379 research outputs found

    Automatic system for the determination of metals by anodic stripping potentiometry in non-deaerated samples

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    An automatic system for the determination of Zn, Cd, Pb and Cu by anodic stripping potentiometry using the oxygen dissolved in the sample as oxidant is reported. The system relies on the use of a PC-compatible computer for instrumental control and data acquisition and processing

    A fully automatic system for acid-base coulometric titrations

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    An automatic system for acid-base titrations by electrogeneration of H+ and OH- ions, with potentiometric end-point detection, was developed. The system includes a PC-compatible computer for instrumental control, data acquisition and processing, which allows up to 13 samples to be analysed sequentially with no human intervention

    Flavonoids affect host-microbiota crosstalk through TLR modulation

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    Interaction between host cells and microbes is known as crosstalk. Among other mechanisms, this takes place when certain molecules of the micro-organisms are recognized by the toll-like receptors (TLRs) in the body cells, mainly in the intestinal epithelial cells and in the immune cells. TLRs belong to the pattern-recognition receptors and represent the first line of defense against pathogens, playing a pivotal role in both innate and adaptive immunity. Dysregulation in the activity of such receptors can lead to the development of chronic and severe inflammation as well as immunological disorders. Among components present in the diet, flavonoids have been suggested as antioxidant dietary factors able to modulate TLR-mediated signaling pathways. This review focuses on the molecular targets involved in the modulatory action of flavonoids on TLR-mediated signaling pathways, providing an overview of the mechanisms involved in such action. Particular flavonoids have been able to modify the composition of the microbiota, to modulate TLR gene and protein expression, and to regulate the downstream signaling molecules involved in the TLR pathway. These synergistic mechanisms suggest the role of some flavonoids in the preventive effect on certain chronic diseases

    “Cocoa and Chocolate: Science and Gastronomy”—The Second Annual Workshop of the Research Institute on Nutrition and Food Security (INSA): 9 November 2016

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    The Research Institute on Nutrition and Food Security at the University of Barcelona (INSA-UB) was founded in 2005 by twenty-two research groups from the Faculties of Pharmacy and Food Science; Biology; Chemistry; and Geography and History, as well as other UB-affiliated centers and hospitals. Most of the groups at the Institute are, or at least are part of, the research groups established by the Government of Catalonia. INSA-UB was founded to meet the current societal need for research, training and service provision in the sectors related to the agro-alimentary industry. Researchers at the Institute are experts in different fields of nutrition; food analysis and control; food safety and the study of the social and economic impact of food. The main objectives of the institute are to promote research in the fields in which it works; to encourage collaboration between researchers and the establishment of multidisciplinary teams; to promote participation in research programs and institutional administration, particularly in European research projects; to encourage the development of joint projects with companies in the sectors related to its scope; to make available all the social potential of the UB in this area, especially the training of technicians and specialists and provision of services; to promote the transfer of knowledge and the dissemination of research results between society and government; and to advise consumers, businesses and public authorities on nutrition, food safety and quality..

    Cocoa and cocoa fibre differentially modulate IgA and IgM production at mucosal sites

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    Previous studies have shown that a 10% cocoa (C10) diet, containing polyphenols and fibre among others, modifies intestinal and systemic Ig production. The present study aimed at evaluating the impact of C10 on IgA and IgM production in the intestinal and extra-intestinal mucosal compartments, establishing the involvement of cocoa fibre (CF) in such effects. Mechanisms by which C10 intake may affect IgA synthesis in the salivary glands were also studied. To this effect, rats were fed either a standard diet, a diet containing C10, CF or inulin. Intestinal (the gut wash (GW), Peyer's patches (PP) and mesenteric lymph nodes (MLN)) and extra-intestinal (salivary glands) mucosal tissues and blood samples were collected for IgA and IgM quantification. The gene expressions of IgA production-and homing-related molecules were studied in the salivary glands. The C10 diet decreased intestinal IgA and IgM production. Although the CF diet decreased the GW IgA concentration, it increased PP, MLN and serum IgA concentrations. Both the C10 and the CF diets produced a down-regulatory effect on IgA secretion in the extra-intestinal tissues. The C10 diet interacted with the mechanisms involved in IgA synthesis, whereas the CF showed particular effects on the homing and transcytosis of IgA across the salivary glands. Overall, CF was able to up-regulate IgA production in the intestinal-inductor compartments, whereas it down-regulated its production at the mucosal-effector ones. Further studies must be directed to ascertain the mechanisms involved in the effect of particular cocoa components on gut-associated lymphoid tissue

    Sexual selection on multivariate phenotypes in Anastrepha fraterculus (Diptera: Tephritidae) from Argentina

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    Despite the interest in applying environmentally friendly control methods such as sterile insect technique (SIT) against Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae), information about its biology, taxonomy, and behavior is still insufficient. To increase this information, the present study aims to evaluate the performance of wild flies under field cage conditions through the study of sexual competitiveness among males (sexual selection). A wild population from Horco Molle, Tucumán, Argentina was sampled. Mature virgin males and females were released into outdoor field cages to compete for mating. Morphometric analyses were applied to determine the relationship between the multivariate phenotype and copulatory success. Successful and unsuccessful males were measured for 8 traits: head width (HW), face width (FW), eye length (EL), thorax length (THL), wing length (WL), wing width (WW), femur length (FL), and tibia length (TIL). Combinations of different multivariate statistical methods and graphical analyses were used to evaluate sexual selection on male phenotype. The results indicated that wing width and thorax length would be the most probable targets of sexual selection. They describe a nonlinear association between expected fitness and each of these 2 traits. This nonlinear relation suggests that observed selection could maintain the diversity related to body size.Fil:Segura, D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Rodriguero, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Cladera, J.L. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Vilardi, J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

    Intensive Training and Sex Influence Intestinal Microbiota Composition: A Preclinical Approach

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    Lifestyle, including regular physical activity and dietary habits, influences microbiota composition. Although some studies have demonstrated changes in microbiota composition due to moderate or high intensity training in athletes, the relationship between physical activity and changes in the intestinal bacteria is still a matter of discussion. In addition, as most studies are performed on males, the role of sexual dimorphism deserves to be explored. Therefore, the aim of this preliminary study was to ascertain the influence of an intensive training and the rat's sex on caecal microbiota composition. For this purpose, female and male 4-week-old Wistar rats were submitted to a 4-week running training program. At the end, caecal samples were collected immediately after performing an exhaustion test to characterize the microbiota composition by 16S rRNA sequencing technique. Parallel groups of female and male sedentary (SED) rats (age matched) were included. The results showed that young female rats had a higher ability to run than males but no sex- or training-associated changes were observed on microbiota diversity and richness indexes among groups. However, the Actinobacteria, Bifidobacteriaceae and Bifidobacterium spp. proportions were significantly higher in male than in female rats when comparing SED groups (p <0.05), whose proportions in males were decreased by the training program (p < 0.05 vs. SED). On the contrary, female SED rats showed a higher proportion of Odoribacteraceae (belonging to Bacteroidetes), Clostridiaceae and Eubacteriaceae (both Firmicutes) than in the respective male group (p < 0.05), although Eubacteriaceae proportion decreased by running (p < 0.05 vs. SED). However, training increased the proportion of the Paraeggerthella genus (Actinobacteria) in female rats with respect to its sedentary counterpart (p < 0.05). Overall, caecal microbiota composition is modified by intensive training in young rats but there are also sex-based differences that should be considered for interventional studies

    Does Flavonoid Consumption Improve Exercise Performance? Is It Related to Changes in the Immune System and Inflammatory Biomarkers? A Systematic Review of Clinical Studies since 2005

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    Flavonoids are attracting increasing attention due to their antioxidant, cardioprotective, and immunomodulatory properties. Nevertheless, little is known about their role in exercise performance in association with immune function. This systematic review firstly aimed to shed light on the ergogenic potential of flavonoids. A search strategy was run using SCOPUS database. The returned studies were screened by prespecified eligibility criteria, including intervention lasting at least one week and performance objectively quantified, among others. Fifty-one studies (54 articles) met the inclusion criteria, involving 1288 human subjects, either physically untrained or trained. Secondly, we aimed to associate these studies with the immune system status. Seventeen of the selected studies (18 articles) assessed changes in the immune system. The overall percentage of studies reporting an improved exercise performance following flavonoid supplementation was 37%, the proportion being 25% when considering quercetin, 28% for flavanol-enriched extracts, and 54% for anthocyanins enriched extracts. From the studies reporting an enhanced performance, only two, using anthocyanin supplements, focused on the immune system and found certain anti-inflammatory effects of these flavonoids. These results suggest that flavonoids, especially anthocyanins, may exert beneficial effects for athletes' performances, although further studies are encouraged to establish the optimal dosage and to clarify their impact on immune status

    Enabling Large-scale Heterogeneous Collaboration with Opportunistic Communications

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    Multi-robot collaboration in large-scale environments with limited-sized teams and without external infrastructure is challenging, since the software framework required to support complex tasks must be robust to unreliable and intermittent communication links. In this work, we present MOCHA (Multi-robot Opportunistic Communication for Heterogeneous Collaboration), a framework for resilient multi-robot collaboration that enables large-scale exploration in the absence of continuous communications. MOCHA is based on a gossip communication protocol that allows robots to interact opportunistically whenever communication links are available, propagating information on a peer-to-peer basis. We demonstrate the performance of MOCHA through real-world experiments with commercial-off-the-shelf (COTS) communication hardware. We further explore the system's scalability in simulation, evaluating the performance of our approach as the number of robots increases and communication ranges vary. Finally, we demonstrate how MOCHA can be tightly integrated with the planning stack of autonomous robots. We show a communication-aware planning algorithm for a high-altitude aerial robot executing a collaborative task while maximizing the amount of information shared with ground robots. The source code for MOCHA and the high-altitude UAV planning system is available open source: http://github.com/KumarRobotics/MOCHA, http://github.com/KumarRobotics/air_router.Comment: 7 pages, 8 figure
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