1,663 research outputs found

    Resistive relaxation in field-induced insulator-metal transition of a (La0.4_{0.4}Pr0.6_{0.6})1.2_{1.2}Sr1.8_{1.8}Mn2_{2}O7_{7} bilayer manganite single crystal

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    We have investigated the resistive relaxation of a (La0.4_{0.4}Pr0.6_{0.6})1.2_{1.2}Sr1.8_{1.8}Mn2_{2}O7_{7} single crystal, in order to examine the slow dynamics of the field-induced insulator to metal transition of bilayered manganites. The temporal profiles observed in remanent resistance follow a stretched exponential function accompanied by a slow relaxation similar to that obtained in magnetization and magnetostriction data. We demonstrate that the remanent relaxation in magnetotransport has a close relationship with magnetic relaxation that can be understood in the framework of an effective medium approximation by assuming that the first order parameter is proportional to the second order one.Comment: 6 pages,5 figure

    Regional frequency analysis of extreme precipitation for Sicily (Italy)

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    The analysis of extreme precipitation has always been included among most relevant hydrological applications because of the several important activities linked to the availability of tools for the estimation of extreme rainfall quantiles. These activities include the design of hydraulic civil structures and the evaluation and management of hydraulic and hydrological risk. In this study a frequency analysis of annual maxima precipitation measurements has been carried out for the area of Sicily (Italy). A typical hierarchical regional approach has been adopted for the parameter estimation procedure based on the L-moments method. The identification of homogeneous regions within the procedure has been pursued with a data driven procedure constituted by a principal component analysis of an ensemble of selected auxiliary variables, and a K-means cluster analysis algorithm. Auxiliary variables comprise meteo-climatic information and a representation of the average seasonal distribution of intense events. Results have been evaluated by means of a Monte Carlo experiment based on the comparison between at-site and regional fitted frequency distributions. Moreover, results have been compared with previous analyses performed for the same area. The study provides an updated tool for the modelling of extreme precipitation for the area of Sicily (Italy), with different features respect to previous tools both in terms of definition of homogeneous zones and in terms of parameters of the frequency distribution. Meteo-climatic information and the seasonality of extreme events retrieved from the dataset has been proficuously exploited in the analysis

    In-plane thermal conductivity of large single crystals of Sm-substituted (Y1x_{1-x}Smx_{x})Ba2_{2}Cu3_{3}O7δ_{7-\delta}

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    We have investigated the in-plane thermal conductivity κab(T,H)\kappa_{ab}(T,H) of large single crystals of optimally oxygen-doped (Y1x_{1-x},Smx_{x})Ba2_{2}Cu3_{3}O7δ_{7-\delta} (xx=0, 0.1, 0.2 and 1.0) and YBa2_{2}(Cu1y_{1-y}Zny_{y})3_{3}O7δ_{7-\delta}(yy=0.0071) as functions of temperature and magnetic field (along the c axis). For comparison, the temperature dependence of κab\kappa_{ab} for as-grown crystals with the corresponding compositions are presented. The nonlinear field dependence of κab\kappa_{ab} for all crystals was observed at relatively low fields near a half of TcT_{c}. We make fits of the κ(H)\kappa(H) data to an electron contribution model, providing both the mean free path of quasiparticles 0\ell_{0} and the electronic thermal conductivity κe\kappa_{e}, in the absence of field. The local lattice distortion due to the Sm substitution for Y suppresses both the phonon and electron contributions. On the other hand, the light Zn doping into the CuO 2_{2} planes affects solely the electron component below TcT_{c}, resulting in a substantial decrease in 0\ell_{0} .Comment: 7 pages,4 figures,1 tabl

    Quasi-Particle Spectra, Charge-Density-Wave, Superconductivity and Electron-Phonon Coupling in 2H-NbSe2

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    High-resolution photoemission has been used to study the electronic structure of the charge density wave (CDW) and superconducting (SC) dichalcogenide, 2H- NbSe2. From the extracted self-energies, important components of the quasiparticle (QP) interactions have been identified. In contrast to previously studied TaSe2, the CDW transition does not affect the electronic properties significantly. The electron-phonon coupling is identified as a dominant contribution to the QP self-energy and is shown to be very anisotropic (k-dependent) and much stronger than in TaSe2.Comment: 4 pages, 3 figures, minor changes, to appear in PR

    Microtubule assembly and in vitro development of bovine oocytes with increased intracellular glutathione level prior to vitrification and in vitro fertilization

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    Although vitrification is a useful technique for preservation of bovine oocytes, the yield of blastocysts derived from the vitrified oocytes is still low. We have recently reported a new type of cryoinjury, multiple aster formation, by which pronuclear migration and development of vitrified–warmed and in vitro-fertilized bovine oocytes are impaired. The aim of the present study was to investigate the effect of glutathione (GSH) content of vitrified bovine oocytes on multiple aster formation and subsequent in vitro development. Treatment of bovine cumulus–oocyte complexes with β-mercaptoethanol (βME) and l-cysteine (Cys) during in vitro maturation resulted in 2.5-fold higher GSH content not only in fresh control but also in vitrified–warmed oocytes. The percentage of normally fertilized zygotes exhibiting sperm aster(s) was >95% in all four groups (with or without βME/Cys × fresh control or vitrified). The frequency of multiple aster formation in vitrified oocytes (three-fold higher than that in fresh control oocytes) was not affected by the increased level of intracellular GSH with βME/Cys. Consequently, the migration and development of pronuclei as well as the yield of blastocysts from vitrified–warmed oocytes (17 versus 41%) were not improved. In addition, there was no effect of increased GSH level on the yield of blastocysts in fresh control groups.ArticleZYGOTE. 22(4):476-482 (2014)journal articl

    The Effects of Cultivation Site on Forage Quality of Calliandra calothyrsus var. Patulul

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    An in vitro experiment was performed to compare the forage quality of foliage of Calliandra (Calliandra calothyrsus Meissner var. Patulul) cultivated on either low or medium-fertility soils in Colombia and Kenya, respectively. A grass-alone diet, with and without urea supplementation, and five legume-supplemented diets (1/3 of dietary dry matter) were tested with the rumen simulation technique (Rusitec) (n=4). The legume supplements consisted of Cratylia (Cratylia argentea), Calliandra from Colombia or Kenya, or 1:1 mixtures of Cratylia with Calliandra Colombia or Kenya. The tannin content of Calliandra Colombia was almost twice as high as that of Calliandra Kenya. Supplementation with urea or Cratylia alone, but not with Calliandra alone, increased ammonia concentration in the fermenter fluid. Unlike Calliandra Colombia, Calliandra Kenya in mixture with Cratylia increased ammonia concentration. The apparent degradation of organic matter increased with all types of supplementation, except with Calliandra Colombia alone. Although the foliage of Calliandra from the two cultivation sites had similar contents of organic matter, crude protein and neutral detergent fibre, they differed in␣nearly all fermentation properties. The material from Kenya showed a higher apparent nutrient degradability. These results indicate that C. calothyrsus var. Patulul cultivated at the Kenyan site had a clearly higher forage quality than foliage from the same variety cultivated in Colombia. However, both materials had a much lower forage quality than Cratylia. The Cratylia-related effects on ruminal fermentation were mainly the results of an increased supply of fermentable nitrogenous compounds as was obvious from the comparison with the urea-supplemented gras

    Research and Development for Pressurized He II Cooled Superconducting Magnets(Part II. Several Instruments and Techniques Developed in HFLSM)

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    New high field superconducting magnets have been studied as the research and development for the next phase 35 T hybrid magnet plan. A 13 T superconducting magnet employing a NbTiHf ternary alloy superconductor and a 16.7 T superconducting magnet employing a Ti doped Nb_3Sn superconductor have been successfully operated in the pressurized superfluid helium bath

    Attitudes and Practice Patterns in the Use of OMM in Patients with Serious Illness

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    INTRODUCTION: In addition to evidence-based medicine, the osteopathic approach to person-centered care consists of the osteopathic philosophy of integrated structure and function and applying manual techniques to treat somatic dysfunction. Known collectively as Osteopathic Manipulative Medicine (OMM), this approach can be utilized when treating patients with both chronic and acute conditions; however, there is limited data on how often or to what extent OMM is used to treat pain and other symptoms in patients facing serious or life-limiting illnesses. METHODS: A voluntary, anonymous survey was created to capture the practice patterns and attitudes of osteopathic physicians, regardless of specialty, in the uses and benefits of OMM in treating patients with serious illness. The survey was approved by the IRB and designed using a Likert-scale, multiple choice format using Redcap software and permission to distribute the survey electronically was granted from various national and local professional organizations including the American Osteopathic Association (AOA), Pennsylvania Osteopathic Medical Association (POMA) and the PCOM alumni association. Among key data analyzed were the frequency of OMM use in serious or life-limiting illness (Cancer, CHF, and COPD), attitudes about OMM, beliefs about OMM, and use of OMM in older adults. RESULTS: Osteopathic Physicians that utilize OMM when treating patients with serious illness have found OMM to be beneficial when treating certain conditions such as chronic and musculoskeletal pain, shortness of breath, and nausea. The physicians who use OMM also felt comfortable and proficient when utilizing it to treat certain conditions. They also felt their foundation in osteopathic Medicine enabled them to approach and care for patients with empathy and compassion. DISCUSSION: OMM is used by many osteopathic physicians when treating pain and other symptoms of patients who have serious illness. OMM has been found to be beneficial when treating conditions related to CHF, COPD, and Cancer. Osteopathic Physicians who do utilize Osteopathic Manipulative Medicine believe that their training has allowed them to engage and treat patients with compassion and empathy
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