1,295 research outputs found

    Economic Evaluation of Fungal Meningitis Outbreak Response in New River Valley: Local Health Department Perspective

    Get PDF
    Background: The multi-state fungal meningitis outbreak started in September 2012 in Tennessee. The cause of the outbreak was injection of contaminated lots of methylprednisolone acetate used in epidural spinal injections. Roanoke and New River Valley were the epicenter of this outbreak in Virginia, with two clinical centers having administered the contaminated injections to their patients. New River Health District, in coordination with hospitals, and state and federal agencies, deployed its resources to control the local impact of the outbreak. Purpose: The objective of this study was to conduct an economic evaluation of the fungal meningitis outbreak response in New River Valley of Virginia, from the local public health department perspective. Methods: The health department conducted the outbreak investigation from October 2012 until March 2013 to ascertain that all possible cases were identified and treated. Data were collected on the costs associated with the local health department in the outbreak response, and the epidemiologic effectiveness estimated, using the metric of disability adjusted life years (DALYs). Results: The cost incurred by the local health department was estimated to be 30,493;theepidemiologiceffectivenesswasestimatedtobe138DALYsavertedamongthepatients,foranincrementalcost−effectivenessratioof30,493; the epidemiologic effectiveness was estimated to be 138 DALYs averted among the patients, for an incremental cost-effectiveness ratio of 221 per DALY averted. Implications: The incremental cost effectiveness ratio of the fungal meningitis outbreak response in New River Valley assists the local health department to analyze the costs and epidemiologic effectiveness of the outbreak response

    The Îą1 Subunit of the GABA(A) Receptor Modulates Fear Learning and Plasticity in the Lateral Amygdala

    Get PDF
    Synaptic plasticity in the amygdala is essential for emotional learning. Fear conditioning, for example, depends on changes in excitatory transmission that occur following NMDA receptor activation and AMPA receptor modification in this region. The role of these and other glutamatergic mechanisms have been studied extensively in this circuit while relatively little is known about the contribution of inhibitory transmission. The current experiments addressed this issue by examining the role of the GABA(A) receptor subunit Îą1 in fear learning and plasticity. We first confirmed previous findings that the Îą1 subunit is highly expressed in the lateral nucleus of the amygdala. Consistent with this observation, genetic deletion of this subunit selectively enhanced plasticity in the lateral amygdala and increased auditory fear conditioning. Mice with selective deletion of Îą1 in excitatory cells did not exhibit enhanced learning. Finally, infusion of a Îą1 receptor antagonist into the lateral amygdala selectively impaired auditory fear learning. Together, these results suggest that inhibitory transmission mediated by Îą1-containing GABA(A) receptors plays a critical role in amygdala plasticity and fear learning

    Nutrient Source and Tillage Effects on Maize: II. Yield, Soil Carbon, and Carbon Dioxide Emissions

    Get PDF
    There is a need to understand the potential benefits of using the biotechnology waste by‐product from manufacturing as a fertilizer replacement in agriculture, by quantifying the economic value for the farmer and measuring the environmental impact. Measuring CO2 emissions can be used to assess environmental impact, including three widely used micrometeorological methodologies: (i) the Bowen Ratio Energy Balance (BREB), (ii) aerodynamic flux‐gradient theory, and (iii) eddy covariance (EC). As a first step in quantifying benefits of applying biotechnology waste in agriculture, a detailed examination of these three methods was conducted to understand their effectiveness in quantifying CO2 emissions for this specific circumstance. The study measured micrometeorological properties over a field planted to maize (Zea mays L. var. indentata ), one plot treated with biotechnology waste applied as a nutrient amendment, and one plot treated with a typical farmer fertilizer practice. Carbon dioxide flux measurements took place over 1 yr, using both BREB and EC systems. The aerodynamic method was used to gap‐fill BREB system measurements, and those flux estimates were compared with estimates produced separately by the aerodynamic and EC methods. All methods found greater emissions over the biotechnology waste application. The aerodynamic method CO2 flux estimates were considerably greater than both the EC and a combined BREB‐aerodynamic approach. During the day, the EC and BREB methods agree. At night, the aerodynamic approach detects and accounts for buildup of CO2 at the surface during stable periods. The BREB systems combined with aerodynamic approaches provide alternate methods to EC in examining micrometeorological properties near the surface

    Conservation agriculture as a climate change mitigation strategy in Zimbabwe

    Get PDF
    There is a need to quantify agriculture’s potential to sequester carbon (C) to inform global approaches aimed at mitigating climate change effects. Many factors including climate, crop, soil management practices, and soil type can influence the contribution of agriculture to the global carbon cycle. The objective of this study was to investigate the C sequestration potential of conservation agriculture (CA) (defined by minimal soil disturbance, maintaining permanent soil cover, and crop rotations). This study used micrometeorological methods to measure carbon dioxide (CO2) flux from several alternative CA practices in Harare, central Zimbabwe. Micrometeorological methods can detect differences in total CO2 emissions of agricultural management practices; our results show that CA practices produce less CO2 emissions. Over three years of measurement, the mean and standard error (SE) of CO2 emissions for the plot with the most consistent CA practices was 0.564 ± 0.0122 g CO2 m-2 h-1, significantly less than 0.928 ± 0.00859 g CO2 m-2 h-1 for the conventional tillage practice. Overall CA practices of no-till with the use of cover crops produced fewer CO2 emissions than conventional tillage or fallow

    Modelling massive star feedback with Monte Carlo radiation hydrodynamics: photoionization and radiation pressure in a turbulent cloud (article)

    Get PDF
    This is the final version of the article. Available from Oxford University Press via the DOI in this record.The dataset associated with this article is located in ORE at: https://doi.org/10.24378/exe.1163We simulate a self-gravitating, turbulent cloud of 1000 M⊙ with photoionization and radiation pressure feedback from a 34 M⊙ star. We use a detailed Monte Carlo radiative transfer scheme alongside the hydrodynamics to compute photoionization and thermal equilibrium with dust grains and multiple atomic species. Using these gas temperatures, dust temperatures, and ionization fractions, we produce self-consistent synthetic observations of line and continuum emission. We find that all material is dispersed from the (15.5 pc)3 grid within 1.6 Myr or 0.74 free-fall times. Mass exits with a peak flux of 2 × 10−3 M⊙ yr−1, showing efficient gas dispersal. The model without radiation pressure has a slight delay in the breakthrough of ionization, but overall its effects are negligible. 85 per cent of the volume, and 40 per cent of the mass, become ionized – dense filaments resist ionization and are swept up into spherical cores with pillars that point radially away from the ionizing star. We use free–free emission at 20 cm to estimate the production rate of ionizing photons. This is almost always underestimated: by a factor of a few at early stages, then by orders of magnitude as mass leaves the volume. We also test the ratio of dust continuum surface brightnesses at 450 and 850 µm to probe dust temperatures. This underestimates the actual temperature by more than a factor of 2 in areas of low column density or high line-of-sight temperature dispersion; the HII region cavity is particularly prone to this discrepancy. However, the probe is accurate in dense locations such as filaments.We thank the referee, Alejandro Raga, for helpful comments. We also thank Thomas Haworth and David Acreman for useful discussions. AA is funded by an STFC studentship. TJH and TAD are funded by STFC Consolidated Grant ST/M00127X/1. The calculations for this paper were performed on the DiRAC Complexity system at the University of Leicester and the DiRAC Data Centric system at Durham University. These form part of the STFC DiRAC HPC Facility (www.dirac.ac.uk). Complexity is funded by BIS National E-Infrastructure capital grant ST/K000373/1 and STFC DiRAC Operations grants ST/K0003259/1 and ST/M006948/1. Data Centric is funded by a BIS National E-infrastructure capital grant ST/K00042X/1, STFC capital grants ST/K00087X/1 and ST/P002307/1, DiRAC Operations grant ST/K003267/1, and Durham University. We also used the University of Exeter Supercomputer, Zen, a DiRAC Facility jointly funded by STFC, the Large Facilities Capital fund of BIS, and the University of Exeter

    Why do some young cool stars show spot modulation while others do not?

    Full text link
    We present far-red, intermediate resolution spectroscopy of 572 photometrically selected, low-mass stars (0.2<M/M_sun<0.7) in the young open cluster NGC 2516, using the FLAMES spectrograph at the Very Large Telescope. Precise radial velocities confirm membership for 210 stars that have published rotation periods from spot-modulated light curves and for another 144 stars in which periodic modulation could not be found. The two sub-samples are compared and no significant differences are found between their positions in colour-magnitude diagrams, the distribution of their projected equatorial velocities or their levels of chromospheric activity. We rule out differing observational sensitivity as an explanation and conclude that otherwise similar objects, with equally high levels of chromospheric activity, do not exhibit spot-induced light curve modulation because their significant spot coverage is highly axisymmetric. We propose that the spot coverage consists of large numbers of small, dark spots with diameters of about 2 degrees. This explains why about half of cluster members do not exhibit rotationally modulated light curves and why the light curve amplitudes of those that do have mean values of only 0.01-0.02 mag.Comment: Accepted for publication in MNRAS, 11 pages. Electronic tables available from the author

    Search for gravitational waves associated with the InterPlanetary Network short gamma ray bursts

    Full text link
    We outline the scientific motivation behind a search for gravitational waves associated with short gamma ray bursts detected by the InterPlanetary Network (IPN) during LIGO's fifth science run and Virgo's first science run. The IPN localisation of short gamma ray bursts is limited to extended error boxes of different shapes and sizes and a search on these error boxes poses a series of challenges for data analysis. We will discuss these challenges and outline the methods to optimise the search over these error boxes.Comment: Methods paper; Proceedings for Eduardo Amaldi 9 Conference on Gravitational Waves, July 2011, Cardiff, U

    Implementation and testing of the first prompt search for gravitational wave transients with electromagnetic counterparts

    Get PDF
    Aims. A transient astrophysical event observed in both gravitational wave (GW) and electromagnetic (EM) channels would yield rich scientific rewards. A first program initiating EM follow-ups to possible transient GW events has been developed and exercised by the LIGO and Virgo community in association with several partners. In this paper, we describe and evaluate the methods used to promptly identify and localize GW event candidates and to request images of targeted sky locations. Methods. During two observing periods (Dec 17 2009 to Jan 8 2010 and Sep 2 to Oct 20 2010), a low-latency analysis pipeline was used to identify GW event candidates and to reconstruct maps of possible sky locations. A catalog of nearby galaxies and Milky Way globular clusters was used to select the most promising sky positions to be imaged, and this directional information was delivered to EM observatories with time lags of about thirty minutes. A Monte Carlo simulation has been used to evaluate the low-latency GW pipeline's ability to reconstruct source positions correctly. Results. For signals near the detection threshold, our low-latency algorithms often localized simulated GW burst signals to tens of square degrees, while neutron star/neutron star inspirals and neutron star/black hole inspirals were localized to a few hundred square degrees. Localization precision improves for moderately stronger signals. The correct sky location of signals well above threshold and originating from nearby galaxies may be observed with ~50% or better probability with a few pointings of wide-field telescopes.Comment: 17 pages. This version (v2) includes two tables and 1 section not included in v1. Accepted for publication in Astronomy & Astrophysic

    Search for a heavy resonance decaying into a Z+jet final state in p-pbar collisions at sqrt(s) = 1.96 TeV using the D0 detector

    Full text link
    We have searched for a heavy resonance decaying into a Z+jet final state in p-pbar collisions at a center of mass energy of 1.96 TeV at the Fermilab Tevatron collider using the D0 detector. No indication for such a resonance was found in a data sample corresponding to an integrated luminosity of 370/pb. We set upper limits on the cross section times branching fraction for heavy resonance production at the 95% C.L. as a function of the resonance mass and width. The limits are interpreted within the framework of a specific model of excited quark production.Comment: 8 pages, 5 figures, submitted to Physical Review

    Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

    Get PDF
    A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE
    • …
    corecore