1,520 research outputs found

    Effective theory for wall-antiwall system

    Full text link
    We propose a useful method for deriving the effective theory for a system where BPS and anti-BPS domain walls coexist. Our method respects an approximately preserved SUSY near each wall. Due to the finite width of the walls, SUSY breaking terms arise at tree-level, which are exponentially suppressed. A practical approximation using the BPS wall solutions is also discussed. We show that a tachyonic mode appears in the matter sector if the corresponding mode function has a broader profile than the wall width.Comment: LaTeX file, 30 page, 5 eps figures, references adde

    Experimental Control and Characterization of Autophagy in Drosophila

    Get PDF
    Insects such as the fruit fly Drosophila melanogaster, which fundamentally reorganize their body plan during metamorphosis, make extensive use of autophagy for their normal development and physiology. In the fruit fly, the hepatic/adipose organ known as the fat body accumulates nutrient stores during the larval feeding stage. Upon entering metamorphosis, as well as in response to starvation, these nutrients are mobilized through a massive induction of autophagy, providing support to other tissues and organs during periods of nutrient deprivation. High levels of autophagy are also observed in larval tissues destined for elimination, such as the salivary glands and larval gut. Drosophila is emerging as an important system for studying the functions and regulation of autophagy in an in vivo setting. In this chapter we describe reagents and methods for monitoring autophagy in Drosophila, focusing on the larval fat body. We also describe methods for experimentally activating and inhibiting autophagy in this system and discuss the potential for genetic analysis in Drosophila to identify novel genes involved in autophagy

    The algebra of adjacency patterns: Rees matrix semigroups with reversion

    Full text link
    We establish a surprisingly close relationship between universal Horn classes of directed graphs and varieties generated by so-called adjacency semigroups which are Rees matrix semigroups over the trivial group with the unary operation of reversion. In particular, the lattice of subvarieties of the variety generated by adjacency semigroups that are regular unary semigroups is essentially the same as the lattice of universal Horn classes of reflexive directed graphs. A number of examples follow, including a limit variety of regular unary semigroups and finite unary semigroups with NP-hard variety membership problems.Comment: 30 pages, 9 figure

    History of clinical transplantation

    Get PDF
    How transplantation came to be a clinical discipline can be pieced together by perusing two volumes of reminiscences collected by Paul I. Terasaki in 1991-1992 from many of the persons who were directly involved. One volume was devoted to the discovery of the major histocompatibility complex (MHC), with particular reference to the human leukocyte antigens (HLAs) that are widely used today for tissue matching.1 The other focused on milestones in the development of clinical transplantation.2 All the contributions described in both volumes can be traced back in one way or other to the demonstration in the mid-1940s by Peter Brian Medawar that the rejection of allografts is an immunological phenomenon.3,4 © 2008 Springer New York

    Wilson Renormalization Group Analysis of Theories with Scalars and Fermions

    Full text link
    The continuous block spin (Wilson) renormalization group equation governing the scale dependence of the action is constructed for theories containing scalars and fermions. A locally approximated form of this equation detailing the structure of a generalized effective potential is numerically analyzed. The role of the irrelevant operators in the nonperturbative renormalization group running is elucidated and a comparison with the 1-loop perturbative results is drawn. Focusing on the spontaneously broken phase of a model possessing a discrete symmetry forbidding an explicit fermion mass term, mass bounds on both the scalar and fermion degrees of freedom are established. The effect of the generalized Yukawa coupling on the scalar mass upper bound is emphasized.Comment: 40, PURD-TH-92-

    Corn particle size and pelleting influence on growth performance, fecal shedding, and lymph node infection rates of salmonella enterica serovar typhimurium

    Get PDF
    Ninety-six pigs (initially 13.8 lb.) were used in a 28-d trial to determine the interactive effects between pelleting and particle size on Salmonella serovar Typhimurium shedding and colonization in a young growing pig model. The experiment was a 2 × 2 factorial arrangement consisting of meal or pelleted diets with fine or coarse ground corn. Pigs were fed the diets 1 wk pre-salmonella inoculation and allotted based on weight to one of four dietary treatments. For the main effect of particle size, pigs fed finer ground corn had significantly improved feed efficiency (P0.82). There was no difference in salmonella infection rates of mesenteric lymph nodes obtained on d 28 between treatments or main effects. Finer grinding and meal diets generally improved growth, feed intake, and feed efficiency compared to pigs fed coarser ground or pelleted feeds. However, particle size or diet form did not alter fecal shedding or mesenteric lymph node infection rates of salmonella organisms in our study

    A study of semi-inclusive charmless BπXB \to \pi X decays

    Full text link
    We study semi-inclusive charmless decays BπXB \to \pi X in detail, such as Bˉ0π±(0)X\bar B^0 \to \pi^{\pm (0)} X, B0π±(0)XB^0 \to \pi^{\pm (0)} X, B±π±(0)XB^{\pm} \to \pi^{\pm (0)} X, where XX does not contain a charm (anti)quark. We find that the process Bˉ0πX\bar B^0 \to \pi^- X (B0π+XB^0 \to \pi^+ X) can be particularly useful for determination of the CKM matrix element Vub|V_{ub}|. We calculate and present the branching ratio (BR) of Bˉ0πX\bar B^0 \to \pi^- X as a function of Vub|V_{ub}|, with an estimate of possible uncertainties. It is expected that the BR is an order of 10410^{-4}. Our estimation indicates that one can phenomenologically determine Vub|V_{ub}| with reasonable accuracy by measuring the BR of Bˉ0πX\bar B^0 \to \pi^- X (B0π+XB^0 \to \pi^+ X).Comment: 18 pages, 7 figures; Revtex; version accepted for publication in Eur. Phys. J.
    corecore