4,882 research outputs found

    First report on the prevalence of Klossiella muris in Mus musculus for S. Miguel Island : Azores (Portugal)

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    Klossiella is a genus of apicomplexan coccidian parasites with a global distribution, whose members typically infect the renal tissue of a wide variety of vertebrate hosts with a high level of host specificity. The presence of this parasite has been previously associated with kidney inflammatory processes. To our knowledge, this is the first report on the prevalence of Klossiella muris in the house mouse (Mus musculus) in Portugal (São Miguel Island – Azores). The prevalence of K. muris was determined through histopathological examination of renal tissue collected during necropsy of 130 mice captured between the years of 2011–2019. K. muris was diagnosed in 45.38% (CI95: 40.9–85.4) of the examined mice. Infection with this parasite was associated with mild to severe kidney inflammation, assessed by the presence of inflammatory processes in the renal cortex and medulla. Capsule First record on coccidiosis caused by infection of Klossiella muris in Mus musculus in Portugal.Ricardo Camarinho is currently supported by a PhD fellowship grant (M3.1.a/F/048/2015) from Fundo Regional da Ciência (Regional Government of the Azores).info:eu-repo/semantics/publishedVersio

    Neutrinos and the matter-antimatter asymmetry in the Universe

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    The discovery of neutrino oscillations provides a solid evidence for nonzero neutrino masses and leptonic mixing. The fact that neutrino masses are so tiny constitutes a puzzling problem in particle physics. From the theoretical viewpoint, the smallness of neutrino masses can be elegantly explained through the seesaw mechanism. Another challenging issue for particle physics and cosmology is the explanation of the matter-antimatter asymmetry observed in Nature. Among the viable mechanisms, leptogenesis is a simple and well-motivated framework. In this talk we briefly review these aspects, making emphasis on the possibility of linking neutrino physics to the cosmological baryon asymmetry originated from leptogenesis.Comment: 8 pages, 1 table, 1 figure; Based on talk given at the Symposium STARS2011, 1 - 4 May 2011, Havana, Cuba; to be published in the Proceeding

    How complete should be the landslide inventory to generate a reliable landslide susceptibility model?

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    Historical landslide inventory maps are frequently incomplete and this is usually pointed out as a source of uncertainty affecting the predictive ability of data-driven landslide susceptibility models. Nevertheless, the concept of having a complete landslide inventory seems far from reaching a consensual definition, both from the theoretical and practical point of view. Landslide mapping over time depends on a wide range of factors, some of them as simple as the ambitious capability to regionally map all the landslide features/signatures, detectable by fieldwork or image interpretation, which are often lost in a short period due to erosion or man intervention, which erase the morphological signs of instability. Within this framework, the main goal of the present work is to assess to what extent a presumed complete shallow slides inventory map is necessary to consistently assess the susceptibility to shallow slides in a certain area. The working hypothesis is tested in the Grande da Pipa river (GPR) basin, which extends for 110 square kilometers in the north of Lisbon region, Portugal. To assess susceptibility to shallow slides occurrence, we apply a bivariate statistical method (the Information Value), using an inventory containing more than 500 shallow slides ranging in size from 10 to 8000 square meters; and a dataset of eight terrain predisposing factors (lithology, slope, aspect, plan curvature, slope area ratio, topographic position index, soil type and land use), supported by automated R routines. In a first moment, the modelling strategy encompasses the creation of three independent blocks of landslide cases to be used for training (70 % of the landslides) and validation (30 % of the landslides) based on a random partition of the shallow slides inventory. In a second phase, each training group, for the different blocks, is randomly split in 14 new landslide sample groups, through a progressive increment of 5 % in the number of landslide cases included, from sample group 1 (with only 5 % of the total landslides) to sample group 14 (with 70 % of the total landslides), to obtain the shallow slides susceptibility scores. The validation of each of the 14 susceptibility map, from the different blocks, is done independently with the validation group of shallow slides (30 %) previously set aside and not used for susceptibility modelling. To accomplish that, we graphically compute prediction rate curves and calculate the respective area under the curve.N/

    Assessment of physical vulnerability of buildings and analysis of landslide risk at the municipal scale: application to the Loures municipality, Portugal

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    This study offers a semi-quantitative assessment of the physical vulnerability of buildings to landslides in a Portuguese municipality (Loures), as well as the quantitative landslide risk analysis computed as the product of the landslide hazard by the vulnerability and the economic value of the buildings. The hazard was assessed by combining the spatiotemporal probability and the frequency–magnitude relationship of the landslides. The physical vulnerability assessment was based on an inquiry of a pool of European landslide experts and a sub-pool of landslide experts who know the study area, and the answers’ variability was assessed with standard deviation. The average vulnerability of the basic geographic entities was compared by changing the map unit and applying the vulnerability to all the buildings of a test site, the inventory of which was listed on the field. The economic value was calculated using an adaptation of the Portuguese Tax Services approach, and the risk was computed for different landslide magnitudes and different spatiotemporal probabilities. As a rule, the vulnerability values given by the sub-pool of experts who know the study area are higher than those given by the European experts, namely for the high-magnitude landslides. The obtained vulnerabilities vary from 0.2 to 1 as a function of the structural building types and the landslide magnitude, and are maximal for 10 and 20m landslide depths. However, the highest risk was found for the landslides that are 3m deep, because these landslides combine a relatively high frequency in the Loures municipality with a substantial potential damage.info:eu-repo/semantics/publishedVersio

    Integration of landslide susceptibility maps for land use planning and civil protection emergency management

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    Landslides are one of the most relevant geomorphological hazards in Portugal, by the high levels of people affected, destruction of assets and disruption of economic and social activities. Regarding the Portuguese territorial land use planning and emergency management, regulation, practice, prevention and risk management have been promoted in different ways. In Portugal, the areas susceptible to landslides are included in the 'National Ecological Reserve', which is a public utility restriction legal figure that rules the land use planning at the municipal level. In addition, the Municipal Emergency Plans include landslide susceptibility maps that are combined with the map of the exposed elements, allowing the assessment of exposure to landslides. This study is applied to the Loures municipality located to the north of Lisbon. In this municipality 621 landslides registered in a landslide inventory (rotational slides, deep-seated translational slides and shallow translational slides) that affected 1,469,577 m2 (0.87 %) of the Loures territory. The final landslide susceptibility map shows that in Loures municipality 1,347 ha are associated to a Very high landslide susceptibility and 2,372 ha to High landslide susceptibility, which corresponds both to 22.1 % of the entire municipality, and constitutes the larger fraction of the National Ecological Reserve, related to landslides. These areas do not present geomorphological and geotechnical suitability for building structures or infrastructures. From the civil protection and emergency management point of views 34 classes of exposed elements were identified in the municipality, with point, linear and polygonal representations. The elements at risk located in the Very High or High landslide susceptibility classes were summarized and correspond to: high voltage poles; wind turbines; transmission/reception antennas; industrial areas; water tanks; silo; gas station/tank; service area; buildings of educational institutions; worship buildings; buildings of electricity facilities; regular buildings; gas pipeline; motorways; national roads; and municipal roads.info:eu-repo/semantics/publishedVersio

    Rainfall-triggered landslides in the Lisbon region over 2006 and relationships with the North Atlantic Oscillation

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    Landslides occurred in the Lisbon area during the last 50 years were almost always induced by rainfall and have been used to establish rainfall thresholds for regional landslide activity. In 2006, three new rainfall-triggered landslide events occurred in the study area, namely on the 20 March, the 25–27 October, and the 28 November. Landslide events occurred in March and October 2006 include shallow translational slides and few debris flows, and the corresponding absolute antecedent rainfall was found to be above the threshold for durations ranging from 4 to 10 days. These events also fit the combined threshold of daily precipitation and 5 days calibrated antecedent rainfall values. Likewise the landslide event that took place in late November 2006 includes some slope movements with deeper slip surfaces, when compared with landslides dating from March and October. Moreover, the corresponding absolute antecedent rainfall was also found to be above the 40-day period rainfall threshold. Here we characterize in detail the short and long-term atmospheric circulation conditions that were responsible for the intense rainfall episodes that have triggered the corresponding landslide events. It is shown that the three rainfall episodes correspond to considerably different synoptic atmospheric patterns, with the March episode being associated to an intense cut-off low system while the October and November episodes appear to be related to more typical Atlantic low pressure systems (and associated fronts) travelling eastwards. Finally, we analyse the role played by the North Atlantic Oscillation (NAO) during those months marked by landslide activity. It is shown that the NAO index was consistently negative (usually associated with above average precipitation) for the months prior to the landslide events, i.e. between October 2005 and March 2006, and again between August and October 2006.info:eu-repo/semantics/publishedVersio

    Regional rainfall thresholds for landslide occurrence using a centenary database

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    This work proposes a comprehensive method to assess rainfall thresholds for landslide initiation using a centenary landslide database associated with a single centenary daily rainfall data set. The method is applied to the Lisbon region and includes the rainfall return period analysis that was used to identify the critical rainfall combination (cumulated rainfall duration) related to each landslide event. The spatial representativeness of the reference rain gauge is evaluated and the rainfall thresholds are assessed and calibrated using the receiver operating characteristic (ROC) metrics. Results show that landslide events located up to 10 km from the rain gauge can be used to calculate the rainfall thresholds in the study area; however, these thresholds may be used with acceptable confidence up to 50 km from the rain gauge. The rainfall thresholds obtained using linear and potential regression perform well in ROC metrics. However, the intermediate thresholds based on the probability of landslide events established in the zone between the lower-limit threshold and the upper-limit threshold are much more informative as they indicate the probability of landslide event occurrence given rainfall exceeding the threshold. This information can be easily included in landslide early warning systems, especially when combined with the probability of rainfall above each threshold.info:eu-repo/semantics/publishedVersio

    Aplicação exploratória de análise multicritério para representação municipal da susceptibilidade a cheias rápidas em Portugal continental

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    [...] Este estudo descreve uma metodologia exploratória de avaliação de susceptibilidade a cheias rápidas para Portugal Continental, adotando uma abordagem multicritério, a partir de um conjunto de 9 fatores condicionantes, definidos ao município: escoamento acumulado, hierarquia fluvial de Strahler, rugosidade, declive, depósitos aluvionares, grau de impermeabilização, litologia de elevada permeabilidade, Landform Classification e escoamento anual. A atribuição do peso de cada fator baseou-se em Análise Hierárquica de Processos (AHP) [...]info:eu-repo/semantics/publishedVersio

    Damaging flood risk in the Portuguese municipalities

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    Modeling and understanding the impact of climate change on flooding processes in Mediterranean climate areas, namely in southern Europe, is a complex endeavor, which must also consider exposure and vulnerability patterns. Assuming that vulnerability plays a relevant role in explaining the degree of loss due to natural hazards, the present research compares a flood-susceptibility index with a social-vulnerability index and a historical record of flood losses, both aggregated at the municipal level. The purpose of this research is to define municipal flood risk profiles that would rank the 278 municipalities and contribute to the strategic allocation of resources and flood risk management [...]info:eu-repo/semantics/publishedVersio
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