Expressive attributes

Environmental toxicology is based on the premise that the amount of chemical reaching an active site in, or on the surface of, an organism determines whether a compound will exert a specific beneficial or adverse effect or pose an ecological or health risk. This basic toxicological principle is embodied in the expression attributed to Paracelsus that it is "the dose that makes the poison."... 

Assume that every element in T C 5 has an attribute. Using the concept of characteristic functions to express attributed elements, we extend them as follows. 

Using the free-volume theory, the following polymer diffiisivity expression attributed to Achillas and Kiparissides (1992) was used, which in turn was based on the scaling theory predications of De Gennes (1979)... 

For the diffusivity of the monomer, the following pseudobinary expression attributed to Vrentasand Duda (1977) was used (Dar and Caneba, 2002) ... 

Here the ijk coordinate system represents the laboratory reference frame the primed coordinate system i j k corresponds to coordinates in the molecular system. The quantities Tj, are the matrices describing the coordinate transfomiation between the molecular and laboratory systems. In this relationship, we have neglected local-field effects and expressed the in a fomi equivalent to simnning the molecular response over all the molecules in a unit surface area (with surface density N. (For simplicity, we have omitted any contribution to not attributable to the dipolar response of the molecules. In many cases, however, it is important to measure and account for the background nonlinear response not arising from the dipolar contributions from the molecules of interest.) In equation B 1.5.44, we allow for a distribution of molecular orientations and have denoted by () the corresponding ensemble average ... 

Because of the interrelationship of the system measures, rehabihty should not be considered by itself since, if taken alone, it does not express the totahty of attributes that contribute to system effectiveness. However, in practice, rehabihty has gained the most acceptance and uniformity of definition. The other concepts described are not always defined uniformly from group to group and are sometimes used interchangeably. Further discussion of these concepts is found in References 1 and 2. 

For purposes of dosage, the specific activity of an enzyme is usually expressed as International Units (lU) rather than in terms of weight. However, unit measurements do not provide information on the absolute purity of a given product. Moreover, purity is not as critical an attribute for oral enzymes, as opposed to those adrninistered parenteraHy, inasmuch as the gastrointestinal tract is capable of disposing of most inert contaminants. 

The salt consumption with a sodium 0.275 and 0.533 Lbs of salt per 1,000 grains of hardness, expressed as calcium carbonate, removed. This range is attributed to two factors (1) the water composition, and (2) the operating exchange value at which the exchange resin is to be worked. The lower salt consumption may be attained with waters that are not excessively hard nor high in sodium salts, and where the exchange resin is not worked at its maximum capacity. 

Overall efficiency of air conditioning equipment steadily rose starting in the mid-1970s, attributed to consumer demand, government mandate, and incentive programs. For example, the average efficiency, as expressed in seasonal energy efficiency ratio, of new central air conditioners increased about 35 percent between 1976 and 1991. After national standards took effect in 1992, efficiency has increased as much as another 15 percent. 

The conclusions are evidently relevant to the amount of entropy lost by ions in methanol solution—see Table 29. If, however, the expression (170) is used for an atomic ion, we know that it is applicable only for values of R that are large compared with the ionic radius—that is to say, it will give quantitative results only when applied to the solvent dipoles in the outer parts of the co-sphere. The extent to which it applies also to the dipoles in the inner parts of the co-sphere must depend on the degree to which the behavior of these molecules simulates that of the more distant molecules. This can be determined only by experiment. In Table 29 we have seen that for the ion pair (K+ + Br ) and for the ion pair (K+ + Cl-) in methanol the unitary part of ASa amounts to a loss of 26.8 e.u. and 30.5 e.u., respectively, in contrast to the values for the same ions in aqueous solution, where the loss of entropy in the outer parts of the co-sphere is more than counterbalanced by a gain in entropy that has been attributed to the disorder produced by the ionic field. 

Whereas treatment of ( )-29 with camphanic chloride achieves the selective esterification of the hindered C-9 hydroxyl group, the action of acetic anhydride on (+)- 29 results in the equally selective acetylation of the C-10 hydroxyl group It is not clear to what this discrepancy should be attributed, so we will not offer a rationalization here. This unexpected result is, however, most gratifying because TPAP-NMO oxidation27 of the remaining C-9 hydroxyl furnishes keto acetate 6 (88 % overall yield). You will note that the contiguous keto and acetate functions in 6 are both expressed in the natural product. 

The expressions acyclic or cyclic precursors indicate whether a heteropyran ring does or does not occur during a given synthesis. No importance is attributed to the fact that reactants may already contain a ring. 

Conversion tables and charts now available make it possible to express I.C.I. data in forms in which a specified color and the significance of measured color differences can be more easily visualized. For example, I.C.I. values calculated from objective instrumental readings can be converted into the Munsell notation which evaluates the three psychological color attributes—hue, lightness (Munsell value), saturation (Munsell chroma)—on scales of approximately equal visual steps. In addition, the Munsell color charts offer one of the most convenient sources of material standards for direct color comparisons. 

In addition, ETB receptors are upregulated in vessels with atherosclerotic lesions and in pulmonary vessels of patients with severe pulmonary hypertension. The upregulation can be attributed to increased ETB receptor expression in smooth muscle cells and to ETB receptors expressed on infiltrating macrophages. 

Another type of NR crosstalk, which has only recently been recognized, is the so-called nongenomic actions of several receptors that induce very rapid cellular effects. Effectively, evidence has accumulated over several decades that steroid receptors may have a role that does not require their transcriptional activation, such as modifying the activity of enzymes and ion channels. While the effects of steroids that are mediated by the modulation of gene expression do occur with a time lag of hours, steroids can induce an increase in several second messengers such as inositol triphosphate, cAMP, Ca2+, and the activation of MARK and PI3 kinase within seconds or minutes. Many mechanistic details of these nongenomic phenomena remain poorly understood. Notably, controversy still exists as to the identity of the receptors that initiate the non-genomic steroid actions. However, it now appears that at least some of the reported effects can be attributed to the same steroid receptors that are known as NRs. 

The diffuse nature of orexinergic projections is consistent with combined patterns of expression of the two orexin receptors, which is widespread but differential and often complementary within and even outside the CNS. OX2Rs are found primarily in structures attributed to control of sleq)-wake functions, whereas OXIRs are more abundant in limbic structures controlling aspects of feeding, autonomic outflow, energy homeostasis, and to a lesser extent also REM-sleq). 

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