Convergence of the Crank-Nicolson-Galerkin finite element method for a class of nonlocal parabolic systems with moving boundaries

The aim of this paper is to establish the convergence and error bounds to the fully discrete solution for a class of nonlinear systems of reaction-diffusion nonlocal type with moving boundaries, using a linearized Crank-Nicolson-Galerkin finite element method with polynomial approximations of any degree. A coordinate transformation which fixes the boundaries is used. Some numerical tests to compare our Matlab code with some existing moving finite elements methods are investigated

Fish-based groups for ecological assessment in rivers: the importance of environmental drivers on taxonomic and functional traits of fish Assemblages

The use of river-types is of practical value, serving as groups for which assessment procedures can be developed and applied. An abiotic typology was set by the Portuguese Water Agency, mainly based on 6 major morphoclimatic regions. However, to be biologically meaningful, this typology should fit the distribution patterns of the biological quality elements communities proposed in Water Framework Directive under the lowest possible human pressure. This study aimed to identify and characterize fish-based geographical groups for continental Portugal and their environmental and geographical discriptors, using taxonomic and functional traits. Sampling took place between 2004 and 2006 during Spring. Fish fauna from 155 reference sites was analysed using a multivariate approach. Cluster Analysis on fish composition identified 10 fish-groups, expressing a clear correspondence to the river basin level, due to the restrict basin distribution of many species. Groups showed a wider aggregation in 4 regions with a larger geographical correspondence, statistically supported by Similarity Analysis, both on fish composition and mostly on fish metrics/guilds. Principal Components Analysis revealed major environmental drivers associated to fish-groups and fish-regions. Fish-groups were hierarchically grouped over major and local regions, expressing a large-scale response to a North-South environmental gradient defined by temperature, precipitation, mineralization and altitude, and a regional scale response mainly to drainage area and flow discharge. From North to South, fish-regions were related to the morphoclimatic regions. Results contributed to reduce redundance in abiotic river-types and set the final typology for Portuguese rivers, constituting a fundamental tool for planning and managing water resources

ROAZ Autonomous Surface Vehicle Design and Implementation

The design of an Autonomous Surface Vehicle for operation in river and estuarine scenarios is presented. Multiple operations with autonomous underwater vehicles and support to AUV missions are one of the main design goals in the ROAZ system. The mechanical design issues are discussed. Hardware, software and implementation status are described along with the control and navigation system architecture. Some preliminary test results concerning a custom developed thruster are presented along with hydrodynamic drag calculations by the use of computer fluid dynamic methods

R&D dynamics with asymmetric efficiency

We consider an R&D investment function in a Cournot duopoly competition model inspired in the logistic equation. We study the economical effects resulting from the firms having different R&D efficiencies. We present three cases: (1) both firms are efficient and have the same degree of efficiency; (2) both firms are less efficient and have the same degree of efficiency; (3) firms are asymmetric in terms of the efficiency of their R&D investment programs. We study the myopic dynamics on the production costs obtained from investing the Nash investment equilibria.info:eu-repo/semantics/publishedVersio

Essencial oil components of Hypericum androsaemum infusions and their nematotoxic effects against Meloidogyne javanica (Treub) Chitwood.

Real Sociedad Española de Química, CITAB -UM, CBMA - UM, FCTUniversidade do Minho - CITAB -UM, CBMA - UMFundação para a Ciência e a Tecnologia (FCT

A study of the antitumour potential of three Portuguese wild mushrooms

Natural matrixes such as mushrooms represent a rich source of biologically active compounds with recognized potential in drug discovery and development [1,2]. Indeed, many pre-clinical studies have been conducted in human tumour cell lines and in some cases, a number of compounds extracted from mushrooms have entered clinical trials [3]. Our previous results showed that extracts from Agaricus arvensis, Suillus collinitus and Clytocibe alexandri are promising sources of low molecular weight bioactive compounds [4]. The aim of the present work was to study the antitumour potential of the extracts and isolated compounds from three Portuguese wild mushrooms by verifying their effect on various human tumour cell lines in what concerns effect on cell growth, cell cycle profile and programmed cell death. Wild mushrooms were collected from the Northeast of Portugal and classified as Agaricus arvensis, Suillus collinitus and Clitocybe alexandri. Phenolic (methanolic and ethanolic) and polissacharidic extracts were prepared. The effect of the extracts on tumour cell growth inhibition was verified with the SRB assay and the GI50 of each extract was determined for each of the cell lines studied (NCI-H460, MCF-7, AGS and HCT-15). Our preliminary results revealed that all the extracts from Clitocybe alexandri are capable of causing cell growth inhibition and provided GI50 concentrations bellow 60µg/ml in all the cell lines tested [4]. Regarding the effect of the Agaricus arvensis extracts, they all caused an inhibition of cell growth in all cell lines, particularly the methanolic extract which revealed to be a very potent inhibitor of cell growth, especially in the MCF-7 cell line. The evaluation of the effect of the Suillus collinitus extracts will be carried out as well as cell cycle and apoptosis analyses, by flow cytometry. Finally, the isolation and characterization of compounds from these extracts will also be carried out, using HPLC-DAD or HPLC-RI. The structures of the compounds will be established by NMR spectral analysis (1H, 13C, DEPT, COSY, HSQC and HMBC).FCT and COMPETE/QREN/UE- project PTDC/AGR-ALI/110062/200

Adenoid cystic carcinoma of tha larynx: Case report

O carcinoma adenóide cístico (CAC) é a neoplasia maligna mais frequente das glândulas salivares minor mas, dada a escassez destas glândulas ao nível da laringe, nesta localização, corresponde a menos de 0,2% das neoplasias. Na laringe, localiza-se mais frequentemente na região subglótica, sendo os primeiros sintomas muitas vezes tardios. Estes incluem estridor, dispneia, tosse e obstrução da via aérea. Neste caso clínico, apresenta-se uma doente de 50 anos, com um CAC da região subglótica, cujo primeiro sintoma foi dispneia progressiva. Por má resposta terapêutica foi realizada uma broncofibroscopia onde foi detectada uma neoformação subglótica. Biópsia posterior diagnosticou um CAC do tipo cribriforme. Foi submetida a laringectomia total, seguida de Radioterapia (RT). O seguimento ao longo de 15 meses após cirurgia revela que a doente se encontra sem evidência de recidiva local ou metástases à distância. O seguimento prolongado destes doentes é obrigatório, dada a possível metastização tardia.info:eu-repo/semantics/publishedVersio