437 research outputs found

    LH RECEPTORS AND STEROIDOGENESIS IN DISTINCT POPULATIONS OF LEYDIG CELLS *

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74634/1/j.1749-6632.1982.tb23168.x.pd

    "You should go so that others can come"; The Role of Facilities in Determining an Early Departure after Childbirth in Morogoro Region, Tanzania.

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    Tanzania is among ten countries that account for a majority of the world's newborn deaths. However, data on time-to-discharge after facility delivery, receipt of postpartum messaging by time to discharge and women's experiences in the time preceding discharge from a facility after childbirth are limited. Household survey of 1267 women who delivered in the preceding 2-14 months; in-depth interviews with 24 women, 12 husbands, and 5 community elders. Two-thirds of women with vaginal, uncomplicated births departed within 12 h; 90 % within 24 h, and 95 % within 48 h. Median departure times varied significantly across facilities (hospital: 23 h, health center: 10 h, dispensary: 7 h, p < 0.001). Quantitative and qualitative data highlight the importance of type of facility and facility amenities in determining time-to-discharge. In multiple logistic regression, level of facility (hospital, health center, dispensary) was the only significant predictor of early discharge (p = 0.001). However across all types of facilities a majority of women depart before 24 h ranging from hospitals (54 %) to health centers (64 %) to dispensaries (74 %). Most women who experienced a delivery complication (56 %), gave birth by caesarean section (90 %), or gave birth to a pre-term baby (70 %) stayed longer than 24 h. Reasons for early discharge include: facility practices including discharge routines and working hours and facility-based discomforts for women and those who accompany them to facilities. Provision of postpartum counseling was inadequate regardless of time to discharge and regardless of type of facility where delivery occurred. Our quantitative and qualitative findings indicate that the level of facility care and comforts existing or lacking in a facility have the greatest effect on time to discharge. This suggests that individual or interpersonal characteristics play a limited role in deciding whether a woman would stay for shorter or longer periods. Implementation of a policy of longer stay must incorporate enhanced postpartum counseling and should be sensitive to women's perceptions that it is safe and beneficial to leave hospitals soon after birth

    Classification of the Nuclear Multifragmentation Phase Transition

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    Using a recently proposed classification scheme for phase transitions in finite systems [Phys.Rev.Lett.{\bf 84},3511 (2000)] we show that within the statistical standard model of nuclear multifragmentation the predicted phase transition is of first order.Comment: 5 pages, 4 eps figures, accepted for publication in Phys.Rev.C (in press

    Low Temperature Opacities

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    Previous computations of low temperature Rosseland and Planck mean opacities from Alexander & Ferguson (1994) are updated and expanded. The new computations include a more complete equation of state with more grain species and updated optical constants. Grains are now explicitly included in thermal equilibrium in the equation of state calculation, which allows for a much wider range of grain compositions to be accurately included than was previously the case. The inclusion of high temperature condensates such as Al2_2O3_3 and CaTiO3_3 significantly affects the total opacity over a narrow range of temperatures before the appearance of the first silicate grains. The new opacity tables are tabulated for temperatures ranging from 30000 K to 500 K with gas densities from 10−4^{-4} g cm−3^{-3} to 10−19^{-19} g cm−3^{-3}. Comparisons with previous Rosseland mean opacity calculations are discussed. At high temperatures, the agreement with OPAL and Opacity Project is quite good. Comparisons at lower temperatures are more divergent as a result of differences in molecular and grain physics included in different calculations. The computation of Planck mean opacities performed with the opacity sampling method are shown to require a very large number of opacity sampling wavelength points; previously published results obtained with fewer wavelength points are shown to be significantly in error. Methods for requesting or obtaining the new tables are provided.Comment: 39 pages with 12 figures. To be published in ApJ, April 200

    Analysis of genetically driven alternative splicing identifies FBXO38 as a novel COPD susceptibility gene

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    While many disease-associated single nucleotide polymorphisms (SNPs) are associated with gene expression (expression quantitative trait loci, eQTLs), a large proportion of complex disease genome-wide association study (GWAS) variants are of unknown function. Some of these SNPs may contribute to disease by regulating gene splicing. Here, we investigate whether SNPs that are associated with alternative splicing (splice QTL or sQTL) can identify novel functions for existing GWAS variants or suggest new associated variants in chronic obstructive pulmonary disease (COPD). RNA sequencing was performed on whole blood from 376 subjects from the COPDGene Study. Using linear models, we identified 561,060 unique sQTL SNPs associated with 30,333 splice sites corresponding to 6,419 unique genes. Similarly, 708,928 unique eQTL SNPs involving 15,913 genes were detected at 10% FDR. While there is overlap between sQTLs and eQTLs, 55.3% of sQTLs are not eQTLs. Co-localization analysis revealed that 7 out of 21 loci associated with COPD (p</p

    Representation of Time-Varying Stimuli by a Network Exhibiting Oscillations on a Faster Time Scale

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    Sensory processing is associated with gamma frequency oscillations (30–80 Hz) in sensory cortices. This raises the question whether gamma oscillations can be directly involved in the representation of time-varying stimuli, including stimuli whose time scale is longer than a gamma cycle. We are interested in the ability of the system to reliably distinguish different stimuli while being robust to stimulus variations such as uniform time-warp. We address this issue with a dynamical model of spiking neurons and study the response to an asymmetric sawtooth input current over a range of shape parameters. These parameters describe how fast the input current rises and falls in time. Our network consists of inhibitory and excitatory populations that are sufficient for generating oscillations in the gamma range. The oscillations period is about one-third of the stimulus duration. Embedded in this network is a subpopulation of excitatory cells that respond to the sawtooth stimulus and a subpopulation of cells that respond to an onset cue. The intrinsic gamma oscillations generate a temporally sparse code for the external stimuli. In this code, an excitatory cell may fire a single spike during a gamma cycle, depending on its tuning properties and on the temporal structure of the specific input; the identity of the stimulus is coded by the list of excitatory cells that fire during each cycle. We quantify the properties of this representation in a series of simulations and show that the sparseness of the code makes it robust to uniform warping of the time scale. We find that resetting of the oscillation phase at stimulus onset is important for a reliable representation of the stimulus and that there is a tradeoff between the resolution of the neural representation of the stimulus and robustness to time-warp. Author Summary Sensory processing of time-varying stimuli, such as speech, is associated with high-frequency oscillatory cortical activity, the functional significance of which is still unknown. One possibility is that the oscillations are part of a stimulus-encoding mechanism. Here, we investigate a computational model of such a mechanism, a spiking neuronal network whose intrinsic oscillations interact with external input (waveforms simulating short speech segments in a single acoustic frequency band) to encode stimuli that extend over a time interval longer than the oscillation's period. The network implements a temporally sparse encoding, whose robustness to time warping and neuronal noise we quantify. To our knowledge, this study is the first to demonstrate that a biophysically plausible model of oscillations occurring in the processing of auditory input may generate a representation of signals that span multiple oscillation cycles.National Science Foundation (DMS-0211505); Burroughs Wellcome Fund; U.S. Air Force Office of Scientific Researc
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