611 research outputs found
Interactions and entrepreneurial agency; : a relational view of entrepreneurs’ control cognitions
Peer reviewe
Estabilidade do desempenho e eficácia do ensino: Implicações para as políticas de avaliação de professores
The last five to ten years has seen a renewed interest in the stability of teacher behavior and effectiveness. Data on teacher performance and teacher effectiveness are being used increasingly as the basis for decisions about continued employment, tenure and promotion, and financial bonuses. The purpose of this study is to explore the stability of both teacher performance and effectiveness by determining the extent to which performances and effectiveness of individual teachers fluctuate over time. The sample consisted of 132 teachers for whom both observational and state standardized test data were available for five consecutive years. Neither teacher performance nor effectiveness were highly stable over multiple years of the study. The observed relationship between teacher performance and teacher effectiveness was reasonably stable over time, but the magnitude of the relationship was quite small. Teacher performance was also likely to be inflated in low performing schools. We also discuss when different observed patterns may be acceptable based on the purpose for which the data are used.En los últimos cinco a diez años ha visto un renovado interés en la estabilidad de la conducta y la efectividad de los maestros. Los datos sobre el desempeño de los docentes y la eficacia docente se están utilizando cada vez más como la base para las decisiones sobre el mantenimiento del empleo, la tenencia y la promoción, y los bonos financieros. El propósito de este estudio es explorar la estabilidad de rendimiento y eficacia de los docentes analizando en que medida las actuaciones y la eficacia de los profesores individuales fluctúan con el tiempo. La muestra estuvo constituida estaban disponibles datos tanto observacionales y de pruebas estandarizadas durante cinco años consecutivos. Ni el desempeño docente ni la eficacia era muy estable a lo largo de varios años de estudio. La relación observada entre el desempeño de los docentes y la efectividad del maestro era razonablemente estable en el tiempo, pero la magnitud de la relación era bastante pequeña. Es probable que el desempeño de los docentes también se halla incrementado en escuelas de bajo rendimiento. También discutimos en que medida los diferentes patrones observados pueden ser aceptables como una base confiable para los fines propuestos por esas políticas. Nos últimos cinco a dez anos tem visto um renovado interesse na estabilidade do comportamento e da eficácia dos professores. Os dados sobre o desempenho e eficácia dos professores são cada vez mais usados como base para a toma de decisões sobre emprego retenção, posse e promoção, e incentivos. O objetivo deste estudo é explorar a estabilidade do desempenho e eficácia de professores analisando em que medida as ações e efetividade dos professores muda ao longo do tempo. A amostra foi composta por dados de 132 professores de exames e observações obtidos por cinco anos consecutivos. Nem o desempenho e a eficácia dos professores foram muito estáveis ao longo dos vários anos de estudo. A relação observada entre o desempenho do professor e eficácia do professor era razoavelmente estável ao longo do tempo, mas a magnitude da relação foi muito pequena. Desempenho dos professores também parece aumentar em escolas de baixo desempenho. Discutimos, também, em que medida os diferentes padrões observados podem ser aceitáveis para os objetivos das politicas.
Yehyatonhserayenteri: A Haudenosaunee Model for Onkwehon:we (Indigenous) Education
Focusing on Onkwehon:we (Indigenous) ways of knowing, and Haudenosaunee ways of knowing in particular, this article showcases the strengths of Onkwehon:we-led education and leadership. Under the leadership of our Youth Advisory Council, 22 young people (11 Onkwehon:we and 11 non-Onkwehon:we) took part in three days of workshops on Six Nations. The workshops were led and conducted by Haudenosaunee knowledge keepers who covered a range of topics. Six months after the completion of the workshops, 18 of the 22 youth participated in one-on-one follow-up interviews. We also conducted community impact interviews with 10 adult community members from Six Nations and Brantford. Through the workshops and interviews, we learned that Nation-specific learning helped to inform non-Onkwehon:we youth about the history of the lands on which they live, granting them access to traditions and ceremonies that resonated with them in both emotional and intellectual ways. Through experiential education and Haudenosaunee leadership, both Onkwehon:we and non-Onkwehon:we youth learned to value the original instructions, build relationships, and address the challenges of decolonization in an increasingly uncertain world
Yehyatonhserayenteri: A Haudenosaunee Model for Onkwehon:we (Indigenous) Education
Focusing on Onkwehon:we (Indigenous) ways of knowing, and Haudenosaunee ways of knowing in particular, this article showcases the strengths of Onkwehon:we-led education and leadership. Under the leadership of our Youth Advisory Council, 22 young people (11 Onkwehon:we and 11 non-Onkwehon:we) took part in three days of workshops on Six Nations. The workshops were led and conducted by Haudenosaunee knowledge keepers who covered a range of topics. Six months after the completion of the workshops, 18 of the 22 youth participated in one-on-one follow-up interviews. We also conducted community impact interviews with 10 adult community members from Six Nations and Brantford. Through the workshops and interviews, we learned that Nation-specific learning helped to inform non-Onkwehon:we youth about the history of the lands on which they live, granting them access to traditions and ceremonies that resonated with them in both emotional and intellectual ways. Through experiential education and Haudenosaunee leadership, both Onkwehon:we and non-Onkwehon:we youth learned to value the original instructions, build relationships, and address the challenges of decolonization in an increasingly uncertain world
Biotic homogenisation and differentiation as directional change in beta diversity: synthesising driver–response relationships to develop conceptualmodels across ecosystems
Biotic homogenisation is defined as decreasing dissimilarity among ecological assemblages sampled within a given spatial area over time. Biotic differentiation, in turn, is defined as increasing dissimilarity over time. Overall, changes in the spatial dissimilarities among assemblages (termed ‘beta diversity’) is an increasingly recognised feature of broader biodiversity change in the Anthropocene. Empirical evidence of biotic homogenisation and biotic differentiation remains scattered across different ecosystems. Most meta-analyses quantify the prevalence and direction of change in beta diversity, rather than attempting to identify underlying ecological drivers of such changes. By conceptualising the mechanisms that contribute to decreasing or increasing dissimilarity in the composition of ecological assemblages across space, environmental managers and conservation practitioners can make informed decisions about what interventions may be required to sustain biodiversity and can predict potential biodiversity outcomes of future disturbances. We systematically reviewed and synthesised published empirical evidence for ecological drivers of biotic homogenisation and differentiation across terrestrial, marine, and freshwater realms to derive conceptual models that explain changes in spatial beta diversity. We pursued five key themes in our review: (i) temporal environmental change; (ii) disturbance regime; (iii) connectivity alteration and species redistribution; (iv) habitat change; and (v) biotic and trophic interactions. Our first conceptual model highlights how biotic homogenisation and differentiation can occur as a function of changes in local (alpha) diversity or regional (gamma) diversity, independently of species invasions and losses due to changes in species occurrence among assemblages. Second, the direction and magnitude of change in beta diversity depends on the interaction between spatial variation (patchiness) and temporal variation (synchronicity) of disturbance events. Third, in the context of connectivity and species redistribution, divergent beta diversity outcomes occur as different species have different dispersal characteristics, and the magnitude of beta diversity change associated with species invasions also depends strongly on alpha and gamma diversity prior to species invasion. Fourth, beta diversity is positively linked with spatial environmental variability, such that biotic homogenisation and differentiation occur when environmental heterogeneity decreases or increases, respectively. Fifth, species interactions can influence beta diversity via habitat modification, disease, consumption (trophic dynamics), competition, and by altering ecosystem productivity. Our synthesis highlights the multitude of mechanisms that cause assemblages to be more or less spatially similar in composition (taxonomically, functionally, phylogenetically) through time. We consider that future studies should aim to enhance our collective understanding of ecological systems by clarifying the underlying mechanisms driving homogenisation or differentiation, rather than focusing only on reporting the prevalence and direction of change in beta diversity, per se. biodiversity, beta diversity, biotic homogenisation, biotic differentiation, species assemblage, turnoverpublishedVersio
Prime mover or fellow traveller:25-hydroxy vitamin D’s seasonal variation, cardiovascular disease and death in the Scottish Heart Health Extended Cohort (SHHEC)
BACKGROUND: Theoretical links between seasonal lack of sunlight, hypovitaminosis D and excess cardiovascular disease and death prompted our adding novel to conventional cohort analyses. METHODS: We tested three postulates on 13 224 Scottish Heart Health Extended Cohort participants, assayed for 25-hydroxyvitamin D (25OHD) and followed for 22 years. (i) Endpoints enumerated by month of occurrence mirror annual seasonal oscillation in 25OHD. (ii) Endpoint seasonality is increased in people with below median 25OHD. (iii) Low 25OHD predicts endpoints independently of major risk factors. RESULTS: Baseline median 25OHD level was 36.4 (other quartiles 26.7, 51.7) nmol/l. The March trough was half the August peak, both well after seasonal solstices. (i) There was no demonstrable monthly variation in First Cardiovascular Event (n = 3307). Peaks and troughs for All Death and Cardiovascular Death (n = 2987, 1350) were near the solstices, earlier than extremes of 25OHD. (ii) Endpoint variability showed no difference between those above and below median 25OHD. (iii) Cox model hazard ratios (HR), by decreasing 25OHD, increased modestly and nonspecifically for all endpoints examined, with no threshold, the gradients diminishing by ∼ : 60% following multiple adjustment. For Cardiovascular Disease, HR, by 20 (∼SD) nmol/l decrease, = 1.224 (1.175, 1.275) adjusted for age and sex; additionally adjusted for family history, deprivation index, smoking, systolic blood pressure, total and HDL cholesterol, = 1.093 (1.048, 1.139); All Deaths = 1.238 (1.048, 1.139) and 1.098 (1.050, 1.149). 25OHD made no independent contribution to cardiovascular discrimination and reclassification. CONCLUSIONS: Our analyses challenge vitamin D's alleged role as major prime mover in cardiovascular disease and mortality.</p
Vitamin D with Calcium reduces mortality: patient level pooled analysis of 70,528 patients from eight major vitamin D trials
Introduction: Vitamin D may affect multiple health outcomes. If so, an effect on mortality is to be expected. Using pooled data from randomized controlled trials, we performed individual patient data (IPD) and trial level meta-analyses to assess mortality among participants randomized to either vitamin D alone or vitamin D with calcium.
Subjects and Methods: Through a systematic literature search, we identified 24 randomized controlled trials reporting data on mortality in which vitamin D was given either alone or with calcium. From a total of 13 trials with more than 1000 participants each, eight trials were included in our IPD analysis. Using a stratified Cox regression model, we calculated risk of death during 3 yr of treatment in an intention-to-treat analysis. Also, we performed a trial level meta-analysis including data from all studies.
Results: The IPD analysis yielded data on 70,528 randomized participants (86.8% females) with a median age of 70 (interquartile range, 62–77) yr. Vitamin D with or without calcium reduced mortality by 7% [hazard ratio, 0.93; 95% confidence interval (CI), 0.88–0.99]. However, vitamin D alone did not affect mortality, but risk of death was reduced if vitamin D was given with calcium (hazard ratio, 0.91; 95% CI, 0.84–0.98). The number needed to treat with vitamin D plus calcium for 3 yr to prevent one death was 151. Trial level meta-analysis (24 trials with 88,097 participants) showed similar results, i.e. mortality was reduced with vitamin D plus calcium (odds ratio, 0.94; 95% CI, 0.88–0.99), but not with vitamin D alone (odds ratio, 0.98; 95% CI, 0.91–1.06).
Conclusion: Vitamin D with calcium reduces mortality in the elderly, whereas available data do not support an effect of vitamin D alone
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