Body composition, differences

However, these researches included obese and elderly cohorts respectively in which body composition differ from the young people in this study [19]. 

BARDOCZ S, GRANT G, PUSZTAI A, FRANKLIN M F, CARVALHO A (1996) The effect of phytohaemagglutinin at different dietary concentrations on the growth, body composition and plasma insulin of the rat. Br J Nutr. 76 613-26. 

Body composition varies with age. The pediatric population has unique physiologic needs that make nutritional requirements distinctly different than adults. In children, caloric requirements per kilogram are higher because of their higher basal metabolic rate (BMR). BMR is approximately 50-55 kcal/ kg/day in infancy and declines to about 20-25 kcal/kg/day during adolescence. 

Much of the material presented in previous chapters relating to compositional and enzymic differences has a bearing on this problem, and it tends to support the concept that these urinary patterns arise, in part at least, because of the differences in the fundamental body chemistry (differing specific reaction rates) of each individual concerned. 

Body fluids are partitioned between the intracellular fluids (ICF), which constitute two-thirds of total body water, and extracellular fluids (ECF), which constitute one-third of total body water. The ECF consists of plasma and interstitial fluid plus lymph. The ionic composition differs substantially between ECF and ICF (Table 21.1). Sodium is the primary cation in ECF, whereas potassium is the principal intracellular cation. 

Differentiation of other terrestrial planets must have varied in important ways from that of the Earth, because of differences in chemistry and conditions. For example, in Chapter 13, we learned that the crusts of the Moon and Mars are anorthosite and basalt, respectively - both very different from the crust of the Earth. N either has experienced recycling of crust back into the mantle, because of the absence of plate tectonics, and neither has sufficient water to help drive repeated melting events that produced the incompatible-element-rich continental crust (Taylor and McLennan, 1995). The mantles of the Moon and Mars are compositionally different from that of the Earth, although all are ultramafic. Except for these bodies, our understanding of planetary differentiation is rather unconstrained and details are speculative. 

No description of our sofar system s formation wouid be complete without a discussion of the profound changes wrought by its orbital and collisional evolution. Although these physical processes may not seem to be related to cosmochemistry, they have changed the spatial distribution of planets and small bodies of differing compositions within the solar system, and in some cases, even the bulk compositions of large bodies. Understanding these processes can help us appreciate how some of the cosmochemical conundrums and complexities of the solar system arose. 

It is possible to predict what happens to Vd when fu or fur changes as a result of physiological or disease processes in the body that change plasma and/or tissue protein concentrations. For example, Vd can increase with increased unbound toxicant in plasma or with a decrease in unbound toxicant tissue concentrations. The preceding equation explains why because of both plasma and tissue binding, some Vd values rarely correspond to a real volume such as plasma volume, extracellular space, or total body water. Finally interspecies differences in Vd values can be due to differences in body composition of body fat and protein, organ size, and blood flow as alluded to earlier in this section. The reader should also be aware that in addition to Vd, there are volumes of distribution that can be obtained from pharmacokinetic analysis of a given data set. These include the volume of distribution at steady state (Vd]SS), volume of the central compartment (Vc), and the volume of distribution that is operative over the elimination phase (Vd ea). The reader is advised to consult other relevant texts for a more detailed description of these parameters and when it is appropriate to use these parameters. 

Kostic, E. and Momcilovic, I., Reaction sintered MgAl204 bodies from different batch compositions , Ceramurgia International, 1977 3(2) 57-60. 

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