vegetation/anti-fisheries ==== The United States developed an anti-crop capability during the Cold War that used plant diseases (bioherbicides, or mycoherbicides) for destroying enemy agriculture. Biological weapons also target fisheries as well as water-based vegetation. It was believed that the destruction of enemy agriculture on a strategic scale could thwart Sino-Soviet aggression in a general war. Diseases such as wheat blast and rice blast were weaponized in aerial spray tanks and cluster bombs for delivery to enemy watersheds in agricultural regions to initiate epiphytotic (epidemics among plants). On the other hand, some sources report that these agents were stockpiled but never weaponized. When the United States renounced its offensive biological warfare program in 1969 and 1970, the vast majority of its biological arsenal was composed of these plant diseases. Enterotoxins and Mycotoxins were not affected by Nixon's order. Though herbicides are chemicals, they are often grouped with biological warfare and chemical warfare because they may work in a similar manner as biotoxins or bioregulators. The Army Biological Laboratory tested each agent and the Army's Technical Escort Unit was responsible for the transport of all chemical, biological, radiological (nuclear) materials. Biological warfare can also specifically target plants to destroy crops or defoliate vegetation. The United States and Britain discovered plant growth regulators (i.e., herbicides) during the Second World War, which were then used by the UK in the counterinsurgency operations of the Malayan Emergency. Inspired by the use in Malaysia, the US military effort in the Vietnam War included a mass dispersal
|
{
"page_id": 4361,
"source": null,
"title": "Biological warfare"
}
|
of a variety of herbicides, famously Agent Orange, with the aim of destroying farmland and defoliating forests used as cover by the Viet Cong. Sri Lanka deployed military defoliants in its prosecution of the Eelam War against Tamil insurgents. ==== Anti-livestock ==== During World War I, German saboteurs used anthrax and glanders to sicken cavalry horses in US and France, sheep in Romania, and livestock in Argentina intended for the Entente forces. One of these German saboteurs was Anton Dilger. Also, Germany itself became a victim of similar attacks – horses bound for Germany were infected with Burkholderia by French operatives in Switzerland. During World War II, the US and Canada secretly investigated the use of rinderpest, a highly lethal disease of cattle, as a bioweapon. In the 1980s Soviet Ministry of Agriculture had successfully developed variants of foot-and-mouth disease, and rinderpest against cows, African swine fever for pigs, and psittacosis for chickens. These agents were prepared to spray them down from tanks attached to airplanes over hundreds of miles. The secret program was code-named "Ecology". During the Mau Mau Uprising in 1952, the poisonous latex of the African milk bush was used to kill cattle. == Defensive operations == === Medical countermeasures === In 2010 at The Meeting of the States Parties to the Convention on the Prohibition of the Development, Production and Stockpiling of Bacteriological (Biological) and Toxin Weapons and Their Destruction in Geneva the sanitary epidemiological reconnaissance was suggested as well-tested means for enhancing the monitoring of infections and parasitic agents, for the practical implementation of the International Health Regulations (2005). The aim was to prevent and minimize the consequences of natural outbreaks of dangerous infectious diseases as well as the threat of alleged use of biological weapons against BTWC States Parties. Many countries require their active-duty
|
{
"page_id": 4361,
"source": null,
"title": "Biological warfare"
}
|
military personnel to get vaccinated for certain diseases that may potentially be used as a bioweapon such as anthrax, smallpox, and various other vaccines depending on the Area of Operations of the individual military units and commands. === Public health and disease surveillance === Most classical and modern biological weapons' pathogens can be obtained from a plant or an animal which is naturally infected. In the largest biological weapons accident known—the anthrax outbreak in Sverdlovsk (now Yekaterinburg) in the Soviet Union in 1979—sheep became ill with anthrax as far as 200 kilometers (120 mi) from the release point of the organism from a military facility in the southeastern portion of the city and still off-limits to visitors today, (see Sverdlovsk Anthrax leak). Thus, a robust surveillance system involving human clinicians and veterinarians may identify a bioweapons attack early in the course of an epidemic, permitting the prophylaxis of disease in the vast majority of people (and animals) exposed but not yet ill. For example, in the case of anthrax, it is likely that by 24–36 hours after an attack, some small percentage of individuals (those with the compromised immune system or who had received a large dose of the organism due to proximity to the release point) will become ill with classical symptoms and signs (including a virtually unique chest X-ray finding, often recognized by public health officials if they receive timely reports). The incubation period for humans is estimated to be about 11.8 days to 12.1 days. This suggested period is the first model that is independently consistent with data from the largest known human outbreak. These projections refine previous estimates of the distribution of early-onset cases after a release and support a recommended 60-day course of prophylactic antibiotic treatment for individuals exposed to low doses of anthrax. By
|
{
"page_id": 4361,
"source": null,
"title": "Biological warfare"
}
|
making these data available to local public health officials in real time, most models of anthrax epidemics indicate that more than 80% of an exposed population can receive antibiotic treatment before becoming symptomatic, and thus avoid the moderately high mortality of the disease. === Common epidemiological warnings === From most specific to least specific: Single cause of a certain disease caused by an uncommon agent, with lack of an epidemiological explanation. Unusual, rare, genetically engineered strain of an agent. High morbidity and mortality rates in regards to patients with the same or similar symptoms. Unusual presentation of the disease. Unusual geographic or seasonal distribution. Stable endemic disease, but with an unexplained increase in relevance. Rare transmission (aerosols, food, water). No illness presented in people who were/are not exposed to "common ventilation systems (have separate closed ventilation systems) when illness is seen in persons in close proximity who have a common ventilation system." Different and unexplained diseases coexisting in the same patient without any other explanation. Rare illness that affects a large, disparate population (respiratory disease might suggest the pathogen or agent was inhaled). Illness is unusual for a certain population or age-group in which it takes presence. Unusual trends of death and illness in animal populations, previous to or accompanying illness in humans. Many affected reaching out for treatment at the same time. Similar genetic makeup of agents in affected individuals. Simultaneous collections of similar illness in non-contiguous areas, domestic, or foreign. An abundance of cases of unexplained diseases and deaths. === Bioweapon identification === The goal of biodefense is to integrate the sustained efforts of the national and homeland security, medical, public health, intelligence, diplomatic, and law enforcement communities. Health care providers and public health officers are among the first lines of defense. In some countries private, local, and
|
{
"page_id": 4361,
"source": null,
"title": "Biological warfare"
}
|
provincial (state) capabilities are being augmented by and coordinated with federal assets, to provide layered defenses against biological weapon attacks. During the first Gulf War the United Nations activated a biological and chemical response team, Task Force Scorpio, to respond to any potential use of weapons of mass destruction on civilians. The traditional approach toward protecting agriculture, food, and water: focusing on the natural or unintentional introduction of a disease is being strengthened by focused efforts to address current and anticipated future biological weapons threats that may be deliberate, multiple, and repetitive. The growing threat of biowarfare agents and bioterrorism has led to the development of specific field tools that perform on-the-spot analysis and identification of encountered suspect materials. One such technology, being developed by researchers from the Lawrence Livermore National Laboratory (LLNL), employs a "sandwich immunoassay", in which fluorescent dye-labeled antibodies aimed at specific pathogens are attached to silver and gold nanowires. In the Netherlands, the company TNO has designed Bioaerosol Single Particle Recognition eQuipment (BiosparQ). This system would be implemented into the national response plan for bioweapon attacks in the Netherlands. Researchers at Ben Gurion University in Israel are developing a different device called the BioPen, essentially a "Lab-in-a-Pen", which can detect known biological agents in under 20 minutes using an adaptation of the ELISA, a similar widely employed immunological technique, that in this case incorporates fiber optics. == List of programs, projects and sites by country == === United States === Fort Detrick, Maryland US Army Biological Warfare Laboratories (1943–69) Building 470 One-Million-Liter Test Sphere Operation Sea-Spray Operation Whitecoat (1954–73) US entomological warfare program Operation Big Itch Operation Big Buzz Operation Drop Kick Operation May Day Project Bacchus Project Clear Vision Project SHAD Project 112 Horn Island Testing Station Fort Terry Granite Peak Installation Vigo Ordnance Plant
|
{
"page_id": 4361,
"source": null,
"title": "Biological warfare"
}
|
=== United Kingdom === Porton Down Gruinard Island Nancekuke Operation Vegetarian (1942–1944) Open-air field tests: Operation Harness off Antigua, 1948–1950. Operation Cauldron off Stornoway, 1952. Operation Hesperus off Stornoway, 1953. Operation Ozone off Nassau, 1954. Operation Negation off Nassau, 1954–5. === Soviet Union and Russia === Biopreparat (18 labs and production centers) Stepnogorsk Scientific and Technical Institute for Microbiology, Stepnogorsk, northern Kazakhstan Institute of Ultra Pure Biochemical Preparations, Leningrad, a weaponized plague center Vector State Research Center of Virology and Biotechnology (VECTOR), a weaponized smallpox center Institute of Applied Biochemistry, Omutninsk Kirov bioweapons production facility, Kirov, Kirov Oblast Zagorsk smallpox production facility, Zagorsk Berdsk bioweapons production facility, Berdsk Bioweapons research facility, Obolensk Sverdlovsk bioweapons production facility (Military Compound 19), Sverdlovsk, a weaponized anthrax center Institute of Virus Preparations Poison laboratory of the Soviet secret services Vozrozhdeniya Project Bonfire Project Factor === Japan === Unit 731 Zhongma Fortress Kaimingjie germ weapon attack Khabarovsk War Crime Trials Epidemic Prevention and Water Purification Department === Iraq === Al Hakum Salman Pak facility Al Manal facility === South Africa === Project Coast Delta G Scientific Company Roodeplaat Research Laboratories Protechnik === Rhodesia === === Canada === Grosse Isle, Quebec, site (1939–45) of research into anthrax and other agents DRDC Suffield, Suffield, Alberta == List of associated people == Bioweaponeers: Includes scientists and administrators Writers and activists: == In popular culture == == See also == == References == == Further reading == == External links == Biological weapons and international humanitarian law Archived 11 August 2010 at the Wayback Machine, ICRC WHO: Health Aspects of Biological and Chemical Weapons "Biological Warfare". National Library of Medicine. Archived from the original on 26 April 2017. Retrieved 28 May 2013. USAMRIID (Archived 5 June 2016 at the Wayback Machine)—U.S. Army Medical Research Institute of Infectious Diseases
|
{
"page_id": 4361,
"source": null,
"title": "Biological warfare"
}
|
In the petroleum refining and petrochemical industries, the initialism BTX refers to mixtures of benzene, toluene, and the three xylene isomers, all of which are aromatic hydrocarbons. The xylene isomers are distinguished by the designations ortho- (or o-), meta- (or m-), and para- (or p-) as indicated in the adjacent diagram. If ethylbenzene is included, the mixture is sometimes referred to as BTEX. The BTX aromatics are very important petrochemical materials. Global consumption of benzene, estimated at more than 40,000,000 tons in 2010, showed an unprecedented growth of more than 3,000,000 tons from the level seen in 2009. Likewise, the para-xylene consumption showed unprecedented growth in 2010, growing by 2,800,000 tons, a full ten percent growth from 2009. Toluene is also a valuable petrochemical for use as a solvent and intermediate in chemical manufacturing processes and as a high octane gasoline component. == Properties of BTX hydrocarbons == The table below lists some of the properties of the BTX aromatic hydrocarbons, all of which are liquids at typical room conditions: == Production of BTX hydrocarbons == Benzene, toluene, and xylenes can be made by various processes. However, most BTX production is based on the recovery of aromatics derived from the catalytic reforming of naphtha in a petroleum refinery. Catalytic reforming usually utilizes a feedstock naphtha that contains non-aromatic hydrocarbons with 6 to 12 carbon atoms and typically produces a reformate product containing C6 to C8 aromatics (benzene, toluene, xylenes) as well as paraffins and heavier aromatics containing 9 to 12 carbon atoms. Another process for producing BTX aromatics involves the steam cracking of hydrocarbons which typically produces a cracked naphtha product commonly referred to as pyrolysis gasoline, pyrolysis gas or pygas. The pyrolysis gasoline typically consists of C6 to C8 aromatics, heavier aromatics containing 9 to 12 carbon atoms, and
|
{
"page_id": 35131662,
"source": null,
"title": "BTX (chemistry)"
}
|
non-aromatic cyclic hydrocarbons (naphthenes) containing 6 or more carbon atoms. The adjacent table compares the BTX content of pyrolysis gasoline produced at standard cracking severity or at medium cracking severity with the BTX content of catalytic reformate produced by either a continuous catalytic regenerative (CCR) reformer or by a semi-regenerative catalytic reformer. About 70 percent of the global production of benzene is by extraction from either reformate or pyrolysis gasoline. The BTX aromatics can be extracted from catalytic reformate or from pyrolysis gasoline by many different methods. Most of those methods, but not all, involve the use of a solvent either for liquid-liquid extraction or extractive distillation. Many different solvents are suitable, including sulfolane (C4H8O2S), furfural (C5H4O2), tetraethylene glycol (C8H18O5), dimethylsulfoxide (C2H6OS), and N-methyl-2-pyrrolidone (C5H9NO). Below is a schematic flow diagram of one method, involving extractive distillation, for extraction of the BTX aromatics from a catalytic reformate: == Petrochemicals produced from BTX == There are a very large number of petrochemicals produced from the BTX aromatics. The following diagram shows the chains leading from the BTX components to some of the petrochemicals that can be produced from those components: == See also == == External links == J.H. Gary and G.E. Handwerk (1984). Petroleum Refining Technology and Economics (3rd ed.). Marcel Dekker, Inc. ISBN 0-8247-9157-6. (see Chapter 15 available here). Donald L. Burdick and William L. Leffler. Petrochemicals in Nontechnical Language (3rd ed.). PennWell Publishing. ISBN 0-87814-798-5. Available at Google Books. Benzene Supply Trends and Proposed Method For Enhanced Recovery, David Netzer. Presented to 2005 World Petrochemical Conference, March 2005, Houston, Texas, U.S.A. Aromatics Complex, James A. Johnson, Feb. 12, 2009. Para – xylene Production. From the website of GTC Technology, Houston, Texas. == References ==
|
{
"page_id": 35131662,
"source": null,
"title": "BTX (chemistry)"
}
|
Classical thermodynamics considers three main kinds of thermodynamic processes: (1) changes in a system, (2) cycles in a system, and (3) flow processes. (1) A Thermodynamic process is a process in which the thermodynamic state of a system is changed. A change in a system is defined by a passage from an initial to a final state of thermodynamic equilibrium. In classical thermodynamics, the actual course of the process is not the primary concern, and often is ignored. A state of thermodynamic equilibrium endures unchangingly unless it is interrupted by a thermodynamic operation that initiates a thermodynamic process. The equilibrium states are each respectively fully specified by a suitable set of thermodynamic state variables, that depend only on the current state of the system, not on the path taken by the processes that produce the state. In general, during the actual course of a thermodynamic process, the system may pass through physical states which are not describable as thermodynamic states, because they are far from internal thermodynamic equilibrium. Non-equilibrium thermodynamics, however, considers processes in which the states of the system are close to thermodynamic equilibrium, and aims to describe the continuous passage along the path, at definite rates of progress. As a useful theoretical but not actually physically realizable limiting case, a process may be imagined to take place practically infinitely slowly or smoothly enough to allow it to be described by a continuous path of equilibrium thermodynamic states, when it is called a "quasi-static" process. This is a theoretical exercise in differential geometry, as opposed to a description of an actually possible physical process; in this idealized case, the calculation may be exact. A really possible or actual thermodynamic process, considered closely, involves friction. This contrasts with theoretically idealized, imagined, or limiting, but not actually possible, quasi-static processes which
|
{
"page_id": 3281166,
"source": null,
"title": "Thermodynamic process"
}
|
may occur with a theoretical slowness that avoids friction. It also contrasts with idealized frictionless processes in the surroundings, which may be thought of as including 'purely mechanical systems'; this difference comes close to defining a thermodynamic process. (2) A cyclic process carries the system through a cycle of stages, starting and being completed in some particular state. The descriptions of the staged states of the system are not the primary concern. The primary concern is the sums of matter and energy inputs and outputs to the cycle. Cyclic processes were important conceptual devices in the early days of thermodynamical investigation, while the concept of the thermodynamic state variable was being developed. (3) Defined by flows through a system, a flow process is a steady state of flows into and out of a vessel with definite wall properties. The internal state of the vessel contents is not the primary concern. The quantities of primary concern describe the states of the inflow and the outflow materials, and, on the side, the transfers of heat, work, and kinetic and potential energies for the vessel. Flow processes are of interest in engineering. == Kinds of process == === Cyclic process === Defined by a cycle of transfers into and out of a system, a cyclic process is described by the quantities transferred in the several stages of the cycle. The descriptions of the staged states of the system may be of little or even no interest. A cycle is a sequence of a small number of thermodynamic processes that indefinitely often, repeatedly returns the system to its original state. For this, the staged states themselves are not necessarily described, because it is the transfers that are of interest. It is reasoned that if the cycle can be repeated indefinitely often, then it can
|
{
"page_id": 3281166,
"source": null,
"title": "Thermodynamic process"
}
|
be assumed that the states are recurrently unchanged. The condition of the system during the several staged processes may be of even less interest than is the precise nature of the recurrent states. If, however, the several staged processes are idealized and quasi-static, then the cycle is described by a path through a continuous progression of equilibrium states. === Flow process === Defined by flows through a system, a flow process is a steady state of flow into and out of a vessel with definite wall properties. The internal state of the vessel contents is not the primary concern. The quantities of primary concern describe the states of the inflow and the outflow materials, and, on the side, the transfers of heat, work, and kinetic and potential energies for the vessel. The states of the inflow and outflow materials consist of their internal states, and of their kinetic and potential energies as whole bodies. Very often, the quantities that describe the internal states of the input and output materials are estimated on the assumption that they are bodies in their own states of internal thermodynamic equilibrium. Because rapid reactions are permitted, the thermodynamic treatment may be approximate, not exact. == A cycle of quasi-static processes == A quasi-static thermodynamic process can be visualized by graphically plotting the path of idealized changes to the system's state variables. In the example, a cycle consisting of four quasi-static processes is shown. Each process has a well-defined start and end point in the pressure-volume state space. In this particular example, processes 1 and 3 are isothermal, whereas processes 2 and 4 are isochoric. The PV diagram is a particularly useful visualization of a quasi-static process, because the area under the curve of a process is the amount of work done by the system during
|
{
"page_id": 3281166,
"source": null,
"title": "Thermodynamic process"
}
|
that process. Thus work is considered to be a process variable, as its exact value depends on the particular path taken between the start and end points of the process. Similarly, heat may be transferred during a process, and it too is a process variable. == Conjugate variable processes == It is often useful to group processes into pairs, in which each variable held constant is one member of a conjugate pair. === Pressure – volume === The pressure–volume conjugate pair is concerned with the transfer of mechanical energy as the result of work. An isobaric process occurs at constant pressure. An example would be to have a movable piston in a cylinder, so that the pressure inside the cylinder is always at atmospheric pressure, although it is separated from the atmosphere. In other words, the system is dynamically connected, by a movable boundary, to a constant-pressure reservoir. An isochoric process is one in which the volume is held constant, with the result that the mechanical PV work done by the system will be zero. On the other hand, work can be done isochorically on the system, for example by a shaft that drives a rotary paddle located inside the system. It follows that, for the simple system of one deformation variable, any heat energy transferred to the system externally will be absorbed as internal energy. An isochoric process is also known as an isometric process or an isovolumetric process. An example would be to place a closed tin can of material into a fire. To a first approximation, the can will not expand, and the only change will be that the contents gain internal energy, evidenced by increase in temperature and pressure. Mathematically, δ Q = d U {\displaystyle \delta Q=dU} . The system is dynamically insulated, by a
|
{
"page_id": 3281166,
"source": null,
"title": "Thermodynamic process"
}
|
rigid boundary, from the environment. === Temperature – entropy === The temperature-entropy conjugate pair is concerned with the transfer of energy, especially for a closed system. An isothermal process occurs at a constant temperature. An example would be a closed system immersed in and thermally connected with a large constant-temperature bath. Energy gained by the system, through work done on it, is lost to the bath, so that its temperature remains constant. An adiabatic process is a process in which there is no matter or heat transfer, because a thermally insulating wall separates the system from its surroundings. For the process to be natural, either (a) work must be done on the system at a finite rate, so that the internal energy of the system increases; the entropy of the system increases even though it is thermally insulated; or (b) the system must do work on the surroundings, which then suffer increase of entropy, as well as gaining energy from the system. An isentropic process is customarily defined as an idealized quasi-static reversible adiabatic process, of transfer of energy as work. Otherwise, for a constant-entropy process, if work is done irreversibly, heat transfer is necessary, so that the process is not adiabatic, and an accurate artificial control mechanism is necessary; such is therefore not an ordinary natural thermodynamic process. === Chemical potential - particle number === The processes just above have assumed that the boundaries are also impermeable to particles. Otherwise, we may assume boundaries that are rigid, but are permeable to one or more types of particle. Similar considerations then hold for the chemical potential–particle number conjugate pair, which is concerned with the transfer of energy via this transfer of particles. In a constant chemical potential process the system is particle-transfer connected, by a particle-permeable boundary, to a constant-μ
|
{
"page_id": 3281166,
"source": null,
"title": "Thermodynamic process"
}
|
reservoir. The conjugate here is a constant particle number process. These are the processes outlined just above. There is no energy added or subtracted from the system by particle transfer. The system is particle-transfer-insulated from its environment by a boundary that is impermeable to particles, but permissive of transfers of energy as work or heat. These processes are the ones by which thermodynamic work and heat are defined, and for them, the system is said to be closed. == Thermodynamic potentials == Any of the thermodynamic potentials may be held constant during a process. For example: An isenthalpic process introduces no change in enthalpy in the system. == Polytropic processes == A polytropic process is a thermodynamic process that obeys the relation: P V n = C , {\displaystyle PV^{\,n}=C,} where P is the pressure, V is volume, n is any real number (the "polytropic index"), and C is a constant. This equation can be used to accurately characterize processes of certain systems, notably the compression or expansion of a gas, but in some cases, liquids and solids. == Processes classified by the second law of thermodynamics == According to Planck, one may think of three main classes of thermodynamic process: natural, fictively reversible, and impossible or unnatural. === Natural process === Only natural processes occur in nature. For thermodynamics, a natural process is a transfer between systems that increases the sum of their entropies, and is irreversible. Natural processes may occur spontaneously upon the removal of a constraint, or upon some other thermodynamic operation, or may be triggered in a metastable or unstable system, as for example in the condensation of a supersaturated vapour. Planck emphasised the occurrence of friction as an important characteristic of natural thermodynamic processes that involve transfer of matter or energy between system and surroundings.
|
{
"page_id": 3281166,
"source": null,
"title": "Thermodynamic process"
}
|
=== Effectively reversible process === To describe the geometry of graphical surfaces that illustrate equilibrium relations between thermodynamic functions of state, no one can fictively think of so-called "reversible processes". They are convenient theoretical objects that trace paths across graphical surfaces. They are called "processes" but do not describe naturally occurring processes, which are always irreversible. Because the points on the paths are points of thermodynamic equilibrium, it is customary to think of the "processes" described by the paths as fictively "reversible". Reversible processes are always quasistatic processes, but the converse is not always true. === Unnatural process === Unnatural processes are logically conceivable but do not occur in nature. They would decrease the sum of the entropies if they occurred. === Quasistatic process === A quasistatic process is an idealized or fictive model of a thermodynamic "process" considered in theoretical studies. It does not occur in physical reality. It may be imagined as happening infinitely slowly so that the system passes through a continuum of states that are infinitesimally close to equilibrium. == See also == Flow process Heat Phase transition Work (thermodynamics) == References == == Further reading == Physics for Scientists and Engineers - with Modern Physics (6th Edition), P. A. Tipler, G. Mosca, Freeman, 2008, ISBN 0-7167-8964-7 Encyclopaedia of Physics (2nd Edition), R.G. Lerner, G.L. Trigg, VHC publishers, 1991, ISBN 3-527-26954-1 (Verlagsgesellschaft), ISBN 0-89573-752-3 (VHC Inc.) McGraw Hill Encyclopaedia of Physics (2nd Edition), C.B. Parker, 1994, ISBN 0-07-051400-3 Physics with Modern Applications, L.H. Greenberg, Holt-Saunders International W.B. Saunders and Co, 1978, ISBN 0-7216-4247-0 Essential Principles of Physics, P.M. Whelan, M.J. Hodgeson, 2nd Edition, 1978, John Murray, ISBN 0-7195-3382-1 Thermodynamics, From Concepts to Applications (2nd Edition), A. Shavit, C. Gutfinger, CRC Press (Taylor and Francis Group, USA), 2009, ISBN 9781420073683 Chemical Thermodynamics, D.J.G. Ives, University Chemistry, Macdonald
|
{
"page_id": 3281166,
"source": null,
"title": "Thermodynamic process"
}
|
Technical and Scientific, 1971, ISBN 0-356-03736-3 Elements of Statistical Thermodynamics (2nd Edition), L.K. Nash, Principles of Chemistry, Addison-Wesley, 1974, ISBN 0-201-05229-6 Statistical Physics (2nd Edition), F. Mandl, Manchester Physics, John Wiley & Sons, 2008, ISBN 9780471915331
|
{
"page_id": 3281166,
"source": null,
"title": "Thermodynamic process"
}
|
Sexual objectification is the act of treating a person solely as an object of sexual desire (a sex object). Objectification more broadly means treating a person as a commodity or an object without regard to their personality or dignity. Objectification is most commonly examined at the level of a society (sociology), but can also refer to the behavior of individuals (psychology), and is a type of dehumanization. Although both men and women can be sexually objectified, the concept is mainly associated with the objectification of women, and is an important idea in many feminist theories, and psychological theories derived from them. Many feminists argue that sexual objectification of girls and women contributes to gender inequality, and many psychologists associate objectification with a range of physical and mental health risks in women. Research suggests that the psychological effects of objectification of men are similar to those of women, leading to negative body image among men. The concept of sexual objectification is controversial, and some feminists and psychologists have argued that at least some degree of objectification is a normal part of human sexuality. == Sexual objectification of women == === General === The sexual objectification of women involves them being viewed primarily as an object of heteronormative male sexual desire, rather than as a whole person. Although opinions differ as to which situations are objectionable, many see the objectification of women taking place in the sexually oriented depictions of women in advertising, art and media, pornography, the occupations of stripping and prostitution, and women being brazenly evaluated or judged sexually or aesthetically in public spaces and events, such as beauty contests. Some feminists and psychologists argue that sexual objectification can lead to negative psychological effects including eating disorders, depression and sexual dysfunction, and can give women negative self-images because of the
|
{
"page_id": 200977,
"source": null,
"title": "Sexual objectification"
}
|
belief that their intelligence and competence are currently not being, nor will ever be, acknowledged by society. Sexual objectification of women has also been found to negatively affect women's performance, confidence, and level of position in the workplace. How objectification has affected women and society in general is a topic of academic debate, with some saying girls' understanding of the importance of appearance in society may contribute to feelings of fear, shame, and disgust during the transition to womanhood, and others saying that young women are especially susceptible to objectification, as they are often taught that power, respect, and wealth can be derived from one's outward appearance. == Sexual objectification of men == === General === "Male sexual objectification" involves a man being in public in a sexual context. Instances where men may be viewed as sexualized can be in advertisements, music videos, films, television shows, beefcake calendars, women's magazines, male strip shows, and clothed female/nude male (CFNM) events. Women also purchase and consume pornography. In her 1992 book, Sexual Reality: A Virtual Sex World Reader, feminist Susie Bright dedicated a chapter to a salon gathering she co-hosted with fellow feminists Laura Miller, Amy Wallace, and Lisa Palac at Wallace's Berkeley Hills mansion, attended by 16 women writers and served by fully nude men they called "slaveboys". The hosts had advertised for "slaveboys" in the San Francisco Weekly, stating, "Genteel and Bohemian gathering of women writers requires comely slaveboys to serve at our tea party. You will serve nude and will not speak unless spoken to. [...]". The ad received about 100 responses, from which six were selected after "nude auditions". The "slaveboys" served tea and meals, provided foot massages, polished nails, brushed hair, tended the fire, and posed for photographs with the guests. Bright also addresses criticism from unattended
|
{
"page_id": 200977,
"source": null,
"title": "Sexual objectification"
}
|
friends who called the setup "reverse sexism", to which she responded unapologetically, adding a note of regret for not having sex with them. Within gay male communities, men are often objectified. In 2007 a study found discussing negative effects of objectification was met with considerable resistance in the community. The sexual objectification of men of color may force them to play specific roles in sexual encounters that are not necessarily of their own choosing. Research suggests that the psychological effects of objectification on men are similar to those of women, leading to negative body image among men. === Media === Men's bodies have become more objectified than they previously were, though because of society's established gaze on the objectification of women, the newfound objectification of men is not as widespread. Even with this increase of male objectification, men are still seen as the dominant figures and so the focus is still primarily on women. Male sexual objectification has been found in 37% of advertisements featuring men's body parts to showcase a product. Similar to the issues of sexual objectification in women, it is common for said objectification to lead men to body shaming, eating disorders, and a drive for perfection. The continued exposure of these "ideal" men subject society to expect all men to fit this role. Male actors featured in TV shows and movies are oftentimes in excellent shape and have the "ideal" bodies. These men often fill the leading roles. When society is subjected to men who do not have ideal bodies, we typically see them as the comic relief. It is rare to see an out of shape man have a leading role. Leanne Dawson writes that "There are temporal, cultural and geographical "norms" of gender and other aspects of identity, which are often incorrectly considered to
|
{
"page_id": 200977,
"source": null,
"title": "Sexual objectification"
}
|
be inherent or natural." In the media, the ideal version of a man is seen as a strong, toned man. The idealized version of a woman is thin. Body evaluation is more commonly used to criticize women than men, and it can take different forms for men. For example, body evaluation is often directed at men's nonverbal cues. By contrast, women more often are subject to body evaluation in the form of sexual, sometimes offensive, verbal remarks. Men tend to experience this from other men, whereas women experience it from both sexes. The Interpersonal Sexual Objectification Scale (ISOS) is a scale that shows sexual objectification of respondents, both men and women. While experiencing sexual objectification it creates the need to constantly maintain and critique one's physical appearance. This leads to other things like eating disorders, body shaming, and anxiety. The ISOS scale can be related to objectification theory and sexism. Self-objectification, which is the way in which people evaluate themselves, is concentrated more on women. Men typically experience it through media display. To the extent that men do experience self-objectification, studies have shown that men typically do not experience its negative effects to the extent that women do. In the media, sexual objectification has been used as a way to sell products to the general public. Sexual objectification has been used as a marketing strategy for many decades according to the Journal of Advertising. This specific strategy targets the public in selling products that will make them look and feel desirable and attractive. It is stated that this strategy sells well by grabbing the attention of the public. The journal states that explicit advertisements do better in marketing than other non-explicit ads. == Views on sexual objectification == While the concept of sexual objectification is important within feminist theory, ideas
|
{
"page_id": 200977,
"source": null,
"title": "Sexual objectification"
}
|
vary widely on what constitutes sexual objectification and what are the ethical implications of such objectification. Some feminists such as Naomi Wolf find the concept of physical attractiveness itself to be problematic, with some radical feminists being opposed to any evaluation of another person's sexual attractiveness based on physical characteristics. John Stoltenberg goes so far as to condemn as wrongfully objectifying any sexual fantasy that involves the visualization of a woman. Radical feminists view objectification as playing a central role in reducing women to what they refer to as the "oppressed sex class". While some feminists view mass media in societies that they argue are patriarchal as objectifying, they often focus on pornography as playing an egregious role in habituating men to objectify women. Cultural critics such as Robert Jensen and Sut Jhally accuse mass media and advertising of promoting the objectification of women to help promote goods and services, and the television and film industries are commonly accused of normalizing the sexual objectification of women. The objection to the objectification of women is not a recent phenomenon. In the French Enlightenment, for example, there was a debate as to whether a woman's breasts were merely a sensual enticement or rather a natural gift. In Alexandre Guillaume Mouslier de Moissy's 1771 play The True Mother (La Vraie Mère), the title character rebukes her husband for treating her as merely an object for his sexual gratification: "Are your senses so gross as to look on these breasts – the respectable treasures of nature – as merely an embellishment, destined to ornament the chest of women?" The issues concerning sexual objectification became first problemized during the 1970s by feminist groups. Since then, it has been argued that the phenomenon of female sexual objectification has increased drastically since its problematization in all levels
|
{
"page_id": 200977,
"source": null,
"title": "Sexual objectification"
}
|
of life, and has resulted in negative consequences for women, especially in the political sphere. However, a rising form of new third-waver feminist groups have also taken the increased objectification of women as an opportunity to use the female body as a mode of power. Some social conservatives have taken up aspects of the feminist critique of sexual objectification. In their view, however, the increase in the sexual objectification of both sexes in Western culture is one of the negative legacies of the sexual revolution. These critics, notably Wendy Shalit, advocate a return to pre-sexual revolution standards of sexual morality, which Shalit refers to as a "return to modesty", as an antidote to sexual objectification. Some social conservatives have argued that the feminist movement itself has contributed to the problem of the sexual objectification of women by promoting "free" love (i.e. men and women choosing to have non-reproductive sex outside of marriage and for their own pleasure). Others such as civil libertarians and sex-positive feminists contest feminist claims about the objectification of women. Camille Paglia holds that "[t]urning people into sex objects is one of the specialties of our species." In her view, objectification is closely tied to (and may even be identical with) the highest human faculties toward conceptualization and aesthetics. Feminist author Wendy Kaminer criticized feminist support for anti-pornography laws, arguing that pornography does not cause sexual violence, and bans on such material infantilize women. She has noted that radical feminists have often allied themselves with the Christian right in supporting these laws and denouncing the depiction of sex in popular culture although the two groups strongly disagree on virtually everything else. Her ACLU colleagues Nadine Strossen and Nan D. Hunter have made similar criticisms. Strossen has argued that objectification is not in and of itself dehumanizing, and
|
{
"page_id": 200977,
"source": null,
"title": "Sexual objectification"
}
|
may fulfill women's own fantasies. Psychologist Nigel Barber argues that men, and to a lesser extent, women, are naturally inclined to focus on the physical attractiveness of the opposite sex (or the same sex in the case of gays and lesbians), and that this has been widely misinterpreted as sexism. === Female self-objectification === Ariel Levy contends that Western women who exploit their sexuality by, for example, wearing revealing clothing and engaging in lewd behavior, engage in female self-objectification, meaning they objectify themselves. While some women see such behaviour as a form of empowerment, Levy contends that it has led to greater emphasis on a physical criterion or sexualization for women's perceived self-worth, which Levy calls "raunch culture". In a study conducted by the State University of New York, it is found that women self-objectify when trying to fit the "perfect" female standard according to the male gaze. Levy discusses this phenomenon in Female Chauvinist Pigs: Women and the Rise of Raunch Culture. Levy followed the camera crew from the Girls Gone Wild video series, and argues that contemporary America's sexualized culture not only objectifies women, it encourages women to objectify themselves. In today's culture, Levy writes, the idea of a woman participating in a wet T-shirt contest or being comfortable watching explicit pornography has become a symbol of feminist strength. Jordan Peterson has asked why women need to wear make-up or high-heels in the workplace, that a double standard exists for sexual harassment and women who self-objectify themselves in society. Social media has made a major impact on the self-objectification of women. Through social media, women self-objectify by posting provocative images they know will be objectified by their viewers as a form of seeking validation of posting images that fits the mold of society. === Latina women === Latina
|
{
"page_id": 200977,
"source": null,
"title": "Sexual objectification"
}
|
women face a particular form of sexual objectification based on stereotypes relating to Latina women. American media often portrays Latina women as being sexually promiscuous and curvaceous, having large breasts and buttocks, being melodramatic, or having a feisty attitude. Keller identifies three main stereotypes that contribute to the objectification of Latinas. (Cantina Girl, Suffering Senorita, and Vamp). The “Cantina Girl” is characterized as being an alluring sexual presence. The “Suffering Senorita” is the Latina who goes “bad” due to her love of the (usually Anglo) love interest. Lastly, the “Vamp” is seen as beautiful but devious, and a psychological threat for her wit or charm. All three of these categorizations stem from the sexual objectification of Latina women's bodies and identities. Such sexual objectifications hold real-world consequences for Latina women. For instance, the prevalence of negative Latina stereotypes (such as hypersexualization) has led to a decrease in positive in-group attitudes among the Latina community. === Black women === Black women have been fetishized and objectified throughout history. They may be portrayed as having a more animalistic nature than their non-black counterparts. People who fetishize black women are sometimes pejoratively said to have "jungle fever". Black women are widely objectified in the media and in pornography, and are scrutinized more closely for doing the same things as their non-black counterparts. They are also stereotyped in the media as having more curvaceous bodies and bigger lips. == Objectification theory == Objectification theory is a framework for understanding the experiences of women in cultures that sexually objectify them, proposed by Barbara Fredrickson and Tomi-Ann Roberts in 1997. Within this framework, Fredrickson and Roberts draw conclusions about women's experiences. This theory states that, because of sexual objectification, women learn to internalize an outsider's view of their bodies as the primary view of themselves. Women,
|
{
"page_id": 200977,
"source": null,
"title": "Sexual objectification"
}
|
they explain, begin to view their bodies as objects separate from their person. This internalization has been termed self-objectification. This theory does not seek to prove the existence of sexual objectification; the theory assumes its existence in culture. This self-objectification then, according to objectification theory, leads to increased habitual body monitoring. With this framework in mind, Fredrickson and Roberts suggest explanations for consequences they believe are the result of sexual objectification. The consequences suggested are: increased feelings of shame, increased feelings of anxiety, decreased peak motivational state, and decreased awareness of internal bodily states. Sexual objectification has been studied based on the proposition that girls and women develop their primary view of their physical selves from observing others. These observations can take place in the media or through personal experience.: 26 Through a blend of expected and actual exposure, women are socialized to objectify their own physical characteristics from a third-person perception, which is identified as self-objectification. Women and girls develop an expected physical appearance for themselves, based on observations of others; and are aware that others are likely to observe as well. The sexual objectification and self-objectification of women is believed to influence social gender roles and inequalities between the sexes. === Self-objectification === Self-objectification can increase in situations which heighten the awareness of an individual's physical appearance.: 82 Here, the presence of a third-person observer is enhanced. Therefore, when individuals know others are looking at them, or will be looking at them, they are more likely to care about their physical appearance. Examples of the enhanced presence of an observer include the presence of an audience, camera, or other known observer. === Women, girls, and self-objectification === Primarily, objectification theory describes how women and girls are influenced as a result of expected social and gender roles. Research indicates
|
{
"page_id": 200977,
"source": null,
"title": "Sexual objectification"
}
|
not all women are influenced equally, due to the anatomical, hormonal, and genetic differences of the female body; however, women's bodies are often objectified and evaluated more frequently.: 90–95 Self-objectification in girls tends to stem from two main causes: the internalization of traditional beauty standards as translated through media as well as any instances of sexual objectification that they might encounter in their daily lives. It is not uncommon for women to translate their anxieties over their constant sense of objectification into obsessive self-surveillance. This, in turn, can lead to many serious problems in women and girls, including "body shame, anxiety, negative attitudes toward menstruation, a disrupted flow of consciousness, diminished awareness of internal bodily states, depression, sexual dysfunction, and disordered eating." Sexual objectification occurs when a person is identified by their sexual body parts or sexual function. In essence, an individual loses their identity, and is recognized solely by the physical characteristics of their body. The purpose of this recognition is to bring enjoyment to others, or to serve as a sexual object for society. Sexual objectification can occur as a social construct among individuals. Sexual objectification has been around and present in society for many but has increased with the introduction of social media according to “Objectification, Sexualization, and Misrepresentation: Social Media and the College Experience - Stefanie E Davis, 2018” This journal shows a clear explanation for how young girls are influenced by social media to be sexually objectified. The platform is meant to share a glimpse into a person's life through photos to share with friends, family and mutuals. For many individuals, social media applications like Instagram, Snapchat, TikTok, and X (formerly Twitter) are used to glamorize and romanticize certain lifestyles. Examples of this can be young women using their platform (however big it may be)
|
{
"page_id": 200977,
"source": null,
"title": "Sexual objectification"
}
|
to pose as an older age by uploading provocative photos. This behavior promotes sexual objectification of young girls that participate on social media. === Psychological consequences === Objectification theory suggests both direct and indirect consequences of objectification to women. Indirect consequences include self consciousness in terms that a woman is consistently checking or rearranging her clothes or appearance to ensure that she is presentable. More direct consequences are related to sexual victimization. Rape and sexual harassment are examples of this. Doob (2012) states that sexual harassment is one of the challenges faced by women in workplace. This may constitute sexual jokes or comments, most of which are degrading. Research indicates that objectification theory is valuable to understanding how repeated visual images in the media are socialized and translated into mental health problems, including psychological consequences on the individual and societal level. These include increased self-consciousness, increased body anxiety, heightened mental health threats (depression, anorexia nervosa, bulimia, and sexual dysfunction), and increased body shame. Therefore, the theory has been used to explore an array of dependent variables including disordered eating, mental health, depression, motor performance, body image, idealized body type, stereotype formation, sexual perception and sexual typing. Body shame is a byproduct of the concept of an idealized body type adopted by most Western cultures that depicts a thin, model-type figure. Thus, women will engage in actions meant to change their body such as dieting, exercise, eating disorders, cosmetic surgery, etc. Effects of objectification theory are identified on both the individual and societal levels. === Causes of depression === Learned helplessness theory posits that because human bodies are only alterable to a certain point, people develop a sense of body shame and anxiety from which they create a feeling of helplessness in relation to correcting their physical appearance and helplessness in
|
{
"page_id": 200977,
"source": null,
"title": "Sexual objectification"
}
|
being able to control the way in which others perceive their appearance. This lack of control often results in depression. In relating to a lack of motivation, objectification theory states that women have less control in relationships and the work environment because they have to depend on the evaluation of another who is typically basing their evaluation on physical appearance. Since the dependence on another's evaluation limits a woman's ability to create her own positive experiences and motivation, it adversely increases her likelihood for depression. Furthermore, sexual victimization may be a cause. Specifically, victimization within the workplace degrades women. Harassment experienced every day wears on a woman, and sometimes this results in a state of depression. == Alternatives and critique == Ann J. Cahill uses the concept of derivitization as an alternative to objectification when trying to address sexual objectification's seeming judgment of all physical interactions (termed somatophobia by Cahill). Cahill criticizes the notion of objectification as marginalizing the role of the body in one's subjective experience and therefore making it impossible to understand how being viewed as a sexually appealing body can enhance an individual's notion of self. : 842 Instead, Cahill uses the concept of subjectivity from the study of intersubjectivity. A subject is an individual with their unique experience of reality. Derivitization is then defined as limiting another person's subjective behaviour and experience to align with or serve your own subjective experience. In this framing, the objectification exists in sex work is viewed instead as the derivitization of having another act for only one's own subjective experience and ignoring the sex worker's experience. Drawing comparisons to the doctor–patient relationship, Cahill argues that a recognition of what both people bring to a relationship and their subjective goals is what makes a relationship ethical.: 843–847 === Free use ===
|
{
"page_id": 200977,
"source": null,
"title": "Sexual objectification"
}
|
"Free use" describes a sexual fetish involving being consensually "used" as a sex object at any time and anywhere by a sexual partner when they are aroused, including while doing chores or while sleeping. It became popular online in the mid-2020s, including in gay pornography, on Reddit—where one subreddit dedicated to the fetish had over 1.4 million members by 2023—and on TikTok. == See also == == References == == Further reading == Bartky, Sandra Lee (1990). Femininity and domination: studies in the phenomenology of oppression. New York: Routledge. ISBN 978-0-415-90186-4. Berger, John (1972). Ways of Seeing. London: BBC and Penguin Books. ISBN 0-563-12244-7 (BBC), ISBN 0-14-021631-6, ISBN 0-14-013515-4 (pbk). Bridges, Ana J.; Johnson, Jennifer A.; Dines, Gail; Condit, Deirdre M.; West, Carolyn M. (April 2015). "Introducing Sexualization, Media & Society". Sexualization, Media, & Society. 1 (1): 487–515. doi:10.1177/2374623815588763. Brooks, Gary R. (1995). The centerfold syndrome: how men can overcome objectification and achieve intimacy with women. San Francisco: Jossey-Bass. ISBN 978-0-7879-0104-2. Coy, Maddy; Garner, Maria (November 2010). "Glamour modelling and the marketing of self-sexualization: critical reflections". International Journal of Cultural Studies. 13 (6): 657–675. doi:10.1177/1367877910376576. S2CID 145230875. Eames, Elizabeth R. (1976). "Sexism and woman as sex object". Journal of Thought. 11 (2): 140–143. Preview. [Link Broken] Holroyd, Julia (2005). Sexual objectification: The unlikely alliance of feminism and Kant (PDF). Society for Applied Philosophy International Congress. Oxford, UK. Archived from the original (PDF) on 2005-05-21. (conference paper) LeMoncheck, Linda (1985). Dehumanizing Women: Treating Persons as Sex Objects. New York: Rowman & Littlefield. ISBN 978-0-8476-7386-5. Nussbaum, Martha C. (October 1995). "Objectification". Philosophy & Public Affairs. 24 (4): 249–291. doi:10.1111/j.1088-4963.1995.tb00032.x. JSTOR 2961930. Papadaki, Evangelia (Lina) (August 2007). "Sexual objectification: From Kant to contemporary feminism" (PDF). Contemporary Political Theory. 6 (3): 330–348. doi:10.1057/palgrave.cpt.9300282. S2CID 144197352. Parker, Kathleen (30 June 2008). "'Save the males': Ho
|
{
"page_id": 200977,
"source": null,
"title": "Sexual objectification"
}
|
culture lights fuses, but confuses". Daily News. New York. Paul, Pamela (2005). Pornified: how pornography is transforming our lives, our relationships, and our families. New York: Times Books. ISBN 978-0-8050-8132-9. Mario Perniola, The Sex-appeal of the inorganic, translated by Massimo Verdicchio, London-New York, Continuum, 2004. Sharge, Laurie (April 2005). "Exposing the fallacies of anti-porn feminism". Feminist Theory. 6 (1): 45–65. doi:10.1177/1464700105050226. S2CID 145194517. Soble, Alan (2002). Pornography, Sex, and Feminism. Amherst, New York: Prometheus Books. ISBN 978-1-57392-944-8. Ward, L. Monique; Daniels, Elizabeth A.; Zurbriggen, Eileen L.; Rosenscruggs, Danielle (2023). "The sources and consequences of sexual objectification". Nature Reviews Psychology. 2 (8): 496–513. doi:10.1038/s44159-023-00192-x. == External links == Papadaki, Evangelia (March 10, 2010), "Feminist perspectives on objectification", in Zalta, Edward N. (ed.). Stanford Encyclopedia of Philosophy. Shrage, Laurie (July 13, 2007), "Feminist perspectives on sex markets: 1.3 sexual objectification", in Zalta, Edward N. (ed.). Stanford Encyclopedia of Philosophy. Steinberg, David (March 5, 1993). "On Sexual Objectification". Spectator Magazine | Comes Naturally column #5. – Sex-positive feminist perspective on sexual objectification. Wyatt, Petronella (October 5, 1996). "Women like seeing men as sex objects". Daily Telegraph. Archived from the original on May 30, 2008. Interview with Janet Anderson. Kalyanaraman, Sriram; Redding, Michael; Steele, Jason (2000). "Sexual suggestiveness in online ads: effects of objectification on opposite genders". psu.edu/dept/medialab. Media Effects Research Laboratory, Pennsylvania State University. Archived from the original on February 8, 2008. Davis, Stefanie E (July 13, 2018) "Objectification, Sexualization and Misrepresentation: Social Media and the College Experience" Sage Journals Bello, D. C., Pitts, R. E., & Etzel, M. J. (1983). The communication effects of controversial sexual content in television programs and commercials. Journal of Advertising, 12(3), 32–42. Hill, M. S., & Fischer, A. R. (2008). Examining objectification theory: Lesbian and heterosexual women's experiences with sexual-and self-objectification. The Counseling Psychologist, 36(5), 745–776. https://doi.org/10.1177/0011000007301669
|
{
"page_id": 200977,
"source": null,
"title": "Sexual objectification"
}
|
User-generated content Tigtog (March 23, 2007). "FAQ: What is sexual objectification?". finallyfeminism101.wordpress.com. Finally, A Feminism 101 Blog via WordPress. Karen Straughan (March 28, 2012). I'm a sexy woman, so stop objectifying me! (Video). Karen Straughan via YouTube. Retrieved June 7, 2017.
|
{
"page_id": 200977,
"source": null,
"title": "Sexual objectification"
}
|
Amnon Albeck (Hebrew: אמנון אלבק; born August 1, 1958) is an organic and bioorganic chemist. == Biography == Amnon Albeck was born in Jerusalem, Israel, to Michael and Shulamit Albeck on August 1, 1958. Amnon's father is the chemist Prof. Michael Albeck, the fifth president of Bar Ilan University (1986-1989) and former president of The Israel Chemical Society (1977-1980). His grandfather, Hanoch Albeck was a professor of Talmud at the Hebrew University of Jerusalem who was one of the founders of the scientific approach to the study of the Mishna. Albeck graduated from Bar Ilan University (Ramat Gan, Israel) with a BSc in chemistry in 1982, and earned his PhD from The Weizmann Institute of Science (Rehovot, Israel), under the supervision of Mordechai (Mudi) Sheves, in 1988. He then spent two years as a post-doctoral Fellow with Robert H. Abeles at Brandeis University in Massachusetts, USA. In 1990 he returned to Bar Ilan University as a faculty member at the Department of Chemistry, where Albeck is now a Professor and the head of The Julius Spokojny Bioorganic Chemistry Laboratory. He is also a member of The Marcus Center for Medicinal Chemistry at Bar Ilan University. Albeck served as The Department of Chemistry Chairman in 2008-2011, and he is Bar Ilan University's Vice-Rector since 2014. In July 2020 he was elected Rector of Bar-Ilan University, due to replace Prof. Miriam Faust in office. Amnon and his wife Shira, who is a staff scientist at the Weizmann Institute of Science, have five children and seven grandchildren. == Scientific interests and publications == Albeck's research interests include: (1) Organic chemistry of peptides and peptidomimetics; (2) Enzyme mechanisms and inhibition, in particular the study of proteases; (3) Drug development and drug delivery; (4) Development of computational tools for the study of enzyme mechanisms and
|
{
"page_id": 48828689,
"source": null,
"title": "Amnon Albeck"
}
|
for drug development; (5) Chemistry and biological activity of tellurium compounds. == References ==
|
{
"page_id": 48828689,
"source": null,
"title": "Amnon Albeck"
}
|
The Hatta number (Ha) was developed by Shirôji Hatta (1895-1973 ) in 1932, who taught at Tohoku University from 1925 to 1958. It is a dimensionless parameter that compares the rate of reaction in a liquid film to the rate of diffusion through the film. It is related to one of the many Damköhler numbers, Hatta being the square root of such a Damköhler number of the second type. Conceptually the Hatta number bears strong resemblance to the Thiele modulus for diffusion limitations in porous catalysts, which also is the square root of a Damköhler number. For a second order reaction (rA = k2CBCA) Hatta is defined via: H a 2 = k 2 C A , i C B , b u l k δ L D A δ L C A , i = k 2 C B , b u l k D A ( D A δ L ) 2 = k 2 C B , b u l k D A k L 2 {\displaystyle Ha^{2}={{k_{2}C_{A,i}C_{B,bulk}\delta _{L}} \over {{\frac {D_{A}}{\delta _{L}}}\ C_{A,i}}}={{k_{2}C_{B,bulk}D_{A}} \over ({\frac {D_{A}}{\delta _{L}}})^{2}}={{k_{2}C_{B,bulk}D_{A}} \over {{k_{L}}^{2}}}} For a reaction mth order in A and nth order in B: H a = 2 m + 1 k m , n C A , i m − 1 C B , b u l k n D A k L {\displaystyle Ha={{\sqrt {{\frac {2}{{m}+1}}k_{m,n}{C_{A,i}}^{m-1}C_{B,bulk}^{n}{D}_{A}}} \over {{k}_{L}}}} For gas-liquid absorption with chemical reactions, a high Hatta number indicates the reaction is much faster than diffusion, usually referred to as the "fast reaction" or "chemically enhanced" regime. In this case, the reaction occurs within a thin (hypothetical) film, and the surface area and the Hatta number itself limit the overall rate. For Ha>2, with a large excess of B, the maximum rate of reaction assumes that the
|
{
"page_id": 14356754,
"source": null,
"title": "Hatta number"
}
|
liquid film is saturated with gas at the interfacial (CA,i) and that the bulk concentration of A remains zero; the flux and hence the rate of reaction becomes proportional to the mass transfer coefficient kL and the Hatta number: kLCA,iHa. Conversely, a Hatta number smaller than unity suggests the reaction is the limiting factor, and the reaction takes place in the bulk fluid; the concentration of A needs to be calculated taking the mass transfer limitation - without enhancement - into account. == References == == See also == Dimensionless quantity Dimensional analysis
|
{
"page_id": 14356754,
"source": null,
"title": "Hatta number"
}
|
Newly created taxonomic names in biological nomenclature often reflect the discoverer's interests or honour those the discoverer holds in esteem. This is a list of real organisms with scientific names chosen to reference the fictional Harry Potter series by J.K. Rowling. == Named after wizards == == Named after magical creatures == == Named after spells, objects, and locations == == See also == List of unusual biological names List of organisms named after works of fiction List of organisms named after famous people == References ==
|
{
"page_id": 56299797,
"source": null,
"title": "List of organisms named after the Harry Potter series"
}
|
Endogeny, in biology, refers to the property of originating or developing from within an organism, tissue, or cell. For example, endogenous substances, and endogenous processes are those that originate within a living system (e.g. an organism or a cell). For instance, estradiol is an endogenous estrogen hormone produced within the body, whereas ethinylestradiol is an exogenous synthetic estrogen, commonly used in birth control pills. In contrast, exogenous substances and exogenous processes are those that originate from outside of an organism. == References == == External links == The dictionary definition of endogeny at Wiktionary
|
{
"page_id": 790808,
"source": null,
"title": "Endogeny (biology)"
}
|
Dan Shechtman (Hebrew: דן שכטמן; born January 24, 1941) is the Philip Tobias Professor of Materials Science at the Technion – Israel Institute of Technology, an Associate of the US Department of Energy's Ames National Laboratory, and Professor of Materials Science at Iowa State University. On April 8, 1982, while on sabbatical at the U.S. National Bureau of Standards in Washington, D.C., Shechtman discovered the icosahedral phase, which opened the new field of quasiperiodic crystals, also referred to as "quasicrystals." He was awarded the 2011 Nobel Prize in Chemistry for the discovery of quasicrystals, making him one of six Israelis who have won the Nobel Prize in Chemistry. == Biography == Dan Shechtman was born in 1941 in Tel Aviv, in what was then Mandatory Palestine; the city became part of the new state of Israel in 1948. He grew up in Petah Tikva and Ramat Gan in a Jewish family. His grandparents had immigrated to Palestine during the Second Aliyah (1904–1914) and founded a printing house. As a child Shechtman was fascinated by Jules Verne's The Mysterious Island (1874), which he read many times. His childhood dream was to become an engineer like the main protagonist, Cyrus Smith. I thought that was the best thing a person could do. The engineer in the book knows mechanics and physics, and he creates a whole way of life on the island out of nothing. I wanted to be like that. Shechtman is married to Prof. Tzipora Shechtman, Head of the Department of Counseling and Human Development at Haifa University, and author of two books on psychotherapy. They have a son Yoav Shechtman (a postdoctoral researcher in the lab of W. E. Moerner) and three daughters: Tamar Finkelstein (an organizational psychologist at the Israeli police leadership center), Ella Shechtman-Cory (a PhD in
|
{
"page_id": 3674396,
"source": null,
"title": "Dan Shechtman"
}
|
clinical psychology), and Ruth Dougoud-Nevo (also a PhD in clinical psychology). == Academic career == After receiving his Ph.D. in Materials Engineering from the Technion in 1972, where he also obtained his B.Sc. in Mechanical Engineering in 1966 and M.Sc. in Materials Engineering in 1968, Shechtman was an NRC fellow at the Aerospace Research Laboratories at Wright Patterson AFB, Ohio, where he studied for three years the microstructure and physical metallurgy of titanium aluminides. In 1975, he joined the department of materials engineering at Technion. In 1981–1983 he was on sabbatical at Johns Hopkins University, where he studied rapidly solidified aluminum transition metal alloys, in a joint program with NBS. During this study he discovered the icosahedral phase which opened the new field of quasiperiodic crystals. In 1992–1994 he was on sabbatical at National Institute of Standards and Technology (NIST), where he studied the effect of the defect structure of CVD diamond on its growth and properties. Shechtman's Technion research is conducted in the Louis Edelstein Center, and in the Wolfson Centre which is headed by him. He served on several Technion Senate Committees and headed one of them. Shechtman joined the Iowa State faculty in 2004. He currently spends about five months a year in Ames on a part-time appointment. Since 2014 he has been the head of the International Scientific Council of Tomsk Polytechnic University. == Work on quasicrystals == From the day Shechtman published his findings on quasicrystals in 1984 to the day Linus Pauling died in 1994, Shechtman experienced hostility from him toward the non-periodic interpretation. "For a long time it was me against the world," he said. "I was a subject of ridicule and lectures about the basics of crystallography. The leader of the opposition to my findings was the two-time Nobel Laureate Linus Pauling,
|
{
"page_id": 3674396,
"source": null,
"title": "Dan Shechtman"
}
|
the idol of the American Chemical Society and one of the most famous scientists in the world. For years, 'til his last day, he fought against quasi-periodicity in crystals. He was wrong, and after a while, I enjoyed every moment of this scientific battle, knowing that he was wrong." Linus Pauling is noted saying "There is no such thing as quasicrystals, only quasi-scientists." Pauling was apparently unaware of a paper in 1981 by H. Kleinert and K. Maki which had pointed out the possibility of a non-periodic Icosahedral Phase in quasicrystals (see the historical notes). The head of Shechtman's research group told him to "go back and read the textbook" and a couple of days later "asked him to leave for 'bringing disgrace' on the team." Shechtman felt rejected. On publication of his paper, other scientists began to confirm and accept empirical findings of the existence of quasicrystals. The Nobel Committee at the Royal Swedish Academy of Sciences said that "his discovery was extremely controversial," but that his work "eventually forced scientists to reconsider their conception of the very nature of matter." Through Shechtman's discovery, several other groups were able to form similar quasicrystals by 1987, finding these materials to have low thermal and electrical conductivity, while possessing high structural stability. Quasicrystals have also been found naturally. A quasiperiodic crystal, or, in short, quasicrystal, is a structure that is ordered but not periodic. A quasicrystalline pattern can continuously fill all available space, but it lacks translational symmetry. "Aperiodic mosaics, such as those found in the medieval Islamic mosaics of the Alhambra palace in Spain and the Darb-i Imam shrine in Iran, have helped scientists understand what quasicrystals look like at the atomic level. In those mosaics, as in quasicrystals, the patterns are regular – they follow mathematical rules – but
|
{
"page_id": 3674396,
"source": null,
"title": "Dan Shechtman"
}
|
they never repeat themselves.""An intriguing feature of such patterns, [which are] also found in Arab mosaics, is that the mathematical constant known as the Greek letters phi or tau, or the "golden ratio", occurs over and over again. Underlying it is a sequence worked out by Fibonacci in the 13th century, where each number is the sum of the preceding two." Quasicrystalline materials could be used in a large number of applications, including the formation of durable steel used for fine instrumentation, and non-stick insulation for electrical wires and cooking equipment., but presently have no technological applications. The Nobel prize was 10 million Swedish krona (approximately US$1.5 million). == Presidential bid == On January 17, 2014, in an interview with Israel's Channel One, Shechtman announced his candidacy for President of Israel. Shechtman received the endorsement of the ten Members of Knesset required to run. In the elections, held on June 10, 2014, he was awarded only one vote. This led Israeli press and Israeli humorists to qualify Shechtman as "quasi-president" in reference to the "quasi-scientist" quote. == Awards == 2019 Honorary John von Neumann Professor title 2014 Fray International Sustainability Award, SIPS 2014 2013 Honorary doctorate from Bar-Ilan University 2011 Nobel Prize in Chemistry for the discovery of quasicrystals 2008 European Materials Research Society (E-MRS) 25th Anniversary Award 2002 EMET Prize in Chemistry 2000 Muriel & David Jacknow Technion Award for Excellence in Teaching 2000 Gregori Aminoff Prize of the Royal Swedish Academy of Sciences 1999 Wolf Prize in Physics 1998 Israel Prize, for Physics 1993 Weizmann Science Award 1990 Rothschild Prize in Engineering 1988 New England Academic Award of the Technion 1988 International Award for New Materials of the American Physical Society 1986 Physics Award of the Friedenberg Fund for the Advancement of Science and Education == Published works
|
{
"page_id": 3674396,
"source": null,
"title": "Dan Shechtman"
}
|
== Shechtman, D.; Blech, I.; Gratias, D.; Cahn, J.W. (1984). "Metallic Phase with Long-Range Orientational Order and No Translational Symmetry". Physical Review Letters. 53 (20): 1951. Bibcode:1984PhRvL..53.1951S. doi:10.1103/PhysRevLett.53.1951. Swartzendruber, L.; Shechtman, D.; Bendersky, L.; Cahn, J.W. (1985). "Nuclear γ-ray resonance observations in an aluminum-based icosahedral quasicrystal". Physical Review B. 32 (2): 1383–1385. Bibcode:1985PhRvB..32.1383S. doi:10.1103/PhysRevB.32.1383. PMID 9937171. Cahn, John W.; Gratias, Denis; Shechtman, Dan (1986). "Pauling's model not universally accepted". Nature. 319 (6049): 102. Bibcode:1986Natur.319..102C. doi:10.1038/319102a0. S2CID 4372556. Shechtman, Dan (1988). "The Icosahedral Quasiperiodic Phase". Physica Scripta. T23: 49. Bibcode:1988PhST...23...49S. doi:10.1088/0031-8949/1988/T23/008. S2CID 250844166. Cahn, John W.; Shechtman, Dan; Gratias, Denis (1986). "Indexing of icosahedral quasiperiodic crystals". Journal of Materials Research. 1 (1): 13. Bibcode:1986JMatR...1...13C. doi:10.1557/JMR.1986.0013. S2CID 138068389. == See also == List of Israel Prize recipients List of Israeli Nobel laureates List of Jewish Nobel laureates Science and technology in Israel == References == == Further reading == D. P. DiVincenzo and P. J. Steinhardt, eds. 1991. Quasicrystals: The State of the Art. Directions in Condensed Matter Physics, Vol 11. ISBN 981-02-0522-8. T. Janssen. 2007. Quasicrystals: Comparative dynamics. Nature Materials, Vol 6., 925–926. == External links == Dan Shechtman on Nobelprize.org Nobel Laureates from Technion – Israel Institute of Technology. Story of quasicrystals as told by Shechtman to APS News in 2002. Biography/CV Page – Technion TechnionLIVE e-newsletter Archived November 25, 2015, at the Wayback Machine Dan Shechtman (Iowa State faculty page) 2012 interview with The Times of Israel
|
{
"page_id": 3674396,
"source": null,
"title": "Dan Shechtman"
}
|
Sir John Bertram Adams (24 May 1920 – 3 March 1984) was an English accelerator physicist and administrator. Adams is mostly known for his work at CERN and Culham Laboratory. Despite a lack of formal university education, Adams worked for organizations like the Telecommunications Research Establishment and the Atomic Energy Research Establishment in the 1940s and early 1950s. He served as acting director and eventually as elected director of CERN, from 1976 until 1981. == Biography == === Early life === Born in Kingston, Surrey on 24 May 1920. He attended Eltham College from 1931 until 1936, after which he began to work for Siemens Laboratories in Woolwich. He continued studying at the South East London Technical Institute until 1939 earning a Higher National Certificate. Adams received no university education. === Professional career === At Siemens, his work was concerned with the acoustic properties of telephones. Between 1940 and 1945, he worked the Telecommunications Research Establishment being particularly responsible for developing the microwave radar After, Adams moved to the Atomic Energy Research Establishment until 1953. In 1953, he moved once more to the new CERN Laboratory, serving in the General Physics Division as the engineer in charge of designing and building the Harwell Synchrocyclotron, Europe's first large accelerator which operated successfully for 30 years until shutdown due to lack of funding. Also in late 1953, he was noted serving as a full staff member of the Proton Synchrotron Group. As CERN's proton synchrotron became fully operational in 1959, Adams was important to defining the methods and organization by which physicists would conduct testing. His work organizing CERN's administrative structure and measurement equipment were prepared for experimentation leading up until the synchrotron's start up at the end of 1959. After the death of Cornelis Bakker, CERN Director-General, in April 1960, the
|
{
"page_id": 1249565,
"source": null,
"title": "John Adams (physicist)"
}
|
Council of CERN appointed Adams to the post of acting Director-General. He held this post until August 1961 when he returned to the UK as director of the Culham Fusion Laboratory, and then from 1966 to 1971 he was a member of the United Kingdom Atomic Energy Authority. He also became a Fellow of the Royal Society. Returning to CERN in 1971 as Director-General of Laboratory II, he led the design of the Super Proton Synchrotron. He split the duties of CERN Director General with Willibald Jentschke and then Léon Van Hove during the 1970s. His careful management of CERN's new projects were important to getting funding and approval from CERN's council. His designs were cautious and focused on reliability while providing the ability for new improvements to be built. The Super Proton Synchrotron was able to reach energies of 540 GeV. With the reorganization of CERN in 1976, he became the executive Director-General, working on obtaining funding for the LEP collider. The new collider used magnet systems for acceleration that were designed by Adams in his previous accelerators. He was chair of the International Committee for Future Accelerators, a working group of the International Union of Pure and Applied Physics, from 1978 to 1982. Adams was knighted in 1981. === Personal life === Adams married Renie Warburton on 24 January 1943. They had two daughters and a son . He resided in Founex (Vaud), Switzerland. == Awards and honors == Rontegen Prize, University of Giessen (1960) D. Sc. (Honorary), University of Geneva Duddell Medal, Physical Society (1961) D. Sc. (Honorary), University of Birmingham (1961) Fellow of Royal Society (1963) Leverhulme Medal (Royal Society) (1972) Royal Medal, Royal Society (1977) Knight Bachelor (1981) == John Adams Institute for Accelerator Science == The John Adams Institute for Accelerator Science (JAI), in
|
{
"page_id": 1249565,
"source": null,
"title": "John Adams (physicist)"
}
|
the Denys Wilkinson Building, an accelerator physics research institute comprising researchers from Royal Holloway, University of London, University of Oxford and Imperial College London is named in his honour. A main road ("Route Adams") in CERN's Prevessin site is also named after him. == See also == List of Directors General of CERN == References == == External links == Media related to John Adams (physicist) at Wikimedia Commons The John Adams Accelerator Institute
|
{
"page_id": 1249565,
"source": null,
"title": "John Adams (physicist)"
}
|
A reducing sugar is any sugar that is capable of acting as a reducing agent. In an alkaline solution, a reducing sugar forms some aldehyde or ketone, which allows it to act as a reducing agent, for example in Benedict's reagent. In such a reaction, the sugar becomes a carboxylic acid. All monosaccharides are reducing sugars, along with some disaccharides, some oligosaccharides, and some polysaccharides. The monosaccharides can be divided into two groups: the aldoses, which have an aldehyde group, and the ketoses, which have a ketone group. Ketoses must first tautomerize to aldoses before they can act as reducing sugars. The common dietary monosaccharides galactose, glucose and fructose are all reducing sugars. Disaccharides are formed from two monosaccharides and can be classified as either reducing or nonreducing. Nonreducing disaccharides like sucrose and trehalose have glycosidic bonds between their anomeric carbons and thus cannot convert to an open-chain form with an aldehyde group; they are stuck in the cyclic form. Reducing disaccharides like lactose and maltose have only one of their two anomeric carbons involved in the glycosidic bond, while the other is free and can convert to an open-chain form with an aldehyde group. The aldehyde functional group allows the sugar to act as a reducing agent, for example, in the Tollens' test or Benedict's test. The cyclic hemiacetal forms of aldoses can open to reveal an aldehyde, and certain ketoses can undergo tautomerization to become aldoses. However, acetals, including those found in polysaccharide linkages, cannot easily become free aldehydes. Reducing sugars react with amino acids in the Maillard reaction, a series of reactions that occurs while cooking food at high temperatures and that is important in determining the flavor of food. Also, the levels of reducing sugars in wine, juice, and sugarcane are indicative of the quality of
|
{
"page_id": 987423,
"source": null,
"title": "Reducing sugar"
}
|
these food products. == Terminology == === Oxidation-reduction === A reducing sugar is one that reduces another compound and is itself oxidized; that is, the carbonyl carbon of the sugar is oxidized to a carboxyl group. A sugar is classified as a reducing sugar only if it has an open-chain form with an aldehyde group or a free hemiacetal group. === Aldoses and ketoses === Monosaccharides which contain an aldehyde group are known as aldoses, and those with a ketone group are known as ketoses. The aldehyde can be oxidized via a redox reaction in which another compound is reduced. Thus, aldoses are reducing sugars. Sugars with ketone groups in their open chain form are capable of isomerizing via a series of tautomeric shifts to produce an aldehyde group in solution. Therefore, ketones like fructose are considered reducing sugars but it is the isomer containing an aldehyde group which is reducing since ketones cannot be oxidized without decomposition of the sugar. This type of isomerization is catalyzed by the base present in solutions which test for the presence of reducing sugars. === Reducing end === Disaccharides consist of two monosaccharides and may be either reducing or nonreducing. Even a reducing disaccharide will only have one reducing end, as disaccharides are held together by glycosidic bonds, which consist of at least one anomeric carbon. With one anomeric carbon unable to convert to the open-chain form, only the free anomeric carbon is available to reduce another compound, and it is called the reducing end of the disaccharide. A nonreducing disaccharide is that which has both anomeric carbons tied up in the glycosidic bond. Similarly, most polysaccharides have only one reducing end. == Examples == All monosaccharides are reducing sugars because they either have an aldehyde group (if they are aldoses) or can
|
{
"page_id": 987423,
"source": null,
"title": "Reducing sugar"
}
|
tautomerize in solution to form an aldehyde group (if they are ketoses). This includes common monosaccharides like galactose, glucose, glyceraldehyde, fructose, ribose, and xylose. Many disaccharides, like cellobiose, lactose, and maltose, also have a reducing form, as one of the two units may have an open-chain form with an aldehyde group. However, sucrose and trehalose, in which the anomeric carbon atoms of the two units are linked together, are nonreducing disaccharides since neither of the rings is capable of opening. In glucose polymers such as starch and starch-derivatives like glucose syrup, maltodextrin and dextrin the macromolecule begins with a reducing sugar, a free aldehyde. When starch has been partially hydrolyzed the chains have been split and hence it contains more reducing sugars per gram. The percentage of reducing sugars present in these starch derivatives is called dextrose equivalent (DE). Glycogen is a highly branched polymer of glucose that serves as the main form of carbohydrate storage in animals. It is a reducing sugar with only one reducing end, no matter how large the glycogen molecule is or how many branches it has (note, however, that the unique reducing end is usually covalently linked to glycogenin and will therefore not be reducing). Each branch ends in a nonreducing sugar residue. When glycogen is broken down to be used as an energy source, glucose units are removed one at a time from the nonreducing ends by enzymes. == Characterization == Several qualitative tests are used to detect the presence of reducing sugars. Two of them use solutions of copper(II) ions: Benedict's reagent (Cu2+ in aqueous sodium citrate) and Fehling's solution (Cu2+ in aqueous sodium tartrate). The reducing sugar reduces the copper(II) ions in these test solutions to copper(I), which then forms a brick red copper(I) oxide precipitate. Reducing sugars can also be
|
{
"page_id": 987423,
"source": null,
"title": "Reducing sugar"
}
|
detected with the addition of Tollen's reagent, which consist of silver ions (Ag+) in aqueous ammonia. When Tollen's reagent is added to an aldehyde, it precipitates silver metal, often forming a silver mirror on clean glassware. 3,5-dinitrosalicylic acid is another test reagent, one that allows quantitative detection. It reacts with a reducing sugar to form 3-amino-5-nitrosalicylic acid, which can be measured by spectrophotometry to determine the amount of reducing sugar that was present. Some sugars, such as sucrose, do not react with any of the reducing-sugar test solutions. However, a non-reducing sugar can be hydrolyzed using dilute hydrochloric acid. After hydrolysis and neutralization of the acid, the product may be a reducing sugar that gives normal reactions with the test solutions. All carbohydrates are converted to aldehydes and respond positively in Molisch's test. But the test has a faster rate when it comes to monosaccharides. == Importance in medicine == Fehling's solution was used for many years as a diagnostic test for diabetes, a disease in which blood glucose levels are dangerously elevated by a failure to produce enough insulin (type 1 diabetes) or by an inability to respond to insulin (type 2 diabetes). Measuring the amount of oxidizing agent (in this case, Fehling's solution) reduced by glucose makes it possible to determine the concentration of glucose in the blood or urine. This then enables the right amount of insulin to be injected to bring blood glucose levels back into the normal range. == Importance in food chemistry == === Maillard reaction === The carbonyl groups of reducing sugars react with the amino groups of amino acids in the Maillard reaction, a complex series of reactions that occurs when cooking food. Maillard reaction products (MRPs) are diverse; some are beneficial to human health, while others are toxic. However, the overall
|
{
"page_id": 987423,
"source": null,
"title": "Reducing sugar"
}
|
effect of the Maillard reaction is to decrease the nutritional value of food. One example of a toxic product of the Maillard reaction is acrylamide, a neurotoxin and possible carcinogen that is formed from free asparagine and reducing sugars when cooking starchy foods at high temperatures (above 120 °C). However, evidence from epidemiological studies suggest that dietary acrylamide is unlikely to raise the risk of people developing cancer. === Food quality === The level of reducing sugars in wine, juice, and sugarcane are indicative of the quality of these food products, and monitoring the levels of reducing sugars during food production has improved market quality. The conventional method for doing so is the Lane-Eynon method, which involves titrating the reducing sugar with copper(II) in Fehling's solution in the presence of methylene blue, a common redox indicator. However, it is inaccurate, expensive, and sensitive to impurities. == References ==
|
{
"page_id": 987423,
"source": null,
"title": "Reducing sugar"
}
|
This is a list of physicists who have worked in or made notable contributions to the field of plasma physics. == See also == Whistler (radio) waves Langmuir waves
|
{
"page_id": 1839391,
"source": null,
"title": "List of plasma physicists"
}
|
Conjunctive use is often used in discussing water supplies and water conservation. This phrase usually is used to describe the practice of storing surface water in a groundwater basin in wet years and withdrawing it from the basin in dry years. Conjunctive use consists of harmoniously combining the use of both surface water and groundwater in order to minimise the undesirable physical, environmental and economical effects of each solution and to optimise the water demand == References == This article incorporates public domain material from Jasper Womach. Report for Congress: Agriculture: A Glossary of Terms, Programs, and Laws, 2005 Edition (PDF). Congressional Research Service.
|
{
"page_id": 23597348,
"source": null,
"title": "Conjunctive use"
}
|
Heptyl acetate (C9H18O2), also known as acetate C-7, is a colorless alcohol-soluble liquid that is the ester formed by the condensation of 1-heptanol and acetic acid. Heptyl acetate is used as a fruit essence flavoring in foods and as a scent in perfumes. It has a woody, fruity, rumlike odor and a spicy, floral taste with a soapy, fatty texture. == References ==
|
{
"page_id": 5116197,
"source": null,
"title": "Heptyl acetate"
}
|
Olive oil regulation and adulteration are complex issues overseen and studied by various governmental bodies, non-governmental organizations, and private researchers across the world. The most frequent type of adulteration is that oil of lower quality is mixed into olive oil. == Background of regulation == The EU regulates the use of different protected designation of origin labels for olive oils. The International Olive Council (IOC) is an intergovernmental organization with 16 member states plus the European Union based in Madrid, Spain. It promotes olive oil around the world by tracking production, defining quality standards, and monitoring authenticity. More than 98 percent of the world's olives are grown in IOC member nations. The IOC officially governs 95 per cent of international production and holds great influence over the rest. IOC terminology is precise, but it can lead to confusion between the words that describe production and the words used on retail labels. Olive oil is classified by how it was produced, by its chemistry, and by its flavor. All production begins by transforming the olive fruit into olive paste. This paste is then malaxed to allow the microscopic oil droplets to concentrate. The oil is extracted by means of pressure (traditional method) or centrifugation (modern method). After extraction the remnant solid substance, called pomace, still contains a small quantity of oil. === United States === The United States is not a member of the IOC, and the US Department of Agriculture does not legally recognize its classifications, such as extra-virgin olive oil. In October 2011, the United States adopted new olive oil standards, revising those that had been in place since 1948, which affected importers and domestic growers and producers by ensuring conformity with the benchmarks commonly accepted in the U.S. and abroad. As of 1998, US Customs regulations on "country
|
{
"page_id": 21762341,
"source": null,
"title": "Olive oil regulation and adulteration"
}
|
of origin" have stated that if a non-origin nation is shown on the label, then the real origin must be shown on the same side of the label and in comparable size letters so as not to mislead the consumer. Yet most major US brands continue to put "imported from Italy" on the front label in large letters and other origins on the back in very small print. These products are a mixture of olive oil from more than one nation and it is not clear what percentage of the olive oil is really of Italian origin. This practice makes it difficult for high quality, lower cost producers outside of Italy to enter the US market, and for genuine Italian producers to compete. In the United States, the Food & Drug Administration (FDA) does not routinely test imported olive oil for adulteration. == Testing for purity == The detection of olive oil adulteration is often complicated with no single test that can accomplish the task. A battery of tests is employed to determine olive oil authenticity and identity of the adulterant. Included in this testing regime is the determination of free acidity, peroxide value, Ultraviolet light extinction, fatty acid composition, sterol composition, triglyceride composition, wax content, steroidal hydrocarbons, and the Bellier test. Methods employing chromatography/mass spectrometry and spectroscopy are also used to detect adulteration of olive oil Test results are measured against the International Olive Council trade standard to identify abnormalities. Each test provides key information which allows a decision to be made with respect to the grade of olive oil and the identity of any adulterants. However, the International Olive Council does not test for deodorisation which makes up the bulk of fake extra-virgin oils. Soft column deodorisation is the process where steam is forced through a tank of
|
{
"page_id": 21762341,
"source": null,
"title": "Olive oil regulation and adulteration"
}
|
inferior oil which removes all taste, colour and nutrients, colouring is then added before the tank is topped up with real extra-virgin oil to add flavour. A test published in 1887 described the detection of olive oil adulterated with mineral oil by a simple titration of the carboxylic acid moieties present in natural vegetable oils. The procedure involved boiling 10 milliliters of olive oil with 40 milliliters of approximately 1 molar potassium hydroxide in 95% ethanol, adding water to 100 grams to dissolve the saponified lipids, and titrating against a normal sulfuric acid solution using phenolphthalein as a pH indicator dye. The base stock solution was titrated to neutralize an equal quantity of the acid, so without the presence of vegetable oil it would require 40 milliliters of acid to cause a color change, but in the pure oils tested (almond, benne, cottonseed, cod liver oil, linseed oil, and olive oil, only 6 milliliters were required. In accordance with this, olive oil adulterated with 10% mineral oil required 8 milliliters, and with 20% 11 milliliters. The adulterated oil tested in 1887 required 14 to 17 milliliters to neutralize, so it might have been 30–40% mineral oil. DNA analysis methods, based on the use of polymerase chain reaction (PCR) (e.g. DNA fingerprinting), have also been used. These techniques require extensive sample preparation, which needs specific optimization to ensure extraction of sufficient DNA, and that PCR inhibitors are not affecting the analysis. To date, there is no DNA extraction method applicable to any sample. In 2014, an “invisible oil tag” using artificial, sub-micrometer-sized DNA barcodes was suggested by researchers from ETH Zurich. The barcodes consist of magnetically recoverable silica particles containing synthetic DNA sequences, which are added to the oil in a very small amount (down to 1 ppb) and can be
|
{
"page_id": 21762341,
"source": null,
"title": "Olive oil regulation and adulteration"
}
|
retrieved at any time for authenticity test by PCR/sequencing. The advantages of this method, compared to conventional techniques are its low-cost, minimal sample preparation and minute volumes, and its universalness, since it can be applied to any oil type/sample. === Industry certifications of quality === As of 2015, the North American Olive Oil Association offered a Quality Seal Program to guarantee authenticity of olive oil. Members of the association agreed to have their oils tested twice a year to ensure the oil meets or exceeds the International Olive Council (IOC) standards. The testing includes both sensory (taste/smell) and chemical tests for purity. Samples are purchased from the retail marketplace to ensure that the products tested are the same as the ones purchased by consumers. The test samples are not selected and submitted by olive oil producers. Brands pay for the testing through a yearly licensing fee. The California Olive Oil Council tests samples of olive oil submitted by producers for extra virgin quality. The samples are provided by the producers. The testing is primarily sensory with some chemical tests. The Extra Virgin Alliance offers the EVA Mark of quality and authenticity. The EVA standard includes both sensory and chemical parameters for olive oils at their Best Before Date. === Simple home tests === ==== Refrigeration ==== There is a persistent mistaken belief that when genuine olive oil (or, in some versions, extra virgin olive oil specifically) is refrigerated, it will solidify or become much more viscous. This mistaken belief is based on the fact that olive oil is composed mainly of the monounsaturated fat oleic acid, and pure oleic acid (triolein) has a melting point of 5 ˚C, which is slightly above the high end of proper refrigerator temperature. Thus, if olive oil were pure triolein, it would solidify in
|
{
"page_id": 21762341,
"source": null,
"title": "Olive oil regulation and adulteration"
}
|
a properly set refrigerator. However, olive oil is a complex mixture with significant variability in its fatty acid structure, and can be anywhere from 55% to 83% oleic acid, with the remainder a mixture of polyunsaturated fat and saturated fat, as well as containing waxes, phytosterols, and other compounds that affect its melting temperature. Thus, in practice, many olive oils have significantly lower melting temperatures. In fact, one might expect a refined seed oil with very high oleic acid content (such as high oleic sunflower oil) to be more likely to solidify in the refrigerator, based on their fatty acid composition and lack of minor compounds. The "fridge test" for adulteration was evaluated by scientists at the Olive Center at the University of California, Davis. Researchers put seven samples of different oils into a refrigerator at 4.7 ˚C, including a premium extra-virgin olive oil; low-quality extra-virgin olive oil; a blend of virgin and refined olive oil; refined canola oil; refined safflower oil; a 50:50 mixture of the premium extra virgin olive oil with the blended olive oil; and a 50:50 mixture of the premium extra virgin olive oil with the refined safflower oil. Several days of refrigeration was required before congealing of any of the samples became apparent. Although none of the samples solidified fully, the three which contained either 100% extra virgin olive oil or a 50:50 mix of extra virgin and blended olive oil had partially solidified after a week, whereas the other samples remained clear. The authors conclude that refrigeration is not reliable in detecting olive oil adulteration. However, based on these results, the absence or any visible congealing after a week of refrigeration would not be an encouraging sign if the olive oil had been sold as pure extra virgin. ==== Ignition ==== Pure olive oil
|
{
"page_id": 21762341,
"source": null,
"title": "Olive oil regulation and adulteration"
}
|
should burn in an oil lamp. The ignition test however, like the refrigerator test, is not conclusive. == Investigations, incidents, and recalls == As of 2021, the most frequent type of adulteration of olive oil is that oil of lower quality is mixed into it. Adulterated oil is usually no more serious than passing off inferior, but safe, products as superior olive oil, however in 1981 almost 700 people died, it is believed, as a consequence of consuming rapeseed (canola) oil adulterated with aniline intended for use as an industrial lubricant, but sold as olive oil in Spain (see toxic oil syndrome). In 1993, the FDA ordered a recall of Rubino U.S.A. Inc., (Cincinnati, Ohio) olive oils which were nothing more than canola oil. In 1997, the Canadian Food Inspection Agency began conducting tests on 100 oils claimed to be 100% olive oil and in 1999 the CFIA concluded that 20 per cent of the oils were fake. In 2007, NPR reported that with Italian extra-virgin olive oil in high demand with concomitant high prices, adulterated olive oil had become the biggest source of agricultural fraud problems in the European Union. Some oil labeled "extra-virgin" is diluted with cheaper olive oils or other vegetable oils. In some cases, lampante, or "lamp oil," which is made from spoiled olives fallen from trees, is used, even though it can't legally be sold as food. One fraud ring was accused of coloring low-grade soy oil and canola oil with industrial chlorophyll, and flavoring it with beta-carotene. In August 2007, The New Yorker stated that major Italian shippers routinely adulterate olive oil and that only about 40% of olive oil sold as "extra virgin" actually meets the specification. In some cases, colza oil with added color and flavor has been labeled and sold as
|
{
"page_id": 21762341,
"source": null,
"title": "Olive oil regulation and adulteration"
}
|
olive oil. This extensive fraud prompted the Italian government to mandate a new labeling law in 2007 for companies selling olive oil, under which every bottle of Italian olive oil would have to declare the farm and press on which it was produced, as well as display a precise breakdown of the oils used, for blended oils. In February 2008, however, EU officials took issue with the new law, stating that under EU rules such labeling should be voluntary rather than compulsory. Under EU rules, olive oil may be sold as Italian even if it only contains a small amount of Italian oil. In March 2008, 400 Italian police officers conducted "Operation Golden Oil", arresting 23 people and confiscating 85 farms after an investigation revealed a large-scale scheme to relabel oils from other Mediterranean nations as Italian. In April 2008, another operation impounded seven olive oil plants and arrested 40 people in nine provinces of northern and southern Italy for adding chlorophyll to sunflower and soybean oil and selling it as extra virgin olive oil, both in Italy and abroad. 25,000 liters of the fake oil were seized and prevented from being exported. In December 2008, the Guardia Civil in La Rioja (Spain) warned about the possible sale of adulterated olive oil in the area. This warning came after 550 litres of oil was found in a large container labelled "Astispumante 1510" in Rincón de Soto and after the theft of 1,750 litres of oil was reported in the area on December 18, 2008. In the first week of March 2010, researchers at the University of California at Davis' Olive Center purchased three bottles each of 14 imported olive oils and five California oils at retail stores in three different regions of California (Sacramento County, San Francisco Bay Area and
|
{
"page_id": 21762341,
"source": null,
"title": "Olive oil regulation and adulteration"
}
|
Los Angeles County). All of the oils were labeled "extra-virgin olive oil." Samples were shipped to the Australian Oils Research Laboratory in Wagga Wagga, and were analyzed by their laboratory (which is recognized by the IOC to provide chemical analysis of olive oil) and tested by their sensory panel (which is recognized by the IOC as qualified to perform olive oil sensory analysis). Duplicate testing was performed at the UC Davis olive oil research project laboratories. Sixty-nine percent of the imported olive oils and 10% of the California oils failed to meet the IOC/USDA taste standards for extra-virgin olive oil. Samples that failed had a median of up to 3.5 IOC-standardized sensory defects (such as rancid, fusty, and musty). The standard IOC/USDA chemical tests only identified 31% of the failed oils as defective, primarily by exceeding the IOC/USDA limit for ultraviolet absorbance of late oxidation products (K232 and K268); two more recently introduced German chemical tests (now incorporated into the Australian extra-virgin standard) were each more than twice as effective at detection of defective oils. A subsequent round of testing in 2011 found similar results. The UC Davis report was contested by the North American Olive Oil Association on the grounds that UC Davis has a conflict of interest due to the fact that they market their own olive oil and have an interest in promoting olive oil from California. The IOC stated that the study contained "[an] evident undercurrent of aggressive, inexplicable criticism of imported olive oil quality". In March 2011, the Florence, Italy, prosecutor’s office, working in conjunction with the forestry department, indicted two managers and an officer of Carapelli, one of the brands of the Spanish company Grupo SOS (which recently changed its name to Deoleo) and Pietro Coricelli. The charges involved falsified documents and food fraud.
|
{
"page_id": 21762341,
"source": null,
"title": "Olive oil regulation and adulteration"
}
|
Carapelli lawyer Neri Pinucci said the company was not worried about the charges and that "the case is based on an irregularity in the documents". However, in June 2017 the Italian Antitrust Authority (Autorità Garante della Concorrenza e del Mercato), found them guilty of unfair business practices regarding their olive oil brands and imposed fines on them and the discount supermarket chain Lidl, amounting to nearly €1 million. In 2012, The Advertiser wrote that while only less than 10% of world olive oil production met the criteria for labeling as extra-virgin, it had been estimated that up to 50% of retail oil is labeled "extra-virgin". Tests by the Australian Olive Association (AOA) in 2012 showed that every imported brand of extra-virgin olive oil fell below the standard that would be required for AOA certification. The AOA has been campaigning to have the Australian Competition & Consumer Commission force supermarkets to adhere to the code. Standards Australia has adopted a code of practice for the testing of olive oils; however, while allowing oils to be certified as being genuine extra-virgin, the code regarding labeling is voluntary. In 2013, "Figures released at the [IOC's] Workshop on Olive Oil Authentication, held in Madrid June 10–11, showed that one in four olive oils sampled in Spain, and nearly one in three in Canada, failed recent official fraud tests." In June 2017, the Olive Oil Times published, that according to independent testing, oil from the brands Bertolli, Carapelli, Coricelli, Primadonna, and Sasso labelled as "extra virgin" was in fact only "virgin". In December 2023, it was reported that the Spanish Civil Guard and the Italian Carabinieri together with Europol had arrested 11 people, who adulterated more than 260,000 liters, or roughly 68,000 gallons, of olive oil with lampante oil in november in Sicily, Tuscany and
|
{
"page_id": 21762341,
"source": null,
"title": "Olive oil regulation and adulteration"
}
|
Ciudad Real in Spain. See Olive oil raids of 2023 in Europe for more. == See also == Extra Virginity: The Sublime and Scandalous World of Olive Oil Tom Mueller's book on olive oil == References ==
|
{
"page_id": 21762341,
"source": null,
"title": "Olive oil regulation and adulteration"
}
|
In the placenta, the intervillous space is the space between chorionic villi, and contains maternal blood. The trophoblast, which is a collection of cells that invades the maternal endometrium to gain access to nutrition for the fetus, proliferates rapidly and forms a network of branching processes which cover the entire embryo and invade and destroy the maternal tissues. With this physiologic destructive process, the maternal blood vessels of the endometrium are opened, with the result that the spaces in the trophoblastic network are filled with maternal blood; these spaces communicate freely with one another and become greatly distended and form the intervillous space from which the fetus gains nutrition. Maternal arteries and veins directly enter the intervillous space after 8 weeks gestation, and the intervillous space will contain about a unit of blood (400–500 mL). Much of this blood is returned to the mother with normal uterine contractions; thus, when a woman has a cesarean section, she is liable to lose more blood than a woman who has a vaginal delivery, as the blood from the intervillous space is not pushed back toward her body during such a delivery. == References == This article incorporates text in the public domain from page 59 of the 20th edition of Gray's Anatomy (1918) == External links == Histology image: 19902loa – Histology Learning System at Boston University
|
{
"page_id": 8196390,
"source": null,
"title": "Intervillous space"
}
|
This is a list of sulfonamides used in medicine. == Antimicrobials == Short-acting Sulfacetamide Sulfadiazine Sulfadimidine Sulfafurazole (sulfisoxazole) Sulfisomidine (sulfaisodimidine) Sulfaguanidine Intermediate-acting Sulfamethoxazole Sulfamoxole Sulfanitran Long-acting Sulfadimethoxine Sulfamethoxypyridazine Sulfametoxydiazine Ultra long-acting Sulfadoxine Sulfametopyrazine Terephtyl == Sulfonylureas (anti-diabetic agents) == Acetohexamide Carbutamide Chlorpropamide Glibenclamide (glyburide) Glibornuride Gliclazide Glyclopyramide Glimepiride Glipizide Gliquidone Glisoxepide Glicaramide Tolazamide Tolbutamide == Diuretics == Acetazolamide Bumetanide Chlorthalidone Chlorothiazide Clopamide Furosemide Hydrochlorothiazide Indapamide Mefruside Metolazone Xipamide Methazolamide Torasemide == Anticonvulsants == Ethoxzolamide Sultiame Zonisamide == Dermatologicals == Mafenide == Antiretrovirals == Amprenavir (HIV protease inhibitor) Darunavir (HIV protease inhibitor) Delavirdine (non-nucleoside reverse transcriptase inhibitor) Fosamprenavir (HIV protease inhibitor) Tipranavir (HIV protease inhibitor) == Hepatitis C antivirals == Asunaprevir (NS3/4A protease inhibitor) Beclabuvir (NS5B RNA polymerase inhibitor) Dasabuvir (NS5B RNA polymerase inhibitor) Grazoprevir (NS3/4A protease inhibitor) Paritaprevir (NS3/4A protease inhibitor) Simeprevir (NS3/4A protease inhibitor) == Stimulants == Azabon == NSAIDs == Apricoxib (COX-2 inhibitor) Celecoxib (COX-2 inhibitor) Parecoxib (COX-2 inhibitor) == Cardiac and Vasoactive Medications == Bosentan (endothelin receptor antagonist) Diazoxide (insulin release inhibitor and vasodilator) Dofetilide (class III antiarrhythmic) Dronedarone (class III antiarrhythmic) Ibutilide (class III antiarrhythmic) Sotalol (β blocker) Tamsulosin (α blocker) Udenafil (PDE5 inhibitor) == Triptans == Almotriptan (antimigraine) Sumatriptan (antimigraine) Naratriptan (antimigraine) == Others == Brinzolamide (carbonic anhydrase inhibitor for glaucoma) Dorzolamide (anti-glaucoma carbonic anhydrase inhibitor) Famotidine (histamine H2 receptor antagonist) Probenecid (uricosuric) Sulfasalazine (anti-inflammatory agent and a DMARD) Vemurafenib (anticancer B-Raf inhibitor) == References == == External links == List of sulfonamides Author of The Demon Under the Microscope, a history of the discovery of the sulfa drugs A History of the Fight Against Tuberculosis in Canada (Chemotherapy) Presentation speech, Nobel Prize in Physiology and Medicine, 1939 The History of WW II Medicine "Five Medical Miracles of the Sulfa Drugs". Popular Science, June 1942, pp. 73–78. A history of antibiotics
|
{
"page_id": 65736999,
"source": null,
"title": "List of sulfonamides"
}
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.