Gender Differences in Cooperative Learning with University Students

Differences in achievement were investigated for 80 female and 80 male university students who were randomly assigned to either cooperative or competitive teaching methods. After viewing a videotaped instruction on research design, participants completed a mini-assignment either individually in the competitive condition or with a same-sex partner in the cooperative condition. All participants individually completed a multiple-choice test to assess achievement. Although no differences were found on the multiple-choice test, on the mini-assignment women scored significantly higher in the cooperative than in the competitive condition, whereas men performed about equally in both conditions.Nous avons étudié les différences de performance chez 80 étudiants et 80 étudiantes universitaires à qui l’on avait assigné, par hasard, un projet conforme, soit à des méthodes de coopération, soit à des méthodes concurrentielles. Après avoir visionné une vidéo de directives portant sur la méthodologie de recherche, les participants ont complété un petit travail seul, dans un contexte concurrentiel, ou bien avec un partenaire de même sexe dans un contexte de coopération. De plus, tous les participants ont complété un examen à choix multiples individuellement, pour mesurer leur performance. Les résultats de cet examen ne révèlent aucune différence. Toutefois, la note e qu’ont obtenue les femmes pour le petit travail était bien plus élevée pour celui accompli dans un contexte de coopération que dans un contexte de concurrence. La performance des hommes était semblable dans les deux contextes

Exploring Attitudes of Future Educators About Sexual Minority Youth

Fifty-two secondary teacher candidates from a Canadian university completed questionnaires assessing levels of homoprejudice, knowledge of homosexuality, and perceptions of professional issues related to sexual minority youth. The level of homoprejudice in this sample was lower than in earlier studies with teachers, and lower homoprejudice was found to be significantly related to higher professional commitment and willingness to assist sexual minority students. As well greater knowledge of homosexual issues was significantly related to lower levels of homoprejudice, and men had significantly more homoprejudiced attitudes than women.Cinquante-deux stagiaires d’une université canadienne ont complété des questionnaires évaluant les préjugés contre l’homosexualité, les connaissances sur l’homosexualité et les perceptions des enjeux professionnels liés aux jeunes appartenant à une minorité sexuelle. Cet échantillon a démontré moins de préjugés face à l’homosexualité que ceux des études précédentes impliquant des enseignants; or, un rapport significatif existe entre des niveaux peu élevés de préjugés face à l’homosexualité d’une part, et un plus grand engagement des les jeunes membres d’une minorité sexuelle et une volonté accrue de leur venir en aide d’autre part. Un lien significatif existe également entre des connaissances plus importantes relatives aux enjeux touchant les homosexuels et des niveaux moins élevés de préjugés face à l’homosexualité. Finalement, les hommes ont démontré, de manière significative, plus d’attitudes homophobes que les femmes

Social Workers’ Perceptions of Working with People who have HIV/AIDS

This article presents the results of a cross-sectional online survey sent to a national sample of licensed social workers to examine their attitudes toward individuals living with HIV/AIDS. The survey included the AIDS Attitude Scale (Froman, Owen & Daisy, 1992), the HIV Knowledge Questionnaire-18 (Carey & Schroder, 2002), and the Modern Homonegativity Scale (Morrison & Morrison, 2002). Factors related to education, training, and other personal characteristics are explored. In this sample, 45% of the social workers indicated that more education and training would be beneficial to them in their current position, and greater HIV knowledge was associated with more positive attitudes toward people living with HIV/AIDS. Additionally, 57% of those surveyed indicated knowing someone personally who has HIV/AIDS, and demonstrated overall higher scores on empathy, and lower scores on avoidance. Those social workers who had higher avoidance of people living with HIV/AIDS were also found to be higher in homonegativity. The findings of this study add to the body of knowledge regarding social work attitudes, and provide further insight into an area with little existing data. The authors propose further research to identify causes of attitudes, potential gender and cultural differences, and the impact of the National Association of Social Workers Code of Ethics on social workers’ attitudes

An AUC-based Permutation Variable Importance Measure for Random Forests

The random forest (RF) method is a commonly used tool for classification with high dimensional data as well as for ranking candidate predictors based on the so-called random forest variable importance measures (VIMs). However the classification performance of RF is known to be suboptimal in case of strongly unbalanced data, i.e. data where response class sizes differ considerably. Suggestions were made to obtain better classification performance based either on sampling procedures or on cost sensitivity analyses. However to our knowledge the performance of the VIMs has not yet been examined in the case of unbalanced response classes. In this paper we explore the performance of the permutation VIM for unbalanced data settings and introduce an alternative permutation VIM based on the area under the curve (AUC) that is expected to be more robust towards class imbalance. We investigated the performance of the standard permutation VIM and of our novel AUC-based permutation VIM for different class imbalance levels using simulated data and real data. The results suggest that the standard permutation VIM loses its ability to discriminate between associated predictors and predictors not associated with the response for increasing class imbalance. It is outperformed by our new AUC-based permutation VIM for unbalanced data settings, while the performance of both VIMs is very similar in the case of balanced classes. The new AUC-based VIM is implemented in the R package party for the unbiased RF variant based on conditional inference trees. The codes implementing our study are available from the companion website: http://www.ibe.med.uni-muenchen.de/organisation/mitarbeiter/070_drittmittel/janitza/index.html

Nursing home administrators’ perspectives on a study feedback report : a cross sectional survey

BackgroundThis project is part of the Translating Research in Elder Care (TREC) program of research, a multi-level and longitudinal research program being conducted in 36 nursing homes in three Canadian Prairie Provinces. The overall goal of TREC is to improve the quality of care for older persons living in nursing homes and the quality of work life for care providers. The purpose of this paper is to report on development and evaluation of facility annual reports (FARs) from facility administrators&rsquo; perspectives on the usefulness, meaningfulness, and understandability of selected data from the TREC survey. MethodsA cross sectional survey design was used in this study. The feedback reports were developed in collaboration with participating facility administrators. FARs presented results in four contextual areas: workplace culture, feedback processes, job satisfaction, and staff burnout. Six weeks after FARs were mailed to each administrator, we conducted structured telephone interviews with administrators to elicit their evaluation of the FARs. Administrators were also asked if they had taken any actions as a result of the FAR. Descriptive and inferential statistics, as well as content analysis for open-ended questions, were used to summarize findings. ResultsThirty-one facility administrators (representing thirty-two facilities) participated in the interviews. Six administrators had taken action and 18 were planning on taking action as a result of FARs. The majority found the four contextual areas addressed in FAR to be useful, meaningful, and understandable. They liked the comparisons made between data from years one and two and between their facility and other TREC study sites in their province. Twenty-two indicated that they would like to receive information on additional areas such as aggressive behaviours of residents and information sharing. Twenty-four administrators indicated that FARs contained enough information, while eight found FARs &lsquo;too short&rsquo;. Administrators who reported that the FAR contained enough information were more likely to take action within their facilities than administrators who reported that they needed more information. ConclusionsAlthough the FAR was brief, the presentation of the four contextual areas was relevant to the majority of administrators and prompted them to plan or to take action within their facility. <br /

Prebiotic effects: metabolic and health benefits

The different compartments of the gastrointestinal tract are inhabited by populations of micro-organisms. By far the most important predominant populations are in the colon where a true symbiosis with the host exists that is a key for well-being and health. For such a microbiota, 'normobiosis' characterises a composition of the gut 'ecosystem' in which micro-organisms with potential health benefits predominate in number over potentially harmful ones, in contrast to 'dysbiosis', in which one or a few potentially harmful micro-organisms are dominant, thus creating a disease-prone situation. The present document has been written by a group of both academic and industry experts (in the ILSI Europe Prebiotic Expert Group and Prebiotic Task Force, respectively). It does not aim to propose a new definition of a prebiotic nor to identify which food products are classified as prebiotic but rather to validate and expand the original idea of the prebiotic concept (that can be translated in 'prebiotic effects'), defined as: 'The selective stimulation of growth and/or activity(ies) of one or a limited number of microbial genus(era)/species in the gut microbiota that confer(s) health benefits to the host.' Thanks to the methodological and fundamental research of microbiologists, immense progress has very recently been made in our understanding of the gut microbiota. A large number of human intervention studies have been performed that have demonstrated that dietary consumption of certain food products can result in statistically significant changes in the composition of the gut microbiota in line with the prebiotic concept. Thus the prebiotic effect is now a well-established scientific fact. The more data are accumulating, the more it will be recognised that such changes in the microbiota's composition, especially increase in bifidobacteria, can be regarded as a marker of intestinal health. The review is divided in chapters that cover the major areas of nutrition research where a prebiotic effect has tentatively been investigated for potential health benefits. The prebiotic effect has been shown to associate with modulation of biomarkers and activity(ies) of the immune system. Confirming the studies in adults, it has been demonstrated that, in infant nutrition, the prebiotic effect includes a significant change of gut microbiota composition, especially an increase of faecal concentrations of bifidobacteria. This concomitantly improves stool quality (pH, SCFA, frequency and consistency), reduces the risk of gastroenteritis and infections, improves general well-being and reduces the incidence of allergic symptoms such as atopic eczema. Changes in the gut microbiota composition are classically considered as one of the many factors involved in the pathogenesis of either inflammatory bowel disease or irritable bowel syndrome. The use of particular food products with a prebiotic effect has thus been tested in clinical trials with the objective to improve the clinical activity and well-being of patients with such disorders. Promising beneficial effects have been demonstrated in some preliminary studies, including changes in gut microbiota composition (especially increase in bifidobacteria concentration). Often associated with toxic load and/or miscellaneous risk factors, colon cancer is another pathology for which a possible role of gut microbiota composition has been hypothesised. Numerous experimental studies have reported reduction in incidence of tumours and cancers after feeding specific food products with a prebiotic effect. Some of these studies (including one human trial) have also reported that, in such conditions, gut microbiota composition was modified (especially due to increased concentration of bifidobacteria). Dietary intake of particular food products with a prebiotic effect has been shown, especially in adolescents, but also tentatively in postmenopausal women, to increase Ca absorption as well as bone Ca accretion and bone mineral density. Recent data, both from experimental models and from human studies, support the beneficial effects of particular food products with prebiotic properties on energy homaeostasis, satiety regulation and body weight gain. Together, with data in obese animals and patients, these studies support the hypothesis that gut microbiota composition (especially the number of bifidobacteria) may contribute to modulate metabolic processes associated with syndrome X, especially obesity and diabetes type 2. It is plausible, even though not exclusive, that these effects are linked to the microbiota-induced changes and it is feasible to conclude that their mechanisms fit into the prebiotic effect. However, the role of such changes in these health benefits remains to be definitively proven. As a result of the research activity that followed the publication of the prebiotic concept 15 years ago, it has become clear that products that cause a selective modification in the gut microbiota's composition and/or activity(ies) and thus strengthens normobiosis could either induce beneficial physiological effects in the colon and also in extra-intestinal compartments or contribute towards reducing the risk of dysbiosis and associated intestinal and systemic pathologies

Bias in random forest variable importance measures: Illustrations, sources and a solution

BACKGROUND: Variable importance measures for random forests have been receiving increased attention as a means of variable selection in many classification tasks in bioinformatics and related scientific fields, for instance to select a subset of genetic markers relevant for the prediction of a certain disease. We show that random forest variable importance measures are a sensible means for variable selection in many applications, but are not reliable in situations where potential predictor variables vary in their scale of measurement or their number of categories. This is particularly important in genomics and computational biology, where predictors often include variables of different types, for example when predictors include both sequence data and continuous variables such as folding energy, or when amino acid sequence data show different numbers of categories. RESULTS: Simulation studies are presented illustrating that, when random forest variable importance measures are used with data of varying types, the results are misleading because suboptimal predictor variables may be artificially preferred in variable selection. The two mechanisms underlying this deficiency are biased variable selection in the individual classification trees used to build the random forest on one hand, and effects induced by bootstrap sampling with replacement on the other hand. CONCLUSION: We propose to employ an alternative implementation of random forests, that provides unbiased variable selection in the individual classification trees. When this method is applied using subsampling without replacement, the resulting variable importance measures can be used reliably for variable selection even in situations where the potential predictor variables vary in their scale of measurement or their number of categories. The usage of both random forest algorithms and their variable importance measures in the R system for statistical computing is illustrated and documented thoroughly in an application re-analyzing data from a study on RNA editing. Therefore the suggested method can be applied straightforwardly by scientists in bioinformatics research

Private provider participation in statewide immunization registries

BACKGROUND: Population-based registries have been promoted as an effective method to improve childhood immunization rates, yet rates of registry participation in the private sector are low. We sought to describe, through a national overview, the perspectives of childhood immunization providers in private practice regarding factors associated with participation or non-participation in immunization registries. METHODS: Two mailed surveys, one for 264 private practices identified as registry non-participants and the other for 971 identified as registry participants, from 15 of the 31 states with population-based statewide immunization registries. Frequency distributions were calculated separately for non-participants and participants regarding the physician-reported factors that influenced decisions related to registry participation. Pearson chi-square tests of independence were used to assess associations among categorical variables. RESULTS: Overall response rate was 62% (N = 756). Among non-participants, easy access to records of vaccines provided at other sites (N = 101, 68%) and printable immunization records (N = 82, 55%) were most often cited as "very important" potential benefits of a registry, while the most commonly cited barriers to participation were too much cost/staff time (N = 36, 38%) and that the practice has its own system for recording and monitoring immunizations (N = 35, 37%). Among registry participants, most reported using the registry to input data on vaccines administered (N = 326, 87%) and to review immunization records of individual patients (N = 302, 81%). A minority reported using it to assess their practice's immunization coverage (N = 110, 29%) or generate reminder/recall notices (N = 54, 14%). Few participants reported experiencing "significant" problems with the registry; the most often cited was cost/staff time to use the registry (N = 71, 20%). CONCLUSION: Most registry participants report active participation with few problems. The problems they report are generally consistent with the barriers anticipated by non-participants, but did not impede participation. Recruitment efforts should focus on demonstrating the benefits of the registry to providers. In addition, many participants are not utilizing the full range of registry features; further study is needed to determine how best to increase use of these features