247 research outputs found

    Restricted gene flow and genetic drift in recently fragmented populations of an endangered steppe bird

    Get PDF
    Identifying the genetic processes derived from habitat fragmentation is critical for the conservation of endangered species. We conducted an integrated analysis of genetic patterns in the endangered Dupont’s lark (Chersophilus duponti), a circum-Mediterranean songbird threatened by the loss and fragmentation of natural steppes in recent decades. After sampling all the remaining Spanish populations and the two clos¬est North African ones, we found that the Mediterranean Sea acts as a major barrier against gene flow and that recent habitat fragmentation is isolating Spanish populations at different spatial scales. While we found a historical signal of gene flow among Spanish regions, a coalescent model supported that the ancestral panmictic population is evolving into several different units in the absence of current gene flow, genetic drift being more intense in the smaller and more isolated populations. Moreover, small-scale spa¬tial autocorrelation analyses showed that genetic differentiation is also acting within populations. The spatial genetic structure, significant levels of inbreeding and high relatedness within patches raise con¬cerns on the viability of most of the extant populations. We highlight the urgency for steppe patches to be protected, expanded and reconnected, considering the genetic clusters identified here rather than the previously considered eco-geographic regions occupied by the species. Meanwhile, translocations could be considered as a complementary, faster management action to attenuate the crowding and genetic effects of population fragmentation and the extinction risk of small populations without compromising the current local adaptations, culture diversity and genetic clusters already known for the species.Peer Reviewe

    Статистические методы и анализ проблем управления качеством

    Get PDF
    В работе И.В. Плотниковой и Л.А. Редько проведен анализ проблем управления качеством на приборостроительном предприятии с использованием статистических методов. Определены основные значимые факторы появления несоответствий

    Rethinking 'Progress': an Evaluation of the Wellington Region Genuine Progress Index

    Get PDF
    There is widespread and long-running discontent with the Gross Domestic Product (GDP) as a measure of progress for society. A number of alternative measures have been proposed, including the Genuine Progress Index (GPI). A GPI has been developed by local government in the Wellington region (New Zealand) to facilitate a rethinking of conventional notions of 'progress'. The Wellington Region GPI (WRGPI) is modelled upon the Nova Scotia GPI, which is a pluralistic index consisting of environmental, social, economic and cultural indicators with either physical or monetary values. The study explores a 'good practice' approach to public participation in the development of the GPI, and provides an overview of the context within which it fits. A synergistic link was found between the Nova Scotia GPI framework and the framework provided by the Local Government Act community outcomes process. Despite this synergy, and the commitment to the GPI on the part of local authorities, a number of challenges emerged from the context. These include the poor integration of the existing community outcomes into institutional decision-making, a weak institutional commitment to the economic valuation procedure of the GPI, and the desire on the part of the present local government minister to reduce the scope of local government. In light of these challenges, a 'good practice' approach has been developed with a normative component: deliberation, influence & inclusion, and a methodological component: purpose, process & context. Deliberation was stressed as a particularly important tool to facilitate institutional and social learning around the WRGPI and to build the value case and a constituency for the WRGPI across the local authorities and community, and therefore increasing the likelihood that conventional notions of 'progress' will be replaced with more holistic ones. While this case study provides insights into the challenge of integrating a GPI into local governance, it is still too early to judge whether the initiative will emerge as a viable alternative to the GDP for the Wellington region

    Neutron diffraction study and theoretical analysis of the antiferromagnetic order and diffuse scattering in the layered Kagome system CaBaCo2_2Fe2_2O7_7

    Get PDF
    The hexagonal swedenborgite, CaBaCo2_2Fe2_2O7_7, is a chiral frustrated antiferromagnet, in which magnetic ions form alternating Kagome and triangular layers. We observe a long range 3×3\sqrt{3} \times \sqrt{3} antiferromagnetic order setting in below TN=160T_N = 160 K by neutron diffraction on single crystals of CaBaCo2_2Fe2_2O7_7. Both magnetization and polarized neutron single crystal diffraction measurements show that close to TNT_N spins lie predominantly in the abab-plane, while upon cooling the spin structure becomes increasingly canted due to Dzyaloshinskii-Moriya interactions. The ordered structure can be described and refined within the magnetic space group P31mP31m^\prime. Diffuse scattering between the magnetic peaks reveals that the spin order is partial. Monte Carlo simulations based on a Heisenberg model with two nearest-neighbor exchange interactions show a similar diffuse scattering and coexistence of the 3×3\sqrt{3} \times \sqrt{3} order with disorder. The coexistence can be explained by the freedom to vary spins without affecting the long range order, which gives rise to ground-state degeneracy. Polarization analysis of the magnetic peaks indicates the presence of long-period cycloidal spin correlations resulting from the broken inversion symmetry of the lattice, in agreement with our symmetry analysis.Comment: 12 pages, 13 figures, 2 table

    The development of data measuring systems by means of a mobile complex "Vibroregistrator-M2"

    Get PDF
    Статья посвящена вопросам развития информационно-измерительных систем на базе гидравлических агрегатов. Цель работы - создание и апробация гидравлического стенда для вибродиагностики элементов технологического оборудования посредством мобильного диагностического комплекса "Виброрегистратор-М2".The article is devoted to the development of information-measuring systems based on hydraulic units. The purpose of the work is to create and test a hydraulic stand for vibration diagnostics of process equipment elements by means of a mobile diagnostic complex "Vibroregistrator - M2"
    corecore