Interdependent Risks Research Articles

Interdependence of ecological risk and economic profit in the exploitation of renewable resources

A new stochastic optimal control approach is introduced which quantifies the risk of extinction of a population associated with its optimal exploitation. In addition the maximization of the profit can be performed subject to the constraint that the mentioned risk does not exceed a given limit. As a first example for this general method an exponentially growing population is investigated. The interdependence of the risk and the profit is discussed. This model reveals the possibility of reducing the risk considerably without a substantial decrease of profit.

PARENT-CHILD CORONARY HEART DISEASE RISK FACTOR ASSOCIATIONS

The aim of this study was to assess parent-child interactions of coronary heart disease risk factors (total cholesterol, high and low density lipoprotein cholesterols, systolic and diastolic blood pressures, and relative ponderosity) in parents and their pediatric-aged children in the Princeton School study. The study population included 430 parent-child pairs from 301 families. Forty-seven of these 301 families were "nuclear" (both parents and at least one child) and included 118 parent-child pairs. Univariate analyses of covariance were used to assess parent-child risk factor interactions and interrelationships. Interdependent coronary heart disease risk factor relationships were extensively shared by parents with their children. Knowledge of parental risk factor levels and their relationships and interactions with children's risk factor levels should be useful in identifying children at presumptively increased long-term risk as adults, and should illuminate metabolic relationships between parents and children for coronary heart disease risk factors.

Preoperative Predictors of Operative Mortality for Coronary Bypass Grafting in Patients With Unstable Angina Pectoris

Preoperative risk factors for operative mortality were studied in 124 consecutive patients undergoing coronary bypass surgery for unstable angina pectorls. Of the 124 patients, 53 responded to maximal medical therapy within 48 hours after admission (Group A) and 71 continued to have typical angina pectoris despite medical therapy (Group B). Of the 124 patients, 37 had hypertension, 77 had triple vessel coronary artery disease, 16 had left main coronary artery disease and all except 15 were receiving propranolol therapy. The operative mortality rate was 4.8 percent (6 of 124) for the entire group. The factors that significantly increased operative mortality were failure of in-hospital maximal medical therapy (8.5 percent, 6 of 71), hypertension (13.5 percent, 5 of 37) and triple vessel disease (7.8 percent, 6 of 77). To predict more accurately the outcome of Individual patients, combinations of two and three risk factors were examined to determine interdependent variables that might influence operative mortality. The combination of failure to respond to medical therapy, hypertension and three vessel disease yield an operative mortality rate of 41.7 percent (5 of 12). If only two of these interdependent risk factors existed, the operative mortality rate was 1.9 percent (1 of 54), and the presence of only one or no risk factors resulted in no mortality (0 of 58). Failure to respond to in-hospital maximal medical therapy, hypertension and three vessel disease are potent risk factors in patients undergoing coronary bypass grafting and allow effective prediction of operative mortality for this procedure in patients with unstable angina pectoris: