| 1. |
- Ageron, M., et al.
(författare)
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Studies of a full-scale mechanical prototype line for the ANTARES neutrino telescope and tests of a prototype instrument for deep-sea acoustic measurements
- 2007
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 581:3, s. 695-708
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Tidskriftsartikel (refereegranskat)abstract
- full-scale mechanical prototype line was deployed to a depth of 2500 m to test the leak tightness of the electronics containers and the pressure-resistant properties of an electromechanical cable under evaluation for use in the ANTARES deep-sea neutrino telescope. During a month-long immersion study, line parameter data were taken using miniature autonomous data loggers and shore-based optical time domain reflectometry. Details of the mechanical prototype line, the electromechanical cable and data acquisition are presented. Data taken during the immersion study revealed deficiencies in the pressure resistance of the electromechanical cable terminations at the entry points to the electronics containers. The improvements to the termination, which have been integrated into subsequent detection lines, are discussed. The line also allowed deep-sea acoustic measurements with a prototype hydrophone system. The technical setup of this system is described, and the first results of the data analysis are presented. (c) 2007 Elsevier B.V. All rights reserved.
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| 2. |
- Ageron, M., et al.
(författare)
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The ANTARES optical beacon system
- 2007
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 578:3, s. 498-509
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Tidskriftsartikel (refereegranskat)abstract
- ANTARES is a neutrino telescope being deployed in the Mediterranean Sea. It consists of a three-dimensional array of photomultiplier tubes that can detect the Cherenkov light induced by charged particles produced in the interactions of neutrinos with the surrounding medium. High angular resolution can be achieved, in particular, when a muon is produced, provided that the Cherenkov photons are detected with sufficient timing precision. Considerations of the intrinsic time uncertainties stemming from the transit time spread in the photomultiplier tubes and the mechanism of transmission of light in sea water lead to the conclusion that a relative time accuracy of the order of 0.5 ns is desirable. Accordingly, different time calibration systems have been developed for the ANTARES telescope. In this article, a system based on Optical Beacons, a set of external and well-controlled pulsed light sources located throughout the detector, is described. This calibration system takes into account the optical properties of sea water, which is used as the detection volume of the ANTARES telescope. The design, tests, construction and first results of the two types of beacons, LED and laser-based, are presented. (C) 2007 Elsevier B.V. All rights reserved.
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| 3. |
- Aguilar, J. A., et al.
(författare)
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First results of the instrumentation line for the deep-sea ANTARES neutrino telescope
- 2006
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Ingår i: Astroparticle physics. - : Elsevier. - 0927-6505 .- 1873-2852. ; 26:4-5, s. 314-324
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Tidskriftsartikel (refereegranskat)abstract
- In 2005, the ANTARES Collaboration deployed and operated at a depth of 2500 m a so-called Mini Instrumentation Line equipped with Optical Modules (MILOM) at the ANTARES site. The various data acquired during the continuous operation from April to December 2005 of the MILOM confirm the satisfactory performance of the Optical Modules, their front-end electronics and readout system. as well as the calibration devices of the detector. The in situ measurement of the Optical Module time response yields a resolution better than 0.5 ns. The performance of the acoustic positioning system, which enables the spatial reconstruction of the ANTARES detector with a precision of about 10 cm, is verified. These results demonstrate that with the full ANTARES neutrino telescope the design angular resolution of better than 0.3 degrees can be realistically achieved.
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| 4. |
- Aguilar, J. A., et al.
(författare)
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The data acquisition system for the ANTARES neutrino telescope
- 2007
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 570:1, s. 107-116
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Tidskriftsartikel (refereegranskat)abstract
- The ANTARES neutrino telescope is being constructed in the Mediterranean Sea. It consists of a large three-dimensional array of photo-multiplier tubes. The data acquisition system of the detector takes care of the digitisation of the photo-multiplier tube signals, data transport, data filtering, and data storage. The detector is operated using a control program interfaced with all elements. The design and the implementation of the data acquisition system are described. (c) 2006 Elsevier B.V. All rights reserved.
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| 5. |
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| 6. |
- Clark, Andrew G., et al.
(författare)
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Evolution of genes and genomes on the Drosophila phylogeny
- 2007
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 450:7167, s. 203-218
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Tidskriftsartikel (refereegranskat)abstract
- Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.
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| 7. |
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| 8. |
- Campbell, William A, et al.
(författare)
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Zebrafish lacking Alzheimer presenilin enhancer 2 (Pen-2) demonstrate excessive p53-dependent apoptosis and neuronal loss.
- 2006
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Ingår i: Journal of neurochemistry. - : Wiley. - 0022-3042. ; 96:5, s. 1423-40
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Tidskriftsartikel (refereegranskat)abstract
- Gamma-secretase cleavage, mediated by a complex of presenilin, presenilin enhancer (Pen-2), nicastrin, and Aph-1, is the final proteolytic step in generating amyloid beta protein found in brains of Alzheimer's disease patients and Notch intracellular domain critical for proper neuronal development. Here, we employ the zebrafish model to study the role of Pen-2 in neuronal survival. We found that (i) knockdown of Pen-2 using antisense morpholino led to a reduction of islet-1 positive neurons, (ii) Notch signaling was reduced in embryos lacking Pen-2 or other gamma-secretase components, (iii) neuronal loss in Pen-2 knockdown embryos is not as a result of a lack of neuronal precursor cells or cell proliferation, (iv) absence of Pen-2 caused massive apoptosis in the whole animal, which could be suppressed by simultaneous knockdown of the tumor suppressor p53, (v) loss of islet-1 or acetylated tubulin positive neurons in Pen-2 knockdown embryos could be partially rescued by knockdown of p53. Our results demonstrate that knockdown of Pen-2 directly induces a p53-dependent apoptotic pathway that contributes to neuronal loss and suggest that Pen-2 plays an important role in promoting neuronal cell survival and protecting from apoptosis in vivo.
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| 9. |
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| 10. |
- Sun, Jielin, et al.
(författare)
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Evidence for two independent prostate cancer risk-associated loci in the HNF1B gene at 17q12
- 2008
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Ingår i: Nature Genetics. - London : Nature Publishing Group. - 1061-4036 .- 1546-1718. ; 40:10, s. 1153-1155
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We carried out a fine-mapping study in the HNF1B gene at 17q12 in two study populations and identified a second locus associated with prostate cancer risk, 26 kb centromeric to the first known locus (rs4430796); these loci are separated by a recombination hot spot. We confirmed the association with a SNP in the second locus (rs11649743) in five additional populations, with P = 1.7 10-9 for an allelic test of the seven studies combined. The association at each SNP remained significant after adjustment for the other SNP.
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| 11. |
- Sun, Y. H., et al.
(författare)
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Theoretical studies on nonlinear optical properties of two newly synthesized compounds : EPVPC and OPVPC
- 2005
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Ingår i: Chinese Physics. - : IOP Publishing. - 1009-1963 .- 1741-4199. ; 14:1, s. 115-119
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Tidskriftsartikel (refereegranskat)abstract
- The nonlinear optical properties of two newly synthesized molecules 9-Ethyl-3-{2-[4-(2-Pyridin-4-yl-vinyl)-phenyl]vinyl}-9H-carbazole (EPVPC) and 9-Octadecyl-3-{2-[4-(2-Pyridin-4-yl-vinyl)-phenyl]-vinyl}-9H-carbazole (OPVPC) have been studied with hybrid density functional theory (DFT/B3LYP). The generalized few-state model is employed to calculate the two-photon absorption cross sections of the compounds. The theoretical results are in good agreement with the available experimental measurements. It is found that the maximal two-photon absorption (TPA) cross sections of the compounds can be well described by a three-state model. The numerical simulation shows that both compounds have large two-photon absorption (TPA) cross sections and, furthermore, OPVPC displays a little stronger TPA activity than EPVPC in a lower frequency region.
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| 12. |
- Tao, C., et al.
(författare)
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Impact of circuit non-idealities on wireless interconnect based on OOK modulated RF transceiver
- 2009
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Ingår i: NORCHIP, 2009. - 9781424443109
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Konferensbidrag (refereegranskat)abstract
- In this work, a system model for RF wireless interconnect has been proposed based on digital on-off keying (OOK) modulated RF transceiver with 2 Gb/s transmission rate and 40 GHz carrier frequency. To evaluate performance of wireless interconnect, the impact of critical non-idealities caused by circuit blocks has been analyzed and simulated in Matlab® Simulink® environment. A set of rough circuit specifications and BER performances of such system are obtained, through which key points during actual circuit design has come into view. The result of this work has verified the potential feasibility and reliability, and pointed out possible circuit design stresses for wireless interconnect system.
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| 13. |
- Tao, C., et al.
(författare)
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RF Transceiver Circuit Technology Based Wireless Interconnects for Inter- and Intra-Chip Communication System
- 2008
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Ingår i: EPTC. ; , s. 1409-1414
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Konferensbidrag (refereegranskat)abstract
- In this work, some most frequently studied interconnect solutions in recent years have been discussed and compared to show their advantages and limitations. RF wireless interconnect (RFWI) method is further studied by system modeling in simulink environment and successful communication between transmitter and receiver is obtained. The results indicate the potential feasibility and reliability of the inter-chip and intra-chip communication system using integrated RF transceiver and antenna to replace the present metal wiring interconnect. The fact that lots of the existing experiences on RF transceiver and antenna design makes RFWI an attractive interconnect solution.
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| 14. |
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| 15. |
- Xu, Tao, et al.
(författare)
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A pillar-array based 2-dimensional photonic crystal microcavity
- 2009
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 94, s. 241110-
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Tidskriftsartikel (refereegranskat)abstract
- Experimental results are presented for a high quality factor cavity based on pillar arrays. The cavityis formed from a square lattice of silicon pillars of finite height. The quality factor of the fundamental mode is about 7300 when the cavity is in air and 7800 when it is immersed in water.Since a pillar array has a large percent of connected void space and confines TM modes effectively,it has great promise for use in numerous areas including biochemical sensing and quantum cascade lasers.
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