46 research outputs found

    Maintaining sagittal plane balance compromises frontal plane balance during reactive stepping in people post-stroke

    Get PDF
    Background. Maintaining balance in response to perturbations during walking often requires the use of corrective responses to keep the center of mass within the base of support. The relationship between the center of mass and base of support is often quantified using the margin of stability. Although people post-stroke increase the margin of stability following perturbations, control deficits may lead to asymmetries in regulation of margins of stability, which may also cause maladaptive coupling between the sagittal and frontal planes during balance-correcting responses. Methods. We assessed how paretic and non-paretic margins of stability are controlled during recovery from forward perturbations and determined how stroke-related impairments influence the coupling between the anteroposterior and mediolateral margins of stability. Twenty-one participants with post-stroke hemiparesis walked on a treadmill while receiving slip-like perturbations on both limbs at foot-strike. We assessed anteroposterior and mediolateral margins of stability before perturbations and during perturbation recovery. Findings. Participants walked with smaller anteroposterior and larger mediolateral margins of stability on the paretic versus non-paretic sides. When responding to perturbations, participants increased the anteroposterior margin of stability bilaterally by extending the base of support and reducing the excursion of the extrapolated center of mass. The anteroposterior and mediolateral margins of stability in the paretic limb negatively covaried during reactive steps such that increases in anteroposterior were associated with reductions in mediolateral margins of stability. Interpretation. Balance training interventions to reduce fall risk post-stroke may benefit from incorporating strategies to reduce maladaptive coupling of frontal and sagittal plane stability

    Challenges experienced with early introduction and sustained consumption of allergenic foods in the Enquiring About Tolerance (EAT) study: A qualitative analysis.

    Get PDF
    BACKGROUND: The early introduction group participants of the Enquiring About Tolerance study were asked to undertake a proscriptive regimen of early introduction and sustained consumption of 6 allergenic foods. It was envisaged that this might be challenging, and early introduction group families were presented with an open-text question to express any problems they were experiencing with the regimen in recurring online questionnaires. OBJECTIVE: We sought to analyze these open-text questionnaire responses with the aim of identifying challenges associated with the introduction and regular consumption of allergenic foods. METHODS: Three combinations of interim questionnaire responses were selected for analysis, representing the early period (4, 5, and 6 months), middle period (8 and 12 months), and late period (24 and 36 months) of participation in the Enquiring About Tolerance study. Responses were assigned a code to describe their content and subsequently grouped into themes to portray key messages. A thematic content analysis allowed for conversion of qualitative codes into quantitative summaries. RESULTS: Three main challenges to allergenic food consumption were identified. First, some children refused the allergenic food, causing a sense of defeat among caregivers. Second, caregivers were concerned that allergenic foods might be causing a reaction, triggering a need for reassurance. Third, practical problems associated with the regimen compromised caregivers' capacity to persist. CONCLUSION: Understanding the challenges experienced with allergenic food introduction and sustained consumption is the necessary precursor to developing specific communication and support strategies that could be used by caregivers, practitioners, policymakers, and key stakeholders to address these problems

    Conserved Genes Act as Modifiers of Invertebrate SMN Loss of Function Defects

    Get PDF
    Spinal Muscular Atrophy (SMA) is caused by diminished function of the Survival of Motor Neuron (SMN) protein, but the molecular pathways critical for SMA pathology remain elusive. We have used genetic approaches in invertebrate models to identify conserved SMN loss of function modifier genes. Drosophila melanogaster and Caenorhabditis elegans each have a single gene encoding a protein orthologous to human SMN; diminished function of these invertebrate genes causes lethality and neuromuscular defects. To find genes that modulate SMN function defects across species, two approaches were used. First, a genome-wide RNAi screen for C. elegans SMN modifier genes was undertaken, yielding four genes. Second, we tested the conservation of modifier gene function across species; genes identified in one invertebrate model were tested for function in the other invertebrate model. Drosophila orthologs of two genes, which were identified originally in C. elegans, modified Drosophila SMN loss of function defects. C. elegans orthologs of twelve genes, which were originally identified in a previous Drosophila screen, modified C. elegans SMN loss of function defects. Bioinformatic analysis of the conserved, cross-species, modifier genes suggests that conserved cellular pathways, specifically endocytosis and mRNA regulation, act as critical genetic modifiers of SMN loss of function defects across species

    The United States COVID-19 Forecast Hub dataset

    Get PDF
    Academic researchers, government agencies, industry groups, and individuals have produced forecasts at an unprecedented scale during the COVID-19 pandemic. To leverage these forecasts, the United States Centers for Disease Control and Prevention (CDC) partnered with an academic research lab at the University of Massachusetts Amherst to create the US COVID-19 Forecast Hub. Launched in April 2020, the Forecast Hub is a dataset with point and probabilistic forecasts of incident cases, incident hospitalizations, incident deaths, and cumulative deaths due to COVID-19 at county, state, and national, levels in the United States. Included forecasts represent a variety of modeling approaches, data sources, and assumptions regarding the spread of COVID-19. The goal of this dataset is to establish a standardized and comparable set of short-term forecasts from modeling teams. These data can be used to develop ensemble models, communicate forecasts to the public, create visualizations, compare models, and inform policies regarding COVID-19 mitigation. These open-source data are available via download from GitHub, through an online API, and through R packages

    Enquiring About Tolerance (EAT) study: Feasibility of an early allergenic food introduction regimen.

    Get PDF
    BACKGROUND: The influence of early exposure to allergenic foods on the subsequent development of food allergy remains uncertain. OBJECTIVE: We sought to determine the feasibility of the early introduction of multiple allergenic foods to exclusively breast-fed infants from 3 months of age and the effect on breastfeeding performance. METHODS: We performed a randomized controlled trial. The early introduction group (EIG) continued breastfeeding with sequential introduction of 6 allergenic foods: cow's milk, peanut, hard-boiled hen's egg, sesame, whitefish (cod), and wheat; the standard introduction group followed the UK infant feeding recommendations of exclusive breastfeeding for around 6 months with no introduction of allergenic foods before 6 months of age. RESULTS: One thousand three hundred three infants were enrolled. By 5 months of age, the median frequency of consumption of all 6 foods was 2 to 3 times per week for every food in the EIG and no consumption for every food in the standard introduction group (P < .001 for every comparison). By 6 months of age, nonintroduction of the allergenic foods in the EIG was less than 5% for each of the 6 foods. Achievement of the stringent per-protocol consumption target for the EIG proved more difficult (42% of evaluable EIG participants). Breastfeeding rates in both groups significantly exceeded UK government data for equivalent mothers (P < .001 at 6 and at 9 months of age). CONCLUSION: Early introduction, before 6 months of age, of at least some amount of multiple allergenic foods appears achievable and did not affect breastfeeding. This has important implications for the evaluation of food allergy prevention strategies

    The Best Constant in an Inequality of Ostrowski Type

    Get PDF
    We prove that the constant ½ in Dragomir-Wang's inequality [2] is best
    corecore