4,831 research outputs found

    THE KINDERGARTEN BUDDY PROGRAM AND ITS EFFECT ON READING ACHIEVEMENT FOR AT-RISK KINDERGARTEN STUDENTS

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    Research states that more time and attention is needed for some students to acquire the necessary skills which allow them to become successful learners. Full-day kindergarten programs are desirable to ensure that all students have the necessary time to be successful. Due to lack of funds many school districts are unable to offer full-day kindergarten programs. The Kindergarten Buddy Program is a viable alternative for school systems seeking ways to provide opportunities for students who require extra support. The effectiveness of providing additional instruction in phonological awareness for at-risk learners needs to be explored to determine its impact on reading achievement. This information will be beneficial to school districts as they struggle to meet the needs of at-risk students in a fiscally responsible manner. The purpose of this study was to determine if additional instruction in phonological awareness, the Kindergarten Buddy Program, had an effect on reading achievement for at-risk kindergarten students. Students’ reading achievement was analyzed to see if participation in the Kindergarten Buddy Program enabled them to reach grade level expectations. Using a convenience sample (N = 92), scores on the Gates MacGinitie Reading Test and the Kindergarten Inventory of Skills in the half-day extended Kindergarten Buddy Program were compared to students scores in half-day kindergarten without an extended program and in a ii full-day kindergarten without an extended program. An ANOVA was conducted to determine if there were differences in the post-test scores of the different groups. Differences over time were also analyzed using a repeated measures ANOVA to determine if there was a significant difference in the means of the scores of the three groups as measured by the Inventory of Skills. The study revealed that half-day Buddy students scored significantly higher than half-day kindergarten students on the letter and letter/sound subscores on the Gates MacGinitie. Scores comparing the Buddy Program to a full-day program were similar as were the half-day kindergarten and full-day programs. This suggested the Kindergarten Buddy Program made significant strides in improving letter and letter/sound abilities of the at-risk students and therefore, it was as effective as the full-day program in assisting at-risk students in reaching grade level expectations

    Folding and cytoplasm viscoelasticity contribute jointly to chromosome dynamics

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    The chromosome is a key player of cell physiology, and its dynamics provides valuable information about its physical organization. In both prokaryotes and eukaryotes, the short-time motion of chromosomal loci has been described as a Rouse model in a simple or viscoelastic medium. However, little emphasis has been put on the role played by the folded organization of chromosomes on the local dynamics. Clearly, stress-propagation, and thus dynamics, must be affected by such organization, but a theory allowing to extract such information from data, e.g.\ of two-point correlations, is lacking. Here, we describe a theoretical framework able to answer this general polymer dynamics question, and we provide a general scaling analysis of the stress-propagation time between two loci at a given arclength distance along the chromosomal coordinate. The results suggest a precise way to detect folding information from the dynamical coupling of chromosome segments. Additionally, we realize this framework in a specific theoretical model of a polymer with variable-range interactions in a viscoelastic medium characterized by a tunable scaling exponent, where we derive analytical estimates of the correlation functions.Comment: 14 pages including supplementary material

    11th European Headache Federation Congress jointly with 31st Congress of the Italian Society for the Study of Headaches : Rome, Italy. 01-03 December 2017

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    . Aims of the study were explore the relationship between peripheral chromatic and central visual dysfunction evaluating also the presence of functional receptor impairment in patients with migraine, with and without aura examined interictally

    Influence of interface potential on the effective mass in Ge nanostructures

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    The role of the interface potential on the effective mass of charge carriers is elucidated in this work. We develop a new theoretical formalism using a spatially dependent effective mass that is related to the magnitude of the interface potential. Using this formalism we studied Ge quantum dots (QDs) formed by plasma enhanced chemical vapour deposition (PECVD) and co-sputtering (sputter). These samples allowed us to isolate important consequences arising from differences in the interface potential. We found that for a higher interface potential, as in the case of PECVD QDs, there is a larger reduction in the effective mass, which increases the confinement energy with respect to the sputter sample. We further understood the action of O interface states by comparing our results with Ge QDs grown by molecular beam epitaxy. It is found that the O states can suppress the influence of the interface potential. From our theoretical formalism we determine the length scale over which the interface potential influences the effective mass

    Preparation and characterisation of titania/hydroxyapatite composite coatings obtained by sol-gel process

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    In the present work a titania network encapsulating a hydroxyapatite particulate phase is proposed as a bioceramic composite coating. The coating on a titanium substrate was produced starting from a sol containing a mixture of titania colloidal particles and hydroxyapatite submicron particles using the dip-coating technique. The microstructure, the morphology and the surface chemical composition of the coating were characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. Adhesion tests were also performed. These analyses showed that the obtained coating was chemically clean, homogeneous, rough, porous, with a low thickness and well-defined phase composition as well as a good adhesion to the substrate. Copyright © 2001 Elsevier Science Ltd

    Computational approaches to shed light on molecular mechanisms in biological processes

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    Computational approaches based on Molecular Dynamics simulations, Quantum Mechanical methods and 3D Quantitative Structure-Activity Relationships were employed by computational chemistry groups at the University of Milano-Bicocca to study biological processes at the molecular level. The paper reports the methodologies adopted and the results obtained on Aryl hydrocarbon Receptor and homologous PAS proteins mechanisms, the properties of prion protein peptides, the reaction pathway of hydrogenase and peroxidase enzymes and the defibrillogenic activity of tetracyclines. © Springer-Verlag 2007

    Light harvesting with Ge quantum dots embedded in SiO2 and Si3N4

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    Cataloged from PDF version of article.Germanium quantum dots (QDs) embedded in SiO2 or in Si3N4 have been studied for light harvesting purposes. SiGeO or SiGeN thin films, produced by plasma enhanced chemical vapor deposition, have been annealed up to 850 degrees C to induce Ge QD precipitation in Si based matrices. By varying the Ge content, the QD diameter can be tuned in the 3-9 nm range in the SiO2 matrix, or in the 1-2 nm range in the Si3N4 matrix, as measured by transmission electron microscopy. Thus, Si3N4 matrix hosts Ge QDs at higher density and more closely spaced than SiO2 matrix. Raman spectroscopy revealed a higher threshold for amorphous-to-crystalline transition for Ge QDs embedded in Si3N4 matrix in comparison with those in the SiO2 host. Light absorption by Ge QDs is shown to be more effective in Si3N4 matrix, due to the optical bandgap (0.9-1.6 eV) being lower than in SiO2 matrix (1.2-2.2 eV). Significant photoresponse with a large measured internal quantum efficiency has been observed for Ge QDs in Si3N4 matrix when they are used as a sensitive layer in a photodetector device. These data will be presented and discussed, opening new routes for application of Ge QDs in light harvesting devices. (C) 2014 AIP Publishing LLC

    A vigorous activity cycle mimicking a planetary system in HD200466

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    Stellar activity can be a source of radial velocity (RV) noise and can reproduce periodic RV variations similar to those produced by an exoplanet. We present the vigorous activity cycle in the primary of the visual binary HD200466, a system made of two almost identical solar-type stars with an apparent separation of 4.6 arcsec at a distance of 44+/-2 pc. High precision RV over more than a decade, adaptive optics (AO) images, and abundances have been obtained for both components. A linear trend in the RV is found for the secondary. We assumed that it is due to the binary orbit and once coupled with the astrometric data, it strongly constrains the orbital solution of the binary at high eccentricities (e~0.85) and quite small periastron of ~21 AU. If this orbital motion is subtracted from the primary radial velocity curve, a highly significant (false alarm probability <0.1%) period of about 1300 d is obtained, suggesting in a first analysis the presence of a giant planet, but it turned out to be due to the stellar activity cycle. Since our spectra do not include the Ca~II resonance lines, we measured a chromospheric activity indicator based on the Halpha line to study the correlation between activity cycles and long-term activity variations. While the bisector analysis of the line profile does not show a clear indication of activity, the correlation between the Halpha line indicator and the RV measurements identify the presence of a strong activity cycle.Comment: Accepted on Astronomy and Astrophysics Main Journal 2014, 16 pages, 18 figure
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