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William Abbott Herdman
Sir William Abbott Herdman FRS FRSE FLS (5 September 1858, Edinburgh – 21 July 1924) was a Scottish marine zoologist and oceanographer. His zoological author abbreviation is Herdman. Life He was born in Edinburgh the son of the artist Robert Herdman RSA and his wife, Emma Abbott. They lived at 32 Danube Street. He was educated at Edinburgh Academy from 1870 to 1875. Archibald Geikie taught him geology during his time at the University of Edinburgh. Herdman graduated BSc in 1879 and became the assistant of Sir Charles Wyville Thomson. In this capacity he was placed as Secretary to the Challenger Expedition Commission: overseeing the deciphering of the huge catalogue of information found during this important exploration. In 1880 he became Demonstrator of Zoology at the University of Edinburgh and then, in 1881, the first holder of the Derby Chair of Natural History at Liverpool University College (later to become the University of Liverpool). In 1881 he was elected a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spawn (biology)
Spawn is the Egg cell, eggs and Spermatozoa, sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of releasing the eggs and sperm, and the act of both sexes is called spawning. Most aquatic animals, except for aquatic mammals and marine reptile, reptiles, reproduce through the process of spawning. Spawn consists of the reproductive cells (gametes) of many aquatic animals, some of which will become fertilized and produce offspring. The process of spawning typically involves females releasing Ovum, ova (unfertilized eggs) into the water, often in large quantities, while males simultaneously or sequentially release spermatozoa (milt) to fertilize the eggs. Most fish reproduce by spawning, as do most other aquatic animals, including crustaceans such as crabs and shrimps, molluscs such as oysters and squid, echinoderms such as sea urchins and sea cucumbers, amphibians such as frogs and newts, aquatic insects such as mayflies and mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stolidobranchia
Stolidobranchia is an order of tunicates in the class Ascidiacea.Lambert, G.; Gittenberger, A.; Sanamyan, K. (2015)Stolidobranchia.In: Shenkar, N.; Gittenberger, A.; Lambert, G.; Rius, M.; Moreira Da Rocha, R.; Swalla, B.J.; Turon, X. (2015) Ascidiacea World Database. Accessed through: World Register of Marine Species on 2015-12-23 The group includes both colonial and solitary animals. They are distinguished from other tunicates by the presence of folded pharyngeal baskets. This provides the etymology of their name: in ancient Greek, means the "fold" of a cloth. Stolidobranchian sea squirts are also characterized by the complete absence of an abdomen. The abdominal organs of other tunicates are instead located to one side of the pharyngeal basket in this group. Taxonomy *Molgulidae Lacaze-Duthiers 1877 exacrobylidae Seeliger 1906; Caesiridae**''Anomopera'' Hartmeyer, 1923 **''Asajirus'' Kott, 1989 'Hexadactylus'' Monniot & Monniot 1990**''Bostrichobranchus'' Traustedt, 1883 * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States National Agricultural Library
The United States National Agricultural Library (NAL) is one of the world's largest agricultural research libraries, and serves as a national library of the United States and as the library of the United States Department of Agriculture. Located in Beltsville, Maryland, it is one of five national libraries of the United States (along with the Library of Congress, the National Library of Medicine, the National Transportation Library, and the National Library of Education). It is also the coordinator for the Agriculture Network Information Center (AgNIC), a national network of state land-grant institutions and coordinator for the U.S. Department of Agriculture (USDA) field libraries. NAL was established on May 15, 1862, by the signing of the Organic Act by Abraham Lincoln. It served as a departmental library until 1962, when the Secretary of Agriculture officially designated it as the National Agricultural Library. The first librarian, appointed in 1867, was Aaron B. Grosh, one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Étang De Thau
The Étang de Thau (; oc, Estanh de Taur) or Bassin de Thau is the largest of a string of lagoons (''étangs'') that stretch along the French coast from the Rhône river to the foothills of the Pyrenees and the border to Spain in the Languedoc-Roussillon. Although it has a high salinity, it is considered the second largest lake in France. Description It is about 21 km long and 8 km wide, with an area of . The mean depth of the lagoon is 4.5 m, but in the central navigation channel it can be 10 m deep. Near Bouzigues there is a 100-metre diameter depression of 30 metres. This 'Fosse de la Vise' is the source of a hot spring that feeds the spa in Balaruc. Its size and depth, which distinguish it from other lagoons of the region, is explained by the geomorphology of the region: it is the syncline formed from folding which produced the corresponding anticline of the Gardiole in the north east. Until relatively recently the lagoons from Marseillan to the Rhône wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biodiversity
Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic (''genetic variability''), species (''species diversity''), and ecosystem (''ecosystem diversity'') level. Biodiversity is not distributed evenly on Earth; it is usually greater in the tropics as a result of the warm climate and high primary productivity in the region near the equator. Tropical forest ecosystems cover less than 10% of earth's surface and contain about 90% of the world's species. Marine biodiversity is usually higher along coasts in the Western Pacific, where sea surface temperature is highest, and in the mid-latitudinal band in all oceans. There are latitudinal gradients in species diversity. Biodiversity generally tends to cluster in hotspots, and has been increasing through time, but will be likely to slow in the future as a primary result of deforestation. It encompasses the evolutionary, ecological, and cultural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benthic Zone
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βÎνθος (bénthos), meaning "the depths." Organisms living in this zone are called benthos and include microorganisms (e.g., bacteria and fungi) as well as larger invertebrates, such as crustaceans and polychaetes. Organisms here generally live in close relationship with the substrate and many are permanently attached to the bottom. The benthic boundary layer, which includes the bottom layer of water and the uppermost layer of sediment directly influenced by the overlying water, is an integral part of the benthic zone, as it greatly influences the biological activity that takes place there. Examples of contact soil layers include sand bottoms, rocky outcrops, coral, and bay mud. Description Oceans The benthic region of the ocean begins at the shore line (intertida ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global Warming
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global average temperature is more rapid than previous changes, and is primarily caused by humans burning fossil fuels. Fossil fuel use, deforestation, and some agricultural and industrial practices increase greenhouse gases, notably carbon dioxide and methane. Greenhouse gases absorb some of the heat that the Earth radiates after it warms from sunlight. Larger amounts of these gases trap more heat in Earth's lower atmosphere, causing global warming. Due to climate change, deserts are expanding, while heat waves and wildfires are becoming more common. Increased warming in the Arctic has contributed to melting permafrost, glacial retreat and sea ice loss. Higher temperatures are also causing m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Korean War
, date = {{Ubl, 25 June 1950 – 27 July 1953 (''de facto'')({{Age in years, months, weeks and days, month1=6, day1=25, year1=1950, month2=7, day2=27, year2=1953), 25 June 1950 – present (''de jure'')({{Age in years, months, weeks and days, month1=6, day1=25, year1=1950) , place = Korean Peninsula, Yellow Sea, Sea of Japan, Korea Strait, China–North Korea border , territory = Korean Demilitarized Zone established * North Korea gains the city of Kaesong, but loses a net total of {{Convert, 1506, sqmi, km2, abbr=on, order=flip, including the city of Sokcho, to South Korea. , result = Inconclusive , combatant1 = {{Flag, First Republic of Korea, name=South Korea, 1949, size=23px , combatant1a = {{Plainlist , * {{Flagicon, United Nations, size=23px United Nations Command, United Nations{{Refn , name = nbUNforces , group = lower-alpha , On 9 July 1951 troop constituents were: US: 70.4%, ROK: 23.3% other UNC: 6.3%{{Cite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Impact On The Environment
Human impact on the environment (or anthropogenic impact) refers to changes to biophysical environments and to ecosystems, biodiversity, and natural resources caused directly or indirectly by humans. Modifying the environment to fit the needs of society is causing severe effects including global warming, environmental degradation (such as ocean acidification), mass extinction and biodiversity loss, ecological crisis, and ecological collapse. Some human activities that cause damage (either directly or indirectly) to the environment on a global scale include population growth, overconsumption, overexploitation, pollution, and deforestation. Some of the problems, including global warming and biodiversity loss, have been proposed as representing catastrophic risks to the survival of the human species. The term ''anthropogenic'' designates an effect or object resulting from human activity. The term was first used in the technical sense by Russian geologist Alexey Pavlov, and it w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desiccation
Desiccation () is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic (attracts and holds water) substance that induces or sustains such a state in its local vicinity in a moderately sealed container. Industry Desiccation is widely employed in the oil and gas industry. These materials are obtained in a hydrated state, but the water content leads to corrosion or is incompatible with downstream processing. Removal of water is achieved by cryogenic condensation, absorption into glycols, and absorption onto desiccants such as silica gel. Laboratory A desiccator is a heavy glass or plastic container, now somewhat antiquated, used in practical chemistry for drying or keeping small amounts of materials very dry. The material is placed on a shelf, and a drying agent or ''desiccant'', such as dry silica gel or anhydrous sodium hydroxide, is placed below the shelf. Often some sort of humidity indicator is included in the desiccator to show, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oviparity
Oviparous animals are animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, most reptiles, and all pterosaurs, dinosaurs (including birds), and monotremes. In traditional usage, most insects (one being ''Culex pipiens'', or the common house mosquito), molluscs, and arachnids are also described as oviparous. Modes of reproduction The traditional modes of reproduction include oviparity, taken to be the ancestral condition, traditionally where either unfertilised oocytes or fertilised eggs are spawned, and viviparity traditionally including any mechanism where young are born live, or where the development of the young is supported by either parent in or on any part of their body. However, the biologist Thierry Lodé recently divided the traditional category of oviparous reproduction into two modes that he named ovuliparity and (true) oviparity respectively. He distinguished the tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
