4,699 research outputs found

    Fibroblasts Inform the Heart: Control of Cardiomyocyte Cycling and Size by Age-Dependent Paracrine Signals

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    Within the developing and adult heart, the fibroblast is often dismissed as merely a structural element, important just to mechanical integrity or to scarring when excessive in disease. Ieda et al. in this issue of Developmental Cell now report an essential program of paracrine factor production in cardiac fibroblasts that controls heart muscle cell growth, driving cycling or enlargement depending on the fibroblasts' developmental stage

    Architecture Based Workload Analysis of UAS Multi-Aircraft Control: Implications of Implementation on MQ-1B Predator

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    An increased demand for use of Unmanned Aircraft Systems (UASs) without commensurate increases in pilot manpower has prompted proposals for simultaneous control of multiple aircraft by a single pilot or Multi-Aircraft Control (MAC). To understand the potential effects of MAC, an IMPRINT Pro, Multi-Resource Theory, pilot workload model was developed from pedigreed system architecture. Feedback from active UAS pilots was used to validate the model and establish a workload saturation threshold value of 60, above which pilots may experience performance degradation over extended periods of time. The model predicts that pilots experience low workload when operating one or two UASs during benign operations, and operate 91% of the time below a workload of 25 without saturation. However, conflict from multi-task overlap builds rapidly when the pilot is required to operate three or more aircraft. The percentage of time over the saturation threshold increases to 21% with four aircraft under benign operating conditions. When dynamic events are introduced the workload becomes unmanageable, with estimates regularly over 100 due to multi-task overlap and communication activities. The analysis indicates the need for techniques and technology to reduce task and communications demands on UAS pilots to effectively implement MAC

    Learning from failure: congestive heart failure in the postgenomic age

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    Cosmic Shear Results from the Deep Lens Survey - II: Full Cosmological Parameter Constraints from Tomography

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    We present a tomographic cosmic shear study from the Deep Lens Survey (DLS), which, providing a limiting magnitude r_{lim}~27 (5 sigma), is designed as a pre-cursor Large Synoptic Survey Telescope (LSST) survey with an emphasis on depth. Using five tomographic redshift bins, we study their auto- and cross-correlations to constrain cosmological parameters. We use a luminosity-dependent nonlinear model to account for the astrophysical systematics originating from intrinsic alignments of galaxy shapes. We find that the cosmological leverage of the DLS is among the highest among existing >10 sq. deg cosmic shear surveys. Combining the DLS tomography with the 9-year results of the Wilkinson Microwave Anisotropy Probe (WMAP9) gives Omega_m=0.293_{-0.014}^{+0.012}, sigma_8=0.833_{-0.018}^{+0.011}, H_0=68.6_{-1.2}^{+1.4} km/s/Mpc, and Omega_b=0.0475+-0.0012 for LCDM, reducing the uncertainties of the WMAP9-only constraints by ~50%. When we do not assume flatness for LCDM, we obtain the curvature constraint Omega_k=-0.010_{-0.015}^{+0.013} from the DLS+WMAP9 combination, which however is not well constrained when WMAP9 is used alone. The dark energy equation of state parameter w is tightly constrained when Baryonic Acoustic Oscillation (BAO) data are added, yielding w=-1.02_{-0.09}^{+0.10} with the DLS+WMAP9+BAO joint probe. The addition of supernova constraints further tightens the parameter to w=-1.03+-0.03. Our joint constraints are fully consistent with the final Planck results and also the predictions of a LCDM universe.Comment: Accepted for publication in Ap
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