Phosphorus balance

The water fluxes of the ECS are chiefly influenced by the Kuroshio surface water (KSW), the Kuroshio tropical water (KTW), and the Taiwan Strait water (TSW) entering into the ECS, and by the shelf surface water (SSW) leaving the ECS. The annual variation in concentration of DIP in these waters is small. If the geochemical cycle of phosphorus in the ECS is assumed to have reached a steady state, then the P budget of the ECS can be calculated using water and phosphorus mass-balance, using data obtained in previous studies. 

Based on the above information, a simple box model (Fig. 4.44, Fang, 2004) was used to calculate the P budget of the ECS according to the water and P mass balance, as shown in the following equations  

The import flux of DOP from the Changjiang River and the inputs of atmospheric P fluxes into the ECS were excluded from the calculation because measurements were not available. Table 4.15 (Fang, 2004) summarizes the parameters used to calculate the P budget of each water mass in the ECS and the calculated results. The high annual flux of these parameters was calculated from the high value of water flux and high concentration in each column, and low annual flux was calculated from the low value of the water flux and low concentration. The average value was calculated from the value without error constraint. The results show that the P input flux from the various water masses into the ESC was (78.8 48.8)xl0 mol P/yr. The inputs of the TSW and the KIW were the major sources, and both contributed more than 65% of 

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Calcium-phosphorus balance is mediated through a complex interplay of hormones and their effects on bone, GI tract, kidney, and parathyroid gland. As kidney disease progresses, renal activation of vitamin D is impaired, which reduces gut absorption of calcium. Low blood calcium concentration stimulates secretion of parathyroid hormone (PTH). As renal function declines, serum calcium balance can be maintained only at the expense of increased bone resorption, ultimately resulting in renal osteodystrophy (ROD) (Fig. 76-7). 

Table VI shows the effect of 0.75% dietary zinc on the phosphorus balance in young rats. A decrease in the apparent retention of phosphorus was noted in the zinc-fed rats as early as the end of the first week. Possibly a more significant observation was the apparent movement of phosphorus excretion from the urine, the normal pathway for phosphorus excretion, to the feces in rats fed the high zinc diet. Such a shifting of the phosphorus excretion to the fecal pathway in animals fed a high zinc diet should result in an increase...

Table VIII shows the phosphorus balance of zinc-fed and non-zinc-fed rats supplemented with 0.8% calcium and/or phosphorus. A dietary level of 0.75% zinc was associated with decreases in the apparent retention of phosphorus, and these data support the findings of Sadasivan (2-4). Calcium supplements were associated with slight increases in the retention of phosphorus, while phos-...

Abnormal mineral balance in low-dose diet normal calcium, magnesium, and phosphorus balance in 2.7 mg/kg supplement (28)... 

The phosphorus balance data (Table II) show that the urinary phosphorus excretion Increased approximately two- to three-fold In all three high phosphorus studies, while the fecal phosphorus excretion Increased to a considerably lesser extent. The phosphorus balance of all three patients became more positive during the high phosphorus Intake. These studies have shown that Increasing the phosphorus Intake up to 2000 mg/day did not affect the excretions of zinc nor the zinc balance, despite the fact that there were marked changes In phosphorus metabolism, primarily a marked Increase of the urinary phosphorus excretion, while the fecal phosphorus excretion Increased to a lesser extent. 

Miller, E. R., Ullrey, D. E., Zutaut, C. L., ] loefer, j- A., and Luecke, R. W. (1964). Mineral balance studies with the baby pig Effects of dietary phosphorus level upon calcium and phosphorus balance. ]. Ntiir. 82,111-114. 

Carbon dioxide is an important component of the body and would not be expected to have a chronic toxicity. Flowever, long-term exposures to levels as low as 0.5-1%, while being generally well tolerated, can alter the acid base and calcium-phosphorus balance resulting in metabolic acidosis and increased calcium deposits in soft tissues. Long-term exposures in the range of 1-2% can stress the adrenal cortex because of constant respiratory stimuli and this level of exposure is considered dangerous after several hours. Exposure to 2% for several hours produces... 

Kelsay, J.L., Jacob, R.A. and Prather, E.S. 1979a. Effect of fiber from fruits and vegetables on metabolic responses of human subjects, III. Zinc, copper, and phosphorus balances, Am. J. Clin. Nutr., 32(11) 2307-2311. 

Antacids with aluminum in them block phosphorus intake, as will an excess of iron. Lack of vitamin D or a high blood level of calcium will block phosphorus assimilation. The hormone calcitonin causes rapid loss of phosphorus, and sugar upsets the calcium-phosphorus balance. Alcohol also interferes with phos-... 

Jaworski, N. A., Groffman, P. M., Keller, A. A. Prager, J. C. (1992). A watershed nitrogen and phosphorus balance the Upper Potomac River basin. Estuaries, 15, 83-95. 

In some cases atmospheric phosphorus inputs can be important contributions to the overall phosphorus balance in both terrestrial and aquatic ecosystems, notably where dust deposition provides phosphorus to highly oligotrophia lakes (Gibson etal, 1995 Newman, 1995). Further, modelling studies indicate that the deposition of phosphorus in dust can have a marked influence on longterm ecosystem development, at least in tropical forests (see Parton et al.. Chapter 15, this volume). However, organic phosphorus is rarely quantified in precipitation, and little published data exists. 

If the result is to be given in mg of POz /l, mg of P2O3/I or mg of P/1, when preparing a phosphorus balance or for some other reason, the following factors are used for conversion ... 

It is noteworthy that positive phosphorus balance preceded positive calcium balance in this infant in a fashion similar to that which usually occurs in infants fed by mouth. 

Fig. 1. Postoperative nitrogen, potassium, and phosphorus balances. Patient operated on 5th day of life for duodenal stenosis. No postoperative intakes whatsoever until the 3rd day, when 90 ml 5% glucose was infused. From the 4th postoperative day on increasing amounts of human milk was given. Cow s milk mixture was added from the 8th day. Balance diagrams are conventional, with negative balances marked in solid black.

Studies of the Stavropol Scientific Research Institute of Agriculture [9] showed that in conditions of ordinary loamy chernozem annual fertilizer phosphorus application for crops of a six coarse rotation rate of N,2oP9oKj2o first rotation of crop rotation ensured positive phosphorus balance (the content of phosphorus was determined by the method of Machigin) 270 kg/ha (Table 20.2, Figure 20.5). 

Mobile phosphorus content in subsurface soil in the end of the rotation increased to 26 mg/kg or 13 mg/kg compared with the beginning of the rotation. During the second and third rotations at the same rate and the same total phosphorus balance 542 kg/ha mobile phosphorus content in the soil of the variant increased to 52 mg/kg, for example, 26 mg/kg compared with the beginning of the second rotation. But to the end of fifth rotation of crop rotation, for example, 12 years after the end of the third rotation in spite of systematic mineral fertilizer application at the same rate with phosphorus balance for these years 250-kg/ha mobile phosphorus content in the surface soil increased by only 2 mg/kg. 

In comparison with calcium, experimental work on phosphorus balance has been scanty. It appears to have been generally assumed that there is little chance of a deficiency of phosphorus arising from any diet which... 

There are three major tubular functions to be recognised (1) salt and water balance, (2) potassium and acid/base homeostasis, and (3) calcium and phosphorus balance. 

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