256 research outputs found

    Universal turbulence on branes in holography

    Full text link
    At a meson melting transition in holographic QCD, a weak turbulence of mesons was found with critical embeddings of probe D-branes in gravity duals. The turbulent mesons have a power-law energy distribution εn(ωn)α\varepsilon_n \propto (\omega_n)^\alpha where ωn\omega_n is the mass of the nn-th excited resonance of the meson tower. In this paper, we find that the turbulence power α\alpha is universal, irrespective of how the transition is driven, by numerically calculating the power in various static brane setups at criticality. We also find that the power α\alpha depends only on the cone dimensions of the probe D-branes.Comment: 28 pages, 16 figures, v2: a reference adde

    Microphase Separation of Block Polymers

    Get PDF
    Block polymers composed of incompatible block chains of A and B undergo a microphase separation due to the repulsive interaction between A and B in solutions at concentrations above the critical concentration, or in bulk at temperatures below the critical temperature, Tc, (for the A-B system having an upper critical solution temperature) or above Tc (for the system having a lower critical temperature). The microphase separation results in a microdomain structure in solid state, the morphology of which controls the unique physical properties of the block polymer systems. This article reviews recent developments in the area of (i) microphase separation and phase-separated structure in solution and in bulk (ii) microdomain structure in solid state and (iii) polymer-polymer interphase in block polymers for amorphous and linear block polymer systems having simple architectures (e.g., polystyrene and polyisoprene or polystyrene and polybutadiene diblock or triblock polymers)

    CONSTRUCTION PLACEMENT, HARDENED PROPERTIES AND DURABILITY OF SHOTCRETE WITH HIGHLY FUNCTIONAL FLY ASH

    Get PDF
    Shikoku Electric Power Co., Inc. has developed the technology to manufacture a brand name “Finash” about 12 years ago, by sorting and classifying coal ash generated in coal fired power plants. “Finash” is highly functional fly ash (HFA) is produced by removing irregular coarse particles. It is important for the production of HFA to minimize the variation in quality of coal ash with sophisticated classification technique and extracting good-quality spherical fine particles. The specific surface of HFA is more than 5000 cm2/g. It is now widely utilized as concrete admixture for general civil engineering structures and buildings in Japan. When highly functional fly ash (HFA) is used as shotcrete admixture to substitute for fine aggregate of 100kg/m3, the shotcrete has the advantages of decreasing the amount of dust and rebound during spraying operation, improving the hardened properties and durability of concrete, etc. Therefore, it has been applied in many tunnels by NATM. In order to verify the high performance of shotcrete with HFA, firstly it was carried out the spray tests at the model tunnel using the shotcrete with HFA having the specific surface of 5530cm2/g compared with normal shotcrete without fly ash and shotcrete with the lower fly ash (class 4th-FA) having the specific surface of 1770cm2/g. Secondly it was carried out the spray tests at an actual road tunnel using the shotcrete with HFA having the specific surface of 5450cm2/g compared with normal shotcrete without fly ash and shotcrete with the conventional dust reducing agent of 0.1% mass of the cement. This paper discusses about the various characteristics such as construction placement (dust concentration and rebound rate), hardened properties and durability (compressive strength, accelerating neutralization depth and dry shrinkage) on theses several sorts of shotcrete

    GG-prime and GG-primary GG-ideals on GG-schemes

    Full text link
    Let GG be a flat finite-type group scheme over a scheme SS, and XX a noetherian SS-scheme on which GG-acts. We define and study GG-prime and GG-primary GG-ideals on XX and study their basic properties. In particular, we prove the existence of minimal GG-primary decomposition and the well-definedness of GG-associated GG-primes. We also prove a generalization of Matijevic-Roberts type theorem. In particular, we prove Matijevic-Roberts type theorem on graded rings for FF-regular and FF-rational properties.Comment: 54pages, added Example 6.16 and the reference [8]. The final versio

    Feasibility of cryopreserved tracheal xenotransplants with the use of short-course immunosuppression

    Get PDF
    AbstractObjective: We evaluated the feasibility of discordant xenotransplantation of the cryopreserved trachea with intermittent immunosuppression to help solve the shortage of donor tracheas. Methods: Two experiments were performed with heterotopic transplantation models in 14 guinea pigs and 85 rats. So that the minimal dose of FK506 for viable fresh xenografts could be determined, FK506 was given in escalating doses (0, 1.5, 2.5, and 3.5 mg/kg) for recipient animals after xenogeneic transplantation. With the goal of obtaining a long-term survival of the xenografts, the effect of cryopreservation on xenografts was assessed and thereafter different cycles of immunosuppression every third week were evaluated in fresh or cryopreserved xenografts in the second experiment. Results: An FK506 dosage of more than 2.5 mg/kg per day was much more effective than smaller dosages, as demonstrated by morphologic assessment. A higher dosage of FK506 potentially delayed the rejection of xenografts and can thus maintain tracheal xenograft viability for less than 4 weeks in rat recipients. In experiment 2, the cryopreserved xenografts showed less histologic viability than fresh xenografts but greater patency of the lumen. The patency of cryopreserved xenografts was favorably maintained for a longer period than that of fresh xenografts with either the same number or more cycles of immunosuppression. Conclusions: We conclude that the synergistic effect of cryopreservation and adequate intermittent immunosuppression may enable tracheal xenografts to remain viable over longer periods. (J Thorac Cardiovasc Surg 2001;121:241-8

    Migration, early axonogenesis, and Reelin-dependent layer-forming behavior of early/posterior-born Purkinje cells in the developing mouse lateral cerebellum

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Cerebellar corticogenesis begins with the assembly of Purkinje cells into the Purkinje plate (PP) by embryonic day 14.5 (E14.5) in mice. Although the dependence of PP formation on the secreted protein Reelin is well known and a prevailing model suggests that Purkinje cells migrate along the 'radial glial' fibers connecting the ventricular and pial surfaces, it is not clear how Purkinje cells behave in response to Reelin to initiate the PP. Furthermore, it is not known what nascent Purkinje cells look like <it>in vivo</it>. When and how Purkinje cells start axonogenesis must also be elucidated.</p> <p>Results</p> <p>We show that Purkinje cells generated on E10.5 in the posterior periventricular region of the lateral cerebellum migrate tangentially, after only transiently migrating radially, towards the anterior, exhibiting an elongated morphology consistent with axonogenesis at E12.5. After their somata reach the outer/dorsal region by E13.5, they change 'posture' by E14.5 through remodeling of non-axon (dendrite-like) processes and a switchback-like mode of somal movement towards a superficial Reelin-rich zone, while their axon-like fibers remain relatively deep, which demarcates the somata-packed portion as a plate. In <it>reeler </it>cerebella, the early born posterior lateral Purkinje cells are initially normal during migration with anteriorly extended axon-like fibers until E13.5, but then fail to form the PP due to lack of the posture-change step.</p> <p>Conclusions</p> <p>Previously unknown behaviors are revealed for a subset of Purkinje cells born early in the posteior lateral cerebellum: tangential migration; early axonogenesis; and Reelin-dependent reorientation initiating PP formation. This study provides a solid basis for further elucidation of Reelin's function and the mechanisms underlying the cerebellar corticogenesis, and will contribute to the understanding of how polarization of individual cells drives overall brain morphogenesis.</p

    Transient and permanent gene transfer into the brain of the teleost fish medaka (Oryzias latipes) using human adenovirus and the Cre-loxP system

    Get PDF
    AbstractIn this study, we demonstrated that human type-5 adenovirus infected the brain of the teleost fish, medaka (Oryzias latipes), in vivo. Injection of adenoviral vector into the mesencephalic ventricle of medaka larvae induced the expression of reporter genes in some parts of the telencephalon, the periventricular area of the mesencephalon and diencephalon, and the cerebellum. Additionally, the Cre-loxP system works in medaka brains using transgenic medaka carrying a vector containing DsRed2, flanked by loxP sites under control of the β-actin promoter and downstream promoterless enhanced green fluorescent protein (EGFP). We demonstrated that the presence of green fluorescence depended on injection of adenoviral vector expressing the Cre gene and confirmed that EGFP mRNA was transcribed in the virus-injected larvae

    Development of cosmic x-ray polarimeter

    Get PDF
    We present a performance study of a cosmic X-ray polarimeter which is based on the photoelectric effect in gas, and sensitive to a few to 30 keV range. In our polarimeter, the key device would be the 50 μm pitch Gas Electron Multiplier (GEM). We have evaluated the modulation factor using highly polarized X-ray, provided by a synchrotron accelerator. In the analysis, we selected events by the eccentricity of the charge cloud of the photoelectron track. As a result, we obtained the relationship between the selection criteria for the eccentricity and the modulation factors; for example, when we selected the events which have their eccentricity of > 0.95, the polarimeter exhibited with the modulation factor of 0.32. In addition, we estimated the Minimum Detectable Polarization degree (MDP) of Crab Nebula with our polarimeter and found 10 ksec observation is enough to detect the polarization, if we adopt suitable X-ray mirrors

    Effect of Hyperosmotic Stimulation and Adrenalectomy on Vasopressin mRNA Levels in the Paraventricular and Supraoptic Nuclei of the Hypothalamus:

    Get PDF
    The effects of salt loading and adrenalectomy on arginine vasopressin (AVP) mRNA levels in the paraventricular nucleus (PVN) and the supraoptic nucleus (SON) of the hypothalamus were studied by semiquantitative in situ hybridization histochemistry, using a synthetic oligonucleotide probe and a computer-assisted image analysis system. Salt loading (2% NaCl) for 7 days produced marked increases in AVP mRNA levels in the magnocellular neurons of the PVN, SON, and accessory nuclei. Adrenalectomy caused an increase in AVP mRNA expression in the magnocellular part of the PVN and the expansion of hybridization signals into its medial parvocellular region, where the cell bodies of corticotropin-releasing hormone (CRH) neurons are located. No apparent alteration of AVP mRNA levels was observed in the SON following adrenalectomy. These results indicate that hyperosmotic stimulation and the loss of circulating glucocorticoids had differential effects on AVP gene expression in the PVN and SON, and that the magnocellular PVN and SON neurons responded in different manners to the loss of feedback signals.</p
    corecore