A Importância Estratégica do Mar para Portugal

O autor analisa a importância do mar para Portugal, à luz do seu posicionamento geoestratégico. Como país de tradição marítima, Portugal pode projectar a sua marca distintiva no panorama internacional servindo de ponte entre três continentes – Europa, África e América. O mar português é não só um activo crítico com vastas potencialidades económicas como também espaço de cultura, turismo e lazer. Referindo-se ao Relatório elaborado pela Comissão Estratégica dos Oceanos, destaca as três áreas em que o posicionamento estratégico referido tem maior impacto: Defesa, Economia, e Relações Internacionais, Diplomacia e Cooperação. Na área da Defesa salienta o valor estratégico que o território nacional, continental e insular, tem para a União Europeia e para a NATO. No que respeita à Economia recomenda uma exploração criteriosa dos recursos marinhos e, por outro lado, que os portos nacionais, em particular Sines, devem ser um terminal das ligações transoceânicas, para penetração não só na Península Ibérica, como ligação ao Norte da Europa, e à costa ocidental africana. Nas Relações Internacionais, Diplomacia e Cooperação, Portugal como membro empenhado da União Europeia deve utilizar a experiência adquirida ao longo da sua história ao cruzar-se com outras culturas. A participação nas Nações Unidas na negociação da agenda internacional dos oceanos e do direito do mar, confere-lhe abertura a “alianças estratégicas e tácticas” com outros países de vocação marítima, e o estabelecimento de parcerias público-privadas multilaterais ou bilaterais

Case report: Stenosis turned leak … and turned stenosis-complications of paravalvular prosthetic leak closure with a plug device.

Paravalvular leak is one of the most common complications and is among the most important prognostic factors of short- and long-term mortality after transcatheter aortic valve implantation (TAVI). Percutaneous valvular leak repair constitutes a first-line treatment for paravalvular leaks and is associated with high success rates and few serious complications nowadays. To the best of our knowledge, this is the first case where placement of the device through the stenting of the bioprosthesis resulted in creating a new symptomatic stenosis that required surgery. We present a case of a patient with low-flow, low-gradient aortic stenosis treated with transfemoral implantation of a biological aortic prosthesis. One month after the procedure, the patient presented with acute pulmonary oedema and a paravalvular leak was discovered, which was corrected by percutaneous repair with a plug device. Five weeks after the valvular leak repair, the patient was readmitted for heart failure. At this time, a new aortic stenosis and paravalvular leak were diagnosed and the patient was referred for surgery. The new aortic mixed diseased was caused by the positioning of the plug device through the valve's metal stenting, which resulted in a paravalvular leak and pressed against the valve's leaflets, causing valvular stenosis. The patient was referred for surgical replacement and evolved well afterward. This case illustrates a rare complication of a complex procedure, and it highlights the need for multidisciplinary decisions and good cooperation between the cardiology and cardiac surgery teams to develop better criteria in the selection of the appropriate technique for managing paravalvular leaks after TAVI

Dissolved organic matter cycling in eastern Mediterranean rivers experiencing multiple pressures. The case of the trans-boundary Evros River

The objective of our study was to provide a comprehensive evaluation on C, N, P cycling in medium sized Mediterranean rivers, such as the Evros, experiencing multiple pressures (intensive agriculture, industrial activities, population density). Our work aims also to contribute to the development of integrated management policies. Dissolved organic matter (DOM) cycling were investigated, during a one-year study. It was shown that the organic component of N and P was comparable to those of large Mediterranean rivers (Rhone, Po). In the lower parts of the river where all point and non-point inputs converge, the high inorganic N input favour elevated assimilation rates by phytoplankton and result in increased chl-a concentrations and autochthonous dissolved organic matter (DOM) production during the dry season with limited water flow. Moreover, carbohydrate distribution revealed that there is a constant background of soil derived mono-saccharides on top of which are superimposed impulses of poly-saccharides during blooms. During the dry season, inorganic nutrients and DOM are trapped in the lower parts of the river, whereas during high flow conditions DOM is flushed towards the sea and organic nitrogen forms can become an important TDN constituent (at least 40%) transported to shelf waters. The co-existence of terrigenous material with autochthonous and some anthropogenic is supported by the relatively low DOC:DON and DOC:DOP ratios, the positive correlation of DOC vs chl-a and the decoupling between DOC and DON. Overall, this study showed that in medium size Mediterranean rivers, such as the Evros, intensive agriculture and pollution sources in combination with water management practices and climatic variability are important factors determining C, N, P dynamics and export to coastal seas. Also, it highlights the importance of the organic fraction of N and P when considering management practices

Cultivo do milho: diagnose foliar do estado nutricional da planta.

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Inibição do crescimento de raiz pelo alumínio e toxidez por prótons em milho.

Com o objetivo de investigar a tolerancia diferencial de linhagens de milho ao Al e sua interacao com alta atividade de protons, foram conduzidos dois experimentos em solucao nutritiva. No primeiro foram avaliadas seis linhagens de milho e quatro doses de Al (0, 55, 111 e 222 M) e no segundo as mesmas linhagens e quatro valores de pH (3,8, 4,2, 4,6 e 5,0). Verificou-se que a melhor separacao entre os materiais tolerantes e sensiveis ocorreu na dose de 222 M de Al, visto que em doses mais baixas deste elemento houve estimulo do crescimento radicular, sendo este mais acentuado nas linhagens SLP 181 e L 3, tolerantes ao AL. Entretanto o estimulo do crescimento foi temporario e a toxidez se manifestou apos cinco dias de tratamento. Quatro linhagens estudadas foram sensiveis a alta atividade de protons, sendo duas tolerantes ao Al e duas sensiveis. Conclui-se que em milho nao houve correlacao definida entre tolerancia ao Al e tolerancia a alta atividade de protons, em solucao nutritiva