128 research outputs found

    e-Learning Artefacts: Are They Based on Learning Theory?

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    With the advent of e-learning, educators and designers of learning resources should view technology as a tool and a medium, but not as the message. This paper poses the rhetorical question as to whether e-learning artefacts and variants are based on sound learning theory. It traces the evolution of e-learning and describes characteristics that indicate underlying theoretical biases in traditional educational software, as well as in online courses and web-based instruction. The paper introduces a synthesis of contemporary learning theory, the Hexa-C Metamodel (De Villiers, 2002, 2003), whose six elements can playa role in the design and development of e-learning environments and instructional systems, and which can also be used in evaluating educational applications from a learning theory perspective.Computin

    Integrating a software engineering approach and instructional factors in instructional software development--illustrated by a prototype in theoretical computer science

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    This dissertation is a multi-disciplinary study, which integrates a software engineering approach with instructional factors in the decision-making, analysis, design and development processes of instructional software. Software engineering models, tools and representations are used in the process of software construction. With reference to the fundamental characteristics of the software product, several disciplines and factors, from both instructional and computing perspectives are considered, and the most appropriate approach/es selected. Software engineering, instructional design and instructional theory are considered as pillars of courseware engineering. The object-oriented design paradigm and a prototyping life-cycle model are found to be most suitable for development of computer-aided instruction. The conceptual study is illustrated by prototype development of a component-based multi-activity practice environment in theoretical Computer Science. It offers perusal or practice, in various instructional modes, according to the user's preferred learning style or need.ComputingM. Sc. (Information Systems

    Hormonal therapy of menopause: 2004 position of the Department of Female Endocrinology and Andrology of the Brazilian Society of Endocrinology and Metabolism

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    After randomized clinical trials produced impact and questions at the medical community on menopause hormonal therapy (MHT), the Department of Female Endocrinology and Andrology of the Brazilian Society of Endocrinology convened a group of specialists to produce an informative, critical and position paper, offering guidelines for those who practice or are called to express their opinion on menopause therapy. MHT is indicated for relief of vasomotor symptoms, maintenance of vaginal trophism, bone mass and collagen preservation, sexual and general well-being. Studies on primary cardiovascular prevention are not conclusive, and thus insufficient to indicate or not MHT for this purpose. Schemes and forms of association should de individualized. Whenever possible, one should use 17-beta estradiol, associated to natural progesterone or its derivatives in women with an intact uterus, at the lowest effective doses. Duration of therapy depends on its aims, and should be periodically re-evaluated through an individual indication/contra-indication balance. Orientation toward a healthier lifestyle, with smoking cessation, adequate calcium intake and a low fat diet, together with regular physical activity is fundamental during menopause.Após os estudos clínicos randomizados produzirem impacto e questionamentos sobre terapia hormonal da menopausa (THM) na comunidade médica, o Departamento de Endocrinologia Feminina e Andrologia da SBEM reuniu um grupo de especialistas para formular um documento informativo, crítico e de posicionamento que pudesse servir de orientação aos que praticam ou opinam sobre tratamento da menopausa. THM está indicada para alívio dos sintomas motores, conservação do trofismo vaginal, preservação de massa óssea e colágeno, melhora do bem estar e sexualidade. Os estudos sobre prevenção cardiovascular primária não são conclusivos, portanto insuficientes para indicar ou deixar de indicar THM com este objetivo. Esquemas e tipos de associação devem ser individualizados. Sempre que possível deve-se optar pelas menores doses eficazes de 17-beta estradiol, associado a progesterona natural ou seus derivados nas mulheres com útero. A duração do tratamento é vinculada a seus objetivos, devendo ser reavaliada periodicamente através de um balanço individual entre indicação e contra-indicação. Orientação quanto a um estilo de vida mais saudável, com eliminação de tabagismo, alimentação adequada em cálcio e pobre em gorduras e atividade física regular são fundamentais como cuidados associados durante a menopausa.Ministério da Saúde Setor de Endocrinologia Hospital da LagoaInstituto Estadual de Diabetes e EndocrinologiaUniversidade do Estado do Rio de JaneiroMinistério da Saúde FIOCRUZ Instituto Fernandes FigueiraUniversidade Federal de São Paulo (UNIFESP)UNIFESPSciEL

    Bridging geometries and potentials in DBI cosmologies

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    We investigate the link between the warp function and the potential in DBI cosmologies in connection with the possibility they represent power-law solutions. A prescription is given to take advantage of the known result that given a warp factor there is always a choice of potential resulting in a constant ratio between pressure and energy density. The method is illustrated with examples with interesting models for either the warp factor or the potential. We complete this investigation by giving a recipe to exploit symmetries in order to generate new solutions from existing ones; this method can be applied, for instance, to the power-law cosmologies obtained using our prescription.Comment: 7 pages, 3 figures, revte

    Physical activity attenuates the influence of FTO variants on obesity risk: A meta-analysis of 218,166 adults and 19,268 children

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    Background: The FTO gene harbors the strongest known susceptibility locus for obesity. While many individual studies have suggested that physical activity (PA) may attenuate the effect of FTO on obesity risk, other studies have not been able to confirm this interaction. To confirm or refute unambiguously whether PA attenuates the association of FTO with obesity risk, we meta-analyzed data from 45 studies of adults (n = 218,166) and nine studies of children and adolescents (n = 19,268). Methods and Findings: All studies identified to have data on the FTO rs9939609 variant (or any proxy [r2>0.8]) and PA were invited to participate, regardless of ethnicity or age of the participants. PA was standardized by categorizing it into a dichotomous variable (physically inactive versus active) in each study. Overall, 25% of adults and 13% of children were categorized as inactive. Interaction analyses were performed within each study by including the FTO×PA interaction term in an additive model, adjusting for age and sex. Subsequently, random effects meta-analysis was used to pool the interaction terms. In adults, the minor (A-) allele of rs9939609 increased the odds of obesity by 1.23-fold/allele (95% CI 1.20-1.26), but PA attenuated this effect (pinteraction= 0.001). More specifically, the minor allele of rs9939609 increased the odds of obesity less in the physically active group (odds ratio = 1.22/allele, 95% CI 1.19-1.25) than in the inactive group (odds ratio = 1.30/allele, 95% CI 1.24-1.36). No such interaction was found in children and adolescents. Concl

    Genome-wide association and Mendelian randomisation analysis provide insights into the pathogenesis of heart failure

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    Heart failure (HF) is a leading cause of morbidity and mortality worldwide. A small proportion of HF cases are attributable to monogenic cardiomyopathies and existing genome-wide association studies (GWAS) have yielded only limited insights, leaving the observed heritability of HF largely unexplained. We report results from a GWAS meta-analysis of HF comprising 47,309 cases and 930,014 controls. Twelve independent variants at 11 genomic loci are associated with HF, all of which demonstrate one or more associations with coronary artery disease (CAD), atrial fibrillation, or reduced left ventricular function, suggesting shared genetic aetiology. Functional analysis of non-CAD-associated loci implicate genes involved in cardiac development (MYOZ1, SYNPO2L), protein homoeostasis (BAG3), and cellular senescence (CDKN1A). Mendelian randomisation analysis supports causal roles for several HF risk factors, and demonstrates CAD-independent effects for atrial fibrillation, body mass index, and hypertension. These findings extend our knowledge of the pathways underlying HF and may inform new therapeutic strategies

    Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

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    The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR

    Relationship of edge localized mode burst times with divertor flux loop signal phase in JET

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    A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM

    Adjuvant bevacizumab for melanoma patients at high risk of recurrence: survival analysis of the AVAST-M trial

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    Background: Bevacizumab is a recombinant humanised monoclonal antibody to vascular endothelial growth factor shown to improve survival in advanced solid cancers. We evaluated the role of adjuvant bevacizumab in melanoma patients at high risk of recurrence. Patients and methods: Patients with resected AJCC stage IIB, IIC and III cutaneous melanoma were randomised to receive either adjuvant bevacizumab (7.5?mg/kg i.v. 3 weekly for 1?year) or standard observation. The primary end point was detection of an 8% difference in 5-year overall survival (OS) rate; secondary end points included disease-free interval (DFI) and distant metastasis-free interval (DMFI). Tumour and blood were analysed for prognostic and predictive markers. Results: Patients (n=1343) recruited between 2007 and 2012 were predominantly stage III (73%), with median age 56?years (range 18-88?years). With 6.4-year median follow-up, 515 (38%) patients had died [254 (38%) bevacizumab; 261 (39%) observation]; 707 (53%) patients had disease recurrence [336 (50%) bevacizumab, 371 (55%) observation]. OS at 5?years was 64% for both groups [hazard ratio (HR) 0.98; 95% confidence interval (CI) 0.82-1.16, P?=?0.78). At 5?years, 51% were disease free on bevacizumab versus 45% on observation (HR 0.85; 95% CI 0.74-0.99, P?=?0.03), 58% were distant metastasis free on bevacizumab versus 54% on observation (HR 0.91; 95% CI 0.78-1.07, P?=?0.25). Forty four percent of 682 melanomas assessed had a BRAFV600 mutation. In the observation arm, BRAF mutant patients had a trend towards poorer OS compared with BRAF wild-type patients (P?=?0.06). BRAF mutation positivity trended towards better OS with bevacizumab (P?=?0.21). Conclusions: Adjuvant bevacizumab after resection of high-risk melanoma improves DFI, but not OS. BRAF mutation status may predict for poorer OS untreated and potential benefit from bevacizumab. Clinical Trial Information: ISRCTN 81261306; EudraCT Number: 2006-005505-64
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