62 research outputs found

    The Gambian Epauletted Fruit Bat Shows Increased Genetic Divergence in the Ethiopian Highlands and in an Area of Rapid Urbanisation

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    The Gambian epauletted fruit bat (Epomophorus gambianus) is an abundant species that roosts in both urban and rural settings. The possible role of E. gambianus as a reservoir host of zoonotic diseases underlines the need to better understand the species movement patterns. So far, neither observational nor phylogenetic studies have identified the dispersal range or behavior of this species. Comparative analyses of mitochondrial and nuclear markers from 20 localities across the known distribution of E. gambianus showed population panmixia, except for the populations in Ethiopia and southern Ghana (Accra and Ve‐Golokwati). The Ethiopian population may be ancestral and is highly divergent to the species across the rest of its range, possibly reflecting isolation of an ancient colonization along an east–west axis. Mitochondrial haplotypes in the Accra population display a strong signature of a past bottleneck event; evidence of either an ancient or recent bottleneck using microsatellite data, however, was not detected. Demographic analyses identified population expansion in most of the colonies, except in the female line of descent in the Accra population. The molecular analyses of the colonies from Ethiopia and southern Ghana show gender dispersal bias, with the mitochondrial DNA fixation values over ten times those of the nuclear markers. These findings indicate free mixing of the species across great distances, which should inform future epidemiological studies

    Phylogeography and demographic history of Epomophorus gambianus: contrasting nuclear and mitochondrial DNA

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    The Gambian epauletted fruit bat (Epomophorus gambianus) is an abundant species that roosts in both urban and rural settings. The possible role of E. gambianus as a reservoir host of zoonotic diseases underlines the need to better understand the species movement patterns. So far, neither observational nor phylogenetic studies have identified the dispersal range or behavior of this species. Comparative analyses of mitochondrial and nuclear markers from 20 localities across the known distribution of E. gambianus showed population panmixia, except for the populations in Ethiopia and southern Ghana (Accra and Ve‐Golokwati). The Ethiopian population may be ancestral and is highly divergent to the species across the rest of its range, possibly reflecting isolation of an ancient colonization along an east–west axis. Mitochondrial haplotypes in the Accra population display a strong signature of a past bottleneck event; evidence of either an ancient or recent bottleneck using microsatellite data, however, was not detected. Demographic analyses identified population expansion in most of the colonies, except in the female line of descent in the Accra population. The molecular analyses of the colonies from Ethiopia and southern Ghana show gender dispersal bias, with the mitochondrial DNA fixation values over ten times those of the nuclear markers. These findings indicate free mixing of the species across great distances, which should inform future epidemiological studies

    Post-glacial colonisation of Europe by the wood mouse, Apodemus sylvaticus : evidence of a northern refugium and dispersal with humans

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    The wood mouse Apodemus sylvaticus is an opportunistic rodent that is found throughout most of the European mainland. It is present on many islands around the margins of the continent and in northern Africa. The species has been the subject of previous phylogeographic studies but these have focussed on the more southerly part of its range. A substantial number of new samples, many of them from the periphery of the species’ range, contribute to an exceptional dataset comprising 981 mitochondrial cytochrome b sequences. These new data provide sufficient resolution to transform our understanding of the species’ survival through the last glaciation and its subsequent re-colonisation of the continent. The deepest genetic split we found is in agreement with previous studies and runs from the Alps to central Ukraine, but we further distinguish two separate lineages in wood mice to the north and west of this line. It is likely that this part of Europe was colonised from two refugia, putatively located in the Iberian peninsula and the Dordogne or Carpathian region. The wood mouse therefore joins the growing number of species with extant populations that appear to have survived the Last Glacial Maximum in northern refugia, rather than solely in traditionally recognised refugial locations in the southern European peninsulas. Furthermore, the existence of a northern refugium for the species was predicted in a study of mitochondrial variation in a specific parasite of the wood mouse, demonstrating the potential value of data from parasites to phylogeographic studies. Lastly, the presence of related haplotypes in widely disparate locations, often on islands or separated by substantial bodies of water, demonstrates the propensity of the wood mouse for accidental human-mediated transport

    Context-based storage management for wearable and portable devices

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    In our information-rich world, managing the data we collect is becoming a significant bottleneck for users. This issue has triggered considerable research in so-called semantic file systems, relying on the attachment of meta-data to files. Such data is useful for dynamically arranging files in virtual directories, according to the user's request or task at hand. However, current research typically concerns the desktop and little work has been done taking into account mobile devices, which in addition to being generators of data themselves are now also capable of carrying significant amounts of information. In this paper we discuss how context information can be exploited to attach semantics to files residing on portable devices, and we show how such information can be used by the storage system itself to enhance data management while on the move. We also describe a storage framework which integrates smoothly with semantic file systems by facilitating automatic annotation of files generated by portables, as well as by exploiting this information to better integrate with infrastructure data stores. © Springer-Verlag Berlin Heidelberg 2005

    OmniStore: A system for ubiquitous personal storage management

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    As personal area networking becomes a reality, the collective management of storage in portable devices such as mobile phones, cameras and music players will grow in importance. The increasing wireless communication capability of such devices makes it possible for them to interact with each other and implement more advanced storage functionality. This paper introduces OmniStore, a system which employs a unified data management approach that integrates portable and backend storage, but also exhibits self-organizing behavior through spontaneous device collaboration. © 2006 IEEE

    High-throughput sockets over RDMA for the intel xeon phi coprocessor

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    In this paper we describe the design, implementation and performance of Trans4SCIF, a user-level socket-like transport library for the Intel Xeon Phi coprocessor. Trans4SCIF library is primarily intended for high-throughput applications. It uses RDMA transfers over the native SCIF support, in a way that is transparent for the application, which has the illusion of using conventional stream sockets. We also discuss the integration of Trans4SCIF with the ZeroMQ messaging library, used extensively by several applications running at CERN. We show that this can lead to a substantial, up to 3x, increase of application throughput compared to the default TCP/IP transport option. © Springer International Publishing AG 2017

    Exploiting co-location history for efficient service selection in ubiquitous computing systems

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    As the ubiquitous computing vision materializes, the number and diversity of digital elements in our environment increases. Computing capability comes in various forms and is embedded in different physical objects, ranging from miniature devices such as human implants and tiny sensor particles, to large constructions such as vehicles and entire buildings. The number of possible interactions among such elements, some of which may be invisible or offer similar functionality, is growing fast so that it becomes increasingly hard to combine or select between them. Mechanisms are thus required for intelligent matchmaking that will achieve controlled system behavior, yet without requiring the user to continuously input desirable options in an explicit manner. In this paper we argue that information about the colocation relationship of computing elements is quite valuable in this respect and can be exploited to guide automated service selection with minimal or no user involvement. We also discuss the implementation of such mechanism that is part of our runtime system for smart objects. © 2005 IEEE
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