63 research outputs found

    Testing, Modeling and System Impact of Metabolic Heat Regenerated Temperature Swing Adsorption

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    Metabolic heat regenerated temperature swing adsorption (MTSA) technology is being developed for removal and rejection of carbon dioxide (CO2) and heat from a portable life support system (PLSS) to the Martian environment. Previously, hardware was built and tested to demonstrate using heat from simulated, dry ventilation loop gas to affect the temperature swing required to regenerate an adsorbent used for CO2 removal. New testing has been performed using a moist, simulated ventilation loop gas to demonstrate the effects of water condensing and freezing in the heat exchanger during adsorbent regeneration. In addition, thermal models of the adsorbent during regeneration were modified and calibrated with test data to capture the effect of the CO2 heat of desorption. Finally, MTSA impact on PLSS design was evaluated by performing thermal balances assuming a specific PLSS architecture. Results using NASA s Extravehicular Activity System Sizing Analysis Tool (EVAS_SAT), a PLSS system evaluation tool, are presented

    A special gift we bestow on you for being representative of us: Considering leader

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    Two experiments tested hypotheses, derived from social identity and self-categorization theories, regarding the attribution of charisma to leaders. In Experiment I (N = 203), in-group prototypical leaders were attributed greater levels of charisma and were perceived to be more persuasive than in-group non-prototypical leaders. In Experiment 2 (N = 220), leaders described with in-group stereotypical characteristics were attributed relatively high levels of charisma regardless of their group-oriented versus exchange rhetoric. Leaders described with out-group stereotypical characteristics, however, had to employ group-oriented rhetoric to be attributed relatively high levels of charisma. We conclude that leadership emerges from being representative of 'us'; charisma may, indeed, be a special gift, but it is one bestowed on group members by group members for being representative of, rather than distinct from, the group itself. © 2006 The British Psychological Society

    Conducting Online Expert panels: a feasibility and experimental replicability study

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    <p>Abstract</p> <p>Background</p> <p>This paper has two goals. First, we explore the feasibility of conducting online expert panels to facilitate consensus finding among a large number of geographically distributed stakeholders. Second, we test the replicability of panel findings across four panels of different size.</p> <p>Method</p> <p>We engaged 119 panelists in an iterative process to identify definitional features of Continuous Quality Improvement (CQI). We conducted four parallel online panels of different size through three one-week phases by using the RAND's ExpertLens process. In Phase I, participants rated potentially definitional CQI features. In Phase II, they discussed rating results online, using asynchronous, anonymous discussion boards. In Phase III, panelists re-rated Phase I features and reported on their experiences as participants.</p> <p>Results</p> <p>66% of invited experts participated in all three phases. 62% of Phase I participants contributed to Phase II discussions and 87% of them completed Phase III. Panel disagreement, measured by the mean absolute deviation from the median (MAD-M), decreased after group feedback and discussion in 36 out of 43 judgments about CQI features. Agreement between the four panels after Phase III was fair (four-way kappa = 0.36); they agreed on the status of five out of eleven CQI features. Results of the post-completion survey suggest that participants were generally satisfied with the online process. Compared to participants in smaller panels, those in larger panels were more likely to agree that they had debated each others' view points.</p> <p>Conclusion</p> <p>It is feasible to conduct online expert panels intended to facilitate consensus finding among geographically distributed participants. The online approach may be practical for engaging large and diverse groups of stakeholders around a range of health services research topics and can help conduct multiple parallel panels to test for the reproducibility of panel conclusions.</p

    Toward a Unified Framework of Perceived Negative Leader Behaviors Insights from French and British Educational Sectors

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    In this paper, we challenge the commonly held assumption that actors in the education sector are largely ethical, and that there is therefore little need to scrutinize leader behaviors in this sector. We also overcome past scholars’ tendencies to either focus selectively on positive leader behaviors, or to stay content with categorizing leader behaviors into effective and ineffective (if at all they do focus on negative leader behaviors). Using data (Critical Incidents) from three case studies previously conducted in eight British and French academic establishments, we show that not only do negative leader behaviors abound in the education sector, but they can also be differentiated into three types: (1) behaviors emanating from leaders’ lack of functional skills i.e., ineffective behaviors, (2) behaviors emanating from leaders’ insouciance toward harming the organization and its members i.e., dysfunctional behaviors, and (3) behaviors emanating from leaders’ lack of honesty, integrity, ethicality, and transparency i.e., unauthentic behaviors. We enrich current understanding on ineffective, dysfunctional, and unauthentic leader behaviors, and offer a unified (yet differentiated) framework of negative leader behaviors in the academic sector. Since each type of negative behavior emanates from different motivational drivers, different measures are required to curb them. These are also discussed. A comparison of our findings with those from leadership studies in other sectors reveals that negative leader behaviors in the education sector are quite similar to those in other sectors

    Cardiac fibroblast sub-types in vitro reflect pathological cardiac remodeling in vivo

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    Many heart diseases are associated with fibrosis, but it is unclear whether different types of heart disease correlate with different subtypes of activated fibroblasts and to which extent such diversity is modeled during in vitro activation of primary cardiac fibroblasts. Analyzing the expression of 82 fibrosis related genes in 65 heart failure (HF) patients, we identified a panel of 12 genes clearly distinguishing HF patients better from healthy controls than measurement of the collagen-related hydroxyproline content. A subcluster enriched in ischemic HF was recognized, but not for diabetes, high BMI, or gender. Single-cell transcriptomic analysis of in vitro activated mouse cardiac fibroblasts distinguished 6 subpopulations, including a contractile Acta2(high) precursor population, which was predicted by time trajectory analysis to develop into Acta2(low) subpopulations with high production of extracellular matrix molecules. The 12 gene profile identified in HF patients showed highest similarity to the fibroblast subset with the strongest expression of extracellular matrix molecules. Population markers identified were furthermore able to clearly cluster different disease stages in a murine model for myocardial infarct. These data suggest that major features of cardiac fibroblast activation in heart failure patients, in murine heart disease models, and in cell culture of primary murine cardiac fibroblast are shared

    Parental unemployment and youth life satisfaction: The moderating roles of satisfaction with family life

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    Abstract While Europe is slowly recovering from the economic recession, its effects on labour markets are still visible. The number of jobless families has increased and previous research has shown that unemployment can affect the wellbeing of both parents and their children. In this study we explored the links between parental unemployment and youth life satisfaction by considering the potential moderating roles played by satisfaction with family life and perceived family wealth. We used descriptive statistics, correlations, simple moderation and moderated moderation models of regression on data from a representative sample of 3937 Portuguese students (Mage = 13.9 years; SD ± 1.7; 48 % boys). Results showed that the negative effects of parental unemployment on youth life satisfaction were moderated by youth perceived satisfaction with family life but not by perceived wealth. This suggested that during family unemployment, young people satisfied with their family life are less vulnerable to the negative effects of parental unemployment on their life satisfaction. The relationship between parental unemployment and youth well-being requires further research, especially during periods of labour market crisis.Fundação para a Ciência e a Tecnologia (FCT
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