6,399 research outputs found
Small area estimation of general parameters with application to poverty indicators: A hierarchical Bayes approach
Poverty maps are used to aid important political decisions such as allocation
of development funds by governments and international organizations. Those
decisions should be based on the most accurate poverty figures. However, often
reliable poverty figures are not available at fine geographical levels or for
particular risk population subgroups due to the sample size limitation of
current national surveys. These surveys cannot cover adequately all the desired
areas or population subgroups and, therefore, models relating the different
areas are needed to 'borrow strength" from area to area. In particular, the
Spanish Survey on Income and Living Conditions (SILC) produces national poverty
estimates but cannot provide poverty estimates by Spanish provinces due to the
poor precision of direct estimates, which use only the province specific data.
It also raises the ethical question of whether poverty is more severe for women
than for men in a given province. We develop a hierarchical Bayes (HB) approach
for poverty mapping in Spanish provinces by gender that overcomes the small
province sample size problem of the SILC. The proposed approach has a wide
scope of application because it can be used to estimate general nonlinear
parameters. We use a Bayesian version of the nested error regression model in
which Markov chain Monte Carlo procedures and the convergence monitoring
therein are avoided. A simulation study reveals good frequentist properties of
the HB approach. The resulting poverty maps indicate that poverty, both in
frequency and intensity, is localized mostly in the southern and western
provinces and it is more acute for women than for men in most of the provinces.Comment: Published in at http://dx.doi.org/10.1214/13-AOAS702 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Homogenization Model for Aberrant Crypt Foci
Several explanations can be found in the literature about the origin of
colorectal cancer. There is however some agreement on the fact that the
carcinogenic process is a result of several genetic mutations of normal cells.
The colon epithelium is characterized by millions of invaginations, very small
cavities, called crypts, where most of the cellular activity occurs. It is
consensual in the medical community, that a potential first manifestation of
the carcinogenic process, observed in conventional colonoscopy images, is the
appearance of Aberrant Crypt Foci (ACF). These are clusters of abnormal crypts,
morphologically characterized by an atypical behavior of the cells that
populate the crypts. In this work an homogenization model is proposed, for
representing the cellular dynamics in the colon epithelium. The goal is to
simulate and predict, in silico, the spread and evolution of ACF, as it can be
observed in colonoscopy images. By assuming that the colon is an heterogeneous
media, exhibiting a periodic distribution of crypts, we start this work by
describing a periodic model, that represents the ACF cell-dynamics in a
two-dimensional setting. Then, homogenization techniques are applied to this
periodic model, to find a simpler model, whose solution symbolizes the averaged
behavior of ACF at the tissue level. Some theoretical results concerning the
existence of solution of the homogenized model are proven, applying a fixed
point theorem. Numerical results showing the convergence of the periodic model
to the homogenized model are presented.Comment: 26 pages, 4 figure
Doxorubicin Affects Testicular Lipids with Long-Chain (C18-C22) and Very Long-Chain (C24-C32) Polyunsaturated Fatty Acids
Doxorubicin disrupts spermatogenesis by causing apoptosis of spermatogonia and primary spermatocytes. The aim of this study was to examine the effect of this agent on adult rat testicular lipids and their fatty acids. A single dose (7.5 mg/kg) and a multidose regime (3 mg/kg once a week for 4 weeks) were evaluated. Both treatments resulted in the gradual loss of spermatogenic cells and determined a marked reduction in testicular size and weight 9 weeks after their start. Germ cell loss was accompanied by a decrease in phospholipids, including glycerophospholipids and sphingomyelin. Concomitantly, glycerophospholipids lost selectively their major polyunsaturated fatty acid (PUFA), 22:5n-6, and sphingomyelin lost its major very long-chain PUFA (VLCPUFA), 28:4n-6 and 30:5n-6. The molecular species from which the lost polyenes originated were thus a trait of germ cells. A transient peak of 16:0-ceramide was observed 48 h after the single dose. In both doxorubicin regimes, sphingomyelin and ceramide with reduced amounts of VLCPUFA after about 4 weeks and with no VLCPUFA after 9 weeks resulted. By contrast, triglycerides and especially cholesterol esters (CE) tended to accumulate in the testes undergoing germ cell death, probably in the surviving Sertoli cells, their fatty acid patterns suggesting that initially, these lipids retained part of the PUFA coming from, or no longer used for, the synthesis of germ cell glycerophospholipids. As the latter decreased, CE accumulated massively 9 weeks after starting doxorubicin treatment, 20:4n-6 becoming their major PUFA. Part of these CEs may derive from surviving steroidogenic cells.Fil: Zanetti, Samanta Romina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - BahÃa Blanca. Instituto de Investigaciones BioquÃmicas de BahÃa Blanca. Universidad Nacional del Sur. Instituto de Investigaciones BioquÃmicas de BahÃa Blanca; ArgentinaFil: Maldonado, Eduardo N.. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - BahÃa Blanca. Instituto de Investigaciones BioquÃmicas de BahÃa Blanca. Universidad Nacional del Sur. Instituto de Investigaciones BioquÃmicas de BahÃa Blanca; ArgentinaFil: Aveldaño, Marta Isabel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - BahÃa Blanca. Instituto de Investigaciones BioquÃmicas de BahÃa Blanca. Universidad Nacional del Sur. Instituto de Investigaciones BioquÃmicas de BahÃa Blanca; Argentin
Snapshot of macroalgae and fish assemblages in temperate reefs in the Southern European Atlantic Ecoregion
Most of the biodiversity studies in the South European Atlantic Shelf ecoregion are limited to shallow subtidal or intertidal habitats, while deeper reef habitats, also of relevant ecological importance, are particularly understudied. Macroalgal communities, associated fauna, and sea surface temperature were studied in deep reefs (25-30 m) at two locations in this ecoregion: Parcel, North of Portugal (41 degrees N), and Tarifa, Southern Spain (35 degrees N). Specifically, algal assemblages were assessed using biomass collection and associated ichthyofauna was assessed using visual census techniques using scuba. Seawater surface temperature was higher (>3 degrees C) in the southern region-Tarifa, compared to the northern region-Parcel. Our survey revealed 18 fish species and 23 algae species. The highest abundance of cold-water species (both macroalgae and fish species) was recorded in Parcel and warm-water species were dominant in Tarifa. In light of climate global trends, both regions might experience biodiversity shifts towards tropicalization. Current knowledge on their biodiversity is imperative to further evaluate potential shifts.info:eu-repo/semantics/publishedVersio
Orange-Flesh Sweet Potato - Promising Partnerships for Assuring the Integration of Nutritional Concerns into Agricultural Research and Extension
Research Results from the Department of Policy Analysis MARD-Directorate of Economicsfood security, food policy, Mozambique, sweet potato, malnutrition, Crop Production/Industries, Food Security and Poverty, Q18,
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Electric Scooter Injuries and Hospital Admissions in the United States, 2014-2018.
This study investigates trends of injury and hospital admission associated with electric scooter use
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