149 research outputs found

    Jitter Evaluation of Real-Time Control Systems

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    The implementation of industrial control applications typically introduces complexities like sampling jitter and control jitter, which have usually not been considered at the design stage. Consequently, the system behaves in a non-periodic manner and the real performance is degraded with regard to the expected response. This paper proposes a hybrid task model to reduce the impact of the scheduling on control performance. For a large batch of typical plants, we analyze how sensitive a control system is to jitter when the sampling rate is slow or fast compared to the bandwidth of the system

    Spermiogram and sperm head morphometry assessed by multivariate cluster analysis results during adolescence (12-18 years) and the effect of varicocele

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    Artículo científicoThis work evaluates sperm head morphometric characteristics in adolescents from 12 to 18 years of age, and the effect of varicocele. Volunteers between 150 and 224 months of age (mean 191, n = 87), who had reached oigarche by 12 years old, were recruited in the area of Barranquilla, Colombia. Morphometric analysis of sperm heads was performed with principal component (PC) and discriminant analysis. Combining seminal fluid and sperm parameters provided five PCs: two related to sperm morphometry, one to sperm motility, and two to seminal fluid components. Discriminant analysis on the morphometric results of varicocele and nonvaricocele groups did not provide a useful classification matrix. Of the semen-related PCs, the most explanatory (40%) was related to sperm motility. Two PCs, including sperm head elongation and size, were sufficient to evaluate sperm morphometric characteristics. Most of the morphometric variables were correlated with age, with an increase in size and decrease in the elongation of the sperm head. For head size, the entire sperm population could be divided into two morphometric subpopulations, SP1 and SP2, which did not change during adolescence. In general, for varicocele individuals, SP1 had larger and more elongated sperm heads than SP2, which had smaller and more elongated heads than in nonvaricocele men. In summary, sperm head morphometry assessed by CASA-Morph and multivariate cluster analysis provides a better comprehension of the ejaculate structure and possibly sperm function. Morphometric analysis provides much more information than data obtained from conventional semen analysis

    The crystal structure of Fe₄S₄ quinolinate synthase unravels an enzymatic dehydration mechanism that uses tyrosine and a hydrolase-type triad.

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    International audienceQuinolinate synthase (NadA) is a Fe4S4 cluster-containing dehydrating enzyme involved in the synthesis of quinolinic acid (QA), the universal precursor of the essential nicotinamide adenine dinucleotide (NAD) coenzyme. A previously determined apo NadA crystal structure revealed the binding of one substrate analog, providing partial mechanistic information. Here, we report on the holo X-ray structure of NadA. The presence of the Fe4S4 cluster generates an internal tunnel and a cavity in which we have docked the last precursor to be dehydrated to form QA. We find that the only suitably placed residue to initiate this process is the conserved Tyr21. Furthermore, Tyr21 is close to a conserved Thr-His-Glu triad reminiscent of those found in proteases and other hydrolases. Our mutagenesis data show that all of these residues are essential for activity and strongly suggest that Tyr21 deprotonation, to form the reactive nucleophilic phenoxide anion, is mediated by the triad. NadA displays a dehydration mechanism significantly different from the one found in archetypical dehydratases such as aconitase, which use a serine residue deprotonated by an oxyanion hole. The X-ray structure of NadA will help us unveil its catalytic mechanism, the last step in the understanding of NAD biosynthesis

    Alteractions in the mucosal immune system by a chronic exhausting exercise in Wistar rats

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    Exhausting exercise can disturb immune and gastrointestinal functions. Nevertheless, the impact of it on mucosal-associated lymphoid tissue has not been studied in depth. Here, we aim to establish the effects of an intensive training and exhausting exercise on the mucosal immunity of rats and to approach the mechanisms involved. Rats were submitted to a high-intensity training consisting of running in a treadmill 5 days per week for 5 weeks, involving 2 weekly exhaustion tests. At the end, samples were obtained before (T), immediately after (TE) and 24 h after (TE24) an additional final exhaustion test. The training programme reduced the salivary production of immunoglobulin A, impaired the tight junction proteins' gene expression and modified the mesenteric lymph node lymphocyte composition and function, increasing the ratio between Tαβ+ and B lymphocytes, reducing their proliferation capacity and enhancing their interferon-γ secretion. As a consequence of the final exhaustion test, the caecal IgA content increased, while it impaired the gut zonula occludens expression and enhanced the interleukin-2 and interferon-γ secretion. Our results indicate that intensive training for 5 weeks followed or not by an additional exhaustion disrupts the mucosalassociated lymphoid tissue and the intestinal epithelial barrier integrity in rats

    Jitter Evaluation of Real-Time Control Systems

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    The implementation of industrial control applications typically introduces complexities like sampling jitter and control jitter, which have usually not been considered at the design stage. Consequently, the system behaves in a non-periodic manner and the real performance is degraded with regard to the expected response. This paper proposes a hybrid task model to reduce the impact of the scheduling on control performance. For a large batch of typical plants, we analyze how sensitive a control system is to jitter when the sampling rate is slow or fast compared to the bandwidth of the system

    Changes in lymphocyte composition and functionality after intensive training and exhausting exercise in rats

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    Exhausting exercise can have a deleterious effect on the immune system. Nevertheless, the impact of exercise intensity on lymphocyte composition and functionality remains uncertain. The aim of this study was to establish the influence of intensive training on lymphoid tissues (blood, thymus, and spleen) in Wistar rats. Two intensive training programs were performed: a short program, running twice a day for 2 weeks and ending with a final exhaustion test (S-TE group), and a longer program, including two exhaustion tests plus three runs per week for 5 weeks. After this last training program, samples were obtained 24 h after a regular training session (T group), immediately after an additional exhaustion test (TE group) and 24 h later (TE24 group). The composition of lymphocytes in the blood, thymus, and spleen, the function of spleen cells and serum immunoglobulins were determined. In the blood, only the TE group modified lymphocyte proportions. Mature thymocytes' proportions decreased in tissues obtained just after exhaustion. There was a lower percentage of spleen NK and NKT cells after the longer training program. In these rats, the T group showed a reduced lymphoproliferative activity, but it was enhanced immediately after the final exhaustion. Cytokine secretion was modified after the longer training (T group), which decreased IFN-g and IL-10 secretion but increased that of IL-6. Higher serum IgG concentrations after the longer training program were detected. In conclusion, the intensive training for 5 weeks changed the lymphocyte distribution among primary and secondary lymphoid tissues and modified their function

    Influence of hesperidin on systemic immunity of rats following an intensive training and exhausting exercise

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    Intensive training and exhausting exercise can disrupt innate and acquired immunity. The flavanone hesperidin has shown immunomodulatory properties in physiological and some pathological conditions, and positive e ects on exercise-induced oxidative stress. Nevertheless, it remains uncertain whether it also prevents exhausting exercise-induced immune alterations. The aim of this study was to establish the e ect of oral hesperidin supplementation on the systemic immune system in rats following an intensive training and exhausting exercise. For this purpose, female Wistar rats were randomized into an intensive training group or a sedentary group. Intensive training was induced by running in a treadmill 5 days per week (including two exhausting tests) for five weeks. Throughout the training period, 200 mg/kg of hesperidin or vehicle was administered by oral gavage three times per week. At the end, blood, thymus, spleen and macrophages were collected before, immediately after and 24 h after an additional final exhaustion test. Hesperidin supplementation enhanced natural killer cell cytotoxicity and the proportion of phagocytic monocytes, attenuated the secretion of cytokines by stimulated macrophages, prevented the leukocytosis induced by exhaustion and increased the proportion of T helper cells in the thymus, blood and spleen. These results suggest that hesperidin can prevent exhausting exercise-induced immune alteration

    Protective effect of a cocoa-enriched diet on oxidative stress induced by intensive acute exercise in rats

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    Intensive acute exercise can induce oxidative stress, leading to muscle damage and immune function impairment. Cocoa diet could prevent this oxidative stress and its consequences on immunity. Our aim was to assess the effect of a cocoa-enriched diet on the reactive oxygen species (ROS) production by peritoneal macrophages, blood immunoglobulin (Ig) levels, leukocyte counts, and the physical performance of rats submitted to an intensive acute exercise, as well as to elucidate the involvement of cocoa fiber in such effects. For this purpose, Wistar rats were fed either a standard diet, i.e., a diet containing 10% cocoa (C10), or a diet containing 5% cocoa fiber (CF) for 25 days. Then, half of the rats of each diet ran on a treadmill until exhaustion, and 16 h later, the samples were obtained. Both C10 and CF diets significantly prevented the increase in ROS production. However, neither the cocoa diet or the cocoa fiber-enriched diet prevented the decrease in serum IgG induced by acute exercise. Therefore, although the cocoa-enriched diet was able to prevent the excessive oxidative stress induced by intensive exercise, this was not enough to avoid the immune function impairment due to exercise

    A cocoa diet can partially attenuate the alterations in microbiota and mucosal immunity induced by a single session of intensive exercise in rats

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    Background: Following intensive sports events, a higher rate of upper respiratory tract infections and the appearance of gastrointestinal symptomatology have been reported. We aimed to evaluate the effect of a cocoa-enriched diet on the cecal microbiota and mucosal immune system of rats submitted to high-intensity acute exercise, as well as to elucidate the involvement of cocoa fiber in such effects. Methods: Wistar rats were fed either a standard diet, a diet containing 10% cocoa providing 5% fiber and a diet containing only 5% cocoa fiber. After 25 days, half of the rats of each diet performed an exhaustion running test. Sixteen hours later, samples were obtained to assess, among others, the cecal microbiota and short chain fatty acids (SCFAs) composition, mesenteric lymph nodes (MLNs) and Peyer's patches (PPs) lymphocyte composition, and immunoglobulin (Ig) content in salivary glands. Results: The intake of cocoa, partially due to its fiber content, improved the SCFA production, prevented some changes in PPs and in MLNs lymphocyte composition and also decreased the production of proinflammatory cytokines. Cocoa diet, contrary to cocoa fiber, did not prevent the lower salivary IgM induced by exercise. Conclusion: A cocoa dietary intake can partially attenuate the alterations in microbiota and mucosal immunity induced by a single session of intensive exercise

    Para un debate sobre los derechos colectivos de los pueblos en acción

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    Este texto, pretende presentar y contribuir a la conformación de una sección especial dentro de la Revista ReDeA. Derechos en Acción, prevista a partir de su número 15, de otoño de 2020. Se trata de una sección especial sobre Pluralismo Jurídico, Pueblos y Estados, para la Revista Derechos en Acción (ReDeA), propuesta a instancias del Programa Memorias, Pueblos y Estados, dependiente de la Secretaría de Relaciones Institucionales y radicado en el Centro de Investigación en derecho Crítico, de la Facultad de Ciencias Jurídicas y Sociales de la Universidad nacional de La Plata, que empezó a gestarse en el año 2018, con la colaboración de diversos miembros del CIDer­Crit, y el patrocinio y apoyo del Colectivo de Acción Jurídica, Social y Cultural Copolis-Adalquí (Sede Atlántica de la Universidad Nacional de Río Negro/Fundación Adalquí), el Col·lectiu de Solidaritat amb els Països Catalans, y el Grupo Interuniversitario Copolis. Bienestar, Comunidad y Control Social (Universidad de Barcelona)
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