120 research outputs found

    An Estimate of Avian Mortality at Communication Towers in the United States and Canada

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    Avian mortality at communication towers in the continental United States and Canada is an issue of pressing conservation concern. Previous estimates of this mortality have been based on limited data and have not included Canada. We compiled a database of communication towers in the continental United States and Canada and estimated avian mortality by tower with a regression relating avian mortality to tower height. This equation was derived from 38 tower studies for which mortality data were available and corrected for sampling effort, search efficiency, and scavenging where appropriate. Although most studies document mortality at guyed towers with steady-burning lights, we accounted for lower mortality at towers without guy wires or steady-burning lights by adjusting estimates based on published studies. The resulting estimate of mortality at towers is 6.8 million birds per year in the United States and Canada. Bootstrapped subsampling indicated that the regression was robust to the choice of studies included and a comparison of multiple regression models showed that incorporating sampling, scavenging, and search efficiency adjustments improved model fit. Estimating total avian mortality is only a first step in developing an assessment of the biological significance of mortality at communication towers for individual species or groups of species. Nevertheless, our estimate can be used to evaluate this source of mortality, develop subsequent per-species mortality estimates, and motivate policy action

    Wire Marking Results in a Small but Significant Reduction in Avian Mortality at Power Lines: A BACI Designed Study

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    10 paginas, 4 figuras y 4 tablesBackground: Collision with electric power lines is a conservation problem for many bird species. Although the implementation of flight diverters is rapidly increasing, few well-designed studies supporting the effectiveness of this costly conservation measure have been published. Methodology/Principal Findings: We provide information on the largest worldwide marking experiment to date, including carcass searches at 35 (15 experimental, 20 control) power lines totalling 72.5 km, at both transmission (220 kV) and distribution (15 kV-45 kV) lines. We found carcasses of 45 species, 19 of conservation concern. Numbers of carcasses found were corrected to account for carcass losses due to removal by scavengers or being overlooked by researchers, resulting in an estimated collision rate of 8.2 collisions per km per month. We observed a small (9.6%) but significant decrease in the number of casualties after line marking compared to before line marking in experimental lines. This was not observed in control lines. We found no influence of either marker size (large vs. small spirals, sample of distribution lines only) or power line type (transmission vs. distribution, sample of large spirals only) on the collision rate when we analyzed all species together. However, great bustard mortality was slightly lower when lines were marked with large spirals and in transmission lines after marking. Conclusions: Our results confirm the overall effectiveness of wire marking as a way to reduce, but not eliminate, bird collisions with power lines. If raw field data are not corrected by carcass losses due to scavengers and missed observations, findings may be biased. The high cost of this conservation measure suggests a need for more studies to improve its application, including wire marking with non-visual devices. Our findings suggest that different species may respond differently to marking, implying that species-specific patterns should be explored, at least for species of conservation concern.We thank A. Garcıa Fernandez and M. Carrasco for their assistance during the field work. We also thank J. Camaño and J. Velasco of HENARSA, and the electric companies Iberdrola, Union Fenosa and Red Electrica de España for their cooperation. S. Young reviewed the English. RB was contracted within the project CGL2008-02567 of the Direccion General de Investigacion, Spanish Ministry of Science and Innovation and later supported by a postdoctoral grant from Junta de Comunidades de Castilla-La Mancha. C. Ponce, C. Palacın, CM and BM were supported by contracts CSICHENARSA. This study was carried out within the Preventive, corrective and compensatory measures to balance the impact of the M-50 and R-2 highways on the population of great bustards and other steppe-land birds in the Important Bird Area Talamanca-Camarma and the Site of Community Importance Cuenca de los rıos Jarama y Henares, supported by a contract HENARSA-CSIC. Additional financial support was provided by project GL2008-02567 of the Direccion General de Investigacion, Spanish Ministry of Science and Innovation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe

    Learning from the UK’s research impact assessment exercise: a case study of a retrospective impact assessment exercise and questions for the future

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    National governments spend significant amounts of money supporting public research. However, in an era where the international economic climate has led to budget cuts, policymakers increasingly are looking to justify the returns from public investments, including in science and innovation. The so-called ‘impact agenda’ which has emerged in many countries around the world is part of this response; an attempt to understand and articulate for the public what benefits arise from the research that is funded. The United Kingdom is the most progressed in implementing this agenda and in 2014 the national research assessment exercise, the Research Excellence Framework, for the first time included the assessment of research impact as a component. For the first time within a dual funding system, funding would be awarded not only on the basis of the academic quality of research, but also on the wider impacts of that research. In this paper we outline the context and approach taken by the UK government, along with some of the core challenges that exist in implementing such an exercise. We then synthesise, together for the first time, the results of the only two national evaluations of the exercise and offer reflections for future exercises both in the UK and internationally

    Tephrochronology

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    Tephrochronology is the use of primary, characterized tephras or cryptotephras as chronostratigraphic marker beds to connect and synchronize geological, paleoenvironmental, or archaeological sequences or events, or soils/paleosols, and, uniquely, to transfer relative or numerical ages or dates to them using stratigraphic and age information together with mineralogical and geochemical compositional data, especially from individual glass-shard analyses, obtained for the tephra/cryptotephra deposits. To function as an age-equivalent correlation and chronostratigraphic dating tool, tephrochronology may be undertaken in three steps: (i) mapping and describing tephras and determining their stratigraphic relationships, (ii) characterizing tephras or cryptotephras in the laboratory, and (iii) dating them using a wide range of geochronological methods. Tephrochronology is also an important tool in volcanology, informing studies on volcanic petrology, volcano eruption histories and hazards, and volcano-climate forcing. Although limitations and challenges remain, multidisciplinary applications of tephrochronology continue to grow markedly

    Factors influencing user acceptance of public sector big open data

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    In recent years Government departments and public/private organizations are becoming increasingly transparent with their data to establish the whole new paradigm of big open data. Increasing research interest arises from the claimed usability of big open data in improving public sector reforms, facilitating innovation, improving supplier and distribution networks and creating resilient supply chains that help improve the efficiency of public services. Despite the advantages of big open data for supply chain and operations management, there is severe shortage of empirical analyses in this field, especially with regards to its acceptance. To address this gap, in this paper we use an extended Technology Acceptance Model (TAM) to empirically examine the factors affecting users’ behavioural intentions towards public sector big open data. We outline the importance of our model for operations and supply chain managers, the limitations of the study, and future research directions

    Knowledge management: a dilemma

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    Coalinga Chrysotile: A Short Fibre, Amphibole Free, Chrysotile: Part V - Lack of Amphibole Asbestos Contamination

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