234 research outputs found

    A global cline in a colour polymorphism suggests a limited contribution of gene flow towards the recovery of a heavily exploited marine mammal

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    Evaluating how populations are connected by migration is important for understanding species resilience because gene flow can facilitate recovery from demographic declines. We therefore investigated the extent to which migration may have contributed to the global recovery of the Antarctic fur seal (Arctocephalus gazella), a circumpolar distributed marine mammal that was brought to the brink of extinction by the sealing industry in the eighteenth and nineteenth centuries. It is widely believed that animals emigrating from South Georgia, where a relict population escaped sealing, contributed to the re-establishment of formerly occupied breeding colonies across the geographical range of the species. To investigate this, we interrogated a genetic polymorphism (S291F) in the melanocortin 1 receptor gene, which is responsible for a cream-coloured phenotype that is relatively abundant at South Georgia and which appears to have recently spread to localities as far afield as Marion Island in the sub-Antarctic Indian Ocean. By sequencing a short region of this gene in 1492 pups from eight breeding colonies, we showed that S291F frequency rapidly declines with increasing geographical distance from South Georgia, consistent with locally restricted gene flow from South Georgia mainly to the South Shetland Islands and Bouvetøya. The S291F allele was not detected farther afield, suggesting that although emigrants from South Georgia may have been locally important, they are unlikely to have played a major role in the recovery of geographically more distant populations

    Modelling Hierarchy and Specialization of a System of Cities from an Evolutionary Perspective on Firms' Interactions

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    Despite their great diversity, most systems of cities show remarkably similar patterns when comparing the size distribution and the economic specialization of their constitutive cities. The universality of these patterns sparked the interest of geographers, economists and physicists. However, until now, no economic model has relied on a micro-based and evolutionary approach to reproduce these regularities. In this chapter, we intend to fill this gap by proposing a model where the micro dynamics of localized firms generate the two macro regularities of size distribution and economic specialization. The model is based on boundedly rational firms’ competition and path dependent innovation. We discuss the possible emergence of macro properties from these micro behaviors of firms

    Digital strategies to a local cultural tourism development: Project e-Carnide

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    Digital humanities and smart economy strategies are being seen as an important link between tourism and cultural heritage, as they may contribute to differentiate the audiences and to provide different approaches. Carnide is a peripheral neighbourhood of Lisbon with an elderly population, visible traces of rurality, and strong cultural and religious traditions. The academic project e-Carnide concerns its tangible and intangible cultural heritage and the data dissemination through a website and a mobile app, with textual and visual information. The project aims to analyse the impact of technological solutions on cultural tourism development in a sub-region, involving interdisciplinary research in heritage, history of art, ethnography, design communication and software engineering and the collaboration between the university and local residents in a dynamic and innovative way. Framed by a theoretical approach about the role of smart economy for the cultural tourism development in peripheral areas, this paper focuses on a case study, dealing with documents, interviews and observations, in order to understand how the e-Carnide project evolves. The study comprises an analysis about the strengths, weaknesses, opportunities and threats (SWOT analysis) of the project in view to realize its social and cultural implications and to appreciate how it can be applied in other similar and enlarged projects. Results of the research indicates that the new technological strategies can promote the involvement of the population in the knowledge of its own heritage as a factor of cultural and creative tourism development centred on an authentic and immersive experience of the places

    Machi: Neighborhood and Small Town—The Foundation for Urban Transformation in Japan

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    The term machi, signifying both neighborhood and small town, is a key element for understanding Japanese urban form and city planning. After tracing the origins of the term, this article explores the historic and contemporary significance of the concept and its particular spatial and socioeconomic forms. The article then argues that the concept of machi influenced the ways in which Japanese planners picked up foreign concepts through the nineteenth and particularly the twentieth century, absorbing some ideas and rejecting others. Building on their perception of the city as composed of urban units that allowed for planning in patchwork patterns, leading Japanese planners carefully selected models—independently of international appreciation—making, for example, the book The New Town by the German planner Gottfried Feder a standard reference. The article concludes by arguing that foreign observers must understand the concept of machi to comprehend contemporary Japanese neighborhoods, city life, and urban forms

    A global cline in a colour polymorphism suggests a limited contribution of gene flow towards the recovery of a heavily exploited marine mammal

    Get PDF
    Evaluating how populations are connected by migration is important for understanding species resilience because gene flow can facilitate recovery from demographic declines. We therefore investigated the extent to which migration may have contributed to the global recovery of the Antarctic fur seal (Arctocephalus gazella), a circumpolar distributed marine mammal that was brought to the brink of extinction by the sealing industry in the eighteenth and nineteenth centuries. It is widely believed that animals emigrating from South Georgia, where a relict population escaped sealing, contributed to the re-establishment of formerly occupied breeding colonies across the geographical range of the species. To investigate this, we interrogated a genetic polymorphism (S291F) in the melanocortin 1 receptor gene, which is responsible for a cream-coloured phenotype that is relatively abundant at South Georgia and which appears to have recently spread to localities as far afield as Marion Island in the sub-Antarctic Indian Ocean. By sequencing a short region of this gene in 1492 pups from eight breeding colonies, we showed that S291F frequency rapidly declines with increasing geographical distance from South Georgia, consistent with locally restricted gene flow from South Georgia mainly to the South Shetland Islands and Bouvetøya. The S291F allele was not detected farther afield, suggesting that although emigrants from South Georgia may have been locally important, they are unlikely to have played a major role in the recovery of geographically more distant populations.J.I.H., E.B., A.J.P., E.H., L.M.B., C.K., F.C., N.K., B.F. and A.M. were funded by Deutsche Forschungsgemeinschaft (DFG) standard grant no. (HO 5122/3-1) and this research was also partly funded by the DFG as part of the SFB TRR 212 (NC3, project A01). A.C.C., C.L., K.M.K. and A.L. were funded by projects from the Norwegian Antarctic Research Expeditions. The Department of Science and Technology of South Africa provided funding through the National Research Foundation (NRF) for Marion Island research. Support for the publication fee was provided by the DFG and the Open Access Publication Funds of Bielefeld University.http://rsos.royalsocietypublishing.orgam2019Mammal Research InstituteZoology and Entomolog

    Economies of Scale: A Survey of the Empirical Literature

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    a multi scalar approach to long term dynamics spatial relations and economic networks of roman secondary settlements in italy and the ombrone valley system southern tuscany towards a model

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    In Roman landscapes, the particular sites defined as secondary settlements (also known as vici/villages, minor centres, agglomerations secondaires and/or stationes/mansiones) have played an 'intermediary' role between the cities and other rural structures (villae/farms), linked to medium- and long-distance economic and commercial trajectories. The aim of this paper is to apply a multi-scalar approach to model their long-term spatial relationships and connectivity with the Mediterranean exchange network. On the macro-scale, we have analysed a sample of 219 reviewed sites to understand the diachronic trends and spatial dynamics of attraction/proximity to significant elements of the landscape such as towns, roads, rivers and coastline. The Ombrone Valley (Tuscany, Italy) represents a micro-scale case study of a complex system, in which the imported pottery (amphorae, African Red Slip ware, ingobbiata di rosso) found in the vicus/mansio of Santa Cristina in Caio, the Roman villa of La Befa and the town of Siena (Saena Iulia) provided diagnostic 'macroeconomic' perspectives. The results show how the secondary settlements occupied a nodal position in the Roman landscape in terms of resilience (long period of occupation until the Early Middle Ages) and spatial organization with a close relationship to natural and anthropic infrastructures and trade functions linked to Mediterranean routes
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