662 research outputs found
Integrating data from heterogeneous DNA microarray platforms
DNA microarrays are one of the most used technologies for gene expression measurement. However, there are several distinct microarray platforms, from different manufacturers, each with its own measurement protocol, resulting in data that can hardly be compared or directly integrated. Data integration from multiple sources aims to improve the assertiveness of statistical tests, reducing the data dimensionality problem. The integration of heterogeneous DNA microarray platforms comprehends a set of tasks that range from the re-annotation of the features used on gene expression, to data normalization and batch effect elimination. In this work, a complete methodology for gene expression data integration and application is proposed, which comprehends a transcript-based re-annotation process and several methods for batch effect attenuation. The integrated data will be used to select the best feature set and learning algorithm for a brain tumor classification case study. The integration will consider data from heterogeneous Agilent and Affymetrix platforms, collected from public gene expression databases, such as The Cancer Genome Atlas and Gene Expression Omnibus.The authors thank the FCT Strategic Project of UID/BIO/04469/2013 unit, the project RECI/BBBEBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and the project BioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Foodprocesses”, REF.NORTE-07-0124FEDER-000028 Co-funded by the Programa Operacional Regional do Norte (ON.2 O Novo Norte), QREN, FEDER
Modelling fed-batch fermentation processes: An approach based on artificial neural networks
Publicado em "2nd International Workshop on Practical Applications of Computational Biology and Bioinformatics (IWPACBB 2008)", ISBN 978-3-540-85860-7Artificial Neural Networks (ANNs) have shown to be powerful tools for solving several problems which, due to their complexity, are extremely difficult to unravel with other methods. Their capabilities of massive parallel processing and learning from the environment make these structures ideal for prediction of nonlinear events. In this work, a set of computational tools are proposed, allowing researchers in Biotechnology to use ANNs for the modelling of fed-batch fermentation processes. The main task is to predict the values of kinetics parameters from the values of a set of state variables. The tools were validated with two case studies, showing the main functionalities of the application.This work was supported by the Portuguese FCT under project POSC/EIA/59899/2004
“MAS QUAL REFORMA AGRÁRIA?” – REVISITANDO UM INCONCLUSO DEBATE
O tema da reforma agrária é examinado por três ângulos: a ação do Estado, a demanda existente e o debate acadêmico. A partir da análise de diferentes perspectivas em jogo, indica-se como possível resposta ao título do texto, que sejam concentrados recursos humanos, financeiros e logísticos numa região que cubra a metade norte de Minas Gerais e se estenda até o Maranhão. Os mecanismos de desapropriação e aquisição ali ainda são possíveis por serem mais baratas as terras do Nordeste, levando em conta a escassez de recursos e a necessidade de maximizar a eficácia governamental. Devido à expressiva presença negra, também essa escolha estabelece a transversalidade com a questão étnica. A reforma agrária poderia, assim, torna-se uma política expressiva no Brasil, beneficiando segmentos sociais em maior escala e com resultados efetivos na redução da pobreza rural.------------------------------------The land reform issue is examined by three angles: the state action, the existing demand and the academic debate. From the analysis of different perspectives, indicates as a possible answer to the title of the text, which are concentrated human resources, financial and logistics in a region covering the northern half of Minas Gerais and that extends to Maranhao. The expropriation mechanisms and acquisition are still possible because the land are cheaper in the Northeast, taking into account the scarcity of resources and the need to maximize the governmental effectiveness. Because of the expressive presence of black people, this choice also establish a connection with the ethnic issue. Land reform could thus becomes an expressive policy in Brazil, benefiting social segments on a larger scale and with effective results in the reduction of rural poverty.reforma agrária, foco regional e étnico, land reform, regional and ethnic focus, Community/Rural/Urban Development, Land Economics/Use,
Sharing economy: becoming an Uber driver in a developing country
Purpose – The purpose of this paper is to analyze why people have become suppliers in the sharing economy (SE) as Uber drivers in a developing country. Design/methodology/approach – From a background on SE, car sharing and gig economy, the authors carried out a qualitative research. The analysis was based on 20 semi-structured interviews conducted with Uber drivers, and on the authors’ participant observation as Uber drivers and passengers in the third largest Brazilian city, Belo Horizonte. Findings – Empirical evidence shows that becoming an Uber driver is more a matter of solving unemployment on a more permanent way rather than a search for a temporary and flexible work to supplement income. Although there are benefits related to flexibility, income and social interactions, negative externalities identified herein lead to the conclusion that the overall work relations and conditions are negative. Originality/value – Much in the literature of the SE is focused on understanding consumer behavior; this research, on the contrary, is focused on understanding producers, which indicates an incipient perspective. The contributions of this paper show that the SE merges into different distributive decentralized means of production that are seeing as profit/income generated from shareable assets
Chronic Kidney Disease and Coronary Artery Disease
Chronic kidney disease (CKD) and coronary artery disease (CAD) are conditions that, when present together, is considered a high-risk feature. Despite the high prevalence, few studies are dedicated to studying CAD specifically in individuals with CKD, and it is a common exclusion criterion in most trials. This fact leads to gap in the evidence for the management of CAD, which, sometimes, results in undertreatment of CKD patients. In this chapter, authors present peculiarities related to CAD among patients with CKD from physiopathology to diagnostic and therapeutic decisions. An evidence-based approach was used to explore this high-risk subset of CAD patients
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