5,413 research outputs found
SPATIAL ACCESSIBILITY OF HEALTH CARE IN INDIANA
Healthy populations and access to health care services are significant factors influencing economic development and prosperity. Since geographic access is an essential feature of an overall health system, it is important for health service researchers to develop accurate measures of physical access to health. In this paper we develop a series of gravity-based health care accessibility measures for all the counties in Indiana. The measures go beyond local availability of health care services within a county and account for travel impedance via distance-discounted health care services accessible throughout the state. When applied to Indiana counties, the results show sharp disparities in health care accessibility with extensive pockets of poor accessibility in rural and peripheral areas. The research concludes with a demonstration of how spatial accessibility measures can be beneficially used to evaluate of policies indicative of changes in the provision of health services.spatial accessibility, health care, geographic information systems (GIS),
Spectral formation in a radiative shock: application to anomalous X-ray pulsars and soft gamma-ray repeaters
In the fallback disk model for the persistent emission of Anomalous X-ray
pulsars (AXPs) and soft gamma-ray repeaters (SGRs), the hard X-ray emission
arises from bulk- and thermal Comptonization of bremsstrahlung photons, which
are generated in the accretion column. The relatively low X-ray luminosity of
these sources implies a moderate transverse optical depth to electron
scattering, with photons executing a small number of shock crossings before
escaping sideways. We explore the range of spectral shapes that can be obtained
with this model and characterize the most important parameter dependencies. We
use a Monte Carlo code to study the crisscrossing of photons in a radiative
shock in an accretion column and compute the resulting spectrum. As expected,
high-energy power-law X-ray spectra are produced in radiative shocks with
photon-number spectral index larger than or about 0.5. We find that the
required transverse optical depth is between 1 and 7. Such spectra are observed
in low-luminosity X-ray pulsars. We demonstrate here with a simple model that
Compton upscattering in the radiative shock in the accretion column can produce
hard X-ray spectra similar to those seen in the persistent and transient
emission of AXPs and SGRs. In particular, one can obtain a high-energy
power-law spectrum, with photon-number spectral index ~ 1 and a cutoff at 100 -
200 keV, with a transverse Thomson optical depth of ~ 5, which is shown to be
typical in AXPs/SGRs.Comment: Accepted for publication in A&
Comparing primary prevention with secondary prevention to explain decreasing Coronary Heart Disease death rates in Ireland, 1985-2000.
BACKGROUND: To investigate whether primary prevention might be more favourable than secondary prevention (risk factor reduction in patients with coronary heart disease(CHD)).
METHODS: The cell-based IMPACT CHD mortality model was used to integrate data for Ireland describing CHD patient numbers, uptake of specific treatments, trends in major cardiovascular risk factors, and the mortality benefits of these specific risk factor changes in CHD patients and in healthy people without recognised CHD.
RESULTS: Between 1985 and 2000, approximately 2,530 fewer deaths were attributable to reductions in the three major risk factors in Ireland. Overall smoking prevalence declined by 14% between 1985 and 2000, resulting in about 685 fewer deaths (minimum estimate 330, maximum estimate 1,285) attributable to smoking cessation: about 275 in healthy people and 410 in known CHD patients. Population total cholesterol concentrations fell by 4.6%, resulting in approximately 1,300 (minimum estimate 1,115, maximum estimate 1,660) fewer deaths attributable to dietary changes(1,185 in healthy people and 115 in CHD patients) plus 305 fewer deaths attributable to statin treatment (45 in people without CHD and 260 in CHD patients). Mean population diastolic blood pressure fell by 7.2%, resulting in approximately 170 (minimum estimate 105, maximum estimate 300) fewer deaths attributable to secular falls in blood pressure (140 in healthy people and 30 in CHD patients), plus approximately 70 fewer deaths attributable to antihypertensive treatments in people without CHD. Of all the deaths attributable to risk factor falls, some 1,715 (68%) occurred in people without recognized CHD and 815(32%) in CHD patients.
CONCLUSION: Compared with secondary prevention, primary prevention achieved a two-fold larger reduction in CHD deaths. Future national CHD policies should therefore prioritize nationwide interventions to promote healthy diets and reduce smoking
Larvaecidal effects of azadirachtin on the pine processionary moth
The effects of azadirachtin, a natural extract of the neem tree Azadirachta indica A. Juss, on larval growth and feeding activity of pine processionary moth (Thaumetopoea pityocampa (Schiff.)) was investigated in laboratory experiments conducted in 2007 - 2008. The organic insecticide NeemAzal-T/S(a commercial neem preparation) was applied as suspension in distilled water at concentration levels of 0.3, 0.5 and 1%. Comparing with the untreated leaves, the effect of the insecticide NeemAzal-T/S was tested on the 10th day after treatment. The results obtained in conducted experiments indicated thatNeemAzal-T/S was effective against T. pityocampa larvae, significantly inhibiting larval growth and reducing feeding activity
Mapping Wheat Growing Areas of Turkey by Integrating Multi-Temporal NDVI Data and Official Crop Statistics
Wheat is the most widely cultivated crop in the world providing critical food source of most countries. It exceeds most of the grain crops in acreage and production because of its ability to grow in wide range of climatic and geographic conditions. Timely and reliable information on wheat acreages is essential for government services in order to formulate their policies for planning of agricultural production and monitoring their food supply. Traditionally, agricultural statistics is considered as the main source of such information. Unfortunately, existing statistical data of wheat acreages of Turkey, mostly dependent on farmers’ declarations, does not provide spatial information of where this crop specifically is grown. Satellite remote sensing technology can enable the acquisition of such information indirectly with the use of ancillary data of crop statistics. This study aims to determine wheat cultivation areas of Turkey as percentage per unit area in a crop map by integrating time series satellite NDVI imagery with the official crop statistics through regression analysis. The regression results indicated that satellite data explained 95.8% of the variability in official wheat crop statistics and actual wheat cropping areas were significantly related to NDVI-based wheat classes. Validation of the produced wheat map showed that there was good agreement between actual wheat fractions and estimated NDVI-based wheat fractions explaining approximately 69% (Adj. R2) of the total variability between them. This study suggests use of the methodology employed here to governing bodies that need to identify and to map current wheat cropping areas
Restoration of error-diffused images using projection onto convex sets
Cataloged from PDF version of article.In this paper, a novel inverse halftoning method is
proposed to restore a continuous tone image from a given half-tone
image. A set theoretic formulation is used where three sets are defined
using the prior information about the problem. A new spacedomain
projection is introduced assuming the halftoning is performed
using error diffusion, and the error diffusion filter kernel is
known. The space-domain, frequency-domain, and space-scale domain
projections are used alternately to obtain a feasible solution
for the inverse halftoning problem which does not have a unique
solution
Nanoplasmonic surfaces enabling strong surface-normal electric field enhancement
Cataloged from PDF version of article.Conventional two-dimensional (2D) plasmonic arrays provide electric field intensity enhancement in the plane, typically with a surface coverage around 50% in the plan-view. Here, we show nanoplasmonic three-dimensional (3D) surfaces with 100% surface coverage enabling strong surface-normal field enhancement. Experimental measurements are found to agree well with the full electromagnetic solution. Along with the surface-normal localization when using the plasmonic 3D-surface, observed maximum field enhancement is 7.2-fold stronger in the 3D-surface than that of the 2D counterpart structure. 3D-plasmonic nonplanar surfaces provide the ability to generate volumetric field enhancement, possibly useful for enhanced plasmonic coupling and interactions. © 2013 Optical Society of America
Combustion within Porous Waste
Flammable gases (primarily hydrogen and nitrous oxide but also ammonia and methane) are continuously being generated within the waste contained in the tank farms at Hanford Site. Some portions of the waste are porous and conceivably, a combustion event could occur within the waste due to accidental ignition. This has been postulated as a potential hazard since deflagrations and detonations are observed in laboratory experiments to propagate through combustible gases in porous materials, or through interconnected flammable gas voids. The waste in Hanford storage tanks are mainly in three different forms, a: salt cake, b: sludge, c: supernatant. Formation of a crust layer on the top of the waste is also observed in some tanks. The salt cake waste and crust resemble porous materials while sludge and supernatant looks like highly viscous fluids retaining flammable gas as bubbles or inclusions. Although laboratory experiments showed the possibility of propagation of deflagration or detonation in waste-like porous materials filled by flammable gases, the relevance of this issue to safety evaluations at Hanford is a matter of contention.
In order to clarify this issue, we have reviewed the relevant data on laboratory experiments related to combustion in porous material. in doing this, we have concentrated on the flame literature rather than the detonation literature, since Makris et al. (1995) have already examined that. Further, significant mechanisms for the initiation of detonation (i.e., geometries resulting in strong flame acceleration within the dome) have not been identified therefore making flames a much more likely outcome of accidental ignition than detonation. ignition of flammable waste gases in the waste or the dome space of a tank can occur during intrusive operations into the waste or dome. External events which are not foreseeable such as lightning can also ignite the flammable gas retained in the waste. The present report only examines the basic issues in propagation of deflagration or detonation within waste. The process or probability of combustion ignition and other combustion events such as burns in the dome are not considered.
After our review of the literature, some simple estimates of the potential for flame and detonation propagation are given. We conclude with a discussion of the uncertainties and measurements required to resolve this issue
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