3,632 research outputs found
Influence of Perinatal Exposure to a Polychlorinated Biphenyl Mixture on Learning and Memory, Hippocampal Size, and Estrogen Receptor-Beta Expression
Author Institution: Department of Biological Sciences, Bowling Green State UniversityAuthor Institution: Department of Psychology, Bowling Green State UniversityPerinatal exposure to PCB has been reported to cause a variety of health effects including endocrine disruption, and immunologic, reproductive, neurologic, and behavioral deficits. In the present study, a mixture of two PCB congeners, one noncoplanar (PCB 47) and one coplanar (PCB 77), were administered to young female Sprague-Dawley rats by route of maternal dietary consumption (either 12.5 ppm or 25.0 ppm, w/w). Impact on learning and memory were examined by radial arm maze on postnatal day 24-27. After behavioral tests were completed, the rats were transcardially perfused, and brains were excised. Immunohistochemistry for ER- β was carried out on free-floating sections. Sections were stained with cresyl violet stain, and hippocampal area was measured. A subjective comparison of staining density suggested a greater intensity of ER- β staining in female rat hippocampus exposed to PCB 47/77 at 25 ppm concentration. A decrease in the hippocampal area measurement was observed in the case of 25 ppm PCB exposed rats. Significant behavioral effects involving spatial learning and memory were not observed. However, animals exposed to PCB 47/77 at 25 ppm displayed a trend toward improved performance. Taken together, the combination in PCB exposed rats of reduced hippocampal size, increased ER-β concentration, and unaltered behavior suggests the existence of compensatory mechanisms in the animals
Identification of a novel retroviral gene unique to human immunodeficiency virus type 2 and simian immunodeficiency virus SIVMAC
Human and simian immunodeficiency-associated retroviruses are extraordinarily complex, containing at least five genes, tat, art, sor, R, and 3' orf, in addition to the structural genes gag, pol, and env. Recently, nucleotide sequence analysis of human immunodeficiency virus type 2 (HIV-2) and simian immunodeficiency virus SIVMAC revealed the existence of still another open reading frame, termed X, which is highly conserved between these two viruses but absent from HIV-1. In this report, we demonstrate for the first time that the X open reading frame represents a functional retroviral gene in both HIV-2 and SIVMAC and that it encodes a virion-associated protein of 14 and 12 kilodaltons, respectively. We also describe the production of recombinant TrpE/X fusion proteins in Escherichia coli and show that sera from some HIV-2-infected individuals specifically recognize these proteins
MO0NFALL: The Great Filter and Exo-Moon Occurrence
We observe neither life beyond Earth, nor moons around exoplanets, despite
the prevalence of Earth-like planets across the galaxy. We suggest Moonfall as
a possible mechanism to explain both simultaneously
Compendium-Wide Analysis of Pseudomonas aeruginosa Core and Accessory Genes Reveals Transcriptional Patterns across Strains PAO1 and PA14.
Pseudomonas aeruginosa is an opportunistic pathogen that causes difficult-to-treat infections. Two well-studied divergent P. aeruginosa strain types, PAO1 and PA14, have significant genomic heterogeneity, including diverse accessory genes present in only some strains. Genome content comparisons find core genes that are conserved across both PAO1 and PA14 strains and accessory genes that are present in only a subset of PAO1 and PA14 strains. Here, we use recently assembled transcriptome compendia of publicly available P. aeruginosa RNA sequencing (RNA-seq) samples to create two smaller compendia consisting of only strain PAO1 or strain PA14 samples with each aligned to their cognate reference genome. We confirmed strain annotations and identified other samples for inclusion by assessing each sample\u27s median expression of PAO1-only or PA14-only accessory genes. We then compared the patterns of core gene expression in each strain. To do so, we developed a method by which we analyzed genes in terms of which genes showed similar expression patterns across strain types. We found that some core genes had consistent correlated expression patterns across both compendia, while others were less stable in an interstrain comparison. For each accessory gene, we also determined core genes with correlated expression patterns. We found that stable core genes had fewer coexpressed neighbors that were accessory genes. Overall, this approach for analyzing expression patterns across strain types can be extended to other groups of genes, like phage genes, or applied for analyzing patterns beyond groups of strains, such as samples with different traits, to reveal a deeper understanding of regulation
Effects of Starting Stance on Base Running Sprint Speed in Softball Players
International Journal of Exercise Science 11(6): 179-186, 2018. Speed is a crucial aspect in softball, and can be the difference between winning and losing. Base stealing is a method used to produce runs. There has been debate over which starting position is the most advantageous to maximize acceleration and speed to reach the next base the fastest. The purpose of this study was to examine the effect of different starting stances on acceleration and speed phases in collegiate softball players. Seventeen healthy NCAA Division I women’s softball players (age = 19.9 ± 1.3yrs, height = 167.0 ± 5.4cm, mass = 74.8 ± 14.1kg) volunteered to participate. Three maximum 45 ft sprints, with one minute rest, were performed (with splits at 15, 30 and 45ft) for each of three starting stances (front foot on the base, back foot on the base, and cross over stance). A 1x3 repeated measures ANOVA for total time demonstrated that front foot on the base was significantly faster (2.51 ± 0.18s) than back foot on the base (2.70 ± 0.19s) and the cross over step (2.66 ± 0.23s). For all three splits, front foot on the base was also significantly faster (0.96 ± 0.07s, 0.81 ± 0.06s, and 0.73 ± 0.06s) than back foot on the base (1.10 ± 0.13s, 0.84 ± 0.05s, and 0.75 ± 0.43s) and cross over step (1.04 ± 0.09s, 0.84 ± 0.06s, and 0.75 ± 0.07s). The decrease in time for front foot on the base was probably the result of using the base to push against, like a sprinter’s block, to produce greater horizontal force to accelerate faster and reach a greater top speed. Coaches should teach their softball athletes to stand with their front foot on the base when base running
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