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Quantifying uncertainty in the biospheric carbon flux for England and Wales   总被引:1,自引:0,他引:1  
Summary.  A crucial issue in the current global warming debate is the effect of vegetation and soils on carbon dioxide (CO2) concentrations in the atmosphere. Vegetation can extract CO2 through photosynthesis, but respiration, decay of soil organic matter and disturbance effects such as fire return it to the atmosphere. The balance of these processes is the net carbon flux. To estimate the biospheric carbon flux for England and Wales, we address the statistical problem of inference for the sum of multiple outputs from a complex deterministic computer code whose input parameters are uncertain. The code is a process model which simulates the carbon dynamics of vegetation and soils, including the amount of carbon that is stored as a result of photosynthesis and the amount that is returned to the atmosphere through respiration. The aggregation of outputs corresponding to multiple sites and types of vegetation in a region gives an estimate of the total carbon flux for that region over a period of time. Expert prior opinions are elicited for marginal uncertainty about the relevant input parameters and for correlations of inputs between sites. A Gaussian process model is used to build emulators of the multiple code outputs and Bayesian uncertainty analysis is then used to propagate uncertainty in the input parameters through to uncertainty on the aggregated output. Numerical results are presented for England and Wales in the year 2000. It is estimated that vegetation and soils in England and Wales constituted a net sink of 7.55 Mt C (1 Mt C = 1012 g of carbon) in 2000, with standard deviation 0.56 Mt C resulting from the sources of uncertainty that are considered.  相似文献   
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This article contributes to the ongoing debate on the economic determinants of fertility behavior by addressing the role of job insecurity in couples’ intentions concerning parenthood and its timing. It starts from the hypothesis that cultural values moderate individuals’ reactions to job insecurity and the way it is related to family formation. With a systematic thematic content analysis of a set of semi-structured interviews with childless men and women around the age of 30 in eastern and western Germany, we are able to show that there are substantial differences in the consequences of job insecurity on intentions to have a first child. In western Germany, a relatively secure job career is expected to precede family formation, and this sequence of transitions is rather rigid, whereas in eastern Germany job security and family formation are thought of and practiced as parallel investments. We suggest that the lack of convergence in family formation patterns between eastern and western Germany after the unification of the country in 1990 is partially related to different attitudes toward job insecurity in the two contexts.  相似文献   
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Previous research shows that work ability of nurses decreases with age. In our study we therefore addressed the following questions: Do successful ageing strategies at work in terms of selection, optimization, and compensation (SOC) support the work ability of nurses? Does SOC mediate the relationship between job control (i.e., decision opportunities at work) and work ability? Does the mediation differ between age-groups? 438 nurses (Age Range 21-63 years) completed a questionnaire in the course of an employee survey. Results show that SOC is positively related with work ability. The positive effect of job control on work ability is significantly mediated by SOC. There are stronger mediating effects for elder nurses than for younger nurses. Results indicate that the interplay of job control and SOC at work helps to maintain the work ability of nurses in nursing care.  相似文献   
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Interaction with employees is essential for organizational leaders. If executives do not communicate well, important processes like giving feedback, setting goals or guiding change processes can nevertheless lead to resistance from subordinates when communication is received as more threatening than challenging. Conveying messages in ways that provoke challenge instead of threat appraisals can be achieved via employee-oriented communication, but this may require taking peoples’ differing motivational orientations into account. This is because motivational orientations partially determine what kind of information is motivating to us, which goals and strategies we prefer, and how we deal with changes. In this regard, Regulatory Focus Theory (Higgins 1997) compares the gain- and success-sensitive promoter with the loss- and failure-sensitive preventer. This article applies this theory to the organizational psychological context and outlines practical implications for managers. The goal of the piece is to provide managers a leadership tool that acknowledges the diversity of peoples’ motivational styles and by that revealing a need-oriented and more efficient way in communication with subordinates.  相似文献   
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In recent years the welfare sector has encountered numerous and often challenging changes, such as marketisation, New Public Management, and demands for evidence-based practices. These changes can be seen as a shift between the two logics of creating and maintaining authority, and as a movement from occupational towards organizational professionalism. Perhaps the most important difference between these logics is that, in occupational professionalism, authority is built on trust in the professionals’ education and ethics, whilst in organizational professionalism it is grounded in regulation and control expressed, for example, in rules, regulations, and routines. The article focuses on the ways in which two groups of social workers in Swedish social welfare offices orient themselves towards organizational and occupational professionalism in constructing themselves and in the construction of each other, as well as the work that is carried out by each group. The aim is thus to elaborate on what these logics mean at the micro-level. In this respect, pertinent questions such as ‘How are they to be understood?’, ‘Regarded from the point of view of micro politics, what do these logics mean?’ and ‘How are the logics internalized by the social workers?’ are posed.  相似文献   
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This paper describes an experimental study investigating pilots' manual flying skills. In today's line oriented flight training, basic flying skills are neglected frequently. So, the study examines the manual flying skills of commercial airline pilots under the influence of several performance shaping factors like training, practice or fatigue in a landing scenario. The landing phase shows a disproportionate high percentage of aircraft accidents and it is typically flown by hand. The study is to be undertaken with randomly selected pilots in a full motion flight simulator to ensure a high validity of the results.  相似文献   
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