Model ranking evaluation

Model ranking evaluation for each element the interval of each experimental attribute is compared with the interval derived lfom the model ranking. 

Experimental and model ranking comparison evaluation of the degree of agreement between two rankings, i.e. analysis of model ranking reliability. 

At the fundamental level of equilibrium modeling the advantages are many. The model can combine a number of compartments through simple relationship to describe a realistic environment within which chemicals can be ranked and compared. Primary compartments that chemicals will tend to migrate toward or accumulate in can be identified. The arrangement of compartments and their volumes can be selected to address specific environmental scenarios. Data requirements are minimal, if the water solubility and vapor pressure of a chemical are known, other properties can be estimated, and a reasonable estimate of partitioning characteristics can be made. This is an invaluable tool in the early evaluation of chemical, whether the model be applied to projected environmental hazard or evaluation of the behavior of a chemical in an environmental application, as with pesticides. Finally, the approach is mathematically very simple and can be handled on simple computing devices. 

During the 1970 s and early 1980 s a large number of test methods were developed to measure the toxic potency of the smoke produced from burning materials. The ones most widely used are in refs. 29-32. These tests differ in several respects the conditions under which the material is burnt, the characteristics of the air flow (i.e. static or dynamic), the type of method used to evaluate smoke toxicity (i.e. analytical or bioassay), the animal model used for bioassay tests, and the end point determined. As a consequence of all these differences the tests result in a tremendous variation of ranking for the smoke of various materials. A case in point was made in a study of the toxic potency of 14 materials by two methods [33]. It showed (Table I) that the material ranked most toxic by one of the protocols used was ranked least toxic by the other protocol Although neither of these protocols is in common use in the late 1980 s, it illustrates some of the shortcomings associated with small scale toxic potency of smoke tests. 

Finally, as previously stated, if in vitro models are to be fully effective, the underlying mechanisms of ocular irritation need to be identified. Many of the in vitro assays proposed as alternatives to in vivo testing are based on correlations rather than mechanisms of irritation. The scoring or ranking of substances utilizing the in vitro endpoint may correlate with the severity of the in vivo response, but the reason for the agreement may be unclear and strictly fortuitous for the compounds evaluated. The ideal assay would monitor several biochemical or biological events specifically... 

On the basis of their evaluation and our internal predictive VolSurf model [160] for this series (r 0.81, q 0.60, 4 PLS components), it can be concluded that factors like size and shape, which had previously been reported to affect paracellular permeability, are indeed important in the VolSurf PLS model to explain the local structure-permeability relationship of one particular scaffold. Hence, local statistical models provide a qualitative ranking of candidates, and thus are valuable for optimization of pharmaceutically relevant compounds, especially if combined with additional models to understand affinity, selectivity or any particular pharmacokinetic behavior. 

Environment Canada recently developed an evaluation system based on effluent toxicity testing, capable of ranking the environmental hazards of industrial effluents [185]. This so-called Potential Ecotoxic Effects Probe (PEEP) incorporates the results of a variety of small-scale toxicity tests into one relative toxicity index to prioritize effluents for sanitation. In the index no allowance has been made for in-stream dilution, therefore the acmal risk for environmental effects is not modeled. The tests performed on each effluent are the following bacterial assay [V.fisheri (P. phosphoreum), Microtox], microalgal assay S. capricornutum) crustacean assay (C. dubiay, and bacterial genotoxicity test E. coli, SOS-test). 

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