5,283 research outputs found
Full-field pulsed magneto-photoelasticity – 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
Sector Guidance to Address Staff Sexual Misconduct in UK Higher Education: Recommendations for reporting, investigation and decision-making processes relating to student complaints of staff sexual misconduct in UK higher education
UK higher education currently lacks specific guidance on procedures to address student complaints about staff sexual misconduct. This guidance aims to fill that void, drawing on evidence and research from the sector, both in the UK and internationally. It is intended to help higher education institutions (HEIs) resolve the tension arising from having distinct procedures for handling student complaints and staff discipline; to provide a framework that engenders trust in HEIs to respond effectively to student complaints; to meet regulatory requirements; and to provide fair and equitable outcomes for both students and staff
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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 μg 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 ± 16.4%). Difference among subjects was explained by dose of B12, with percent bioavailability from 2.6 μg only half that from 1.4 μg. The total amount of B12 absorbed was limited to 0.5-0.8 μg (mean 0.55 ± 0.19 μg 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 μg/day)
An Exploration of Supports for Increasing Classroom Physical Activity within Elementary Schools
Classroom-based physical activity (CBPA) can significantly benefit students’ health and educational outcomes, but many teachers do not utilize CBPA. This study examined teachers’ perceptions about the value and impact of several approaches to support CBPA implementation, and teachers’ weekly self-reported CBPA use. Interviews were conducted with 35 classroom teachers (including those using and not using CBPA) at two public elementary schools, and CBPA tracking logs were collected on a weekly basis. Interview transcripts were interpreted through key domains within implementation science. On average, teachers reported using one activity every other day. Interview data revealed that utilizing professional collaboration time for peer-to-peer feedback and getting informal support from the school’s physical education teacher both have some promise for increasing implementation of CBPA. However, teachers largely felt these strategies were unnecessary. Explicit administrator support was reported by teachers as the most promising mechanism for increasing their CBPA implementation
Pregnancy has a minimal impact on the acute transcriptional signature to vaccination.
Vaccination in pregnancy is an effective tool to protect both the mother and infant; vaccines against influenza, pertussis and tetanus are currently recommended. A number of vaccines with a specific indication for use in pregnancy are in development, with the specific aim of providing passive humoral immunity to the newborn child against pathogens responsible for morbidity and mortality in young infants. However, the current understanding about the immune response to vaccination in pregnancy is incomplete. We analysed the effect of pregnancy on early transcriptional responses to vaccination. This type of systems vaccinology approach identifies genes and pathways that are altered in response to vaccination and can be used to understand both the acute inflammation in response to the vaccine and to predict immunogenicity. Pregnant women and mice were immunised with Boostrix-IPV, a multivalent vaccine, which contains three pertussis antigens. Blood was collected from women before and after vaccination and RNA extracted for analysis by microarray. While there were baseline differences between pregnant and non-pregnant women, vaccination induced characteristic patterns of gene expression, with upregulation in interferon response and innate immunity gene modules, independent of pregnancy. We saw similar patterns of responses in both women and mice, supporting the use of mice for preclinical screening of novel maternal vaccines. Using a systems vaccinology approach in pregnancy demonstrated that pregnancy does not affect the initial response to vaccination and that studies in non-pregnant women can provide information about vaccine immunogenicity and potentially safety
‘Our voice started off as a whisper and now it is a great big roar’ : The Salford Dementia Associate Panel as a model of involvement in research activities
This paper presents the work of the ‘Salford Dementia Associate Panel’, based at the Salford Institute for Dementia, Salford University (UK). We discuss the roles of the Dementia Associates, in particular around the areas of engagement and research. The panel is made up of people living with dementia, and current and former care partners. It highlights the development of this group over a four-year period and demonstrates over time how the role of a Dementia Associate member has evolved. The panel is involved in research, education and public engagement activities conducted by staff and students within the Institute. The motivations for becoming involved are clearly articulated and demonstrate how the personal backgrounds of individuals have driven the collective involvement and desire to bring about change. The benefits and challenges associated with working as part of a panel are discussed. We conclude by bringing together our experiences as a set of suggestions for others who may wish to create a similar forum to promote the involvement of people living with dementia and former and current care partners
Stereolithography for 3D photoelasticity
Recently, the use of photoelasticity has become more widespread due to the development of digital methods of fringe analysis [1] that allow a significant reduction in the time taken to achieve a stress map for any given model, particularly when only fractional fringe orders are displayed. However, in order for the full potential of the photoelastic method to be realised, a technique for rapidly producing complex 3-dimensional photoelastic models must be developed. Stereolithography is one so-called ‘rapid-prototype’ method that works by building a laminar model from a tank of photo-curing resin. A perforated metal plate is submerged in the liquid resin to a depth of typically around 0.1mm. A laser then traces the shape of the first layer of the component onto the plate, curing a thin layer of the resin. The plate is lowered by 0.1mm, and a further layer of resin cured by the laser. By this method, complex structures may be ‘laid-up’ in a matter of hours.
Previous studies concerned with the use of stereolithography for the production of photoelastic models [2] have noted that unacceptable levels of residual birefringence and stress have remained in the photoelastic model even after conventional annealing methods. Thus the use of such methods has been limited. If the stereolithographic method were developed for photoelasticity, one possible area of interest would be the design and analysis of orthopedic implants.
This paper outlines a series of studies looking at the requirements of photoelastic materials for three-dimensional stress analysis
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Electrophysiological Guidance of Epidural Electrode Array Implantation over the Human Lumbosacral Spinal Cord to Enable Motor Function after Chronic Paralysis.
Epidural electrical stimulation (EES) of the spinal cord has been shown to restore function after spinal cord injury (SCI). Characterization of EES-evoked motor responses has provided a basic understanding of spinal sensorimotor network activity related to EES-enabled motor activity of the lower extremities. However, the use of EES-evoked motor responses to guide EES system implantation over the spinal cord and their relation to post-operative EES-enabled function in humans with chronic paralysis attributed to SCI has yet to be described. Herein, we describe the surgical and intraoperative electrophysiological approach used, followed by initial EES-enabled results observed in 2 human subjects with motor complete paralysis who were enrolled in a clinical trial investigating the use of EES to enable motor functions after SCI. The 16-contact electrode array was initially positioned under fluoroscopic guidance. Then, EES-evoked motor responses were recorded from select leg muscles and displayed in real time to determine electrode array proximity to spinal cord regions associated with motor activity of the lower extremities. Acceptable array positioning was determined based on achievement of selective proximal or distal leg muscle activity, as well as bilateral muscle activation. Motor response latencies were not significantly different between intraoperative recordings and post-operative recordings, indicating that array positioning remained stable. Additionally, EES enabled intentional control of step-like activity in both subjects within the first 5 days of testing. These results suggest that the use of EES-evoked motor responses may guide intraoperative positioning of epidural electrodes to target spinal cord circuitry to enable motor functions after SCI
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