1,449 research outputs found

    Differences Between Mothers’ and Fathers’ Advice-Giving Style and Content: Relations With Social Competence and Psychological Functioning in Middle Childhood

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    The current study examines the relation between mothers’ and fathers’ advicegiving style and content and children’s social competence and psychosocial functioning at a single time point and across a 1-year period. Fifty-eight 3rdgrade children (50% Euro American, 40% Latino, and 10% African American, Asian American, or other) participated at Time 1 in this short-term longitudinal study. At Time 2, 46 of these children participated. Parental advice-giving style predicted social competence concurrently and one year later above and beyond content. In addition, results also indicate that fathers’ advice giving predicted peer and teacher ratings of social competence over and above mothers’ advice giving both concurrently and one year later. Parental advice-giving style was also related to children’s psychosocial functioning as measured by self-reports of loneliness and depression

    Targeted in vivo extracellular matrix formation promotes neovascularization in a rodent model of myocardial infarction.

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    BackgroundThe extracellular matrix plays an important role in tissue regeneration. We investigated whether extracellular matrix protein fragments could be targeted with antibodies to ischemically injured myocardium to promote angiogenesis and myocardial repair.Methodology/principal findingsFour peptides, 2 derived from fibronectin and 2 derived from Type IV Collagen, were assessed for in vitro and in vivo tendencies for angiogenesis. Three of the four peptides--Hep I, Hep III, RGD--were identified and shown to increase endothelial cell attachment, proliferation, migration and cell activation in vitro. By chemically conjugating these peptides to an anti-myosin heavy chain antibody, the peptides could be administered intravenously and specifically targeted to the site of the myocardial infarction. When administered into Sprague-Dawley rats that underwent ischemia-reperfusion myocardial infarction, these peptides produced statistically significantly higher levels of angiogenesis and arteriogenesis 6 weeks post treatment.Conclusions/significanceWe demonstrated that antibody-targeted ECM-derived peptides alone can be used to sufficiently alter the extracellular matrix microenvironment to induce a dramatic angiogenic response in the myocardial infarct area. Our results indicate a potentially new non-invasive strategy for repairing damaged tissue, as well as a novel tool for investigating in vivo cell biology

    VLA Observations of the Infrared Dark Cloud G19.30+0.07

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    We present Very Large Array observations of ammonia (NH3) (1,1), (2,2), and CCS (2_1-1_0) emission toward the Infrared Dark Cloud (IRDC) G19.30+0.07 at ~22GHz. The NH3 emission closely follows the 8 micron extinction. The NH3 (1,1) and (2,2) lines provide diagnostics of the temperature and density structure within the IRDC, with typical rotation temperatures of ~10 to 20K and NH3 column densities of ~10^15 cm^-2. The estimated total mass of G19.30+0.07 is ~1130 Msun. The cloud comprises four compact NH3 clumps of mass ~30 to 160 Msun. Two coincide with 24 micron emission, indicating heating by protostars, and show evidence of outflow in the NH3 emission. We report a water maser associated with a third clump; the fourth clump is apparently starless. A non-detection of 8.4GHz emission suggests that the IRDC contains no bright HII regions, and places a limit on the spectral type of an embedded ZAMS star to early-B or later. From the NH3 emission we find G19.30+0.07 is composed of three distinct velocity components, or "subclouds." One velocity component contains the two 24 micron sources and the starless clump, another contains the clump with the water maser, while the third velocity component is diffuse, with no significant high-density peaks. The spatial distribution of NH3 and CCS emission from G19.30+0.07 is highly anti-correlated, with the NH3 predominantly in the high-density clumps, and the CCS tracing lower-density envelopes around those clumps. This spatial distribution is consistent with theories of evolution for chemically young low-mass cores, in which CCS has not yet been processed to other species and/or depleted in high-density regions.Comment: 29 pages, 9 figures, accepted for publication by ApJ. Please contact the authors for higher resolution versions of the figure

    Two Massive, Low-Luminosity Cores Toward Infrared Dark Clouds

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    This article presents high-resolution interferometric mosaics in the 850 micron waveband of two massive, quiescent infrared dark clouds. The two clouds were chosen based on their likelihood to represent environments preceding the formation of massive stars. The brightest compact sources detected in each cloud have masses of approximately 110 and 60 solar masses with radii < 0.1 pc, implying mean volume densities of approximately 1 million particles per cubic centimeter and mean column densities of about 1 gram per square centimeter. Supplementary data show these cores to be cold and inactive. Low upper limits to their bolometric luminosities and temperatures place them at a very early stage of evolution while current models of massive star formation suggest they have the potential to form massive stars.Comment: 6 pages, 5 figures. Accepted for publication by the Astrophysical Journa

    The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: tomographic BAO analysis of DR12 combined sample in configuration space

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    We perform a tomographic baryon acoustic oscillations analysis using the two-point galaxy correlation function measured from the combined sample of BOSS DR12, which covers the redshift range of 0.2<z<0.750.2<z<0.75. Splitting the sample into multiple overlapping redshift slices to extract the redshift information of galaxy clustering, we obtain a measurement of DA(z)/rdD_A(z)/r_d and H(z)rdH(z)r_d at nine effective redshifts with the full covariance matrix calibrated using MultiDark-Patchy mock catalogues. Using the reconstructed galaxy catalogues, we obtain the precision of 1.3%2.2%1.3\%-2.2\% for DA(z)/rdD_A(z)/r_d and 2.1%6.0%2.1\%-6.0\% for H(z)rdH(z)r_d. To quantify the gain from the tomographic information, we compare the constraints on the cosmological parameters using our 9-bin BAO measurements, the consensus 3-bin BAO and RSD measurements at three effective redshifts in \citet{Alam2016}, and the non-tomographic (1-bin) BAO measurement at a single effective redshift. Comparing the 9-bin with 1-bin constraint result, it can improve the dark energy Figure of Merit by a factor of 1.24 for the Chevallier-Polarski-Linder parametrisation for equation of state parameter wDEw_{\rm DE}. The errors of w0w_0 and waw_a from 9-bin constraints are slightly improved when compared to the 3-bin constraint result.Comment: 14 pages, 21 figures, 7 Tables. Submitted to MNRA

    Changes in Floquet state structure at avoided crossings: delocalization and harmonic generation

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    Avoided crossings are common in the quasienergy spectra of strongly driven nonlinear quantum wells. In this paper we examine the sinusoidally driven particle in a square potential well to show that avoided crossings can alter the structure of Floquet states in this system. Two types of avoided crossings are identified: on type leads only to temporary changes (as a function of driving field strength) in Floquet state structure while the second type can lead to permanent delocalization of the Floquet states. Radiation spectra from these latter states show significant increase in high harmonic generation as the system passes through the avoided crossing.Comment: 8 pages with 10 figures submitted to Physical Review

    The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: single-probe measurements from CMASS anisotropic galaxy clustering

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    With the largest spectroscopic galaxy survey volume drawn from the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS), we can extract cosmological constraints from the measurements of redshift and geometric distortions at quasi-linear scales (e.g. above 50 h1h^{-1}Mpc). We analyze the broad-range shape of the monopole and quadrupole correlation functions of the BOSS Data Release 12 (DR12) CMASS galaxy sample, at the effective redshift z=0.59z=0.59, to obtain constraints on the Hubble expansion rate H(z)H(z), the angular-diameter distance DA(z)D_A(z), the normalized growth rate f(z)σ8(z)f(z)\sigma_8(z), and the physical matter density Ωmh2\Omega_mh^2. We obtain robust measurements by including a polynomial as the model for the systematic errors, and find it works very well against the systematic effects, e.g., ones induced by stars and seeing. We provide accurate measurements {DA(0.59)rs,fid/rs\{D_A(0.59)r_{s,fid}/r_s Mpc\rm Mpc, H(0.59)rs/rs,fidH(0.59)r_s/r_{s,fid} kms1Mpc1km s^{-1} Mpc^{-1}, f(0.59)σ8(0.59)f(0.59)\sigma_8(0.59), Ωmh2}\Omega_m h^2\} = {1427±26\{1427\pm26, 97.3±3.397.3\pm3.3, 0.488±0.0600.488 \pm 0.060, 0.135±0.016}0.135\pm0.016\}, where rsr_s is the comoving sound horizon at the drag epoch and rs,fid=147.66r_{s,fid}=147.66 Mpc is the sound scale of the fiducial cosmology used in this study. The parameters which are not well constrained by our galaxy clustering analysis are marginalized over with wide flat priors. Since no priors from other data sets, e.g., cosmic microwave background (CMB), are adopted and no dark energy models are assumed, our results from BOSS CMASS galaxy clustering alone may be combined with other data sets, i.e., CMB, SNe, lensing or other galaxy clustering data to constrain the parameters of a given cosmological model. The uncertainty on the dark energy equation of state parameter, ww, from CMB+CMASS is about 8 per cent. The uncertainty on the curvature fraction, Ωk\Omega_k, is 0.3 per cent. We do not find deviation from flat Λ\LambdaCDM.Comment: 15 pages, 11 figures. The latest version matches and the accepted version by MNRAS. A bug in the first version has been identified and fixed in the new version. We have redone the analysis with newest data (BOSS DR12

    Quantifying Inactive Lithium in Lithium Metal Batteries

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    Inactive lithium (Li) formation is the immediate cause of capacity loss and catastrophic failure of Li metal batteries. However, the chemical component and the atomic level structure of inactive Li have rarely been studied due to the lack of effective diagnosis tools to accurately differentiate and quantify Li+ in solid electrolyte interphase (SEI) components and the electrically isolated unreacted metallic Li0, which together comprise the inactive Li. Here, by introducing a new analytical method, Titration Gas Chromatography (TGC), we can accurately quantify the contribution from metallic Li0 to the total amount of inactive Li. We uncover that the Li0, rather than the electrochemically formed SEI, dominates the inactive Li and capacity loss. Using cryogenic electron microscopies to further study the microstructure and nanostructure of inactive Li, we find that the Li0 is surrounded by insulating SEI, losing the electronic conductive pathway to the bulk electrode. Coupling the measurements of the Li0 global content to observations of its local atomic structure, we reveal the formation mechanism of inactive Li in different types of electrolytes, and identify the true underlying cause of low Coulombic efficiency in Li metal deposition and stripping. We ultimately propose strategies to enable the highly efficient Li deposition and stripping to enable Li metal anode for next generation high energy batteries

    Floquet scattering theory of quantum pumps

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    We develop the Floquet scattering theory for quantum mechanical pumping in mesoscopic conductors. The nonequilibrium distribution function, the dc charge and heat currents are investigated at arbitrary pumping amplitude and frequency. For mesoscopic samples with discrete spectrum we predict a sign reversal of the pumped current when the pump frequency is equal to the level spacing in the sample. This effect allows to measure the phase of the transmission coefficient through the mesoscopic sample. We discuss the necessary symmetry conditions (both spatial and temporal) for pumping.Comment: 11 pages, 5 figure

    Gain without population inversion in V-type systems driven by a frequency-modulated field

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    We obtain gain of the probe field at multiple frequencies in a closed three-level V-type system using frequency modulated pump field. There is no associated population inversion among the atomic states of the probe transition. We describe both the steady-state and transient dynamics of this system. Under suitable conditions, the system exhibits large gain simultaneously at series of frequencies far removed from resonance. Moreover, the system can be tailored to exhibit multiple frequency regimes where the probe experiences anomalous dispersion accompanied by negligible gain-absorption over a large bandwidth, a desirable feature for obtaining superluminal propagation of pulses with negligible distortion.Comment: 10 pages + 8 figures; To appear in Physical Review
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