Flow Equation for Supersymmetric Quantum Mechanics

We study supersymmetric quantum mechanics with the functional RG formulated in terms of an exact and manifestly off-shell supersymmetric flow equation for the effective action. We solve the flow equation nonperturbatively in a systematic super-covariant derivative expansion and concentrate on systems with unbroken supersymmetry. Already at next-to-leading order, the energy of the first excited state for convex potentials is accurately determined within a 1% error for a wide range of couplings including deeply nonperturbative regimes.Comment: 24 pages, 8 figures, references added, typos correcte

Analysis of shear test method for composite laminates

An elastic plane stress finite element analysis of the stress distributions in four flat test specimens for in-plane shear response of composite materials subjected to mechanical or thermal loads is presented. The shear test specimens investigated include: slotted coupon, cross beam, losipescu, and rail shear. Results are presented in the form of normalized shear contour plots for all three in-plane stess components. It is shown that the cross beam, losipescu, and rail shear specimens have stress distributions which are more than adequate for determining linear shear behavior of composite materials. Laminate properties, core effects, and fixture configurations are among the factors which were found to influence the stress distributions

Wie Du mir so ich Dir - Das Vergeltungsverhalten von Kunden nach Servicefehlern

Reaktionen von Kunden auf Servicefehler können von direkten Beschwerden über negative Mund-zu-Mund-Propaganda bis hin zur Meidung des Unternehmens führen. Da derartige Vergeltungsmaßnahmen von Kunden zu unternehmensseitigen Imageschäden und Umsatzverlusten führen, sind fundierte Kenntnisse des Vergeltungsverhaltens notwendig, um diesem bereits im Vorfeld wirksam entgegensteuern zu können. Die vorliegende Studie greift das praxisrelevante Problem der kundenseitigen Vergeltung auf und erarbeitet ein Modell zur Prognose des Vergeltungsverhaltens. Den Kern des Modells bildet dabei das Konzept der retributiven Gerechtigkeit. Retributive Gerechtigkeit beschreibt das Verlangen des Kunden, eine von ihm als unfair wahrgenommene Situation zu korrigieren. Diese Korrektur wird mittels konkreter Maßnahmen wie bspw. der Bekanntmachung eines schlechten Konsum-erlebnisses bei Verbraucherschutzzentralen durchgeführt. Der Kunde betrachtet Vergeltung somit als Kompensationsmittel, um das ihm durch das Unternehmen widerfahrene Unrecht auszugleichen. Zur Untersuchung des kundenseitigen Wunsches nach Vergeltung wird auf Basis eines szenariobasierten Online-Experiments (n=381) das Potenzial unterschiedlich ausgestalteter Service Recovery-Maßnahmen (monetäre Entschädigung, zeitliche Effizienz des Service Recovery-Prozesses, Art und Weise des Auftretens der Mitarbeiter) zur Reduktion der Kundenvergeltung analysiert. Anhand eines Strukturgleichungsmodells wird überprüft, inwieweit die verschiedenen Recovery-Strategien in der Lage sind, Vergeltungsabsichten und daraus resultierende Vergeltungsmaßnahmen von Kunden zu verringern. Die Ergebnisse der Studie bestätigen, dass insbesondere eine auf Wertschätzung und Transparenz basierende Interaktion zwischen Kunden und Servicemitarbeitern den Wunsch nach retributiver Gerechtigkeit senkt und somit als Strategie zur Linderung von kundenseitigen Vergeltungsabsichten nach Servicefehlern sehr effektiv ist

Genotoxicity of nitroso compounds and sodium dichromate in a model combining organ cultures of human nasal epithelia and the comet assay

Genotoxic effects of xenobiotics are a possible step in tumor initiation in the mucosa of the upper aerodigestive tract. Using the comet assay, detecting genotoxicity in human tissue has been restricted to single incubations in vitro, but in vivo most xenobiotics harm their target in a repetitive or chronic manner. Therefore, we propose a model, which provides repetitive incubations in human upper aerodigestive tract mucosa cultures. Samples of human inferior nasal turbinate mucosa (n = 25) were cultured according to a modified version of a technique originally described by Steinsvag. On day 1 fresh samples and on days 7, 9 and 11 organ cultures were incubated with N-nitrosodiethylamine (NDEA), sodium dichromate (Na2Cr2O7) and N'-methyl-N-nitro-N-nitrosoguanidine(MNNG). Mucosa samples and organ cultures, respectively, underwent a modified comet assay on days 1, 7 and 11. Genotoxicity could be shown for NDEA, Na2Cr2O7 and MNNG on days 1, 7 and 11. Duration of tissue culture and repetitive incubations did not significantly influence the results for NDEA. Nevertheless, Na2Cr2O7 and MNNG caused higher genotoxic effects on cultures subjected to the comet assay on day 11. This model may help to assess genotoxic hazards posed by environ mental pollutants that have a cumulative character in repetitive or chronic exposure in vivo. Copyright (C) 2001 S. Karger AG, Basel

On the estimation of brain signal entropy from sparse neuroimaging data

Multi-scale entropy (MSE) has been recently established as a promising tool for the analysis of the moment-to-moment variability of neural signals. Appealingly, MSE provides a measure of the predictability of neural operations across the multiple time scales on which the brain operates. An important limitation in the application of the MSE to some classes of neural signals is MSE’s apparent reliance on long time series. However, this sparse-data limitation in MSE computation could potentially be overcome via MSE estimation across shorter time series that are not necessarily acquired continuously (e.g., in fMRI block-designs). In the present study, using simulated, EEG, and fMRI data, we examined the dependence of the accuracy and precision of MSE estimates on the number of data points per segment and the total number of data segments. As hypothesized, MSE estimation across discontinuous segments was comparably accurate and precise, despite segment length. A key advance of our approach is that it allows the calculation of MSE scales not previously accessible from the native segment lengths. Consequently, our results may permit a far broader range of applications of MSE when gauging moment-to- moment dynamics in sparse and/or discontinuous neurophysiological data typical of many modern cognitive neuroscience study designs

Why Do secondary cracks preferentially form in hot-rolled ODS steels in comparison with hot-extruded ODS steels?

Secondary cracks are known to absorb energy, retard primary crack propagation and initiate at lower loads than primary cracks. They are observed more often in hot-rolled than in hot-extruded ODS steels. In this work, the microstructural factors responsible for this observation are investigated. Better understanding of these factors can lead to tailoring of improved ODS steels. Fracture toughness testing of two batches of 13Cr ODS steel, one hot-rolled and the other hot-extruded, was carried out. The fracture behaviour of secondary cracks was investigated using scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). Crystallographic texture and grain morphology play a predominant role in preventing secondary cracks in hot-extruded ODS steels. At lower temperatures, secondary cracks occur predominantly via transgranular cleavage. The fracture mode changes to ductile and intergranular at higher temperatures

Navigating the Accounting Academic Job Market and Related Advice

Purpose: To disseminate helpful advice to current and future candidates about the accounting academic job market. Methodology/Approach: Literature review, interviews with recently hired faculty members, insights from the author’s experiences as both job candidates and search committee members, and discussions with colleagues. Findings: In this chapter, we discuss the current state of the job market for accounting professors and offer our insights as well as those from a group of recent graduates. It is our recent experience that many rookie candidates pursue initial faculty positions with an incomplete understanding of many aspects of the market, including how the market clears, job expectations, and other issues that we believe are important. While others have adequately addressed the importance of research in the profession and alluded to some aspects of the market, we provide additional useful information about the market and other career aspects in order to assist new graduates in their quests to find fulfilling appointments. Our chapter complements existing literature to form an updated and more complete picture of the market and profession. Practical Implications: This chapter helps prepare candidates for the job market by providing information and advice that complements advice given in Ph.D. programs and the existing literature. Social Implications: Candidates entering the job market will better understand the nuances of the market and can make more informed decisions about the institutions that best meet their needs. Originality/Value of Article: The chapter provides important practical advice for job seekers about the accounting academic job market not available elsewhere

Effects of different regions of the developing gut on the migration of enteric neural crest-derived cells: A role for Sema3A, but not Sema3F

AbstractThe enteric nervous system arises from vagal (caudal hindbrain) and sacral level neural crest-derived cells that migrate into and along the developing gut. Data from previous studies have suggested that (i) there may be gradients along the gut that induce the caudally directed migration of vagal enteric neural precursors (ENPs), (ii) exposure to the caecum might alter the migratory ability of vagal ENPs and (iii) Sema3A might regulate the entry into the hindgut of ENPs derived from sacral neural crest. Using co-cultures we show that there is no detectable gradient of chemoattractive molecules along the pre-caecal gut that specifically promotes the caudally directed migration of vagal ENPs, although vagal ENPs migrate faster caudally than rostrally along explants of hindgut. Exposure to the caecum did not alter the rate at which ENPs colonized explants of hindgut, but it did alter the ability of ENPs to colonize the midgut. The co-cultures also revealed that there is localized expression of a repulsive cue in the distal hindgut, which might delay the entry of sacral ENPs. We show that Sema3A is expressed by the hindgut mesenchyme and its receptor, neuropilin-1, is expressed by migrating ENPs. Furthermore, there is premature entry of sacral ENPs and extrinsic axons into the distal hindgut of fetal mice lacking Sema3A. These data show that Sema3A expressed by the distal hindgut regulates the entry of sacral ENPs and extrinsic axons into the hindgut. ENPs did not express neuropilin-2 and there was no detectable change in the timetable by which ENPs colonize the gut in mice lacking neuropilin-2

Ground state properties of heavy alkali halides

We extend previous work on alkali halides by calculations for the heavy-atom species RbF, RbCl, LiBr, NaBr, KBr, RbBr, LiI, NaI, KI, and RbI. Relativistic effects are included by means of energy-consistent pseudopotentials, correlations are treated at the coupled-cluster level. A striking deficiency of the Hartree-Fock approach are lattice constants deviating by up to 7.5 % from experimental values which is reduced to a maximum error of 2.4 % by taking into account electron correlation. Besides, we provide ab-initio data for in-crystal polarizabilities and van der Waals coefficients.Comment: accepted by Phys. Rev.