109 research outputs found

    The Rivillas flood of 5–6 November 1997 (Badajoz, Spain) revisited: an approach based on Iber+ modelling

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    Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGThe flash flood registered in November 1997 in the city of Badajoz (Spain) in the basin of Rivillas river is analysed by means of the numerical code Iber+. This event constitutes one of the most destructive flash-floods registered in an urban area in the Iberian Peninsula. Starting from precipitation data obtained from rain stations, the runoff of the entire river basin was simulated to obtain the discharge of the Rivillas river in Badajoz. The flood maps obtained with Iber+ reproduce accurately the field data registered during the actual event. Likewise, the numerical time evolution of the flood and water depths are in accordance with testimonies of the witnesses. Once the capability of Iber+ to reproduce the event was assessed, several scenarios were considered in order to analyse the main causes of the event. In particular, simulations show that the catastrophic magnitude of the flood was mainly due to the blockage of bridges. Different hypothetical scenarios were simulated to analyze the role of rain intensity and bridge maintenance, concluding that similar floods can occur under much lower rainfall but with poor bridge maintenance.Xunta de Galicia | Ref. ED431C 2021/44Xunta de Galicia | Ref. ED481B-2021-10

    Numerical simulation of the deadliest flood event of Portugal: Unravelling the causes of the disaster

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    The flood event of November 25 and 26, 1967 corresponds to the deadliest storm affecting Portugal in recent centuries being responsible for >500 fatalities. The main trigger was the heavy rain that fell in just a few hours, provoking a rapid increase in river flows, although other concurrent circumstances had to occur to reach the dramatic water levels estimated in some affected places. However, even today, several important uncertainties related to water levels achieved and timing of floods remain. Here we aim to clarify some of the pending issues by applying suitable high performance numerical tools to elucidate the main conditioning factors that played a key role in the intensification of this dramatic flood. In particular, the analysis has been focused on Quintas village, the location most affected, where >100 fatalities were recorded, close to 2/3 of its total population at the time. The main conclusion provided by the numerical simulations was that a plugging of water flow downstream of Quintas village, favoured by a poor terrain maintenance coupled with the bottleneck created by topographic features, caused the critical over-elevation of water levels. Simulations also corroborate the rapid increase in water levels in Quintas village, with an estimated rise of >2 m in just two hours, as well as the occurrence of the flood during the night, preventing many people to be aware of the extreme danger they were facing and safeguarding themselves.Universidade de Vigo/CISU

    Perceptual-motor coupling betwwen Helicopter and ship during ship deck landing maneuvers

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    Helicopter ship landings are challenging operations appealing for further researches and innovations to help pilots safely dealing with a variety of environmental, visual and operational contexts. Indeed, landing on ship not only differs from land-based landings in the extent that the landing area is located on the flight deck, which is most of the time oscillating, but also because the visual environment is often impoverished (e.g., rain, fog, night conditions). In order to improve safety at deck-landing, the French Aerospace Lab (ONERA) and the French Defense Agency (DGA) are interested in understanding pilots’ perceptual-motor strategies involved in a such complex task so as to design ecological interfaces assisting pilots’ landing maneuvers

    Optical fiber sensors based on sol-gel materials: design, fabrication and application in concrete structures

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    Optical fiber sensing systems have been widely developed for several fields such as biomedical diagnosis, food technology, military and industrial applications and civil engineering. Nowadays, the growth and advances of optical fiber sensors (OFS) are focused on the development of novel sensing concepts and transducers as well as sensor cost reduction. This review provides an overview of the state-of-the-art of OFS based on sol-gel materials for diverse applications with particular emphasis on OFS for structural health monitoring of concrete structures. The types of precursors used in the development of sol-gel materials for OFS functionalization to monitor a wide range of analytes are debated. The main advantages of OFS compared to other sensing systems such as electrochemical sensors are also considered. An interdisciplinary review to a broad audience of engineers and materials scientists is provided and the relationship between the chemistry of sol-gel material synthesis and the development of OFS is considered. To the best of the authors' knowledge, no review manuscripts were found in which the fields of sol-gel chemistry and OFS are correlated. The authors consider that this review will serve as a reference as well as provide insights for experts into the application of sol-gel chemistry and OFS in the civil engineering field. (c) The Royal Society of Chemistry

    Solução salina hipertônica aumenta a pressão de perfusão cerebral no transplante do fígado para hepatite fulminante: resultados preliminares

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    During orthotopic liver transplantation for fulminant hepatic failure, some patients may develop sudden deterioration of cerebral perfusion and oxygenation, mainly due to increased intracranial pressure and hypotension, which are likely responsible for postoperative neurological morbidity and mortality. In the present study, we hypothesized that the favorable effects of hypertonic saline solution (NaCl 7.5%, 4 mL/kg) infusion on both systemic and cerebral hemodynamics, demonstrated in laboratory and clinical settings of intracranial hypertension and hemorrhagic shock resuscitation, may attenuate the decrease in cerebral perfusion pressure that often occurs during orthotopic liver transplantation for fulminant hepatic failure. METHODS: 10 patients with fulminant hepatic failure in grade IV encephalopathy undergoing orthotopic liver transplantation with intracranial pressure monitoring were included in this study. The effect on cerebral and systemic hemodynamics in 3 patients who received hypertonic saline solution during anhepatic phase (HSS group) was examined, comparing their data with historical controls obtained from surgical procedure recordings in 7 patients (Control group). The maximal intracranial pressure and the corresponding mean arterial pressure values were collected in 4 time periods: (T1) the last 10 min of the dissection phase, (T2) the first 10 minutes at the beginning of anhepatic phase, (T3) at the end of the anhepatic phase, and (T4) the first 5 minutes after graft reperfusion. RESULTS: Immediately after hypertonic saline solution infusion, intracranial pressure decreased 50.4%. During the first 5 min of reperfusion, the intracranial pressure remained stable in the HSS group, and all these patients presented an intracranial pressure lower than 20 mm Hg, while in the Control group, the intracranial pressure increased 46.5% (P < 0.001). The HSS group was the most hemodynamically stable; the mean arterial pressure during the first 5 min of reperfusion increased 21.1% in the HSS group and decreased 11.1% in the Control group (P < 0.001). During the first 5 min of reperfusion, cerebral perfusion pressure increased 28.3% in the HSS group while in the Control group the cerebral perfusion pressure decreased 28.5% (P < 0.001). Serum sodium at the end of the anhepatic phase and 3 hours after reperfusion was significantly higher in the HSS group (153.00 &plusmn; 2.66 and 149.00 &plusmn; 1.73 mEq/L) than in the Control group (143.71 &plusmn; 3.30 and 142.43 &plusmn; 1.72 mEq/L), P = 0.003 and P < 0.001 respectively. CONCLUSION: Hypertonic saline solution can be successfully used as an adjunct in the neuroprotective strategy during orthotopic liver transplantation for fulminant hepatic failure, reducing intracranial pressure while restoring arterial blood pressure, promoting sustained increase in the cerebral perfusion pressure.Neste estudo testamos a hipótese de que os efeitos benéficos decorrentes da administração da solução salina hipertônica (NaCl 7,5%, 4 mL/kg) sobre a hemodinâmica sistêmica e cerebral na hipertensão intracraniana e no choque hemorrágico, possam atenuar a diminuição da pressão de perfusão cerebral que freqüentemente acompanha o transplante do fígado para hepatite fulminante. MÉTODO: Foram estudados 10 pacientes com hepatite fulminante em encefalopatia grau IV e monitorização de pressão intracraniana submetidos ao transplante do fígado. A hemodinâmica sistêmica e cerebral de 3 pacientes que receberam solução salina hipertônica durante a fase anepática (Grupo SSH) foi analisada comparando com os dados obtidos de 7 pacientes transplantados anteriormente nas mesmas condições (Grupo Controle). Os valores de pressão intracraniana máxima e a correspondente pressão arterial média foram coletados em quatro tempos: (T1) nos últimos 10 min da fase de disseccão, (T2) nos primeiros 10 minutos da fase anepática, (T3) no final da fase anepática e (T4) nos primeiros 5 min da reperfusão RESULTADO: Imediatamente após a infusão da solução salina hipertônica a pressão intracraniana diminuiu 50,4%. Nos primeiros 5 min da reperfusão a pressão intracraniana no Grupo SSH se manteve estável e todos os pacientes apresentavam pressão intracraniana menor que 20 mmHg enquanto no Grupo Controle a pressão intracraniana aumentou 46,5% (

    The effect of early treatment with ivermectin on viral load, symptoms and humoral response in patients with non-severe COVID-19: A pilot, double-blind, placebo-controlled, randomized clinical trial.

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    Background Ivermectin inhibits the replication of SARS-CoV-2 in vitro at concentrations not readily achievable with currently approved doses. There is limited evidence to support its clinical use in COVID-19 patients. We conducted a Pilot, randomized, double-blind, placebo-controlled trial to evaluate the efficacy of a single dose of ivermectin reduce the transmission of SARS-CoV-2 when administered early after disease onset. Methods Consecutive patients with non-severe COVID-19 and no risk factors for complicated disease attending the emergency room of the Clínica Universidad de Navarra between July 31, 2020 and September 11, 2020 were enrolled. All enrollments occurred within 72 h of onset of fever or cough. Patients were randomized 1:1 to receive ivermectin, 400 mcg/kg, single dose (n = 12) or placebo (n = 12). The primary outcome measure was the proportion of patients with detectable SARS-CoV-2 RNA by PCR from nasopharyngeal swab at day 7 post-treatment. The primary outcome was supported by determination of the viral load and infectivity of each sample. The differences between ivermectin and placebo were calculated using Fisher's exact test and presented as a relative risk ratio. This study is registered at ClinicalTrials.gov: NCT04390022. Findings All patients recruited completed the trial (median age, 26 [IQR 19-36 in the ivermectin and 21-44 in the controls] years; 12 [50%] women; 100% had symptoms at recruitment, 70% reported headache, 62% reported fever, 50% reported general malaise and 25% reported cough). At day 7, there was no difference in the proportion of PCR positive patients (RR 0·92, 95% CI: 0·77-1·09, p = 1·0). The ivermectin group had non-statistically significant lower viral loads at day 4 (p = 0·24 for gene E; p = 0·18 for gene N) and day 7 (p = 0·16 for gene E; p = 0·18 for gene N) post treatment as well as lower IgG titers at day 21 post treatment (p = 0·24). Patients in the ivermectin group recovered earlier from hyposmia/anosmia (76 vs 158 patient-days; p < 0.001). Interpretation Among patients with non-severe COVID-19 and no risk factors for severe disease receiving a single 400 mcg/kg dose of ivermectin within 72 h of fever or cough onset there was no difference in the proportion of PCR positives. There was however a marked reduction of self-reported anosmia/hyposmia, a reduction of cough and a tendency to lower viral loads and lower IgG titers which warrants assessment in larger trials. Funding ISGlobal, Barcelona Institute for Global Health and Clínica Universidad de Navarra

    Application of Decision Theory methods for a Community of Madrid Soil classification case

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    A land classification method was designed for the Community of Madrid (CM), which has lands suitable for either agriculture use or natural spaces. The process started from an extensive previous CM study that contains sets of land attributes with data for 122 types and a minimum-requirements method providing a land quality classification (SQ) for each land. Borrowing some tools from Operations Research (OR) and from Decision Science, that SQ has been complemented by an additive valuation method that involves a more restricted set of 13 representative attributes analysed using Attribute Valuation Functions to obtain a quality index, QI, and by an original composite method that uses a fuzzy set procedure to obtain a combined quality index, CQI, that contains relevant information from both the SQ and the QI methods

    Accessibility levels of Portuguese Enterprise websites: Equal opportunities for all?

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    Artigo revisto disponível online 18 Maio, 2011 (iFirst)Web accessibility is growing in importance as time goes by. Alongside this growth we find an increasing need for access to Web resources by those with some sort of disability. The Web is very important for spreading information and for promoting interaction between the various elements in society. Given this, it is essential that the Web presents itself as a totally accessible resource, so that it can help disabled citizens and their integration in society. This obligation should be even greater for enterprises as primarily the Web is used as a marketing and business platform. With this document we present indicators regarding the [lack of] accessibility levels of Portuguese websites. This article is divided into eight parts containing theoretical and background considerations leading up to two different studies which the research team undertook. In the first study (considering WCAG 1.0) we make a comparison between the 1,000 largest Portuguese enterprises (annual sales volume) and the 1,000 best Portuguese SMEs1 using a specialized software tool. In the second study a group of recommendations towards accessibility are made; these recommendations were achieved through a focus group interaction. We do also, however, present an insight into the WCAG 2.0 influence on existent accessibility levels
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