Search results for "focal"
showing 10 items of 803 documents
Increased electron donor and electron acceptor characters enhance the adhesion between oil droplets and cells of Yarrowia lipolytica as evaluated by …
2003
International audience; The adhesion of methyl ricinoleate droplets to cells of the yeast Yarrowia lipolytica was investigated. A new cytometric method, relying on the double staining of fatty globules with Nile Red and of cells with Calcofluor, enabled us to quantify methyl ricinoleate droplet adhesion to cells precultured on a hydrophilic or on a hydrophobic carbon source. In this last case, droplet adsorption was enhanced and a MATS (microbial adhesion to solvents) test revealed that this increase was due to Lewis acid-base interactions and not to an increase in the hydrophobic properties of the cell surface. These preliminary results demonstrate that the developed cytometric method is p…
Exploring the diversity of listeria monocytogenes biofilm architecture by high-throughput confocal laser scanning microscopy and the predominance of …
2015
ABSTRACT Listeria monocytogenes is involved in food-borne illness with a high mortality rate. The persistence of the pathogen along the food chain can be associated with its ability to form biofilms on inert surfaces. While most of the phenotypes associated with biofilms are related to their spatial organization, most published data comparing biofilm formation by L. monocytogenes isolates are based on the quantitative crystal violet assay, which does not give access to structural information. Using a high-throughput confocal-imaging approach, the aim of this work was to decipher the structural diversity of biofilms formed by 96 L. monocytogenes strains isolated from various environments. Pr…
Analysis of fluorescent MRI contrast agent behavior in the liver and thoracic aorta of mice.
2004
To characterize the behavior of magnetofluorescent products injected in mice intravenously.The magnetic resonance imaging (MRI) products were labelled with fluorescent molecules to examine the biodistribution process in vivo and observe them at the cellular level by means of confocal microscopy. Three-dimensional (3D) sequences of images were obtained by spectral analysis of sample preparations in a multiphoton confocal microscope and analyzed by the factor analysis of medical image sequence algorithm, which provides factor curves. Factor images are the result of image-processing methods that utilize information from emission spectra. Preparations are also screened in the counting mode to p…
Localisation et visualisation de transcrits fongiques in situ: Une méthode originale qui combine biologie moléculaire et microscopie confocale
2011
National audience; Les Gloméromycètes, formant la symbiose mycorhizienne à arbuscules, sont des champignons biotrophes obligatoires qui sont intimement associés aux tissus végétaux qu’ils colonisent. Les techniques utilisées pour suivre l’expression des gènes fongiques dans les racines mycorhizées ne permettent pas de définir le profil spatio-temporel de leur activité. Afin de tracer l’activité transcriptionnelle fongique dans les racines mycorhizées, une méthode innovante, basée sur la RT-PCR in situ, a donc été développée. Cette technique permet de localiser, en microscopie optique confocale à balayage laser, des transcrits fongiques, à l’aide d’amorces spécifiques marquées par un fluoroc…
Influence des conditions environnementales (statique versus dynamique) sur le développement en biofilm de Listeria monocytogenes EGD-e. Developpement…
2008
National audience
Approche tridimensionnelle de la répartition spatiale du champignon mycorhizien à arbuscule sur racines transparisées
2022
L’imagerie tridimensionnelle d’échantillons volumineux est limitée par les phénomènes de réfraction et d’absorption de la lumière par les composants tissulaires (lipides, pigments...). Afin de limiter ses phénomènes et permettre l’acquisition d’image sur toute l’épaisseur d’une racine mycorhizée, il est nécessaire de rendre transparent les échantillons. Cela est possible en dépigmentant et en homogénéisant les différents indices de réfraction au sein du tissu, via des traitements chimiques. Cette technique, appelée transparisation, permet une analyse tridimensionnelle sur échantillon entier des structures d’intérêt marquées par fluorescence. Une vingtaine de techniques différentes de clarif…
Models and tools for territorial dynamic studies (chapter 1)
2012
As part of the ArchaeDyn project, a workgroup was formed to coordinate the development, implementation and application of methods and tools for spatial analysis. The workgroup's activities were directed at various problems. The first was to construct a grid common to all the workgroups and to homogenize the study areas used by the different workgroups in their databases. The 'confidence maps' method was suggested for assessing the quality and quantity of information inventoried in the databases. Confidence maps are produced from representation and reliability maps by simple map algebra and they can be considered as 'masks' for interpreting spatial analysis results. Finally, the research tea…
Focal Points in Collective Free Improvisation
2013
OLLECTIVE FREE IMPROVISATION (herein abbreviated as CFI), while not a recent phenomenon in music (free jazz’s first experiments date from the late 1950s), remains under-studied. The extant literature either deals with political aspects (Carles and Comolli 2000) or tries to analyze the resulting music, using musicological tools (Jost 1994) or new concepts drawn from the complexity sciences (Borgo 2005). My research on CFI focuses on a cognitive approach, in order to understand the process of collective improvisation: 1 how a group of improvisers who do not know each other and are not using a common referent 2 (Pressing 1988) can answer the challenge of making music together. This paper deals…
Extremely low frequency electromagnetic fields (ELF-EMFs) induce in vitro angiogenesis process in human endothelial cells.
2008
Effects of extremely low frequency (ELF) electromagnetic fields (EMFs) on activation of angiogenesis were analysed using cultured umbilical human vein endothelial cells (HUVECs). The cultures were exposed to a sinusoidal EMF to intensity of 1 mT, 50 Hz for up to 12 h. EMFs increased the degree of endothelial cell proliferation and tubule formation, coupled by an acceleration in the process of wound healing. Since this process is physiologically accompanied by a large modification in the structural organization of actin and focal adhesions, we analyzed the rearrangement of some cytoskeleton elements demonstrating a major reorganization of the fibres and of the focal adhesion complexes after …
Non-structural proteins P17 and P33 are involved in the assembly of the internal membrane-containing virus PRD1.
2015
AbstractBacteriophage PRD1, which has been studied intensively at the structural and functional levels, still has some gene products with unknown functions and certain aspects of the PRD1 assembly process have remained unsolved. In this study, we demonstrate that the phage-encoded non-structural proteins P17 and P33, either individually or together, complement the defect in a temperature-sensitive GroES mutant of Escherichia coli for host growth and PRD1 propagation. Confocal microscopy of fluorescent fusion proteins revealed co-localisation between P33 and P17 as well as between P33 and the host chaperonin GroEL. A fluorescence recovery after photobleaching assay demonstrated that the diff…