The Importance of Biological Realism in Dioxin Risk Assessment Models Michael

Mechanistic mathematical models of hepatocarcinogenesis in the female rat were constructed to investigate possible relationships among the Ah, estrogen, and EGF receptors in TCDD hepato-carcinogenicity. Each model generates dose-response curves for the expression of biomarker liver proteins CYP1A1, CYP1A2, and residual plasma membrane EGF receptor consequent to exposure to TCDD. The shapes of the response curves were strongly dependent on the assumed mechanisms of constitutive expression of these proteins. Assuming a constant level of the hepatic Ah receptor, a sigmoidal dose-response of hepatic CYP1A1 to total liver TCDD was computed. However, inclusion of induction of the Ah receptor by TCDD in a physiologically realistic dosimetric model produced a linear low-dose response of CYP1A1. This behavior was computed to arise from the net effect of sublinear response of CYP1A1 mRNA to the concentration of the Ah-TCDD complex and supralinear response of the protein concentration to the mRNA level, illustrating the importance of biological realism in dose-response modeling. The dosimetric model also computed effects of TCDD on the hepatic estradiol concentration and consequent effects on the binding capacity of the EGF receptor and suggests plausible mechanisms for tumor promotion by TCDD. Setting circulating estradiol levels in the model to values typical of the male rat indicated possible sources of the differences in the responses of the EGF receptor and in development of tumors in the two sexes.     

Family Factors, Theft, Vandalism, and Major Deviance Among a Multiracial/Multiethnic Sample of Adolescent Girls

This article reports on a study of 503 African-American, Hispanic, and White non-Hispanic adolescent girls attending public schools in Miami, Florida, The primary objectives of the study were to determine the prevalence of 13 self-reported delinquent behaviors in the sample, to compare these rates among the three groups of students, and to explore the predictive influences of several family factors that correlate with delinquency. It was found that 37.5% of the sample engaged in one or more acts of serious delinquency, with African-Americans reporting they had engaged in significantly more of these behaviors. The best predictors of theft/vandalism were low family pride and family substance abuse for Hispanics, low family communication for African-Americans, and low family pride for White non-Hispanics. The findings indicate that traditional family factors that have been used repeatedly to understand delinquency by male adolescents were not strong predictors of delinquency among the adolescent girls in the sample.     

Diagnosis and therapy for the disruptive physician.

A disruptive physician can alienate staff, drive away patients, and even land your organization in a lawsuit. Consider some practical advice on how to identify and deal with disruptive physicians.     

Towards a Two-dimensional Analysis of Welfare Ideologies

This article provides a critical analysis of some accounts of welfare ideologies which have appeared in the last eight years. It is argued that in these accounts welfare ideologies have been presented as ranged along a continuum from "anti-collectivist", "market liberal", or "residual" to "Marxist" or "structural" with intermediate positions variously described as "political liberal", "reluctant collectivist", "social democratic", "Fabian socialist", or "institutional". It is further argued that these one-dimensional accounts are seriously misleading because they fail to give sufficient recognition to the part played by conservatism in the development and justification of modern interventionist states and because they identify Marxism with collectivism and ignore the anti-collectivist strand in socialist thought. These elements are more easily accommodated within an alternative two-dimensional framework for the analysis of welfare ideologies which is briefly outlined.     

The evolution of human warfare

Here we propose a new theory for the origins and evolution of human warfare as a complex social phenomenon involving several behavioral traits, including aggression, risk taking, male bonding, ingroup altruism, outgroup xenophobia, dominance and subordination, and territoriality, all of which are encoded in the human genome. Among the family of great apes only chimpanzees and humans engage in war; consequently, warfare emerged in their immediate common ancestor that lived in patrilocal groups who fought one another for females. The reasons for warfare changed when the common ancestor females began to immigrate into the groups of their choice, and again, during the agricultural revolution.     

Physical activity and cognitive-health content in top-circulating magazines, 2006-2008

Physical activity may promote cognitive health in older adults. Popular media play an important role in preventive health communication. This study examined articles discussing associations between physical activity and cognitive health in top-circulating magazines targeting older adults. 42,753 pages of magazines published from 2006 to 2008 were reviewed; 26 articles met inclusion criteria. Explanations regarding the link between physical activity and cognitive health were provided in 57.7% of articles. These explanations were generally consistent with empirical evidence; however, few articles included empirical evidence. Physical activity recommendations were presented in 80.8% of articles; a wide range was recommended (90-300 min of physical activity per wk). Socioeconomic status and education level were not mentioned in the text. Results suggest an opportunity for greater coverage regarding the role of physical activity in promoting cognitive health in popular media. Magazine content would benefit from including more empirical evidence, culturally sensitive content, and physical activity recommendations that are consistent with U.S. guidelines.     

The Influences of Career Support and Sexual Identity on Sexual Minority Women's Career Aspirations

The authors examined the relationship between sexual identity, family/friend career support, and career aspirations in a sample of 381 sexual minority women. The results indicated that family career support and friend career support were positively related to career aspirations of sexual minority women. The results also indicated that the relationship between family career support and career aspirations depended on the level of negative sexual identity. The findings demonstrate the utility of social cognitive career theory (Lent, Brown, & Hackett, 1994, 2002) with this particular population. Limitations and implications for further research and practice are discussed.