653 research outputs found
Branched-chain amino acid supplementation attenuates a decrease in muscle function following acute strength training
Purpose: Branched-chain amino acid (BCAA) supplementation has been shown to attenuate the decrement in performance and increase in muscle soreness, following protocols that aim to induce muscle damage through loaded dynamic eccentric muscle actions (Jackman et al., 2010; Howatson et al., 2012). However, the application of these findings to an athletic setting is limited, since such protocols are designed to overtly cause muscle damage rather than replicate the demands of strength and power training sessions practiced by athletes (Byrne et al., 2004; Gee et al., 2012). This study aimed to investigate the effects of BCAA supplementation on muscle function following a resistance exercise session that featured multi-joint exercises that are typically utilised as part of a strength and conditioning regimen.
Methods: In a randomised single-blind crossover study, eleven resistance-trained males (Mean ± SD, age: 24.7 ± 5.9 years, stature: 1.80 ± 0.07 m, body mass: 79.0 ± 7.6 kg), performed baseline measures of a countermovement jump (CMJ) and seated shot putt throw (SSPT). In a counterbalanced fashion separated by a seven day washout period, participants were provided with either 20 g of BCAA or a placebo. Each dose was divided into two equal quantities and consumed 5-min before and 5-min after a strength training session (ST) consisting of various multi-joint barbell exercises. For both conditions, the CMJ and SSPT were repeated at 24 h post-ST, in addition participants attributed their perceived muscle soreness level via a 20 cm visual analogue scale (Howatson et al. 2012).
Results: A repeated measures ANOVA test showed that following ST there were significant decrements in CMJ and SSPT for both conditions in comparison to baseline values (P < 0.05). However, BCAA was shown to attenuate the decrements in performance compared to placebo (CMJ; 52.8 ± 5.9 cm vs. 50.6 ± 7.3 cm, SSPT; 4.37 ± 0.61 m vs. 4.22 ± 0.64 m, P < 0.05). Muscle soreness was significantly increased following ST for both conditions, there was a non-significant trend for lower attributed values following BCAA ingestion in comparison to placebo (P = 0.09).
Conclusions: In conclusion, BCAA administered acutely before and following intensive strength training attenuates a decrease in muscle function experienced by resistance-trained males. These small but significant effects on muscle function suggest that BCAA is an effective ergogenic aid for athletes who require augmented recovery of power-producing ability following intensive strength training
Importancia de la implementación de una escala para predecir la muerte por infarto cerebral agudo
Las estadÃsticas sanitarias mundiales publicadas en el año 2020 y en el anuario estadÃstico cubano, coinciden en que la enfermedad cerebrovascular es la tercera causa de muerte. En el anciano, la incidencia de estas entidades se duplica y llega a ser la primera causa de discapacidad crónica, la cuarta de años perdidos y la segunda de demencia. La identificación precoz de estos factores que conducen a la muerte, puede modificar el curso de la enfermedad, sobre todo si se ajustan los protocolos de actuación. La Escala Estimador de Riesgo de Muerte para el Infarto Cerebral Agudo, por sus siglas (ERMICA), es la primera escala en Cuba y en Mayabeque destinada al adulto mayor y especÃfica para identificar el riesgo de muerte por infarto cerebral agudo; por lo que se recomienda su implementación para predecir la muerte por infarto cerebral agudo
Comparació de diferents mètodes de determinació del contingut en nitrats i fosfats i de l’alcalinitat de l’aigua d’una instal·lació IMTA-RAS
Aquatic organisms play a vital role in the world's food supply. The high demand for these products has led to strong pressures on natural aquatic systems and harvesting by capture has become insufficient to meet market needs. In this context, aquatic organism farming techniques and the institutions that are researching to improve them are gaining importance. The UPC's Sistemes de Producció AqüÃcola or SPAq research group focuses on optimising the design and management of integrated recirculating multi-trophic aquaculture systems (IMTA RAS) and currently has a laboratory-scale plant that combines the cultivation of the macroalgae seaweed (Ulva sp.) with that of sole (Solea solea). The control of water quality in this system is key, and among the characteristics of the water that are determined periodically are the parameters nitrate concentration, phosphate concentration and alkalinity, which are being worked on in the present study. All three are currently monitored using classic and standardised methods which, although they provide reliable results, involve laborious procedures and require specialised equipment and personnel. There are also two commercial methods available for each of them, which have simpler and quicker procedures. This paper characterises the commercial methods and compares their results and characteristics with those of their respective reference analyses in order to assess their potential to replace or complement them. The results are compared using descriptive statistics and graphically. For quantitative methods, in addition, an ANOVA study is carried out. Characteristics related to the productivity of each method are also considered, such as the unit cost of each analysis, the sample volume required, the determination time and the volume of waste to be managed. In addition, personnel-related characteristics such as the material requirements, the difficulty of the technique, the necessary preliminary steps and the dangerousness of the reagents are valued. The commercial Hanna Checker methods have shown good results in terms of precision and accuracy. All three have obtained, in at least one sample, results without significant difference with those of the reference method (for a confidence level of 95 %) and all three represent a considerable improvement in terms of time, material and personnel requirements and sample volume that compensates for their higher cost. They are considered good candidates to carry out the controls of the three parameters. On the other hand, the JBL methods used do not offer sufficient quality to be considered good complements to the classical methods, as both show a great deal of variability in their results. Finally, the Hanna chemical alkalinity kit has presented a constant relative error that has allowed us to deduct a correction factor that, once applied, has represented a significant improvement that has allowed us to obtain results in two of the three samples without significant differences with those of the reference method (for a confidence of 95 %).Los organismos acuáticos desempeñan un papel vital en el suministro mundial de alimentos. La gran demanda de estos productos ha provocado fuertes presiones sobre los sistemas acuáticos naturales y la recolección mediante captura se ha vuelto insuficiente para satisfacer las necesidades del mercado. En este contexto, cobran importancia las técnicas de cultivo de organismos acuáticos y las instituciones que investigan para mejorarlas. El grupo de investigación Sistemes de Producció AqüÃcola o SPAq de la UPC se centra en la optimización del diseño y la gestión de sistemas integrados de acuicultura multitrófica de recirculación (IMTA RAS) y actualmente dispone de una planta a escala de laboratorio que combina el cultivo de la macroalga alga lechuga de mar (Ulva sp.) con el de lenguado (Solea solea). El control de la calidad del agua en este sistema es clave y entre las caracterÃsticas del agua que se determinan periódicamente se encuentran los parámetros concentración de nitratos, concentración de fosfatos y alcalinidad, sobre los que se trabaja en el presente estudio. Los tres se controlan actualmente mediante métodos clásicos y normalizados que, aunque proporcionan resultados fiables, implican procedimientos laboriosos y requieren equipos y personal especializados. También se dispone de dos métodos comerciales para cada uno de ellos, cuyos procedimientos són más sencillos y rápidos. En este artÃculo se caracterizan los métodos comerciales y se comparan sus resultados y caracterÃsticas con los de sus respectivos análisis de referencia, a fin de evaluar su potencial para sustituirlos o complementarlos. Los resultados se comparan mediante estadÃsticas descriptivas y gráficamente. En el caso de los métodos cuantitativos, además, se realiza un estudio ANOVA. También se tienen en cuenta caracterÃsticas relacionadas con la productividad de cada método, como el coste unitario de cada análisis, el volumen de muestra necesario, el tiempo de determinación y el volumen de residuos que hay que gestionar. Además, se valoran caracterÃsticas relacionadas con el personal, como las necesidades de material, la dificultad de la técnica, los pasos previos necesarios y la peligrosidad de los reactivos. Los métodos comerciales Hanna Checker han mostrado buenos resultados en cuanto a precisión y exactitud. Los tres han obtenido, en al menos una muestra, resultados sin diferencias significativas con los del método de referencia (para un nivel de confianza del 95 %) y los tres suponen una mejora considerable en términos de tiempo, material y personal necesarios y volumen de muestra que compensa su mayor coste. Se consideran buenos candidatos para realizar los controles de los tres parámetros. Por otro lado, los métodos JBL utilizados no ofrecen la calidad suficiente para ser considerados buenos complementos de los métodos clásicos, ya que ambos muestran una gran variabilidad en sus resultados. Finalmente, el kit de alcalinidad quÃmica Hanna ha presentado un error relativo constante que nos ha permitido deducir un factor de corrección que, una vez aplicado, ha representado una mejora significativa que nos ha permitido obtener resultados en dos de las tres muestras sin diferencias significativas con los del método de referencia (para una confianza del 95 %).Els organismes aquà tics juguen un paper vital en l’alimentació mundial. L’elevada demanda d’aquests productes ha originat fortes pressions sobre els sistemes naturals aquà tics i l’obtenció mitjançant la captura s’ha convertit en insuficient per satisfer les necessitats del mercat. En aquest context cobren importà ncia les tècniques de cultiu d’organismes aquà tics i les institucions que investiguen per millorar-les. El grup de recerca Sistemes de Producció AqüÃcola o SPAq de la UPC es centra en l’optimització del disseny i maneig de sistemes d’aqüicultura multitròfica integrada en recirculació (IMTA RAS) i actualment compta amb una planta, a escala laboratori, que combina el cultiu de la macroalga enciam de mar (Ulva sp.) amb el de llenguado (Solea solea). El control de la qualitat de l’aigua en aquest sistema és clau i entre les caracterÃstiques de l’aigua que es determinen periòdicament es troben els parà metres concentració de nitrats, concentració de fosfats i alcalinitat amb els que es treballa en el present estudi. Tots tres es controlen actualment mitjançant mètodes clà ssics i estandarditzats que, tot i proporcionar resultats fiables, presenten procediments laboriosos i requereixen de material i personal especialitzat. També es disposa, per cada un d’ells, de dos mètodes comercials que compten amb procediments més senzills i rà pids. En aquest treball es realitza la caracterització dels mètodes comercials i la comparació dels seus resultats i caracterÃstiques amb els dels seus respectius anà legs de referència per avaluar el seu potencial per substituir-los o complementar-los. La comparació dels resultats es realitza a partir d’estadÃstics descriptius i grà ficament. Pels mètodes quantitatius, a més, es realitza un estudi ANOVA. També es consideren caracterÃstiques vinculades a la productivitat de cada mètode, com el cost unitari de cada anà lisi, el volum de mostra requerit, el temps de determinació i el volum de residus a gestionar. A més, es posen en valor caracterÃstiques relacionades amb el personal com són els requeriments de material, la dificultat de la tècnica, els passos previs necessaris i la perillositat dels reactius. Els mètodes comercials Hanna Checker han presentat bons resultats de precisió i d’exactitud. Pels tres s’ha obtingut, en almenys una mostra, resultats sense diferencia significativa amb els del mètode de referència (per un nivell de confiança del 95 %) i tots tres representen una millora considerable en termes de temps, requeriments de material i personal i volum mostral que compensa el seu cost superior. Es consideren bons candidats per realitzar els controls dels tres parà metres. Contrà riament els mètodes JBL assajats no ofereixen la qualitat suficient per considerar-se bons complements dels mètodes clà ssics, doncs els dos presenten massa variabilitat entre els seus resultats. Per últim, el Kit quÃmic Hanna d’alcalinitat ha presentat un error relatiu constant que ha permès deduir un factor de correcció que, un cop aplicat, ha representat una millora significativa que ha permès obtenir en dos de les tres mostres resultats sense diferència significativa amb els del mètode de referència (per una confiança del 95 %).Objectius de Desenvolupament Sostenible::6 - Aigua Neta i Sanejamen
Julia Torlet, Le Monde de la prostitution à Paris au xviiie siècle. Métier de corps, corps de métier ?
Julia Torlet s’attache à décrire le monde de la prostitution à Paris au xviiie siècle dans un ouvrage synthétique et accessible aux amateurs d’histoire. Les chapitres, courts et équilibrés, sont rédigés dans un style agréable et fluide, doté d’un appareil critique limité. Dans un chapitre liminaire (chap. 1), l’autrice a à cœur de montrer la pluralité des prostituées, dont elle dresse une typologie volontairement simplifiée, soulignant la variété des situations autant que les parcours sinueux..
Étude du traitement et du recyclage des eaux issues des serres horticoles
La gestion de l'eau dans les systèmes de culture hors-sol fait apparaître deux problèmes distincts. D'une part, les ressources en eau doivent être de bonne qualité et ne pas contenir de pesticides ou de germes pathogènes. D'autre part, les rejets fortement " chargés " en nutriments (NO3-, PO43-) polluants pour l'environnement, doivent être limités par le biais de leur recyclage ce qui implique nécessairement la désinfection des effluents.La technique mise en œuvre pour obtenir cette maîtrise de la qualité tant chimique que microbiologique des solutions circulantes en culture hors-sol est celle d'une oxydation à l'ozone seul et couplé au peroxyde d'hydrogène dans des réacteurs constitués de mélangeurs statiques. Les conditions de traitement sont une dose d'oxydant de 10 g O3/m3 d'effluent à traiter, un rapport H2O2/O3 de 0,15 g/g pour un temps de contact dans le réacteur de l'ordre de la seconde. Etudié sur site dans le cadre du traitement de effluents de serre réels, le procédé s'est révélé tout à fait adapté pour abattre les pesticides (# 90 % pour l'atrazine), maîtriser la prolifération des micro-organismes (Flore aérobie mésophile, flore fongique) et en particulier des germes pathogènes (Clavibacter michiganensis, Fusarium, Pythium sp ).Le procédé novateur O3/H2O2 sur mélangeurs statiques constitue donc pour les serristes une réponse nouvelle dont l'un des intérêts est de combiner les effets " détoxiquant " et désinfectant.The management of water resources in soil-less cultures presents two difficulties. On one hand, the quality of these resources has to be good, that is to say without pesticides or pathogens. On the other hand, the effluents contain high concentrations of nutrients (NO3-, PO43-), damageable for the environment, and should be recycled. Thus, recycling has to include necessarily a disinfection step to satisfy the quality requirement. The main disinfection treatments used in soil-less cultures are slow sand filtration, ultraviolet treatment, heat treatment, nanofiltration, ozone or hydrogen peroxide oxidation, iodine or chlorine treatment.In order to control the chemical as well as the microbiological quality of the recycled nutrient solution, we suggest oxidation (O3) and advanced oxidation (O3/H2O2) processes, carried out in static mixers as chemical reactors instead of bubble columns. We have been studying this process in situ for the treatment of a 1-hectare greenhouse. The pilot plant unit can be configured under three setups (Figure 2) according to the aim to favor either the molecular action of ozone or the formation of very reactive radical species such as the hydroxyl radical. In this second case, the mechanism of ozone decomposition is given by Figure 1.The first step of the study was to measure the influence of the nutrient solution to be recycled on the efficiency of atrazine removal (Figures 3 and 4). In comparison with tap water, the percentage of pesticide removal is lower by about 10 to 20 %. Solutions with nutrients do not drastically change the process efficiency. The experiments were carried out with various ozone dosages and various ozone / hydrogen peroxide mass ratios, using the three configurations (Figures 5 and 6). With these results, the best operating conditions for micropollutant removal are a treatment rate of about 10 g O3 /m3 of treated solution, a H2O2/O3 ratio equal to 0.15 g/g and a contact time in the reactor in the range of 1 to 2 seconds. The influence of the configuration type is not really marked. The results show that, under these conditions, this technique leads to good pesticide removal efficiencies (about 90 % for atrazine).In a second step, experiments were carried out on real solutions containing microorganisms from the greenhouse, sometimes spiked with special bacteria (Clavibacter) or fungi (Fusarium). Some results are reported in Figures 7, 8 and 9. With the same oxidant dosage conditions, the role of the configuration is clearly demonstrated. The best results are obtained with a molecular action of ozone in the first static mixed reactor followed by a free-radical action within the second reactor. Thus, it is possible to prevent germ proliferation (aerobic mesophilic flora and fungi flora) and particularly pathogenic species. The abatement of Clavibacter michiganensis reaches 3.5 to 4 logarithmic units, 1 to 1.5 units for Pythium and 2 to 4 units for Fusarium. The treatment does not effect a complete sterilization, e.g., the beneficial bacterium Pseudomonas fluorescens survives. The global impact of the treatment on the nutritive quality of the treated solution is negligible. Nevertheless, we can note that the process induces a decrease of the ion concentrations of Fe (II) (- 5 to 30 %) and Mn (II) (-10 to 15 %) as a result of the oxidation of the EDTA chelate. In fact, this problem is observed with all oxidation and UV treatments. The residual oxidant (O3, H2O2) concentrations are low and do not induce obvious toxic effects on the cultures.Thus, the technique is consistent with a recycling of the treated effluents. The advantages of the process include very short contact times, compactness of the equipment, no need for pretreatment, reasonable investment and operating costs, an increase of the oxygen concentration in the treated effluent, and possible curative effects on the culture's germ contamination due to the residual concentration of hydrogen peroxide. The disinfection efficiency of this suggested process is similar to those obtained with more common techniques like UV irradiation. Moreover, the studied process can also reduce, for example, an eventual chemical pollution of the water resource. In conclusion, the O3, H2O2 process in static mixers appears to be a new solution for greenhouse farmers
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