136 research outputs found

    Seismic Retrofitting Using Micropile Systems Centrifugal Model Studies

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    A series of centrifuge tests were conducted on micropile group and network systems in order to investigate the response to earthquake loading and soil-micropile interaction behavior. Model tests on group and network systems embedded in loose to medium dry sand are described. Micropile bending moment, deflection, and acceleration were measured during testing. Dynamic p-y curves were derived from the measurements for low and high levels of shaking and were compared with the backbone p-y curves for sand recommended by API and other published data. Group and network effects were investigated for different configurations and at different levels of loading. For the selected frequency of excitation, the results indicate a positive group effect increasing with the number of piles and the batter angle. This paper describes the experimental procedures used to carry out the centrifugal model tests and summarizes the main preliminary results

    Antenna Diversity for a Narrow-Band Successive-Cancellation Multiuser Detector

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    Electron irradiation induced reduction of the permittivity in chalcogenide glass (As2S3) thin film

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    We investigate the effect of electron beam irradiation on the dielectric properties of As2S3 Chalcogenide glass. By means of low-loss Electron Energy Loss Spectroscopy, we derive the permittivity function, its dispersive relation, and calculate the refractive index and absorption coefficients under the constant permeability approximation. The measured and calculated results show, to the best of our knowledge, a heretofore unseen phenomenon: the reduction in the permittivity of <40%, and consequently a modification of the refractive index follows, reducing it by 20%, hence suggesting a significant change on the optical properties of the material. The plausible physical phenomena leading to these observations are discussed in terms of the homopolar and heteropolar bond dynamics under high energy absorption.Comment: 22 pages, 7 figures, manuscript in preparation to send to Physical Review

    Comparative Outer Membrane Protein Analysis of High and Low-Invasive Strains of Cronobacter malonaticus

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    are an important group of foodborne pathogens that has been linked to life-threatening infections in both infants and adults. The major infections associated with species are neonatal meningitis, necrotizing enterocolitis, and septicaemia. There are seven species in the genus, of which only three are of clinical importance; , and . To date most studies have focussed on as it is the major species associated with neonatal infections. However, recently , in particular sequence type 7 (ST7), has been noted as being prevalent in adult infections and therefore warranting further investigation. In this study, eight strains of ST7, that had been isolated from a wide range of sources and varied in their virulence, were chosen for proteomic analysis of their outer membrane proteins (OMPs). One-dimensional gel analysis revealed a ~29 kDa size band that was only present in the highly invasive strains. Subsequent mass spectrometric analysis identified several peptides that matched the flagellin protein. The presence of flagellin protein was confirmed in 2D gel spot. Mass spectrometry analysis of total OMPs revealed that the four highly invasive strains expressed the main flagellum proteins that were absent from the four low invasive strains. These were the flagellar hook protein FlgE, flagellar hook-associated protein 1, flagellar hook-associated protein, flagellin, and flagellar hook-filament junction protein FlgL. This data indicates that flagellar proteins may have an important role in the organism's invasion properties

    Séminome Spermatocytaire: à Propos d’un Cas et Revue de La Littérature Spermatocytic Seminoma

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    Le séminome spermatocytaire est une tumeur rare, représentant moins de 2% des cancers du testicule, survenant essentiellement chez le sujet âgé. Nous rapportons une nouvelle observation d’un patient âgé de 48 ans. La tumeur se présentait comme une prolifération de cellules en nappescompactes, avec 3 types cellulaires, des cellules de petite taille, des cellules intermédiaires et des grandes cellules. Il n’a été retrouvé ni contingent sarcomateux, ni séminome classique. L’analyse en immun histochimie n’a retrouvé aucune expression des cellules tumorales pour les anticorpsclassiques testés, notamment l’Ac anti PLAP et les marqueurs lymphoïdes. Le séminome spermatocytaire doit être reconnu, car son évolution est très favorable et ne nécessite qu’une simple orchidectomie, en l’absence d’un exceptionnel contingent sarcomateux ou de métastase où une chimiothérapie s’impose

    An Approach to Construct Dynamic Service Mashups using Lightweight Semantics

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    Thousands of Web services have been available online, and mashups built upon them have been creating added value. However, mashups are mostly developed with a predefined set of services and components. The extensions to them always involve programming work. Furthermore, when a service is unavailable, it is challenging for mashups to smoothly switch to an alternative that others similar functionalities. To address these problems, this paper presents a novel approach to enable mashups to select and invoke semantic Web services on they. To extend a mashup with new semantic services, developers are only required to register and publish them as Linked Data. By refining the strategies of service selection, mashups can behave more adaptively and other higher fault-tolerance

    Déclin précipité du Triton de Poiret Pleurodeles poireti Gervais, 1835 et autres changements du statut des amphibiens de Numidie, Algérie du Nord-Est

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    The worldwide erosion of biological diversity has not spared amphibians which are amongst the most affected taxa with numerous extinct or near-extinct species. Our knowledge of the status and ecology of amphibians of Algeria is still limited whereas local natural habitats are fast disappearing under a strong anthropogenic pressure. Eighty two localities were sampled between 1996 and 2010, to survey the amphibian community within Numidia, North-Eastern Algeria. Nine species, three Urodeles (Pleurodeles poireti, Pleurodeles nebulosus and Salamandra algira and six Anurans (Bufo bufo spinosus, Bufo mauritanicus, Bufo viridis, Discoglossus pictus, Hyla meridionalis and Pelophylax saharicus) were found within the region. Results suggest a marked, rapid and unexplained crash of the Algerian Newt Pleurodeles poireti, a species endemic to a small area in and around Djebel Edough (Annaba). Information on the status (abundance and distribution) of each recorded taxon is provided and conservation measures are discussed in the light of an apparent local decline of Anurans and the vulnerability of three species (S. algira, P. nebulosus and B. bufo spinosus)La crise aiguë que traverse la biodiversité à l'échelle planétaire n'a pas épargné les amphibiens qui figurent parmi les taxons les plus touchés, illustrés par le déclin prononcé ou la disparition de plusieurs espèces. Notre connaissance du statut et de l'écologie des amphibiens d'Algérie reste limitée alors que les milieux naturels locaux subissent une pression anthropique intense qui ne fait que s'accroître et qui risque de s'exacerber sous l'effet du réchauffement climatique. Dans le but d'inventorier et d'évaluer le statut du peuplement d'amphibiens du complexe de zones humides de la Numidie, «point chaud» pour de nombreux taxons aquatiques et poche relictuelle afrotropicale, nous avons échantillonné 82 sites entre 1996 et 2010. Un total de neuf espèces dont trois Urodèles (Pleurodeles poireti Gervais, 1835, Pleurodeles nebulosus (Guichenot, 1850) et Salamandra algira Bedriaga, 1883) et six Anoures (Bufo bufo spinosus, Bufo mauritanicus Schlegel, 1841, Bufo viridis Laurenti, 1768, Discoglossus picrus Otth, 1837, HYla meridionalis Boettger, 1874 et Pelophylax saharicus Boulanger in Hartert, 1913) ont été inventoriées. Un fait marquant est le déclin net, rapide et inexpliqué du Triton de Poiret Pleurodeles poireti, espèce endémique à une région limitée au Djebel Edough et ses environs, au cours des dernières années. Le statut de trois espèces (S. algira, P. nebulosus and B. bufo spinosus) semble préoccupant au vu des pressions anthropogéniques qui s'exercent sur la Numidie qui abrite 82% des amphibiens d'Algérie

    Expression of Protease-Activated Receptor 1 and 2 and Anti-Tubulogenic Activity of Protease-Activated Receptor 1 in Human Endothelial Colony-Forming Cells

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    Endothelial colony-forming cells (ECFCs) are obtained from the culture of human peripheral blood mononuclear cell (hPBMNC) fractions and are characterised by high proliferative and pro-vasculogenic potential, which makes them of great interest for cell therapy. Here, we describe the detection of protease-activated receptor (PAR) 1 and 2 amongst the surface proteins expressed in ECFCs. Both receptors are functionally coupled to extracellular signal-regulated kinase (ERK) 1 and 2, which become activated and phosphorylated in response to selective PAR1- or PAR2-activating peptides. Specific stimulation of PAR1, but not PAR2, significantly inhibits capillary-like tube formation by ECFCs in vitro, suggesting that tubulogenesis is negatively regulated by proteases able to stimulate PAR1 (e.g. thrombin). The activation of ERKs is not involved in the regulation of tubulogenesis in vitro, as suggested by use of the MEK inhibitor PD98059 and by the fact that PAR2 stimulation activates ERKs without affecting capillary tube formation. Both qPCR and immunoblotting showed a significant downregulation of vascular endothelial growth factor 2 (VEGFR2) in response to PAR1 stimulation. Moreover, the addition of VEGF (50–100 ng/ml) but not basic Fibroblast Growth Factor (FGF) (25–100 ng/ml) rescued tube formation by ECFCs treated with PAR1-activating peptide. Therefore, we propose that reduction of VEGF responsiveness resulting from down-regulation of VEGFR2 is underlying the anti-tubulogenic effect of PAR1 activation. Although the role of PAR2 remains elusive, this study sheds new light on the regulation of the vasculogenic activity of ECFCs and suggests a potential link between adult vasculogenesis and the coagulation cascade

    A PBIL for load balancing in network coding based multicasting

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    One of the most important issues in multicast is how to achieve a balanced traffic load within a communications network. This paper formulates a load balancing optimization problem in the context of multicast with network coding and proposes a modified population based incremental learning (PBIL) algorithm for tackling it. A novel probability vector update scheme is developed to enhance the global exploration of the stochastic search by introducing extra flexibility when guiding the search towards promising areas in the search space. Experimental results demonstrate that the proposed PBIL outperforms a number of the state-of-the-art evolutionary algorithms in terms of the quality of the best solution obtained
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