910 research outputs found

    Traditional Cardiovascular Risk Factors as Predictors of Cardiovascular Events in the U.S. Astronaut Corps

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    Risk prediction equations from the Framingham Heart Study are commonly used to predict the absolute risk of myocardial infarction (MI) and coronary heart disease (CHD) related death. Predicting CHD-related events in the U.S. astronaut corps presents a monumental challenge, both because astronauts tend to live healthier lifestyles and because of the unique cardiovascular stressors associated with being trained for and participating in space flight. Traditional risk factors may not hold enough predictive power to provide a useful indicator of CHD risk in this unique population. It is important to be able to identify individuals who are at higher risk for CHD-related events so that appropriate preventive care can be provided. This is of special importance when planning long duration missions since the ability to provide advanced cardiac care and perform medical evacuation is limited. The medical regimen of the astronauts follows a strict set of clinical practice guidelines in an effort to ensure the best care. The purpose of this study was to evaluate the utility of the Framingham risk score (FRS), low-density lipoprotein (LDL) and high-density lipoprotein levels, blood pressure, and resting pulse as predictors of CHD-related death and MI in the astronaut corps, using Cox regression. Of these factors, only two, LDL and pulse at selection, were predictive of CHD events (HR(95% CI)=1.12 (1.00-1.25) and HR(95% CI)=1.70 (1.05-2.75) for every 5-unit increase in LDL and pulse, respectively). Since traditional CHD risk factors may lack the specificity to predict such outcomes in astronauts, the development of a new predictive model, using additional measures such as electron-beam computed tomography and carotid intima-media thickness ultrasound, is planned for the future

    Detection of Gravitational Redshift on the Solar Disk by Using Iodine-Cell Technique

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    With an aim to examine whether the predicted solar gravitational redshift can be observationally confirmed under the influence of the convective Doppler shift due to granular motions, we attempted measuring the absolute spectral line-shifts on a large number of points over the solar disk based on an extensive set of 5188-5212A region spectra taken through an iodine-cell with the Solar Domeless Telescope at Hida Observatory. The resulting heliocentric line shifts at the meridian line (where no rotational shift exists), which were derived by finding the best-fit parameterized model spectrum with the observed spectrum and corrected for the earth's motion, turned out to be weakly position-dependent as ~ +400 m/s near the disk center and increasing toward the limb up to ~ +600 m/s (both with a standard deviation of sigma ~ 100 m/s). Interestingly, this trend tends to disappear when the convectiveshift due to granular motions (~-300 m/s at the disk center and increasing toward the limb; simulated based on the two-component model along with the empirical center-to-limb variation) is subtracted, finally resulting in the averaged shift of 698 m/s (sigma = 113 m/s). Considering the ambiguities involved in the absolute wavelength calibration or in the correction due to convective Doppler shifts (at least several tens m/s, or more likely up to <~100 m/s), we may regard that this value is well consistent with the expected gravitational redshift of 633 m/s.Comment: 28 pages, 12 figures, electronic materials as ancillary data (table3, table 4, ReadMe); accepted for publication in Solar Physic

    Circulation and Oxygen Distribution in the Tropical Atlantic Cruise No. 80, Leg 1; October 26 to November 23, 2009 Mindelo (Cape Verde) to Mindelo (Cape Verde)

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    METEOR cruise 80/1 was a contribution to the SFB 754 “Climate-Biogeochemistry Interactions in the Tropical Ocean”. Shipboard, glider and moored observations are used to study the temporal and spatial variability of physical and biogeochemical parameters within the oxygen minimum zone (OMZ) of the tropical North Atlantic. As part of the BMBF “Nordatlantik” project, it further focuses on the equatorial current system including the Equatorial Undercurrent (EUC) and intermediate currents below. During the cruise, hydrographic station observations were performed using a CTD/O2 rosette, including water sampling for salinity, oxygen, nutrients and other biogeochemical tracers. Underway current measurements were successfully carried out with the 75 kHz ADCP borrowed from R/V POSEIDON during the first part of the cruise, and R/V METEOR’s 38 kHz ADCP during the second part. During M80/1, an intensive mooring program was carried out with 8 mooring recoveries and 8 mooring deployments. Right at the beginning of the cruise, a multidisciplinary mooring near the Cape Verde Islands was recovered and redeployed. Within the framework of SFB 754, two moorings with CTD/O2 profilers were recovered and redeployed with other instrumentation in the center and at the southern rim of the OMZ of the tropical North Atlantic. The equatorial mooring array as part of BMBF “North Atlantic” project consists of 5 current meter moorings along 23°W between 2°S and 2°N. It is aimed at quantifying the variability of the thermocline water supply toward the equatorial cold tongue which develops east of 10°W during boreal summer. Several glider missions were performed during the cruise. One glider was recovered that was deployed two months earlier. Another glider was deployed for two short term missions, near the equator for about 8 days and near 8°N for one day. This glider was equipped with a new microstructure probe in addition to standard sensors, i.e. CTD/O2, chlorophyll and turbidity

    Molecular characterization of Miraflores peach variety and relatives using SSRs

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    The definitive version is published in: http://www.sciencedirect.com/science/journal/03044238Some traditional peach varieties, originated from the region of Aragón (Spain), were analysed by SSRs (Simple Sequence Repeats). The aim of this research was to characterize 19 clones related to ‘Miraflores’ variety, with unknown pedigrees, to assess their genetic diversity and to elucidate their possible relationships with 10 traditional peach varieties. Twenty SSR primer pairs with high levels of polymorphism, which have been previously developed for peach, were used in this study. A total of 46 alleles were obtained for all the microsatellites studied, ranging from one to six alleles per locus, with a mean value of 2.3 alleles per locus. Fourteen SSRs were polymorphic in the set of varieties studied and permitted to distinguish 16 different genotypes out of the 30 initially studied, although fourteen ‘Miraflores’ clones showed identical gel profiles. The genetic distance matrix was used to construct Neighbor joining cluster and to perform principal coordinate analysis which allowed the arrangement of all the genotypes according to their genetic relationships. The genetic relationships among these traditional peach varieties, and in particular among ‘Miraflores’ clones are discussed. The obtained results confirm that microsatellite markers are very useful for these purposes.We are thankful to T.N. Zhebentyayeva and G.L. Reighard for helpful comments on the manuscript. This research was funded by CICYT (Comisión Interministerial de Ciencia y Tecnología, AGL2002-04219 and AGL 2005-05533), INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentación, RF03-014-C2), Bilateral Spain-France (HF03-273) and DGA (A28, A44) projects and co-funded by the European Regional Development Fund. M. Bouhadida was supported by a fellowship from the AECI (Agencia Española de Cooperación Internacional) of the Spanish Ministry of Foreign Affairs.Peer reviewe

    The impact of the Calman–Hine report on the processes and outcomes of care for Yorkshire's colorectal cancer patients

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    The 1995 Calman–Hine plan outlined radical reform of the UK's cancer services with the aim of improving outcomes and reducing inequalities in NHS cancer care. Its main recommendation was to concentrate care into the hands of site-specialist, multi-disciplinary teams. This study aimed to determine if the implementation of Calman–Hine cancer teams was associated with improved processes and outcomes of care for colorectal cancer patients. The design included longitudinal survey of 13 colorectal cancer teams in Yorkshire and retrospective study of population-based data collected by the Northern and Yorkshire Cancer Registry and Information Service. The population was all colorectal cancer patients diagnosed and treated in Yorkshire between 1995 and 2000. The main outcome measures were: variations in the use of anterior resection and preoperative radiotherapy in rectal cancer, chemotherapy in Dukes stage C and D patients, and five-year survival. Using multilevel models, these outcomes were assessed in relation to measures of the extent of Calman–Hine implementation throughout the study period, namely: (i) each team's degree of adherence to the Manual of Cancer Service Standards (which outlines the specification of the ‘ideal’ colorectal cancer team) and (ii) the extent of site specialisation of each team's surgeons. Variation was observed in the extent to which the colorectal cancer teams in Yorkshire had conformed to the Calman–Hine recommendations. An increase in surgical site specialisation was associated with increased use of preoperative radiotherapy (OR=1.43, 95% CI=1.04–1.98, P<0.04) and anterior resection (OR=1.43, 95% CI=1.16–1.76, P<0.01) in rectal cancer patients. Increases in adherence to the Manual of Cancer Service Standards was associated with improved five-year survival after adjustment for the casemix factors of age, stage of disease, socioeconomic status and year of diagnosis, especially for colon cancer (HR=0.97, 95% CI=0.94–0.99 P<0.01). There was a similar trend of improved survival in relation to increased surgical site specialisation for rectal cancer, although the effect was not statistically significant (HR=0.93, 95% CI=0.84–1.03, P=0.15). In conclusion, the extent of implementation of the Calman–Hine report has been variable and its recommendations are associated with improvements in processes and outcomes of care for colorectal cancer patients

    Combined pesticide exposure severely affects individual- and colony-level traits in bees

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    Reported widespread declines of wild and managed insect pollinators have serious consequences for global ecosystem services and agricultural production [1–3]. Bees contribute approximately 80% of insect pollination, so it is important to understand and mitigate the causes of current declines in bee populations [4–6]. Recent studies have implicated the role of pesticides in these declines, as exposure to these chemicals has been associated with changes in bee behaviour [7–11] and reductions in colony queen production [12]. However, the key link between changes in individual behaviour and the consequent impact at the colony level has not been shown. Social bee colonies depend on the collective performance of many individual workers. Thus, although field-level pesticide concentrations can have subtle or sublethal effects at the individual level [8], it is not known whether bee societies can buffer such effects or whether it results in a severe cumulative effect at the colony level. Furthermore, widespread agricultural intensification means that bees are exposed to numerous pesticides when foraging [13–15], yet the possible combinatorial effects of pesticide exposure have rarely been investigated [16,17]. Here we show that chronic exposure of bumblebees to two pesticides (neonicotinoid and pyrethroid) at concentrations that could approximate field-level exposure impairs natural foraging behaviour and increases worker mortality leading to significant reductions in brood development and colony success. We found that worker foraging performance, particularly pollen collecting efficiency, was significantly reduced with observed knock-on effects for forager recruitment, worker losses and overall worker productivity. Moreover, we provide evidence that combinatorial exposure to pesticides increases the propensity of colonies to fail

    Doubling of marine dinitrogen-fixation rates based on direct measurements

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    Biological dinitrogen fixation provides the largest input of nitrogen to the oceans, therefore exerting important control on the ocean’s nitrogen inventory and primary productivity. Nitrogen-isotope data fromocean sediments suggest that the marine-nitrogen inventory has been balanced for the past 3,000 years (ref. 4). Producing a balanced marine-nitrogenbudget based on direct measurements has proved difficult, however, with nitrogen loss exceeding the gain from dinitrogen fixation by approximately 200 TgNyr-1 (refs 5, 6). Here we present data from the Atlantic Ocean and show that the most widely used method of measuring oceanic N2-fixation rates underestimates the contribution of N2-fixing microorganisms (diazotrophs) relative to a newly developed method. Using molecular techniques to quantify the abundance of specific clades of diazotrophs in parallel with rates of 15N2 incorporation into particulate organic matter, we suggest that the difference between N2-fixation rates measured with the established method and those measured with the new method8 can be related to the composition of the diazotrophic community. Our data show that in areas dominated by Trichodesmium, the established method underestimatesN2-fixation rates by an averageof 62%. We also find that the newly developed method yields N2-fixation rates more than six times higher than those from the established method when unicellular, symbiotic cyanobacteria and c-proteobacteria dominate the diazotrophic community. On the basis of average areal rates measured over the Atlantic Ocean, we calculated basin-wide N2-fixation rates of 14+/-1TgNyr-1 and 24+/-1TgNyr-1 for the established and new methods, respectively. If our findings can be extrapolated to other ocean basins, this suggests that the global marine N2-fixation rate derived from direct measurements may increase from 103+/-8TgNyr-1 to 177+/-8TgNyr-1, and that the contribution of N2 fixers other than Trichodesmium is much more significant than was previously thought

    Neonicotinoid Insecticides and Their Impacts on Bees: A Systematic Review of Research Approaches and Identification of Knowledge Gaps

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    It has been suggested that the widespread use of neonicotinoid insecticides threatens bees, but research on this topic has been surrounded by controversy. In order to synthesize which research approaches have been used to examine the effect of neonicotinoids on bees and to identify knowledge gaps, we systematically reviewed research on this subject that was available on the Web of Science and PubMed in June 2015. Most of the 216 primary research studies were conducted in Europe or North America (82%), involved the neonicotinoid imidacloprid (78%), and concerned the western honey bee Apis mellifera (75%). Thus, little seems to be known about neonicotinoids and bees in areas outside Europe and North America. Furthermore, because there is considerable variation in ecological traits among bee taxa, studies on honey bees are not likely to fully predict impacts of neonicotinoids on other species. Studies on crops were dominated by seed-treated maize, oilseed rape (canola) and sunflower, whereas less is known about potential side effects on bees from the use of other application methods on insect pollinated fruit and vegetable crops, or on lawns and ornamental plants. Laboratory approaches were most common, and we suggest that their capability to infer real-world consequences are improved when combined with information from field studies about realistic exposures to neonicotinoids. Studies using field approaches often examined only bee exposure to neonicotinoids and more field studies are needed that measure impacts of exposure. Most studies measured effects on individual bees. We suggest that effects on the individual bee should be linked to both mechanisms at the sub-individual level and also to the consequences for the colony and wider bee populations. As bees are increasingly facing multiple interacting pressures future research needs to clarify the role of neonicotinoids in relative to other drivers of bee declines
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