A Sketch-Based Interface for Annotation of 3D Brain Vascular Reconstructions

Within the medical imaging community, 3D models of anatomical structures are now widely used in order to establish more accurate diagnoses than those based on 2D images. Many research works focus on an automatic process to build such 3D models. However automatic reconstruction induces many artifacts if the anatomical structure exhibits tortuous and thin parts (such as vascular networks) and the correction of these artifacts involves 3D-modeling skills and times that radiologists do not have. This article presents a semi-automatic approach to build a correct topology of vascular networks from 3D medical images. The user interface is based on sketching; user strokes both defines a command and the part of geometry where the command is applied to. Moreover the user-gesture speed is taken into account to adjust the command: a slow and precise gesture will correct a local part of the topology while a fast gesture will correct a larger part of the topology. Our system relies on an automatic segmentation that provides a initial guess that the user can interactively modify using the proposed set of commands. This allows to correct the anatomical aberrations or ambiguities that appear on the segmented model in a few strokes.Dans le domaine de l'imagerie médicale, la modélisation 3D de structures anatomiques est maintenant largement utilisée dans l'optique d'é}tablir des diagnostics plus précis qu'avec des données basées sur des images 2D. Aujourd'hui, de nombreux travaux mettent l'accent sur les méthodes automatique de reconstruction de modèles 3D mais ces méthodes induisent de nombreuses erreurs. Avec une structure anatomique (réseau cérébral) présente des parties assez fines et tortueuses, des erreurs sont introduites, cela nécessitent de la correction du modèle 3D, mais aussi des compétences et des heures que les radiologistes ne possèdent pas. Cet article présente une approche semi-automatique de reconstruction d'une topologie correcte de réseaux vasculaires issus d'images médicales en 3D. Notre système repose sur une segmentation automatique qui fournit une estimation initiale dont l'utilisateur peut modifier interactivement en utilisant un jeu proposé de commandes basées sur le croquis. Cela permet de corriger les aberrations anatomiques ou les ambiguïtés qui apparaissent sur le modèle segmenté en quelques traits

First evidence of mutualism between ancient plant lineages (Haplomitriopsida liverworts) and Mucoromycotina fungi and its response to simulated Palaeozoic changes in atmospheric CO2

© 2014 The Authors. New Phytologist © 2014 New Phytologist Trust. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. The attached file is the published version of the article

Rapid Evolution of Enormous, Multichromosomal Genomes in Flowering Plant Mitochondria with Exceptionally High Mutation Rates

A pair of species within the genus Silene have evolved the largest known mitochondrial genomes, coinciding with extreme changes in mutation rate, recombination activity, and genome structure

A Sketch-Based Interface for Annotation of 3D Brain Vascular Reconstructions

International audienceWithin the medical imaging community, 3D models of anatomical structures are now widely used in order to establish more accurate diagnoses than those based on 2D images. Many research works focus on an automatic process to build such 3D models. However automatic reconstruction induces many artifacts if the anatomical structure exhibits tortuous and thin parts (such as vascular networks) and the correction of these artifacts involves 3D-modeling skills and times that radiologists do not have. This article presents a semi-automatic approach to build a correct topology of vascular networks from 3D medical images. The user interface is based on sketching; user strokes both defines a command and the part of geometry where the command is applied to. Moreover the user-gesture speed is taken into account to adjust the command: a slow and precise gesture will correct a local part of the topology while a fast gesture will correct a larger part of the topology. This allows to correct the anatomical aberrations or ambiguities that appear on the segmented model in a few strokes

Pterostylis nutans (Orchidaceae) has a specific association with two ceratobasidium root-associated fungi across its range in eastern Australia

In this study, we have identified the root-associated fungi of a common species of terrestrial orchid across its range in eastern Australia. We have amplified and cloned fungal ITS DNA extracted from roots of 15 Pterostylis nutans R. Br. plants from six separate geographic localities. Sequencing and GenBank comparison demonstrated two species of Ceratobasidium fungi as the main fungal partners of the orchid. Uncommon fungal associates included homobasidiomycete species such as a Gymnomyces sp. and a Tricholoma sp., Leptodontidium orchidicola, and an unidentified soil fungus. These results demonstrate that specifi city for fungal partners occurs in P. nutans and reinforces the idea that conservation measures for endangered Australian orchids must include ex situ perpetuation of fungal symbionts as well as plant material

Posttraumatic anger: a confirmatory factor analysis of the Dimensions of Anger Reactions Scale-5 (DAR-5) – French adaptation

Background: Research has shown that posttraumatic anger is common after a traumatic experience, represents a risk factor for post-trauma psychopathology, and can be screened for using the Dimensions of Anger Reactions Scale-5 (DAR-5), a concise five-item measure. However, a French version of the DAR-5 is not yet available. Objective: We aimed to provide a French adaptation (DAR-5-F) and to replicate, in a French community sample, the psychometric properties of the original DAR-5. Method: After translation using transcultural psychometric principles, the DAR-5-F was presented to 822 fluent French speakers alongside validated scales of anger (State-Trait Anger Expression Inventory-2), anxiety and depression (Hospital Anxiety and Depression Scale), alcohol misuse (Alcohol Use Disorders Identification Test-Consumption), and trauma exposure (Life Events Checklist-5). Results: Confirmatory factor analyses confirmed that DAR-5-F scores fit a single-factor model as described with the English version of the scale. The scale showed noteworthy internal consistency and robust convergent validity with trait anger. The screening DAR-5-F cut-off of ≥12 successfully differentiated high from low scores of STAXI-2, anxiety, depression, and traumatic exposure. Conclusions: The DAR-5 is a robust, psychometrically strong brief scale of anger useful for post-trauma screening, with the DAR-5-F now available for use in French-speaking populations. Future research that examines relationships between the DAR-5-F and variables such as trauma severity and posttraumatic stress symptoms will further improve our understanding of these phenomena

Regards croisés sur les pandémies: Écologie, évolution et sociétés

International audienceLa grave crise pandémique que nous vivons n’est pas seulement sanitaire, elle est aussi écologique et sociale. Si elle remet en cause le dualisme nature/culture, elle appelle également à renouveler les rapports qu’entretiennent science et société. Changement d’usage des terres, déforestation et fragmentation, élevage intensif, exploitation minière ou forestière, chasse, urbanisation, diminution de la biodiversité : autant d’éléments qui perturbent la faune sauvage, et favorisent les transferts de pathogènes entre espèces. La mondialisation des échanges rend ensuite possible la diffusion de virus à l’échelle planétaire.Mais les sociétés humaines ne sont pas toutes égales face au risque infectieux. Il y a à cela des causes génétiques, parce que les populations humaines ne sont pas génétiquement uniformes et que les pathogènes ont une grande capacité d’adaptation, mais aussi des causes culturelles et sociales, en raison du rôle majeur des comportements. Si les épidémies d’ampleur sont relativement fréquentes dans l’histoire humaine, celles du passé, et leur gestion par les sociétés d’alors, ne sont que depuis peu étudiées en profondeur. Or cette étude est un élément indispensable pour modéliser, et donc prévoir, l’évolution de la pandémie actuelle comme des prochaines, et l’impact qu’elles auront sur nos sociétés.L’Institut Écologie et Environnement du CNRS, dont l’objectif est de répondre aux enjeux planétaires posés par le changement global aux interfaces entre les sciences de la Terre, de la vie, de l’Homme et de la société, réunit toutes les compétences nécessaires pour étudier cet ensemble