13,876 research outputs found

    Effect of Perceived Stress on Cytokine Production in Healthy College Students

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    Chronic psychological stress impairs antibody synthesis following influenza vaccination. Chronic stress also increases circulating levels of proinflammatory cytokines and glucocorticoids in elders and caregivers, which can impair antibody synthesis. The purpose of this study was to determine whether psychological stress increases ex vivo cytokine production or decreases glucocorticoid sensitivity (GCS) of peripheral blood leukocytes from healthy college students. A convenience sample of Reserve Officer Training Corps (ROTC) students completed the Perceived Stress Scale (PSS). Whole blood was incubated in the presence of influenza vaccine and dexamethasone to evaluate production of interleukin-6 (IL-6), interleukin-1-beta (IL-1β), tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-γ). Multiple regression models controlling for age, gender, and grade point average revealed a negative relationship between PSS and GCS for vaccine-stimulated production of IL-1β, IL-6, and TNF-α. These data increase our understanding of the complex relationship between chronic stress and immune function

    Calcium Exerts a Strong Influence upon Phosphohydrolase Gene Abundance and Phylogenetic Diversity in Soil

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    The mechanisms by which microbial communities maintain functions within the context of changing environments are key to a wide variety of environmental processes. In soil, these mechanisms support fertility. Genes associated with hydrolysis of organic phosphoesters represent an interesting set of genes with which to study maintainance of function in microbiomes, since they participate in the same process and so in many respects are interchangeable. Here, we shown that the richness of ecotypes for each gene varies considerably in response to organic manuring and various inorganic fertilizer combinations . We show, at unprecedented phylogenetic resolution, that phylogenetic diversity of phosphohydrolase genes are more responsive to soil management and edaphic factors than the taxonomic biomarker 16S rRNA gene. Available phosphorus exerted no significant influence on gene distribution: instead we observed gene niche separation according to soil pH and exchangeable calcium. We infer a degree of competition between genes, ensuring that a gene most optimally adapted to the prevailing edaphic factors spreads through the population, thus maintaining microbiome function

    Systemic defense priming by Pseudomonas putida KT2440 in maize depends on benzoxazinoid exudation from the roots

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    Exudation of benzoxazinoid metabolites from roots of young maize seedlings recruits the rhizobacterial strain Pseudomonas putida KT2440 from the soil to the rhizosphere. In this study, we have investigated whether these rhizobacteria are beneficial for maize by eliciting systemic defense priming. Root colonization of the maize hybrid cultivar Delprim by P. putida primed wound- and jasmonic acid (JA)-inducible emission of aromatic and terpenoid volatiles, but not the emission of the green leaf volatile (Z)-3-hexenyl acetate. Furthermore, root colonization by P. putida primed stress-inducible transcription of the JA-dependent gene SerPIN, whereas JA-dependent induction of the MPI gene was unaffected. Systemic priming of SerPIN by P. putida only occurred in benzoxazinoid-producing plants, and was absent in benzoxazinoid-deficient plants. The results from this study suggest that root colonization by P. putida primes a selection of JA-dependent defenses in Maize, which is reliant on benzoxazinoid exudation from the roots

    Out Online: The Experiences of Lesbian, Gay, Bisexual and Transgender Youth on the Internet

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    This report examines the online experiences of LGBT students in 6-12th grade. LGBT youth experience nearly three times as much bullying and harassment online as non-LGBT youth, but also find greater peer support, access to health information and opportunities to be civically engaged

    Oxidation processes in magneto-optic and related materials

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    The surface oxidation processes of thin films of magneto-optic materials, such as the rare-earth transition metal alloys have been studied, starting in ultrahigh vacuum environments, using surface analysis techniques, as a way of modeling the oxidation processes which occur at the base of a defect in an overcoated material, at the instant of exposure to ambient environments. Materials examined have included FeTbCo alloys, as well as those same materials with low percentages of added elements, such a Ta, and their reactivities to both O2 and H2O compared with materials such as thin Fe films coated with ultrathin adlayers of Ti. The surface oxidation pathways for these materials is reviewed, and XPS data presented which indicates the type of oxides formed, and a critical region of Ta concentration which provides optimum protection

    Star Formation and AGN in the Core of the Shapley Supercluster: A VLA Survey of A3556, A3558, SC1327-312, SC1329-313, and A3562

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    The core of the Shapley supercluster (A3556, A3558, SC1327-312, SC1329-313, and A3562) is an ideal region in which to study the effects of cluster mergers on the activity of individual galaxies. This paper presents the most comprehensive radio continuum investigation of the region, relying on a 63-pointing mosaic obtained with the Very Large Array yielding an areal coverage of nearly 7 square degrees. The mosaic provides a typical sensitivity of about 80 uJy at a resolution of 16", enabling detection of galaxies with star formation rates as low as 1 solar mass per year. The radio data are complemented by optical imaging in B and R, producing a catalog of 210 radio-detected galaxies with m_R <= 17.36 (M_R <= -19). At least 104 of these radio-detected galaxies are members of the supercluster on the basis of public velocity measurements. Across the entire core of the supercluster, there appears to be a significant deficit of radio galaxies at intermediate optical magnitudes (M_R between -21 and -22). This deficit is offset somewhat by an increase in the frequency with which brighter galaxies (M_R less than -22) host radio sources. More dramatic is the highly significant increase in the probability for fainter galaxies (M_R between -20 and -21) in the vicinity of A3562 and SC1329-313 to be associated with radio emission. The radio and optical data for these sources strongly suggest that these active galaxies are powered by star formation. In conjunction with recent X-ray analysis, this is interpreted as young starbursts related to the recent merger of SC1329-313 with A3562 and the rest of the supercluster.Comment: Accepted by AJ; 50 pages, including 16 figures (for full resolution PDF, see http://mywebpages.comcast.net/nealamiller2/Shapley_pp.pdf

    Measuring gravitational lens time delays using low-resolution radio monitoring observations

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    Obtaining lensing time delay measurements requires long-term monitoring campaigns with a high enough resolution (< 1 arcsec) to separate the multiple images. In the radio, a limited number of high-resolution interferometer arrays make these observations difficult to schedule. To overcome this problem, we propose a technique for measuring gravitational time delays which relies on monitoring the total flux density with low-resolution but high-sensitivity radio telescopes to follow the variation of the brighter image. This is then used to trigger high-resolution observations in optimal numbers which then reveal the variation in the fainter image. We present simulations to assess the efficiency of this method together with a pilot project observing radio lens systems with the Westerbork Synthesis Radio Telescope (WSRT) to trigger Very Large Array (VLA) observations. This new method is promising for measuring time delays because it uses relatively small amounts of time on high-resolution telescopes. This will be important because instruments that have high sensitivity but limited resolution, together with an optimum usage of followup high-resolution observations from appropriate radio telescopes may in the future be useful for gravitational lensing time delay measurements by means of this new method.Comment: 10 pages, 7 figures, accepted by MNRA
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