1,180 research outputs found

    Heterogeneity, Communication, Coordination and Voluntary Provision of a Public Good

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    The results of twenty-four laboratory sessions are evaluated with respect to the role of alternative definitions of equity when communication is introduced into an environment in which voluntary contributions determine the level of public good provision to small groups of individuals. Individuals experience both non-communication and communication treatments. Additional treatments include the extent to which subjects have information about others’ payoffs from (preferences for) the consumption of public goods and about others’ incomes and payoff functions (preferences). With communication, participants in incomplete information environments are less able to coordinate their contributions while those in complete information environments succeed more often. Under complex heterogeneity payoff distributions widen with the introduction of communication. The data do not support the emergence of a particular pattern of coordination across all treatments.

    Characterization of the spore surface and exosporium proteins of Clostridium sporogenes; implications for Clostridium botulinum group I strains.

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    Clostridium sporogenes is a non-pathogenic close relative and surrogate for Group I (proteolytic) neurotoxin-producing Clostridium botulinum strains. The exosporium, the sac-like outermost layer of spores of these species, is likely to contribute to adhesion, dissemination, and virulence. A paracrystalline array, hairy nap, and several appendages were detected in the exosporium of C. sporogenes strain NCIMB 701792 by EM and AFM. The protein composition of purified exosporium was explored by LC-MS/MS of tryptic peptides from major individual SDS-PAGE-separated protein bands, and from bulk exosporium. Two high molecular weight protein bands both contained the same protein with a collagen-like repeat domain, the probable constituent of the hairy nap, as well as cysteine-rich proteins CsxA and CsxB. A third cysteine-rich protein (CsxC) was also identified. These three proteins are also encoded in C. botulinum Prevot 594, and homologues (75-100% amino acid identity) are encoded in many other Group I strains. This work provides the first insight into the likely composition and organization of the exosporium of Group I C. botulinum spores

    Key dating features for timber-framed dwellings in Surrey

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    This article is made available through the Brunel Open Access Publishing Fund. Copyright @ The Vernacular Architecture Group 2013. MORE OpenChoice articles are open access and distributed under the terms of the Creative Commons Attribution License 3.0.The main component of the Surrey Dendrochronology Project is the accurate dating of 177 ‘dwellings’, nearly all by tree-ring analysis. The dates are used to establish date ranges for 52 ‘key features’, which cover many aspects of timber-framing from building type to details of carpentry. It is shown that changes of method and fashion were in many cases surprisingly rapid, almost abrupt in historical terms. Previous dating criteria for timber-framed dwellings in the county have been refined and new criteria introduced. Clusters of change from the 1440s and the 1540s are shown and some possible historical links suggested.The Heritage Lottery Fund, the Domestic Buildings Research Group (Surrey), the Surrey Archaeological Society and the historical societies of Charlwood, Farnham and Nutfield

    Rationale and Design of an Online Educational Program Using Game-Based Learning to Improve Nutrition and Physical Activity Outcomes Among University Students in the United Kingdom.

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    OBJECTIVE: To assess the impact of an online game-based educational program on nutrition knowledge and dietary and physical activity habits among university students in the United Kingdom. DESIGN: Randomized controlled trial with pre- and postintervention comparisons. SETTING: Two higher education settings in London, UK. SUBJECTS: Current undergraduate and postgraduate students of two universities (n = 88) aged 18-34 years are randomly allocated to an intervention (n = 44) or a control group (n = 44). INTERVENTION: The intervention group will receive access to an educational website and online quizzes with gamification elements, including information about healthy eating and physical activity. The control group will receive no information. Duration of the intervention will be 10 weeks. MEASURES OF OUTCOME: Primary outcome is nutrition knowledge. Secondary outcomes include dietary and activity habits. Nutrition knowledge and dietary and activity habits will be assessed using questionnaires. Weekly steps will be counted using pedometers. Assessment of anthropometric and metabolic risk factors will take place. ANALYSIS: Quantitative analysis will investigate changes in nutrition knowledge between the two groups of the study population. Linear regression analysis will be used, if the data follow the normal distribution (otherwise binomial regression analysis), to examine whether field of study, residence status, body mass index (BMI), and demographic factors affect nutrition knowledge. Associations between changes in knowledge and dietary and physical activity behavior will be assessed by correlations. CONCLUSIONS/IMPLICATIONS: The study will provide insights with regard to the design and use of online game-playing as a cost-effective approach to improve nutritional knowledge among university students

    Scale-invariant magnetoresistance in a cuprate superconductor

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    The anomalous metallic state in high-temperature superconducting cuprates is masked by the onset of superconductivity near a quantum critical point. Use of high magnetic fields to suppress superconductivity has enabled a detailed study of the ground state in these systems. Yet, the direct effect of strong magnetic fields on the metallic behavior at low temperatures is poorly understood, especially near critical doping, x=0.19x=0.19. Here we report a high-field magnetoresistance study of thin films of \LSCO cuprates in close vicinity to critical doping, 0.161x0.1900.161\leq x\leq0.190. We find that the metallic state exposed by suppressing superconductivity is characterized by a magnetoresistance that is linear in magnetic field up to the highest measured fields of 8080T. The slope of the linear-in-field resistivity is temperature-independent at very high fields. It mirrors the magnitude and doping evolution of the linear-in-temperature resistivity that has been ascribed to Planckian dissipation near a quantum critical point. This establishes true scale-invariant conductivity as the signature of the strange metal state in the high-temperature superconducting cuprates.Comment: 10 pages, 3 figure

    Autonomic Dysregulation in Adolescent Concussion Is Sex- and Posture-Dependent

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    Objective: To study autonomic responses to postural changes in concussed adolescents. The influence of sex was also studied. Design: Longitudinal cohort observational study. Participants: Concussed adolescents (CONC; n = 65; 26 male adolescents; age 15 ± 1 years, range = 12-18 years) and a control (CTRL) group of nonconcussed adolescents of similar age and sport (CTRL; n = 54; 29 male adolescents; age 14 ± 1 years, range = 12-18 years). Interventions: Concussed participants were monitored through 6 weekly visits throughout usual physician care. Control participants underwent 2 visits separated by at least 1 week to account for intrapersonal variation in testing measures. Main Outcome Measures: Heart rate variability as the root mean square of successive differences in R–R intervals (RMSSD), heart rate (HR), and blood pressure [mean arterial pressure (MAP) and diastolic blood pressure (DBP)] were measured in supine, sitting, and standing postures. Results: A mixed analysis of variance revealed a group 3 sex 3 posture interaction (P = 0.04) where seated values of RMSSD were less in concussed female participants versus control female participants (42 ± 4 vs 61 ± 7 ms; P = 0.01; Mann–Whitney rank test). Compared with CTRL, CONC exhibited increased pretesting seated DBP (69 ± 1 vs 74 ± 1 mm Hg; P\u3c 0.01), MAP (83 ± 1 vs 86 ± 1 mm Hg; P = 0.02), and baseline seated HR (72 ± 1 vs 77 ± 2 bpm; P = 0.03). Values of DBP (P = 0.03) and MAP (P, 0.01) improved at clinical discharge, whereas the RMSSD in female participants did not (P \u3e 0.5). Data are mean ± SEM. Conclusions: A modest reduction in female cardiac autonomic regulation was observed during seated postures. Alterations in seated concussed DBP and MAP, but not RMSSD, resolved at clinical discharge (median = 37 days). The results indicate that, in adolescents, concussion may impair cardiovagal function in a sex- and posture-dependent manner. The findings also suggest that BP metrics, but not RMSSD, are associated with clinical concussion recovery
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