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- Scandale, Walter, et al.
(författare)
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Apparatus to study crystal channeling and volume reflection phenomena at the SPS H8 beamline
- 2008
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 79:2
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Tidskriftsartikel (refereegranskat)abstract
- A high performance apparatus has been designed and built by the H8-RD22 collaboration for the study of channeling and volume reflection phenomena in the interaction of 400 GeVc protons with bent silicon crystals, during the 2006 data taking in the external beamline H8 of the CERN SPS. High-quality silicon short crystals were bent by either anticlastic or quasimosaic effects. Alignment with the highly parallel (8 μrad divergence) proton beam was guaranteed through a submicroradian goniometric system equipped with both rotational and translational stages. Particle tracking was possible by a series of silicon microstrip detectors with high-resolution and a parallel plate gas chamber, triggered by various scintillating detectors located along the beamline. Experimental observation of volume reflection with 400 GeVc protons proved true with a deflection angle of (10.4±0.5) μrad with respect to the unperturbed beam, with a silicon crystal whose (111) planes were parallel to the beam. © 2008 American Institute of Physics.
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| 2. |
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| 3. |
- Scandale, Walter, et al.
(författare)
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Deflection of 400GeV/c proton beam with bent silicon crystals at the CERN Super Proton Synchrotron
- 2008
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Ingår i: Physical Review Special Topics - Accelerators and Beams. - 1098-4402. ; 11:6
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a detailed study of the deflection phenomena of a 400GeV/c proton beam impinging on a new generation of bent silicon crystals; the tests have been performed at the CERN Super Proton Synchrotron H8 beam line. Channeling and volume reflection angles are measured with an extremely precise goniometer and with high resolution silicon microstrip detectors. Volume reflection has been observed and measured for the first time at this energy, with a single-pass efficiency as large as 98%, in good agreement with the simulation results. This efficiency makes volume reflection a possible candidate for collimation with bent crystals at the CERN Large Hadron Collider. © 2008 The American Physical Society.
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| 4. |
- Afanasiev, Sergey V., et al.
(författare)
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Experimental apparatus to study crystal channeling in an external SPS beamline
- 2007
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Ingår i: Proceedings of SPIE, the International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 6634
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Tidskriftsartikel (refereegranskat)abstract
- For the new generation of high intensity hadronic machines as, for instance, LHC, halo collimation is a necessary issue for the accelerator to operate at the highest possible luminosity and to prevent the damage of superconductor magnets.1 We propose an experiment aimed to systematic study of the channeling phenomenology and of the newly observed "volume reflection" effect. This experiment will be performed for an external SPS beamline and will make use of a primary proton beam with 400 GeV/c momentum and very small (∼ 3 μrad) divergence. The advantage of a proposed experiment is precise tracking of particles that interacted with a crystal, so that to determine the single-pass efficiency for all the processes involved. For this purpose, a telescope equipped with high-resolution silicon microstrip detectors will be used. New generation silicon crystals and an extra-precise goniometer are mandatory issues. Main goal of the experiment is to get the precise information on channeling of relativistic particles and, ultimately, on the feasibility of such technique for halo collimation at LHC. In this contribution we review the status of the setting-up of experimental apparatus and its future development in sight of the planned run in September 2006.
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| 5. |
- Gheit, Tarik, et al.
(författare)
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Development of a sensitive and specific multiplex PCR method combined with DNA microarray primer extension to detect beta-papillomavirus types.
- 2007
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Ingår i: Journal of Clinical Microbiology. - 1098-660X. ; 45:8, s. 2537-2544
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Tidskriftsartikel (refereegranskat)abstract
- Emerging lines of evidence indicate that the cutaneous human papillomavirus (HPV) types that belong to the genus Betapapillomavirus (beta HPV) are involved in the development of nonmelanoma skin cancer. Unlike the situation for mucosal HPV types, highly sensitive and reliable methods to identify characterized cutaneous HPV types in a single assay are limited. Here, we describe a novel one-shot method for the detection of all characterized beta HPV types, namely, HPV type 5 (HPV5), 8, 9, 12, 14, 15, 17, 19, 20, 21, 22, 23, 24, 25, 36, 37, 38, 47, 49, 75, 76, 80, 92, 93, and 96. This assay combines two different techniques: multiplex PCR using HPV type-specific primers for amplification of each E7 gene and array primer extension (APEX) for typing. This method has been validated using clinical samples which were analyzed simultaneously for the presence of cutaneous HPV types by two additional methods, i.e., the FAP59/64 PCR protocol and a commercially available PCR-reverse hybridization assay (PM-PCR RHA). Our data show good agreement between the results obtained with the multiplex PCR/APEX assay and the PM-PCR RHA method (overall HPV positivity of 92.2% for multiplex PCR/APEX assay versus 90.6% with the PM-PCR RHA) (kappa value, 50; 95% confidence interval, 13 to 88). In addition, the multiplex PCR/APEX assay showed higher sensitivity than the PM-PCR RHA did. This favorable feature and the high-throughput potential make this assay ideal for large-scale clinical and epidemiological studies aimed at determining the spectrum of cutaneous types in skin cancer.
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| 6. |
- Haas, Brian J., et al.
(författare)
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Genome sequence and analysis of the Irish potato famine pathogen Phytophthora infestans
- 2009
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 461:7262, s. 393-398
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Tidskriftsartikel (refereegranskat)abstract
- Phytophthora infestans is the most destructive pathogen of potato and a model organism for the oomycetes, a distinct lineage of fungus-like eukaryotes that are related to organisms such as brown algae and diatoms. As the agent of the Irish potato famine in the mid-nineteenth century, P. infestans has had a tremendous effect on human history, resulting in famine and population displacement(1). To this day, it affects world agriculture by causing the most destructive disease of potato, the fourth largest food crop and a critical alternative to the major cereal crops for feeding the world's population(1). Current annual worldwide potato crop losses due to late blight are conservatively estimated at $6.7 billion(2). Management of this devastating pathogen is challenged by its remarkable speed of adaptation to control strategies such as genetically resistant cultivars(3,4). Here we report the sequence of the P. infestans genome, which at similar to 240 megabases (Mb) is by far the largest and most complex genome sequenced so far in the chromalveolates. Its expansion results from a proliferation of repetitive DNA accounting for similar to 74% of the genome. Comparison with two other Phytophthora genomes showed rapid turnover and extensive expansion of specific families of secreted disease effector proteins, including many genes that are induced during infection or are predicted to have activities that alter host physiology. These fast-evolving effector genes are localized to highly dynamic and expanded regions of the P. infestans genome. This probably plays a crucial part in the rapid adaptability of the pathogen to host plants and underpins its evolutionary potential.
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