A nonparametric test for serial independence of errors in linear regression

A test for serial independence of regression errors, consistent in the direction of first order alternatives, is proposed. The test statistic is a function of a Hoeffding-Blum-Kiefer-Rosenblatt type of empirical process, based on residuals. The resultant statistic converges, surprisingly, to the same limiting distribution as the corresponding statistic based on true errors

Nonparametric and semiparametric estimation with discrete regressors

This paper presents and discusses procedures for estimating regression curves when regressors are discrete and applies them to semiparametric inference problems. We show that pointwise root-n-consistency and global consistency of regression curve estimates are achieved without employing any smoothing, even for discrete regressors with unbounded support. These results still hold when smoothers are used, under much weaker conditions than those required with continuous regressors. Such estimates are useful in semiparametric inference problems. We discuss in detail the partially linear regression model and shape-invariant modelling. We also provide some guidance on estimation in semiparametric models where continuous and discrete regressors are present. The paper also includes a Monte Carlo study

Inference on semiparametric models with discrete regressors

We study statistical properties of coefficient estimates of the partially linear regression model when some or all regressors, in the unknown part of the model, are discrete. The method does not require smoothing in the discrete variables. Unlike when there are continuous regressors. when all regressors are discrete independence between regressors and regression errors is not required. We also give some guidance on how to implement the estimate when there are both continuous and discrete regressors in the unknown part of the model. Weights employed in this paper seem straightforwardly applicable to other semiparametric problems

- A NONPARAMETRIC TEST FOR SERIAL INDEPENDENCE OF REGRESSION ERRORS.

A test for serial independence of regression errors is proposed that is consistent in the direction ofserial dependence alternatives of first order. The test statistic is a function of aHoeffding-Blum-Kiefer-Rosenblatt type of empirical process, based on residuals. The resultantstatistic converges, surprisingly, to the same limiting distribution as the corresponding statisticbased on true errors.Empirical process based on residuals; Hoeffding-Blum-Kiefer-Rosenblatt statistic; Serial independence test

Aprendizaje colaborativo guiado: Fundamentos y aplicaciones

El objetivo de esta exposición es describir un tipo de sistemas para la enseñanza asistida por ordenador de reciente aparición, basados en el aprendizaje colaborativo guiado. Se muestra así mismo el contexto en el que han surgido estos sistemas y las principales ideas subyacentes. Igualmente se describe FACT, un framework para el desarrollo de aplicaciones educativas basadas en aprendizaje colaborativo guiado, y algunas aplicaciones desarrolladas con él

Developing applications with a framework for the analysis of the learning process and collaborative tutoring

In this paper we describe FACT, a Framework for the Analysis of the learning process and Collaborative Tutoring, developed at Universidad Autónoma de Madrid, Spain. First we describe guided collaborative tutoring; the type of tutoring that FACT makes possible. After that, we show the architecture of FACT, and different applications developed with it, as well as how it can be used to build new teaching tools from simple training applications. FACT uses learning histories and related annotations to enhance the guidance of the teaching process. It allows students and tutors to review the work of the students and the history of their work sessions, using the original application, while allowing reviewers to extend that history. Optionally, reviewers can attach commentaries to some points of the extended and revised histories. The generated applications can be used collaboratively, either synchronously or asynchronously. The generated histories can be stored in order to create a knowledge database with solved problems and commentaries from tutors and students

Chloroplast fructose-1,6-bisphosphatase: Modification of non-covalent interactions promote the activation by chimeric Escherichia coli thioredoxins

AbstractAlthough all thioredoxins contain a highly conserved amino acid sequence responsible for thiol/disulfide exchanges, only chloroplast thioredoxin-f is effective in the reductive stimulation of chloroplast fructose- 1,6-bisphosphatase. We set out to determine whether Escherichia coli thioredoxin becomes functional when selected modulators alter the conformation of the target enzyme. Wild type and chimeric Escherichia coli thioredoxins match the chloroplast counterpart when the activation of chloroplast fructose- 1,6-bssphosphatase is performed in the presence of fructose 1,6-bisphosphate, Ca2+, and either trichloroacetate or 2-propanol. These modulators of enzyme activity do change the conformation of chloroplast fructose-1,6-bisphosphatase whereas bacterial thioredoxins remain unaltered. Given that fructose 1,6-bisphosphate, Ca2+, and non-physiological perturbants modify non-covalent interactions of the protein but do not participate in redox reactions, these results strongly suggest that the conformation of the target enzyme regulates the rate of thiol/disulfide exchanges catalyzed by protein disulfide oxidoreductases

Generación de cursos interactivos y análisis colaborativo del proceso de aprendizaje

Tesis doctoral inédita. Universidad Autónoma de Madrid, Escuela Politécnica Superior, Octubre 200

DE LINGÜÍSTICA, TRADUCCIÓN Y LEXICO-FRASEOLOGÍA. HOMENAJE A JUAN DE DIOS LUQUE DURÁN

Esta monografía colectiva, editada por Antonio Pamies Bertrán, es el resultado de una obra de homenaje al lingüista granadino Juan de Dios Luque Durán, con motivo de sus 65 años. La obra y la propia biografía de este catedrático de Lingüista general de la Universidad de Granada, con más de 40 años de actividad docente e investigadora, como reza en la nota autobiográfica que, a modo de epílogo, cierra esta monografía, nos permiten comprender, de primera mano, la evolución exponencial que, sobre todo a partir de los años 80, ha sufrido la investigación lingüística y traductológica en nuestro país