Search results for "Investigación operativa"
showing 10 items of 24 documents
Identification and visualization of differential isoform expression in RNA-seq time series
2018
Abstract Motivation As sequencing technologies improve their capacity to detect distinct transcripts of the same gene and to address complex experimental designs such as longitudinal studies, there is a need to develop statistical methods for the analysis of isoform expression changes in time series data. Results Iso-maSigPro is a new functionality of the R package maSigPro for transcriptomics time series data analysis. Iso-maSigPro identifies genes with a differential isoform usage across time. The package also includes new clustering and visualization functions that allow grouping of genes with similar expression patterns at the isoform level, as well as those genes with a shift in major …
La Muestra Continua de Vidas Laborales (MCVL) como fuente generadora de datos para el estudio del sistema de pensiones
2015
Esta tesis tiene como elemento fundamental de análisis la denominada Muestra Continua de Vidas Laborales (MCVL), como fuente generadora de datos para el estudio del sistema de público de pensiones de España. La MCVL es un conjunto de microdatos individuales anonimizados extraídos de los registros de la Seguridad Social de España. La MCVL se obtiene a partir de un Muestreo Aleatorio Simple (MAS) sobre la población de referencia (conjunto de personas relacionadas durante todo el año con la Seguridad Social, bien como afiliadas o bien como perceptoras de prestaciones, pero con ciertos matices en dicha relación). Los objetivos principales de esta tesis son: - Contribuir a aumentar el conocimien…
Model and solution methods for some hub location problems
2016
In this thesis we study some hub location problems in the context of transportation networks. These are combinatorial optimization problems appearing in situations where there is a need of transporting some traffic, like items, people, and information, from many origins to many destinations. Instead of sending these flows using a direct shipment between all pairs of nodes in the network, a subset of these nodes is selected to use as hubs, with the aim of consolidating and distribute the flows. Thus, hubs induce a subnetwork that sends the traffic more efficiently and at a cheaper cost, allowing economies of scale when large amounts of traffic between nodes on this subnet are transported. We…
A game theory approach to conflicting preferences, service search and peer review problems
2014
Este trabajo está compuesto por dos estudios teóricos y uno experimental, en los cuales se utiliza la teoría de juegos para modelar la interacción estratégica de los agentes económicos que toman parte en ellos y caracterizar y analizan las estrategias de equilibrio en los juegos, y en dos de ellos se utilizan estructuras de red para especificar sus inter-relaciones. Además, en uno se utiliza la Economía Experimental para obtener datos empíricos sobre el comportamiento de las personas a quienes se les presenta el juego. El primer trabajo de la tesis ‘Conflict and segregation in networks: An experiment on the interplay between individual preferences and social influence’ utiliza la metodologí…
The effect of cholecalciferol for lowering albuminuria in chronic kidney disease: a prospective controlled study.
2013
Background. Growing evidence indicates that vitamin D receptor activation may have antiproteinuric effects. We aimed to evaluate whether vitamin D supplementation with daily cholecalciferol could reduce albuminuria in proteinuric chronic kidney disease (CKD) patients. Methods. This 6-month prospective, controlled, intervention study enrolled 101 non-dialysis CKD patients with albuminuria. Patients with low 25(OH) vitamin D [25(OH)D] and high parathyroid hormone (PTH) levels (n = 50; 49%) received oral cholecalciferol (666 IU/day), whereas those without hyperparathyroidism (n = 51; 51%), independent of their vitamin D status, did not receive any cholecalciferol, and were considered as the co…
Pathway network inference from gene expression data
2014
[EN] Background: The development of high-throughput omics technologies enabled genome-wide measurements of the activity of cellular elements and provides the analytical resources for the progress of the Systems Biology discipline. Analysis and interpretation of gene expression data has evolved from the gene to the pathway and interaction level, i.e. from the detection of differentially expressed genes, to the establishment of gene interaction networks and the identification of enriched functional categories. Still, the understanding of biological systems requires a further level of analysis that addresses the characterization of the interaction between functional modules. Results: We presen…
La contabilidad como sistema de información para el control de la gestión social y ambiental de las empresas. Un estudio comparado de los casos exito…
2017
La presente investigación responde a criterios de oportunidad e interés desde el discurso sobre la gestión socialmente responsable y ambientalmente sostenible en el ámbito más amplio de las organizaciones, cuyo aspecto central, para la comprensión del fenómeno, se posiciona desde la contabilidad como sistema de información para el control de las externalidades generadas en el desarrollo de los negocios. La hipótesis central es qué la contabilidad, al capturar la realidad de la organización y ser el lenguaje del negocio permite articular variables para el análisis social y ambiental, como parte integral de la información financiera y no financiera. Lo anterior, además de responder a las diná…
The effect of high-volume online haemodiafiltration on nutritional status and body composition: the ProtEin Stores prEservaTion (PESET) study
2018
Background Compared with conventional haemodialysis (HD), online haemodiafiltration (OL-HDF) achieves a more efficient removal of uraemic toxins and reduces inflammation, which could favourably affect nutritional status. We evaluate the effect of OL-HDF on body composition and nutritional status in prevalent high-flux HD (HF-HD) patients. Methods In all, 33 adults with chronic kidney disease (CKD) Stage 5 undergoing maintenance HF-HD were assigned to post-dilution OL-HDF (n = 17) or to remain on HF-HD (n = 16, control group) for 12 months. The primary outcome was the change in lean tissue mass (LTM), intracellular water (ICW) and body cell mass (BCM) assessed by multifrequency bioimpedance …
On the dynamics of eco-efficiency performance in the European Union
2016
This paper evaluates the evolution of environmental performance in the context of the European Union (EU), over the period 1993–2010. The context is particularly relevant, due to the traditionally high concerns of the EU about these issues, which has triggered off several initiatives and regulations on environmental protection. In this setting, we conduct a two-stage analysis which develops environmental performance indicators in the first stage for each pair country-year, and evaluates its evolution in the second. More specifically, in the first stage we estimate specific efficiencies for three air-pollutants (CO2e, SO2, NOx), along with an eco-efficiency indicator, for which we use the sl…
Strengthened splitting methods for computing resolvents
2021
In this work, we develop a systematic framework for computing the resolvent of the sum of two or more monotone operators which only activates each operator in the sum individually. The key tool in the development of this framework is the notion of the “strengthening” of a set-valued operator, which can be viewed as a type of regularisation that preserves computational tractability. After deriving a number of iterative schemes through this framework, we demonstrate their application to best approximation problems, image denoising and elliptic PDEs. FJAA and RC were partially supported by the Ministry of Science, Innovation and Universities of Spain and the European Regional Development Fund …