Gruppenzusammensetzung und Interaktion bei kooperativem lernen in Mathematik

Kernfrage dieses Forschungsprojekts ist die Bedeutung von Individuellen-, Kleingruppen- und Klassenvariablen für kognitive und affektive Lernergebnisse in Mathematik von Schülern der Sekundarstufe.Selected paper, originally presented at the International Convention Utrecht 1-4 July, 1992 of the International Association of Co-operation in Education (IASCE), Co-chaired by Prof. dr. Elizabeth Cohen, Stanford University & prof. dr. Jan Terwel, Utrecht University

A study of the relationship between health awareness, lifestyle behaviour and food label usage in Gauteng

Background: The objectives of the study were to determine whether consumers who read food labels, were also more aware of health and lifestyle issues, in terms of nutrition and other health-related lifestyle behaviours, and whether there was a relationship between food-label reading, health awareness and lifestyle behaviour. A quantitative descriptive (survey) design was selected to investigate the relationship between food-label reading on the one hand, and health awareness and lifestyle behavior on the other.Method: A two-stage, stratified-proportionate and systematic sampling strategy was applied to select a sample of 357 Gauteng respondents to complete a telephonic questionnaire. Respondents who were most likely to read food label information were selected. Food label information is prescribed by comprehensive label legislation. Data report on respondents’ label-reading habits, attitudes towards health awareness, lifestyle behaviour and biographic data. Nonparametric analysis, scale reliability tests, analysis of variance (ANOVA) and Bonferroni multiple comparisons of means tests were used to analyse the results.Results: Results indicate that the two-thirds of respondents who, to some extent read nutritional information on food labels, were concerned about their personal health, were interested in health-related information, and followed a healthy lifestyle, such as regularly eating fresh fruit and vegetables, cutting back on alcohol, and other positive lifestyle behaviours. They were unsure about how their own knowledge of nutrition,and their understanding of nutrition information on food labels, compared with that of other consumers.Conclusion: A relationship was found between patterns of reading food labels, health awareness and lifestyle behaviour. People who often read food labels were more health-conscious, and maintained a healthier lifestyle.Keywords: health awareness, lifestyle, food labels, South Africa, consumer

Different Slopes for Different Folks: Socioeconomic and Racial/Ethnic Disparities in Asthma and Hay Fever among 173,859 U.S. Men and Women.

Although allergic diseases such as asthma and hay fever are a major cause of morbidity in industrialized countries, most studies have focused on patterns of prevalence among children and adolescents, with relatively few studies on variations in prevalence by race/ethnicity and socioeconomic position among adults. Our study examined racial/ethnic and socioeconomic patterns in the prevalence of asthma overall, asthma with hay fever, asthma without hay fever, and hay fever overall, in a population of 173,859 women and men in a large prepaid health plan in northern California. Using education as a measure of socioeconomic position, we found evidence of a positive gradient for asthma with hay fever with increasing level of education but an inverse gradient for asthma without hay fever. Hay fever was also strongly associated with education. Compared with their White counterparts, Black women and men were more likely to report asthma without hay fever, and Black women were less likely to have asthma with hay fever. Asian men were also more likely to report asthma with hay fever, and Asian women and men were much more likely to have hay fever. Racial/ethnic disparities in prevalence of allergic diseases were largely independent of education. We discuss implications for understanding these social inequalities in allergic disease risk in relation to possible differences in exposure to allergens and determinants of immunologic susceptibility and suggest directions for future research

A high throughput zebrafish chemical screen reveals ALK5 and non-canonical androgen signalling as modulators of the pkd2−/− phenotype

Autosomal dominant polycystic kidney disease (ADPKD) is the most common monogenic cause of end-stage renal failure in humans and results from germline mutations in PKD1 or PKD2. Despite the recent approval of tolvaptan, safer and more effective alternative drugs are clearly needed to slow disease progression. As a first step in drug discovery, we conducted an unbiased chemical screen on zebrafish pkd2 mutant embryos using two publicly available compound libraries (Spectrum, PKIS) totalling 2,367 compounds to identify novel treatments for ADPKD. Using dorsal tail curvature as the assay readout, three major chemical classes (steroids, coumarins, flavonoids) were identified from the Spectrum library as the most promising candidates to be tested on human PKD1 cystic cells. Amongst these were an androgen, 5α−androstane 3,17-dione, detected as the strongest enhancer of the pkd2 phenotype but whose effect was found to be independent of the canonical androgen receptor pathway. From the PKIS library, we identified several ALK5 kinase inhibitors as strong suppressors of the pkd2 tail phenotype and in vitro cyst expansion. In summary, our results identify ALK5 and non-canonical androgen receptors as potential therapeutic targets for further evaluation in drug development for ADPKD

An Application Of Multivariate Analysis To Some Tranquilzer Comparison Experiments

1 online resource (PDF, 13 pages

The merger of vertically offset quasi-geostrophic vortices

We examine the critical merging distance between two equal-volume, equal-potential-vorticity quasi-geostrophic vortices. We focus on how this distance depends on the vertical offset between the two vortices, each having a unit mean height-to-width aspect ratio. The vertical direction is special in the quasi-geostrophic model (used to capture the leading-order dynamical features of stably stratified and rapidly rotating geophysical flows) since vertical advection is absent. Nevertheless vortex merger may still occur by horizontal advection. In this paper, we first investigate the equilibrium states for the two vortices as a function of their vertical and horizontal separation. We examine their basic properties together with their linear stability. These findings are next compared to numerical simulations of the nonlinear evolution of two spheres of potential vorticity. Three different regimes of interaction are identified, depending on the vertical offset. For a small offset, the interaction differs little from the case when the two vortices are horizontally aligned. On the other hand, when the vertical offset is comparable to the mean vortex radius, strong interaction occurs for greater horizontal gaps than in the horizontally aligned case, and therefore at significantly greater full separation distances. This perhaps surprising result is consistent with the linear stability analysis and appears to be a consequence of the anisotropy of the quasi-geostrophic equations. Finally, for large vertical offsets, vortex merger results in the formation of a metastable tilted dumbbell vortex.Publisher PDFPeer reviewe