Fundamental determination

We have seen that many different factors can contribute to chemical hazard in the workplace. The degree of hazard, however, is fundamentally determined by two factors the basic toxicity of the agent concerned, that is, its intrinsic capacity to damage or affect biological tissue and the severity of the exposure, or what is sometimes called the dose-response relationship. The duration of the exposure, of course, must also be considered. 

Cell migration involves transient formation of membrane protmsions (lamellipodia, cell membrane ruffles) at the leading edge of the cell that are thought to require rapid local changes in ion fluxes and cell volume, probably accompanied by rapid transmembrane water movement (Condeelis 1993 Lauffenburger and Horwitz 1996). If transmembrane water movement is a fundamental determinant of cell motility, then a different water channel... 

The first assumption simply asserts that the extent to which a chemical is absorbed from its site of administration, distributed within the body, eliminated, and ultimately excreted is fundamentally determined by its physicochemical properties (which are ultimately dictated by its structure). Numerous precedents from the medicinal chemistry literature support this assertion. 

Babbitt, P.C. Gerlt, J.A. (1997) Understanding enzyme super-families chemistry as the fundamental determinant in the evolution of new catalytic activities. J. Biol. Chem. 27, 30,591-30,594. An interesting description of the evolution of enzymes with different catalytic specificities, and the use of a limited repertoire of protein structural motifs. 

We want to outline such an experiment. The precision of the metastable atomic beam experiments is fundamentally determined by the short interaction... 

This expression for E emphasizes the fact that the most specific reagents will have the largest values for k2/Kr. The expression /c2/KR is the parameter which is the most fundamental determinant of labeling specificity. It has a very simple kinetic significance reference to Equation 7 shows that it is the second-order rate constant for the inactivation reaction which is obtained at low [R]. 

In terms of the Bloch equations as given in the preceding text, both of these processes result in decrease in T2, but only the first is considered as contributing to a fundamental determination of T2 as a molecular parameter. The second process is an artifact of the experimental measurement (inhomogeneity in B0).The term T2 is used to denote the effective T2, that is, to encompass both processes ... 

Water solubility is a crucial parameter affecting the toxicological potency of a compound. Solubility of non-hydrolyzed nerve agents is fundamentally determined by the hydrophobicity and extent of organic substituents. On the... 

The reliance that can be placed in a computer system is fundamentally determined by the integrity of the data it processes. It must be recognized that data accuracy is absolutely vital in the business context. However well an application works, it will be fimdamentally undermined if the data it processes is dubious. Data load is a key task that must be adequately managed to satisfy business and regulatory needs. Loading of data can be broken down into five basic steps data sourcing, data mapping, data collection, data entry, and data verihcation. 

As mentioned above the structure of zeolite and its pore size fundamentally determine the cracking property of the catalyst. The difference in activity of mordenite and zeolite catalysts (e.g. HZSM-5, Y-zeolite) is unambiguously due to variation in structure [1]. Mordenite contains pores of relatively large size (about 7 x 8 A), while the pores of... 

It follows then that the electrostatic potential can also be regarded as a fundamental determinant of a system s properties [88-90], one which may in some instances be more amenable to further analysis and application. For example, it has proven possible to derive exact expressions that relate atomic and molecular energies to V(r) at the positions of the nuclei [90-92], It should be noted that V(r) is a physical observable, which can be... 

Earlier experiments of Evans and Ray (1969) with substances inhibiting protein synthesis also seem to disprove the theory that disturbance of protein synthesis is a fundamental determinant of biological action. Rubery and Northcote (1970) proved by in vivo experiments that herbicides with auxin action stimulate cell wall synthesis. The investigations carried out on cell-free plasma membranes isolated from onion stalk treated with 2,4-D, furnished further proof of the stimulation of polysaccharide synthesis. 

Finally, we must recognize that the design of a process fundamentally determines how it will respond dynamically and how it can be controlled. Considerations of controllability need to be incorporated into the process design. Sometimes the solution to a control problem does not have anything to do with the control system but requires some modification to the process itself. 

The key concept is that of differentiation this is the process by which the whole genome in each cell is selectively switched off or silenced in specific places on the chromosomal DNA, leaving only a subset of all possible genes available to be translated into proteins. It is the characteristics of the proteins in the set of all proteins in a cell, and their relative amounts, that are the fundamental determinants of the final nature of a cell, and hence what tissue name we might assign to it. 

The chemical structure of the polymer s constitutional unit is the fundamental determinant of the polymer s barrier behavior. In addition to chemical composition, polarity, stiffness of the polymer chain, bulkiness of side and backbone-chain groups, and degree of crystallinity significantly impact the sorption and diffusion of penetrants, and hence permeability. Of particular significance are influences on the free volume and molecular mobility of the polymer, and influences on the affinity between the permeant and the polymer. 

A more fundamental determination of looking at change is to decide if the process is to be taken outside its current, predefined, safe operating limits (Chapter 1). Therefore, another way in which change can be defined is as follows ... 

REACH is the most detailed legislation in the histoiy of the European Union. The length of text exceeds 1200 pages. It is veiy implausible to expect a decision maker to read and understand it, this would be a daunting task even for a chemical expert. However, the devil is in the details, maybe more so in this case than in many others. The details of the legislation fundamentally determine its benefits for the citizens of the EU. 

---