927 research outputs found
Una revolución cientÃfica a la que Caderno Brasileiro de Ensino de FÃsica quiere contribuir
Al inicio de este siglo XXI ha comenzado a desarrollarse un nuevo dominio cientÃfico, la Ciencia de la Sostenibilidad (KATES et al., 2001), con el objetivo de integrar las aportaciones a la Sostenibilidad de distintas disciplinas que están dando una respuesta positiva a los numerosos llamamientos realizados para que la comunidad cientÃfica contribuya a hacer frente a la grave situación de emergencia planetaria (LUBCHENCO, 1998). Una integración necesaria debido a la estrecha vinculación de los problemas que se pretende resolver (DIAMOND, 2006; DUARTE, 2006), que incluyen desde el agotamiento de recursos esenciales y una contaminación que está degradando todos los ecosistemas, a una explosión demográfica que ha sobrepasado ya la capacidad de carga del planeta, pasando por el desarreglo climático, la pérdida de diversidad biológica y cultural, desigualdades inaceptables o conflictos y violencias fruto de un sistema socioeconómico insolidario, guiado por la búsqueda del máximo beneficio particular a corto plazo
Um estudo a respeito das concepções alternativas sobre calor e temperatura
Neste trabalho, foi realizada uma investigação que teve por objetivo verificar se um planejamento de ensino, tendo como ponto de partida as concepções alternativas dos alunos da 2ª série do Ensino Médio, resultava em uma aprendizagem mais eficiente. Também foram identificadas, através de um teste, as similaridades entre as concepções alternativas apresentadas por estes alunos com as de três cursos de formação de professores (Magistério, Licenciatura Plena em Matemática e Licenciatura Plena em FÃsica). No trabalho desenvolvido, foi possÃvel perceber que apesar do estudo das concepções alternativas ter praticamente se esgotado em termos de pesquisa, pouco chegou até hoje na sala de aula
Dominance of a clonal green sulfur bacterial population in a stratified lake
For many years, the chemocline of the meromictic Lake Cadagno, Switzerland, was dominated by purple sulfur bacteria. However, following a major community shift in recent years, green sulfur bacteria (GSB) have come to dominate. We investigated this community by performing microbial diversity surveys using FISH cell counting and population multilocus sequence typing [clone library sequence analysis of the small subunit (SSU) rRNA locus and two loci involved in photosynthesis in GSB: fmoA and csmCA]. All bacterial populations clearly stratified according to water column chemistry. The GSB population peaked in the chemocline (c. 8 × 106 GSB cells mL−1) and constituted about 50% of all cells in the anoxic zones of the water column. At least 99.5% of these GSB cells had SSU rRNA, fmoA, and csmCA sequences essentially identical to that of the previously isolated and genome-sequenced GSB Chlorobium clathratiforme strain BU-1 (DSM 5477). This ribotype was not detected in Lake Cadagno before the bloom of GSB. These observations suggest that the C. clathratiforme population that has stabilized in Lake Cadagno is clonal. We speculate that such a clonal bloom could be caused by environmental disturbance, mutational adaptation, or invasio
Experimenting clinical pathways in general practice: a focus group investigation with Italian General Practitioners
Background. Clinical governance is considered crucial in primary care. Since 2005, clinical pathways have been experimentally implemented at the Local Health Authority of Monza Brianza (ASLMB), Italy, to develop general practitioners\u2019 (GPs) care of patients affected by some chronic diseases. The experimentation was aimed at introducing clinical governance in primary care, increasing GPs\u2019 involvement in the care of their patients, and improving both patients\u2019 and professionals\u2019 satisfaction. In the period 2005-2006, 12% of the 763 employed GPs in the ASLMB were involved in the experiment, while this percentage increased to 15-20% in 2007-2008. Design and Methods. Twenty-four GPs were purposively sampled, randomly divided into two groups and asked to participate in focus groups (FGs) held in 2008, aimed at evaluating their perception of the experiment. The FGs were audio-recorded, dialogues were typed out and undergone to a thematic analysis, according to the Interpretative Phenomenological Approach. Results. Four major themes emerged: i) clinical pathways can result in GPs working in a more efficient and effective fashion; ii) they can assure higher levels of both patient and professional satisfaction, since they sustain a caring approach and strengthen the GPs\u2019 role; iii) nevertheless, clinical pathways increase the bureaucratic workload and problems can arise in relationships among GPs and the LHA; iv) the implementation of clinical pathways can be improved, especially by reducing bureaucracy and by assuring their continuity. Conclusions. Managerial aspects should be considered with care in order to experimentally introduce clinical pathways in general practice, and continuity of the experimentation should be guaranteed to improve GPs\u2019 adherence and commitment
Recommended from our members
Anti-Hypertensive Medications and Cardiovascular Events in Older Adults with Multiple Chronic Conditions
Importance Randomized trials of anti-hypertensive treatment demonstrating reduced risk of cardiovascular events in older adults included participants with less comorbidity than clinical populations. Whether these results generalize to all older adults, most of whom have multiple chronic conditions, is uncertain. Objective: To determine the association between anti-hypertensive medications and CV events and mortality in a nationally representative population of older adults. Design: Competing risk analysis with propensity score adjustment and matching in the Medicare Current Beneficiary Survey cohort over three-year follow-up through 2010. Participants and Setting 4,961 community-living participants with hypertension. Exposure Anti-hypertensive medication intensity, based on standardized daily dose for each anti-hypertensive medication class participants used. Main Outcomes and Measures Cardiovascular events (myocardial infarction, unstable angina, cardiac revascularization, stroke, and hospitalizations for heart failure) and mortality. Results: Of 4,961 participants, 14.1% received no anti-hypertensives; 54.6% received moderate, and 31.3% received high, anti-hypertensive intensity. During follow-up, 1,247 participants (25.1%) experienced cardiovascular events; 837 participants (16.9%) died. Of deaths, 430 (51.4%) occurred in participants who experienced cardiovascular events during follow-up. In the propensity score adjusted cohort, after adjusting for propensity score and other covariates, neither moderate (adjusted hazard ratio, 1.08 [95% CI, 0.89–1.32]) nor high (1.16 [0.94–1.43]) anti-hypertensive intensity was associated with experiencing cardiovascular events. The hazard ratio for death among all participants was 0.79 [0.65–0.97] in the moderate, and 0.72 [0.58–0.91] in the high intensity groups compared with those receiving no anti-hypertensives. Among participants who experienced cardiovascular events, the hazard ratio for death was 0.65 [0.48–0.87] and 0.58 [0.42–0.80] in the moderate and high intensity groups, respectively. Results were similar in the propensity score-matched subcohort. Conclusions and Relevance In this nationally representative cohort of older adults, anti-hypertensive treatment was associated with reduced mortality but not cardiovascular events. Whether RCT results generalize to older adults with multiple chronic conditions remains uncertain
Changes in impacts of climate extremes: human systems and ecosystems
In this chapter, two different types of impacts on human and ecological systems are examined: (i) impacts of extreme weather and climate events; and (ii) extreme impacts triggered by less-than-extreme weather or climate events (in combination with non-climatic factors, such as high exposure and/or vulnerability). Where data are available, impacts are examined from sectoral and regional perspectives.Peer Reviewe
Combining estimates of interest in prognostic modelling studies after multiple imputation: current practice and guidelines
Background: Multiple imputation (MI) provides an effective approach to handle missing covariate
data within prognostic modelling studies, as it can properly account for the missing data
uncertainty. The multiply imputed datasets are each analysed using standard prognostic modelling
techniques to obtain the estimates of interest. The estimates from each imputed dataset are then
combined into one overall estimate and variance, incorporating both the within and between
imputation variability. Rubin's rules for combining these multiply imputed estimates are based on
asymptotic theory. The resulting combined estimates may be more accurate if the posterior
distribution of the population parameter of interest is better approximated by the normal
distribution. However, the normality assumption may not be appropriate for all the parameters of
interest when analysing prognostic modelling studies, such as predicted survival probabilities and
model performance measures.
Methods: Guidelines for combining the estimates of interest when analysing prognostic modelling
studies are provided. A literature review is performed to identify current practice for combining
such estimates in prognostic modelling studies.
Results: Methods for combining all reported estimates after MI were not well reported in the
current literature. Rubin's rules without applying any transformations were the standard approach
used, when any method was stated.
Conclusion: The proposed simple guidelines for combining estimates after MI may lead to a wider
and more appropriate use of MI in future prognostic modelling studies
Contributions of team climate in the study of interprofessional collaboration: a conceptual analysis
The concept of team climate is widely used to understand and evaluate working environments. It shares some important features with Interprofessional Collaboration (IPC). The four-factor theory of climate for work group innovation, which underpins team climate, could provide a better basis for understanding both teamwork and IPC. This article examines in detail the common ground between team climate and IPC, and assesses the relevance of team climate as a theoretical approach to understanding IPC. There are important potential areas of overlap between team climate and IPC that we have grouped under four headings: (1) interaction and communication between team members; (2) common objectives around which collective work is organised; (3) responsibility for performing work to a high standard; and (4) promoting innovation in working practices. These overlapping areas suggest common characteristics that could provide elements of a framework for considering the contribution of team climate to
collaborative working, both from a conceptual perspective and, potentially, in operational terms as, for example, a diagnostic tool
- …