Collaborative Hierarchical Sparse Modeling

Sparse modeling is a powerful framework for data analysis and processing. Traditionally, encoding in this framework is done by solving an l_1-regularized linear regression problem, usually called Lasso. In this work we first combine the sparsity-inducing property of the Lasso model, at the individual feature level, with the block-sparsity property of the group Lasso model, where sparse groups of features are jointly encoded, obtaining a sparsity pattern hierarchically structured. This results in the hierarchical Lasso, which shows important practical modeling advantages. We then extend this approach to the collaborative case, where a set of simultaneously coded signals share the same sparsity pattern at the higher (group) level but not necessarily at the lower one. Signals then share the same active groups, or classes, but not necessarily the same active set. This is very well suited for applications such as source separation. An efficient optimization procedure, which guarantees convergence to the global optimum, is developed for these new models. The underlying presentation of the new framework and optimization approach is complemented with experimental examples and preliminary theoretical results.Comment: To appear in CISS 201

The relation of acculturation, criminal history, and social integration of Mexican American and non -Mexican students to assaults on intimate partners

Studies that have compared intimate partner violence among Mexican Americans and Non-Mexican Whites have found conflicting results. The results can be grouped into three categories, those that found Mexican Americans have higher assault rates, those that found Mexican Americans have lower assault rates, and those that found no differences between both ethnic groups. This study analyzed a sample of 348 college students to examine the role that Mexican ethnicity and acculturation into Anglo American society by Mexican Americans plays in predicting intimate partner violence. Additionally, the role of criminal history and integration into society were analyzed to understand their unique effects on intimate partner violence. Furthermore, differences between Mexican Americans and Non-Mexicans in the relation of criminal history and social integration to intimate partner violence were investigated. The results indicated that Mexican American ethnicity and acculturation into Anglo American society by Mexican Americans had no effect on intimate partner violence. Respondents who committed crimes in the past (before the age of 15) had a higher probability of severely physically assaulting a partner than those respondents who had committed crime later in life (after the age of 15). A history of property crime was found to be a better predictor of severe partner assault than a history of violent crime. One of the most consistent findings in this study was that integration into society decreased the probability of severely assaulting a partner among both Mexican Americans and Non-Mexicans. This research found that there is no difference between Mexican Americans and Non-Mexicans in the rate of intimate partner violence, and no difference in two etiological factors: criminal history and social integration. The results support a generalist perspective on crime, which states that individuals do not solely commit one type of crime but commit a variety of different crimes (property and violent). Furthermore, the results found support for a control theory perspective on intimate partner violence

The odd fiscal ‘implicit bargain’ in the Eurozone. A continental view of sovereignty.

At present, the European customs and currency union finds itself in a transitional period. It has not yet politically unified in a federal body, nonetheless it has prematurely bound constituents by ‘hard law’ fiscal limitations mainly by way of the Maastricht Treaty. In other words, it is caught in an odd \u27implicit bargain’ (Goodhart) where members are expected to abide by de jure fiscal constraints with no central authority having the fiscal capabilities for stabilization, redistribution, and state-building (Arrighi) expenditures --all of which are indispensable in modern credit (money) economies. The belief underlying the present paper is that by making use of continental economic traditions, reliant on statecraft, an alternative conceptual basis for rethinking continental unity can be forged. Specifically, we look at the work of List, Keynes, and the chartalists. The work of F. List sets European economic unification in its historic place as a strategy founded in large part on exploiting economies of scale (demand and supply-side), by political and economic aggregation of smaller non-self sustaining markets, for ‘catching-up’ with world economic leaders. Keynes’s international economics is revisited as an orienting blueprint for how the European customs and currency union can address the particularity of economic unification among sovereigns absent political unity. Chartalist views are invaluable for an understanding of the political nature of the European Central Bank as it often clumsily attempts to hold together the Union. Despite its differential treatment of members, the ECB has the potential to become a centerpiece institution in the consolidation of Europe as a self-sustaining pole of international effective demand. The overriding leitmotiv binding together the different authors and traditions discussed is that of European economic sovereignty in a region continuously struggling to balance political independence with economic co-dependence and unity

Second generation sparse models

Sparse data models, where data is assumed to be well represented as a linear combination of a few elements from a learned dictionary, have gained considerable attention in recent years, and their use has led to state-of-the-art results in many applications. The success of these models is largely attributed to two critical features: the use of sparsity as a robust mechanism for regularizing the linear coefficients that represent the data, and the flexibility provided by overcomplete dictionaries that are learned from the data. These features are controlled by two critical hyper-parameters: the desired sparsity of the coefficients, and the size of the dictionaries to be learned. However, lacking theoretical guidelines for selecting these critical parameters, applications based on sparse models often require hand-tuning and cross-validation to select them, for each application, and each data set. This can be both inefficient and ineffective. On the other hand, there are multiple scenarios in which imposing additional constraints to the produced representations, including the sparse codes and the dictionary itself, can result in further improvements. This thesis is about improving and/or extending current sparse models by addressing the two issues discussed above, providing the elements for a new generation of more powerful and flexible sparse models. First, we seek to gain a better understanding of sparse models as data modeling tools, so that critical parameters can be selected automatically, efficiently, and in a principled way. Secondly, we explore new sparse modeling formulations for effectively exploiting the prior information present in different scenarios. In order to achieve these goals, we combine ideas and tools from information theory, statistics, machine learning, and optimization theory. The theoretical contributions are complemented with applications in audio, image and video processing

Análisis estadístico multivariante de la incidencia de la sigatoka negra frentes a los diferentes pesticidas y su rendimiento en los cultivos

Cuantificar los diferente grados de infección que se dan, una vez contraído el virus de la Sigatoka negra, relacionándolos con la aplicación de los fungicidas durante las fechas encontradas para tales aplicaciones y de aquellas fechas que no presentan mayor intensidad en la infección, luego obtendremos que productos controlo mejor la enfermedad y en que condiciones obtuvo esos resultados cuando se presentaron todas las condiciones para el brot

The impact of adverse maternal environments on resistance artery function and mechanical characteristics in offspring

Includes vita.Cardiovascular disease is one of the leading causes of death worldwide. Maternal obesity, gestational diabetes mellitus (GMD) and assisted reproductive technologies (ART) have been associated with cardiovascular deficiencies in offspring. Obese women often suffer from infertility and use ART to achieve a pregnancy. Children of mothers that undergo ART or experience GDM have a higher risk of developing hypertension, but little is known about the mechanisms that control this process. Here, I report that in offspring, the interaction between a high fructose and high fat diet (also known as western diet, WD) and ART exhibited impaired endothelialdependent dysfunction in mesenteric resistance arteries, this was determined by the presence of reduced acetylcholine vasodilation. Arteries from WD-ART male mice had greater wall cross-sectional area (CSA) and wall-to-lumen ratio (W/L) compared to their respective ART control, indicative of vascular hypertrophic remodeling. Another adverse maternal environment during pregnancy is GDM, with 2-10 [percent] of pregnancies in the US being affected. To study this model, we designed a two-by-two experiment array using male mice, with main effects genotype and diet. In resistance mesenteric arteries of wild type (WT) offspring fed a WD experienced enhanced vasodilation to acetylcholine. Furthermore, in offspring of hyperleptinemic dams WD reduced vasodilation to insulin. Offspring of hyperleptinemic dams had stiffer arteries regardless of the diet. Therefore, we conclude that while maternal hyperleptinemia was beneficial to offspring vascular health fed a standard diet (SD), it had detrimental effects when fed a WD. The results of these two projects suggest that an adverse maternal environment (i.e. ART or GDM) in combination with a WD favors the development of endothelial dysfunction and arterial stiffening in resistance mesenteric arteries of offspring.Includes bibliographical reference

La integración de Redes de Colaboración entre Cuerpos Académicos

El tema de redes de colaboración nos involucra a quienes estamos cursando estudios de posgrado o realizando investigación en las Instituciones de Educación Superior al ser considerado por el Programa de Mejoramiento del Profesorado vigente, como una de las modalidades prioritarias para apoyar a quienes se han integrado, o lo están haciendo, a cuerpos académicos bajo esta nueva forma de organización del trabajo académico en colectivo que no necesariamente es en colaboración. En el curso del trabajo, se precisa el término redes pues, por ser polisémico, ha llegado a ser utilizado de tan diversas maneras que algunas de ellas suelen ser antónimas; aquí introduciremos el término cuerpo académico. En un segundo momento nos permitimos abrir un amplio paréntesis para tratar, de manera breve, algunos conceptos de Michel Gibbons sobre la nueva forma, o Modo 2, de producción del conocimiento. Posteriormente, retomando el concepto de redes y las características aplicables a redes educativas, veremos los planteamientos de otros autores, para concluir sobre cómo los cuerpos académicos podrán integrar las redes de colaboración

Regulation of brain endothelial barrier function by microRNAs in health and neuroinflammation

Brain endothelial cells constitute the major cellular element of the highly specialized blood–brain barrier (BBB) and thereby contribute to CNS homeostasis by restricting entry of circulating leukocytes and blood-borne molecules into the CNS. Therefore, compromised function of brain endothelial cells has serious consequences for BBB integrity. This has been associated with early events in the pathogenesis of several disorders that affect the CNS, such as multiple sclerosis, HIV-associated neurologic disorder, and stroke. Recent studies demonstrate that brain endothelial microRNAs play critical roles in the regulation of BBB function under normal and neuroinflammatory conditions. This review will focus on emerging evidence that indicates that brain endothelial microRNAs regulate barrier function and orchestrate various phases of the neuroinflammatory response, including endothelial activation in response to cytokines as well as restoration of inflamed endothelium into a quiescent state. In particular, we discuss novel microRNA regulatory mechanisms and their contribution to cellular interactions at the neurovascular unit that influence the overall function of the BBB in health and during neuroinflammatio