Browsing by Issue Date, starting with "2013"
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- Site preparation impacts on physical and chemical forest soil quality indicatorsPublication . Fonseca, Felícia; Figueiredo, Tomás de; Martins, AfonsoForest soils in the Mediterranean region frequently have limited rooting depth, high coarse elements and low organic matter content, which tend to limit water storage in the soil profile. Accordingly, application of site preparation techniques is essential to enhance soil water storage and availability in these environments (Querejeta et al., 2001; Alcázar et al., 2002; Piatek et al., 2003; Imaz et al., 2010). However, site preparation for afforestation currently lacks accurate planning, based on sound experimental results driving to techniques most adequate to each situation and respecting stand productivity and ecosystem sustainability requirements. Improving soil quality is one of the most important factors for sustaining the global biosphere and fundamental in forest systems sustainability (Wang and Gong, 1998). A simple set of established soil properties can provide useful information on soil quality (Sparling et al., 2004). Soil quality has been defined as “the capacity of a soil to function within ecosystem boundaries to sustain biological productivity, maintain environmental quality, and promote plant and animal health'' (Doran and Parkin, 1994). Land use and management practices seriously impact the direction and degree of soil quality changes in time and space (Wang and Gong, 1998). Possibly the most significant impact of site preparation from a soil quality perspective is on rooting depth and soil hydrological processes, because increase the availability of resources that plants have access (water and nutrients). Runoff and sediment loss is commonly highest in the first few years after site preparation, for the reason that canopy cover is scarce and ground vegetation may be insufficient for controlling erosion (Lucci and Della Lena 1994; Figueiredo et al., 2011).
- Colocação de cateter venoso periférico em ambiente de práticas laboratoriais e sucesso da primeira punção venosa em contexto real (Ensino clínico/ Estágio). Estudo realizado em estudantes de enfermagemPublication . Preto, Leonel; Martins, MatildeA simulação é uma estratégia formativa que tem como objetivo principal melhorar competências clínicas. Na formação em enfermagem, pode ser útil quando desejamos aperfeiçoar técnicas que envolvam um certo risco para o paciente ou quando desejamos promover a confiança do aluno na execução de cuidados complexos. Analisar a primeira punção venosa periférica com cateter realizadas em utentes do foro médico-cirúrgico por alunos de enfermagem em ensino clínico/estágio; descrevendo as dificuldades sentidas na execução da técnica, e relacionando o sucesso da mesma com o tipo de aulas práticas simuladas e orientadas, que os formandos previamente tiveram em ensino teórico-prático. Estudo descritivo correlacional e de natureza quantitativa realizado na em alunos de enfermagem da Escola Superior de Saúde de Bragança. Amostra predominantemente feminina (82,1%) com uma média de idades de 22 anos (22,12 ± 3,95). Verificámos que 72,6% dos alunos consideram ter tido sucesso na primeira vez que colocaram cateteres. A destreza manual foi a principal dificuldade relatada (19%), seguida da introdução do cateter (14,9%). Cerca de 81% dos estudantes fizeram simulação prévia da técnica, antes do Ensino Clínico, a grande maioria em braços de punção (n= 103) ou no membro superior de uma colega (n= 33). Concluímos que a prática simulada e orientada em ambiente laboratorial melhora o desempenho do aluno em ensino clínico, embora o tipo de simulação (braço ou simuladores de alta fidelidade) não pareça estar associado com o sucesso (X2= 2,820; gl= 1p= 0,093).
- Modeling and simulation of a laser scanner sensor : an industrial application case studyPublication . Lima, José; Gonçalves, José; Costa, Paulo Gomes da; Moreira, António Paulo G. M.A laser scanner is a popular sensor widely used in industry and mobile robots applications that measures the distance to the sensor on a slice of the plan. At the same time, simulation has becoming more and more used in industries and academia since it presents several advantages. It takes the building and rebuilding phase out of the loop by using the model already created in the design phase. Further, simulation time on testing is cheaper and faster than performing the multiple tests of the design each time. Besides, it is easier to measure some variables in simulation than in real scenarios. In this paper, a laser scanner sensor is modeled and implemented in a developed simulator that already has several other sensors and actuators models. The presented simulation reflects the laser model properties such as target color dependences, noise, limits, time constraints, and target angle functions. As a case study, the same scenario is assembled with real components on a conveyer belt and in simulation. Results from both approaches are compared and validate the proposed model methodology. As an example, a 3D object recognition task is addressed highlighting the developed realistic model. Further industrial and R&D implementations based on this sensor could be stressed in simulation before implementation.
- The usefulness of financial reporting for internal decision-making in portuguese municipalitiesPublication . Nogueira, Sónia P.; Jorge, Susana M.; Cervera Oliver, MercedesThe purpose of this paper is to analyse the perception of internal users regarding the usefulness of municipal financial reporting in the context of decision-making in Portuguese Local Administration. This research is quantitative and positive, based on a cross-section analysis through online application of a questionnaire to decision-makers (politicians and technicians) of the 308 Portuguese municipalities. The approach is based on the information usefulness paradigm. Results indicate a high usefulness for decision-making of the municipal financial reporting, in its current form and content. However, this usefulness would increase if information, other than what is mandatory, were introduced. In general, the two different groups of decision-makers, politicians and technicians, behave somewhat differently, regarding the usefulness financial reporting holds for them. Technical decision-makers consider it of greater value. There is no statistical evidence showing that there is a link between the training area and professional experience of the internal decision-makers and the usefulness of municipal financial reporting. Both types of users show a preference for the information set within the budgetary accounts, although accrual-based information also proved to be of very high value. This study has important repercussions on internal decision-makers concerning the usefulness of municipal financial reporting. Particularly, the general approach towards reporting usefulness could become a solid work basis for the regulatory bodies to enhance the current reporting model in the light of its suitability for internal decision-making.
- The evolution and current status of organic beekeeping in PortugalPublication . Gomes, Mário; Cabo, Paula; Dias, L.G.; Casaca, João; Gonçalves, Manuel; Vilas-Boas, MiguelThe Portuguese beekeeping sector is one of the most resilient and persistent farming activities in the last decade. In the last five years, the figures reveal a counter cycle behavior with an increment in the number of colonies, apiaries and beekeepers, as shown in the National Beekeeping Program: there are 16.403 beekeepers with a total of 550.757 colonies. Following the same positive trend, the conversion from conventional to organic production as evolved in the period 2004/2012, from 738 up to 28.607 colonies (5% of the beekeeping sector), with a estimated production of 570 tons of certified honey, corresponding to an income of € 1.800.000. Even so, these figures are still below other European countries with similar environment potentialities like Italy, where the organic beekeeping represents more than 100.000 colonies (8% of total colonies) and even below the 7.6% that the organic farming represents in the Portuguese agriculture, which would be equivalent to more than 42.000 colonies. The sector organization and professionalization, the country natural resources (diverse nectar flows of high value) and the additional value given to organic products were expected to be self-sufficient factors for a sustainable enhancement of the number of organic beekeepers. However, it is been clear from the Portuguese experience that those key factors do not work alone without a continuous promotion of the production mode, focusing in the certification procedure, the specificities of beekeeping management and in the market approach: the distribution of Portuguese organic beekeepers is more concentrated in areas where the local organizations are more proactive towards the organic production. Additionally, it is interesting to notice that the profile of the organic beekeeper reveal some particularities: it is younger, with an academic background, frequently a degree in natural sciences or technologies complemented by specific beekeeping training. The interest for organic beekeeping, which represents the main income, arose from the commercial advantages, the environment protection but also from the influence of the local organization. More than 90% of the present Portuguese organic beekeepers are strongly engaged with the production mode, but highlight as the weakest points the efficacy and limitations of varroa treatments and a market value below their expectations.
- Efeito da intervenção cultural na caracterização morfológica de diferentes proveniências de Quercus suberPublication . Patrício, Maria Sameiro; Nunes, Luís; Almeida, Maria HelenaO sobreiro (Quercus suber L.) é uma espécie muito importante nas áreas de influência mediterrânea por razões económicas, ecológicas e ambientais. É uma espécie com elevado potencial de expansão considerando os cenários das alterações climáticas. Apesar da sua importância, a adaptação da espécie às condições ambientais está pouco estudada. Com o objetivo de compreender o determinismo genético dos traços adaptativos da espécie e estudar padrões de variação adaptativa, assumindo que existe diferenciação genética nos traços fenológicos encontrados nas populações de sobreiro, estabeleceu-se um ensaio em Mogadouro - Trás-os-Montes com 34 proveniências oriundas da bacia do Mediterrâneo onde a espécie tem a sua distribuição natural. Considerando que não só a adaptação, mas também a melhoria da qualidade do material reprodutivo em termos de forma e da cortiça produzida, são importantes, e que a melhoria da forma pode ser induzida artificialmente através da técnica de assentamento de cortes de formação, neste trabalho testou-se a influência das podas de formação na melhoria da forma das proveniências. A caracterização morfológica das proveniências foi efetuada com recurso à avaliação de características qualitativas do fuste, inclinação e dominância da árvore individual, utilizando uma escala de 1 (pior característica) a 6 valores (melhor característica), antes dos cortes e cinco anos depois da aplicação dos mesmos. As podas de formação parecem não ter efeito ou ter um efeito muito reduzido no escalonamento das proveniências que anteriormente revelavam já as piores características morfológicas como o grupo das italianas e o das francesas e algumas proveniências dos grupos de portuguesas e espanholas. As proveniências marroquinas revelam boas características adaptativas que são potenciadas pelos cortes de formação.
- Training neural networks by resilient backpropagation algorithm for tourism forecastingPublication . Fernandes, Paula Odete; Teixeira, João Paulo; Ferreira, João José; Azevedo, Susana GarridoThe main objective of this study is to presents a set of models for tourism destinations competitiveness, using the Artificial Neural Networks (ANN) methodology. The time series of two regions (North and Centre of Portugal) has used to predict the tourism demand. The prediction for two years ahead gives a mean absolute percentage error between 5 and 9 %. Therefore, the ANN model is adequate for modelling and prediction of the reference time series. This model is an important and useful framework for better planning and development of these two regions as they operate in highly competitive markets.
- Synthesis of new N-[3-(thieno[3,2-b]pyridine-7-ylthio)phenyl]benzamides as potential inhibitors of VEGFR2 using rational designPublication . Queiroz, Maria João R.P.; Begouin, Agathe; Campos, Joana F.; Peixoto, Daniela; Froufe, Hugo J.C.; Calhelha, Ricardo C.; Abreu, Rui M.V.; Ferreira, Isabel C.F.R.Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) is the major receptor of the angiogenic effects when linked to VEGF released by tumors. It has a well known role as a transmembrane receptor activating multiple signaling pathways of proliferation and migration of endothelial cells [1], thus leading to the formation and the expansion of new blood vessels (vasculogenesis and angiogenesis) towards the tumor [2]. Therefore, several approaches have been developed to inhibit VEGFR activation and signaling [3]. Some thienopyridine derivatives have already been shown to be inhibitors of the tyrosine kinase domain of VEGFR2 preventing its activation [4]. Herein, we describe the synthesis of new N-[3-(thieno[3,2-b]pyridine-7 -ylthio )phenyl]benzamides, suggested by rational design as potential inhibitors of this domain, either through a Cu-catalyzed C-N coupling of a brominated di(hetero)arylthioether thieno[3,2-b]pyridine with benzamides, or through a reaction of an aminated di(hetero )arylthioether thieno[3,2-b ]pyridine with benzoyl chlorides, as presented below. The inhibition of the tyrosine kinase domain of VEGFR2 by the synthesized compounds will be evaluated by enzymatic and biomolecular assays using VEGF-stimulated Human Umbilical Vein Endothelial Cells (HUVECs).
- Proficiência motora, atividade física e excesso de peso em crianças, que relação?Publication . Lopes, Vitor P.; Sousa, José Florêncio; Rodrigues, Luis PauloA prevalência da obesidade na infância tem vindo a aumentar globalmente. Um dos principais fatores associados à obesidade é o sedentarismo. Recentemente tem-se verificado o interesse em estudar a associação entre a proficiência motora, os níveis de atividade física (AF) e a obesidade nas crianças. A presente revisão da literatura pretende mostrar a importância da proficiência motora nos níveis de AF e no estatuto ponderal das crianças. A análise é feita tendo em consideração o modelo de (Stodden et al., 2008) que apresenta os mecanismos de desenvolvimento que hipoteticamente influenciam a trajetória da atividade física em crianças. Os resultados dos diferentes estudos analisados sugerem que a melhoria da proficiência motora em idades precoces tem o potencial para influenciar os níveis de AF em anos posteriores e logo implicações no estatuto ponderal.
- Pork meat quality of Preto Alentejano and commercial largewhite landrace crossPublication . Teixeira, Alfredo; Rodrigues, SandraThis work aimed to evaluate the physical-chemical characteristics of pork from a local breed (Portuguese black pork called Preto Alentejano) and a commercial breed. Sixteen animals were used, 4 females and 4 males from each breed. Animals had 80-100 kg of live weight. The longissimus muscle between the 5th thoracic vertebra and the 10th lumbar vertebra was used in the analysis. Samples were analysed for protein, fat, pigments, ashes, dry mater, water-holding capacity, and texture. Results of fat and pigments contents indicate significant (P<0.05 and P<0.01) differences for all treatments. For protein, ashes, dry mater, water-holding capacity and texture, no significant differences were found for sex. In the analysis of fatty acids composition, ten were detected, being the main ones C16:0, C18:0, C16:1, C18:1, C18:2. There was a predominance of monounsaturated fatty acids (MUFA), followed by saturated (SFA) and polyunsaturated (PUFA). Differences were significant for sex (P<0.01) and breed (P<0.01). Preto Alentejano breed and females presented the higher percentages of SFA (P<0.01) and MUFA (P<0.001) fatty acids. Differences between breeds might be due to breed production system and feed differences.