Search results for "Verdi"
showing 10 items of 139 documents
Spatial analysis of traffic accidents near and between road intersections in a directed linear network.
2019
Although most of the literature on traffic safety analysis has been developed over areal zones, there is a growing interest in using the specific road structure of the region under investigation, which is known as a linear network in the field of spatial statistics. The use of linear networks entails several technical complications, ranging from the accurate location of traffic accidents to the definition of covariates at a spatial micro-level. Therefore, the primary goal of this study was to display a detailed analysis of a dataset of traffic accidents recorded in Valencia (Spain), which were located into a linear network representing more than 30 km of urban road structure corresponding t…
Fitness in soil and rhizosphere of Pseudomonas fluorescens C7R12 compared with a C7R12 mutant affected in pyoverdine synthesis and uptake.
2000
International audience; Fluorescent pseudomonads have evolved an efficient strategy of iron uptake based on the synthesis of the siderophore pyoverdine and its relevant outer membrane receptor. The possible implication of pyoverdine synthesis and uptake on the ecological competence of a model strain (Pseudomonas fluorescens C7R12) in soil habitats was evaluated using a pyoverdine minus mutant (PL1) obtained by random insertion of the transposon Tn5. The Tn5 flanking DNA was amplified by inverse PCR and sequenced. The nucleotide sequence was found to show a high level of identity with pvsB, a pyoverdine synthetase. As expected, the mutant PL1 was significantly more susceptible to iron starva…
Protonation of the Biliverdin IXα Chromophore in the Red and Far-Red Photoactive States of a Bacteriophytochrome
2019
The tetrapyrrole chromophore biliverdin IXα (BV) in the bacteriophytochrome from Deinococcus radiodurans (DrBphP) is usually assumed to be fully protonated, but this assumption has not been systematically validated by experiments or extensive computations. Here, we use force field molecular dynamics simulations and quantum mechanics/molecular mechanics calculations with density functional theory and XMCQDPT2 methods to investigate the effect of the five most probable protonation forms of BV on structural stability, binding pocket interactions, and absorption spectra in the two photochromic states of DrBphP. While agreement with X-ray structural data and measured UV/vis spectra suggest that …
Focal lesions in cirrhosis: Not always HCC.
2017
Even though most hepatocellular carcinomas (HCC) develop in the setting of cirrhosis, numerous other focal liver lesions and pseudolesions may be encountered. The role of the radiologist is therefore to differentiate these lesions from HCC to avoid under- and overdiagnosis. There are several ways of classifying these lesions: those which predate the development of fibrosis and cirrhosis (cystic lesions, hemangioma), those related to or a consequence of cirrhosis (regenerative nodules, dysplastic nodules, focal fibrosis, peribiliary cysts, shunts, or even cholangiocarcinoma), and those related to the underlying cause of chronic liver disease (lymphoma). Finally, some may develop independentl…
Les dynamiques du périurbain dijonnais entre 1990 et 1999
2009
Un étalement urbain accompagne désormais la croissance des villes, notamment les plus grandes. Principalement expliqué par un desserrement résidentiel, il est aussi la résultante des dynamiques de centralisation de l’emploi et de spécialisation des zones d’activité à l’intérieur des aires urbaines. L’exemple dijonnais met bien en lumière ce double mouvement qui affecte les communes de sa périphérie et contribue à accroître les mobilités. Urban sprawl arises from the growth of cities, especially of the biggest cities. This urban sprawl is accounted for mainly by residential clearing. It results also from the dynamics of centralization of employment and from specialization of activity zones i…
Investigation of the physiological impact and the mode of action of the pyoverdine from Pseudomonas fluorescens on Arabidopsis thaliana : links with …
2015
Siderophores are strong iron chelators produced by bacteria under iron deficiency conditions. In the present work, we studied the impact of the siderophore pyoverdine, produced by the plant growth promoting rhizobacteria Pseudomonas fluorescens C7R12, on plant physiology from phenotypic to molecular effects with a specific focus on plant growth, immune response and iron homeostasis. Based on our analysis of the mode of action of the non-protein amino acid β-aminobutyric acid (BABA), a priming inducer in plants, we studied more specifically the functional link between iron homeostasis and plant immunity. Under iron deficiency, P. fluorescens excretes the iron free form of pyoverdine (apo-pyo…
Analyzing chemical changes in verdigris pictorial specimens upon bacteria and fungi biodeterioration using voltammetry of microparticles
2017
[EN] It is reported the application of the voltammetry of microparticles (VMP), complemented with attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and field emission scanning electron microscopy (FESEM) techniques, to monitor the deterioration of verdigris pictorial specimens under the action of different biological agents. This methodology would be of application for identifying the type of biological agent causing deterioration of paintings, which is an important problem affecting cultural heritage. The analysis of biodeterioration processes is complicated by the fact that the action of microorganisms can affect both pigment and binding media. The deteriorat…
Tracking Changes in Protonation and Conformation during Photoactivation of a Phytochrome Protein
2016
Phytochromes are photosensor proteins in plants and bacteria. The biological response is mediated by structural changes that follow photon absorption in the protein complex. The initial step is the photoisomerization of the biliverdin chromophore. How this leads to large-scale structural changes of the whole complex is, however, poorly understood. In this work, we use molecular dynamics (MD) simulations to investigate the structural changes after isomerization. In particular, we perform MD simulations at constant pH, using a recently developed method, to explore the effect of chromophore isomerization on the protonation (pKa) of nearby residues. In addition, we use a hybrid quantum mechanic…
Identification of inorganic pigments from paintings and polychromed sculptures immobilized into polymer film electrodes by stripping differential pul…
2000
Abstract Inorganic pigments in paintings and polychromed sculptures are studied by cyclic voltammetry and differential pulse stripping voltammetry using micro-sample coatings in Paraloid B72-film modified electrodes. Characteristic cathodic and anodic differential pulse profiles were obtained in the +0.4 to −1.0 V vs. SCE potential range for different cadmium, copper, lead, mercury and zinc pigments used in traditional colour palettes. Under optimized conditions, excellent reproducibility was obtained. Microsamples extracted from polychromed sculptures, wall paintings, canvas paintings, panel paintings and altarpieces from Spain, Ethiopia and Italy from the 12th to the 20th centuries have b…
Children may not benefit from neuroblastoma screening at 1 year of age. Updated results of the population based controlled trial in Germany
2003
Neuroblastoma is the second most frequent malignancy in childhood. We investigated whether screening for neuroblastoma at 1 year of age reduces the incidence of metastatic disease or mortality. Screening was offered in 6 of the 16 German states from 1995 to 2000 with the remaining states serving as controls. We studied 2,581,188 children in the screening area born between 1994 and 1999 and 2,117,600 in the control area. We compared mortality from neuroblastoma and the incidence of disseminated disease in the two groups. The screened group and the control group had similar rates of stage 4 neuroblastoma and mortality due to neuroblastoma. Comparison of the screened group and the control area…