271 research outputs found

    Cooperativeness and Impatience in the Tragedy of the Commons

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    This paper examines the role of other-regarding and time preferences for cooperation in the field. We study the preferences of fishermen whose main, and often only, source of income stems from using a common pool resource (CPR). The exploitation of a CPR involves a negative interpersonal and inter-temporal externality because individuals who exploit the CPR reduce the current and the future yield for both others and themselves. Accordingly, economic theory predicts that more cooperative and more patient individuals should be less likely to exploit the CPR. Our data supports this prediction because fishermen who exhibit a higher propensity for cooperation in a laboratory public goods experiment, and those who show more patience in a laboratory time preference experiment, exploit the fishing grounds less in their daily lives. Moreover, because the laboratory public goods game exhibits no inter-temporal spillovers, measured time preferences should not predict cooperative behavior in the laboratory. This prediction is also borne out by our data. Thus, laboratory preference measures are useful to capture important dimensions of field behavior.cooperation, common pool resource, experiments, generalizability, methodology

    Functional profiling of mercuric reductase (mer A) genes in biofilm communities of a technical scale biocatalyzer

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    BACKGROUND: Bacterial mercury resistance is based on enzymatic reduction of ionic mercury to elemental mercury and has recently been demonstrated to be applicable for industrial wastewater clean-up. The long-term monitoring of such biocatalyser systems requires a cultivation independent functional community profiling method targeting the key enzyme of the process, the merA gene coding for the mercuric reductase. We report on the development of a profiling method for merA and its application to monitor changes in the functional diversity of the biofilm community of a technical scale biocatalyzer over 8 months of on-site operation. RESULTS: Based on an alignment of 30 merA sequences from Gram negative bacteria, conserved primers were designed for amplification of merA fragments with an optimized PCR protocol. The resulting amplicons of approximately 280 bp were separated by thermogradient gelelectrophoresis (TGGE), resulting in strain specific fingerprints for mercury resistant Gram negative isolates with different merA sequences. The merA profiling of the biofilm community from a technical biocatalyzer showed persistence of some and loss of other inoculum strains as well as the appearance of new bands, resulting in an overall increase of the functional diversity of the biofilm community. One predominant new band of the merA community profile was also detected in a biocatalyzer effluent isolate, which was identified as Pseudomonas aeruginosa. The isolated strain showed lower mercury reduction rates in liquid culture than the inoculum strains but was apparently highly competitive in the biofilm environment of the biocatalyzer where moderate mercury levels were prevailing. CONCLUSIONS: The merA profiling technique allowed to monitor the ongoing selection for better adapted strains during the operation of a biocatalyzer and to direct their subsequent isolation. In such a way, a predominant mercury reducing Ps. aeruginosa strain was identified by its unique mercuric reductase gene

    Der CDU/CSU-Vorschlag zur Gesundheitspauschale: Pro und Kontra

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    Die Einführung einer Pauschalprämie in der Gesetzlichen Krankenversicherung (GKV) wird von wirtschaftswissenschaftlichen Experten schon seit Jahren gefordert. Der Kompromiss, der zwischen CDU und CSU gefunden wurde und von Christa Stewens, bayerische Sozialministerin, hier erläutert wird, enthält zwar im Grundsatz die Pauschalprämie, schwächt aber ihre verteilungspolitischen Wirkungen gegenüber dem reinen Konzept ab. Prof. Dr. Andreas Haufler, Universität München, erwartet von dieser Reform keine nennenswerten Effizienzgewinne und Gerrit Roth, ebenfalls Universität München, lehnt eine Gesundheitsprämie generell ab. Für Prof. Dr. Hans Fehr, Universität Würzburg, fällt das vereinbarte Kompromissmodell bei nahezu allen relevanten Kriterien gegenüber dem ursprünglichen Konzept zurück, und für Prof. Dr. Friedrich Breyer, Universität Konstanz, weist das CDU/CSU-Modell ein Höchstmaß an Intransparenz auf.Gesetzliche Krankenversicherung, Gesundheitskosten, Einkommen, Gesundheitsfinanzierung, Kopfsteuer, Deutschland

    When Social Forces Remove the Impact of Competition. Social Exchange in Experimental Labor Markets

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    Do competitive markets remove the impact of social norms and customs on market out-comes? Or are these social forces capable of exerting a persistent influence? Many economists seem to believe that social norms and customs have, if at all, only temporary effects in competitive markets. So far this belief has been confirmed by the evidence of many competitive market experiments. In this paper we report the results of a series of competitive market and bilateral bargaining experiments. They indicate that social norms may not only persist in a competitive environment but that they may completely remove the impact of competition on the market outcome.Competition, Social Exchange, Trust, Reciprocity, Social Norms

    Risk Factors for Surgical Site Infection in a Tanzanian District Hospital: A Challenge for the Traditional National Nosocomial Infections Surveillance System Index

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    The incidence of surgical site infections (SSIs) was 24% in a district hospital in Tanzania. Wound classification was not an independent risk factor for SSI, indicating that risk scores developed in industrialized countries may require adjustments for nonindustrialized countries. The National Nosocomial Infections Surveillance system score required adjustments to reliably predict SSI, probably to account for improper hygiene and the lack of adjustment for the duration of surgery (defined as the 75th percentile of the duration for each type of operative procedure) to reflect local circumstances. Multidrug-resistant pathogens, such as methicillin-resistant Staphylococcus aureus and gram-negative pathogens expressing broad-spectrum β-lactamases, have already emerge

    Thermal analysis of new transdermal devices for power transfer to ventricular assist devices

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    Different engineered approaches have led the design of implants with controlled physical features to minimize adverse effects in biological tissues. Aiming to prevent infection, similar efforts have focused on optimizing the design features of drivelines used to transfer power to percutaneous ventricular assistance devices (VAD), omitting however a thorough look on the implant-skin interactions that govern local tissue reactions. Here, we utilized an integrated approach for the biophysical modification of transdermal implants and their evaluation by chronic sheep implantation in comparison to the standard of care VAD drivelines. We developed a novel method for the transfer of breath topographical features on thin wires with modular size. Moreover, we examined the impact of implant’s diameter, surface topography, and chemistry on macroscopic, histological, and physical markers of inflammation, fibrosis, and mechanical adhesion. All implants demonstrated infection-free performance. The fibrotic response was enhanced by the increasing diameter of implants but not influenced by their surface properties. The implants of 0.2 mm diameter promoted mild inflammatory responses with improved mechanical adhesion and restricted epidermal downgrowth, in both silicone and polyurethane coated transdermal wires. On the contrary, the VAD drivelines with larger diameter triggered severe inflammatory reactions with frequent epidermal downgrowth [1]. Furthermore, we performed COMSOL simulations to investigate the electrothermal implications of conductive wires with different sizes for the power transfer to VADs. In our model, we simulate the electrical properties of the prototype’s wires, to confirm that it does not produce a significant body temperature rise. The skin model (Fig. 1a) mimics the multiple skin layer’ properties of epidermis, dermis, fat and muscle [2]. Also, we include a PDMS layer (5 mm thickness) that represents the silicon-based material of the conductive skin. During the study, different thicknesses of the polyurethane (PU) insulating coating were tested for the wire of 0.2 mm diameter. However, no significant improvement was observed when increasing the insulation layer, since the temperature difference in the model was due to the temperature skin gradient and not the electric current. In this model, the dimensions of both the inner copper diameter and the PU coating thickness were obtained from the manufacturer’s specifications (0.2030 mm and 0.0105 mm, respectively). Our results show that when the wires are subject to the peak voltage for VADs (~14.5 V) and a steady-state current of 1.2 A (Fig. 1b), the temperature increases 0.65°C in the core of the copper wires (Fig. 1c), due to the inrush current. Nonetheless, the surface temperature of the patch in the steady state remains around 0.02°C, indicating that there is no significant risk for skin injury from heat dissipation. This combination of experimental and computational findings will enable the design of new percutaneous medical devices to support therapies that require safe exchange of power, signal, and mass through the human body

    Development and clinical validation of the LymphMonitor technology to quantitatively assess lymphatic function

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    Current diagnostic methods for evaluating the functionality of the lymphatic vascular system usually do not provide quantitative data and suffer from many limitations including high costs, complexity, and the need to perform them in hospital settings. In this work, we present a quantitative, simple outpatient technology named LymphMonitor to quantitatively assess lymphatic function. This method is based on the painless injection of the lymphatic-specific near-infrared fluorescent tracer indocyanine green complexed with human serum albumin, using MicronJet600TM microneedles, and monitoring the disappearance of the fluorescence signal at the injection site over time using a portable detection device named LymphMeter. This technology was investigated in 10 patients with unilateral leg or arm lymphedema. After injection of a tracer solution into each limb, the signal was measured over 3 h and the area under the normalized clearance curve was calculated to quantify the lymphatic function. A statistically significant difference in lymphatic clearance in the healthy versus the lymphedema extremities was found, based on the obtained area under curves of the normalized clearance curves. This study provides the first evidence that the LymphMonitor technology has the potential to diagnose and monitor the lymphatic function in patients

    Outbreaks of Pneumocystis Pneumonia in 2 Renal Transplant Centers Linked to a Single Strain of Pneumocystis: Implications for Transmission and Virulence

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    By restriction fragment length polymorphism analysis, 2 outbreaks of Pneumocystis pneumonia in renal transplant patients in Europe were shown to be caused by the same strain of Pneumocystis; another outbreak in Japan was caused by a different strai

    Incomplete Punishment Networks in Public Goods Games: Experimental Evidence

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    Abundant evidence suggests that high levels of contributions to public goods can be sustained through self-governed monitoring and sanctioning. This experimental study investigates the effectiveness of decentralized sanctioning institutions in alternative punishment networks. Our results show that the structure of punishment network significantly affects allocations to the public good. In addition, we observe that network configurations are more important than punishment capacities for the levels of public good provision, imposed sanctions and economic efficiency. Lastly, we show that targeted revenge is a major driver of anti-social punishment
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