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Spirochaeta Americana
''Spirochaeta americana'' is a single-celled extremophile. This haloalkaliphilic and obligately anaerobic bacterium can be found in the highly alkaline, salty, deep waters of California's Mono Lake. Physical characteristics ''S. americana'' has long helically coiled cells, is gram-negative, and is chemotrophic in its metabolism. Spirochaeta also have unique flagella, sometimes called ''axial filaments'', which run lengthwise between the cytoplasmic membrane and outer membrane. These cause a twisting motion which allows the spirochaete to move about. Despite the extreme environment that they require, "their cell walls are very delicate, and it is difficult to keep them alive for long periods in the laboratory," says Dr. Elena Pikuta, one of the discoverers of ''S. americana''. Environment ''S. americana'' thrives in the lake-bottom mud of Lake Mono, a 13 mile wide former monomictic volcanic basin which is fed by numerous small Sierra streams and which has no outflow except ev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Hoover
Richard Brice Hoover (born January 3, 1943) is a physicist who has authored 33 volumes and 250 papers on astrobiology, extremophiles, diatoms, solar physics, X-ray/EUV optics and meteorites. He holds 11 U.S. patents and was 1992 NASA Inventor of the Year. He was employed at the United States' NASA Marshall Space Flight Center from 1966 to 2012, where he worked on astrophysics and astrobiology. He established the Astrobiology Group there in 1997 and until his retirement in late 2011 he headed their astrobiology research. He conducted research on microbial extremophiles in the Antarctic, microfossils, and chemical biomarkers in precambrian rocks and in carbonaceous chondrite meteorites. Hoover has published claims to have discovered fossilized microorganisms in a collection of select meteorites on multiple occasions. Early life Hoover was born in Sikeston, Missouri on January 3, 1943. He obtained his B.Sc. degree with majors in physics, mathematics and French in 1964 from Henderson ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcano
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and most are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, deep in the Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic plates slide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maltose
} Maltose ( or ), also known as maltobiose or malt sugar, is a disaccharide formed from two units of glucose joined with an α(1→4) bond. In the isomer isomaltose, the two glucose molecules are joined with an α(1→6) bond. Maltose is the two-unit member of the amylose homologous series, the key structural motif of starch. When beta-amylase breaks down starch, it removes two glucose units at a time, producing maltose. An example of this reaction is found in germinating seeds, which is why it was named after malt. Unlike sucrose, it is a reducing sugar. History Maltose was discovered by Augustin-Pierre Dubrunfaut, although this discovery was not widely accepted until it was confirmed in 1872 by Irish chemist and brewer Cornelius O'Sullivan. Its name comes from malt, combined with the suffix ' -ose' which is used in names of sugars. Structure and nomenclature Carbohydrates are generally divided into monosaccharides, oligosaccharides, and polysaccharides depending on the nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fructose
Fructose, or fruit sugar, is a Ketose, ketonic monosaccharide, simple sugar found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed by the gut directly into the blood of the portal vein during digestion. The liver then converts both fructose and galactose into glucose, so that dissolved glucose, known as blood sugar, is the only monosaccharide present in circulating blood. Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847. The name "fructose" was coined in 1857 by the English chemist William Allen Miller. Pure, dry fructose is a sweet, white, odorless, crystalline solid, and is the most water-soluble of all the sugars. Fructose is found in honey, tree and vine fruits, flowers, Berry, berries, and most List of root vegetables, root vegetables. Commercially, fructose is derived from sugar cane, sugar beets, and maize. Hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucose
Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using energy from sunlight, where it is used to make cellulose in cell walls, the most abundant carbohydrate in the world. In energy metabolism, glucose is the most important source of energy in all organisms. Glucose for metabolism is stored as a polymer, in plants mainly as starch and amylopectin, and in animals as glycogen. Glucose circulates in the blood of animals as blood sugar. The naturally occurring form of glucose is -glucose, while -glucose is produced synthetically in comparatively small amounts and is less biologically active. Glucose is a monosaccharide containing six carbon atoms and an aldehyde group, and is therefore an aldohexose. The glucose molecule can exist in an open-chain (acyclic) as well as ring (cyclic) form. Gluco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celsius
The degree Celsius is the unit of temperature on the Celsius scale (originally known as the centigrade scale outside Sweden), one of two temperature scales used in the International System of Units (SI), the other being the Kelvin scale. The degree Celsius (symbol: °C) can refer to a specific temperature on the Celsius scale or a unit to indicate a difference or range between two temperatures. It is named after the Swedish astronomer Anders Celsius (1701–1744), who developed a similar temperature scale in 1742. Before being renamed in 1948 to honour Anders Celsius, the unit was called ''centigrade'', from the Latin ''centum'', which means 100, and ''gradus'', which means steps. Most major countries use this scale; the other major scale, Fahrenheit, is still used in the United States, some island territories, and Liberia. The Kelvin scale is of use in the sciences, with representing absolute zero. Since 1743 the Celsius scale has been based on 0 °C for the freezing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytoplasm
In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. The main components of the cytoplasm are cytosol (a gel-like substance), the organelles (the cell's internal sub-structures), and various cytoplasmic inclusions. The cytoplasm is about 80% water and is usually colorless. The submicroscopic ground cell substance or cytoplasmic matrix which remains after exclusion of the cell organelles and particles is groundplasm. It is the hyaloplasm of light microscopy, a highly complex, polyphasic system in which all resolvable cytoplasmic elements are suspended, including the larger organelles such as the ribosomes, mitochondria, the plant plastids, lipid droplets, and vacuoles. Most cellular activities take place within the cytoplasm, such as many metabolic pathways including glycolysis, and proces ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Fission
Binary may refer to: Science and technology Mathematics * Binary number, a representation of numbers using only two digits (0 and 1) * Binary function, a function that takes two arguments * Binary operation, a mathematical operation that takes two arguments * Binary relation, a relation involving two elements * Binary-coded decimal, a method for encoding for decimal digits in binary sequences * Finger binary, a system for counting in binary numbers on the fingers of human hands Computing * Binary code, the digital representation of text and data * Bit, or binary digit, the basic unit of information in computers * Binary file, composed of something other than human-readable text ** Executable, a type of binary file that contains machine code for the computer to execute * Binary tree, a computer tree data structure in which each node has at most two children Astronomy * Binary star, a star system with two stars in it * Binary planet, two planetary bodies of comparable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Untersee
Lake Untersee (german: Untersee, "Lower Lake") is the largest surface freshwater lake in the interior of the Gruber Mountains of central Queen Maud Land in East Antarctica. It is situated to the southwest of the Schirmacher Oasis. The lake is approximately long and wide, with a surface area of , and a maximum depth of . The lake is permanently covered with ice and is partly bounded by glacier ice. Lake Untersee is an unusual lake, with pH between 9.8 and 12.1, dissolved oxygen at 150 percent supersaturation, and very low primary production in the water column. Despite the high oxygen supersaturation in most of the lake, there is a small sub-basin at the southern end that is anoxic and its sediments may have a higher methane concentration than those of any other known lake on Earth. Much of the primary production is in microbial communities that grow on the floor of the lake as stromatolites. The water temperature varies between and and the ice cover on the lake is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest continent, being about 40% larger than Europe, and has an area of . Most of Antarctica is covered by the Antarctic ice sheet, with an average thickness of . Antarctica is, on average, the coldest, driest, and windiest of the continents, and it has the highest average elevation. It is mainly a polar desert, with annual precipitation of over along the coast and far less inland. About 70% of the world's freshwater reserves are frozen in Antarctica, which, if melted, would raise global sea levels by almost . Antarctica holds the record for the lowest measured temperature on Earth, . The coastal regions can reach temperatures over in summer. Native species of animals include mites, nematodes, penguins, seals and tardigrades. Where vegetation o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Negit Island
Negit Island is an island in Mono Lake. Negit (along with nearby Paoha Island) is a volcanic cone less than 2000 years old. It can be considered to be the northernmost of the Mono Craters. Negit is composed of three dark dacite lava flows. Negit is an important nesting ground for migratory birds, including the California gull, which can often be seen wheeling in the air above Mono Lake. The fall of the lake level since 1941 created a land bridge to the island. The land bridge permitted predators, such as coyotes, to raid the bird eggs of the island. However, since 1994, the lake level has been permitted to rise and the land bridge is currently submerged. Negit Island is accessible by boats (commonly kayaks). However, the island is off-limits from April 1 through August 1, to protect the nesting gulls. See also * Mono Lake Tufa State Reserve * Mono Basin National Scenic Area * List of islands of California This list of islands of California is organized into sections, gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
