2,215 research outputs found

    Heterotrophy mitigates the response of the temperate coral

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    Anthropogenic increases in atmospheric carbon dioxide concentration have caused global average sea surface temperature (SST) to increase by approximately 0.11°C per decade between 1971 and 2010 - a trend that is projected to continue through the 21st century. A multitude of research studies have demonstrated that increased SSTs compromise the coral holobiont (cnidarian host and its symbiotic algae) by reducing both host calcification and symbiont density, among other variables. However, we still do not fully understand the role of heterotrophy in the response of the coral holobiont to elevated temperature, particularly for temperate corals. Here, we conducted a pair of independent experiments to investigate the influence of heterotrophy on the response of the temperate scleractinian coral Oculina arbuscula to thermal stress. Colonies of O. arbuscula from Radio Island, North Carolina, were exposed to four feeding treatments (zero, low, moderate, and high concentrations of newly hatched Artemia sp. nauplii) across two independent temperature experiments (average annual SST (20°C) and average summer temperature (28°C) for the interval 2005-2012) to quantify the effects of heterotrophy on coral skeletal growth and symbiont density. Results suggest that heterotrophy mitigated both reduced skeletal growth and decreased symbiont density observed for unfed corals reared at 28°C. This study highlights the importance of heterotrophy in maintaining coral holobiont fitness under thermal stress and has important implications for the interpretation of coral response to climate change

    The use of an unsupervised learning approach for characterizing latent behaviors in accelerometer data

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    Acknowledgments This project and the tags deployed on both seabird's species were fund by NERC (grant number NE/K007440/1), Marine Scotland Science and Seabird Tracking and Research (STAR) Project led by the Royal Society for the Protection of Birds (RSPB). We would like to thank Rob Hughes, Tessa Cole and Ruth Brown for helping in the data collection, the Bird Observatory of Fair Isle for supporting the fieldwork and the Marine Collaboration Research Forum (MarCRF).Peer reviewedPublisher PD

    Collateral donor artery physiology and the influence of a chronic total occlusion on fractional flow reserve

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    Background— The presence of a concomitant chronic total coronary occlusion (CTO) and a large collateral contribution might alter the fractional flow reserve (FFR) of an interrogated vessel, rendering the FFR unreliable at predicting ischemia should the CTO vessel be revascularized and potentially affecting the decision on optimal revascularization strategy. We tested the hypothesis that donor vessel FFR would significantly change after percutaneous coronary intervention of a concomitant CTO. Methods and Results— In consecutive patients undergoing percutaneous coronary intervention of a CTO, coronary pressure and flow velocity were measured at baseline and hyperemia in proximal and distal segments of both nontarget vessels, before and after percutaneous coronary intervention. Hemodynamics including FFR, absolute coronary flow, and the coronary flow velocity–pressure gradient relation were calculated. After successful percutaneous coronary intervention in 34 of 46 patients, FFR in the predominant donor vessel increased from 0.782 to 0.810 (difference, 0.028 [0.012 to 0.044]; P=0.001). Mean decrease in baseline donor vessel absolute flow adjusted for rate pressure product: 177.5 to 139.9 mL/min (difference −37.6 [−62.6 to −12.6]; P=0.005), mean decrease in hyperemic flow: 306.5 to 272.9 mL/min (difference, −33.5 [−58.7 to −8.3]; P=0.011). Change in predominant donor vessel FFR correlated with angiographic (%) diameter stenosis severity (r=0.44; P=0.009) and was strongly related to stenosis severity measured by the coronary flow velocity–pressure gradient relation (r=0.69; P<0.001). Conclusions— Recanalization of a CTO results in a modest increase in the FFR of the predominant collateral donor vessel associated with a reduction in coronary flow. A larger increase in FFR is associated with greater coronary stenosis severity

    The C-Band All-Sky Survey: Instrument design, status, and first-look data

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    The C-Band All-Sky Survey (C-BASS) aims to produce sensitive, all-sky maps of diffuse Galactic emission at 5 GHz in total intensity and linear polarization. These maps will be used (with other surveys) to separate the several astrophysical components contributing to microwave emission, and in particular will allow an accurate map of synchrotron emission to be produced for the subtraction of foregrounds from measurements of the polarized Cosmic Microwave Background. We describe the design of the analog instrument, the optics of our 6.1 m dish at the Owens Valley Radio Observatory, the status of observations, and first-look data.Comment: 10 pages, 11 figures, published in Proceedings of SPIE MIllimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy V (2010), Vol. 7741, 77411I-1 - 77411I-1

    A Surgeon's Eye View Noninvasively

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    Risk assessment of feed ingredients of porcine origin as vehicles for transmission of Porcine Epidemic Diarrhea Virus (PEDV)

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    The objective of this project was to assess the likelihood that feed ingredients of porcine origin may function as vehicles of Porcine Epidemic Diarrhea virus (PEDV) transmission via feed. The scope of the assessment included rendered ingredients, ingredients derived through spray drying porcine blood, and ingredients derived by hydrolyzing porcine tissues. For any feed ingredient, the risk of the release of infective PEDV is a function of: (1) the concentration of PEDV in the raw materials; (2) the virus survival after ingredient processing (3) the survival of virus during post-processing storage and distribution; and 4) the likelihood of post-processing contamination incorporating PEDV into the finished ingredient. No data on PEDV contamination of raw materials were available for the rendering and hydrolyzed protein sources. Estimates of PEDV contamination of liquid plasma were available from industry, based on PCR testing of ingredients over time, and were used in quantitative modeling. The assessments made in this project were constrained by a paucity of specific data on several aspects that are germane to the risk of PEDV transmission in feed ingredients of porcine origin. Available data on thermal inactivation of PEDV indicate that risk of virus surviving the processes of rendering and hydrolysis (peptone production) are negligible. The time and temperature profiles used in spray-drying are much less severe, and therefore, the possibility of virus survival is inherently greater if non-thermal mechanisms are ignored. Overall, currently available data indicate that probability of PEDV surviving the spray-drying process and current commercial storage periods is extremely small. In the course of the project, several data gaps were identified that contributed to the uncertainty. Risk assessment is an iterative process and the findings of this report may be revised in the future if new knowledge becomes available.National Pork Board, Des Moines, I

    Continuity, Deconfinement, and (Super) Yang-Mills Theory

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    We study the phase diagram of SU(2) Yang-Mills theory with one adjoint Weyl fermion on R^3xS^1 as a function of the fermion mass m and the compactification scale L. This theory reduces to thermal pure gauge theory as m->infinity and to circle-compactified (non-thermal) supersymmetric gluodynamics in the limit m->0. In the m-L plane, there is a line of center symmetry changing phase transitions. In the limit m->infinity, this transition takes place at L_c=1/T_c, where T_c is the critical temperature of the deconfinement transition in pure Yang-Mills theory. We show that near m=0, the critical compactification scale L_c can be computed using semi-classical methods and that the transition is of second order. This suggests that the deconfining phase transition in pure Yang-Mills theory is continuously connected to a transition that can be studied at weak coupling. The center symmetry changing phase transition arises from the competition of perturbative contributions and monopole-instantons that destabilize the center, and topological molecules (neutral bions) that stabilize the center. The contribution of molecules can be computed using supersymmetry in the limit m=0, and via the Bogomolnyi--Zinn-Justin (BZJ) prescription in the non-supersymmetric gauge theory. Finally, we also give a detailed discussion of an issue that has not received proper attention in the context of N=1 theories---the non-cancellation of nonzero-mode determinants around supersymmetric BPS and KK monopole-instanton backgrounds on R^3xS^1. We explain why the non-cancellation is required for consistency with holomorphy and supersymmetry and perform an explicit calculation of the one-loop determinant ratio.Comment: A discussion of the non-cancellation of the nonzero mode determinants around supersymmetric monopole-instantons in N=1 SYM on R^3xS^1 is added, including an explicit calculation. The non-cancellation is, in fact, required by supersymmetry and holomorphy in order for the affine-Toda superpotential to be reproduced. References have also been adde
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