457 research outputs found

    A pulsating auroral X-ray hot spot on Jupiter

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    Jupiter's X-ray aurora has been thought to be excited by energetic sulphur and oxygen ions precipitating from the inner magnetosphere into the planet's polar regions(1-3). Here we report high-spatial-resolution observations that demonstrate that most of Jupiter's northern auroral X-rays come from a 'hot spot' located significantly poleward of the latitudes connected to the inner magnetosphere. The hot spot seems to be fixed in magnetic latitude and longitude and occurs in a region where anomalous infrared(4-7) and ultraviolet(8) emissions have also been observed. We infer from the data that the particles that excite the aurora originate in the outer magnetosphere. The hot spot X-rays pulsate with an approximately 45-min period, a period similar to that reported for high-latitude radio and energetic electron bursts observed by near-Jupiter spacecraft(9,10). These results invalidate the idea that jovian auroral X-ray emissions are mainly excited by steady precipitation of energetic heavy ions from the inner magnetosphere. Instead, the X-rays seem to result from currently unexplained processes in the outer magnetosphere that produce highly localized and highly variable emissions over an extremely wide range of wavelengths.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62624/1/4151000a.pd

    Sugary interfaces mitigate contact damage where stiff meets soft

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    The byssal threads of the fan shell Atrina pectinata are non-living functional materials intimately associated with living tissue, which provide an intriguing paradigm of bionic interface for robust load-bearing device. An interfacial load-bearing protein (A. pectinata foot protein-1, apfp-1) with L-3,4-dihydroxyphenylalanine (DOPA)-containing and mannose-binding domains has been characterized from Atrina's foot. apfp-1 was localized at the interface between stiff byssus and the soft tissue by immunochemical staining and confocal Raman imaging, implying that apfp-1 is an interfacial linker between the byssus and soft tissue, that is, the DOPA-containing domain interacts with itself and other byssal proteins via Fe3(+)-DOPA complexes, and the mannose-binding domain interacts with the soft tissue and cell membranes. Both DOPA-and sugar-mediated bindings are reversible and robust under wet conditions. This work shows the combination of DOPA and sugar chemistry at asymmetric interfaces is unprecedented and highly relevant to bionic interface design for tissue engineering and bionic devices

    Sexual Health and Well-being Among Older Men and Women in England: Findings from the English Longitudinal Study of Ageing

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    We describe levels of sexual activity, problems with sexual functioning, and concerns about sexual health among older adults in the English Longitudinal Study of Ageing (ELSA), and associations with age, health, and partnership factors. Specifically, a total of 6,201 core ELSA participants (56 % women) aged 50 to >90 completed a comprehensive Sexual Relationships and Activities questionnaire (SRA-Q) included in ELSA Wave 6 (2012/13). The prevalence of reporting any sexual activity in the last year declined with age, with women less likely than men at all ages to report being sexually active. Poorer health was associated with lower levels of sexual activity and a higher prevalence of problems with sexual functioning, particularly among men. Difficulties most frequently reported by sexually active women related to becoming sexually aroused (32 %) and achieving orgasm (27 %), while for men it was erectile function (39 %). Sexual health concerns most commonly reported by women related to their level of sexual desire (11 %) and frequency of sexual activities (8 %). Among men it was level of sexual desire (15 %) and erectile difficulties (14 %). While the likelihood of reporting sexual health concerns tended to decrease with age in women, the opposite was seen in men. Poor sexual functioning and disagreements with a partner about initiating and/or feeling obligated to have sex were associated with greater concerns about and dissatisfaction with overall sex life. Levels of sexual activity decline with increasing age, although a sizable minority of men and women remain sexually active until the eighth and ninth decades of life. Problems with sexual functioning were relatively common, but overall levels of sexual health concerns were much lower. Sexually active men reported higher levels of concern with their sexual health and sexual dissatisfaction than women at all ages. Older peoples’ sexual health should be managed, not just in the context of their age, gender, and general health, but also within their existing sexual relationship

    Search for time-dependent B0s - B0s-bar oscillations using a vertex charge dipole technique

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    We report a search for B0s - B0s-bar oscillations using a sample of 400,000 hadronic Z0 decays collected by the SLD experiment. The analysis takes advantage of the electron beam polarization as well as information from the hemisphere opposite that of the reconstructed B decay to tag the B production flavor. The excellent resolution provided by the pixel CCD vertex detector is exploited to cleanly reconstruct both B and cascade D decay vertices, and tag the B decay flavor from the charge difference between them. We exclude the following values of the B0s - B0s-bar oscillation frequency: Delta m_s < 4.9 ps-1 and 7.9 < Delta m_s < 10.3 ps-1 at the 95% confidence level.Comment: 18 pages, 3 figures, replaced by version accepted for publication in Phys.Rev.D; results differ slightly from first versio

    A point mutation in cpsE renders Streptococcus pneumoniae nonencapsulated and enhances its growth, adherence and competence.

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    BACKGROUND: The polysaccharide capsule is a major virulence factor of the important human pathogen Streptococcus pneumoniae. However, S. pneumoniae strains lacking capsule do occur. RESULTS: Here, we report a nasopharyngeal isolate of Streptococcus pneumoniae composed of a mixture of two phenotypes; one encapsulated (serotype 18C) and the other nonencapsulated, determined by serotyping, electron microscopy and fluorescence isothiocyanate dextran exclusion assay.By whole genome sequencing, we demonstrated that the phenotypes differ by a single nucleotide base pair in capsular gene cpsE (C to G change at gene position 1135) predicted to result in amino acid change from arginine to glycine at position 379, located in the cytoplasmic, enzymatically active, region of this transmembrane protein. This SNP is responsible for loss of capsule production as the phenotype is transferred with the capsule operon. The nonencapsulated variant is superior in growth in vitro and is also 117-fold more adherent to and more invasive into Detroit 562 human epithelial cells than the encapsulated variant.Expression of six competence pathway genes and one competence-associated gene was 11 to 34-fold higher in the nonencapsulated variant than the encapsulated and transformation frequency was 3.7-fold greater. CONCLUSIONS: We identified a new single point mutation in capsule gene cpsE of a clinical S. pneumoniae serotype 18C isolate sufficient to cause loss of capsule expression resulting in the co-existence of the encapsulated and nonencapsulated phenotype. The mutation caused phenotypic changes in growth, adherence to epithelial cells and transformability. Mutation in capsule gene cpsE may be a way for S. pneumoniae to lose its capsule and increase its colonization potential

    Pharmacist provision of primary health care: a modified Delphi validation of pharmacists' competencies

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    <p>Abstract</p> <p>Background</p> <p>Pharmacists have expanded their roles and responsibilities as a result of primary health care reform. There is currently no consensus on the core competencies for pharmacists working in these evolving practices. The aim of this study was to develop and validate competencies for pharmacists' effective performance in these roles, and in so doing, document the perceived contribution of pharmacists providing collaborative primary health care services.</p> <p>Methods</p> <p>Using a modified Delphi process including assessing perception of the frequency and criticality of performing tasks, we validated competencies important to primary health care pharmacists practising across Canada.</p> <p>Results</p> <p>Ten key informants contributed to competency drafting; thirty-three expert pharmacists replied to a second round survey. The final primary health care pharmacist competencies consisted of 34 elements and 153 sub-elements organized in seven CanMeds-based domains. Highest importance rankings were allocated to the domains of care provider and professional, followed by communicator and collaborator, with the lower importance rankings relatively equally distributed across the manager, advocate and scholar domains.</p> <p>Conclusions</p> <p>Expert pharmacists working in primary health care estimated their most important responsibilities to be related to direct patient care. Competencies that underlie and are required for successful fulfillment of these patient care responsibilities, such as those related to communication, collaboration and professionalism were also highly ranked. These ranked competencies can be used to help pharmacists understand their potential roles in these evolving practices, to help other health care professionals learn about pharmacists' contributions to primary health care, to establish standards and performance indicators, and to prioritize supports and education to maximize effectiveness in this role.</p

    Distribution and Habitat Associations of Billfish and Swordfish Larvae across Mesoscale Features in the Gulf of Mexico

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    Ichthyoplankton surveys were conducted in surface waters of the northern Gulf of Mexico (NGoM) over a three-year period (2006–2008) to determine the relative value of this region as early life habitat of sailfish (Istiophorus platypterus), blue marlin (Makaira nigricans), white marlin (Kajikia albida), and swordfish (Xiphias gladius). Sailfish were the dominant billfish collected in summer surveys, and larvae were present at 37.5% of the stations sampled. Blue marlin and white marlin larvae were present at 25.0% and 4.6% of the stations sampled, respectively, while swordfish occurred at 17.2% of the stations. Areas of peak production were detected and maximum density estimates for sailfish (22.09 larvae 1000 m−2) were significantly higher than the three other species: blue marlin (9.62 larvae 1000 m−2), white marlin (5.44 larvae 1000 m−2), and swordfish (4.67 larvae 1000 m−2). The distribution and abundance of billfish and swordfish larvae varied spatially and temporally, and several environmental variables (sea surface temperature, salinity, sea surface height, distance to the Loop Current, current velocity, water depth, and Sargassum biomass) were deemed to be influential variables in generalized additive models (GAMs). Mesoscale features in the NGoM affected the distribution and abundance of billfish and swordfish larvae, with densities typically higher in frontal zones or areas proximal to the Loop Current. Habitat suitability of all four species was strongly linked to physicochemical attributes of the water masses they inhabited, and observed abundance was higher in slope waters with lower sea surface temperature and higher salinity. Our results highlight the value of the NGoM as early life habitat of billfishes and swordfish, and represent valuable baseline data for evaluating anthropogenic effects (i.e., Deepwater Horizon oil spill) on the Atlantic billfish and swordfish populations
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