3,282 research outputs found

    How robust is the evidence of an emerging or increasing female excess in physical morbidity between childhood and adolescence? Results of a systematic literature review and meta-analyses

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    For asthma and psychological morbidity, it is well established that higher prevalence among males in childhood is replaced by higher prevalence among females by adolescence. This review investigates whether there is evidence for a similar emerging female ‘excess’ in relation to a broad range of physical morbidity measures. Establishing whether this pattern is generalised or health outcome-specific will further understandings of the aetiology of gender differences in health. Databases (Medline; Embase; CINAHL; PsycINFO; ERIC) were searched for English language studies (published 1992–2010) presenting physical morbidity prevalence data for males and females, for at least two age-bands within the age-range 4–17 years. A three-stage screening process (initial sifting; detailed inspection; extraction of full papers), was followed by study quality appraisals. Of 11 245 identified studies, 41 met the inclusion criteria. Most (n = 31) presented self-report survey data (five longitudinal, 26 cross-sectional); 10 presented routinely collected data (GP/hospital statistics). Extracted data, supplemented by additional data obtained from authors of the included studies, were used to calculate odds ratios of a female excess, or female:male incident rate ratios as appropriate. To test whether these changed with age, the values were logged and regressed on age in random effects meta-regressions. These showed strongest evidence of an emerging/increasing female excess for self-reported measures of headache, abdominal pain, tiredness, migraine and self-assessed health. Type 1 diabetes and epilepsy, based on routinely collected data, did not show a significant emerging/increasing female excess. For most physical morbidity measures reviewed, the evidence broadly points towards an emerging/increasing female excess during the transition to adolescence, although results varied by morbidity measure and study design, and suggest that this may occur at a younger age than previously thought

    Late Quaternary Paleoceanography and Sedimentary Environments in Hudson Strait

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    Airgun and high resolution Huntec seismic reflection profiles are interpreted to show up to 130 m of glacial, glaciomarine and postglacial sediments overlying bedrock. In a basin at the eastern entrance to Hudson Strait most of the surficial sediment was deposited during the last déglaciation, but in western Hudson Strait multiple till sequences from previous glaciations are recognized. Five acoustic units were identified, at least three of which were penetrated with piston cores. Foraminifera of the stratigraphically deepest core in the eastern basin indicate a proximal glaciomarine environment and a likely presence of an ice shelf. A 14C date of 8060 ± 70 yBP (TO 750) on molluscan shells gives a minimum age for the top of the acoustically laminated distal glaciomarine sediments. The early postglacial foraminifera suggest a period of increased influence of offshore bottom waters restricted to the deep eastern basin. The surface sediments of all cores contain species indigenous of colder and fresher inshore waters of the present time. The ratio of 18CV16O in the benthic foraminifer Cibicides lobatulus is herein related to bottom salinity. Downcore measurements of 8'8O on C. lobatulus tests indicate bottom paleosalinities lower by about 0.5%o shortly before the dated horizon of 8000 yBP. By this time Hudson Strait was sufficiently clear of glacial ice for establishment of the present tidal regime. The lower bottom salinities indicate that tidal mixing took place between glacial meltwater leaving Hudson Bay and the offshore counterflow. This process is thought to have reduced the sharpness of the salinity difference between the offshore water and the surface plume of Laurentide meltwater as it entered the ocean.L'utilisation d'un fusil à air comprimé et d'un dispositif explosif Huntec en sismique réflexion a permis d'obtenir des profils à haute résolution révélant que des sédiments glaciaires, glaciomarins et postglaciaires d'une épaisseur de 130 m surmontent la roche en place. Un bassin, à l'entrée est du détroit d'Hudson, renferme des sédiments de surface qui, pour la plupart, se sont déposés au cours de la dernière glaciation. On a relevé cinq unités acoustiques dont au moins trois ont été explorées par carottage. Les foraminifères de la carotte extraite, dans le bassin est, à la plus grande profondeur révèlent qu'existaient un milieu glaciomarin proximal et, vraisemblablement, une plate-forme de glace flottante. La datation au 14C fait remonter à 8060 ± 70 BP (TO 750) les coquilles de mollusques et confère ainsi un âge minimal à la portion supérieure des sédiments glaciomarins distaux, laminés par acoustique. Les foraminifères du début de la période postglaciaire laissent croire que les eaux profondes du large ont pendant un certain temps exercé une influence accrue sur les fonds du bassin de l'est. Dans toutes les carottes, les sédiments de surface renferment des espèces indigènes au milieu aquatique actuel, plus froid et moins salé. Le taux 18OZ16O trouvé chez le foraminifère benthique Cibicides lobatulus se rapporte ici à la salinité des fonds aquatiques. Plus bas, dans les carottes, on a relevé sur C. lobatulus un taux de 818O qui révèle une paléosalinité plus faible d'environ 0,5%o, précédant tout juste l'horizon daté à 8000 BP. À cette époque, le détroit d'Hudson était suffisamment libre de glace pour que s'établissent les marées telles qu'on les connaît actuellement. Plus bas encore, la salinité révèle que les eaux de fusion glaciaire provenant de la baie d'Hudson se sont mêlées aux contre-courants venus du large.Mit Hilfe eines Luftgewehrs und einer Huntec Explosionsanlage mit seismischer Reflexion gewonnene Profile mit hoher Auflôsung lassen bis zu 130 m glazialer, glaziomariner und postglazialer Sedimente erkennen, die den FeIs ùberlagern, In einem Bassin am ôstlichen Eingang zur Hudson-Meerenge ist der grôsste Teil der Oberflàchensedimente wâhrend der letzten Vereisung abgelagert worden, aber in der westlichen Hudson-Meerenge lassen sich vielfache Grundmorànen-Sequenzen von frùheren Vereisungen erkennen. Fùnf akustische Einheiten wurden identifiziert, von denen mindestens drei durch Kernbohrung ergrûndet wurden. Die Foraminifera des stratigraphisch tiefsten Kerns im ôstlichen Bassin weisen auf eine proximale glaziomarine Umwelt und die môgliche Existenz einer Eisdecke. Eine 14C Datierung von 8060 ± 70 Jahren v.u.Z. (bis 750) fur Molluskenschalen ergibt ein Minimalalter fur den oberen Teil der distalen glaziomarinen Sedimente, die durch Akustik eine blàttrige Struktur bekommen haben. Die frùhen postglazialen Foraminifera lassen auf eine Période wachsenden Einflusses des kùstenfernen Tiefwassers auf das tiefe ôstliche Bassin schliessen. Die Oberflàchensedimente aller Bohrkerne enthalten Gattungen, die spezifisch fur die kàlteren und frischeren Kùstengewàsser der gegenwârtigen Zeit sind. Der Anteil an 18OZ16O in dem benthischen Foraminifer Cibicides lobatulus ist hierin mit dem Salzgehalt auf dem Grund verbunden. Tiefer im Bohrkern hat man auf C. lobatulus Werte von 818O gefunden, was einen um etwa 0.5% geringeren Grund-Palàosalzgehalt ergibt, kurz vor dem auf 8000 Jahre v.u.Z. datierten Horizont. Zu diesem Zeitpunkt war die Hudson-Meerenge von glazialem Eis ausreichend befreit, so dass sich der gegenwârtige Gezeiten-Wechsel etablieren konnte

    Morphological and physiological determinants of local adaptation to climate in Rocky Mountain butterflies

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    Flight is a central determinant of fitness in butterflies and other insects, but it is restricted to a limited range of body temperatures. To achieve these body temperatures, butterflies use a combination of morphological, behavioural and physiological mechanisms. Here, we used common garden (without direct solar radiation) and reciprocal transplant (full solar radiation) experiments in the field to determine the thermal sensitivity of flight initiation for two species of Colias butterflies along an elevation gradient in the southwestern Rocky Mountains. The mean body temperature for flight initiation in the field was lower (24–26°C) than indicated by previous studies (28–30°C) in these species. There were small but significant differences in thermal sensitivity of flight initiation between species; high-elevation Colias meadii initiated flight at a lower mean body temperature than lower-elevation Colias eriphyle. Morphological differences (in wing melanin and thoracic setae) drive body temperature differences between species and contributed strongly to differences in the time and probability of flight and air temperatures at flight initiation. Our results suggest that differences both in thermal sensitivity (15% contribution) and in morphology (85% contribution) contribute to the differences in flight initiation between the two species in the field. Understanding these differences, which influence flight performance and fitness, aids in forecasting responses to climate change

    Magnetic Order and Dynamics in an Orbitally Degenerate Ferromagnetic Insulator

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    Neutron scattering was used to determine the spin structure and the magnon spectrum of the Mott--Hubbard insulator YTiO3_3. The magnetic structure is complex, comprising substantial G-type and A-type antiferromagnetic components in addition to the predominant ferromagnetic component. The magnon spectrum, on the other hand, is gapless and nearly isotropic. We show that these findings are inconsistent with the orbitally ordered states thus far proposed for YTiO3_3 and discuss general implications for a theoretical description of exchange interactions in orbitally degenerate systems.Comment: to appear in Phys. Rev. Let

    ENVIRONMENTAL IMPACTS OF USING DESALINATED WATER IN CONCRETE PRODUCTION IN AREAS AFFECTED BY FRESHWATER SCARCITY

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    Up to 500 litres of water may be consumed at the batching plant per cubic meter of ready mix concrete, if water for washing mixing trucks and equipment is included. Demand for concrete is growing almost everywhere, regardless of local availability of freshwater. The use of freshwater for concrete production exacerbates stress on natural water resources. In water-stressed coastal countries such as Israel, desalinated seawater (DSW) is often used in the production of concrete. However, the environmental impacts of this practice have not yet been assessed. In this study the effect of using DSW on the water and carbon footprints of concrete was investigated using life cycle assessment. Water footprint results highlight the benefits of using DSW rather than freshwater to produce concrete in Israel. In contrast, because desalination is an energy intensive process, using DSW increases the greenhouse gas intensity of concrete. Nevertheless, this increase (0.27 kg CO2e/m3 concrete) is small, if compared to the life cycle greenhouse gas emissions of concrete. Our results show that using untreated seawater in the mix (transported by truck from the coast) in place of DSW, would be beneficial in terms of water and carbon footprints if the batching plant were located less than 13 km from the withdrawal point. However, use of untreated seawater increases steel reinforcement corrosion, resulting in loss of structural integrity of the reinforced concrete composite. Sustainability of replacing steel with non-corrosive materials should be explored as a way to reduce both water and carbon footprints of concrete

    PepServe: a web server for peptide analysis, clustering and visualization

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    Peptides, either as protein fragments or as naturally occurring entities are characterized by their sequence and function features. Many times the researchers need to massively manage peptide lists concerning protein identification, biomarker discovery, bioactivity, immune response or other functionalities. We present a web server that manages peptide lists in terms of feature analysis as well as interactive clustering and visualization of the given peptides. PepServe is a useful tool in the understanding of the peptide feature distribution among a group of peptides. The PepServe web application is freely available at http://bioserver-1.bioacademy.gr/Bioserver/PepServe/

    Decontamination of the hospital environment : new technologies for infection control

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    Environmental contamination is being increasingly recognized as a significant source of healthcare-associated infection (HAI). Cross-contamination of the patient from the environment can result from the direct transfer of organisms from the air and surfaces, or indirectly from the hospital environment via contact with healthcare workers or equipment. Traditional methods of environmental decontamination, including cleaning with disinfectants, and the standard infection control procedures implemented by modern Health Services, are critical to controlling the spread of potentially pathogenic microbial contaminants from environmental sources to the patient; however there is constant pressure to maintain, and indeed, improve on the standards that are in place to ensure optimal patient care. To address this issue, much research has been directed towards the development and testing of novel ‘whole-room’ environmental decontamination methods which could be used to enhance hospital hygiene, and consequently reduce the risk of HAI-acquisition from environmental sources. Gaseous methods such as the use of hydrogen peroxide, chlorine dioxide, ozone and steam, as well as ultraviolet and violet-blue visible light methods have all been laboratory tested, and to varying extents, clinically evaluated to assess their efficacy for environmental decontamination. This review article considers these different decontamination technologies, discussing their mechanism of action, antimicrobial efficacy, and advantages and limitations, with a view to providing the reader with a comprehensive overview of the technological advances being developed to reduce the levels of environmental contamination around patient areas, thus aiding in the fight against healthcare-associated infection

    Is null-point reconnection important for solar flux emergence?

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    The role of null-point reconnection in a 3D numerical MHD model of solar emerging flux is investigated. The model consists of a twisted magnetic flux tube rising through a stratified convection zone and atmosphere to interact and reconnect with a horizontal overlying magnetic field in the atmosphere. Null points appear as the reconnection begins and persist throughout the rest of the emergence, where they can be found mostly in the model photosphere and transition region, forming two loose clusters on either side of the emerging flux tube. Up to 26 nulls are present at any one time, and tracking in time shows that there is a total of 305 overall, despite the initial simplicity of the magnetic field configuration. We find evidence for the reality of the nulls in terms of their methods of creation and destruction, their balance of signs, their long lifetimes, and their geometrical stability. We then show that due to the low parallel electric fields associated with the nulls, null-point reconnection is not the main type of magnetic reconnection involved in the interaction of the newly emerged flux with the overlying field. However, the large number of nulls implies that the topological structure of the magnetic field must be very complex and the importance of reconnection along separators or separatrix surfaces for flux emergence cannot be ruled out.Comment: 26 pages, 12 figures. Added one referenc
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