483 research outputs found

    Neodymium and gadolinium extraction from molten fluorides by reduction on a reactive electrode

    Get PDF
    This work describes the electrochemical extraction on a reactive cathode (Cu, Ni) of two lanthanides Ln (Ln = Nd and Gd) from molten LiF-CaF2 medium at 840 and 920°C for Nd and 940°C for Gd. Extraction runs have been performed and the operating conditions (cathodic material and temperature) optimised. The titration of the Nd and Gd concentrations in the melt during extraction used square wave voltammetry. At the end of each run, the residual Ln content was checked by ICP-AES; the extraction efficiencies of the two lanthanides were found to be more than 99.8% on both reactive substrates

    Female common lizards (Lacerta vivipara) do not adjust their sex-biased investment in relation to the adult sex ratio.

    Get PDF
    Sex allocation theory predicts that facultative maternal investment in the rare sex should be favoured by natural selection when breeders experience predictable variation in adult sex ratios (ASRs). We found significant spatial and predictable interannual changes in local ASRs within a natural population of the common lizard where the mean ASR is female-biased, thus validating the key assumptions of adaptive sex ratio models. We tested for facultative maternal investment in the rare sex during and after an experimental perturbation of the ASR by creating populations with female-biased or male-biased ASR. Mothers did not adjust their clutch sex ratio during or after the ASR perturbation, but produced sons with a higher body condition in male-biased populations. However, this differential sex allocation did not result in growth or survival differences in offspring. Our results thus contradict the predictions of adaptive models and challenge the idea that facultative investment in the rare sex might be a mechanism regulating the population sex ratio

    Interseismic Strain Accumulation on the Himalayan Crustal Ramp (Nepal)

    Get PDF
    The Departement of Mines and Geology has been monitoring the seismicity of the Central Himalayas of Nepal since 1985. Intense microseismicity and frequent medium‐size earthquakes (mL<4) tend to cluster beneath the topographic front of the Higher Himalaya. This 10–20km deep seismicity also correlates with a zone of localized uplift that has been evidenced from geodetic data. Both microseismic and geodetic data indicate strain accumulation on a mid‐crustal ramp that had been previously inferred from geological and geophysical evidence. This ramp connects a flat decollement under the Lesser and Sub‐Himalaya with a deeper decollement under the Higher Himalaya, and probably acts as a geometric asperity where strain and stress build up during the interseismic period. The large Himalayan earthquakes could nucleate there and probably activate the whole flat‐and‐ramp system up to the blind thrusts of the Sub‐Himalaya

    Flavonoids affect host-microbiota crosstalk through TLR modulation

    Get PDF
    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

    Get PDF
    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

    Get PDF
    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

    Un Spongiaire Sphinctozoaire colonial apparenté aux constructeurs de récifs triasiques survivant dans le bathyal de Nouvelle-Calédonie

    Get PDF
    Un second représentant actuel des Sphinctozoaires, importants constructeurs de récifs au Permo-Trias, a été découvert dans la zone bathyale de la NouvelleCalédonie. Contrairement au survivant déjà connu, #Valecetia crypta$, il a conservé le mode de croissance colonial et les capacités constructrices de ses analogues fossiles. Sa croissance est bien plus lente que celle des coraux récifaux actuels. La base d'une construction de 10 cm d'épaisseur a été datée de 700 ans. (Résumé d'auteur

    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

    Get PDF
    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
    • 

    corecore