197 research outputs found
Deceleration and Dispersion of Large-scale Coronal Bright Fronts
One of the most dramatic manifestations of solar activity are large-scale
coronal bright fronts (CBFs) observed in extreme ultraviolet (EUV) images of
the solar atmosphere. To date, the energetics and kinematics of CBFs remain
poorly understood, due to the low image cadence and sensitivity of previous EUV
imagers and the limited methods used to extract the features. In this paper,
the trajectory and morphology of CBFs was determined in order to investigate
the varying properties of a sample of CBFs, including their kinematics and
pulse shape, dispersion, and dissipation. We have developed a semi-automatic
intensity profiling technique to extract the morphology and accurate positions
of CBFs in 2.5-10 min cadence images from STEREO/EUVI. The technique was
applied to sequences of 171A and 195A images from STEREO/EUVI in order to
measure the wave properties of four separate CBF events. Following launch at
velocities of ~240-450kms^{-1} each of the four events studied showed
significant negative acceleration ranging from ~ -290 to -60ms^{-2}. The CBF
spatial and temporal widths were found to increase from ~50 Mm to ~200 Mm and
~100 s to ~1500 s respectively, suggesting that they are dispersive in nature.
The variation in position-angle averaged pulse-integrated intensity with
propagation shows no clear trend across the four events studied. These results
are most consistent with CBFs being dispersive magnetoacoustic waves.Comment: 15 pages, 18 figure
Revisiting the symptom iceberg in today's primary care: results from a UK population survey
Peer reviewedPublisher PD
Circulating endothelial cell-derived extracellular vesicles mediate the acute phase response and sickness behaviour associated with CNS inflammation.
Brain injury elicits a systemic acute-phase response (APR), which is responsible for co-ordinating the peripheral immunological response to injury. To date, the mechanisms responsible for signalling the presence of injury or disease to selectively activate responses in distant organs were unclear. Circulating endogenous extracellular vesicles (EVs) are increased after brain injury and have the potential to carry targeted injury signals around the body. Here, we examined the potential of EVs, isolated from rats after focal inflammatory brain lesions using IL-1ÎČ, to activate a systemic APR in recipient naĂŻve rats, as well as the behavioural consequences of EV transfer. Focal brain lesions increased EV release, and, following isolation and transfer, the EVs were sequestered by the liver where they initiated an APR. Transfer of blood-borne EVs from brain-injured animals was also enough to suppress exploratory behaviours in recipient naĂŻve animals. EVs derived from brain endothelial cell cultures treated with IL-1ÎČ also activated an APR and altered behaviour in recipient animals. These experiments reveal that inflammation-induced circulating EVs derived from endothelial cells are able to initiate the APR to brain injury and are sufficient to generate the associated sickness behaviours, and are the first demonstration that EVs are capable of modifying behavioural responses
Association of Variants in RETN With Plasma Resistin Levels and Diabetes-Related Traits in the Framingham Offspring Study
OBJECTIVEâ The RETN gene encodes the adipokine resistin. Associations of RETN with plasma resistin levels, type 2 diabetes, and related metabolic traits have been inconsistent. Using comprehensive linkage disequilibrium mapping, we genotyped tag single nucleotide polymorphisms (SNPs) in RETN and tested associations with plasma resistin levels, risk of diabetes, and glycemic traits
Quantitative 3-Dimensional Imaging of Murine Neointimal and Atherosclerotic Lesions by Optical Projection Tomography
Traditional methods for the analysis of vascular lesion formation are labour intensive to perform - restricting study to âsnapshotsâ within each vessel. This study was undertaken to determine the suitability of optical projection tomographic (OPT) imaging for the 3-dimensional representation and quantification of intimal lesions in mouse arteries.â=â0.85), confirming both the accuracy of this methodology and its non-destructive nature. It was also possible to record volumetric measurements of lesion and lumen and these were highly reproducible between scans (coefficient of variationâ=â5.36%, 11.39% and 4.79% for wire- and ligation-injury and atherosclerosis, respectively).These data demonstrate the eminent suitability of OPT for imaging of atherosclerotic and neointimal lesion formation, providing a much needed means for the routine 3-dimensional analysis of vascular morphology in studies of this type
Advances in MRI-Based Detection of Cerebrovascular Changes after Experimental Traumatic Brain Injury
Traumatic brain injury is a heterogeneous and multifaceted neurological disorder that involves diverse pathophysiological pathways and mechanisms. Thorough characterization and monitoring of the brainâs status after neurotrauma is therefore highly complicated. Magnetic resonance imaging (MRI) provides a versatile tool for in vivo spatiotemporal assessment of various aspects of central nervous system injury, such as edema formation, perfusion disturbances and structural tissue damage. Moreover, recent advances in MRI methods that make use of contrast agents have opened up additional opportunities for measurement of events at the level of the cerebrovasculature, such as bloodâbrain barrier permeability, leukocyte infiltration, cell adhesion molecule upregulation and vascular remodeling. It is becoming increasingly clear that these cerebrovascular alterations play a significant role in the progression of post-traumatic brain injury as well as in the process of post-traumatic brain repair. Application of advanced multiparametric MRI strategies in experimental, preclinical studies may significantly aid in the elucidation of pathomechanisms, monitoring of treatment effects, and identification of predictive markers after traumatic brain injury
Developing theory-informed behaviour change interventions to implement evidence into practice : a systematic approach using the Theoretical Domains Framework
PMID: 22531013 [PubMed - indexed for MEDLINE] PMCID: PMC3443064 Free PMC ArticlePeer reviewedPublisher PD
The relationship between a trusted adult and adolescent outcomes:A protocol of a scoping review
Abstract Background Although documentation of harm towards children and young people has existed for centuries, it was not until the 1960s that it became a specific focus for health professionals. Since that time, the importance of protective social networks has become better understood. The concept of trusted adults has come into sharper focus, with children being encouraged to develop networks of dependable adults to turn to for support in times of need. While many child protection processes highlight risks to younger children, there has been less emphasis on older children. The role of trusted adults may be particularly important during adolescence, due to burgeoning independence, developing sexuality, relationship formation, and associated vulnerabilities. While important choices relating to health and education are made during this period, there is little formal evidence relating to the impact of trusted adults on such outcomes. This review therefore aims to focus on the role and influence of trusted adults for adolescents. Methods This study is a scoping review. A broad range of databases will be searched, including MEDLINE, ERIC, Education Abstracts, Web of Science, ASSIA, Sociological Abstracts, and PsycINFO. Predefined inclusion/exclusion criteria will be used, with a focus on outcomes relating to health and education. Two reviewers will blind screen papers independently at all screening stages, with conflicts being resolved by a third reviewer. Quantitative and qualitative studies, as well as unpublished (grey) literature/reports, will be included. We will use the World Health Organizationâs âsecond decadeâ definition of adolescence. We aim to collate and map evidence in a broad overview and produce meta-analyses of homogenous data. Where this is not possible, a narrative summary will be produced. Discussion There appears to be sparse knowledge regarding the role of trusted adults for adolescents. Potential benefits to health and wellbeing may impact on educational attainment, and vice versa. These areas are of particular relevance during the second decade, when decisions that affect future direction, achievement, and wellbeing are being made. The increased understanding of the role of trusted adults provided by this review may help to inform practice and policy and lead to potential benefits for the health and education of adolescents. Systematic review registration PROSPERO CRD 4201707673
Applying Kolb's Experiential Learning Cycle for Laboratory Education
This article was published in the journal, Journal of Engineering Education [© American Society for Engineering Education] and the definitive version is available at: http://www.asee.org/publications/jee/index.cfmThis paper describes a model for laboratory education based on
Kolbâs experiential learning theory. The method is implemented
using modern teaching technologies and a combination of remote,
virtual, and hands-on laboratory sessions and have been applied to
the teaching of the undergraduate process control laboratory at the
Chemical Engineering Department at Loughborough University,
United Kingdom. An argument that poor learning in the laboratory
is due to insufficient activation of the prehension dimension
of Kolbâs cycle was suggested and verified, providing a pedagogical
explanation. The quantitative analysis showed significant
enhancement of the learning outcomes of the experimental group
compared with the control group. Apart from the hands-on
session, the proposed model involves additional activities, such as
pre- and post-lab tests and virtual laboratory sessions, which are
associated with Kolbâs cycle to facilitate constructivist learning.
The paper provides the first laboratory education model that
builds thoroughly on Kolbâs experiential learning theory
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