525 research outputs found

    THE GOAL AND ISSUES OF THE FORMAL DESCRIPTION OF ARMENIAN VOCABULARY AND CREATION OF THE ELECTRONIC DATABASE

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    The article is devoted to the goals and issues of formal description of Armenian word formation. Although recently formal description of the language has become more practical, it should be noted that the full formal description of the Armenian language has not been done yet. The author of the article states that the formal description of the Armenian vocabulary will enable to reveal as the regular structures, as well as the variative forms, deflections, and irregularities with frequency data with their automatic analysis and the possibility of derivation. It has an informative value, it can clarify and explain many problems in Armenian linguistics, and also can give much material for the further researches of Armenian grammar.The article is devoted to the goals and issues of formal description of Armenian word formation. Although recently formal description of the language has become more practical, it should be noted that the full formal description of the Armenian language has not been done yet. The author of the article states that the formal description of the Armenian vocabulary will enable to reveal as the regular structures, as well as the variative forms, deflections, and irregularities with frequency data with their automatic analysis and the possibility of derivation. It has an informative value, it can clarify and explain many problems in Armenian linguistics, and also can give much material for the further researches of Armenian grammar

    High contrast D1_{1} line electromagnetically induced transparency in nanometric-thin rubidium vapor cell

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    Electromagnetically induced transparency (EIT) on atomic D1_{1} line of rubidium is studied using a nanometric-thin cell with atomic vapor column length in the range of L= 400 - 800 nm. It is shown that the reduction of the cell thickness by 4 orders as compared with an ordinary cm-size cell still allows to form an EIT resonance for L=λL= \lambda (λ=794\lambda =794 nm) with the contrast of up to 40%. Remarkable distinctions of EIT formation in nanometric-thin and ordinary cells are demonstrated. Despite the Dicke effect of strong spectral narrowing and increase of the absorption for L=L= λ/2\lambda /2, EIT resonance is observed both in the absorption and the fluorescence spectra for relatively low intensity of the coupling laser. Well resolved splitting of the EIT resonance in moderate magnetic field for L=L= λ\lambda can be used for magnetometry with nanometric spatial resolution. The presented theoretical model well describes the observed results.Comment: Submitted to Applied Physics B: Lasers and Optics, 9 pages, 10 figure

    Three-photon electromagnetically induced transparency using Rydberg states

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    We demonstrate electromagnetically induced transparency in a four-level cascade system where the upper level is a Rydberg state. The observed spectral features are sub-Doppler and can be enhanced due to the compensation of Doppler shifts with AC Stark shifts. A theoretical description of the system is developed that agrees well with the experimental results, and an expression for the optimum parameters is derived

    Unfolded protein response is involved in the pathology of human congenital hypothyroid goiter and rat non-goitrous congenital hypothyroidism

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    Copyright: Copyright 2008 Elsevier B.V., All rights reserved.The unfolded protein response (UPR) is an intracellular signaling pathway that regulates the protein folding and processing capacity of the endoplasmic reticulum (ER). The UPR is induced by the pharmacological agents that perturb ER functions but is also activated upon excessive accumulation of the mutant secretory proteins that are unable to attain correct three-dimensional structure and are thus retained in the ER. Such defects in intracellular protein transport underlie the development of a number of phenotypically diverse inherited pathologies, termed endoplasmic reticulum storage diseases (ERSD). We have studied UPR development in two similar ERSDs, human congenital goiter caused by the C1264R and C1996S mutations in the thyroglobulin (Tg) gene and non-goitrous congenital hypothyroidism in rdw dwarf rats determined by the G2320R Tg mutation. In both cases, these mutations rendered Tg incapable of leaving the ER. A major ER chaperone immunoglobulin-binding protein (BiP), and a novel putative escort chaperone endoplasmic reticulum protein 29 KDa (ERp29) were found to be associated with Tg, which might be interpreted as the contribution of the quality control machinery to the previously shown retention of Tg in the ER. We have extended our earlier observations of ER chaperone induction with the identification of the additional ER (ERp29, ERp72, calreticulin, protein disulfide isomerase (PDI)), cytoplasmic (heat shock protein (HSP)70, HSP90) and mitochondrial (mtHSP70) upregulated chaperones and folding enzymes. Activation of the transcriptional arm of UPR, as judged by the appearance of the spliced (active) form of X-box binding protein (XBP1) and processed activating transcription factor 6 (ATF6) transcription factors was suggested to contribute to the overexpression of the ER chaperones. The processing of ATF6 was observed in both human and rat tissues with Tg mutations. Whereas, in human tissues, weak splicing of XBP1 mRNA was detected only in the C1264R mutant, all rat thyroids including wild-type contained significant amounts of the spliced form of XBP1 as opposed to human liver and rat brain tissues, implying the existence of a previously unknown tissue-specific regulation of XBP1 processing.publishersversionPeer reviewe
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