SU(3) Breaking Effects in Hyperon Semi-Leptonic Decays and the extraction of F and D

The analysis of hyperon semi-leptonic decay data is re-examined in the light of a recent suggestion that SU(3) symmetry breaking effects may be taken into account by applying a correction to the $F/D$ ratio obtained via naive linear extrapolation in the hyperon masses. Comparison is made with the physically better motivated approach of applying so-called centre-of-mass corrections. This study (including all available data) reveals certain short-comings of the former of the above treatments, highlights some interesting aspects of this type of analysis and attempts to pinpoint the decay data that might usefully be improved. A tantalising result of the SU(3) breaking analysis performed here is that the magnitude of recoil correction required by the data corresponds closely to that required for the standard explanation of the reduction of \gA from its SU(6) value of 5/3. We also comment on other recent suggestions for taking into account the effects of SU(3) breaking. Finally a few remarks are made on the relevance for predicting the flavour non-singlet contribution to the proton $g_1$ and the Ellis-Jaffe sum rule.Comment: 12 pages, latex, no figures. Removed extended ascii set characters in the source file that were being corrupted by some mailer

Marburg Virus Infection Detected in a Common African Bat

Marburg and Ebola viruses can cause large hemorrhagic fever (HF) outbreaks with high case fatality (80–90%) in human and great apes. Identification of the natural reservoir of these viruses is one of the most important topics in this field and a fundamental key to understanding their natural history. Despite the discovery of this virus family almost 40 years ago, the search for the natural reservoir of these lethal pathogens remains an enigma despite numerous ecological studies. Here, we report the discovery of Marburg virus in a common species of fruit bat (Rousettus aegyptiacus) in Gabon as shown by finding virus-specific RNA and IgG antibody in individual bats. These Marburg virus positive bats represent the first naturally infected non-primate animals identified. Furthermore, this is the first report of Marburg virus being present in this area of Africa, thus extending the known range of the virus. These data imply that more areas are at risk for MHF outbreaks than previously realized and correspond well with a recently published report in which three species of fruit bats were demonstrated to be likely reservoirs for Ebola virus

SU(3) Breaking in Hyperon Beta Decays: a Prediction for Xi^0 -> Sigma^+ e nu-bar

On the basis of a previous analysis of hyperon semi-leptonic decay data, a prediction is presented for g_1/f_1 in the Xi^0 -> Sigma^+ e nu-bar beta-decay. The analysis takes into account SU(3) breaking in this sector via the inclusion of mass-driven corrections. A rather precise measurement of the above channel by the KTeV experiment at Fermilab will shortly be available. Since the dependence on the SU(3) parameters, F and D, is identical to that of the neutron beta-decay, such a measurement will provide a rather stringent test of SU(3) and the models used to describe its violation in these decays. The prediction given here for the above decay is g_1/f_1=1.17, which leads to a rate of 0.80 x 10^6 s^-1 and thus a branching fraction of 2.3 x 10^-4.Comment: LaTeX, 7 pages, uses acromake, cite and topcapt packages. Non-printing extended ascii characters replaced plus minor correction

Preventing childhood scalds within the home: overview of systematic reviews and a systematic review of primary studies

Objective: To synthesise and evaluate the evidence of the effectiveness of interventions to prevent scalds in children. Methods: An overview of systematic reviews (SR) and a SR of primary studies were performed evaluating interventions to prevent scalds in children. A comprehensive literature search was conducted covering various resources up to October 2012. Experimental and controlled observational studies reporting scald injuries, safety practices and safety equipment use were included. Results: Fourteen systematic reviews and 39 primary studies were included. There is little evidence that interventions are effective in reducing the incidence of scalds in children. More evidence was found that inventions are effective in promoting safe hot tap water temperature, especially when home safety education, home safety checks and discounted or free safety equipment including thermometers and thermostatic mixing valves were provided. No consistent evidence was found for the effectiveness of interventions on the safe handling of hot food or drinks nor improving kitchen safety practices. Conclusion: Education, home safety checks along with thermometers or thermostatic mixing valves should be promoted to reduce tap water scalds. Further research is needed to evaluate the effectiveness of interventions on scald injuries and to disentangle the effects of multifaceted interventions on scald injuries and safety practices

Keeping children safe: a multicentre programme of research to increase the evidence base for preventing unintentional injuries in the home in the under-fives

Background: Unintentional injuries among 0- to 4-year-olds are a major public health problem incurring substantial NHS, individual and societal costs. However, evidence on the effectiveness and cost-effectiveness of preventative interventions is lacking. Aim: To increase the evidence base for thermal injury, falls and poisoning prevention for the under-fives. Methods: Six work streams comprising five multicentre case–control studies assessing risk and protective factors, a study measuring quality of life and injury costs, national surveys of children’s centres, interviews with children’s centre staff and parents, a systematic review of barriers to, and facilitators of, prevention and systematic overviews, meta-analyses and decision analyses of home safety interventions. Evidence from these studies informed the design of an injury prevention briefing (IPB) for children’s centres for preventing fire-related injuries and implementation support (training and facilitation). This was evaluated by a three-arm cluster randomised controlled trial comparing IPB and support (IPB+), IPB only (no support) and usual care. The primary outcome was parent-reported possession of a fire escape plan. Evidence from all work streams subsequently informed the design of an IPB for preventing thermal injuries, falls and poisoning. Results: Modifiable risk factors for falls, poisoning and scalds were found. Most injured children and their families incurred small to moderate health-care and non-health-care costs, with a few incurring more substantial costs. Meta-analyses and decision analyses found that home safety interventions increased the use of smoke alarms and stair gates, promoted safe hot tap water temperatures, fire escape planning and storage of medicines and household products, and reduced baby walker use. Generally, more intensive interventions were the most effective, but these were not always the most cost-effective interventions. Children’s centre and parental barriers to, and facilitators of, injury prevention were identified. Children’s centres were interested in preventing injuries, and believed that they could prevent them, but few had an evidence-based strategic approach and they needed support to develop this. The IPB was implemented by children’s centres in both intervention arms, with greater implementation in the IPB+ arm. Compared with usual care, more IPB+ arm families received advice on key safety messages, and more families in each intervention arm attended fire safety sessions. The intervention did not increase the prevalence of fire escape plans [adjusted odds ratio (AOR) IPB only vs. usual care 0.93, 95% confidence interval (CI) 0.58 to 1.49; AOR IPB+ vs. usual care 1.41, 95% CI 0.91 to 2.20] but did increase the proportion of families reporting more fire escape behaviours (AOR IPB only vs. usual care 2.56, 95% CI 1.38 to 4.76; AOR IPB+ vs. usual care 1.78, 95% CI 1.01 to 3.15). IPB-only families were less likely to report match play by children (AOR 0.27, 95% CI 0.08 to 0.94) and reported more bedtime fire safety routines (AOR for a 1-unit increase in the number of routines 1.59, 95% CI 1.09 to 2.31) than usual-care families. The IPB-only intervention was less costly and marginally more effective than usual care. The IPB+ intervention was more costly and marginally more effective than usual care. Limitations: Our case–control studies demonstrate associations between modifiable risk factors and injuries but not causality. Some injury cost estimates are imprecise because of small numbers. Systematic reviews and meta-analyses were limited by the quality of the included studies, the small numbers of studies reporting outcomes and significant heterogeneity, partly explained by differences in interventions. Network meta-analysis (NMA) categorised interventions more finely, but some variation remained. Decision analyses are likely to underestimate cost-effectiveness for a number of reasons. IPB implementation varied between children’s centres. Greater implementation may have resulted in changes in more fire safety behaviours. Conclusions: Our studies provide new evidence about the effectiveness of, as well as economic evaluation of, home safety interventions. Evidence-based resources for preventing thermal injuries, falls and scalds were developed. Providing such resources to children’s centres increases their injury prevention activity and some parental safety behaviours. Future work: Further randomised controlled trials, meta-analyses and NMAs are needed to evaluate the effectiveness and cost-effectiveness of home safety interventions. Further work is required to measure NHS, family and societal costs and utility decrements for childhood home injuries and to evaluate complex multicomponent interventions such as home safety schemes using a single analytical model. Trial registration: Current Controlled Trials ISRCTN65067450 and ClinicalTrials.gov NCT01452191. Funding: The National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 5, No. 14. See the NIHR Journals Library website for further project information

Recreating the OSIRIS-REx Slingshot Manoeuvre from a Network of Ground-Based Sensors

Optical tracking systems typically trade-off between astrometric precision and field-of-view. In this work, we showcase a networked approach to optical tracking using very wide field-of-view imagers that have relatively low astrometric precision on the scheduled OSIRIS-REx slingshot manoeuvre around Earth on September 22nd, 2017. As part of a trajectory designed to get OSIRIS-REx to NEO 101955 Bennu, this flyby event was viewed from 13 remote sensors spread across Australia and New Zealand to promote triangulatable observations. Each observatory in this portable network was constructed to be as lightweight and portable as possible, with hardware based off the successful design of the Desert Fireball Network. Over a 4 hour collection window, we gathered 15,439 images of the night sky in the predicted direction of the OSIRIS-REx spacecraft. Using a specially developed streak detection and orbit determination data pipeline, we detected 2,090 line-of-sight observations. Our fitted orbit was determined to be within about 10~km of orbital telemetry along the observed 109,262~km length of OSIRIS-REx trajectory, and thus demonstrating the impressive capability of a networked approach to SSA

Longitudinal Analysis of the Temporal Evolution of Acinetobacter baumannii Strains in Ohio, USA, by Using Rapid Automated Typing Methods

Genotyping methods are essential to understand the transmission dynamics of Acinetobacter baumannii. We examined the representative genotypes of A. baumannii at different time periods in select locations in Ohio, using two rapid automated typing methods: PCR coupled with electrospray ionization mass spectrometry (PCR/ESI-MS), a form of multi-locus sequence typing (MLST), and repetitive-sequence-based-PCR (rep-PCR). Our analysis included 122 isolates from 4 referral hospital systems, in 2 urban areas of Ohio. These isolates were associated with outbreaks at 3 different time periods (1996, 2000 and 2005–2007). Type assignments of PCR/ESI-MS and rep-PCR were compared to each other and to worldwide (WW) clone types. The discriminatory power of each method was determined using the Simpson's index of diversity (DI). We observed that PCR/ESI-MS sequence type (ST) 14, corresponding to WW clone 3, predominated in 1996, whereas ST 12 and 14 co-existed in the intermediate period (2000) and ST 10 and 12, belonging to WW clone 2, predominated more recently in 2007. The shift from WW clone 3 to WW clone 2 was accompanied by an increase in carbapenem resistance. The DI was approximately 0.74 for PCR/ESI-MS, 0.88 for rep-PCR and 0.90 for the combination of both typing methods. We conclude that combining rapid automated typing methods such as PCR/ESI-MS and rep-PCR serves to optimally characterize the regional molecular epidemiology of A. baumannii. Our data also sheds light on the changing sequence types in an 11 year period in Northeast Ohio