Phosphorus, effect total

Auclair, J. C. 1995. Implications of increased UV-B induced photoreduction Iron(II) enrichment stimulated picocyanobacterial growth and the microbial food web in clear-water acidic Canadian Shield lakes. Canadian Journal of Fisheries and Aquatic Sciences 52 1782—1788. Auclair, J. C., P. Brassard, and P. Couture. 1985. Total dissolved phosphorus Effects of two molecular weight fractions on phosphorus cycling in natural phytoplankton communities. Water Research 19 1447—1453. 

The above description of eutrophication has illustrated the complex nature of the problem, particularly in relation to the influence of nutrients, the multiplicity of sources of phosphorus and the spectrum of its bio-availability. Clearly, the most effective long-term solution to many of our eutrophication problems will be to reduce the nutrient load to affected waters. However, it has also been shown that, because the concentrations of available phosphorus required to impose a control on primary production is very low (e.g. 5-10/rgU total dissolved phosphorus), the reduction of nutrients from any one source alone is unlikely to be effective. 

The effects of varying either the calcium or phosphorus level in conjunction with a high beef meal on the urinary calcium excretion of men are shown in Table IV. Urinary calcium excretion (total and ionized) was significantly elevated (P < 0.005) when the high protein beef meal contained 466 mg rather than 166 mg calcium. Increasing the phosphorus level from 308 mg to 700 mg in the high beef meal reduced both total and ionized calcium excretion in the urine, but the response was not statistically significant. Serum levels of calcium (ionized and total) and phosphorus were within normal limits and were unaffected by any of the dietary treatments. 

It has been reported that in normal individuals who eat a standard breakfast there is no significant change in blood urea nitrogen, carbon dioxide content, chloride, sodium, potassium, calcium, phosphorus, total protein, albumin, creatinine, uric acid, cholesterol, and cholesterol esters (A4). It should be emphasized again that the effects of fasting are quite different in normal, healthy persons than in sick people. 

In a 1-1. round-bottomed flask are placed 74 g. (0.5 mole) of phthalic anhydride and 30 ml. (0.5 mole) of freshly distilled monoethanolamine. The mixture is heated on a steam bath for 30 minutes the initial reaction is vigorous (Note 1). The reaction mixture is cooled to room temperature, and a reflux condenser is attached to the flask. To the cooled reaction mixture is added slowly, with shaking, 32 ml. (91.3 g., 0.337 mole) of freshly distilled phosphorus tribromide. The reaction flask is then placed on a steam bath and heated under reflux with occasional shaking for 1.25 hours (Note 2). The hot liquid reaction mixture is poured with stirring onto 750 g. of crushed ice. When the ice has melted completely, the crude /3-bromoethylphthali-mide is collected on a Buchner funnel, washed with cold water, and allowed to dry for a few minutes. The crude product (Note 3) is dissolved in 1.2 1. of aqueous ethanol (50% by volume) with the aid of heat. If necessary a small amount of 95% ethanol is added to effect complete solution. The hot solution is filtered and cooled in a refrigerator. A white crystalline product weighing 94-99 g. is obtained. Concentration of the mother liquor to 400 ml. yields an additional 1-3 g. of product. The total yield of product is 95-102 g. (75-80%) m.p. 80-82°. 

Since all condensed phosphates are ultimately degraded to monophosphate in hot solution, especially at low pH, the total phosphorus(V) content of a substance may readily be determined after hydrolysis either gravimetrically or titrimetrically (109). However, as soon as it is a question of estimating the content of separate components in mixtures of condensed phosphates insuperable difficulties are encountered if methods depending on precipitation, titration, or a combination of the two are used. Even a quantitative precipitation of monophosphate is impossible if polyphosphates with chain length of n = 3 or more arc present in the solution. The precipitating cation and the compound to be precipitated by it are partly kept in solution by the polyphosphate part of the polyphosphate is also carried down by the precipitate. Both of these effects depend in their extent in different ways on the nature and quantity of the substances present and the analysis gives a correct quantitative result only in isolated instances... 

UHT processing and storage have no effect on the total calcium content or calcium bioavailability. Calcium, phosphorus, and magnesium are shown to be equally bioavailable to rats from UHT milk, raw milk, and traditionally processed milk (Katz et al. 1981). Also, human infants retain similar amounts of calcium, potassium, and phosphorus whether fed UHT milk or conventionally pasteurized milk (Renner 1980 Mehta 1980). Data to date indicate no significant changes in the nutritional value of UHT milk under controlled heat treatment and subsequent storage. 

Extraction of soils for analysis of die readily available nutrients include replacement of exchangeable cations by salt solutions, dilute acids, and dilute alkalies such as NaHCCh. Fluoride solutions ate employed to repress iron, aluminum, and calcium activity during the extraction of phosphorus. Extraction of the soil solution is effected by displacement in a soil column, often through the application of pressure across a pressure membrane. The soil solution is analyzed by conductance and elemental analysis methods. Also, the total elemental analysis of soils is made by Na2CC>3 fusion of the soil followed by classical geochemical analysis methods. 

There have been several calculations dealing with AH5 species where A is a second-row atom, S, Si, or P. PH5 is a hypothetical molecule and has been extensively studied as the prototype quinquevalent phosphorus compound. Earlier calculations by Rauk et al.2S1 found that -functions had a significant effect on the total energy, but primarily act to overcome deficiencies in the basis set used which was (12,9,1/5)->[6,4,1/2]. ... 

The conformation of the synthetic putative ligatin receptor has been determined by its phosphorus carbon and phosphorus hydrogen coupling constants [234]. The pseudo-saccharide bond to phosphorus adopts a normal conformation and obeys the exo anomeric effect. The total shape of this pseudo disaccharide is a stretched out conformation. 

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