Actualización, consolidación, migración y contingencia de un entorno hardware y software para la gestión de bases de datos

[ES]El objetivo de este Trabajo es el de actualizar un entorno de gestión de bases de datos existente a la versión 11.2 del software de bases de datos Oracle y a una plataforma hardware de última generación. Se migran con tiempo de parada cero varias bases de datos dispersas en distintos servidores a un entorno consolidado de dos nodos dispuestos en alta disponibilidad tipo "activo-activo" mediante Oracle RAC y respaldado por un entorno de contingencia totalmente independiente y sincronizado en tiempo real mediante Oracle GoldenGate. Se realiza un estudio del entorno actual y, realizando una estimación de crecimiento, se propone una configuración de hardware y software mínima para implementar con garantías de éxito los requerimientos del entorno de gestión de bases de datos a corto y medio plazo. Una vez adquirido el hardware, se lleva a cabo la instalación, actualización y configuración del Sistema Operativo y el acceso redundado de los servidores a la cabina de almacenamiento. Posteriormente se instala el software de clúster de Oracle, el software de la base de datos y se crea una instancia que albergará los esquemas requeridos de las bases de datos a consolidar. Seguidamente se migran los esquemas al entorno consolidado y se establece la replicación de éstos en tiempo real con la máquina de contingencia usando en ambos casos Oracle GoldenGate. Finalmente se crea y prueba un esquema de copias de seguridad que incluye copias lógicas y físicas de la propia base de datos y de archivos de configuración del clúster a partir de los cuales será posible restaurar el entorno completamente.

Turismo y administración local en Canarias: un problema pendiente. Bases para un debate

[ES] Las administraciones locales deben gestionar una parte importante de las infraestructuras y servicios demandados por el turismo. En estas áreas se combina la prestación de servicios a la población turística y población local, lo que supone su redimensionamiento y diversificación. Como resultado, los municipios afectados por esta dualidad deben adaptar la gestión de sus recursos, produciéndose importantes desequilibrios. Esta distinción ha abierto un importante debate en torno a la figura del «municipio turístico» y su «discriminación positiva» frente al resto de municipios. Una fórmula que trata de compensar el desequilibrio que genera la actividad turística en la gestión local. Actualmente las islas Canarias carecen de criterios oficiales para la definición de un municipio turístico, así como no se ha consensuado un listado oficial que los identifique. En este sentido, el presente artículo pretende hacer algunas aportaciones a este debate, planteando una propuesta de delimitación.

Las bases de datos

[ES] Prezi del curso virtual Adquisición de Habilidades en Información. Nivel I. En él se explica qué es una base de datos, su interfaz y cómo buscar la información en ellas.

Molecular bases, pathogenic mechanisms and possible therapeutic approach in Leber's Hereditary Optic Neuropathy

Leber’s hereditary optic neuropathy (LHON) is a mitochondrial disease characterized by a rapid loss of central vision and optic atrophy, due to the selective degeneration of retinal ganglion cells. The age of onset is around 20, and the degenerative process is fast and usually the second eye becomes affected in weeks or months. Even if this pathology is well known and has been well characterized, there are still open questions on its pathophysiology, such as the male prevalence, the incomplete penetrance and the tissue selectivity. This maternally inherited disease is caused by mutations in mitochondrial encoded genes of NADH ubiquinone oxidoreductase (complex I) of the respiratory chain. The 90% of LHON cases are caused by one of the three common mitochondrial DNA mutations (11778/ND4, 14484/ND6 and 3460/ND1) and the remaining 10% is caused by rare pathogenic mutations, reported in literature in one or few families. Moreover, there is also a small subset of patients reported with new putative pathogenic nucleotide changes, which awaits to be confirmed. We here clarify some molecular aspects of LHON, mainly the incomplete penetrance and the role of rare mtDNA mutations or variants on LHON expression, and attempt a possible therapeutic approach using the cybrids cell model. We generated novel structural models for mitochondrial encoded complex I subunits and a conservation analysis and pathogenicity prediction have been carried out for LHON reported mutations. This in-silico approach allowed us to locate LHON pathogenic mutations in defined and conserved protein domains and can be a useful tool in the analysis of novel mtDNA variants with unclear pathogenic/functional role. Four rare LHON pathogenic mutations have been identified, confirming that the ND1 and ND6 genes are mutational hot spots for LHON. All mutations were previously described at least once and we validated their pathogenic role, suggesting the need for their screening in LHON diagnostic protocols. Two novel mtDNA variants with a possible pathogenic role have been also identified in two independent branches of a large pedigree. Functional studies are necessary to define their contribution to LHON in this family. It also been demonstrated that the combination of mtDNA rare polymorphic variants is relevant in determining the maternal recurrence of myoclonus in unrelated LHON pedigrees. Thus, we suggest that particular mtDNA backgrounds and /or the presence of specific rare mutations may increase the pathogenic potential of the primary LHON mutations, thereby giving rise to the extraocular clinical features characteristic of the LHON “plus” phenotype. We identified the first molecular parameter that clearly discriminates LHON affected individuals from asymptomatic carriers, the mtDNA copy number. This provides a valuable mechanism for future investigations on variable penetrance in LHON. However, the increased mtDNA content in LHON individuals was not correlated to the functional polymorphism G1444A of PGC-1 alpha, the master regulator of mitochondrial biogenesis, but may be due to gene expression of genes involved in this signaling pathway, such as PGC-1 alpha/beta and Tfam. Future studies will be necessary to identify the biochemical effects of rare pathogenic mutations and to validate the novel candidate mutations here described, in terms of cellular bioenergetic characterization of these variants. Moreover, we were not able to induce mitochondrial biogenesis in cybrids cell lines using bezafibrate. However, other cell line models are available, such as fibroblasts harboring LHON mutations, or other approaches can be used to trigger the mitochondrial biogenesis.

Fault detection, diagnosis and active fault tolerant control for a satellite attitude control system

Modern control systems are becoming more and more complex and control algorithms more and more sophisticated. Consequently, Fault Detection and Diagnosis (FDD) and Fault Tolerant Control (FTC) have gained central importance over the past decades, due to the increasing requirements of availability, cost efficiency, reliability and operating safety. This thesis deals with the FDD and FTC problems in a spacecraft Attitude Determination and Control System (ADCS). Firstly, the detailed nonlinear models of the spacecraft attitude dynamics and kinematics are described, along with the dynamic models of the actuators and main external disturbance sources. The considered ADCS is composed of an array of four redundant reaction wheels. A set of sensors provides satellite angular velocity, attitude and flywheel spin rate information. Then, general overviews of the Fault Detection and Isolation (FDI), Fault Estimation (FE) and Fault Tolerant Control (FTC) problems are presented, and the design and implementation of a novel diagnosis system is described. The system consists of a FDI module composed of properly organized model-based residual filters, exploiting the available input and output information for the detection and localization of an occurred fault. A proper fault mapping procedure and the nonlinear geometric approach are exploited to design residual filters explicitly decoupled from the external aerodynamic disturbance and sensitive to specific sets of faults. The subsequent use of suitable adaptive FE algorithms, based on the exploitation of radial basis function neural networks, allows to obtain accurate fault estimations. Finally, this estimation is actively exploited in a FTC scheme to achieve a suitable fault accommodation and guarantee the desired control performances. A standard sliding mode controller is implemented for attitude stabilization and control. Several simulation results are given to highlight the performances of the overall designed system in case of different types of faults affecting the ADCS actuators and sensors.

Magnetic actuators for nanosatellite attitude control

The research and the activities presented in the following thesis report have been led at the California Polytechnic State University (US) under the supervision of Prof. Jordi Puig Suari. The objective of the research has been the study of magnetic actuators for nanosatellite attitude control, called magnetorquer. Theese actuators are generally divided in three different kinds: air core torquer, embedded coil and torquerod. In a first phase of the activity, each technology has been analyzed, defining advantages and disadvantages, determining manufacturing procedures and creating mathematical model and designing equation. Dimensioning tools have been then implemented in numerical software to create an instrument that permits to determine the optimal configuration for defined requirements and constraints. In a second phase of the activities the models created have been validated exploiting prototypes and proper instruments for measurements. The instruments and the material exploited for experiments and prototyping have been provided by the PolySat and CubeSat laboratories. The results obtained led to the definition of a complete designing tool and procedure for nanosatellite magnetic actuators, introducing a cost analysis for each kind of solution. The models and the tools have been maintained fully parametric in order to offer a universal re-scalable instrument for satellite of different dimension class.

Influence of single peer interventions on the recovery attitude of persons with a psychiatric disability

This study examined the influence of single peer to peer interventions on participants' recovery attitudes.