11 research outputs found
Wasserstein-distance-based temporal clustering for capacity-expansion planning in power systems
As variable renewable energy sources are steadily incorporated in European power systems, the need for higher temporal resolution in capacity-expansion models also increases.Naturally, there exists a trade-off between the amount of temporal data used to plan power systems for decades ahead and time resolution needed to represent renewable energy variability accurately. We propose the use of the Wasserstein distance as a measure of cluster discrepancy using it to cluster demand, wind availability, and solar availability data. When compared to the Euclidean distance and the maximal distance, the hierarchical clustering performed using the Wasserstein distance leads to capacity-expansion planning that 1) more accurately estimates system costs and 2) more efficiently adopts storage resources. Numerical results indicate an improvement in cost estimation by up to 5% vis-Ă -vis the Euclidean distance and a reduction of storage investment that is equivalent to nearly 100% of the installed capacity under the benchmark full time resolution
AnĂĄlise da relação entre a expressĂŁo da proteĂna VEGF e o estadiamento do cĂąncer colorretal Analysis of relationship between VEGF protein expression and colorectal cĂąncer staging
Os estudos em biologia molecular desenvolvidos nas Ășltimas dĂ©cadas, possibilitaram grandes avanços para uma maior compreensĂŁo da carcinogĂȘnese colorretal. Na dĂ©cada de 80 pesquisadores descobriram uma proteĂna com a capacidade de aumentar a permeabilidade dos vasos sangĂŒĂneos. Inicialmente esta proteĂna foi denominada como fator de permeabilidade vascular. Estudos posteriores correlacionaram esta proteĂna com o crescimento de novos vasos sangĂŒĂneos (angiogĂȘnese), quando passou a ser chamada de fator de crescimento endotelial vascular (VEGF). A proteĂna VEGF tem sido apontada como o principal fator promotor da angiogĂȘnese, dentre os vĂĄrios jĂĄ conhecidos. Neste trabalho o objetivo foi quantificar a proteĂna VEGF, e correlacionar os resultados com o estadiamento tumoral em amostras de adenocarcinoma colorretal. Foram incluĂdos 56 adenocarcinomas colorretais, nos quais a detecção da proteĂna VEGF foi realizada por imunoistoquĂmica atravĂ©s da construção de uma matriz tecidual e sua quantificação com anĂĄlise digital de imagens assistida por computador. Nossos resultados nĂŁo evidenciaram relação estatisticamente significativa entre a expressĂŁo da proteĂna VEGF e o estadiamento tumoral, ou presença e nĂșmero de linfonodos comprometidos. Baseado no nĂvel de expressĂŁo da proteĂna VEGF nĂŁo foi possĂvel inferir a presença de linfonodos comprometidos nas amostras analisadas.<br>Development of studies in molecular biology over the last decades has contributed for better knowledge about colorectal carcinogenesis. An important landmark in this process was the identification of a protein with effect on vascular permeability eventually named as vascular endothelial growth factor (VEGF), which seems to be essential for the angiogenesis activation of tumor development. The aim of this study was to assess the VEGF expression and correlate to tumor staging in colorectal cancer. Surgical specimens from 56 colorectal cancer patients were analyzed by immunohistochemistry for VEGF expression using a multitissue array and a computer-assisted image system. No significant result was found between VEGF expression and tumor staging or lymph nodes metastasis. We concluded that no predictive value for lymph nodes metastasis could be demonstrated by VEGF immunostaining in this study