4,652 research outputs found
Full-field pulsed magneto-photoelasticity ā Experimental Implementation
This paper contains a description of the experimental procedure employed when using a pulsed-magneto-polariscope (PMP) and some initial full-field through-thickness measurements of the stress distribution present in samples containing 3D stresses. The instrument uses the theory of magneto-photoelasticity (MPE), which is an experimental stress analysis technique that involves the application of a magnetic field to a birefringent model within a polariscope. MPE was developed for through-thickness stress measurement where the integrated through-thickness birefringent measurement disguises the actual stress distribution. MPE is mainly used in toughened glass where the through-thickness distribution can reduce its overall strength and so its determination is important.
To date MPE has been a single-point 2D through-thickness measurement and the analysis time is prohibitive for the investigation of an area which may contain high localised stresses. The pulsed-magneto-polariscope (PMP) has been designed to enable the application of full-field 3D MPE [ ]. Using a proof-of concept PMP several experimental measurements were made, these were promising and demonstrate the potential of the new instrument. Further development of this technique presents several exciting possibilities including a tool for the measurement of the distribution of principal stress difference seen in a general 3D model
Effects of Acute Physical Activity on NIH Toolbox-Measured Cognitive Functions Among Children in Authentic Education Settings
Introduction: Identifying a dose of physical activity (PA) that can improve cognitive function in children has important implications for school-day PA recommendations. Researchers and educators have interest in this link as it relates to both health and academic performance. This study examined the dose-response relationship between PA and improvement in cognition in a sample of fifth and sixth grade students.
Methods: Participants (n = 156) from eight classes each completed two of four different cognitive assessments on an iPad, both before and after exposure to one of four randomized, 10-min PA conditions (sedentary, light, moderate, and vigorous). Conditions were standardized through use of videos to lead movement, and participants wore accelerometers to confirm fidelity to PA condition. The four cognitive assessments were selected from the NIH Toolbox Cognition Battery, and included Dimensional Change Card Sort, Flanker, Pattern Comparison, and Picture Sequence Memory tests. Hierarchical linear regression models were used to estimate the effects of condition on each test using an intention to treat analysis.
Results: Fidelity to PA condition was acceptable for sedentary and light conditions, but became less precise for moderate and vigorous conditions. No significant time by condition interaction was observed for any of the cognitive assessment scores.
Conclusions: Results did not substantiate a dose-response link between PA intensity and selected measures of cognitive function. More research is needed to investigate the potentially nuanced effects of short bouts of PA on cognitive functioning in children
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14C-Cobalamin Absorption from Endogenously Labeled Chicken Eggs Assessed in Humans Using Accelerator Mass Spectrometry.
Traditionally, the bioavailability of vitamin B-12 (B12) from in vivo labeled foods was determined by labeling the vitamin with radiocobalt (57Co, 58Co or 60Co). This required use of penetrating radioactivity and sometimes used higher doses of B12 than the physiological limit of B12 absorption. The aim of this study was to determine the bioavailability and absorbed B12 from chicken eggs endogenously labeled with 14C-B12 using accelerator mass spectrometry (AMS). 14C-B12 was injected intramuscularly into hens to produce eggs enriched in vivo with the 14C labeled vitamin. The eggs, which provided 1.4 to 2.6 Ī¼g of B12 (~1.1 kBq) per serving, were scrambled, cooked and fed to 10 human volunteers. Baseline and post-ingestion blood, urine and stool samples were collected over a one-week period and assessed for 14C-B12 content using AMS. Bioavailability ranged from 13.2 to 57.7% (mean 30.2 Ā± 16.4%). Difference among subjects was explained by dose of B12, with percent bioavailability from 2.6 Ī¼g only half that from 1.4 Ī¼g. The total amount of B12 absorbed was limited to 0.5-0.8 Ī¼g (mean 0.55 Ā± 0.19 Ī¼g B12) and was relatively unaffected by the amount consumed. The use of 14C-B12 offers the only currently available method for quantifying B12 absorption in humans, including food cobalamin absorption. An egg is confirmed as a good source of B12, supplying approximately 20% of the average adult daily requirement (RDA for adults = 2.4 Ī¼g/day)
The Indian family on UK reality television: Convivial culture in salient contexts
This is the author's accepted manuscript. The final published article is available from the link below, copyright 2012 @ the author.This article demonstrates how The Family (2009), a fly-on-the wall UK reality series about a British Indian family, facilitates both current public service broadcasting requirements and mass audience appeal. From a critical cultural studies perspective, the author examines the journalistic and viewer responses to the series where authenticity, universality, and comedy emerge as major themes. Textual analysis of the racialized screen representations also helps locate the series within the contexts of contested multiculturalism, genre developments in reality television and public service broadcasting. Paul Gilroyās concept of convivial culture is used as a frame in understanding how meanings of the series are produced within a South Asian popular representational space. The author suggests that the social comedy taxonomy is a prerequisite for the making of this particular observational documentary. Further, the popular (comedic) mode of conviviality on which the series depends is both expedient and necessary within the various sociopolitical contexts outlined
A comparison of the development of audiovisual integration in children with autism spectrum disorders and typically developing children
This study aimed to investigate the development of audiovisual integration in children with Autism Spectrum Disorder (ASD). Audiovisual integration was measured using the McGurk effect in children with ASD aged 7ā16 years and typically developing children (control group) matched approximately for age, sex, nonverbal ability and verbal ability. Results showed that the children with ASD were delayed in visual accuracy and audiovisual integration compared to the control group. However, in the audiovisual integration measure, children with ASD appeared to ācatch-upā with their typically developing peers at the older age ranges. The suggestion that children with ASD show a deficit in audiovisual integration which diminishes with age has clinical implications for those assessing and treating these children
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