91 research outputs found

    Three-dimensional structure of a low-Reynolds-number turbulent boundary layer

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    A low-Reynolds-number zero-pressure-gradient incompressible turbulent boundary layer was investigated using a volumetric imaging technique. The Reynolds number based on momentum thickness was 700. The flow was tagged with a passive scalar from two spanwise dye slots to distinguish between fluid motions originating in the inner and outer portions of the boundary layer. The resulting volumetric scalar field was interrogated using a laser sheet scanner developed for this study. Two- and three-dimensional time-dependent visualizations of a 50 volume time series are presented (equivalent to 17δ in length). In the outer portion of the boundary layer, scalar structures were observed to lie along lines in the (x, z)-plane, inclined to the streamwise (x-)direction in the range ±50°. The ejection of brightly dyed fluid packets from the near-wall region was observed to be spatially organized, and related to the passage of the large-scale scalar structures.Carl J Delo, Richard M Kelson and Alexander J Smit

    Relation of Thomson’s Seasons to Vergil’s Georgics

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    Novelty detection across a small population of real structures: A negative selection approach

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    Vibration-based Structural Health Monitoring (SHM), exploits a variety of approaches for novelty detection. In particular, many data-based methods try to recognise patterns by exploiting analogies with the human body's natural defences at a cellular level. These algorithms fall within the Artificial Immune System (AIS) class and can be chosen, according to their peculiarities, to solve specific problems in diverse application areas. This study investigates the damage-detection process in different operational conditions, obtained by applying structural modifications to a laboratory-scale aeroplane, which follows the geometric features of the GARTEUR benchmark project. Damage identification is performed by exploiting the Negative Selection Algorithm (NSA), already applied by some of the authors on numerically-simulated case studies, and chosen for its capability of self/non-self discrimination under varying operational or environmental conditions. The research is expanded by using sparse autoencoders for feature dimensionality reduction. The method is applied to an experimental dataset acquired via Scanning Laser Doppler Vibrometer (SLDV) measurements, to identify consistent damage-sensitive features from the frequency response functions, and to obtain a reliable fault-detection performance

    Analysis of the variability of nursing care by pathology in a sample of nine Belgian hospitals

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    info:eu-repo/semantics/published27th Patient Classification Systems International (PCSI) Working Conference, Montreal, Canada, October 201

    Proliferation and survival of human amniotic epithelial cells during their hepatic differentiation

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    Stem cells derived from placental tissues are an attractive source of cells for regenerative medicine. Amniotic epithelial cells isolated from human amnion (hAECs) have desirable and competitive characteristics that make them stand out between other stem cells. They have the ability to differentiate toward all three germ layers, they are not tumorigenic and they have immunosuppressive properties. Although liver transplantation is the best way to treat acute and chronic hepatic failure patients, there are several obstacles. Recently, stem cells have been spotlighted as alternative source of hepatocytes because of their potential for hepatogenic differentiation. In this work, we aimed to study the proliferation and survival of the hAECs during their hepatic differentiation. We have also analyzed the changes in pluripotency and hepatic markers. We differentiated amniotic cells applying a specific hepatic differentiation (HD) protocol. We determined by qRT-PCR that hAECs express significant levels of SOX-2, OCT-4 and NANOG during at least 15 days in culture and these pluripotent markers diminish during HD. SSEA-4 expression was reduced during HD, measured by immunofluorescence. Morphological characteristics became more similar to hepatic ones in differentiated cells and representative hepatic markers significantly augmented their expression, measured by qRT-PCR and Western blot. Cells achieved a differentiation efficiency of 75%. We observed that HD induced proliferation and promoted survival of hAECs, during 30 days in culture, evaluated by 3H-thymidine incorporation and MTT assay. HD also promoted changes in hAECs cell cycle. Cyclin D1 expression increased, while p21 and p53 levels were reduced. Immunofluorescence analysis showed that Ki-67 expression was upregulated during HD. Finally, ERK 1/2 phosphorylation, which is intimately linked to proliferation and cell survival, augmented during all HD process and the inhibition of this signaling pathway affected not only proliferation but also differentiation. Our results suggest that HD promotes proliferation and survival of hAECs, providing important evidence about the mechanisms governing their hepatic differentiation. We bring new knowledge concerning some of the optimal transplantation conditions for these hepatic like cells.Fil: Maymo, Julieta Lorena. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Riedel, Rodrigo Nicolas. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Pérez Alcázar, Germán Antonio. Hospital Universitario Virgen Macarena;Fil: Magatti, Marta. Istituto Ospedaliero;Fil: Maskin, Bernardo. Hospital Nacional Professor Dr. Alejandro Posadas; ArgentinaFil: Dueñas, José Luis. Hospital Universitario Virgen Macarena;Fil: Parolini, Ornella. Istituto Ospedaliero;Fil: Sánchez-Margalet, Víctor. Hospital Universitario Virgen Macarena;Fil: Varone, Cecilia Laura. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentin

    "Feed from the Service": Corruption and Coercion in the State-University Relations in Central Eurasia

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    Education in Central Eurasia has become one of the industries, most affected by corruption. Corruption in academia, including bribery, extortions, embezzlement, nepotism, fraud, cheating, and plagiarism, is reflected in the region’s media and addressed in few scholarly works. This paper considers corruption in higher education as a product of interrelations between the government and academia. A substantial block of literature considers excessive corruption as an indicator of a weak state. In contrast to standard interpretations, this paper argues that in non-democratic societies corruption is used on a systematic basis as a mechanism of direct and indirect administrative control over higher education institutions. Informal approval of corrupt activities in exchange for loyalty and compliance with the regime may be used in the countries of Central Eurasia for the purposes of political indoctrination. This paper presents the concept of corruption and coercion in the state-university relations in Central Eurasia and outlines the model which incorporates this concept and the “feed from the service” approach. It presents implications of this model for the state-university relations and the national educational systems in Central Eurasia in general and offers some suggestions on curbing corruption

    Production of the rho(770)(0) meson in pp and Pb-Pb collisions at root S-NN=2.76 TeV

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    The production of the ρ(770)0 meson has been measured at midrapidity (|y|<0.5) in pp and centrality differential Pb-Pb collisions at sNN= 2.76 TeV with the ALICE detector at the Large Hadron Collider. The particles have been reconstructed in the ρ(770)0→π+π- decay channel in the transverse-momentum (pT) range 0.5-11 GeV/c. A centrality-dependent suppression of the ratio of the integrated yields 2ρ(770)0/(π++π-) is observed. The ratio decreases by ∼40% from pp to central Pb-Pb collisions. A study of the pT-differential 2ρ(770)0/(π++π-) ratio reveals that the suppression occurs at low transverse momenta, pT<2 GeV/c. At higher momentum, particle ratios measured in heavy-ion and pp collisions are consistent. The observed suppression is very similar to that previously measured for the K∗(892)0/K ratio and is consistent with EPOS3 predictions that may imply that rescattering in the hadronic phase is a dominant mechanism for the observed suppression

    Production of the ρ(770)<SUP>0</SUP> meson in <i>pp</i> and Pb-Pb collisions at √<i>S<sub>NN</sub></i>=2.76 TeV

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    The production of the ρ(770)0 meson has been measured at midrapidity (|y|<0.5) in pp and centrality differential Pb-Pb collisions at sNN= 2.76 TeV with the ALICE detector at the Large Hadron Collider. The particles have been reconstructed in the ρ(770)0→π+π- decay channel in the transverse-momentum (pT) range 0.5-11 GeV/c. A centrality-dependent suppression of the ratio of the integrated yields 2ρ(770)0/(π++π-) is observed. The ratio decreases by ∼40% from pp to central Pb-Pb collisions. A study of the pT-differential 2ρ(770)0/(π++π-) ratio reveals that the suppression occurs at low transverse momenta, pT<2 GeV/c. At higher momentum, particle ratios measured in heavy-ion and pp collisions are consistent. The observed suppression is very similar to that previously measured for the K∗(892)0/K ratio and is consistent with EPOS3 predictions that may imply that rescattering in the hadronic phase is a dominant mechanism for the observed suppression

    Laboratory testing of muds

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    The equipment and techniques used at H. R. Wallingford Limited (HR) for testing the properties of estuarine muds are described. Erosion under unidirectional currents is measured in an annular flume; a relationship between shear strength, tau(e), and density, rho(d), is determined in the form: tau(e) = a rho(d)b. Self-weight consolidation tests are run in settling columns, with density profiles and excess pore pressures measured during the consolidation period. An empirical relationship between effective stress, sigma', and density is determined in the form: sigma' = a0 + a1-rho + a2-rho-2. Permeability, k, against density is determined in the form: log(k) = c0 + c1-rho

    Sediment transport model for muddy tidal rivers

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