435 research outputs found

    Religious Influences on Work–Family Trade-Offs

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    Despite a large body of research on the influences of religion on family life and gender ideology, few studies examined how religion affects work—family strategies. One set of strategies involves making employment or family trade-offs—strategies of devoting time or attention to either work or family in a situation in which one cannot devote the preferred amount of time and attention to both, strategies that may be experienced as making sacrifices, hard choices, or accommodations. Using 1996 General Social Survey data, the authors analyze how religion affects employment and family trade-offs. They develop hypotheses about the institutional effects of religious involvement and effects of involvement in a conservative religious subculture. They find that religious involvement and religious subculture shape trade-offs in gender-specific ways, and that religion affects more of men\u27s trade-offs. They conclude by calling for further research on the social sources of cultural frameworks that shape men\u27s and women\u27s work—family strategies

    Coz: Finding Code that Counts with Causal Profiling

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    Improving performance is a central concern for software developers. To locate optimization opportunities, developers rely on software profilers. However, these profilers only report where programs spent their time: optimizing that code may have no impact on performance. Past profilers thus both waste developer time and make it difficult for them to uncover significant optimization opportunities. This paper introduces causal profiling. Unlike past profiling approaches, causal profiling indicates exactly where programmers should focus their optimization efforts, and quantifies their potential impact. Causal profiling works by running performance experiments during program execution. Each experiment calculates the impact of any potential optimization by virtually speeding up code: inserting pauses that slow down all other code running concurrently. The key insight is that this slowdown has the same relative effect as running that line faster, thus "virtually" speeding it up. We present Coz, a causal profiler, which we evaluate on a range of highly-tuned applications: Memcached, SQLite, and the PARSEC benchmark suite. Coz identifies previously unknown optimization opportunities that are both significant and targeted. Guided by Coz, we improve the performance of Memcached by 9%, SQLite by 25%, and accelerate six PARSEC applications by as much as 68%; in most cases, these optimizations involve modifying under 10 lines of code.Comment: Published at SOSP 2015 (Best Paper Award

    Joint Strong and Weak Lensing Analysis of the Massive Cluster Field J0850+3604

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    We present a combined strong and weak lensing analysis of the J085007.6+360428 (J0850) field, which was selected by its high projected concentration of luminous red galaxies and contains the massive cluster Zwicky 1953. Using Subaru/Suprime-Cam BVRcIcizBVR_{c}I_{c}i^{\prime}z^{\prime} imaging and MMT/Hectospec spectroscopy, we first perform a weak lensing shear analysis to constrain the mass distribution in this field, including the cluster at z=0.3774z = 0.3774 and a smaller foreground halo at z=0.2713z = 0.2713. We then add a strong lensing constraint from a multiply-imaged galaxy in the imaging data with a photometric redshift of z5.03z \approx 5.03. Unlike previous cluster-scale lens analyses, our technique accounts for the full three-dimensional mass structure in the beam, including galaxies along the line of sight. In contrast with past cluster analyses that use only lensed image positions as constraints, we use the full surface brightness distribution of the images. This method predicts that the source galaxy crosses a lensing caustic such that one image is a highly-magnified "fold arc", which could be used to probe the source galaxy's structure at ultra-high spatial resolution (<30< 30 pc). We calculate the mass of the primary cluster to be Mvir=2.930.65+0.71×1015 M\mathrm{M_{vir}} = 2.93_{-0.65}^{+0.71} \times 10^{15}~\mathrm{M_{\odot}} with a concentration of cvir=3.460.59+0.70\mathrm{c_{vir}} = 3.46_{-0.59}^{+0.70}, consistent with the mass-concentration relation of massive clusters at a similar redshift. The large mass of this cluster makes J0850 an excellent field for leveraging lensing magnification to search for high-redshift galaxies, competitive with and complementary to that of well-studied clusters such as the HST Frontier Fields.Comment: Accepted for publication in The Astrophysical Journal; 14 pages, 13 figures, 3 table

    Analyzing NGSS Scientific Practices in Action.

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    This poster presentation will present ongoing research on the Science Practices in the Classroom Matrix (SPCM), an analytical tool used for identifying the level of sophistication of scientific practices occurring in classroom lessons and the level of student versus teacher centeredness. The SPCM has been used to analyze video recordings of middle grades teachers who participated in a professional development program on inquiry, the nature of science (NOS), and evolutionary concepts. Pre- and post-tests revealed participant teachers’ knowledge and views of inquiry and NOS. This poster highlights interactions, if any, between implementation of the scientific practices and teacher knowledge and views of inquiry and NOS. Implications for prospective teacher education related to using the SPCM to enhance teacher knowledge and views on the scientific practices will be addressed

    Identifying Very Metal-Rich Stars with Low-Resolution Spectra: Finding Planet-Search Targets

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    We present empirical calibrations that estimate stellar metallicity, effective temperature and surface gravity as a function of Lick/IDS indices. These calibrations have been derived from a training set of 261 stars for which (1) high-precision measurements of [Fe/H], T_eff and log g have been made using spectral-synthesis analysis of HIRES spectra, and (2) Lick indices have also been measured. Our [Fe/H] calibration, which has precision 0.07 dex, has identified a number of bright (V < 9) metal-rich stars which are now being screened for hot Jupiter-type planets. Using the Yonsei-Yale stellar models, we show that the calibrations provide distance estimates accurate to 20% for nearby stars. This paper outlines the second tier of the screening of planet-search targets by the N2K Consortium, a project designed to identify the stars most likely to harbor extrasolar planets. Discoveries by the N2K Consortium include the transiting hot Saturn HD 149026 b (Sato et al. 2005, astro-ph/0507009) and HD 88133 b (Fischer et al. 2005). See Ammons et al. (2005, In Press) for a description of the first tier of N2K metallicity screening, calibrations using broadband photometry.Comment: Accepted for publication in the Astrophysical Journa

    The N2K Consortium. II. A Transiting Hot Saturn Around HD 149026 With a Large Dense Core

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    Doppler measurements from Subaru and Keck have revealed radial velocity variations in the V=8.15, G0IV star HD 149026 consistent with a Saturn-Mass planet in a 2.8766 day orbit. Photometric observations at Fairborn Observatory have detected three complete transit events with depths of 0.003 mag at the predicted times of conjunction. HD 149026 is now the second brightest star with a transiting extrasolar planet. The mass of the star, based on interpolation of stellar evolutionary models, is 1.3 +/- 0.1 solar masses; together with the Doppler amplitude, K=43.3 m s^-1, we derive a planet mass Msin(i)=0.36 Mjup, and orbital radius of 0.042 AU. HD 149026 is chromospherically inactive and metal-rich with spectroscopically derived [Fe/H]=+0.36, Teff=6147 K, log g=4.26 and vsin(i)=6.0 km s^-1. Based on Teff and the stellar luminosity of 2.72 Lsun, we derive a stellar radius of 1.45 Rsun. Modeling of the three photometric transits provides an orbital inclination of 85.3 +/- 1.0 degrees and (including the uncertainty in the stellar radius) a planet radius of 0.725 +/- 0.05 Rjup. Models for this planet mass and radius suggest the presence of a ~67 Mearth core composed of elements heavier than hydrogen and helium. This substantial planet core would be difficult to construct by gravitational instability.Comment: 25 pages, 5 figures, accepted by the Astrophysical Journa

    Adaptive Optics Imaging of QSOs with Double-Peaked Narrow Lines: Are they Dual AGNs?

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    Active galaxies hosting two accreting and merging super-massive black holes (SMBHs) -- dual Active Galactic Nuclei (AGN) -- are predicted by many current and popular models of black hole-galaxy co-evolution. We present here the results of a program that has identified a set of probable dual AGN candidates based on near Infra-red (NIR) Laser Guide-Star Adaptive Optics (LGS AO) imaging with the Keck II telescope. These candidates are selected from a complete sample of radio-quiet Quasi-stellar Objects (QSOs) drawn from the Sloan Digital Sky Survey (SDSS), which show double-peaked narrow AGN emission lines. Of the twelve AGNs imaged, we find six with double galaxy structure, of which four are in galaxy mergers. We measure the ionization of the two velocity components in the narrow AGN lines to test the hypothesis that both velocity components come from an active nucleus. The combination of a well-defined parent sample and high-quality imaging allows us to place constraints on the fraction of SDSS QSOs that host dual accreting black holes separated on kiloparsec (kpc) scales: ~0.3%-0.65%. We derive from this fraction the time spent in a QSO phase during a typical merger and find a value that is much lower than estimates that arise from QSO space densities and galaxy merger statistics. We discuss possible reasons for this difference. Finally, we compare the SMBH mass distributions of single and dual AGN and find little difference between the two within the limited statistics of our program, hinting that most SMBH growth happens in the later stages of a merger process.Comment: 9 pages, 4 figures, 1 table; accepted to the Astrophysical Journa

    Verification and calibration of a commercial anisotropic magnetoresistive magnetometer by multivariate non-linear regression

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    Commercially available anisotropic magnetoresistive (AMR) magnetometers exhibit on the order of 1 nanotesla (nT) sensitivity in small size, weight, and power (SWaP) packages. However, AMR magnetometer accuracy is diminished by properties such as static offsets, gain uncertainty, off-axis coupling, and temperature effects. This work presents a measurement of the magnitude of these effects for a Honeywell HMC1053 magnetometer and evaluates a method for calibrating the observed effects by multivariate non-linear regression using a 24-parameter measurement equation. The presented calibration method has reduced the vector norm of the root mean square error from 4300 to 72 nT for the data acquired in this experiment. This calibration method has been developed for use on the AERO (Auroral Emissions Radio Observer) and VISTA (Vector Interferometry Space Technology using AERO) CubeSat missions, but the methods and results may be applicable to other resource-constrained magnetometers whose accuracies are limited by the offset, gain, off-axis, and thermal effects that are similar to the HMC1053 AMR magnetometer.</p

    Early Childhood/Child Welfare Priority

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    This is the executive summary of a white paper that describes the context, current capacity, areas of opportunity, and next steps for the UNO Early Childhood/Child Welfare Priority (ECCW). It responds to the need for comprehensive integrated systems of services designed to give all young children (birth through age eight) access to what they need in the early years to succeed in school and in life. In this context, UNO recognizes ECCW as critical to our metropolitan university mission. Further, we must come together with early childhood service providers, P-12 districts, parents, policy makers, other University of Nebraska campuses, community service agencies and businesses to improve learning and developmental outcomes for all children, with emphasis on children who are at-risk and those with special needs
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