68 research outputs found

    Hammerhead flatworms (Platyhelminthes, Geoplanidae, Bipaliinae): mitochondrial genomes and description of two new species from France, Italy, and Mayotte

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    Background: New records of alien land planarians are regularly reported worldwide, and some correspond to undescribed species of unknown geographic origin. The description of new species of land planarians (Geoplanidae) should classically be based on both external morphology and histology of anatomical structures, especially the copulatory organs, ideally with the addition of molecular data. Methods: Here, we describe the morphology and reproductive anatomy of a species previously reported as Diversibipalium “black”, and the morphology of a species previously reported as Diversibipalium “blue”. Based on next generation sequencing, we obtained the complete mitogenome of five species of Bipaliinae, including these two species. Results: The new species Humbertium covidum n. sp. (syn: Diversibipalium “black” of Justine et al., 2018) is formally described on the basis of morphology, histology and mitogenome, and is assigned to Humbertium on the basis of its reproductive anatomy. The type-locality is Casier, Italy, and other localities are in the Department of Pyrénées-Atlantiques, France; some published or unpublished records suggest that this species might also be present in Russia, China, and Japan. The mitogenomic polymorphism of two geographically distinct specimens (Italy vs France) is described; the cox1 gene displayed 2.25% difference. The new species Diversibipalium mayottensis n. sp. (syn: Diversibipalium “blue” of Justine et al., 2018) is formally described on the basis of external morphology and complete mitogenome and is assigned to Diversibipalium on the basis of an absence of information on its reproductive anatomy. The type- and only known locality is the island of Mayotte in the Mozambique Channel off Africa. Phylogenies of bipaliine geoplanids were constructed on the basis of SSU, LSU, mitochondrial proteins and concatenated sequences of cox1, SSU and LSU. In all four phylogenies, D. mayottensis was the sister-group to all the other bipaliines. With the exception of D. multilineatum which could not be circularised, the complete mitogenomes of B. kewense, B. vagum, B. adventitium, H. covidum and D. mayottensis were colinear. The 16S gene in all bipaliine species was problematic because usual tools were unable to locate its exact position. Conclusion: Next generation sequencing, which can provide complete mitochondrial genomes as well as traditionally used genes such as SSU, LSU and cox1, is a powerful tool for delineating and describing species of Bipaliinae when the reproductive structure cannot be studied, which is sometimes the case of asexually reproducing invasive species. The unexpected position of the new species D. mayottensis as sister-group to all other Bipaliinae in all phylogenetic analyses suggests that the species could belong to a new genus, yet to be described

    Robustness of the wide-field imaging Mueller polarimetry for brain tissue differentiation and white matter fiber tract identification in a surgery-like environment: an ex vivo study.

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    During neurooncological surgery, the visual differentiation of healthy and diseased tissue is often challenging. Wide-field imaging Muller polarimetry (IMP) is a promising technique for tissue discrimination and in-plane brain fiber tracking in an interventional setup. However, the intraoperative implementation of IMP requires realizing imaging in the presence of remanent blood, and complex surface topography resulting from the use of an ultrasonic cavitation device. We report on the impact of both factors on the quality of polarimetric images of the surgical resection cavities reproduced in fresh animal cadaveric brains. The robustness of IMP is observed under adverse experimental conditions, suggesting a feasible translation of IMP for in vivo neurosurgical applications

    Modelling human choices: MADeM and decision‑making

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    Research supported by FAPESP 2015/50122-0 and DFG-GRTK 1740/2. RP and AR are also part of the Research, Innovation and Dissemination Center for Neuromathematics FAPESP grant (2013/07699-0). RP is supported by a FAPESP scholarship (2013/25667-8). ACR is partially supported by a CNPq fellowship (grant 306251/2014-0)

    Reportage au cœur du laboratoire souterrain de l’Andra

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    Bienvenue au laboratoire souterrain de l’Andra, une installation en perpétuelle évolution située entre les départements de la Meuse et de la Haute-Marne. Le site, creusé dès l’an 2000, permet de préparer la construction et l’exploitation de Cigéo, le projet français de stockage géologique qui pourrait recevoir une autorisation de création en 2027

    Indexation de séquences de descripteurs

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    L'exploitation de documents multimédia est en plein essor. Nous savons maintenant bien exploiter de très grandes bases d'images photographiques et y faire des recherches par le contenu efficaces. L'étape suivante consiste à se tourner vers des documents plus complexes, comme le sont les vidéos et les bandes sonores. Une des principales difficultés afférentes au traitement de tels documents vient de leur caractère temporel. Décrire de l'audio et de la vidéo revient ainsi à fabriquer des séquences de descriptions dont il est important de préserver l'ordre et l'enchaînement. Cette thèse propose deux méthodes d'indexation de documents multimédia séquentiels. La première se base sur l'utilisation de l'alignement dynamique (DTW) pour la comparaison de séquences et propose une méthode présentant des gains significatifs en termes de coût de calcul par rapport aux méthodes existantes. La seconde méthode est appliquée spécifiquement à la recherche de reprises musicales. Il s'agit d'effectuer un premier filtrage des régions temporelles susceptibles d'être mises en correspondance avec la requête, avant d'appliquer une robustification temporelle.Getting information from multimedia documents is a very important field of research. We can now process huge image databases and do effective content-based searches. Processing more complex documents such as video or audio streams appears to be the next step in the development of content-based search tools. Video and audio streams are different as they embed the notion of descriptors sequences, in which the order between described elements is a key. This thesis proposes two indexing methods for temporal multimedia documents. The first one is based on the use of the Dynamic Time Warping (DTW) algorithm to compare sequences. This thesis introduces a method that presents significant improvement in terms of response time when compared to already existing methods. The second one is specifically applied to cover song detection. It consists in a first filtering stage of temporal regions of the database that are possible matches for elements of the query song and a second robustification stage that ensures temporal consistency.RENNES1-BU Sciences Philo (352382102) / SudocSudocFranceF

    Effect of combined stress (salinity and temperature) in European sea bass Dicentrarchus labrax osmoregulatory processes

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    International audienceEuropean sea bass Dicentrarchus Iabrax undertake seasonal migrations to estuaries and lagoons that are characterized by fluctuations in environmental conditions. Their ability to cope with these unstable habitats is undeniable, but it is still not clear how and to what extent salinity acclimation mechanisms are affected at temperatures higher than in the sea. In this study, juvenile sea bass were pre-acclimated to seawater (SW) at 18 degrees C (temperate) or 24 degrees C (warm) for 2 weeks and then transferred to fresh water (FW) or SW at the respective temperature. Transfer to FW for two weeks resulted in decreased blood osmolalities and plasma Cl- at both temperatures. In FW warm conditions, plasma Na+ was similar to 15% lower and Cl- was similar to 32% higher than in the temperate-water group. Branchial Na+/K+-ATPase (NKA) activity measured at the acclimation temperature (V-apparent) did not change according to the conditions. Branchial Na+/K+-ATPase activity measured at 37 degrees C (V-max) was lower in warm conditions and increased in FW compared to SW conditions whatever the considered temperature. Mitochondrion-rich cell (MRC) density increased in FW, notably due to the appearance of lamellar MRCs, but this increase was less pronounced in warm conditions where MRC's size was lower. In SW warm conditions, pavement cell apical microridges are less developed than in other conditions. Overall gill morphometrical parameters (filament thickness, lamellar length and width) differ between fish that have been pre acclimated to different temperatures. This study shows that a thermal change affects gill plasticity affecting whole-organism ion balance two weeks after salinity transfer
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