| 1. |
- Acciari, V. A., et al.
(författare)
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Radio Imaging of the Very-High-Energy gamma-Ray Emission Region in the Central Engine of a Radio Galaxy
- 2009
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 325:5939, s. 444-448
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Tidskriftsartikel (refereegranskat)abstract
- The accretion of matter onto a massive black hole is believed to feed the relativistic plasma jets found in many active galactic nuclei (AGN). Although some AGN accelerate particles to energies exceeding 10(12) electron volts and are bright sources of very-high-energy (VHE) gamma-ray emission, it is not yet known where the VHE emission originates. Here we report on radio and VHE observations of the radio galaxy Messier 87, revealing a period of extremely strong VHE gamma-ray flares accompanied by a strong increase of the radio flux from its nucleus. These results imply that charged particles are accelerated to very high energies in the immediate vicinity of the black hole.
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| 2. |
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| 3. |
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| 4. |
- Hsu, Li-Han, 1981, et al.
(författare)
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Fabrication process and 110 GHz measurement result of MS-to-CPW RF-via transition for RF-MEMS devices packaging applications
- 2009
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Ingår i: 2009 International Conference on Compound Semiconductor Manufacturing Technology, CS MANTECH 2009. - 9781893580138
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Konferensbidrag (refereegranskat)abstract
- This paper presents the fabrication process of RF-via (0-level) and flip-chip bump (1-level) transitions for applications of packaging MS (microstrip) RF-MEMS devices. The interconnect structure with MS-to-CPW transition between GaAs MEMS substrate and Al2O3 motherboard was in-house fabricated. A novel fabrication process for RF-MEMS packaging is in detail. After fabrication, the samples were measured up to 110 GHz using on-wafer probing measurement. From the measured results, the insertion loss of entire interconnect structure is better than -2 dB up to 100 GHz, documenting the feasibility for millimeter-wave RF-MEMS devices packaging applications.
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| 5. |
- Zhao, Ming, et al.
(författare)
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Low-temperature molecular beam epitaxy growth of Si/SiGe THz quantum cascade structures on virtual substrates
- 2006
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Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090. ; 508:1-2, s. 24-28
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Tidskriftsartikel (refereegranskat)abstract
- Si/SiGe quantum cascade structures containing superlattice up to 100 periods have been grown on SiGe virtual substrates by using solid-source molecular beam epitaxy at low temperature. The surface morphology and structural properties of the grown samples were characterized using various experimental techniques. It has been concluded that the structures were completely symmetrically strained with high crystalline quality, precise layer parameters, and excellent reproducibility. Electroluminescence was observed with peaked intensity at 3 THz at both 4 and 40 K, which agrees very well with expected interwell intersubband transition according to the design.
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| 6. |
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| 7. |
- Gilbert, M. Thomas P., et al.
(författare)
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Intraspecific phylogenetic analysis of Siberian woolly mammoths using complete mitochondrial genomes
- 2008
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 105:24, s. 8327-8332
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Tidskriftsartikel (refereegranskat)abstract
- We report five new complete mitochondrial DNA (mtDNA) genomes of Siberian woolly mammoth (Mammuthus primigenius), sequenced with up to 73-fold coverage from DNA extracted from hair shaft material. Three of the sequences present the first complete mtDNA genomes of mammoth clade II. Analysis of these and 13 recently published mtDNA genomes demonstrates the existence of two apparently sympatric mtDNA clades that exhibit high interclade divergence. The analytical power afforded by the analysis of the complete mtDNA genomes reveals a surprisingly ancient coalescence age of the two clades, approximate to 1-2 million years, depending on the calibration technique. Furthermore, statistical analysis of the temporal distribution of the C-14 ages of these and previously identified members of the two mammoth clades suggests that clade II went extinct before clade I. Modeling of protein structures failed to indicate any important functional difference between genomes belonging to the two clades, suggesting that the loss of clade II more likely is due to genetic drift than a selective sweep.
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| 8. |
- Hsu, Fang-Chi, et al.
(författare)
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A novel prostate cancer susceptibility locus at 19q13.
- 2009
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Ingår i: Cancer research. - 1538-7445. ; 69:7, s. 2720-3
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Tidskriftsartikel (refereegranskat)abstract
- A two-stage genome-wide association study (GWAS) of the Cancer Genetic Markers of Susceptibility (CGEMS) initiative identified single nucleotide polymorphisms (SNP) in 150 regions across the genome that may be associated with prostate cancer (PCa) risk. We filtered these results to identify 43 independent SNPs where the frequency of the risk allele was consistently higher in cases than in controls in each of the five CGEMS study populations. Genotype information for 22 of these 43 SNPs was obtained either directly by genotyping or indirectly by imputation in our PCa GWAS of 500 cases and 500 controls selected from a population-based case-control study in Sweden [Cancer of the Prostate in Sweden (CAPS)]. Two of these 22 SNPs were significantly associated with PCa risk (P<0.05). We then genotyped these two SNPs in the remaining cases (n=2,393) and controls (n=1,222) from CAPS and found that rs887391 at 19q13 was highly associated with PCa risk (P=9.4 x 10(-4)). A similar trend of association was found for this SNP in a case-control study from Johns Hopkins Hospital (JHH), albeit the result was not statistically significant. Altogether, the frequency of the risk allele of rs887391 was consistently higher in cases than controls among each of seven study populations examined, with an overall P=3.2 x 10(-7) from a combined allelic test. A fine-mapping study in a 110-kb region at 19q13 among CAPS and JHH study populations revealed that rs887391 was the most strongly associated SNP in the region. Additional confirmation studies of this region are warranted.
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| 9. |
- Shell, Y. H., et al.
(författare)
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A generic symbiotic simulation framework
- 2006
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Ingår i: Proceedings - Workshop on Principles of Advanced and Distributed Simulation, PADS. - 0769525873 - 9780769525877
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Konferensbidrag (refereegranskat)abstract
- A symbiotic or online simulation is defined as one that interacts with the physical system in a mutually beneficial way. The simulation is driven by real time data collected from a physical system under control and needs to meet the real-time requirements of the physical system. In turn, the results from the "what-if experiments performed by the simulator can be used to control the dynamic behaviour of the physical system. Such a simulation tool is for real-time planning and is to foresee and advise on real time problems. It aims to improve performance, to adapt to sudden and unexpected events and to improve aspects of safety and security of the physical system. There are some research efforts, for example, the Dynamic Data-Driven Application Systems (DDDAS) which are currently advocated by the National Science Foundation (NSF) of the United States. However, work in this area is far from complete and many of the research issues are not fully addressed. We see the need for a general framework for symbiotic simulation. In this project, simulators based on the same general framework will be developed using symbiotic simulation techniques and will be used to provide adaptive decision support to manage the resources in several application environments. The objectives of this project are: To develop a generic, agent-based, symbiotic simulation system architecture. To develop mechanisms to support dynamic coupling between the symbiotic simulation system and the physical system. To conduct pilot case studies of the simulation framework. To explore and evaluate the service oriented architecture approach for parallel simulation in the multi-agent symbiotic simulation framework.
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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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