8,256 research outputs found

    A layered fuzzy logic controller for nonholonomic car-like robot

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    A system for real time navigation of a nonholonomic car-like robot in a dynamic environment consists of two layers is described: a Sugeno-type fuzzy motion planner; and a modified proportional navigation based fuzzy controller. The system philosophy is inspired by human routing when moving between obstacles based on visual information including right and left views to identify the next step to the goal. A Sugeno-type fuzzy motion planner of four inputs one output is introduced to give a clear direction to the robot controller. The second stage is a modified proportional navigation based fuzzy controller based on the proportional navigation guidance law and able to optimize the robot's behavior in real time, i.e. to avoid stationary and moving obstacles in its local environment obeying kinematics constraints. The system has an intelligent combination of two behaviors to cope with obstacle avoidance as well as approaching a target using a proportional navigation path. The system was simulated and tested on different environments with various obstacle distributions. The simulation reveals that the system gives good results for various simple environments

    Acceptability of a digital health intervention alongside physiotherapy to support patients following anterior cruciate ligament reconstruction

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    BACKGROUND: Physiotherapy rehabilitation following surgical reconstruction to the Anterior Cruciate Ligament (ACL) can take up to 12 months to complete. Given the lengthy rehabilitation process, a blended intervention can be used to compliment face-to-face physiotherapy with a digital exercise intervention. In this study, we used TRAK, a web–based tool that has been developed to support knee rehabilitation, which provides individually tailored exercise programs with videos, instructions and progress logs for each exercise, relevant health information and a contact option that allows a patient to email a physiotherapist for additional support. The aim of this study was to evaluate the acceptability of TRAK–based blended intervention in post ACL reconstruction rehabilitation. METHODS: A qualitative research design using semi-structured interviews was used on a convenience sample of participants following an ACL reconstruction, and their treating physiotherapists, in a London NHS hospital. Participants were asked to use TRAK alongside face-to-face physiotherapy for 16 weeks. Interviews were carried out, audio recorded, transcribed verbatim and coded by two researchers independently. Data were analyzed using thematic analysis. RESULTS: Of the 25 individuals that were approached to be part of the study, 24 consented, comprising 8 females and 16 males, mean age 30 years. 17 individuals used TRAK for 16 weeks and were available for interview. Four physiotherapists were also interviewed. The six main themes identified from patients were: the experience of TRAK rehabilitation, personal characteristics for engagement, strengths and weaknesses of the intervention, TRAK in the future and attitudes to digital healthcare. The main themes from the physiotherapist interviews were: potential benefits, availability of resources and service organization to support use of TRAK. CONCLUSIONS: TRAK was found to be an acceptable method of delivering ACL rehabilitation alongside face-to-face physiotherapy. Patients reported that TRAK, specifically the videos, increased their confidence and motivation with their rehabilitation. They identified ways in which TRAK could be developed in the future to meet technological expectations and further support rehabilitation. For Physiotherapists time and availability of computers affected acceptability. Organization of care to support integration of digital exercise interventions such as TRAK into a blended approach to rehabilitation is required

    Polyglutamine diseases

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    Polyglutamine diseases are a collection of nine CAG trinucleotide expansion disorders, presenting with a spectrum of neurological and clinical phenotypes. Recent human, mouse and cell studies of Huntington's disease have highlighted the role of DNA repair genes in somatic expansion of the CAG repeat region, modifying disease pathogenesis. Incomplete splicing of the HTT gene has also been shown to occur in humans, with the resulting exon 1 fragment most probably contributing to the Huntington's disease phenotype. In the spinocerebellar ataxias, studies have converged on transcriptional dysregulation of ion channels as a key disease modifier. In addition, advances have been made in understanding how increased levels of toxic, polyglutamine-expanded proteins can arise in the spinocerebellar ataxias through post-transcriptional and -translational modifications and autophagic mechanisms. Recent studies in spinal and bulbar muscular atrophy implicate similar pathogenic pathways to the more common polyglutamine diseases, highlighting autophagy stimulation as a potential therapeutic target. Finally, the therapeutic use of antisense oligonucleotides in several polyglutamine diseases has shown preclinical benefits and serves as potential future therapies in humans

    In situ imaging of mitochondrial translation shows weak correlation with nucleoid DNA intensity and no suppression during mitosis

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    Although mitochondrial translation produces only 13 proteins, we show here how this can be labelled and detected in situ by fluorescence microscopy with a simple, rapid and inexpensive procedure using non-canonical amino acid labelling and click chemistry. This allows visualisation of the translational output in different mitochondria within a cell, their position within that cell and a comparison of mitochondrial translation between cells. Most highly translationally active mitochondria were closest to the nucleus but were also found at the distal end of long cellular projections. There were substantial differences in translation between adjacent mitochondria and this did not readily correlate with apparent Mt-genome content. Mitochondrial translation was unchanged during mitosis when cytoplasmic translation was suppressed. This method will serve both fundamental cell biology and clinically orientated studies in which mitochondrial function is a key parameter

    Recycling of municipal solid waste in the Gaza strip

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    This paper argues that recycling should be a more wide spread practice especially in the Gaza Strip where the Palestinians are facing financial and economic constraints. Some of the questions on recycling were raised with municipal officials, decision makers, street sweepers, United Nations Relief and Works Agency (UNRWA), and Non Governmental Organization (NGO’s). Responses and interpretations have shown great sympathy with the recycling option as a strategic disposal option alternative to landfilling

    Fossil evidence for a pharyngeal origin of the vertebrate pectoral girdle

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    The origin of vertebrate paired appendages is one of the most investigated and debated examples of evolutionary novelty. Paired appendages are widely considered key innovations that allowed new opportunities for controlled swimming and gill ventilation and were prerequisites for the eventual transition from water to land. The last 150 years of debate has been shaped by two contentious theories: the ventrolateral fin-fold hypothesis and the archipterygium hypothesis. The latter proposes that fins and girdles evolved from an ancestral gill arch. Although tantalizing developmental evidence has revived interest in this idea, it is apparently unsupported by fossil evidence. Here we present fossil evidence of a pharyngeal basis for the vertebrate shoulder girdle. We use CT scanning to reveal details of the braincase of Kolymaspis sibirica, a placoderm fish from the Early Devonian of Siberia that suggests a pharyngeal component of the shoulder. We combine these findings with refreshed comparative anatomy of placoderms and jawless outgroups to place the origin of the shoulder girdle on the sixth branchial arch. These findings provide a novel framework for understanding the origin of the pectoral girdle. Our new evidence clarifies the location of the presumptive head-trunk interface in jawless fishes and explains the constraint on branchial arch number in gnathostomes. The results revive a key aspect of the archipterygium hypothesis, but also reconciles it with the ventrolateral fin fold model

    Enhanced Photocatalytic Degradation of the Imidazolinone Herbicide Imazapyr upon UV/Vis Irradiation in the Presence of CaxMnOy-TiO2 Hetero-Nanostructures: Degradation Pathways and Reaction Intermediates

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    [Abstract] The determination of reaction pathways and identification of products of pollutants degradation is central to photocatalytic environmental remediation. This work focuses on the photocatalytic degradation of the herbicide Imazapyr (2-(4-methyl-5-oxo-4-propan-2-yl-1H-imidazol-2-yl) pyridine-3-carboxylic acid) under UV-Vis and visible-only irradiation of aqueous suspensions of CaᵪMnOᵧ-TiO₂, and on the identification of the corresponding degradation pathways and reaction intermediates. CaᵪMnOᵧ-TiO₂ was formed by mixing CaᵪMnOᵧ and TiO₂ by mechanical grinding followed by annealing at 500 °C. A complete structural characterization of CaᵪMnOᵧ-TiO₂ was carried out. The photocatalytic activity of the hetero-nanostructures was determined using phenol and Imazapyr herbicide as model pollutants in a stirred tank reactor under UV-Vis and visible-only irradiation. Using equivalent loadings, CaᵪMnOᵧ-TiO₂ showed a higher rate (10.6 μM·h⁻¹) as compared to unmodified TiO₂ (7.4 μM·h⁻¹) for Imazapyr degradation under UV-Vis irradiation. The mineralization rate was 4.07 μM·h⁻¹ for CaᵪMnOᵧ-TiO₂ and 1.21 μM·h⁻¹ for TiO₂. In the CaᵪMnOᵧ-TiO₂ system, the concentration of intermediate products reached a maximum at 180 min of irradiation that then decreased to a half in 120 min. For unmodified TiO₂, the intermediates continuously increased with irradiation time with no decrease observed in their concentration. The enhanced efficiency of the CaᵪMnOᵧ-TiO₂ for the complete degradation of the Imazapyr and intermediates is attributed to an increased adsorption of polar species on the surface of CaᵪMnOᵧ. Based on LC-MS, photocatalytic degradation pathways for Imazapyr under UV-Vis irradiation have been proposed. Some photocatalytic degradation was obtained under visible-only irradiation for CaᵪMnOᵧ-TiO₂. Hydroxyl radicals were found to be main reactive oxygen species responsible for the photocatalytic degradation through radical scavenger investigations.This research received external funding from the British Council under the STREAM-MENA Institutional Links Scheme Grant number 278072873. This is a collaboration between Ulster University (UK), Technion Institute (Israel) and Rabat University (Morocco). MC acknowledges support from Ministerio de Economía y Competitividad (Spain) through project CTQ2015-71238-R (MINECO/FEDER). AS would like to acknowledge the financial support received from Ulster University (UK) through the VCRS scholarship. PS would like to acknowledge funding from Invest Northern Ireland for the BioDevices projectBritish Council; 27807287

    Wide twin binaries are extremely eccentric: evidence of twin binary formation in circumbinary disks

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    The Gaia mission recently revealed an excess population of equal-mass "twin" wide binaries, with mass ratio q0.95q\gtrsim 0.95, extending to separations of at least 1000 AU. The origin of this population is an enigma: twin binaries are thought to form via correlated accretion in circumbinary disks, but the typical observed protostellar disks have radii of 100\sim100 AU, far smaller than the separations of the widest twins. Here, we infer the eccentricity distribution of wide twins from the distribution of their vv-rr angles, i.e., the angle between the components' separation and relative velocity vectors. We find that wide twins must be on extremely eccentric orbits. For the excess-twin population at 400-1000 AU, we infer a near-delta function excess of high-eccentricity system, with eccentricity 0.95e10.95 \lesssim e \leq 1. These high eccentricities for wide twins imply pericenter distances of order 1010 AU and suggest that their orbits were scattered via dynamical interactions in their birth environments, consistent with a scenario in which twins are born in circumbinary disks and subsequently widened. These results further establish twin wide binaries as a distinct population and imply that wide twins can be used as a probe of the dynamical history of stellar populations.Comment: accepted for publication in The Astrophysical Journal Lette

    From scandal to monastic penance: a reconciliatory manuscript from the early twelfth-century abbey of St. Laurent in Liège

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    An important element of monastic penance and conflict resolution was its repetitive, almost cyclical nature. The manuscripts that were used during these performances often proceed implicitly, which makes them difficult to contextualize and understand. This article considers a possible example of such "hidden" reconciliatory discourse in a manuscript that was produced for the congregation of St. Laurent in Liege around the turn of the eleventh century: Brussels, Royal Library 9361-9367. It examines the sin of pride in monastic dignitaries, discusses the best way to atone for it, and provides tools for the penitent to start living a more virtuous life in the future. The surviving evidence suggests that this manuscript was produced in reaction to the deeds of abbot Berenger, whose actions in 1095 were considered scandalous by contemporaries because he had led his monks into confusion and sin. The article shows how the combination of texts in this manuscript takes on a different meaning because of these politically charged circumstances, and argues that the St. Laurent manuscript was a discreet but methodical way to end the resulting estrangement between Berenger and his monks. In this interpretation, Brussels RL 9361-9367 is a rare and highly relevant testimony to the ways in which monks in the early twelfth century dealt with psychological and social tensions in the wake of an intra-group conflict
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