Crystallographic studies on two hyperthermophilic enzymes

Dissertation presented to obtain the Ph.D degree in BiochemistryWhile Aristotle cautioned “everything in moderation”, the Romans, known for their eccentricities, coined the word “extremus”, the superlative of exter, “being on the outside”. By the fifteenth century “extreme” had arrived to English, via Middle French. At the beginning of the 21st century, we know that Earth contains environmental extremes unimaginable to our ancestors of the 19th century. Even more unimaginable to them would be the fact that there are organisms that live, and grow, in these environmental extremes. R. D. MacElroy named these organisms lovers (from the Greek “philos”), “extremophiles” as in “lovers of extreme environments”. The discovery of extremophiles has put vitality in the biotechnology industry as this discipline has exploded in the past 20 years. Several reviews have been published on extremophiles and an increasing number of meetings and conferences are organised around the theme. Genomes of extremophiles have been sequenced, patents have been filed and several funding programmes have been launched namely the US National Science Foundation and NASA’s programmes in “Life in Extreme Environments, Exobiology and Astrobiology”, and the European Union’s “Biotechnology of Extremophiles” and “Extremophiles as Cell Factories”(...)Fundação para a Ciência e a Tecnologia (FCT), e Fundo Social Europeu (FSE), o apoio financeiro no âmbito do Quadro Comunitário de apoio (Bolsa de Doutoramento SFRH/BD/30512/2006

Impact of 3D EM model configuration on the direct optimization of microstrip structures

We apply the classical Nelder-Mead optimization algorithm to a low fidelity EM model, using different mesh and bounding-box configurations. We demonstrate that the interaction of the coarse mesh with the bounding box size can determine whether the optimization is successful or not.ITESO, A.C.Intel Lab

An experimental investigation on the influence of deactivation of a groove on the performance of a twin groove journal bearing

Laboratory tests have been carried out in order to assess the influence of groove activation and deactivation on the performance of a twin axial groove steadily loaded hydrodynamic journal bearing. Temperature distribution at the oil–bush interface, oil outlet temperature, total oil flow rate, partial oil flow rate (at each groove), and motor consumption were measured for several journal speeds and loads under constant feeding pressure (pf) and constant feeding temperature (Tf), at five different loading angles ( ). In this study, the corresponding groove was deactivated whenever negative oil flow rate was observed in it and results were compared. It was found that the groove deactivation strategy has profound influence on the bearing performance when negative flow rate occurs at one groove, preventing such undesirable effects as lubricant starvation at the loaded region of the bearing. Groove deactivation in the event of negative flow rate may be easily implemented by incorporating a check valve to the feeding system of each groove. Such strategy seems to be highly recommended for the safe operation of bearings subjected to high loads and load angles deviated from 90º

Luminescent and Scintillating Properties of Lanthanum Fluoride Nanocrystals in Response to Gamma/Neutron Irradiation: Codoping with Ce Activator, Yb Wavelength Shifter, and Gd Neutron Captor

A novel concept for detection and spectroscopy of gamma rays, and detection of thermal neutrons based on codoped lanthanum fluoride nanocrystals containing gadolinium is presented.The trends of colloidal synthesis of the mentioned material, LaF3 co-doped with Ce as the activator, Yb as the wavelength-shifter and Gd as the neutron captor, is reported. Nanocrystals of the mentioned material were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), optical absorption, and photoluminescence spectroscopy. Gamma detection and its potential spectroscopy feature have been confirmed. The neutron detection capability has been confirmed by experiments performed using a 252Cf neutron source.Comment: 5 figures, 16 page

Probabilistic clustering of interval data

In this paper we address the problem of clustering interval data, adopting a model-based approach. To this purpose, parametric models for interval-valued variables are used which consider configurations for the variance-covariance matrix that take the nature of the interval data directly into account. Results, both on synthetic and empirical data, clearly show the well-founding of the proposed approach. The method succeeds in finding parsimonious heterocedastic models which is a critical feature in many applications. Furthermore, the analysis of the different data sets made clear the need to explicitly consider the intrinsic variability present in interval data.info:eu-repo/semantics/publishedVersio

Development of self-diagnosis tests system using a DSL for creating new test suites for integration in a cyber-physical system

Testing Cyber-physical systems (CPS) requires highly qualified engineers to design the tests since its computational part is programmed in low-level languages. The origin of this work arises from the need to find a solution that optimizes this problem and allows abstracting the current methods so that the tests can be created and executed more efficiently. We intend to do this by creating a self-diagnosis tests system that allows us to automate some of the current processes in the creation and execution of test suites. The work presented here addresses the problem by creating a new self-diagnosis tests system that will guarantee the reliability and integrity of the CPS. In detail, this paper begins by exposing a study on the current state of the art of test automation, Keyword-driven Testing (KDT) methodology and Domain-specific Languages (DSL). A new modular and extensible architecture is proposed for self-diagnosis tests systems based on two main concepts: the creation of a DSL combined with the use of the KDT methodology, as well as a methodology to extend it and integrate it into a CPS. A new self-diagnosis tests system has been proposed that applies the proposed architecture proving that it is possible to carry out the self-diagnosis in real-time of the CPS and allowing the integration of any type of test. To validate the implementation of the system, 28 test cases were carried out to cover all its functionalities. The results show that all test cases passed and, therefore, the system meets all the proposed objectives.(undefined

Identifying Special Structures in Interval-Data via Model-Base Clustering

In this paper we present a model-based approach to the clustering of interval data building on recently proposed parametric models. These methods consider configurations for the variance-covariance matrix that take the nature of the interval data directly into account. The proposed framework relies on parametrizations considering the inherent variability of the relevant data units and the relation that may exist between this variability and the corresponding value levels. Using both synthetic and real data sets the pertinence of the proposed methodology is shown, as the method effectively selects heterocedastic models with restricted covariance structures when they are the most suitable, even in situations with limited information. Moreover, considering special configurations of the variance-covariance matrix, adapted to nature of interval data, proves to be the adequate approach. The presented study also makes clear the need to consider both the information about position (conveyed by the MidPoints) and intrinsic variability (conveyed by the Log-Ranges) when analysing interval data.info:eu-repo/semantics/publishedVersio

Estrategias de búsqueda para la psicología de la competición deportiva en Google académico vs. Medline, Sportdiscus y Psycinfo

Searching Strategies in data bases Medline, SportDiscus, Psycinfo and the search engine Google Scholar presents a set of peculiarities in retrieving information about sport competition psychology. We have consulted teachers who teach such item in Departamento de Educación Física de la ULPGC to establish the terminology in Spanish and English. The documents recovered are mostly articles in journals from anglophone area. As the results are more relevant to retrieve such information and a comparison between what recovered from the specialized databases and Google Schola