65,405 research outputs found
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A critical analysis of COA research.
Five experts respected for their significant contributions to the scientific literature on children of alcoholics (COA's) offer their perspectives in a panel discussion format. The panel members reflect on the historical roots of COA research and comment on its current status and future direction. Enriched by the panelists' variety of backgrounds, research interests, and approaches, the discussion emphasizes the need to consider multiple variables that influence the risk for alcoholism among COA's
The Case for Combining a Large Low-Band Very High Frequency Transmitter With Multiple Receiving Arrays for Geospace Research: A Geospace Radar
We argue that combining a highâpower, largeâaperture radar transmitter with several largeâaperture receiving arrays to make a geospace radarâa radar capable of probing nearâEarth space from the upper troposphere through to the solar coronaâwould transform geospace research. We review the emergence of incoherent scatter radar in the 1960s as an agent that unified early, pioneering research in geospace in a common theoretical, experimental, and instrumental framework, and we suggest that a geospace radar would have a similar effect on future developments in space weather research. We then discuss recent developments in radioâarray technology that could be exploited in the development of a geospace radar with new or substantially improved capabilities compared to the radars in use presently. A number of applications for a geospace radar with the new and improved capabilities are reviewed including studies of meteor echoes, mesospheric and stratospheric turbulence, ionospheric flows, plasmaspheric and ionospheric irregularities, and reflection from the solar corona and coronal mass ejections. We conclude with a summary of technical requirements
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Following the rivers: historical reconstruction of California voles Microtus californicus (Rodentia: Cricetidae) in the deserts of eastern California
The California vole, Microtus californicus, restricted to habitat patches where water is available nearly year-round, is a remnant of the mesic history of the southern Great Basin and Mojave deserts of eastern California. The history of voles in this region is a model for species-edge population dynamics through periods of climatic change. We sampled voles from the eastern deserts of California and examined variation in the mitochondrial cytb gene, three nuclear intron regions, and across 12 nuclear microsatellite markers. Samples are allocated to two mitochondrial clades: one associated with southern California and the other with central and northern California. The limited mtDNA structure largely recovers the geographical distribution, replicated by both nuclear introns and microsatellites. The most remote population, Microtus californicus scirpensis at Tecopa near Death Valley, was the most distinct. This population shares microsatellite alleles with both mtDNA clades, and both its northern clade nuclear introns and southern clade mtDNA sequences support a hybrid origin for this endangered population. The overall patterns support two major invasions into the desert through an ancient system of riparian corridors along streams and lake margins during the latter part of the Pleistocene followed by local in situ divergence subsequent to late Pleistocene and Holocene drying events. Changes in current water resource use could easily remove California voles from parts of the desert landscape
Mechanisms of dysregulation of low-density lipoprotein receptor expression in vascular smooth muscle cells by inflammatory cytokines
Objective - Although inflammation is a recognized feature of atherosclerosis, the impact of inflammation on cellular cholesterol homeostasis is unclear. This study focuses on the molecular mechanisms by which inflammatory cytokines disrupt low-density lipoprotein (LDL) receptor regulation.Methods and Results - IL-1 beta enhanced transformation of vascular smooth muscle cells into foam cells by increasing uptake of unmodified LDL via LDL receptors and by enhancing cholesterol esterification as demonstrated by Oil Red O staining and direct assay of intracellular cholesterol concentrations. In the absence of IL-1 beta, a high concentration of LDL decreased LDL receptor promoter activity, mRNA synthesis and protein expression. However, IL-1 beta enhanced LDL receptor expression, overriding the suppression usually induced by a high concentration of LDL and inappropriately increasing LDL uptake. Exposure to IL-1 beta also caused overexpression of the sterol regulatory element binding protein ( SREBP) cleavage-activating protein ( SCAP), and enhanced its translocation from the endoplasmic reticulum to the Golgi, where it is known to cleave SREBP, thereby enhancing LDL receptor gene expression.Conclusions - These observations demonstrate that IL-1 beta disrupts cholesterol-mediated LDL receptor feedback regulation, permitting intracellular accumulation of unmodified LDL and causing foam cell formation. The implication of these findings is that inflammatory cytokines may contribute to intracellular LDL accumulation without previous modification of the lipoprotein
Timescale Spectra in High Energy Astrophysics
A technique of timescale analysis performed directly in the time domain has
been developed recently. We have applied the technique to studying rapid
variabilities of hard X-rays from neutron star and black hole binaries,
gamma-ray bursts and terrestrial gamma-ray flashes. The results indicate that
the time domain method of spectral analysis is a powerful tool in revealing the
underlying physics in high-energy processes in objects.Comment: 7 pages, 4 figures. Invited talk at the 6th Pacific Rim Conference on
Steller Astrophysic
A Neural Attention Model for Categorizing Patient Safety Events
Medical errors are leading causes of death in the US and as such, prevention
of these errors is paramount to promoting health care. Patient Safety Event
reports are narratives describing potential adverse events to the patients and
are important in identifying and preventing medical errors. We present a neural
network architecture for identifying the type of safety events which is the
first step in understanding these narratives. Our proposed model is based on a
soft neural attention model to improve the effectiveness of encoding long
sequences. Empirical results on two large-scale real-world datasets of patient
safety reports demonstrate the effectiveness of our method with significant
improvements over existing methods.Comment: ECIR 201
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Follow-up examination of linkage and association to chromosome 1q43 in multiple sclerosis.
Multiple sclerosis (MS) is a debilitating neuroimmunological and neurodegenerative disease affecting >4,00,000 individuals in the United States. Population and family-based studies have suggested that there is a strong genetic component. Numerous genomic linkage screens have identified regions of interest for MS loci. Our own second-generation genome-wide linkage study identified a handful of non-major histocompatibility complex regions with suggestive linkage. Several of these regions were further examined using single-nucleotide polymorphisms (SNPs) with average spacing between SNPs of approximately 1.0 Mb in a dataset of 173 multiplex families. The results of that study provided further evidence for the involvement of the chromosome 1q43 region. This region is of particular interest given linkage evidence in studies of other autoimmune and inflammatory diseases including rheumatoid arthritis and systemic lupus erythematosus. In this follow-up study, we saturated the region with approximately 700 SNPs (average spacing of 10 kb per SNP) in search of disease-associated variation within this region. We found preliminary evidence to suggest that common variation within the RGS7 locus may be involved in disease susceptibility
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