Search results for "Color"

Unravelling the DNA sequences carried by Streptomyces coelicolor membrane vesicles

2022

AbstractMembrane vesicles (MVs) are spherical particles with nanoscale dimensions and characterized by the presence of diverse cargos, such as nucleic acids, proteins, lipids, and cellular metabolites. Many examples of (micro)organisms producing MVs are reported in literature. Among them, bacterial MVs are of particular interest because they are now considered as the fourth mechanism of horizontal gene transfer. Streptomyces bacteria are well-known for their ecological roles and ability to synthesize bioactive compounds, with Streptomyces coelicolor being the model organism. It was previously demonstrated that it can produce distinct populations of MVs characterized by different protein and…

A Red Eye Colour Mutation in Culex pipiens after X-irradiation

1963

FOUR 1–2-day-old males of Culex pipiens were irradiated with a dose of 4,000 r. The mutant ‘red eye’ (r) was isolated from F3 cultures of two of the irradiated males (♂ II and ♂ IV). From male II, there were three red-eyed females which arose out of a single F2 brother–sister mating; from male IV, 80 red-eyed females and one red-eyed male from 14 F2 brother–sister matings. According to the experimental procedure, this means that at least one sperm from male II and at least fourteen sperms from male IV carried the mutation r. Thus, the same mutation was recovered in parallel from two irradiated males. The clustered appearance of the mutation in male IV was presumably caused by the occurrence…

2018

Previous studies have reported that bright ceilings appear higher than dark ceilings, irrespective of the other colorimetric properties of the ceiling color (hue, saturation) and irrespective of the luminance of the remaining room surfaces (walls, floor). In the present study, we expand these findings to width and depth estimates. We presented stereoscopic full-scale room simulations on a head-mounted display and varied the luminance of the side walls, rear wall, and ceiling independently of each other. Participants judged the width and depth of the simulated rooms. Our results show that the perceived spatial layout of a given room is significantly influenced by the luminance of the direct …

A Neural Network-Based Algorithm for 3D Multispectral Scanning Applied to Multimedia

2005

We describe a new stereoscopic system based on a multispectral camera and an LCD-Projector. The novel concept we want to show consists in the use of multispectral information for 3D-scenes reconstruction. Each 3D point is linked to a curve representing the spectral reflectance. This latter is a physical representation of the matter and presents the advantage over color information, which is perceptual, that it is independent from both illuminant and observer. We first present an easy methodology to geometrically and spectrally calibrate such a system. We then describe an algorithm for recovering 3D coordinates based on triangulation and an algorithm for reflectance curves reconstruction bas…

Model and quality assessment of single image dehazing

2016

This thesis is mainly related to color imaging science, involving many disciplines, such as color image enhancement, image formation, color reproduction, optical physics, radiometry, colorimetry, image quality and psychophysics.Dehazing aims at recovering the image information degraded by light scattering, e.g. bad weather. This process is an ill-posed and a challenging problem. Although a variety of approaches have been proposed, there is still room for further improvement and standardization. In this work, we investigate the limitations of haze model in terms of accuracy of color image recovery. We address also the link between the visibility deterioration and the spectral content of the …

Havep53gene mutations and protein expression a different biological significance in colorectal cancer?*

2002

p53 alterations are considered the most common genetic events in many types of neoplasms, including colorectal carcinoma (CRC). These alterations include mutations of the gene and/or overexpression of the protein. The aim of our study was to assess whether in 160 patients undergoing resective surgery for primary operable CRC there was an association between p53 mutations and protein overexpression and between these and other biological variables, such as cell DNA content (DNA-ploidy) and S-phase fraction (SPF), and the traditional clinicopathological variables. p53 mutations, identified by PCR-SSCP-sequencing analysis, were found in 68/160 patients (43%) and positive staining for p53 protei…

Colorimetric gas detection by the varying thickness of a thin film of ultrasmall PTSA-coated TiO

2016

Colorimetric gas sensing is demonstrated by thin films based on ultrasmall TiO2 nanoparticles (NPs) on Si substrates. The NPs are bound into the film by p-toluenesulfonic acid (PTSA) and the film is made to absorb volatile organic compounds (VOCs). Since the color of the sensing element depends on the interference of reflected light from the surface of the film and from the film/silicon substrate interface, colorimetric detection is possible by the varying thickness of the NP-based film. Indeed, VOC absorption causes significant swelling of the film. Thus, the optical path length is increased, interference wavelengths are shifted and the refractive index of the film is decreased. This cause…

Optical characterization of YCa4O(BO3)3 and Nd:YCa4O(BO3)3 crystals

2007

International audience; We report a complete optical characterization of YCa4O(BO3)3 and Nd:YCa4O(BO3)3 crystals. We studied the relative orientation between the dielectric and the crystallographic frames as a function of the wavelength and performed accurate phase-matching angles measurements for second harmonic generation, using a single crystal cut as a sphere. We also recorded polarized luminescence spectra of Nd:YCOB along the principal axes of the dielectric frame. For both crystals, we measured the gray-tracking and the thermo-optic properties as a function of temperature and wavelength using oriented slabs. Finally, we measured all their dielectric and electro-optic coefficients, as…

Abstract 448: Molecular analysis of BRAF gene and PTEN gene expression in metastatic colorectal cancer patients: Feasibility study

2014

Abstract Introduction There are numerous causes triggering CRC. 25-80% of CRC shown a deregulation in Epidermal Growth Factor Receptor (EGFR) pathway. Two signaling pathways downstream of the EGFR are dysregulated in CRC the mitogen-activated protein kinase (MAPK) and the phosphoinositide-3-kinase (PI3K) pathway. Activating mutations in KRAS and BRAF (MAPK pathway) and PIK3CA affect prognosis and/or response to anti-EGFR MoAb. PTEN is a downstream effector of EGFR pathway and is involved in PI3K pathway. Loss of PTEN protein expression can occur through epigenetic silencing and mutation or allelic loss. Immunohistochemistry (IHC) is the most effective way to assay for loss of PTEN expressio…

Updated analysis of KRAS/NRAS and BRAF mutations in study 20050181 of panitumumab (pmab) plus FOLFIRI for second-line treatment (tx) of metastatic co…

2014

3568 Background: Previously, extended RAS analysis from this study showed a trend toward improvements in HR on OS and PFS with pmab + FOLFIRI vs FOLFIRI in WT RAS group vs WT KRAS exon 2 group. Her...