107 research outputs found

    You Don‘t Know what You‘ve got till It‘s Gone! Unemployment and Intertemporal Changes in Self-Reported Life Satisfaction

    Get PDF
    This paper uses concurrently and – for the first time – retrospectively reported life satisfaction from the 1984 to 1987 waves of the German Socio-Economic Panel to study the importance of different comparison standards for the empirical correlation of unemployment and subjective life satisfaction. It is found that unemployed individuals do not only report significantly lower concurrent satisfaction, but also recall reduced satisfaction from past unemployment well, and retrospectively upgrade their past satisfaction scores. Therefore, the short-term negative effects of unemployment on individual life satisfaction reported in the literature so far are likely underestimated. At the same time, the empirical findings cast doubts on the usefulness of subjective life satisfaction for the precise quantification of welfare effects because of changing comparison standards which greatly limit the intertemporal comparability of the data.For this reason, such data also appear to be of limited use for monitoring long-term economic or social development.Life satisfaction; well-being; unemployment; longitudinal and retrospective studies

    Double or Nothing!? Small Groups Making Decisions Under Risk in “Quiz Taxi”

    Get PDF
    This paper investigates the behavior of contestants in the game show “Quiz Taxi” when faced with the decision whether to bet the winnings they have acquired on a fi nal “double or nothing” question. The decision is made by groups of two or three persons. This set-up enables the decision making process to be studied by observing group communication. There is a strong correlation between communication content and the fi nal choice, indicating that, from the contestant‘s perspective, the decisions are rational and that the context is an important factor in the fi nal decision. This is particularly so for individual valuations of the money at stake. More extensive discussions help to make the right decision. As contestants do not apply to go on the show, they represent a less selected sample than those in previous game show studies. Overall, the contestants show risk averse behavior, suggesting CRRA-parameters larger than 1. The study also shows some heterogeneity in attitude to risk. Contestants who do better in the show are more likely to go for the risky option, because they are more knowledgeable and more confi dent. All-female groups are less likely and three-person groups more likely to choose the risky option.Risk attitude; game show; communication; group decision

    Topology of biological networks and reliability of information processing

    Full text link
    Biological systems rely on robust internal information processing: Survival depends on highly reproducible dynamics of regulatory processes. Biological information processing elements, however, are intrinsically noisy (genetic switches, neurons, etc.). Such noise poses severe stability problems to system behavior as it tends to desynchronize system dynamics (e.g. via fluctuating response or transmission time of the elements). Synchronicity in parallel information processing is not readily sustained in the absence of a central clock. Here we analyze the influence of topology on synchronicity in networks of autonomous noisy elements. In numerical and analytical studies we find a clear distinction between non-reliable and reliable dynamical attractors, depending on the topology of the circuit. In the reliable cases, synchronicity is sustained, while in the unreliable scenario, fluctuating responses of single elements can gradually desynchronize the system, leading to non-reproducible behavior. We find that the fraction of reliable dynamical attractors strongly correlates with the underlying circuitry. Our model suggests that the observed motif structure of biological signaling networks is shaped by the biological requirement for reproducibility of attractors.Comment: 7 pages, 7 figure

    Insights into 6S RNA in lactic acid bacteria (LAB)

    Get PDF
    Background: 6S RNA is a regulator of cellular transcription that tunes the metabolism of cells. This small non-coding RNA is found in nearly all bacteria and among the most abundant transcripts. Lactic acid bacteria (LAB) constitute a group of microorganisms with strong biotechnological relevance, often exploited as starter cultures for industrial products through fermentation. Some strains are used as probiotics while others represent potential pathogens. Occasional reports of 6S RNA within this group already indicate striking metabolic implications. A conceivable idea is that LAB with 6S RNA defects may metabolize nutrients faster, as inferred from studies of Echerichia coli. This may accelerate fermentation processes with the potential to reduce production costs. Similarly, elevated levels of secondary metabolites might be produced. Evidence for this possibility comes from preliminary findings regarding the production of surfactin in Bacillus subtilis, which has functions similar to those of bacteriocins. The prerequisite for its potential biotechnological utility is a general characterization of 6S RNA in LAB. Results: We provide a genomic annotation of 6S RNA throughout the Lactobacillales order. It laid the foundation for a bioinformatic characterization of common 6S RNA features. This covers secondary structures, synteny, phylogeny, and product RNA start sites. The canonical 6S RNA structure is formed by a central bulge flanked by helical arms and a template site for product RNA synthesis. 6S RNA exhibits strong syntenic conservation. It is usually flanked by the replication-associated recombination protein A and the universal stress protein A. A catabolite responsive element was identified in over a third of all 6S RNA genes. It is known to modulate gene expression based on the available carbon sources. The presence of antisense transcripts could not be verified as a general trait of LAB 6S RNAs. Conclusions: Despite a large number of species and the heterogeneity of LAB, the stress regulator 6S RNA is well-conserved both from a structural as well as a syntenic perspective. This is the first approach to describe 6S RNAs and short 6S RNA-derived transcripts beyond a single species, spanning a large taxonomic group covering multiple families. It yields universal insights into this regulator and complements the findings derived from other bacterial model organisms.Fil: Cataldo, Pablo Gabriel. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - TucumĂĄn. Centro de Referencia para Lactobacilos; ArgentinaFil: Klemm, Paul. Universitat Phillips; AlemaniaFil: ThĂŒring, Marietta. Universitat Phillips; AlemaniaFil: Saavedra, Maria Lucila. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - TucumĂĄn. Centro de Referencia para Lactobacilos; ArgentinaFil: Hebert, Elvira Maria. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - TucumĂĄn. Centro de Referencia para Lactobacilos; ArgentinaFil: Hartmann, Roland K.. Universitat Phillips; AlemaniaFil: Lechner, Marcus. Universitat Phillips; Alemani

    Two-loop Renormalization for Nonanticommutative N=1/2 Supersymmetric WZ Model

    Full text link
    We study systematically, through two loops, the divergence structure of the supersymmetric WZ model defined on the N=1/2 nonanticommutative superspace. By introducing a spurion field to represent the supersymmetry breaking term F^3 we are able to perform our calculations using conventional supergraph techniques. Divergent terms proportional to F, F^2 and F^3 are produced (the first two are to be expected on general grounds) but no higher-point divergences are found. By adding ab initio F and F^2 terms to the original lagrangian we render the model renormalizable. We determine the renormalization constants and beta functions through two loops, thus making it possible to study the renormalization group flow of the nonanticommutation parameter.Comment: 36 pages, 25 figures, Latex fil

    Non(anti)commutative SYM theory: Renormalization in superspace

    Full text link
    We present a systematic investigation of one-loop renormalizability for nonanticommutative N=1/2, U(N) SYM theory in superspace. We first discuss classical gauge invariance of the pure gauge theory and show that in contradistinction to the ordinary anticommutative case, different representations of supercovariant derivatives and field strengths do not lead to equivalent descriptions of the theory. Subsequently we develop background field methods which allow us to compute a manifestly covariant gauge effective action. One-loop evaluation of divergent contributions reveals that the theory simply obtained from the ordinary one by trading products for star products is not renormalizable. In the case of SYM with no matter we present a N=1/2 improved action which we show to be one-loop renormalizable and which is perfectly compatible with the algebraic structure of the star product. For this action we compute the beta functions. A brief discussion on the inclusion of chiral matter is also presented.Comment: Latex file, 59 pages, 10 figures, One reference adde

    DUALITY SYMMETRY GROUP OF TWO DIMENSIONAL HETEROTIC STRING THEORY

    Get PDF
    The equations of motion of the massless sector of the two dimensional string theory, obtained by compactifying the heterotic string theory on an eight dimensional torus, is known to have an affine o(8,24) symmetry algebra generating an O(8,24) loop group. In this paper we study how various known discrete S- and T- duality symmetries of the theory are embedded in this loop group. This allows us to identify the generators of the discrete duality symmetry group of the two dimensional string theory.Comment: LaTeX, 30 page

    World-Volume Action of the M Theory Five-Brane

    Full text link
    This paper presents a 6d world-volume action that describes the dynamics of the M theory five-brane in a flat 11d space-time background. The world-volume action has global 11d super-Poincare invariance, as well as 6d general coordinate invariance and kappa symmetry, which are realized as local symmetries. The paper mostly considers a formulation in which general coordinate invariance is not manifest in one direction. However, it also describes briefly an alternative formulation, due to Pasti, Sorokin, and Tonin, in which general coordinate invariance is manifest. The latter approach requires auxiliary fields and new gauge invariances.Comment: 30 pages, latex, no figure

    Nonanticommutative superspace and N= 1/2 WZ model

    Full text link
    In these proceedings we review the main results concerning superspace geometries with nonanticommutative spinorial variables and field theories formulated on them. In particular, we report on the quantum properties of the WZ model formulated in the N=1/2 nonanticommutative superspace.Comment: 9 pages, plain Latex, contribution to the proceedings of the Copenhagen RTN workshop, 15-20 September 200

    Proteinortho6: pseudo-reciprocal best alignment heuristic for graph-based detection of (co-)orthologs

    Get PDF
    Proteinortho is a widely used tool to predict (co)-orthologous groups of genes for any set of species. It finds application in comparative and functional genomics, phylogenomics, and evolutionary reconstructions. With a rapidly increasing number of available genomes, the demand for large-scale predictions is also growing. In this contribution, we evaluate and implement major algorithmic improvements that significantly enhance the speed of the analysis without reducing precision. Graph-based detection of (co-)orthologs is typically based on a reciprocal best alignment heuristic that requires an all vs. all comparison of proteins from all species under study. The initial identification of similar proteins is accelerated by introducing an alternative search tool along with a revised search strategy—the pseudo-reciprocal best alignment heuristic—that reduces the number of required sequence comparisons by one-half. The clustering algorithm was reworked to efficiently decompose very large clusters and accelerate processing. Proteinortho6 reduces the overall processing time by an order of magnitude compared to its predecessor while maintaining its small memory footprint and good predictive quality
    • 

    corecore