Parental Emotional Support,Science Self‐Efficacy,and Choice of Science Major in Undergraduate Women

Former participants in a high school enrichment program for girls interested in science careers were surveyed 1 to 2 years after high school graduation. After reporting their college major, they completed measures of science self‐efficacy and quality of emotional bonds with parents. Of the 41 women, 5 were not enrolled in college. Those actually majoring in science (n = 23) reported significantly higher science self‐efficacy than those who were undecided or had chosen nonscicnce majors (n = 13). Science self‐efficacy was significantly negatively associated with recollections of fathers as having been highly controlling and likely to use a “love withdrawal” parenting style.     

Group sequential tests for treatment effect on survival and cumulative incidence at a fixed time point

Lifetime Data Analysis - Medical research frequently involves comparing an event time of interest between treatment groups. Rather than comparing the entire survival or cumulative incidence curves,...     

A Calibrated Human PBPK Model for Benzene Inhalation with Urinary Bladder and Bone Marrow Compartments

A physiologically‐based pharmacokinetic (PBPK) model of benzene inhalation based on a recent mouse model was adapted to include bone marrow (target organ) and urinary bladder compartments. Empirical data on human liver microsomal protein levels and linked CYP2E1 activities were incorporated into the model, and metabolite‐specific conversion rate parameters were estimated by fitting to human biomonitoring data and adjusting for background levels of urinary metabolites. Human studies of benzene levels in blood and breath, and phenol levels in urine were used to validate the rate of human conversion of benzene to benzene oxide, and urinary benzene metabolites from Chinese benzene worker populations provided model validation for rates of human conversion of benzene to muconic acid (MA) and phenylmercapturic acid (PMA), phenol (PH), catechol (CA), hydroquinone (HQ), and benzenetriol (BT). The calibrated human model reveals that while liver microsomal protein and CYP2E1 activities are lower on average in humans compared to mice, the mouse also shows far lower rates of benzene conversion to MA and PMA, and far higher conversion of benzene to BO/PH, and of BO/PH to CA, HQ, and BT. The model also differed substantially from existing human PBPK models with respect to several metabolic rate parameters of importance to interpreting benzene metabolism and health risks in human populations associated with bone marrow doses. The model provides a new methodological paradigm focused on integrating linked human liver metabolism data and calibration using biomonitoring data, thus allowing for model uncertainty analysis and more rigorous validation.     

A theoretical model of religiosity and drug use with reciprocal relationships: A test using structural equation modeling

Abstract

This study of 1093 adolescents from 6 public high schools was designed to test a hypothesized model formulated by theoretical elaboration of control theory with elements from social learning theory using structural equation modeling procedures. The primary purpose was to establish that religion is relevant to illicit drug use when its direct, indirect and reciprocal effects are tested within a more complete system of relationships than found in existing studies. Most aspects of the model were supported by data and religion had direct inverse effects on illegal drug use for all adolescents studied. However, the feedback effects of drug use on religion were significant only among younger adolescents and females. Other age and gender differences were observed when the hypothesized model was tested with structural equation modeling procedures. The implications of these findings were discussed in regard to future conceptual work and intervention.     

Trust and embedded markets: A multi-method investigation of consumer transactions

Previous work shows that, as the buyer's uncertainty about the quality of some good or service increases, so does the tendency to purchase that good or service via embedded transactions, rather than from strangers. While this previous work explains variation in embedded exchange across different types of purchases, it does not address variation in embedded exchange across persons. Our research integrates the embeddedness and trust literatures to explain variation in within-network exchanges based on an interaction of the purchaser's generalized trust and the level of uncertainty entailed in the purchase (i.e., whether there exists an incentive for the seller to misrepresent the quality of some good or service). For purchases involving uncertainty, low-trusters will tend to forgo risky transactions with strangers, opting instead for the increased certainty of embedded markets. High-trusters, on the other hand, will be more likely to transact with strangers (despite the increased risk), from whom they can often find better deals. We should not expect any differences between high- and low-trusters for products that do not entail uncertainty. Results from two data sources, responses from a nationally representative survey of the U.S. population and behavioral responses in new laboratory experiments, provide support for the arguments.     

The Reflexive Producer: The Influence of Farmer Knowledge Upon the Use of Bt Corn*

Abstract This paper examines the influence of farmer knowledge upon decision making processes. Drawing upon the sociological debates around the ideas of reflexive modernity and biotechnology as well as from classic adoption and diffusion studies, I explore the influences upon farmers' use of Bacillus thuringiensis (Bt) corn. Utilizing survey data gathered from corn farmers in Minnesota and Wisconsin, I argue that farmers are ‘reflexive’ actors who actively negotiate between ‘expert’ and ‘local’ knowledges when deciding to plant Bt corn. Furthermore, I hypothesize that farmers are more likely to be influenced by their first‐hand or local experiences than by state or expert observations.     

The Role of Domain Satisfaction in Explaining the Paradoxical Association Between Life Satisfaction and Age

Although aging is associated with declines in many life domains, overall life satisfaction does not appear to decline sharply with age. One explanation for this paradoxical finding is that several life domains improve with age such that increases in certain domains balance the decreases in others. Because different issues are problematic at different life stages, it is likely that specific domains display different life trajectories compared to overall life satisfaction. The observed pattern for overall life satisfaction is likely due to a bottom-up approach. Life and domain satisfaction data from 8?years of the British Household Panel Study were analyzed to evaluate this hypothesis. Results indicated that satisfaction with some life domains increased after middle age (e.g. social life), whereas satisfaction with other life domains decreased (e.g. health). Additionally, results illustrated that although domain satisfaction scores demonstrate distinct trajectories, the aggregate of these distinct domains resembled the overall life satisfaction trajectory. These findings have implications for top-down and bottom-up models of life satisfaction.     

Optimal One-Way Random Effects Designs for the Intraclass Correlation Based on Confidence Intervals

ABSTRACT

Confidence intervals for the intraclass correlation coefficient (ρ) are used to determine the optimal allocation of experimental material in one-way random effects models. Designs that produce narrow intervals are preferred since they provide greater precision to estimate ρ. Assuming the total cost and the relative cost of the two stages of sampling are fixed, the authors investigate the number of classes and the number of individuals per class required to minimize the expected length of confidence intervals. We obtain results using asymptotic theory and compare these results to those obtained using exact calculations. The best design depends on the unknown value of ρ. Minimizing the maximum expected length of confidence intervals guards against worst-case scenarios. A good overall recommendation based on asymptotic results is to choose a design having classes of size 2 + √4 + 3r, where r is the relative cost of sampling at the class-level compared to the individual-level. If r = 0, then the overall cost is the sample size and the recommendation reduces to a design having classes of size 4.