144 research outputs found
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Health care system planning for and response to a nuclear detonation
The hallmark of a successful response to a nuclear detonation will be the resilience of the community, region, and nation. An incident of this magnitude will rapidly become a national incident; however, the initial critical steps to reduce lives lost, save the lives that can be saved with the resources available, and understand and apply resources available to a complex and dynamic situation will be the responsibility of the local and regional responders and planners. Expectations of the public health and health care systems will be met to the extent possible by coordination, cooperation, and an effort to produce as consistent a response as possible for the victims. Responders will face extraordinarily stressful situations, and their own physical and psychological health is of great importance to optimizing the response. This article illustrates through vignettes and supporting text how the incident may unfold for the various components of the health and medical systems and provides additional context for the discipline-related actions outlined in the state and local planners’ playbook
GJ 3236: a new bright, very low-mass eclipsing binary system discovered by the MEarth observatory
We report the detection of eclipses in GJ 3236, a bright (I = 11.6) very low
mass binary system with an orbital period of 0.77 days. Analysis of light- and
radial velocity curves of the system yielded component masses of 0.38 +/- 0.02
and 0.28 +/- 0.02 Msol. The central values for the stellar radii are larger
than the theoretical models predict for these masses, in agreement with the
results for existing eclipsing binaries, although the present 5% observational
uncertainties limit the significance of the larger radii to approximately 1
sigma. Degeneracies in the light curve models resulting from the unknown
configuration of surface spots on the components of GJ 3236 currently dominate
the uncertainties in the radii, and could be reduced by obtaining precise,
multi-band photometry covering the full orbital period. The system appears to
be tidally synchronized and shows signs of high activity levels as expected for
such a short orbital period, evidenced by strong Halpha emission lines in the
spectra of both components. These observations probe an important region of
mass-radius parameter space around the predicted transition to fully-convective
stellar interiors, where there are a limited number of precise measurements
available in the literature.Comment: 14 pages, 5 figures, 10 tables, emulateapj format. Accepted for
publication in Ap
Correlating Remote Sensing Data with the Abundance of Pupae of the Dengue Virus Mosquito Vector, Aedes aegypti, in Central Mexico
Using a geographic transect in Central Mexico, with an elevation/climate gradient, but uniformity in socio-economic conditions among study sites, this study evaluates the applicability of three widely-used remote sensing (RS) products to link weather conditions with the local abundance of the dengue virus mosquito vector, Aedes aegypti (Ae. aegypti). Field-derived entomological measures included estimates for the percentage of premises with the presence of Ae. aegypti pupae and the abundance of Ae. aegypti pupae per premises. Data on mosquito abundance from field surveys were matched with RS data and analyzed for correlation. Daily daytime and nighttime land surface temperature (LST) values were obtained from Moderate Resolution Imaging Spectroradiometer (MODIS)/Aqua cloud-free images within the four weeks preceding the field survey. Tropical Rainfall Measuring Mission (TRMM)-estimated rainfall accumulation was calculated for the four weeks preceding the field survey. Elevation was estimated through a digital elevation model (DEM). Strong correlations were found between mosquito abundance and RS-derived night LST, elevation and rainfall along the elevation/climate gradient. These findings show that RS data can be used to predict Ae. aegypti abundance, but further studies are needed to define the climatic and socio-economic conditions under which the correlations observed herein can be assumed to apply
Mapping Threats to Agriculture in East Africa: Performance of MODIS Derived LST for Frost Identification in Kenya's Tea Plantations
Increased prevalence of weather related hazards in eastern Africa including drought, floods, hail and frost threatening agricultural productivity. Kenya is heavily dependent on agriculture for economic growth (FAO 2013); (1) Agriculture contributed 23.5% and 21.5% of GDP in 2009 and 2010 respectively, (2) Employment to half a million households of smallholders and 150,000 on large tea estates. Tea growing in Kenya depends on stability of the weather; (1) Weather is unpredictable, (2) Frost has contributed 30% of tea leaf losses, (3) Drought has contributed 14-30%, (4) The losses are experienced between January and march - frost and dry season
New insights on the Draco dwarf spheroidal galaxy from SDSS: a larger radius and no tidal tails
We have investigated the spatial extent and structure of the Draco dwarf
spheroidal galaxy using deep wide-field multicolor CCD photometry from the
Sloan Digital Sky Survey (SDSS). Our study covers an area of 27 square degrees
around the center of the Draco dwarf. We show that the spatial distribution of
Draco's red giants, red horizontal branch stars and subgiants down to i=21.7
mag does not provide evidence for the existence of tidally induced tails or a
halo of unbound stars. The radial profile can be fit by King models as well as
by a generalized exponential. The core radius and the limiting (or tidal)
radius along the major axis are 7.7' and 40.1', respectively, making Draco 40%
larger than previously measured. Down to our magnitude limit tidal effects can
only exist at a level of 10^-3 of the central surface density of Draco or
below. The regular structure of Draco found from the new data argues against it
being a portion of an unbound tidal stream and lends support to the assumption
of dynamical equilibrium. We estimate Draco's total mass to be 2.2 - 3.5 times
10^7 solar masses. We obtain an overall mass-to-light ratio of 146+-42 or
92+-28 solar masses depending on the details of the mass and luminosity
estimates. In summary, our results strengthen the case for a strongly dark
matter dominated, bound stellar system. (Abstract strongly abridged).Comment: 30 pages, 11 figures (in part with degraded resolution). Accepted for
publication in the Astronomical Journa
The Primordial Inflation Polarization Explorer (PIPER): Current Status and Performance of the First Flight
The Primordial Inflation Polarization ExploreR (PIPER) is a balloon-borne instrument optimized to measure the polarization of the CMB at large angular scales. It will map 85% of the sky over a series of conventional balloon flights from the Northern and Southern hemispheres, measuring the B-mode polarization power spectrumover a range of multipoles from 2-300 covering both the reionization bump and the recombination peak, with sensitivity to measure the tensor-to-scalar ratio down to r = 0.007. PIPER will observe in four frequency bands centered at 200, 270, 350, and 600 GHz to characterize dust foregrounds. The instrument has background-limited sensitivity provided by fully cryogenic (1.7 K) optics focusing the sky signal onto kilo-pixel arrays of time-domain multiplexed Transition-Edge Sensor (TES) bolometers held at 100 mK. Polarization sensitivity and systematiccontrol are provided by front-end Variable-delay Polarization Modulators (VPMs). PIPER had its engineering flight in October 2017 from Fort Sumner, New Mexico. This papers outlines the major components in the PIPER system discussing the conceptual design as well as specific choices made for PIPER. We also report on the results of the engineering flight, looking at the functionality of the payload systems, particularly VPM, as well as pointing out areas of improvement
Dark sectors 2016 Workshop: community report
This report, based on the Dark Sectors workshop at SLAC in April 2016,
summarizes the scientific importance of searches for dark sector dark matter
and forces at masses beneath the weak-scale, the status of this broad
international field, the important milestones motivating future exploration,
and promising experimental opportunities to reach these milestones over the
next 5-10 years
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