1,231 research outputs found

    A Test for Penicillins on Chromatograms and in Spot Tests

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    Author Institution: Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 4522

    Charmed Mesons Have No Discernable Color-Coulomb Attraction

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    Starting with a confining linear Lorentz scalar potential V_s and a Lorentz vector potential V_v which is also linear but has in addition a color-Coulomb attraction piece, -alpha_s/r, we solve the Dirac equation for the ground-state c- and u-quark wave functions. Then, convolving V_v with the u-quark density, we find that the Coulomb attraction mostly disappears, making an essentially linear barV_v for the c-quark. A similar convolution using the c-quark density also leads to an essentially linear tildeV_v for the u-quark. For bound cbar-c charmonia, where one must solve using a reduced mass for the c-quarks, we also find an essentially linear widehatV_v. Thus, the relativistic quark model describes how the charmed-meson mass spectrum avoids the need for a color-Coulomb attraction.Comment: 9 pages, 5 PDF figure

    The Impact of Medicare's Prospective Payment System on Psychiatric Patients Treated in Scatterbeds

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    Medicare's Prospective Payment System (PPS) for hospitals was phased-in during the 1884 Federal Fiscal Year. While many providers of psychiatric inpatient care were exempted from PPS patients treated in general hospital beds outside of psychiatric units (scatterbeds) were not. This allows for an initial assessment of the impact of PPS on psychiatric patients. We use a single equation model of hospital length of stay to estimate the impact of PPS. We allow for the possibility of both anticipating behavior and slow adjustment to the new payment scheme. The results indicate a substantial response to PPS over the first year of implementation. The estimated response includes sizable anticipatory and slow adjustment components. The findings suggest that policy discussions may be weighted too heavily in the direction of concern over hospital financial status given the ability of hospitals to change their behavior.

    Dietetics program directors in the United States support teaching vegetarian and vegan nutrition and half connect vegetarian and vegan diets to environmental impact

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    Registered Dietitian Nutritionists (RDNs) are clinicians trained in the application of food, nutrition, and dietetics. Vegetarians and vegans have a lower risk of many nutrition-related chronic diseases that are epidemic while vegetarian and vegan diets are associated with reduced environmental impact. Despite this strong diet-disease and diet-environment connection, it is not known if dietetics students are taught the principles of vegetarian and vegan nutrition. The overarching goal of our study was to investigate curricular practices in accredited dietetics training programs in the United States (U.S.) including (1) the prevalence and perceived importance of vegetarian and vegan nutrition instruction and (2) if program directors connect vegetarian and vegan diets to climate change mitigation and resource conservation. Primary data were collected by way of a cross-sectional, Internet-based survey. All Accreditation Council for Education in Nutrition and Dietetics (ACEND) program directors in the U.S. (N = 574) were sent a 37-question survey and invited to participate in the study. Outcome measures included the prevalence of vegetarian and vegan nutrition instruction, quantifying if relationships exist among variables, and the frequency of connecting vegetarian and vegan diets to environmental impact. Descriptive and inferential statistics were utilized. Respondents (n = 205) indicated that over 51% of programs teach vegetarian nutrition while 49% teach vegan nutrition. There were significant differences between program type and the prevalence of vegetarian (p = 0.00005) and vegan (p = 0.00005) nutrition instruction. Over 90% of program directors believe that vegetarian and vegan nutrition should be taught. Over 50% of programs identify the connection between vegetarian and vegan diets in climate change mitigation and resource conservation. Most ACEND program directors believe vegetarian and vegan nutrition should be taught and half connect diet to environmental concern. Nevertheless, there is a discrepancy between beliefs and practice behaviors. These results suggest the need for increased collaboration and the use of novel techniques that better incorporate vegan and vegetarian nutrition throughout dietetics education

    Effect of Hadron Dynamics on the Proton Lifetime

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    A detailed, quantitative re-examination of the effect of hadron dynamics on baryon decay, modeled in terms of Skyrme-field tunneling, indicates that any hadronic suppression should be quite mild. This appears to be another illustration of the `Cheshire-cat' phenomenon, that variation of the apportionment between description of the nucleon as a bag of quarks and description as a Skyrme field configuration has little influence on many nucleon properties. Perhaps the largest remaining uncertainty in evaluating the decay rate has to do with the overlap between a specified quark-antiquark configuration and a final meson state.Comment: minor corrections, 19 pages, 9 figure

    Competitiveness a Masculinity-Femininity Cultural Dimension and Multinational Corporations’ Performance in Uganda

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    This study conducted under strategy management sought to examine the influence of competitiveness within masculinity-femininity cultural dimension on performance of multinational corporations (MNCs) in Uganda. Specifically, it focused on aspects of competitiveness within the masculinity-femininity cultural dimension that included aggressiveness and materialism. The interest in this study was aroused because of MNCs performance challenges such as struggling to maintain businesses acumen, market share, growth and closure of businesses. This study adopted a cross-sectional research design using a quantitative approach and it involved 50 participants who responded to statements in a questionnaire. A simple regression analysis and a multiple-regression analysis were conducted to assess the influence investigated in this study. Results revealed that competitiveness within masculinity-femininity cultural dimension that included both aggressiveness and materialism had a significant positive influence on performance of MNCs in Uganda. In particular, low levels work aggressiveness and work materialism among MNCs’ employees contributed to the low levels of performance of MNCs in Uganda. The study recommends MNCs to align their strategic vision and mission towards competitiveness to instilling employee work aggressiveness and materialism toward achieving the objectives of the MNCs. Keywords: Masculinity-femininity, competitiveness, aggressiveness, materialism and performance DOI: 10.7176/EJBM/15-12-03 Publication date:June 30th 202

    Solving the radial Dirac equations: a numerical odyssey

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    We discuss, in a pedagogical way, how to solve for relativistic wave functions from the radial Dirac equations. After an brief introduction, in Section II we solve the equations for a linear Lorentz scalar potential, V_s(r), that provides for confinement of a quark. The case of massless u and d quarks is treated first, as these are necessarily quite relativistic. We use an iterative procedure to find the eigenenergies and the upper and lower component wave functions for the ground state and then, later, some excited states. Solutions for the massive quarks (s, c, and b) are also presented. In Section III we solve for the case of a Coulomb potential, which is a time-like component of a Lorentz vector potential, V_v(r). We re-derive, numerically, the (analytically well-known) relativistic hydrogen atom eigenenergies and wave functions, and later extend that to the cases of heavier one-electron atoms and muonic atoms. Finally, Section IV finds solutions for a combination of the V_s and V_v potentials. We treat two cases. The first is one in which V_s is the linear potential used in Sec. II and V_v is Coulombic, as in Sec. III. The other is when both V_s and V_v are linearly confining, and we establish when these potentials give a vanishing spin-orbit interaction (as has been shown to be the case in quark models of the hadronic spectrum).Comment: 39 pages (total), 23 figures, 2 table

    Does the revised cardiac risk index predict cardiac complications following elective lung resection?

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    Background: Revised Cardiac Risk Index (RCRI) score and Thoracic Revised Cardiac Risk Index (ThRCRI) score were developed to predict the risks of postoperative major cardiac complications in generic surgical population and thoracic surgery respectively. This study aims to determine the accuracy of these scores in predicting the risk of developing cardiac complications including atrial arrhythmias after lung resection surgery in adults. Methods: We studied 703 patients undergoing lung resection surgery in a tertiary thoracic surgery centre. Observed outcome measures of postoperative cardiac morbidity and mortality were compared against those predicted by risk. Results: Postoperative major cardiac complications and supraventricular arrhythmias occurred in 4.8% of patients. Both index scores had poor discriminative ability for predicting postoperative cardiac complications with an area under receiver operating characteristic (ROC) curve of 0.59 (95% CI 0.51-0.67) for the RCRI score and 0.57 (95% CI 0.49-0.66) for the ThRCRI score. Conclusions: In our cohort, RCRI and ThRCRI scores failed to accurately predict the risk of cardiac complications in patients undergoing elective resection of lung cancer. The British Thoracic Society (BTS) recommendation to seek a cardiology referral for all asymptomatic pre-operative lung resection patients with > 3 RCRI risk factors is thus unlikely to be of clinical benefit
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