Driving under the influence of risky peers: An experimental study of adolescent risk taking

Both passive and active social influences may affect adolescents' dangerous driving. In this study, we used an experimental paradigm to delineate these two influences with actual peers. Adolescents completed a simulated driving task, and we measured risk preferences of each member of the peer group. We used hierarchical linear modeling to partition variance in risky decisions. Adolescents experienced many more crashes when they had “passengers” present who reported a strong preference for risk taking and who actively provided decision-making guidance. Although youth in the passive peer condition were also influenced by the riskiness of their peers, this relation was less strong relative to the active condition. We discuss the need for interventions focussing on active and passive peer influence

Effect of nutrition education and dairy group membership on nutrition knowledge, practices and diet quality for rural Kenyan farm women

The typical high-starch, low diversity diet in developing countries is associated withundernutrition, morbidity and mortality. Previous research with households inMukurwe-ini Division (Central Kenya) found that members of a community-baseddairy development group were more food secure and had higher intake of certainmicronutrients compared with non-members; however, the prevalence of inadequateintake of multiple micronutrients was high among all women. A nutrition educationintervention was developed to enhance women’s nutrition knowledge and food skills toultimately improve diet quality and micronutrient intakes for women and their families.In addition, it was proposed that the intervention effects would be greater for dairygroup members. The Mukurwe-ini study group consisted of 88 women in four dairymembership-duration categories (n=4 x 22) and non-member women (n=23). The studygroup was previously selected using chain referral sampling. For the intervention,women from each duration-group and non-member women were randomly allocated tointervention (n=55) and control (n=56) groups. Nutrition knowledge and dietary intake(24-hour recall) data were collected from all women over three weeks immediatelyprior to the intervention (baseline) and again, six months post-intervention, inindividual face-to-face interviews. The intervention encouraged food-based strategiesto improve intake of vitamin A, iron and zinc and was developed and delivered incollaboration with a Kenyan dietitian. WFood2 was used to compute food and nutrientintakes, dietary diversity and the phytate:zinc molar ratio. Descriptive statistics andlinear and logistic regressions analyses were performed using Stata10. Independent ofdairy-group membership, a larger proportion of intervention group women, comparedto control group women, had the targeted nutrition knowledge and practiced thestrategies to improve intake of vitamin A (76% vs 67%, respectively) and zinc and iron(soaked beans and maize 80% vs 13%; avoided tea with meals 67 % vs 5%,respectively). A positive effect of the intervention on dietary diversity was dependenton dairy-group membership status. Positive intervention effects on intake of vitamin Aand C were found for non-member women. This study provided evidence that certainintervention effects were dependent on poverty reduction and that all women were ableto make positive dietary changes when informed. There is a need to examine longertermimpacts of nutrition education interventions and to explore effective methods todisseminate nutrition information and food-based strategies.Key words: nutrition intervention, micronutrients, food-based strategy, rural, women,dairy, smallholder farme

Driving under the influence of risky peers : an experimental study of adolescent risk taking.

Both passive and active social influences may affect adolescents' dangerous driving. In this study, we used an experimental paradigm to delineate these two influences with actual peers. Adolescents completed a simulated driving task, and we measured risk preferences of each member of the peer group. We used hierarchical linear modeling to partition variance in risky decisions. Adolescents experienced many more crashes when they had “passengers” present who reported a strong preference for risk taking and who actively provided decision-making guidance. Although youth in the passive peer condition were also influenced by the riskiness of their peers, this relation was less strong relative to the active condition. We discuss the need for interventions focussing on active and passive peer influence

Tissue-specific regulatory elements in mammalian promoters

Transcription factor-binding sites and the cis-regulatory modules they compose are central determinants of gene expression. We previously showed that binding site motifs and modules in proximal promoters can be used to predict a significant portion of mammalian tissue-specific transcription. Here, we report on a systematic analysis of promoters controlling tissue-specific expression in heart, kidney, liver, pancreas, skeletal muscle, testis and CD4 T cells, for both human and mouse. We integrated multiple sources of expression data to compile sets of transcripts with strong evidence for tissue-specific regulation. The analysis of the promoters corresponding to these sets produced a catalog of predicted tissue-specific motifs and modules, and cis-regulatory elements. Predicted regulatory interactions are supported by statistical evidence, and provide a foundation for targeted experiments that will improve our understanding of tissue-specific regulatory networks. In a broader context, methods used to construct the catalog provide a model for the analysis of genomic regions that regulate differentially expressed genes

Academic achievement : the role of praise in motivating students

The motivation of students is an important issue in higher education, particularly in the context of the increasing diversity of student populations. A social-cognitive perspective assumes motivation to be dynamic, context-sensitive and changeable, thereby rendering it to be a much more differentiated construct than previously understood. This complexity may be perplexing to tutors who are keen to develop applications to improve academic achievement. One application that is within the control of the tutor, at least to some extent, is the use of praise. Using psychological literature the article argues that in motivating students, the tutor is not well served by relying on simplistic and common sense understandings of the construct of praise and that effective applications of praise are mediated by students' goal orientations, which of themselves may be either additive or interactive composites of different objectives and different contexts

Helping education undergraduates to use appropriate criteria for evaluating accounts of motivation

The aim of the study was to compare students in a control group with those in a treatment group with respect to evaluative comments on psychological accounts of motivation. The treatment group systematically scrutinized the nature and interpretation of evidence that supported different accounts, and the assumptions, logic, coherence and clarity of accounts. Content analysis of 74 scripts (using three categories) showed that the control group students made more assertions than either evidential or evaluative points, whereas the treatment group used evaluative statements as often as they used assertion. The findings provide support for privileging activities that develop understanding of how knowledge might be contested, and suggest a need for further research on pedagogies to serve this end. The idea is considered that such understanding has a pivotal role in the development of critical thinking

Multifunctional cytokine production reveals functional superiority of memory CD4 T cells

T cell protective immunity is associated with multifunctional memory cells that produce several different cytokines. Currently, our understanding of when and how these cells are generated is limited. We have used an influenza virus mouse infection model to investigate whether the cytokine profile of memory T cells is reflective of primary responding cells or skewed towards a distinct profile. We found that, in comparison to primary cells, memory T cells tended to make multiple cytokines simultaneously. Analysis of the timings of release of cytokine by influenza virus‐specific T cells, demonstrated that primary responding CD4 T cells from lymphoid organs were unable to produce a sustained cytokine response. In contrast CD8 T cells, memory CD4 T cells, and primary responding CD4 T cells from the lung produced a sustained cytokine response throughout the restimulation period. Moreover, memory CD4 T cells were more resistant than primary responding CD4 T cells to inhibitors that suppress T cell receptor signalling. Together, these data suggest that memory CD4 T cells display superior cytokine responses compared to primary responding cells. These data are key to our ability to identify the cues that drive the generation of protective memory CD4 T cells following infection