120 research outputs found
Small-Group Learning in an Upper-Level University Biology Class Enhances Academic Performance and Student Attitudes Toward Group Work
To improve science learning, science educators' teaching tools need to address two major criteria: teaching practice should mirror our current understanding of the learning process; and science teaching should reflect scientific practice. We designed a small-group learning (SGL) model for a fourth year university neurobiology course using these criteria and studied student achievement and attitude in five course sections encompassing the transition from individual work-based to SGL course design. All students completed daily quizzes/assignments involving analysis of scientific data and the development of scientific models. Students in individual work-based (Individualistic) sections usually worked independently on these assignments, whereas SGL students completed assignments in permanent groups of six. SGL students had significantly higher final exam grades than Individualistic students. The transition to the SGL model was marked by a notable increase in 10th percentile exam grade (Individualistic: 47.5%; Initial SGL: 60%; Refined SGL: 65%), suggesting SGL enhanced achievement among the least prepared students. We also studied student achievement on paired quizzes: quizzes were first completed individually and submitted, and then completed as a group and submitted. The group quiz grade was higher than the individual quiz grade of the highest achiever in each group over the term. All students â even term high achievers âcould benefit from the SGL environment. Additionally, entrance and exit surveys demonstrated student attitudes toward SGL were more positive at the end of the Refined SGL course. We assert that SGL is uniquely-positioned to promote effective learning in the science classroom
The efficacy of the quercetin analogue LY294002 in immortalized cancer cell lines is related to the oxygenic and metabolic status of cells
Purpose: LY294002, a promising drug for chemotherapy, suppresses the activity of Phosphatidylinositol 3-Kinase (PI3K) which is pivotal to a number of processes such as proliferation, metabolism, and apoptosis. The compound has, however, been seen to have very variable efficacy in vivo.Methods: Proliferation and viability of two immortalized cells with divergent bioenergetic profiles was determined using crystal violet staining, and the 3-(4, 5-dimethylthiazol-2yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. Oxygen consumption rates were determined using MitoXpress-Xtra probes, and lactate generation was assessed with pH-Xtra probe and BM-lactate strips. Immunoblotting was performed with phospho-Akt-Ser 473 and Akt-pan primary antibodies.Results: U87 cells were shown to have a glycolytic metabolism, whereas RD cells exhibited a more aerobic metabolism. In both lines, hypoxia was shown to increase lactate production, and LY294002 reduced lactate production. The drug decreased cell proliferation and viability under all conditions, but the effect was greatest in U87 cells under normoxic conditions.Conclusion: Metabolic analysis showed a link between a glycolytic cell status and LY294002 induced cell death. However, in both cell lines the drug was also less effective under hypoxic conditions, as would be found in a tumour in vivo. Furthermore, in the presence of LY294002 the phosphorylation status of Akt, a target of PI3K, was found to be related to both the mechanism of cell respiration, and the oxygenic status of the cells
The developmental effects of media-ideal internalization and self-objectification processes on adolescentsâ negative body-feelings, dietary restraint, and binge eating
Despite accumulated experimental evidence of the negative effects of exposure to media-idealized images, the degree to which body image, and eating related disturbances are caused by media portrayals of gendered beauty ideals remains controversial. On the basis of the most up-to-date meta-analysis of experimental studies indicating that media-idealized images have the most harmful and substantial impact on vulnerable individuals regardless of gender (i.e., âinternalizersâ and âself-objectifiersâ), the current longitudinal study examined the direct and mediated links posited in objectification theory among media-ideal internalization, self-objectification, shame and anxiety surrounding the body and appearance, dietary restraint, and binge eating. Data collected from 685 adolescents aged between 14 and 15 at baseline (47 % males), who were interviewed and completed standardized measures annually over a 3-year period, were analyzed using a structural equation modeling approach. Results indicated that media-ideal internalization predicted later thinking and scrutinizing of oneâs body from an external observerâs standpoint (or self-objectification), which then predicted later negative emotional experiences related to oneâs body and appearance. In turn, these negative emotional experiences predicted subsequent dietary restraint and binge eating, and each of these core features of eating disorders influenced each other. Differences in the strength of these associations across gender were not observed, and all indirect effects were significant. The study provides valuable information about how the cultural values embodied by gendered beauty ideals negatively influence adolescentsâ feelings, thoughts and behaviors regarding their own body, and on the complex processes involved in disordered eating. Practical implications are discussed
Secular trends in pediatric antiretroviral treatment programs in rural and urban Zambia: a retrospective cohort study
<p>Abstract</p> <p>Background</p> <p>Since 2003 pediatric antiretroviral treatment (ART) programs have scaled-up in sub-Saharan Africa and should be evaluated to assess progress and identify areas for improvement. We evaluated secular trends in the characteristics and treatment outcomes of children in three pediatric ART clinics in urban and rural areas in Zambia.</p> <p>Methods</p> <p>Routinely collected data were analyzed from three ART programs in rural (Macha and Mukinge) and urban (Lusaka) Zambia between program implementation and July 2008. Data were obtained from electronic medical record systems and medical record abstraction, and were categorized by year of program implementation. Characteristics of all HIV-infected and exposed children enrolled in the programs and all children initiating treatment were compared by year of implementation.</p> <p>Results</p> <p>Age decreased and immunologic characteristics improved in all groups over time in both urban and rural clinics, with greater improvement observed in the rural clinics. Among children both eligible and ineligible for ART at clinic enrollment, the majority started treatment within a year. A high proportion of children, particularly those ineligible for ART at clinic enrollment, were lost to follow-up prior to initiating ART. Among children initiating ART, clinical and immunologic outcomes after six months of treatment improved in both urban and rural clinics. In the urban clinics, mortality after six months of treatment declined with program duration, and in the rural clinics, the proportion of children defaulting by six months increased with program duration.</p> <p>Conclusions</p> <p>Treatment programs are showing signs of progress in the care of HIV-infected children, particularly in the rural clinics where scale-up increased rapidly over the first three years of program implementation. However, continued efforts to optimize care are needed as many children continue to enroll in ART programs at a late stage of disease and thus are not receiving the full benefits of treatment.</p
Self-reported health status of older adults in Malaysia and Singapore: evidence from the 2007 Global Ageing Survey
The aim of this study is to investigate the correlates of self-reported health (SRH) among older adults in Malaysia and Singapore. The study uses data collected in the Global Ageing Study (GLAS) 2007, one of the largest surveys of its kind, specially designed to investigate attitudes towards later life, ageing and retirement. Data were collected from 1002 and 1004 respondents from Malaysia and Singapore respectively. The study found that Singaporeans report a healthier life than Malaysians. The two countries have consistent results with regard to the influences of selected covariates on individual health. Poorer health is more prevalent among people with lower education, among those widowed, divorced or separated, and those working in blue-collar occupations. Although social support is found to be an important determinant of SRH, the effects are partially confounded with other covariates. These findings enhance our knowledge about the health status of older people, and in turn will be useful for governments to ensure effective policy making
Outcomes and associated risk factors of patients traced after being lost to follow-up from antiretroviral treatment in Lilongwe, Malawi
Abstract Background Loss to follow-up is a major challenge of antiretroviral treatment (ART) programs in sub-Saharan Africa. Our objective was to a) determine true outcomes of patients lost to follow-up (LTFU) and b) identify risk factors associated with successful tracing and deaths of patients LTFU from ART in a large public sector clinic in Lilongwe, Malawi. Methods Patients who were more than 2 weeks late according to their last ART supply and who provided a phone number or address in Lilongwe were eligible for tracing. Their outcomes were updated and risk factors for successful tracing and death were examined. Results Of 1800 patients LTFU with consent for tracing, 724 (40%) were eligible and tracing was successful in 534 (74%): 285 (53%) were found to be alive and on ART; 32 (6%) had stopped ART; and 217 (41%) had died. Having a phone contact doubled tracing success (adjusted odds ratio, aOR = 2.1, 95% CI 1.4-3.0) and odds of identifying deaths [aOR = 1.8 (1.2-2.7)] in patients successfully traced. Mortality was higher when ART was fee-based at initiation (aOR = 2.3, 95% CI 1.1-4.7) and declined with follow-up time on ART. Limiting the analysis to patients living in Lilongwe did not change the main findings. Conclusion Ascertainment of contact information is a prerequisite for tracing, which can reveal outcomes of a large proportion of patients LTFU. Having a phone contact number is critical for successful tracing, but further research should focus on understanding whether phone tracing is associated with any differential reporting of mortality or LTFU
Unpacking the relationships between impulsivity, neighborhood disadvantage, and adolescent violence : an application of a neighborhood-based group decomposition
The research leading to these results has received funding from the European Research Council under the European Unionâs Seventh Framework Programme (FP/2007â2013)/ERC Grant Agreement no. 615159 (ERC Consolidator Grant DEPRIVEDHOODS, Socio-spatial inequality, deprived neighbourhoods, and neighbourhood effects); and from the Marie Curie programme under the European Unionâs Seventh Framework Programme (FP/2007â2013)/Career Integration Grant no. PCIG10-GA-2011-303728 (CIG Grant NBHCHOICE, Neighbourhood choice, neighbourhood sorting, and neighbourhood effects).Scholars have become increasingly interested in how social environments condition the relationships between individual risk-factors and adolescent behavior. An appreciable portion of this literature is concerned with the relationship between impulsivity and delinquency across neighborhood settings. The present article builds upon this growing body of research by considering the more nuanced pathways through which neighborhood disadvantage shapes the development of impulsivity and provides a situational context for impulsive tendencies to manifest in violent and aggressive behaviors. Using a sample of 12,935 adolescent from the National Longitudinal Study of Adolescent to Adult Health (Add Health) (mean age = 15.3, 51% female; 20% Black, 17% Hispanic), we demonstrate the extent to which variation in the association between impulsivity and delinquency across neighborhoods can be attributed to (1) differences in mean-levels of impulsivity and violence and (2) differences in coefficients across neighborhoods. The results of a series of multivariate regression models indicate that impulsivity is positively associated with self-reported violence, and that this relationship is strongest among youth living in disadvantaged neighborhoods. The moderating effect of neighborhood disadvantage can be attributed primarily to the stronger effect of impulsivity on violence in these areas, while differences in average levels of violence and impulsivity account for a smaller, yet nontrivial portion of the observed relationship. These results indicate that the differential effect of impulsivity on violence can be attributed to both developmental processes that lead to the greater concentration of violent and impulsive adolescents in economically deprived neighborhoods as well as the greater likelihood of impulsive adolescents engaging in violence when they reside in economically disadvantaged communities.Publisher PDFPeer reviewe
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