360 research outputs found

    Event generation with SHERPA 1.1

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    In this paper the current release of the Monte Carlo event generator Sherpa, version 1.1, is presented. Sherpa is a general-purpose tool for the simulation of particle collisions at high-energy colliders. It contains a very flexible tree-level matrix-element generator for the calculation of hard scattering processes within the Standard Model and various new physics models. The emission of additional QCD partons off the initial and final states is described through a parton-shower model. To consistently combine multi-parton matrix elements with the QCD parton cascades the approach of Catani, Krauss, Kuhn and Webber is employed. A simple model of multiple interactions is used to account for underlying events in hadron--hadron collisions. The fragmentation of partons into primary hadrons is described using a phenomenological cluster-hadronisation model. A comprehensive library for simulating tau-lepton and hadron decays is provided. Where available form-factor models and matrix elements are used, allowing for the inclusion of spin correlations; effects of virtual and real QED corrections are included using the approach of Yennie, Frautschi and Suura.Comment: 47 pages, 21 figure

    Future business and the role of purchasing and supply management: Opportunities for ‘business-not-as-usual’ PSM research

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    The raison d'ĂȘtre for this article is simple: traditional ways of researching, theorizing, and practicing purchasing and supply management (PSM) are no longer sufficient to ‘meet the moment’. Scholars need to advance a “business-not-as-usual” footing approach to their work, if they are to make a meaningful contribution to addressing the current and future emergencies, as highlighted by recent extreme weather and the COVID-19 pandemic. Yet, what can this, or should this, mean for a field rooted in traditional business thinking? This article builds on the Journal of Purchasing and Supply Management's (JPSM) 25th Anniversary Special Issue editorial (2019); members of the JPSM's editorial team advance their unique perspectives on what “business-not-as-usual” means for PSM. Specifically, we advocate both thinking much more widely, in scope and ambition, than we currently do, and simultaneously building our ability to comprehend supply chains in a more nuanced and granular way. We explore whether the bias toward positivist work has omitted potentially interesting findings, and viewpoints. This leads to a call to re-think how we approach our work: should the key criteria always be to focus on theory development or testing? Should academics “think bigger”? Turning to specific research themes, illustrations of how our current thinking can be challenged or broadened by addressing the circular economy, and role of purchasing and innovation. Specifically, the focus on the PSM function as an intrapreneur within the larger organization, and the role of innovation and technology in PSM work. Taken together, we hope the ideas and arguments presented here will inform and inspire ambitious and novel approaches to PSM research with significant and enduring impact on the transformation of business

    Search for the Magnetic Monopole at a Magnetoelectric Surface

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    We show, by solving Maxwell’s equations, that an electric charge on the surface of a slab of a linear magnetoelectric material generates an image magnetic monopole below the surface provided that the magnetoelectric has a diagonal component in its magnetoelectric response. The image monopole, in turn, generates an ideal monopolar magnetic field outside of the slab. Using realistic values of the electric and magnetic field susceptibilities, we calculate the magnitude of the effect for the prototypical magnetoelectric material Cr2O3. We use low-energy muon spin rotation to measure the strength of the magnetic field generated by charged muons as a function of their distance from the surface of a Cr2O3 film and show that the results are consistent with the existence of the monopole. We discuss other possible routes to detecting the monopolar field, and show that, while the predicted monopolar field generated by Cr2O3 is above the detection limit for standard magnetic force microscopy, the detection of the field using this technique is prevented by surface charging effects

    Calmodulin Interaction with hEAG1 Visualized by FRET Microscopy

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    BACKGROUND: Ca(2+)-mediated regulation of ion channels provides a link between intracellular signaling pathways and membrane electrical activity. Intracellular Ca(2+) inhibits the voltage-gated potassium channel EAG1 through the direct binding of calmodulin (CaM). Three CaM binding sites (BD-C1: 674-683, BD-C2: 711-721, BD-N: 151-165) have been identified in a peptide screen and were proposed to mediate binding. The participation of the three sites in CaM binding to the native channel, however, remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: Here we studied the binding of Ca(2+)/CaM to the EAG channel by visualizing the interaction between YFP-labeled CaM and Cerulean-labeled hEAG1 in mammalian cells by FRET. The results of our cellular approach substantiate that two CaM binding sites are predominantly involved; the high-affinity 1-8-14 based CaM binding domain in the N-terminus and the second C-terminal binding domain BD-C2. Mutations at these sites completely abolished CaM binding to hEAG1. CONCLUSIONS/SIGNIFICANCE: We demonstrated that the BD-N and BD-C2 binding domains are sufficient for CaM binding to the native channel, and, therefore, that BD-C1 is unable to bind CaM independently

    Resonant Spin Excitation in an Overdoped High Temperature Superconductor

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    An inelastic neutron scattering study of overdoped Bi_2Sr_2CaCu_2O_{8+\delta} $ (T_c = 83 K) has revealed a resonant spin excitation in the superconducting state. The mode energy is E_res=38 meV, significantly lower than in optimally doped Bi_2Sr_2CaCu_2O_{8+\delta} (T_c = 91 K, E_ res =43 meV). This observation, which indicates a constant ratio E_res /k_B T_c \sim 5.4, helps resolve a long-standing controversy about the origin of the resonant spin excitation in high-temperature superconductors.Comment: final version: PRL 86, 1610 (2001

    Quality of Recovery After Rotator Cuff Repair With Interscalene Liposomal Bupivacaine Versus Interscalene Nerve Catheter

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    Background: Interscalene nerve catheters have been proven to be effective in managing pain after rotator cuff repair (RCR) surgery. Liposomal bupivacaine is a newer approved therapy for use around the interscalene brachial plexus, but its analgesic efficacy has limited supporting data in various patient populations. Purpose/Hypothesis: The purpose of this study was to investigate the quality of recovery after arthroscopic RCR in patients who received either single-injection interscalene liposomal bupivacaine or an interscalene peripheral nerve catheter. It was hypothesized that interscalene peripheral nerve catheters would provide more reliable analgesia and improved patient satisfaction 48 hours after surgery. Study Design: Cohort study; Level of evidence, 2.Methods:Enrolled were 93 consecutive patients who underwent arthroscopic rotator cuff surgery at a single ambulatory surgery center between October 2020 and June 2021. Of these patients, 13 were lost to follow-up; thus, 80 patients were included in statistical analysis. One group of patients (n = 48) received a preoperative interscalene nerve block placed with 10 mL 0.5% bupivacaine and 10 mL 1.3% liposomal bupivacaine. The second group (n = 32) received a preoperative interscalene catheter with an initial bolus of 20 mL 0.25% bupivacaine and a 0.2% ropivacaine infusion by an elastomeric pump set at 10 mL/hr for 48 hours. The primary outcome was the difference between preoperative and 48-hour postoperative quality of recovery-15 (QoR-15) scores. Secondary outcomes included visual analog pain scores, opioid use, and patient satisfaction. Complications and adverse effects were also noted. The Kruskal-Wallis test was used to analyze means and standard deviations for continuous endpoints; Fisher exact test was used to analyze counts and proportions for categorical endpoints. Results: The liposomal bupivacaine group had a mean reduction of 3.9 in their postoperative QoR-15 scores, and the catheter group had a mean reduction of 25.1 in their postoperative QoR-15 scores, indicating a significantly worse functional recovery period compared with liposomal bupivacaine within the first 48 hours (P < .001). Patients who received liposomal bupivacaine also had significantly lower pain scores on the second postoperative day, improved quality of sleep, and improved satisfaction with analgesia (P < .05 for all). Conclusion: The use of interscalene liposomal bupivacaine demonstrated significantly improved quality of recovery when compared with interscalene nerve catheter after RCR

    Testing a communication assessment tool for ethically sensitive scenarios: Protocol of a validation study

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    Background: Although well-designed instruments to assess communication during medical interviews and complex encounters exist, assessment tools that differentiate between communication, empathy, decision-making, and moral judgment are needed to assess different aspects of communication during situations defined by ethical conflict. To address this need, we developed an assessment tool that differentiates competencies associated with practice in ethically challenging situations. The competencies are grouped into three distinct categories
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