330 research outputs found

    Genetic similarity promotes evolution of cooperation under lethal intergroup competition

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    Altruism (helping others at a cost to oneself) may evolve via group selection if the cost of altruism to the individual is compensated for by growth differences among groups when (1) there is high genetic variation among members of different groups; (2) more altruistic groups grow faster and (3) between-group migration is low. Nevertheless, group selection may not fully explain the actual evolution of helping behaviour if between-group migration was sufficiently common to have reduced between-group genetic variance. Lethal intergroup competition, which amplifies such growth differences between groups, appears to have been frequent in humans'; ancestral environments and could bear importantly on the evolution of altruism. Here we show that between-group migration and resulting genetic similarity can promote the evolution of costly helping behavior in the context of lethal intergroup conflict, albeit by selection at the individual level and not by group selection. The standard group selection models do not capture such basic elements of lethal intergroup competition as the possibility of an individual's altruism being critical to the group's success when that possibility is inversely proportional to genetic variation among members of the competing groups

    Workings of the Melting Pot: Social Networks and the Evolution of Population Attributes

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    This paper links the two nascent economic literatures on social networks and cultural assimilation by investigating the evolution of population attributes in a simple model where agents are influenced by their acquaintances. The main conclusion of the analysis is that attributes converge to a melting-pot equilibrium, where everyone is identical, provided the social network exhibits a sufficient degree of interconnectedness. When the model is extended to allow an expanding acquaintance set, convergence is guaranteed provided a weaker interconnectedness condition is satisfied, and convergence is rapid. If the intensity of interactions with acquaintances becomes endogenous, convergence (when it occurs) is slowed when agents prefer to interact with people like themselves and hastened when interaction with dissimilar agents is preferred.melting pot, social networks, cultural assimilation, population attributes

    Mathematical methods in solutions of the problems from the Third International Students' Olympiad in Cryptography

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    The mathematical problems and their solutions of the Third International Students' Olympiad in Cryptography NSUCRYPTO'2016 are presented. We consider mathematical problems related to the construction of algebraic immune vectorial Boolean functions and big Fermat numbers, problems about secrete sharing schemes and pseudorandom binary sequences, biometric cryptosystems and the blockchain technology, etc. Two open problems in mathematical cryptography are also discussed and a solution for one of them proposed by a participant during the Olympiad is described. It was the first time in the Olympiad history

    INFORMATION SYSTEM OF AIRPORT NETWORK DEVELOPMENT MONITORING FORMATION

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    The article analyzes the approaches to the development of information system in public administration of this important branch of transport civil aviation. In particular, it is shown that the application of algorithmic elements allows to increase the objectivity and transparency when making decisions regarding the regulation of development of the airport network

    Context-Equivalence of Algebras with Involutions.

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    Conferencia CientíficaMorita equivalence is the central concept of celebrated Morita theory. Two algebras are Morita equivalent if their categories of modules are equivalent. A Morita context is a useful technical concept that allows one to establish Morita equivalence. Based on this concept B. Muller introduced the notion of context-equivalence in 1972. Later S. A. Amitsur showed that although the context-equivalence is coarser than Morita equivalence, many algebraic properties are still invariant relative to this new equivalence. In this talk we will we will present a version of context-equivalence suitable for the category of algebras with involution. The main result is a criterion of context-equivalence of such algebras.Departamento de Álgebra, Geometría y Topología. Facultad de Ciencias, Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Nuclear physics for geo-neutrino studies

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    Geo-neutrino studies are based on theoretical estimates of geo-neutrino spectra. We propose a method for a direct measurement of the energy distribution of antineutrinos from decays of long-lived radioactive isotopes. We present preliminary results for the geo-neutrinos from Bi-214 decay, a process which accounts for about one half of the total geo-neutrino signal. The feeding probability of the lowest state of Bi-214 - the most important for geo-neutrino signal - is found to be p_0 = 0.177 \pm 0.004 (stat) ^{+0.003}_{-0.001} (sys), under the hypothesis of Universal Neutrino Spectrum Shape (UNSS). This value is consistent with the (indirect) estimate of the Table of Isotopes (ToI). We show that achievable larger statistics and reduction of systematics should allow to test possible distortions of the neutrino spectrum from that predicted using the UNSS hypothesis. Implications on the geo-neutrino signal are discussed.Comment: 8 pages RevTex format, 8 figures and 2 tables. Submitted to PR

    Equity and Excellence in Research Funding

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    The tension between equity and excellence is fundamental in science policy. This tension might appear to be resolved through the use of merit-based evaluation as a criterion for research funding. This is not the case. Merit-based decision making alone is insufficient because of inequality aversion, a fundamental tendency of people to avoid extremely unequal distributions. The distribution of performance in science is extremely unequal, and no decision maker with the power to establish a distribution of public money would dare to match the level of inequality in research performance. We argue that decision makers who increase concentration of resources because they accept that research resources should be distributed according to merit probably implement less inequality than would be justified by differences in research performance. Here we show that the consequences are likely to be suppression of incentives for the very best scientists. The consequences for the performance of a national research system may be substantial. Decision makers are unaware of the issue, as they operate with distributional assumptions of normality that guide our everyday intuitions
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