4,492 research outputs found

    SDSS J080434.20+510349.2: Eclipsing WZ Sge-Type Dwarf Nova with Multiple Rebrightenings

    Full text link
    We observed the 2006 superoutburst of SDSS J080434.20+510349.2 during its plateau phase, rebrightening phase, and post-superoutburst final decline. We found that this object is a grazing eclipsing system with a period of 0.0590048(2) d. Well-defined eclipses were only observed during the late stage of the superoutburst plateau and the depth decreased during the subsequent stages. We determined the superhump period during the superoutburst plateau to be 0.059539(11) d, giving a fractional superhump excess of 0.90(2)%. During the rebrightening and post-superoutburst phases, persisting superhumps with periods longer than those of superhumps during the plateau phase: 0.059632(6) during the rebrightening phase and 0.05969(4) d during the final fading. This phenomenon is very well in line with the previously known long-period "late superhumps" in GW Lib, V455 And and WZ Sge. The amplitudes of orbital humps between different states of rebrightenings suggest that these humps do not arise from the classical hot spot, but are more likely a result of projection effect in a high-inclination system. There was no clear evidence for the enhanced hot spot during the rebrightening phase. We also studied previously reported "mini-outbursts" in the quiescent state and found evidence that superhumps were transiently excited during these mini-outbursts. The presence of grazing eclipses and distinct multiple rebrightenings in SDSS J080434.20+510349.2 would provide a unique opportunity to understanding the mechanism of rebrightenings in WZ Sge-type dwarf novae.Comment: 14 pages, 12 figures, PASJ accepte

    Increasing microbiological confirmation and changing epidemiology of meningococcal disease on Merseyside, England

    Get PDF
    ObjectivesTo determine, for the last 5 years in children on Merseyside with clinical meningococcal disease (MCD), the impact on diagnostic yield of newer bacteriologic methods; bacterial antigen detection (AD) and polymerase chain reaction (PCR).MethodsProspective data collection at Royal Liverpool Children's Hospital over two epochs: 1 September 1992 to 30 April 1994 (epoch A, n = 126) and 17 November 1997 to 15 September 1998 (epoch B, n = 85).ResultsEpoch Awas compared with epoch B. Diagnosis was confirmed by detection of meningococci in 78 of 126 (61.9%) versus 64 of 85 (75.3%, P = 0.04), but with a significantly lower rate of positive blood and cerebrospinal fluid culture in the later epoch. The proportion of cases receiving penicillin pretreatment was unchanged at 32%, but the proportion undergoing lumbar puncture decreased significantly. Median ages were higher in epoch B: 1.7 years versus 2.49 years (P = 0.013, Mann-Whitney). There was a significant increase in the proportion of cases due to serogroup C (14/78 (18%) versus 30/64 (46.9%), P = 0.001).ConclusionsCulture detection of meningococci from children with MCD has reduced, as less lumbar punctures are done. However, improved diagnosis by PCR and AD has increased microbiological confirmation overall. Serogroup C disease and the median age of cases continue to rise

    Beyond the control of the care home: A meta‐ethnography of qualitative studies of Infection Prevention and Control in residential and nursing homes for older people

    Get PDF
    OBJECTIVE: This study aimed to develop interpretive insights concerning Infection Prevention and Control (IPC) in care homes for older people. DESIGN: This study had a meta‐ethnography design. DATA SOURCES: Six bibliographic databases were searched from inception to May 2020 to identify the relevant literature. REVIEW METHODS: A meta‐ethnography was performed. RESULTS: Searches yielded 652 records; 15 were included. Findings were categorized into groups: The difficulties of enacting IPC measures in the care home environment; workload as an impediment to IPC practice; the tension between IPC and quality of life for care home residents; and problems dealing with medical services located outside the facility including diagnostics, general practice and pharmacy. Infection was revealed as something seen to lie ‘outside’ the control of the care home, whether according to origins or control measures. This could help explain the reported variability in IPC practice. Facilitators to IPC uptake involved repetitive training and professional development, although such opportunities can be constrained by the ways in which services are organized and delivered. CONCLUSIONS: Significant challenges were revealed in implementing IPC in care homes including staffing skills, education, workloads and work routines. These challenges cannot be properly addressed without resolving the tension between the objectives of maintaining resident quality of life while enacting IPC practice. Repetitive staff training and professional development with parallel organisational improvements have prospects to enhance IPC uptake in residential and nursing homes. PATIENT OR PUBLIC CONTRIBUTION: A carer of an older person joined study team meetings and was involved in writing a lay summary of the study findings

    Diver-generated photomosaics as a tool for monitoring temperate rocky reef ecosystems

    Get PDF
    Robust monitoring data provides important information on ecosystem responses to anthropogenic stressors; however, traditional monitoring methodologies, which rely heavily on time in the field, are resource intensive. Consequently, trade-offs between data metrics captured and overall spatial and temporal coverage are necessary to fit within realistic monitoring budgets and timeframes. Recent advances in remote sensing technology have reduced the severity of these trade-offs by providing cost-effective, high-quality data at greatly increased temporal and spatial scales. Structure-from-motion (SfM) photogrammetry, a form of remote sensing utilising numerous overlapping images, is well established in terrestrial applications and can be a key tool for monitoring changes in marine benthic ecosystems, which are particularly vulnerable to anthropogenic stressors. Diver-generated photomosaics, an output of SfM photogrammetry, are increasingly being used as a benthic monitoring tool in clear tropical waters, but their utility within temperate rocky reef ecosystems has received less attention. Here we compared benthic monitoring data collected from virtual quadrats placed on photomosaics with traditional diver-based field quadrats to understand the strengths and weaknesses of using photomosaics for monitoring temperate rocky reef ecosystems. In north-eastern New Zealand, we evaluated these methods at three sites where sea urchin barrens were prevalent. We found key metrics (sea urchin densities, macroalgae canopy cover and benthic community cover) were similar between the two methods, but data collected via photogrammetry were quicker, requiring significantly less field time and resources, and allowed greater spatial coverage than diver-based field quadrats. However, the use of photomosaics was limited by high macroalgal canopy cover, shallow water and rough sea state which reduced stitching success and obscured substratum and understory species. The results demonstrate that photomosaics can be used as a resource efficient and robust method for effectively assessing and monitoring key metrics on temperate rocky reef ecosystems

    Transcriptomics and proteomics reveal two waves of translational repression during the maturation of malaria parasite sporozoites.

    Get PDF
    Plasmodium sporozoites are transmitted from infected mosquitoes to mammals, and must navigate the host skin and vasculature to infect the liver. This journey requires distinct proteomes. Here, we report the dynamic transcriptomes and proteomes of both oocyst sporozoites and salivary gland sporozoites in both rodent-infectious Plasmodium yoelii parasites and human-infectious Plasmodium falciparum parasites. The data robustly define mRNAs and proteins that are upregulated in oocyst sporozoites (UOS) or upregulated in infectious sporozoites (UIS) within the salivary glands, including many that are essential for sporozoite functions in the vector and host. Moreover, we find that malaria parasites use two overlapping, extensive, and independent programs of translational repression across sporozoite maturation to temporally regulate protein expression. Together with gene-specific validation experiments, these data indicate that two waves of translational repression are implemented and relieved at different times during sporozoite maturation, migration and infection, thus promoting their successful development and vector-to-host transition

    Determination of alpha_s using Jet Rates at LEP with the OPAL detector

    Full text link
    Hadronic events produced in e+e- collisions by the LEP collider and recorded by the OPAL detector were used to form distributions based on the number of reconstructed jets. The data were collected between 1995 and 2000 and correspond to energies of 91 GeV, 130-136 GeV and 161-209 GeV. The jet rates were determined using four different jet-finding algorithms (Cone, JADE, Durham and Cambridge). The differential two-jet rate and the average jet rate with the Durham and Cambridge algorithms were used to measure alpha(s) in the LEP energy range by fitting an expression in which order alpah_2s calculations were matched to a NLLA prediction and fitted to the data. Combining the measurements at different centre-of-mass energies, the value of alpha_s (Mz) was determined to be alpha(s)(Mz)=0.1177+-0.0006(stat.)+-0.0012$(expt.)+-0.0010(had.)+-0.0032(theo.) \.Comment: 40 pages, 17 figures, Submitted to Euro. Phys. J.

    Colour reconnection in e+e- -> W+W- at sqrt(s) = 189 - 209 GeV

    Full text link
    The effects of the final state interaction phenomenon known as colour reconnection are investigated at centre-of-mass energies in the range sqrt(s) ~ 189-209 GeV using the OPAL detector at LEP. Colour reconnection is expected to affect observables based on charged particles in hadronic decays of W+W-. Measurements of inclusive charged particle multiplicities, and of their angular distribution with respect to the four jet axes of the events, are used to test models of colour reconnection. The data are found to exclude extreme scenarios of the Sjostrand-Khoze Type I (SK-I) model and are compatible with other models, both with and without colour reconnection effects. In the context of the SK-I model, the best agreement with data is obtained for a reconnection probability of 37%. Assuming no colour reconnection, the charged particle multiplicity in hadronically decaying W bosons is measured to be (nqqch) = 19.38+-0.05(stat.)+-0.08 (syst.).Comment: 30 pages, 9 figures, Submitted to Euro. Phys. J.
    • 

    corecore