868 research outputs found

    Every partridge counts, successful techniques used in the captive conservation breeding programme for wild grey partridge in Ireland

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    Between 1998 and 2001 the last remaining wild grey partridge (Perdix perdix) population in Ireland faced imminent extinction with an estimated spring population of 4–6 pairs, and an autumn population of 22–24 birds. A captive breeding programme began in 2002 with two pairs of grey partridge. In the most successful year in 2010, 39 pairs produced a total of 510 chicks. Average chick survival rate was 65.13%. At 88.9 the highest chick survival rate was achieved in 2011. Chick survival of parent–reared birds in captivity is defined by the number of juveniles surviving at age six weeks: similar to estimations used for wild populations of grey partridge. Family coveys were released in late summer to early autumn. In most instances the entire family cohort was released as one unit. However, in coveys of twenty or above, an average of five parent–reared poults were held back as breeding stock for the following year. In early spring of the following year, birds held back were paired with single males or females trapped from the wild. The techniques we used were traditional and labour intensive but highly effective. We recommend that other grey partridge recovery projects should consider captive breeding using the methods employed in this programme to compliment other game management methods used

    Statistics of an Unstable Barotropic Jet from a Cumulant Expansion

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    Low-order equal-time statistics of a barotropic flow on a rotating sphere are investigated. The flow is driven by linear relaxation toward an unstable zonal jet. For relatively short relaxation times, the flow is dominated by critical-layer waves. For sufficiently long relaxation times, the flow is turbulent. Statistics obtained from a second-order cumulant expansion are compared to those accumulated in direct numerical simulations, revealing the strengths and limitations of the expansion for different relaxation times.Comment: 23 pages, 8 figures. Version to appear in J. Atmos. Sc

    Extrasolar Planet Transits Observed at Kitt Peak National Observatory

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    We obtained J-, H- and JH-band photometry of known extrasolar planet transiting systems at the 2.1-m Kitt Peak National Observatory Telescope using the FLAMINGOS infrared camera between October 2008 and October 2011. From the derived lightcurves we have extracted the mid-transit times, transit depths and transit durations for these events. The precise mid-transit times obtained help improve the orbital periods and also constrain transit-time variations of the systems. For most cases the published system parameters successfully accounted for our observed lightcurves, but in some instances we derive improved planetary radii and orbital periods. We complemented our 2.1-m infrared observations using CCD z'-band and B-band photometry (plus two Hydrogen Alpha filter observations) obtained with the Kitt Peak Visitor's Center telescope, and with four H-band transits observed in October 2007 with the NSO's 1.6-m McMath-Pierce Solar Telescope. The principal highlights of our results are: 1) our ensemble of J-band planetary radii agree with optical radii, with the best-fit relation being: (Rp/R*)J = 0.0017 + 0.979 (Rp/R*)optical, 2) We observe star spot crossings during the transit of WASP-11/HAT-P-10, 3) we detect star spot crossings by HAT-P-11b (Kepler-3b), thus confirming that the magnetic evolution of the stellar active regions can be monitored even after the Kepler mission has ended, and 4) we confirm a grazing transit for HAT-P-27/WASP-40. In total we present 57 individual transits of 32 known exoplanet systems.Comment: 33 pages, 6 figures, accepted in Publications of the Astronomical Society of the Pacifi

    New strategies for sustainable fisheries management: A case study of Atlantic salmon

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    This briefing paper considers the alarming declines in fish stocks in recent years, and how holistic, integrated approaches can help manage fish stocks within biologically sustainable limits. Using Atlantic salmon as a case study, the authors highlight the challenges facing fisheries management and conservation, and the implications for policy and management

    Contrasting responses of mean and extreme snowfall to climate change

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    Snowfall is an important element of the climate system, and one that is expected to change in a warming climate. Both mean snowfall and the intensity distribution of snowfall are important, with heavy snowfall events having particularly large economic and human impacts. Simulations with climate models indicate that annual mean snowfall declines with warming in most regions but increases in regions with very low surface temperatures. The response of heavy snowfall events to a changing climate, however, is unclear. Here I show that in simulations with climate models under a scenario of high emissions of greenhouse gases, by the late twenty-first century there are smaller fractional changes in the intensities of daily snowfall extremes than in mean snowfall over many Northern Hemisphere land regions. For example, for monthly climatological temperatures just below freezing and surface elevations below 1,000 metres, the 99.99th percentile of daily snowfall decreases by 8% in the multimodel median, compared to a 65% reduction in mean snowfall. Both mean and extreme snowfall must decrease for a sufficiently large warming, but the climatological temperature above which snowfall extremes decrease with warming in the simulations is as high as −9 °C, compared to −14 °C for mean snowfall. These results are supported by a physically based theory that is consistent with the observed rain–snow transition. According to the theory, snowfall extremes occur near an optimal temperature that is insensitive to climate warming, and this results in smaller fractional changes for higher percentiles of daily snowfall. The simulated changes in snowfall that I find would influence surface snow and its hazards; these changes also suggest that it may be difficult to detect a regional climate-change signal in snowfall extremes.National Science Foundation (U.S.) (Grant AGS-1148594)United States. National Aeronautics and Space Administration (ROSES Grant 09-IDS09-0049

    Text Line Segmentation of Historical Documents: a Survey

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    There is a huge amount of historical documents in libraries and in various National Archives that have not been exploited electronically. Although automatic reading of complete pages remains, in most cases, a long-term objective, tasks such as word spotting, text/image alignment, authentication and extraction of specific fields are in use today. For all these tasks, a major step is document segmentation into text lines. Because of the low quality and the complexity of these documents (background noise, artifacts due to aging, interfering lines),automatic text line segmentation remains an open research field. The objective of this paper is to present a survey of existing methods, developed during the last decade, and dedicated to documents of historical interest.Comment: 25 pages, submitted version, To appear in International Journal on Document Analysis and Recognition, On line version available at http://www.springerlink.com/content/k2813176280456k3

    Incomplete Punishment Networks in Public Goods Games: Experimental Evidence

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    Abundant evidence suggests that high levels of contributions to public goods can be sustained through self-governed monitoring and sanctioning. This experimental study investigates the effectiveness of decentralized sanctioning institutions in alternative punishment networks. Our results show that the structure of punishment network significantly affects allocations to the public good. In addition, we observe that network configurations are more important than punishment capacities for the levels of public good provision, imposed sanctions and economic efficiency. Lastly, we show that targeted revenge is a major driver of anti-social punishment

    Special and inclusive education in the Republic of Ireland: reviewing the literature from 2000 to 2009

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    Provision for pupils with special educational needs in Ireland has undergone considerable change and review in the first decade of the twenty first century. In response to international demands for a more equitable education system which recognises diversity and considers how schools might address the needs of pupils who have been previously marginalised, Irish legislation has focused upon the development of inclusive schooling. Researchers during this period have endeavoured to understand how responses to the demand for greater inclusion have impacted upon the perceived need for change. This paper reviews the research literature for this period and identifies four key themes under which research has been conducted. The literature pertaining to these themes is explored and a possible agenda for future researchers identifie

    OpenFermion: The Electronic Structure Package for Quantum Computers

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    Quantum simulation of chemistry and materials is predicted to be an important application for both near-term and fault-tolerant quantum devices. However, at present, developing and studying algorithms for these problems can be difficult due to the prohibitive amount of domain knowledge required in both the area of chemistry and quantum algorithms. To help bridge this gap and open the field to more researchers, we have developed the OpenFermion software package (www.openfermion.org). OpenFermion is an open-source software library written largely in Python under an Apache 2.0 license, aimed at enabling the simulation of fermionic models and quantum chemistry problems on quantum hardware. Beginning with an interface to common electronic structure packages, it simplifies the translation between a molecular specification and a quantum circuit for solving or studying the electronic structure problem on a quantum computer, minimizing the amount of domain expertise required to enter the field. The package is designed to be extensible and robust, maintaining high software standards in documentation and testing. This release paper outlines the key motivations behind design choices in OpenFermion and discusses some basic OpenFermion functionality which we believe will aid the community in the development of better quantum algorithms and tools for this exciting area of research.Comment: 22 page
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