742 research outputs found

    Anthropogenic Space Weather

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    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

    Bentham, Not Epicurus: The Relevance of Pleasure to Studies of Drug-Involved Pain

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    There is a disproportionate focus on pain over pleasure in policy-relevant research on drugs. This is unfortunate because theories of and findings on drug-involved pleasure can be used to inform knowledge of drug-involved pain. The cross-fertilization of theories and findings is bolstered by the availability of a conceptual framework that links drug-involved pain and pleasure in a comprehensive, powerful, simple, and instrumental manner. This article proposes such a framework. It consists of four types of drug-involved pain and pleasure: drug-specific corporal; drug-related corporal; economic; and, social. This quaternary scheme is illustrated with findings from four literatures, namely those on methamphetamine use; alcohol-related sexual contact among college students; resource transfer among drug users and dealers; and, relational and communal issues related to drugs. The article concludes with implications for the field

    Integrating Omic Technologies into Aquatic Ecological Risk Assessment and Environmental Monitoring: Hurdles, Achievements, and Future Outlook

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    Background: In this commentary we present the findings from an international consortium on fish toxicogenomics sponsored by the U.K. Natural Environment Research Council (Fish Toxicogenomics—Moving into Regulation and Monitoring, held 21–23 April 2008 at the Pacific Environmental Science Centre, Vancouver, BC, Canada). Objectives: The consortium from government agencies, academia, and industry addressed three topics: progress in ecotoxicogenomics, regulatory perspectives on roadblocks for practical implementation of toxicogenomics into risk assessment, and dealing with variability in data sets. Discussion: Participants noted that examples of successful application of omic technologies have been identified, but critical studies are needed to relate molecular changes to ecological adverse outcome. Participants made recommendations for the management of technical and biological variation. They also stressed the need for enhanced interdisciplinary training and communication as well as considerable investment into the generation and curation of appropriate reference omic data. Conclusions: The participants concluded that, although there are hurdles to pass on the road to regulatory acceptance, omics technologies are already useful for elucidating modes of action of toxicants and can contribute to the risk assessment process as part of a weight-of-evidence approach

    Intradialytic versus home based exercise training in hemodialysis patients: a randomised controlled trial

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    Background: Exercise training in hemodialysis patients improves fitness, physical function, quality of life and markers of cardiovascular disease such as arterial stiffness. The majority of trials investigating this area have used supervised exercise training during dialysis (intradialytic), which may not be feasible for some renal units. The aim of this trial is to compare the effects of supervised intradialytic with unsupervised home-based exercise training on physical function and arterial stiffness

    Nitrosylation of Myoglobin and Nitrosation of Cysteine by Nitrite in a Model System Simulating Meat Curing

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    Demand is growing for meat products cured without the addition of sodium nitrite. Instead of the direct addition of nitrite to meat in formulation, nitrite is supplied by bacterial reduction of natural nitrate often added as vegetable juice/powder. However, the rate of nitrite formation in this process is relatively slow, and the total ingoing nitrite is typically less than in conventional curing processes. The objective of this study was to determine the impact of the rate of addition of nitrite and the amount of nitrite added on nitrosylation/nitrosation reactions in a model meat curing system. Myoglobin was preferentially nitrosylated as no decrease in sulfhydryl groups was found until maximum nitrosylmyoglobin color was achieved. The cysteine–myoglobin model retained more sulfhydryl groups than the cysteine-only model (p \u3c 0.05). The rate of nitrite addition did not alter nitrosylation/nitrosation reactions (p \u3e 0.05). These data suggest that the amount of nitrite but not the rate of addition impacts the nitrosylation/nitrosation reactions this syste

    Teleconsultation service to improve healthcare in rural areas: acceptance, organizational impact and appropriateness

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    Background: Nowadays, new organisational strategies should be indentified to improve primary care and its link with secondary care in terms of efficacy and timeliness of interventions thus preventing unnecessary hospital accesses and costs saving for the health system. The purpose of this study is to assess the effects of the use of teleconsultation by general practitioners in rural areas. Methods: General practitioners were provided with a teleconsultation service from 2006 to 2008 to obtain a second opinion for cardiac, dermatological and diabetic problems. Access, acceptance, organisational impact, effectiveness and economics data were collected. Clinical and access data were systematically entered in a database while acceptance and organisational data were evaluated through ad hoc questionnaires. Results: There were 957 teleconsultation contacts which resulted in access to health care services for 812 symptomatic patients living in 30 rural communities. Through the teleconsultation service, 48 general practitioners improved the appropriateness of primary care and the integration with secondary care. In fact, the level of concordance between intentions and consultations for cardiac problems was equal to 9%, in 86% of the cases the service entailed a saving of resources and in 5% of the cases, it improved the timeliness. 95% of the GPs considered the overall quality positively. For a future routine use of this service, trust in specialists, duration and workload of teleconsultations and reimbursement should be taken into account. Conclusions: Managerial and policy implications emerged mainly related to the support to GPs in the provision of high quality primary care and decision-making processes in promoting similar services

    Neighborhood socioeconomic status, Medicaid coverage and medical management of myocardial infarction: Atherosclerosis risk in communities (ARIC) community surveillance

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    <p>Abstract</p> <p>Background</p> <p>Pharmacologic treatments are efficacious in reducing post-myocardial infarction (MI) morbidity and mortality. The potential influence of socioeconomic factors on the receipt of pharmacologic therapy has not been systematically examined, even though healthcare utilization likely influences morbidity and mortality post-MI. This study aims to investigate the association between socioeconomic factors and receipt of evidence-based treatments post-MI in a community surveillance setting.</p> <p>Methods</p> <p>We evaluated the association of census tract-level neighborhood household income (nINC) and Medicaid coverage with pharmacologic treatments (aspirin, beta [β]-blockers and angiotensin converting enzyme [ACE] inhibitors; optimal therapy, defined as receipt of two or more treatments) received during hospitalization or at discharge among 9,608 MI events in the ARIC community surveillance study (1993-2002). Prevalence ratios (PR, 95% CI), adjusted for the clustering of hospitalized MI events within census tracts and within patients, were estimated using Poisson regression.</p> <p>Results</p> <p>Seventy-eight percent of patients received optimal therapy. Low nINC was associated with a lower likelihood of receiving β-blockers (0.93, 0.87-0.98) and a higher likelihood of receiving ACE inhibitors (1.13, 1.04-1.22), compared to high nINC. Patients with Medicaid coverage were less likely to receive aspirin (0.92, 0.87-0.98), compared to patients without Medicaid coverage. These findings were independent of other key covariates.</p> <p>Conclusions</p> <p>nINC and Medicaid coverage may be two of several socioeconomic factors influencing the complexities of medical care practice patterns.</p
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