1,688 research outputs found
Anthropogenic Space Weather
Anthropogenic effects on the space environment started in the late 19th
century and reached their peak in the 1960s when high-altitude nuclear
explosions were carried out by the USA and the Soviet Union. These explosions
created artificial radiation belts near Earth that resulted in major damages to
several satellites. Another, unexpected impact of the high-altitude nuclear
tests was the electromagnetic pulse (EMP) that can have devastating effects
over a large geographic area (as large as the continental United States). Other
anthropogenic impacts on the space environment include chemical release ex-
periments, high-frequency wave heating of the ionosphere and the interaction of
VLF waves with the radiation belts. This paper reviews the fundamental physical
process behind these phenomena and discusses the observations of their impacts.Comment: 71 pages, 35 figure
Energy and Climate Implications for Agricultural Nutrient Use Efficiency
Energy and climate change are beginning to dominate the global political agenda and will drive policy formation that will shape the future of agriculture. Energy issues threaten national security and economic stability, as well as access to low-cost nutrient inputs for agriculture. Climate change has the potential to cause serious disruption to agricultural productivity. Paradoxically, nutrient use in agriculture to increase crop yields has the potential to negatively impact climate. This chapter will discuss recent and future energy and climate trends, the relationships between agricultural nutrient use efficiency and biofuels, and how global land limitations will shape agriculture in the future. Comparative gross energy yield and nitrogen use efficiency for ethanol production from crop residue, switchgrass, grain sorghum, sweet sorghum, and corn grain is presented, showing small differences in nitrogen use efficiency, but large differences in gross energy yields. In addition to considering the need to increase crop productivity to meet the demands of a growing population and bioenergy, agricultural nutrient use efficiency must be reconsidered with respect to the important energy and climate challenges shaping agriculture today
Tobacco cessation Clinical Practice Guideline use by rural and urban hospital nurses: a pre-implementation needs assessment
<p>Abstract</p> <p>Background</p> <p>This study was a pre-program evaluation of hospital-based nurses' tobacco intervention beliefs, confidence, training, practice, and perceived intervention barriers and facilitators. It was designed to identify relevant information prior to implementing tobacco cessation guidelines across a large northern rural region, home to 1 urban and 12 rural hospitals.</p> <p>Methods</p> <p>This cross-sectional survey was distributed by nurse managers to nurses in the 13 hospitals and returned by nurses (N = 269) via mail to the researchers.</p> <p>Results</p> <p>Nurses were somewhat confident providing cessation interventions, agreed they should educate patients about tobacco, and 94% perceived tobacco counselling as part of their role. Although only 11% had received cessation training, the majority reported intervening, even if seldom--91% asked about tobacco-use, 96% advised quitting, 89% assessed readiness to quit, 88% assisted with quitting, and 61% arranged post-discharge follow-up. Few performed any of these steps frequently, and among those who intervened, the majority spent < 10 minutes. The most frequently performed activities tended to take the least amount of time, while the more complex activities (e.g., teaching coping skills and pharmacotherapy education) were seldom performed. Patient-related factors (quitting benefits and motivation) encouraged nurses to intervene and work-related factors discouraged them (time and workloads). There were significant rural-urban differences--more rural nurses perceived intervening as part of their role, reported having more systems in place to support cessation, reported higher confidence for intervening, and more frequently assisted patients with quitting and arranged follow-up.</p> <p>Conclusions</p> <p>The findings showed nurses' willingness to engage in tobacco interventions. What the majority were doing maps onto the recommended minimum of 1-3 minutes but intervention frequency and follow-up were suboptimal. The rural-urban differences suggest a need for more research to explore the strengths of rural practice which could potentially inform approaches to smoking cessation in urban hospitals.</p
Subclinical Thyroid Disorders and Cognitive Performance Among Adolescents in the United States
Background: Thyroid hormone plays a crucial role in the growth and function of the central nervous system. The purpose of the study was to examine the relationships between the status of subclinical thyroid conditions and cognition among adolescents in the United States. Methods: Study sample included 1,327 adolescents 13 to 16 years old who participated in the Third National Health and Nutrition Examination Survey (NHANES III). Serum thyroxine (T4) and thyroid stimulating hormone (TSH) were measured and subclinical hypothyroidism, subclinical hyperthyroidism, and euthyroid groups were defined. Cognitive performance was assessed using the subscales of the Wide Range Achievement Test-Revised (WRAT-R) and the Wechsler Intelligence Scale for Children-Revised (WISC-R). The age-corrected scaled scores for arithmetic, reading, block design, and digit span were derived from the cognitive assessments. Results: Subclinical hypothyroidism was found in 1.7% and subclinical hyperthyroidism was found in 2.3% of the adolescents. Cognitive assessment scores on average tended to be lower in adolescents with subclinical hyperthyroidism and higher in those with subclinical hypothyroidism than the score for the euthyroid group. Adolescents with subclinical hypothyroidism had significantly better scores in block design and reading than the euthyroid subjects even after adjustment for a number of variables including sex, age, and family income level. Conclusion: Subclinical hypothyroidism was associated with better performance in some areas of cognitive functions while subclinical hyperthyroidism could be a potential risk factor
Assessing the distribution of volatile organic compounds using land use regression in Sarnia, "Chemical Valley", Ontario, Canada
<p>Abstract</p> <p>Background</p> <p>Land use regression (LUR) modelling is proposed as a promising approach to meet some of the challenges of assessing the intra-urban spatial variability of ambient air pollutants in urban and industrial settings. However, most of the LUR models to date have focused on nitrogen oxides and particulate matter. This study aimed at developing LUR models to predict BTEX (benzene, toluene, ethylbenzene, m/p-xylene and o-xylene) concentrations in Sarnia, 'Chemical Valley', Ontario, and model the intra-urban variability of BTEX compounds in the city for a community health study.</p> <p>Method</p> <p>Using Organic Vapour Monitors, pollutants were monitored at 39 locations across the city of Sarnia for 2 weeks in October 2005. LUR models were developed to generate predictor variables that best estimate BTEX concentrations.</p> <p>Results</p> <p>Industrial area, dwelling counts, and highways adequately explained most of the variability of BTEX concentrations (<it>R</it><sup>2</sup>: 0.78 – 0.81). Correlations between measured BTEX compounds were high (> 0.75). Although most of the predictor variables (e.g. land use) were similar in all the models, their individual contributions to the models were different.</p> <p>Conclusion</p> <p>Yielding potentially different health effects than nitrogen oxides and particulate matter, modelling other air pollutants is essential for a better understanding of the link between air pollution and health. The LUR models developed in these analyses will be used for estimating outdoor exposure to BTEX for a larger community health study aimed at examining the determinants of health in Sarnia.</p
Trends in socioeconomic inequalities in smoking prevalence, consumption, initiation, and cessation between 2001 and 2008 in the Netherlands. Findings from a national population survey
<p>Abstract</p> <p>Background</p> <p>Widening of socioeconomic status (SES) inequalities in smoking prevalence has occurred in several Western countries from the mid 1970’s onwards. However, little is known about a widening of SES inequalities in smoking consumption, initiation and cessation.</p> <p>Methods</p> <p>Repeated cross-sectional population surveys from 2001 to 2008 (n ≈ 18,000 per year) were used to examine changes in smoking prevalence, smoking consumption (number of cigarettes per day), initiation ratios (ratio of ever smokers to all respondents), and quit ratios (ratio of former smokers to ever smokers) in the Netherlands. Education level and income level were used as indicators of SES and results were reported separately for men and women.</p> <p>Results</p> <p>Lower educated respondents were significantly more likely to be smokers, smoked more cigarettes per day, had higher initiation ratios, and had lower quit ratios than higher educated respondents. Income inequalities were smaller than educational inequalities and were not all significant, but were in the same direction as educational inequalities. Among women, educational inequalities widened significantly between 2001 and 2008 for smoking prevalence, smoking initiation, and smoking cessation. Among low educated women, smoking prevalence remained stable between 2001 and 2008 because both the initiation and quit ratio increased significantly. Among moderate and high educated women, smoking prevalence decreased significantly because initiation ratios remained constant, while quit ratios increased significantly. Among men, educational inequalities widened significantly between 2001 and 2008 for smoking consumption only.</p> <p>Conclusions</p> <p>While inequalities in smoking prevalence were stable among Dutch men, they increased among women, due to widening inequalities in both smoking cessation and initiation. Both components should be addressed in equity-oriented tobacco control policies.</p
Understanding why adult participants at the World Senior Games choose a healthy diet
BACKGROUND: Identifying those seniors most likely to adopt a healthy diet, the relative importance they place on certain perceived benefits associated with a healthy diet, and whether these perceived benefits are associated with selected demographic, lifestyle, and health history variables is important for directing effective dietary health promotion programs. METHODS: Analyses are based on a cross-sectional convenience sample of 670 seniors aged 50 years and older at the 2002 World Senior Games in St. George, Utah. Data are assessed using frequencies, bivariate analysis, analysis of variance, and multiple logistic regression analysis. RESULTS: Fruit and vegetable consumption was significantly higher in individuals aged 70–79, in women, in those not overweight or obese, and in those with excellent overall health. Dietary fiber consumption was significantly higher in former or never smokers, current and previous alcohol drinkers, in those not overweight or obese, and in those with excellent health. The strongest motivating factors identified for adopting a healthy diet were to improve the quality of life, to increase longevity, and to prevent disease. Of intermediate importance were the need to feel a sense of control and to satisfy likes or dislikes. Least important were the desire to experience a higher level of spirituality, social reasons, and peer acceptance. CONCLUSION: Seniors who have adopted a healthy diet are more likely to have chosen that behavior because of perceived health benefits than for personal and social benefits. Overweight or obese individuals and those in poor health were less likely to be engaged in healthy eating behavior and require special attention by dieticians and public health professionals
The quality of preventive health care delivered to adults: results from a cross-sectional study in Southern Italy
<p>Abstract</p> <p>Background</p> <p>It is assumed that providing clinical preventive services to patients can identify or detect early important causes of adult mortality. The aim of this study was to quantify access to preventive services in Southern Italy and to assess whether and how the provision of preventive care was influenced by any specific characteristics of patients.</p> <p>Methods</p> <p>In a cross-sectional study adults aged 18 years and over attending primary care physician (PCP) offices located in Southern Italy were interviewed from June through December 2007. Quality indicators of preventive health care developed from RAND's Quality Assessment Tools and Behavioral Risk Factor Surveillance System (BRFSS) were used. Multivariate analysis was performed to identify and to assess the role of patients' characteristics on delivery of clinical preventive services.</p> <p>Results</p> <p>A total of 1467 subjects participated in the study. Excepting blood pressure preventive check (delivered to 64.4% of eligible subjects) and influenza vaccination (recommended to 90.2% of elderly), the rates of delivery of clinical preventive services were low across all measures, particularly for screening and counseling on health habits. Rates for providing cancer screening tests at recommended times were 21.3% for colonoscopy, 51.5% for mammography and 52.4% for Pap smear. Statistical analysis showed clear disparities in the provision of clinical preventive services associated with age, gender, education level, perceived health status, current health conditions and primary care access measures.</p> <p>Conclusions</p> <p>There is overwhelming need to develop and implement effective interventions to improve delivery of routine clinical preventive services.</p
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