1,269 research outputs found

    High fidelity imaging and high performance computing in nonlinear EIT

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    We show that nonlinear EIT provides images with well defined characteristics when smoothness of the image is used as a constraint in the reconstruction process. We use the gradient of the logarithm of resistivity as an effective measure of image smoothness, which has the advantage that resistivity and conductivity are treated with equal weight. We suggest that a measure of the fidelity of the image to the object requires the explicit definition and application of such a constraint. The algorithm is applied to the simulation of intra-ventricular haemorrhaging (IVH) in a simple head model. The results indicate that a 5% increase in the blood content of the ventricles would be easily detectable with the noise performance of contemporary instrumentation. The possible implementation of the algorithm in real time via high performance computing is discussed

    The eyes have it: Infant gaze as an indicator of hunger and satiation

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    Infant gaze serves as a measure of attention to food cues in adults and children and may play a role in signalling infant hunger and satiation. Maternal responsiveness to infant satiation cues, including gaze, supports healthy appetite development and may reduce obesity risk. However, mothers often experience difficulty in interpreting feeding cues, and there have been few attempts to study cues systematically. This study aimed to develop a reliable coding scheme for categorising and tracking infant gaze behaviours during complementary feeding (CF). Twenty infants aged between six and eighteen months were filmed during typical meals on two occasions at home. The Infant Gaze at Mealtime (IGM) coding scheme was devised from the analysis of a sample of videos, a piloting and testing process, and the feeding cues and developmental psychology literature. Inter and intra-rater reliability tests of the scheme with 20% of the study videos revealed high levels of reliability. When applied to the full sample of 225 video clips, the IGM coding scheme revealed a significant decrease over time in the frequency of infants gazing at food and a significant increase in exploratory gaze behaviour within a meal. These changes were consistent across main and dessert courses, suggesting they may be indicative of changes in infant feeding state. The results suggest that infant gaze may offer a means of identifying infant hunger and satiation and, as an easily observed behaviour, an effective tool for mothers and professionals for promoting responsive feeding

    The effect of food type on the portion size effect in children aged 2-12 years: A systematic review and meta-analysis.

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    Visual cues such as plate size, amount of food served and packaging are known to influence the effects of portion size on food intake. Unit bias is a well characterised heuristic and helps to determine consumption norms. In an obesogenic environment where large portions are common place, the unit or segmentation bias may be overridden promoting overconsumption of both amorphous or unit foods. The aim of this review was to investigate the impact of offering unit or amorphous food on the portion size effect (PSE) in children aged 2–12 years. A systematic search for literature was conducted in Medline, PsycInfo and Web of Science in February 2018. A total of 1197 papers were retrieved following the searches. Twenty-one papers were included in the systematic review, of which 15 provided requisite statistical information for inclusion in a random effects meta-analysis. Increasing children's food portion size by 51–100% led to a significant increase in intake (SMD = 0.47, 95% CI: 0.39–0.55). There was no evidence to suggest that increases in consumption were related to food type (p = 0.33), child age (p = 0.47) or initial portion size served (p=0.14). Residual heterogeneity was not significant (p=0.24). The PSE was demonstrated in children aged 2–12 years when offered both unit and amorphous food items. The effect was not restricted by food type, child age or influenced by initial portion size served. Of the studies included in the meta-analysis between study heterogeneity was low suggesting minimal variation in treatment effects between studies, however, more research is required to understand the mechanisms of the PSE in preschool children. Future research should determine feasible methods to downsize portion sizes served to children

    Impacts of added roughage on growth performance, digestibility, ruminal fermentation, and ruminal pH of feedlot steers fed wheat-based feedlot diets containing 30% modified distillers grains with solubles

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    Two experiments were conducted to evaluate the inclusion rate roughage in wheat-based diets containing modified distillers grains with solubles (MDGS) on feedlot performance (Feedlot Experiment), as well as digestibility, ruminal pH, and ruminal fermentation characteristics (Digestibility Experiment). The feedlot experiment utilized 72 Angus steers (392 ± 46.3 kg initial body weight) which were randomly assigned to 1 of 12 pens, 3 pens per treatment, to evaluate feedlot performance and carcass characteristics. Dietary treatments were 1) control; 10% roughage, 2) 12% roughage, 3) 14% roughage, and 4) 16% roughage. The digestibility experiment used four ruminally and duodenally cannulated steers (393 ± 33.0 kg) in a 4 × 4 Latin Square with either 10%, 12%, 14%, or 16% roughage as in the feedlot experiment. However, dietary roughage source was different between these two experiments and included a combination of grass hay and wheat straw (Feedlot Experiment), and corn silage (Digestibility Experiment). All data were analyzed with the Mixed Procedures of SAS. Feed intake was recorded, with duodenal and fecal output calculated using chromic oxide. Ruminal pH and fermentation were assessed. Growth performance and most carcass characteristics were not affected by increasing roughage (P ≥ 0.11). Marbling tended to decrease linearly (P = 0.10) with increasing roughage inclusion. Increasing dietary roughage content had no effect on organic matter intake (P = 0.60) in the digestibility experiment. Intake, duodenal flow, and digestibility of neutral detergent fiber and acid detergent fiber were not affected by treatment (P ≥ 0.16). Ruminal pH increased linearly (P \u3c 0.01) as rate of roughage inclusion increased. Ruminal concentrations of acetate and butyrate increased, and propionate decreased in a linear fashion (P \u3c 0.01) thereby increasing (P \u3c 0.01) acetate and butyrate to propionate ratio with increasing dietary roughage. Our data indicate that increasing roughage inclusion in wheat-based diets including 30% MDGS increased ruminal pH and shifted ruminal fermentation patterns. Additionally, increasing roughage inclusion did not affect feedlot performance in steers fed wheat at 36% to 42% of dietary dry matter in combination with 30% MDGS

    Improving temperature‐based predictions of the timing of flowering in cotton

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    Key management recommendations for cotton (Gossypium hirsutum L.) management require estimates of the timing of crop phenology. Most commonly growing day degree (DD) (thermal time) approaches are used. Currently, across many cotton production regions, there is no consistent approach to predicting first square and flower timing. Day degree approaches vary considerably, with base thresholds different (12.0–15.6 °C) with no consistency using an optimum temperature threshold (i.e., temperature where development ceases to increase). As cotton is grown in variable and changing climates, and cultivars change, there is a need to ensure the accuracy of this approach for predicting timing of flowering for assisting cotton management. In this study new functions to predict first square and first flower were developed and validated using data collected in multiple seasons and regions (Australia and the United States). Earlier controlled environment studies that monitored crop development were used to assess in more detail how temperatures were affecting early cotton development. New DD functions developed predicted first square and first flower better than the existing Australian and U.S. approaches. The best performing functions had base temperatures like those of existing U.S. functions (15.6 °C) and an optimum threshold temperature of 32.0 °C. New universal DD targets for first square (343 DD [°C]) and first flower (584 DD) were developed. Controlled environment studies supported this base temperature outcome; however, it was less clear that 32.0 °C was the optimum threshold temperature from these data. Precise predictions of cotton development will facilitate accurate growth stage assessments and hence better cotton management decisions

    Interaction of replacing corn silage with soyhulls as a roughage source with or without 3% added wheat straw in the diet: impacts on intake, digestibility, and ruminal fermentation in steers fed high-concentrate diets

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    Six ruminally cannulated steers [475.0 ± 49.6 kg initial body weight (BW)] were used in a 6 × 3 incomplete Latin square design (six treatments and three periods), to evaluate the impacts replacing of corn silage with pelleted soyhulls as roughage in high-concentrate finishing diets containing 30% modified distillers grains with solubles. Treatments were based on increasing dietary inclusion of soyhulls and consisted of: (1) Control (0), roughage supplied by dietary inclusion of 20% corn silage [dry matter (DM) basis]; (2) 50% replacement of corn silage with soyhulls (50); (3) 100% replacement of corn silage with soyhulls (100), and the same three treatments repeated with 3% added wheat straw (DM basis) replacing corn in the diet (0S, 50S, and 100S, respectively). Absolute dry matter intake (DMI; kg/d basis) tended to decrease both linearly and quadratically (P ≤ 0.09) and proportional DMI (% of BW) decreased linearly (P = 0.04) with increasing soyhull inclusion but was not affected by the addition of straw in the diet (P = 0.68). Total tract digestibility of organic matter and crude protein were not affected by soyhull inclusion or added straw (P ≥ 0.32). Ruminal pH did not differ (P = 0.65) with increasing soyhull inclusion but increased with the addition of straw (P \u3c 0.01; 5.9 vs. 6.1 for no straw and straw, respectively). Molar proportions of acetate and butyrate decreased while propionate increased with increased soyhull inclusion (P ≤ 0.03; linearly and quadratically, respectively). Ruminal fluid kinetics were unaffected by either rate of replacement of corn silage with soyhulls or wheat straw inclusion (P ≥ 0.13). Decreases in DMI observed in this study would likely decrease finishing cattle performance and underscores the need for additional research before recommending this practice to cattle feeders

    Using rhythm for rehabilitation: evaluation of a novel haptic device

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    This project explored how new and novel approaches to stroke rehabilitation could improve physical function and the confidence of stroke survivors to remain active and engaged in the community. The innovation trialed was a ‘Haptic bracelet/cueing device’, developed at The Open University. An overview of the Haptic device, its development and role in stroke rehabilitation can be viewed at: https://www.youtube.com/watch?v=S4ZxN6H6XGk The Haptic bracelets provide a physical (embodied) beat that someone can walk to as an alternative to existing audio cuing ways of working. The haptic device provides a non-invasive, relatively cheap way of facilitating people after stroke to continue to maintain or even improve their mobility after intensive rehabilitation has finished. This research explored the impact of the haptic device to gains in mobility. The project had two key aims: 1. To develop a usable and practical prototype of a haptic device to restore gait symmetry after stroke. 2. To investigate the feasibility and acceptability of the prototype in stroke patients. Summary of findings and recommendations When introduced to the Haptic Bracelets participants hoped the product would provide them with: • More confidence and make them feel safer when walking. • Greater ability to take bigger strides rather than little steps. • A way to combat the silly mistakes participants reported making due to tiredness. • Reduced pain (knees, hips) The physiotherapists saw potential for the Haptic devices as part of post stroke rehabilitation, but expressed concern about their lack of access to mobile technologies when out in community practice settings. There were also concerns about use with some stroke survivors because of issues of cognition; and the sensation from the Haptic beat. In the Haptic gait testing • All the participants demonstrated good mobility performance prior to the study (high score on the Rivermead mobility scale) • 4/7* (57.1%) participants who were the most asymmetrical at baseline improved their gait symmetry whilst wearing the haptic device • 3/7* (42%) participant’s gait symmetry continued to improve in the post off condition. • All the participants walked quicker in post-op condition. However, gait speed varied between participants when they were wearing the haptic bracelets. • Participants were had had their strokes between 3-10 years ago, but there was still an indication that the Haptic bracelets were having some impact on mobility. • Syncing of the Haptic device and more mobile Inertial Measurement Unit (IMU) to the fixed gait laboratory (gold standard) system has improved the potential for more community based rehabilitation and commercialisation of the Haptic bracelets. • Post Haptic interviews identified that there were mixed participant feelings about the bracelets. However, some did express positive experiences from testing the Haptic bracelets, including a carry over effect after the devices were removed. Recommendations As this was a pilot study more work is now required to explore the: • use of the Haptic bracelets in community rehabilitation settings • feasibility of the using Haptic bracelets in community settings, particularly looking at staff access to new technologies • potential for the Haptic bracelets to be used in the home as part of ongoing rehabilitation • benefits of Haptic bracelets in the context of longer term stroke rehabilitation • future design needs to improve the look, size and ease of application • cost benefits of using Haptic bracelets as part of an overall program of stroke rehabilitation

    Scaling and root planing with and without periodontal flap surgery

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    . Complete removal of calculus is a primary part of achieving a “biologically acceptable” tooth surface in the treatment of periodontitis. Rabbani et al. reported that a single episode of scaling did not completely remove subgingival calculus and that the deeper the periodontal pocket, the less complete the calculus removal. The purpose of the present study was to evaluate the effectiveness of scaling relative to calculus removal following reflection of a periodontal flap. Each of 21 patients who required multiple extractions had 2 teeth scaled, 2 teeth scaled following the reflection of a periodontal flap, and 2 teeth serve as controls. Local anesthesia was used. Following extraction, the % of subgingival tooth surfaces free of calculus was determined using the method described by Rabbani with a stereomicroscope. Results showed that while scaling only (SO) and scaling with a flap (SF) increased the % of root surface without calculus, scaling following the reflection of a flap aided calculus removal in pockets 4 mm and deeper. Comparison of SO versus SF at various pocket depths for % of tooth surfaces completely free of calculus showed 1 to 3 mm pockets to be 86% versus 86%, 4 to 6 mm pockets to be 43% versus 76% and >6 mm pockets to be 32% versus 50%. The extent of residual calculus was directly related to pocket depth, was greater following scaling only, and was greatest at the CEJ or in association with grooves, fossae or furcations. No differences were noted between anterior and posterior teeth or between different tooth surfaces.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73823/1/j.1600-051X.1986.tb01461.x.pd
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