12 research outputs found

    Systématique, biogéographie et diversification du genre Crudia (Leguminosae, Detarioideae)

    Full text link
    In the subfamily Detarioideae (Leguminosae), the genus Crudia Schreb. shows an unusual pantropical distribution and high species richness compared to closely related genera. Crudia species, spread throughout South America, West Africa and Southeastern Asia, have been the focus of independent taxonomic studies conducted by several consecutive authors. To date, however, the evolution and biogeographic history of this genus remain poorly understood. We propose a multidisciplinary approach to study this poorly known genus and to improve our understanding of its evolutionary history. First, we conducted a taxonomic revision of Asian species within the genus Crudia, in accordance with the recent revisions of African and American species. We used traditional taxonomic methods by compiling morphological data based on the study of herbarium specimens. From an initial description of thirty five species from the literature, we retained fourteen species and synonymized the others except for one we consider as a doubtful species. A newly described species was also added. Species geographic distributions were reevaluated and new conservation statuses were suggested. Second, we established a conceptual framework to study the evolution, biogeographic history, and relationship between species of this genus. We sequenced five nuclear regions (ITS, ETS, AGT1, CALTL, and AIGP) on numerous sampled herbarium specimens (K, US, P, L, WAG, U). The phylogenetic analyses resolve Crudia as monophyletic with a well-identified internal structure composed of one clade grouping all Asian species and one clade grouping both African and American species, with the American species grouped in a single clade. Reconstructions of biogeographic history and an associated divergence time analysis calibrated with macrofossils show Crudia originated in Africa during the Eocene and underwent two independent dispersal events during mid-Eocene: from Africa to South America and from Africa to Southeastern Asia. Third, we tested if species richness in the genus Crudia is associated with changes in diversification rates through time and with ecological niche shifts throughout its global distribution. We used species occurrence data, carefully selected to avoid identification errors, associated with environmental data retrieved from the literature. Diversification rates were studied both at the scale of the genus Crudia and the Detarioideae subfamily. We conclude that ecological niches differ from one continent to another and no diversification rates changes were detected in the genus Crudia. Our finding suggest that the greater species richness in Crudia compared to sister genera may be the consequence of relatively older age of this genus.Le genre Crudia Schreb. prĂ©sente une distribution pantropicale et une richesse spĂ©cifique Ă©levĂ©e, inhabituelles pour un genre appartenant Ă  la sous famille des Detarioideae (Leguminosae). Les espĂšces de Crudia, rĂ©parties en AmĂ©rique du Sud, en Afrique de l’Ouest et en Asie du Sud Est, ont fait l’objet de plusieurs Ă©tudes de taxonomie indĂ©pendantes, rĂ©alisĂ©es par plusieurs auteurs successifs. En revanche, l’évolution et l’histoire biogĂ©ographique du genre sont inconnues Ă  ce jour. Afin de mieux comprendre l’histoire Ă©volutive de Crudia, nous proposons une approche pluridisciplinaire visant Ă  mettre Ă  jour les connaissances Ă  propos de ce genre mĂ©connu. La premiĂšre partie de cette Ă©tude a pour objectif de rĂ©aliser une rĂ©vision taxonomique des espĂšces asiatiques du genre Crudia, les espĂšces africaines et amĂ©ricaines ayant dĂ©jĂ  Ă©tĂ© traitĂ©es par d’autres auteurs. Nous avons pour cela utilisĂ© des mĂ©thodes de taxonomie traditionnelle en compilant des donnĂ©es morphologiques sur un grand nombre de spĂ©cimens d’herbier. Sur les trente-cinq espĂšces initiales dĂ©crites en Asie, nous en avons retenu quatorze et avons ajoutĂ© une nouvelle espĂšce. Les autres espĂšces ont Ă©tĂ© mises en synonymie pour la plupart, exceptĂ©e l’une d’entre elle qui est Ă  prĂ©sent considĂ©rĂ©e comme douteuse. Suite Ă  ces rĂ©assignations taxonomiques, les distributions gĂ©ographiques respectives des espĂšces ont Ă©tĂ© rĂ©Ă©valuĂ©es et des nouveaux statuts de conservation ont Ă©tĂ© proposĂ©s. La seconde partie de cette Ă©tude a pour objectif de poser un cadre conceptuel afin d’étudier dans le dĂ©tail l’évolution de ce genre, son histoire biogĂ©ographique et les relations entre espĂšces. Nous avons pour cela sĂ©quencĂ© cinq rĂ©gions nuclĂ©aires (ITS, ETS, AGT1, CALTL, AIGP) pour de nombreux spĂ©cimens, principalement prĂ©levĂ©s sur des Ă©chantillons d’herbiers (K, US, P, L, WAG, U). Les phylogĂ©nies rĂ©alisĂ©es montrent que Crudia est monophylĂ©tique et possĂšde une structure interne bien dĂ©finie, avec un clade regroupant toutes les espĂšces asiatiques et un autre regroupant les espĂšces africaines et amĂ©ricaines, ces derniĂšres formant elles-mĂȘmes un clade clairement identifiable. La reconstruction de l’histoire biogĂ©ographique, associĂ©e Ă  la datation Ă  l’aide d’un macrofossile, montre que Crudia trouve son origine en Afrique au cours de l’ÉocĂšne, puis subit deux Ă©vĂšnements indĂ©pendants de dispersion vers l’AmĂ©rique du Sud et vers l’Asie au cours de l’ÉocĂšne moyen. La troisiĂšme partie de cette Ă©tude a pour objectif d’identifier si la richesse spĂ©cifique du genre Crudia pouvait ĂȘtre associĂ©e Ă  un Ă©vĂšnement de changement des taux de diversification au cours du temps, mais Ă©galement savoir si les niches Ă©cologiques des diffĂ©rentes espĂšces Ă©taient semblables Ă  travers l’aire de distribution du genre au complet. Nous avons utilisĂ© pour cela des donnĂ©es d’occurrences des espĂšces, ainsi que des donnĂ©es reliĂ©es au rĂ©gime de prĂ©cipitations et Ă  la tempĂ©rature. ParallĂšlement, les taux de diversification ont Ă©tĂ© Ă©tudiĂ©s Ă  l’échelle du genre et Ă  l’échelle des Detarioideae. Au final, il s’est avĂ©rĂ© que les niches Ă©cologiques diffĂ©raient d’un continent Ă  l’autre, et qu’il n’existait pas de changement des taux de diversification dans le genre Crudia pouvant ĂȘtre reliĂ© prĂ©cisĂ©ment Ă  la richesse spĂ©cifique. Le nombre Ă©levĂ© d’espĂšces au sein du genre Crudia pourrait en revanche ĂȘtre liĂ© Ă  un Ăąge relativement plus vieux de ce genre, comparĂ© aux autres genres Ă©volutivement proches

    AplicaciĂłn de la topologĂ­a molecular en la bĂșsqueda de nuevos compuestos derivados del 4-nitro-imidazol activos frente al Tripanosoma brucei

    Get PDF
    Human African Trypanosomiasis, caused by the protozoan parasite Trypanosoma brucei, is characterized by a disabling chronic infectious process affecting millions of people worldwide. The therapeutic arsenal against this disease usually requires intravenous suministración, hindering accessibility and adherence to therapy. It has developed a topological mathematical model aimed to finding new compounds derived from 1-aryl-4-nitro-1H-imidazol with potential anti-trypanosome activity. Using linear discriminant analysis (LDA) was obtained a model capable of predicting correctly the activity of 93% of the studied compounds. The model has been subjected to an internal validation using the jack-knife test or leave-one-out and an internal cross-validation. Following a virtual sweep or virtual screening ten new imidazole derivatives are proposed, with potential anti-trypanosome activity.La Tripanosomiasis Humana Africana, causada por el paråsito protozoario de la especie Trypanosoma brucei, estå caracterizada por un proceso infectivo crónico discapacitante que afecta a millones de personas en todo el mundo. El arsenal terapéutico frente a esta enfermedad, requiere generalmente suministración por vía parenteral, lo que dificulta la adhesión y accesibilidad del paciente al tratamiento. Se ha desarrollado un modelo topológico-matemåtico encaminado a buscar nuevos compuestos derivados del 1-aril-4-nitro-1H-imidazol con potencial actividad anti-tripanosómica. Utilizando el anålisis lineal discriminante se ha obtenido un modelo capaz de predecir correctamente la actividad del 93% de los compuestos estudiados. Se ha sometido al modelo a una validación interna por medio del test de Jack-knife y de una validación cruzada. Tras realizar un cribado molecular virtual se proponen diez nuevos derivados imidazólicos con potencial actividad anti-tripanosómica

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

    Get PDF
    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Club des Laboratoires AccrĂ©ditĂ©s : partage d’expĂ©rience, audits croisĂ©s et amĂ©lioration de la qualitĂ© des mesures

    No full text
    Depuis 2011, le Club de Laboratoires AccrĂ©ditĂ©s se rĂ©unit une fois par semestre et le nombre de participants est chaque fois grandissant. Les premiĂšres rĂ©unions ont regroupĂ© une trentaine de participants venant de laboratoires aussi variĂ©s qu’EDF, CEA Cadarache, LDA 13, PROTEC LEA, LASEM Marine nationale, Institut CoopĂ©ratif du Vin, LERM, SCP, Avepharm, IGNA, Quadlab, ITGA, EUROCOPTER,... Ces laboratoires sont tous accrĂ©ditĂ©s ou en dĂ©marche d’accrĂ©ditation selon l’ISO 17025. La participation au Club des Laboratoires AccrĂ©ditĂ©s est totalement gratuite. Les rĂ©unions se font sur une demi-journĂ©e dans un laboratoire accueillant qui est diffĂ©rent Ă  chaque fois, et se dĂ©roulent en quatre temps : Sans un premier temps : prĂ©sentation des Ă©volutions de l’accrĂ©ditation ISO 17025 Ă  travers un thĂšme d’actualitĂ©. Dans un deuxiĂšme temps, il y a des Echanges entre les laboratoires accrĂ©ditĂ©s sur les relations avec les auditeurs Cofrac et sur les Ă©carts rĂ©currents (Ă  travers la prĂ©sentation d’écarts d’audits Cofrac des laboratoires participants). Dans un troisiĂšme temps, il y a des Ă©changes d’auditeurs et prĂ©sentation des pages internet du Club des Laboratoires AccrĂ©ditĂ©s dĂ©diĂ©es aux audits croisĂ©s. Et enfin dans un quatriĂšme et dernier temps, il y a des visites du laboratoire accueillant et plus particuliĂšrement des activitĂ©s accrĂ©ditĂ©es

    A phylogenetic analysis of palm subtribe Archontophoenicinae (Arecaceae) based on 14 DNA regions

    No full text
    International audienceSubtribe Archontophoenicinae belongs to Areceae, the largest of all palm tribes. It includes 15 species distributed in five genera, all found in the south-western Pacific Region. Archontophoenicinae are rather homogeneous in morphology, making phylogenetic relationships problematic to reconstruct using morphological characters. In this study we investigated phylogenetic relationships in Archontophoenicinae based on all 15 species of the subtribe, using a combination of nine plastid and five nuclear DNA sequence markers. The plastid regions used were the coding rbcL, matK, ndhF and rpoC1 (exon 2) and the non-coding rps16 intron, atpF-atpH, psbK-psbI, trnL-trnF and trnQ-rps16. The nuclear regions used were AG1, BRSC, ITS2, PRK and RPB2, which have all proved useful in palm systematics. We compared the phylogenetic hypotheses resulting from the plastid versus nuclear datasets, and combined both datasets to retrieve as much phylogenetic information as possible. Our results strongly support a clade composed of all species of Archontophoenix, Actinokentia, Chambeyronia and Kentiopsis, but raise the question of whether Actinorhytis, the fifth genus, should remain in Archontophoenicinae. Interspecific relationships in ‘core Archontophoenicinae’ still remain incompletely resolved, despite the gene and taxon sampling being substantially greater than in previous studies, and question the monophyly of the New Caledonian genera Chambeyronia and Kentiopsis
    corecore