2,326 research outputs found

    A general resonance theory based on Mourre's inequality

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    We study the perturbation of bound states embedded in the continuous spectrum which are unstable by the Fermi Golden Rule. The approach to resonance theory based on spectral deformation is extended to a more general class of quantum systems characterized by Mourre's inequality and smoothness of the resolvent. Within the framework of perturbation theory it is still possible to give a definite meaning to the notion of complex resonance energies and of corresponding metastable states. The main result is a quasi-exponential decay estimate up to a controlled error of higher order in perturbation theory.Comment: 17 page

    Archaeological Testing at Goliad State Park, Goliad County, Texas

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    In December 1996, the Center for Archaeological Research (CAR) of The University of Texas at San Antonio entered into a contract with the Texas Parks and Wildlife Department to conduct archaeological investigations at Mission Espiritu Santo in Goliad State Park. On December 17, 1996, a seven-member field crew from CAR excavated 32 shovel tests along the proposed trench for replacement of existing park water and electrical lines between the mission compound and the camping area. Artifacts recovered from the shovel tests include Spanish colonial ceramics, glass, metal, stone tools and debitage, and a large quantity of animal bone. Most of the artifacts were recovered from the shovel test pits near the mission wall. Any new trenching in this area would disturb possible intact Colonial deposits. Very few artifacts were recovered from the remainder of the proposed trench line

    Free Fermionic Heterotic Model Building and Root Systems

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    We consider an alternative derivation of the GSO Projection in the free fermionic construction of the weakly coupled heterotic string in terms of root systems, as well as the interpretation of the GSO Projection in this picture. We then present an algorithm to systematically and efficiently generate input sets (i.e. basis vectors) in order to study Landscape statistics with minimal computational cost. For example, the improvement at order 6 is approximately 10^{-13} over a traditional brute force approach, and improvement increases with order. We then consider an example of statistics on a relatively simple class of models.Comment: Standard Latex, 12 page

    Canonical Expansion of PT-Symmetric Operators and Perturbation Theory

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    Let HH be any \PT symmetric Schr\"odinger operator of the type 2Δ+(x12+...+xd2)+igW(x1,...,xd) -\hbar^2\Delta+(x_1^2+...+x_d^2)+igW(x_1,...,x_d) on L2(Rd)L^2(\R^d), where WW is any odd homogeneous polynomial and gRg\in\R. It is proved that H\P H is self-adjoint and that its eigenvalues coincide (up to a sign) with the singular values of HH, i.e. the eigenvalues of HH\sqrt{H^\ast H}. Moreover we explicitly construct the canonical expansion of HH and determine the singular values μj\mu_j of HH through the Borel summability of their divergent perturbation theory. The singular values yield estimates of the location of the eigenvalues \l_j of HH by Weyl's inequalities.Comment: 20 page

    Extrakorporale Stoßwellentherapie eines komplizierten chronischen Ulcus cruris venosum

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    Zusammenfassung: Extrakorporale Stoßwellen werden definiert als eine Sequenz von akustischen Schallimpulsen, die einen charakteristisch schnellen Druckanstieg auf über 100MPa mit Abfall auf Normaldruck in wenigen Mikrosekunden aufweisen. In den 1980er-Jahren wurde die extrakorporale Stoßwellenlithotripsie (ESWL) erstmals zur Behandlung der Urolithiasis angewandt. Orthopäden setzten anschließend die extrakorporale Stoßwellentherapie (ESWT) zur Behandlung von nicht heilenden Frakturen, Tendinopathien und Osteonekrose ein. Die erste Anwendung von ESWT in der Dermatologie erfolgte zur Behandlung des chronischen Ulcus cruris. Verschiedene Studien der letzten 10Jahre zeigten, dass die ESWT die Angiogenese stimuliert und die Perfusion im ischämischen Gewebe verbessert, die Entzündungsreaktion mindert, die Zelldifferenzierung unterstützt und hiermit die Wundheilung deutlich verbessern kann. Wir setzten die ESWT erfolgreich zur Behandlung eines komplizierten chronischen venösen Ulcus cruris ein. Weiter konnten wir eine Verbesserung des lymphatischen Abflusses nach Applikation von ESWT beobachten. Die ESWT stellt somit eine nebenwirkungsarme und effiziente physikalische Therapiemodalität zur Behandlung von therapieresistenten chronischen Wunden da

    Fire-cracked Rock Use and Reuse in the Hueco Bolson, Fort Bliss, Texas

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    The Center for Archaeological Research of The University of Texas at San Antonio conducted an analysis of 29,058 pieces of fire-cracked rock and burned caliche selected from a sample of hundreds of features tested as part of the Hueco Mountain Archaeological Project at Fort Bliss, Texas. Feature and non-feature material included in this analysis were collected from site FB 13237 located on the proximal fan, FB 12719 within the basin area, and FB 12412 situated in the transitional zone between the two. The goal of the analysis was to identify patterns of attribute variability in burned rock that could be used to infer function of the various features and sites in the sample. Specific burned rock attributes used in the study were material type, size, weight, and the presence or absence of fracturing, cortex, and discoloration. These attributes were recorded and compared in various combinations at course- and fme-grained levels of intensity to address issues of reuse, recycling, feature function, thermally induced morphological variability, and how these variables might relate to specific land forms through time. Through these comparisons, patterns relating to expedient material selection, feature type, reuse and feature function were identified

    Der internistische Check-up

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    Zusammenfassung: Viele präventive Maßnahmen bei gesunden Erwachsenen werden in zunehmendem Maße durch Evidenz gestützt oder verworfen. Dabei sind v.a. die Beratung bezüglich Tabakabstinenz, indizierte Impfungen und das Screening in Bezug auf Übergewicht, hohen Blutdruck, Hyperlipidämie, Zervixkarzinom, kolorektales Karzinom und Mammakarzinom bewiesenermaßen wichtig und sinnvoll. Nicht empfohlen wird ein Screening für Bronchial-, Pankreas- und Ovarialkarzinom. Ein Screening für Diabetes mellitus beim jüngeren Erwachsenen, Schilddrüsenerkrankungen und Prostatakarzinom wird nicht routinemäßig empfohlen, sollte aber je nach persönlichem Risikoprofil im Sinne eines sog. "Case findings" erwogen werden. Aus ärztlicher Sicht ist es auch wichtig, auf mögliche nicht deklarierte Beweggründe für eine Check-up-Untersuchung einzugehen, um so mögliche "Hidden Agendas" der Konsultationen aufzudecke

    Archeological Testing Associated with theStabilization of the Convento at Mission San Juan Capistrano (41BX5), San Antonio, Bexar County, Texas

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    In January and April, 2005, the Center for Archaeological Research (CAR) of The University of Texas at San Antonio conducted test excavations at Mission San Juan Capistrano (41BX5) for the San Antonio Missions National Historical Park of the National Park Service. The site is located approximately eight miles south of downtown San Antonio on the left bank of the San Antonio River. The purpose of the excavations was to provide information on the nature and content of the subsurface deposits in preparation for a major stabilization campaign around the convento at Mission San Juan that will result in the installation of an impermeable barrier around the structure. Concrete footers will also be installed under each buttress, if necessary. Six 1-x-1-meter units were excavated around the convento and Rooms 19 and 21. Excavations conducted by CAR revealed disturbed deposits on the west side of the convento. A cut-stone step feature was encountered on the southeast side of the convento, along with a footer that was exposed near the northeast corner of the building. Excavations also revealed the original sandstone foundation of San Juan Capistrano on the south side of Room 21. These investigations were conducted under Texas Antiquities Committee permit no. 3655 with Dr. Steve A. Tomka, CAR Director, serving as Principal Investigator. All cultural materials recovered and project-related documents are permanently curated at the Center for Archaeological Research

    28-jähriger Patient mit erfolgreich behandelter dilatativer Kardiomyopathie

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    Zusammenfassung: Ein 28-jähriger Patient wurde mit dekompensierter Herzinsuffizienz notfallmäßig zugewiesen. In der Vorgeschichte bestand ein hypogonadotroper Hypogonadismus. Echokardiographisch fand sich eine dilatative Kardiomyopathie. Ein erhöhtes Serumferritin und eine Eisenüberladung in der Leberbiopsie ließen eine hereditäre Hämochromatose vermuten. Die kardiale Beteiligung konnte mittels Magnetresonanztomographie nachgewiesen werden. Genetische Abklärungen ergaben eine homozygote Mutation für G320V und bewiesen eine juvenile Hämochromatose. Eine Aderlasstherapie führte innerhalb eines Jahres zur Normalisierung des Eisenstatus und der kardialen Pumpfunktio

    Effects of sevoflurane and propofol on left ventricular diastolic function in patients with pre-existing diastolic dysfunction

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    Background. The effects of anaesthetics on left ventricular (LV) diastolic function in patients with pre-existing diastolic dysfunction are not well known. We hypothesized that propofol but not sevoflurane will worsen the pre-existing LV diastolic dysfunction. Methods. Of 24 randomized patients, 23 fulfilled the predefined echocardiographic criterion for diastolic dysfunction. They received general anaesthesia with sevoflurane 1 MAC (n=12) or propofol 4 μg ml−1 (n=11). Echocardiographic examinations were performed at baseline and in anaesthetized patients under spontaneous breathing and under positive pressure ventilation. Analysis focused on peak early diastolic velocity of the mitral annulus (Ea). Results. During spontaneous breathing, Ea was higher in the sevoflurane than in the propofol group [mean (95% CI) 7.0 (5.9-8.1) vs 5.5 (4.7-6.3) cm s−1; P<0.05], reflecting an increase of Ea from baseline only in the sevoflurane group (P<0.01). Haemodynamic findings were similar in both groups, but the end-tidal carbon dioxide content was more elevated in the propofol group (P<0.01). During positive pressure ventilation, Ea was similarly low in the sevoflurane and propofol groups [5.3 (4.2-6.3) and 4.4 (3.6-5.2) cm s−1, respectively]. Conclusions. During spontaneous breathing, early diastolic function improved in the sevoflurane but not in the propofol group. However, during positive pressure ventilation and balanced anaesthesia, there was no evidence of different effects caused by the two anaesthetic
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