419 research outputs found
Application of statistical process control and process capability analysis procedures in orbiter processing activities at the Kennedy Space Center
Successful ground processing at KSC requires that flight hardware and ground support equipment conform to specifications at tens of thousands of checkpoints. Knowledge of conformance is an essential requirement for launch. That knowledge of conformance at every requisite point does not, however, enable identification of past problems with equipment, or potential problem areas. This paper describes how the introduction of Statistical Process Control and Process Capability Analysis identification procedures into existing shuttle processing procedures can enable identification of potential problem areas and candidates for improvements to increase processing performance measures. Results of a case study describing application of the analysis procedures to Thermal Protection System processing are used to illustrate the benefits of the approaches described in the paper
Behavioral Mechanisms, Elevated Depressive Symptoms, and the Risk for Myocardial Infarction or Death in Individuals With Coronary Heart Disease The REGARDS (Reason for Geographic and Racial Differences in Stroke) Study
ObjectivesThe aim of this study was to determine whether behavioral mechanisms explain the association between depressive symptoms and myocardial infarction (MI) or death in individuals with coronary heart disease (CHD).BackgroundDepressive symptoms are associated with increased morbidity and mortality in individuals with CHD, but it is unclear how much behavioral mechanisms contribute to this association.MethodsThe study included 4,676 participants with a history of CHD. Elevated depressive symptoms were defined as scores ≥4 on the Center for Epidemiologic Studies Depression 4-item Scale. The primary outcome was definite/probable MI or death from any cause. Incremental proportional hazards models were constructed by adding demographic data, comorbidities, and medications and then 4 behavioral mechanisms (alcohol use, smoking, physical inactivity, and medication non-adherence).ResultsAt baseline, 638 (13.6%) participants had elevated depressive symptoms. Over a median 3.8 years of follow up, 125 of 638 (19.6%) participants with and 657 of 4,038 (16.3%) without elevated depressive symptoms had events. Higher risk of MI or death was observed for elevated depressive symptoms after adjusting for demographic data (hazard ratio [HR]: 1.41, 95% confidence interval [CI]: 1.15 to 1.72) but was no longer significant after adjusting for behavioral mechanisms (HR: 1.14, 95% CI: 0.93 to 1.40). The 4 behavioral mechanisms together significantly attenuated the risk for MI or death conveyed by elevated depressive symptoms (−36.9%, 95% CI: −18.9 to −119.1%), with smoking (−17.6%, 95% CI: −6.5% to −56.0%) and physical inactivity (−21.0%, 95% CI: −9.7% to −61.1%) having the biggest explanatory roles.ConclusionsOur findings suggest potential roles for behavioral interventions targeting smoking and physical inactivity in patients with CHD and comorbid depression
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Concurrent Stress and Depressive Symptoms Increase Risk of Myocardial Infarction or Death
BACKGROUND: Depression and stress have each been found to be associated with poor prognosis in patients with coronary heart disease. A recently offered psychosocial perfect storm conceptual model hypothesizes amplified risk will occur in those with concurrent stress and depressive symptoms. We tested this hypothesis in a large sample of US adults with coronary heart disease. METHODS AND RESULTS: Participants included 4487 adults with coronary heart disease from the Reasons for Geographic and Racial Differences in Stroke study, a prospective cohort study of 30,239 black and white adults. We conducted Cox proportional hazards regression with the composite outcome of myocardial infarction or death and adjustment for demographic, clinical, and behavioral factors. Overall, 6.1% reported concurrent high stress and high depressive symptoms at baseline. During a median 5.95 years of follow-up, 1337 events occurred. In the first 2.5 years of follow-up, participants with concurrent high stress and high depressive symptoms had increased risk for myocardial infarction or death (adjusted hazard ratio, 1.48 [95% confidence interval, 1.08-2.02]) relative to those with low stress and low depressive symptoms. Those with low stress and high depressive symptoms (hazard ratio, 0.92 [95% confidence interval, 0.66-1.28]) or high stress and low depressive symptoms (hazard ratio, 0.86 [95% confidence interval, 0.57-1.29]) were not at increased risk. The association on myocardial infarction or death was not significant after the initial 2.5 years of follow-up (hazard ratio, 0.89 [95% confidence interval, 0.65-1.22]). CONCLUSIONS: Our results provide initial support for a psychosocial perfect storm conceptual model; the confluence of depressive symptoms and stress on medical prognosis in adults with coronary heart disease may be particularly destructive in the shorter term
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Effects of Concurrent Depressive Symptoms and Perceived Stress on Cardiovascular Risk in Low‐ and High‐Income Participants: ...
Background: Psychosocial risk for cardiovascular disease (CVD) may be especially deleterious in persons with low socioeconomic status. Most work has focused on psychosocial factors individually, but emerging research suggests that the confluence of psychosocial risk may be particularly harmful. Using data from the Reasons for Geographical and Racial Differences in Stroke (REGARDS) study, we examined associations among depressive symptoms and stress, alone and in combination, and incident CVD and all‐cause mortality as a function of socioeconomic status.
Methods and Results At baseline, 22 658 participants without a history of CVD (58.8% female, 41.7% black, mean age 63.9±9.3 years) reported on depressive symptoms, stress, annual household income, and education. Participants were classified into 1 of 3 psychosocial risk groups at baseline: (1) neither depressive symptoms nor stress, (2) either depressive symptoms or stress, or (3) both depressive symptoms and stress. Cox proportional hazards models were used to predict physician‐adjudicated incident total CVD events (nonfatal myocardial infarction, nonfatal stroke, and cardiovascular death) and all‐cause mortality over a median of 7.0 years (interquartile range 5.4–8.3 years) of follow‐up. In fully adjusted models, participants with both depressive symptoms and stress had the greatest elevation in risk of developing total CVD (hazard ratio 1.48, 95% CI 1.21–1.81) and all‐cause mortality (hazard ratio 1.33, 95% CI 1.13–1.56) but only for those with low income (< 35 000) income. This pattern of results was not observed in models stratified by education.
Conclusions Findings suggest that screening for a combination of elevated depressive symptoms and stress in low‐income persons may help identify those at increased risk of incident CVD and mortality
The species diversity × fire severity relationship is hump-shaped in semiarid yellow pine and mixed conifer forests
The combination of direct human influences and the effects of climate change are resulting in altered ecological disturbance regimes, and this is especially the case for wildfires. Many regions that historically experienced low–moderate severity fire regimes are seeing increased area burned at high severity as a result of interactions between high fuel loads and climate warming with a number of negative ecological effects. While ecosystem impacts of altered fire regimes have been examined in the literature, little is known of the effects of changing fire regimes on forest understory plant diversity even though understory taxa comprise the vast majority of forest plant species and play vital roles in overall ecosystem function. We examined understory plant diversity across gradients of wildfire severity in eight large wildfires in yellow pine and mixed conifer temperate forests of the Sierra Nevada, California, USA. We found a generally unimodal hump-shaped relationship between local (alpha) plant diversity and fire severity. High-severity burning resulted in lower local diversity as well as some homogenization of the flora at the regional scale. Fire severity class, post-fire litter cover, and annual precipitation were the best predictors of understory species diversity. Our research suggests that increases in fire severity in systems historically characterized by low and moderate severity fire may lead to plant diversity losses. These findings indicate that global patterns of increasing fire size and severity may have important implications for biodiversity
An analysis of the effect of statins on the risk of Non-Hodgkin\u27s Lymphoma in the Women\u27s Health Initiative cohort.
Statins have been shown to induce a phosphoprotein signature that modifies MYC (myelocytomatosis viral oncogene) activation and to have anti-inflammatory activity that may impact the risk of Non-Hodgkin\u27s lymphoma (NHL). We analyzed the relationship between statins and risk of NHL using data from the Women\u27s Health Initiative (WHI). The study population included 161,563 postmenopausal women ages 50-79 years from which 712 cases of NHL were diagnosed after 10.8 years of follow-up. Information on statin use and other risk factors was collected by self- and interviewer-administered questionnaires. Multivariable-adjusted HR and 95% CI evaluating the relationship between statin use at baseline, as well as in a time-dependent manner and risk of NHL, were computed from Cox proportional hazards analyses. A separate analysis was performed for individual NHL subtypes: diffuse large B-Cell lymphoma (DLBCL) (n = 228), follicular lymphoma (n = 169), and small lymphocytic lymphoma (n = 74). All statistical tests were two-sided. There was no significant association between use of statins at baseline and risk of NHL (HR 0.85, 95% C.I. 0.67-1.08). However, in the multivariable-adjusted time-dependent models, statin use was associated with a borderline lower risk of NHL (HR 0.81, 95% C.I. 0.66-1.00). Considering subtypes of NHL, statin use was associated with a lower risk of DLBCL (HR 0.62, 95% C.I. 0.42-0.91). This effect was driven by lipophilic statins (HR 0.62, 95% C.I. 0.40-0.96). In the WHI, statins were associated with a lower overall risk of DLBCL, particularly attributable to lipophilic statins. These results may have impact on primary or secondary prevention of NHL, particularly DLBCL
Cardiovascular Health and Incident Cardiovascular Disease and Cancer
The American Heart Association's “Simple 7” offers a practical public health conceptualization of cardiovascular health (CVH). CVH predicts incident cardiovascular disease (CVD) in younger populations, but has not been studied in a large, diverse population of aging postmenopausal women. The extent to which CVH predicts cancer in postmenopausal women is unknown
Wildfire management in Mediterranean-type regions: paradigm change needed
PerspectiveDuring the last decades, climate and land use changes led to an increased prevalence ofmegafires in
Mediterranean-type climate regions (MCRs).Here, we argue that current wildfire management policies in
MCRs are destined to fail.Focused on fire suppression, these policies largely ignore ongoing climate warming
and landscape-scale buildup of fuels.The result is a ‘firefighting trap’ that contributes to ongoing fuel
accumulation precluding suppression under extreme fire weather, and resulting in more severe and larger
fires.We believe that a ‘business as usual’ approach to wildfire in MCRs will not solve the fire problem, and
recommend that policy and expenditures be rebalanced between suppression and mitigation of the negative
impacts of fire.This requires a paradigm shift: policy effectiveness should not be primarily measured as a
function of area burned (as it usually is), but rather as a function of avoided socio-ecological damage and lossinfo:eu-repo/semantics/publishedVersio
Prospects for Payments for Ecosystem Services in the Brazilian Pantanal: A Scenario Analysis
The present study investigates the prospects for a large-scale implementation of Payments for Ecosystem Services (PES) schemes in the Brazilian Pantanal wetland. Despite increasing environmental threats associated with development pressures and the growing interest of public and private organizations, no PES schemes are currently in place in the Pantanal. Through an exploratory scenario analysis, this article determines the prospects for PES in the area. The findings suggest that a large-scale implementation is unlikely, as this would require much higher levels of environmental awareness among local decision makers and low substitution rates of ecosystem services by technology. Furthermore, strong socioeconomic inequality between inhabitants of the Pantanal lowlands and wealthy farmers of the neighboring uplands means that potential suppliers of ecosystem services would face very high opportunity costs to participate in PES schemes. The research findings are also relevant to other environmentally sensitive regions experiencing rapid economic growth and weak environmental regulation. </jats:p
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