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Cannabis indica is an annual plant species in the family Cannabaceae indigenous to the Hindu Kush mountains of Southern Asia. The plant produces large amounts of tetrahydrocannabinol (THC) and tetrahydrocannabivarin (THCV), with total cannabinoid levels being as high as 53.7%. It is now widely grown in China, India, Ne... | Cannabis indica | Wikipedia | 417 | 2154325 | https://en.wikipedia.org/wiki/Cannabis%20indica | Biology and health sciences | Rosales | Plants |
Broad-leafed C. indica plants in the Indian Subcontinent are traditionally cultivated for the production of charas, a form of hashish. Pharmacologically, C. indica landraces tend to have higher THC content than C. sativa strains. Some users report more of a "stoned" feeling and less of a "high" from C. indica when comp... | Cannabis indica | Wikipedia | 322 | 2154325 | https://en.wikipedia.org/wiki/Cannabis%20indica | Biology and health sciences | Rosales | Plants |
Cannabis ruderalis is a variety, subspecies, or species of Cannabis native to Central and Eastern Europe and Russia. It contains a relatively low quantity of psychoactive compound tetrahydrocannabinol (THC) and does not require photoperiod to blossom (unlike C. indica and C. sativa). Some scholars accept C. ruderalis a... | Cannabis ruderalis | Wikipedia | 469 | 2154347 | https://en.wikipedia.org/wiki/Cannabis%20ruderalis | Biology and health sciences | Rosales | Plants |
C. sativa
C. sativa subsp. sativa var. sativa
C. sativa subsp. sativa var. spontanea
C. sativa subsp. indica var. kafiristanica
C. indica
C. indica
C. indica sensu
C. chinensis
C. ruderalis.
Clarke and Merlin carried out more studies in 2013 to analyze the genus mixing molecular markers, chemotypes and morpholo... | Cannabis ruderalis | Wikipedia | 458 | 2154347 | https://en.wikipedia.org/wiki/Cannabis%20ruderalis | Biology and health sciences | Rosales | Plants |
C. ruderalis has lower THC content than either C. sativa or C. indica, so it is rarely grown for recreational use. Also, the shorter stature of C. ruderalis limits its application for hemp production. C. ruderalis strains are high in the cannabіnoid cannabidiol (CBD), so they are grown by some medical marijuana users.
... | Cannabis ruderalis | Wikipedia | 492 | 2154347 | https://en.wikipedia.org/wiki/Cannabis%20ruderalis | Biology and health sciences | Rosales | Plants |
In ecology, resilience is the capacity of an ecosystem to respond to a perturbation or disturbance by resisting damage and subsequently recovering. Such perturbations and disturbances can include stochastic events such as fires, flooding, windstorms, insect population explosions, and human activities such as deforestat... | Ecological resilience | Wikipedia | 354 | 13224331 | https://en.wikipedia.org/wiki/Ecological%20resilience | Biology and health sciences | Ecology | Biology |
The concept of resilience in ecological systems was first introduced by the Canadian ecologist C.S. Holling in order to describe the persistence of natural systems in the face of changes in ecosystem variables due to natural or anthropogenic causes. Resilience has been defined in two ways in ecological literature:
as ... | Ecological resilience | Wikipedia | 380 | 13224331 | https://en.wikipedia.org/wiki/Ecological%20resilience | Biology and health sciences | Ecology | Biology |
Latitude: the maximum amount a system can be changed before losing its ability to recover (before crossing a threshold which, if breached, makes recovery difficult or impossible).
Resistance: the ease or difficulty of changing the system; how “resistant” it is to being changed.
Precariousness: how close the current s... | Ecological resilience | Wikipedia | 365 | 13224331 | https://en.wikipedia.org/wiki/Ecological%20resilience | Biology and health sciences | Ecology | Biology |
Agriculture can be used as a significant case study in which the resilience of terrestrial ecosystems should be considered. The organic matter (elements carbon and nitrogen) in soil, which is supposed to be recharged by multiple plants, is the main source of nutrients for crop growth. In response to global food demand ... | Ecological resilience | Wikipedia | 512 | 13224331 | https://en.wikipedia.org/wiki/Ecological%20resilience | Biology and health sciences | Ecology | Biology |
In addition to overfishing, coastal communities are suffering the impacts of growing numbers of large commercial fishing vessels in causing reductions of small local fishing fleets. Many local lowland rivers which are sources of fresh water have become degraded because of the inflows of pollutants and sediments.
Dumpi... | Ecological resilience | Wikipedia | 422 | 13224331 | https://en.wikipedia.org/wiki/Ecological%20resilience | Biology and health sciences | Ecology | Biology |
Eutrophication and algal blooms
The Woods Hole Oceanographic Institution calls nutrient pollution the most widespread, chronic environmental problem in the coastal ocean. The discharges of nitrogen, phosphorus, and other nutrients come from agriculture, waste disposal, coastal development, and fossil fuel use. Once nut... | Ecological resilience | Wikipedia | 417 | 13224331 | https://en.wikipedia.org/wiki/Ecological%20resilience | Biology and health sciences | Ecology | Biology |
The purpose of ecological resilience that is proposed is ultimately about averting our extinction as Walker cites Holling in his paper: "[..] "resilience is concerned with [measuring] the probabilities of extinction” (1973, p. 20)". Becoming more apparent in academic writing is the significance of the environment and r... | Ecological resilience | Wikipedia | 474 | 13224331 | https://en.wikipedia.org/wiki/Ecological%20resilience | Biology and health sciences | Ecology | Biology |
Because climate change is a major and growing driver of biodiversity loss, and that biodiversity and ecosystem functions and services, significantly contribute to climate change adaptation, mitigation and disaster risk reduction, proponents of ecosystem-based adaptation suggest that the resilience of vulnerable human p... | Ecological resilience | Wikipedia | 469 | 13224331 | https://en.wikipedia.org/wiki/Ecological%20resilience | Biology and health sciences | Ecology | Biology |
Some examples of the consideration of ecosystem resilience within legislation include:
Environmental Planning and Assessment Act 1979 (NSW) – A key goal of the Environmental Assessment procedure is to determine whether proposed development will have a significant impact upon ecosystems.
Protection of the Environment (... | Ecological resilience | Wikipedia | 461 | 13224331 | https://en.wikipedia.org/wiki/Ecological%20resilience | Biology and health sciences | Ecology | Biology |
By the mid 1970s, resilience began gaining momentum as an idea in anthropology, culture theory, and other social sciences. There was significant work in these relatively non-traditional fields that helped facilitate the evolution of the resilience perspective as a whole. Part of the reason resilience began moving away ... | Ecological resilience | Wikipedia | 124 | 13224331 | https://en.wikipedia.org/wiki/Ecological%20resilience | Biology and health sciences | Ecology | Biology |
Clostridium tetani is a common soil bacterium and the causative agent of tetanus. Vegetative cells of Clostridium tetani are usually rod-shaped and up to 2.5 μm long, but they become enlarged and tennis racket- or drumstick-shaped when forming spores. C. tetani spores are extremely hardy and can be found globally in so... | Clostridium tetani | Wikipedia | 507 | 13233321 | https://en.wikipedia.org/wiki/Clostridium%20tetani | Biology and health sciences | Gram-positive bacteria | Plants |
While C. tetani is frequently benign in the soil or in the intestinal tracts of animals, it can sometimes cause the severe disease tetanus. Disease generally begins with spores entering the body through a wound. In deep wounds, such as those from a puncture or contaminated needle injection the combination of tissue dea... | Clostridium tetani | Wikipedia | 511 | 13233321 | https://en.wikipedia.org/wiki/Clostridium%20tetani | Biology and health sciences | Gram-positive bacteria | Plants |
Damage from C. tetani infection is generally prevented by administration of a tetanus vaccine consisting of tetanospasmin inactivated by formaldehyde, called tetanus toxoid. This is made commercially by growing large quantities of C. tetani in fermenters, then purifying the toxin and inactivating in 40% formaldehyde fo... | Clostridium tetani | Wikipedia | 487 | 13233321 | https://en.wikipedia.org/wiki/Clostridium%20tetani | Biology and health sciences | Gram-positive bacteria | Plants |
In chemistry, the ball-and-stick model is a molecular model of a chemical substance which displays both the three-dimensional position of the atoms and the bonds between them. The atoms are typically represented by spheres, connected by rods which represent the bonds. Double and triple bonds are usually represented by ... | Ball-and-stick model | Wikipedia | 485 | 7115718 | https://en.wikipedia.org/wiki/Ball-and-stick%20model | Physical sciences | Substance | Chemistry |
The Beeverses Miniature Models company in Edinburgh (now operating as Miramodus) produced small models beginning in 1961 using PMMA balls and stainless steel rods. In these models, the use of individually drilled balls with precise bond angles and bond lengths enabled large crystal structures to be accurately created ... | Ball-and-stick model | Wikipedia | 64 | 7115718 | https://en.wikipedia.org/wiki/Ball-and-stick%20model | Physical sciences | Substance | Chemistry |
The element sulfur exists as many allotropes. In number of allotropes, sulfur is second only to carbon. In addition to the allotropes, each allotrope often exists in polymorphs (different crystal structures of the same covalently bonded Sn molecules) delineated by Greek prefixes (α, β, etc.).
Furthermore, because elem... | Allotropes of sulfur | Wikipedia | 462 | 14383139 | https://en.wikipedia.org/wiki/Allotropes%20of%20sulfur | Physical sciences | Group 16 | Chemistry |
Solid cyclo allotrope preparation
Two methods exist for the preparation of the cyclo-sulfur allotropes. One of the methods, which is most famous for preparing hexasulfur, is to treat hydrogen polysulfides with polysulfur dichloride:
A second strategy uses titanocene pentasulfide as a source of the unit. This complex ... | Allotropes of sulfur | Wikipedia | 399 | 14383139 | https://en.wikipedia.org/wiki/Allotropes%20of%20sulfur | Physical sciences | Group 16 | Chemistry |
α-Sulfur
α-Sulfur is the form most commonly found in nature. When pure it has a greenish-yellow colour (traces of cyclo- in commercially available samples make it appear yellower). It is practically insoluble in water and is a good electrical insulator with poor thermal conductivity. It is quite soluble in carbon disul... | Allotropes of sulfur | Wikipedia | 503 | 14383139 | https://en.wikipedia.org/wiki/Allotropes%20of%20sulfur | Physical sciences | Group 16 | Chemistry |
These allotropes have been synthesised by various methods for example, treating titanocene pentasulfide and a dichlorosulfane of suitable sulfur chain length, :
or alternatively treating a dichlorosulfane, and a polysulfane, :
, , and can also be prepared from . With the exception of cyclo-, the rings contain S–S b... | Allotropes of sulfur | Wikipedia | 393 | 14383139 | https://en.wikipedia.org/wiki/Allotropes%20of%20sulfur | Physical sciences | Group 16 | Chemistry |
Amorphous sulfur
Amorphous sulfur is the quenched product from molten sulfur hotter than the λ-transition at 160 °C, where polymerization yields catena sulfur molecules. (Above this temperature, the properties of the liquid melt change remarkably. For example, the viscosity increases more than 10000-fold as the tempera... | Allotropes of sulfur | Wikipedia | 481 | 14383139 | https://en.wikipedia.org/wiki/Allotropes%20of%20sulfur | Physical sciences | Group 16 | Chemistry |
ψ-Sulfur
This form, also called fibrous sulfur or ω1-sulfur, has been well characterized. It has a density of 2.01 g·cm−3 (α-sulfur 2.069 g·cm−3) and decomposes around its melting point of 104 °C. It consists of parallel helical sulfur chains. These chains have both left and right-handed "twists" and a radius of 95 pm.... | Allotropes of sulfur | Wikipedia | 505 | 14383139 | https://en.wikipedia.org/wiki/Allotropes%20of%20sulfur | Physical sciences | Group 16 | Chemistry |
List of allotropes and forms
Allotropes are in Bold. | Allotropes of sulfur | Wikipedia | 16 | 14383139 | https://en.wikipedia.org/wiki/Allotropes%20of%20sulfur | Physical sciences | Group 16 | Chemistry |
The Oriental rat flea (Xenopsylla cheopis), also known as the tropical rat flea or the rat flea, is a parasite of rodents, primarily of the genus Rattus, and is a primary vector for bubonic plague and murine typhus. This occurs when a flea that has fed on an infected rodent bites a human, although this flea can live on... | Oriental rat flea | Wikipedia | 355 | 5444531 | https://en.wikipedia.org/wiki/Oriental%20rat%20flea | Biology and health sciences | Insects: General | Animals |
There are four stages in a flea's life. The first stage is the egg stage. Microscopic white eggs fall easily from the female to the ground or from the animal she lays on. If they are laid on an animal, they soon fall off in the dust or in the animal's bedding. If the eggs do fall immediately on the ground, then they fa... | Oriental rat flea | Wikipedia | 422 | 5444531 | https://en.wikipedia.org/wiki/Oriental%20rat%20flea | Biology and health sciences | Insects: General | Animals |
Plain weave (also called tabby weave, linen weave or taffeta weave) is the most basic of three fundamental types of textile weaves (along with satin weave and twill). It is strong and hard-wearing, and is used for fashion and furnishing fabrics. Fabrics with a plain weave are generally strong, durable, and have a smoot... | Plain weave | Wikipedia | 466 | 5446107 | https://en.wikipedia.org/wiki/Plain%20weave | Technology | Weaving | null |
In graph theory, Vizing's theorem states that every simple undirected graph may be edge colored using a number of colors that is at most one larger than the maximum degree of the graph. At least colors are always necessary, so the undirected graphs may be partitioned into two classes: "class one" graphs for which co... | Vizing's theorem | Wikipedia | 508 | 5449464 | https://en.wikipedia.org/wiki/Vizing%27s%20theorem | Mathematics | Graph theory | null |
This is equivalent, because if (1) doesn't hold, then we can interchange the colors and on the -path and set the color of to be , thus creating a proper -edge-coloring of from . The other way around, if a proper -edge-coloring exists, then we can delete , restrict the coloring and (1) won't hold either.
Now, let ... | Vizing's theorem | Wikipedia | 487 | 5449464 | https://en.wikipedia.org/wiki/Vizing%27s%20theorem | Mathematics | Graph theory | null |
Planar graphs
showed that a planar graph is of class one if its maximum degree is at least eight.
In contrast, he observed that for any maximum degree in the range from two to five, there exist
planar graphs of class two. For degree two, any odd cycle is such a graph, and for degree three, four, and five, these graph... | Vizing's theorem | Wikipedia | 465 | 5449464 | https://en.wikipedia.org/wiki/Vizing%27s%20theorem | Mathematics | Graph theory | null |
describe a polynomial time algorithm for coloring the edges of any graph with colors, where is the maximum degree of the graph. That is, the algorithm uses the optimal number of colors for graphs of class two, and uses at most one more color than necessary for all graphs. Their algorithm follows the same strategy as ... | Vizing's theorem | Wikipedia | 479 | 5449464 | https://en.wikipedia.org/wiki/Vizing%27s%20theorem | Mathematics | Graph theory | null |
History
In both and , Vizing mentions that his work was motivated by a theorem of showing that multigraphs could be colored with at most colors. Although Vizing's theorem is now standard material in many graph theory textbooks, Vizing had trouble publishing the result initially, and his paper on it appears in an obs... | Vizing's theorem | Wikipedia | 71 | 5449464 | https://en.wikipedia.org/wiki/Vizing%27s%20theorem | Mathematics | Graph theory | null |
Helminthiasis, also known as worm infection, is any macroparasitic disease of humans and other animals in which a part of the body is infected with parasitic worms, known as helminths. There are numerous species of these parasites, which are broadly classified into tapeworms, flukes, and roundworms. They often live in ... | Helminthiasis | Wikipedia | 459 | 971658 | https://en.wikipedia.org/wiki/Helminthiasis | Biology and health sciences | Concepts | Health |
Roundworm infection (nematodiasis)
Filariasis (Wuchereria bancrofti, Brugia malayi infection)
Onchocerciasis (Onchocerca volvulus infection)
Soil-transmitted helminthiasis – this includes ascariasis (Ascaris lumbricoides infection), trichuriasis (Trichuris infection), and hookworm infection (includes necatoriasis an... | Helminthiasis | Wikipedia | 462 | 971658 | https://en.wikipedia.org/wiki/Helminthiasis | Biology and health sciences | Concepts | Health |
Mass and volume
In extreme cases of intestinal infestation, the mass and volume of the worms may cause the outer layers of the intestinal wall, such as the muscular layer, to tear. This may lead to peritonitis, volvulus, and gangrene of the intestine.
Immunological response
As pathogens in the body, helminths induce a... | Helminthiasis | Wikipedia | 439 | 971658 | https://en.wikipedia.org/wiki/Helminthiasis | Biology and health sciences | Concepts | Health |
Malnutrition
Helminthiasis may cause chronic illness through malnutrition including vitamin deficiencies, stunted growth, anemia, and protein-energy malnutrition. Worms compete directly with their hosts for nutrients, but the magnitude of this effect is likely minimal as the nutritional requirements of worms is relativ... | Helminthiasis | Wikipedia | 472 | 971658 | https://en.wikipedia.org/wiki/Helminthiasis | Biology and health sciences | Concepts | Health |
Cognitive changes
Malnutrition due to helminths may affect cognitive function leading to low educational performance, decreased concentration and difficulty with abstract cognitive tasks. Iron deficiency in infants and preschoolers is associated with "lower scores ... on tests of mental and motor development ... [as we... | Helminthiasis | Wikipedia | 470 | 971658 | https://en.wikipedia.org/wiki/Helminthiasis | Biology and health sciences | Concepts | Health |
Specific helminths can be identified through microscopic examination of their eggs (ova) found in faecal samples. The number of eggs is measured in units of eggs per gram. However, it does not quantify mixed infections, and in practice, is inaccurate for quantifying the eggs of schistosomes and soil-transmitted helmint... | Helminthiasis | Wikipedia | 492 | 971658 | https://en.wikipedia.org/wiki/Helminthiasis | Biology and health sciences | Concepts | Health |
If complications of helminthiasis, such as intestinal obstruction occur, emergency surgery may be required. Patients who require non-emergency surgery, for instance for removal of worms from the biliary tree, can be pre-treated with the anthelmintic drug albendazole.
Epidemiology
Areas with the highest prevalence of h... | Helminthiasis | Wikipedia | 506 | 971658 | https://en.wikipedia.org/wiki/Helminthiasis | Biology and health sciences | Concepts | Health |
The most common intestinal parasites in the United States are Enterobius vermicularis, Giardia lamblia, Ancylostoma duodenale, Necator americanus, and Entamoeba histolytica.
In a developing country like Bangladesh, the most common species are round worm (Ascaris lumbricoides), whipworm (Tricurias tricuras) and hookwor... | Helminthiasis | Wikipedia | 449 | 971658 | https://en.wikipedia.org/wiki/Helminthiasis | Biology and health sciences | Concepts | Health |
Plant reproductive morphology is the study of the physical form and structure (the morphology) of those parts of plants directly or indirectly concerned with sexual reproduction.
Among all living organisms, flowers, which are the reproductive structures of angiosperms, are the most varied physically and show a corresp... | Plant reproductive morphology | Wikipedia | 387 | 971961 | https://en.wikipedia.org/wiki/Plant%20reproductive%20morphology | Biology and health sciences | Plant reproduction | null |
In the bryophytes (liverworts, mosses, and hornworts), the sexual gametophyte is the dominant generation. In ferns and seed plants (including cycads, conifers, flowering plants, etc.) the sporophyte is the dominant generation; the obvious visible plant, whether a small herb or a large tree, is the sporophyte, and the g... | Plant reproductive morphology | Wikipedia | 500 | 971961 | https://en.wikipedia.org/wiki/Plant%20reproductive%20morphology | Biology and health sciences | Plant reproduction | null |
Each carpel in Ranunculus species is an achene that produces one ovule, which when fertilized becomes a seed. If the carpel contains more than one seed, as in Eranthis hyemalis, it is called a follicle. Two or more carpels may be fused together to varying degrees and the entire structure, including the fused styles an... | Plant reproductive morphology | Wikipedia | 397 | 971961 | https://en.wikipedia.org/wiki/Plant%20reproductive%20morphology | Biology and health sciences | Plant reproduction | null |
Most hollies (members of the genus Ilex) are dioecious. Each plant produces either functionally male flowers or functionally female flowers. In Ilex aquifolium (see the illustration), the common European holly, both kinds of flower have four sepals and four white petals; male flowers have four stamens, female flowers u... | Plant reproductive morphology | Wikipedia | 305 | 971961 | https://en.wikipedia.org/wiki/Plant%20reproductive%20morphology | Biology and health sciences | Plant reproduction | null |
A species such as Fraxinus excelsior, the common ash of Europe, demonstrates one possible kind of variation. Ash flowers are wind-pollinated and lack petals and sepals. Structurally, the flowers may be bisexual, consisting of two stamens and an ovary, or may be male (staminate), lacking a functional ovary, or female (c... | Plant reproductive morphology | Wikipedia | 406 | 971961 | https://en.wikipedia.org/wiki/Plant%20reproductive%20morphology | Biology and health sciences | Plant reproduction | null |
The complexity of the morphology of flowers and its variation within populations has led to a rich terminology.
Androdioecious: having male flowers on some plants, bisexual ones on others.
Androecious: having only male flowers (the male of a dioecious population); producing pollen but no seed.
Androgynous: see bisex... | Plant reproductive morphology | Wikipedia | 297 | 971961 | https://en.wikipedia.org/wiki/Plant%20reproductive%20morphology | Biology and health sciences | Plant reproduction | null |
Mass wasting, also known as mass movement, is a general term for the movement of rock or soil down slopes under the force of gravity. It differs from other processes of erosion in that the debris transported by mass wasting is not entrained in a moving medium, such as water, wind, or ice. Types of mass wasting include ... | Mass wasting | Wikipedia | 472 | 972457 | https://en.wikipedia.org/wiki/Mass%20wasting | Physical sciences | Geomorphology: General | Earth science |
Soil creep is a slow and long term mass movement. The combination of small movements of soil or rock in different directions over time is directed by gravity gradually downslope. The steeper the slope, the faster the creep. The creep makes trees and shrubs curve to maintain their perpendicularity, and they can trigger ... | Mass wasting | Wikipedia | 511 | 972457 | https://en.wikipedia.org/wiki/Mass%20wasting | Physical sciences | Geomorphology: General | Earth science |
Deposits and landforms
Mass wasting affects geomorphology, most often in subtle, small-scale ways, but occasionally more spectacularly.
Soil creep is rarely apparent but can produce such subtle effects as curved forest growth and tilted fences and telephone poles. It occasionally produces low scarps and shallow depres... | Mass wasting | Wikipedia | 463 | 972457 | https://en.wikipedia.org/wiki/Mass%20wasting | Physical sciences | Geomorphology: General | Earth science |
Rockslides or landslides can have disastrous consequences, both immediate and delayed. The Oso disaster of March 2014 was a landslide that caused 43 fatalities in Oso, Washington, US. Delayed consequences of landslides can arise from the formation of landslide dams, as at Thistle, Utah, in April 1983.
Volcano flanks c... | Mass wasting | Wikipedia | 215 | 972457 | https://en.wikipedia.org/wiki/Mass%20wasting | Physical sciences | Geomorphology: General | Earth science |
In model theory, a branch of mathematical logic, two structures M and N of the same signature σ are called elementarily equivalent if they satisfy the same first-order σ-sentences.
If N is a substructure of M, one often needs a stronger condition. In this case N is called an elementary substructure of M if every first... | Elementary equivalence | Wikipedia | 466 | 972601 | https://en.wikipedia.org/wiki/Elementary%20equivalence | Mathematics | Model theory | null |
More generally, any first-order theory with an infinite model has non-isomorphic, elementarily equivalent models, which can be obtained via the Löwenheim–Skolem theorem. Thus, for example, there are non-standard models of Peano arithmetic, which contain other objects than just the numbers 0, 1, 2, etc., and yet are ele... | Elementary equivalence | Wikipedia | 445 | 972601 | https://en.wikipedia.org/wiki/Elementary%20equivalence | Mathematics | Model theory | null |
Let M be a structure of signature σ and N a substructure of M. Then N is an elementary substructure of M if and only if for every first-order formula φ(x, y1, …, yn) over σ and all elements b1, …, bn from N, if M x φ(x, b1, …, bn), then there is an element a in N such that M φ(a, b1, …, bn).
Elementary embeddings
A... | Elementary equivalence | Wikipedia | 264 | 972601 | https://en.wikipedia.org/wiki/Elementary%20equivalence | Mathematics | Model theory | null |
An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between . Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth's surface. They are among the flattest, smoothest, and least explored regions on Earth. Abyssal... | Abyssal plain | Wikipedia | 499 | 972800 | https://en.wikipedia.org/wiki/Abyssal%20plain | Physical sciences | Oceanic and coastal landforms | null |
Abyssal plains were not recognized as distinct physiographic features of the sea floor until the late 1940s and, until recently, none had been studied on a systematic basis. They are poorly preserved in the sedimentary record, because they tend to be consumed by the subduction process. Due to darkness and a water press... | Abyssal plain | Wikipedia | 362 | 972800 | https://en.wikipedia.org/wiki/Abyssal%20plain | Physical sciences | Oceanic and coastal landforms | null |
The euphotic zone is somewhat arbitrarily defined as extending from the surface to the depth where the light intensity is approximately 0.1–1% of surface sunlight irradiance, depending on season, latitude and degree of water turbidity. In the clearest ocean water, the euphotic zone may extend to a depth of about 150 me... | Abyssal plain | Wikipedia | 505 | 972800 | https://en.wikipedia.org/wiki/Abyssal%20plain | Physical sciences | Oceanic and coastal landforms | null |
Oceanic crust, which forms the bedrock of abyssal plains, is continuously being created at mid-ocean ridges (a type of divergent boundary) by a process known as decompression melting. Plume-related decompression melting of solid mantle is responsible for creating ocean islands like the Hawaiian islands, as well as the ... | Abyssal plain | Wikipedia | 488 | 972800 | https://en.wikipedia.org/wiki/Abyssal%20plain | Physical sciences | Oceanic and coastal landforms | null |
New oceanic crust, closest to the mid-oceanic ridges, is mostly basalt at shallow levels and has a rugged topography. The roughness of this topography is a function of the rate at which the mid-ocean ridge is spreading (the spreading rate). Magnitudes of spreading rates vary quite significantly. Typical values for fast... | Abyssal plain | Wikipedia | 412 | 972800 | https://en.wikipedia.org/wiki/Abyssal%20plain | Physical sciences | Oceanic and coastal landforms | null |
The landmark scientific expedition (December 1872 – May 1876) of the British Royal Navy survey ship HMS Challenger yielded a tremendous amount of bathymetric data, much of which has been confirmed by subsequent researchers. Bathymetric data obtained during the course of the Challenger expedition enabled scientists to d... | Abyssal plain | Wikipedia | 474 | 972800 | https://en.wikipedia.org/wiki/Abyssal%20plain | Physical sciences | Oceanic and coastal landforms | null |
The Challenger Deep is the deepest surveyed point of all of Earth's oceans; it is at the south end of the Mariana Trench near the Mariana Islands group. The depression is named after HMS Challenger, whose researchers made the first recordings of its depth on 23 March 1875 at station 225. The reported depth was 4,475 fa... | Abyssal plain | Wikipedia | 397 | 972800 | https://en.wikipedia.org/wiki/Abyssal%20plain | Physical sciences | Oceanic and coastal landforms | null |
Sister Peak (Comfortless Cove Hydrothermal Field, , elevation −2996 m), Shrimp Farm and Mephisto (Red Lion Hydrothermal Field, , elevation −3047 m), are three hydrothermal vents of the black smoker category, on the Mid-Atlantic Ridge near Ascension Island. They are presumed to have been active since an earthquake shook... | Abyssal plain | Wikipedia | 484 | 972800 | https://en.wikipedia.org/wiki/Abyssal%20plain | Physical sciences | Oceanic and coastal landforms | null |
Though the plains were once assumed to be vast, desert-like habitats, research over the past decade or so shows that they teem with a wide variety of microbial life. However, ecosystem structure and function at the deep seafloor have historically been poorly studied because of the size and remoteness of the abyss. Rece... | Abyssal plain | Wikipedia | 442 | 972800 | https://en.wikipedia.org/wiki/Abyssal%20plain | Physical sciences | Oceanic and coastal landforms | null |
CeDAMar scientists have demonstrated that some abyssal and hadal species have a cosmopolitan distribution. One example of this would be protozoan foraminiferans, certain species of which are distributed from the Arctic to the Antarctic. Other faunal groups, such as the polychaete worms and isopod crustaceans, appear to... | Abyssal plain | Wikipedia | 409 | 972800 | https://en.wikipedia.org/wiki/Abyssal%20plain | Physical sciences | Oceanic and coastal landforms | null |
Peracarid crustaceans, including isopods, are known to form a significant part of the macrobenthic community that is responsible for scavenging on large food falls onto the sea floor. In 2000, scientists of the Diversity of the deep Atlantic benthos (DIVA 1) expedition (cruise M48/1 of the German research vessel RV Met... | Abyssal plain | Wikipedia | 482 | 972800 | https://en.wikipedia.org/wiki/Abyssal%20plain | Physical sciences | Oceanic and coastal landforms | null |
While similar lifeforms have been known to exist in shallower oceanic trenches (>7,000 m) and on the abyssal plain, the lifeforms discovered in the Challenger Deep may represent independent taxa from those shallower ecosystems. This preponderance of soft-shelled organisms at the Challenger Deep may be a result of selec... | Abyssal plain | Wikipedia | 275 | 972800 | https://en.wikipedia.org/wiki/Abyssal%20plain | Physical sciences | Oceanic and coastal landforms | null |
Within the abyssal and hadal zones, the areas around submarine hydrothermal vents and cold seeps have by far the greatest biomass and biodiversity per unit area. Fueled by the chemicals dissolved in the vent fluids, these areas are often home to large and diverse communities of thermophilic, halophilic and other extrem... | Abyssal plain | Wikipedia | 485 | 972800 | https://en.wikipedia.org/wiki/Abyssal%20plain | Physical sciences | Oceanic and coastal landforms | null |
As fish stocks dwindle in the upper ocean, deep-sea fisheries are increasingly being targeted for exploitation. Because deep sea fish are long-lived and slow growing, these deep-sea fisheries are not thought to be sustainable in the long term given current management practices. Changes in primary production in the phot... | Abyssal plain | Wikipedia | 479 | 972800 | https://en.wikipedia.org/wiki/Abyssal%20plain | Physical sciences | Oceanic and coastal landforms | null |
Limited knowledge of the taxonomy, biogeography and natural history of deep sea communities prevents accurate assessment of the risk of species extinctions from large-scale mining. Data acquired from the abyssal North Pacific and North Atlantic suggest that deep-sea ecosystems may be adversely affected by mining operat... | Abyssal plain | Wikipedia | 263 | 972800 | https://en.wikipedia.org/wiki/Abyssal%20plain | Physical sciences | Oceanic and coastal landforms | null |
The Gerridae are a family of insects in the order Hemiptera, commonly known as water striders, water skeeters, water scooters, water bugs, pond skaters, water skippers, water gliders, water skimmers or puddle flies. Consistent with the classification of the Gerridae as true bugs (i.e., suborder Heteroptera), gerrids ha... | Gerridae | Wikipedia | 392 | 972966 | https://en.wikipedia.org/wiki/Gerridae | Biology and health sciences | Hemiptera (true bugs) | Animals |
Size
They are generally small, long-legged insects and the body length of most species is between . A few are between . Among widespread genera, the North Hemisphere Aquarius includes the largest species, generally exceeding , at least among females, and the largest species averaging about . Females typically average l... | Gerridae | Wikipedia | 493 | 972966 | https://en.wikipedia.org/wiki/Gerridae | Biology and health sciences | Hemiptera (true bugs) | Animals |
Wings
Some water striders have wings present on the dorsal side of their thorax, while other species of Gerridae do not, particularly Halobates. Water striders experience wing length polymorphism that has affected their flight ability and evolved in a phylogenetic manner where populations are either long-winged, wing-d... | Gerridae | Wikipedia | 293 | 972966 | https://en.wikipedia.org/wiki/Gerridae | Biology and health sciences | Hemiptera (true bugs) | Animals |
Wing polymorphism
Wing polymorphism (i.e., the presence of multiple wing morphs in a given species) has independently evolved multiple times in Gerridae, as well as complete wing loss, something that has been important for the evolution of the variety in species we see today, and dispersal of Gerridae. The existence of... | Gerridae | Wikipedia | 260 | 972966 | https://en.wikipedia.org/wiki/Gerridae | Biology and health sciences | Hemiptera (true bugs) | Animals |
Wing polymorphism is common in the Gerridae despite most univoltine populations being completely apterous (wingless) or macropterous (with wings). Apterous populations of gerrids would be restricted to stable aquatic habitats that experience little change in environment, while macropterous populations can inhabit more ... | Gerridae | Wikipedia | 366 | 972966 | https://en.wikipedia.org/wiki/Gerridae | Biology and health sciences | Hemiptera (true bugs) | Animals |
The legs of a water strider are long and slender, allowing the weight of the water strider body to be distributed over a large surface area. The legs are strong, but have flexibility that allows the water striders to keep their weight evenly distributed and flow with the water movement. Hydrofuge hairs line the body su... | Gerridae | Wikipedia | 468 | 972966 | https://en.wikipedia.org/wiki/Gerridae | Biology and health sciences | Hemiptera (true bugs) | Animals |
Gerrids go through the egg stage, five instar stages of nymphal forms, and then the adult stage. Instar durations of water striders are highly correlated throughout the larval period. This means that individuals tend to develop at the same rate through each instar stage. Each nymphal stage lasts 7–10 days and the water... | Gerridae | Wikipedia | 386 | 972966 | https://en.wikipedia.org/wiki/Gerridae | Biology and health sciences | Hemiptera (true bugs) | Animals |
Gerrids are aquatic predators and feed on invertebrates, mainly spiders and insects, that fall onto the water surface. Water striders are attracted to this food source by ripples produced by the struggling prey. The water strider uses its front legs as sensors for the vibrations produced by the ripples in the water. Th... | Gerridae | Wikipedia | 440 | 972966 | https://en.wikipedia.org/wiki/Gerridae | Biology and health sciences | Hemiptera (true bugs) | Animals |
Dispersal
Sudden increases in salt concentration in the water of gerrid habitats can trigger migration of water striders. Water striders will move to areas of lower salt concentration, resulting in the mix of genes within brackish and freshwater bodies. Nymphal population density also affects the dispersal of water str... | Gerridae | Wikipedia | 216 | 972966 | https://en.wikipedia.org/wiki/Gerridae | Biology and health sciences | Hemiptera (true bugs) | Animals |
Sex discrimination in some Gerridae species is determined through communication of ripple frequency produced on the water surface. Males predominantly produce these ripples in the water. There are three main frequencies found in ripple communication: 25 Hz as a repel signal, 10 Hz as a threat signal, and 3 Hz as a cour... | Gerridae | Wikipedia | 492 | 972966 | https://en.wikipedia.org/wiki/Gerridae | Biology and health sciences | Hemiptera (true bugs) | Animals |
Social behavior
Kin discrimination is rare in Gerridae, only really being seen in Halobates. Without hunger playing a role, several studies have shown that neither Aquarius remigis nor Limnoporus dissortis parents preferentially cannibalize on non-kin. Those two species are highly prevalent in American waters. These sp... | Gerridae | Wikipedia | 404 | 972966 | https://en.wikipedia.org/wiki/Gerridae | Biology and health sciences | Hemiptera (true bugs) | Animals |
In computing, formatted text, styled text, or rich text, as opposed to plain text, is digital text which has styling information beyond the minimum of semantic elements: colours, styles (boldface, italic), sizes, and special features in HTML (such as hyperlinks).
Terminology
Formatted text cannot rightly be identified... | Formatted text | Wikipedia | 468 | 973737 | https://en.wikipedia.org/wiki/Formatted%20text | Technology | Data storage and memory | null |
Formatted document files
Since the invention of MacWrite, the first WYSIWYG word processor, in which the typist codes the formatting visually rather than by inserting textual markup, word processors have tended to save to binary files. Opening such files with a text editor reveals them embedded with various binary char... | Formatted text | Wikipedia | 331 | 973737 | https://en.wikipedia.org/wiki/Formatted%20text | Technology | Data storage and memory | null |
Erinaceidae is a family in the order Eulipotyphla, consisting of the hedgehogs and moonrats. Until recently, it was assigned to the order Erinaceomorpha, which has been subsumed with the paraphyletic Soricomorpha into Eulipotyphla. Eulipotyphla has been shown to be monophyletic; Soricomorpha is paraphyletic because bo... | Erinaceidae | Wikipedia | 477 | 973884 | https://en.wikipedia.org/wiki/Erinaceidae | Biology and health sciences | Eulipotyphla | Animals |
Female erinaceids give birth after a gestation period of around six to seven weeks. The young are born blind and hairless, although hedgehogs begin to sprout their spines within 36 hours of birth.
Evolution
Erinaceids are a group of placental mammals that have retained many of their ancestral traits, having changed li... | Erinaceidae | Wikipedia | 137 | 973884 | https://en.wikipedia.org/wiki/Erinaceidae | Biology and health sciences | Eulipotyphla | Animals |
Order Eulipotyphla
†Family Amphilemuridae
†Genus Alsaticopithecus
†Genus Amphilemur
†Genus Gesneropithex
†Genus Macrocranion
†Macrocranion germonpreae
†Macrocranion junnei
†Macrocranion nitens
†Macrocranion robinsoni
†Macrocranion tenerum
†Macrocranion vandebroeki
†Genus Pholidocercus
†Pholidocercus hassiacus
Family Er... | Erinaceidae | Wikipedia | 512 | 973884 | https://en.wikipedia.org/wiki/Erinaceidae | Biology and health sciences | Eulipotyphla | Animals |
†Genus Deinogalerix
†Deinogalerix brevirostris
†Deinogalerix freudenthali
†Deinogalerix intermedius
†Deinogalerix koenigswaldi
†Deinogalerix minor
Genus Echinosorex
Moonrat, Echinosorex gymnura
†Genus Galerix
†Galerix aurelianensis
†Galerix exilis
†Galerix kostakii
†Galerix remmerti
†Galerix rutlandae
†Galerix ... | Erinaceidae | Wikipedia | 264 | 973884 | https://en.wikipedia.org/wiki/Erinaceidae | Biology and health sciences | Eulipotyphla | Animals |
The backstaff is a navigational instrument that was used to measure the altitude of a celestial body, in particular the Sun or Moon. When observing the Sun, users kept the Sun to their back (hence the name) and observed the shadow cast by the upper vane on a horizon vane. It was invented by the English navigator John D... | Backstaff | Wikipedia | 450 | 974163 | https://en.wikipedia.org/wiki/Backstaff | Technology | Navigation | null |
The next version of his quadrant is shown in Figure 2. The arc on the top of the instrument in the previous version was replaced with a shadow vane placed on a transom. This transom could be moved along a graduated scale to indicate the angle of the shadow above the staff. Below the staff, a 30° arc was added. The h... | Backstaff | Wikipedia | 501 | 974163 | https://en.wikipedia.org/wiki/Backstaff | Technology | Navigation | null |
A later modification of the Davis quadrant was to use a Flamsteed glass in place of the shadow vane; this was suggested by John Flamsteed. This placed a lens on the vane that projected an image of the sun on the horizon vane instead of a shadow. It was useful under conditions where the sky was hazy or lightly overcast... | Backstaff | Wikipedia | 462 | 974163 | https://en.wikipedia.org/wiki/Backstaff | Technology | Navigation | null |
The plough was the name given to an unusual instrument that existed for a short time. It was part cross-staff and part backstaff. In Figure 5, A is the transom that casts its shadow on the horizon vane at B. It functions in the same manner as the staff in Figure 1. C is the sighting vane. The navigator uses the sightin... | Backstaff | Wikipedia | 396 | 974163 | https://en.wikipedia.org/wiki/Backstaff | Technology | Navigation | null |
Initially, the transom and yard are set so that the two are joined at their respective 45° settings. The instrument is held so that the yard is horizontal (the navigator can view the horizon along the yard to assist in this). The socket is loosened so that the transom is moved vertically until the shadow of the vane ... | Backstaff | Wikipedia | 486 | 974163 | https://en.wikipedia.org/wiki/Backstaff | Technology | Navigation | null |
This instrument is interesting in that the arc is 120° but is only graduated as a 90° arc. As such, the angular spacing of a degree on the arc is slightly greater than one degree. Examples of the instrument can be found with a 0° to 90° graduation or with two mirrored 0° to 45° segments centred on the midpoint of the ... | Backstaff | Wikipedia | 219 | 974163 | https://en.wikipedia.org/wiki/Backstaff | Technology | Navigation | null |
In mathematics, an algebraic function is a function that can be defined
as the root of an irreducible polynomial equation. Algebraic functions are often algebraic expressions using a finite number of terms, involving only the algebraic operations addition, subtraction, multiplication, division, and raising to a fracti... | Algebraic function | Wikipedia | 477 | 974169 | https://en.wikipedia.org/wiki/Algebraic%20function | Mathematics | Functions: General | null |
Introduction and overview
The informal definition of an algebraic function provides a number of clues about their properties. To gain an intuitive understanding, it may be helpful to regard algebraic functions as functions which can be formed by the usual algebraic operations: addition, multiplication, division, and ... | Algebraic function | Wikipedia | 474 | 974169 | https://en.wikipedia.org/wiki/Algebraic%20function | Mathematics | Functions: General | null |
For the square root is real and the cubic root is thus well defined, providing the unique real root. On the other hand, for the square root is not real, and one has to choose, for the square root, either non-real square root. Thus the cubic root has to be chosen among three non-real numbers. If the same choices are d... | Algebraic function | Wikipedia | 506 | 974169 | https://en.wikipedia.org/wiki/Algebraic%20function | Mathematics | Functions: General | null |
since the fi are by definition the distinct zeros of p. The monodromy group acts by permuting the factors, and thus forms the monodromy representation of the Galois group of p. (The monodromy action on the universal covering space is related but different notion in the theory of Riemann surfaces.)
History
The idea... | Algebraic function | Wikipedia | 175 | 974169 | https://en.wikipedia.org/wiki/Algebraic%20function | Mathematics | Functions: General | null |
The Rialto Bridge (; ) is the oldest of the four bridges spanning the Grand Canal in Venice, Italy. Connecting the (districts) of San Marco and San Polo, it has been rebuilt several times since its first construction as a pontoon bridge in 1173, and is now a significant tourist attraction in the city.
The present sto... | Rialto Bridge | Wikipedia | 485 | 974321 | https://en.wikipedia.org/wiki/Rialto%20Bridge | Technology | Bridges | null |
Other names
It was called Shylock's bridge in Robert Browning's poem "A Toccata of Galuppi's". | Rialto Bridge | Wikipedia | 29 | 974321 | https://en.wikipedia.org/wiki/Rialto%20Bridge | Technology | Bridges | null |
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