2,584 research outputs found

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    Walter A. Barker & Elizabeth W. Curry, Getting the most out of county extension meetings, Kansas State University, Nov. 2000

    Reading and mathematics intervention programmes with parents of nursery children in disadvantaged areas : a psychological and methodological study

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    Theoretical models of early educational attainment are explored and the limitations of some current theories are discussed. Many of the more important intervention progres aimed at helping disadvantaged pre-school children in Britain and the United States are reviewed and alternative interpretations of some of their findings are proposed. A progre of intervention, based on the parents of 159 nursery children at inner city primary schools, has been carried out for the study and is described here in detail. Various methodological issues are examined in relation to the study's goal of improving the reading or mathematical attainment of these children, when assessed near the end of reception class. The nature of the intervention prograe, which has taken the form of eight fortnightly meetings for each of 25 groups of parents, is set out in full. New forms of quantitative indices are developed to define the nomological validities of the individual variables and of the multivariate evaluation models. The study also reports the practical development of a new form of non-stochastic ridge regression, named V-ridge in recognition of the imerican statistician (ED. Vinod) who created the original algorithm; it is shown here that this method offers regression coefficients which are far more stable across samples, and often more credible, than are the equivalent ordinary least squarei coefficients. Ten path analysis models based on the study data yield a wealth of insights. The models show, inter alia: major differences in the contribution of home environments to the educational attainment of advantaged and disadvantaged children; the importance of the nursery school experience for disadvantaged children; the significant though modest contributions of the parent intervention prograame to the outcomes of reading competence and mathematical concepts, but not to the outcome of mathematical nwneracy; and the stronger integration of cognitive and academic characteristics in advantaged children than in their disadvantaged peers. The major conclusion is that a nursery class programne of parent guidance, structured and focused on the presentation of practical activities enabling parents to foster children's early reading and early mathematical development within the home, is effective and should be a regular feature of nursery education in disadvantaged areas

    Can 4-H/FCS Curricula and Program Activities Increase Self-Esteem in At-Risk Youth Ages 8-15?

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    Nationally 4-H programs develop educational strategies and provide opportunities for youth and adults to work in partnership as they develop life skills. This study looks at some curricula that enhance self-esteem in at-risk youth ages 8 to 15. The Coopersmith Self-Esteem Instrument (CSI) measured changes in participants’ self-esteem while the Massachusetts Youth Screening Instrument (MAYSl), used only at the onset of the study, alert the staff of potential mental/emotional distress and other behavior that might require an immediate response. The CSI results showed increases in self-esteem. Girls showed a higher increase in self-esteem over the boys

    A low H I column density filament in NGC 2403 : signature of interaction or accretion

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    Date of acceptance: 12/07/2014Observed H i accretion around nearby galaxies can only account for a fraction of the gas supply needed to sustain the currently observed star formation rates. It is possible that additional accretion occurs in the form of low column density cold flows, as predicted by numerical simulations of galaxy formation. To constrain the presence and properties of such flows, we present deep H i observations obtained with the NRAO Green Bank Telescope of an area measuring 4° × 4° around NGC 2403. These observations, with a 5σ detection limit of 2.4 × 1018 cm-2 over a 20 km s-1 linewidth, reveal a low column density, extended cloud outside the main H i disk, about 17′ (~ 16 kpc or ~ 2 R25) to the NW of the center of the galaxy. The total H i mass of the cloud is 6.3 × 106 M⊙, or 0.15 percent of the total H i mass of NGC 2403. The cloud is associated with an 8 kpc anomalous-velocity H i filament in the inner disk, that was previously observed in deep VLA observations. We discuss several scenarios for the origin of the cloud, and conclude that it is either accreting from the intergalactic medium, or is the result of a minor interaction with a neigboring dwarf galaxyPeer reviewe

    A Multi-wavelength analysis of M81: insight on the nature of Arp's loop

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    Context: The optical ring like structure detected by Arp (1965) around M81 (commonly referenced as "Arp's loop") represents one of the most spectacular feature observed in nearby galaxies. Arp's loop is commonly interpreted as a tail resulting from the tidal interaction between M81 and M82. However, since its discovery the nature of this feature has remained controversial. Aims: Our primary purpose was to identify the sources of optical and infrared emission observed in Arp's loop. Methods: The morphology of the Arp's loop has been investigated with deep wide-field optical images. We also measured its colors using IRAS and Spitzer-MIPS infrared images and compared them with those of the disk of M81 and Galactic dust cirrus that fills the area where M81 is located. Results: Optical images reveal that this peculiar object has a filamentary structure characterized by many dust features overlapping M81's field. The ratios of far-infrared fluxes and the estimated dust-to-gas ratios indicate the infrared emission of Arp's loop is dominated by the contribution of cold dust that is most likely from Galactic cirrus. Conclusions: The above results suggest that the light observed at optical wavelengths is a combination of emission from i) a few recent star forming regions located close to M81, where both bright UV complexes and peaks in the HI distribution are found, ii) the extended disk of M81 and iii) scattered light from the same Galactic cirrus that is responsible for the bulk of the far infrared emission.Comment: 7 pages, 7 figures, accepted for publication by A&

    The empirical replicability of task-based fMRI as a function of sample size

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    Replicating results (i.e. obtaining consistent results using a new independent dataset) is an essential part of good science. As replicability has consequences for theories derived from empirical studies, it is of utmost importance to better understand the underlying mechanisms influencing it. A popular tool for non-invasive neuroimaging studies is functional magnetic resonance imaging (fMRI). While the effect of underpowered studies is well documented, the empirical assessment of the interplay between sample size and replicability of results for task-based fMRI studies remains limited. In this work, we extend existing work on this assessment in two ways. Firstly, we use a large database of 1400 subjects performing four types of tasks from the IMAGEN project to subsample a series of independent samples of increasing size. Secondly, replicability is evaluated using a multi-dimensional framework consisting of 3 different measures: (un)conditional test-retest reliability, coherence and stability. We demonstrate not only a positive effect of sample size, but also a trade-off between spatial resolution and replicability. When replicability is assessed voxelwise or when observing small areas of activation, a larger sample size than typically used in fMRI is required to replicate results. On the other hand, when focussing on clusters of voxels, we observe a higher replicability. In addition, we observe variability in the size of clusters of activation between experimental paradigms or contrasts of parameter estimates within these

    The ACS Nearby Galaxy Survey Treasury IV. The Star Formation History of NGC 2976

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    We present resolved stellar photometry of NGC 2976 obtained with the Advanced Camera for Surveys (ACS) as part of the ACS Nearby Galaxy Survey Treasury (ANGST) program. The data cover the radial extent of the major axis of the disk out to 6 kpc, or ~6 scale lengths. The outer disk was imaged to a depth of M_F606W ~ 1, and an inner field was imaged to the crowding limit at a depth of M_F606W ~ -1. Through detailed analysis and modeling of these CMDs we have reconstructed the star formation history of the stellar populations currently residing in these portions of the galaxy, finding similar ancient populations at all radii but significantly different young populations at increasing radii. In particular, outside of the well-measured break in the disk surface brightness profile, the age of the youngest population increases with distance from the galaxy center, suggesting that star formation is shutting down from the outside-in. We use our measured star formation history, along with H I surface density measurements, to reconstruct the surface density profile of the disk during previous epochs. Comparisons between the recovered star formation rates and reconstructed gas densities at previous epochs are consistent with star formation following the Schmidt law during the past 0.5 Gyrs, but with a drop in star formation efficiency at low gas densities, as seen in local galaxies at the present day. The current rate and gas density suggest that rapid star formation in NGC 2976 is currently in the process of ceasing from the outside-in due to gas depletion. This process of outer disk gas depletion and inner disk star formation was likely triggered by an interaction with the core of the M81 group >~1 Gyr ago that stripped the gas from the galaxy halo and/or triggered gas inflow from the outer disk toward the galaxy center.Comment: 22 pages, 14 figures, 2 tables, accepted for publication by Ap
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