86 research outputs found

    Terrestrial impact structures as geoheritage: an assessment method of their scientific value and its application to Brazil

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    Terrestrial impact structures are geological and geomorphological features with particular importance to understand the history and evolution of the planet. Impact structures are scattered around the world but in many countries these features are under threat, essentially due to anthropic factors. Impact structures with higher scienti c value should be considered as geological heritage and, consequently, be subjected to geoconservation strategies. In order to select the most important impact structures to be properly conserved and managed, this paper proposes a quantitative assessment method of the scienti c value of these structures. The eight Brazilian impact structures were used to test this method that has the potential to be applied to any geological context in any country. The structures known as Araguainha Dome-MT and Serra da Cangalha-TO reached a higher scienti c value, which justi es the need to develop geoconservation strategies and a proper management.The Conselho Nacional de Pesquisa e Desenvolvimento (CNPq / National Council for Research and Development) and the Programa Ciências sem Fronteiras / Science Without Borders Programme are acknowledged for the support of the postdoctoral grant No 233209/2013-1 of the 1st author. The work was co-funded by the European Union through the European Regional Development Fund, based on COMPETE 2020 (Programa Operacional da Competitividade e Internacionalização), project ICT (UID/ GEO/04683/2013) with reference POCI-01-0145- FEDER-007690 and Portuguese funds provided by Fundação para a Ciência e Tecnologia.info:eu-repo/semantics/publishedVersio

    Inventory and quantitative assessment of geosites and geodiversity sites: a review

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    "Published online: 15 January 2015"The inventory and quantitative assessment of the most valuable occurrences of geodiversity are essential steps in any geoconservation strategy and in the establishment of priorities in site management. Despite the existence of many site inventories applied to different scales (countries, municipalities, parks, etc.), the criteria used for their selection are often unclear and poorly defined. This paper proposes a new approach to the concepts of geosite and geodiversity site and reviews the procedures used in the development of a systematic site inventory applied to different scales and values. Procedures to achieve a numerical evaluation of the value and degradation risk of sites are reviewed and new criteria are proposed. Finally, guidelines are presented, bearing in mind the preparation of effective geodiversity inventories, to support geoparks’ strategies. This paper aims to contribute to a better understanding and use of the above-mentioned concepts, which are essential for the implementation of geoconservation actions worldwide.The author thanks Diamantino Pereira, Flavia Lima, and Paulo Pereira for fruitful discussions and insights; Teresa Mota for the English revision; and the reviewers for significant improvements of the first submitted version. This paper results of the research done at the University of Minho and at the Geology Centre of the University of Porto, partially founded by the Foundation for Science and Technology (Portugal), strategic project with reference PEst-OE/CTE/UI0039/2014

    Lithic technological responses to Late Pleistocene glacial cycling at Pinnacle Point Site 5-6, South Africa

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    There are multiple hypotheses for human responses to glacial cycling in the Late Pleistocene, including changes in population size, interconnectedness, and mobility. Lithic technological analysis informs us of human responses to environmental change because lithic assemblage characteristics are a reflection of raw material transport, reduction, and discard behaviors that depend on hunter-gatherer social and economic decisions. Pinnacle Point Site 5-6 (PP5-6), Western Cape, South Africa is an ideal locality for examining the influence of glacial cycling on early modern human behaviors because it preserves a long sequence spanning marine isotope stages (MIS) 5, 4, and 3 and is associated with robust records of paleoenvironmental change. The analysis presented here addresses the question, what, if any, lithic assemblage traits at PP5-6 represent changing behavioral responses to the MIS 5-4-3 interglacial-glacial cycle? It statistically evaluates changes in 93 traits with no a priori assumptions about which traits may significantly associate with MIS. In contrast to other studies that claim that there is little relationship between broad-scale patterns of climate change and lithic technology, we identified the following characteristics that are associated with MIS 4: increased use of quartz, increased evidence for outcrop sources of quartzite and silcrete, increased evidence for earlier stages of reduction in silcrete, evidence for increased flaking efficiency in all raw material types, and changes in tool types and function for silcrete. Based on these results, we suggest that foragers responded to MIS 4 glacial environmental conditions at PP5-6 with increased population or group sizes, 'place provisioning', longer and/or more intense site occupations, and decreased residential mobility. Several other traits, including silcrete frequency, do not exhibit an association with MIS. Backed pieces, once they appear in the PP5-6 record during MIS 4, persist through MIS 3. Changing paleoenvironments explain some, but not all temporal technological variability at PP5-6.Social Science and Humanities Research Council of Canada; NORAM; American-Scandinavian Foundation; Fundacao para a Ciencia e Tecnologia [SFRH/BPD/73598/2010]; IGERT [DGE 0801634]; Hyde Family Foundations; Institute of Human Origins; National Science Foundation [BCS-9912465, BCS-0130713, BCS-0524087, BCS-1138073]; John Templeton Foundation to the Institute of Human Origins at Arizona State Universit

    Screening for latent tuberculosis infection among undocumented immigrants in Swiss healthcare centres; a descriptive exploratory study

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    BACKGROUND: Migration is one of the major causes of tuberculosis in developed countries. Undocumented patients are usually not screened at the border and are not covered by a health insurance increasing their risk of developing the disease unnoticed. Urban health centres could help identify this population at risk. The objective of this study is to assess the prevalence of latent tuberculosis infection (LTBI) and adherence to preventive treatment in a population of undocumented immigrant patients. METHODS: All consecutive undocumented patients that visited two urban healthcare centres for vulnerable populations in Lausanne, Switzerland for the first time were offered tuberculosis screening with an interferon-gamma assay. Preventive treatment was offered if indicated. Adherence to treatment was evaluated monthly over a nine month period. RESULTS: Of the 161 participants, 131 (81.4%) agreed to screening and 125 had complete examinations. Twenty-four of the 125 patients (19.2%; CI95% 12.7;27.2) had positive interferon-gamma assay results, two of which had active tuberculosis. Only five patients with LTBI completed full preventive treatments. Five others initiated the treatment but did not follow through. CONCLUSION: Screening for tuberculosis infection in this hard-to-reach population is feasible in dedicated urban clinics, and the prevalence of LTBI is high in this vulnerable population. However, the low adherence to treatment is an important public health concern, and new strategies are needed to address this problem

    The genetic epidemiology of joint shape and the development of osteoarthritis

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    Congruent, low-friction relative movement between the articulating elements of a synovial joint is an essential pre-requisite for sustained, efficient, function. Where disorders of joint formation or maintenance exist, mechanical overloading and osteoarthritis (OA) follow. The heritable component of OA accounts for ~ 50% of susceptible risk. Although almost 100 genetic risk loci for OA have now been identified, and the epidemiological relationship between joint development, joint shape and osteoarthritis is well established, we still have only a limited understanding of the contribution that genetic variation makes to joint shape and how this modulates OA risk. In this article, a brief overview of synovial joint development and its genetic regulation is followed by a review of current knowledge on the genetic epidemiology of established joint shape disorders and common shape variation. A summary of current genetic epidemiology of OA is also given, together with current evidence on the genetic overlap between shape variation and OA. Finally, the established genetic risk loci for both joint shape and osteoarthritis are discussed

    Paysages géomorphologiques

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