633 research outputs found

    Gegenbauer-solvable quantum chain model

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    In an innovative inverse-problem construction the measured, experimental energies E1E_1, E2E_2, ...ENE_N of a quantum bound-state system are assumed fitted by an N-plet of zeros of a classical orthogonal polynomial fN(E)f_N(E). We reconstruct the underlying Hamiltonian HH (in the most elementary nearest-neighbor-interaction form) and the underlying Hilbert space H{\cal H} of states (the rich menu of non-equivalent inner products is offered). The Gegenbauer's ultraspherical polynomials fn(x)=Cnα(x)f_n(x)=C_n^\alpha(x) are chosen for the detailed illustration of technicalities.Comment: 29 pp., 1 fi

    Osmolyte solutions and protein folding

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    In this brief review we discuss the evolution of recent thought regarding the role and mechanism of osmolytes with respect to protein stability. Osmolytes are naturally occurring intracellular compounds that change the protein folding landscape. Contributions from experiments are considered in the context of current theory and simulation results

    Kinetics of Co-oxidation of Ethylene Glycol & Propan-2-ol by Acid Bromate

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    211-21

    Optimizing global health experiences in emergency medicine residency programs: A consensus statement from the Council of Emergency Medicine Residency Directors 2011 Academic Assembly global health specialty track

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    BACKGROUND: An increasing number of emergency medicine (EM) residency training programs have residents interested in participating in clinical rotations in other countries. However, the policies that each individual training program applies to this process are different. To our knowledge, little has been done in the standardization of these experiences to help EM residency programs with the evaluation, administration and implementation of a successful global health clinical elective experience. The objective of this project was to assess the current status of EM global health electives at residency training programs and to establish recommendations from educators in EM on the best methodology to implement successful global health electives. METHODS: During the 2011 Council of Emergency Medicine Residency Directors (CORD) Academic Assembly, participants met to address this issue in a mediated discussion session and working group. Session participants examined data previously obtained via the CORD online listserve, discussed best practices in global health applications, evaluations and partnerships, and explored possible solutions to some of the challenges. In addition a survey was sent to CORD members prior to the 2011 Academic Assembly to evaluate the resources and processes for EM residents’ global experiences. RESULTS: Recommendations included creating a global health working group within the organization, optimizing a clearinghouse of elective opportunities for residents and standardizing elective application materials, site evaluations and resident assessment/feedback methods. The survey showed that 71.4% of respondents have global health partnerships and electives. However, only 36.7% of programs require pre-departure training, and only 20% have formal competency requirements for these global health electives. CONCLUSIONS: A large number of EM training programs have global health experiences available, but these electives and the trainees may benefit from additional institutional support and formalized structure

    The impact of due process and disruptions on emergency medicine education in the United States

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    INTRODUCTION: Academic Emergency Medicine (EM) departments are not immune to natural disasters, economic or political forces that disrupt a training program\u27s operations and educational mission. Due process concerns are closely intertwined with the challenges that program disruption brings. Due process is a protection whereby an individual will not lose rights without access to a fair procedural process. Effects of natural disasters similarly create disruptions in the physical structure of training programs that at times have led to the displacement of faculty and trainees. Variation exists in the implementation of transitions amongst training sites across the country, and its impact on residency programs, faculty, residents and medical students. METHODS: We reviewed the available literature regarding due process in emergency medicine. We also reviewed recent examples of training programs that underwent disruptions. We used this data to create a set of best practices regarding the handling of disruptions and due process in academic EM. RESULTS: Despite recommendations from organized medicine, there is currently no standard to protect due process rights for faculty in emergency medicine training programs. Especially at times of disruption, the due process rights of the faculty become relevant, as the multiple parties involved in a transition work together to protect the best interests of the faculty, program, residents and students. Amongst training sites across the country, there exist variations in the scope and impact of due process on residency programs, faculty, residents and medical students. CONCLUSION: We report on the current climate of due process for training programs, individual faculty, residents and medical students that may be affected by disruptions in management. We outline recommendations that hospitals, training programs, institutions and academic societies can implement to enhance due process and ensure the educational mission of a residency program is given due consideration during times of transition

    Impaired phloem loading in zmsweet13a,b,c sucrose transporter triple knock-out mutants in Zea mays

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    Crop yield is critical for human nutrition, yet the underlying machinery that ultimately determines yield potential is still not understood. Crop productivity under ideal conditions is determined by the efficiency with which plants intercept light, convert it into chemical energy, translocate photosynthates and convert these to storage products in harvestable organs (Zhu et al., 2010). In many crops, sucrose is the primary form for translocation inside the conduit (i.e. the phloem). A combination of SWEETmediated efflux from phloem parenchyma and subsequent secondary active sucrose import by SUT sucrose/H+ symporters is thought to create the driving force for pressure gradient-driven phloem transport and retrieval of sucrose leaking along the translocation path (Chen et al., 2015a)

    Quantitative analysis of proximity effect in Nb/Co60Fe40Nb/Co_{60}Fe_{40}, Nb/Ni, and Nb/Cu40Ni60Nb/Cu_{40}Ni_{60} bilayers

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    We have studied the behavior of the superconducting critical temperature Tc in Nb/Co60Fe40Nb/Co_{60}Fe_{40}, Nb/Ni, and Nb/Cu40Ni60Nb/Cu_{40}Ni_{60} bilayers as a function of the thickness of each ferromagnetic metal layer. The Tc s of three sets of bilayers exhibit non-monotonic behavior as a function of each ferromagnetic metal thickness. Employing the quantitative analysis based on Usadel formalism of the effect of the exchange energy, we observed that the Tc behavior of Nb/Co60Fe40Nb/Co_{60}Fe_{40} bilayers is in good agreement with the theoretical values over the entire range of the data. On the other hand, the Tc s of Nb/Ni and Nb/Cu40Ni60Nb/Cu_{40}Ni_{60} bilayers show a higher value in the small thickness regime than the theoretical prediction obtained from the calculation, which matches the dip position and the saturation value of Tc in the large thickness limit. This discrepancy is probably due to the weakened magnetic properties of Ni and Cu40Ni60Cu_{40}Ni_{60} when they are thin. We discuss the values of our fitting parameters and its implication on the validity of the current Usadel formalism of the effect of the exchange energy.Comment: 10 pages, 5 figures and 1 tabl

    X-ray diffraction measurements of the c-axis Debye-Waller factors of YBa2Cu3O7 and HgBa2CaCu2O6

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    We report the first application of x-rays to the measurement of the temperature dependent Bragg peak intensities to obtain Debye-Waller factors on high-temperature superconductors. Intensities of (0,0,l) peaks of YBa2Cu3O7 and HgBa2CaCu2O6 thin films are measured to obtain the c-axis Debye-Waller factors. While lattice constant and some Debye-Waller factor measurements on high Tc superconductors show anomalies at the transition temperature, our measurements by x-ray diffraction show a smooth transition of the c-axis Debye-Waller factors through Tc_c. This suggests that the dynamic displacements of the heavy elements along the c-axis direction in these compounds do not have anomalies at Tc. This method in combination with measurements by other techniques will give more details concerning dynamics of the lattice.Comment: 4 pages, 2 figures. To be published in Physical Review B (Brief Report
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