The fine sugar specificity of the Lathyrus ochrus seed lectin and isolectins

AbstractGlycoproteins and their derived glycopeptides have been used to define the specificity of the Lathyrus ochrus lectin and isolectins, by determining their ability to inhibit the agglutination of human erythrocytes induced by the lectin or isolectins. This α-D-mannose/α-D-glucose-specific lectin possessess the ability to recognize a well-defined saccharide sequence on a bi-antennary N-acetyllactosamine-type glycan. For other Vicieae lectins, the best inhibitor is a glycopeptide from human lactotransferrin with an α-L-fucose residue at the C-6 position on the N-acetylglucosamine residue involved in the N-glycosylamine bond. This fucose seems to be a major determinant of the binding since its removal with an α-L-fucosidase gives glycopeptides 8-fold less inhibitory. Our results confirm that the Vicieae lectins are evolutionarily related proteins even at the level of their binding sites

Do Cities exist in all Shapes and Sizes? An EO based Investigation

In this work, unsupervised clustering on Earth Observation (EO) data was applied to investigate cities' morphology across the globe. Based on 110 cities, we found seven city types of similar morphologic patterns whose geographical distribution underpins the influence of urbanistic culture on the built landscape

Lectins from the Red Marine Algal Species Bryothamnion seaforthii and Bryothamnion triquetrum as Tools to Differentiate Human Colon Carcinoma Cells

The carbohydrate-binding activity of the algal lectins from the closely related red marine algal species Bryothamnion triquetrum (BTL) and Bryothamnion seaforthii (BSL) was used to differentiate human colon carcinoma cell variants with respect to their cell membrane glyco-receptors. These lectins interacted with the cells tested in a dose-dependent manner. Moreover, the fluorescence spectra of both lectins clearly differentiated the cells used as shown by FACS profiles. Furthermore, as observed by confocal microscopy, BTL and BSL bound to cell surface glycoproteins underwent intense internalization, which makes them possible tools in targeting strategies

Hidden magnetism at the pseudogap critical point of a high temperature superconductor

The mysterious pseudogap phase of cuprate superconductors ends at a critical hole doping level p* but the nature of the ground state below p* is still debated. Here, we show that the genuine nature of the magnetic ground state in La2-xSrxCuO4 is hidden by competing effects from superconductivity: applying intense magnetic fields to quench superconductivity, we uncover the presence of glassy antiferromagnetic order up to the pseudogap boundary p* ~ 0.19, and not above. There is thus a quantum phase transition at p*, which is likely to underlie highfield observations of a fundamental change in electronic properties across p*. Furthermore, the continuous presence of quasi-static moments from the insulator up to p* suggests that the physics of the doped Mott insulator is relevant through the entire pseudogap regime and might be more fundamentally driving the transition at p* than just spin or charge ordering.Comment: 26 pages, supplementary info include

Structural basis for both pro- and anti-inflammatory response induced by mannose-specific legume lectin from Cymbosema roseum

Legume lectins, despite high sequence homology, express diverse biological activities that vary in potency and efficacy. In studies reported here, the mannose-specific lectin from Cymbosema roseum (CRLI), which binds N-glycoproteins, shows both pro-inflammatory effects when administered by local injection and anti-inflammatory effects when by systemic injection. Protein sequencing was obtained by Tandem Mass Spectrometry and the crystal structure was solved by X-ray crystallography using a Synchrotron radiation source. Molecular replacement and refinement were performed using CCP4 and the carbohydrate binding properties were described by affinity assays and computational docking. Biological assays were performed in order to evaluate the lectin edematogenic activity. The crystal structure of CRLI was established to a 1.8 Å resolution in order to determine a structural basis for these differing activities. The structure of CRLI is closely homologous to those of other legume lectins at the monomer level and assembles into tetramers as do many of its homologues. The CRLI carbohydrate binding site was predicted by docking with a specific inhibitory trisaccharide. CRLI possesses a hydrophobic pocket for the binding of α-aminobutyric acid and that pocket is occupied in this structure as are the binding sites for calcium and manganese cations characteristic of legume lectins. CRLI route-dependent effects for acute inflammation are related to its carbohydrate binding domain (due to inhibition caused by the presence of α-methyl-mannoside), and are based on comparative analysis with ConA crystal structure. This may be due to carbohydrate binding site design, which differs at Tyr12 and Glu205 position. © 2011 Elsevier Masson SAS. All rights reserved

Analyze of the Relation between Cultural Areas and Urban Morphologies through remote sensing / Analyse des liens entre cultures et formes urbaines par utilisation de télédétection

From one country to the next, from a city to the next, the sensible feeling of the urban atmosphere differs. Shape, forms, shadows, and colors change. But the smaller the distance between two cities, the smaller the differences are. Nowadays, remote-sensing and earth observations products allow an analysis of cities at a global scale. The German Aerospace Center (DLR) recently produced two global datasets on urban morphology: an urban land cover classification and a set of boundaries for cities sprawl. This report presents the outcomes of my final internship at the Earth Observation Center of the DLR supervised by Dr. Hannes Taubenböck. This internship is the ending milestone of my engineer’s curriculum. My main goal during this internship was to develop and apply a framework to process those data in order to analyze the influence of culture on the morphological structure of cities. We led this survey on 110 cities all across the world. We propose here an approach based on an automated GIS preprocessing and an unsupervised clustering of the dataset. K-means and EM proved themselves to suite at best this task. The clustering they hence defined came close to the dividing of cultural spheres proposed by ethnologist and historian. Those results bring a new scope on the typologies of cities at both global and local scales

Contribution a l'etude des modifications affectant les glycannes des N-glycosylproteines membranaires lors de la transformation maligne des cellules et de la diffusion metastatique

SIGLEINIST TD 19509 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

7. Laboratoire de chimie de l'Ecole normale supérieure

Debray Henri. 7. Laboratoire de chimie de l'Ecole normale supérieure. In: Rapport sur l'École pratique des hautes études, 1884-1885. 1884. pp. 33-39

L'utilisation de la stimulation magnétique transcrânienne répétitive associée à une revalidation motrice dans le but d'améliorer les capacités fonctionnelles des patients atteints d'un AVC : revue systématique de littérature

Objectif : Les effets de la stimulation magnétique transcrânienne répétitive (rTMS) sur l’excitabilité corticale motrice commencent à être connus mais ceux-ci ne sont pas suffisants sur le long terme. D’un autre côté, l’exécution d’un acte moteur permet également de stimuler le cortex moteur. L’association des deux approches permettrait de potentialiser les effets de l’une sur l’autre tout en garantissant une sécurité pour le patient. En dressant une analyse de la littérature actuelle, les effets synergiques de ces deux approches ont été synthétisés. Méthode : La sélection des études portait sur l’association de la rTMS combinée avec une rééducation motrice comme thérapie additionnelle, comparée à un groupe contrôle qui recevait de la fausse rTMS. Les évaluations des patients devaient porter sur l’aspect moteur (la préhension et la locomotion). Résultats: Des améliorations significatives ont été constatées pour le groupe interventionnel à tous les stades de l’AVC (aigu, subaigu et chronique). Ces améliorations ont été observées jusqu’à 6 mois après l’intervention pour 89% des études incluses (8 sur 9). Conclusion: D’après les résultats obtenus, on peut affirmer en globalité que la rTMS associée à une rééducation motrice a un rôle certain à jouer dans la récupération fonctionnelle post AVC. Cependant, de nombreuses questions persistent encore sur le protocole idéal de rTMS à adopter ainsi que sur le type d’AVC enclin à la meilleure réponse.Master [60] en kinésithérapie et réadaptation, Université catholique de Louvain, 201