71 research outputs found

    Individual-environment interactions in swimming: The smallest unit for analysing the emergence of coordination dynamics in performance?

    Get PDF
    Displacement in competitive swimming is highly dependent on fluid characteristics, since athletes use these properties to propel themselves. It is essential for sport scientists and practitioners to clearly identify the interactions that emerge between each individual swimmer and properties of an aquatic environment. Traditionally, the two protagonists in these interactions have been studied separately. Determining the impact of each swimmer’s movements on fluid flow, and vice versa, is a major challenge. Classic biomechanical research approaches have focused on swimmers’ actions, decomposing stroke characteristics for analysis, without exploring perturbations to fluid flows. Conversely, fluid mechanics research has sought to record fluid behaviours, isolated from the constraints of competitive swimming environments (e.g. analyses in two-dimensions, fluid flows passively studied on mannequins or robot effectors). With improvements in technology, however, recent investigations have focused on the emergent circular couplings between swimmers’ movements and fluid dynamics. Here, we provide insights into concepts and tools that can explain these on-going dynamical interactions in competitive swimming within the theoretical framework of ecological dynamics

    Regulation of immunity during visceral Leishmania infection

    Get PDF
    Unicellular eukaryotes of the genus Leishmania are collectively responsible for a heterogeneous group of diseases known as leishmaniasis. The visceral form of leishmaniasis, caused by L. donovani or L. infantum, is a devastating condition, claiming 20,000 to 40,000 lives annually, with particular incidence in some of the poorest regions of the world. Immunity to Leishmania depends on the development of protective type I immune responses capable of activating infected phagocytes to kill intracellular amastigotes. However, despite the induction of protective responses, disease progresses due to a multitude of factors that impede an optimal response. These include the action of suppressive cytokines, exhaustion of specific T cells, loss of lymphoid tissue architecture and a defective humoral response. We will review how these responses are orchestrated during the course of infection, including both early and chronic stages, focusing on the spleen and the liver, which are the main target organs of visceral Leishmania in the host. A comprehensive understanding of the immune events that occur during visceral Leishmania infection is crucial for the implementation of immunotherapeutic approaches that complement the current anti-Leishmania chemotherapy and the development of effective vaccines to prevent disease.The research leading to these results has received funding from the European Community’s Seventh Framework Programme under grant agreement No.602773 (Project KINDRED). VR is supported by a post-doctoral fellowship granted by the KINDReD consortium. RS thanks the Foundation for Science and Technology (FCT) for an Investigator Grant (IF/00021/2014). This work was supported by grants to JE from ANR (LEISH-APO, France), Partenariat Hubert Curien (PHC) (program Volubilis, MA/11/262). JE acknowledges the support of the Canada Research Chair Program

    Neutrophils Reduce the Parasite Burden in Leishmania (Leishmania) amazonensis-Infected Macrophages

    Get PDF
    Background: Studies on the role of neutrophils in Leishmania infection were mainly performed with L. (L) major, whereas less information is available for L. (L) amazonensis. Previous results from our laboratory showed a large infiltrate of neutrophils in the site of infection in a mouse strain resistant to L. (L.) amazonensis (C3H/HePas). in contrast, the susceptible strain (BALB/c) displayed a predominance of macrophages harboring a high number of amastigotes and very few neutrophils. These findings led us to investigate the interaction of inflammatory neutrophils with L. (L.) amazonensis-infected macrophages in vitro.Methodology/Principal Findings: Mouse peritoneal macrophages infected with L. (L.) amazonensis were co-cultured with inflammatory neutrophils, and after four days, the infection was quantified microscopically. Data are representative of three experiments with similar results. the main findings were 1) intracellular parasites were efficiently destroyed in the co-cultures; 2) the leishmanicidal effect was similar when cells were obtained from mouse strains resistant (C3H/HePas) or susceptible (BALB/c) to L. (L.) amazonensis; 3) parasite destruction did not require contact between infected macrophages and neutrophils; 4) tumor necrosis factor alpha (TNF-alpha), neutrophil elastase and platelet activating factor (PAF) were involved with the leishmanicidal activity, and 5) destruction of the parasites did not depend on generation of oxygen or nitrogen radicals, indicating that parasite clearance did not involve the classical pathway of macrophage activation by TNF-alpha, as reported for other Leishmania species.Conclusions/Significance: the present results provide evidence that neutrophils in concert with macrophages play a previously unrecognized leishmanicidal effect on L. (L.) amazonensis. We believe these findings may help to understand the mechanisms involved in innate immunity in cutaneous infection by this Leishmania species.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilWeb of Scienc

    Analyzing factors that influence the folk use and phytonomy of 18 medicinal plants in Navarra

    Get PDF
    BACKGROUND: This article analyzes whether the distribution or area of use of 18 medicinal plants is influenced by ecological and cultural factors which might account for their traditional use and/or phytonymy in Navarra. This discussion may be helpful for comparative studies, touching as it does on other ethnopharmacological issues: a) which cultural and ecological factors affect the selection of medicinal plants; b) substitutions of medicinal plants in popular medicine; c) the relation between local nomenclature and uses. To analyze these questions, this paper presents an example of a species used for digestive disorders (tea and camomile: Jasonia glutinosa, J. tuberosa, Sideritis hyssopifolia, Bidens aurea, Chamaemelum nobile, Santolina chamaecyparissus...), high blood pressure (Rhamnus alaternus, Olea europaea...) or skin diseases (Hylotelephium maximum, H. telephium, Anagallis arvensis, A. foemina). METHODS: Fieldwork began on January 2004 and continued until December 2006. During that time we interviewed 505 informants in 218 locations in Navarra. Information was collected using semi-structured ethnobotanical interviews, and we subsequently made maps using Arc-View 8.0 program to determine the area of use of each taxon. Each map was then compared with the bioclimatic and linguistic map of Navarra, using the soil and ethnographic data for the region, and with other ethnobotanical and ethnopharmacological studies carried out in Europe. RESULTS: The results clearly show that ecological and cultural factors influence the selection of medicinal plants in this region. Climate and substrate are the most important ecological factors that influence the distribution and abundance of plants, which are the biological factors that affect medicinal plant selection. CONCLUSION: The study of edaphological and climatological factors, on the one hand, and culture, on the other, can help us to understand why a plant is replaced by another one for the same purposes, either in the same or in a different area. In many cases, the cultural factor means that the use of a species is more widespread than its ecological distribution. This may also explain the presence of synonyms and polysemies which are useful for discussing ethnopharmacological data

    First comprehensive contribution to medical ethnobotany of Western Pyrenees

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>An ethnobotanical and medical study was carried out in the Navarre Pyrenees, an area known both for its high biological diversity and its cultural significance.</p> <p>As well as the compilation of an ethnopharmacological catalogue, a quantitative ethnobotanical comparison has been carried out in relation to the outcomes from other studies about the Pyrenees. A review of all drugs used in the area has also been carried out, through a study of the monographs published by the institutions and organizations responsible for the safety and efficacy of medicinal plants (WHO, ESCOP, and the E Commission of the German Department of Health) in order to ascertain the extent to which the Navarre Pyrenees ethnopharmacology has been officially evaluated.</p> <p>Methods</p> <p>Fieldwork was carried out over two years, from November 2004 to December 2006. During that time we interviewed 88 local people in 40 villages. Information was collected using semi-structured ethnobotanical interviews and the data was analyzed using quantitave indexes: Ethnobotonicity Index, Shannon-Wiener's Diversity, Equitability and The Informant Consensus Factor. The official review has been performed using the official monographs published by the WHO, ESCOP and the E Commission of the German Department of Health.</p> <p>Results</p> <p>The ethnobotanical and medical catalogue of the Navarre Pyrenees Area comprises 92 species, of which 39 have been mentioned by at least three interviewees. The quantitative ethnobotany results show lower values than those found in other studies about the Pyrenees; and 57.6% of the Pyrenees medical ethnobotany described does not figure in documents published by the above mentioned institutions.</p> <p>Conclusion</p> <p>The results show a reduction in the ethnobotanical and medical knowledge in the area of study, when compared to other studies carried out in the Pyrenees. Nevertheless, the use of several species that may be regarded as possible sources for pharmacological studies is reported here such as the bark of <it>Sambucus nigra</it>, the roots of <it>Fragaria vesca</it>, or the leaves of <it>Scrophularia nodosa</it>. These species are not currently approved by the WHO, ESCOP and the E Commission of the German Department of Health, institutions that, apart from encouraging the greater use of plants for medicinal purposes, may help in the design of development plans for these rural areas by validating their traditional medicine.</p
    corecore