3,078 research outputs found

    Isolated Photons in Deep Inelastic Scattering

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    Photon radiation at large transverse momenta at colliders is a detailed probe of hard interaction dynamics. The isolated photon production cross section in deep inelastic scattering was measured recently by the ZEUS experiment, and found to be considerably larger than theoretical predictions obtained with widely used event generators. To investigate this discrepancy, we perform a dedicated parton-level calculation of this observable, including contributions from fragmentation and large-angle radiation. Our results are in good agreement with all aspects of the experimental measurement.Comment: 4 pages, 3 figure

    How A Vessel of This Magnitude Was Moved : A Comparative Analysis of Confederate Ironclad Steam Engines, Boilers, and Propulsion Systems

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    The development of steam propulsion machinery in warships during the 19th century in conjunction with iron armor and shell guns resulted in a technological revolution in the world's navies. Warships utilizing all of these technologies had been built in France and Great Britain dating back to the 1850s, but it was during the American Civil War that ironclads powered solely by steam proved themselves in large numbers. The armored warships built by the Confederate States of America especially represented a style adapted to scarce industrial resources and facilities. The development and / or procurement of propulsion machinery for these warships have received only peripheral study. Through historical and archaeological investigation, this thesis consolidates and expands on the scattered existing information on Confederate ironclad steam engines, boilers, and propulsion systems. Using a comparative analytical approach, the steam plants of 27 ironclads are assessed by source, type, and performance, among other factors. This has resulted in an analysis of steam machinery development during the Civil War and also adds to the relatively small knowledge base relating to Confederate ironclads.  M.A

    The Scuppernong River Project, Volume 1: Explorations of Tyrrell County Maritime History

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    PAST Foundation, UNC Coastal Studies Institute, East Carolina Universit

    Acid-Labile Traceless Click Linker for Protein Transduction

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    Intracellular delivery of active proteins presents an interesting approach in research and therapy. We created a protein transduction shuttle based on a new traceless click linker that combines the advantages of click reactions with implementation of reversible pH-sensitive bonds. The azidomethyl-methylmaleic anhydride (AzMMMan) linker was found compatible with different click chemistries, demonstrated in bioreversible protein modification with dyes, polyethylene glycol, or a transduction carrier. Linkages were stable at physiological pH but reversible at the mild acidic pH of endosomes or lysosomes. We show that pH-reversible attachment of a defined endosome-destabilizing three-arm oligo(ethane amino)amide carrier generates an effective shuttle for protein delivery. The cargo protein nlsEGFP, when coupled via the traceless AzMMMan linker, experiences efficient cellular uptake and endosomal escape into the cytosol, followed by import into the nucleus. In contrast, irreversible linkage to the same shuttle hampers nuclear delivery of nlsEGFP which after uptake remains trapped in the cytosol. Successful intracellular delivery of bioactive Ăź-galactosidase as a model enzyme was also demonstrated using the pH-controlled shuttle system

    Production, Decay, and Polarization of Excited Heavy Hadrons

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    We discuss the production via fragmentation of excited heavy mesons and baryons, and their subsequent decay. In particular, we consider the question of whether a net polarization of the initial heavy quark may be detected, either in a polarization of the final ground state or in anisotropies in the decay products of the excited hadron. The result hinges in part on a nonperturbative parameter which measures the net transverse alignment of the light degrees of freedom in the fragmentation process. We use existing data on charmed mesons to extract this quantity for certain excited mesons. Using this result, we estimate the polarization retention of charm and bottom baryons.Comment: 37 pages, 3 figures available upon request, uses phyzzx forma

    Prevalence and characteristics of gastrointestinal infections in men who have sex with men diagnosed with rectal chlamydia infection in the UK: an 'unlinked anonymous' cross-sectional study.

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    INTRODUCTION: Gastrointestinal infections (GII) can cause serious ill health and morbidity. Although primarily transmitted through faecal contamination of food or water, transmission through sexual activity is well described, especially among men who have sex with men (MSM). METHODS: We investigated the prevalence of GIIs among a convenience sample of MSM who were consecutively diagnosed with rectal Chlamydia trachomatis (CT) at 12 UK genitourinary medicine clinics during 10 weeks in 2012. Residual rectal swabs were coded, anonymised and tested for Shigella, Campylobacter, Salmonella, shiga toxin-producing Escherichia coli and enteroaggregative E. coli (EAEC) using a real-time PCR. Results were linked to respective coded and anonymised clinical and demographic data. Associations were investigated using Fisher's exact tests. RESULTS: Of 444 specimens tested, overall GII prevalence was 8.6% (95% CI 6.3% to 11.6%): 1.8% (0.9% to 3.6%) tested positive for Shigella, 1.8% (0.9% to 3.6%) for Campylobacter and 5.2% (3.5% to 7.7%) for EAEC. No specimens tested positive for Salmonella or other diarrhoeagenic E. coli pathotypes. Among those with any GII, 14/30 were asymptomatic (2/7 with Shigella, 3/6 with Campylobacter and 9/17 with EAEC). Shigella prevalence was higher in MSM who were HIV-positive (4.7% (2.1% to 10.2%) vs 0.5%(0.1% to 3.2%) in HIV-negative MSM; p=0.01). CONCLUSIONS: In this small feasibility study, MSM with rectal CT appeared to be at appreciable risk of GII. Asymptomatic carriage may play a role in sexual transmission of GII

    Eikonal analysis of Coulomb distortion in quasi-elastic electron scattering

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    An eikonal expansion is used to provide systematic corrections to the eikonal approximation through order 1/k21/k^2, where kk is the wave number. Electron wave functions are obtained for the Dirac equation with a Coulomb potential. They are used to investigate distorted-wave matrix elements for quasi-elastic electron scattering from a nucleus. A form of effective-momentum approximation is obtained using trajectory-dependent eikonal phases and focusing factors. Fixing the Coulomb distortion effects at the center of the nucleus, the often-used ema approximation is recovered. Comparisons of these approximations are made with full calculations using the electron eikonal wave functions. The ema results are found to agree well with the full calculations.Comment: 12 pages, 6 Postscript figure

    IMPlementing IMProved Asthma self-management as RouTine (IMP2ART) in primary care: study protocol for a cluster randomised controlled implementation trial

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    BACKGROUND: Asthma is a common long-term condition and major public health problem. Supported self-management for asthma that includes a written personalised asthma action plan, supported by regular professional review, reduces unscheduled consultations and improves asthma outcomes and quality of life. However, despite unequivocal inter/national guideline recommendations, supported self-management is poorly implemented in practice. The IMPlementing IMProved Asthma self-management as RouTine (IMP2ART) implementation strategy has been developed to address this challenge. The aim of this implementation trial is to determine whether facilitated delivery of the IMP2ART strategy increases the provision of asthma action plans and reduces unscheduled care in the context of routine UK primary care. METHODS: IMP2ART is a parallel group, cluster randomised controlled hybrid II implementation trial. One hundred forty-four general practices will be randomly assigned to either the IMP2ART implementation strategy or control group. Following a facilitation workshop, implementation group practices will receive organisational resources to help them prioritise supported self-management (including audit and feedback; an IMP2ART asthma review template), training for professionals and resources to support patients to self-manage their asthma. The control group will continue with usual asthma care. The primary clinical outcome is the between-group difference in unscheduled care in the second year after randomisation (i.e. between 12 and 24 months post-randomisation) assessed from routine data. Additionally, a primary implementation outcome of asthma action plan ownership at 12 months will be assessed by questionnaire to a random sub-group of people with asthma. Secondary outcomes include the number of asthma reviews conducted, prescribing outcomes (reliever medication and oral steroids), asthma symptom control, patients' confidence in self-management and professional support and resource use. A health economic analysis will assess cost-effectiveness, and a mixed methods process evaluation will explore implementation, fidelity and adaptation. DISCUSSION: The evidence for supported asthma self-management is overwhelming. This study will add to the literature regarding strategies that can effectively implement supported self-management in primary care to reduce unscheduled consultations and improve asthma outcomes and quality of life. TRIAL REGISTRATION: ISRCTN15448074. Registered on 2 December 2019

    A unitary model for meson-nucleon scattering

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    In an effective Lagrangian model employing the K-matrix approximation we extract nucleon resonance parameters. To this end we analyze simultaneously all available data for reactions involving the final states πN\pi N, ππN\pi\pi N, ηN\eta N and KΛK \Lambda in the energy range mN+mπ≤s≤1.9m_N + m_{\pi} \le \sqrt s \le 1.9 GeV. The background contributions are generated consistently from the relevant Feynman amplitudes, thus significantly reducing the number of free parameters.Comment: Revised version. 60 pages, 17 figures. Two figures and a short discussion (\pi N \to \eta N, K \Lambda amplitudes) added, typos and minor errors in the citations correcte
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