2,069 research outputs found

    Programa multidisciplinar de monitorização de curto termo para apoio ao planeamento e gestão da zona costeira

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    A zona costeira do noroeste de Portugal tem vindo a sofrer processos erosivos de modo progressivo que têm preocupado os responsáveis políticos e os cidadãos em geral. Esta realidade é especialmente notória nas zonas costeiras com altas pressões de ocupação. A zona costeira de Vila Nova de Gaia apresenta ocupação intensa, tendo vários segmentos que evidenciam elevada vulnerabilidade à erosão costeira. Com o objectivo de avaliar os segmentos mais vulneráveis foi implementado um programa global de monitorização iniciado em 2007. Pretende-se avaliar as tendências de evolução morfodinâmica do sistema costeiro, incluindo prépraia, praia e dunas. Este programa compreendeu a realização de duas campanhas anuais, durante dois anos, utilizando um conjunto de metodologias de monitorização inovadoras: observações de campo, fotografias aéreas, levantamentos topográficos com um sistema móvel com DGPS e câmaras de vídeo; levantamentos batimétricos utilizando uma embarcação autónoma flutuante; recolha de amostras de sedimentos e realização de perfis de praia. A informação produzida foi processada para utilização na avaliação da vulnerabilidade à erosão e produção das cartas de risco associadas, as quais estão em fase de elaboração. Todos os dados são processados e analisados em ambiente SIG. Neste artigo são apresentados resultados obtidos nas quatro campanhas de monitorização, incluindo aspectos da morfodinâmica local com base na análise dos Modelos Digitais de Terreno e as principais mudanças morfológicas e sedimentares verificadas no período de monitorização

    Integração de metodologias no estabelecimento de um programa de monitorização costeira para avaliação de risco

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    Na zona costeira do noroeste de Portugal os processos erosivos em curso têm vindo progressivamente a constituir motivo de preocupação, quer para os responsáveis pela gestão da zona costeira, quer para a população em geral. As principais causas apontadas para a origem destes processos são: (i) diminuição dos caudais sedimentares fluviais, devido à construção de barragens, dragagens, extracção de inertes e esgotamento dos depósitos sedimentares da plataforma interna, (ii) influência de estruturas de protecção costeira, (iii) aumento do nível do mar e da frequência e intensidade das tempestades. Tomando como caso de estudo a zona costeira de Vila Nova de Gaia, exemplo paradigmático de grande ocupação do litoral, implementou-se em 2008 um novo programa extensivo de monitorização, integrando diferentes tecnologias, de forma a avaliar as tendências evolutivas da morfodinâmica do sistema costeiro, incluindo a faixa litoral submersa, a praia e as dunas. O programa de monitorização integra observações de campo, amostragem de sedimentos e de perfis de praia, fotografia aérea, levantamentos batimétricos, e levantamentos com um sistema de mapeamento móvel com GPS e câmaras de vídeo. Desde 2008 têm sido efectuadas duas campanhas anuais utilizando esta metodologia de monitorização que permitiu avaliar as tendências evolutivas da morfodinâmica costeira e obter a informação de base para estabelecer mapas de risco de erosão para a zona de estudo. Observam-se três tendências ao longo da zona estudada: segmentos com erosão, segmentos com acreção e segmentos estáveis. Para além dos processos naturais decorrentes da morfologia da costa e das condições meteorológicas, as causas de origem antropogénica surgem como um dos principais factores desequilibradores na dinâmica costeira. Exemplos disso são a obra do emissário da praia de Canide e do quebra-mar do portinho da Aguda. Nestes locais observa-se uma forte erosão nos segmentos a sul das estruturas, enquanto a barlamar dá-se tendencialmente uma deposição de sedimentos. Concluiu-se que a maioria dos segmentos está sujeita a processos de erosão, com algumas zonas de acreção, em parte resultantes de recarga artificial das praias. Estas conclusões constituem motivo de preocupação pelo facto de a mobilidade natural dos sistemas costeiros se encontrar reduzida devido à artificialização da costa, numa zona de elevada ocupação populacional

    Small harbours risks: lowering for fishery and increasing erosion. The case of Portinho da Aguda (NW Portugal)

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    The harbour Portinho da Aguda was established between October 2001 and July 2002, at Aguda village. The area presented some rocky outcrops that, in some way, protected the coastal border against direct wave impact, on a coastal stretch where erosion has been a continuing problem. In an attempt to create a protected area for the entrance and way out of the community’s small fishing boats a detached curved breakwater was built. After some months, still during the works, a wedge beach was created against the temporary groin, promoting the enlargement of the beach located updrift and the erosion of the downdrift coastal segment (Granja Beach). To remediate this situation, sand transfer from the updrift area was done, to compensate the accentuated loss of sediments of Granja Beach, a famous old seaside resort. But, due to the very high energetic conditions, sands did not remain on the beach, and new spring to early summer recharges became necessary. Based on results from a comprehensive monitoring program of the coastal border north and south of Aguda between 2001 and 2009 with DGPS, sedimentary budgets were calculated and morphological changes identified, comparing situations before and after breakwater construction. Breakwater impacts on neighbouring areas of the harbour are presented, as are the evolution trends of the harbour itself. Some possible mitigation measures are pointed out and the efficiency and relevance of this kind of coastal structures is discussed

    Methods for coastal monitoring and erosion risk assessment: two Portuguese case studies

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    Coastal zones are naturally dynamic and mobile systems exposed to natural (river flows, waves and storms) as well as human interventions that continuously reshape their morphology. Erosion phenomena related to extreme weather events and sediment scarcity are common, threatening buildings and infrastructures, as well as beaches, ecosystems and valuable wetland; conditions that pose challenges to coastal security and defence. Regular monitoring of coastal areas, assessment of their morphodynamics and identification of the processes influencing sediment transport are thus increasingly important for a better understanding of changes and evolutionary trends in coastal systems. This demands a multi-disciplinary approach involving researchers with expertise in coastal processes and state-of-the-art observation technologies. In this paper state-of-the-art surveying methods for an efficient quantification of changes in coastal environments are described and evaluated, and two NW-Portuguese case studies are presented. Survey methods included: topographic surveys based on terrestrial videogrammetric mobile mapping and aerial photogrammetry; sub-tidal bathymetry with sonar imagery using an Autonomous Surface Vehicle (ASV); as well as field observations, with sediment sampling and beach characterisation. In the first case study erosion/accretion patterns in the Douro estuary sand spit are analysed, considering its breakwater, river flow, wave and wind effects. Prior to the construction of a detached breakwater, the spitâ s morphodynamics was related to extreme river flow events, wave and wind conditions; afterwards the spit stabilized its shape and increased its area and volume. In the second case study the coast of Vila Nova de Gaia was broadly analysed, including the shoreface, foreshore and dunes, the characterization of major features and a short-period analysis of installed dynamics. Results obtained from field data, topographical surveys and numerical wave models were combined for the erosion risk assessment, using a methodology specifically developed for the study area. Both monitoring programs achieved their proposed objectives and provided valuable information to the local authorities, as gathered and processed information constitutes a valuable database for coastal planning and for ICZM purposes. They demonstrate the potential of several approaches, supported by advanced technologies, for the study of complex coastal morphodynamic processes.Zonas costeiras são sistemas naturalmente dinâmicos e móveis, expostos a fatores naturais (fluxos de rios, ondas e tempestades) e intervenções humanas, que alteram continuamente a sua morfologia. Fenómenos de erosão relacionados com temporais e escassez de sedimentos são comuns. Eles ameaçam construções e infraestruturas, praias, ecossistemas e zonas húmidas, o que constitui um desafio para a segurança e defesa costeiras. Uma monitorização regular de áreas costeiras, com avaliação da sua morfodinâmica e identificação dos processos que influenciam o transporte de sedimentos, visando uma melhor compreensão das alterações e tendências evolutivas nos sistemas costeiros, torna-se portanto cada vez mais importante. Para tal necessita-se de uma abordagem multidisciplinar e investigadores especializados em processos costeiros e tecnologias de observação de ponta. O presente trabalho descreve e avalia métodos de monitorização de última geração para uma quantificação eficiente de alterações em ambientes costeiros e apresenta dois estudos de caso Portugueses. Os métodos de observação incluem: levantamentos topográficos terrestres em modo cinemático baseados em videogrametria; levantamentos topográficos aéreos baseados em fotogrametria; batimetria sub-tidal e imagens de fundo obtidas com sonar a partir de um veículo autónomo de superfície; e observações de campo com análise de sedimentos e caracterização de praias. O primeiro caso de estudo referese à análise de padrões de erosão e acreção na restinga do estuário do Douro, tendo em conta efeitos causados pelo molhe, o caudal do rio, ondas e vento. Antes da construção de um molhe destacado, a morfodinâmica da restinga estava relacionada com eventos extremos de caudal, agitação marítima e vento. Após a construção, a forma da restinga estabilizou e observou-se um aumento da sua área e do seu volume. No segundo caso de estudo, a costa de Vila Nova de Gaia foi amplamente estudada, incluindo shoreface, foreshore e dunas, com a caracterização dos principais atributos e uma análise de curto-período da dinâmica instalada. Os resultados obtidos a partir de dados de campo, dos levantamentos topográficos e de modelos numéricos de ondas foram combinados numa análise de risco com métodos especificamente desenvolvidos para a área de estudos. Ambos os programas de monitorização atingiram os seus objetivos e geraram informação relevante para as autoridades locais. A informação recolhida e processada constitui uma base de dados valiosa para o planeamento costeiro e a Gestão Integrada de Zonas Costeiras. Os estudos demonstram o potencial das diversas abordagens, apoiadas por tecnologias avançadas, para o estudo dos processos complexos de morfodinâmica costeira.This research was partially supported by the European Regional Development Fund (ERDF) through the COMPETE – Operational Competitiveness Programme and national funds through FCT – Foundation for Science and Technology, under the project “Pest-C/ MAR/LA0015/2013”, and partially funded by the Project ECORISK (reference NORTE-07-0124-FEDER- 000054), co-financed by the North Portugal Regional Operational Programme (ON.2 – O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF). Wave climate analyses were supported by the FCT-funded RAP project (PTDC/MAR/111223/2009)

    Coastal zone geomorphologic interactions: natural versus human-induced driving factors

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    Sediment dynamics in the vicinity of river mouths reveal complex patterns due to the joined effect of river discharges, tides and waves. These phenomena underlie current mathematical and simulation models, which constitute powerful tools that can be used as a complement to monitoring field work for the characterization of morphodynamical patterns in these complex coastal environments. The Cávado estuary inlet is situated near Esposende and the Douro Estuary about 50 km south of it, next to Porto. During the last years, inland beach migration, sand loss and cliff retreat have been recurrent in this North Portuguese, Atlantic coastal areas, which can be considered to be of the mixed energy and wave-dominated type. Local tides are mesotidal and semidiurnal, with a maximum equinoctial spring tide high-water level of about 3.9 m and 4.0 m and a minimum low-water level of 0.2 m and 0.1 m, for the Esposende and Porto regions, respectively. Mean spring tides are about 3.5 m. The Cávado estuary inlet, enclosed between a breakwater on the northern side and the end of a migrant sandy spit on the southern side, has been subject to silting up. The spit’s resilience is crucial as a natural defense against sea incursions for the town of Esposende which lies behind the spit. During the last twenty years the sea has repeatedly flooded and twice ruptured the spit. To decrease silting-up and increase navigability, the building of two breakwaters and an artificial inlet management has been suggested. The Douro Estuary inlet is also protected by a northern breakwater and has a protective estuarine barrier sand spit, though in a more inland position than the Cávado spit. This spit protects Douro harbor facilities and the heavily populated river banks against wave and tide actions. Facing similar problems as in the Cávado (silting-up of the navigation channel that runs north of the spit and spit vulnerability to wave and wind action and, particularly to the recurrent river floods) the northern breakwater was extended and an additional breakwater was built (between 2004 and 2008) attached to the spit, to protect it. The present work discusses and synthesizes results from an integrated approach, involving monitoring field surveys and the application of mathematical models, to describe the main features of these two coastal inlets and adjacent costal zones, considering the 15 km from the Neiva River to Apúlia for the Cávado river and the 22 km from Crestuma dam to Porto for the Douro river. The influence of river and tidal characteristics are discussed for both cases

    The transcriptome analysis of early morphogenesis in Paracoccidioides brasiliensis mycelium reveals novel and induced genes potentially associated to the dimorphic process

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    BACKGROUND: Paracoccidioides brasiliensis is a human pathogen with a broad distribution in Latin America. The fungus is thermally dimorphic with two distinct forms corresponding to completely different lifestyles. Upon elevation of the temperature to that of the mammalian body, the fungus adopts a yeast-like form that is exclusively associated with its pathogenic lifestyle. We describe expressed sequence tags (ESTs) analysis to assess the expression profile of the mycelium to yeast transition. To identify P. brasiliensis differentially expressed sequences during conversion we performed a large-scale comparative analysis between P. brasiliensis ESTs identified in the transition transcriptome and databases. RESULTS: Our analysis was based on 1107 ESTs from a transition cDNA library of P. brasiliensis. A total of 639 consensus sequences were assembled. Genes of primary metabolism, energy, protein synthesis and fate, cellular transport, biogenesis of cellular components were represented in the transition cDNA library. A considerable number of genes (7.51%) had not been previously reported for P. brasiliensis in public databases. Gene expression analysis using in silico EST subtraction revealed that numerous genes were more expressed during the transition phase when compared to the mycelial ESTs [1]. Classes of differentially expressed sequences were selected for further analysis including: genes related to the synthesis/remodeling of the cell wall/membrane. Thirty four genes from this family were induced. Ten genes related to signal transduction were increased. Twelve genes encoding putative virulence factors manifested increased expression. The in silico approach was validated by northern blot and semi-quantitative RT-PCR. CONCLUSION: The developmental program of P. brasiliensis is characterized by significant differential positive modulation of the cell wall/membrane related transcripts, and signal transduction proteins, suggesting the related processes important contributors to dimorphism. Also, putative virulence factors are more expressed in the transition process suggesting adaptation to the host of the yeast incoming parasitic phase. Those genes provide ideal candidates for further studies directed at understanding fungal morphogenesis and its regulation

    The prevalence of diabetes and stress hyperglycemia in the acute myocardial infarction patients

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    OBJETIVOS: Determinar a prevalência do diabetes melito (DM) e da hiperglicemia de estresse (HE) em pacientes com infarto agudo do miocárdio (IAM) admitidos em unidade de emergência cardiológica. MÉTODOS: Análise retrospectiva de 2.262 pacientes com IAM, avaliando, além da prevalência de diabetes referido, o diagnosticado e a hiperglicemia de estresse. RESULTADOS: Apesar de referido em 12,1% dos pacientes (H: 10,7%, M: 15,8%), o DM ocorria efetivamente em 24,8% (H: 22,9%, M: 29,7%) e a HE em 13,6% (H: 14,3%, M: 11,7%) dos indivíduos dessa população. Portanto, alterações glicêmicas ocorreram em 37,4% dos indivíduos com IAM (H: 37,2%, M: 41,4%). Nos pacientes com DM, observou-se maior precocidade etária do IAM, maior prevalência de óbitos (DM: 20,7%, ND:13,8%, HE: 13,4%) e de procedimentos cirúrgicos (ND: 33,8%, HE: 18,0%, DM: 21,7%). CONCLUSÃO: A elevada prevalência de DM e hiperglicemia de estresse observada em nosso estudo indica que as alterações glicêmicas constituem um dos mais importantes fatores de risco para o IAM.OBJECTIVES: To evaluate in our population the real prevalence of diabetes (DM) and stress hyperglycemia (HE) in patients with myocardial infarction (IAM) admitted in a cardiologic emergency unit. METHODS: A retrospective analysis of 2262 patients with AMI evaluating the prevalence of DM (referred and diagnosed) and stress hyperglycemia. RESULTS: Besides 12,1% of subjects were previously referred to be diabetic (men: 10.7% and women: 15.8%), diabetes was effectively diagnosed in 24,8% (M: 22,9%, W: 29,7%) and stress hyperglycemia in 13,6% HE of the patients (M: 14,3%, W: 11,7%) indicating that glycemic alterations were effectively observed in 37.2.% of the patients with IAM (M: 37,2%, W: 41,4%). In DM subjects IAM events occurred earlier, total intra-hospital mortality was higher (DM: 20.7%, ND: 13,8%, HE: 13,4%) and less surgical procedures were performed (ND 33.8%, DM: 21.7%, HE: 18.0%). CONCLUSION: The elevated DM and stress hyperglycemia prevalence observed in our study indicates that glycemic alterations is one of the most important risk factors for IAM

    [1-(3-Chloro­phen­yl)-1H-1,2,3-triazol-4-yl]methanol hemihydrate

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    The asymmetric unit of the title hydrate, C9H8ClN3O·0.5H2O, comprises two independent 1,2,3-triazole mol­ecules and a water mol­ecule of crystallization. The dihedral angles between the six- and five-membered rings in the 1,2,3-triazole mol­ecules are 12.71 (19) and 17.3 (2)°. The most significant different between them is found in the relative orientations of the terminal CH2OH groups with one being close to perpendicular to the five-membered ring [N—C—C—O torsion angle = 82.2 (5)°], while in the other mol­ecule, a notable deviation from a perpendicular disposition is found [torsion angle = −60.3 (5)°]. Supra­molecular chains feature in the crystal packing sustained by O—H⋯(O,N) inter­actions along the a-axis direction. The chains are connected via C—H⋯N inter­actions and the resultant layers stack along the b axis

    DMSO removal reduces stem-cell infusion-related toxicity and allows excellent engraftment of cryopreserved unrelated cord blood and autologous stem cells

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    UNIFESP, GRAACC, Pediat Oncol Inst, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilUNIFESP, GRAACC, Pediat Oncol Inst, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc
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