727 research outputs found

    Consumption experience, choice experience and the endowment effect

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    We report experiments investigating how experience influences the endowment effect. Our experiments feature endowments which are bundles of unfamiliar consumption goods. We examine how a subject’s willingness to swap items from their endowment is influenced by prior experiences of tasting the goods in question and by prior experiences of choosing between them. We do not find a statistically significant endowment effect in our baseline treatment and, because of this, we are unable to test for an effect of consumption experience. We do find an endowment effect when the endowment is acquired in two instalments and, in this setting, we find some evidence that choice experience increases trading. In a follow up experiment, we find evidence that the absence of an endowment effect in our baseline treatment is due to subjects being more willing to swap when they do not have to give up the last unit of their endowment

    Disposition of Federally Owned Surpluses

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    PDZ domains are scaffolding modules in protein-protein interactions that mediate numerous physiological functions by interacting canonically with the C-terminus or non-canonically with an internal motif of protein ligands. A conserved carboxylate-binding site in the PDZ domain facilitates binding via backbone hydrogen bonds; however, little is known about the role of these hydrogen bonds due to experimental challenges with backbone mutations. Here we address this interaction by generating semisynthetic PDZ domains containing backbone amide-to-ester mutations and evaluating the importance of individual hydrogen bonds for ligand binding. We observe substantial and differential effects upon amide-to-ester mutation in PDZ2 of postsynaptic density protein 95 and other PDZ domains, suggesting that hydrogen bonding at the carboxylate-binding site contributes to both affinity and selectivity. In particular, the hydrogen-bonding pattern is surprisingly different between the non-canonical and canonical interaction. Our data provide a detailed understanding of the role of hydrogen bonds in protein-protein interactions

    Supervised team management, with or without structured psychotherapy, in heavy users of a mental health service with borderline personality disorder: a two-year follow-up preliminary randomized study

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    <p>Abstract</p> <p>Background</p> <p>Individuals affected by severe Borderline Personality Disorder (BPD) are often heavy users of Mental Health Services (MHS). Short-term treatments currently used in BPD therapy are useful to target disruptive behaviors but they are less effective in reducing heavy MHS use. Therefore, alternative short-term treatments, less complex than long-term psychodynamic psychotherapies but specifically oriented to BPD core problems, need to be developed to reduce MHS overuse. This study aimed to evaluate the efficacy of adding Sequential Brief Adlerian Psychodynamic Psychotherapy (SB-APP) to Supervised Team Management (STM) in BPD treatment compared to STM alone in a naturalistic group of heavy MHS users with BPD. Effectiveness was evaluated 6 times along a two-year follow-up.</p> <p>Methods</p> <p>Thirty-five outpatients who met inclusion criteria were randomly assigned to two treatment groups (STM = 17; SB-APP = 18) and then compared. Clinical Global Impression (CGI) and CGI-modified (CGI-M) for BPD, Global Assessment of Functioning (GAF), State-Trait Anger Expression Inventory (STAXI), and Symptom Checklist-90 Revised (SCL-90-R) were administered at T1, T3, T6, T12, T18 and T24. At T12 the Working Alliance Inventory-Short Form (WAI-S) was also completed. At the one-year follow-up, SB-APP group did not receive any additional individual psychological support. MHS team was specifically trained in BPD treatment and had regular supervisions.</p> <p>Results</p> <p>All patients improved on CGI, GAF, and STAXI scores after 6 and 12 months, independently of treatment received. SB-APP group showed better outcome on impulsivity, suicide attempts, chronic feelings of emptiness, and disturbed relationships. We found a good stabilization at the one year follow-up, even after the interruption of brief psychotherapy in the SB-APP group.</p> <p>Conclusions</p> <p>Although STM for BPD applied to heavy MHS users was effective in reducing symptoms and improving their global functioning, adding a time-limited and focused psychotherapy was found to achieve a better outcome. In particular, focusing treatment on patients' personality with a specific psychotherapeutic approach (i.e. SB-APP) seemed to be more effective than STM alone.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT1356069">NCT1356069</a></p

    PhyloPattern: regular expressions to identify complex patterns in phylogenetic trees

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    <p>Abstract</p> <p>Background</p> <p>To effectively apply evolutionary concepts in genome-scale studies, large numbers of phylogenetic trees have to be automatically analysed, at a level approaching human expertise. Complex architectures must be recognized within the trees, so that associated information can be extracted.</p> <p>Results</p> <p>Here, we present a new software library, PhyloPattern, for automating tree manipulations and analysis. PhyloPattern includes three main modules, which address essential tasks in high-throughput phylogenetic tree analysis: node annotation, pattern matching, and tree comparison. PhyloPattern thus allows the programmer to focus on: i) the use of predefined or user defined annotation functions to perform immediate or deferred evaluation of node properties, ii) the search for user-defined patterns in large phylogenetic trees, iii) the pairwise comparison of trees by dynamically generating patterns from one tree and applying them to the other.</p> <p>Conclusion</p> <p>PhyloPattern greatly simplifies and accelerates the work of the computer scientist in the evolutionary biology field. The library has been used to automatically identify phylogenetic evidence for domain shuffling or gene loss events in the evolutionary histories of protein sequences. However any workflow that relies on phylogenetic tree analysis, could be automated with PhyloPattern.</p

    Roy-Steiner equations for pion-nucleon scattering

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    Starting from hyperbolic dispersion relations, we derive a closed system of Roy-Steiner equations for pion-nucleon scattering that respects analyticity, unitarity, and crossing symmetry. We work out analytically all kernel functions and unitarity relations required for the lowest partial waves. In order to suppress the dependence on the high-energy regime we also consider once- and twice-subtracted versions of the equations, where we identify the subtraction constants with subthreshold parameters. Assuming Mandelstam analyticity we determine the maximal range of validity of these equations. As a first step towards the solution of the full system we cast the equations for the ππNˉN\pi\pi\to\bar NN partial waves into the form of a Muskhelishvili-Omn\`es problem with finite matching point, which we solve numerically in the single-channel approximation. We investigate in detail the role of individual contributions to our solutions and discuss some consequences for the spectral functions of the nucleon electromagnetic form factors.Comment: 106 pages, 18 figures; version published in JHE

    Global Health Education: a cross-sectional study among German medical students to identify needs, deficits and potential benefits (Part 1 of 2: Mobility patterns & educational needs and demands)

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    <p>Abstract</p> <p>Background</p> <p>In recent years, education and training in global health has been the subject of recurring debate in many countries. However, in Germany, there has been no analysis of the educational needs or demands of medical students, or the educational deficits or potential benefits involved in global health education. Our purpose is to analyse international health elective patterns of medical students enrolled at German universities and assess whether or how they prepare for their electives abroad. We examine the exposure of medical students enrolled at German universities to training courses in tropical medicine or global health and assess students' perceived needs and demands for education in global health.</p> <p>Methods</p> <p>Cross-sectional study among medical students in Germany including all 36 medical schools during the second half of the year 2007. All registered medical students were eligible to participate in the study. Recruitment occurred via electronic mailing-lists of students' unions. We developed a web-based, semi-structured questionnaire to capture students' international mobility patterns, preparation before electives, destination countries, exposure to and demand for global health learning opportunities.</p> <p>Results</p> <p>1126 online-replies were received and analysed from all registered medical students in Germany (N = 78.067). 33.0% of all respondents (370/1126) declared at least one international health elective and of these, 36.0% (133/370) completed their electives in developing countries. 36.0% (131/363) did not prepare specifically at all, 59.0% (214/363) prepared either by self-study or declared a participation in specific preparation programmes. 87.8% of 5<sup>th </sup>and 6<sup>th </sup>year students had never participated in a global health course and 72.6% (209/288) had not completed a course in tropical medicine. 94.0% (861/916) endorsed the idea of introducing global health into medical education.</p> <p>Conclusion</p> <p>Students in our sample are highly mobile during their studies. International health electives are common, also in developing countries. Formal preparation beyond self-study is virtually non-existent amongst our sample and the participation rate in courses of tropical medicine or global health is appallingly low. We have identified unmet perceived needs and the demand for more learning opportunities in global health in our sample, urging for reforms to adjust curricula to a globalising world.</p
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