Semigroups of matrices of intermediate growth

Finitely generated linear semigroups over a field K that have intermediate growth are considered. New classes of such semigroups are found and a conjecture on the equivalence of the subexponential growth of a finitely generated linear semigroup S and the nonexistence of free noncommutative subsemigroups in S, or equivalently the existence of a nontrivial identity satisfied in S, is stated. This ���growth alternative��� conjecture is proved for linear semigroups of degree 2, 3 or 4. Certain results supporting the general conjecture are obtained. As the main tool, a new combinatorial property of groups is introduced and studied.

Spectral analysis of random sparse matrices

"Vegeu el resum a l'inici del document del fitxer adjunt."

Topolog��as en espacios de matrices y sistemas Leontief y Leontief-Sraffa

Se demuestra que todo sistema tipo Leontief (o Leontief-Sraffa) puede ser transformado en uno estructuralmente equivalente en el que la matriz tecnol��gica A tenga la propiedad de que la suma de los elementos de cada columna sea el autovalor m��ximo a de A; lo que equivale a transformar las unidades f��sicas originales en unidades que (haciendo abstracci��n de la componente trabajo) tengan id��ntica composici��n de capital. A un tal sistema transformado lo denominaremos homogeneizado. En este tipo de sistemas aparecen m��s c��modos los estudios del sistema de precios de Sraffa, la limitaci��n del tipo de beneficio, el reparto del excedente, la interpretaci��n econ��mica de 1/(I - A), la interpretaci��n de los precios utilizando el teorema del punto fijo, la evoluci��n de los precios al variar el tipo de beneficio, etc. Se demuestra que en un sistema homogeneizado "id��ntica composici��n org��nica de capital" (Marx) equivale a id��ntica cantidad de trabajo directo.

Parametrization of spectral surfaces of a class of periodic 5-diagonal matrices

The main result of this work is a parametric description of the spectral surfaces of a class of periodic 5-diagonal matrices, related to the strong moment problem. This class is a self-adjoint twin of the class of CMV matrices. Jointly they form the simplest possible classes of 5-diagonal matrices.

Uso de matrices biodegradables enriquecidas con PRP, para restituci��n inmediata de volumen y regeneraci��n tisular

Se plantea un ensayo cl��nico a fin de determinar la utilidad de una matriz estructural biodegradable (ME, en tr��mite de licencia de patente) enriquecida con fibrina y/o plasma rico en plaquetas (PRP) para restituci��n de volumen y regeneraci��n tisular. Consta de dos fases. La primera in vitro, donde se definen las caracter��sticas f��sicas y qu��micas de la matriz estructural. La segunda, in vivo, que consiste en el an��lisis de la matriz enriquecida implantada en el tejido subcut��neo abdominal de animales de experimentaci��n, mediante pruebas de im��genes, histolog��a y pruebas de biodistribuci��n.

Implementation of zonal control algorithms in adaptive optical systems with sparse control matrices

Miralls deformables m��s i m��s grans, amb cada cop m��s actuadors estan sent utilitzats actualment en aplicacions d'��ptica adaptativa. El control dels miralls amb centenars d'actuadors ��s un tema de gran inter��s, ja que les t��cniques de control cl��ssiques basades en la seudoinversa de la matriu de control del sistema es tornen massa lentes quan es tracta de matrius de dimensions tan grans. En aquesta tesi doctoral es proposa un m��tode per l'acceleraci�� i la paral.lelitzac�� dels algoritmes de control d'aquests miralls, a trav��s de l'aplicaci�� d'una t��cnica de control basada en la reducci�� a zero del components m��s petits de la matriu de control (sparsification), seguida de l'optimitzaci�� de l'ordenaci�� dels accionadors de comandament atenent d'acord a la forma de la matriu, i finalment de la seva posterior divisi�� en petits blocs tridiagonals. Aquests blocs s��n molt m��s petits i m��s f��cils de fer servir en els c��lculs, el que permet velocitats de c��lcul molt superiors per l'eliminaci�� dels components nuls en la matriu de control. A m��s, aquest enfocament permet la paral.lelitzaci�� del c��lcul, donant una com0onent de velocitat addicional al sistema. Fins i tot sense paral. lelitzaci��, s'ha obtingut un augment de gaireb�� un 40% de la velocitat de converg��ncia dels miralls amb nom��s 37 actuadors, mitjan��ant la t��cnica proposada. Per validar aix��, s'ha implementat un muntatge experimental nou complet , que inclou un modulador de fase programable per a la generaci�� de turbul��ncia mitjan��ant pantalles de fase, i s'ha desenvolupat un model complert del bucle de control per investigar el rendiment de l'algorisme proposat. Els resultats, tant en la simulaci�� com experimentalment, mostren l'equival��ncia total en els valors de desviaci�� despr��s de la compensaci�� dels diferents tipus d'aberracions per als diferents algoritmes utilitzats, encara que el m��tode proposat aqu�� permet una c��rrega computacional molt menor. El procediment s'espera que sigui molt exit��s quan s'aplica a miralls molt grans.

Dos cuestiones pendientes de la sintaxis de los pronombres ��tonos: enclisis como fen��meno asociado a las oraciones matrices y doble cl��tico en las construcciones perifr��sticas = The Remainders of the Syntax of Clitics: Enclisis as a Root Phenomenon, and Clitic Doubling in Periphrastic Constructions

Confer��ncia centrada en dos aspectes concrets de la sintaxi dels pronoms ��tons: l' enclisis que es dona en algunes oracions subordinades de les variants iberrom��niques modernes de l'oest peninsular i les configuracions de doble c��clic en les construccions perifr��stiques

Energy dispersive X-Ray fluorescence : measuring elements in solid and liquid matrices

The subject of this project is about ���Energy Dispersive X-Ray Fluorescence ��� (EDXRF).This technique can be used for a tremendous variety of elemental analysis applications.It provides one of the simplest, most accurate and most economic analytical methods for thedetermination of the chemical composition of many types of materials.The purposes of this project are:- To give some basic information about Energy Dispersive X-ray Fluorescence.- To perform qualitative and quantitative analysis of different samples (water-dissolutions,powders, oils,..) in order to define the sensitivity and detection limits of the equipment.- To make a comprehensive and easy-to-use manual of the ���ARL QUANT���X EnergyDispersive X-Ray Fluorescence��� apparatus

Bioinform��tica: base de datos de matrices de expresi��n g��nica para su an��lisis v��a web

El IBB ha desarrollado un servidor de aplicaciones: http://revolutionresearch.uab.es para el an��lisis de microarrays. Estas microarrays las obtienen y las suben a la base de datos local los usuarios de la aplicaci��n. En la presente memoria se detalla el proceso realizado para automatizar la subida de microarrays p��blicas a la base de datos local. Estas microarrays se obtendr��n del NCBI. El proceso de descarga de microarrays se realizar�� cada dos meses y estar�� sincronizado con un proceso de descarga de genes marcadores de microarrays del NCBI. En la memoria tambi��n se describen las fases realizadas para crear la interfaz web para gestionar estas microarrays p��blicas y las modificaciones realizadas sobre el aplicativo web para permitir realizar an��lisis con estas microarrays.

Generalized canonical correlation analysis of matrices with different row and column orders

A Method is offered that makes it possible to apply generalized canonicalcorrelations analysis (CANCOR) to two or more matrices of different row and column order. The new method optimizes the generalized canonical correlationanalysis objective by considering only the observed values. This is achieved byemploying selection matrices. We present and discuss fit measures to assessthe quality of the solutions. In a simulation study we assess the performance of our new method and compare it to an existing procedure called GENCOM,proposed by Green and Carroll. We find that our new method outperforms the GENCOM algorithm both with respect to model fit and recovery of the truestructure. Moreover, as our new method does not require any type of iteration itis easier to implement and requires less computation. We illustrate the methodby means of an example concerning the relative positions of the political parties inthe Netherlands based on provincial data.

Analysis of matched matrices

We consider the joint visualization of two matrices which have common rowsand columns, for example multivariate data observed at two time pointsor split accord-ing to a dichotomous variable. Methods of interest includeprincipal components analysis for interval-scaled data, or correspondenceanalysis for frequency data or ratio-scaled variables on commensuratescales. A simple result in matrix algebra shows that by setting up thematrices in a particular block format, matrix sum and difference componentscan be visualized. The case when we have more than two matrices is alsodiscussed and the methodology is applied to data from the InternationalSocial Survey Program.

Period-Luminosity-Colour distribution and classification of Galactic oxygen-rich LPVs I. Luminosity calibrations

The absolute K magnitudes and kinematic parameters of about 350 oxygen-rich Long-Period Variable stars are calibrated, by means of an up-to-date maximum-likelihood method, using HIPPARCOS parallaxes and proper motions together with radial velocities and, as additional data, periods and V-K colour indices. Four groups, differing by their kinematics and mean magnitudes, are found. For each of them, we also obtain the distributions of magnitude, period and de-reddened colour of the base population, as well as de-biased period-luminosity-colour relations and their two-dimensional projections. The SRa semiregulars do not seem to constitute a separate class of LPVs. The SRb appear to belong to two populations of different ages. In a PL diagram, they constitute two evolutionary sequences towards the Mira stage. The Miras of the disk appear to pulsate on a lower-order mode. The slopes of their de-biased PL and PC relations are found to be very different from the ones of the Oxygen Miras of the LMC. This suggests that a significant number of so-called Miras of the LMC are misclassified. This also suggests that the Miras of the LMC do not constitute a homogeneous group, but include a significant proportion of metal-deficient stars, suggesting a relatively smooth star formation history. As a consequence, one may not trivially transpose the LMC period-luminosity relation from one galaxy to the other.

Rat splanchnic net oxygen consumption. Energetic implications

1. The blood flow, PO2, pH and PCO2 have been estimated in portal and suprahepatic veins as well as in hepatic artery of fed and overnight starved rats given an oral glucose load. From these data the net intestinal, hepatic and splanchnic balances for oxygen and bicarbonate were calculated. The oxygen consumption of the intact animal has also been measured under comparable conditions. 2. The direct utilization of oxygen balances as energy equivalents when establishing the contribution of energy metabolism of liver and intestine to the overall energy expenses of the rat, has been found to be incorrect, since it incorporates the intrinsic error of interorgan proton transfer through bicarbonate. Liver and intestine produced high net bicarbonate balances in all situations tested, implying the elimination (by means of oxidative pathways, i.e. consuming additional oxygen) of high amounts of H+ generated with bicarbonate. The equivalence in energy output of the oxygen balances was then corrected for bicarbonate production to 11-54% lower values. 3. Intestine and liver consume a high proportion of available oxygen, about one-half in basal (fed or starved) conditions and about one-third after gavage, the intestine consumption being about 15% in all situations tested and the liver decreasing its oxygen consumption with gavage.

Edelfosine-induced metabolic changes in cancer cells that precede the overproduction of reactive oxygen species and apoptosis

Background: Metabolic flux profiling based on the analysis of distribution of stable isotope tracer in metabolites is an important method widely used in cancer research to understand the regulation of cell metabolism and elaborate new therapeutic strategies. Recently, we developed software Isodyn, which extends the methodology of kinetic modeling to the analysis of isotopic isomer distribution for the evaluation of cellular metabolic flux profile under relevant conditions. This tool can be applied to reveal the metabolic effect of proapoptotic drug edelfosine in leukemia Jurkat cell line, uncovering the mechanisms of induction of apoptosis in cancer cells. Results: The study of 13C distribution of Jukat cells exposed to low edelfosine concentration, which induces apoptosis in ��5% of cells, revealed metabolic changes previous to the development of apoptotic program. Specifically, it was found that low dose of edelfosine stimulates the TCA cycle. These metabolic perturbations were coupled with an increase of nucleic acid synthesis de novo, which indicates acceleration of biosynthetic and reparative processes. The further increase of the TCA cycle fluxes, when higher doses of drug applied, eventually enhance reactive oxygen species (ROS) production and trigger apoptotic program. Conclusion: The application of Isodyn to the analysis of mechanism of edelfosine-induced apoptosis revealed primary drug-induced metabolic changes, which are important for the subsequent initiation of apoptotic program. Initiation of such metabolic changes could be exploited in anticancer therapy.