A comprehensive mathematical model for three-body binding equilibria

Three-component systems are often more complex than their two-component counterparts. Although the reversible association of three components in solution is critical for a vast array of chemical and biological processes, no general physical picture of such systems has emerged. Here we have developed a general, comprehensive framework for understanding ternary complex equilibria, which relates directly to familiar concepts such as EC50 and IC50 from simpler (binary complex) equilibria. Importantly, application of our model to data from the published literature has enabled us to achieve new insights into complex systems ranging from coagulation to therapeutic dosing regimens for monoclonal antibodies. We also provide an Excel spreadsheet to assist readers in both conceptualizing and applying our models. Overall, our analysis has the potential to render complex three-component systems--which have previously been characterized as "analytically intractable"--readily comprehensible to theoreticians and experimentalists alike.

Dental visits by income and race in ten urban and two rural areas

Household surveys in 12 low income areas found large differences in dental visit rates after control for income and race. The dental visit rate for Red Hook (NYC) exceeded the national rate whereas in seven of the areas the rate was below national averages by 40 per cent or more. The ranges in dental visit rate for low income Blacks was from two-thirds the national rate (in two areas of the South) to two to three times greater than the comparable national rate (in three areas of the Northeast). Lesser but nevertheless large variations among area dental visit rates existed for other race and income groups.

Access to usual source of care by race and income in ten urban areas

In terms of less access to private sources of care (as distinguished from hospital-public clinics) and longer travel time to usual source of care, poverty areas are at a disadvantage. Within the ten areas studied, the poor have less access than the nonpoor, with access differences even greater between the races than between income groups. Blacks generally have less than whites when income differences are taken into account. Both the type of usual source of care and travel time appear to be related to differential utilizations of ambulatory care resources: persons reporting private sources of care and persons with shorter travel time to their usual source of care tend to make more physician visits in a year. Mechanisms for public financing of health care will not likely alleviate the problems of inaccessibility presented by poverty areas. It is in these areas of low access that public responsibility to organize and locate facilities will continue even after the advent of a fairly comprehensive payment mechanism for health care among the poor.

OEO drug treatment programs

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