Evolution of cooperation in stochastic games

Social dilemmas occur when incentives for individuals are misaligned with group interests 1-7 . According to the 'tragedy of the commons', these misalignments can lead to overexploitation and collapse of public resources. The resulting behaviours can be analysed with the tools of game theory 8 . The theory of direct reciprocity 9-15 suggests that repeated interactions can alleviate such dilemmas, but previous work has assumed that the public resource remains constant over time. Here we introduce the idea that the public resource is instead changeable and depends on the strategic choices of individuals. An intuitive scenario is that cooperation increases the public resource, whereas defection decreases it. Thus, cooperation allows the possibility of playing a more valuable game with higher payoffs, whereas defection leads to a less valuable game. We analyse this idea using the theory of stochastic games 16-19 and evolutionary game theory. We find that the dependence of the public resource on previous interactions can greatly enhance the propensity for cooperation. For these results, the interaction between reciprocity and payoff feedback is crucial: neither repeated interactions in a constant environment nor single interactions in a changing environment yield similar cooperation rates. Our framework shows which feedbacks between exploitation and environment - either naturally occurring or designed - help to overcome social dilemmas

Schinus terebinthifolius Raddi ( Aroeira) leaves oil attenuates inflammatory responses in cutaneous wound healing in mice

Purpose: To investigated the inflammatory, angiogenic and fibrogenic activities of the Schinus terebinthifolius Raddi leaves oil (STRO) on wound healing. Methods: The excisional wound healing model was used to evaluate the effects of STRO. The mice were divided into two groups: Control, subjected to vehicle solution (ointment lanolin/vaseline base), or STRO-treated group, administered topically once a day for 3, 7 and 14 days post-excision. We evaluated the macroscopic wound closure ratethe inflammation was evaluated by leukocytes accumulation and cytokine levels in the wounds. The accumulation of neutrophil and macrophages in the wounds were determined by assaying myeloperoxidase and N-acetyl-beta-D-glucosaminidase activities. The levels of TNF-alpha, CXCL-1 and CCL-2 in wound were evaluated by ELISA assay. Angiogenesis and collagen fibers deposition were evaluated histologically. Results: We observed that macroscopic wound closure rate was improved in wounds from STRO-group than Control-group. The wounds treated with STRO promoted a reduction in leucocyte accumulation and in pro-inflammatory cytokine. Moreover, STRO treatment increased significantly the number of blood vessels and collagen fibers deposition, as compared to control group. Conclusion: Topical application of STRO display anti-inflammatory and angiogenic effects, as well as improvement in collagen replacement, suggesting a putative use of this herb for the development of phytomedicines to treat inflammatory diseases, including wound healing.Fundação de Amparo a Ciência e Tecnologia do Estado de Pernambuco (FACEPE)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Fed Rural Pernambuco UFRPE, Dept Morphol & Anim Physiol, Recife, PE, BrazilUniv Fed São Paulo UNIFESP, Dept Morphol & Genet, São Paulo, BrazilUniv Fed Rural Pernambuco, Dept Chem, Recife, PE, BrazilUniv Fed Rural Pernambuco, Dept Morphol & Anim Physiol, Recife, PE, BrazilUniv Fed São Paulo UNIFESP, Dept Morphol & Genet, São Paulo, BrazilWeb of Scienc

Body composition impacts appetite regulation in middle childhood. A prospective study of Norwegian community children

Background Research suggests a role for both fat mass and muscle mass in appetite regulation, but the longitudinal relationships between them have not yet been examined in children. The present study therefore aimed to explore the prospective relationships between fat mass, muscle mass and the appetitive traits food responsiveness and satiety responsiveness in middle childhood. Methods Food responsiveness and satiety responsiveness were measured using the parent-reported Children’s Eating Behavior Questionnaire in a representative sample of Norwegian 6 year olds, followed up at 8 and 10 years of age (n = 807). Body composition was measured by bioelectrical impedance. Results Applying a structural equation modeling framework we found that higher fat mass predicted greater increases in food responsiveness over time, whereas greater muscle mass predicted decreases in satiety responsiveness. This pattern was consistent both from ages 6 to 8 and from ages 8 to 10 years. Conclusions Our study is the first to reveal that fat mass and muscle mass predict distinct changes in different appetitive traits over time. Replication of findings in non-European populations are needed, as are studies of children in other age groups. Future studies should also aim to reveal the underlying mechanisms

Activation of cGMP-Dependent Protein Kinase Stimulates Cardiac ATP-Sensitive Potassium Channels via a ROS/Calmodulin/CaMKII Signaling Cascade

) channels, an ion channel critical for stress adaptation in the heart; however, the underlying mechanism remains largely unknown. The present study was designed to address this issue. channels was confirmed in intact ventricular cardiomyocytes, which was ROS- and CaMKII-dependent. Kinetically, PKG appeared to stimulate these channels by destabilizing the longest closed state while stabilizing the long open state and facilitating opening transitions. channels and contribute to cardiac protection against ischemia-reperfusion injury

The Transcriptome of Trichuris suis – First Molecular Insights into a Parasite with Curative Properties for Key Immune Diseases of Humans

Iatrogenic infection of humans with Trichuris suis (a parasitic nematode of swine) is being evaluated or promoted as a biological, curative treatment of immune diseases, such as inflammatory bowel disease (IBD) and ulcerative colitis, in humans. Although it is understood that short-term T. suis infection in people with such diseases usually induces a modified Th2-immune response, nothing is known about the molecules in the parasite that induce this response.As a first step toward filling the gaps in our knowledge of the molecular biology of T. suis, we characterised the transcriptome of the adult stage of this nematode employing next-generation sequencing and bioinformatic techniques. A total of ∼65,000,000 reads were generated and assembled into ∼20,000 contiguous sequences ( = contigs); ∼17,000 peptides were predicted and classified based on homology searches, protein motifs and gene ontology and biological pathway mapping.These analyses provided interesting insights into a number of molecular groups, particularly predicted excreted/secreted molecules (n = 1,288), likely to be involved in the parasite-host interactions, and also various molecules (n = 120) linked to chemokine, T-cell receptor and TGF-β signalling as well as leukocyte transendothelial migration and natural killer cell-mediated cytotoxicity, which are likely to be immuno-regulatory or -modulatory in the infected host. This information provides a conceptual framework within which to test the immunobiological basis for the curative effect of T. suis infection in humans against some immune diseases. Importantly, the T. suis transcriptome characterised herein provides a curated resource for detailed studies of the immuno-molecular biology of this parasite, and will underpin future genomic and proteomic explorations

Framing tourist risk in UK press accounts of Hurricane Ivan

This article examines the coverage of selected UK press reports of Hurricane Ivan in September 2004 that was the most powerful storm to hit the Caribbean within the last 10 years. Quantitative content analysis has been utilised in this study to determine the main sources of information on the Hurricane and to examine the framing of tourist risk in the press accounts of this disaster. It is demonstrated that the reporting of Hurricane Ivan in the news items tended to convey information that amplified tourist vulnerability and risk. Institutional official sources were often quoted to reinforce danger and ‘no-escape’ rather than reporting on management strategies to reduce these risks or measures that were implemented to ensure visitor safety. This article therefore contends that media management strategies on disasters need to employ more precise and careful monitoring of media accounts of disasters in major generating markets. Such activities may be invaluable in providing assistance to tourism managers regarding decisions on communications strategies and marketing activity aimed at repairing damage and returning to normality in an affected country or region

Pilot parallel randomised controlled trial of protective socks against usual care to reduce skin tears in high risk people: 'STOPCUTS'.

Skin tears are common in older adults and those taking steroids and warfarin. They are traumatic, often blunt injuries caused by oblique knocks to the extremities. The epidermis may separate from the dermis or both layers from underlying tissues leaving a skin flap or total loss of tissue, which is painful and prone to infection. 'Dermatuff™' knee-length socks containing Kevlar fibres (used in stab-proof vests and motorcyclists' clothing) aim to prevent skin tears. The acceptability of the socks and the feasibility of a randomised controlled trial (RCT) had not been explored.Royal Devon & Exeter NHS Foundation TrustThis article is freely available via Open Access. Click on the Additional Link above to access the full-text via the publisher's site.NIHR Research for Patient BenefitEDGE Project ID: 1854