469 research outputs found

    Impacts of climate variability and future climate change on harmful algal blooms and human health

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    This is the final version of the article. Available from BioMed Central via the DOI in this record.Anthropogenically-derived increases in atmospheric greenhouse gas concentrations have been implicated in recent climate change, and are projected to substantially impact the climate on a global scale in the future. For marine and freshwater systems, increasing concentrations of greenhouse gases are expected to increase surface temperatures, lower pH, and cause changes to vertical mixing, upwelling, precipitation, and evaporation patterns. The potential consequences of these changes for harmful algal blooms (HABs) have received relatively little attention and are not well understood. Given the apparent increase in HABs around the world and the potential for greater problems as a result of climate change and ocean acidification, substantial research is needed to evaluate the direct and indirect associations between HABs, climate change, ocean acidification, and human health. This research will require a multidisciplinary approach utilizing expertise in climatology, oceanography, biology, epidemiology, and other disciplines. We review the interactions between selected patterns of large-scale climate variability and climate change, oceanic conditions, and harmful algae.This work was funded in part through grants from the NSF/NIEHS Centers for Oceans and Human Health, grant numbers NSF OCE04-32479 and NIEHS P50 ES012740 (EAL), NSF OCE-0432368 and NIEHS P50 ES012736 (LEF), NIEHS P50 ES012762 and NSF OCE-0434087 (SKM, MSP). SKM, VLT and NJM also were supported in part by the West Coast Center for Oceans and Human Health (WCCOHH) as part of the NOAA Oceans and Human Health Initiative, and this is WCCOHH publication no. 26. The WCCOHH is part of the National Marine Fisheries Service's Northwest Fisheries Science Center, Seattle, Washington

    Superconducting magnet needs for the ILC

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    The ILC Reference Design Report was completed early in February 2007. The Magnet Systems Group was formed to translate magnetic field requirements into magnet designs and cost estimates for the Reference Design. As presently configured, the ILC will have more than 13,000 magnetic elements of which more than 2300 will be based on superconducting technology. This paper will describe the major superconducting magnet needs for the ILC as presently determined by the Area Systems Groups, responsible for beam line design, working with the Magnet Systems Group. The superconducting magnet components include Main Linac quadrupoles, Positron Source undulators, Damping Ring wigglers, a complex array of Final Focus superconducting elements in the Beam Delivery System, and large superconducting solenoids in the e{sup +} and e{sup -} Sources, and the Ring to Main Linac lines

    The evaluation of disability and its related factors among the elderly population in Kashan, Iran

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    <p>Abstract</p> <p>Background</p> <p>Recent literature indicates that developing countries in Asia are aging faster than other countries in the world and disability has become one of the greater public health concern in these countries. Pausity of published data on the elderly disability in Iran signifies the importance of this study designed to evaluate the disability and its related factors among the elderly population in Kashan, Iran during 2006–2007.</p> <p>Methods/Design</p> <p>A cross-sectional study is conducting on a multy-stage random sample of elderly people in Kashan ages 65 years and older. Volunteer participants were included by age 65 and older and excluded if they had the medical diagnosis of Alzhimer disease. The WHO DAS II was used as the generic disability measure in this survey. The original version of WHO DAS II was translated into Farsi according to the standardized guidelines for cross-cultural adaptation of health-related measures. Upon completion of data collection the descriptive statistics will compute all the variables. Chi-square, t-test analysis and ANOVA will be used to examine significant differences between the subgroups.</p> <p>Discussion</p> <p>This is the first research protocol to study disability among the Iranian elderly population. Presently, 80% of eligible subjects have been selected. The results of this study will help to develop more effective protocols to assist Iranian elderly population with disabilities.</p

    Childhood solid tumours in relation to infections in the community in Cumbria during pregnancy and around thetime of birth

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    In a retrospective cohort study of all 99 976 live births in Cumbria, 1975–1992, we investigated whether higher levels of community infections during the mother's pregnancy and in early life were risk factors for solid tumours (brain/spinal and other tumours), diagnosed 1975–1993 under age 15 years. Logistic regression was used to relate risk to incidence of community infections in three prenatal and two postnatal quarters. There was an increased risk of brain/spinal tumours among children exposed around or soon after birth to higher levels of community infections, in particular measles (OR for trend=2.1, 95%CI : 1.3–3.6, P=0.008) and influenza (OR for exposure=3.3, 95%CI : 1.5–7.4, P=0.005). There was some evidence of an association between exposure to infections around and soon after birth and risk of other tumours, but this may have been a chance finding. The findings are consistent with other recent epidemiological studies suggesting brain tumours may be associated with perinatal exposure to infections

    Anticipatory nausea in cyclical vomiting

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    BACKGROUND: Cyclical Vomiting Syndrome (CVS) is characterised by discrete, unexplained episodes of intense nausea and vomiting, and mainly affects children and adolescents. Comprehending Cyclical Vomiting Syndrome requires awareness of the severity of nausea experienced by patients. As a subjective symptom, nausea is easily overlooked, yet is the most distressing symptom for patients and causes many behavioural changes during attacks. CASE PRESENTATION: This first-hand account of one patient's experience of Cyclical Vomiting Syndrome shows how severe nausea contributed to the development of anticipatory nausea and vomiting (ANV), a conditioned response frequently observed in chemotherapy patients. This conditioning apparently worsened the course of the patient's disease. Anticipatory nausea and vomiting has not previously been recognised in Cyclical Vomiting Syndrome, however predictors of its occurrence in oncology patients indicate that it could complicate many cases. CONCLUSION: We suggest a model whereby untreated severe and prolonged nausea provokes anxiety about further cyclical vomiting attacks. This anxiety facilitates conditioning, thus increasing the range of triggers in a self-perpetuating manner. Effective management of the nausea-anxiety feedback loop can reduce the likelihood of anticipatory nausea and vomiting developing in other patients

    Sex-biased parental care and sexual size dimorphism in a provisioning arthropod

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    The diverse selection pressures driving the evolution of sexual size dimorphism (SSD) have long been debated. While the balance between fecundity selection and sexual selection has received much attention, explanations based on sex-specific ecology have proven harder to test. In ectotherms, females are typically larger than males, and this is frequently thought to be because size constrains female fecundity more than it constrains male mating success. However, SSD could additionally reflect maternal care strategies. Under this hypothesis, females are relatively larger where reproduction requires greater maximum maternal effort – for example where mothers transport heavy provisions to nests. To test this hypothesis we focussed on digger wasps (Hymenoptera: Ammophilini), a relatively homogeneous group in which only females provision offspring. In some species, a single large prey item, up to 10 times the mother’s weight, must be carried to each burrow on foot; other species provide many small prey, each flown individually to the nest. We found more pronounced female-biased SSD in species where females carry single, heavy prey. More generally, SSD was negatively correlated with numbers of prey provided per offspring. Females provisioning multiple small items had longer wings and thoraxes, probably because smaller prey are carried in flight. Despite much theorising, few empirical studies have tested how sex-biased parental care can affect SSD. Our study reveals that such costs can be associated with the evolution of dimorphism, and this should be investigated in other clades where parental care costs differ between sexes and species

    The Contribution of Cancer Incidence, Stage at Diagnosis and Survival to Racial Differences in Years of Life Expectancy

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    African Americans have higher cancer mortality rates than whites. Understanding the relative contribution of cancer incidence, stage at diagnosis and survival after diagnosis to the racial gap in life expectancy has important implications for directing future health disparity interventions toward cancer prevention, screening and treatment. We estimated the degree to which higher cancer mortality among African Americans is due to higher incidence rates, later stage at diagnosis or worse survival after diagnosis. Stochastic model of cancer incidence and survival after diagnosis. Surveillance and Epidemiology End Result cancer registry and National Health Interview Survey data. Life expectancy if African Americans had the same cancer incidence, stage and survival after diagnosis as white adults. African-American men and women live 1.47 and 0.91 fewer years, respectively, than whites as the result of all cancers combined. Among men, racial differences in cancer incidence, stage at diagnosis and survival after diagnosis account for 1.12 (95% CI: 0.52 to 1.36), 0.17 (95% CI: −0.03 to 0.33) and 0.21 (95% CI: 0.05 to 0.34) years of the racial gap in life expectancy, respectively. Among women, incidence, stage and survival after diagnosis account for 0.41 (95% CI: −0.29 to 0.60), 0.26 (95% CI: −0.06 to 0.40) and 0.31 (95% CI: 0.05 to 0.40) years, respectively. Differences in stage had a smaller impact on the life expectancy gap compared with the impact of incidence. Differences in cancer survival after diagnosis had a significant impact for only two cancers—breast (0.14 years; 95% CI: 0.05 to 0.16) and prostate (0.05 years; 95% CI 0.01 to 0.09). In addition to breast and colorectal cancer screening, national efforts to reduce disparities in life expectancy should also target cancer prevention, perhaps through smoking cessation, and differences in survival after diagnosis among persons with breast and prostate cancer

    X-Ray Spectroscopy of Stars

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    (abridged) Non-degenerate stars of essentially all spectral classes are soft X-ray sources. Low-mass stars on the cooler part of the main sequence and their pre-main sequence predecessors define the dominant stellar population in the galaxy by number. Their X-ray spectra are reminiscent, in the broadest sense, of X-ray spectra from the solar corona. X-ray emission from cool stars is indeed ascribed to magnetically trapped hot gas analogous to the solar coronal plasma. Coronal structure, its thermal stratification and geometric extent can be interpreted based on various spectral diagnostics. New features have been identified in pre-main sequence stars; some of these may be related to accretion shocks on the stellar surface, fluorescence on circumstellar disks due to X-ray irradiation, or shock heating in stellar outflows. Massive, hot stars clearly dominate the interaction with the galactic interstellar medium: they are the main sources of ionizing radiation, mechanical energy and chemical enrichment in galaxies. High-energy emission permits to probe some of the most important processes at work in these stars, and put constraints on their most peculiar feature: the stellar wind. Here, we review recent advances in our understanding of cool and hot stars through the study of X-ray spectra, in particular high-resolution spectra now available from XMM-Newton and Chandra. We address issues related to coronal structure, flares, the composition of coronal plasma, X-ray production in accretion streams and outflows, X-rays from single OB-type stars, massive binaries, magnetic hot objects and evolved WR stars.Comment: accepted for Astron. Astrophys. Rev., 98 journal pages, 30 figures (partly multiple); some corrections made after proof stag
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