Search results for "RECOMBINATION"
showing 10 items of 270 documents
Etude des mécanismes à l'origine de la dispersion des gènes codant les enzymes responsables de la minéralisation de l'atrazine au sein de la microflo…
2006
Rbt1 Protein Domains Analysis in Candida albicans Brings Insights into Hyphal Surface Modifications and Rbt1 Potential Role during Adhesion and Biofi…
2013
Cell wall proteins are central to the virulence of Candida albicans. Hwp1, Hwp2 and Rbt1 form a family of hypha-associated cell surface proteins. Hwp1 and Hwp2 have been involved in adhesion and other virulence traits but Rbt1 is still poorly characterized. To assess the role of Rbt1 in the interaction of C. albicans with biotic and abiotic surfaces independently of its morphological state, heterologous expression and promoter swap strategies were applied. The N-terminal domain with features typical of the Flo11 superfamily was found to be essential for adhesiveness to polystyrene through an increase in cell surface hydrophobicity. A 42 amino acid-long domain localized in the central part o…
Smad7 controls resistance of colitogenic T cells to regulatory T cell-mediated suppression.
2008
Background & Aims Foxp3-expressing regulatory T cells (Tregs) play a key role in the maintenance of the gut immune homeostasis, and an intact transforming growth factor (TGF)-β signaling is required for their function. In inflammatory bowel disease (IBD), the TGF-β signaling is impaired because of high expression of the inhibitory molecule Smad7. Although no intrinsic defects in Tregs function have been shown in IBD, it is still unknown whether colitogenic T cells are susceptible to Treg-mediated suppression. In this study, we have investigated whether IBD mucosal CD4+ T cells are resistant to Tregs and whether Smad7 is involved in this process. Methods IBD lamina propria mononuclear cells …
The caramel flavour: impacts of the volatile and the non-volatile fraction on perception
2013
The aim of this thesis was to investigate the impact of the volatile odorant fraction and the non-volatile fraction on the perception of caramel flavour. The first step focused on the analytical characterization of the volatile odorant fraction of caramel using Gas Chromatography coupled to Olfactometry (GC/O), GC/Mass Spectrometry (GC/MS) and heart-cutting MDGC/MS/O. Results highlighted the presence of more than one hundred compounds and demonstrated the complexity of the caramel volatile fraction. The objective of the second step was to understand the contribution of odorant compounds identified to the caramel aroma typicality. Literature shows that odour intensity is not sufficient to ev…
Efficient Monolithic Perovskite/Perovskite Tandem Solar Cells
2016
Thin-film solar cells suffer from various types of recombination, of which leakage current usually dominates at lower voltages. Herein, we demonstrate first a three-order reduction of the shunt loss mechanism in planar methylammonium lead iodide perovskite solar cells by replacing the commonly used hole transport layer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) with a better hole-selective polyarylamine. As a result, these cells exhibit superior operation under reduced light conditions, which we demonstrate for the extreme case of moonlight irradiance, at which open-circuit voltages of 530 mV can still be obtained. By the shunt removal we also observe the VOC to dro…
Relaxation of electron-hole pairs and scintillation mechanism in alkali halide crystals
1997
Abstract The mechanism of the ionizing radiation energy transfer from host lattice to luminescence centers is discussed taking into account the results of the recent experimental investigations of electron-hole pair relaxation in alkali iodide crystals. The high scintillation yield in CsI-Tl, CsI-Na and partially in Nal-Tl crystals is explained by the process of the motion and capture of a one-center self-trapped exciton by impurity ions.
Targeting DNA double strand break repair with hyperthermia and DNA-PKcs inhibition to enhance the effect of radiation treatment
2016
// Bregje van Oorschot 1 , Giovanna Granata 1 , Simone Di Franco 2 , Rosemarie ten Cate 1 , Hans M. Rodermond 1 , Matilde Todaro 3 , Jan Paul Medema 1 , Nicolaas A.P. Franken 1 1 Laboratory for Experimental Oncology and Radiobiology (LEXOR), Center for Experimental Molecular Medicine, Department of Radiation Oncology, Academic Medical Center, Cancer Genomics Center, Amsterdam, The Netherlands 2 Department of Surgical, Oncological and Stomatological Sciences (DICHIRONS), Cellular and Molecular Pathophysiology Laboratory, University of Palermo, Palermo, Italy 3 Biomedical Department of Internal and Specialistic Medicine (DIBIMIS), University of Palermo, Palermo, Italy Correspondence to: Nicol…
On the Bias of Syntactic Geometric Recombination in Genetic Programming and Grammatical Evolution
2015
For fixed-length binary representations as used in genetic algorithms, standard recombination operators (e.g.,~one-point crossover) are unbiased. Thus, the application of recombination only reshuffles the alleles and does not change the statistical properties in the population. Using a geometric view on recombination operators, most search operators for fixed-length strings are geometric, which means that the distances between offspring and their parents are less than, or equal to, the distance between their parents. In genetic programming (GP) and grammatical evolution (GE), the situation is different since the recombination operators are applied to variable-length structures. Thus, most r…
In vitro evolution of an atrazine-degrading population under cyanuric acid selection pressure: Evidence for the selective loss of a 47kb region on th…
2011
International audience; The adaptation of microorganisms to pesticide biodegradation relies on the recruitment of catabolic genes by horizontal gene transfer and homologous recombination mediated by insertion sequences (IS). This environment-friendly function is maintained in the degrading population but it has a cost which could diminish its fitness. The loss of genes in the course of evolution being a major mechanism of ecological specialization, we mimicked evolution in vitro by sub-culturing the atrazine-degrading Pseudomonas sp. ADP in a liquid medium containing cyanuric acid as the sole source of nitrogen. After 120 generations, a new population evolved, which replaced the original on…
Quarkonium suppression in heavy-ion collisions: an open quantum system approach
2016
We address the evolution of heavy-quarkonium states in an expanding quark-gluon plasma by implementing effective field theory techniques in the framework of open quantum systems. In this setting we compute the nuclear modification factors for quarkonia that are $S$-wave Coulombic bound states in a strongly-coupled quark-gluon plasma. The calculation is performed at an accuracy that is leading-order in the heavy-quark density expansion and next-to-leading order in the multipole expansion. The quarkonium density-matrix evolution equations can be written in the Lindblad form, and, hence, they account for both dissociation and recombination. Thermal mass shifts, thermal widths and the Lindblad …