418 research outputs found

    Variscan overthrusting, fluid flow and the genesis of magnetite ore-bodies at Azenhas area (Pedrógão, Ossa-Morena Zone, SE Portugal)

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    In the Azenhas area (SE Portugal), an important segment of a regional WNW-ESE Variscan thrust can be observed. The hanging wall felsic metavolcanics carried from ENE are evolved rhyolite tuffs. The underlying sequence is mainly composed of variably metasomatised allochthonous amphibolites that are believed to represent an ophiolite slice tectonically overlying the autochthonous Moura-Ficalho Complex. Within this latter sequence, numerous WNW-ESE thrusts with prevailing displacement towards W-SW cut prior sub-parallel structures with northwards thrust shear. According to the observed crosscutting relationships and to the available petrographic data, the metasomatism experienced by the lower amphibolite sequence took place mainly before the emplacement of the upper slices of amphibolites, preceding therefore the installation of the felsic metatuffs. Magnetite ore-bodies are found within strongly metasomatised amphibolites immediately below the major WNW-ESE thrust zone or its subsidiary thrust structures. Their genesis is envisaged as a result of a complex chemical reaction path that involves the ascent of aqueous oxidising fluids under a reverse temperature gradient generated during the tectonic emplacement of amphibolites. In order to test the geological plausibility of the thermal evolution and the time span needed for ore genesis a one-dimensional numerical model was developed. This model enables the tracing of vertical thermal profiles at different times and accounts for the thrust emplacement history, incorporating variable erosion rates of the rock sequence. The results obtained show that an inverted thermal gradient in the thrusted sequence is kept for over 1 Ma and a regular temperature increase (from 400ºC to 500ºC) is observed in the underlying rocks lasting for 4.5 to 5.5 Ma.info:eu-repo/semantics/publishedVersio

    Cu- and Za-soil anomalies in the NE border of the South Portuguese Zone (Iberian Variscides, Portugal). Identified by multifractal and geostatistical analysis

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    Extensive Cu- and Zn-soil geochemical data in the Albernoa/Entradas–S. Domingos region (NE border of the Iberian Pyrite Belt, South Portuguese Zone) were examined to separate anomalies from background using the concentration–area fractal model. Distribution patterns of Cu and Zn concentrations in soil are primarily influenced by bedrock. The regional threshold values of Cu- and Zn-soil contents over metasedimentary sequences are 20–25 and 20–60 ppm, respectively, becoming 30–50 and 20–90 ppm, respectively, when metavolcanic rocks are present. The first-order threshold values for Cu are 80–90 ppm in soils over metasediments and 70–80 ppm in soils over sequences bearing metavolcanics. For Zn, the first-order threshold values are 40–80 and 90–100 ppm in soils over metasediments and metavolcanic rocks, respectively. Metasediments and metavolcanics comprising significant sulphide disseminations are outlined by Cu- and Zn-soil values above 100 and 300 ppm in soil, respectively. On the basis of these results, Alvares and Albernoa/Entradas areas emerge as the first priority targets for exploration. The observed non-coincidence of Cu- and Zn-soil anomalies in soil in the area could reflect difference in element dispersion during weathering, they mostly indicate distinct metal sources related to the original composition of different rock types or to chemical changes developed during Variscan deformation/re-crystallization path. The established regional baseline data can be used as reference for environmental studies

    Geochemistry of stream sediments southwards of the SW Variscan suture in Portugal (Guadiana and Chança river basins) : insights into element anomalies of variable origin and intensity

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    Stream sediment samples were collected in the Trindade–Chança region at 1034 sites for mineral exploration purposes during 1996–97. Concentrations of Cu, Zn, Pb, Co, Cr and Ni are high enough in most sample sites to allow data assessment by multi-element anomaly definition and threshold computation using the area concentration multifractal model technique. The regional threshold values are 20, 45, 30 and 15 ppm for Cu, Zn, Pb and Co respectively. Anomalies for Cu, Zn, Pb, Co, Cr and Ni are delimited by first order local threshold values at 40, 94, 70, 21, 37 and 42 ppm. The main anomalies are clustered to the east-southeast of the surveyed region and reflect mixed contributions from a variety of sources, namely different volcanic units with local contributions from pelite rocks, contamination from old (abandoned) mining activities and hydrothermal mineralisation controlled by different fault zones

    Vascular trauma: a five year review

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    O presente trabalho pretende avaliar a casuística dos traumatismos vasculares agudos admitidos no Serviço de Cirurgia Vascular dos Hospitais da Universidade de Coimbra (HUC) durante o período de 5 anos, compreendido entre Julho de 2004 e Junho de 2009. Foram avaliados 97 doentes, sendo a principal causa de traumatismo as lesões iatrogénicas, seguida dos acidentes de viação. No grupo de doentes não relacionados com procedimentos coronários percutâneos verificou-se que no membro superior as artérias umeral e radial foram as mais afectadas, enquanto no membro inferior foram as artérias femoral superficial e poplítea. A isquémia aguda foi a principal forma de apresentação. Relativamente ao tratamento deste grupo de doentes, a RATT (ressecção e anastomose topo-topo) e o enxerto foram os mais utlizados no membro superior, enquanto a trombectomia e o bypass foram as técnicas mais aplicadas a nível do membro inferior. Não houve mortalidade mas a morbilidade foi elevada, predominando as lesões neurológicas nos traumatismos do membro superior, e a amputação nos do membro inferior. Os resultados deste trabalho foram concordantes com o que está publicado na literatura em que se demonstra um aumento progressivo dos traumatismos de origem iatrogénica

    Innovative moments and poor outcome in narrative therapy

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    To analyse a poor outcome case of narrative therapy with a woman victim of intimate violence. Method: The Innovative Moments Coding System: version 1 was applied to all sessions to track the innovative moments (i-moments) in the therapeutic process. I moments are the narrative details that occur in psychotherapeutic conversations that are outside the influence of the problematic narrative. This research aims to describe the processes involved in the stability of meanings in psychotherapy through a dialogical approach to meaning making. Findings: Contrarily to what usually occurs in good outcome cases, re-conceptualization i-moments are absent. Moreover, two specific types of i-moments emerged with higher duration: reflection and protest. Qualitative analysis showed that the potential meanings of these i-moments were surpassed by a return to the problematic narrative. Conclusion: The therapeutic stability seems to be maintained by a systematic return to the problematic narrative after the emergence of novelties. This process was referred from a dialogical perspective as a mutual in-feeding of voices, one that emerges in the i-moment and another one that supports the problematic narrative, which is maintained by an oscillation between these two types of voices during therapy.This article was supported by the Portuguese Foundation for Science and Technology (FCT), by the Grant PTDC/PSI/72846/2006 (Narrative Processes in Psychotherapy, 2007-2010) and by the PhD Grant SFRH/BD/16995/2004

    Bilateral knee dislocation with associated bilateral popliteal arterial injury

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    Tibiofemoral unilateral knee dislocations are uncommon, making bilateral dislocations even rarer injuries. Knee dislocation is considered one of the most serious injuries that can affect this joint. Associated complications such as popliteal artery injury are responsible for the important morbidity in these patients. The authors report the case of a 52-year-old man with a traumatic bilateral knee dislocation with associated bilateral popliteal arterial injury. His clinical presentation along with radiographic and angiographic findings are described. Surgical and non-surgical treatment and functional outcomes are also reported.info:eu-repo/semantics/publishedVersio

    A rare cause of portal hypertension: case report

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    Apresenta-se caso clínico de doente com quadro de hipertensão portal pela presença de fístula artério-venosa entre a artéria gastroduodenal e a veia porta. Indivíduo do sexo masculino, de 77 anos, previamente saudável, com ascite volumosa de instalação recente. Hemorragia digestiva alta por rotura de varizes esofágicas. TAC abdominal revelando acentuada dilatação da veia porta (30 mm), envolvida em fístula artério-venosa com origem na artéria gastroduodenal; fígado sem estigmas de hepatopatia crónica e sem nódulos; ascite volumosa. Procedeu-se à laparotomia com drenagem de ascite, isolamento e laqueação do trajecto fístuloso entre a artéria gastroduodenal e a veia porta. Sem complicações intra-operatórias. Ao 18º dia, após regressão da ascite, teve alta medicado com diurético

    Which are the factors that may explain the differences in water and energy consumptions in urban and rural environments?

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    Rural and urban environments present significant differences between water and energy consumptions. It is important to know, in detail, which factors related to the consumption of these two resources are different in both environments, once that will be those important to manage and discuss in order to improve its use efficiency and sustainability. This research work involves a survey whose aim is to find the factors that in rural and urban environments may justify the differences found in water and energy consumptions. Besides the collection of water and energy consumption data, this survey analyzed 80 variables (socio-demographic, economic, household characterization, among others), that were chosen among the bibliography as possible factors that should influence water and energy consumptions. After the survey application in rural and urban areas and the data statistical treatment, 42 variables remained as truly differentiating factors of rural and urban environments and so as possible determinants of water and energy consumptions. In order to achieve these objectives, a descriptive data analysis and statistical inference (Mann-Whitney-Wilcoxon test and the Chi-square test of homogeneity) were performed. All the 42 differentiating variables that result from this study may be able to justify these differences, however this will not be presented in the paper and it is reserved for future work.POCI-0-0145-FEDER-016730 Project (PTDC/AAG-REC/4700/2014) with the designation ENERWAT: Water to energy: characterization, modelling and measures for the reduction of urban and rural household consumption, financed by the Foundation for Science and Technology and co-financed by the European Regional Development Fund (FEDER) through the COMPETE 2020 - Programme Operational Competitiveness and Internationalization (POCI). This work was partially supported by the FCT (Portuguese Foundation for Science and Technology) through the project PEst-OE/ECI/UI4082/2013 (C-MADE

    A Novel p.Leu213X Mutation in GJB2 Gene in a Portuguese Family

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