2,488 research outputs found

    IPD - the Immuno Polymorphism Database

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    The Immuno Polymorphism Database (IPD) (http://www.ebi.ac.uk/ipd/) is a set of specialist databases related to the study of polymorphic genes in the immune system. IPD currently consists of four databases: IPD-KIR, contains the allelic sequences of Killer-cell Immunoglobulin-like Receptors; IPD-MHC, a database of sequences of the Major Histocompatibility Complex of different species; IPD-HPA, alloantigens expressed only on platelets; and IPD-ESTAB, which provides access to the European Searchable Tumour Cell-Line Database, a cell bank of immunologically characterized melanoma cell lines. The IPD project works with specialist groups or nomenclature committees who provide and curate individual sections before they are submitted to IPD for online publication. The IPD project stores all the data in a set of related databases. Those sections with similar data, such as IPD-KIR and IPD-MHC share the same database structure. The sharing of a common database structure makes it easier to implement common tools for data submission and retrieval. The data are currently available online from the website and ftp directory; files will also be made available in different formats to download from the website and ftp server. The data will also be included in SRS, BLAST and FASTA search engines at the European Bioinformatics Institute

    The influence of cam geometry and operating conditions on chaotic mixing of viscous fluids in a twin cam mixer

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    Smooth particle hydrodynamica (SPH) simulations were used to better understand the mixing performance of a class of two-dimensional Twin Cam mixers. The chaotic manifolds of the flow are used to describe the mixing and to identify isolated regions. For an equilateral triangle cam geometry, a figure-eight manifold structure traps a layer of fluid against the cam boundaries. Changes in the differential rotation and phase offsets between the cams results in modest improvements in the mixing rate across the manifold barrier. Reducing the apex angle of the triangle changes the manifold structure and allows the trapped layer of fluid to mix more effectively with the rest of the domain. This article shows that examining the chaotic manifolds within a typical industrial mixer can provide valuable insight into both the transient and long-term mixing processes, leading to a more focused exploration of possible mixer configurations and to practical improvements in mixing efficienc

    Development and early growth of fatigue cracks from corrosion damage in high strength stainless steel

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    AbstractThis paper investigates the influence of localised corrosion flaws caused by pitting and crevice corrosion in 15-5PH high strength stainless steel on the development and early growth of fatigue cracks. Fatigue specimens fitted with a crevice former were exposed to a 5%NaCl solution in a salt spray cabinet to produce a single flaw in the middle of the specimen and then tested in fatigue. The development and early growth of fatigue cracks were recorded using a range of techniques. After failure the shape and size of corrosion flaws where cracks initiated were measured and their largest Kt values determined by finite element analysis. Considerable variability in life response to defect Kt was found. Comparison of experimental crack growth data with fracture mechanics predictions showed evidence of a significant number of cycles occupied in transforming defects into cracks in some initiating flaws

    Reduction of Coincident Photomultiplier Noise Relevant to Astroparticle Physics Experiment

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    In low background and low threshold particle astrophysics experiments using observation of Cherenkov or scintillation light it is common to use pairs or arrays of photomultipliers operated in coincidence. In such circumstances, for instance in dark matter and neutrino experiments, unexpected PMT noise events have been observed, probably arising from generation of light from one PMT being detected by one or more other PMTs. We describe here experimental investigation of such coincident noise events and development of new techniques to remove them using novel pulse shape discrimination procedures. When applied to data from a low background NaI detector with facing PMTs the new procedures are found to improve noise rejection by a factor of 20 over conventional techniques, with significantly reduced loss of signal events.Comment: Submitted to NIM

    Making the invisible visible : the availability and desirability of adherence data in routine CF care– findings from a national questionnaire survey

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    Background: Inhaled medications for cystic fibrosis (CF) are effective but adherence is low. Clinicians find it difficult to estimate how much treatment people with CF (PWCF) take, whilst objective adherence measurement demonstrates that patients are poorly calibrated with a tendency to over-estimate actual adherence. The diagnostic approach to a PWCF with deteriorating clinical status and very low adherence is likely to be different to the approach to a deteriorating patient with optimal adherence. Access to objective adherence data in routine consultations could help to overcome diagnostic challenges for clinicians and people with CF. Attitudes of clinicians to the use and importance of routinely available adherence data is unknown. Methods: We conducted an online questionnaire survey with UK CF centres. We asked five questions relating to the current use and perception of objective measurements of adherence in routine care. Results: A total of eight CF centres completed the questionnaire. Few of the responding centres have adherence data readily available in routine clinics (13% of centres use medicines possession ratio; of centres with access to I-nebs® it was estimated that 17% of patients had I-neb data regularly available in clinics). All centres considered the availability of objectively measured adherence data to be important. Respondents identified that systems developed to provide adherence data in clinical practice must provide data to both clinicians and patients that is readily understood and easy to use. Conclusions: Centres perceived the availability of adherence data in routine care to be important but objective measures of adherence is rarely available at present

    First measurement of low intensity fast neutron background from rock at the Boulby Underground Laboratory

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    A technique to measure low intensity fast neutron flux has been developed. The design, calibrations, procedure for data analysis and interpretation of the results are discussed in detail. The technique has been applied to measure the neutron background from rock at the Boulby Underground Laboratory, a site used for dark matter and other experiments, requiring shielding from cosmic ray muons. The experiment was performed using a liquid scintillation detector. A 6.1 litre volume stainless steel cell was filled with an in-house made liquid scintillator loaded with Gd to enhance neutron capture. A two-pulse signature (proton recoils followed by gammas from neutron capture) was used to identify the neutron events from much larger gamma background from PMTs. Suppression of gammas from the rock was achieved by surrounding the detector with high-purity lead and copper. Calibrations of the detector were performed with various gamma and neutron sources. Special care was taken to eliminate PMT afterpulses and correlated background events from the delayed coincidences of two pulses in the Bi-Po decay chain. A four month run revealed a neutron-induced event rate of 1.84 +- 0.65 (stat.) events/day. Monte Carlo simulations based on the GEANT4 toolkit were carried out to estimate the efficiency of the detector and the energy spectra of the expected proton recoils. From comparison of the measured rate with Monte Carlo simulations the flux of fast neutrons from rock was estimated as (1.72 +- 0.61 (stat.) +- 0.38 (syst.))*10^(-6) cm^(-2) s^(-1) above 0.5 MeV.Comment: 37 pages, 24 figures, to be published in Astroparticle Physic

    Galois theory and Lubin-Tate cochains on classifying spaces

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    We consider brave new cochain extensions F(BG +,R) → F(EG +,R), where R is either a Lubin-Tate spectrum E n or the related 2-periodic Morava K-theory K n , and G is a finite group. When R is an Eilenberg-Mac Lane spectrum, in some good cases such an extension is a G-Galois extension in the sense of John Rognes, but not always faithful. We prove that for E n and K n these extensions are always faithful in the K n local category. However, for a cyclic p-group C p r, the cochain extension F(BC p r +,E n ) → F(EC p r +, E n ) is not a Galois extension because it ramifies. As a consequence, it follows that the E n -theory Eilenberg-Moore spectral sequence for G and BG does not always converge to its expected target
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