2,588 research outputs found
Variation in African American parents' use of early childhood physical discipline
Physical discipline is endorsed by a majority of adults in the U.S. including African American (AA) parents who have high rates of endorsement. Although many studies have examined physical discipline use among AA families, few have considered how early
childhood physical discipline varies within the population. Individuals within a cultural group may differ in their engagement in cultural practices (Rogoff, 2003). Furthermore, AA familiesâ characteristics and their contexts, which are shaped by the interaction of social position, racism, and segregation (GarcĂa Coll et al., 1996), likely influence how AA families physically discipline their young children. This study examined variation in early childhood physical discipline among AA families living in low-income communities and relations with demographic and contextual factors. Year 1 data from 310 AA parents living in three regionally distinct low-income communities were used from a sequential longitudinal intervention program study of the development and prevention of conduct disorder. Latent class analyses were conducted using parentsâ responses on a measure, of the frequency of overall physical discipline, spanking, and hitting during prekindergarten and kindergarten. The associations between latent classes and six demographic and contextual factors were examined using the Bolck, Croon, and Hagenaars (BCH) method. The factors were: child gender (59% male); marital status (51% never married); parental education (66% high school graduates and beyond); income (mean = $16.66K, S.D. = 12.50), family stress, and perception of neighborhood safety. Measures included the Family Information Form, Life Changes, and the Neighborhood Questionnaire. After considering two to seven class solutions, five physical discipline classes or sub-groups were identified. Classes were defined by discipline frequency (âInfrequentâ, âWeeklyâ, âMonthlyâ, âAlmost-Every-Dayâ and âWeekly-Allâ) as well as by discipline type (only parents in the âWeekly-Allâ class hit their children). Significant associations were found between class membership, and child gender, marital status, income, and perception of neighborhood safety. Girls were more likely to be physically disciplined infrequently, Ï2(4, N = 310) = 11.88, p = .05. The âWeeklyâ class had significantly fewer married parents than all classes except âAlmost-Every-Dayâ, Ï2(4, N = 310) = 21.56, p < .001. Parents in the âAlmost-Every-Dayâ class had a significantly lower income than parents in all other classes except âWeekly-Allâ, Ï2(4, N = 310) = 10.88, p = .03. Finally, parents in the âAlmost-Every-Dayâ class perceived their neighborhood as significantly less safe compared to those in all other classes except the âWeekly-Allâ class, Ï2(4, N = 310) = 14.13 p = .01. These findings suggest that AA families vary in physical discipline during early childhood; this variation may result in sub-groups with different demographic characteristics. Associations between frequent discipline classes and perceptions of neighborhood safety implies that some AA parents may use physical discipline to protect their children from being harmed if they believe their communities are unsafe. Future research should qualitatively examine how AA parents respond to unsafe neighborhoods in their parenting behaviors, including physical discipline
A Search for Binary Stars at Low Metallicity
We present initial results measuring the companion fraction of metal-poor
stars ([Fe/H]2.0). We are employing the Lick Observatory planet-finding
system to make high-precision Doppler observations of these objects. The binary
fraction of metal-poor stars provides important constraints on star formation
in the early Galaxy (Carney et al. 2003). Although it has been shown that a
majority of solar metallicity stars are in binaries, it is not clear if this is
the case for metal-poor stars. Is there a metallicity floor below which binary
systems do not form or become rare? To test this we are determining binary
fractions at metallicities below [Fe/H]. Our measurments are not as
precise as the planet finders', but we are still finding errors of only 50 to
300 m/s, depending on the signal-to-noise of a spectrum and stellar atmosphere
of the star. At this precision we can be much more complete than previous
studies in our search for stellar companions.Comment: To appear in conference proceedings,"First Stars III", eds. B.
O'Shea, A. Heger & T. Abel. 3 pages, 5 figure
Chemical Abundances For Evolved Stars In M5: Lithium Through Thorium
We present analysis of high-resolution spectra of a sample of stars in the globular cluster M5 (NGC 5904). The sample includes stars from the red giant branch (RGB; seven stars), the red horizontal branch (two stars), and the asymptotic giant branch (AGB; eight stars), with effective temperatures ranging from 4000 K to 6100 K. Spectra were obtained with the HIRES spectrometer on the Keck I telescope, with a wavelength coverage from 3700 angstrom to 7950 angstrom for the HB and AGB sample, and 5300 angstrom to 7600 angstrom for the majority of the RGB sample. We find offsets of some abundance ratios between the AGB and the RGB branches. However, these discrepancies appear to be due to analysis effects, and indicate that caution must be exerted when directly comparing abundance ratios between different evolutionary branches. We find the expected signatures of pollution from material enriched in the products of the hot hydrogen burning cycles such as the CNO, Ne-Na, and Mg-Al cycles, but no significant differences within these signatures among the three stellar evolutionary branches especially when considering the analysis offsets. We are also able to measure an assortment of neutron-capture element abundances, from Sr to Th, in the cluster. We find that the neutron-capture signature for all stars is the same, and shows a predominately r-process origin. However, we also see evidence of a small but consistent extra s-process signature that is not tied to the light-element variations, pointing to a pre-enrichment of this material in the protocluster gas.National Science Foundation AST-0802292NSF AST-0406988, AST-0607770, AST-0607482DFGW. M. Keck FoundationAstronom
Carbon and Strontium Abundances of Metal-Poor Stars
We present carbon and strontium abundances for 100 metal-poor stars measured
from R7000 spectra obtained with the Echellette Spectrograph and Imager
at the Keck Observatory. Using spectral synthesis of the G-band region, we have
derived carbon abundances for stars ranging from [Fe/H] to
[Fe/H]. The formal errors are dex in [C/Fe]. The strontium
abundance in these stars was measured using spectral synthesis of the resonance
line at 4215 {\AA}. Using these two abundance measurments along with the barium
abundances from our previous study of these stars, we show it is possible to
identify neutron-capture-rich stars with our spectra. We find, as in other
studies, a large scatter in [C/Fe] below [Fe/H]. Of the stars with
[Fe/H], 94% can be classified as carbon-rich metal-poor stars. The Sr
and Ba abundances show that three of the carbon-rich stars are
neutron-capture-rich, while two have normal Ba and Sr. This fraction of carbon
enhanced stars is consistent with other studies that include this metallicity
range.Comment: ApJ, Accepte
Takotsubo Cardiomyopathy: A Case Series and Review of the Literature
Takotsubo cardiomyopathy (TCM) is an unusual form of acute cardiomyopathy showing left ventricular apical ballooning. It is often triggered by intense physical or emotional distress. We report here four cases of TCM and a review of the literature on the topic
Towards the Promotion of Positive Development among Boys in Challenging Contexts: A Mixed-Methods Study of Engagement in the Scoutreach Initiative
Engagement in youth development programs reflects the quality of young peopleâs program-related experiences. However, more research is needed that explores cognitive, emotional, and behavioral dimensions of engagement in programs that serve underrepresented youth of color. The present cross-sectional and mixed-methods study assessed potential relations among dimensions of engagement in the Boston-area Scoutreach initiative, character attributes, self-perceived school competence, and intentional self-regulation. We analyzed data from 32 Scouts (Mage = 9.97 years, SD = 2.46, Range = 6 to 14), 32 parents/guardians, and five Scoutreach leaders. Scouts demonstrated that they were cognitively, emotionally, and behaviorally engaged in Scoutreach, and these dimensions were related differentially to indicators of healthy development. Qualitative data elucidated key aspects of Scoutreach (e.g., camping, peer relationships) that were linked to youth engagement. We discuss limitations of the present study and implications for future research and practice
Measuring nonuse damages using contingent valuation
This second edition of Measuring Nonuse Damages Using Conjoint Valuation is essentially a reprint of a 1992 monograph that has been in steady demand since its original appearance. The RTI Press edition, which is intended to meet continued inquiries and requests for the monograph, contains a Foreword and a Preface to the second edition that put the original work into historical perspective. These studies of ways to value stated preferences, as applied then to the Exxon Valdez oil spill, continue to be a timely and still-rigorous examination of such methods; even with the passage of time and statistical advances from the past two decades, the conclusions and insights as to whether and how these techniques might still be employed in valuing use or nonuse losses from similar events remain valid.Publishe
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