43 research outputs found
Theano: new features and speed improvements
Theano is a linear algebra compiler that optimizes a user's
symbolically-specified mathematical computations to produce efficient low-level
implementations. In this paper, we present new features and efficiency
improvements to Theano, and benchmarks demonstrating Theano's performance
relative to Torch7, a recently introduced machine learning library, and to
RNNLM, a C++ library targeted at recurrent neural networks.Comment: Presented at the Deep Learning Workshop, NIPS 201
Isolation of nuclear proteins from flax (Linum usitatissimum L.) seed coats for gene expression regulation studies
<p>Abstract</p> <p>Background</p> <p>While seed biology is well characterized and numerous studies have focused on this subject over the past years, the regulation of seed coat development and metabolism is for the most part still non-elucidated. It is well known that the seed coat has an essential role in seed development and its features are associated with important agronomical traits. It also constitutes a rich source of valuable compounds such as pharmaceuticals. Most of the cell genetic material is contained in the nucleus; therefore nuclear proteins constitute a major actor for gene expression regulation. Isolation of nuclear proteins responsible for specific seed coat expression is an important prerequisite for understanding seed coat metabolism and development. The extraction of nuclear proteins may be problematic due to the presence of specific components that can interfere with the extraction process. The seed coat is a rich source of mucilage and phenolics, which are good examples of these hindering compounds.</p> <p>Findings</p> <p>In the present study, we propose an optimized nuclear protein extraction protocol able to provide nuclear proteins from flax seed coat without contaminants and sufficient yield and quality for their use in transcriptional gene expression regulation by gel shift experiments.</p> <p>Conclusions</p> <p>Routinely, around 250 ÎŒg of nuclear proteins per gram of fresh weight were extracted from immature flax seed coats. The isolation protocol described hereafter may serve as an effective tool for gene expression regulation and seed coat-focused proteomics studies.</p
Theano: new features and speed improvements.
Abstract Theano is a linear algebra compiler that optimizes a user's symbolically-specified mathematical computations to produce efficient low-level implementations. In this paper, we present new features and efficiency improvements to Theano, and benchmarks demonstrating Theano's performance relative to Torch7, a recently introduced machine learning library, and to RNNLM, a C++ library targeted at recurrent neural networks
Expression and implication of clusterin in left ventricular remodeling after myocardial infarction
International audienceBACKGROUND: Left ventricular remodeling (LVR) after myocardial infarction is associated with an increased risk of heart failure and death. In spite of a modern therapeutic approach, LVR remains relatively frequent and difficult to predict in clinical practice. Our aim was to identify new biomarkers of LVR and understand their involvement in its development.METHODS AND RESULTS:Proteomic analysis of plasma from the REVE-2 study (Remodelage Ventriculaire)-a study dedicated to the analysis of LVR which included 246 patients after a first anterior myocardial infarction-identified increased plasma levels of CLU (clusterin) in patients with high LVR. We used a rat model of myocardial infarction to analyze CLU expression in the LV and found a significant increase that was correlated with LVR parameters. We found increased CLU expression and secretion in primary cultures of rat neonate cardiomyocytes hypertrophied by isoproterenol. Silencing of CLU in hypertrophied neonate cardiomyocytes induced a significant decrease in cell size, ANP (atrial natriuretic peptide), and BNP (B-type natriuretic peptide) expression, associated with a decreased ERK (extracellular signal-regulated kinase) 1/2 activity, suggesting a prohypertrophic role of CLU. We then confirmed a significant increase of both intracellular p-CLU (precursor form of CLU) and m-CLU (mature form of CLU) in failing human hearts. Finally, the circulating levels of CLU (secreted form) were increased in patients with chronic heart failure who died from cardiovascular cause during a 3-year follow-up (n=99) compared with survivors (n=99).CONCLUSIONS: Our results show for the first time that plasma CLU levels are associated with LVR post-myocardial infarction, have in part a cardiac origin, and are a predictor of early death in heart failure patients
Identification by NMR and accumulation of a neolignan, the dehydrodiconiferyl alcohol-4-ÎČ-d-glucoside, in <i>Linum usitatissimum</i> cell cultures
Régulation transcriptionnelle de la biosynthÚse des lignanes du lin (Linum usitatissimum et Linum flavum) et amélioration de l'extraction des lignanes
Les lignanes sont des mĂ©tabolites secondaires vĂ©gĂ©taux, dont la fonction biologique reste aujourd hui inconnue in planta, mais qui prĂ©sentent un intĂ©rĂȘt en santĂ© humaine. Cette Ă©tude vise Ă progresser dans la connaissance de la fonction des lignanes dans la plante en Ă©tudiant la rĂ©gulation de la biosynthĂšse de ces molĂ©cules. Cette Ă©tude a Ă©tĂ© menĂ©e chez des lins : Linum usitatissimum (espĂšce cultivĂ©e) et Linum flavum (espĂšce sauvage). Chez Linum usitatissimum, la rĂ©gulation spatio-temporelle de la biosynthĂšse des lignanes a Ă©tĂ© Ă©tablie et il a Ă©tĂ© dĂ©montrĂ© que l acide abscissique rĂ©gulait la biosynthĂšse des lignanes dans la graine. Chez Linum flavum, un gĂšne clĂ© dans la production de lignanes a Ă©tĂ© isolĂ© et la rĂ©gulation spatiotemporelle de la biosynthĂšse des lignanes a Ă©tĂ© Ă©tablie. Un protocole amĂ©liorĂ© d extraction de sĂ©coisolaricirĂ©sinol utilisant une cellulase a Ă©tĂ© mis au point Ă partir de tĂ©guments de graines de Linum usitatissimum. Enfin de nouvelles sources de lignanes cytotoxiques parmi les Juniperus et Callitris ont Ă©tĂ© identifiĂ©es, et l extraction de ces composĂ©s Ă partir de feuilles a Ă©tĂ© optimisĂ©e.Lignans are plant secondary metabolites whose in planta biological function is still unknown but are of interest for human health. This work aims at understanding the function of plant lignans through the study of the lignans biosynthesis regulation. This study was conducted in flax: Linum usitatissimum (cultivated species) and Linum flavum (wild species). In Linum usitatissimum, spatial and temporal regulation of lignans biosynthesis has been established and it has been shown that abscisic acid regulates the lignan biosynthesis in seed coats. In Linum flavum, a key gene of lignans production has been isolated, spatial and temporal regulation of lignans biosynthesis has been established. An improved protocol for secoisolariciresinol extraction from Linum usitatissimum seed teguments involving the use of a cellulase was developed. Finally new sources of cytotoxic lignans were identified among Juniperus and Callitris species and extraction from leaves was optimized.ORLEANS-SCD-Bib. electronique (452349901) / SudocSudocFranceF
Régulation de la biosynthÚse des lignanes chez le Lin oléagineux (Linum usitatissimum)
Les graines de lin (Linum usitatissimum) accumulent de grandes quantités de SDG, un lignane phyto-oestrogÚne possédant des propriétés biologiques intéressantes pour la santé humaine, mais dont le rÎle in planta reste inconnu. Comme la lignine, les lignanes sont issus de la polymérisation des monolignols, et l'enzyme clef de la synthÚse des lignanes du lin est la Pinorésinol-Laricirésinol Réductase (PLR). Ce travail a conduit à l isolement de séquences codantes et promotrice de gÚnes de la biosynthÚse des lignanes, dont celui codant la PLR. Cela a permis d'étudier ensuite la régulation de l expression des gÚnes de synthÚse des lignanes. Cette étude, ainsi que des dosages d'activités enzymatiques et de produits finaux, permet d'avoir un aperçu de la répartition des monolignols au cours du développement et sous l'influence d'éliciteurs fongiques.ORLEANS-BU Sciences (452342104) / SudocSudocFranceF
Militantisme associatif
Fragen an vereine
In einem Umfeld des Ăbergangs von der Regierung zur «Governance» wird der dritte Sektor aufgefordert als Folge des Auftretens von neuen soczialen Bewegungen. Der Autor befragt das Vereinswesen in seinen fruchtbaren Zweideutigkeiten zwischen Markt, staatlicher Zuweisung und kollektiver Aktion.Associative militancy
FrĂ©dĂ©ric Lamblin and Carole Saleres try to answer a fundamental question : How to incite young people to get more involved in associations ? Setting out the challenges that the associations must take up to ensure a renewal and rejuvenation of their leaders and members, the authors analyse the youth commitment from a grid including the catalyst elements of contribution and the brakes on involvement, a grid based on an investigation carried out with associations, members of the CNAJEP.FrĂ©dĂ©ric Lamblin et Carole Saleres tentent de rĂ©pondre Ă une question fondamentale : comment inciter les jeunes Ă sâimpliquer davantage dans les associations ? Posant dâemblĂ©e les dĂ©fis que les associations doivent relever pour assurer un renouvellement et un rajeunissement de leurs cadres et de leurs adhĂ©rents, les auteurs analysent lâengagement des jeunes Ă partir dâune grille comprenant les Ă©lĂ©ments catalyseurs de lâinvestissement et les freins Ă lâimplication, grille issue dâun travail dâenquĂȘte menĂ©e auprĂšs dâassociations membres du CNAJEP.Militantismo asociativo
Frederic Lamblin y Carole Saleres intentan responder a una cuestiĂłn fundamental : Âż CĂłmo incitar a los jĂłvenes a implicarse aĂșn mĂĄs en las asociaciones ? Planteando en primera instancia los retos que las asociaciones deben aceptar para asegurar una renovaciĂłn y un rejuvenecimiento de sus directivos y de sus afiliados, los autores analizan el compromiso de los jĂłvenes a partir de una parrilla compuesta por los elementos catalizadores del compromiso y los frenos a la implicaciĂłn, parrilla elaborada en un trabajo de sondeo llevado a cabo ante asociaciones miembros del CNAJEP.Lamblin FrĂ©dĂ©ric, Saleres Carole, Ragi Tariq, Labadie Francine. Militantisme associatif . In: Agora dĂ©bats/jeunesses, 31, 2003. Lâengagement syndical et associatif des jeunes. pp. 28-39
IntĂ©rĂȘt des lignanes dans la prĂ©vention et le traitement de cancers
Les lignanes sont des polyphĂ©nols sâaccumulant dans les tissus ligneux, les graines et les racines de nombreuses plantes. Ces molĂ©cules, vraisemblablement impliquĂ©es dans les mĂ©canismes de dĂ©fense chez la plante, sont Ă©galement utiles pour lâhomme. Les lignanes du lin (Linum usitatissimum L.) sont des phyto-ĆstrogĂšnes, qui, mĂ©tabolisĂ©s en entĂ©rolignanes aprĂšs leur ingestion par les mammifĂšres, offrent une protection face Ă lâapparition et au dĂ©veloppement de certains cancers hormono-dĂ©pendants. Les Ă©tudes menĂ©es in vitro sur des modĂšles cellulaires de mammifĂšres tendent Ă confirmer les effets bĂ©nĂ©fiques observĂ©s lors dâĂ©tudes Ă©pidĂ©miologiques et apportent des Ă©clairages sur leurs mĂ©canismes dâaction. Par ailleurs, le plus Ă©tudiĂ© des lignanes, la podophyllotoxine, et ses dĂ©rivĂ©s hĂ©misynthĂ©tiques, dont lâĂ©toposide, ont des propriĂ©tĂ©s cytotoxiques utilisĂ©es en chimiothĂ©rapie anti-cancĂ©reuse. Leur mĂ©canisme dâaction bien connu passe par une interaction avec la topo-isomĂ©rase II. Lâutilisation accrue de ces drogues anticancĂ©reuses risque cependant de conduire Ă un problĂšme dâapprovisionnement en podophyllotoxine, principalement extraite des rhizomes et racines dâune plante himalayenne en voie de rarĂ©faction, Podophyllum hexandrum. DiffĂ©rentes stratĂ©gies sont envisagĂ©es pour obtenir des sources alternatives de podophyllotoxine Ă©conomiquement viables. Une espĂšce amĂ©ricaine de podophylle (P. peltatum) et certaines espĂšces de lin sauvages (L. flavum, L. album) sont des candidats intĂ©ressants pour une production de podophyllotoxine ou de dĂ©rivĂ©s proches Ă partir de la plante entiĂšre ou de cultures in vitro