251 research outputs found

    Using X-ray Diffraction to Determine Stresses

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    In recent years 3D printing has emerged as an increasingly intriguing technology: used to create toys, models, and even full size houses. Though most common in plastics, 3D printing is being considered for commercial metal products as well. As in other casting and processing techniques, the properties of materials that are 3D printed can vary greatly. For example, in the manufacturing of hot metals, controlled cooling is necessary to avoid embrittlement. In 3D printed metals, one property of particular concern is residual stress, as it can cause metal parts to warp when cut free from their base plates. It is therefore, important to understand how the 3D printing process effects the distribution of the stresses in parts. High energy x-ray diffraction (HEXD) is one of the tools that can be used to investigate residual stresses. HEXD measures volumetric strain profiles, which can then be analyzed to find out more about the stress characteristics of the part. We will use these profiles to measure the residual stress depth in several aluminum bars and present the results

    Ol Woman Blong Wota (The Women of the Water)

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    The women of Leweton have been performing Water Music for international audiences since the founding of the Leweton Cultural Village in 2008, and have been practising this tradition for as long as they remember. The women performers who feature in this film are Denilla Frazer, Melinda Frazer, Jerolyn Frazer, Beverley Frazer, Cecilia Tingris, Cicilia Wari, Marie Sur, Sonrin Sur, Trisha Sur, and Margaret Tingris

    Breast Feeding and Childhood Obesity

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    Obesity is an epidemic in today\u27s obesogenic society, a society that encourages excess food consumption but also idealizes thinness (Golan & Crow, 2004). One at-risk population that is gathering much attention, and much concern, is children. Obesity is the most frequent nutritional disorder in children (von Kries et al., 1999). Recent numbers indicate that the prevalence of obesity in children (ages six-11) has doubled, from seven percent in 1980 to 15.3 percent in 2000; the prevalence for adolescents (ages 12-19) has tripled, from five percent in 1980 to 15.5 percent in 2000 (AOA, 2004)

    Does high-intensity exercise better improve ambulation in the population with chronic stroke, as compared to standard care?: A Systematic Review of the Literature

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    Purpose: To assess the effectiveness of high-intensity exercise on the improvement of gait deficits in survivors of chronic stroke as compared to standard care.https://jdc.jefferson.edu/dptcapstones/1006/thumbnail.jp

    Wide-field dynamic astronomy in the near-infrared with Palomar Gattini-IR and DREAMS

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    There have been a dramatic increase in the number of optical and radio transient surveys due to astronomical transients such as gravitational waves and gamma ray bursts, however, there have been a limited number of wide-field infrared surveys due to narrow field-of-view and high cost of infrared cameras, we present two new wide-field near-infrared fully automated surveyors; Palomar Gattini-IR and the Dynamic REd All-sky Monitoring Survey (DREAMS). Palomar Gattini-IR, a 25 square degree J-band imager that begun science operations at Palomar Observatory, USA in October 2018; we report on survey strategy as well as telescope and observatory operations and will also providing initial science results. DREAMS is a 3.75 square degree wide-field imager that is planned for Siding Spring Observatory, Australia; we report on the current optical and mechanical design and plans to achieve on-sky results in 2020. DREAMS is on-track to be one of the first astronomical telescopes to use an Indium Galium Arsenide (InGaAs) detector and we report initial on-sky testing results for the selected detector package. DREAMS is also well placed to take advantage and provide near-infrared follow-up of the LSST

    Wheels, skills and thrills: A social marketing trial to reduce aggressive driving from young men in deprived areas

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    Young men from poorer backgrounds are associated with high road traffic collision levels. However, solving this problem has proven very difficult. Hence this paper summarises the findings of a UK government funded two-year trial of a cross-discipline intervention to reduce aggressive driving amongst this group. The intervention reported on here departed from traditional approaches such as fear appeals, standalone educational approaches, or punitive measures. Instead, the discipline of social marketing was used to provide overarching direction and structure for the trial, with a key focus on motivation and engagement. The project rested on a strong education and training platform and included a bespoke coaching programme, incentives, and an in-vehicle measurement and feedback device. The project had three development phases leading to the final trial. First, a literature and case study review identified possible design strategies. Second, these strategies were explored using primary research in the form of a qualitative inquiry. Third, a pre-trial design phase sought to introduce key components of the intervention to the trial cohort, retaining some flexibility before committing to the final design. Young males with a history of challenging behaviour (e.g. criminal records, driving convictions) from an economically deprived area within a UK city were recruited. Of 42 recruits, 23 successfully completed the trial. Behaviour changes were measured pre-, during and post-trial through a combination of driver performance data measured by in-vehicle data recorders (IVDRs), assessments of driving undertaken by trained observers, and self-assessment surveys and interviews with trial participants. Results indicate a significant average improvement in driving skills amongst participants who completed the trial. Given the difficulty in engaging and changing behaviour of this specific group, this is regarded as a significant finding. In summary the study provides an indication of proof of concept for the intervention in improving driving skills. However the limited sample size and lack of control group mean that further work will be required to validate these findings. It is recommended that a feasibility study with higher cohort volumes is undertaken, before attempting a full scale trial. © 2013 Elsevier Ltd. All rights reserved

    Constraining the X-ray - Infrared spectral index of second-timescale flares from SGR1935+2154 with Palomar Gattini-IR

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    The Galactic magnetar SGR1935+2154 has been reported to produce the first known example of a bright millisecond duration radio burst (FRB 200428) similar to the cosmological population of fast radio bursts (FRBs), bolstering the association of FRBs to active magnetars. The detection of a coincident bright X-ray burst has revealed the first observed multi-wavelength counterpart of a FRB. However, the search for similar emission at optical wavelengths has been hampered by the high inferred extinction on the line of sight. Here, we present results from the first search for second-timescale emission from the source at near-infrared wavelengths using the Palomar Gattini-IR observing system in J-band, made possible by a recently implemented detector read-out mode that allowed for short exposure times of 0.84 s with 99.9% observing efficiency. With a total observing time of 12 hours (47728 images) on source, we place median 3 σ3\,\sigma limits on the second-timescale emission of <20< 20 mJy (13.1 AB mag). We present non-detection limits from epochs of four simultaneous X-ray bursts detected by the Insight-{\it HXMT} and {\it NuSTAR} telescopes during our observing campaign. The limits translate to an extinction corrected fluence limit of <125< 125 Jy ms for an estimated extinction of AJ=2.0A_J = 2.0 mag. These limits provide the most stringent constraints to date on the fluence of flares at frequencies of ∼1014\sim 10^{14} Hz, and constrain the ratio of the near-infrared (NIR) fluence to that of coincident X-ray bursts to RNIR<2.5×10−2R_{\rm NIR} < 2.5 \times 10^{-2}. Our observations were sensitive enough to easily detect a near-infrared counterpart of FRB 200428 if the NIR emission falls on the same power law as that observed across its radio to X-ray spectrum. The non-detection of NIR emission around the coincident X-ray bursts constrains the fluence index of the brightest burst to be steeper than 0.350.35.Comment: 10 pages, 4 figures, submitted to ApJL. Comments welcom

    Mapping and phasing of structural variation in patient genomes using nanopore sequencing

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    Despite improvements in genomics technology, the detection of structural variants (SVs) from short-read sequencing still poses challenges, particularly for complex variation. Here we analyse the genomes of two patients with congenital abnormalities using the MinION nanopore sequencer and a novel computational pipeline—NanoSV. We demonstrate that nanopore long reads are superior to short reads with regard to detection of de novo chromothripsis rearrangements. The long reads also enable efficient phasing of genetic variations, which we leveraged to determine the parental origin of all de novo chromothripsis breakpoints and to resolve the structure of these complex rearrangements. Additionally, genome-wide surveillance of inherited SVs reveals novel variants, missed in short-read data sets, a large proportion of which are retrotransposon insertions. We provide a first exploration of patient genome sequencing with a nanopore sequencer and demonstrate the value of long-read sequencing in mapping and phasing of SVs for both clinical and research applications
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