800 research outputs found
Optimism and Physical Health: A Meta-analytic Review
Background—Prior research links optimism to physical health, but the strength of the association has not been systematically evaluated.
Purpose—The purpose of this study is to conduct a meta-analytic review to determine the strength of the association between optimism and physical health.
Methods—The findings from 83 studies, with 108 effect sizes (ESs), were included in the analyses, using random-effects models.
Results—Overall, the mean ES characterizing the relationship between optimism and physical health outcomes was 0.17, p<.001. ESs were larger for studies using subjective (versus objective) measures of physical health. Subsidiary analyses were also conducted grouping studies into those that focused solely on mortality, survival, cardiovascular outcomes, physiological markers (including immune function), immune function only, cancer outcomes, outcomes related to pregnancy, physical symptoms, or pain. In each case, optimism was a significant predictor of health outcomes or markers, all p<.001.
Conclusions—Optimism is a significant predictor of positive physical health outcomes
An application of hybrid life cycle assessment as a decision support framework for green supply chains
In an effort to achieve sustainable operations, green supply chain management has become an important area for firms to concentrate on due to its inherent involvement with all the processes that provide foundations to successful business. Modelling methodologies of product supply chain environmental assessment are usually guided by the principles of life cycle assessment (LCA). However, a review of the extant literature suggests that LCA techniques suffer from a wide range of limitations that prevent a wider application in real-world contexts; hence, they need to be incorporated within decision support frameworks to aid environmental sustainability strategies. Thus, this paper contributes in understanding and overcoming the dichotomy between LCA model development and the emerging practical implementation to inform carbon emissions mitigation strategies within supply chains. Therefore, the paper provides both theoretical insights and a practical application to inform the process of adopting a decision support framework based on a LCA methodology in a real-world scenario. The supply chain of a product from the steel industry is considered to evaluate its environmental impact and carbon ‘hotspots’. The study helps understanding how operational strategies geared towards environmental sustainability can be informed using knowledge and information generated from supply chain environmental assessments, and for highlighting inherent challenges in this process
Effect of the subjective intensity of fatigue and interoception on perceptual regulation and performance during sustained physical activity
BACKGROUND: The subjective experience of fatigue impairs an individual’s ability to sustain physical endurance performance. However, precise understanding of the specific role perceived fatigue plays in the central regulation of performance remains unclear. Here, we examined whether the subjective intensity of a perceived state of fatigue, pre-induced through prior upper body activity, differentially impacted performance and altered perceived effort and affect experienced during a sustained, isometric contraction in lower body. We also explored whether (cardiac) interoception predicted the intensity of experienced perceptual and affective responses and moderated the relationships between constructs during physical activity. METHODS: Using a repeated-measures study design, thirty male participants completed three experimental conditions, with the intensity of a pre-induced state of fatigue manipulated to evoke moderate (MOD), severe (SEV) and minimal (control; CON) intensity of perceptions prior to performance of the sustained contraction. RESULTS: Performance of the sustained contraction was significantly impaired under a perceived state of fatigue, with reductions of 10% and 14% observed in the MOD and SEV conditions, respectively. Performance impairment was accompanied by greater perceived effort and more negative affective valence reported during the contraction. However, effects were limited to comparisons to CON, with no difference evident between the two experimental trials (i.e. MOD vs. SEV). Individuals’ awareness of their accuracy in judging resting heartbeats was shown to predict the subjective intensity of fatigue experienced during the endurance task. However, interoception did not moderate the relationships evident between fatigue and both perceived effort and affective valence. CONCLUSIONS: A perceived state of fatigue limits endurance performance, influencing both how effortful activity is perceived to be and the affective experience of activity. Though awareness of interoceptive representations of bodily states may be important to the subjective experience of fatigue, interoception does not modulate the relationships between perceived fatigue and other perceptual (i.e. effort) and affective constructs
Epidemiology of Subpatent Plasmodium Falciparum Infection: Implications for Detection of Hotspots with Imperfect Diagnostics.
At the local level, malaria transmission clusters in hotspots, which may be a group of households that experience higher than average exposure to infectious mosquitoes. Active case detection often relying on rapid diagnostic tests for mass screen and treat campaigns has been proposed as a method to detect and treat individuals in hotspots. Data from a cross-sectional survey conducted in north-western Tanzania were used to examine the spatial distribution of Plasmodium falciparum and the relationship between household exposure and parasite density. Dried blood spots were collected from consenting individuals from four villages during a survey conducted in 2010. These were analysed by PCR for the presence of P. falciparum, with the parasite density of positive samples being estimated by quantitative PCR. Household exposure was estimated using the distance-weighted PCR prevalence of infection. Parasite density simulations were used to estimate the proportion of infections that would be treated using a screen and treat approach with rapid diagnostic tests (RDT) compared to targeted mass drug administration (tMDA) and Mass Drug Administration (MDA). Polymerase chain reaction PCR analysis revealed that of the 3,057 blood samples analysed, 1,078 were positive. Mean distance-weighted PCR prevalence per household was 34.5%. Parasite density was negatively associated with transmission intensity with the odds of an infection being subpatent increasing with household exposure (OR 1.09 per 1% increase in exposure). Parasite density was also related to age, being highest in children five to ten years old and lowest in those > 40 years. Simulations of different tMDA strategies showed that treating all individuals in households where RDT prevalence was above 20% increased the number of infections that would have been treated from 43 to 55%. However, even with this strategy, 45% of infections remained untreated. The negative relationship between household exposure and parasite density suggests that DNA-based detection of parasites is needed to provide adequate sensitivity in hotspots. Targeting MDA only to households with RDT-positive individuals may allow a larger fraction of infections to be treated. These results suggest that community-wide MDA, instead of screen and treat strategies, may be needed to successfully treat the asymptomatic, subpatent parasite reservoir and reduce transmission in similar settings
Breakthrough capability for the NASA Astrophysics Explorer Program: Reaching the darkest sky
We describe a mission architecture designed to substantially increase the
science capability of the NASA Science Mission Directorate (SMD) Astrophysics
Explorer Program for all AO proposers working within the near-UV to
far-infrared spectrum. We have demonstrated that augmentation of Falcon 9
Explorer launch services with a 13 kW Solar Electric Propulsion (SEP) stage can
deliver a 700 kg science observatory payload to extra-Zodiacal orbit. This new
capability enables up to ~13X increased photometric sensitivity and ~160X
increased observing speed relative to a Sun-Earth L2, Earth-trailing, or Earth
orbit with no increase in telescope aperture. All enabling SEP stage
technologies for this launch service augmentation have reached sufficient
readiness (TRL-6) for Explorer Program application in conjunction with the
Falcon 9. We demonstrate that enabling Astrophysics Explorers to reach
extra-zodiacal orbit will allow this small payload program to rival the science
performance of much larger long development time systems; thus, providing a
means to realize major science objectives while increasing the SMD Astrophysics
portfolio diversity and resiliency to external budget pressure. The SEP
technology employed in this study has strong applicability to SMD Planetary
Science community-proposed missions. SEP is a stated flight demonstration
priority for NASA's Office of the Chief Technologist (OCT). This new mission
architecture for astrophysics Explorers enables an attractive realization of
joint goals for OCT and SMD with wide applicability across SMD science
disciplines.Comment: Submitted to proceedings of the SPIE Astronomical Telescopes and
Instrumentation conference, Amsterdam, The Netherlands, July 201
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