2,004 research outputs found

    Pulsar Wind Nebulae in EGRET Error Boxes

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    A remarkable number of pulsar wind nebulae (PWN) are coincident with EGRET gamma-ray sources. X-ray and radio imaging studies of unidentified EGRET sources have resulted in the discovery of at least 6 new pulsar wind nebulae (PWN). Stationary PWN (SPWN) appear to be associated with steady EGRET sources with hard spectra, typical for gamma-ray pulsars. Their toroidal morphologies can help determine the geometry of the pulsar which is useful for constraining models of pulsed gamma-ray emission. Rapidly moving PWN (RPWN) with more cometary morphologies seem to be associated with variable EGRET sources in regions where the ambient medium is dense compared to what is typical for the ISM.Comment: 8 pages, 5 figures, to appear in the proceedings of "The Multiwavelength Approach to Unidentified Sources", ed. G. Romero & K.S. Chen

    A Guide to Missouri\u27s Freshwater Mussels

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    https://bearworks.missouristate.edu/books/1017/thumbnail.jp

    Improving response rates using a monetary incentive for patient completion of questionnaires: an observational study

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    Background: Poor response rates to postal questionnaires can introduce bias and reduce the statistical power of a study. To improve response rates in our trial in primary care we tested the effect of introducing an unconditional direct payment of 5 pound for the completion of postal questionnaires. Methods: We recruited patients in general practice with knee problems from sites across the United Kingdom. An evidence-based strategy was used to follow-up patients at twelve months with postal questionnaires. This included an unconditional direct payment of 5 pound to patients for the completion and return of questionnaires. The first 105 patients did not receive the 5 pound incentive, but the subsequent 442 patients did. We used logistic regression to analyse the effect of introducing a monetary incentive to increase the response to postal questionnaires. Results: The response rate following reminders for the historical controls was 78.1% ( 82 of 105) compared with 88.0% ( 389 of 442) for those patients who received the 5 pound payment (diff = 9.9%, 95% CI 2.3% to 19.1%). Direct payments significantly increased the odds of response ( adjusted odds ratio = 2.2, 95% CI 1.2 to 4.0, P = 0.009) with only 12 of 442 patients declining the payment. The incentive did not save costs to the trial - the extra cost per additional respondent was almost 50 pound. Conclusion: The direct payment of 5 pound significantly increased the completion of postal questionnaires at negligible increase in cost for an adequately powered study

    Dark Matter and Gas Concentrations in the NGC 4532 / DDO 137 System

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    Neutral hydrogen synthesis mapping of NGC 4532 and DDO 137, a pair of Sm galaxies on the edge of the Virgo cluster, is used to determine rotation curves for each of the galaxies and to resolve the structure and kinematics of three distinct HI concentrations embedded in an extended envelope of diffuse HI discovered in earlier Arecibo studies of the system. The HI masses of the three concentrations do not appear to be sufficient for them to be self-gravitating; however, their HImasses and dynamical masses are very similar to those of faint Im galaxies in the Virgo cluster. The peak HI column density of each of the clouds is close to the star formation threshold, but CCD images in B and R reveal no trace of stars nor star formation. If the system is gravitationally bound and in Virial equilibrium, we find its total mass to be ten times that within the outermost HI contours of the individual galaxies and clouds. Thirty-seven percent of the total HI lies outside the boundaries of the individual galaxies as determined by the VLA mapping; 28% cannot be ascribed to either galaxy nor to the discrete concentrations. One possible way to account for the velocity field and the large quantity of diffuse gas is to assume that DDO 137, the gas concentrations and other apparent tidal features are due to gas infall into clumps within the dark matter potential of the group, and that prior to the interaction the group consisted of an irregular galaxy (NGC 4532) and a large, star-poor HI cloud like HI 1225+01 (Giovanelli et al. 1991)

    TERMINAL FLOWER-1/CENTRORADIALIS inhibits tuberization via protein interaction with the tuberigen activation complex

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    This work was funded by the Scottish Government Rural and Environment Science and Analytical Services Division as part of the Strategic Research Programme 2016-2021, by a GCRF Foundation Awards for Global Agricultural and Food Systems Research funded by the BBSRC project BB/P022553/1 and also received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie SkƂodowska-Curie grant agreement number 835704. Research in Prat’s lab was funded by the Spanish Ministerio de Economía y Competitividad BIO2015-73019-EXP, and the aligned Japan EIG CONCERT (PIA102017-1) projects.Potato tuber formation is a secondary developmental program by which cells in the subapical stolon region divide and radially expand, to further differentiate into starch accumulating parenchyma. Whilst some details of the molecular pathway that signals tuberization are known, important gaps in our knowledge persist. Here the role of a member of the TERMINAL FLOWER 1/ CENTRORADIALIS gene family (termed StCEN ) in the negative control of tuberization is demonstrated for the first time. It is shown that reduced expression of StCEN accelerates tuber formation whereas transgenic lines over‐expressing this gene display delayed tuberization and reduced tuber yield. Protein‐protein interaction studies (yeast two hybrid and bimolecular fluorescence complementation) demonstrate that StCEN binds components of the recently described tuberigen activation complex. Using transient transactivation assays we show that the StSP6A tuberization signal is an activation target of the tuberigen activation complex, and that co‐expression of StCEN blocks StFD‐Like‐1 activation of the StSP6A gene. Transcriptomic analysis of transgenic lines mis‐expressing StCEN identify early transcriptional events in tuber formation. These results demonstrate that StCEN suppresses tuberization by directly antagonizing StSP6A function in stolons, identifying StCEN as a breeding marker to improve tuber initiation and yield, through the selection of genotypes with reduced StCEN expression.Publisher PDFPeer reviewe
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