Data Science and Big Data in Energy Forecasting

This editorial summarizes the performance of the special issue entitled Data Science and Big Data in Energy Forecasting, which was published at MDPI’s Energies journal. The special issue took place in 2017 and accepted a total of 13 papers from 7 different countries. Electrical, solar and wind energy forecasting were the most analyzed topics, introducing new methods with applications of utmost relevance.Ministerio de Competitividad TIN2014-55894-C2-RMinisterio de Competitividad TIN2017-88209-C2-

Estudo do metaboloma de linhas celulares de cancro da próstata por FTIR

Cancer is one of the leading causes of death worldwide, with prostate cancer being the second most common neoplasia amongst men. Thus, strategies that can provide an early diagnosis of this disease are of great importance. Because biochemical alterations precede morphological changes in cells, cancer metabolome has gained relevance and may contribute to the understanding of tumor biology and to the identification of early diagnostic biomarkers. Fourier-transform infrared (FTIR) spectroscopy is a metabolomics technique that, unlike staining procedures and other histopathologic approaches, is rapid, non-destructive and does not require reagents. This technique probes the biochemical composition of the analyzed samples and allows the discrimination of samples with distinct metabolic profiles, thus discriminating cancerous and non-cancerous samples. The main goals of this work were to explore the ability of FTIR spectroscopy, coupled with multivariate analysis, in the: (1) discrimination between prostate cancer cells derived from a primary tumor (22Rv1) and normal epithelial cells (PNT1A and PNT2); and (2) discrimination between prostate primary tumor cells (22Rv1) from metastatic cells derived from two distinct sites (LNCaP, from lymph node, and PC-3, from bone). A clear discrimination between the different prostate cell lines was observed, indicating that they exhibit different metabolic profiles. This discrimination can be attributed to an altered lipid metabolism (3000-2800 cm-1, 1800-1700 cm-1 and 1500-1400 cm-1) and the presence of protein aggregates (1622 cm-1). Our results suggest that studying cancer metabolome with FTIR spectroscopy not only allows the understanding of tumor pathogenesis, but also may be a valuable tool for the identification of early diagnostic biomarkers, which are crucial for a good prognosis.O cancro é uma das principais causas de morte no mundo, sendo o cancro da próstata o segundo mais comum nos homens. Por isso, o desenvolvimento de estratégias que possam fornecer um diagnóstico precoce é de extrema relevância. Uma vez que as alterações bioquímicas precedem as modificações morfológicas nas células, o estudo do metaboloma do cancro tem ganhado relevância e poderá contribuir para a compreensão da biologia do cancro e identificação de biomarcadores de diagnóstico precoce. A espectroscopia de infravermelho, em particular por FTIR, é uma técnica de metabolómica que, ao contrário de procedimentos histopatológicos, é rápida, não destrutiva e não requer o uso de reagentes. Esta técnica é capaz de detetar a composição bioquímica das amostras e permite a distinção de amostras com perfis metabólicos distintos, possibilitando, assim, a discriminação de células tumorais e normais. Os principais objetivos deste estudo foram explorar a capacidade do FTIR, acoplado a análise multivariada, na: (1) discriminação entre células de tumor primário de próstata (22Rv1) e células epiteliais normais (PNT1A e PNT2); e (2) discriminação entre células de tumor primário e células provenientes de metástases (LNCaP, de nódulo linfático, e PC-3, de osso). Através da análise por PCA observou-se uma discriminação entre as diferentes linhas celulares, sugerindo que possuem diferentes perfis metabólicos. A separação entre as diferentes células pode ser atribuída a alterações no metabolismo lipídico (3000-2800 cm-1, 1800-1700 cm-1 and 1500-1400 cm-1) e à presença de agregados proteicos (1622 cm-1). Os nossos resultados sugerem que o estudo do metaboloma do cancro, por FTIR, não só permite a compreensão da patogénese tumoral, como também poderá contribuir para a identificação de biomarcadores de diagnóstico precoce, que são importantes para um bom prognóstico.POCI-01-0145-FEDER-016728; PTDC/DTP-DES/6077/2014; POCI-01-0145-FEDER-007628Mestrado em Biomedicina Molecula

Foliations, solvability and global injectivity

Let F: R^n -> R^n be a C^\infty map such that DF(x) is invertible for all x in R^n. We know that F is a local diffeomorphism but, in general, it is not globally injective. We discuss the relations between some additional hypothesis that guarantee the global injectivity of F. Further, based on one of these hypotheses, we establish a necessary condition for the existence of F: R^n -> R^n such that det DF = h, where h: R^n -> [0,\infty) is a given C^\infty function

Solutions for linear conservation laws with gradient constraint

We consider variational inequality solutions with prescribed gradient constraints for first order linear boundary value problems. For operators with coefficients only in L^2, we show the existence and uniqueness of the solution by using a combination of parabolic regularization with a penalization in the nonlinear diffusion coefficient. We also prove the continuous dependence of the solution with respect to the data, as well as, in a coercive case, the asymptotic stabilization as time t tends to infinity towards the stationary solution. In particular situation, motivated by the transported sandpile problem, we give sufficient conditions for the equivalence of the first order problem with gradient constraint with a two obstacles problem, the obstacles being the signed distances to the boundary. This equivalence, in special conditions, illustrates also the possible stabilization of the solution in finite time.This research was partially supported by CMAT-"Centro de Matematica da Universidade do Minho'', financed by FEDER Funds through "Programa Operacional Factores de Competitividade-COMPETE'' and by Portuguese Funds through FCT, "Fundacao para a Ciencia e a Tecnologia'', within the Project PEst-OE/MAT/UI0013/2014

On a constrained reaction-diffusion system related to a multiphase problem

We solve and characterize the Lagrange multipliers of a reaction- -diffusion system in the Gibbs simplex of $\R^{N+1}$ by considering strong solutions of a system of parabolic variational inequalities in $\R^N$. Exploring properties of the two obstacles evolution problem, we obtain and approximate a $N$-system involving the characteristic functions of the saturated and/or degenerated phases in the nonlinear reaction terms. We also show continuous dependence results and we establish sufficient conditions of non-degeneracy for the stability of those phase subregions.Fundação para a Ciência e a Tecnologia (FCT) - Project POCI/MAT/57546/200

A unilateral multiphase problem with Neumann type boundary condition

Fundação para a Ciência e a Tecnologia (FCT) - Project POCI/MAT/57546/200

Entrepreneurial intention, cognitive social capital and culture : empirical anaylisis for Spain and Taiwan

The main purpose of this paper is building a research model to integrate the socioeconomic concept of social capital within intentional models of new firm creation. Nevertheless, some researchers have found cultural differences between countries and regions to have an effect on economic development. Therefore, a second objective of this study is exploring whether those cultural differences affect entrepreneurial cognitions. Research design and methodology: Two samples of last year university students from Spain and Taiwan are studied through an Entrepreneurial Intention Questionnaire (EIQ). Structural equation models (Partial Least Squares) are used to test the hypotheses. The possible existence of differences between both sub-samples is also empirically explored through a multigroup analysis. Main outcomes and results: The proposed model explains 54.5% of the variance in entrepreneurial intention. Besides, there are some significant differences between both subsamples that could be attributed to cultural diversity. Conclusions: This paper has shown the relevance of cognitive social capital in shaping individuals' entrepreneurial intentions across different countries. Furthermore, it suggests that national culture could be shaping entrepreneurial perceptions, but not cognitive social capital. Therefore, both cognitive social capital and culture (made up essentially of values and beliefs), may act together to reinforce the entrepreneurial intention