59,976 research outputs found

    Regulation of tissue crosstalk by skeletal muscle-derived myonectin and other myokines.

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    The integrated control of animal physiology requires intimate tissue crosstalk, a vital task mediated by circulating humoral factors. As one type of these factors, adipose tissue-derived adipokines have recently garnered attention as important regulators of systemic insulin sensitivity and metabolic homeostasis. However, the realization that skeletal muscle also secretes a variety of biologically and metabolically active polypeptide factors (collectively called myokines) has provided a new conceptual framework to understand the critical role skeletal muscle plays in coordinating whole-body energy balance. Here, we highlight recent progress made in the myokine field and discuss possible roles of myonectin, which we have recently identified as a potential postprandial signal derived from skeletal muscle to integrate metabolic processes in other tissues, such as adipose and liver; one of its roles is to promote fatty acid uptake into cells. Myonectin is also likely an important mediator in inter-tissue crosstalk

    Synthesising and utilising complex evidence to inform policy in education and health.

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    Oslo, Norway, May 19 to 21, 200

    Random Feature Maps via a Layered Random Projection (LaRP) Framework for Object Classification

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    The approximation of nonlinear kernels via linear feature maps has recently gained interest due to their applications in reducing the training and testing time of kernel-based learning algorithms. Current random projection methods avoid the curse of dimensionality by embedding the nonlinear feature space into a low dimensional Euclidean space to create nonlinear kernels. We introduce a Layered Random Projection (LaRP) framework, where we model the linear kernels and nonlinearity separately for increased training efficiency. The proposed LaRP framework was assessed using the MNIST hand-written digits database and the COIL-100 object database, and showed notable improvement in object classification performance relative to other state-of-the-art random projection methods.Comment: 5 page

    Surface roughness influence on the quality factor of high frequency nanoresonators

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    Surface roughness influences significantly the quality factor of high frequency nanoresonators for large frequency - relaxation times within the non-Newtonian regime, where a purely elastic dynamics develops. It is shown that the influence of sort wavelength roughness, which is expressed by the roughness exponent H for the case of self-affine roughness, plays significant role in comparison with the effect of the long wavelength roughness parameters such as the rms roughness amplitude and the lateral roughness correlation length. Therefore, the surface morphology can play important role in designing high-frequency resonators operating within the non-Newtonian regime.Comment: 13 pages, 4 figures, To appear in J. Appl. Phys. (2008

    RAMESES publication standards: realist syntheses

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    PMCID: PMC3558331This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

    Cold-air performance of a 15.41-cm-tip-diameter axial-flow power turbine with variable-area stator designed for a 75-kW automotive gas turbine engine

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    An experimental evaluation of the aerodynamic performance of the axial flow, variable area stator power turbine stage for the Department of Energy upgraded automotive gas turbine engine was conducted in cold air. The interstage transition duct, the variable area stator, the rotor, and the exit diffuser were included in the evaluation of the turbine stage. The measured total blading efficiency was 0.096 less than the design value of 0.85. Large radial gradients in flow conditions were found at the exit of the interstage duct that adversely affected power turbine performance. Although power turbine efficiency was less than design, the turbine operating line corresponding to the steady state road load power curve was within 0.02 of the maximum available stage efficiency at any given speed

    The mystery of the 'Kite' radio source in Abell 2626: insights from new Chandra observations

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    We present the results of a new Chandra study of the galaxy cluster A2626. The radio emission of the cluster shows a complex system of four symmetric arcs without known correlations with the X-ray emission. The mirror symmetry of the radio arcs toward the center and the presence of two optical cores in the central galaxy suggested that they may be created by pairs of precessing radio jets powered by dual AGNs inside the cD galaxy. However, previous observations failed to observe the second jetted AGN and the spectral trend due to radiative age along the radio arcs, thus challenging this interpretation. The new Chandra observation had several scientific objectives, including the search for the second AGN that would support the jet precession model. We focus here on the detailed study of the local properties of the thermal and non-thermal emission in the proximity of the radio arcs, in order to get more insights into their origin. We performed a standard data reduction of the Chandra dataset deriving the radial profiles of temperature, density, pressure and cooling time of the intra-cluster medium. We further analyzed the 2D distribution of the gas temperature, discovering that the south-western junction of the radio arcs surrounds the cool core of the cluster. We studied the X-ray SB and spectral profiles across the junction, finding a cold front spatially coincident with the radio arcs. This may suggest a connection between the sloshing of the thermal gas and the nature of the radio filaments, raising new scenarios for their origin. A possibility is that the radio arcs trace the projection of a complex surface connecting the sites where electrons are most efficiently reaccelerated by the turbulence that is generated by the gas sloshing. In this case, diffuse emission embedded by the arcs and with extremely steep spectrum should be most visible at very low radio frequencies.Comment: 7 pages, 7 figures. Accepted for publication on A&

    X-ray Observations of Parsec-Scale Tails behind Two Middle-Aged Pulsars

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    Chandra and XMM-Newton resolved extremely long tails behind two middle-aged pulsars, J1509-5850 and J1740+1000. The tail of PSR J1509-5850 is discernible up to 5.6' from the pulsar (6.5 pc at a distance of 4 kpc), with a flux of 2*10^{-13} erg s^{-1} cm^{-2} in 0.5-8 keV. The tail spectrum fits an absorbed power-law (PL) model with the photon index of 2.3\pm0.2, corresponding to the 0.5-8 keV luminosity of 1*10^{33} ergs s^{-1}, for n_H= 2.1*10^{22} cm^{-2}. The tail of PSR J1740+1000 is firmly detected up to 5' (2 pc at a 1.4 kpc distance), with a flux of 6*10^{-14} ergs cm^{-2} s^{-1} in 0.4-10 keV. The PL fit yields photon index of 1.4-1.5 and n_H=1*10^{21} cm^{-2}. The large extent of the tails suggests that the bulk flow in the tails starts as mildly relativistic downstream of the termination shock, and then gradually decelerates. Within the observed extent of the J1509-5850 tail, the average flow speed exceeds 5,000 km s^{-1}, and the equipartition magnetic field is a few times 10^{-5} G. For the J1740+1000 tail, the equipartition field is a factor of a few lower. The harder spectrum of the J1740+1000 tail implies either less efficient cooling or a harder spectrum of injected electrons. For the high-latitude PSR J1740+1000, the orientation of the tail on the sky shows that the pulsar is moving toward the Galactic plane, which means that it was born from a halo-star progenitor. The comparison between the J1509 and J1740 tails and the X-ray tails of other pulsars shows that the X-ray radiation efficiency correlates poorly with the pulsar spin-down luminosity or age. The X-ray efficiencies of the ram-pressure confined pulsar wind nebulae (PWNe) are systematically higher than those of PWNe around slowly moving pulsars with similar spin-down parameters.Comment: 14 pages, 16 figures and 5 table

    Perspective on Quark Mass and Mixing Relations

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    Recent data indicate that Vub≅λ4≅(0.22)4V_{ub}\cong \lambda^4 \cong (0.22)^4, while mtm_t seems to be 174174 GeV. The relations md/ms∼ms/mb∼δ∼λ2≃∣Vcb∣m_d/m_s\sim m_s/m_b \sim \delta \sim \lambda^2 \simeq \vert V_{cb}\vert and mu/mc∼mc/mt∼δ2∼λ4∼∣Vub∣m_u/m_c\sim m_c/m_t \sim \delta^2 \sim \lambda^4 \sim \vert V_{ub}\vert suggest that %a plausible clean separation of the %origin of the quark mixing matrix: the down type sector is responsible for ∣Vus∣\vert V_{us}\vert and ∣Vcb∣\vert V_{cb}\vert, while VubV_{ub} comes from the up type sector. Five to six parameters might suffice to account for the ten quark mass and mixing parameters, resulting in specific power series representations for the mass matrices. In this picture, δ\delta seems to be the more sensible expansion parameter, while λ≅md/ms∼δ\lambda \cong \sqrt{m_d/m_s} \sim \sqrt{\delta} is tied empirically to (Md)11=0(M_d)_{11} = 0.Comment: 10 pages, ReVtex, no figure
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