Resistência de Pedobacter lusitanus NL19 a antibióticos, metais e metalóides e das suas espécies estreitamente relacionadas

Mestrado em MicrobiologiaPedobacter lusitanus NL19 was isolated from a sludge collected from a deactivated uranium mine, Quinta do Bispo (Viseu, Portugal). The sampling site is characterized by high levels of metals and radionuclides. In silico genome analysis of NL19 disclosed several antibiotic resistancerelated genes (β-lactamase, efflux pumps, etc.) and also genetic determinants related with the resistance/tolerance to metal(loid)s (arsenic, zinc, cobalt and cadmium). The main objective of this study was to investigate the antibiotic resistance and metal(loid)s tolerance of P. lusitanus NL19, the closely-related species P. himalayensis MTCC 6384T, P. hartonius DSM 19033T, P. cryoconitis DSM 14825T and P. westerhofensis DSM 19036T as well as the genus type strain, P. heparinus DSM 2366T. The results of disk-diffusion susceptibility testing and MIC determination showed that all the strains are resistant to amoxicillin/clavulanic acid, ampicillin, apramycin sulfate, aztreonam, cefepime, cefoxitin, ceftazidime, cefuroxime, penicillin G, piperacillin, piperacillin/tazobactam, amikacin, gentamicin, netilmicin, streptomycin, tobramycin, ciprofloxacin and colistin. Regarding the carbapenems all the strains are resistant to ertapenem and the majority were sensitive to meropenem and imipenem. The exceptions included resistance to meropenem by P. westerhofensis and decreased susceptibility to imipenem by P. himalayensis. The tolerance to metal(loid)s was tested through the determination of the MIC. P. lusitanus exhibited higher MICs than all the other strains, for copper and cadmium. P. lusitanus, P. himalayensis and P. hartonius were the most tolerant to zinc and nickel. Two genes encoding putative β-lactamases were identified in the genome of P. lusitanus NL19. The proteins encoded by these genes are novel members of class A β-lactamases (LUS-1) and subclass B3 metallo-β- lactamases (PLN-1), considering their low scores with other β-lactamases. To futher understand if these two enzymes had the ability to hydrolyse β- lactams, the genes blaLUS-1 and blaPLN-1 were expressed in E. coli (fused to an E. coli signal peptide) and MIC to β-lactams were determined. Results indicate that PLN-1 is able to degrade carbapenems and 1st, 3rd and 4th generation cephalosporins and cephamycines. However, no significant activity was detected for LUS-1. Our study shows that the multiresistance phenotype identified in P. lusitanus NL19 is also observed in its closely-related species. In addition, it seems clear that the Pedobacter genus have an underexplored pool of antibiotic resistance genes as well as putative novel antibiotic resistance mechanisms. The tolerance to metal(loid)s was more strain-specific and, therefore, it appears to be related to the ecological niches that these strains occupy.Pedobacter lusitanus NL19 foi isolada de lamas recolhidas numa mina de urânio desativada, na Quinta do Bispo (Viseu, Portugal). O local da recolha das amostras é caracterizado pela presença de elevadas concentrações de metais e radionuclídeos. A análise do genoma da estirpe NL19 revelou a presença de vários genes de resistência a antibióticos (β-lactamases, bombas de efluxo, e outros) e também de determinantes genéticos de resistência a metais e metalóides (arsénio, zinco, cobalto e cádmio). O principal objetivo deste estudo foi investigar a resistência a antibióticos e a tolerância a metais e metalóides por P. lusitanus NL19, por outras quatro espécies próximas, P. himalayensis MTCC 6384T, P. hartonius DSM 19033T, P. cryoconitis DSM 14825T e P. westerhofensis DSM 19036T, e ainda pela estirpe tipo deste género, P. heparinus DSM 2366T. Os resultados de teste de difusão em disco e a determinação da MIC monstraram que todas as estirpes são resistentes à amoxicilina/ácido clavulânico, ampicilina, apramicina, aztreoname, cefepima, cefoxitina, ceftazidima, cefuroxima, penicilina G, piperacilina, piperacilina/tazobactama, amicacina, gentamicina, netilmicina, streptomicina, tobramicina, ciprofloxacina e colistina. No que se refere aos carbapenemos, todas as estirpes são resistentes ao ertapenemo e a maioria é sensível ao meropenemo e ao imipenemo. As excepções incluem a resistência ao meropenemo de P. westerhofensis e diminuição da susceptibilidade ao imipenemo de P. himalayensis. No que se refere à tolerância aos metais, valores de MIC mais elevados foram registados para P. lusitanus para o cobre e o cádmio. P. lusitanus, P. himalayensis e P. hartonius são as estirpes mais tolerantes ao zinco e níquel. A análise do genome de P. lusitanus NL19 permitiu a identificação de dois genes que codificam para β-lactamases putativas. Estas proteínas foram consideradas como novos membros das β-lactamases de classe A (LUS- 1) e da subclasse B3 metalo-β-lactamases (PLN-1) devido aos seus baixos scores com outras β-lactamases. Para compreender se estas enzimas têm a capacidade de hidrolisar β-lactâmicos, os genes blaLUS-1 e blaPLN-1 foram expressos em E. coli (fundidos com um péptido sinal de E. coli). A determinação dos valores da MIC para β-lactâmicos indicam que PLN-1 é capaz de hidrolisar carbapenemos e cefalosporinas de 1ª, 3ª e 4ª geração e cefamicinas. Contudo, não foi detectada nenhuma atividade significativa para a LUS-1. Este estudo mostra que o fenótipo de multi-resistência identificado em P. lusitanus NL19 também é comum a outras espécies estreitamente relacionadas do mesmo género. Para além disso, é possível perceber que as espécies do género Pedobacter possuem um pool inexplorado de genes de resistência a antibióticos bem como de putativos novos mecanismos de resistência a antibióticos. A tolerância a metais e metalóides é específica para cada estirpe, podendo estar associda ao nicho ecológico que estas estirpes ocupam

Traductor de consultas SPARQL, formuladas sobre fuentes de datos incompletamente alineadas, que aporta una estimación de la calidad de la traducción.

147 p.Hoy en día existe en la Web un número cada vez mayor de conjuntos de datos enlazados de distinta procedencia, referentes a diferentes dominios y que se encuentran accesibles al público en general para ser libremente explotados. Esta tesis doctoral centra su estudio en el ámbito del procesamiento de consultas sobre dicha nube de conjuntos de datos enlazados, abordando las dificultades en su acceso por aspectos relacionados con su heterogeneidad. La principal contribución reside en el planteamiento de una nueva propuesta que permite traducir la consulta realizada sobre un conjunto de datos enlazado a otro sin que estos se encuentren completamente alineados y sin que el usuario tenga que conocer las características técnicas inherentes a cada fuente de datos. Esta propuesta se materializa en un traductor que transforma una consulta SPARQL, adecuadamente expresada en términos de los vocabularios utilizados en un conjunto de datos de origen, en otra consulta SPARQL adecuadamente expresada para un conjunto de datos objetivo que involucra diferentes vocabularios. La traducción se basa en alineaciones existentes entre términos en diferentes conjuntos de datos. Cuando el traductor no puede producir una consulta semánticamente equivalente debido a la escasez de alineaciones de términos, elsistema produce una aproximación semántica de la consulta para evitar devolver una respuesta vacía al usuario. La traducción a través de los distintos conjuntos de datos se logra gracias a la aplicación de un variado grupo de reglas de transformación. En esta tesis se han definido cinco tipos de reglas, dependiendo de la motivación de la transformación, que son: equivalencia, jerarquía, basadas en las respuestas de la consulta, basadas en el perfil de los recursos que aparecen en la consulta y basadas en las características asociadas a los recursos que aparecen en la consulta.Además, al no garantizar el traductor la preservación semántica debido a la heterogeneidad de los vocabularios se vuelve crucial el obtener una estimación de la calidad de la traducción producida. Por ello otra de las contribuciones relevantes de la tesis consiste en la definición del modo en que informar al usuario sobre la calidad de la consulta traducida, a través de dos indicadores: un factor de similaridad que se basa en el proceso de traducción en sí, y un indicador de calidad de los resultados, estimado gracias a un modelo predictivo.Finalmente, esta tesis aporta una demostración de la viabilidad estableciendo un marco de evaluación sobre el que se ha validado un prototipo del sistema

Choice of Product Variety for the Durable Goods Monopolist

This paper analyzes the strategic choice of variety by a monopolist seller of a durable good as a means to mitigate his commitment problem. The monopolist chooses his product variety with a goal of ensuring that a strong reduction in future prices will not be profitable because it allows the firm to attract few additional consumers. The main result that emerges from considering product variety as an endogenous variable is that, contrary to the case in which it is exogenously determined, social welfare is always higher when the monopolist cannot commit that when he can.durable goods monopolist, commitment, product variety

El derecho al aprovechamiento urbanístico de los bienes de dominio público obtenidos onerosamente, con especial referencia a Canal de Isabel II

El objeto del presente trabajo es analizar y justificar desde un punto de vista jurídico el derecho al aprovechamiento urbanístico de los bienes de dominio público, con especial referencia a Canal de Isabel II como propietario de bienes de dominio público, obtenidos onerosamenteMáster en Política Territorial y Urbanística. 21ª ed. Curso 2010/201

Policy Coordination in an Oligopolistic Housing Market

This paper analyzes the consequences of the interaction between two different levels of government (regulators) in the development of housing policy when their decisions determine the level of competition in the housing market. The analysis discusses the implications derived from a lack of coordination between a local regulator who controls the supply of land for housing development and a central regulator who decides on housing subsidies. The results suggest that lack of coordination has significant effects on prices and supply of houses, housing developers’ profits, and buyers’ surplus.imperfect competition, housing policy coordination

The Supercore for Normal Form Games

We study the supercore of a system derived from a normal form game. For the case of a finite game with pure strategies, we define a sequence of games and show that the supercore of that system coincides with the set of Nash equilibrium strategy profiles of the last game in the sequence. This result is illustrated with the characterization of the supercore for the n-person prisoners’ dilemma. With regard to the mixed extension of a normal form game, we show that the set of Nash equilibrium profiles coincides with the supercore for games with a finite number of Nash equilibria. For games with an infinite number of Nash equilibria this need not be no longer the case. Yet, it is not difficult to find a binary relation which guarantees the coincidence of these two sets.individual contingent threat situation, Nash equilibrium, subsolution, Morgenstern stable set, Von Neumann

Analysis of assessment tools of Engineering degrees

This work presents an analysis of the assessment tools used by professors at the Universitat Politécnica de Catalunya to assess the generic competencies introduced in the Bachelor’s Degrees in Engineering. In order to conduct this study, a survey was designed and administered anonymously to a sample of the professors most receptive to educational innovation at their own university. All total, 80 professors responded to this survey, of whom 26% turned out to be members of the university’s own evaluation innovation group (https://www.upc.edu/rima/grups/grapa), GRAPA. This percentage represents 47% of the total GRAPA membership, meaning that nearly half of the professors most concerned about evaluation at the university chose to participate. The analysis of the variables carried out using the statistical program SPSS v19 shows that for practically 49% of those surveyed, rubrics are the tools most commonly used to assess generic competencies integrated in more specific ones. Of those surveyed, 60% use them either frequently or always. The most frequently evaluated generic competencies were teamwork (28%), problem solving (26%), effective oral and written communication (24%) and autonomous learning (13%), all of which constitute commonly recognized competencies in the engineering profession. A two-dimensional crosstabs analysis with SPSS v19 shows a significant correlation (Asymp. Sig. 0.001) between the type of tool used and the competencies assessed. However, no significant correlation was found between the type of assessment tool used and the type of subject, type of evaluation (formative or summative), frequency of feedback given to the students or the degree of student satisfaction, and thus none of these variables can be considered to have an influence on the kind of assessment tool used. In addition, the results also indicate that there are no significant differences between the instructors belonging to GRAPA and the rest of those surveyed.Preprin