724 research outputs found

    Reconnecting the Sciences

    Get PDF
    During the last three years at the Illinois Mathematics and Science Academy, we have been working on a partial reconstruction of Whitehead\u27s one subject matter, a course reconnecting biology, chemistry, earth and space sciences, and physics into an Integrated Science program

    Light-Induced Metastable Magnetic Texture Uncovered by in situ Lorentz Microscopy

    Get PDF
    Magnetic topological defects, such as vortices and Skyrmions, can be stabilized as equilibrium structures in nanoscale geometries and by tailored intrinsic magnetic interactions. Here, employing rapid quench conditions, we report the observation of a light-induced metastable magnetic texture, which consists of a dense nanoscale network of vortices and antivortices. Our results demonstrate the emergence of ordering mechanisms in quenched optically driven systems, which may give a general access to novel magnetic structures on nanometer length scales

    Energy Analysis, Baselining and Modeling of Prairie View A&M University

    Get PDF
    The thermal metering installations in 29 buildings were inspected. They were generally found to be in good condition, with a flow meter and the two required temperature sensors installed in the hot water and chilled water lines. However, in 14 of the installations, it was observed that either the hot water flow meter or the chilled water flow meter was located so close to a bend, valve, or other obstruction in the line that substantial errors in the flow (and Btu) readings are likely. In five of the buildings, both the hot water and chilled water flow meters were located too close to obstructions. Only 10 buildings had both flow meters placed properly. Temperature sensors were generally placed properly, although it was not possible to locate five (of 58) sensors to verify proper placement, and two others were located in the air handler piping rather than in the main building chilled and hot water lines.Analysis of the available data found that electricity savings in the J.B. Coleman Library for June - September, 1998 were 298 MWh, or 38% of the baseline consumption during these months. Extrapolation of these savings to a full year leads would result in savings of 894 MWh/year. This would result in annual electricity cost savings of 42,500attheaveragecostof42,500 at the average cost of 0.0475/kWh which was paid by the University for the period October, 1997 - September, 1998. Smaller savings were expected in chilled water, but were not evident in the data available. Likewise, no significant increase in hot water use was observed during the June - September period analyzed

    Optimizing insect metabarcoding using replicated mock communities

    Get PDF
    1. Metabarcoding (high-throughput sequencing of marker gene amplicons) has emerged as a promising and cost-effective method for characterizing insect community samples. Yet, the methodology varies greatly among studies and its performance has not been systematically evaluated to date. In particular, it is unclear how accurately metabarcoding can resolve species communities in terms of presence-absence, abundance and biomass.2. Here we use mock community experiments and a simple probabilistic model to evaluate the effect of different DNA extraction protocols on metabarcoding performance. Specifically, we ask four questions: (Q1) How consistent are the recovered community profiles across replicate mock communities?; (Q2) How does the choice of lysis buffer affect the recovery of the original community?; (Q3) How are community estimates affected by differing lysis times and homogenization? and (Q4) Is it possible to obtain adequate species abundance estimates through the use of biological spike-ins?3. We show that estimates are quite variable across community replicates. In general, a mild lysis protocol is better at reconstructing species lists and approximate counts, while homogenization is better at retrieving biomass composition. Small insects are more likely to be detected in lysates, while some tough species require homogenization to be detected. Results are less consistent across biological replicates for lysates than for homogenates. Some species are associated with strong PCR amplification bias, which complicates the reconstruction of species counts. Yet, with adequate spike -in data, species abundance can be determined with roughly 40% standard error for homogenates, and with roughly 50% standard error for lysates, under ideal conditions. In the latter case, however, this often requires species-specific reference data, while spike -in data generalize better across species for homogenates.4. We conclude that a nondestructive, mild lysis approach shows the highest promise for the presence/absence description of the community, while also allowing future morphological or molecular work on the material. However, homogeniza- tion protocols perform better for characterizing community composition, in par- ticular in terms of biomass

    Portable, field-based neuroimaging using high-density diffuse optical tomography

    Get PDF
    Behavioral and cognitive tests in individuals who were malnourished as children have revealed malnutrition-related deficits that persist throughout the lifespan. These findings have motivated recent neuroimaging investigations that use highly portable functional near-infrared spectroscopy (fNIRS) instruments to meet the demands of brain imaging experiments in low-resource environments and enable longitudinal investigations of brain function in the context of long-term malnutrition. However, recent studies in healthy subjects have demonstrated that high-density diffuse optical tomography (HD-DOT) can significantly improve image quality over that obtained with sparse fNIRS imaging arrays. In studies of both task activations and resting state functional connectivity, HD-DOT is beginning to approach the data quality of fMRI for superficial cortical regions. In this work, we developed a customized HD-DOT system for use in malnutrition studies in Cali, Colombia. Our results evaluate the performance of the HD-DOT instrument for assessing brain function in a cohort of malnourished children. In addition to demonstrating portability and wearability, we show the HD-DOT instrument\u27s sensitivity to distributed brain responses using a sensory processing task and measurements of homotopic functional connectivity. Task-evoked responses to the passive word listening task produce activations localized to bilateral superior temporal gyrus, replicating previously published work using this paradigm. Evaluating this localization performance across sparse and dense reconstruction schemes indicates that greater localization consistency is associated with a dense array of overlapping optical measurements. These results provide a foundation for additional avenues of investigation, including identifying and characterizing a child\u27s individual malnutrition burden and eventually contributing to intervention development

    Application Evaluation of the Market Square Project, Cleveland, Ohio

    Get PDF
    This report for Technical Support Services: Task 1. Application Evaluation of the Market Square Project, Cleveland, Ohio, is provided to the Ohio Air Quality Development Authority (OAQDA) by the Energy Systems Laboratory (ESL) of the Texas A&M Engineering Experiment Station (TEES), in collaboration with the University of Dayton. We would like to acknowledge the Ohio Air Quality Development Authority (OAQDA) personnel for their guidance, cooperation and contribution during this process. Special thanks to Ms. Christina O'Keeffe, Executive Director, and Ms. Sandra Langston, Executive Assistant. Additional thanks to the Market Square Project team: Mr. Steve Willobee, Vice President, Government Affairs & Public Relations, Harbor Bay Real Estate Advisors; Mr. James Litwin, Vice President of Construction, Harbor Bay Real Estate Advisors; Mr. Randy Olson, PE, LEED AP, Partner – Mechanical, Dunham Engineers; Mr. Mark Bell, CEO, Harbor Bay; Mr. Dan Whalen, Director, Harbor Bay; Mr. Christopher Jones, Senior Counsel, Calfee, Halter & Griswold

    Best practices for fNIRS publications

    Get PDF
    The application of functional near-infrared spectroscopy (fNIRS) in the neurosciences has been expanding over the last 40 years. Today, it is addressing a wide range of applications within different populations and utilizes a great variety of experimental paradigms. With the rapid growth and the diversification of research methods, some inconsistencies are appearing in the way in which methods are presented, which can make the interpretation and replication of studies unnecessarily challenging. The Society for Functional Near-Infrared Spectroscopy has thus been motivated to organize a representative (but not exhaustive) group of leaders in the field to build a consensus on the best practices for describing the methods utilized in fNIRS studies. Our paper has been designed to provide guidelines to help enhance the reliability, repeatability, and traceability of reported fNIRS studies and encourage best practices throughout the community. A checklist is provided to guide authors in the preparation of their manuscripts and to assist reviewers when evaluating fNIRS papers

    Restricted and Repetitive Behavior and Brain Functional Connectivity in Infants at Risk for Developing Autism Spectrum Disorder

    Get PDF
    Background: Restricted and repetitive behaviors (RRBs), detectable by 12 months in many infants in whom autism spectrum disorder (ASD) is later diagnosed, may represent some of the earliest behavioral markers of ASD. However, brain function underlying the emergence of these key behaviors remains unknown. Methods: Behavioral and resting-state functional connectivity (fc) magnetic resonance imaging data were collected from 167 children at high and low familial risk for ASD at 12 and 24 months (n = 38 at both time points). Twenty infants met criteria for ASD at 24 months. We divided RRBs into four subcategories (restricted, stereotyped, ritualistic/sameness, self-injurious) and used a data-driven approach to identify functional brain networks associated with the development of each RRB subcategory. Results: Higher scores for ritualistic/sameness behavior were associated with less positive fc between visual and control networks at 12 and 24 months. Ritualistic/sameness and stereotyped behaviors were associated with less positive fc between visual and default mode networks at 12 months. At 24 months, stereotyped and restricted behaviors were associated with more positive fc between default mode and control networks. Additionally, at 24 months, stereotyped behavior was associated with more positive fc between dorsal attention and subcortical networks, whereas restricted behavior was associated with more positive fc between default mode and dorsal attention networks. No significant network-level associations were observed for self-injurious behavior. Conclusions: These observations mark the earliest known description of functional brain systems underlying RRBs, reinforce the construct validity of RRB subcategories in infants, and implicate specific neural substrates for future interventions targeting RRBs
    corecore