4,917 research outputs found

    A cohort study of duplex Doppler examinations of the carotid artery in primary open angle glaucoma

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    Objectives To explore the possibility of pathological change in the common carotid artery at the bifurcation and in the internal carotid artery beyond the bifurcation which could contribute to a reduced diastolic pressure as observed in primary open angle glaucoma. Design Duplex ultrasonic examinations of carotid bifurcations were conducted on 80 patients. Carotid artery defects were allocated into three types: no demonstrable flow defects, internal carotid artery abnormalities and disease in the carotid bulb. Setting Bristol Royal Infirmary Vascular Laboratory. Participants Eighty patients (mean age 69.6 years) providing a total of 160 sides to the analysis. Main outcome measures An estimated central retinal artery pressure, intraocular pressure and field loss were recorded for each side measured. Results Doppler investigations revealed significant levels of pathological change in the internal carotid distinct from changes at the carotid bulb. The disease revealed in the internal carotid artery was significantly associated with intraocular pressure (p = 0.032), with an effect small to medium in magnitude. The Q2 measure, derived from mean arterial pressure and intraocular pressure, was also substantively associated with disease in the internal carotid artery. Both intraocular pressure and the Q2 measure effectively discriminated between groups, with field loss providing rather less discriminating capability. There was a strong trend towards a higher intraocular pressures and a greater visual field loss with internal carotid artery disease. Conclusions Pathological changes in the extra cranial carotid artery in primary open angle glaucoma exceed those in the arteries classified as normal. The presence of disease specifically in the internal carotid artery emphasised the need for a mechanism for the evaluation of the internal carotid apart from the carotid bulb. A basis for clarifying the presence of an ischaemic zone is proposed

    Consistent services throughout the week for acute medical care.

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    Pest-predator spatial relationships in winter rape: implications for integrated crop management

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    Douglas Warner, Les J Allen-Williams, Andrew W Ferguson, and Ingrid H Williams, 'Pest–predator spatial relationships in winter rape: implications for integrated crop management', Pest Management Science, Vol. 56 (11): 977-982, November 2000, doi: 10.1002/1526-4998(200011)56:113.0.CO;2-U. Copyright © 2000 Society of Chemical IndustryThe brassica pod midge (Dasineura brassicae) is an important and widespread pest of winter and spring oilseed rape throughout Europe. Pods infested by D brassicae larvae split prematurely, releasing seeds, and the larvae drop to the soil into which they burrow to pupate. At this stage in its lifecycle D brassicae is potentially vulnerable to predation by carabid beetles foraging on the soil surface. This is the first study in the UK to focus on carabid beetles as predators of D brassicae in the oilseed rape crop. The spatio-temporal distributions of larvae of D brassicae dropping to the soil from the crop canopy and of adult carabid beetles active on the soil surface were analysed in two consecutive years. Insect samples were collected from spatially referenced sampling points across each crop. Counts of insects were mapped and analysed, and the degree of spatial association between predator and prey determined using Spatial Analysis by Distance Indices (SADIE). Carabid species abundant and active during peak drop of first generation D brassicae larvae included Agonum dorsale, Amara similata, Harpalus rufipes and Nebria brevicollis. The larvae of D brassicae had a marked edge distribution within the crop. SADIE analysis revealed significant spatial association between larvae of D brassicae and adult H rufipes (P <0.05) in 1998, but not with adults of A dorsale, A similata or N brevicollis. In 1999, there was strong spatial association only between larvae of D brassicae and adult A dorsale (P <0.01). Aggregation of N brevicollis adults occurred in some areas of greatest D brassicae larval counts in 1999, but overall spatial association was not signi®cant. The distributions are discussed in terms of their relevance to integrated crop management (ICM) strategies and spatial targeting of insecticides.Peer reviewe

    A systematic approach to atomicity decomposition in Event-B

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    Event-B is a state-based formal method that supports a refinement process in which an abstract model is elaborated towards an implementation in a step-wise manner. One weakness of Event-B is that control flow between events is typically modelled implicitly via variables and event guards. While this fits well with Event-B refinement, it can make models involving sequencing of events more difficult to specify and understand than if control flow was explicitly specified. New events may be introduced in Event-B refinement and these are often used to decompose the atomicity of an abstract event into a series of steps. A second weakness of Event-B is that there is no explicit link between such new events that represent a step in the decomposition of atomicity and the abstract event to which they contribute. To address these weaknesses, atomicity decomposition diagrams support the explicit modelling of control flow and refinement relationships for new events. In previous work,the atomicity decomposition approach has been evaluated manually in the development of two large case studies, a multi media protocol and a spacecraft sub-system. The evaluation results helped us to develop a systematic definition of the atomicity decomposition approach, and to develop a tool supporting the approach. In this paper we outline this systematic definition of the approach, the tool that supports it and evaluate the contribution that the tool makes

    Genomic plasticity and rapid host switching can promote the evolution of generalism : a case study in the zoonotic pathogen Campylobacter

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    This work was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) grant BB/I02464X/1, the Medical Research Council (MRC) grants MR/M501608/1 and MR/L015080/1, and the Wellcome Trust grant 088786/C/09/Z. GM was supported by a NISCHR Health Research Fellowship (HF-14–13).Peer reviewedPublisher PD

    A de novo reference transcriptome for Bolitoglossa vallecula, an Andean mountain salamander in Colombia

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    © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Arenas Gomez, C. M., Woodcock, M. R., Smith, J. J., Voss, S. R., & Delgado, J. P. A de novo reference transcriptome for Bolitoglossa vallecula, an Andean mountain salamander in Colombia. Data in Brief, 29, (2020): 105256, doi:10.1016/j.dib.2020.105256.The amphibian order Caudata, contains several important model species for biological research. However, there is need to generate transcriptome data from representative species of the primary salamander families. Here we describe a de novo reference transcriptome for a terrestrial salamander, Bolitoglossa vallecula (Caudata: Plethodontidae). We employed paired-end (PE) illumina RNA sequencing to assemble a de novo reference transcriptome for B. vallecula. Assembled transcripts were compared against sequences from other vertebrate taxa to identify orthologous genes, and compared to the transcriptome of a close plethodontid relative (Bolitoglossa ramosi) to identify commonly expressed genes in the skin. This dataset should be useful to future comparative studies aimed at understanding important biological process, such as immunity, wound healing, and the production of antimicrobial compounds.This work was funded by a research grant from COLCIENCIAS 569 (GRANT 027-2103) and CODI (Programa Sostenibilidad) 2013–2014 of the University of Antioquia. A PhD fellowship to the first author, Claudia Arenas was funded by the COLCIENCIAS 567 Grant. We thank the lab of Juan Fernando Alzate from the University of Antioquia for their help in developing our bioinformatic methodological approach. We thank Andrea Gómez and Melisa Hincapie for their help in animal collection and husbandry

    Scents and sex: insect pheromones

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    Pheromones are chemical signals (semiochemicals) that act between members of the same species, sex pheromones being the signals that facilitate sexual reproduction. Many organisms use such semiochemicals, but it is insects to which the main research attention has been directed. This article will therefore concentrate on the insect sex pheromones

    Game Workers and the Empire: Unionisation in the UK Video Game Industry

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    This article investigates some of the key debates that have emerged within the nascent union organising project Game Workers Unite, with a specific focus on its UK branch (GWU UK). The analysis is based on a period of participatory observation and a series of interviews with board members of GWU UK. This article evaluates Game Workers Unite (GWU) in relation to other recent attempts at unionising the game industry. It concludes that the strategies adopted to counter the hyper-visibility and individualisation of the game worker are key contributions of GWU in contemporary video game labour. This article draws on the work of Dyer-Witheford and de Peuter (2009) Games of empire: Global capitalism and video games to evaluate the historical specificity of GWU and the importance of the organisation for the contemporary video game industry

    Overview study of Space Power Technologies for the advanced energetics program

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    Space power technologies are reviewed to determine the state-of-the-art and to identify advanced or novel concepts which promise large increases in performance. The potential for incresed performance is judged relative to benchmarks based on technologies which have been flight tested. Space power technology concepts selected for their potentially high performance are prioritized in a list of R & D topical recommendations for the NASA program on Advanced Energetics. The technology categories studied are solar collection, nuclear power sources, energy conversion, energy storage, power transmission, and power processing. The emphasis is on electric power generation in space for satellite on board electric power, for electric propulsion, or for beamed power to spacecraft. Generic mission categories such as low Earth orbit missions and geosynchronous orbit missions are used to distinguish general requirements placed on the performance of power conversion technology. Each space power technology is judged on its own merits without reference to specific missions or power systems. Recommendations include 31 space power concepts which span the entire collection of technology categories studied and represent the critical technologies needed for higher power, lighter weight, more efficient power conversion in space

    Editors Note

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    The Society for Comparative Cultural Inquiry at UCL (SCCI) is delighted to introduce the fourth issue of our postgraduate journal, Tropos. The papers included were all presented at the 2016 Conference, titled ‘Belonging and Transgression’. The papers addressed a wide variety of disciplinary interests in connection with the title theme, intended to allow a point of convergence for scholars from a number of eclectic intellectual backgrounds. The submissions each explored how notions of Belonging and Transgression could be understood and interpreted across a number of cultural, linguistic, and theoretical contexts. This edition of Tropos presents an exclusive selection of the papers presented at the conference, which in 2016 enjoyed its fourth year running. The conference was held at University College London on 23rd-24th June 2016 and was organised by members of the Society from both the School of European Language, Culture, and Societies (SELCS) and the Centre for Multidisciplinary and Intercultural Inquiry (CMII). It featured numerous postgraduate speakers from across the UK and Europe as well as keynote addresses from Professor Mairéad Hanrahan (Chair of French, UCL) and Professor John Sutherland (Emeritus Lord Northcliffe Professor of Modern English Literature, UCL) The research presented at the conference drew on a wide variety of disciplines, speaking to a range of different subjects as diverse as writings on the politics of AIDS/HIV in France, the 16th century legal discussions on the rights of free-movement of peoples, and mid-twentieth century Hungarian theatre. The conference stimulated lively discussions provoked by the theme and the different methods of addressing it throughout the papers. These conversations continued long after the formal proceedings concluded. We are delighted to share a selection of the papers from this conference with you in these pages, and we hope that a similarly lasting discussion will occur between you, the reader, and the articles in this third edition of Tropos. The conference series will continue in 2017 and organised by the Graduate Society for Comparative Cultural Inquiry
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