Characterization of Nitric Oxide Reductase (NOR) from pseudomonas nautica, a study on biologic nitric oxide reduction

Dissertation submitted to obtain the phD degree in Biochemistry, specialty in Physical- Biochemistry, by the Faculdade de Ciências e Tecnologia from the Universidade Nova de LisboaDenitrification is a metabolic pathway from the nitrogen cycle where nitrate is reduced to dinitrogen. This pathway involves four reduction steps: the nitrate reduction to nitrite, followed by the reduction to nitric oxide (NO), from this to nitrous oxide (N2O), and finally to dinitrogen. The enzymes involved in the mentioned steps are the nitrate reductases, the nitrite reductases, the nitric oxide reductases (NOR) and the nitrous oxide reductases, respectively. The NORs perform the NO reduction to N2O, using two substrate molecules, two protons and two electrons with the consequent product formation and water. These enzymes belong to the heme copper oxidase superfamily, since they are integral membrane proteins, with 12 transmembrane α-helixes and a set of conserved residues. They are composed by two subunits. The NorC subunit with a molecular weight of 17 kDa, comprises a low-spin heme c covalently bound to the polypeptide chain, with a His/Met coordination. The second subunit, NorB, also named the catalytic subunit, with a molecular weight of 56 kDa, harbouring two b-type hemes, one low-spin bis-His coordinated (heme b), a high-spin heme b (heme b3), His coordinated and a non-heme FeB. These last two iron centers are antiferromagnetic coupled and bridged by a μ- oxo/hydroxo group, and together they compose the catalytic diiron center. Recently Mössbauer spectroscopy proved that the catalytic heme b3 is in fact low-spin in both ferric and ferrous states, indicating a six-coordination environment for this iron center in both redox states. The Pseudomonas (Ps.) aeruginosa NOR crystal structure shows the presence of the His ligand simultaneously with the μ-oxo bridge in the as-isolated form. The substrate reduction mechanism is an issue of intense discussion, with the cis and trans-mechanisms taken in consideration. The cis-mechanism descries that NO reduction occurs in the catalytic center and only one of the iron atoms is coordinating the substrate during catalysis. The trans-mechanism describes NO reduction with the binding of one substrate molecule to each one of the iron atoms of the catalytic center. Different isolated NORs have the ability of reducing O2 to H2O in a four electrons/four protons reaction. The mechanism for O2 reduction is unknown, but it is presumed that substrate binds to the catalytic heme b3, analogous to the terminal oxidases. The main objective of this work was to isolate and characterize the Ps. nautica NOR, using different biochemical, and spectroscopic techniques.Fundação para a Ciência e Tecnologia - bolsa de doutoramento (SFRH/BD/39009/2007

Naturalness Confronts Nature: Searches for Supersymmetry with the CMS Detector in pp Collisions at √s = 8 and 13 TeV

In this thesis, we present two inclusive searches for supersymmetric particles at 8 and 13 TeV using the razor variables and guided by the principle of naturalness. We build a framework to explore the natural supersymmetry parameter space of gluino and top squark masses and branching ratios, which is a unique attempt to cover this parameter space in a more complete way than ever before using LHC data. With this approach, the production of top squarks and gluinos are excluded below 700 GeV and 1.6 TeV, respectively, independent of the branching ratios, constituting one of the tightest constraints on natural supersymmetry from the LHC. Motivated by the need to mitigate the effects of multiple interactions per bunch crossing (pileup), an essential feature of present and future hadron colliders, in this thesis we also study the precision timing capabilities of a LYSO-based sampling calorimeter, and achieve a time resolution of 30 ps in electron test beam measurements. The achieved resolution corresponds to the precision needed to significantly reduce the inclusion of pileup particles in the reconstruction of the event of interest. This study is foundational in building an R and D program on precision timing for the high-luminosity LHC and other future hadron colliders. We also propose alternative simplified models to study Higgs-plus-jets events at the LHC, and reinterpret an excess observed at 8 TeV in the context of these models. Finally, we discuss a search for narrow resonances in the dijet mass spectrum at 13 TeV using the data-scouting technique at CMS, which records a smaller event format to increase the maximum recordable rate. For the benchmark models with a vector or axial-vector mediator that couples to quarks and dark matter particles, the dijet search excludes mediator masses from 0.5 TeV up to 2.7 TeV largely independent of the dark matter particle mass, which constitutes a larger exclusion than traditional mono-X searches at the LHC. In the plane of the dark matter-nucleon interaction cross section versus dark matter mass, the dijet search is also more sensitive than direct detection experiments for spin-dependent cross sections

Actitudes del profesorado de lengua castellana y literatura de 4º curso de Educación Primaria ante los procesos de innovación educativa

It is evident that the educational system needs permanent changes. Pedagogical innovation plays a fundamental role in this process. However, not all teachers are aware of the importance of it when it comes to improving the quality of teaching and properly addressing the needs of the students.In the present TFG we have done further research into the attitudes that the teachers have towards these processes, and also the limitations that prevent these processes from taking place in the classroom. We decided to develop a research proposal in order to identify these attitudes, specifically those of teaching professionals who teach Spanish Language and Literature in the 4th year of Primary Education.After the sharing and analysis of the obtained results, we conclude that the teachers who have fewer years of teaching experience make more ofan effort to use innovative teaching techniques in the classroom. However, those who have been teaching for longer are less likely to use these innovative processes and still use obsolete methods, techniques and resources.Resulta evidente que el sistema educativo necesita cambios que realmente arraiguen en el mismo. La innovación pedagógica desempeña un papel fundamental en este proceso. No obstante, no todos los docentes son conscientes de la importancia de la misma a la hora de mejorar la calidad de la enseñanza y atender correctamente a las necesidades del alumnado.En el presente TFG hemos profundizado acerca de las actitudes que tienen los profesores ante dichos procesos, además de las limitaciones que impiden que se lleven a cabo en las aulas. Es por ello que decidimos elaborar una propuesta de investigación, a través de la cual pudiéramos conocer dichas actitudes, concretamente de aquellos profesionales de la enseñanza que imparten la asignatura de Lengua Castellana y Literatura en 4º curso de Educación Primaria.Tras el análisis y puesta en común delos resultados obtenidos, concluimos que aquellos profesores que cuentan con menos años de experiencia en la docencia se preocupan más por innovar en las aulas. Sin embargo, aquellos que tienen más experiencia están menos familiarizados con este tipo de procesos, y siguen utilizando métodos, técnicas y recursos obsoletos.Universidad de Sevilla. Grado en Pedagogí

Co-evolution of industry strategies and government policies: The case of the brazilian automotive industry

This study examines the evolution of the automotive industry in Brazil and its key drivers. We argue that the rules of the game – industry policies – are an outcome of exchanges between the host government and industry. These arise from changes in economic and political environments and interdependence between industry and the country’s economy. To this end, we draw upon literature on institutions and co-evolution to understand the industry footprint over a 50-year period, as well as its relationship with changes in government policies. This study generates new insights on institutional and co-evolution political perspectives by showing that the rules of the game are not only the making of the government, but are also the result of interdependencies between industry and government

Post-acquisition Changes Beyond the Dyad: Power at the Net Level in Cross-Border Acquisitions(1)

A common feature of the literature on post-acquisition changes is its dyadic feature, i.e. the emphasis is placed on the actors directly involved in the acquisition, often represented by the acquiree and the acquirer. Accordingly, actors outside the dyad, such as suppliers and buyers, are usually disregarded. There is, however, a relevant exception in this literature. Recently, some Nordic authors have claimed that if actors other than the acquiree and the acquirer are not taken into account, the existing literature may only present a partial view of changes following acquisitions. Consequently, they have suggested that changes following this type of operation can be analysed fruitfully at the network level. Our article adds to the efforts of these scholars to understand post-acquisition changes at a broader level by bringing to the fore two issues that have received scarce attention in the literature: i) nets rather than the network level appears to be the locus where post-acquisition changes beyond the dyad take place; ii) relational power can be regarded as an independent variable in post-acquisitionchanges beyond the dyad. These arguments are illustrated by three brief case studies of cross-border acquisitions

Modelling chemical processes in explicit solvents with machine learning potentials

Solvent effects influence all stages of the chemical processes, modulating the stability of intermediates and transition states, as well as altering reaction rates and product ratios. However, accurately modelling these effects remains challenging. Here, we present a general strategy for generating reactive machine learning potentials (MLPs) to model chemical processes in solution. Our approach combines active learning with descriptor-based selectors and automation, enabling the construction of data-efficient training sets that span the relevant chemical and conformational space. We demonstrate the versatility of this strategy by applying it to investigate a Diels-Alder reaction in water and methanol. The generated MLPs exhibit excellent agreement with experimental data and provide insights into the differences in reaction rates observed between the two solvents. Our strategy offers an efficient approach to the routine modelling of chemical reactions in solution, opening up avenues for studying complex chemical processes in an efficient manner

Incidencia de la Gestión en el Área Financiera de la Cooperativa Agropecuaria de Producción Mario Dávila Molina R.L, en el Municipio de San Isidro, Departamento de Matagalpa, en el I semestre del año 2014

La Gestión Financiera de las empresas muestra de forma muy significativa los cambios que se producen de manera inesperada, es por ello que el tema que hemos abordado en esta investigación es Gestiones en el Área Financiera de la Cooperativa Agropecuaria de Producción Mario Dávila Molina R.L, en el municipio de San Isidro, Departamento de Matagalpa, en el I semestre del año 2014. Este trabajo se realizó con el propósito de analizar la Incidencia de las Gestiones en el Área Financiera de la Cooperativa Agropecuaria de Producción Mario Dávila Molina R.L, en el municipio de San Isidro, Departamento de Matagalpa, en el I semestre del año 2014. Cabe señalar que la importancia de este tema permite conocer de manera más directa la situación en que la empresa se encuentra operando, mostrando el impacto que provocan los cambios que se generan debido al mal uso de las Finanzas. A pesar de las dificultades que se presentan en la cooperativa esta se encuentra operando por el bienestar de la sociedad, recibiendo financiamiento a corto plazo para atender la demanda del cultivo del arroz y buscando implementación de nuevas estrategias en la realización de sus gestiones para el desarrollo cooperativ

Aplicación web para el proceso de divulgación del programa ambiental de gestión de riesgo y cambio climático (PAGRICC-MARENA) Matagalpa, año 2013

En el trabajo realizado se evaluó el proceso de divulgación del programa ambiental de gestión de riesgo y cambio climático, el cual describe el proceso actual de trabajo, identificando dificultades en el proceso existente y proponiendo una alternativa para mejorar este proceso en PAGRICC-MARENA, MATAGALPA año 2013. En la actualidad el programa presenta retraso en su proceso de divulgación debido a que no cuentan con un presupuesto asignado directamente para este, por lo cual MARENA CENTRAL divulga en forma general sus proyectos. Por lo que PAGRICC-MARENA, MATAGALPA no puede mantener informado a sus participantes de sus labores ambientales que ayuden a la prevención y conservación de los recursos naturales en el municipio como parte independiente de sus servicios que brindan a la población. Después de los resultados obtenidos identificamos la necesidad de implementar una aplicación web en PAGRICC-MARENA, MATAGALPA. Que permita que la población se involucre en las actividades que realizan y sean partícipes de intercambio de experiencias que den paso a nuevas estrategias de trabajo como principales participantes que deseen trabajar en conjunto con el programa para beneficio de ambos en cuanto a las labores que son atendidas dentro del mismo para beneficio del medio ambient

Host–Guest chemistry of self-assembled hemi-cage systems: The dramatic effect of lost pre-organization

New hemi‐cage compounds with the formula Pd2(L1)2(L2)2 (L1=ditopic pyridine ligand, L2=bpy or TMEDA) have been synthesized and characterized by spectroscopic methods, X‐ray crystallography and electronic structure methods. The host‐guest chemistry of these new structures, with naphthoquinone as a guest, reveals the key role of the host shape and flexibility on competitive binding processes. The influence of counteranions, solvent and non‐covalent interactions to binding were quantified by Density Functional Theory calculations. Together, this study provides new insights into the concept of pre‐organized guest binding when applied to charged, coordination‐assembled hosts