583 research outputs found

    Des modèles biologiques à l'amélioration des plantes

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    An Investigation on the Morphological and Mineralogical Characteristics of Posidonius Floor Fractured Lunar Impact Crater Using Lunar Remote Sensing Data

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    Lunar floor‐fractured craters (FFCs) are a distinguished type of crater found on the surface of the Moon with radial, concentric, and/or polygonal fractures. In the present study, we selected the Posidonius FCC to explore the mineralogy, morphology and tectonic characteristics using remote sensing datasets. The Posidonius crater is vested with a wide moat of lava separating the crater rim inner wall terraces from the fractured central floor. Lunar Reconnaissance Orbiter’s (LRO) images and Digital Elevation Model (DEM) data were used to map the tectonics and morphology of the present study. The Moon Mineralogy Mapper (M3) data of Chandrayaan‐1 were used to inves-tigate the mineralogy of the region through specified techniques such as integrated band depth, band composite and spectral characterization. The detailed mineralogical analysis indicates the nor-itic‐rich materials in one massif among four central peak rings and confirm intrusion (mafic pluton). Spectral analysis from the fresh crater of the Posidonius moat mare unit indicates clinopyroxene pigeonite in nature. Integrated studies of the mineralogy, morphology and tectonics revealed that the study region belongs to the Class‐III category of FFCs. The lithospheric loading by adjacent volcanic load (Serenitatis basin) generates a stress state and distribution of the fracture system

    Preservation of endangered Tunisian grapevine cultivars using embryogenic cultures

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    The preservation of embryogenic lines derived from several endangered local grapevine cultivars was studied. Embryogenic calluses were obtained from immature anthers of eight cultivars, sampled on both fruity-cuttings and field grown vines. Anthers at the 'separated flower' stage, derived from fruity-cuttings, resulted in an increased induction of somatic embryogenesis, compared to those derived from the The preservation of embryogenic lines derived from several endangered local grapevine cultivars was studied. Embryogenic calluses were obtained from immature anthers of eight cultivars, sampled on both fruity-cuttings and field grown vines. Anthers at the 'separated flower' stage, derived from fruity-cuttings, resulted in an increased induction of somatic embryogenesis, compared to those derived from the 15.6% and 34.8% in 'Kahli Kerkennah' and 'Muscat Raf-raf' cultivars, respectively. Although, morphological diversifications of pro-embryogenic calluses (several necrosis and spontaneous maturation) were observed on the induction mediumafter 5 subcultures. The reduction of 2,4-D and TDZ levels to 4.52 \u3bcM and 2.89 \u3bcM respectively, induced granular and yellowish embryogenic material. Thus, Ch\ue9e and Pool (1987) (CP) enriched with 4.52 \u3bcM of 2,4-D and 2.89 \u3bcM of TDZ revealed to be the most appropriate for long-term maintenance. In fact, all the cultivars presented high and regular embryo maturation rates after 12, 24, 36 and 48 months of cultivation on this medium, under light conditions. After 4 years, they still exhibit high germination and regeneration abilities. Germination of somatic embryos was achieved on Murashige and Skoog (1962) basal-medium, with rates ranging from 69% to 96%. Only 5% of somatic embryos were concerned by morphological variations. The regenerated plantlets presented a normal phenotype under controlled greenhouse conditions, compared to mother plants

    Identification of the Cellular Mechanisms That Modulate Trafficking of Frizzled Family Receptor 4 (FZD4) Missense Mutants Associated With Familial Exudative Vitreoretinopathy

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    Citation: Milhem RM, Ben-Salem S, AlGazali L, Ali BR. Identification of the cellular mechanisms that modulate trafficking of frizzled family receptor 4 (FZD4) missense mutants associated with familial exudative vitreoretinopathy. Invest Ophthalmol Vis Sci. 2014;55:3423-3431. DOI:10.1167/ iovs.14-13885 PURPOSE. Fifteen missense mutations in the frizzled family receptor 4 (FZD4) reported to cause familial exudative vitreoretinopathy (FEVR) were evaluated to establish the pathological cellular mechanism of disease and to explore novel therapeutic strategies. METHODS. The mutations were generated by site-directed mutagenesis and expressed in HeLa and COS-7 cell lines. Confocal fluorescence microscopy and N-glycosylation profiling were used to observe the subcellular localization of the mutant proteins relative to wild-type (WT). Polyubiquitination studies were used to establish the involvement of the proteasome. Culturing at reduced temperatures and incubation in the presence of chemical compounds were used to enhance mutant protein processing and exit out of the endoplasmic reticulum (ER). RESULTS. Confocal fluorescence microscopy of the mutants showed three distinct subcellular localizations, namely, a plasma membrane pattern, an ER pattern, and a mixed pattern to both compartments. Confocal fluorescence microscopy and N-glycosylation profiling established the predominant ER localization of P33S, G36N, H69Y, M105T, M105V, C181R, C204R, C204Y, and G488D mutants. Coexpression of these mutants with WT FZD4 showed the inability of the mutants to trap WT FZD4. Culturing the expressing cells at reduced temperatures or in the presence of chemical agents directed at ameliorating protein misfolding resulted in partial rescue of trafficking defects observed for M105T and C204Y mutants. CONCLUSIONS. Defective trafficking resulting in haploinsufficiency is a major cellular mechanism for several missense FEVR-causing FZD4 mutants. Our findings indicate that this trafficking defect might be correctable for some mutants, which may offer opportunities for the development of novel therapeutics approaches for this condition

    SmartEx: a case study on user profiling and adaptation in exhibition booths

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    An investigation into user profiling and adaptation with exhibition booth as a case study is reported. First a review of the field of exhibitions and trade fairs and a summary introduction to adaptation and profiling are given. We then introduce three criteria for the evaluation of exhibition booth: effectiveness, efficiency and affect. Effectiveness is related the amount of information collected, efficiency is a measurement of the time taken to collect the information, and affect is the perception of the experience and the mood booth visitors have during and after their visit. We have selected these criteria to assess adaptive and profiled exhibition booths, we call smart exhibition (SmartEx). The assessment is performed with an experiment with three test conditions (non-profiled/non adaptive, profiled/non-adaptive and profiled adaptive presentations). Results of the experiment are presented along discussion. While there is significant improvements of effectiveness and efficiency between the two-first test conditions, the improvement is not significant for the last test condition, for reasons explained. As for the affect, the results show that it has an under-estimated importance in people minds and that it should be addressed more carefully

    Forecast of the demand for hourly electric energy by artificial neural networks

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    Obtaining an accurate forecast of the energy demand is fundamental to support the several decision processes of the electricity service agents in a country. For market operators, a greater precision in the short-term load forecasting implies a more efficient programming of the electricity generation resources, which means a reduction in costs. In the long term, it constitutes a main indicator for the generation of investment signals for future installed capacity. This research proposes a prognostic model for the demand of electrical energy in Bogota, Colombia at hourly level in a full week, through Artificial Neural Network
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