Saccharomyces cerevisiae glutaredoxin 5-deficient cells subjected to constitutive oxidizing conditions are affected in the expression of specific sets of genes

The Saccharomyces cerevisiae GRX5 gene codes for a mitochondrial glutaredoxin involved in the synthesis ofiron/sulfur clusters. Its absence prevents respiratory growth and causes the accumulation of iron inside cellsand constitutive oxidation of proteins. Null Δgrx5 mutants were used as an example of continuously oxidizedcells, as opposed to situations in which oxidative stress is instantaneously caused by addition of external oxidants.Whole transcriptome analysis was carried out in the mutant cells. The set of genes whose expression wasaffected by the absence of Grx5 does not significantly overlap with the set of genes affected in respiratorypetite mutants. Many Aft1-dependent genes involved in iron utilization that are up-regulated in a frataxin mutantwere also up-regulated in the absence of Grx5. BIO5 is another Aft1-dependent gene induced both upon irondeprivation and in Δgrx5 cells; this links iron and biotin metabolism. Other genes are specifically affected underthe oxidative conditions generated by the grx5 mutation. One of these is MLP1, which codes for a homologueof the Slt2 kinase. Cells lacking MLP1 and GRX5 are hypersensitive to oxidative stress caused by externalagents and exhibit increased protein oxidation in relation to single mutants. This in turn points to a role forMlp1 in protection against oxidative stress. The genes of the Hap4 regulon, which are involved in respiratorymetabolism, are down-regulated in Δgrx5 cells. This effect is suppressed by HAP4 overexpression. Inhibition ofrespiratory metabolism during continuous moderately oxidative conditions could be a protective response bythe cell

Analysis of a sensor fusion hybrid solution for indoor/outdoor robot navigation

Proceedings of: 5th ESA Workshop on Satellite Navigation Technologies and European Workshop on GNSS Signals and Signal Processing (NAVITEC 2010). Noordwij, Netherlands, 8-10 December 2010Autonomous mobile robots need robust, flexible and accurate navigation algorithms. One approach consists in fusing as many information sources as possible, integrating measures from internal sensors with data obtained from external sensing entities. This work presents a solution for combined indoor/outdoor robot navigation, and analyzes some preliminary results in an outdoor environment using a Particle Filter for GPS/INS sensor fusion. Experiments are based in predesigned trajectories which have been simulated in first place and then reproduced using a robotic platform. As a concluding remark, some considerations about the use of Particle Filters and the differences between simulated and real data are presentedThis work was supported in part by Projects ATLANTIDA, CICYT TIN2008-06742-C02-02/TSI, CICYT TEC2008- 06732-C02-02/TEC, SINPROB, CAM MADRINET S- 0505/TIC/0255 DPS2008-07029-C02-02.Publicad

Neighborhood-based Regularization of Proposal Distribution for Improving Resampling Quality in Particle Filters

Proceedings of: 14th International Conference on Information Fusion (FUSION 2011). Chicago, Illinois, USA 5-8 July 2011Particle Filter is a sequential Montecarlo algorithm extensively used for solving estimation problems with non-linear and non-Gaussian features. In spite of its relative simplicity, it is known to suffer some undesired effects that can spoil its performance. Among these problems we can account the one known as sample depletion. This paper reviews the different causes of sample depletion and the many solutions proposed in the existing literature. It also introduces a new strategy for particle resampling which relies in a local linearization of the proposal distribution. The particles drawn using the proposed method are not affected by sample impoverishment and can indirectly lead to better results thanks to a reduction in the plant noise employed, as well to increased performance because of requiring a lower number of particles to achieve same results.Publicad

¿Qué (nos) está pasando en la universidad?

Este texto es una presentación del monográfico "¿Qué (nos) está pasando en la universidad?". En él damos cuenta de las motivaciones y el proceso que nos han llevado hasta la redacción final de los trabajos que aquí se presentan. Podríamos clasificar los temas que hemos tratado en tres grandes grupos. En primer lugar, nos preguntamos por la naturaleza y la función que la universidad ha tenido a lo largo de sus ocho siglos de existencia. En segundo, nos adentramos en el análisis de determinados dispositivos de evaluación del profesorado y de los estudiantes, sus presupuestos y sus efectos. Por último, nos preguntamos por las modificaciones, las posibles resistencias e invenciones en el territorio de las prácticas docentes.This text is an introduction to the monograph entitled "What is going on (with us) at university? In it we explain the motivations and the process that lead us to write the articles that we present here. We could classify in three groups the topics that we discuss. In the first place, we ask ourselves about the nature and function that the university has had during its eight centuries of existence. In the second place, we concentrate on the analysis of certain forms of evaluation of teachers and students, its presuppositions and effects. Finally, we ask ourselves about the transformations, and the possible resistances and inventions that can take place when teaching

Pixel Features for Self-organizing Map Based Detection of Foreground Objects in Dynamic Environments

Among current foreground detection algorithms for video sequences, methods based on self-organizing maps are obtaining a greater relevance. In this work we propose a probabilistic self-organising map based model, which uses a uniform distribution to represent the foreground. A suitable set of characteristic pixel features is chosen to train the probabilistic model. Our approach has been compared to some competing methods on a test set of benchmark videos, with favorable results.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Efficient Model-Based 3D Tracking of Deformable Objects

Efficient incremental image alignment is a topic of renewed interest in the computer vision community because of its applications in model fitting and model-based object tracking. Successful compositional procedures for aligning 2D and 3D models under weak-perspective imaging conditions have already been proposed. Here we present a mixed compositional and additive algorithm which is applicable to the full projective camera case

A model of brightness variations due to illumination changes and non-rigid motion using spherical harmonics

Pixel brightness variations in an image sequence depend both on the objects ‘surface reflectance and on the motion of the camera and object. In the case of rigid shapes some proposed models have been very successful explaining the relation among these strongly coupled components. On the other hand, shapes which deform pose new challenges since the relation between pixel brightness variation with non-rigid motion is not yet clear. In this paper, we introduce a new model which describes brightness variations with two independent components represented as linear basis shapes. Lighting influence is represented in terms of Spherical Harmonics and non-rigid motion as a linear model which represents image coordinates displacement. We then propose an efficient procedure for the estimation of this image model in two distinct steps. First, shape normal’s and albedo are estimated using standard photometric stereo on a sequence with varying lighting and no deformable motion. Then, given the knowledge of the object’s shape normal’s and albedo, we efficiently compute the 2D coordinates bases by minimizing image pixel residuals over an image sequence with constant lighting and only non-rigid motion. Experiments on real tests show the effectiveness of our approach in a face modelling context

Recursos de la empresa y pertenencia a un sector industrial: un estudio empírico de su influencia sobre la rentabilidad empresarial

En esta investigación tratamos de analizar cuál es la importancia relativa del conjunto de factores industriales (efecto sector) frente al conjunto de características internas de las empresas (efecto empresa) en la determinación de la rentabilidad empresarial. Para ello, realizamos un análisis de componentes de la varianza, con el objetivo de confirmar o refutar los resultados obtenidos por los estudios previos, utilizando un conjunto distinto de empresas con datos más actualizados sobre su rentabilidad. En concreto, nuestra muestra está compuesta por 1453 empresas de la Comunidad Valenciana de las que se dispone de datos sobre su rentabilidad durante cinco años (1994-1998), de forma que el análisis estadístico se aplica sobre 7265 observaciones