759 research outputs found

    Learning from the children : exploring preschool children's encounters with ICT at home

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    This paper is an account of our attempts to understand preschool children's experiences with information and communication technologies (ICT) at home. Using case study data, we focus on what we can learn from talking directly to the children that might otherwise have been overlooked and on describing and evaluating the methods we adopted to ensure that we maximised the children's contributions to the research. By paying attention to the children's perspectives we have learned that they are discriminating users of ICT who evaluate their own performances, know what gives them pleasure and who differentiate between operational competence and the substantive activities made possible by ICT

    Searching for solar-like oscillations in pre-main sequence stars using APOLLO

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    In recent years, our understanding of solar-like oscillations from main sequence to red giant stars has improved dramatically thanks to pristine data collected from space telescopes. One of the remaining open questions focuses around the observational identification of solar-like oscillations in pre-main sequence stars. We aim to develop an improved method to search for solar-like oscillations in pre-main sequence stars and apply it to data collected by the Kepler K2 mission. Our software APOLLO includes a novel way to detect low signal-to-noise ratio solar like oscillations in the presence of a high background level. By calibrating our method using known solar-like oscillators from the main Kepler mission, we apply it to T Tauri stars observed by Kepler K2 and identify several candidate pre-main sequence solar-like oscillators. We find that our method is robust even when applied to time-series of observational lengths as short as those obtained with the TESS satellite in one sector. We identify EPIC 205375290 as a possible candidate for solar-like oscillations in a pre-main sequence star with Îœmax≃242 Ό\nu_\mathrm{max} \simeq 242\,\muHz. We also derive EPIC 205375290's fundamental parameters to be TeffT_\mathrm{eff} = 3670±\pm180 K, log gg = 3.85±\pm0.3, vvsinii = 8 ±\pm 1 km s−1^{-1}, and about solar metallicity from a high-resolution spectrum obtained from the Keck archive.Comment: 14 pages, 13 figure

    Limits on surface gravities of Kepler planet-candidate host stars from non-detection of solar-like oscillations

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    We present a novel method for estimating lower-limit surface gravities log g of Kepler targets whose data do not allow the detection of solar-like oscillations. The method is tested using an ensemble of solar-type stars observed in the context of the Kepler Asteroseismic Science Consortium. We then proceed to estimate lower-limit log g for a cohort of Kepler solar-type planet-candidate host stars with no detected oscillations. Limits on fundamental stellar properties, as provided by this work, are likely to be useful in the characterization of the corresponding candidate planetary systems. Furthermore, an important byproduct of the current work is the confirmation that amplitudes of solar-like oscillations are suppressed in stars with increased levels of surface magnetic activity.Comment: Accepted for publication in ApJ; 35 pages, 10 figures, 5 table

    'The terrible twos': Gaining control in the nursery?

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    'The terrible twos' are often described as a time of 'gaining control', usually thought of as adults asserting control over children, who learn to control themselves. However, toddlerhood is as much about children learning to take control for themselves. This paper is an attempt to detail something of the social geography in the toddler room of a Scottish nursery, considering both styles of adult control and the ways in which toddlers attempt to appropriate and reconfigure space and time for themselves. That is, the ways in which space and time are negotiated in the course of day-to-day nursery life

    Human PrP90-231-induced cell death is associated with intracellular accumulation of insoluble and protease-resistant macroaggregates and lysosomal dysfunction

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    To define the mechanisms by which hPrP90-231 induces cell death, we analyzed its interaction with living cells and monitored its intracellular fate. Treatment of SH-SY5Y cells with fluorescein-5-isothiocyanate (FITC)-conjugated hPrP90-231 caused the accumulation of cytosolic aggregates of the prion protein fragment that increased in number and size in a time-dependent manner. The formation of large intracellular hPrP90-231 aggregates correlated with the activation of apoptosis. hPrP90-231 aggregates occurred within lysotracker-positive vesicles and induced the formation of activated cathepsin D (CD), indicating that hPrP90-231 is partitioned into the endosomal–lysosomal system structures, activating the proteolytic machinery. Remarkably, the inhibition of CD activity significantly reduced hPrP-90-231-dependent apoptosis. Internalized hPrP90-231 forms detergent-insoluble and SDS-stable aggregates, displaying partial resistance to proteolysis. By confocal microscopy analysis of lucifer yellow (LY) intracellular partition, we show that hPrP90-231 accumulation induces lysosome destabilization and loss of lysosomal membrane impermeability. In fact, although control cells evidenced a vesicular pattern of LY fluorescence (index of healthy lysosomes), hPrP90-231-treated cells showed diffuse cytosolic fluorescence, indicating LY diffusion through damaged lysosomes. In conclusion, these data indicate that exogenously added hPrP90-231 forms intralysosomal deposits having features of insoluble, protease-resistant aggregates and could trigger a lysosome-mediated apoptosis by inducing lysosome membrane permeabilization, followed by the release of hydrolytic enzymes

    Asteroseismic fundamental properties of solar-type stars observed by the NASA Kepler Mission

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    We use asteroseismic data obtained by the NASA Kepler Mission to estimate the fundamental properties of more than 500 main-sequence and sub-giant stars. Data obtained during the first 10 months of Kepler science operations were used for this work, when these solar-type targets were observed for one month each in a survey mode. Stellar properties have been estimated using two global asteroseismic parameters and complementary photometric and spectroscopic data. Homogeneous sets of effective temperatures were available for the entire ensemble from complementary photometry; spectroscopic estimates of T_eff and [Fe/H] were available from a homogeneous analysis of ground-based data on a subset of 87 stars. [Abbreviated version... see paper for full abstract.]Comment: Accepted for publication in ApJS; 90 pages, 22 figures, 6 tables. Units on rho in tables now listed correctly as rho(Sun

    PBjam: A Python package for automating asteroseismology of solar-like oscillators

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    Asteroseismology is an exceptional tool for studying stars by using the properties of observed modes of oscillation. So far the process of performing an asteroseismic analysis of a star has remained somewhat esoteric and inaccessible to non-experts. In this software paper we describe PBjam, an open-source Python package for analyzing the frequency spectra of solar-like oscillators in a simple but principled and automated way. The aim of PBjam is to provide a set of easy-to-use tools to extract information about the radial and quadrupole oscillations in stars that oscillate like the Sun, which may then be used to infer bulk properties such as stellar mass, radius and age or even structure. Asteroseismology and its data analysis methods are becoming increasingly important as space-based photometric observatories are producing a wealth of new data, allowing asteroseismology to be applied in a wide range of contexts such as exoplanet, stellar structure and evolution, and Galactic population studies.Comment: 12 Pages, 4 figures. Accepted for publication in AJ. Associated software available at https://doi.org/10.5281/zenodo.430007

    The biosocial event : responding to innovation in the life sciences

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    Innovation in the life sciences calls for reflection on how sociologies separate and relate life processes and social processes. To this end we introduce the concept of the ‘biosocial event’. Some life processes and social processes have more mutual relevance than others. Some of these relationships are more negotiable than others. We show that levels of relevance and negotiability are not static but can change within existing relationships. Such changes, or biosocial events, lie at the heart of much unplanned biosocial novelty and much deliberate innovation. We illustrate and explore the concept through two examples – meningitis infection and epidemic, and the use of sonic ‘teen deterrents’ in urban settings. We then consider its value in developing sociological practice oriented to critically constructive engagement with innovation in the life sciences

    Notions of agency in early literacy classrooms: assemblages and productive intersections

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    Agency and its role in the early literacy classroom has long been a topic for debate. While sociocultural accounts often portray the child as a cultural agent who negotiates their own participation in classroom culture and literacy learning, more recent framings draw attention from the individual subject, instead seeing agency as dispersed across people and materials. In this article I draw on my experiences of following children as they followed their interests in an early literacy classroom, drawing on the concepts of assemblage and people yet to come, as defined by Deleuze and Guattari and Spinoza’s common notion. I provide one illustrative account of moment-by-moment activity and suggest that in education settings it is useful to see activity as a direct and ongoing interplay of three dimensions: children’s moving bodies; the classroom; and its materials. I propose that children’s ongoing movements create possibilities for ‘doing’ and ‘being’ that flow across and between children. I argue that thinking with assemblage can draw attention to both the potentiality and the power dynamics inherent in the ongoing present and also counter preconceived notions of individual child agency and linear trajectories of literacy development, and the inequalities this these concepts can perpetuate within early education settings
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