1,127 research outputs found

    R-matrix theory of driven electromagnetic cavities

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    Resonances of cylindrical symmetric microwave cavities are analyzed in R-matrix theory which transforms the input channel conditions to the output channels. Single and interfering double resonances are studied and compared with experimental results, obtained with superconducting microwave cavities. Because of the equivalence of the two-dimensional Helmholtz and the stationary Schroedinger equations, the results present insight into the resonance structure of regular and chaotic quantum billiards.Comment: Revtex 4.

    Meliador de Jean Froissart, son importance littéraire : le vrai dans la fiction

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    Le grand chroniqueur français, Jean Froissart, a composé vers 1380 un long roman en vers octosyllabiques. L'action de ce dernier roman français en vers se déroule au moment de la jeunesse des héros arthuriens. Complètement fictif, ne comprenant aucun des realia historiques, ce roman exprime mieux que les Chroniques les aspirations et les mentalités des nobles de l'époque

    dbUNiFier: A Framework for Automated Unification of Textual Data in Multiple Remote Data Sources

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    Over time, advances in database technology and utilization have resulted in a rapid increase in the number and types of data sources. Simultaneously, numerous methods of unifying these various data sources have emerged. Research has shown that a more comprehensive set of data attribute matches between multiple schemas can be detected by combining a number of the unification methodologies as opposed to using a single method. In this research project, a unification framework, dbUNiFier, has been proposed as an approach to allow for easy integration of both existing and future unification methods and data sources

    Probiotics and gut-skin axis - new look on factors affecting skin condition

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    Introduction and purpose  The human gut microbiota consists of trillions of microscopic organisms, mostly bacterias. They play a significant role in nutrient metabolism, maintenance of structural integrity of the gut mucosal barrier, immunomodulation and protection against pathogens. Many factors can influence the composition of the intestinal microbiota, for example antibiotics, diet or stress. These factors may lead to dysbiosis which causes activation of neurotransmitters. It can results in the entry of metabolites to the blood stream, systemic immune dysregulation and alteration of skin microbiota. The aim of the study was to review the literature and determine the effects of intestinal microbiota and probiotics in selected skin diseases and what is new - skin aging process.  State of knowledge  We analyzed numerous studies which indicate that disturbed gut microbiota can be related to some chronic diseases, including skin disorders such as atopic dermatitis, acne vulgaris, psoriasis and rosacea. Additionally, it has been proven that bacterial dysbiosis can intensify the skin aging proces. In order to reproduce normal gut microbiota probiotics are used. Despite the fact that there are only a few studies showing the unequivocal effect of probiotics on skin diseases, their results seem to be encouraging.  Conclusions  Proper composition of the intestinal microbiome determines the homeostasis of the human body. Disturbance of the gut microbiome play a significant role not only in development and aggravation of many skin diseases, but also have an impact on the skin aging. Despite quite a lot number of studies assessing the impact of microbiota on certain skin disorders, there is still a need to evaluate impact of probiotics. Researches indicate that they can be used as a helpful therapeutic tool. Taking this into account, it is worth considering it in the treatment process.&nbsp

    Selective Recruitment of Nuclear Factors to Productively Replicating Herpes Simplex Virus Genomes

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    Much of the HSV-1 life cycle is carried out in the cell nucleus, including the expression, replication, repair, and packaging of viral genomes. Viral proteins, as well as cellular factors, play essential roles in these processes. Isolation of proteins on nascent DNA (iPOND) was developed to label and purify cellular replication forks. We adapted aspects of this method to label viral genomes to both image, and purify replicating HSV-1 genomes for the identification of associated proteins. Many viral and cellular factors were enriched on viral genomes, including factors that mediate DNA replication, repair, chromatin remodeling, transcription, and RNA processing. As infection proceeded, packaging and structural components were enriched to a greater extent. Among the more abundant proteins that copurified with genomes were the viral transcription factor ICP4 and the replication protein ICP8. Furthermore, all seven viral replication proteins were enriched on viral genomes, along with cellular PCNA and topoisomerases, while other cellular replication proteins were not detected. The chromatin-remodeling complexes present on viral genomes included the INO80, SWI/SNF, NURD, and FACT complexes, which may prevent chromatinization of the genome. Consistent with this conclusion, histones were not readily recovered with purified viral genomes, and imaging studies revealed an underrepresentation of histones on viral genomes. RNA polymerase II, the mediator complex, TFIID, TFIIH, and several other transcriptional activators and repressors were also affinity purified with viral DNA. The presence of INO80, NURD, SWI/SNF, mediator, TFIID, and TFIIH components is consistent with previous studies in which these complexes copurified with ICP4. Therefore, ICP4 is likely involved in the recruitment of these key cellular chromatin remodeling and transcription factors to viral genomes. Taken together, iPOND is a valuable method for the study of viral genome dynamics during infection and provides a comprehensive view of how HSV-1 selectively utilizes cellular resources

    Anderson Localization in a String of Microwave Cavities

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    The field distributions and eigenfrequencies of a microwave resonator which is composed of 20 identical cells have been measured. With external screws the periodicity of the cavity can be perturbed arbitrarily. If the perturbation is increased a transition from extended to localized field distributions is observed. For very large perturbations the field distributions show signatures of Anderson localization, while for smaller perturbations the field distribution is extended or weakly localized. The localization length of a strongly localized field distribution can be varied by adjusting the penetration depth of the screws. Shifts in the frequency spectrum of the resonator provide further evidence for Anderson localization.Comment: 7 pages RevTex, to be published in Phys. Rev.
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