3,029 research outputs found

    Use of Rapid-Scan EPR to Improve Detection Sensitivity for Spin-Trapped Radicals

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    AbstractThe short lifetime of superoxide and the low rates of formation expected in vivo make detection by standard continuous wave (CW) electron paramagnetic resonance (EPR) challenging. The new rapid-scan EPR method offers improved sensitivity for these types of samples. In rapid-scan EPR, the magnetic field is scanned through resonance in a time that is short relative to electron spin relaxation times, and data are processed to obtain the absorption spectrum. To validate the application of rapid-scan EPR to spin trapping, superoxide was generated by the reaction of xanthine oxidase and hypoxanthine with rates of 0.1–6.0 μM/min and trapped with 5-tert-butoxycarbonyl-5-methyl-1-pyrroline-N-oxide (BMPO). Spin trapping with BMPO to form the BMPO-OOH adduct converts the very short-lived superoxide radical into a more stable spin adduct. There is good agreement between the hyperfine splitting parameters obtained for BMPO-OOH by CW and rapid-scan EPR. For the same signal acquisition time, the signal/noise ratio is >40 times higher for rapid-scan than for CW EPR. Rapid-scan EPR can detect superoxide produced by Enterococcus faecalis at rates that are too low for detection by CW EPR

    Proof of polar ejection fom the close-binary core of the planetary nebula Abell 63

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    We present the first detailed kinematical analysis of the planetary nebula Abell 63, which is known to contain the eclipsing close-binary nucleus UU Sge. Abell 63 provides an important test case in investigating the role of close-binary central stars on the evolution of planetary nebulae. Longslit observations were obtained using the Manchester echelle spectrometer combined with the 2.1-m San Pedro Martir Telescope. The spectra reveal that the central bright rim of Abell 63 has a tube-like structure. A deep image shows collimated lobes extending from the nebula, which are shown to be high-velocity outflows. The kinematic ages of the nebular rim and the extended lobes are calculated to be 8400+/-500 years and 12900+/-2800 years, respectively, which suggests that the lobes were formed at an earlier stage than the nebular rim. This is consistent with expectations that disk-generated jets form immediately after the common envelope phase. A morphological-kinematical model of the central nebula is presented and the best-fit model is found to have the same inclination as the orbital plane of the central binary system; this is the first proof that a close-binary system directly affects the shaping of its nebula. A Hubble-type flow is well-established in the morphological-kinematical modelling of the observed line profiles and imagery. Two possible formation models for the elongated lobes of Abell 63 are considered (1) a low-density, pressure-driven jet excavates a cavity in the remnant AGB envelope; (2) high-density bullets form the lobes in a single ballistic ejection event.Comment: 11 pages, 8 figures, accepted by MNRAS for publicatio

    Sequence and the Developmental and Tissue-Specific Regulation of the First Complete Vitellogenin Message From Ticks

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    The first full-length mRNA for vitellogenin (Vg) from ticks was sequenced. This also represents the first complete sequence of Vg from the Chelicerata and of a heme binding Vg. The Vg cDNA from the American dog tick, Dermacentor variabilis was 5744nt in length (GenBank Accession number AY885250), which coded for a protein of 1843aa with a calculated molecular weight of 208kD. This protein had an 18 aa signal sequence, a single RXXR cleavage signal that would generate two subunits (49.5 and 157K in molecular weight) and lipoprotein N-terminal and carboxy von Willebrand factor type D domains. Tryptic digest MS analysis of vitellin protein confirmed the function of the cDNA as the tick yolk protein. Apparently, vitellin in D. variabilis is oligomeric (possibly dimeric) and is comprised of a mixture of the uncleaved monomer and subunits that were predicted from the single RXXR cleavage signal. The highly conserved GL/ICG motif close to the C-terminus in insect Vg genes was different in the tick Vg message, i.e., GLCS. This variant was also present in a partial sequence of Vg from Boophilus microplus. Phylogenic analysis showed that the full length Vg cDNA from D. variabilis and the partial cDNA from B. microplus were distinct from insects and Crustacea. The Vg message was not found in whole body RNA from unfed or fed males or in unfed and partially fed (virgin) females as determined by Northern blotting. The message was found in replete (mated) pre-ovipositional females, increased to higher levels in ovipositing females and was absent after egg laying was complete. The endocrine regulation of the Vg mRNA is discussed. The tissue sources of the Vg message are both the gut and fat body. Tryptic digest MS fingerprinting suggests that a second Vg mRNA might be present in the American dog tick, which needs further study

    An oxytocin antagonist infused into the central nucleus of the amygdala increases maternal aggressive behavior.

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    Decreased oxytocin levels in the amygdalas of rat dams following chronic gestational cocaine exposure have been correlated with heightened maternal aggressive behavior. In this experiment, drug-naive dams were implanted with bilateral cannulas into the central nucleus of the amygdala (CNA) or control area and infused with 1,000 or 500 ng of an oxytocin antagonist (OTA) or buffer, 4 hr before testing. Behavior was compared among dams infused with OTA into target areas just outside the CNA and cocaine-treated dams (infused with buffer). Dams infused with 1,000 ng OTA attacked intruders significantly more often than buffer-infused dams. OTA did not affect other behaviors, suggesting that disruption of oxytocin activity in the CNA may be sufficient to selectively alter maternal aggressive behavior

    In Vivo Role of 20-hydroxyecdysone in the Regulation of the Vitellogenin mRNA and Egg Development in the American Dog Tick, Dermacentor variabilis (Say)

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    Injection of the hormone 20-hydroxyecdysone (20-E) into partially fed (virgin) female adults of the American dog tick, Dermacentor variabilis, while they are attached and feeding on the rabbit host, initiated the expression of the vitellogenin (Vg) gene, and Vg protein secretion and uptake by the ovary. The induction of egg production by 20-E in this bioassay was dose dependent in the range of 1-50 times the concentration normally found in a replete, vitellogenic female. Ticks examined 4d after the 50x treatment were still attached to the host, had numerous enlarged vitellin-filled (brown) oocytes in their ovaries, but had not engorged to repletion. The ovaries reached weights similar to those found in untreated, replete (mated) females (pre-oviposition) while solvent-injected controls demonstrated no increase in oocyte size or increase in ovary weight. An increase in the levels of a putative Vg protein was observed in hemolymph samples collected 1, 2 and 3d post-20-E injection but was not observed in the corresponding solvent controls as determined by native PAGE. Analysis of the ecdysteroid-induced protein by tryptic digestion-mass fingerprinting and BLASTP found that the putative Vg had the strongest match to GP80 (U49934), the partial sequence for the vitellogenin protein from Boophilus microplus. A partial Vg cDNA was cloned and sequenced from replete females of D. variabilis with a high similarity to GP80. Using this message as a probe, Northern blots conducted with RNA collected from partially fed, virgin females 1, 2 and 3d post-20-E injection showed upregulation of the Vg mRNA on all 3 days. Controls injected with solvent only showed no Vg mRNA. Injections with juvenile hormone III did not stimulate Vg expression, oocyte growth or full engorgement. These studies indicate that ecdysteroids and not JH can initiate expression of the Vg gene, Vg protein synthesis and release into hemolymph, and Vg uptake into developing oocytes under bioassay conditions mimicking normal feeding on the host

    Using workplace population statistics to understand retail store performance

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    We explore the value of recently released workplace geographies and accompanying census-based workplace zone statistics (WZS) and an associated classification of workplace zones (COWZ). We consider how these data could support retailers in their operational and strategic decision making, including the evaluation of retail demand and retail store performance in localities where trade is driven by non-residential demand. In collaboration with major UK grocery retailer ‘The Co-operative Group’ we explore the relationship between workplace population composition and store trading characteristics using a series of case study stores within Inner London. We use empirical store trading data to identify store and product category level temporal sales fluctuations attributable to workplace populations. We also use census-derived flow data to identify the spatial origins of workplace population inflow. We identify that store performance exhibits characteristics attributable to demand driven by these populations. We conclude that workplace population geographies, WZS and the COWZ afford considerable potential for understanding drivers of store performance, observed store trading patterns and evaluation of retail store performance. We suggest that the next step is to build these populations and their micro geography spatial and temporal characteristics into predictive models and evaluate their potential for store performance evaluation and location-based store and network decision making within this sector

    Ancylostoma ceylanicum Hookworm in Myanmar Refugees, Thailand, 2012–2015

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    During 2012–2015, US-bound refugees living in Myanmar– Thailand border camps (n = 1,839) were surveyed for hookworm infection and treatment response by using quantitative PCR. Samples were collected at 3 time points: after each of 2 treatments with albendazole and after resettlement in the United States. Baseline prevalence of Necator americanus hookworm was 25.4%, Ancylostoma duodenale 0%, and Ancylostoma ceylanicum (a zoonosis) 5.4%. Compared with N. americanus prevalence, A. ceylanicum hookworm prevalence peaked in younger age groups, and blood eosinophil concentrations during A. ceylanicum infection were higher than those for N. americanus infection. Female sex was associated with a lower risk for either hookworm infection. Cure rates after 1 dose of albendazole were greater for A. ceylanicum (93.3%) than N. americanus (65.9%) hookworm (p\u3c0.001). Lower N. americanus hookworm cure rates were unrelated to β-tubulin single-nucleotide polymorphisms at codons 200 or 167. A. ceylanicum hookworm infection might be more common in humans than previously recognized

    Caring for the patient, caring for the record: an ethnographic study of 'back office' work in upholding quality of care in general practice

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    © 2015 Swinglehurst and Greenhalgh; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Additional file 1: Box 1. Field notes on summarising (Clover Surgery). Box 2. Extract of document prepared for GPs by summarisers at Clover Surgery. Box 3. Fieldnotes on coding incoming post, Clover (original notes edited for brevity).This work was funded by a research grant from the UK Medical Research Council (Healthcare Electronic Records in Organisations 07/133) and a National Institute of Health Research doctoral fellowship award for DS (RDA/03/07/076). The funders were not involved in the selection or analysis of data nor did they make any contribution to the content of the final manuscript

    Research Agenda of the Oncology Nursing Society: 2019-2022.

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    PROBLEM STATEMENT: To define the Oncology Nursing Society Research Agenda for 2019-2022. DESIGN: Multimethod, consensus-building approach by members of the Research Agenda Project Team. DATA SOURCES: Expert opinion, literature review, surveys, interviews, focus groups, town hall, and review of research priorities from other cancer care organizations and funding agencies. ANALYSIS: Content analysis and descriptive statistics were used to synthesize research priority themes that emerged. FINDINGS: Three priority areas for scientific development were identified IMPLICATIONS FOR NURSING: The Research Agenda can be used to focus oncology nurses' research, scholarship, leadership, and health policy efforts to advance quality cancer care, inform research funding priorities, and align initiatives and resources across the ONS enterprise
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