Evaluation of 3D/2D Imaging and Image Processing Techniques for the Monitoring of Seed Imbibition

Seed imbibition is a very important process in plant biology by which, thanks to a simple water income, a dry seed may turn into a developing organism. In natural conditions, this process occurs in the soil, e.g., with difficult access for a direct observation. Monitoring the seed imbibition with non-invasive imaging techniques is therefore an important and possibly challenging task if one tries to perform it in natural conditions. In this report, we describe a set of four different imaging techniques that enable to addressing this task either in 3D or in 2D. For each technique, the following items are proposed. A detailed experimental protocol is provided to acquire images of the imbibition process. With the illustration of real data, the significance of the physical quantities measured in terms of their relation to the income of water in the seed is presented. Complete image analysis pipelines are then proposed to extract dynamic information on the imbibition process from such monitoring experiments. A final discussion compares the advantages and current limitations of each technique in addition to elements concerning the associated throughput and cost. These are criteria especially relevant in the field of plant phenotyping where large populations of plants are imaged to produce quantitatively significative traits after image processin

Coe Genes Are Expressed in Differentiating Neurons in the Central Nervous System of Protostomes

Genes of the coe (collier/olfactory/early B-cell factor) family encode Helix-Loop-Helix transcription factors that are widely conserved in metazoans and involved in many developmental processes, neurogenesis in particular. Whereas their functions during vertebrate neural tube formation have been well documented, very little is known about their expression and role during central nervous system (CNS) development in protostomes. Here we characterized the CNS expression of coe genes in the insect Drosophila melanogaster and the polychaete annelid Platynereis dumerilii, which belong to different subgroups of protostomes and show strikingly different modes of development. In the Drosophila ventral nerve cord, we found that the Collier-expressing cells form a subpopulation of interneurons with diverse molecular identities and neurotransmitter phenotypes. We also demonstrate that collier is required for the proper differentiation of some interneurons belonging to the Eve-Lateral cluster. In Platynereis dumerilii, we cloned a single coe gene, Pdu-coe, and found that it is exclusively expressed in post mitotic neural cells. Using an original technique of in silico 3D registration, we show that Pdu-coe is co-expressed with many different neuronal markers and therefore that, like in Drosophila, its expression defines a heterogeneous population of neurons with diverse molecular identities. Our detailed characterization and comparison of coe gene expression in the CNS of two distantly-related protostomes suggest conserved roles of coe genes in neuronal differentiation in this clade. As similar roles have also been observed in vertebrates, this function was probably already established in the last common ancestor of all bilaterians

ATLAS Run 1 searches for direct pair production of third-generation squarks at the Large Hadron Collider

This paper reviews and extends searches for the direct pair production of the scalar supersymmetric partners of the top and bottom quarks in proton-proton collisions collected by the ATLAS collaboration during the LHC Run 1. Most of the analyses use 20 fb$^{-1}$ of collisions at a centre-of-mass energy of $\sqrt{s}$ = 8 TeV, although in some case an additional 4.7 fb$^{-1}$ of collision data at $\sqrt{s}$ = 7 TeV are used. New analyses are introduced to improve the sensitivity to specific regions of the model parameter space. Since no evidence of third-generation squarks is found, exclusion limits are derived by combining several analyses and are presented in both a simplified model framework, assuming simple decay chains, as well as within the context of more elaborate phenomenological supersymmetric models

Neurogenèse et architecture du neurectoderme chez l'annélide Platynereis dumerilii

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

HELLSCAPE : Escape game pédagogique sur le thème des fake news

<p>Hellscape est un jeu pédagogique mis en place à la bibliothèque des licences de Sorbonne Université et dérivé de l'univers du jeu vidéo Hellink (https://hellink.fr/). Conçu pour les étudiants de licence mais également proposé dans le cadre de certains masters, il offre une introduction pratique et ludique aux thématiques d'évaluation de la fiabilité des sources et de détection des fausses informations.</p> <p>Ce dépôt contient tous les documents constitutifs du jeu, ainsi qu'un mode d'emploi détaillé permettant sa préparation, mise en place et animation.</p&gt

LA MUSE : Jeu de piste poétique à la bibliothèque Malesherbes

<p>La Muse est un jeu de piste sur le thème de la poésie mis en place à la bibliothèque Malesherbes de Sorbonne Université et utilisé dans le cadre de formation des étudiants ainsi que d'actions culturelles. En lançant les joueurs sur la piste d'une muse à qui ils devront déclamer un poème, ce jeu permet de se familiariser de façon ludique et poétique avec les espaces et les services de la bibliothèque. </p> <p>Ce dépôt contient tous les documents constitutifs du jeu, ainsi qu'un mode d'emploi détaillé permettant sa préparation, mise en place et animation</p&gt

Germ-layer commitment and axis formation in sea anemone embryonic cell aggregates

Significance Embryonic development of any animal species is a robust series of morphogenetic events tightly controlled by molecular signals. However, the variety of developmental trajectories undertaken by different members of the same phylum suggests that normal development in each particular species might involve only a subset of morphogenetic capacities available to the highly developmentally plastic embryonic cells. Here we show that, faced by a new developmental context, the aggregates of dissociated gastrula cells of the sea anemone Nematostella vectensis use an alternative developmental trajectory typical for other, distantly related members of the cnidarian phylum. We conclude that new modes of development may evolve relatively easily due to the versatility and developmental plasticity of embryonic cells. </jats:p