377 research outputs found
Natural resource dependence in rural Mexico
The relationship between poverty and natural resources is complex and the empirical evidence to date, mostly from studies of forest activities and poverty, is inconclusive. The main purpose of this paper is to empirically identify the effects of household characteristics and of inequality at the village level on natural resource extraction and dependence. To do so we use data from the Mexico National Rural Household Survey (ENHRUM). Our results show that in rural Mexico natural resource extraction is predominantly an activity carried out by poor households. The same is true for dependence. We also show that there are important differences across Mexico in terms of both participation and dependence on resource income. These differences are most evident when one compares the south and north of the country. We also show that when relatively rich households participate in resource extraction their natural resource income is considerably higher than that of the poor
Natural resource dependence in rural Mexico
The relationship between poverty and natural resources is complex and the empirical evidence to date, mostly from studies of forest activities and poverty, is inconclusive. The main purpose of this paper is to empirically identify the effects of household characteristics and of inequality at the village level on natural resource extraction and dependence. To do so we use data from the Mexico National Rural Household Survey (ENHRUM). Our results show that in rural Mexico natural resource extraction is predominantly an activity carried out by poor households. The same is true for dependence. We also show that there are important differences across Mexico in terms of both participation and dependence on resource income. These differences are most evident when one compares the south and north of the country. We also show that when relatively rich households participate in resource extraction their natural resource income is considerably higher than that of the poor
Centerscope
Centerscope, formerly Scope, was published by the Boston University Medical Center "to communicate the concern of the Medical Center for the development and maintenance of improved health care in contemporary society.
Probing Planckian physics: resonant production of particles during inflation and features in the primordial power spectrum
The phenomenon of resonant production of particles {\it after} inflation has
received much attention in the past few years. In a new application of resonant
production of particles, we consider the effect of a resonance {\em during}
inflation. We show that if the inflaton is coupled to a massive particle,
resonant production of the particle during inflation modifies the evolution of
the inflaton, and may leave an imprint in the form of sharp features in the
primordial power spectrum. Precision measurements of microwave background
anisotropies and large-scale structure surveys could be sensitive to the
features, and probe the spectrum of particles as massive as the Planck scale.Comment: 19 pages, 11 eps figure
Clinicians' caseload management behaviours as explanatory factors in patients' length of time on caseloads : a predictive multilevel study in paediatric community occupational therapy
Peer reviewedPublisher PD
Mapping gene associations in human mitochondria using clinical disease phenotypes
Nuclear genes encode most mitochondrial proteins, and their mutations cause diverse and debilitating clinical disorders. To date, 1,200 of these mitochondrial genes have been recorded, while no standardized catalog exists of the associated clinical phenotypes. Such a catalog would be useful to develop methods to analyze human phenotypic data, to determine genotype-phenotype relations among many genes and diseases, and to support the clinical diagnosis of mitochondrial disorders. Here we establish a clinical phenotype catalog of 174 mitochondrial disease genes and study associations of diseases and genes. Phenotypic features such as clinical signs and symptoms were manually annotated from full-text medical articles and classified based on the hierarchical MeSH ontology. This classification of phenotypic features of each gene allowed for the comparison of diseases between different genes. In turn, we were then able to measure the phenotypic associations of disease genes for which we calculated a quantitative value that is based on their shared phenotypic features. The results showed that genes sharing more similar phenotypes have a stronger tendency for functional interactions, proving the usefulness of phenotype similarity values in disease gene network analysis. We then constructed a functional network of mitochondrial genes and discovered a higher connectivity for non-disease than for disease genes, and a tendency of disease genes to interact with each other. Utilizing these differences, we propose 168 candidate genes that resemble the characteristic interaction patterns of mitochondrial disease genes. Through their network associations, the candidates are further prioritized for the study of specific disorders such as optic neuropathies and Parkinson disease. Most mitochondrial disease phenotypes involve several clinical categories including neurologic, metabolic, and gastrointestinal disorders, which might indicate the effects of gene defects within the mitochondrial system. The accompanying knowledgebase (http://www.mitophenome.org/) supports the study of clinical diseases and associated genes
The Multi-Object, Fiber-Fed Spectrographs for SDSS and the Baryon Oscillation Spectroscopic Survey
We present the design and performance of the multi-object fiber spectrographs
for the Sloan Digital Sky Survey (SDSS) and their upgrade for the Baryon
Oscillation Spectroscopic Survey (BOSS). Originally commissioned in Fall 1999
on the 2.5-m aperture Sloan Telescope at Apache Point Observatory, the
spectrographs produced more than 1.5 million spectra for the SDSS and SDSS-II
surveys, enabling a wide variety of Galactic and extra-galactic science
including the first observation of baryon acoustic oscillations in 2005. The
spectrographs were upgraded in 2009 and are currently in use for BOSS, the
flagship survey of the third-generation SDSS-III project. BOSS will measure
redshifts of 1.35 million massive galaxies to redshift 0.7 and Lyman-alpha
absorption of 160,000 high redshift quasars over 10,000 square degrees of sky,
making percent level measurements of the absolute cosmic distance scale of the
Universe and placing tight constraints on the equation of state of dark energy.
The twin multi-object fiber spectrographs utilize a simple optical layout
with reflective collimators, gratings, all-refractive cameras, and
state-of-the-art CCD detectors to produce hundreds of spectra simultaneously in
two channels over a bandpass covering the near ultraviolet to the near
infrared, with a resolving power R = \lambda/FWHM ~ 2000. Building on proven
heritage, the spectrographs were upgraded for BOSS with volume-phase
holographic gratings and modern CCD detectors, improving the peak throughput by
nearly a factor of two, extending the bandpass to cover 360 < \lambda < 1000
nm, and increasing the number of fibers from 640 to 1000 per exposure. In this
paper we describe the original SDSS spectrograph design and the upgrades
implemented for BOSS, and document the predicted and measured performances.Comment: 43 pages, 42 figures, revised according to referee report and
accepted by AJ. Provides background for the instrument responsible for SDSS
and BOSS spectra. 4th in a series of survey technical papers released in
Summer 2012, including arXiv:1207.7137 (DR9), arXiv:1207.7326 (Spectral
Classification), and arXiv:1208.0022 (BOSS Overview
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