Higher-body distribution functions

Because electrons interact only in pairs (i.e. there are no specifically many-body effects), there is no need to consider distribution functions higher than the pair function Pz. or> if spin-dependent properties are... 

Equation 68 is referred to as the high-temperature approximation because the potential appears in the integral as the product 0 V. Thus, the approximation is valid for small perturbations or high temperatures. Higher-order terms can be included, in principle, to obtain more accuracy. However, the derivatives of the distribution functions with respect to X involve higher-order distribution functions 170 e.g., the first-order correction in X to the distribution function involves three- and four-body distribution functions which are usually difficult to obtain. In some cases, the superposition approximation or other approximate expressions for the higher-order distributions have been introduced.175 However, the first-order result is the one that has been employed in most applications.176... 

These drugs exert their effects on airway function by mediation of P -receptors located on the surface of the smooth muscle and other tissues of the airways. Pj-and Pj-receptors are, however, distributed throughout the body. Stimulation of these receptors are considered to be responsible for side effects, such as tachycardia, arrhythmias, prolongation of the Q-Tc interval, tremor, and decrease in serum potassium, and become generally apparent when higher than conventional doses are inhaled (32-34). The relationship between increase in FEV, and the inhaled dose of a Pj-agonist is not linear but consists of a steep part followed by a plateau (34). 

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