326 research outputs found

    Female Reproductive Traits in Selected Arkansas Snakes

    Get PDF
    Female reproductive characteristics of 17 genera of Arkansas snakes (27 species and subspecies) were examined. Most of the snakes (n= 495) were collected over a 10-year span (1984-1993). Methods used to estimate clutch and/or litter size were as follows: 1) counts of previtellogenic ovarian follicles,2) counts of vitellogenic ovarian follicles,3) counts of oviductal eggs or embryos, 4) counts of corpora luteal scars, and 5) counts of neonates from egg clutches or litters. In several species, Method 1 tended to overestimate clutch size as determined by Method 2 by as much as 100% (e.g., in Diadophis punctatus, Elaphe obsoleta, and Lampropeltis getula), whereas these methods produced similar counts in Virginia striatula and Thamnophis proximus. The largest clutch size as estimated by Method 1 was 79 ova in a 744 mm in snout-vent length (SVL) individual of Thamnophis sirtalis; the smallest clutch size as recorded by this method was in Carphophis vermis (2 ova; 182 mm in SVL). Method 2 reduces the total egg count by one third over Method 1 in most species, and this count was very similar to the estimates obtained by Method 3, the most reliable way to estimate clutch or litter size (without actually having counts from egg clutches or litters). The presence of atretic ovarian follicles accounts for discrepancies found between clutch size estimates using Methods 1 and 2 as compared to Method 3. Comparisons of clutch sizes in Arkansas specimens to those recorded for snake species in neighboring states revealed similar sizes in 13 species; counts were larger in 8 species from Arkansas and smaller in only one species

    Pulmonary arterial pressures, arterial blood-gas tensions, and serum biochemistry of beef calves born and raised at high altitude

    Get PDF
    Includes bibliographical references (page 8).High-altitude exposure is physiologically challenging. This is particularly true for animals native to low-altitude environments, such as British breeds of cattle. The objective of this study was to document the effect of high altitude on select physiological parameters of healthy beef calves (Bos taurus) born and raised on a high-altitude ranch typical of the Rocky Mountain region. Pulmonary arterial pressures, arterial blood-gas tensions, serum biochemistry, and hematocrit were evaluated. The calves studied were a composite of British (50%-75%) and Continental (25-50%) breeds born on one ranch at an altitude of 2410 m. Calves were sampled at an altitude of 2410 m when 1 month old and again at an altitude of 2730 m when 3 and 6 months old. Between 3 and 6 months of age, calves had access to grazing from 2730 m to approximately 3500 m above sea level. On each occasion, 16 to 50 calves were sampled. Only calves that remained healthy throughout all three testing periods were included in the dataset. Calves with the highest pulmonary arterial pressures at 1 month of age tended to have the highest pressures at 6 months of age (r = 0.43, P = 0.16, n = 12). Respiratory alkalosis was greatest at 6 months of age (pH 7.48 ± 0.06). Mean alveolar-arterial oxygen pressure gradients were 11.7and 11.6 mmHg at 3 and 6 months of age, indicating poor transfer of oxygen from the alveoli into the pulmonary blood. Median values for blood lactate ranged from 1.4 to 3.4 mmol/L indicating substantial anaerobic respiration at all ages. Mean hematocrits were ≤ 35.7%, only slightly higher than values obtained from age-matched calves at sea level. These results suggest that the provision of oxygen to the peripheral tissues of beef calves may be compromised at altitudes over 2410 m. This may have implications for diseases of the cardiopulmonary system.Published with support from the Colorado State University Libraries Open Access Research and Scholarship Fund

    Genome Report: Whole Genome Sequence of Two Wild-Derived Mus musculus domesticus Inbred Strains, LEWES/EiJ and ZALENDE/EiJ, with Different Diploid Numbers

    Get PDF
    Wild-derived mouse inbred strains are becoming increasingly popular for complex traits analysis, evolutionary studies, and systems genetics. Here, we report the whole-genome sequencing of two wild-derived mouse inbred strains, LEWES/EiJ and ZALENDE/EiJ, of Mus musculus domesticus origin. These two inbred strains were selected based on their geographic origin, karyotype, and use in ongoing research. We generated 14× and 18× coverage sequence, respectively, and discovered over 1.1 million novel variants, most of which are private to one of these strains. This report expands the number of wild-derived inbred genomes in the Mus genus from six to eight. The sequence variation can be accessed via an online query tool; variant calls (VCF format) and alignments (BAM format) are available for download from a dedicated ftp site. Finally, the sequencing data have also been stored in a lossless, compressed, and indexed format using the multi-string Burrows-Wheeler transform. All data can be used without restriction

    Polymorphisms in leucine-rich repeat genes are associated with autism spectrum disorder susceptibility in populations of European ancestry

    Get PDF
    BACKGROUND: Autism spectrum disorders (ASDs) are a group of highly heritable neurodevelopmental disorders which are characteristically comprised of impairments in social interaction, communication and restricted interests/behaviours. Several cell adhesion transmembrane leucine-rich repeat (LRR) proteins are highly expressed in the nervous system and are thought to be key regulators of its development. Here we present an association study analysing the roles of four promising candidate genes - LRRTM1 (2p), LRRTM3 (10q), LRRN1 (3p) and LRRN3 (7q) - in order to identify common genetic risk factors underlying ASDs. METHODS: In order to gain a better understanding of how the genetic variation within these four gene regions may influence susceptibility to ASDs, a family-based association study was undertaken in 661 families of European ancestry selected from four different ASD cohorts. In addition, a case-control study was undertaken across the four LRR genes, using logistic regression in probands with ASD of each population against 295 ECACC controls. RESULTS: Significant results were found for LRRN3 and LRRTM3 (P < 0.005), using both single locus and haplotype approaches. These results were further supported by a case-control analysis, which also highlighted additional SNPs in LRRTM3. CONCLUSIONS: Overall, our findings implicate the neuronal leucine-rich genes LRRN3 and LRRTM3 in ASD susceptibility

    Digital Signal Processing

    Get PDF
    Contains research objectives and summary of research on seven research projects.U. S. Navy Office of Naval Research (Contract N00014-75-C-0951)National Science Foundation (Grant ENG71-02319-A02

    Inclusive Electron Scattering from Nuclei at x1x \simeq 1

    Get PDF
    The inclusive A(e,e') cross section for x1x \simeq 1 was measured on 2^2H, C, Fe, and Au for momentum transfers Q2Q^2 from 1-7 (GeV/c)2^2. The scaling behavior of the data was examined in the region of transition from y-scaling to x-scaling. Throughout this transitional region, the data exhibit ξ\xi-scaling, reminiscent of the Bloom-Gilman duality seen in free nucleon scattering.Comment: 4 pages, RevTeX; 4 figures (postscript in .tar.Z file

    A-dependence of nuclear transparency in quasielastic A(e,e'p) at high Q^2

    Get PDF
    The A-dependence of the quasielastic A(e,e'p) reaction has been studied at SLAC with H-2, C, Fe, and Au nuclei at momentum transfers Q^2 = 1, 3, 5, and 6.8 (GeV/c)^2. We extract the nuclear transparency T(A,Q^2), a measure of the average probability that the struck proton escapes from the nucleus A without interaction. Several calculations predict a significant increase in T with momentum transfer, a phenomenon known as Color Transparency. No significant rise within errors is seen for any of the nuclei studied.Comment: 5 pages incl. 2 figures, Caltech preprint OAP-73

    Measurement of Longitudinal Spin Transfer to Lambda Hyperons in Deep-Inelastic Lepton Scattering

    Get PDF
    Spin transfer in deep-inelastic Lambda electroproduction has been studied with the HERMES detector using the 27.6 GeV polarized positron beam in the HERA storage ring. For an average fractional energy transfer = 0.45, the longitudinal spin transfer from the virtual photon to the Lambda has been extracted. The spin transfer along the Lambda momentum direction is found to be 0.11 +/- 0.17 (stat) +/- 0.03 (sys); similar values are found for other possible choices for the longitudinal spin direction of the Lambda. This result is the most precise value obtained to date from deep-inelastic scattering with charged lepton beams, and is sensitive to polarized up quark fragmentation to hyperon states. The experimental result is found to be in general agreement with various models of the Lambda spin content, and is consistent with the assumption of helicity conservation in the fragmentation process.Comment: 8 pages, 3 figures; new version has an expanded discussion and small format change

    Athlete experiences of disordered eating in sport

    Get PDF
    To date, research into disordered eating in sport has focused on the prevalence and the identification of putative risk factors. Findings suggest that elite female athletes participating in sports with a focus on leanness or aesthetics are at greatest risk. A paucity of research remains as to the period after onset and how existing sufferers manage their illness over time. In line with the principles of interpretative phenomenological analysis (IPA), this study 'gives voice' to four athletes who have experienced disordered eating, documenting their personal accounts and interpreting these accounts from a psychological perspective. In‐depth, semi‐structured interviews were conducted and verbatim transcripts were analysed according to the procedures of IPA. Three superordinate themes emerged from the data: the struggle to disclose, social support needs and identity challenges. Athletes' stories provided rich descriptions of their subjective disordered eating experiences. Their accounts give critical insight into the impact of eating disturbance on the lives of athletes. Future research should continue to identify athletes with existing eating problems in order to improve understanding as to how such individuals can best be helped
    corecore