599 research outputs found

    Performance of the Los Alamos National Laboratory spallation-driven solid-deuterium ultra-cold neutron source

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    In this paper, we describe the performance of the Los Alamos spallation-driven solid-deuterium ultra-cold neutron (UCN) source. Measurements of the cold neutron flux, the very low energy neutron production rate, and the UCN rates and density at the exit from the biological shield are presented and compared to Monte Carlo predictions. The cold neutron rates compare well with predictions from the Monte Carlo code MCNPX and the UCN rates agree with our custom UCN Monte Carlo code. The source is shown to perform as modeled. The maximum delivered UCN density at the exit from the biological shield is 52(9) UCN/cc with a solid deuterium volume of ∼1500 cm^3

    Use of Buffers in Specific Contexts : Highly Trained Female Athletes, Extreme Environments and Combined Buffering Agents - A Narrative Review

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    This narrative review evaluated the evidence for buffering agents (sodium bicarbonate, sodium citrate and beta-alanine), with specific consideration of three discrete scenarios: female athletes, extreme environments and combined buffering agents. Studies were screened according to exclusion and inclusion criteria and were analysed on three levels: (1) moderating variables (supplement dose and timing, and exercise test duration and intensity), (2) design factors (e.g., use of crossover or matched group study design, familiarisation trials) and (3) athlete-specific factors (recruitment of highly trained participants, buffering capacity and reported performance improvements). Only 19% of the included studies for the three buffering agents reported a performance benefit, and only 10% recruited highly trained athletes. This low transferability of research findings to athletes’ real-world practices may be due to factors including the small number of sodium citrate studies in females (n = 2), no studies controlling for the menstrual cycle (MC) or menstrual status using methods described in recently established frameworks, and the limited number of beta-alanine studies using performance tests replicating real-world performance efforts (n = 3). We recommend further research into buffering agents in highly trained female athletes that control or account for the MC, studies that replicate the demands of athletes’ heat and altitude camps, and investigations of highly trained athletes’ use of combined buffering agents. In a practical context, we recommend developing evidence-based buffering protocols for individual athletes which feature co-supplementation with other evidence-based products, reduce the likelihood of side-effects, and optimise key moderating factors: supplement dose and timing, and exercise duration and intensity

    2018 GJMPP Monograph Series: Grace Jordan McFadden Professors Program

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    The Grace Jordan McFadden Professors Program (GJMPP), formerly the African American Professors Program (AAPP)/Carolina Diversity Professors Program (CDPP) at the University of South Carolina, is honored to publish its seventeenth edition of this annual monograph series. GJMPP recognizes the significance of offering its scholars a venue through which they have the opportunity to engage in research and to publish their refereed papers that continually contribute to their respective academic areas. Parallel with the publication of their manuscripts is a venue to gain visibility among colleagues throughout postsecondary institutions at national and international levels. Scholars who have contributed papers for this monograph are acknowledged for embracing the value of including this responsibility within their doctoral milieu. Writing across disciplines adds broadly to the intellectual diversity of these manuscripts. From neophytes to quite experienced individuals, the chapters have been researched and written with vigor. Founded in 1997 through the Department of Educational Leadership and Policies in the College of Education, AAPP was designed originally to address the under-representation of African American professors on college and university campuses. Its mission is to expand the pool of these professors in critical academic and research areas. Sponsored historically by the University of South Carolina, the W. K. Kellogg Foundation, and the South Carolina General Assembly, the program recruits doctoral students for disciplines in which African Americans and others are underrepresented among faculty in higher education. The continuation of this monograph series is seen as responding to a window of opportunity to be sensitive to an academic expectation of graduates as they pursue career placement and, at the same time, to allow for the dissemination of products of scholarship to a broader community. The importance of this series has been voiced by one of our 2002 AAPP graduates, Dr. Shundelle LaTjuan Dogan, formerly an Administrative Fellow at Harvard University, a Program Officer for the Southern Education Foundation, and a Program Officer for the Arthur M. Blank Foundation in Atlanta, Georgia. She recently completed an appointment as Corporate Citizenship and Corporate Affairs Manager for IBM International Business Machines in Atlanta and is currently a consultant with a focus on philanthropy and social impact. She is currently Assistant Vice President for Social Impact and Innovation at Emory University. Dr. Dogan has written an impressive Foreword for the 2014 monograph. In a personal letter, which is cited in an earlier monograph, Dr. Dogan penned: “One thing in particular that I want to thank you for is having the African American Professors Program scholars publish articles for the monograph. I have to admit that writing the articles seemed like extra work at the time. However, in my recent interview process, organizations have asked me for samples of my writing. Including an article from a published monograph helped to make my portfolio much more impressive. You were ‘right on target’ in having us do the monograph series” (AAPP 2003, Monograph, p. xi). The Grace Jordan McFadden Professors Program purports to advance the tradition of spearheading international scholarship in higher education as evidenced through inspiration from this group of interdisciplinary manuscripts. I hope that you will envision these published papers to serve as an invaluable contribution to your own professional and career enhancement. John McFadden, PhD The Benjamin Elijah Mays Distinguished Professor Emeritus Director, Grace Jordan McFadden Professors Program University of South Carolina Columbia, South Carolinahttps://scholarcommons.sc.edu/mcfadden_monographs/1010/thumbnail.jp

    Trajectories of depression and anxiety symptom severity during psychological therapy for common mental health problems

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    BACKGROUND: There is substantial variation in patient symptoms following psychological therapy for depression and anxiety. However, reliance on endpoint outcomes ignores additional interindividual variation during therapy. Knowing a patient's likely symptom trajectories could guide clinical decisions. We aimed to identify latent classes of patients with similar symptom trajectories over the course of psychological therapy and explore associations between baseline variables and trajectory class. METHODS: Patients received high-intensity psychological treatment for common mental health problems at National Health Service Improving Access to Psychological Therapies services in South London (N = 16 258). To identify trajectories, we performed growth mixture modelling of depression and anxiety symptoms over 11 sessions. We then ran multinomial regressions to identify baseline variables associated with trajectory class membership. RESULTS: Trajectories of depression and anxiety symptoms were highly similar and best modelled by four classes. Three classes started with moderate-severe symptoms and showed (1) no change, (2) gradual improvement, and (3) fast improvement. A final class (4) showed initially mild symptoms and minimal improvement. Within the moderate-severe baseline symptom classes, patients in the two showing improvement as opposed to no change tended not to be prescribed psychotropic medication or report a disability and were in employment. Patients showing fast improvement additionally reported lower baseline functional impairment on average. CONCLUSIONS: Multiple trajectory classes of depression and anxiety symptoms were associated with baseline characteristics. Identifying the most likely trajectory for a patient at the start of treatment could inform decisions about the suitability and continuation of therapy, ultimately improving patient outcomes

    Student Satisfaction and Performance in an Online Teacher Certification Program

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    The article presents a study which demonstrates the effectiveness of an online post baccalaureate teacher certification program developed by a Wisconsin university. The case method approach employing multiple methods and multiple data sources were used to investigate the degree to which pre-service teachers were prepared to teach. It was concluded that the study supports online delivery as an effective means of teacher preparation, but it was limited in the number of students followed into their first year of teaching

    First direct constraints on Fierz interference in free neutron β\beta decay

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    Precision measurements of free neutron β\beta-decay have been used to precisely constrain our understanding of the weak interaction. However the neutron Fierz interference term bnb_n, which is particularly sensitive to Beyond-Standard-Model tensor currents at the TeV scale, has thus far eluded measurement. Here we report the first direct constraints on this term, finding bn=0.067±0.005stat0.061+0.090sysb_n = 0.067 \pm 0.005_{\text{stat}} {}^{+0.090}_{- 0.061}{}_{\text{sys}}, consistent with the Standard Model. The uncertainty is dominated by absolute energy reconstruction and the linearity of the beta spectrometer energy response

    Determination of the Axial-Vector Weak Coupling Constant with Ultracold Neutrons

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    A precise measurement of the neutron decay β\beta-asymmetry A0A_0 has been carried out using polarized ultracold neutrons (UCN) from the pulsed spallation UCN source at the Los Alamos Neutron Science Center (LANSCE). Combining data obtained in 2008 and 2009, we report A0=0.11966±0.000890.00140+0.00123A_0 = -0.11966 \pm 0.00089_{-0.00140}^{+0.00123}, from which we determine the ratio of the axial-vector to vector weak coupling of the nucleon gA/gV=1.275900.00445+0.00409g_A/g_V = -1.27590_{-0.00445}^{+0.00409}.Comment: 5 pages, 2 figure
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