Coleções gerais - Artigos em revistas internacionais
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- Abscisic acid inhibits type 2C protein phosphatases via the PYR/PYL family of START proteinsPublication . Park, Sang-Youl; Fung, Pauline; Nishimura, Noriyuki; Jensen, Davin R.; Fujii, Hiroaki; Zhao, Yang; Lumba, Shelley; Santiago, Julia; Rodrigues, Américo; Chow, Tsz-fung F.; Alfred, Simon E.; Bonetta, Dario; Finkelstein, Ruth; Provart, Nicholas J.; Desveaux, Darrell; Rodriguez, Pedro L.; McCourt, Peter; Zhu, Jian-Kang; Schroeder, Julian I.; Volkman, Brian F.; Cutler, Sean R.Type 2C protein phosphatases (PP2Cs) are vitally involved in abscisic acid (ABA) signaling. Here, we show that a synthetic growth inhibitor called pyrabactin functions as a selective ABA agonist. Pyrabactin acts through PYRABACTIN RESISTANCE 1 (PYR1), the founding member of a family of START proteins called PYR/PYLs, which are necessary for both pyrabactin and ABA signaling in vivo. We show that ABA binds to PYR1, which in turn binds to and inhibits PP2Cs. We conclude that PYR/PYLs are ABA receptors functioning at the apex of a negative regulatory pathway that controls ABA signaling by inhibiting PP2Cs. Our results illustrate the power of the chemical genetic approach for sidestepping genetic redundancy.
- Are the sustainable development goals being implemented in the Portuguese higher education formative offer?Publication . Aleixo, Ana Marta; Azeiteiro, Ulisses M.; Leal, SusanaPurpose: The study aims to examine the vertical integration of the sustainable development goals (SGDs) in Portuguese public higher education institutions, namely, at the level of undergraduate and master’s degrees, and the extent to which Portuguese higher education institutions (HEI) are preparing for the United Nations’ call to promote SDGs. Design/methodology/approach: A content analysis of the designations and objectives of the 2,556 undergraduate and master’s degrees (in 33 Portuguese public higher education institutions) was done to determine whether they promote at least one SDG. Findings: The results show that 198 courses directly address at least one SDG; on average, each higher education institution (HEI) has six courses that explicitly address at least one SDG; universities have more courses in SDG areas than in polytechnics; more master’s degrees embrace SDGs than undergraduate degrees; and most of the courses addressing SDGs are from the social sciences and humanities areas and from natural and environmental sciences. Originality/value: This paper serves to raise the awareness of Portuguese HEIs of their role and responsibility in furthering SGDs.
- Comparative structural response of two steel bridges constructed 100 years apartPublication . Varum, Humberto; Sousa, Romain; Delgado, Walter; Fernandes, Catarina; Costa, Aníbal; Jara, José; Jara, Manuel; Álvarez, JesúsThis paper presents a comparative numerical analysis of the structural behaviour and seismic performance of two existing steel bridges, the Infiernillo II Bridge and the Pinhão Bridge, one located in Mexico and the other located in Portugal. The two bridges have similar general geometrical characteristics, but their construction is separated by one hundred years. 3D structural models of both bridges were developed and analyzed for various load cases and several seismic conditions. The results of the comparative analysis between the two bridges are presented in terms of natural frequencies and corresponding vibration modes, maximum stresses in the structural elements and maximum displacements. The study aimed at determining the influence of one century period in material properties, transverse sections and expected behaviour of two quite similar bridges. In addition, the influence of the bearing conditions in the global response of the Pinhão Bridge was evaluated.
- Contrato psicológico em tempo de governação austeraPublication . Paraíso, Isabel; Vicente Castro, FlorencioUm modelo de Estado de bem-estar social não pode configurar retórica filosófica ou opção de um sistema político, mas um imperativo soberano para a sobrevivência das sociedades contemporâneas. O presente estudo, de base eminentemente teórica, integra conceções de distintos campos de pesquisa – como a psicologia, sociologia e políticas públicas -, com o propósito de analisar fatores de risco social, para a população adulta, que decorrem da implementação de políticas públicas de austeridade. Se do lado do Estado há um claro entendimento acerca das obrigações dos cidadãos, explícito em normativos legais ou implícito por atitudes e comportamentos de cidadania que o Estado espera de um povo, à sua imagem, “bom aluno”; da parte dos cidadãos é expectável que se reclamem os direitos adquiridos pelo esforço e pelos contributos a que estão vinculados. As políticas de austeridade vigentes mudam o eixo de centralidade de uma relação que se requeria de equilíbrio; simultaneamente, espelham a hegemonia do poder do Estado em arenas de exercício estribadas em marcadores económicos, que nos sugere, em teoria, que os contratos psicológicos possam estar em sucessiva rutura. Será no âmbito da responsabilidade social do Estado que têm de emergir novas dinâmicas que respondam a novas formatações societais e a novas formas de proteção dos cidadãos.
- Contrato psicológico na Administração Pública Portuguesa : termos do seu conteúdoPublication . Paraíso, Isabel; Dias, José Henrique; Castro, Florêncio Vicente
- Dermoscopic assisted diagnosis in melanoma: Reviewing results, optimizing methodologies and quantifying empirical guidelinesPublication . Lee, Huei Diana; Mendes, Ana Isabel; Spolaôr, Newton; Oliva, Jefferson Tales; Parmezan, Antonio Rafael Sabino; Wu, Feng Chung; Fonseca-Pinto, RuiEarly diagnosis is still the most important factor to deal with skin cancer, a disease that challenges physicians and researchers. It has benefited from computer-aided diagnosis methods that successfully combine dermoscopy, Digital Image Processing, and Machine Learning techniques. This paper aims to approximate medical professionals working with dermoscopy to these methods, to join the challenge of melanoma early detection. Accordingly, a proposal for extracting, selecting and combining texture and shape features from dermoscopic images is presented. The Feature Selection task is added to the learning process to potentiate the quality of classification models. Three classical Machine Learning algorithms were applied to differentiate melanoma from non-melanoma images. The models are evaluated by standard performance measures and a multi-criteria decision analysis method. This is the first time such method is used in melanoma diagnosis. As a result, we found a decision tree that performs well and allows the explicit representation and analysis of the knowledge learned from the images. In addition, the competitiveness of our decision models in comparison with literature approaches reviewed in this work encourages further applications of Machine Learning and Feature Selection to assist computer-aided diagnosis.
- Evaluation of analytical methodologies used to derive vulnerability functionsPublication . Silva, V.; Crowley, H.; Varum, H.; Pinho, R.; Sousa, RomainThe recognition of fragility and vulnerability functions as a fundamental tool in seismic risk assessment has led to the development of more and more complex and elaborate procedures for their computation. Although these functions have been traditionally produced using observed damage and loss data, more recent studies propose the employment of analytical methodologies as a way to overcome the frequent lack of post-earthquake data. The variation of the structural modelling approach on the estimation of building capacity has been the target of many studies in the past; however, its influence on the resulting vulnerability model for classes of buildings, the impact in loss estimations or propagation of the uncertainty to the seismic risk calculations has so far been the object of limited scrutiny. In this paper, an extensive study of static and dynamic procedures for estimating the nonlinear response of buildings has been carried out to evaluate the impact of the chosen methodology on the resulting capacity, fragility, vulnerability and risk outputs. Moreover, the computational effort and numerical stability provided by each approach have been evaluated and conclusions drawn regarding the optimal balance between accuracy and complexity. Copyright © 2013 John Wiley & Sons, Ltd.
- A fibre flexure-shear model for seismic analysis of RC-framed structuresPublication . Ceresa, Paola; Petrini, Lorenza; Pinho, Rui; Sousa, RomainWhilst currently existing modelling approaches of reinforced concrete behaviour allow a reasonably accurate prediction of flexural response, the determination of its shear counterpart needs further developments. There are various modelling strategies in literature able to predict the shear response and the shear-flexure coupling under monotonic loading conditions. However, very few are the reported models that have demonstrated successful results under cyclic loading, as in the seismic load case. These considerations lead to this research work focused on the development of a flexure-shear model for reinforced concrete beam-column elements. A reliable constitutive model for cracked reinforced concrete subjected to cyclic loading was implemented as bi-axial fibre constitutive model into a two-dimensional Timoshenko beam-column element. Aim of this research work is to arrive at the definition of a numerical model sufficiently accurate and, at the same time, computationally efficient, that will enable implementation within a Finite Element package for nonlinear dynamic analysis of existing non seismically designed RC structures that are prone to shear-induced damage and collapse.
- Formação de docentes no Ensino Superior: a experiência do Instituto Politécnico de Leiria, PortugalPublication . Seco, Graça; Pereira, Ana Patrícia; Alves, Sandra; Filipe, Luís; Duarte, Ana Lúcia
- Fundamental solution of the time-fractional telegraph Dirac operatorPublication . Ferreira, Milton; Rodrigues, M. Manuela; Vieira, Nelsonn this work, we obtain the fundamental solution (FS) of the multidimensionaltime-fractional telegraph Dirac operator where the 2 time-fractional derivatives oforders𝛼∈]0,1]and𝛽∈]1,2]are in the Caputo sense. Explicit integral and seriesrepresentation of the FS are obtained for any dimension. We present and discusssome plots of the FS for some particular values of the dimension and of the frac-tional parameters𝛼and𝛽. Finally, using the FS, we study some Poisson and Cauchyproblems
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