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- A estabilidade estrutural e a vulnerabilidade dos edifícios em centros históricos face ao risco sísmicoPublication . Vicente, Romeu; Ferreira, Tiago Miguel; Maio, Rui; Estêvão, João M. C.; Rodrigues, HugoPresentemente os países europeus estão a despertar para uma cultura da gestão de risco integrado, quer a nível nacional quer em termos municipais. A gestão de risco é um processo que engloba uma série de ações que apoiam a implementação de medidas que reduzam o potencial de perda na ocorrência de um evento, por exemplo, de natureza sísmica. Porém, a avaliação do risco sísmico é apenas uma das tarefas da teia complexa da gestão de risco e definição de estratégias de intervenção e controlo de um sistema urbano. De entre muitos objetivos que se perspetivam no âmbito do planeamento e gestão urbana, com este artigo abordar a avaliação de risco no domínio específico da segurança estrutural, com enfoque na avaliação do risco sísmico, cujas graves consequências fazem parte da nossa memória coletiva e, infelizmente, em alguns casos, da memória viva de diversas comunidades. A gravidade dos danos que deles decorrem é motivo suficiente para uma forte valorização das estratégias de prevenção, planeamento e mitigação que diminuam a sua probabilidade, limitem as suas consequências e permitam uma ação continuada de melhoria, já que só utopicamente se poderá considerar a possibilidade de transformação integral e imediata das realidades urbanas em situações de risco “zero”.
- Late hospital arrival for thrombolysis after stroke in Southern Portugal: Who is at risk?Publication . Sobral, Sofia; Taveira, Isabel; Seixas, Rui; Vicente, Ana Claudia; Duarte, Josiana; Goes, Ana Teresa; Duran, David; Lopes, Joao; Rita, Henrique; Nzwalo, HipólitoBackground: Delayed hospital arrival remains the main reason for the low rates of thrombolysis in eligible acute ischemic stroke (AIS) patients. The role of socioeconomic and clinical factors for the prehospital delay of AIS remains poor and has never been studied in Portugal. Objectives: Describe the socioeconomic and clinical factors leading to delayed hospital admission of AIS patients eligible to thrombolysis. Methods: A case-control study with a consecutive thrombolyzed AIS patients from 2010 to 2015. Controls were patients who did not receive thrombolysis because of late hospital arrival. Logistic regression with stepwise forward regression analysis was used to identify independent predictors of delayed admission to receive thrombolysis with intravenous tissue-type plasminogen activator (rtPA). Results: Of the 1247 patients admitted with AIS, 76 (6%) arrived on-time and received intravenous rtPA. Controls were 65.8% (146/222) of the total number of patients included in the study. Overall, the mean age was 73 years (+/- 11, 61), a minority were below 60 years, and 43.7% were women. Being beneficiary of social insertion income (odds ratio [OR]: .286; .124-.662, P = .003), not having any telephone contact (OR: .145; .039-.536, .004) or having exclusive landline (.055; .014-.210, < .001) and posterior circulation stroke (OR: .266; .087-.811, P = .020) decreased the likelihood of hospital arrive on-time rtPA. The use of prehospital ambulance services increased (OR: 6.478; 2.751-15.254, P < .001) the odds of ER on-time arrival for thrombolysis. Conclusions: Poverty, lack of stroke awareness, or difficulties in requesting immediate medical help are the main factors implicated in late-hospital admission for thrombolysis in AIS. Stroke awareness campaigns, promotion of activation of national emergency number and stroke code can increase the rate of thrombolysis.
- Effects of tidal and river discharge forcings on tidal propagation along the Guadiana EstuaryPublication . Calero Quesada, Maria Concepcion; Garcia-Lafuente, Jesus; Garel, Erwan; Delgado Cabello, Javier; Martins, Flávio; Moreno-Navas, JuanA numerical model is implemented to explore the effect of the river discharge on tidal propagation along the Guadiana Estuary, a rock-bound estuary located in Southwest Iberia. The MOHID numerical model, in 2D barotropic mode, has been forced by tides at the ocean side and by freshwater at the upstream boundary of the domain. The model was validated using water level and velocity observations at several locations along the estuary. Different scenarios with variable tidal forcings and freshwater discharges were analysed, considering the semi- diurnal constituents and M4 overtide, in order to assess the influence of each external agent on the along-channel hydrodynamics. The model reproduces the expected general tidal properties along the channel in terms of amplitude (of both elevation and current), asymmetry and phase between horizontal and vertical tides. Three zones along the estuary have been defined based on the overtide patterns. Tidal propagation in Zone I, at the lower estuary, vary essentially with the tidal amplitude at the mouth while changes due to river discharge are minor. Along Zone II (middle estuary), the tidal forcing still predominates, for low discharge values only. Along Zone III (upper estuary), the tidal propagation is primarily controlled by the river discharge. Although the discharge threshold vary with the location and parameter considered, it is estimated that a discharge as little as 100 m3/s has a strong effect on the tidal properties along the system as a whole. It is therefore concluded that tidal properties in rock-bound estuaries may be importantly modified by relatively weak river discharge events.
- The role of climate, marine influence and sedimentation rates in late-Holocene estuarine evolution (SW Portugal)Publication . Costa, Ana Maria; Freitas, Maria da Conceicao; Leira, Manel; Costas, S.; Costa, Pedro J. M.; Andrade, Cesar; Bao, Roberto; Duarte, Joao; Rodrigues, Aurora; Cachao, Mario; Araujo, Ana Cristina; Diniz, Mariana; Arias, PabloEstuaries are sensitive to changes in global to regional sea level, to climate-driven variation in rainfall and to fluvial discharge. In this study, we use source and environmentally sensitive proxies together with radiocarbon dating to examine a 7-m-thick sedimentary record from the Sado estuary accumulated throughout the last 3.6 kyr. The lithofacies, geochemistry and diatom assemblages in the sediments accumulated between 3570 and 3240 cal. BP indicate a mixture between terrestrial and marine sources. The relative contribution of each source varied through time as sedimentation progressed in a low intertidal to high subtidal and low-energy accreting tidal flat. The sedimentation proceeded under a general pattern of drier and higher aridity conditions, punctuated by century-long changes of the rainfall regime that mirror an increase in storminess that affected SW Portugal and Europe. The sediment sequence contains evidence of two periods characterized by downstream displacement of the estuarine/freshwater transitional boundary, dated to 3570-3400 cal. BP and 3300-3240 cal. BP. These are intercalated by one episode where marine influence shifted upstream. All sedimentation episodes developed under high terrestrial sediment delivery to this transitional region, leading to exceptionally high sedimentation rates, independently of the relative expression of terrestrial/marine influences in sediment facies. Our data show that these disturbances are mainly climate-driven and related to variations in rainfall and only secondarily with regional sea-level oscillations. From 3240 cal. BP onwards, an abrupt change in sediment facies is noted, in which the silting estuarine bottom reaches mean sea level and continued accreting until present under prevailing freshwater conditions, the tidal flat changing to an alluvial plain. The environmental modification is accompanied by a pronounced change in sedimentation rate that decreased by two orders of magnitude, reflecting the loss of accommodation space rather than the influence of climate or regional sea-level drivers.
- Otimização de amortecedores de massas sintonizadas recorrendo a algoritmos genéticosPublication . Kerkoff, Matheus Abreu; Estêvão, João M. C.; Alves, Élcio CassimiroO software STRUCTURE3D é uma aplicação de informática desenvolvida na Universidade Federal do Espírito Santo, no Brasil, que foi realizada em ambiente MATLAB. No contexto deste trabalho, é apresentado o desenvolvimento de uma nova funcionalidade que foi implementada no STRUCTURE3D, e que foi desenvolvida no âmbito de um trabalho de investigação realizado no Departamento de Engenharia Civil do Instituto Superior de Engenharia da Universidade do Algarve. O objetivo dessa funcionalidade consiste na possibilidade de incluir nos modelos estruturais os sistemas de amortecimento de massa sintonizada, internacionalmente conhecidos por TMD (Tuned Mass Dampers). Atendendo às dificuldades inerentes à seleção das características destes dispositivos, foi concebido um algoritmo que permite a realização da otimização do desempenho da estrutura, através do ajuste automático dos valores da rigidez e/ou da massa de cada TMD. Para este efeito, são usadas rotinas pré-definidas do MATLAB, referentes a algoritmos genéticos, para a obtenção dos valores ótimos das características de cada um dos TMD adicionados ao sistema estrutural. É apresentado um caso de estudo que ilustra as capacidades do programa desenvolvido.
- Palynology of Bonito and Barro Branco coal seams from Rio Bonito Formation (Lower Permian of Parana Basin) in the Criciuma coal region, southernmost BrazilPublication . Pereira, Z.; Mendes, M.; Souza, P. A.; Rodrigues, C.; Fernandes, Paulo; Ade, M.; Araujo, C.; Almeida, J. R. L.; Santos, E. M.; Rocha, H., V; Santos, V. E. S.; Araujo, B. P.; Garavaglia, L.; Lemos de Sousa, M. J.Seven coal seams were sampled from several mines and outcrops of the Rio Bonito Formation, Bonito and Barro Branco coal seams, in the coal mining region of Criciuma, Parana Basin, Santa Catarina State (Brazil), for a detailed palynostratigraphic study. The coal seams sampled yield abundant, diverse and moderately to well preserved palynological assemblages. A total of twenty-seven spore species, fourteen pollen species and four microplanktonic or clorophyceae algae and fungi species were identified. The palyno-assemblages recovered in the Bonito and Barro Branco coal seams are assigned to the Vittatina costabilis Interval Zone, Protohaploxypinus goraiensis Subzone of the Parana Basin, of Asselian? to Artinskian age (Lower Permian). The microflora assemblages identified in these coal seams are very similar in composition, presenting a dominance of arborescent and herbaceous lycophytes. The Barro Branco coal seam shows a relatively higher frequency of algae like composition than in the Bonito coal seam, suggesting a possible fluvial or lagoonal facies influence.
- Pronounced northward shift of the westerlies during MIS 17 leading to the strong 100-kyr ice age cyclesPublication . Goni, Maria Fernanda Sanchez; Ferretti, Patrizia; Polanco-Martinez, Josue M.; Rodrigues, Teresa; Alonso-Garcia, Montserrat; Javier Rodriguez-Tovar, Francisco; Dorador, Javier; Desprat, StephanieThe MIS 17 interglacial, similar to 715-675 ka, marks the end of the Mid-Pleistocene Transition as intensified, long and asymmetrical 100-kyr ice age cycles became eminently established. Increasing arrival of moisture to the Northern Hemisphere high latitudes, resulting from the northwestward migration of the Subpolar Front and the intensification of the Norwegian Greenland Seas (NGS) convection, has been put forward to explain the emergence of this quasi-periodic 100-kyr cycle. However, testing this hypothesis is problematic with the available North Atlantic precipitation data. Here we present new pollen-based quantitative seasonal climate reconstructions from the southwestern Iberian margin that track changes in the position and intensity of the westerlies. Our data compared to changes in North Atlantic deep and surface water conditions show that MIS 17 interglacial was marked by three major changes in the direction and strength of the westerlies tightly linked to oceanographic changes. In particular, we report here for the first time a drastic two-steps northward shift of the westerlies centered at similar to 693 ka that ended up with the sustained precipitation over southern European. This atmospheric reorganization was associated with northwestward migration of the Subpolar Front, strengthening of the NGS deep water formation and cooling of the western North Atlantic region. This finding points to the substantial arrival of moisture to the Northern Hemisphere high latitudes at the time of the decrease in summer energy and insolation contributing to the establishment of strong 100-kyr cycles. (C) 2019 Elsevier B.V. All rights reserved.
- Influence of data pre-processing on the behavior of spatial indicatorsPublication . Rufino, MM; Bez, Nicolas; Brind'Amour, AnikSpatial indicators are widely used to quantify the impact of climate and anthropogenic changes on species spatial distribution. These metrics are thus, determinant to decisions on the conservation measures to be implemented. In the current work, the effect of two common pre-processing methods: gridding and continuous interpolation, on the values given by five spatial indicators: index of aggregation, percentage of presence, center of gravity, inertia and isotropy was studied. Indicators were computed using empirical data of 32 species biomass distributions, obtained from time series of bottom trawl and of acoustic surveys, with different sampling designs. Spatial indicators computed using pre-processed data were compared with spatial indicators estimated without pre-processing the data using the difference between the two approaches. The pre-processing of the data consisted of a series of progressive increase of grid sizes, from 20 to 120 km, and a series of ten different interpolation methods: linear models, inverse distance weighting, bicubic spline, Generalised Additive Models, ordinary, universal kriging and geostatistical conditional simulations. Pre-processing the data, both by gridding or interpolation caused a change of several orders of magnitude on the indicator results, for the two surveys considered. Inertia showed opposite differences for trawl and acoustic datasets whereas the remaining indicators evidenced similar patterns of difference. An index of relative difference, was computed to verify whether the pre-processing effect on the indicator was higher or lower than the observed temporal variability. This index showed that for certain species, the variability of the indicators was over two-fold its respective inter-annual temporal variability, as it was the case of the percentage of presence and the index of aggregation, estimated using interpolated or gridded data. The most important factors explaining most of the difference between results with or without pre-processing the data were the indicator considered. For example, the percentage of presence was much more sensitive to pre-processing than inertia or isotropy. Additionally, the interpolation method ( bi-cubic splines) and gridding size up to a certain level (< 80 km grids) also influenced the results observed. We advise that if pre-processing the data prior to the computation of indicators is required, then detailed choices and hypotheses underlying the approach must be clearly stated, particularly if the indicators are to be compared among studies, countries or case studies.
- Segurança sísmica de escolas do plano dos centenários existentes no Algarve: caso de estudoPublication . Tomás, Bruno Alexandre Cardoso; Estêvão, João M. C.As escolas do “Plano dos Centenários” correspondem à tipologia de escolas do primeiro ciclo do ensino básico existente no Algarve com o maior número de edifícios ainda em funcionamento. Por outro lado, mesmo já não estando a desempenhar as iniciais funções, muitas dessas antigas “Escolas Primárias” são hoje utilizadas para outras funções, designadamente como escolas pré-primárias ou como associações culturais ou recreativas, por exemplo. É inegável o valor patrimonial destas construções, quer pelas suas distintas características arquitetónicas, quer pelo seu valor histórico. Estes edifícios foram construídos com paredes resistentes em alvenaria de pedra da região, antes da publicação em Portugal dos primeiros códigos sísmicos. Assim, é da maior importância o estudo da segurança sísmica destas construções, atendendo à elevada concentração de pessoas que apresentam, sendo a maior parte delas crianças. Estas construções têm sido alvo de obras de reabilitação, mas meramente procurando melhorar a sua habitabilidade, sem qualquer preocupação com a segurança sísmica. É neste contexto que surge o projeto PERSISTAH, que visa, entre outros objetivos, estudar o risco sísmico das escolas do primeiro ciclo que estão em funcionamento nas regiões do Algarve (Portugal) e de Huelva (Espanha). Neste trabalho, é apresentado o estudo de um edifício do “Plano dos Centenários” localizado em Olhão. Em primeiro lugar, foram realizadas análises não lineares do edifício, tendo sido obtidas as correspondentes curvas de capacidade do edifício com o recurso ao programa Tremuri. Depois, as múltiplas curvas de capacidade foram importadas para o programa EC8spec. Este programa permite determinar os pontos de desempenho (deslocamentos alvo) das estruturas através do método N2, e para as ações estabelecidas na NP EN 1998-1:2010, assim como possibilita a determinação das percentagens dessa ação a que correspondem os pontos de desempenho associados aos três estados limites estipulados na NP EN 1998-3:2017: colapso eminente (NC), danos severos (SD) e limitação de dano (DL). De acordo com a NP EN 1998-3:2017, e porque as escolas correspondem a estruturas de classe de importância III, a avaliação da segurança tem de ser realizada para todos estes estados limites. Os resultados obtidos neste estudo revelam que não é possível atingir os níveis de segurança que estão estipulados na NP EN 1998-3:2017 para o Algarve, para todos os estados limites atrás referidos, sendo por isso desejável a realização de um adequado reforço sísmico.
- Species delimitation in Amblyosyllis (Annelida, Syllidae)Publication . Aguado, María Teresa; Capa, María; Lago-Barcia, Domingo; Gil, João; Pleijel, Fredrik; Nygren, ArneAmblyosyllis is a worldwide distributed group of annelids mainly found in coastal environments. It is well known among the polychaete specialists mostly because of its notable beauty, showing bright colourful patterns and outstanding long and coiled appendices. Amblyosyllis is a monophyletic genus easy to identify due to its distinct diagnostic features; however, the species and their boundaries are, in most cases, not well defined. Herein, we provide an extensive sample of Amblyosyllis material (115 specimens) from several world geographic areas. We have studied the morphological features of each specimen and photographed them alive. Two mitochondrial DNA markers (COI and 16S) and one nuclear gene fragment (28S, D1 region) were sequenced. We performed phylogenetic analyses based on each DNA partition, as well as the combined data sets, obtaining congruent results. Species delimitation methods such as distance analyses, statistical parsimony networks and multi-rate Poisson tree processes were also applied. The combined results obtained from different methodologies and data sets are used to differentiate between, at least, 19 lineages compatible with the separately evolving meta-populations species concept. Four of these lineages are identified as nominal species, including the type species of Amblyosyllis, A. rhombeata. For three other lineages previously synonymized names are recovered, and seven lineages are described as new species. All of these species are described and supported by appropriate iconography. We recognize several morphological characters useful to identify species of Amblyosyllis, which in some cases should also be combined with molecular methods for species delineation. The genetic divergence in the genus is high, contrary to the morphological homogeneity observed. Two species show a wide geographical distribution, while the rest have a more restricted distribution. There are several examples of species with overlapping distribution patterns.