460 research outputs found

    Primer informe sobre la ocurrencia de la neumonía enzoótica porcina o VPP en Colombia.

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    Se realizó un estudio sobre la ocurrencia de la neumonía enzoótica porcina o VPP en cerdos del Valle del Cauca. Los exámenes fueron practicados en pulmones macroscópicamente comprometidos en procesos de aconsolidación. En el 60 por ciento de los especímenes sometidos a exámen microscópico se encontraron lesiones indistinguibles de las producidas por el Mycoplasma hyopneumoniae descrito como un agente causal de VPP. En cultivos de macerado de pulmòn se aisló un organismo con las características morfológicas descritas para el M. hyopneumoniae. La caracterización y propagación del agente aislado se encuentran en progresoPorcicultur

    Time-reversal violating rotation of polarization plane of light in gas placed in electric field

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    Rotation of polarization plane of light in gas placed in electric field is considered. Different factors causing this phenomenon are investigated. Angle of polarization plane rotation for transition 6S_{1/2} - 7S_{1/2} in cesium (lambda=539 nm) is estimated. The possibility to observe this effect experimentally is discussed.Comment: 10 pages, Late

    Parton-Hadron Duality in Unpolarised and Polarised Structure Functions

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    We study the phenomenon of parton-hadron duality in both polarised and unpolarised electron proton scattering using the HERMES and the Jefferson Lab data, respectively. In both cases we extend a systematic perturbative QCD based analysis to the integrals of the structure functions in the resonance region. After subtracting target mass corrections and large x resummation effects, we extract the remaining power corrections up to order 1/Q^2. We find a sizeable suppression of these terms with respect to analyses using deep inelastic scattering data. The suppression appears consistently in both polarised and unpolarised data, except for the low Q^2 polarised data, where a large negative higher twist contribution remains. Possible scenarios generating this behavior are discussed.Comment: 17 pages, 9 figure

    Supporting both learning and research in a UK post-1992 university library: a case study

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    Nationally, there has been debate on the role of research within higher education and increased interest in the teaching/research nexus. A team of Academic Liaison Librarians at Anglia Polytechnic University was awarded funding to investigate the extent to which learning resources overlap with research resources, whether researcher/teachers encourage their students to use the resources they use themselves and how far electronic resources have affected the relationship between learning and research materials. Semistructured interviews were carried out with 21 academics who are both teachers and researchers. They proved to be committed to using research in their teaching. Students were encouraged to engage with research through the recommendation of resources, seminar discussion, and researchers’ own work for reading and illustrating methodologies. Respondents claimed to be making significant use of the APU library website, online databases and journals. The majority of them were also recommending the same resources to their students. Convenience, speed and variety of information sources were quoted as some of the advantages of the new e-environment. A loss of a relationship with librarians and with the physical library was cited as an example of negative effects of the electronic resource environment

    A type III complement factor D deficiency: Structural insights for inhibition of the alternative pathway.

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    Abstract Background: Complement factor D (FD) is the rate-limiting enzyme of the alternative complement pathway. Previous reports of FD deficiency featured absent plasma FD (type I deficiency) and susceptibility to meningococcal infection. A new FD mutant, which is non-functional but fully expressed, was identified in a patient with invasive meningococcal disease. Objectives: We sought to investigate the molecular features of this novel FD mutant. Methods: We performed complement haemolytic assays, western blot analysis of serum FD and Sanger sequencing of the CFD gene. Recombinant mutant FD was assessed by in vitro catalytic assays, circular dichroism, thermal shift assays, esterolytic assays and surface plasmon resonance. Molecular dynamics simulation was used to visualise the structural changes in mutant FD. Results: A homozygous single-nucleotide variation of the CFD gene in the patient and their sibling resulted in an arginine to proline (R176P) substitution in FD. While R176P FD was stable and fully expressed in blood, it had minimal catalytic activity. Mutation R176P caused key FD-C3bB binding exosite loop 156-162 to lose its binding-competent conformation and stabilised the inactive conformation of FD. Consequently, R176P FD was unable to bind its natural substrate, C3bB. Neither patient nor sibling demonstrated the glucose homeostasis impairment that occurs in FD-null mice. Conclusions: Here, we report the first genetically confirmed functional, or type III, deficiency of an activating complement serine protease. This novel mechanism of FD inhibition can inform further development of alternative pathway inhibitors to treat common inflammatory diseases such as age-related macular degeneration

    The Fluorescence Detector of the Pierre Auger Observatory

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    The Pierre Auger Observatory is a hybrid detector for ultra-high energy cosmic rays. It combines a surface array to measure secondary particles at ground level together with a fluorescence detector to measure the development of air showers in the atmosphere above the array. The fluorescence detector comprises 24 large telescopes specialized for measuring the nitrogen fluorescence caused by charged particles of cosmic ray air showers. In this paper we describe the components of the fluorescence detector including its optical system, the design of the camera, the electronics, and the systems for relative and absolute calibration. We also discuss the operation and the monitoring of the detector. Finally, we evaluate the detector performance and precision of shower reconstructions.Comment: 53 pages. Submitted to Nuclear Instruments and Methods in Physics Research Section
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