79 research outputs found

    VIBROTHERMOGRAPHY FOR IMPACT DAMAGE DETECTION IN COMPOSITES STRUCTURES

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    The paper investigates modelling aspects related to application of vibrothermography for detection of barely visible impact damage in composite structures. Low-velocity impact tests were performed to introduce multiple delaminations into carbon/epoxy composite plate. Damage severity was revealed using well-established non-destructive evaluation techniques. Vibrothermography was used subsequently to show good agreement with classical damage detection techniques. Following these experimental investigations, numerical simulations were performed to assess feasibility and sensitivity of vibrothermography for impact damage detection. Numerical results were validated using experimental data showing very good qualitative and encouraging quantitative agreement. The study demonstrates that virtual impact damage detection using vibrothermography can be performed as part of structural design to assess sensitivity of the method in real engineering applications. Copyright © 2012 John Wiley & Sons, Ltd

    Ingensalinae subfam. nov. (Hemiptera: Fulgoromorpha: Fulgoroidea: Inoderbidae), a new planthopper subfamily from mid-Cretaceous Kachin amber from Myanmar

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    The second genus and species of recently established planthopper family Inoderbidae, Ingensala xiai gen. et sp. nov., is described based on a well-preserved specimen from mid-Cretaceous Kachin (Burmese) amber, and it can be definitely attributed to Inoderbidae mainly based on its head structure, pronotum, and mesonotum without median and lateral carinae and tegmen venation. Ingensala gen. nov. is superficially similar to Eofulgoridium regarding its venation pattern, rather than to the Inoderbidae type genus Inoderbe, and further confirmed that Inoderbidae might descend from the Jurassic planthopper family Fulgoridiidae. The early fork of CuA and the stem CuA bearing many branches also can be found in Jurassic Qiyangiricaniidae and Eocene Weiwoboidae. Ingensala gen. nov. also superficially resembles some Tropiduchidae: Tropiduchinae. The new genus differs from the type genus Inoderbe to a large extent according to its wide head, frons without fastigium, antennae not so elongate, the tectiform condition of wings' position in repose, large, broad and translucent tegmen, triangular basal cell, single CuA1, legs covered with short setae, and the lack of filamentous wax on body. Therefore, two new subfamilies (Inoderbinae stat. nov. and Ingensalinae subfam. nov.) are established for these two genera respectively. The diversification in planthoppers could be the result of pressure of environmental changes during the mid-Cretaceous, and Inoderbidae provides more information for us to understand the Cretaceous stage of Fulgoroidea evolution and diversification.</p

    Bacterial symbionts of the leafhopper "Evacanthus interruptus" (Linnaeus, 1758) (Insecta, Hemiptera, Cicadellidae : Evacanthinae)

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    Plant sap-feeding hemipterans harbor obligate symbiotic microorganisms which are responsible for the synthesis of amino acids missing in their diet. In this study, we characterized the obligate symbionts hosted in the body of the xylem-feeding leafhopper Evacanthus interruptus (Cicadellidae: Evacanthinae: Evacanthini) by means of histological, ultrastructural and molecular methods. We observed that E. interruptus is associated with two types of symbiotic microorganisms: bacterium ‘Candidatus Sulcia muelleri’ (Bacteroidetes) and betaproteobacterium that is closely related to symbionts which reside in two other Cicadellidae representatives: Pagaronia tredecimpunctata (Evacanthinae: Pagaronini) and Hylaius oregonensis (Bathysmatophorinae: Bathysmatophorini). Both symbionts are harbored in their own bacteriocytes which are localized between the body wall and ovaries. In E. interruptus, both Sulcia and betaproteobacterial symbionts are transovarially transmitted from one generation to the next. In the mature female, symbionts leave the bacteriocytes and gather around the posterior pole of the terminal oocytes. Then, they gradually pass through the cytoplasm of follicular cells surrounding the posterior pole of the oocyte and enter the space between them and the oocyte. The bacteria accumulate in the deep depression of the oolemma and form a characteristic ‘symbiont ball’. In the light of the results obtained, the phylogenetic relationships within modern Cicadomorpha and some Cicadellidae subfamilies are discussed

    Pattern of reading eye movements during monovision contact lens wear in presbyopes

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    Monovision can be used as a method to correct presbyopia with contact lenses (CL) but its effect on reading behavior is still poorly understood. In this study eye movements (EM) were recorded in fifteen presbyopic participants, naĂŻve to monovision, whilst they read arrays of words, non-words, and text passages to assess whether monovision affected their reading. Three conditions were compared, using daily disposable CLs: baseline (near correction in both eyes), conventional monovision (distance correction in the dominant eye, near correction in the non-dominant eye), and crossed monovision (the reversal of conventional monovision). Behavioral measures (reading speed and accuracy) and EM parameters (single fixation duration, number of fixations, dwell time per item, percentage of regressions, and percentage of skipped items) were analyzed. When reading passages, no differences in behavioral and EM measures were seen in any comparison of the three conditions. The number of fixations and dwell time significantly increased for both monovision and crossed monovision with respect to baseline only with word and non-word arrays. It appears that monovision did not appreciably alter visual processing when reading meaningful texts but some limited stress of the EM pattern was observed only with arrays of unrelated or meaningless items under monovision, which require the reader to have more in-depth controlled visual processing

    GBA and APOE Impact Cognitive Decline in Parkinson's Disease : A 10-Year Population-Based Study

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    Acknowledgments: We would like to thank all participants, study personnel from each study, and funders of individual studies and of PICC. We would like to thank Artur Wozniak and Adrian Martin from the University of Aberdeen, Data Management Department, for help in developing the PICC database. We acknowledge the contributions of members of the individual study groups as detailed below. Members of PICC Steering Group: Dr. Angus D. Macleod, Dr. Carl E. Counsell (Chair), University of Aberdeen, UK; Prof. Ole-BjĂžrn Tysnes, University of Bergen, Norway; Marta Camacho, Dr. Caroline WilliamsGray, University of Cambridge, UK; Dr. Rachael A. Lawson, Newcastle University, UK; Dr. Jodi Maple-GrĂždem, Prof. Guido Alves, Stavanger University Hospital, Norway; Prof. Lars Forgren, UmeĂ„ University, Sweden. CamPaIGN study: Roger A. Barker, Thomas Foltynie, Sarah L. Mason, Caroline H. Williams-Gray. ICICLE-PD Study: David Burn, Lynn Rochester, Alison J. Yarnall, Rachael A. Lawson, Gordon W. Duncan, Tien K. Khoo. NYPUM Study: Lars Forsgren, Jan Linder, Mona Edström, Jörgen Andersson, Linda Eriksson, David BĂ€ckström, Gun-Marie Hariz, Magdalena Domellöf. ParkWest Study: ParkWest Principal investigators: Guido Alves (Norwegian Centre for Movement Disorders, Stavanger University Hospital) and Ole-BjĂžrn Tysnes (Haukeland University Hospital). Study personnel: Michaela Dreetz Gjerstad, Kenn Freddy Pedersen, Elin Bjelland Forsaa, VeslemĂžy Hamre Frantzen, Anita Laugaland, Jodi MapleGrĂždem, Johannes Lange, Karen Simonsen, EldbjĂžrg Fiske and Ingvild Dalen (Stavanger University Hospital); Bernd MĂŒller, Geir Olve Skeie and Marit RensĂ„ (Haukeland University Hospital); Wenche Telstad, Aliaksei Labusau and Jane Kastet (FĂžrde Hospital); Ineke HogenEsch, Marianne Kjerandsen and Liv Kari HĂ„land (Haugesund Hospital); Karen Herlofson, Solgunn Ongre, and Siri Bruun (SĂžrlandet Hospital Arendal). PICNICS study: Roger A. Barker, Marta Camacho, Gemma Cummins, Jonathan R. Evans, David P. Breen, Ruwani S. Wijeyekoon, Caroline H. Williams-Gray. PINE Study: Medical: Carl E. Counsell, Kate S. M. Taylor, Robert Caslake, Angus D. Macleod, David J. M. McGhee, Diane Swallow; Research nurse/assistant: Joanne Gordon, Clare Harris, Ann Hayman, Nicola Johannesson, Hazel Forbes; Data management: Valerie Angus, Alasdair Finlayson, David Dawson, Katie Wilde, David Ritchie, Artur Wozniak; Statisticians: Neil Scott, Shona Fielding; Radiology: Prof. Alison Murray; Pathology: Ishbel Gall, Dr. James MacKenzie, Prof. Colin Smith; Secretarial: Aileen Sylvester, Susan Mitchell, Pam Rebecca, Ann Christie, and Diane McCosh. Funding agencies: This work was supported by the Research Council of Norway (287842). The CamPaIGN study has received funding from the Wellcome Trust, the Medical Research Council, the Patrick Berthoud Trust, and the NIHR Cambridge Biomedical Research Centre (BRC-1215-20014). The ICICLE-PD study was funded by Parkinson’s UK (J-0802, G-1301, G-1507) and supported by the Lockhart Parkinson’s Disease Research Fund, National Institute for Health Research (NIHR) Newcastle Biomedical Research Unit and Centre based at Newcastle upon Tyne Hospitals NHS Foundation Trust and Newcastle University. The NYPUM study was supported by grants from the Swedish Medical Research Council, Erling-Persson Foundation, the Swedish Brain Foundation (HjĂ€rnfonden), UmeĂ„ University, VĂ€sterbotten County Council, King Gustaf V and Queen Victoria Freemason Foundation, Swedish Parkinson Foundation, Swedish Parkinson Research Foundation, Kempe Foundation, Swedish PD Association, the European Research Council, and the Knut and Alice Wallenberg Foundation. The Norwegian ParkWest study has received funding from the Research Council of Norway (177966), the Western Norway Regional Health Authority (911218), the Norwegian Parkinson’s Research Foundation, and Rebergs Legacy. The PICNICS study was funded by the Cure Parkinson’s Trust, the Van Geest Foundation, the Medical Research Council, Parkinson’s UK, and the NIHR Cambridge Biomedical Research Centre (BRC-1215-20014). The PINE study was funded by Parkinson’s UK (grant numbers G0502, G0914, and G1302), the Scottish Chief Scientist Office (CAF/12/05, PCL/17/10), Academy of Medical Sciences, NHS Grampian endowments, the BMA Doris Hillier award, RS Macdonald Trust, the BUPA Foundation, and SPRING. The PICC collaboration has been supported by The Chief Scientist Office of the Scottish Government (PCL/17/10), the Academy of Medical Sciences, Parkinson’s UK (initial collaborator meeting) and the Norwegian Association for Public Health. C.R.S.’s work was supported by NIH grants NINDS/NIA R01NS115144, U01NS095736, U01NS100603, and the American Parkinson Disease Association Center for Advanced Parkinson Research. This research was funded in whole, or in part by the UKRI Medical Research Council [MR/R007446/1]. For the purpose of open access, the author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission.Peer reviewedPublisher PD

    The Effect of Sensory Uncertainty Due to Amblyopia (Lazy Eye) on the Planning and Execution of Visually-Guided 3D Reaching Movements

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    Background: Impairment of spatiotemporal visual processing in amblyopia has been studied extensively, but its effects on visuomotor tasks have rarely been examined. Here, we investigate how visual deficits in amblyopia affect motor planning and online control of visually-guided, unconstrained reaching movements. Methods: Thirteen patients with mild amblyopia, 13 with severe amblyopia and 13 visually-normal participants were recruited. Participants reached and touched a visual target during binocular and monocular viewing. Motor planning was assessed by examining spatial variability of the trajectory at 50–100 ms after movement onset. Online control was assessed by examining the endpoint variability and by calculating the coefficient of determination (R 2) which correlates the spatial position of the limb during the movement to endpoint position. Results: Patients with amblyopia had reduced precision of the motor plan in all viewing conditions as evidenced by increased variability of the reach early in the trajectory. Endpoint precision was comparable between patients with mild amblyopia and control participants. Patients with severe amblyopia had reduced endpoint precision along azimuth and elevation during amblyopic eye viewing only, and along the depth axis in all viewing conditions. In addition, they had significantly higher R 2 values at 70 % of movement time along the elevation and depth axes during amblyopic eye viewing. Conclusion: Sensory uncertainty due to amblyopia leads to reduced precision of the motor plan. The ability to implemen

    Changes to the Fossil Record of Insects through Fifteen Years of Discovery

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    The first and last occurrences of hexapod families in the fossil record are compiled from publications up to end-2009. The major features of these data are compared with those of previous datasets (1993 and 1994). About a third of families (>400) are new to the fossil record since 1994, over half of the earlier, existing families have experienced changes in their known stratigraphic range and only about ten percent have unchanged ranges. Despite these significant additions to knowledge, the broad pattern of described richness through time remains similar, with described richness increasing steadily through geological history and a shift in dominant taxa, from Palaeoptera and Polyneoptera to Paraneoptera and Holometabola, after the Palaeozoic. However, after detrending, described richness is not well correlated with the earlier datasets, indicating significant changes in shorter-term patterns. There is reduced Palaeozoic richness, peaking at a different time, and a less pronounced Permian decline. A pronounced Triassic peak and decline is shown, and the plateau from the mid Early Cretaceous to the end of the period remains, albeit at substantially higher richness compared to earlier datasets. Origination and extinction rates are broadly similar to before, with a broad decline in both through time but episodic peaks, including end-Permian turnover. Origination more consistently exceeds extinction compared to previous datasets and exceptions are mainly in the Palaeozoic. These changes suggest that some inferences about causal mechanisms in insect macroevolution are likely to differ as well
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