| 1. |
- 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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| 2. |
- Liu, F., et al.
(författare)
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Silicon-chip-based frequency quadrupling for optical millimeter-wave signal generation
- 2009
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Ingår i: Optoelectronic Materials and Devices IV. - : SPIE - International Society for Optical Engineering. ; , s. 763105-
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Konferensbidrag (refereegranskat)abstract
- We propose a prototype of a silicon-chip-based frequency quadrupling system integrating a single-drive silicon Mach-Zehnder modulator and a race-track resonator as an optical differentiator. A proof-of-concept demonstration of 40-GHz millimeter-wave signal generation using 10-GHz driving signal is experimentally provided. The factors that impacting the purity of the RF spectrum are discussed through simulation.
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| 3. |
- Liu, F., et al.
(författare)
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Silicon-chip-based frequency quadrupling for optical millimeter-wave signal generation
- 2009
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Ingår i: 2009 Asia Communications and Photonics Conference and Exhibition, ACP 2009. - Washington, D.C. : OSA. - 9781557528773 ; , s. 5377263-
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Konferensbidrag (refereegranskat)abstract
- We propose a prototype of a silicon-chip-based frequency quadrupling system integrating a single-drive silicon Mach-Zehnder modulator and a microring resonator. A proof-of-concept demonstration of 40-GHz millimeter-wave signal generation using 10-GHz driving signal is experimentally provided.
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| 4. |
- Zhang, L., et al.
(författare)
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Increasing the delay-bit rate product on silicon chip using Star-16QAM signal with high spectral efficiency
- 2009
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Ingår i: Optical Transmission Systems, Switching, and Subsystems VII. - : SPIE. - 9780819480347 ; , s. 763204-
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Konferensbidrag (refereegranskat)abstract
- We proposed and experimentally demonstrate the generation of a novel star-16QAM using a dual-parallel Mach-Zehnder modulator (DPMZM) followed by a phase modulator (PM). Coherent detection and off-line processing are used to recover constellation diagrams. We also study optical delay of a novel star-16QAM signal through a silicon microring resonator. Delay time of ∼ 30ps is observed by comparing the eye diagram of the star-16QAM signal on-resonance with that off-resonance.
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| 5. |
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