244 research outputs found

    Researching and Designing for the Orchestration of Learning in the CSCL Classroom

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    Designing tools for teachers to orchestrate computer supported collaborative learning activities in their classrooms requires that attention be paid to the range of roles and activities a teacher must take throughout the process. Drawing on the Implementing Collaborative Learning in the Classroom framework proposed by Kaendler, Wiedmann, Rummel and Spada (2014), the contributors to this symposium will speak to the way their designs address the various parts of this framework, allowing us to draw conclusions about what has been successful for different parts of this process, and identifying future directions for development and research

    Genetic association of CDC2 with cerebrospinal fluid tau in Alzheimer's disease

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    We have recently reported that a polymorphism in the cell division cycle (CDC2) gene, designated Ex6 + 7I/D, is associated with Alzheimer's disease (AD). The CDC2 gene is located on chromosome 10q21.1 close to the marker D10S1225 linked to AD. Active cdc2 accumulates in neurons containing neurofibrillary tangles (NFT), a process that can precede the formation of NFT. Therefore, CDC2 is a promising candidate susceptibility gene for AD. We investigated the possible effects of the CDC2 polymorphism on cerebrospinal fluid (CSF) biomarkers in AD patients. CDC2 genotypes were evaluated in relation to CSF protein levels of total tau, phospho-tau and beta-amyloid (1-42) in AD patients and control individuals, and in relation to the amount of senile plaques and NFT in the frontal cortex and in the hippocampus in patients with autopsy-proven AD and controls. The CDC2 Ex6 + 7I allele was associated with a gene dose-dependent increase of CSF total tau levels (F-2,F- 626 = 7.0, p = 0.001) and the homozygous CDC2Ex6 +7II genotype was significantly more frequent among AD patients compared to controls (p = 0.006, OR = 1.57, 95% CI 1.13-2.17). Our results provide further evidence for an involvement of cdc2 in the pathogenesis of AD. Copyright (C) 2005 S. Karger AG, Basel

    Expression of ATF3 and axonal outgrowth are impaired after delayed nerve repair

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    Background: A delay in surgical nerve repair results in impaired nerve function in humans, but mechanisms behind the weakened nerve regeneration are not known. Activating transcription factor 3 (ATF3) increases the intrinsic growth state of injured neurons early after injury, but the role of long-term changes and their relation to axonal outgrowth after a delayed nerve repair are not well understood. ATF3 expression was examined by immunohistochemistry in motor and sensory neurons and in Schwann cells in rat sciatic nerve and related to axonal outgrowth after transection and delayed nerve repair (repair 0, 30, 90 or 180 days post-injury). Expression of the neuronal cell adhesion molecule (NCAM), which is expressed in non-myelinating Schwann cells, was also examined. Results: The number of neurons and Schwann cells expressing ATF3 declined and the length of axonal outgrowth was impaired if the repair was delayed. The decline was more rapid in motor neurons than in sensory neurons and Schwann cells. Regeneration distances over time correlated to number of ATF3 stained neurons and Schwann cells. Many neurofilament stained axons grew along ATF3 stained Schwann cells. If nerve repair was delayed the majority of Schwann cells in the distal nerve segment stained for NCAM. Conclusion: Delayed nerve repair impairs nerve regeneration and length of axonal outgrowth correlates to ATF3 expression in both neurons and Schwann cells. Mainly non-myelinating Schwann cells (NCAM stained) are present in distal nerve segments after delayed nerve repair. These data provide a neurobiological basis for the poor outcomes associated with delayed nerve repair. Nerve trunks should, if possible, be promptly repaired

    Positive and negative well-being and objectively measured sedentary behaviour in older adults: evidence from three cohorts

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    Background: Sedentary behaviour is related to poorer health independently of time spent in moderate to vigorous physical activity. The aim of this study was to investigate whether wellbeing or symptoms of anxiety or depression predict sedentary behaviour in older adults. Method: Participants were drawn from the Lothian Birth Cohort 1936 (LBC1936) (n = 271), and the West of Scotland Twenty-07 1950s (n = 309) and 1930s (n = 118) cohorts. Sedentary outcomes, sedentary time, and number of sit-to-stand transitions, were measured with a three-dimensional accelerometer (activPAL activity monitor) worn for 7 days. In the Twenty-07 cohorts, symptoms of anxiety and depression were assessed in 2008 and sedentary outcomes were assessed ~ 8 years later in 2015 and 2016. In the LBC1936 cohort, wellbeing and symptoms of anxiety and depression were assessed concurrently with sedentary behaviour in 2015 and 2016. We tested for an association between wellbeing, anxiety or depression and the sedentary outcomes using multivariate regression analysis. Results: We observed no association between wellbeing or symptoms of anxiety and the sedentary outcomes. Symptoms of depression were positively associated with sedentary time in the LBC1936 and Twenty-07 1950s cohort, and negatively associated with number of sit-to-stand transitions in the LBC1936. Meta-analytic estimates of the association between depressive symptoms and sedentary time or number of sit-to-stand transitions, adjusted for age, sex, BMI, long-standing illness, and education, were β = 0.11 (95% CI = 0.03, 0.18) and β = − 0.11 (95% CI = − 0.19, −0.03) respectively. Conclusion: Our findings indicate that depressive symptoms are positively associated with sedentary behavior. Future studies should investigate the causal direction of this association

    A meta-analytic review of stand-alone interventions to improve body image

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    Objective Numerous stand-alone interventions to improve body image have been developed. The present review used meta-analysis to estimate the effectiveness of such interventions, and to identify the specific change techniques that lead to improvement in body image. Methods The inclusion criteria were that (a) the intervention was stand-alone (i.e., solely focused on improving body image), (b) a control group was used, (c) participants were randomly assigned to conditions, and (d) at least one pretest and one posttest measure of body image was taken. Effect sizes were meta-analysed and moderator analyses were conducted. A taxonomy of 48 change techniques used in interventions targeted at body image was developed; all interventions were coded using this taxonomy. Results The literature search identified 62 tests of interventions (N = 3,846). Interventions produced a small-to-medium improvement in body image (d+ = 0.38), a small-to-medium reduction in beauty ideal internalisation (d+ = -0.37), and a large reduction in social comparison tendencies (d+ = -0.72). However, the effect size for body image was inflated by bias both within and across studies, and was reliable but of small magnitude once corrections for bias were applied. Effect sizes for the other outcomes were no longer reliable once corrections for bias were applied. Several features of the sample, intervention, and methodology moderated intervention effects. Twelve change techniques were associated with improvements in body image, and three techniques were contra-indicated. Conclusions The findings show that interventions engender only small improvements in body image, and underline the need for large-scale, high-quality trials in this area. The review identifies effective techniques that could be deployed in future interventions

    Seismic investigations of the O'Higgins Seamount Group and Juan Fernández Ridge: aseismic ridge emplacement and lithosphere hydration

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    The O'Higgins Seamount Group is a cluster of volcanic domes located 120 km west of the central Chilean Trench on the crest of the Juan Fernández Ridge. This aseismic hot spot track is subducting under South America triggering a belt of intraslab earthquake hypocenters extending about 700 km inland. The Juan Fernández Ridge marks the southern boundary of a shallow subduction segment. Subduction of oceanic basement relief has been suggested as a cause for the “flat” slab segments characterizing the Andean trench system. The Juan Fernández Ridge, however, shows only moderate crustal thickening, inadequate to cause significant buoyancy. In 2001, wide-angle seismic data were collected along two perpendicular profiles crossing the O'Higgins Group. We present tomographic images of the volcanic edifices and adjacent outer rise-trench environment, which indicate a magmatic origin of the seamounts dominated by extrusive processes. High-resolution bathymetric data yield a detailed image of a network of syngenetic structures reactivated in the outer rise setting. A pervasive fault pattern restricted to the hot spot modified lithosphere coincides with anomalous low upper mantle velocities gained from a tomographic inversion of seismic mantle phases. Reduced uppermost mantle velocities are solely found underneath the Juan Fernández Ridge and may indicate mineral alterations. Enhanced buoyancy due to crustal and upper mantle hydration may contribute an additional mechanism for shallow subduction, which prevails to the north after the southward migration of the Juan Fernández Ridge

    Home: The place the older adult can not imagine living without

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    <p>Abstract</p> <p>Background</p> <p>Rapidly aging populations with an increased desire to remain at home and changes in health policy that promote the transfer of health care from formal places, as hospitals and institutions, to the more informal setting of one's home support the need for further research that is designed specifically to understand the experience of home among older adults. Yet, little is known among health care providers about the older adult's experience of home. The aim of this study was to understand the experience of home as experienced by older adults living in a rural community in Sweden.</p> <p>Methods</p> <p>Hermeneutical interpretation, as developed by von Post and Eriksson and based on Gadamer's philosophical hermeneutics, was used to interpret interviews with six older adults. The interpretation included a self examination of the researcher's experiences and prejudices and proceeded through several readings which integrated the text with the reader, allowed new questions to emerge, fused the horizons, summarized main and sub-themes and allowed a new understanding to emerge.</p> <p>Results</p> <p>Two main and six sub-themes emerged. Home was experienced as the place the older adult could not imagine living without but also as the place one might be forced to leave. The older adult's thoughts vacillated between the well known present and all its comforts and the unknown future with all its questions and fears, including the underlying threat of loosing one's home.</p> <p>Conclusions</p> <p>Home has become so integral to life itself and such an intimate part of the older adult's being that when older adults lose their home, they also loose the place closest to their heart, the place where they are at home and can maintain their identity, integrity and way of living. Additional effort needs to be made to understand the older adult's experience of home within home health care in order to minimize intrusion and maximize care. There is a need to more fully explore the older adult's experience with health care providers in the home and its impact on the older adult's sense of "being at home" and their health and overall well-being.</p

    Cognitive resources moderate the adverse impact of poor perceived neighborhood conditions on self-reported physical activity of older adults

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    Rebar, A ORCiD: 0000-0003-3164-993XPoor neighborhood conditions are associated with lower levels of physical activity for older adults but socio-ecological models posit that physical activity depends on both environmental and individual factors. Older adults' ability to overcome environmental barriers to physical activity may partially rely on cognitive resources. However, evidence on the moderating role of these cognitive resources in the associations between environmental barriers and physical activity is still lacking. We analyzed cross-national and longitudinal data on 28,393 adults aged 50 to 96 years as part of the SHARE. Lack of access to services and neighborhood nuisances were used as indicators of poor neighborhood conditions. Delayed recall and verbal fluency were used as indicators of cognitive resources. Confounder-adjusted generalized estimation equations were conducted to test associations between neighborhood conditions and self-reported moderate physical activity, as well as the moderating role of cognitive resources. Results showed that poor neighborhood conditions reduced the odds of engagement in physical activity. Cognitive resources robustly reduced the adverse influence of poor neighborhood conditions on physical activity. Participants with lower cognitive resource scores showed lower odds of engaging in physical activity when neighborhood conditions were poorer, whereas these conditions were not related to this engagement for participants with higher cognitive resource scores. These findings suggest that cognitive resources can temper the detrimental effect of poor neighborhood conditions on physical activity. Public policies should target both individual and environmental factors to tackle the current pandemic of physical inactivity more comprehensively. © 2019 Elsevier Inc
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