Rôle de l'irradiation de la chaîne mammaire interne après mastectomie dans le cancer du sein

CAEN-BU Médecine pharmacie (141182102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

A Unified French/English Syllabic Model for Handwriting Recognition

International audienceIn this paper we introduce a new unified syllabic model for French and English handwriting recognition, based on hidden Markov models (HMM). The recognition system training and recognition components such as optical models, lexicons and language models are designed to be language independent. In this purpose a syllable based model is proposed for French and English. This model is evaluated and compared to n-gram character and words models. A promising performance is achieved by the syllabic model, which meets the words model performance, with the advantage of a reduced system complexity. Furthermore, the unification of likely similar scripts improves the system performance over all models considering the English and French languages. The French RIMES and the English IAM datasets are used for the evaluation

Change detection for road condition mapping based on dry and rainy season VHR dual-pol radar imagery over tropical areas. Application to Chad

International audienceNew Very High Resolution dual-polarization radar sensors in X-band (TerraSAR-X and Cosmo-Skymed) are offering technical opportunities for the detection of road condition changes between dry and rainy period in tropical areas. We applied classification methods (fuzzy logic and learning algorithms), multi-incidence and optical-radar combination in order to estimate surface elements (relief, flooded areas), soil properties (wetness, surface roughness) and road conditions from multi-date acquisitions over SW Chad. These estimations are calibrated with data measurements on the field. They are included in a road condition service designed for military, humanitarian and industrial logistics

Association of the transcriptional corepressor TIF1β with heterochromatin protein 1 (HP1): an essential role for progression through differentiation

The transcriptional intermediary factor 1β (TIF1β) is a corepressor for KRAB-domain-containing zinc finger proteins and is believed to play essential roles in cell physiology by regulating chromatin organization at specific loci through association with chromatin remodeling and histone-modifying activities and recruitment of heterochromatin protein 1 (HP1) proteins. In this study, we have engineered a modified embryonal carcinoma F9 cell line (TIF1β(HP1box/-)) expressing a mutated TIF1β protein (TIF1β(HP1box)) unable to interact with HP1 proteins. Phenotypic analysis of TIF1β(HP1box/-) and TIF1β(+/-) cells shows that TIF1β–HP1 interaction is not required for differentiation of F9 cells into primitive endoderm-like (PrE) cells on retinoic acid (RA) treatment but is essential for further differentiation into parietal endoderm-like (PE) cells on addition of cAMP and for differentiation into visceral endoderm-like cells on treatment of vesicles with RA. Complementation experiments reveal that TIF1β–HP1 interaction is essential only during a short window of time within early differentiating PrE cells to establish a selective transmittable competence to terminally differentiate on further cAMP inducing signal. Moreover, the expression of three endoderm-specific genes, GATA6, HNF4, and Dab2, is down-regulated in TIF1β(HP1box/-) cells compared with wild-type cells during PrE differentiation. Collectively, these data demonstrate that the interaction between TIF1β and HP1 proteins is essential for progression through differentiation by regulating the expression of endoderm differentiation master players

Selective interaction between the chromatin-remodeling factor BRG1 and the heterochromatin-associated protein HP1α

Mammalian heterochromatin protein 1 (HP1) α, HP1β and HP1γ are closely related non-histone chromosomal proteins that function in gene silencing, presumably by organizing higher order chromatin structures. Here, we show by co-immunoprecipitation that HP1α, but neither HP1β nor HP1γ, forms a complex with the BRG1 chromatin-remodeling factor in HeLa cells. In vitro, BRG1 interacts directly and preferentially with HP1α. The region conferring this preferential binding has been mapped to residues 106–180 of the HP1α C-terminal chromoshadow domain. Using site-directed mutagenesis, we have identified three amino acid residues I113, A114 and C133 in HP1α (K, P and S in HP1β and HP1γ) that are essential for the selective interaction of HP1α with BRG1. Interestingly, these residues were also shown to be critical for the silencing activity of HP1α. Taken together, these results demonstrate that mammalian HP1 proteins are biochemically distinct and suggest an entirely novel function for BRG1 in modulating HP1α-containing heterochromatic structures

TIF1delta, a novel HP1-interacting member of the transcriptional intermediary factor 1 (TIF1) family expressed by elongating spermatids

TIF1 (transcriptional intermediary factor 1) proteins are encoded by an expanding family of developmental and physiological control genes that are conserved from flies to man. These proteins are characterized by an N-terminal RING-B box-coiled-coil (RBCC) motif and a C-terminal PHD finger/bromodomain unit, and have been implicated in epigenetic mechanisms of transcriptional repression involving histone modifiers and heterochromatin-binding proteins. We describe here the isolation and functional characterization of a fourth murine TIF1 gene, TIF1delta. The predicted TIF1delta protein displays all the structural hallmarks of a bona fide TIF1 family member and resembles the other TIF1s in that it can exert a deacetylase-dependent silencing effect when tethered to a promoter region. Moreover, like TIF1alpha and TIF1beta, TIF1delta can homodimerize and contains a PXVXL motif necessary and sufficient for HP1 (heterochromatin protein 1) binding. Although TIF1alpha and TIF1beta also bind nuclear receptors and Kruppel-associated boxes specifically and respectively, TIF1delta appears to lack nuclear receptor- and Kruppel-associated box binding activity. Furthermore, TIF1delta is unique among the TIF1 family proteins in that its expression is largely restricted to the testis and confined to haploid elongating spermatids, where it associates preferentially with HP1 isotype gamma (HP1gamma) and forms discrete foci dispersed within the centromeric chromocenter and the surrounding nucleoplasm. Collectively, these data are consistent with specific, nonredundant functions for the TIF1 family members in vivo and suggest a role for TIF1delta in heterochromatin-mediated gene silencing during postmeiotic phases of spermatogenesis

Characterizing the physical properties of rocks from the Paleozoic to Permo-Triassic transition in the Upper Rhine Graben

International audienceGeothermal energy exploitation in the Upper Rhine Graben currently targets high-temperature anomalies in the crystalline Paleozoic basement at depths up to 5 km. However, at certain locations (e.g. Rittershoffen, France), geothermal installations are actively targeting resources at shallower depths where the Paleozoic granite transitions into the overlying Permo-Triassic sandstones. We here investigate the variation in physical properties—including porosity, P-wave velocity, permeability, uniaxial compressive strength, and thermal properties—in rocks that locally extend across the Paleozoic–Permo-Triassic boundary in four locations to the west of the Upper Rhine Graben. The lithologies investigated include sandstones, breccia, granites, metagranites, dolomite, and altered and unaltered volcanic rocks and represent the variety of lithologies at this transition. We note that while the porosity, permeability, thermal conductivity, and P-wave velocity of the Permo-Triassic sedimentary cover and Paleozoic crystalline basement rocks are consistent with values determined for rocks from exploratory and production boreholes at Soultz-sous-Forêts (France), the other lithologies (belonging to neither the sedimentary nor basement sequences) are conspicuously lower in porosity and permeability. Further, the attendant strength of these other lithologies could make them relatively unamenable to fracturing, reducing the possibility of fracture-controlled permeability in these units. Indeed, we conclude that in areas where these low-permeability and high-strength rocks act to cap the crystalline basement, hydrothermal convection may be curtailed and geothermal exploitation may be rendered untenable