The alternative complex III from Rhodothermus marinus - a prototype of a new family of quinol: electron acceptor oxidoreductase

Dissertation presented to obtain a PhD degree in Biochemistry at the Instituto de Tecnologia Química e Biológica, Universidade Nova de LisboaThe aim of the work presented in this thesis was the characterization of a complex with quinol: electron carrier oxidodoreductase activity present in the membranes of the thermohalophilic bacterium Rhodothermus (R.) marinus. The complexes involved in the R. marinus respiratory chain have been extensively studied in the past few years. Specifically, the purification and characterization of a complex I (NADH: quinone oxidoreductase), a complex II (succinate:quinone oxidoreductase) and of three different oxygen reductases from the heme-copper oxygen reductases superfamily have been performed. Since those oxygen reductases are unable to receive electrons from quinol molecules, the presence of a complex linking complexes I and II to the oxygen reductases was needed. In fact, a complex with quinol: HiPIP oxidoreductase activity was purified and partially characterized. The absence of the Rieske protein indicated that the complex isolated from R. marinus has a different composition when compared with the typical cytochrome bc1 complex.(...

The alternative complex III of Rhodothermus marinus and its structural and functional association with caa3 oxygen reductase

AbstractAn alternative complex III (ACIII) is a respiratory complex with quinol:electron acceptor oxidoreductase activity. It is the only example of an enzyme performing complex III function that does not belong to bc1 complex family. ACIII from Rhodothermus (R.) marinus was the first enzyme of this type to be isolated and characterized, and in this work we deepen its characterization. We addressed its interaction with quinol substrate and with the caa3 oxygen reductase, whose coding gene cluster follows that of the ACIII. There is at least, one quinone binding site present in R. marinus ACIII as observed by fluorescence quenching titration of HQNO, a quinone analogue inhibitor. Furthermore, electrophoretic and spectroscopic evidences, taken together with mass spectrometry revealed a structural association between ACIII and caa3 oxygen reductase. The association was also shown to be functional, since quinol:oxygen oxidoreductase activity was observed when the two isolated complexes were put together. This work is thus a step forward in the recognition of the structural and functional diversities of prokaryotic respiratory chains

Qualitative and quantitative characterization of the in vitro dehydration process of hydrogel contact lenses

PURPOSE: To investigate the in vitro dehydration process of conventional hydrogel and silicone-hydrogel contact lens materials. METHODS: Eight conventional hydrogel and five silicone-hydrogel contact lenses were dehydrated under controlled environmental conditions on an analytical balance. Data were taken at 1-min intervals and dehydration curves of cumulative dehydration (CD), valid dehydration (VD), and dehydration rate (DR) were obtained. Several quantitative descriptors of the dehydration process were obtained by further processing of the information. RESULTS: Duration of phase I (r(2) = 0.921), CD at end of phase I (r(2) = 0.971), time to achieve a DR of -1%/min (r(2) = 0.946) were strongly correlated with equilibrium water content (EWC) of the materials. For each individual sample, the VD at different time intervals can be accurately determined using a 2nd order regression equation (r(2) > 0.99 for all samples). The first 5 min of the dehydration process show a relatively uniform average CD of about -1.5%/min. After that, there was a trend towards higher average CD for the following 15 min as the EWC of the material increases (r(2) = 0.701). As a consequence, average VD for the first 5 min displayed a negative correlation with EWC (r(2) = 0.835), and a trend towards uniformization among CL materials for the following periods (r(2) = 0.014). Overall, silicone-hydrogel materials display a lower dehydration, but this seems to be primarily due to their lower EWC. CONCLUSIONS: DR curves under the conditions of the present study can be described as a three-phase process. Phase I consists of a relatively uniform DR with a duration that ranges from 10 to almost 60 min and is strongly correlated with the EWC of the polymer as it is the CD during this phase. Overall, HEMA-based hydrogels dehydrate to a greater extent and faster than silicone-hydrogel materials. There are differences in water retention between lenses of similar water content and thickness that should be further investigated

Tres símbolos y una metáfora en la poesía de Andrés Sánchez Robayna

Se analizan los símbolos de la barca, la casa y la piedra, así como la metáfora del Libro del Mundo, en la obra poética de Andrés Sánchez Robayna. El análisis se apoya en las aportaciones de la simbología y la historia de las religiones con el objetivo de esclarecer algunos aspectos clave de la cosmovisión del autor y de su poética. La presencia de imágenes pertenecientes al simbolismo del centro, la concepción de la poesía como enigma y la indagación en la memoria como una parte fundamental del proceso creador constituyen los elementos que conducen al surgimiento de una conciencia religiosa del mundo.                                                                                                                                                                                                              This paper aims to analyse three symbols presented in Andrés Sánchez Robayna’s work of poetry: the boat, the house, the stone, and the metaphor of the Book of the World. This analysis is supported by contributions in the fields of symbolism and history of religions and it seeks to shed light on some key aspects of the author’s poetics and world view. The imagery related to the symbolism of the centre, the conception of poetry as an enigma and the search through memory as an essential phase in the creative process represent the main elements which lead to the emergence of a religious view of the world

Implementación de un algoritmo de control adaptativo

[Resumen]: En el presente proyecto se abordará la implementación de un algoritmo de control adaptativo basado en el modelo de planta. Inicialmente se realizará la regulación de un sistema con un PID estándar, a través del Método de Relay-Feedback, para diferentes valores de consigna (en modelos de simulación). Una vez obtenida la respuesta con el PID calculado, se procederá a la implementación de un algoritmo de control adaptativo. La finalidad de este algoritmo es el autoajuste en tiempo real de un PID que obtenga las mejores especificaciones de una planta real para cualquier punto de operación. El primer paso a realizar para el PID adaptativo, consistirá en la implementación del algoritmo RLS, con el cual podrá identificarse la función de transferencia del sistema para posteriormente obtener los parámetros de PID óptimo para el punto de operación sobre el que se esté trabajando. Obtenidos los PID óptimos se aplicarán dichos reguladores a los sistemas a controlar, obteniendo las señales más relevantes del sistema, como son la señal de control u(t),la salida y(t) y el error e(t),con objeto de poder comparar estas señales en ambos reguladores. La importancia del PID adaptativo es que irá adaptando los parámetros del regulador con cada muestra, es decir, irá adaptando los pesos del PID en función de la salida y(t) y la señal de control u(t) obtenidos para cada muestra.Traballo fin de grao (UDC.EUP). Enxeñaría electrónica industrial e automática. Curso 2018/201

Business Survival and the Influence of Innovation on Entrepreneurs in Business Incubators

One of the objectives of this article is to study how innovation influences the results of entrepreneurs located in business incubators. The other objective is to examine how the training of entrepreneurs contributes to creating companies with high sustainability rates over time that are wealth generators in society. To achieve these objectives, entrepreneurs in business incubators in Spain were identified along with their level of training, their experience in business management, how much employment they have generated, their survival rate and the annual accounts (where economic, financial, and management information on the companies is collected). In turn, they were sent a questionnaire that allowed us to classify them by their degree of innovation. The techniques used are independent sample statistics that apply the Levene’s test, the analysis of the balance sheet, the income statements, and management indicators. This study concludes that, from the selected sample, 83.3% of the entrepreneurs established in business incubators in Spain have university training, and 64.2% prefer the branches of science, with 7.75 years of business experience, which favors business survival (100% in the seventh year of life) and the creation of qualified employment. All this favors the sustainability of the productive and business model which, being more intensive in knowledge and R&D, becomes more competitive in the market. On the other hand, there are no significant differences regarding the economic results, nor in the management indicators among the entrepreneurs of the incubators according to their degree of innovation. The value of research lies in the importance of studies on the relationship between innovation, training, and wealth-generating sustainability in incubators in today’s knowledge economyS

The alternative complex III from Rhodothermus marinus – A prototype of a new family of quinol:electron acceptor oxidoreductases

AbstractThe biochemical and genetic search for a bc1 complex in Rhodothermus marinus was always fruitless; however, a functional equivalent, i.e. having quinol:cytochrome c oxidoreductase activity was characterized. Now, with the sequencing of R. marinus genome, it was possible to assign the N-terminal sequences of several proteins of this complex to its coding genes. The alternative complex III from R. marinus has the same genomic organization of the so-called MFIcc complexes, proposed to be oxidoreductases of the respiratory and photosynthetic electron transfer chains. In this report, we establish undoubtedly the existence of an alternative complex III, a functional substitute of the bc1 complex, by its identification at both the biochemical and genomic level

Una experiencia compartida de narración oral

La experiencia que se narra corresponde a una integración de trabajo llevada a cabo en el ISFD Nº 97 de la ciudad de La Plata, entre los años 2012 y 2015. La misma se desarrolló en el Profesorado de Educación Primaria que se allí se dicta y consistió en articular el Trayecto Formativo Opcional de Narración Oral con el Campo de la Práctica docente, ambas materias del 2º año de dicho profesorado. Lo que aquí se intenta contar, mucho más allá de lo anecdótico, es la oportunidad de trabajo y aprendizaje que pudo constituirse a partir de las decisiones institucionales que “obligaron” el encuentro de ambos espacios, los movimientos que desde cada espacio de saber hubo que realizar para lograr lo propuesto, y la posibilidad de generar otros modos de trabajo articulado y de espacios de formación que pudieron habilitarse para los futuros docentes.Facultad de Humanidades y Ciencias de la Educació

Neddylation regulates excitatory synaptic transmission and plasticity

Post-translational modifications, like phosphorylation, ubiquitylation, and sumoylation, have been shown to impact on synaptic neurotransmission by modifying pre- and postsynaptic proteins and therefore alter protein stability, localization, or protein-protein interactions. Previous studies showed that post-translational modifications are essential during the induction of synaptic plasticity, defined by a major reorganization of synaptic proteins. We demonstrated before that neddylation, a post-translational modification that covalently binds Nedd8 to lysine-residues, strongly affects neuronal maturation and spine stability. We now analysed the consequences of inhibiting neddylation on excitatory synaptic transmission and plasticity, which will help to narrow down possible targets, to make educated guesses, and test specific candidates. Here, we show that acute inhibition of neddylation impacts on synaptic neurotransmission before morphological changes occur. Our data indicate that pre- and postsynaptic proteins are neddylated since the inhibition of neddylation impacts on presynaptic release probability and postsynaptic receptor stabilization. In addition, blocking neddylation during the induction of long-term potentiation and long-term inhibition abolished both forms of synaptic plasticity. Therefore, this study shows the importance of identifying synaptic targets of the neddylation pathway to understand the regulation of synaptic transmission and plasticity.Fil: Brockmann, Marisa M.. Universitat Bonn; Alemania. Max Planck Institute Of Psychiatry; AlemaniaFil: Döngi, Michael. Universitat Bonn; AlemaniaFil: Einsfelder, Ulf. Universitat Bonn; AlemaniaFil: Körber, Nils. Universitat Bonn; AlemaniaFil: Refojo, Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación en Biomedicina de Buenos Aires - Instituto Partner de la Sociedad Max Planck; ArgentinaFil: Stein, Valentin. Universitat Bonn; Alemani

Oxygen transmissibility of piggyback systems with conventional soft and silicone hydrogel contact lenses

To investigate the apparent oxygen transmissibility of various piggyback systems using conventional and silicone hydrogel soft contact lenses of different water content and permeability, rigid poly(methyl methacrylate), and rigid gas-permeable lenses of medium, high, and ultrahigh oxygen permeability. The aim of the study was to establish which material (rigid or hydrogel) is more representative of the resulting oxygen performance of piggyback systems. METHODS: The apparent oxygen transmissibility of 66 piggyback systems was measured with an electrochemical method. Eighteen of these combinations involved the use of silicone hydrogel contact lenses currently available. One hyperpermeable rigid gas-permeable contact lens (tisilfocon A) was also included in the study. RESULTS: Measured apparent transmissibility correlates with rigid lens permeability (r = 0.403; SE = +/-3.03 barrer/cm; P < 0.001) and hydrogel lens permeability (r = 0.334; SE = +/-3.2 barrer/cm; P < 0.001). As expected, a linear model comprising permeability values from both rigid and soft materials gave a more precise estimation of the piggyback transmissibility (r = 0.736; SE = +/-2.02 barrer/cm; P < 0.001). The highest values of apparent oxygen transmissibility were found for the combination of tisilfocon A rigid material with any of the 3 silicone hydrogel lenses. Tisilfocon A material significantly improved the transmissibility of all piggyback systems even when conventional hydrogels are involved. CONCLUSION: The combination of hypertransmissible rigid gas permeable lenses with silicone hydrogel soft materials should result in normal corneal function under daily wear conditions. When fitting piggyback systems, clinicians must be aware of material selection to optimize oxygen performance. This is of particular importance in already compromised corneas.This study was supported in part by a grant from the Science and Technology Foundation (FCT), Ministry of Science and Superior Education (MCES), under contract 8281/2002 from the European Social Funding granted to J.M.G.-