204 research outputs found

    Host cellular components adhering to the tegument of schistosomes from cattle, buffalo, hippopotamus and lechwe

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    The teguments of adult Schistosoma mattheei from cattle and buffalo, S. hippopotami from hippopotamus and S. margrebowiei from lechwe were examined by means of scanning electron microscopy for cells possibly engaged in immunological action. Leukocytes were observed on the teguments of the schistosomes from all 4 host species. Although certain of these cells seemed to be fused to the surface membrane of the worms, they did not display pseudopodia. The tegument of certain schistosomes from buffalo exhibited cells the size of platelets with dendritic structures connected to the tegument of the parasite. The results seem to indicate that, as with laboratory hosts, naturally infected domestic and wild hosts are unable to mount an effective cellular response against the tegument of live adult schistosomes. The possible role of platelets in immunology against schistosomes is mentioned.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

    The morphology of a sensory receptor in the nippled tubercles of Schistosoma mattheei

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    During scanning electron microscopy (SEM) of the tegument of Schistosoma mattheei, a structure was observed within the nippled tubercles. It is postulated that it is a sensory receptor with a tactile function.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

    Notes on the occurrence of tubercular spines in Schistosoma margrebowiei and Schistosoma mattheei

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    Scanning electron microscopical (SEM) studies on tegument of the bovid schistosomes, Schistosoma margrebowiei and Schistosoma mattheei have yielded conflicting results; certain authors observed the tubercles on the tegument of these species to be spined, while others reported that they are spineless. The present study indicates that the protrusion of tubercular spines is subject to phenotypic plasticity regulated by external factors such as the identiy of the host species and whether or not the schistosome is paired.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.lmchunu2014mn201

    Scanning electron microscopy of the teguments of males from five populations of Schistosoma mattheei

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    The teguments of males from 5 populations of S. mattheei, of which 3 were sympatric and 2 allopatric with S. haematobium, were studied by means of scanning electron microscopy (SEM). A certain percentage of the males of each sympatric population bore tubercle spines while the allopatric populations were spineless. It is postulated that the presence of tubercle spines is a characteristic inherited from S. haematobium.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

    Phenotypic differences in Schistosoma mattheei ova from populations sympatric and allopatric to S. haematobium

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    Schistosoma mattheei ova were collected from cattle in different localities in South Africa and after hatching, miracidia were used to infest Bulinus (Physopsis) globosus. Cercariae harvested from these snails were used to infest the definitive host Praomys (Mastomys) coucha and eggs from the resulting female S. mattheei were collected. These ova were compared with a Schistosoma haematobium X S. mattheei hybrid similarly collected from an infested P. (M.) coucha. The results indicate that S. mattheei populations which are sympatric to S. haematobium possess S. haematobium characteristics. It is suggested that the gene pools of populations of the parasite in these areas are infiltrated with S. haematobium genes via the S. mattheei X S. haematobium hybrid originating from human hosts.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

    Infrastructure for Detector Research and Development towards the International Linear Collider

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    The EUDET-project was launched to create an infrastructure for developing and testing new and advanced detector technologies to be used at a future linear collider. The aim was to make possible experimentation and analysis of data for institutes, which otherwise could not be realized due to lack of resources. The infrastructure comprised an analysis and software network, and instrumentation infrastructures for tracking detectors as well as for calorimetry.Comment: 54 pages, 48 picture

    Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

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    This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

    Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

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    The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter

    Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

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    We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters
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