1,390 research outputs found

    Force Characterization and Manufacturing of a Dynamic Unilateral Clubfoot Brace

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    Clubfoot is a musculoskeletal birth defect characterized by an inward twisting of an infant’s feet. Currently, a series of casts are used to correct the clubfoot, and a boots-and-bar brace is used to maintain the correction. However, this method has concerns with compliance, comfort, and social stigma. Hope Walks and their clinic in Kijabe, Kenya are interested in implementing a new maintenance brace that addresses these concerns. Mr. Jerald Cunningham, CPO, designed and is utilizing a unilateral clubfoot maintenance brace called the Cunningham Clubfoot Brace. He asserts his brace reduces treatment time, lessens social stigma, and increases child mobility. However, to date, there is not enough published research on its biomechanics and patient success rates to confirm his findings. The Cunningham Clubfoot Brace Collaboratory project seeks to validate the effectiveness of the Cunningham design through biomedical testing and increase brace availability through sustainable manufacturing. To do this, the team is measuring the biomechanical forces applied by the brace with multiple force sensor systems and an infant foot model. The team is assisting Mr. Cunningham in his plans to use injection molding to increase brace production by scanning and creating CAD files of the brace. The team is also completing a failure and reuse analysis of the Cunningham Brace for the clinic in Kijabe. Furthermore, the ongoing clinical study at CURE International\u27s hospital in Kijabe, Kenya, and Dr. Emily Farrar’s research paper will provide greater insight into the effectiveness of the Cunningham Brace. These collaborative efforts will allow for further understanding of the effectiveness of the Cunningham Brace and its acceptance as an alternative clubfoot maintenance brace.https://mosaic.messiah.edu/engr2021/1001/thumbnail.jp

    Force Characterization and Manufacturing of a Dynamic Unilateral Clubfoot Brace

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    Clubfoot is a musculoskeletal birth defect characterized by an inward twisting of an infant’s feet. Currently, a series of casts are used to correct clubfoot and the Steenbeek brace is used to maintain the correction. However, this method has issues with compliance, comfort, and social stigma. Mr. Jerald Cunningham, CPO, designed and is utilizing a unilateral clubfoot maintenance brace called the Cunningham Clubfoot Brace. He expects his brace to reduce treatment time, lessen social stigma, and increase child mobility. Hope Walks, in Kijabe, Kenya, is interested in implementing this new maintenance brace at their clinics. However, there is not enough published research on its biomechanics and patient success rates to confirm Mr. Cunningham’s findings. The Cunningham Clubfoot Brace Collaboratory project seeks to validate the effectiveness of this design through biomedical testing and increase brace accessibility through sustainable manufacturing. The team is measuring the biomechanical forces applied by the brace with multiple force sensors on the Cunningham and Steenbeek braces. Mr. Cunningham plans to use injection molding to increase brace production. The team is completing Finite Element Analysis to determine how the brace’s properties change with injection molding. The team is also completing fatigue analysis with the Cunningham Brace to quantify its reusability. Furthermore, the clinical study in Kenya and Dr. Emily Farrar’s retrospective research paper will contribute to the published research on the Cunningham Brace. The collaborative efforts of the team will increase further understanding of the Cunningham Brace and its acceptance as an alternative clubfoot maintenance brace.https://mosaic.messiah.edu/engr2022/1002/thumbnail.jp

    Above- and below-ground net primary productivity across ten Amazonian forests on contrasting soils

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    Copyright © 2009 European Geosciences Union. This is the published version available at http://www.biogeosciences.net/6/2759/2009/bg-6-2759-2009.html © Author(s) 2009. This work is distributed under the Creative Commons Attribution 3.0 License.The net primary productivity (NPP) of tropical forests is one of the most important and least quantified components of the global carbon cycle. Most relevant studies have focused particularly on the quantification of the above-ground coarse wood productivity, and little is known about the carbon fluxes involved in other elements of the NPP, the partitioning of total NPP between its above- and below-ground components and the main environmental drivers of these patterns. In this study we quantify the above- and below-ground NPP of ten Amazonian forests to address two questions: (1) How do Amazonian forests allocate productivity among its above- and below-ground components? (2) How do soil and leaf nutrient status and soil texture affect the productivity of Amazonian forests? Using a standardized methodology to measure the major elements of productivity, we show that NPP varies between 9.3±1.3MgC ha−1 yr−1 (mean±standard error), at a white sand plot, and 17.0±1.4MgC ha−1 yr−1 at a very fertile Terra Preta site, with an overall average of 12.8±0.9MgC ha−1 yr−1. The studied forests allocate on average 64±3% and 36±3% of the total NPP to the above and below-ground components, respectively. The ratio of above-ground and below-ground NPP is almost invariant with total NPP. Litterfall and fine root production both increase with total NPP, while stem production shows no overall trend. Total NPP tends to increase with soil phosphorus and leaf nitrogen status. However, allocation of NPP to below-ground shows no relationship to soil fertility, but appears to decrease with the increase of soil clay content

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

    Changes of Mind in an Attractor Network of Decision-Making

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    Attractor networks successfully account for psychophysical and neurophysiological data in various decision-making tasks. Especially their ability to model persistent activity, a property of many neurons involved in decision-making, distinguishes them from other approaches. Stable decision attractors are, however, counterintuitive to changes of mind. Here we demonstrate that a biophysically-realistic attractor network with spiking neurons, in its itinerant transients towards the choice attractors, can replicate changes of mind observed recently during a two-alternative random-dot motion (RDM) task. Based on the assumption that the brain continues to evaluate available evidence after the initiation of a decision, the network predicts neural activity during changes of mind and accurately simulates reaction times, performance and percentage of changes dependent on difficulty. Moreover, the model suggests a low decision threshold and high incoming activity that drives the brain region involved in the decision-making process into a dynamical regime close to a bifurcation, which up to now lacked evidence for physiological relevance. Thereby, we further affirmed the general conformance of attractor networks with higher level neural processes and offer experimental predictions to distinguish nonlinear attractor from linear diffusion models

    Climate change and the long-term viability of the World’s busiest heavy haul ice road

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    Climate models project that the northern high latitudes will warm at a rate in excess of the global mean. This will pose severe problems for Arctic and sub-Arctic infrastructure dependent on maintaining low temperatures for structural integrity. This is the case for the economically important Tibbitt to Contwoyto Winter Road (TCWR)—the world’s busiest heavy haul ice road, spanning 400 km across mostly frozen lakes within the Northwest Territories of Canada. In this study, future climate scenarios are developed for the region using statistical downscaling methods. In addition, changes in lake ice thickness are projected based on historical relationships between measured ice thickness and air temperatures. These projections are used to infer the theoretical operational dates of the TCWR based on weight limits for trucks on the ice. Results across three climate models driven by four RCPs reveal a considerable warming trend over the coming decades. Projected changes in ice thickness reveal a trend towards thinner lake ice and a reduced time window when lake ice is at sufficient thickness to support trucks on the ice road, driven by increasing future temperatures. Given the uncertainties inherent in climate modelling and the resultant projections, caution should be exercised in interpreting the magnitude of these scenarios. More certain is the direction of change, with a clear trend towards winter warming that will reduce the operation time window of the TCWR. This illustrates the need for planners and policymakers to consider future changes in climate when planning annual haulage along the TCWR

    Multidisciplinary rehabilitation reduces hypothalamic grey matter volume loss in individuals with preclinical Huntington's disease: A nine-month pilot study

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    Background: Hypothalamic pathology is a well-documented feature of Huntington's disease (HD) and is believed to contribute to circadian rhythm and habitual sleep disturbances. Currently, no therapies exist to combat hypothalamic changes, nor circadian rhythm and habitual sleep disturbances in HD. Objective: To evaluate the effects of multidisciplinary rehabilitation on hypothalamic volume, brain-derived neurotrophic factor (BDNF), circadian rhythm and habitual sleep in individuals with preclinical HD. Methods: Eighteen individuals with HD (ten premanifest and eight prodromal) undertook a nine-month multidisciplinary rehabilitation intervention (intervention group), which included exercise, cognitive and dual task training and social events, and were compared to a community sample of eleven individuals with premanifest HD receiving no intervention (control group). Hypothalamic volume, serum BDNF, salivary cortisol and melatonin concentrations, subjective sleep quality, daytime somnolence, habitual sleep-wake patterns, stress and anxiety and depression symptomatology were evaluated. Results: Hypothalamus grey matter volume loss was significantly attenuated in the intervention group compared to the control group after controlling for age, gender, Unified Huntington's Disease Rating Scale-Total Motor Score and number of cytosine-adenine-guanine repeats. Serum BDNF levels were maintained in the intervention group, but decreased in the control group following the study period. Both groups exhibited decreases in cortisol and melatonin concentrations. No changes were observed in sleep or mood outcomes. Conclusions: This exploratory study provides evidence that multidisciplinary rehabilitation can reduce hypothalamic volume loss and maintain peripheral BDNF levels in individuals with preclinical HD but may not impact on circadian rhythm. Larger, randomised controlled trials are required to confirm these findings

    Race, ethnicity, community-level socioeconomic factors, and risk of COVID-19 in the United States and the United Kingdom

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    BACKGROUND: There is limited prior investigation of the combined influence of personal and community-level socioeconomic factors on racial/ethnic disparities in individual risk of coronavirus disease 2019 (COVID-19). METHODS: We performed a cross-sectional analysis nested within a prospective cohort of 2,102,364 participants from March 29, 2020 in the United States (US) and March 24, 2020 in the United Kingdom (UK) through December 02, 2020 via the COVID Symptom Study smartphone application. We examined the contribution of community-level deprivation using the Neighborhood Deprivation Index (NDI) and the Index of Multiple Deprivation (IMD) to observe racial/ethnic disparities in COVID-19 incidence. ClinicalTrials.gov registration: NCT04331509. FINDINGS: Compared with non-Hispanic White participants, the risk for a positive COVID-19 test was increased in the US for non-Hispanic Black (multivariable-adjusted odds ratio [OR], 1.32; 95% confidence interval [CI], 1.18–1.47) and Hispanic participants (OR, 1.42; 95% CI, 1.33–1.52) and in the UK for Black (OR, 1.17; 95% CI, 1.02–1.34), South Asian (OR, 1.39; 95% CI, 1.30–1.49), and Middle Eastern participants (OR, 1.38; 95% CI, 1.18–1.61). This elevated risk was associated with living in more deprived communities according to the NDI/IMD. After accounting for downstream mediators of COVID-19 risk, community-level deprivation still mediated 16.6% and 7.7% of the excess risk in Black compared to White participants in the US and the UK, respectively. INTERPRETATION: Our results illustrate the critical role of social determinants of health in the disproportionate COVID-19 risk experienced by racial and ethnic minorities. FUNDING: Please refer to the Funding section at the end of the article

    Factors confounding the assessment of reflection: a critical review

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    BACKGROUND: Reflection on experience is an increasingly critical part of professional development and lifelong learning. There is, however, continuing uncertainty about how best to put principle into practice, particularly as regards assessment. This article explores those uncertainties in order to find practical ways of assessing reflection. DISCUSSION: We critically review four problems: 1. Inconsistent definitions of reflection; 2. Lack of standards to determine (in)adequate reflection; 3. Factors that complicate assessment; 4. Internal and external contextual factors affecting the assessment of reflection. SUMMARY: To address the problem of inconsistency, we identified processes that were common to a number of widely quoted theories and synthesised a model, which yielded six indicators that could be used in assessment instruments. We arrived at the conclusion that, until further progress has been made in defining standards, assessment must depend on developing and communicating local consensus between stakeholders (students, practitioners, teachers, supervisors, curriculum developers) about what is expected in exercises and formal tests. Major factors that complicate assessment are the subjective nature of reflection's content and the dependency on descriptions by persons being assessed about their reflection process, without any objective means of verification. To counter these validity threats, we suggest that assessment should focus on generic process skills rather than the subjective content of reflection and where possible to consider objective information about the triggering situation to verify described reflections. Finally, internal and external contextual factors such as motivation, instruction, character of assessment (formative or summative) and the ability of individual learning environments to stimulate reflection should be considered
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