Calcified deposits

About 25% of the carbonates deposited in shallow water are eventually eroded and carried downslope by bottom and turbidity currents to become part of the shelf and pelagic sediments. Shallow-water carbonates are also notable for their mineral composition. In addition to calcite and aragonite, some shallow-water calcifiers deposit hard parts containing high percentages of magnesium. These are referred to as magnesium-rich calcites. 

Start with the ranked list of needs such as those obtained after the previous lesson (Figure 6-2 see also Appendix 6-1). We have given this as a mind map to keep it short. Note that all the regulations have a rank 5 (essential) you must obey these. Some needs in the map are a bit cryptic because we had to keep them short. Tartar is a calcified deposit on your teeth caries is the dental name for holes or cavities. Simulates water is short for bmshing with paste simulates drinking water with a suitable fluoride content . 

Any connection between salivary antibodies and calculus might be expected to be more tenuous, since calculus levels are not associated with any particular bacterium. The present authors are not aware of any study of such an association, though both IgA and IgG, an immunoglobulin originating in crevicular fluid, have been detected in regions of calcified deposits low in mineral [113],... 

Does not damage adjacent tissue or cause calcified deposition on material surface. 

Foldes 2002 Sofka et al. 2002 Frediani et al. 2005). Three main patterns of calcified deposits have been described (Frediani et al. 2005) thin hyperechoic bands parallel to the surface of the hyaline cartilage (more frequent in the knee) a punctate pattern, composed of several thin bright echogenic spots (commonly seen in fibrocartilage and tendons) and homogeneous hyperechoic nodular or oval deposits (found in bursae and articular recesses). 

Calcifying enthesopathy refers to calcified deposits in the more distal portion of the quadriceps tendon. It usually derives from local chronic stresses (excessive loading due to overweight or professional activities) or peripheral involvement in diffuse idiopathic skeletal hyperostosis (DISH) syndrome. Clinically, the enthesopathy at the quadriceps tendon insertion may be completely asymptomatic or may... 

Sur cia.1 Deposits. Uraniferous surficial deposits maybe broadly defined as uraniferous sediments, usually of Tertiary to recent age which have not been subjected to deep burial and may or may not have been calcified to some degree. The uranium deposits associated with calcrete, which occur in Australia, Namibia, and Somaha in semiarid areas where water movement is chiefly subterranean, are included in this type. Additional environments for uranium deposition include peat and bog, karst caverns, as well as pedogenic and stmctural fills (15). 

The sequestering agent tetrasodium pyrophosphate (TSPP) removes calcium and magnesium from the saliva, so they can t deposit on teeth as insoluble deposits called tartar (calcified plaque). In this respect it acts as a water-softening agent. However, it won t remove tartar that already exists. 

These shallow-water deposits were the sole source of biogenic carbonate until the evolution and proliferation of planktonic calcifiers, namely the coccolithophorids and the foraminiferans, around 250mybp. This enabled a shift in the site of sedimentary carbonate acciunulation from the shallow waters to the deep sea. At present, about half of the sedimentary carbonates are being buried on the shelves and the other half in the deep sea and slopes. 

Fluoride is rapidly distributed in plasma and deposited in bone and other calcified tissues that contain 99% of the body s fluoride the remainder is distributed between blood and soft tissues [52]. About 50% of daily fluoride intake is associated with the calcified tissues within 24 h and remaining 50% will be excreted in urine. This 50 50 distribution is strongly shifted to greater retention in the very young and probably towards greater excretion in the later years of life [8]. 

Absorbed fluoride that is not deposited in calcified tissue is excreted. The primary pathway for fluoride excretion is via the kidneys and urine to a lesser extent, fluoride is also excreted in the faeces, sweat and saliva. 

Under certain conditions, the mitochondria of many types of cells from a variety of animal species can accumulate large deposits of stable ACP113( In a tissue which calcifies, these mitochondrial granules might be involved in some aspects of the mineralizing process113. ... 

The aggregate of the various prucesscs by which calcium enlcrs and leaves the body and its various subsystems can be summarized by the term calcium metabolism. The principal pathways of calcium metabolism are intake, digestion and absorption, transport within the body to various sites, deposition in and removal from hone, teeth, and other calcified structures, and excretion in urine and stool. 

The level of calcium in solution will depend upon the presence of precipitating anions, notably phosphate and carbonate. Calcium will precipitate as the phosphate to give hydroxyapatite, Caio(P04)6(OH)2, in bones and teeth, and as the phosphate or carbonate to give other structures, including small crystals, or non-crystalline deposits in cells. Small crystals of calcium carbonate, found in the inner ear of some animals, are responsible for the control of balance. Various calcified tissues result from the precipitation of calcium salts, such as hydroxyapatite in the calcification of the aortic wall, and the oxalate in various stones. 

We further conclude that calcified tissues were not developed for carbonate deposition. They were secreted as components of the cell wall or as excretory byproducts of metabolic processes. As a consequence of a changing habitat, these materials started to calcify or introduced inorganic carbonate deposition. The sudden occurence of highly developed metazoan populations at the boundary Cambrian-Precambrian is frequently explained in terms of an explosive evolution347). For those who are familiar with the mechanism of calcification this deus ex machina explanation is not necessarily the most satisfying one. It may simply be a reflection of the universal adaption of many forms of life to a new environmental setting that developed at that time. Only a slight modification in pH is required (see Fig. 14) to... 

Deakins M, Burt RL. 1944. The deposition of calcium, phosphorus, and carbon dioxide in calcifying dental enamel. J Biol Chem 156 77. 

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