618 research outputs found

    Emittance Measurements Relevant to a 250 W(sub t) Class RTPV Generator for Space Exploration

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    A proposed 250 Wt Radioisotope Thermophotovoltaic (RTPV) power system for utilization in lunar exploration and the subsequent exploration of Mars is described. Details of emitter selection are outlined for use in a maintenance free power supply that is productive over a 14-year mission life. Thorough knowledge of a material s spectral emittance is essential for accurate modeling of the RTPV system. While sometimes treated as a surface effect, emittance involves radiation from within a material. This creates a complex thermal gradient which is a combination of conductive and radiative heat transfer mechanisms. Emittance data available in the literature is a valuable resource but it is particular to the test sample s physical characteristics and the test environment. Considerations for making spectral emittance measurements relevant to RTPV development are discussed. Measured spectral emittance data of refractory emitter materials is given. Planned measurement system modifications to improve relevance to the current project are presented

    Liver stiffness is not associated with short- and long-term plasma HIV RNA replication in immunocompetent patients with HIV infection and with HIV/HCV coinfection

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    Background:Human immunodeficiency virus (HIV) may be directly responsible for liver damage but there are contrasting data regarding the influence of detectable plasma viremia. We analyzed the influence of plasma HIV RNA (pHIV) detectability and of other clinical and viro-immunological variables on liver stiffness (LS) measurement in adult immunocompetent HIV-monoinfected patients and in patients coinfected with hepatitis C virus (HCV). Methods: Logistic regression analysis was performed using the value of LS>7.1 kPa as the dependent variable. A linear regression model was applied using LS measurement after log 10 transformation (lkpa) as the dependent variable and we analyzed the predicted values versus the observed lkpa values; pHIV was classified as detectable or undetectable in the 12- and 36-month study periods before LS measurement. Results: We studied 251 patients (178 with HIV monoinfection), most of whom were on antiviral treatment; 36-month study time was available for 154 subjects. The mean CD4+ cell count was 634 cells/mm3 in HIV-monoinfected patients and 606 cells/mm3 in coinfected patients. No difference in LS was found between patients with detectable or undetectable pHIV in either the 12- or the 36-month study period before transient elastography. The mean LS was higher in HIV/HCV coinfected patients (P<0.0001) than in the HIV-monoinfected subjects; lkpa was positively correlated with HCV coinfection (P<0.0001) and aspartate aminotransferase levels (P<0.0001). Detectable pHIV failed to reach significance. Eight HIV-monoinfected patients had a predicted LS measurement lower than the observed one, while eight patients had the opposite result. Conclusion: LS was not correlated with ongoing HIV replication during the 12- and 36-month study periods in immunocompetent HIV-monoinfected and HIV/HCV-coinfected patients

    Methylmercury Exposure and Adverse Cardiovascular Effects in Faroese Whaling Men

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    Background: Methylmercury (MeHg), a worldwide contaminant found in fish and seafood, has been linked to an increased risk of cardiovascular mortality. Objective: We examined 42 Faroese whaling men (30–70 years of age) to assess possible adverse effects within a wide range of MeHg exposures from consumption of pilot whale meat. Methods: We assessed exposure levels from mercury analysis of toenails and whole blood (obtained at the time of clinical examination), and a hair sample collected 7 years previously. Outcome measures included heart rate variability (HRV), blood pressure (BP), common carotid intima-media thickness (IMT), and brainstem auditory evoked potentials (BAEP). We carried out multiple regression and structural equation model (SEM) analyses to determine the confounder-adjusted effect of mercury exposure. Taking into account correlations among related measures, we categorized exposure and outcomes in groups to derive latent exposure and response variables in SEMs. We used multiple regression analysis to compare the predictive validity of individual exposure biomarkers and the latent exposure variable on individual and latent outcomes. Results: The toenail mercury concentrations varied widely and had a geometric mean of 2.0 μg/g; hair concentrations averaged about 3-fold higher. Mercury exposure was significantly associated with increased BP and IMT. This effect was reflected by SEMs, but mercury in toenails tended to be the best effect predictor. Conclusions: The results support the notion that increased MeHg exposure promotes the development of cardiovascular disease

    Genetic and environmental factors on heart rate, mean arterial pressure and carotid intima–media thickness: A longitudinal twin study

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    Background: Heart rate (HR), mean arterial pressure (MAP) and carotid intima–media thickness (cIMT) are moderately heritable cardiovascular traits, but the environmental effects on the longitudinal change of their heritability have never been investigated. Methods: 368 Italian and Hungarian twins (107 monozygotic, 77 dizygotic) underwent oscillometric measurement and B-mode sonography of bilateral carotid arteries in 2009/2010 and 2014. Within- -individual/cross-study wave, cross-twin/within-study wave and cross-twin/cross-study wave correlations were estimated, and bivariate Cholesky models were fitted to decompose the total variance at each wave and covariance between study waves into additive genetic, shared and unique environmental components. Results: For each trait, a moderate longitudinal stability was observed, with within-individual/crosswave correlations of 0.42 (95% CI: 0.33–0.51) for HR, 0.34 (95% CI: 0.24–0.43) for MAP, and 0.23 (95% CI: 0.12–0.33) for cIMT. Cross-twin/cross-wave correlations in monozygotic pairs were all significant and substantially higher than the corresponding dizygotic correlations. Genetic continuity was the main source of longitudinal stability, with across-time genetic correlations of 0.52 (95% CI: 0.29–0.71) for HR, 0.56 (95% CI: 0.31–0.81) for MAP, and 0.36 (95% CI: 0.07–0.64) for cIMT. Overlapping genetic factors explained respectively 57%, 77%, and 68% of the longitudinal covariance of the HR, MAP and cIMT traits. Conclusions: Genetic factors have a substantial role in the longitudinal change of HR, MAP and cIMT; however, the influence of unique environmental factors remains relevant. Further studies should better elucidate whether epigenetic mechanisms have a role in influencing the stability of the investigated traits over time

    Translation, interpreting, cognition: The way out of the box

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    Cognitive aspects of the translation process have become central in Translation and Interpreting Studies in recent years, further establishing the field of Cognitive Translatology. Empirical and interdisciplinary studies investigating translation and interpreting processes promise a hitherto unprecedented predictive and explanatory power. This collection contains such studies which observe behaviour during translation and interpreting. The contributions cover a vast area and investigate behaviour during translation and interpreting – with a focus on training of future professionals, on language processing more generally, on the role of technology in the practice of translation and interpreting, on translation of multimodal media texts, on aspects of ergonomics and usability, on emotions, self-concept and psychological factors, and finally also on revision and post-editing. For the present publication, we selected a number of contributions presented at the Second International Congress on Translation, Interpreting and Cognition hosted by the Tra&amp;Co Lab at the Johannes Gutenberg University of Mainz

    Translation, interpreting, cognition: The way out of the box

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    Cognitive aspects of the translation process have become central in Translation and Interpreting Studies in recent years, further establishing the field of Cognitive Translatology. Empirical and interdisciplinary studies investigating translation and interpreting processes promise a hitherto unprecedented predictive and explanatory power. This collection contains such studies which observe behaviour during translation and interpreting. The contributions cover a vast area and investigate behaviour during translation and interpreting – with a focus on training of future professionals, on language processing more generally, on the role of technology in the practice of translation and interpreting, on translation of multimodal media texts, on aspects of ergonomics and usability, on emotions, self-concept and psychological factors, and finally also on revision and post-editing. For the present publication, we selected a number of contributions presented at the Second International Congress on Translation, Interpreting and Cognition hosted by the Tra&amp;Co Lab at the Johannes Gutenberg University of Mainz

    Translation, interpreting, cognition: The way out of the box

    Get PDF
    Cognitive aspects of the translation process have become central in Translation and Interpreting Studies in recent years, further establishing the field of Cognitive Translatology. Empirical and interdisciplinary studies investigating translation and interpreting processes promise a hitherto unprecedented predictive and explanatory power. This collection contains such studies which observe behaviour during translation and interpreting. The contributions cover a vast area and investigate behaviour during translation and interpreting – with a focus on training of future professionals, on language processing more generally, on the role of technology in the practice of translation and interpreting, on translation of multimodal media texts, on aspects of ergonomics and usability, on emotions, self-concept and psychological factors, and finally also on revision and post-editing. For the present publication, we selected a number of contributions presented at the Second International Congress on Translation, Interpreting and Cognition hosted by the Tra&amp;Co Lab at the Johannes Gutenberg University of Mainz

    Translation, interpreting, cognition: The way out of the box

    Get PDF
    Cognitive aspects of the translation process have become central in Translation and Interpreting Studies in recent years, further establishing the field of Cognitive Translatology. Empirical and interdisciplinary studies investigating translation and interpreting processes promise a hitherto unprecedented predictive and explanatory power. This collection contains such studies which observe behaviour during translation and interpreting. The contributions cover a vast area and investigate behaviour during translation and interpreting – with a focus on training of future professionals, on language processing more generally, on the role of technology in the practice of translation and interpreting, on translation of multimodal media texts, on aspects of ergonomics and usability, on emotions, self-concept and psychological factors, and finally also on revision and post-editing. For the present publication, we selected a number of contributions presented at the Second International Congress on Translation, Interpreting and Cognition hosted by the Tra&amp;Co Lab at the Johannes Gutenberg University of Mainz

    Translation, interpreting, cognition: The way out of the box

    Get PDF
    Cognitive aspects of the translation process have become central in Translation and Interpreting Studies in recent years, further establishing the field of Cognitive Translatology. Empirical and interdisciplinary studies investigating translation and interpreting processes promise a hitherto unprecedented predictive and explanatory power. This collection contains such studies which observe behaviour during translation and interpreting. The contributions cover a vast area and investigate behaviour during translation and interpreting – with a focus on training of future professionals, on language processing more generally, on the role of technology in the practice of translation and interpreting, on translation of multimodal media texts, on aspects of ergonomics and usability, on emotions, self-concept and psychological factors, and finally also on revision and post-editing. For the present publication, we selected a number of contributions presented at the Second International Congress on Translation, Interpreting and Cognition hosted by the Tra&amp;Co Lab at the Johannes Gutenberg University of Mainz
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