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Cultured Freshwater Pearls
Cultured freshwater pearls are pearls that are farmed and created using freshwater mussels. These pearls are produced in Japan and the United States on a limited scale, but are now almost exclusively produced in China. The U.S. Federal Trade Commission requires that farmed freshwater pearls be referred to as "freshwater cultured pearls" in commerce. Quality of cultured freshwater pearls is evaluated through a grading system of a series of A values, based on luster, shape, surface, colour and matching. Current and historic industry Pearls gathered in the wild from the Holarctic saltwater pearl mussel were important sources of pearls for modern jewelry, with Scotland a major source; this species is now endangered in most areas. Although the Japanese freshwater pearl industry has nearly ceased to exist, it has a normal historic place as the first country to cultivate whole freshwater pearls, which it did in Lake Biwa, using the Biwa pearly mussel (''Hyriopsis schlegeli''). The ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Necklace
The sea, connected as the world ocean or simply the ocean, is the body of water, body of saline water, salty water that covers approximately 71% of the Earth's surface. The word sea is also used to denote List of seas, second-order sections of the sea, such as the Mediterranean Sea, as well as certain large, entirely landlocked, saltwater lakes, such as the Caspian Sea. The sea moderates Earth's climate and has important roles in the water cycle, water, carbon cycle, carbon, and nitrogen cycle, nitrogen cycles. Humans harnessing and studying the sea have been recorded since ancient times, and evidenced well into prehistory, while its modern scientific study is called oceanography. The most abundant solid dissolved in seawater is sodium chloride. The water also contains salt (chemistry), salts of magnesium, calcium, potassium, and Mercury (element), mercury, amongst many other elements, some in minute concentrations. Salinity varies widely, being lower near the surface and the mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Kasumigaura
is the second-largest lake in Japan, located 60 km to the north-east of Tokyo. In a narrower sense and officially, Lake Kasumigaura refers to a waterbody with an area of 167.63 km2. In a wider sense, Lake Kasumigaura can also refer to a group of contiguous lakes, which includes Lake Kasumigaura proper, hereby referred to as Nishiura (西浦), and two smaller lakes, Kitaura (北浦; 35.16 km2) and Sotonasakaura (外浪逆浦; 5.85 km2), and also encompasses the rivers connecting them. In this case the total area is 220 km2. About 45% of the land surrounding the lake is natural landscape and 43.5% is agricultural land. History Lake Kasumigaura originally was a brackish-water lagoon, with indirect connections to the Pacific Ocean via the Hitachigawa and Tone Rivers. In 1963, the construction of a gate near the confluence of these rivers disconnected the lake from its sources of ocean water. As a result, the salinity of Lake Kasumigaura declined, and to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fishing Industry In China
China has one-fifth of the world's population and accounts for one-third of the world's reported fish production as well as two-thirds of the world's reported aquaculture production.FAO Fact sheetAquaculture in China and Asia It is also a major importer of seafood and the country's seafood market is estimated to grow to a market size worth US$53.5 Billion by 2027. China's 2005 reported catch of wild fish, caught in rivers, lakes, and the sea, was 17.1 million tonnes, far ahead of the second-ranked nation, the United States, which reported 4.9 million tonnes. The Chinese commercial fishing fleet is responsible for more illegal, unreported and unregulated fishing than that of any other nation. Aquaculture, the farming of fish in ponds, lakes and tanks, accounts for two-thirds of China's reported output. China's 2005 reported harvest was 32.4 million tonnes, more than 10 times that of the second-ranked nation, India, which reported 2.8 million tonnes. The country's aquaculture marke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cultured Pearl
Cultured pearls are formed within a cultured pearl sac with human intervention in the interior of productive living molluscs in a variety of conditions depending upon the mollusc and the goals. Just as the same as natural pearls, cultured pearls can be cultivated in seawater or freshwater bodies. Nowadays, over 95% of the pearls available on the market would be cultured pearls. Development of a pearl A pearl is formed when the mantle tissue is injured by a parasite, an attack of a fish, or another event that damages the external fragile rim of the shell of a mollusk shell bivalve or gastropod. In response, the mantle tissue of the mollusk secretes nacre into the pearl sac, a cyst that forms during the healing process. Chemically speaking, this is calcium carbonate and a fibrous protein called conchiolin. As the nacre builds up in layers of minute aragonite tablets, it fills the growing pearl sac and eventually forms a pearl. Natural pearls are initiated in nature more or l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hank (textile)
In the textile industry, a hank is a coiled or wrapped unit of yarn or twine, as opposed to other materials like thread or rope, as well as other forms such as ball, cone, bobbin (cylinder-like structure) spool, etc. This is often the best form for use with hand looms, compared to the cone form needed for power looms. Hanks come in varying lengths depending on the type of material and the manufacturer. For instance, a hank of linen is often , and a hank of cotton or silk is . While hanks may differ by manufacturer and by product, a skein is usually considered 1/6th of a hank (either by weight or by length). One source identifies a skein of stranded cotton as being , of tapestry wool as being , and crewel wool as being . In yarns for handcrafts such as knitting or crochet, hanks are not a fixed length but are sold in units by weight, most commonly 50 grams. Depending on the thickness of the strand as well as the inherent density of the material, hanks can range widely in yardage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cornmeal
Cornmeal is a meal (coarse flour) or a cell membrane ground from dried corn. It is a common staple food, and is ground to coarse, medium, and fine consistencies, but not as fine as wheat flour can be.Herbst, Sharon, ''Food Lover's Companion'', Third Edition, Pg. 165, Barrons Educational Series Inc, 2001 In Mexico, very finely ground cornmeal is referred to as corn flour. When fine cornmeal is made from maize that has been soaked in an alkaline solution, e.g., limewater (a process known as nixtamalization), it is called masa harina (or masa flour), which is used for making arepas, tamales and tortillas. Boiled cornmeal is called polenta in Italy and is also a traditional dish and bread substitute in Romania. Types There are various types of cornmeal: *''Blue cornmeal'' is light blue or violet in color. It is ground from whole blue corn and has a sweet flavor. The cornmeal consists of dried corn kernels that have been ground into a fine or medium texture. *''Steel-ground yellow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raisin
A raisin is a dried grape. Raisins are produced in many regions of the world and may be eaten raw or used in cooking, baking, and brewing. In the United Kingdom, Ireland, New Zealand, and Australia, the word ''raisin'' is reserved for the dark-colored dried large grape, with '' sultana'' being a golden-colored dried grape, and '' currant'' being a dried small Black Corinth seedless grape. Etymology The word "raisin" dates back to Middle English and is a loanword from Old French; in modern French, ''raisin'' means "grape", while a dried grape is a ''raisin sec'', or "dry grape". The Old French word, in turn, developed from the Latin word '' racemus'', "a bunch of grapes". Varieties Raisin varieties depend on the type of grape and appear in a variety of sizes and colors including green, black, brown, purple, blue, and yellow. Seedless varieties include the sultana (the common American type is known as Thompson Seedless in the United States), the Zante currants (black Corin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cristaria Plicata
''Cristaria plicata'', the cockscomb pearl mussel, is a freshwater mussel, an aquatic bivalve mollusk in the family Unionidae. Distribution This species is native to northeast Asia and now also present in parts of southeast Asia. This large mussel is listed as endangered in South Korea. Biology The mitochondrial genome Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial D ... of this species was sequenced in 2011 or 2012. Human uses In China, this species is significant as "one of the most important freshwater mussels for pearl production in the country." It is used for medicinal purposes. References * Bogan, A. (2013). "FADA Bivalvia: World checklist of Freshwater Bivalvia Species" (version Jan 2013). In: ''Species 2000 & ITIS Catalogue of Life,'' 11 March 2013 (Roskov, Y.et al., e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pearls
A pearl is a hard, glistening object produced within the soft tissue (specifically the mantle (mollusc), mantle) of a living animal shell, shelled mollusk or another animal, such as fossil conulariids. Just like the shell of a mollusk, a pearl is composed of calcium carbonate (mainly aragonite or a mixture of aragonite and calcite) in minute crystalline form, which has deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other shapes, known as baroque pearls, can occur. The finest quality of natural pearls have been highly valued as gemstones and objects of beauty for many centuries. Because of this, ''pearl'' has become a metaphor for something rare, fine, admirable and valuable. The most valuable pearls occur spontaneously in the wild, but are extremely rare. These wild pearls are referred to as ''natural'' pearls. ''Cultured'' or ''farmed'' pearls from Pinctada, pearl oysters and freshwater mussels make up the majority of those currently ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleation
In thermodynamics, nucleation is the first step in the formation of either a new thermodynamic phase or structure via self-assembly or self-organization within a substance or mixture. Nucleation is typically defined to be the process that determines how long an observer has to wait before the new phase or self-organized structure appears. For example, if a volume of water is cooled (at atmospheric pressure) below 0°C, it will tend to freeze into ice, but volumes of water cooled only a few degrees below 0°C often stay completely free of ice for long periods (supercooling). At these conditions, nucleation of ice is either slow or does not occur at all. However, at lower temperatures nucleation is fast, and ice crystals appear after little or no delay. Nucleation is a common mechanism which generates first-order phase transitions, and it is the start of the process of forming a new thermodynamic phase. In contrast, new phases at continuous phase transitions start to form immedi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterosis
Heterosis, hybrid vigor, or outbreeding enhancement is the improved or increased function of any biological quality in a hybrid offspring. An offspring is heterotic if its traits are enhanced as a result of mixing the genetic contributions of its parents. These effects can be due to Mendelian or non-Mendelian inheritance. Definitions In proposing the term heterosis to replace the older term heterozygosis, G.H. Shull aimed to avoid limiting the term to the effects that can be explained by heterozygosity in Mendelian inheritance. Heterosis is often discussed as the opposite of inbreeding depression, although differences in these two concepts can be seen in evolutionary considerations such as the role of genetic variation or the effects of genetic drift in small populations on these concepts. Inbreeding depression occurs when related parents have children with traits that negatively influence their fitness largely due to homozygosity. In such instances, outcrossing shoul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Latendresse
John Robert Latendresse (July 26, 1925 in South Dakota – July 23, 2000) was an American collector, known for being the "father of American cultured freshwater pearls" - USGS. He left home at 13, and lying about his age, joined the U.S. Marines at 15yo serving 38 months in the south pacific during World War II. On his return he moved to Reno, Nevada where he worked as a casino cashier. Latendresse founded the Tennessee Shell Company in 1954 to supply the shell fragments used to seed pearls to pearl farmers overseas, later founding the American Pearl Company in 1961 to import pearls from Japan. He began experimenting with culturing pearls in the United States resulting in him becoming the first successful North American freshwater pearl farmer and he has been voted one of the pearl industry's most important people of the century. Latendresse established the first experimental U.S. freshwater cultured pearl farm in Tennessee in 1963 which unfortunately was unsuccessful however ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
