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Furthermore, the Arctic region is warming faster than the Antarctic and faster than northern mid-latitudes and subtropics, despite polar regions receiving less sun than lower latitudes.
Altitude
Solar forcing should warm Earth's atmosphere roughly evenly by altitude, with some variation by wavelength/energy regime. H... | Solar activity and climate | Wikipedia | 485 | 47491846 | https://en.wikipedia.org/wiki/Solar%20activity%20and%20climate | Physical sciences | Climate change | Earth science |
Stott's 2003 work largely revised his assessment, and found a significant solar contribution to recent warming, although still smaller (between 16 and 36%) than that of greenhouse gases.
A study in 2004 concluded that solar activity affects the climate - based on sunspot activity, yet plays only a small role in the cu... | Solar activity and climate | Wikipedia | 466 | 47491846 | https://en.wikipedia.org/wiki/Solar%20activity%20and%20climate | Physical sciences | Climate change | Earth science |
Solar activity may also impact regional climates, such as for the rivers Paraná and Po. Measurements from NASA's Solar Radiation and Climate Experiment show that solar UV output is more variable than total solar irradiance. Climate modelling suggests that low solar activity may result in, for example, colder winters in... | Solar activity and climate | Wikipedia | 497 | 47491846 | https://en.wikipedia.org/wiki/Solar%20activity%20and%20climate | Physical sciences | Climate change | Earth science |
The Balinese is a long-haired breed of domestic cat with Siamese-style point coloration and sapphire-blue eyes. The Balinese is also known as the purebred long-haired Siamese since it originated as a natural mutation of that breed and hence is essentially the same cat but with a medium-length silky coat and a distincti... | Balinese cat | Wikipedia | 383 | 42964218 | https://en.wikipedia.org/wiki/Balinese%20cat | Biology and health sciences | Cats | Animals |
A breeder named Sylvia Holland (who was also an illustrator for Walt Disney Studios) worked to further establish the breed standard in the 1960s and 1970s. She recognized only cats showing the classic Siamese points in seal, chocolate, blue, and lilac as true Balinese, refusing to accept others because they had likely ... | Balinese cat | Wikipedia | 503 | 42964218 | https://en.wikipedia.org/wiki/Balinese%20cat | Biology and health sciences | Cats | Animals |
This movement has brought The Cat Fanciers' Association more in line with the other worldwide registries. The Cat Fanciers' Association made this change since the two councils in their organization (Balinese and Javanese) were overlapping around an average of 50 to 75% with the same members who breed and exhibited the ... | Balinese cat | Wikipedia | 459 | 42964218 | https://en.wikipedia.org/wiki/Balinese%20cat | Biology and health sciences | Cats | Animals |
The Cat Fanciers' Federation and most other associations worldwide accept the Balinese breed in seal, blue, chocolate, lilac, red, and cream point, besides tortoiseshell and lynx points in all of these colors. The Cat Fanciers' Association standard continues to accept the Balinese in only the classic seal, blue, chocol... | Balinese cat | Wikipedia | 473 | 42964218 | https://en.wikipedia.org/wiki/Balinese%20cat | Biology and health sciences | Cats | Animals |
Metascience (also known as meta-research) is the use of scientific methodology to study science itself. Metascience seeks to increase the quality of scientific research while reducing inefficiency. It is also known as "research on research" and "the science of science", as it uses research methods to study how research... | Metascience | Wikipedia | 381 | 53147698 | https://en.wikipedia.org/wiki/Metascience | Physical sciences | Science basics | Basics and measurement |
In 1966, an early meta-research paper examined the statistical methods of 295 papers published in ten high-profile medical journals. It found that, "in almost 73% of the reports read ... conclusions were drawn when the justification for these conclusions was invalid." A paper in 1976 called for funding for meta-researc... | Metascience | Wikipedia | 512 | 53147698 | https://en.wikipedia.org/wiki/Metascience | Physical sciences | Science basics | Basics and measurement |
Metascience seeks to identify poor research practices, including biases in research, poor study design, abuse of statistics, and to find methods to reduce these practices. Meta-research has identified numerous biases in scientific literature. Of particular note is the widespread misuse of p-values and abuse of statisti... | Metascience | Wikipedia | 471 | 53147698 | https://en.wikipedia.org/wiki/Metascience | Physical sciences | Science basics | Basics and measurement |
Moreover, replication of research (or failure to replicate) is considered less influential than original research, and is less likely to be published in many fields. This discourages the reporting of, and even attempts to replicate, studies.
Evaluation and incentives
Metascience seeks to create a scientific foundati... | Metascience | Wikipedia | 375 | 53147698 | https://en.wikipedia.org/wiki/Metascience | Physical sciences | Science basics | Basics and measurement |
Assessment factors
Factors other than a submission's merits can substantially influence peer reviewers' evaluations. Such factors may however also be important such as the use of track-records about the veracity of a researchers' prior publications and its alignment with public interests. Nevertheless, evaluation syste... | Metascience | Wikipedia | 420 | 53147698 | https://en.wikipedia.org/wiki/Metascience | Physical sciences | Science basics | Basics and measurement |
Incentives
Various interventions such as prioritization can be important. For instance, the concept of differential technological development refers to deliberately developing technologies – e.g. control-, safety- and policy-technologies versus risky biotechnologies – at different precautionary paces to decrease risks... | Metascience | Wikipedia | 496 | 53147698 | https://en.wikipedia.org/wiki/Metascience | Physical sciences | Science basics | Basics and measurement |
Funding data
Funding information from grant databases and funding acknowledgment sections can be sources of data for scientometrics studies, e.g. for investigating or recognition of the impact of funding entities on the development of science and technology.
Research questions and coordination
Risk governance
Scienc... | Metascience | Wikipedia | 457 | 53147698 | https://en.wikipedia.org/wiki/Metascience | Physical sciences | Science basics | Basics and measurement |
Knowledge integration
Primary studies "without context, comparison or summary are ultimately of limited value" and various types of research syntheses and summaries integrate primary studies. Progress in key social-ecological challenges of the global environmental agenda is "hampered by a lack of integration and synthe... | Metascience | Wikipedia | 500 | 53147698 | https://en.wikipedia.org/wiki/Metascience | Physical sciences | Science basics | Basics and measurement |
Metascience can investigate how scientific processes evolve over time. A study found that teams are growing in size, "increasing by an average of 17% per decade".
It was found that prevalent forms of non-open access publication and prices charged for many conventional journals – even for publicly funded papers – are ... | Metascience | Wikipedia | 484 | 53147698 | https://en.wikipedia.org/wiki/Metascience | Physical sciences | Science basics | Basics and measurement |
Metascience research is investigating the growth of science overall, using e.g. data on the number of publications in bibliographic databases. A study found segments with different growth rates appear related to phases of "economic (e.g., industrialization)" – money is considered as necessary input to the science syste... | Metascience | Wikipedia | 454 | 53147698 | https://en.wikipedia.org/wiki/Metascience | Physical sciences | Science basics | Basics and measurement |
Various ways of measuring "novelty" of studies, novelty metrics, have been proposed to balance a potential anti-novelty bias – such as textual analysis or measuring whether it makes first-time-ever combinations of referenced journals, taking into account the difficulty. Other approaches include pro-actively funding ris... | Metascience | Wikipedia | 452 | 53147698 | https://en.wikipedia.org/wiki/Metascience | Physical sciences | Science basics | Basics and measurement |
Studies about a specific research question or research topic are often reviewed in the form of higher-level overviews in which results from various studies are integrated, compared, critically analyzed and interpreted. Examples of such works are scientific reviews and meta-analyses. These and related practices face var... | Metascience | Wikipedia | 446 | 53147698 | https://en.wikipedia.org/wiki/Metascience | Physical sciences | Science basics | Basics and measurement |
Mentorship, partnerships and social factors
Other researchers reported that the most successful – in terms of "likelihood of prizewinning, National Academy of Science (NAS) induction, or superstardom" – protégés studied under mentors who published research for which they were conferred a prize after the protégés' mento... | Metascience | Wikipedia | 510 | 53147698 | https://en.wikipedia.org/wiki/Metascience | Physical sciences | Science basics | Basics and measurement |
As and for acceleration of progress
A study suggests that improving the way science is done could accelerate the rate of scientific discovery and its applications which could be useful for finding urgent solutions to humanity's problems, improve humanity's conditions, and enhance understanding of nature. Metascientific... | Metascience | Wikipedia | 410 | 53147698 | https://en.wikipedia.org/wiki/Metascience | Physical sciences | Science basics | Basics and measurement |
The EQUATOR (Enhancing the QUAlity and Transparency Of health Research) Network is an international initiative aimed at promoting transparent and accurate reporting of health research studies to enhance the value and reliability of medical research literature. The EQUATOR Network was established with the goals of rais... | Metascience | Wikipedia | 426 | 53147698 | https://en.wikipedia.org/wiki/Metascience | Physical sciences | Science basics | Basics and measurement |
Search engines like Google Scholar are used to find studies and the notification service Google Alerts enables notifications for new studies matching specified search terms. Scholarly communication infrastructure includes search databases.
Shadow library Sci-hub is a topic of metascience
Personal knowledge management... | Metascience | Wikipedia | 463 | 53147698 | https://en.wikipedia.org/wiki/Metascience | Physical sciences | Science basics | Basics and measurement |
Studies have shown that systematic reviews of existing research evidence are sub-optimally used in planning a new research or summarizing the results. Cumulative meta-analyses of studies evaluating the effectiveness of medical interventions have shown that many clinical trials could have been avoided if a systematic re... | Metascience | Wikipedia | 491 | 53147698 | https://en.wikipedia.org/wiki/Metascience | Physical sciences | Science basics | Basics and measurement |
Richard Feynman noted that estimates of physical constants were closer to published values than would be expected by chance. This was believed to be the result of confirmation bias: results that agreed with existing literature were more likely to be believed, and therefore published. Physicists now implement blinding t... | Metascience | Wikipedia | 361 | 53147698 | https://en.wikipedia.org/wiki/Metascience | Physical sciences | Science basics | Basics and measurement |
An anatomical variation, anatomical variant, or anatomical variability is a presentation of body structure with morphological features different from those that are typically described in the majority of individuals. Anatomical variations are categorized into three types including morphometric (size or shape), consiste... | Anatomical variation | Wikipedia | 408 | 51596724 | https://en.wikipedia.org/wiki/Anatomical%20variation | Biology and health sciences | Basic anatomy | Biology |
The evolution of bitter taste receptors has been one of the most dynamic evolutionary adaptations to arise in multiple species. This phenomenon has been widely studied in the field of evolutionary biology because of its role in the identification of toxins often found on the leaves of inedible plants. A palate more sen... | Bitter taste evolution | Wikipedia | 446 | 44419326 | https://en.wikipedia.org/wiki/Bitter%20taste%20evolution | Biology and health sciences | Sensory nervous system | Biology |
Toxins as the primary selective force
The primary selective adaptation that arises from bitter taste is to detect poisonous compounds, as most poisonous compounds in nature are bitter. However, this trait is not always advantageous, as bitter compounds exist in nature that are not poisonous. Exclusive rejection of the... | Bitter taste evolution | Wikipedia | 325 | 44419326 | https://en.wikipedia.org/wiki/Bitter%20taste%20evolution | Biology and health sciences | Sensory nervous system | Biology |
TAS2R development in human history
The pseudogenes mentioned earlier are produced by a number of gene silencing events, the rate of which is constant throughout primate species. Several of these pseudogenes maintain a role in modulating taste response, however. By studying the silencing events in humans, it is possibl... | Bitter taste evolution | Wikipedia | 495 | 44419326 | https://en.wikipedia.org/wiki/Bitter%20taste%20evolution | Biology and health sciences | Sensory nervous system | Biology |
Relaxed constraint
Neutral evolution in the bitter taste trait in humans is well documented by evolutionary biologists. In all human populations there have been high rates of synonymous and non-synonymous substitutions that cause pseudogenization. These events cause alleles that are present to this day because of rela... | Bitter taste evolution | Wikipedia | 329 | 44419326 | https://en.wikipedia.org/wiki/Bitter%20taste%20evolution | Biology and health sciences | Sensory nervous system | Biology |
There are numerous effects of climate change on agriculture, many of which are making it harder for agricultural activities to provide global food security. Rising temperatures and changing weather patterns often result in lower crop yields due to water scarcity caused by drought, heat waves and flooding. These effects... | Effects of climate change on agriculture | Wikipedia | 478 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
The scientific consensus is that global food security will change relatively little in the near-term. 720 million to 811 million people were undernourished in 2021, with around 200,000 people being at a catastrophic level of food insecurity. Climate change is expected to add an additional 8 to 80 million people who are... | Effects of climate change on agriculture | Wikipedia | 414 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
In Europe, between 1950 and 2019, heat extremes have become more frequent and also more likely to occur consecutively, while cold extremes have declined. At the same time, Northern Europe and much of Eastern Europe was found to experience extreme precipitation more often, while the Mediterranean became more affected by... | Effects of climate change on agriculture | Wikipedia | 434 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
Higher winter temperatures and more frost-free days in some regions can currently be disruptive, as they can cause phenological mismatch between flowering time of plants and the activity of pollinators, threatening their reproductive success. In the longer term, however, they would result in longer growing seasons. For... | Effects of climate change on agriculture | Wikipedia | 476 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
In total, this means that droughts have been occurring more frequently on average because of climate change. Africa, southern Europe, the Middle East, most of the Americas, Australia, South and Southeast Asia are the parts of the globe where droughts are expected to become more frequent and intense in spite of the glob... | Effects of climate change on agriculture | Wikipedia | 461 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
Changes in atmospheric carbon dioxide may reduce the nutritional quality of some crops, with for instance wheat having less protein and less of some minerals. The nutritional quality of C3 plants (e.g. wheat, oats, rice) is especially at risk: lower levels of protein as well as minerals (for example zinc and iron) are... | Effects of climate change on agriculture | Wikipedia | 439 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
Alongside a decrease in minerals, evidence shows that plants contain 6% more carbon, 15% less nitrogen, 9% less phosphorus, and 9% less sulfur at double conditions. The increase in carbon is mostly attributed to carbohydrates without a structural role in plants – the human-digestable, calorie-providing starch and simp... | Effects of climate change on agriculture | Wikipedia | 469 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
Agricultural land loss from sea level rise
A rise in the sea level would result in an agricultural land loss, in particular in areas such as South East Asia. Erosion, submergence of shorelines, salinity of the water table due to the increased sea levels, could mainly affect agriculture through inundation of low-lying ... | Effects of climate change on agriculture | Wikipedia | 462 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
Climate change is expected to have a negative effect on many insects, greatly reducing their species distribution and thus increasing their risk of going extinct. Around 9% of agricultural production is dependent in some way on insect pollination, and some pollinator species are also adversely affected, with wild bumbl... | Effects of climate change on agriculture | Wikipedia | 471 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
Weeds also undergo the same acceleration of cycles as cultivated crops, and would also benefit from CO2 fertilization. Since most weeds are C3 plants, they are likely to compete even more than now against C4 crops such as corn. The increased levels are also expected to increase the tolerance of weeds to herbicides, re... | Effects of climate change on agriculture | Wikipedia | 444 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
According to the IPCC Sixth Assessment Report from 2022, there is high confidence that in and of itself, climate change to date has left primarily negative effects on both crop yields and quality of produce, although there has been some regional variation: more negative effects have been observed for some crops in low-... | Effects of climate change on agriculture | Wikipedia | 487 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
Between 1961 and 1985, cereal production more than doubled in developing nations, largely due to the development of irrigation, fertilizer, and seed varieties. Even in the absence of further scientific/technological developments, many of the existing advancements have not been evenly distributed, and their spread from ... | Effects of climate change on agriculture | Wikipedia | 435 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
In 2021, a paper which used an ensemble of 21 climate models estimated that under the most intense climate change scenario used at the time, RCP8.5, global yields of these four crops would decline by between 3–12% around 2050 and by 11–25% by the year 2100. The losses were concentrated in what are currently the major a... | Effects of climate change on agriculture | Wikipedia | 429 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
Studies indicate that on their own, temperature changes reduce global rice yields by 3.2% for every of global warming. Projections become more complicated once the changes in precipitation, fertilization effect and other factors need to be taken into account: for instance, climate effects on rice growth in East Asia ... | Effects of climate change on agriculture | Wikipedia | 458 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
Studies have shown that when levels rise, soybean leaves are less nutritious; therefore plant-eating beetles have to eat more to get their required nutrients. In addition, soybeans are less capable of defending themselves against the predatory insects under high . The diminishes the plant's jasmonic acid production, ... | Effects of climate change on agriculture | Wikipedia | 443 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
As well as affecting potatoes directly, climate change will also affect the distributions and populations of many potato diseases and pests. For instance, late blight is predicted to become a greater threat in some areas (e.g. in Finland) and become a lesser threat in others (e.g. in the United Kingdom Altogether, one ... | Effects of climate change on agriculture | Wikipedia | 491 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
As of 2017, around 821 million people had suffered from hunger. This was equivalent to about 11% of the world population: regionally, this included 23.2% of sub-Saharan Africa, 16.5% of the Caribbean and 14.8% of South Asia. In 2021, 720 million to 811 million people were considered undernourished in 2021 (of whom 200,... | Effects of climate change on agriculture | Wikipedia | 493 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
Some scientists consider the aforementioned projections of crop yields and food security of limited use, because in their view, they primarily model climate change as a change in mean climate state, and are not as well-equipped to consider climatic extremes. For instance, a paper published in 2021 had also attempted to... | Effects of climate change on agriculture | Wikipedia | 432 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
Yet, another paper from 2021 suggested that by 2100, under the high-emission SSP5-8.5, 31% and 34% of the current crop and livestock production would leave what the authors have defined as a "safe climatic space": that is, those areas (most of South Asia and the Middle East, as well as parts of sub-Saharan Africa and C... | Effects of climate change on agriculture | Wikipedia | 456 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
According to a 2016 estimate, if global maize, rice and wheat exports declined by 10%, 55 million people in 58 poor countries lose at least 5% of their food supply. Further, two specific Rossby wave pattern are known to induce simultaneous heat extremes in either Eastern Asia, Eastern Europe and Central North America, ... | Effects of climate change on agriculture | Wikipedia | 457 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
Similarly, North China Plain is also expected to be highly affected, in part due to the region's extensive irrigation networks resulting in unusually moist air. In scenarios without aggressive action to stop climate change, some heatwaves could become extreme enough to cause mass mortality in outdoor labourers, althoug... | Effects of climate change on agriculture | Wikipedia | 467 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
Different Asian Countries have various effects from climate change. China, for example, benefits from a temperature increase scenario accompanying with carbon fertilization and leading to a 3% gain of US$18 billion per year; however, India will face two thirds of the continent's aggregate losses on agriculture because... | Effects of climate change on agriculture | Wikipedia | 477 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
The major agricultural products of Latin America include livestock and grains; such as maize, wheat, soybeans, and rice. Increased temperatures and altered hydrological cycles are predicted to translate to shorter growing seasons, overall reduced biomass production, and lower grain yields. Brazil, Mexico and Argentina ... | Effects of climate change on agriculture | Wikipedia | 493 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
Adaptation
Climate change adaptation measures may reduce the risk of negative effects on agriculture from climate change. Adaptation can occur through changes in management practices, agricultural innovation, institutional changes, and climate-smart agriculture. To create a sustainable food system, these measures are ... | Effects of climate change on agriculture | Wikipedia | 210 | 47512577 | https://en.wikipedia.org/wiki/Effects%20of%20climate%20change%20on%20agriculture | Physical sciences | Climate change | Earth science |
In chemical nomenclature, a descriptor is a notational prefix placed before the systematic substance name, which describes the configuration or the stereochemistry of the molecule. Some of the listed descriptors should not be used in publications, as they no longer accurately correspond with the recommendations of the... | Descriptor (chemistry) | Wikipedia | 411 | 53165654 | https://en.wikipedia.org/wiki/Descriptor%20%28chemistry%29 | Physical sciences | Nomenclature | Chemistry |
For the attribution of (E) or (Z) is based on the relative position of the two substituents of highest priority are on each side of the double bond, while the priority is based on the CIP nomenclature. The (E)/(Z) nomenclature can be applied to any double bond systems (including heteroatoms), but not to substituted rin... | Descriptor (chemistry) | Wikipedia | 504 | 53165654 | https://en.wikipedia.org/wiki/Descriptor%20%28chemistry%29 | Physical sciences | Nomenclature | Chemistry |
If a bridged bicyclic system carries a substituent at the shortest bridge, the exo or endo descriptor can not be used for its assignment. Such isomers are classified by the syn/anti notation. If the substituent to be assigned points towards the ring with the highest number of segments it is syn configured (from Greek s... | Descriptor (chemistry) | Wikipedia | 434 | 53165654 | https://en.wikipedia.org/wiki/Descriptor%20%28chemistry%29 | Physical sciences | Nomenclature | Chemistry |
n, iso, neo, cyclo
The prefixes n (normal), iso (from Greek ísos = equal), neo (Greek néos = young, new) and cyclo (Greek kyklos = circle) are primarily used to describe the arrangement of atoms, usually of carbon atoms in carbon skeleton. n, iso and neo are no longer used in the systematic nomenclature, but still fre... | Descriptor (chemistry) | Wikipedia | 442 | 53165654 | https://en.wikipedia.org/wiki/Descriptor%20%28chemistry%29 | Physical sciences | Nomenclature | Chemistry |
The terms sec and tert are considered obsolete and should only be used for unsubstituted sec-butoxy, sec-butyl or tert-butyl groups. There are various spellings such as "sec-butyl", "s-butyl", "sBu" or "bus" which are also considered obsolete.
spiro
The prefix "spiro" followed by a Von-Baeyer descriptor describes in ... | Descriptor (chemistry) | Wikipedia | 448 | 53165654 | https://en.wikipedia.org/wiki/Descriptor%20%28chemistry%29 | Physical sciences | Nomenclature | Chemistry |
If one molecule contains several stereocenters, a locant must be placed before the descriptor (for example, in (1R, 2S)-2-amino-1-phenylpropan-1-ol, the systematic designation of norephedrine). If all stereocenters are configured the same, the naming of the locants can be omitted in favor of an "all-R" or "(all-S)" spe... | Descriptor (chemistry) | Wikipedia | 510 | 53165654 | https://en.wikipedia.org/wiki/Descriptor%20%28chemistry%29 | Physical sciences | Nomenclature | Chemistry |
The descriptors D- and L- are written as small capitals and separated by a hyphen from the rest of the name.
d-, l-
Sometimes the small capital D- and L- stereodescriptors mentioned above are mistakenly confused with the obsolete italic d- and l- stereodescriptors, which are equivalent with dextrorotatory and levor... | Descriptor (chemistry) | Wikipedia | 102 | 53165654 | https://en.wikipedia.org/wiki/Descriptor%20%28chemistry%29 | Physical sciences | Nomenclature | Chemistry |
The Central Asian Orogenic Belt (CAOB), also called the Altaids, is one of the world's largest Phanerozoic accretionary orogens, and thus a leading laboratory of geologically recent crustal growth. The orogenic belt is bounded by the East European Craton and the North China Craton in the Northwest-Southeast direction, ... | Central Asian Orogenic Belt | Wikipedia | 411 | 68728719 | https://en.wikipedia.org/wiki/Central%20Asian%20Orogenic%20Belt | Physical sciences | Geologic features | Earth science |
Location
Like any typical accretionary orogen, the Central Asian Orogenic Belt is long and wide. It occupies roughly 30% of the land surface area of the entire Asia. It is located within the boundary of six nations, which are China, Kazakhstan, Kyrgyzstan, Mongolia, Russia, and Uzbekistan. The Central Asian Orogenic Be... | Central Asian Orogenic Belt | Wikipedia | 440 | 68728719 | https://en.wikipedia.org/wiki/Central%20Asian%20Orogenic%20Belt | Physical sciences | Geologic features | Earth science |
In Precambrian time, the major terrane of the Kazakhstan orocline was mainly Mesoproterozoic metamorphic rocks, which potentially had Gondwana affinity. They were then covered by the sediments from Neoproterozoic and Cambrian to Lower Ordovician. Island arc volcanic rocks, and chert formed in deep sea environments were... | Central Asian Orogenic Belt | Wikipedia | 386 | 68728719 | https://en.wikipedia.org/wiki/Central%20Asian%20Orogenic%20Belt | Physical sciences | Geologic features | Earth science |
For the northern portion of the orocline, it contains Precambrian to early Paleozoic metamorphic rocks, Neoproterozoic ophiolites, volcanic rocks formed in the early Paleozoic island arcs, and some associated volcaniclastic sediments. These rocks were then covered by the Devonian to Carboniferous sediments and were inf... | Central Asian Orogenic Belt | Wikipedia | 492 | 68728719 | https://en.wikipedia.org/wiki/Central%20Asian%20Orogenic%20Belt | Physical sciences | Geologic features | Earth science |
The first hypothesis states that the southern margin of the Siberian continent was formed from the accretion of multiple oceanic arcs and possibly parts of continents derived from Gondwana, a supercontinent existed from the Neoproterozoic to Jurassic, to the Russia, Siberian, and North China cratons.
This hypothesis s... | Central Asian Orogenic Belt | Wikipedia | 281 | 68728719 | https://en.wikipedia.org/wiki/Central%20Asian%20Orogenic%20Belt | Physical sciences | Geologic features | Earth science |
This hypothesis suggests that Baltica craton was attached with Siberia craton during the period Ediacaran. Their locations during Ediacaran were confirmed from paleomagnetic data. Continental rifting between Baltica and Siberia happened from late Ediacaran to Cambrian (610-520 Myr). During this period, collision of mic... | Central Asian Orogenic Belt | Wikipedia | 473 | 68728719 | https://en.wikipedia.org/wiki/Central%20Asian%20Orogenic%20Belt | Physical sciences | Geologic features | Earth science |
Finally, during the Late Permian (225–251 Myr), the shearing direction of Baltica and Siberia reversed as the Gornostaev shear zone moved to the south and east of Siberia. With this final act during the Late Permian, Sengor's hypothesis on the Central Asian Orogenic Belt evolution was completed | Central Asian Orogenic Belt | Wikipedia | 67 | 68728719 | https://en.wikipedia.org/wiki/Central%20Asian%20Orogenic%20Belt | Physical sciences | Geologic features | Earth science |
It was estimated that around 2.5 million square kilometers of juvenile materials were added to Asia in around 350 million years, making the Central Asian Orogenic Belt to be one of the most important juvenile crust formations since the end of the Proterozoic. However, some geologists suggested that the extent of juveni... | Central Asian Orogenic Belt | Wikipedia | 381 | 68728719 | https://en.wikipedia.org/wiki/Central%20Asian%20Orogenic%20Belt | Physical sciences | Geologic features | Earth science |
For gold, a large gold mine was found in the Nenjian-Heihe melange zone within the CAOB. This gold mine, namely the Yongxin gold deposit, is a fracture-controlled gold deposit with a thickness of 52m at the largest ore body. Pyrite, which is the most important mineral that host gold, could be found in the mine. The CAO... | Central Asian Orogenic Belt | Wikipedia | 343 | 68728719 | https://en.wikipedia.org/wiki/Central%20Asian%20Orogenic%20Belt | Physical sciences | Geologic features | Earth science |
A body () is the physical material of an organism. It is only used for organisms which are in one part or whole. There are organisms which change from single cells to whole organisms: for example, slime molds. For them the term 'body' would mean the multicellular stage. Other uses:
Plant body: plants are modular, with ... | Body (biology) | Wikipedia | 338 | 60871168 | https://en.wikipedia.org/wiki/Body%20%28biology%29 | Biology and health sciences | Animal anatomy and morphology | Biology |
In mathematics and mathematical logic, Boolean algebra is a branch of algebra. It differs from elementary algebra in two ways. First, the values of the variables are the truth values true and false, usually denoted 1 and 0, whereas in elementary algebra the values of the variables are numbers. Second, Boolean algebra u... | Boolean algebra | Wikipedia | 490 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
In the 1930s, while studying switching circuits, Claude Shannon observed that one could also apply the rules of Boole's algebra in this setting, and he introduced switching algebra as a way to analyze and design circuits by algebraic means in terms of logic gates. Shannon already had at his disposal the abstract mathem... | Boolean algebra | Wikipedia | 377 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
Values
Whereas expressions denote mainly numbers in elementary algebra, in Boolean algebra, they denote the truth values false and true. These values are represented with the bits, 0 and 1. They do not behave like the integers 0 and 1, for which , but may be identified with the elements of the two-element field , that ... | Boolean algebra | Wikipedia | 510 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
When used in expressions, the operators are applied according to the precedence rules. As with elementary algebra, expressions in parentheses are evaluated first, following the precedence rules.
If the truth values 0 and 1 are interpreted as integers, these operations may be expressed with the ordinary operations of a... | Boolean algebra | Wikipedia | 164 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
{| class="wikitable" style="text-align: center"
|+Secondary operations. Table 1
|-
!
!
!
!
!
|-
!0
!0
| 1 || 0 || 1
|-
!1
!0
|0 || 1 || 0
|-
!0
!1
|1 || 1 || 0
|-
!1
!1
| 1 || 0 || 1
|}
Material conditional The first operation, x → y, or Cxy, is called material implication. If x is true, then the result of expression ... | Boolean algebra | Wikipedia | 404 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
Laws
A law of Boolean algebra is an identity such as between two Boolean terms, where a Boolean term is defined as an expression built up from variables and the constants 0 and 1 using the operations ∧, ∨, and ¬. The concept can be extended to terms involving other Boolean operations such as ⊕, →, and ≡, but such exte... | Boolean algebra | Wikipedia | 383 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
The following laws hold in Boolean algebra, but not in ordinary algebra:
{|
|- Annihilator for : || ||style="text-align: right"| ||
|-
|Annihilator for : || ||style="text-align: right"|
|
|-
| Idempotence of : || ||style="text-align: right"| ||
|-
| Idempotence of : || ||style="text-align: right"| ||
|-
| Absorp... | Boolean algebra | Wikipedia | 455 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
Completeness
The laws listed above define Boolean algebra, in the sense that they entail the rest of the subject. The laws complementation 1 and 2, together with the monotone laws, suffice for this purpose and can therefore be taken as one possible complete set of laws or axiomatization of Boolean algebra. Every law of... | Boolean algebra | Wikipedia | 469 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
But if in addition to interchanging the names of the values, the names of the two binary operations are also interchanged, now there is no trace of what was done. The end product is completely indistinguishable from what was started with. The columns for and in the truth tables have changed places, but that switch is... | Boolean algebra | Wikipedia | 506 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
For conjunction, the region inside both circles is shaded to indicate that is 1 when both variables are 1. The other regions are left unshaded to indicate that is 0 for the other three combinations.
The second diagram represents disjunction by shading those regions that lie inside either or both circles. The third ... | Boolean algebra | Wikipedia | 443 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
To visualize the first De Morgan's law, , start with the middle diagram for and complement its shading so that only the region outside both circles is shaded, which is what the right hand side of the law describes. The result is the same as if we shaded that region which is both outside the x circle and outside the y ... | Boolean algebra | Wikipedia | 469 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
More generally, one may complement any of the eight subsets of the three ports of either an AND or OR gate. The resulting sixteen possibilities give rise to only eight Boolean operations, namely those with an odd number of 1s in their truth table. There are eight such because the "odd-bit-out" can be either 0 or 1 and ... | Boolean algebra | Wikipedia | 488 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
Example 2. The empty set and X. This two-element algebra shows that a concrete Boolean algebra can be finite even when it consists of subsets of an infinite set. It can be seen that every field of subsets of X must contain the empty set and X. Hence no smaller example is possible, other than the degenerate algebra obta... | Boolean algebra | Wikipedia | 372 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
Subsets as bit vectors
A subset Y of X can be identified with an indexed family of bits with index set X, with the bit indexed by being 1 or 0 according to whether or not . (This is the so-called characteristic function notion of a subset.) For example, a 32-bit computer word consists of 32 bits indexed by the set {0,... | Boolean algebra | Wikipedia | 360 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
The set {0,1} and its Boolean operations as treated above can be understood as the special case of bit vectors of length one, which by the identification of bit vectors with subsets can also be understood as the two subsets of a one-element set. This is called the prototypical Boolean algebra, justified by the followin... | Boolean algebra | Wikipedia | 499 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
Given any complete axiomatization of Boolean algebra, such as the axioms for a complemented distributive lattice, a sufficient condition for an algebraic structure of this kind to satisfy all the Boolean laws is that it satisfy just those axioms. The following is therefore an equivalent definition.
A Boolean algebra is... | Boolean algebra | Wikipedia | 485 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
It is weaker in the sense that it does not of itself imply representability. Boolean algebras are special here, for example a relation algebra is a Boolean algebra with additional structure but it is not the case that every relation algebra is representable in the sense appropriate to relation algebras.
Axiomatizing B... | Boolean algebra | Wikipedia | 489 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
Syntactically, every Boolean term corresponds to a propositional formula of propositional logic. In this translation between Boolean algebra and propositional logic, Boolean variables x, y, ... become propositional variables (or atoms) P, Q, ... Boolean terms such as x ∨ y become propositional formulas P ∨ Q; 0 becomes... | Boolean algebra | Wikipedia | 442 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
Applications
One motivating application of propositional calculus is the analysis of propositions and deductive arguments in natural language. Whereas the proposition "if x = 3, then x + 1 = 4" depends on the meanings of such symbols as + and 1, the proposition "if x = 3, then x = 3" does not; it is true merely by virt... | Boolean algebra | Wikipedia | 434 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
Deductive systems for propositional logic
An axiomatization of propositional calculus is a set of tautologies called axioms and one or more inference rules for producing new tautologies from old. A proof in an axiom system A is a finite nonempty sequence of propositions each of which is either an instance of an axiom o... | Boolean algebra | Wikipedia | 379 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
Entailment differs from implication in that whereas the latter is a binary operation that returns a value in a Boolean algebra, the former is a binary relation which either holds or does not hold. In this sense, entailment is an external form of implication, meaning external to the Boolean algebra, thinking of the read... | Boolean algebra | Wikipedia | 489 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
Computers use two-value Boolean circuits for the above reasons. The most common computer architectures use ordered sequences of Boolean values, called bits, of 32 or 64 values, e.g. 01101000110101100101010101001011. When programming in machine code, assembly language, and certain other programming languages, programmer... | Boolean algebra | Wikipedia | 434 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
A central concept of set theory is membership. An organization may permit multiple degrees of membership, such as novice, associate, and full. With sets, however, an element is either in or out. The candidates for membership in a set work just like the wires in a digital computer: each candidate is either a member or a... | Boolean algebra | Wikipedia | 312 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
Natural language
Natural languages such as English have words for several Boolean operations, in particular conjunction (and), disjunction (or), negation (not), and implication (implies). But not is synonymous with and not. When used to combine situational assertions such as "the block is on the table" and "cats drink ... | Boolean algebra | Wikipedia | 503 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
Naive set theory
Naive set theory interprets Boolean operations as acting on subsets of a given set X. As we saw earlier this behavior exactly parallels the coordinate-wise combinations of bit vectors, with the union of two sets corresponding to the disjunction of two bit vectors and so on.
Video cards
The 256-element... | Boolean algebra | Wikipedia | 469 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
Search engine queries also employ Boolean logic. For this application, each web page on the Internet may be considered to be an "element" of a "set." The following examples use a syntax supported by Google.
Doublequotes are used to combine whitespace-separated words into a single search term.
Whitespace is used to sp... | Boolean algebra | Wikipedia | 137 | 54476844 | https://en.wikipedia.org/wiki/Boolean%20algebra | Mathematics | Algebra | null |
Coronavirus disease 2019 (COVID-19) is a contagious disease caused by the coronavirus SARS-CoV-2. In January 2020 the disease spread worldwide, resulting in the COVID-19 pandemic.
The symptoms of COVID‑19 can vary but often include fever, fatigue, cough, breathing difficulties, loss of smell, and loss of taste. Sympto... | COVID-19 | Wikipedia | 415 | 63030231 | https://en.wikipedia.org/wiki/COVID-19 | Biology and health sciences | Viral diseases | Health |
Several COVID-19 vaccines have been approved and distributed in various countries, many of which have initiated mass vaccination campaigns. Other preventive measures include physical or social distancing, quarantining, ventilation of indoor spaces, use of face masks or coverings in public, covering coughs and sneezes, ... | COVID-19 | Wikipedia | 498 | 63030231 | https://en.wikipedia.org/wiki/COVID-19 | Biology and health sciences | Viral diseases | Health |
Neurologic manifestations include seizure, stroke, encephalitis, and Guillain–Barré syndrome (which includes loss of motor functions). Following the infection, children may develop paediatric multisystem inflammatory syndrome, which has symptoms similar to Kawasaki disease, which can be fatal. In very rare cases, acute... | COVID-19 | Wikipedia | 385 | 63030231 | https://en.wikipedia.org/wiki/COVID-19 | Biology and health sciences | Viral diseases | Health |
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