977 resultados para Social evolution.
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A fundamental problem in biology is understanding how and why things group together. Collective behavior is observed on all organismic levels - from cells and slime molds, to swarms of insects, flocks of birds, and schooling fish, and in mammals, including humans. The long-term goal of this research is to understand the functions and mechanisms underlying collective behavior in groups. This dissertation focuses on shoaling (aggregating) fish. Shoaling behaviors in fish confer foraging and anti-predator benefits through social cues from other individuals in the group. However, it is not fully understood what information individuals receive from one another or how this information is propagated throughout a group. It is also not fully understood how the environmental conditions and perturbations affect group behaviors. The specific research objective of this dissertation is to gain a better understanding of how certain social and environmental factors affect group behaviors in fish. I focus on two ecologically relevant decision-making behaviors: (i) rheotaxis, or orientation with respect to a flow, and (ii) startle response, a rapid response to a perceived threat. By integrating behavioral and engineering paradigms, I detail specifics of behavior in giant danio Devario aequipinnatus (McClelland 1893), and numerically analyze mathematical models that may be extended to group behavior for fish in general, and potentially other groups of animals as well. These models that predict behavior data, as well as generate additional, testable hypotheses. One of the primary goals of neuroethology is to study an organism's behavior in the context of evolution and ecology. Here, I focus on studying ecologically relevant behaviors in giant danio in order to better understand collective behavior in fish. The experiments in this dissertation provide contributions to fish ecology, collective behavior, and biologically-inspired robotics.
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Understanding the evolution of sociality in humans and other species requires understanding how selection on social behaviour varies with group size. However, the effects of group size are frequently obscured in the theoretical literature, which often makes assumptions that are at odds with empirical findings. In particular, mechanisms are suggested as supporting large-scale cooperation when they would in fact rapidly become ineffective with increasing group size. Here we review the literature on the evolution of helping behaviours (cooperation and altruism), and frame it using a simple synthetic model that allows us to delineate how the three main components of the selection pressure on helping must vary with increasing group size. The first component is the marginal benefit of helping to group members, which determines both direct fitness benefits to the actor and indirect fitness benefits to recipients. While this is often assumed to be independent of group size, marginal benefits are in practice likely to be maximal at intermediate group sizes for many types of collective action problems, and will eventually become very small in large groups due to the law of decreasing returns. The second component is the response of social partners on the past play of an actor, which underlies conditional behaviour under repeated social interactions. We argue that under realistic conditions on the transmission of information in a population, this response on past play decreases rapidly with increasing group size so that reciprocity alone (whether direct, indirect, or generalised) cannot sustain cooperation in very large groups. The final component is the relatedness between actor and recipient, which, according to the rules of inheritance, again decreases rapidly with increasing group size. These results explain why helping behaviours in very large social groups are limited to cases where the number of reproducing individuals is small, as in social insects, or where there are social institutions that can promote (possibly through sanctioning) large-scale cooperation, as in human societies. Finally, we discuss how individually devised institutions can foster the transition from small-scale to large-scale cooperative groups in human evolution.
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Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica
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The current study analyzes the birth and development of two strategic alliances established between shrimp producers in Rio Grande do Norte: the Unipesca and the Coopercam. To achieve this aim, two approaches which, at first sight, could be considered contradictory were used: the Transactional Costs Economy and Embeddedness. The first approach is fundamentally based in the studies of Williamson (1985; 1991; 1996; 1999; 2000; 2002). Embededness, on the other hand, went through the review of a series of authors, such as Burt (1992), Granovetter (1973; 1985), Uzzi (1997), Gulati (1994; 1995; 1997; 1998; 1999; 2000), Nielsen (2005), Ring (2002), Ring and Van de Ven (1994), Zafirovski (2002), among others. To analyze the birth and development of the cooperatives in this study, Gulati s work (1998) was used. This study shows the steps to be studied for a better comprehension of an alliance: the decision of starting an alliance and the choice of the partners, the decision about the governance structure, the evolution of the alliance and the development of the companies which established this partnership. To carry this study out, a study case accordingly to Yin s proposal (2001) was adopted. Semi-structured interviews with pre-defined plots were conducted in two phases: in the beginning of 2006 and in the beginning of 2007. The subjects from the research were, in 2006, representative members of the main associations and corporations, besides the shrimp producers from the state, when the context of the activity was set. In the second phase, in 2007, representative members from the two cooperatives that were listed above were interviewed the president from Coopercam and the marketing manager from Unipesca. Besides these two members, directors from two important organizations in each of these cooperatives were also interviewed, giving out the necessary information for the research. Secondary data was also collected from the Brazilian Association of Crab producers website, as well as from news from important newspapers in RN, such as Tribuna do Norte. The primary data was analyzed in terms of quality, accordingly to the documental analysis technique. Thus, through the data that was collected, it can be concluded that the reasons that motivated the companies to cooperate can be explained in terms of the transactional costs economy. However, the choice of partners is more connected to aspects approached by the social embededness. When aspects related to development and evolution were analyzed, it could be seen that both aspects from TCE and Embededness were vital to explain the development of the cooperatives mentioned
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This research explores the business model (BM) evolution process of entrepreneurial companies and investigates the relationship between BM evolution and firm performance. Recently, it has been increasingly recognised that the innovative design (and re-design) of BMs is crucial to the performance of entrepreneurial firms, as BM can be associated with superior value creation and competitive advantage. However, there has been limited theoretical and empirical evidence in relation to the micro-mechanisms behind the BM evolution process and the entrepreneurial outcomes of BM evolution. This research seeks to fill this gap by opening up the ‘black box’ of the BM evolution process, exploring the micro-patterns that facilitate the continuous shaping, changing, and renewing of BMs and examining how BM evolutions create and capture value in a dynamic manner. Drawing together the BM and strategic entrepreneurship literature, this research seeks to understand: (1) how and why companies introduce BM innovations and imitations; (2) how BM innovations and imitations interplay as patterns in the BM evolution process; and (3) how BM evolution patterns affect firm performances. This research adopts a longitudinal multiple case study design that focuses on the emerging phenomenon of BM evolution. Twelve entrepreneurial firms in the Chinese Online Group Buying (OGB) industry were selected for their continuous and intensive developments of BMs and their varying success rates in this highly competitive market. Two rounds of data collection were carried out between 2013 and 2014, which generates 31 interviews with founders/co-founders and in total 5,034 pages of data. Following a three-stage research framework, the data analysis begins by mapping the BM evolution process of the twelve companies and classifying the changes in the BMs into innovations and imitations. The second stage focuses down to the BM level, which addresses the BM evolution as a dynamic process by exploring how BM innovations and imitations unfold and interplay over time. The final stage focuses on the firm level, providing theoretical explanations as to the effects of BM evolution patterns on firm performance. This research provides new insights into the nature of BM evolution by elaborating on the missing link between BM dynamics and firm performance. The findings identify four patterns of BM evolution that have different effects on a firm’s short- and long-term performance. This research contributes to the BM literature by presenting what the BM evolution process actually looks like. Moreover, it takes a step towards the process theory of the interplay between BM innovations and imitations, which addresses the role of companies’ actions, and more importantly, reactions to the competitors. Insights are also given into how entrepreneurial companies achieve and sustain value creation and capture by successfully combining the BM evolution patterns. Finally, the findings on BM evolution contributes to the strategic entrepreneurship literature by increasing the understanding of how companies compete in a more dynamic and complex environment. It reveals that, the achievement of superior firm performance is more than a simple question of whether to innovate or imitate, but rather an integration of innovation and imitation strategies over time. This study concludes with a discussion of the findings and their implications for theory and practice.
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International audience
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The relationship between the socio-economic status of parents and children is referred by the literature as intergenerational social mobility. The scope of this mobility encompasses different aspects such as educational attainment, income, wealth, prestige and occupational status. In particular, intergenerational occupational mobility is an interesting topic in the economic literature because it is positively associated with the economic achievement and the professional success. Low mobility implies that human capital, skills and talent can be misallocated. As a consequence, the workers’ efforts, their motivation and productivity could be negatively affected, which would have adverse effects on the economy growth and its competitiveness. This paper attempts to carry out the study of the evolution of intergenerational social mobility in Spain during the 21st century. The methodology applied involves to associate the National Classification of Occupations (CNO-94) with the New International Socio-economic Index of Occupational Status (ISEI-08), in order to establish a socio-economic hierarchy. Afterwards, once the occupational ranking is defined, we use statistic and econometric methods to assess the occupational transitions between fathers and children and to analyse the covariates’ effects on these transitions, including as explanatory variable the children’s educational attainment. Data used corresponds to the 2005 and 2011 Living Condition Survey (INE, 2005, 2011). The results of the study are displayed by distinguishing children according to their birth cohort.
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This dissertation is an analysis of social activism within women’s professional tennis. In the 46 years since the women known as the Original 9 began protesting against the pay inequality between men’s and women’s tennis, subsequent cohorts of women have brought different issues and concerns to women’s tennis, expanding its scope and efforts. Using qualitative research, including interviews with former players and press conference participation at tournaments to access current players, this study shows the lineage of social activism within women’s tennis and the issues, expressions, risks and effects of each cohort. Intersectionality theoretically frames this study, and analyses of performativity appears regularly. Each generational cohort is a chapter of this study. The Original 9 of the Movement Cohort fought for equal prize money. The Bridge Cohort, the era of Evert and Navratilova, continued the Movement Cohort’s push for equal prize money; however, they also ushered in identity politics (including gender, sexuality, and nationality, but with the notable exception of race). The Professional Cohort, the current era, followed the Bridge Cohort and is characterized by its focus on corporatization and mass-marketing. As such, there is a focus among the players on individualism which can seem like a lack of social activism is occurring. However, race, neglected during the Bridge Cohort, emerged during the Professional Cohort. The individualism of this cohort made space for Blackness to show unapologetically, though, within certain constraints. Finally, a few players are working on social justice issues in society at large, as well as trying to institute change within women’s tennis. These players make up the Post-Professional Cohort (or, as Pam Shriver from the Bridge Cohort calls them, “Bridge Throwbacks”). This study shows the evolution of social activism within women’s tennis, as it reflects larger social change. Though bound together as one unified body, the social activism engaged in by each generation focused on different issues, making each generational cohort distinct from the whole of women’s professional tennis.
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Tese de Doutoramento em Biologia Comportamental apresentada ao ISPA - Instituto Universitário
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El presente artículo se centra en la evolución de uno de los principales linajes judeoconversos del reino de Córdoba en la época Moderna, el de los Ramírez. Naturales de Espejo, pronto encontraron en Lucena, la capital del marquesado de Comares, el lugar perfecto para ocultar su pasado y ennoblecerse al lado de su señor. Son protagonistas de este estudio su estrecha relación con el marqués, su deseo de fabricar una nueva memoria familiar, y las estrategias matrimoniales y económicas que les permitieron convertirse en uno de los grupos más poderosos de la oligarquía de Lucena y en uno de los ejemplos paradigmáticos de integración de cristianos nuevos en el territorio andaluz.
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Material suplementar está disponível em: http://journal.frontiersin.org/article/10.3389/fpsyg. 2016.01509
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The World Order is a concept in constant mutation that has lost a lot of what characterized it when it was established with the Peace of Westphalia. The conflicts also went through changes. They lost its State distinctiveness and became dispersed and chaotic due to multipolarization. These two concepts share some connections and both dissociated from their traditional definition. This paper aims to establish a connection between the contemporary World Order and the conflicts evolution. The threats to the stability of the World Order contribute to the current disorder and reflects how the conflicts distanced themselves from the clausewitzian battles. To understand how these threats impact the World Order stability and evince the conflicts evolution two cases of study were selected: the nuclear proliferation in Iran and the crisis in Ukraine. These two examples will help establishing the link between the contemporary World Disorder and the conflicts evolution.
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(ESPAÑOL) La moda es un fenómeno social y cultural que genera un elevado interés entre muchos colectivos. Es también un sector económico generador de actividad y empleo, que influye además en otros sectores y es capaz de crear imagen de país. La llegada de internet y la explosión de la conectividad han desencadenado importantes cambios, de los que el sector de la moda no es ajeno. Así, se han generado nuevos modos de visibilidad para la moda, se han creado nuevos perfiles profesionales, y se han desarrollado nuevos modelos de negocio. Los prescriptores y marcadores de tendencias han dejado de estar en manos de las marcas y los grupos editoriales, para pasar a manos de los propios consumidores, que crean tendencias con la exhibición de sus propios looks. Blogs, bloggers y redes sociales, entre las que destaca Instagram, se han convertido en instrumentos imprescindibles en las estrategias de marketing de las empresas del sector, desencadenándose una gran transformación. Este es precisamente el eje central del presente trabajo: el análisis del proceso de evolución del sector de la moda, desde un punto de vista tanto económico como social.
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In this paper we prove well-posedness for a measure-valued continuity equation with solution-dependent velocity and flux boundary conditions, posed on a bounded one-dimensional domain. We generalize the results of an earlier paper [J. Differential Equations, 259 (2015), pp. 10681097] to settings where the dynamics are driven by interactions. In a forward-Euler-like approach, we construct a time-discretized version of the original problem and employ those results as a building block within each subinterval. A limit solution is obtained as the mesh size of the time discretization goes to zero. Moreover, the limit is independent of the specific way of partitioning the time interval [0, T]. This paper is partially based on results presented in Chapter 5 of [Evolution Equations for Systems Governed by Social Interactions, Ph.D. thesis, Eindhoven University of Technology, 2015], while a number of issues that were still open there are now resolved.
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El presente estudio de caso documenta los planes y actividades relacionadas con el tema de Responsabilidad Social Empresarial que la multinacional colombiana Crepes & Waffles implementa en sus operaciones. El documento contiene una investigación que incluye antecedentes, análisis del sector, temas estadísticos y una entrevista.