454 research outputs found

    Clinical Typifications by Wives of Professional Athletes: The Field Researcher as Therapist

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    In addressing an often neglected aspect of qualitative research, this paper explores how our research identities are constructed by those we are studying. During my field research on wives of professional athletes, I gradually became aware of the ways in which I was typified as a therapist. Despite my attempts to deconstruct this research identity, and the therapeutic role I was placed in, their construction of a therapist self persisted. I examine how this serendipitous process emerged in the context of sequential interviewing by assessing specific characteristics, and certain conditions, which shaped their typification of a therapist. The ways in which our research identities are constructed by those we study can provide us with another important dimension of knowledge about those we study

    Delayed effects of acute radiation exposure on the cardiovascular system using a murine model of the hematopoietic acute radiation syndrome

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    poster abstractIntroduction. Exposure to high level radiation from accidents or belligerent activities results in acute and chronic organ damage. The hematopoietic system is the most sensitive organ to radiation damage (2-10 Gy) and results in the hematopoietic acute radiation syndrome (H-ARS). Survivors of H-ARS are plagued months to years later with delayed effects of acute radiation exposure (DEARE), characterized by chronic illnesses affecting multiple organ systems. Previous results using the murine H-ARS model showed numerous kidney and heart DEARErelated pathologies similar to humans, including tissue fibrosis and elevated blood urea nitrogen. The goal of this study was to utilize the murine H-ARS model to determine possible roles for abnormal iron metabolism, inflammation, oxidant stress, and senescence in the development of cardiac DEARE. Methods. Mice (C57BL/6; 12 week-old) received total body irradiation (TBI: ~8.5-8.7 Gy, 137Cs, LD50to LD70) and hearts were harvested at various times post-TBI from H-ARS survivors. Paraffin tissue sections were stained with hematoxylin/eosin or Perls Prussian Blue, or reacted with a macrophage-specific antibody (F4/80). Total RNA was purified from fresh tissue and changes in mRNA expression were assessed by real-time PCR for the senescence marker p16 and NADPH oxidase subunits Nox2, Nox4, or p47phox. Results/Significance. Compared to age-matched non-irradiated controls (NI), tissue iron deposits were increased in irradiated (IR) hearts at 4 months, and progressively declined with time post-TBI. Numbers of macrophages were greater in IR vs. NI sections at all time points and decreased with time post-TBI. Nox2 and Nox4 mRNA expression was increased at both 9 and 21 months post-TBI, but p47phox increased only at 21 months. Expression of p16 in IR heart was increased at 7, but not at 22 months post-TBI. Taken together, the results indicate abnormal iron metabolism, inflammation, oxidant stress, and early senescence may contribute to development of cardiac DEARE

    DNA extraction from old herbarium material of Veronica subgen. Pseudolysimachium (Plantaginaceae)

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    Herbarium specimens have become a major source of information in molecular biodiversity research, framing the term "herbarium genomics". However, obtaining good DNA from old herbarium specimens is still a challenge. Currently, DNA extraction methods from old herbarium material often yield highly degraded and fragmented DNA. A number of studies have discussed such methods, especially how to avoid further DNA fragmentation. This study aims to compare different DNA extraction methods applied to old herbarium material from Veronica subg. Pseudolysimachium. One such method is a CTABbased DNA extraction followed by a clean-up with paramagnetic beads that is used in the Jodrell Laboratory, Royal Botanic Gardens Kew, UK. This method was compared to a modified NucleoSpin Plant II protocol, based on silica columns, as used at the Technical University Munich-Freising, which was already successfully used for extracting DNA from a Linnean type specimen. Further tests were conducted on the influence of incubation time on the CTAB DNA extraction protocol with a subsample of specimens. Our preliminary results suggest that CTAB DNA extraction might have some advantages in specific cases but also that silica column-based methods have fewer problems with contamination by polysaccharides and polyphenolic compounds. Regarding the incubation time, we did not observe a clear pattern, but we developed several ideas on how to proceed with tests to find an optimal DNA extraction protocol to deal with highly fragmented DNA. Taking practical considerations into account, the column-based method proves to be preferable, especially when trying to reduce the amount of leaf tissue used, but further modifications of both methods should be explored

    Static Gravitational Global Monopoles

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    Static solutions in spherical symmetry are found for gravitating global monopoles. Regular solutions lacking a horizon are found for η<1/8π\eta < 1/\sqrt{8\pi}, where η\eta is the scale of symmetry breaking. Apparently regular solutions with a horizon are found for 1/\sqrt{8\pi} \le \eta \alt \sqrt{3/8\pi}. Though they have a horizon, they are not Schwarzschild. The solution for η=1/8π\eta = 1/\sqrt{8\pi} is argued to have a horizon at infinity. The failure to find static solutions for η>3/8π0.3455\eta > \sqrt{3/8\pi} \approx 0.3455 is consistent with findings that topological inflation begins at η0.33\eta \approx 0.33.Comment: 4 pages, 6 figure

    Patternize: An R Package For Quantifying Color Pattern Variation

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    The use of image data to quantify, study and compare variation in the colors and patterns of organisms requires the alignment of images to establish homology, followed by color-based segmentation of images. Here we describe an R package for image alignment and segmentation that has applications to quantify color patterns in a wide range of organisms. patternize is an R package that quantifies variation in color patterns obtained from image data. patternize first defines homology between pattern positions across specimens either through manually placed homologous landmarks or automated image registration. Pattern identification is performed by categorizing the distribution of colors using an RGB threshold, k-means clustering or watershed transformation. We demonstrate that patternize can be used for quantification of the color patterns in a variety of organisms by analyzing image data for butterflies, guppies, spiders and salamanders. Image data can be compared between sets of specimens, visualized as heatmaps and analyzed using principal component analysis (PCA). patternize has potential applications for fine scale quantification of color pattern phenotypes in population comparisons, genetic association studies and investigating the basis of color pattern variation across a wide range of organisms.NSF grant DEB-1257839 NIH grant 5P20GM103475-1

    mu-Opioid inhibition of Ca2+ currents and secretion in isolated terminals of the neurohypophysis occurs via ryanodine-sensitive Ca2+ stores

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    mu-Opioid agonists have no effect on calcium currents (I(Ca)) in neurohypophysial terminals when recorded using the classic whole-cell patch-clamp configuration. However, mu-opioid receptor (MOR)-mediated inhibition of I(Ca) is reliably demonstrated using the perforated-patch configuration. This suggests that the MOR-signaling pathway is sensitive to intraterminal dialysis and is therefore mediated by a readily diffusible second messenger. Using the perforated patch-clamp technique and ratio-calcium-imaging methods, we describe a diffusible second messenger pathway stimulated by the MOR that inhibits voltage-gated calcium channels in isolated terminals from the rat neurohypophysis (NH). Our results show a rise in basal intracellular calcium ([Ca(2+)]i) in response to application of [D-Ala(2)-N-Me-Phe(4),Gly5-ol]-Enkephalin (DAMGO), a MOR agonist, that is blocked by D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP), a MOR antagonist. Buffering DAMGO-induced changes in [Ca(2+)]i with BAPTA-AM completely blocked the inhibition of both I(Ca) and high-K(+)-induced rises in [Ca(2+)]i due to MOR activation, but had no effect on kappa-opioid receptor (KOR)-mediated inhibition. Given the presence of ryanodine-sensitive stores in isolated terminals, we tested 8-bromo-cyclic adenosine diphosphate ribose (8Br-cADPr), a competitive inhibitor of cyclic ADP-ribose (cADPr) signaling that partially relieves DAMGO inhibition of I(Ca) and completely relieves MOR-mediated inhibition of high-K(+)-induced and DAMGO-induced rises in [Ca(2+)]i. Furthermore, antagonist concentrations of ryanodine completely blocked MOR-induced increases in [Ca(2+)]i and inhibition of I(Ca) and high-K(+)-induced rises in [Ca(2+)]i while not affecting KOR-mediated inhibition. Antagonist concentrations of ryanodine also blocked MOR-mediated inhibition of electrically-evoked increases in capacitance. These results strongly suggest that a key diffusible second messenger mediating the MOR-signaling pathway in NH terminals is [Ca(2+)]i released by cADPr from ryanodine-sensitive stores

    Impact of mooring activities on carbon stocks in seagrass meadows

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    Boating activities are one of the causes that threaten seagrass meadows and the ecosystem services they provide. Mechanical destruction of seagrass habitats may also trigger the erosion of sedimentary organic carbon (Corg) stocks, which may contribute to increasing atmospheric CO2. This study presents the first estimates of loss of Corg stocks in seagrass meadows due to mooring activities in Rottnest Island, Western Australia. Sediment cores were sampled from seagrass meadows and from bare but previously vegetated sediments underneath moorings. The Corg stores have been compromised by the mooring deployment from 1930s onwards, which involved both the erosion of existing sedimentary Corg stores and the lack of further accumulation of Corg. On average, undisturbed meadows had accumulated ~6.4 Kg Corg m−2 in the upper 50 cm-thick deposits at a rate of 34 g Corg m−2 yr−1. The comparison of Corg stores between meadows and mooring scars allows us to estimate a loss of 4.8 kg Corg m−2 in the 50 cm thick deposits accumulated over ca. 200 yr as a result of mooring deployments. These results provide key data for the implementation of Corg storage credit offset policies to avoid the conversion of seagrass ecosystems and contribute to their preservation

    Homonegativity, Substance Use, Sexual Risk Behaviors, and HIV Status in Poor and Ethnic Men Who Have Sex with Men in Los Angeles

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    This study evaluates associations between internalized homonegativity and demographic factors, drug use behaviors, sexual risk behaviors, and HIV status among men who have sex with men (MSM) and with men and women (MSM/W). Participants were recruited in Los Angeles County using respondent-driven sampling (RDS) and completed the Internalized Homonegativity Inventory (IHNI) and questionnaires on demographic and behavioral factors. Biological samples were tested for HIV and for recent cocaine, methamphetamine, and heroin use. The 722 MSM and MSM/W participants were predominantly African American (44%) and Hispanic (28%), unemployed (82%), homeless (50%), and HIV positive (48%) who used drugs in the past 6&nbsp;months (79.5%). Total and Personal Homonegativity, Gay Affirmation, and Morality of Homosexuality IHNI scores were significantly higher for African American men than for other ethnicities, for MSM/W than for MSM, for recent cocaine users than for recent methamphetamine users, and for HIV-seronegative men than for HIV-seropositive men. Linear regression showed the Gay Affirmation scale significantly and inversely correlated with the number of sexual partners when controlling for effects of ethnicity/race and sexual identification, particularly for men who self-identified as straight. Highest IHNI scores were observed in a small group of MSM/W (n = 62) who never tested for HIV. Of these, 26% tested HIV positive. Findings describe ways in which internalized homophobia is a barrier to HIV testing and associated HIV infection and signal distinctions among participants in this sample that can inform targeted HIV prevention efforts aimed at increasing HIV testing

    The chronology of Gezer from the end of the late bronze age to iron age II:A meeting point for radiocarbon, archaeology egyptology and the Bible

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    The ancient southern Levantine city of Gezer is well-known from Egyptian, Biblical and Assyrian sources, associated with power struggles, conquests, and intriguing tales involving figures such as Milkilu and Amenhotep III, Merneptah, the Philistines, Solomon and his unidentified pharaonic father-in-law, and Shishak / Sheshonq I. Since the identity of Gezer with “Tell Jezer” is quite literally ‘set in stone’ by some dozen boundary inscriptions, along with impressive Bronze and Iron Age remains, research at this site provides a unique opportunity to compare text and archaeology, as well as bring to light the undocumented everyday lives of the city’s inhabitants. In this endeavour, independent scientific dating is crucial for anchoring the remains chronologically. This paper presents the first substantial radiocarbon dataset and Bayesian chronological analysis for Gezer spanning the last part of the Late Bronze Age (LBA; LB IIB) through Iron Age II. The dataset derives from an essentially continuous stratigraphic sequence exposed in recent years by the Tandy expedition along the central-southern edge of the site. The results allow us for the first time to independently determine the site chronology, test the viability (from a chronological perspective) of proposed historical correlations, and contribute to debates on Philistine and Iron Age chronology.</p
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