L-Citrulline and its effect in endurance sports, a sistematic review

En los últimos años, el estudio del suplemento L-Citrulina ha cobrado importancia debido a sus posibles efectos sobre el rendimiento deportivo. La L-Citrulina es un aminoácido no esencial que se obtiene a través de fuentes tanto vegetales como animales. Es precursor del Óxido Nítrico y de la Arginina, que intervienen de forma protagonista durante el ciclo de la urea. Estos factores presuponen que el consumo de este suplemento podrá tener ciertos beneficios sobre el rendimiento deportivo. Por lo tanto, el objetivo de este estudio fue el de realizar una revisión sistemática con la que comprobar la eficacia de la L-Citrulina o el Malato de L-Citrulina sobre varios parámetros determinantes en el rendimiento deportivo: potencia, resistencia, trabajo, así como en las siguientes otras variables: percepción subjetiva del esfuerzo y factores fisiológicos. El estudió estuvo centrado en deportes de resistencia en concreto. Para ello, se realizó una búsqueda de la literatura existente hasta la fecha de aquellos estudios que analizaban el rendimiento deportivo en deportes de resistencia tras el consumo de L-Citrulina. Se obtuvieron un total de 7 trabajos con los que se realizó esta revisión sistemática. Tras el análisis de los trabajos encontrados, se podría decir que la L-Citrulina o Malato de L-Citrulina tiene un efecto positivo sobre el rendimiento deportivo. Sin embargo, se debería de establecer un consenso en la estandarización de los test realizados en los estudios para poder afirmar con evidencia significativa que este suplemento tiene una afectación clara sobre el rendimiento de los deportistas.In the last years, the study of L-Citrulline as a supplement has been gaining interest due to its possible applications over the performance in sports. L-Citrulline is a non-essential aminoacid which can be obtained from vegetable or animal sources. This supplement is a precursor of Nitric Oxide, Arginine and has a principal role in the urea cycle. These factors presuppose that the consume of this ergogenic aid could have positive effects over the sport performance. The purpose of this study was to make a systematic review with which verify the efficacy of L-Citrulline or Citrulline Malate over various determinants parameters over the sport performance and other variables such as perception of effort and physiological factors in endurance sports. To achieve this objective, a research of the existent studies referred to the analysis of the sport performance after the consumption L-Citrulline was made. Finally, 7 studies were obtained and used to make this systematic review. After the analysis of the collected data it can be said that L-Citrulline or Citrulline Malate might have a positive impact over the sport performance. Nevertheless, a consensus must be made in order to achieve the standardization of the protocols and test used in the different studies to say that this supplement has a significant positive impact over the athletes performance

Los servicios a los usuarios en las bibliotecas universitarias

Aquest article vol ser una reflexió sobre com els darrers canvis que han afectat la societat i la universitat (el canvi de paradigma educatiu, el canvi en el model de comunicació científica, les expectatives dels usuaris i el nou model de servei anomenat Centre de Recursos per a l'Aprenentatge i la Investigació) es reflecteixen en els serveis que s'ofereixen als usuaris a les biblioteques universitàries. Sintetitza els serveis que s'ofereixen a les biblioteques universitàries agrupant-los segons tipologies i necessitats dels usuaris i determina els elements clau per estructurar els serveis i les seves característiques. Es conclou que estem davant d'un model de biblioteca híbrida que ha d'enfocar els serveis als usuaris tenint present la diversificació en la tipologia d'usuaris, els canvis en les tecnologies, la cultura de qualitat i la cooperació com a estratègia de servei. En forma d'annex, s'explica el model dels serveis als usuaris del Centre de Recursos per a l'Aprenentatge i la Investigació de la Universitat de Barcelona.This article considers how recent changes that have affected society and universities --changes to the educational paradigm, scientific communication, users' expectations, and the model of user service known as Resource Centres for Learning and Research-- have been reflected in the services offered to users by university libraries. Moreover, the article groups the services according to types and users' needs and discusses both the key elements for structuring the services and their main features. The conclusion points to a model of a hybrid library that must focus on user services, taking into account the broad variety of users, technological changes, quality of culture and cooperation as service strategies. An annex contains a description of the user service model of the Resource Centre for Learning and Research ofthe University of Barcelona.Este artículo pretende ser una reflexión de cómo los últimos cambios que han afectado a la sociedad y a la universidad (el cambio de paradigma educativo, el cambio en el modelo de comunicación científica, las expectativas de los usuarios y el nuevo modelo de servicio llamado Centro de Recursos para el Aprendizaje y la Investigación) se reflejan en los servicios que se ofrecen a los usuarios en las bibliotecas universitarias. Sintetiza los servicios que se ofrecen en las bibliotecas agrupándolos según tipologías y necesidades de los usuarios y determina los elementos clave para estructurar los servicios y las características de los mismos. Se concluye que estamos ante un modelo de biblioteca híbrida que tiene que enfocar los servicios a los usuarios atendiendo a la diversificación en la tipología de usuarios, los cambios en las tecnologías, la cultura de la calidad y la cooperación como estrategia de servicio. En forma de anexo, se presenta el modelo de servicios a los usuarios del Centro de Recursos para el Aprendizaje y la Investigación de la Universidad de Barcelona

Viabilitat dels geopolímers com a matrius sostenibles per a fibrociments reforçats amb fibres vegetals

Nowadays, a new type of climate change is known, aside from the natural caused by the atmosphere gases, which is due to human activity. The construction industry contributes largely to the emission of greenhouse gases because of CO2. Portland cement production is 6 billion tonnes per year, and each ton produced produces 0.55 tonnes of chemical CO2 and 0.39 tonnes of additional CO2 from the fuel used in baking and milling. These facts have led scientific research to focus on sustainable building materials with a low carbon footprint. In this line we find branches of study with the intention of replacing the Portland cement for aluminosilicates activated with alkali and the synthetic fibers for vegetable fibers. The present study aims to verify the viability of geopolymers as a sustainable matrix to produce cement reinforced with plant fibers. To achieve the goal, the dosage with the most optimal properties of the geopolímer matrix has been sought by testing flexibility and compression on samples, as well as the X-ray diffraction analysis (DRX), infrared spectroscopy for Fourier transform (FTIR) and thermogravimetry (TGA). Secondly, the viability and durability of the Kraft pulp incorporated in the geopolímer matrix has been studied by means of the production of samples that have been tested on flexion and compression, subjected to drying humidity cycles, as well as they have also been studied with SEM and BSE SEM. It has been concluded that although the geopolímer matrix with Kraft pulp is a material that has proven to have some mechanical characteristics that make it viable, the incorporated plant fibers showed little durability.Actualment es coneix un nou tipus de canvi climàtic, a banda del provocat naturalment pels gasos de l'atmosfera, que és degut a l'activitat humana. La indústria de la construcció contribueix en gran part a l'emissió de gasos d'efecte hivernacle, en concret CO2. La producció de ciment Portland és de 6 bilions de tones a l'any, i cada tona produïda genera 0.55 tones de CO2 químic i 0.39 tones de CO2 addicionals provinents del combustible usat en la cocció i el molturat. Aquests fets han derivat en que la recerca científica hagi augmentat l'interès en els materials de construcció sostenibles amb una baixa petjada de carboni. En aquesta línia es troben branques d'estudi amb la voluntat de substituir el ciment Portland per aluminosilicats activats amb àlcali i les fibres sintètiques per fibres vegetals. El present estudi té com a objectiu comprovar la viabilitat dels geopolímers com a matriu sostenible per a la producció de fibrociments reforçats amb fibres vegetals. Per arribar a l'objectiu s'ha buscat la dosificació amb propietats més òptimes de la matriu de geopolímer mitjançant l'assaig de provetes a flexió i a compressió, així com també s'ha fet l'anàlisi de difracció de Raigs X (DRX), espectroscòpia d'infrarojos per transformada de Fourier (FTIR) i termogravimetria (TGA). En segon lloc s'ha estudiat la viabilitat i durabilitat de la polpa Kraft incorporada en la matriu de geopolímer mitjançant la realització de provetes que s'han assajat a flexió i a compressió, s'han sotmès a cicles d'assecat-humitejat, així com també s'han estudiat amb SEM i BSE SEM. S'ha conclòs que tot i que la matriu de geopolímer amb polpa Kraft és un material que ha demostrat tenir unes característiques mecàniques que el fan viable, les fibres vegetals incorporades experimenten poca durabilitat.Actualmente se conoce un nuevo tipo de cambio climático, a parte del provocado naturalmente por los gases de la atmosfera, que es debido a la actividad humana. La industria de la construcción contribuye en gran parte a la emisión de gases de efecto invernadero, concretamente CO2. La producción de cemento Portland es de 6 billones de toneladas por año, y cada tonelada producida genera 0.55 toneladas de CO2 químico y 0.39 toneladas de CO2 adicionales procedentes del combustible usado en la cocción y el molturado. Estos hechos han derivado en que la investigación científica haya aumentado el interés en los materiales de construcción sostenibles con baja huella de carbono. En esta línea se encuentran ramas de estudio con la voluntad de sustituir el cemento Portland por aluminosilicatos activados con álcali y las fibras sintéticas por fibras vegetales. El presente estudio tiene como objetivo comprobar la viabilidad de los geopolímeros como matriz sostenible para la producción de fibrocementos reforzados con fibras vegetales. Para alcanzar el objetivo se ha buscado la dosificación con propiedades más optimas de la matriz de geopolímero mediante el ensayo de probetas a flexión y a compresión, así como también se ha hecho el análisis de difracción de rayos X (DRX), espectroscopía de infrarrojos por transformada de Fourier (FTIR) y termogravimetría (TGA). En segundo lugar, se ha estudiado la viabilidad y durabilidad de la pulpa Kraft incorporada en la matriz de geopolímero mediante la realización de probetas que se han ensayado a flexión y a compresión, se han sometido a ciclos seco-húmido, así como también se han estudiado con SEM y BSE SEM. Se ha concluido que, aunque la matriz de geopolímero con pulpa Kraft es un material que ha demostrado tener unes características mecánicas que lo hacen viable, las fibras vegetales incorporadas experimentan poca durabilidad

Bioquímica del surfactante pulmonar. Lisolecitina : Lisolecitina Aciltransferasa del pulmón del conejo

Tesis de la Universidad Complutense de Madrid, 1981.Sección Deptal. de Bioquímica y Biología Molecular (Biológicas)Fac. de Ciencias BiológicasTRUEProQuestpu

Comparison between economic and environmental drivers for demand side aggregator

© 2020 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Demand-side flexibility is a promising source of the energy system that might enhance renewable energy penetration and help to democratize the electricity sector. However, it is not clear what is the best strategy to adopt for Demand Aggregators, especially when flexibility is provided by residential and tertiary buildings. This study compares two Demand Aggregators strategies in the framework of the SABINA (H2020) and the REFER research projects and analyses the effect of CO2 prices on the Demand Aggregator business model. Results show that Demand Response activities reduce both the costs and the building CO2 emissions independently from the strategy adopted.Peer ReviewedPostprint (author's final draft

Bioquímica del surfactante pulmonar. Lisolecitina : Lisolecitina Aciltransferasa del pulmón del conejo

Tesis de la Universidad Complutense de Madrid, 1981.Sección Deptal. de Bioquímica y Biología Molecular (Biológicas)Fac. de Ciencias BiológicasTRUEProQuestpu

Somatotypes and hand-grip strength analysis of elite cadet sambo athletes

The objectives of this research were to establish somatotype and hand-grip strength between elite cadet male and female sambo athletes divided by weight categories. A total of 97 elite cadet sambo athletes, participants of the World Cadets Sambo Championships 2018 participated in the study. Male and female sambo athletes were divided by official weight categories. Anthropometrical variables were taken in order to calculate somatotypes and hand-grip strength. A one-way analysis of variance and Tukey's post hoc tests were used to compare group differences by weight categories. Results of this study provide the first description of somatotype and hand-grip strength of elite male and female cadet sambo athletes in relation to weight category. A typical somatotype in male sambo athletes was endomorphic mesomorphs with a predominance of musculoskeletal tissue, while female athletes differed concerning weight category. Overall, an increase in handgrip strength across weight categories was noted. Hand-grip strength increases linearly from the lightest to the heaviest weight category except in -66 and -84 kg in male athletes. Differences in handgrip strength of female athletes were detected between the lightest group and last six groups in all three variables in favor of last six as well as -44 and kg -48 kg compared with the heaviest. To the best of our knowledge, this study provides the first normative data of somatotype and hand-grip strength analyses in relation to age, gender, and weight categories of cadet sambo athletes. The anthropometric profile of sambo athletes changed according to their weight category. Mesomorphy was the most dominant somatotype component in male athletes, while female had three different types of somatotype component in relation to weight category. In conclusion, we found differences in hand-grip strength related to weight category, which can be linked to the muscle mass of athletes. Future studies should focus on somatotype and strength handgrip values of international compared to national level sambo athletes

Model predictive energy control of ventilation for underground stations

Smart building systems are opening up new markets, nevertheless the implementation of these novel technologies still lacks suitable and proven whole engineering solutions in complex buildings. This paper presents a detailed approach for the ventilation control of an underground space, as an example of application of the developed solution to a very harsh environment but also highly demanding in terms of energy consumption. The underground spaces are characterized by a particular thermal behavior, because of the continuous and huge thermal exchange they have with the outside, via the openings and the ground surrounding the majority of the building. The main objective of the developed methodology is to reduce energy consumption of ventilation control while maintaining acceptable comfort levels: succeeding in achieving this twofold goal in a real station and the generalization of the approach are the most relevant contributions of the paper. The developed solution is based on a Model-based Predictive Control algorithm used together with a proper monitoring platform. The model predictive control is based on a Bayesian environmental prediction model, which works in cooperation with a weather forecast web service, schedule-based predictions about trains and external fans and an occupancy detection system to appraise the real amount of people. The prediction model develops scenarios useful to allow the controller acting in advance in order to adapt the system to the current and future conditions of use, taking profit of the knowledge of the real ventilation demand. Finally, the proposed control architecture is applied to the Passeig de Gràcia metro station in Barcelona as a case study, validating the usefulness of the proposed approach and obtaining more than 30% of energy savings in the ventilation system, while maintaining the pre-existing comfort levels. The saving percentage values estimated by simulation are confirmed by the direct measures continuously taken on site through energy-meters

Estimation of electric vehicle battery capacity requirements based on synthetic cycles

The adoption of the Electric Vehicle requires a switch towards a circular system to reduce their environmental impact. Under this framework, the correct sizing of the batteries and avoiding their underuse are key actions. Based on the analysis of real data, this work proposes a model to synthesize current profiles representative of trips containing urban and highway sections. The model is used to generate cycles for common daily driving distances. Different sized batteries are analysed at their beginning and end of life to evaluate their ability to provide the required range. Based on the results, it is suggested that the ongoing trend of battery capacity increase is not justified. The commonly assumed threshold of 70–80% State of Health has proved to be too conservative in most cases, allowing for an extension of the first life that should be individually defined based on functional aspects.Peer ReviewedPostprint (published version

Redefining the EV battery end of life: internal resistance related limitations

Currently Electric Vehicle batteries are considered to reach the End of Lifeonce their State of Health reaches70-80%. However, notions of circular economy suggest that the battery first-life should be extended as much as possible to reduce their environmental impact.Previous works have considered the range limitations of the drivers, arguing that the End of Lifethreshold is too conservative for many cases. However, to validate this statement, the increase of the internal resistance must be addressed. In this work a battery model is used to simulate the battery performance under different driving cycles synthesized from real data. Results show that the functional End of Life is forced by capacity, power or safety related issues.The dominant cause for reaching the End of Life depends highly on the battery size.The under performance is in most cases found after 70-80% State of Health, validating that the first life of most batteries could be extended without affecting the performance of the vehicle.This work was supported by the ALBATROSS H2020 project with grant agreement ID 963580. Cristina Corchero and Lluc Canals Casals are Serra Hunter Fellows.Peer ReviewedPostprint (published version