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901.
Health risk assessments have become so widely accepted in the United States that their conclusions are a major factor in many environmental decisions. Although the risk assessment paradigm is 10 years old, the basic risk assessment process has been used by certain regulatory agencies for nearly 40 years. Each of the four components of the paradigm has undergone significant refinements, particularly during the last 5 years. A recent step in the development of the exposure assessment component can be found in the 1992 EPA Guidelines for Exposure Assessment. Rather than assuming worst-case or hypothetical maximum exposures, these guidelines are designed to lead to an accurate characterization, making use of a number of scientific advances. Many exposure parameters have become better defined, and more sensitive techniques now exist for measuring concentrations of contaminants in the environnment. Statistical procedures for characterizing variability, using Monte Carlo or similar approaches, eliminate the need to select point estimates for all individual exposure parameters. These probabilistic models can more accurately characterize the full range of exposures that may potentially be encountered by a given population at a particular site, reducing the need to select highly conservative values to account for this form of uncertainty in the exposure estimate. Lastly, our awareness of the uncertainties in the exposure assessment as well as our knowledge as to how best to characterize them will almost certainly provide evaluations that will be more credible and, therein, more useful to risk managers. If these refinements are incorporated into future exposure assessments, it is likely that our resources will be devoted to problems that, when resolved, will yield the largest improvement in public health. 相似文献
902.
Our friendships are a way to think about meaning in life. Friendships are like protein, a psychological essential for growth and development. When we see two three-year-olds playing together at the park running, holding hands, laughing, we cannot help but be filled with a sense of joy and warmth We can view making friendships as a developmental process in itself. In this discussion, I will explore the use of toys as a means of making friends. I will also explore the psychological meaning of toys and how they are a developmental precursor to friendship. Two clinical examples will be given in which friendship was the predominant theme in the therapy.The author would like to thank the late Gary Davis for his enthusiasm and friendship. Also: Mary Louise Denardo, Emily Halstead and Marilyn Silin.Lynn Borenstein MSW is on the faculty of the Institute for Clinical Social Work, and the faculty of the Child and Adolescent Psychotherapy Training Program, Institute for Psychoanalysis. 相似文献
903.
Denise L. Ohler Edward M. Levinson William F. Barker 《The Career development quarterly》1996,44(3):278-288
This study compared levels of career maturity between college students with and without learning disabilities and investigated factors associated with career maturity. Few differences in career maturity were found. However, different predictors of career maturity for the two groups emerged. For students with learning disabilities, number of accommodations and quantity of work experience accounted for 22% of the variance in career maturity. For students without disabilities, academic achievement and type of work experience accounted for 21% of the variance in career maturity. Students with learning disabilities who received more instructional accommodations had lower levels of career maturity. 相似文献
904.
In 1984 Congress amended the antidumping and countervailing duty laws, man-dating that the International Trade Commission (ITC) "cumulate" imports across countries when determining injury. We estimate that cumulation increases the probability of an affirmative injury determination by 20 to 30 percent and has changed the ITC's decision (from negative to affirmative) for about one-third of cumulated cases. We also show that the protective effect of cumulation increases as the number of countries involved increases, holding import market share constant. That is, cumulated imports have a super-additive effect on ITC decision-making. 相似文献
905.
906.
David L. Altheide 《Symbolic Interaction》1992,15(1):69-86
The role of public discourse, social control, punishment and claims about justice are joined in this essay through the concept of gonzo justice. Gonzo justice refers to the use of extraordinary means to demonstrate social control and moral compliance through rule enforcement and punishment designed to stigmatize publicly, often through the mass media, and to demonstrate the moral resolve of those mandating the punishment. The collapsing of distinctions between the news media as chroniclers of public life and formal agents of control is illustrated with materials from an ongoing study of new forms of social control. The implications of making extraordinary sanctioning practices ordinary and routine are noted. 相似文献
907.
908.
For testing the fit of the inverse Gaussian distribution with unknown parameters, the empirical distribution-function statistic A2 is studied. Two procedures are followed in constructing the test statistic; they yield the same asymptotic distribution. In the first procedure the parameters in the distribution function are directly estimated, and in the second the distribution function is estimated by its Rao-Blackwell distribution estimator. A table is given for the asymptotic critical points of A2. These are shown to depend only on the ratio of the unknown parameters. An analysis is provided of the effect of estimating the ratio to enter the table for A2. This analysis enables the proposal of the complete operating procedure, which is sustained by a Monte Carlo study. 相似文献
909.
The authors present a new conceptual framework for assessing and treating traumatized college students. The framework, constructivist self-development theory (CSDT), blends object relations, self-psychology, and social cognition theories. It is founded upon a constructivist view of trauma in which the individual's unique history shapes his or her experience of traumatic events and defines the adaptation to trauma. Within this theory, the authors suggest approaches to setting the frame for trauma therapy, including stabilizing acute symptoms and setting appropriate expectations for treatment. CSDT provides a framework for the systematic assessment and practical treatment of three aspects of the self that are affected by trauma. These include self-capacities, or the ability to tolerate strong affect and regulate self-esteem; cognitive schemas, or beliefs and expectations about self and others in the areas of frame of reference (or identity and world view), safety, trust, esteem, intimacy, power, and independence; and intrusive trauma memories and related distressing affect. Finally, the authors provide guidelines for assessing the need for longer term treatment. 相似文献
910.
Lifetime cancer potency of alfatoxin was assessed based on the Yeh et al. study from China in which both aflatoxin exposure and hepatitis B prevalence were measured. This study provides the best available information for estimating the carcinogenic risk posed by aflatoxin to the U.S. population. Cancer potency of aflatoxin was estimated using a biologically motivated risk assessment model. The best estimate of aflatoxin potency was 9 (mg/kg/day)−1 for individuals negative for hepatitis B and 230 (mg/kg/day)−1 for individuals positive for hepatitis B. 相似文献