36 research outputs found

    Cooperation, Norms, and Revolutions: A Unified Game-Theoretical Approach

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    Cooperation is of utmost importance to society as a whole, but is often challenged by individual self-interests. While game theory has studied this problem extensively, there is little work on interactions within and across groups with different preferences or beliefs. Yet, people from different social or cultural backgrounds often meet and interact. This can yield conflict, since behavior that is considered cooperative by one population might be perceived as non-cooperative from the viewpoint of another. To understand the dynamics and outcome of the competitive interactions within and between groups, we study game-dynamical replicator equations for multiple populations with incompatible interests and different power (be this due to different population sizes, material resources, social capital, or other factors). These equations allow us to address various important questions: For example, can cooperation in the prisoner's dilemma be promoted, when two interacting groups have different preferences? Under what conditions can costly punishment, or other mechanisms, foster the evolution of norms? When does cooperation fail, leading to antagonistic behavior, conflict, or even revolutions? And what incentives are needed to reach peaceful agreements between groups with conflicting interests? Our detailed quantitative analysis reveals a large variety of interesting results, which are relevant for society, law and economics, and have implications for the evolution of language and culture as well

    Molecular Dynamics Simulations Suggest that Electrostatic Funnel Directs Binding of Tamiflu to Influenza N1 Neuraminidases

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    Oseltamivir (Tamiflu) is currently the frontline antiviral drug employed to fight the flu virus in infected individuals by inhibiting neuraminidase, a flu protein responsible for the release of newly synthesized virions. However, oseltamivir resistance has become a critical problem due to rapid mutation of the flu virus. Unfortunately, how mutations actually confer drug resistance is not well understood. In this study, we employ molecular dynamics (MD) and steered molecular dynamics (SMD) simulations, as well as graphics processing unit (GPU)-accelerated electrostatic mapping, to uncover the mechanism behind point mutation induced oseltamivir-resistance in both H5N1 “avian” and H1N1pdm “swine” flu N1-subtype neuraminidases. The simulations reveal an electrostatic binding funnel that plays a key role in directing oseltamivir into and out of its binding site on N1 neuraminidase. The binding pathway for oseltamivir suggests how mutations disrupt drug binding and how new drugs may circumvent the resistance mechanisms

    Modeling a New Water Channel That Allows SET9 to Dimethylate p53

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    SET9, a protein lysine methyltransferase, has been thought to be capable of transferring only one methyl group to target lysine residues. However, some reports have pointed out that SET9 can dimethylate Lys372 of p53 (p53-K372) and Lys4 of histone H3 (H3-K4). In order to understand how p53 can be dimethylated by SET9, we measured the radius of the channel that surrounds p53-K372, first on the basis of the crystal structure of SET9, and we show that the channel is not suitable for water movement. Second, molecular dynamic (MD) simulations were carried out for 204 ns on the crystal structure of SET9. The results show that water leaves the active site of SET9 through a new channel, which is made of G292, A295, Y305 and Y335. In addition, the results of molecular docking and MD simulations indicate that the new water channel continues to remain open when S-adenosyl-L-methionine (AdoMet) or S-adenosyl-L-homocysteine (AdoHcy) is bound to SET9. The changes in the radii of these two channels were measured in the equilibrium phase at the constant temperature of 300 K. The results indicate that the first channel still does not allow water to get into or out of the active site, but the new channel is large enough to allow this water to circulate. Our results indicate that water can be removed from the active site, an essential process for allowing the dimethylation reaction to occur

    Comparative review of human and canine osteosarcoma: morphology, epidemiology, prognosis, treatment and genetics

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    Osteosarcoma (OSA) is a rare cancer in people. However OSA incidence rates in dogs are 27 times higher than in people. Prognosis in both species is poor, with five year osteosarcoma survival rates in people not having improved in decades. For dogs, one year survival rates are only around ~45%. Improved and novel treatment regimens are urgently required to improve survival in both humans and dogs with OSA. Utilising information from genetic studies could assist in this in both species, with the higher incidence rates in dogs contributing to the dog population being a good model of human disease. This review compares the clinical characteristics, gross morphology and histopathology, aetiology, epidemiology, and genetics of canine and human osteosarcoma. Finally, the current position of canine osteosarcoma genetic research is discussed and areas for additional work within the canine population are identified

    Network Development in Films Cast from Emulsions of Polydimethylsiloxane

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