Graviton confinement inside hypermonopoles of any dimension

We show the generic existence of metastable massive gravitons in the four-dimensional core of self-gravitating hypermonopoles in any number of infinite-volume extra-dimensions. Confinement is observed for Higgs and gauge bosons couplings of the order unity. Provided these resonances are light enough, they realise the Dvali-Gabadadze-Porrati mechanism by inducing a four-dimensional gravity law on some intermediate length scales. The effective four-dimensional Planck mass is shown to be proportional to a negative power of the graviton mass. As a result, requiring gravity to be four-dimensional on cosmological length scales may solve the mass hierarchy problem.Comment: 23 pages, 6 figures, uses iopart. Misprints corrected, references added, matches published versio

Short-Term Changes in Ambient Temperature and Risk of Ischemic Stroke

Background: Despite consistent evidence of a higher short-term risk of cardiovascular mortality associated with ambient temperature, there have been discrepant findings on the association between temperature and ischemic stroke. Moreover, few studies have considered potential confounding by ambient fine particulate matter air pollution <2.5 μm in diameter (PM2.5) and none have examined the impact of temperature changes on stroke in the subsequent hours rather than days. The aim of this study was to evaluate whether changes in temperature trigger an ischemic stroke in the following hours and days and whether humid days are particularly harmful. Methods: We reviewed the medical records of 1,705 patients residing in the metropolitan region of Boston, Mass., USA, who were hospitalized with neurologist-confirmed ischemic stroke, and we abstracted data on the time of symptom onset and clinical characteristics. We obtained hourly meteorological data from the National Weather Service station and hourly PM2.5 data from the Harvard ambient monitoring station. We used the time-stratified case-crossover design to assess the association between ischemic stroke and apparent temperature averaged over 1-7 days prior to stroke onset adjusting for PM2.5. We assessed whether differences in apparent temperature trigger a stroke within shorter time periods by examining the association between stroke onset and apparent temperature levels averaged in 2-hour increments prior to stroke onset (0-2 h through 36-38 h). We tested whether the association varied by health characteristics or by PM2.5, ozone or relative humidity. Results: The incidence rate ratio of ischemic stroke was 1.09 (95% confidence interval 1.01-1.18) following a 5°C decrement in average apparent temperature over the 2 days preceding symptom onset. The higher risk associated with cooler temperatures peaked in the first 14-34 h. There was no statistically significant difference in the association between temperature and ischemic stroke across seasons. The risk of ischemic stroke was not meaningfully different across subgroups of patients defined by health characteristics. The association between ischemic stroke and ambient temperature was stronger on days with higher levels of relative humidity. Conclusions: Lower temperatures are associated with a higher risk of ischemic stroke onset in both warm and cool seasons, and the risk is higher on days with higher levels of relative humidity. Based on this study and the body of literature on ambient temperature and cardiovascular events, identifying methods for mitigating cardiovascular risk may be warranted

Titania-doped tantala/silica coatings for gravitational-wave detection

Reducing thermal noise from optical coatings is crucial to reaching the required sensitivity in next generation interferometric gravitational-wave detectors. Here we show that adding TiO2 to Ta2O5 in Ta2O5/SiO2 coatings reduces the internal friction and in addition present data confirming it reduces thermal noise. We also show that TiO2-doped Ta2O5/SiO2 coatings are close to satisfying the optical absorption requirements of second generation gravitational-wave detectors

Genomic Assemblies of Members of Burkholderia and Related Genera as a Resource for Natural Product Discovery.

The genomes of 450 members of Burkholderiaceae, isolated from clinical and environmental sources, were sequenced and assembled as a resource for genome mining. Genomic analysis of the collection has enabled the identification of multiple metabolites and their biosynthetic gene clusters, including the antibiotics gladiolin, icosalide A, enacyloxin, and cepacin A

Autonomic Effects of Controlled Fine Particulate Exposure in Young Healthy Adults: Effect Modification by Ozone

Background: Human controlled-exposure studies have assessed the impact of ambient fine particulate matter on cardiac autonomic function measured by heart rate variability (HRV), but whether these effects are modified by concomitant ozone exposure remains unknown. Objective: In this study we assessed the impact of O$_3$ and particulate matter exposure on HRV in humans. Methods: In a crossover design, 50 subjects (19–48 years of age) were randomized to 2-hr controlled exposures to filtered air (FA), concentrated ambient particles (CAPs), O$_3$, or combined CAPs and ozone (CAPs + O$_3$). The primary end point was change in HRV between the start and end of exposure. Secondary analyses included blood pressure (BP) responses, and effect modification by asthmatic status. Results: Achieved mean CAPs and O$_3$ exposure concentrations were 121.6 ± 48.0 μg/m$^3$ and 113.9 ± 6.6 ppb, respectively. In a categorical analysis, exposure had no consistent effect on HRV indices. However, the dose–response relationship between CAPs mass concentration and HRV indices seemed to vary depending on the presence of O$_3$. This heterogeneity was statistically significant for the low-frequency component of HRV (p = 0.02) and approached significance for the high-frequency component and time-domain measures of HRV. Exposure to CAPs + O$_3$ increased diastolic BP by 2.0 mmHg (SE, 1.2; p = 0.02). No other statistically significant changes in BP were observed. Asthmatic status did not modify these effects. Conclusion: The potentiation by O$_3$ of CAPs effects on diastolic BP and possibly HRV is of small magnitude in young adults. Further studies are needed to assess potential effects in more vulnerable populations

Textural and geochemical features of freshwater microbialites from Laguna Bacalar, Quintana Roo, Mexico

Microbialites provide some of the oldest direct evidence of life on Earth. They reached their peak during the Proterozoic and declined afterward. Their decline has been attributed to grazing and/or burrowing by metazoans, to changes in ocean chemistry, or to competition with other calcifying organisms. The freshwater microbialites at Laguna Bacalar (Mexico) provide an opportunity to better understand microbialite growth in terms of interaction between grazing organisms versus calcium carbonate precipitation. The Laguna Bacalar microbialites are described in terms of their distinct mesostructures. Stromatolites display internal lamination, attributed to the precipitation of calcite and the upward migration of cyanobacteria during periods of low sedimentation. Thrombolitic stromatolites show internal lamination in addition to internal clotting. The clotting is seen as a result of binding and/or trapping of micritic peloids by cyanobacteria and attributed to periods of high sedimentation. The carbonates in both microbialites had similar C- and O-stable–isotopic signatures, both enriched in ^(13)C relative to bivalves, suggesting photosynthetic CO_2 uptake was the trigger for carbonate precipitation. This implies that the rate of microbialite growth is largely a function of ambient carbonate saturation state, while the texture is especially dependent on accretion rates and sediment deposition on their surface. Importantly, the coexistence with grazing animals suggests no significant inhibition on microbialite growth, thereby calling into question the decline of microbialite as a result of metazoan evolution. Varying sedimentation rates are likely important in controlling the distribution of thrombolite–stromatolite packages in the geological record, given the importance of this factor at Bacalar

Genome mining identifies cepacin as a plant-protective metabolite of the biopesticidal bacterium Burkholderia ambifaria.

Beneficial microorganisms are widely used in agriculture for control of plant pathogens, but a lack of efficacy and safety information has limited the exploitation of multiple promising biopesticides. We applied phylogeny-led genome mining, metabolite analyses and biological control assays to define the efficacy of Burkholderia ambifaria, a naturally beneficial bacterium with proven biocontrol properties but potential pathogenic risk. A panel of 64 B. ambifaria strains demonstrated significant antimicrobial activity against priority plant pathogens. Genome sequencing, specialized metabolite biosynthetic gene cluster mining and metabolite analysis revealed an armoury of known and unknown pathways within B. ambifaria. The biosynthetic gene cluster responsible for the production of the metabolite cepacin was identified and directly shown to mediate protection of germinating crops against Pythium damping-off disease. B. ambifaria maintained biopesticidal protection and overall fitness in the soil after deletion of its third replicon, a non-essential plasmid associated with virulence in Burkholderia cepacia complex bacteria. Removal of the third replicon reduced B. ambifaria persistence in a murine respiratory infection model. Here, we show that by using interdisciplinary phylogenomic, metabolomic and functional approaches, the mode of action of natural biological control agents related to pathogens can be systematically established to facilitate their future exploitation.A.J.M. is funded by a Biotechnology and Biological Sciences Research Council (BBSRC) South West doctoral training partnership award (BY1910 7007). E.M., G.L.C., T.R.C. and J.P. acknowledge additional support for genome mining from BBSRC award BB/L021692/1; C.J. and M.J. were funded by this award. M.J. is currently the recipient of a BBSRC Future Leader Fellowship (BB/R01212/1). The Bruker maXis II UHPLC-ESI-Q-TOF-MS system used in this research was funded by the BBSRC (BB/M017982/1). G.W. was supported by awards to E.M. from the Life Sciences Bridging Fund and Wellcome Trust Institutional Strategic Support Fund held at Cardiff University. T.R.C. and M.J.B. acknowledge funding support from the Medical Research Council’s Cloud Infrastructure for Microbial Bioinformatics (MR/L015080/1), which provided the computational resources to undertake the analyses for this work. D.R.N. and A.E.G. acknowledge funding from a Wellcome Trust and Royal Society Sir Henry Dale Fellowship awarded to D.R.N. (grant number 204457/Z/16/Z). G.L.C. is the recipient of a Wolfson Research Merit Award from the Royal Society (WM130033)

Immunization coverage and risk factors for failure to immunize within the Expanded Programme on Immunization in Kenya after introduction of new Haemophilus influenzae type b and hepatitis b virus antigens

Background: Kenya introduced a pentavalent vaccine including the DTP, Haemophilus influenzae type b and hepatitis b virus antigens in Nov 2001 and strengthened immunization services. We estimated immunization coverage before and after introduction, timeliness of vaccination and risk factors for failure to immunize in Kilifi district, Kenya. Methods: In Nov 2002 we performed WHO cluster-sample surveys of > 200 children scheduled for vaccination before or after introduction of pentavalent vaccine. In Mar 2004 we conducted a simple random sample (SRS) survey of 204 children aged 9 - 23 months. Coverage was estimated by inverse Kaplan-Meier survival analysis of vaccine- card and mothers' recall data and corroborated by reviewing administrative records from national and provincial vaccine stores. The contribution to timely immunization of distance from clinic, seasonal rainfall, mother's age, and family size was estimated by a proportional hazards model. Results: Immunization coverage for three DTP and pentavalent doses was 100% before and 91% after pentavalent vaccine introduction, respectively. By SRS survey, coverage was 88% for three pentavalent doses. The median age at first, second and third vaccine dose was 8, 13 and 18 weeks. Vials dispatched to Kilifi District during 2001 - 2003 would provide three immunizations for 92% of the birth cohort. Immunization rate ratios were reduced with every kilometre of distance from home to vaccine clinic (HR 0.95, CI 0.91 - 1.00), rainy seasons ( HR 0.73, 95% CI 0.61 - 0.89) and family size, increasing progressively up to 4 children ( HR 0.55, 95% CI 0.41 - 0.73). Conclusion: Vaccine coverage was high before and after introduction of pentavalent vaccine, but most doses were given late. Coverage is limited by seasonal factors and family siz

NICMOS Observations of the Transiting Hot Jupiter XO-1b

We refine the physical parameters of the transiting hot Jupiter planet XO-1b and its stellar host XO-1 using HST NICMOS observations. XO-1b has a radius Rp=1.21+/-0.03 RJup, and XO-1 has a radius Rs=0.94+/-0.02 RSun, where the uncertainty in the mass of XO-1 dominates the uncertainty of Rp and Rs. There are no significant differences in the XO-1 system properties between these broad-band NIR observations and previous determinations based upon ground-based optical observations. We measure two transit timings from these observations with 9 s and 15 s precision. As a residual to a linear ephemeris model, there is a 2.0 sigma timing difference between the two HST visits that are separated by 3 transit events (11.8 days). These two transit timings and additional timings from the literature are sufficient to rule out the presence of an Earth mass planet orbiting in 2:1 mean motion resonance coplanar with XO-1b. We identify and correct for poorly understood gain-like variations present in NICMOS time series data. This correction reduces the effective noise in time series photometry by a factor of two, for the case of XO-1.Comment: 13 pages, 8 figures, submitted to Ap