407 research outputs found

    A Modular Low-clearance Wrist Orthosis for Improving Wrist Motion in Children with Cerebral Palsy

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    Children with Cerebral Palsy (CP) often exhibit impairments in the coordination of the grip and lift phases of arm movements that directly impact their ability to perform activities of daily living (ADLs). The application of assistive robotic therapy to children with spastic hemiplegic CP has shown that augmented movement training can lead to improved functional outcomes and improved arm kinematics. Assistive robotic therapy of the wrist has been shown to help improve motor skills in stroke patients, but the devices employed are often large and obtrusive, focusing on a repeated motion rather than a task-based itinerary. Here, we propose a lightweight low clearance wrist orthosis for use in children with Cerebral Palsy that actuates pronation/supination and flexion/extension of the wrist

    Chandra and XMM-Newton Observations of the Abell 3391/Abell 3395 Intercluster Filament

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    We present Chandra and XMM-Newton X-ray observations of the Abell 3391/Abell 3395 intercluster filament. It has been suggested that the galaxy clusters Abell 3395, Abell 3391, and the galaxy group ESO-161 located between the two clusters, are in alignment along a large-scale intercluster filament. We find that the filament is aligned close to the plane of the sky, in contrast to previous results. We find a global projected filament temperature kT = 4.450.55+0.894.45_{-0.55}^{+0.89}~keV, electron density ne=1.080.05+0.06×104n_e=1.08^{+0.06}_{-0.05} \times 10^{-4}~cm3^{-3}, and Mgas=2.70.1+0.2×1013M_{\rm gas} = 2.7^{+0.2}_{-0.1} \times 10^{13}~M_\odot. The thermodynamic properties of the filament are consistent with that of intracluster medium (ICM) of Abell 3395 and Abell 3391, suggesting that the filament emission is dominated by ICM gas that has been tidally disrupted during an early stage merger between these two clusters. We present temperature, density, entropy, and abundance profiles across the filament. We find that the galaxy group ESO-161 may be undergoing ram pressure stripping in the low density environment at or near the virial radius of both clusters due to its rapid motion through the filament.Comment: 13 Pages, 12 Figures, 5 Tables. Submitted to ApJ, comments are welcom

    Zebrafish Whole Mount High-Resolution Double Fluorescent In Situ Hybridization

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    Whole mount in situ hybridization is one of the most widely used techniques in developmental biology. Here, we present a high-resolution double fluorescent in situ hybridization protocol for analyzing the precise expression pattern of a single gene and for determining the overlap of the expression domains of two genes. The protocol is a modified version of the standard in situ hybridization using alkaline phosphatase and substrates such as NBT/BCIP and Fast Red 1,2. This protocol utilizes standard digoxygenin and fluorescein labeled probes along with tyramide signal amplification (TSA) 3. The commercially available TSA kits allow flexible experimental design as fluorescence emission from green to far-red can be used in combination with various nuclear stains, such as propidium iodide, or fluorescence immunohistochemistry for proteins. TSA produces a reactive fluorescent substrate that quickly covalently binds to moieties, typically tyrosine residues, in the immediate vicinity of the labeled antisense riboprobe. The resulting staining patterns are high resolution in that subcellular localization of the mRNA can be observed using laser scanning confocal microscopy 3,4. One can observe nascent transcripts at the chromosomal loci, distinguish nuclear and cytoplasmic staining and visualize other patterns such as cortical localization of mRNA. Studies in Drosophila indicate that roughly 70% of mRNAs exhibit specific patterns of subcellular localization that frequently correlate with the function of the encoded protein 5. When combined with computer-aided reconstruction of 3D confocal datasets, our protocol allows the detailed analysis of mRNA distribution with sub-cellular resolution in whole vertebrate embryos

    Upregulation of autophagy genes and the unfolded protein response in human heart failure

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    The cellular environment of the mammalian heart constantly is challenged with environmental and intrinsic pathological insults, which affect the proper folding of proteins in heart failure. The effects of damaged or misfolded proteins on the cell can be profound and result in a process termed “proteotoxicity”. While proteotoxicity is best known for its role in mediating the pathogenesis of neurodegenerative diseases such as Alzheimer’s disease, its role in human heart failure also has been recognized. The UPR involves three branches, including PERK, ATF6, and IRE1. In the presence of a misfolded protein, the GRP78 molecular chaperone that normally interacts with the receptors PERK, ATF6, and IRE-1 in the endoplasmic reticulum detaches to attempt to stabilize the protein. Mouse models of cardiac hypertrophy, ischemia, and heart failure demonstrate increases in activity of all three branches after removing GRP78 from these internal receptors. Recent studies have linked elevated PERK and CHOP in vitro with regulation of ion channels linked with human systolic heart failure. With this in mind, we specifically investigated ventricular myocardium from 10 patients with a history of conduction system defects or arrhythmias for expression of UPR and autophagy genes compared to myocardium from non-failing controls. We identified elevated Chop, Atf3, and Grp78 mRNA, along with XBP-1-regulated Cebpa mRNA, indicative of activation of the UPR in human heart failure with arrhythmias

    Then & Now: SWOSU Sayre Student Anthology 2017

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    This publication contains the works of students attending the Sayre campus of Southwestern Oklahoma State University in the spring, summer and fall semesters of 2017. This year’s edition also includes the winners of the college’s contest for high school juniors, called Timed W.A.R.P. (Writing And Research Project.) This collection of works is produced in conjunction with the annual Literary Festival. Sponsors for the event are Language Arts instructors Terry Ford, Holley Brewer, and Scott Fronenberger, with help from Assistant Professor April Miller, librarian, and special thanks to the Dean of the College of Associates and Applied Sciences, Sherron Manning. Cover Photo (and inside pages) were created by SWOSU Student Kurtis Clark by combining a 1960’s photo of the Sayre Alexander Building with a current one. Special thanks to all the faculty and staff who made Lit Fest 17 a success! This anthology was designed and edited by SWOSU student Edward Almenas, and it is published by University Press, Weatherford, Oklahoma. 2017. 2https://dc.swosu.edu/sayre_writing/1006/thumbnail.jp

    Slotted Rotatable Target Assembley and Systematic Error Analysis for a Search for Long Range Spin Dependent Interactions from Exotic Vector Boson Exchange Using Neutron Spin Rotation

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    We discuss the design and construction of a novel target array of nonmagnetic test masses used in a neutron polarimetry measurement made in search for new possible exotic spin dependent neutron–atominteractions of Nature at sub-mm length scales. This target was designed to accept and efficiently transmit a transversely polarized slow neutron beam through a series of long open parallel slots bounded by flat rectangular plates. These openings possessed equal atom density gradients normal to the slots from the flat test masses with dimensions optimized to achieve maximum sensitivity to an exotic spin-dependent interaction from vector boson exchanges with ranges in the mm - μm regime. The parallel slots were oriented differently in four quadrants that can be rotated about the neutron beam axis in discrete 90°increments using a Geneva drive. The spin rotation signals from the 4 quadrants were measured using a segmented neutron ion chamber to suppress possible systematic errors from stray magnetic fields in the target region. We discuss the per-neutron sensitivity of the target to the exotic interaction, the design constraints, the potential sources of systematic errors which could be present in this design, and our estimate of the achievable sensitivity using this method

    Anomalous lifetime distributions and topological traps in ordering dynamics

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    We address the role of community structure of an interaction network in ordering dynamics, as well as associated forms of metastability. We consider the voter and AB model dynamics in a network model which mimics social interactions. The AB model includes an intermediate state between the two excluding options of the voter model. For the voter model we find dynamical metastable disordered states with a characteristic mean lifetime. However, for the AB dynamics we find a power law distribution of the lifetime of metastable states, so that the mean lifetime is not representative of the dynamics. These trapped metastable states, which can order at all time scales, originate in the mesoscopic network structure.Comment: 7 pages; 6 figure

    3D cell nuclei segmentation based on gradient flow tracking

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    <p>Abstract</p> <p>Background</p> <p>Reliable segmentation of cell nuclei from three dimensional (3D) microscopic images is an important task in many biological studies. We present a novel, fully automated method for the segmentation of cell nuclei from 3D microscopic images. It was designed specifically to segment nuclei in images where the nuclei are closely juxtaposed or touching each other. The segmentation approach has three stages: 1) a gradient diffusion procedure, 2) gradient flow tracking and grouping, and 3) local adaptive thresholding.</p> <p>Results</p> <p>Both qualitative and quantitative results on synthesized and original 3D images are provided to demonstrate the performance and generality of the proposed method. Both the over-segmentation and under-segmentation percentages of the proposed method are around 5%. The volume overlap, compared to expert manual segmentation, is consistently over 90%.</p> <p>Conclusion</p> <p>The proposed algorithm is able to segment closely juxtaposed or touching cell nuclei obtained from 3D microscopy imaging with reasonable accuracy.</p

    Small-Molecule Hydrophobic Tagging Induced Degradation of HaloTag Fusion Proteins

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    The ability to regulate any protein of interest in living systems with small molecules remains a challenge. We hypothesized that appending a hydrophobic moiety to the surface of a protein would mimic the partially denatured state of the protein, thus engaging the cellular quality control machinery to induce its proteasomal degradation. We designed and synthesized bifunctional small molecules to bind a bacterial dehalogenase (the HaloTag protein) and present a hydrophobic group on its surface. Hydrophobic tagging of the HaloTag protein with an adamantyl moiety induced the degradation of cytosolic, isoprenylated and transmembrane HaloTag fusion proteins in cell culture. We demonstrated the in vivo utility of hydrophobic tagging by degrading proteins expressed in zebrafish embryos and by inhibiting Hras1G12V-driven tumor progression in mice. Therefore, hydrophobic tagging of HaloTag fusion proteins affords small-molecule control over any protein of interest, making it an ideal system for validating potential drug targets in disease models
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