1,079 research outputs found

    Dog Ecology and Dog Rabies Control

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    Dog populations, like other populations, depend on the availability of resources (food, water, and shelter). Humans either make available or deliberately withhold resources for varying proportions of dog populations. Dog-keeping practices and the duties of responsible ownership vary with the cultural setting. Dog populations often attain densities that allow the species to be a main host of rabies. The epidemiology of dog rabies is not well understood, despite the easy access to dog populations. Today dog rabies is predomina~t in developing countries. In addition to the high rate of exposure of humans to dogs, tradItional medical beliefs and practices are the most important cultural factors that lead to high numbers of cases of human rabies. Dog rabies control programs have been succe~sful in the past, but most are failing today. Program development should follow managenal principles and take into consideration the biology of dog populations as w~ll as. cultural constraints. Elimination of stray dogs IS not an effIcIent means of controllIng eIther the dog population or rabies, but it may create public awarenes

    A lens-coupled scintillation counter in cryogenic environment

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    In this work we present an elegant solution for a scintillation counter to be integrated into a cryogenic system. Its distinguishing feature is the absence of a continuous light guide coupling the scintillation and the photodetector parts, operating at cryogenic and room temperatures respectively. The prototype detector consists of a plastic scintillator with glued-in wavelength-shifting fiber located inside a cryostat, a Geiger-mode Avalanche Photodiode (G-APD) outside the cryostat, and a lens system guiding the scintillation light re-emitted by the fiber to the G-APD through optical windows in the cryostat shields. With a 0.8mm diameter multiclad fiber and a 1mm active area G-APD the coupling efficiency of the "lens light guide" is about 50%. A reliable performance of the detector down to 3K is demonstrated.Comment: 14 pages, 11 figure

    Early complications after living donor nephrectomy: analysis of the Swiss Organ Living Donor Health Registry.

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    We evaluated the prospectively collected data about the incidence of early peri- and postoperative complications, and potential risk factors for adverse outcomes after living kidney donation in Switzerland. Peri- and postoperative events were prospectively recorded on a questionnaire by the local transplant teams of all Swiss transplant centres and evaluated by the Swiss Organ Living Donor Health Registry. Complications were classified according to the Clavien grading system. A total of 1649 consecutive donors between 1998 and 2015 were included in the analysis. There was no perioperative mortality observed. The overall complication rate was 13.5%. Major complications defined as Clavien ≥3 occurred in 2.1% of donors. Obesity was not associated with any complications. Donor age >70years was associated with major complications (odds ratio [OR] 3.99) and genitourinary complications (urinary tract infection OR 5.85; urinary retention OR 6.61). There were more major complications observed in donors with laparoscopic surgery versus open surgery (p = 0.048), but an equal overall complication rate (p = 0.094). We found a low rate of major and minor complications, independent of surgical technique, after living donor nephrectomy. There was no elevated complication rate in obese donors. In contrast, elderly donors >70 years had an elevated risk for perioperative complications

    The O(N) Model at Finite Temperature: Renormalization of the Gap Equations in Hartree and Large-N Approximation

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    The temperature dependence of the sigma meson and pion masses is studied in the framework of the O(N) model. The Cornwall-Jackiw-Tomboulis formalism is applied to derive gap equations for the masses in the Hartree and large-N approximations. Renormalization of the gap equations is carried out within the cut-off and counter-term renormalization schemes. A consistent renormalization of the gap equations within the cut-off scheme is found to be possible only in the large-N approximation and for a finite value of the cut-off. On the other hand, the counter-term scheme allows for a consistent renormalization of both the large-N and Hartree approximations. In these approximations, the meson masses at a given nonzero temperature depend in general on the choice of the cut-off or renormalization scale. As an application, we also discuss the in-medium on-shell decay widths for sigma mesons and pions at rest.Comment: 21 pages, 6 figures, typos corrected and refs. added, accepted in Journal of Physics

    Quench Induced Vortices in the Symmetry Broken Phase of Liquid 4^4He

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    Motivated by the study of cosmological phase transitions, our understanding of the formation of topological defects during spontaneous symmetry-breaking and the associated non-equilibrium field theory has recently changed. Experiments have been performed in superfluid 4^4He to test the new ideas involved. In particular, it has been observed that a vortex density is seen immediately after pressure quenches from just below the λ\lambda transition. We discuss possible interpretations of these vortices, conclude they are consistent with our ideas of vortex formation and propose a modification of the original experiments.Comment: 29 pages, RevTeX with one EPS figur

    Action functionals of single scalar fields and arbitrary--weight gravitational constraints that generate a genuine Lie algebra

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    We discuss the issue initiated by Kucha\v{r} {\it et al}, of replacing the usual Hamiltonian constraint by alternative combinations of the gravitational constraints (scalar densities of arbitrary weight), whose Poisson brackets strongly vanish and cast the standard constraint-system for vacuum gravity into a form that generates a true Lie algebra. It is shown that any such combination---that satisfies certain reality conditions---may be derived from an action principle involving a single scalar field and a single Lagrange multiplier with a non--derivative coupling to gravity.Comment: 26 pages, plain TE

    Peripheral lymphadenopathy of unknown origin in adults: a diagnostic approach emphasizing the malignancy hypothesis.

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    The term lymphadenopathy refers to an abnormality in size, consistency or morphological aspect of one or several lymph nodes. Although lymphadenopathies are commonly observed in everyday clinical practice, the difficulty of differentiating benign and malignant disease may delay therapeutic approaches. The present review aims to update diagnostic algorithms in different clinical situations based on the currently available literature. A literature review was performed to assess current knowledge of and to update the diagnostic approach. A short clinical vignette was used as an example of a typical clinical presentation. This case of metastatic lymphadenopathy with incomplete patient history demonstrates how misleading such lymphadenopathy may be, leading to a delayed diagnosis and even a fatal outcome. Any lymphadenopathy persisting for more than 2 weeks should be considered suspicious and deserves further investigation. Precise clinical examination, meticulous history-taking and a search for associated symptomatology are still cornerstones for diagnosing the origin of the condition. The next diagnostic step depends on the anatomical region and the specific patient's situation. Imaging starts with ultrasound, while computed tomography (CT) and magnetic resonance imaging (MRI) allow assessment of the surrounding structures. If the diagnosis remains uncertain, tissue sampling and histological analyses should be performed. Except for head and neck loco-regional lymphadenopathy, there are no methodical guidelines for persistent lymphadenopathy. The present review clarifies several confusing and complex situations. The accuracy of fine needle aspiration cytology could be increased by using core needle biopsy with immunocytologic and flow cytometric methods. Notably, except in the head and neck area, open biopsy remains the best option when lymphoma is suspected or when inconclusive results of previous fine needle aspiration cytology or core needle biopsy are obtained. The incidence of malignant lymphadenopathy varies with its location and the various diagnostic strategies. In metastatic lymphadenopathy of unknown primary origin, European Society for Medical Oncology (ESMO) guidelines and modern methods like next-generation sequencing (NGS) may help to manage such complex cases

    Quasiparticle Description of the QCD Plasma, Comparison with Lattice Results at Finite T and Mu

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    We compare our 2+1 flavor, staggered QCD lattice results with a quasiparticle picture. We determine the pressure, the energy density, the baryon density, the speed of sound and the thermal masses as a function of T and μB\mu_B. For the available thermodynamic quantities the difference is a few percent between the results of the two approaches. We also give the phase diagram on the μB\mu_B--T plane and estimate the critical chemical potential at vanishing temperature.Comment: 13 pages, 10 figure

    Some Applications of Thermal Field Theory to Quark-Gluon Plasma

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    The lecture provides a brief introduction of thermal field theory within imaginary time formalism, the Hard Thermal Loop perturbation theory and some of its application to the physics of the quark-gluon plasma, possibly created in relativistic heavy ion collisions.Comment: 17 pages, 12 figures : Lectures given in "Workshop on Hadron Physics" during March 7-17, 2005, Puri, Indi

    An overview of the mid-infrared spectro-interferometer MATISSE: science, concept, and current status

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    MATISSE is the second-generation mid-infrared spectrograph and imager for the Very Large Telescope Interferometer (VLTI) at Paranal. This new interferometric instrument will allow significant advances by opening new avenues in various fundamental research fields: studying the planet-forming region of disks around young stellar objects, understanding the surface structures and mass loss phenomena affecting evolved stars, and probing the environments of black holes in active galactic nuclei. As a first breakthrough, MATISSE will enlarge the spectral domain of current optical interferometers by offering the L and M bands in addition to the N band. This will open a wide wavelength domain, ranging from 2.8 to 13 um, exploring angular scales as small as 3 mas (L band) / 10 mas (N band). As a second breakthrough, MATISSE will allow mid-infrared imaging - closure-phase aperture-synthesis imaging - with up to four Unit Telescopes (UT) or Auxiliary Telescopes (AT) of the VLTI. Moreover, MATISSE will offer a spectral resolution range from R ~ 30 to R ~ 5000. Here, we present one of the main science objectives, the study of protoplanetary disks, that has driven the instrument design and motivated several VLTI upgrades (GRA4MAT and NAOMI). We introduce the physical concept of MATISSE including a description of the signal on the detectors and an evaluation of the expected performances. We also discuss the current status of the MATISSE instrument, which is entering its testing phase, and the foreseen schedule for the next two years that will lead to the first light at Paranal.Comment: SPIE Astronomical Telescopes and Instrumentation conference, June 2016, 11 pages, 6 Figure
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