Statistical inference in two non-standard regression problems

This thesis analyzes two regression models in which their respective least squares estimators have nonstandard asymptotics. It is divided in an introduction and two parts. The introduction motivates the study of nonstandard problems and presents an outline of the contents of the remaining chapters. In part I, the least squares estimator of a multivariate convex regression function is studied in great detail. The main contribution here is a proof of the consistency of the aforementioned estimator in a completely nonparametric setting. Model misspecification, local rates of convergence and multidimensional regression models mixing convexity and componentwise monotonicity constraints will also be considered. Part II deals with change-point regression models and the issues that might arise when applying the bootstrap to these problems. The classical bootstrap is shown to be inconsistent on a simple change-point regression model, and an alternative (smoothed) bootstrap procedure is proposed and proved to be consistent. The superiority of the alternative method is also illustrated through a simulation study. In addition, a version of the continuous mapping theorem specially suited for change-point estimators is proved and used to derive the results concerning the bootstrap

Estudio y diseño de una embarcación de consola central de 13 metros.

El presente proyecto consiste en el diseño de una embarcación de consola central de 13 metros de eslora donde se describen los aspectos a considerar en cada una de las fases de diseño. se empieza con la elaboración de una base de datos de embarcaciones con características similares. a partir de esta base de datos se realizan unas regresiones lineales con las cuales se obtienen las características principales de la embarcación. Estas características sirven de referencia para el diseño de diferentes puntos de la embarcación. posteriormente se crea la carena usando el programa de modelaje rhinoceros y se exporta al programa maxsurf modeler y al programa maxsurf resistance donde se conocen las hidrostáticas y resistencia al avance de la carena respectivamente. Asimismo, habiendo definido la forma de la carena, se determina la disposición general de la embarcación. en una siguiente etapa se define la disposición estructural y se hace un análisis de escantillonado siguiendo la normativa aplicable iso 12215-5. Luego se listan cada uno de los elementos que componen a la embarcación para la estimación del peso total y la posición del centro de gravedad. seguidamente se realiza un estudio de estabilidad siguiendo lo establecido por la normativa aplicable iso 12217 y, por último, una vez realizado el estudio de estabilidad, se finaliza el proyecto con un estudio económico y una descripción de los diferentes sistemas a bordo

Response of Three Different Viruses to Interferon Priming and Dithiothreitol Treatment of Avian Cells

We have previously shown that the replication of avian reovirus (ARV) in chicken cells is much more resistant to interferon (IFN) than the replication of vesicular stomatitis virus (VSV) or vaccinia virus (VV). In this study, we have investigated the role that the double-stranded RNA (dsRNA)-activated protein kinase (PKR) plays in the sensitivity of these three viruses toward the antiviral action of chicken interferon. Our data suggest that while interferon priming of avian cells blocks vaccinia virus replication by promoting PKR activation, the replication of vesicular stomatitis virus appears to be blocked at a pretranslational step. Our data further suggest that the replication of avian reovirus in chicken cells is quite resistant to interferon priming because this virus uses strategies to downregulate PKR activation and also because translation of avian reovirus mRNAs is more resistant to phosphorylation of the alpha subunit of initiation factor eIF2 than translation of their cellular counterparts. Our results further reveal that the avian reovirus protein sigmaA is able to prevent PKR activation and that this function is dependent on its double-stranded RNA-binding activity. Finally, this study demonstrates that vaccinia virus and avian reovirus, but not vesicular stomatitis virus, express/induce factors that counteract the ability of dithiothreitol to promote eIF2 phosphorylation. Our data demonstrate that each of the three different viruses used in this study elicits distinct responses to interferon and to dithiothreitol-induced eIF2 phosphorylation when infecting avian cellsThe Spanish Ministerio de Economía y Competitividad provided funding to Javier Benavente and José Martínez-Costas under grant numbers BFU2010-22228 and BFU2013-43513-R. Support was also provided by the Xunta de Galicia (CN 2012/018). Irene Lostalé-Seijo was a recipient of a predoctoral FPU fellowship (Ministerio de Educación y Ciencia) and a Research Fellowship (Bolsa de Investigación; Deputación Provincial da Coruña)S

Interferon induction by avian reovirus

We have previously shown that the replication of avian reovirus (ARV) in chicken embryo fibroblasts (CEF) is more resistant to the antiviral action of interferon (IFN) than the replication of vesicular stomatitis virus (VSV) or vaccinia virus (VV). In this study we examined the capacity of these three viruses to induce the expression of IFN when infecting avian cells. Efficient expression of both type-α and type-β IFNs, as well as of the double-stranded RNA (dsRNA)-activated protein kinase (PKR), takes place in ARV-infected CEF, but not in cells infected with VSV or VV. PKR expression is not directly induced by ARV infection, but by the IFN secreted by ARV-infected cells. IFN induction in ARV-infected cells requires viral uncoating, but not viral gene expression, a situation similar to that reported for apoptosis induction by ARV-infected cells. However, our results demonstrate that IFN induction by ARV-infected CEF occurs by a caspase-independent mechanismThis work was funded by grants from the Spanish Ministerio de Economia y Competitividad (BFU2010-22228 and BFU2013-43513-R) and from the Xunta de Galicia (CN 2012/018). I.L.S. was a recipient of a predoctoral FPU fellowship (Ministerio de Educación y Ciencia) and a Research Fellowship (Bolsa de Investigación) (Deputación Provincial da Coruña)S

Caracterización fisicoquímica (parámetros generales y componentes mayoritarios) de las aguas minerales naturales envasadas de España

En el presente trabajo se ha realizado un estudio sobre las características fisicoquímicas de 201 marcas de aguas minerales naturales comercializadas en Espana. Las características estudiadas han sido parametros generales (pH, conductividad, residuo seco y potencial redox) y componentes mayoritarios (bicarbonatos, cloruros, sulfatos, nitratos, fluoruros, calcio, magnesio, sodio, potasio y litio). Las muestras estudiadas se han catalogado en las zonas geológicas en que se encuentran respecto a litología general de España y sus acuíferos. En base a los datos analíticos obtenidos se ha realizado un estudio estadístico elemental de la totalidad de las muestras, permitiendo establecer los parámetros estadísticos más relevantes. Se han establecido diferentes clasificaciones con objeto de catalogar las muestras en base a una calidad específica. Las clasificaciones fisicoquímicas se han realizado en base a criterios analíticos como residuo seco, dureza, menciones de etiquetado y facies hidroquímica. Se han realizado también estudios de correlación, observando relaciones lineales de variables analíticas en base a parejas esenciales de macro elementos. Para cada uno de los estudios citados, se han realizado estudios comparativos en base a los datos a nivel nacional y los datos a nivel de las comunidades autónomasIn the present work, a study on physicochemical characteristics of 201 brands of bottled natural mineral waters commercialized in Spain was carried out. The general parameters (pH, electrical conductivity, dry residue and redox potential) and major constituents (bicarbonates, chlorides, sulphates, nitrates, fluorides, calcium, magnesium, sodium, potassium and lithium) were studied. The samples studied are listed in geological areas that are found regarding general lithology of Spain and their aquifers. Using the obtained analytical data, an elementary statistical analysis of all the samples was performed, allowing to establish the most relevant statistical parameters. Different classifications have been established to catalogue the samples based on a specific quality. Physicochemical classifications were made based on analytical criteria as a dry residue, hardness, labeling information and hydrochemical facies. Correlation studies were also carried out, observing linear relationships between macroelements pairs. Comparative studies were performed for each of the cited studies, based on national and regional dat

Mortalidad natural de tres camarones peneidos comerciales (Lithopenaeus vannamei, L. stylirostris y Farfantepenaeus californiensis) del Golfo de California usando intervalos de tiempo gnomónicos

The estimation of natural mortality (M) is critical for stock assessment and fisheries management. The shrimp fishery is the most valuable one in Mexico and along the Pacific Coast of Mexico, and exploitation primarily targets three species: white (Litopenaeus vannamei), blue (L. stylirostris), and brown (Farfantepenaeus californiensis). It is a sequential fishery, so an appropriate estimate of M for different life stages is required for management purposes. Typically, M is estimated from the exploited stock, which is usually composed of adults, assuming a constant value for M, and this estimate is used for studies of population dynamics, stock assessments and determinations of the status of a fishery. In this study, we estimate M-at-age (i.e. life stage) for each species using the gnomonic time division model. The gnomonic intervals correspond to the actual life stages reported in the literature, whose duration was used for model fitting. The gnomonic model showed that M declines sharply in early life stages but declines to an asymptotic value after reaching maturity, and the model provided biologically consistent estimates of M at each life stage for the three shrimp species. Such estimates may be used with confidence to model the dynamics of sequential shrimp fisheries.La estimación de mortalidad natural (M) es crítica para la evaluación de stocks y el manejo de las pesquerías. La pesquería de camarón es la de mayor valor en México y a lo largo de la costa del Pacífico de México, y la explotación tiene primariamente a tres especies como objetivo: blanco (Litopenaeus vannamei), azul (L. stylirostris) y café (Farfantepenaeus californiensis). Se trata de una pesquería secuencial, de tal suerte que para su manejo se requiere de una apropiada estimación de M para los diferentes estadios de vida. Típicamente M es estimada de stocks explotados, los cuales están usualmente compuestos de organismos adultos, se supone un valor de M constante y esta estimación es usada para estudios de dinámica de poblaciones, evaluación de stocks y determinación del estado de las pesquerías. En este estudio estimamos M-a-edad (p.ej. estadios de vida) para cada especie usando el modelo de intervalos de tiempo gnomónicos. La duración de los intervalos gnomónicos corresponde a los estadios de vida reportados en literatura, cuya duración fue usada para ajustar el modelo. El modelo de intervalos gnomónicos mostró que M declina rápidamente en estadios tempranos de vida, cambiando hacia un valor asintótico después de alcanzar la madurez. El modelo provée estimaciones de M biológicamente consistentes para cada estadio de vida para las tres especies. Estas estimaciones pueden ser usadas con confianza para modelar la dinámica de pesquerías secuenciales del camarón

Service Learning for Community Engagement: An Interdisciplinary Approach for Engineering Education

Abstract Interdisciplinary teams of undergraduate students and faculty from different disciplines including civil, electrical, mechanical and chemical engineering as well as biology, business administration, chemistry, and social sciences has been working in communities in Puerto Rico since 2003 as part of an effort from the University of Puerto Rico at Mayagüez to engage into those communities with an innovative educational approach in service learning. The application of service learning in real world scenarios is guided through the use of the participative action research methodology that has been taught by the University Institute for Community Development. This methodology has been complemented with the engineering skills taught in undergraduate courses. Interdisciplinary teams are created to evaluate infrastructure as well as social and environmental conditions for the development and implementation of practical and feasible solutions to the needs of low-income citizens. The engineering students were also motivated in community service through the Engineering Projects in Community Service (EPICS) program. This paper describes the academic as well as the administrative structure developed by the faculty and students from the University Institute for Community Development and EPICS to accomplish interdisciplinary engineering education at the University of Puerto Rico at Mayagüez (UPRM). In addition, several types of projects are described to illustrate the extend of the approach and the challenges that interdisciplinary participants, both faculty and students, faced to achieve service teaching and learning

Different intracellular distribution of avian reovirus core protein sigmaA in cells of avian and mammalian origin

A comparative analysis of the intracellular distribution of avian reovirus (ARV) core protein sigmaA in cells of avian and mammalian origin revealed that, whereas the viral protein accumulates in the cytoplasm and nucleolus of avian cells, most sigmaA concentrates in the nucleoplasm of mammalian cells in tight association with the insoluble nuclear matrix fraction. Our results further showed that sigmaA becomes arrested in the nucleoplasm of mammalian cells via association with mammalian cell-specific factors and that this association prevents nucleolar targeting. Inhibition of RNA polymerase II activity, but not of RNA polymerase I activity, in infected mammalian cells induces nucleus-to-cytoplasm sigmaA translocation through a CRM1- and RanGTP-dependent mechanism, yet a heterokaryon assay suggests that sigmaA does not shuttle between the nucleus and cytoplasm. The scarcity of sigmaA in cytoplasmic viral factories of infected mammalian cells could be one of the factors contributing to limited ARV replication in mammalian cellsThis research was supported by grants from the Spanish Ministerio de Ciencia y Tecnología (BFU2007-61330/BMC) and from the Xunta de Galicia (08CSA009203PR). L. V-I. and I. L-S. were recipients of predoctoral fellowships from the FPI and FPU programs of the Spanish Ministerio de Ciencia y TecnologíaS