431 research outputs found

    Phenotypic integration of brain size and head morphology in Lake Tanganyika Cichlids

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    [Background] Phenotypic integration among different anatomical parts of the head is a common phenomenon across vertebrates. Interestingly, despite centuries of research into the factors that contribute to the existing variation in brain size among vertebrates, little is known about the role of phenotypic integration in brain size diversification. Here we used geometric morphometrics on the morphologically diverse Tanganyikan cichlids to investigate phenotypic integration across key morphological aspects of the head. Then, while taking the effect of shared ancestry into account, we tested if head shape was associated with brain size while controlling for the potentially confounding effect of feeding strategy.[Results] The shapes of the anterior and posterior parts of the head were strongly correlated, indicating that the head represents an integrated morphological unit in Lake Tanganyika cichlids. After controlling for phylogenetic non-independence, we also found evolutionary associations between head shape, brain size and feeding ecology.[Conclusions] Geometric morphometrics and phylogenetic comparative analyses revealed that the anterior and posterior parts of the head are integrated, and that head morphology is associated with brain size and feeding ecology in Tanganyikan cichlid fishes. In light of previous results on mammals, our results suggest that the influence of phenotypic integration on brain diversification is a general process.This study was funded through the student exchange support program (scholarship for long-term study abroad) from the Japanese Student Services Organization (JASSO) to M. Tsuboi, a JAE-Doc postdoctoral fellowship from the Consejo Superior de Investigaciones CientĂ­ficas to A. Gonzalez-Voyer and a Swedish Research Council grant to N. Kolm.Peer Reviewe

    Far-Ultraviolet Number Counts on Field Galaxies

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    The far-ultraviolet (FUV) number counts of galaxies constrain the evolution of the star formation rate density of the universe. We report the FUV number counts computed from FUV imaging of several fields including the Hubble Ultra Deep Field, the Hubble Deep Field North, and small areas within the GOODS-North and South fields. These data were obtained with the Hubble Space Telescope (HST) Solar Blind Channel of the Advance Camera for Surveys. The number counts sample an FUV AB magnitude range from 21 to 29 and cover a total area of 15.9 arcmin^2, ~4 times larger than the most recent HST FUV study. Our FUV counts intersect bright FUV Galaxy Evolution Explorer counts at 22.5 mag and they show good agreement with recent semi-analytic models based on dark matter "merger trees" by R. S. Somerville et al. We show that the number counts are ~35% lower than in previous HST studies that use smaller areas. The differences between these studies are likely the result of cosmic variance; our new data cover more lines of sight and more area than previous HST FUV studies. The integrated light from field galaxies is found to contribute between 65.9^(+8)_(–8) and 82.6^(+12)_(–)12 photons s^(–1) cm^(–2) sr^(–1) Å^(–1) to the FUV extragalactic background. These measurements set a lower limit for the total FUV background light

    Far-Ultraviolet Number Counts of Field Galaxies

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    The far-ultraviolet (FUV) number counts of galaxies constrain the evolution of the star-formation rate density of the universe. We report the FUV number counts computed from FUV imaging of several fields including the Hubble Ultra Deep Field, the Hubble Deep Field North, and small areas within the GOODS-North and -South fields. These data were obtained with the Hubble Space Telescope Solar Blind Channel of the Advance Camera for Surveys. The number counts sample a FUV AB magnitude range from 21-29 and cover a total area of 15.9 arcmin^2, ~4 times larger than the most recent HST FUV study. Our FUV counts intersect bright FUV GALEX counts at 22.5 mag and they show good agreement with recent semi-analytic models based on dark matter "merger trees" by Somerville et al. (2011). We show that the number counts are ~35% lower than in previous HST studies that use smaller areas. The differences between these studies are likely the result of cosmic variance; our new data cover more lines of sight and more area than previous HST FUV studies. The integrated light from field galaxies is found to contribute between 65.9 +/-8 - 82.6 +/-12 photons/s/cm^2/sr/angstrom to the FUV extragalactic background. These measurements set a lower limit for the total FUV background light.Comment: Accepted for publication in ApJ, including 34 pages, 6 figures, and 2 table

    Near-Ultraviolet Sources in the Hubble Ultra Deep Field: The Catalog

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    The catalog from the first high-resolution U-band image of the Hubble Ultra Deep Field, taken with Hubble's Wide-Field Planetary Camera 2 through the F300W filter, is presented. We detect 96 U-band objects and compare and combine this catalog with a Great Observatories Origins Deep Survey B-selected catalog that provides B, V, i, and z photometry, spectral types, and photometric redshifts. We have also obtained far-ultraviolet (FUV, 1614 Ă…) data with Hubble's Advanced Camera for Surveys Solar Blind Channel (ACS/SBC) and with GALEX. We detected 31 sources with ACS/SBC, 28 with GALEX/FUV, and 45 with GALEX/NUV. The methods of observations, image processing, object identification, catalog preparation, and catalog matching are presented

    Maximising community wellbeing: Assessing the threats to the benefits communities derive from the marine estate

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    © 2018 The coastal and marine environment is often managed according to the principles of sustainable development, which include environmental, economic, and social dimensions. While each are equally important, social sustainability receives a lower priority in both policy and research. Methodologies for assessing social sustainability are less developed than for environmental and economic sustainability, and there is a lack of data on the social aspects of sustainable development (such as social equity), which constitutes a barrier to understanding social considerations and integrating them into natural resource management. This paper explores a threat and risk assessment to the marine estate in New South Wales, Australia, which identified and categorised both the benefits that communities gain from the marine estate and the threats to those benefits. A broad range of benefits were identified including participation (e.g., socialising and sense of community), enjoyment (e.g., enjoying the biodiversity and beauty), cultural heritage and use, intrinsic and bequest values, the viability of businesses, and direct economic values. Threats to community benefits were categorised as resource use conflict, environmental, governance, public safety, critical knowledge gaps and lack of access. An integrated threat and risk assessment approach found that the priority threats to community benefits were environmental threats (e.g., water pollution), critical knowledge gaps (e.g., inadequate social and economic information), governance (e.g., lack of compliance), resource-use conflict (e.g., anti-social behaviour), and lack of access (e.g., loss of fishing access). Threat and risk assessment is an evidence-based tool that is useful for marine planning because it provides a structured approach to incorporating multiple types of knowledge and enables limited resources to be targeted to the threats identified as being most important to address

    Using a well-being approach to develop a framework for an integrated socio-economic evaluation of professional fishing

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    © 2017 John Wiley & Sons Ltd The principles of Ecologically Sustainable Development and Ecosystem Based Fisheries Management require that fisheries be managed for social as well as environmental and economic objectives. Comprehensive assessments of the success of fisheries in achieving all three objectives are, however, rare. There are three main barriers to achieving integrated assessments of fisheries. Firstly, disciplinary divides can be considered “too hard” to bridge with inherent conflicts between the predominately empirical and deductive traditions of economics and biophysical sciences and the inductive and interpretative approach of much of the social sciences. Secondly, understanding of the social pillar of sustainability is less well developed. And finally, in-depth analysis of the social aspects of sustainability often involves qualitative analysis and there are practical difficulties in integrating this with largely quantitative economic and ecological assessments. This article explores the social well-being approach as a framework for an integrated evaluation of the social and economic benefits that communities in New South Wales, Australia, receive from professional fish harvesting. Using a review of existing literature and qualitative interviews with more than 160 people associated with the fishing industry the project was able to identify seven key domains of community well-being to which the industry contributes. Identification of these domains provided a framework through which industry contributions could be further explored, through quantitative surveys and economic analysis. This framework enabled successful integration of social and economic, and both qualitative and quantitative information in a manner that enabled a comprehensive assessment of the value of the fishery

    Brains and the city: big-brained passerine birds succeed in urban environments

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    Urban regions are among the most humanaltered environments on Earth and they are poised for rapid expansion following population growth and migration. Identifying the biological traits that determine which species are likely to succeed in urbanized habitats is important for predicting global trends in biodiversity. We provide the first evidence for the intuitive yet untested hypothesis that relative brain size is a key factor predisposing animals to successful establishment in cities. We apply phylogenetic mixed modelling in a Bayesian framework to show that passerine species that succeed in colonizing at least one of 12 European cities are more likely to belong to big-brained lineages than species avoiding these urban areas. These data support findings linking relative brain size with the ability to persist in novel and changing environments in vertebrate populations, and have important implications for our understanding of recent trends in biodiversity.Peer Reviewe

    LUT-less Sensorless Control of Synchronous Reluctance Machines using the Locus of Incremental Saliency Ratio Tracking (LIST)

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    This paper deals with the LUT-less sensorless control of synchronous reluctance (SyR) machines at zero and low speed, where LUT-less stands for avoiding the use of flux-map look-up tables (LUTs) or other pre-determined machine parameters. The new signal-injection based control scheme called the Locus of Incremental Saliency ratio Tracking (LIST) is presented, where a pulsating high-frequency voltage component is used for position tracking and a second rotating signal-injection is dedicated to on-line estimating the incremental saliency ratio. A trajectory of constant incremental saliency ratio is used for torque regulation, resulting in stable control at all operating conditions, including overload. This despite the effect of cross-saturation, which is known to introduce position error and harm the control stability progressively with the load. The proposed scheme is validated experimentally on a 1.1 kW SyR machine test-bench. Alternative LUT-less torque control laws are investigated, and their stability limits put in evidence using convergence analysis and experiments

    The GALEX Ultraviolet Virgo Cluster Survey (GUViCS) III. The Ultraviolet Source Catalogs

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    In this paper we introduce the deepest and most extensive ultraviolet extragalactic source catalogs of the Virgo Cluster area to date. Archival and targeted GALEX imaging is compiled and combined to provide the deepest possible coverage over ~120 deg^2 in the NUV (lambda_eff=2316 angstroms) and ~40 deg^2 in the FUV (lambda_eff=1539 angstroms) between 180 deg <= R.A. <= 195 deg and 0 deg <= Decl. <= 20 deg. We measure the integrated photometry of 1770 extended UV sources of all galaxy types and use GALEX pipeline photometry for 1,230,855 point-like sources in the foreground, within, and behind the cluster. Extended source magnitudes are reliable to m_UV ~22, showing ~0.01 sigma difference from their asymptotic magnitudes. Point-like source magnitudes have a 1 sigma standard deviation within ~0.2 mag down to m_uv ~23. The point-like source catalog is cross-matched with large optical databases and surveys including the SDSS DR9 (> 1 million Virgo Cluster sources), the Next Generation Virgo Cluster Survey (NGVS; >13 million Virgo Cluster sources), and the NED (~30,000 sources in the Virgo Cluster). We find 69% of the entire UV point-like source catalog has a unique optical counterpart, 11% of which are stars and 129 are Virgo cluster members neither in the VCC nor part of the bright CGCG galaxy catalog (i.e., m_pg < 14.5). These data are collected in four catalogs containing the UV extended sources, the UV point-like sources, and two catalogs each containing the most relevant optical parameters of UV-optically matched point-like sources for further studies from SDSS and NGVS. The GUViCS catalogs provide a unique set of data for future works on UV and multiwavelength studies in the cluster and background environments.Comment: 35 pages, 24 figures, 15 tables, Accepted for publication in A&
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