229 research outputs found

    Motion Correction of Whole-Body PET Data with a Joint PET-MRI Registration Functional

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    Respiratory motion is known to degrade image quality in PET imaging. The necessary acquisition time of several minutes per bed position will inevitably lead to a blurring effect due to organ motion. A lot of research has been done with regards to motion correction of PET data. As full-body PET-MRI became available recently, the anatomical data provided by MRI is a promising source of motion information. Current PET-MRI-based motion correction approaches, however, do not take into account the available information provided by PET data. PET data, though, may add valuable additional information to increase motion estimation robustness and precision.In this work we propose a registration functional that is capable of performing motion detection in gated data of two modalities simultaneously. Evaluation is performed using phantom data. We demonstrate that performing a joint registration of both modalities does improve registration accuracy and PET image quality.<br

    Attitudes Toward COVID-19 and COVID-19 Vaccinations Among Athletic Trainers

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    Purpose: Following the beginning of the pandemic brought about by the novel coronavirus which causes COVID-19, the first COVID-19 vaccination received emergency use authorization in the United States of America in December of 2020. Current research has shown the authorized COVID-19 vaccines are safe and effective at preventing severe illness, hospitalizations and death have a good safety profile. Additionally, the side effects associated with these vaccines are typically mild to moderate while the protection against hospitalization and severe disease is substantial. (https://www.cdc.gov/coronavirus/2019-ncov/vaccines/safety/adverse-events.html). At the time of this study, there appears to be a paucity in the research related to the attitudes toward COVID-19 and COVID-19 vaccines among athletic trainers. The purpose of this study is to describe the attitudes toward COVID-19 and COVID-19 vaccines among athletic trainers. Methods: A total of 186 athletic trainers (age= 43 ± 11, years of certified experience = 20 ± 11) opened and completed the survey. Participants were sent an electronic survey via email that collected demographic information and assessed attitudes toward COVID-19 and COVID-19 vaccines. Data was downloaded and analyzed using a commercially available statistics package. Results: The majority of athletic trainers surveyed had received a COVID-19 vaccination at the time of this study (94.1%, n=175). Most athletic trainers also agreed that the health of their patients was more important than disruption of their competition season due to COVID-19 (82.3%, n=153). In general, the most common reason for vaccine hesitancy was the speed with which currently available COVID-19 vaccines were developed. Conclusions: The findings of this study show the majority of surveyed athletic trainers had received a COVID-19 vaccine. The primary reason for athletic trainers not receiving a COVID-19 vaccination appeared to be the speed at which the currently available COVID-19 vaccines were developed. Given the available information on the new mRNA COVID vaccines, this may indicate a lack of education on the development of the COVID-19 vaccines. As athletic trainers continue to work in day-to-day patient care, it is imperative to determine the best methods for educating athletic trainers on the potential benefits of COVID-19 vaccinations

    Coastal squeeze on temperate reefs: Long-term shifts in salinity, water quality, and oyster-associated communities

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    Foundation species, such as mangroves, saltmarshes, kelps, seagrasses, and oysters, thrive within suitable environmental envelopes as narrow ribbons along the land–sea margin. Therefore, these habitat-forming species and resident fauna are sensitive to modified environmental gradients. For oysters, many estuaries impacted by sea-level rise, channelization, and municipal infrastructure are experiencing saltwater intrusion and water-quality degradation that may alter reef distributions, functions, and services. To explore decadal-scale oyster–reef community patterns across a temperate estuary in response to environmental change, we resampled reefs in the Newport River Estuary (NRE) during 2013–2015 that had previously been studied during 1955–1956. We also coalesced historical NRE reef distribution (1880s–2015), salinity (1913–2015), and water-quality-driven shellfish closure boundary (1970s–2015) data to document environmental trends that could influence reef ecology and service delivery. Over the last 60–120 years, the entire NRE has shifted toward higher salinities. Consequently, oyster–reef communities have become less distinct across the estuary, manifest by 20%–27% lower species turnover and decreased faunal richness among NRE reefs in the 2010s relative to the 1950s. During the 2010s, NRE oyster–reef communities tended to cluster around a euhaline, intertidal-reef type more so than during the 1950s. This followed faunal expansions farther up estuary and biological degradation of subtidal reefs as NRE conditions became more marine and favorable for aggressive, reef-destroying taxa. In addition to these biological shifts, the area of suitable bottom on which subtidal reefs persist (contracting due to up-estuary intrusion of marine waters) and support human harvest (driven by water quality, eroding from up-estuary) has decreased by >75% since the natural history of NRE reefs was first explored. This “coastal squeeze” on harvestable subtidal oysters (reduced from a 4.5-km to a 0.75-km envelope along the NRE's main axis) will likely have consequences regarding the economic incentives for future oyster conservation, as well as the suite of services delivered by remaining shellfish reefs (e.g., biodiversity maintenance, seafood supply). More broadly, these findings exemplify how “squeeze” may be a pervasive concern for biogenic habitats along terrestrial or marine ecotones during an era of intense global change

    Pathway to the Square Kilometre Array - The German White Paper -

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    The Square Kilometre Array (SKA) is the most ambitious radio telescope ever planned. With a collecting area of about a square kilometre, the SKA will be far superior in sensitivity and observing speed to all current radio facilities. The scientific capability promised by the SKA and its technological challenges provide an ideal base for interdisciplinary research, technology transfer, and collaboration between universities, research centres and industry. The SKA in the radio regime and the European Extreme Large Telescope (E-ELT) in the optical band are on the roadmap of the European Strategy Forum for Research Infrastructures (ESFRI) and have been recognised as the essential facilities for European research in astronomy. This "White Paper" outlines the German science and R&D interests in the SKA project and will provide the basis for future funding applications to secure German involvement in the Square Kilometre Array.Comment: Editors: H. R. Kl\"ockner, M. Kramer, H. Falcke, D.J. Schwarz, A. Eckart, G. Kauffmann, A. Zensus; 150 pages (low resolution- and colour-scale images), published in July 2012, language English (including a foreword and an executive summary in German), the original file is available via the MPIfR homepag

    First Observation of PP-odd Îł\gamma Asymmetry in Polarized Neutron Capture on Hydrogen

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    We report the first observation of the parity-violating 2.2 MeV gamma-ray asymmetry AÎłnpA^{np}_\gamma in neutron-proton capture using polarized cold neutrons incident on a liquid parahydrogen target at the Spallation Neutron Source at Oak Ridge National Laboratory. AÎłnpA^{np}_\gamma isolates the ΔI=1\Delta I=1, \mbox{3S1→3P1^{3}S_{1}\rightarrow {^{3}P_{1}}} component of the weak nucleon-nucleon interaction, which is dominated by pion exchange and can be directly related to a single coupling constant in either the DDH meson exchange model or pionless EFT. We measured AÎłnp=[−3.0±1.4(stat)±0.2(sys)]×10−8A^{np}_\gamma = [-3.0 \pm 1.4 (stat) \pm 0.2 (sys)]\times 10^{-8}, which implies a DDH weak πNN\pi NN coupling of hπ1=[2.6±1.2(stat)±0.2(sys)]×10−7h_{\pi}^{1} = [2.6 \pm 1.2(stat) \pm 0.2(sys)] \times 10^{-7} and a pionless EFT constant of C3S1→3P1/C0=[−7.4±3.5(stat)±0.5(sys)]×10−11C^{^{3}S_{1}\rightarrow ^{3}P_{1}}/C_{0}=[-7.4 \pm 3.5 (stat) \pm 0.5 (sys)] \times 10^{-11} MeV−1^{-1}. We describe the experiment, data analysis, systematic uncertainties, and the implications of the result.Comment: 6 pages, 5 figure

    Spontaneous resistance of Erwinia amylovora against bacteriophage Y2 affects infectivity of multiple phages

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    Broad application of antibiotics gave rise to increasing numbers of antibiotic resistant bacteria. Therefore, effective alternatives are currently investigated. Bacteriophages, natural predators of bacteria, could work as such an alternative. Although phages can be highly effective at eliminating specific bacteria, phage resistance can be observed after application. The nature of this resistance, however, can differ depending on the phage. Exposing Erwinia amylovora CFBP 1430, the causative agent of fire blight, to the different phages Bue1, L1, S2, S6, or M7 led to transient resistance. The bacteria reversed to a phage sensitive state after the phage was eliminated. When wild type bacteria were incubated with Y2, permanently resistant colonies (1430 Y2R ) formed spontaneously. In addition, 1430 Y2R revealed cross-resistance against other phages (Bue1) or lowered the efficiency of plating (L1, S2, and S6). Pull down experiments revealed that Y2 is no longer able to bind to the mutant suggesting mutation or masking of the Y2 receptor. Other phages tested were still able to bind to 1430 Y2R . Bue1 was observed to still adsorb to the mutant, but no host lysis was found. These findings indicated that, in addition to the alterations of the Y2 receptor, the 1430 Y2R mutant might block phage attack at different stage of infection. Whole genome sequencing of 1430 Y2R revealed a deletion in the gene with the locus tag EAMY_2231. The gene, which encodes a putative galactosyltransferase, was truncated due to the resulting frameshift. The mutant 1430 Y2R was monitored for potential defects or fitness loss. Weaker growth was observed in LB medium compared to the wild type but not in minimal medium. Strain 1430 Y2R was still highly virulent in blossoms even though amylovoran production was observed to be reduced. Additionally, LPS structures were analyzed and were clearly shown to be altered in the mutant. Complementation of the truncated EAMY_2231 in trans restored the wild type phenotype. The truncation of EAMY_2231 can therefore be associated with manifold modifications in 1430 Y2R , which can affect different phages simultaneously

    Optimal Structure and Dissolution of Partnerships

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    We derive the optimal incentive compatible and individually rational mechanisms to reallocate arbitrary given ownership shares among a set of agents. These mechanisms are optimal in the sense that they maximize social surplus of the final allocation subject to the aforementioned constraints and a revenue constraint. We allow for the agents' types to be drawn from non-identical distributions and for interdependent values. Because outside options are type dependent, the critical types for which individual rationality binds must be determined simultaneously with the allocation rule. We show that optimality uniquely pins down the set of critical types, which allows us to fully characterize the optimal mechanisms. Moreover, we find that the value function is Schur-concave in ownership shares when types are identically distributed, so that more symmetric shares are better irrespective of size of the revenue constraint

    First Observation of \u3cem\u3eP\u3c/em\u3e-Odd Îł Asymmetry in Polarized Neutron Capture on Hydrogen

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    We report the first observation of the parity-violating gamma-ray asymmetry AnpÎł in neutron-proton capture using polarized cold neutrons incident on a liquid parahydrogen target at the Spallation Neutron Source at Oak Ridge National Laboratory. AnpÎł isolates the ΔI = 1, 3S1 → 3P1 component of the weak nucleon-nucleon interaction, which is dominated by pion exchange and can be directly related to a single coupling constant in either the DDH meson exchange model or pionless effective field theory. We measured AnpÎł = [−3.0 ± 1.4(stat )± 0.2(syst)] × 10−8, which implies a DDH weak πNN coupling of h1π = [2.6 ± 1.2(stat) ± 0.2(syst)] × 10−7 and a pionless EFT constant of C3S1 → 3P1/C0 = [−7.4 ± 3.5(stat) ± 0.5(syst)] × 10−11  MeV−1. We describe the experiment, data analysis, systematic uncertainties, and implications of the result
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