89 research outputs found

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

    Get PDF
    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

    Get PDF

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

    Get PDF
    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

    Get PDF
    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

    Get PDF
    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

    Get PDF
    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

    Sediment transport model for muddy tidal rivers

    No full text

    Laboratory testing of muds

    No full text
    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

    A Comparative Analysis of Master of Nursing Students\u27 Scholarly Inquiry

    No full text
    Although graduates of master\u27s of nursing programs are expected to demonstrate competence in systematic inquiry, few reports describe how students obtain this skill. We conducted a comparative analysis of 118 scholarly projects from 2004 to 2009 with an earlier sample of 112 projects from 1996 to 2003. We examined changes in the method of scholarly inquiry, population type examined, and outcomes or products of inquiry. Data from a scholarly inquiry evaluation checklist were transcribed and analyzed. Literature review continued to be the most frequent method of scholarly inquiry, with few group differences noted between the time periods. Evidence-based clinical or practice projects increased as an inquiry method, as did health care providers as the population type. Papers of publishable quality and educational materials increased as outcomes of scholarly inquiry. Although this analysis is limited by incomplete data and a need to clarify checklist categories, the increased number of clinical-based projects supports a shift to evidence-based practice outcomes. The expansion in the number of educational scholarly projects is attributed to increasing enrollment in the nurse educator option. With new Essentials of Master\u27s Education in Nursing and the transition of specialty preparation to the doctoral level, revisiting scholarly outcomes for master\u27s degree students is recommended

    Using the inverse finite‐element method to harmonise classical modal analysis with fibre‐optic strain data for robust population‐based structural health monitoring

    No full text
    AbstractVibration‐based approaches to structural health monitoring (SHM) gained increasing significance for assessing the behaviour of existing structures because of their non‐intrusive nature and high sensitivity to damage. However, data availability often limits the application of SHM approaches. The population‐based structural health monitoring (PBSHM) theory addresses this challenge, enhancing diagnostic inferences by sharing knowledge across a population of similar structures. In real‐life scenarios, sharing data from distinct structures requires dealing with results obtained with different experimental setups, multiple sensors, input choices and acquisition systems. Therefore, it is crucial to harmonise various features to achieve accurate and reliable results. The present study presents the results of a classic experimental modal analysis (EMA) using scanning laser Doppler vibrometer (SLDV) measurements and a strain‐based EMA conducted using high‐definition distributed fibre‐optic strain sensors. The experimental case study of a laboratory‐scale steel aircraft subjected to specific operating and damage conditions is introduced, allowing for a comprehensive discussion of the features extracted from the two EMA techniques, which can also be generalised to structures within different domains. This research highlights the advantages and limitations of fibre‐optic‐based EMA compared to classic methods, as fibre‐optic strain sensors offer a cost‐effective alternative to accelerometers or SLDV for dynamic testing. Furthermore, the feasibility of employing the inverse finite‐element method (iFEM) in the dynamic domain is investigated. This method can estimate the whole displacement field of a structure from a limited number of strain values, thus harmonising strain measurements with the SLDV measurements. By analysing the features extracted from different EMA techniques within the PBSHM framework, this study contributes to advancing the understanding and application of the PBSHM approach in diverse experimental scenarios, laying the foundation for further investigation of features and adequate methods for sharing damage‐state knowledge across a population of structures.</jats:p
    corecore