1,951 research outputs found

    Generate tensor network state by sequential single-photon scattering in waveguide QED systems

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    We propose a scheme to generate photonic tensor network states by sequential scattering of photons in waveguide QED systems. We show that sequential scatterings can convert a series of unentangled photons into any type of matrix product states. We also demonstrate the possibility of generating projected entangled pair states with arbitrary network representation by photon re-scattering

    Degradation and sequestration : cellular strategies to counteract proteotoxic stress

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    Maintenance of proteome homeostasis (proteostasis) is essential to preserve cellular function in response to intrinsic and extrinsic stress conditions. This is regulated by the proteostasis network, which is comprised of machineries for protein synthesis, folding, sequestering, and degradation. The collaboration of these machineries is to ensure the functionality, subcellular localization and appropriate protein abundance, thereby preventing proteotoxic stress. Disturbances in proteostasis can be caused by gene mutations, temperature fluctuations, alterations in synthesis or degradation, chemical insult, etc. If a disbalance in proteostasis is not addressed in a timely and correctly manner, aberrant proteins can accumulate and form insoluble aggregates, which are the hallmarks of the majority of neurodegenerative diseases and other so-called proteinopathies. Therefore, extending our knowledge and developing techniques to modulate the proteostasis network are important for the development of new therapeutic strategies for these disorders. The work presented in this thesis describes how the proteostasis network responds to different proteotoxic stress conditions, and how its modulation preserves proteome integrity. In paper Ⅰ, we describe that the sequestration of aberrant, newly synthesized proteins in cellular stress granules prevent impairment of the ubiquitin-proteasome system in the nuclear compartment in response to thermal stress. In stress granuledeficient cells, these newly synthesized proteins passively diffuse into the nucleus instead of being sequestered in cytoplasmic granules. The newly synthesized proteins translocate to nucleoli in an HSP70-dependent manner. Under stress, HSP70 interacts with newly synthesized proteins to maintain their conformation. Our data suggest that heat shock factor 1 is released from HSP70, thereby prematurely activating the heat shock response while recovering from thermal stress. In line with a premature heat shock response, we found enhanced SUMO2/3-dependent degradation of aggregation-prone proteins, and impairs proteasomal degradation in the nuclear compartment. In paper Ⅱ, we characterize the effect of the integrated stress response inhibitor ISRIB on the ubiquitin-proteasome system in response to thermal stress. During thermal stress, the integrated stress response is activated to inhibit protein translation, thereby preventing overloading of the proteostasis network with misfolded, newly synthesized proteins. However, ISRIB restores protein translation during stress, resulting in an increased amount of newly synthesized proteins. Part of the newly synthesized proteins under stress are dysfunctional and therefore polyubiquitinated targeted as substrates for proteasomal degradation. Meanwhile, we show that a large fraction of polyubiquitinated proteasome substrates converts to a detergent insoluble state. We propose that a limitation of ubiquitin availability results in the attenuation of ubiquitin proteasome system. In paper Ⅲ, we studied the effect of a protein aggregation-preventing tag, the NT* domain, on an aggregation-prone protein. The NT* domain is a solubility tag derived from a spider silk protein. The fusion of this solubility tag with an aggregation-prone reporter protein prevented protein aggregation in mammalian cells in the cytosolic and nuclear compartments. This finding provides the possibility to reduce the burden if aggregation-prone proteins on proteostasis with natural anti-aggregation domains. In paper Ⅳ, we characterized CBK79 as a novel proteostasis inhibitor that impairs both proteolytic pathways: the ubiquitin-proteasome system and autophagy. As a consequence of the proteostasis collapse caused by CBK79, the compound activates the heat shock response and induces aggresome formation. Intriguingly, preconditioning of cells by thermal stress relieves the negative effect of CBK79 on ubiquitin-proteasome system but not on autophagy

    Verbal Signs of Value Preferences of Modern Woman (on Material of Marriage Advertisements)

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    The analysis of women’s marriage advertisements presented in the framework of the television talk show “Let’s get married” is presented. The research urgency is caused by the fact that in the marriage advertisement value preferences of contemporary women are verbalized in the context of Russia post-communist transformation. Novelty of research consists in that the work shows the peculiarities of linguistic representation of mosaic gender picture of the world of the modern woman. On the basis of the text material the classification of three models of gender identity is suggested. The first revealed model is based on nominative units of language and usage utterances and manifests the values of a patriarchal culture — the dominance of masculinity in marital relations, the woman’s desire to be dependent on her husband. The androgynous nature of the second model is based on text fragments representing, on the one hand, the value of motherhood as a form of women self-actualization intended by nature, on the other hand, the focus on career advancement and high social status. The third model is represented by verbal signs, representing hypertrophy of masculinity: the rejection of motherhood, independence and ambitions of women in the choice of life and profession. Special attention is paid to the analysis of indirect communication forms, which show the language means to construct gender identity.Излагаются результаты анализа женских брачных объявлений, представленных в рамках телевизионного ток-шоу «Давай поженимся». Актуальность исследования обусловлена тем, что в брачном объявлении вербализованы ценностные предпочтения современной женщины в условиях посткоммунистической трансформации России. Новизна исследования видится в том, что в работе показаны особенности языковой репрезентации мозаичности гендерной картины мира современной женщины. На основе текстового материала предлагается классификация трех моделей гендерной идентичности. Первая модель, выделенная с опорой на номинативные единицы и узуальные речения, манифестирует ценности патриархальной культуры, — доминирование маскулинности в брачных отношениях, желание женщины быть зависимой от мужа. Андрогинный характер второй модели опирается на текстовые фрагменты, репрезентирующие, с одной стороны, ценность материнства как формы самореализации женщины, предназначенной ей от природы, с другой стороны, ориентированность на карьерный рост и высокий социальный статус. Третья модель представлена вербальными знаками, репрезентирующими гипертрофию мужского начала: отказ от материнства, самостоятельность и амбициозность женщин в выборе жизненного пути и профессии. Особое внимание уделяется анализу непрямых форм передачи информации, которые показывают, какими средствами располагает язык для конструирования гендерной идентичности
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