161 research outputs found

    Effect of different 3’ flanking regions on the activity of the Vitis vinifera alcohol dehydrogenase 2 promoter

    Get PDF
    3’untranslated regions (3' UTR) are isogene specific regions which contain sequences likely playing an important role in gene expression. To evaluate the importance of these regions on Vitis vinifera alcohol dehydrogenase 2 (VvAdh2) expression, we designed expression cassettes containing the luciferase reporter gene under the VvAdh2 or CaMV 35S promoters and flanked by different 3’ UTRs. Luciferase activity monitoring was performed through transient expression experiments, using biolistic on Cabernet Sauvignon suspension cells. Results showed that absence of the 3’ region had a strong down-regulating effect on the VvAdh2 promoter activity (but not on the CaMV 35S promoter activity). The nature of the flanking 3' UTR was shown to influence expression cassette activity. Whatever the promoter, VvAdh1 and VvAdh2 terminators had similar effect on expression of luciferase in air leading to an activity level very close to that of CaMV 35S terminator. Under anaerobiosis, luciferase expression was strongly increased with all terminators, VvAdh6 3'-end inducing the highest level of expression. Functional constructs with VvAdh2 promoter and VvAdh terminators designed in this study could be used wherever grapevine-homologous, stress-stimulated cassettes should be of interest

    Above-ground biomass and productivity in a rain forest of eastern South America

    Get PDF
    Abstract: The dynamics of tropical forest woody plants was studied at the Nouragues Field Station, central French Guiana. Stem density, basal area, above-ground biomass and above-ground net primary productivity, including the contribution of litterfall, were estimated from two large permanent census plots of 12 and 10 ha, established on contrasting soil types, and censused twice, first in 1992Âż1994, then again in 2000Âż2002. Mean stem density was 512 stems haÂż1 and basal area, 30m2 haÂż1. Stem mortality rate ranged between 1.51% and 2.06% yÂż1. In both plots, stem density decreased over the study period. Using a correlation between wood density and wood hardness directly measured by a Pilodyn wood tester,we found that the mean wood densitywas 0.63 g cmÂż3, 12% smaller than the mean of wood density estimated from the literature values for the species occurring in our plot. Above-ground biomass ranged from 356 to 398MghaÂż1 (oven-dry mass), and it increased over the census period. Leaf biomass was 6.47Mg haÂż1. Our total estimate of aboveground net primary productivity was 8.81 MgC haÂż1 yÂż1 (in carbon units), not accounting for loss to herbivory, branchfalls, or biogenic volatile organic compounds, whichmay altogether account for an additional 1MgC haÂż1 yÂż1. Coarse wood productivity (stem growth plus recruitment) contributed to 4.16 MgC haÂż1 yÂż1. Litterfall contributed to 4.65MgC haÂż1 yÂż1 with 3.16 MgC haÂż1 yÂż1 due to leaves, 1.10 MgC haÂż1 yÂż1 to twigs, and 0.39MgC haÂż1 yÂż1 to fruits and flowers. The increase in above-ground biomass for both trees and lianas is consistentwith the hypothesis of a shift in the functioning of Amazonian rain forests driven by environmental changes, although alternative hypotheses such as a recovery from past disturbances cannot be ruled out at our site, as suggested by the observed decrease in stem density. Key Words: above-ground biomass, carbon, French Guiana, net primary productivity, tropical fores

    Phthalates: Potential sources and control measures

    Get PDF
    The issue of endocrine disruptors is a subject of debate in the agri-food sector and questioning for consumers through the media. Among these compounds, some of the family of phthalates, are used in the composition of some materials used in wineries. This makes it a worrying issue in terms of image and safety. The objective ok this work was to identify the sources of phthalates and the factors favoring their diffusion in wines to propose preventive and curative solutions to the wine makers. The modalities were therefore selected in different French wine regions to represent the diversity of oenological practices. This survey also led to examine more thoroughly the parameters involved in the situations that favored migration of the highest levels. Additional experiments were performed specifically on certain sources or contributing factors. The first identified sources include epoxy resin, fiberglass reinforced polyester as well as PVC materials (pipes …). Favorable factors include alcohol content, temperature, duration and contact area

    A High Statistics Search for Ultra-High Energy Gamma-Ray Emission from Cygnus X-3 and Hercules X-1

    Full text link
    We have carried out a high statistics (2 Billion events) search for ultra-high energy gamma-ray emission from the X-ray binary sources Cygnus X-3 and Hercules X-1. Using data taken with the CASA-MIA detector over a five year period (1990-1995), we find no evidence for steady emission from either source at energies above 115 TeV. The derived upper limits on such emission are more than two orders of magnitude lower than earlier claimed detections. We also find no evidence for neutral particle or gamma-ray emission from either source on time scales of one day and 0.5 hr. For Cygnus X-3, there is no evidence for emission correlated with the 4.8 hr X-ray periodicity or with the occurrence of large radio flares. Unless one postulates that these sources were very active earlier and are now dormant, the limits presented here put into question the earlier results, and highlight the difficulties that possible future experiments will have in detecting gamma-ray signals at ultra-high energies.Comment: 26 LaTeX pages, 16 PostScript figures, uses psfig.sty to be published in Physical Review

    Epidemiology, Molecular Characterization and Antibiotic Resistance of Neisseria meningitidis from Patients ≤15 Years in Manhiça, Rural Mozambique

    Get PDF
    BACKGROUND: The epidemiology of meningococcal disease in Mozambique and other African countries located outside the "meningitis belt" remains widely unknown. With the event of upcoming vaccines microbiological and epidemiological information is urgently needed. METHODS: Prospective surveillance for invasive bacterial infections was conducted at the Manhiça District hospital (rural Mozambique) among hospitalized children below 15 years of age. Available Neisseria meningitidis isolates were serogrouped and characterized by Multilocus Sequence Typing (MLST). Antibiotic resistance was also determined. RESULTS: Between 1998 and 2008, sixty-three cases of confirmed meningococcal disease (36 meningitis, 26 sepsis and 1 conjunctivitis) were identified among hospitalized children. The average incidence rate of meningococcal disease was 11.6/100,000 (8/100,000 for meningitis and 3.7/100,000 for meningococcemia, respectively). There was a significant rise on the number of meningococcal disease cases in 2005-2006 that was sustained till the end of the surveillance period. Serogroup was determined for 43 of the 63 meningococcal disease cases: 38 serogroup W-135, 3 serogroup A and 2 serogroup Y. ST-11 was the most predominant sequence type and strongly associated with serogroup W-135. Two of the three serogroup A isolates were ST-1, and both serogroup Y isolates were ST-175. N. meningitidis remained highly susceptible to all antibiotics used for treatment in the country, although the presence of isolates presenting intermediate resistance to penicillin advocates for continued surveillance. CONCLUSIONS: Our data show a high rate of meningococcal disease in Manhiça, Mozambique, mainly caused by serogroup W-135 ST-11 strains, and advocates for the implementation of a vaccination strategy covering serogroup W-135 meningococci in the country

    Genetic diversity, linkage disequilibrium and power of a large grapevine (Vitis vinifera L) diversity panel newly designed for association studies

    Get PDF
    UMR-AGAP Equipe DAVV (Diversité, adaptation et amélioration de la vigne) ; équipe ID (Intégration de Données)International audienceAbstractBackgroundAs for many crops, new high-quality grapevine varieties requiring less pesticide and adapted to climate change are needed. In perennial species, breeding is a long process which can be speeded up by gaining knowledge about quantitative trait loci linked to agronomic traits variation. However, due to the long juvenile period of these species, establishing numerous highly recombinant populations for high resolution mapping is both costly and time-consuming. Genome wide association studies in germplasm panels is an alternative method of choice, since it allows identifying the main quantitative trait loci with high resolution by exploiting past recombination events between cultivars. Such studies require adequate panel design to represent most of the available genetic and phenotypic diversity. Assessing linkage disequilibrium extent and panel power is also needed to determine the marker density required for association studies.ResultsStarting from the largest grapevine collection worldwide maintained in Vassal (France), we designed a diversity panel of 279 cultivars with limited relatedness, reflecting the low structuration in three genetic pools resulting from different uses (table vs wine) and geographical origin (East vs West), and including the major founders of modern cultivars. With 20 simple sequence repeat markers and five quantitative traits, we showed that our panel adequately captured most of the genetic and phenotypic diversity existing within the entire Vassal collection. To assess linkage disequilibrium extent and panel power, we genotyped single nucleotide polymorphisms: 372 over four genomic regions and 129 distributed over the whole genome. Linkage disequilibrium, measured by correlation corrected for kinship, reached 0.2 for a physical distance between 9 and 458 Kb depending on genetic pool and genomic region, with varying size of linkage disequilibrium blocks. This panel achieved reasonable power to detect associations between traits with high broad-sense heritability (> 0.7) and causal loci with intermediate allelic frequency and strong effect (explaining > 10 % of total variance).ConclusionsOur association panel constitutes a new, highly valuable resource for genetic association studies in grapevine, and deserves dissemination to diverse field and greenhouse trials to gain more insight into the genetic control of many agronomic traits and their interaction with the environment

    Low incidence of SARS-CoV-2, risk factors of mortality and the course of illness in the French national cohort of dialysis patients

    Get PDF

    Toward osteogenic differentiation of marrow stromal cells and in vitro production of mineralized extracellular matrix onto natural scaffolds

    Get PDF
    Uncorrected proofTissue engineering has emerged as a new interdisciplinary field for the repair of various tissues, restoring their functions by using scaffolds, cells, and/or bioactive factors. A temporary scaffold acts as an extracellular matrix analog to culture cells and guide the development of new tissue. In this chapter, we discuss the preparation of naturally derived scaffolds of polysaccharide origin, the osteogenic differentiation of mesenchymal stem cells cultured on biomimetic calcium phosphate coatings, and the delivery of biomolecules associated with extracellular matrix mineralization
    • …
    corecore