2,339 research outputs found

    Characterization of cells of amniotic fluids by immunological identification of intermediate-sized filaments: Presence of cells of different tissue origin

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    Antibodies against intermediate-sized filaments, of the prekeratin or vimentin type, were used to investigate the presence of these filaments by indirect immunofluorescence microscopy in cultured and non-cultured amniotic fluid cells, in frozen sections of the placenta and in isolated cells of the amniotic epithelium. Two major classes of cells can be cultured from amniotic fluids, namely cells of epithelial origin containing filaments of the prekeratin type and cells of different origin which contain filaments of the vimentin type but are negative when tested with antibodies to epidermal prekeratin. The presence of prekeratin type filaments correlates with the morphology of colonies of amniotic fluid cell cultures in vitro as classified by Hoehn et al. (1974). Cells of E-type colonies are shown to be of epithelial origin. In contrast our data indicate a different origin of almost all cells of F-type colonies and of the large majority of cells of AF-type colonies. Cells of epithelial origin and positively stained with antibodies to epidermal prekeratin are occasionally scattered in F-type colonies and in variable percentages (up to 30%) in AF-type colonies. Surprisingly, cryostat sections of the amniotic epithelium and isolated groups of amniotic cells showed positive reactions with both antibodies to vimentin and prekeratin. The possibility that amniotic cells may be different from other epithelial cells in that they contain both types of filaments simultaneously already in situ is presently under investigation

    Characterization of cells of amniotic fluids by immunological identification of intermediate-sized filaments: Presence of cells of different tissue origin

    Get PDF
    Antibodies against intermediate-sized filaments, of the prekeratin or vimentin type, were used to investigate the presence of these filaments by indirect immunofluorescence microscopy in cultured and non-cultured amniotic fluid cells, in frozen sections of the placenta and in isolated cells of the amniotic epithelium. Two major classes of cells can be cultured from amniotic fluids, namely cells of epithelial origin containing filaments of the prekeratin type and cells of different origin which contain filaments of the vimentin type but are negative when tested with antibodies to epidermal prekeratin. The presence of prekeratin type filaments correlates with the morphology of colonies of amniotic fluid cell cultures in vitro as classified by Hoehn et al. (1974). Cells of E-type colonies are shown to be of epithelial origin. In contrast our data indicate a different origin of almost all cells of F-type colonies and of the large majority of cells of AF-type colonies. Cells of epithelial origin and positively stained with antibodies to epidermal prekeratin are occasionally scattered in F-type colonies and in variable percentages (up to 30%) in AF-type colonies. Surprisingly, cryostat sections of the amniotic epithelium and isolated groups of amniotic cells showed positive reactions with both antibodies to vimentin and prekeratin. The possibility that amniotic cells may be different from other epithelial cells in that they contain both types of filaments simultaneously already in situ is presently under investigation

    Near-optimal asymmetric binary matrix partitions

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    We study the asymmetric binary matrix partition problem that was recently introduced by Alon et al. (WINE 2013) to model the impact of asymmetric information on the revenue of the seller in take-it-or-leave-it sales. Instances of the problem consist of an n×mn \times m binary matrix AA and a probability distribution over its columns. A partition scheme B=(B1,...,Bn)B=(B_1,...,B_n) consists of a partition BiB_i for each row ii of AA. The partition BiB_i acts as a smoothing operator on row ii that distributes the expected value of each partition subset proportionally to all its entries. Given a scheme BB that induces a smooth matrix ABA^B, the partition value is the expected maximum column entry of ABA^B. The objective is to find a partition scheme such that the resulting partition value is maximized. We present a 9/109/10-approximation algorithm for the case where the probability distribution is uniform and a (11/e)(1-1/e)-approximation algorithm for non-uniform distributions, significantly improving results of Alon et al. Although our first algorithm is combinatorial (and very simple), the analysis is based on linear programming and duality arguments. In our second result we exploit a nice relation of the problem to submodular welfare maximization.Comment: 17 page

    Неинвазивные методы изучения коллекторских свойств ископаемых углей

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    Розглянуті фізичні неінвазивні методи дослідження, які дозволяють отримати уявлення про такі властивості вугільної речовини як повна пористість, питома поверхня, розподіл пір по розмірах та ін., що дають уявлення про колекторні властивості вугільних пластів. Отримані характеристики структури порового простору, що визначають транспортні властивості флюїдів.Physical noninvasion methods of studies are considered, which allow characterizing such properties of coal as total porosity, specific surface, size distribution of pores and etc., demonstrating the reservoir features of coal beds. The description of pore space structure, determining transport properties of fluids, is presented

    Data-driven power system operation: Exploring the balance between cost and risk

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    Supervised machine learning has been successfully used in the past to infer a system's security boundary by training classifiers (also referred to as security rules) on a large number of simulated operating conditions. Although significant research has been carried out on using classifiers for the detection of critical operating points, using classifiers for the subsequent identification of suitable preventive/corrective control actions remains underdeveloped. This paper focuses on addressing the challenges that arise when utilizing security rules for control purposes. The inherent trade-off between operating cost and security risk is explored in detail. To optimally navigate this trade-off, a novel approach is proposed that uses an ensemble learning method (AdaBoost) to infer a probabilistic description of a system's security boundary and Platt Calibration to correct the introduced bias. Subsequently, a general-purpose framework for building probabilistic and disjunctive security rules of a system's secure operating domain is developed that can be embedded within classic operation formulations. Through case studies on the IEEE 39-bus system, it is showcased how security rules can be efficiently utilized to optimally operate the system under multiple uncertainties while respecting a user-defined cost-risk balance. This is a fundamental step towards embedding data-driven models within classic optimisation approaches

    Sequential Posted Price Mechanisms with Correlated Valuations

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    We study the revenue performance of sequential posted price mechanisms and some natural extensions, for a general setting where the valuations of the buyers are drawn from a correlated distribution. Sequential posted price mechanisms are conceptually simple mechanisms that work by proposing a take-it-or-leave-it offer to each buyer. We apply sequential posted price mechanisms to single-parameter multi-unit settings in which each buyer demands only one item and the mechanism can assign the service to at most k of the buyers. For standard sequential posted price mechanisms, we prove that with the valuation distribution having finite support, no sequential posted price mechanism can extract a constant fraction of the optimal expected revenue, even with unlimited supply. We extend this result to the the case of a continuous valuation distribution when various standard assumptions hold simultaneously. In fact, it turns out that the best fraction of the optimal revenue that is extractable by a sequential posted price mechanism is proportional to ratio of the highest and lowest possible valuation. We prove that for two simple generalizations of these mechanisms, a better revenue performance can be achieved: if the sequential posted price mechanism has for each buyer the option of either proposing an offer or asking the buyer for its valuation, then a Omega(1/max{1,d}) fraction of the optimal revenue can be extracted, where d denotes the degree of dependence of the valuations, ranging from complete independence (d=0) to arbitrary dependence (d=n-1). Moreover, when we generalize the sequential posted price mechanisms further, such that the mechanism has the ability to make a take-it-or-leave-it offer to the i-th buyer that depends on the valuations of all buyers except i's, we prove that a constant fraction (2-sqrt{e})/4~0.088 of the optimal revenue can be always be extracted.Comment: 29 pages, To appear in WINE 201

    Dissociation and symptom dimensions of obsessive-compulsive disorder: A replication study

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    Background: Obsessive-compulsive disorder (OCD) is a phenotypically very heterogeneous disease with high rates of comorbid psychiatric pathology. Previous studies have indicated that OCD is associated with higher levels of dissociation. The aims of the present study were to replicate and extend previous findings of a significant link between certain OCD symptom dimensions and dissociation. Methods: The study sample comprised 50 patients with OCD, as confirmed by the Mini International Neuropsychiatric Interview,who had a score of at least 16 on the Yale-Brown Obsessive-Compulsive Scale. All patients were assessed with the short version of the Hamburg Obsessive-Compulsive Inventory and the Dissociative Experience Scale (DES). Correlation analyses and multiple regression analyses were performed to evaluate the relationship between OCD symptom dimensions and dissociation. Results: The checking dimension was most strongly related to dissociation, followed by the symmetry/ordering and obsessive thoughts dimensions. In contrast, no significant relationship was found between dissociation and the washing/cleaning, counting/touching, and aggressive impulses/fantasies dimensions. Multiple regression analyses revealed that: (1) only the checking dimension showed an independent positive correlation with dissociation, and (2) only higher scores on the DES subscale "amnestic dissociation" were associated with higher scores for checking compulsions. Conclusions: Our results suggest that there might be a specific link between checking behavior and dissociation in OCD. Moreover, checking compulsions seem to be particularly associated with amnestic dissociation. Further studies focusing on amnestic dissociation as a potentially important determinant of checking compulsions are warrante

    Rankings as a comprehensive model to assess innovation and investment development of mesolevel economic systems (case of Tomsk region)

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    Актуальность определяется растущим интересом зарубежных и отечественных исследователей и практиков к рейтингам как комплексному методу оценки инновационно‐инвестиционого развития регионов. При этом нет единства мнений по методикам формирования рейтингов, отбора показателей и методов расчета. Цель работы: исследование и анализ рейтингов как модели комплексной оценки инновационного и инвестиционного развития экономических систем мезоуровня. Методы исследования: методы сравнительного, логического анализа, анализ и синтез, системный подход. Результаты. Представлен сравни‐ тельный анализ российских инновационно‐инвестиционных рейтингов; рассмотрены методики их составления и используемые системы показателей. Сформулированы ограничения рейтинга как модели комплексной оценки в целом, дана характеристика каждого отдельного рейтинга. В качестве примеров приведены позиции регионов Сибирского федерального округа в пяти российских рейтингах.The relevance of the topic is determined by the growing interest of foreign and domestic researchers and practitioners in ratings as a comprehensive method for assessing the innovative and investment development of the regions. At the same time there is no unity of opinion on the methods of rating formation, selection of indicators and calculation methods. The aim of the study is to research and analyze ratings as a model for integrated assessment of innovation and investment development of meso‐level economic systems. Methods of research: methods of comparative, logical analysis, analysis and synthesis, systematic approach. Results. The paper introduces the comparative analysis of Russian innovation and investment ratings, considers the methods of their compilation and the system of indicators. The rating constraints are formulated as a model of integrated assessment in general, and the characteristics of each individual rating are given. The authors give the positions of the regions of the Siberian Federal District in five Russian rankings as an example
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