Knowledge-based gene expression classification via matrix factorization

Motivation: Modern machine learning methods based on matrix decomposition techniques, like independent component analysis (ICA) or non-negative matrix factorization (NMF), provide new and efficient analysis tools which are currently explored to analyze gene expression profiles. These exploratory feature extraction techniques yield expression modes (ICA) or metagenes (NMF). These extracted features are considered indicative of underlying regulatory processes. They can as well be applied to the classification of gene expression datasets by grouping samples into different categories for diagnostic purposes or group genes into functional categories for further investigation of related metabolic pathways and regulatory networks. Results: In this study we focus on unsupervised matrix factorization techniques and apply ICA and sparse NMF to microarray datasets. The latter monitor the gene expression levels of human peripheral blood cells during differentiation from monocytes to macrophages. We show that these tools are able to identify relevant signatures in the deduced component matrices and extract informative sets of marker genes from these gene expression profiles. The methods rely on the joint discriminative power of a set of marker genes rather than on single marker genes. With these sets of marker genes, corroborated by leave-one-out or random forest cross-validation, the datasets could easily be classified into related diagnostic categories. The latter correspond to either monocytes versus macrophages or healthy vs Niemann Pick C disease patients.Siemens AG, MunichDFG (Graduate College 638)DAAD (PPP Luso - Alem˜a and PPP Hispano - Alemanas

Estudio de necesidades y perfil socio demográfico de los padres de estudiantes de nuevo ingreso del año académico 2009-2010

The family is the first scenario in which students begin to relate positively or negatively with other human beings. It is the most important socializing agency contributing to his and her development. Upbringing patterns and family of origin characteristics exert a great influence in the student's future behavior. Family relationships and the parents'academic standing, among other factors, have a great deal to do with success or failure in their studies. It is important that helping professionals (social workers, professional counselors, and psychologists) get to know the students' family history and background, as well as the family's socio-demographic characteristics in order to help them better attend to their needs and achieve their personal and academic goals. This article presents the findings of the research Needs assessment and socio-demographic profile of parents of new students in the academic year 2009-2010, performed at the Río Piedras Campus of the University of Puerto Rico. A descriptive analysis was done as well as the correlations between parents' socio-demographic profile and the students starting college. As an added contribution, the article documents the most immediate needs these parents face regarding their children.La familiaes el primer laboratorio en el que el estudiante empieza a relacionarse positiva o negativamente con otros seres humanos. Es la agencia socializadora más importante en su desarrollo y los patrones de crianza y las características de su familia de origen pueden ejercer una gran influencia en su conducta futura. Por lo tanto, las relaciones familiares y la preparación académica de sus padres, entre otros, impactan su éxito o fracaso en los estudios. Es meritorio que los profesionales de ayuda (trabajadores sociales, consejeros profesionales y psicólogos), que ofrecen apoyo y ayuda al estudiantado, conozcan su trasfondo familiar y sus características socio demográficas para estar en mejor posición de ayudarlos a atender sus necesidades y a lograr sus metas académicas y personales. Este artículo presenta los resultados del estudio Necesidades y Perfil Socio Demográfico de los Padres de Estudiantes de Nuevo Ingreso del Año Académico 2009-2010 realizado en el Recinto de Río Piedras de la Universidad de Puerto Rico. Se realiza un análisis descriptivo y se establecen correlaciones entre el perfil socio demográfico de los padres y los hijos que inician estudios universitarios; también se documentan las necesidades más apremiantes que presentan estos padres en torno a sus hijos