965 resultados para skill-biased technical change
Resumo:
Adolescents and adults with CF have lower bone mineral density (BMD) than normal, but its relationship with phenotype is not well understood. Point FEV1% predicted (FEV) and rate of change of FEV are biased estimates of disease severity, because progressively older subjects represent a selected survivor population, with females at greater risk of death than males. To investigate the relationship between BMD and phenotype we used an index (predicted age at death) derived from Bayesian estimates of slope and intercept of FEV, age at last measurement and survival status. Predictive equations for the index were derived from 97 subjects (78 survivors) from the RCH CF clinic, and applied to a group of 102 comparable subjects who had BMD measured, classified as having‘mild’ ()75th), ‘moderate’ (25– 75th), or ‘severe’ (-25th centile) phenotype. Total body (TB) and lumbar spine (LS) BMD z-scores (Z) were compared, adjustingfor gender effects, using 2-way ANOVA. Annual mean change in FEV segregated, as expected, according to phenotype, ‘severe’ (ns25), ‘moderate’ (ns51) and ‘mild’ (ns25) y3.01(y3.73 to y2.30)%, y0.85(y1.36 to y0.35)%, 2.70(1.92 to 3.46)%, respectively, with no gender difference. LS and TB BMDZ were different in each phenotype (P-s 0.002), LS BMDZ for ‘severe’, ‘moderate’ and ‘mild’ y1.63(CI: y2.07 to y 1.19), y0.86(CI: y1.17 to y0.55), y0.06(CI: y0.54 to 0.41). Males had lower LS BMDZ than females overall (y1.22 (CI: y1.54 to y0.91) vs. y0.48(CI: y 0.84 to y0.12) Ps0.002). In the ‘severe’ group, males had lower TB BMDZ and LS BMDZ (PF0.002). Low BMD is associated with ‘moderate’ and ‘severe’ phenotypes, with relative preservation in females in the ‘severe’ group. Female biology (reproductive fitness) might promote resistance to bone resorption at a critical level of BMD loss.
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Three studies support the vicarious dissonance hypothesis that individuals change their attitudes when witnessing members of important groups engage in inconsistent behavior. Study 1, in which participants observed an actor in an induced-compliance paradigm, documented that students who identified with their college supported an issue more after hearing an ingroup member make a counterattitudinal speech in favor of that issue. In Study 2, vicarious dissonance occurred even when participants did not hear a speech, and attitude change was highest when the speaker was known to disagree with the issue. Study 3 showed that speaker choice and aversive consequences moderated vicarious dissonance, and demonstrated that vicarious discomfort-the discomfort observers imagine feeling if in an actor's place-was attenuated after participants expressed their revised attitudes.
Resumo:
Regional commodity forecasts are being used increasingly in agricultural industries to enhance their risk management and decision-making processes. These commodity forecasts are probabilistic in nature and are often integrated with a seasonal climate forecast system. The climate forecast system is based on a subset of analogue years drawn from the full climatological distribution. In this study we sought to measure forecast quality for such an integrated system. We investigated the quality of a commodity (i.e. wheat and sugar) forecast based on a subset of analogue years in relation to a standard reference forecast based on the full climatological set. We derived three key dimensions of forecast quality for such probabilistic forecasts: reliability, distribution shift, and change in dispersion. A measure of reliability was required to ensure no bias in the forecast distribution. This was assessed via the slope of the reliability plot, which was derived from examination of probability levels of forecasts and associated frequencies of realizations. The other two dimensions related to changes in features of the forecast distribution relative to the reference distribution. The relationship of 13 published accuracy/skill measures to these dimensions of forecast quality was assessed using principal component analysis in case studies of commodity forecasting using seasonal climate forecasting for the wheat and sugar industries in Australia. There were two orthogonal dimensions of forecast quality: one associated with distribution shift relative to the reference distribution and the other associated with relative distribution dispersion. Although the conventional quality measures aligned with these dimensions, none measured both adequately. We conclude that a multi-dimensional approach to assessment of forecast quality is required and that simple measures of reliability, distribution shift, and change in dispersion provide a means for such assessment. The analysis presented was also relevant to measuring quality of probabilistic seasonal climate forecasting systems. The importance of retaining a focus on the probabilistic nature of the forecast and avoiding simplifying, but erroneous, distortions was discussed in relation to applying this new forecast quality assessment paradigm to seasonal climate forecasts. Copyright (K) 2003 Royal Meteorological Society.
Resumo:
The impacts of climate change in the potential distribution and relative abundance of a C3 shrubby vine, Cryptostegia grandiflora, were investigated using the CLIMEX modelling package. Based upon its current naturalised distribution, C. grandiflora appears to occupy only a small fraction of its potential distribution in Australia under current climatic conditions; mostly in apparently sub-optimal habitat. The potential distribution of C. grandiflora is sensitive towards changes in climate and atmospheric chemistry in the expected range of this century, particularly those that result in increased temperature and water use efficiency. Climate change is likely to increase the potential distribution and abundance of the plant, further increasing the area at risk of invasion, and threatening the viability of current control strategies markedly. By identifying areas at risk of invasion, and vulnerabilities of control strategies, this analysis demonstrates the utility of climate models for providing information suitable to help formulate large-scale, long-term strategic plans for controlling biotic invasions. The effects of climate change upon the potential distribution of C. grandiflora are sufficiently great that strategic control plans for biotic invasions should routinely include their consideration. Whilst the effect of climate change upon the efficacy of introduced biological control agents remain unknown, their possible effect in the potential distribution of C. grandiflora will likely depend not only upon their effects on the population dynamics of C. grandiflora, but also on the gradient of climatic suitability adjacent to each segment of the range boundary.
Resumo:
This paper describes a process-based metapopulation dynamics and phenology model of prickly acacia, Acacia nilotica, an invasive alien species in Australia. The model, SPAnDX, describes the interactions between riparian and upland sub-populations of A. nilotica within livestock paddocks, including the effects of extrinsic factors such as temperature, soil moisture availability and atmospheric concentrations of carbon dioxide. The model includes the effects of management events such as changing the livestock species or stocking rate, applying fire, and herbicide application. The predicted population behaviour of A. nilotica was sensitive to climate. Using 35 years daily weather datasets for five representative sites spanning the range of conditions that A. nilotica is found in Australia, the model predicted biomass levels that closely accord with expected values at each site. SPAnDX can be used as a decision-support tool in integrated weed management, and to explore the sensitivity of cultural management practices to climate change throughout the range of A. nilotica. The cohort-based DYMEX modelling package used to build and run SPAnDX provided several advantages over more traditional population modelling approaches (e.g. an appropriate specific formalism (discrete time, cohort-based, process-oriented), user-friendly graphical environment, extensible library of reusable components, and useful and flexible input/output support framework). (C) 2003 Published by Elsevier Science B.V.
Resumo:
Background. The purpose of this study was to examine the reliability of stage of change (SOC) measures for moderate-intensity and vigorous physical activity in two separate samples of young adults. Staging measures have focused on vigorous exercise, but current public health guidelines emphasize moderate-intensity activity. Method. For college students in the USA (n = 105) and in Australia (n = 123), SOC was assessed separately on two occasions for moderate-intensity activity and for vigorous activity. Test-retest repeatability was determined, using Cohen's kappa coefficient. Results. In both samples, the reliability scores for the moderate-intensity physical activity staging measure were lower than the scores for the vigorous exercise staging measure. Weighted kappa values for the moderate-intensity staging measure were in the fair to good range for both studies (0.50 and 0.45); for the vigorous staging measure kappa values were excellent and fair to good (0.76 and 0.72). Conclusions. There is a need to standardize and improve methods for staging moderate-intensity activity, given that such measures are used in public health interventions targeting HEPA (health-enhancing physical activity). (C) 2003 American Health Foundation and Elsevier Science (USA). All rights reserved.
Resumo:
We consider pure continuous variable entanglement with non-equal correlations between orthogonal quadratures. We introduce a simple protocol which equates these correlations and in the process transforms the entanglement onto a state with the minimum allowed number of photons. As an example we show that our protocol transforms, through unitary local operations, a single squeezed beam split on a beam splitter into the same entanglement that is produced when two squeezed beams are mixed orthogonally. We demonstrate that this technique can in principle facilitate perfect teleportation utilizing only one squeezed beam.
Resumo:
Over the past decade or so, there has been increasing demand for greater clarity about the major causes of disease and injury, how these differentially affect populations, and how they are changing. In part, this demand has been motivated by resource constraints and a realisation that better health is possible with more informed allocation of resources. At the same time, there has been a change in the way population health and its determinants are quantified, with a much closer integration of the quantitative population sciences (such as epidemiology, demography and health economics) to strengthen and broaden the evidence base for healthcare policy.
Resumo:
Este trabalho tem por objetivo identificar a eficiência técnica e as mudanças quanto à produtividade dos Institutos Federais de Educação, Ciência e Tecnologia (IF) no período de 2012 e 2013, perfazendo uma amostra formada por 19 unidades. Paralelamente a isso, procedeu-se a uma análise sobre a expansão da Rede Federal e os gastos correntes por aluno envolvido no processo de interiorização do ensino profissional e tecnológico. Como vertente teórica, discutiu-se a teoria do capital humano (SCHULTZ, 1960, 1961, 1962; BECKER, 1960; MINCER, 1958) junto às formas de investimentos em educação no Brasil e a sua política de prestação de contas. Para operacionalizar a pesquisa, verificou-se a eficiência técnica por meio da metodologia Análise Envoltória de Dados (DEA) utilizando os indicadores elaborados pela Secretaria de Educação Profissional e Tecnológica (SETEC) instituídos pelo Tribunal de Contas da União (TCU) e apresentados anualmente no Relatório de Prestação de Contas Anual. O resultado referente à eficiência demonstra que apenas 31% dos institutos federais analisados atingiram o escore de eficiência em 2012 e também em 2013. Porém, quando analisada a produtividade através do tempo com o Índice de Malmquist, é possível notar que 63% dos institutos federais estão se deslocando para a fronteira de eficiência demonstrando aumento do produto educação dentro das unidades. Adicionalmente, com o teste de diferença de médias (teste t), ocorreram evidências de que os institutos federais considerados eficientes apresentaram melhores resultados médios de concluintes e menores gastos correntes por aluno matriculado indicando que a obtenção do resultado pode não estar condicionada a maiores dispêndios financeiros.
Resumo:
Investiga o processo de transição da Escola Normal para outro espaço físico sob a forma de Instituto de Educação e os desdobramentos dessa mudança na formação de professores no Espírito Santo, segundo as diretrizes instituídas pela Lei nº. 5.692/71, durante o Regime Ditatorial Brasileiro (1964-1985). O recorte temporal inicia-se em 1971, quando ocorreu a transição, e encerra-se no ano 2000, momento em que o Instituto passa a denominar-se Escola Estadual de 2º grau Professor Fernando Duarte Rabelo. Privilegia, como interlocutores teóricos, os historiadores Carlo Ginzburg (1986, 2006), Marc Bloch (2001) e Michel de Certeau (2004) e toma, como corpus documental, propostas curriculares do Estado, portarias, matérias de jornais, fotografias de eventos realizados pela instituição e entrevistas com sujeitos que atuaram naquele espaço como professoras, diretora e aluna. As fontes foram interrogadas a partir das seguintes questões: como se deu a transição da Escola Normal D. Pedro II para o Instituto de Educação de Vitória? Que motivos levaram a essa transição? Como se configurou a formação de professores no Instituto de Educação? Quais os desdobramentos das mudanças ocorridas, em se tratando da formação de professores capixabas? Pareceram intrigantes silêncios e lacunas observados em relação à transição da Escola Normal para o Instituto de Educação e aos motivos que desencadearam essa mudança. Das falas das professoras, depreende-se que decisões sobre a transferência do espaço físico e as modificações no currículo vieram prontas, de cima para baixo. O discurso da modernização alardeia a técnica e o tecnicismo e anuncia novidades. A Escola Normal e as suas tradições passam a habitar o passado como algo que se apaga em nome do avanço técnico. Ainda que sutilmente, o cheiro do cafezinho gratuito e do mingau fizessem espargir o aroma da saudade de um outro tempo em que o lanche dos professores da Escola Normal era um encontro “solene”. Conclui-se que a abrupta descontinuidade da Escola Normal, cujo prédio passou a abrigar a atual Escola Estadual Maria Ortiz, possivelmente não se esgota nas questões de ordem técnico-pedagógica que os documentos deixam explícitas. Entretanto, tendo em vista o cronograma limitado desta pesquisa e a lacuna das fontes, não foi possível explorar outras possibilidades de resposta.
Resumo:
Due to its recent economic success, Brazil is considered an emerging country, but is it an emerging power concerning global environmental governance? This article argues that although Brazil has a sui generis profile, it can only be considered an emerging power in some environmental regimes, such as global climate change. Thus, international relations theory needs more analytical instruments to assess the impact of emerging powers in global environmental governance
Resumo:
The European Union's (EU) decision to include aviation into the Emissions Trade Scheme was heatedly contested. Countries around the world, but mainly the Brazil, Russia, India, China and South Africa group (BRICS) and the US, denounced the EU's initiate as illegal and unilateral. Following a decade of frustrated negotiations at the International Civil Aviation Organization (ICAO), this paper interrogates why such measure, in principle climate-friendly, inspired so much global resentment. I argue that concerns with competitiveness and risks of legal inconsistency are important, but insufficient elements to explain the core of the conflict. The paper suggests that the EU was strongly criticized because third countries perceived this action as an imposed solution, which fostered an environment of distrust. Therefore, I claim that the problem has more to do with a normative divide than with a substantive divergence on what should be done regarding aviation emissions. My analysis is informed by the present literature on the links between trade and climate change, but gives particular weight to first-hand information through interviews with key stakeholders. The paper is divided in three parts. First, it presents the scope of the EU directive in historical perspective. Second, it explores the EU's measure through three different angles: legal, economical and political. The final part explores some possible solutions to overcome these divergences.
Resumo:
In recent years, erratic global climate conditions have generated an incessant series of natural disasters in China. This article seeks to explore China's climate change policies. This article addresses the impacts of climate change on China's environment and China's perception, principle, objective and policy actions in response to climate change.
Resumo:
Como organização regional, o papel da União Europeia na governança global do clima enfrenta obstáculos que não se aplicam a nenhuma outra parte da Convenção-Quadro das Nações Unidas sobre a Mudança do Clima (CQNUMC) e do Protocolo de Quioto. Avaliando essa singularidade, este artigo fornece uma analise teórica e empírica de como os elementos de actorness (reconhecimento, capacidade, oportunidade e coesão) definem a participação da UE no regime internacional de mudanças climáticas.
Resumo:
This article describes the Brazilian position on forests and climate change from 1997 to 2012. It argues that it has evolved from a veto, which excluded from the climate change regime emissions from the conversion of native forests, to a proposition, as Brazil offered its approach to the international community. It explains the change with domestic developments: governance over deforestation, the emergence of new and relevant actors, and presidential diplomacy.