162 research outputs found

    The Importance of Early Number Concepts for Learning Mathematics in Deaf and Hard of Hearing Children

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    This chapter discusses important background knowledge and research findings from a variety of disciplines that inform best practices for supporting optimal mathematical achievement in all children. First, discussion will begin with the importance of early numeracy for later academic outcomes, and why prioritization of instruction time and early intervention are needed to increase the likelihood of a strong foundation in numeracy. Second, a brief overview of numeracy development milestones will provide a basis for discussion of our central thesis: language experiences can impact numerical cognition, which then have a significant impact on academic outcomes. Third, given the importance of numeracy skills in academic outcomes, we describe pedagogical trends that are likely to support the development of numerical cognition. This discussion will justify language remediation, increased mathematics talk, and visual-spatial representation as key goals for early intervention programs. Finally, we offer some future directions of research that will further account for underlying mechanisms of numeracy development in very young and preschool-aged children

    Is tagging with visual implant elastomer a reliable technique for marking earthworms?

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    Visual implant elastomer (VIE) has recently been employed to investigate different aspects of earthworm ecology. However, a number of fundamental questions relating to the detection and positioning of the tag, its persistence and potential effects on earthworms remain unknown. Seven earthworm species belonging to three ecological groupings, with different pigmentation and burrowing behaviour, were tagged using different coloured VIE. External inspection after two days, one week and 1, 10 and 27 months were followed by preservation, dissection and internal inspection. Tags could be seen in living specimens to 27 months, and dissection revealed that in most cases they were lodged in the coelomic cavity, held in place by septa. However, over longer time periods (more than two years), the chlorogogenous tissue tended to bind to the tags and made external observation increasingly difficult. Migration of the VIE material towards the posterior of the earthworm and potential loss of the tag were only observed on rare occasions, and a recovery rate in excess of 98% was recorded. By introducing a reasonable amount of VIE into segments, just after the clitellum, this technique can become a valuable tool in earthworm ecology and life history studies, particularly in short-medium term laboratory and field experiments

    Impact of amoxicillin-clavulanate followed by autologous fecal microbiota transplantation on fecal microbiome structure and metabolic potential

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    The spread of multidrug resistance among pathogenic organisms threatens the efficacy of antimicrobial treatment options. The human gut serves as a reservoir for many drug-resistant organisms and their resistance genes, and perturbation of the gut microbiome by antimicrobial exposure can open metabolic niches to resistant pathogens. Once established in the gut, antimicrobial-resistant bacteria can persist even after antimicrobial exposure ceases. Strategies to prevent multidrug-resistant organism (MDRO) infections are scarce, but autologous fecal microbiota transplantation (autoFMT) may limit gastrointestinal MDRO expansion. AutoFMT involves banking one’s feces during a healthy state for later use in restoring gut microbiota following perturbation. This pilot study evaluated the effect of amoxicillin-clavulanic acid (Amox-Clav) exposure and autoFMT on gastrointestinal microbiome taxonomic composition, resistance gene content, and metabolic capacity. Importantly, we found that metabolic capacity was perturbed even in cases where gross phylogeny remained unchanged and that autoFMT was safe and well tolerated.Strategies to prevent multidrug-resistant organism (MDRO) infections are scarce, but autologous fecal microbiota transplantation (autoFMT) may limit gastrointestinal MDRO expansion. AutoFMT involves banking one’s feces during a healthy state for later use in restoring gut microbiota following perturbation. This pilot study evaluated the effect of autoFMT on gastrointestinal microbiome taxonomic composition, resistance gene content, and metabolic capacity after exposure to amoxicillin-clavulanic acid (Amox-Clav). Ten healthy participants were enrolled. All received 5 days of Amox-Clav. Half were randomized to autoFMT, derived from stool collected pre-antimicrobial exposure, by enema, and half to saline enema. Participants submitted stool samples pre- and post-Amox-Clav and enema and during a 90-day follow-up period. Shotgun metagenomic sequencing revealed taxonomic composition, resistance gene content, and metabolic capacity. Amox-Clav significantly altered gut taxonomic composition in all participants (n = 10, P  0.05, compared to enrollment). Alterations to microbial metabolic capacity occurred following antimicrobial exposure even in participants without substantial taxonomic disruption, potentially creating open niches for pathogen colonization. Our findings suggest that metabolic potential is an important consideration for complete assessment of antimicrobial impact on the microbiome. AutoFMT was well tolerated and may have contributed to phylogenetic recovery. (This study has been registered at ClinicalTrials.gov under identifier NCT02046525.

    Visualizing the role of Cbl-b in control of islet-reactive CD4 T cells and susceptibility to Type 1 Diabetes

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    The E3 ubiquitin ligase Cbl-b regulates T cell activation thresholds and has been associated with protecting against Type 1 diabetes, but its in vivo role in the process of self-tolerance has not been examined at the level of potentially auto-aggressive CD4+ T cells. Here we visualize the consequences of Cbl-b deficiency on self-tolerance to lysozyme antigen expressed in transgenic mice under control of the insulin promoter (insHEL). By tracing the fate of pancreatic islet-reactive CD4+ T cells in pre-diabetic 3A9-TCR x insHEL double-transgenic mice, we find that Cbl-b deficiency contrasts with AIRE or IL-2 deficiency because it does not affect thymic negative selection of islet-reactive CD4+ cells nor the numbers of islet-specific CD4+ or CD4+ FOXP3+ T cells in the periphery, although it decreased differentiation of inducible Treg (iTreg) cells from TGF-b treated 3A9-TCR cells in vitro. When removed from Tregs and placed in culture, Cblb-deficient islet-reactive CD4+ cells reveal a capacity to proliferate to HEL antigen that is repressed in wild-type cells. This latent failure of T cell anergy is nevertheless controlled in vivo in pre-diabetic mice, so that islet-reactive CD4+ cells in spleen and pancreatic lymph node of Cblb-deficient mice show no evidence of increased activation or proliferation in situ. Cblb-deficiency subsequently precipitated diabetes in most TCR:insHEL animals by 15 wks of age. These results reveal a role for peripheral T cell anergy in organ-specific self-tolerance, and illuminate the interplay between Cblb-dependent anergy and other mechanisms for preventing organ-specific autoimmunity

    Towards an Understanding of the Effect of Adding a Foam Core on the Blast Performance of Glass Fibre Reinforced Epoxy Laminate Panels

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    This paper presents insights into the blast response of sandwich panels with lightweight foam cores and asymmetric (different thicknesses) glass fibre epoxy face sheets. Viscously damped elastic vibrations were observed in the laminates (no core), while the transient response of the sandwich panels was more complex, especially after the peak displacement was observed. The post-peak residual oscillations in the sandwich panels were larger and did not decay as significantly with time when compared to the equivalent mass laminate panel test. Delamination was the predominant mode of failure on the thinner facesheet side of the sandwich panel, whereas cracking and matrix failure were more prominent on the thicker side (which was exposed to the blast). The type of constituent materials used and testing conditions, including the clamping method, influenced the resulting failure modes observed. A probable sequence of damage in the sandwich panels was proposed, based on the transient displacement measurements, a post-test failure analysis, and consideration of the stress wave propagation through the multilayered, multimaterial structure. This work demonstrates the need for detailed understanding of the transient behaviour of multilayered structures with significant elastic energy capacity and a wide range of possible damage mechanisms. The work should prove valuable to structural engineers and designers considering the deployment of foam-core sandwich panels or fibre reinforced polymer laminates in applications when air-blast loading may pose a credible threat
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