Facilitating the Calculation of the Efficient Score Using Symbolic Computing

The score statistic continues to be a fundamental tool for statistical inference. In the analysis of data from high-throughput genomic assays, inference on the basis of the score usually enjoys greater stability, considerably higher computational efficiency, and lends itself more readily to the use of resampling methods than the asymptotically equivalent Wald or likelihood ratio tests. The score function often depends on a set of unknown nuisance parameters which have to be replaced by estimators, but can be improved by calculating the efficient score, which accounts for the variability induced by estimating these parameters. Manual derivation of the efficient score is tedious and error-prone, so we illustrate using computer algebra to facilitate this derivation. We demonstrate this process within the context of a standard example from genetic association analyses, though the techniques shown here could be applied to any derivation, and have a place in the toolbox of any modern statistician. We further show how the resulting symbolic expressions can be readily ported to compiled languages, to develop fast numerical algorithms for high-throughput genomic analysis. We conclude by considering extensions of this approach. The code featured in this report is available online as part of the supplementary material.     

Mechanistic Insights Aid the Search for CFC Substitutes: Risk Assessment of HCFC-123 as an Example

An international consensus on the need to reduce the use of chlorofluorocarbons (CFCs) and other ozone-depleting gases such as the halons led to the adoptions of the 1987 Montreal Protocol and Title VI of the 1990 Clean Air Act Amendments, "Protecting Stratospheric Ozone." These agreements included major provisions for reducing and eventually phasing out production and use of CFCs and halons as well as advancing the development of replacement chemicals. Because of the ubiquitous use and benefits of CFCs and halons, an expeditious search for safe replacements to meet the legislative deadlines is of critical importance. Toxicity testing and health risk assessment programs were established to evaluate the health and environmental impact of these replacement chemicals. Development and implementation of these programs as well as the structural-activity relationships significant for the development of the replacement chemicals are described below. A dose-response evaluation for the health risk assessment of the replacement chemical HCFC-123 (2,2-dichloro-1,1,1-trifluoroethane) is also presented to show an innovative use of physiologically based pharmacokinetic (PBPK) modeling. This is based on a parallelogram approach using data on the anesthetic gas halothane, a structural analog to HCFC-123. Halothane and HCFC-123 both form the same metabolite, trifluoroacetic acid (TFA), indicative of the same metabolic oxidative pathway attributed to hepatotoxicity. The parallelogram approach demonstrates the application of template model structures and shows how PBPK modeling, together with judicious experimental design, can be used to improve the accuracy of health risk assessment and to decrease the need for extensive laboratory animal testing.     

FEMALE-HEADED FAMILIES: EFFECTS ON CHILDREN AND CLINICAL IMPLICATIONS*

The social psychological research pertaining to female-headed families published between 1970–1980 is reviewed. The literature indicates that theoretically children do not need the presence of the same-sex/opposite-sex parents in the family in order to develop sex-role behavior. Children in female-headed families are likely to have good emotional adjustment, good self-esteem except when they are stigmatized, intellectual development comparable to others in the same socioeconomic status, and rates of juvenile delinquency comparable to others in the same socioeconomic status. In light of these findings, suggestions are made for counseling women who head families.     

Moving youth participation into the classroom: students as allies

The experiences of urban public high school students, told in their own words, offer new and veteran teachers guidance on how to reach adolescent learners and illustrate what youth-adult partnerships in the classroom might look like.     

Understanding the Juggling Act: Gendered Preferences and Social Structural Constraints

In this paper we use longitudinal data to test the strength of individual preferences and structural variables as explanations for married women's labor force participation. Data drawn from a subset of the Career Development Study are used to compare gendered preferences measured toward the end of adolescence vs. work and family structural variables as predictors of the actual number of hours married women work for pay. Family structures that push women out of the labor force and pull them into family work prove to be the strongest predictor of married women's employment hours, with work structures (e.g., aspects of good jobs) and the subjective definition of paid work as a career also being substantively important for explaining hours in the labor force. Our findings also indicate that attitudes formed before and during early adolescence do have a weak but statistically significant effect on married women's labor force participation, at least for baby boom women.     

Canadian corporate charitable contributions: Trends and policies

Corporate contributions play a significant role in the funding of Canadian charitable institutions. In this paper, the trends of absolute and relative contributions, as reported by taxation Statistics and Statistics Canada figures, are given on a yearly and industry basis. some reasons for the trends are suggested. A number of policy issues related to contributions are presented. Their role in the present contribution situation is set out and a number of suggestions for changes are given in an attempt to create a dialogue between the various parties affected — charitable institutions, corporations, individual citizens and governments.     

HEALTHY FAMILY FUNCTIONING: WHAT THERAPISTS SAY AND WHAT FAMILIES WANT

The findings from a questionnaire survey of 208 non-clinical family members about their views of the nature of a healthy family are presented. These results are compared to the results of a previous study of family therapists' perceptions of healthy family functioning. Differences and similarities between these two samples are discussed, and the results are considered in light of the findings of another major independent study of healthy family functioning.