| 1. |
- Tuskan, G A, et al.
(författare)
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The genome of black cottonwood, Populus trichocarpa (Torr. & Gray).
- 2006
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 313:5793, s. 1596-604
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Tidskriftsartikel (refereegranskat)abstract
- We report the draft genome of the black cottonwood tree, Populus trichocarpa. Integration of shotgun sequence assembly with genetic mapping enabled chromosome-scale reconstruction of the genome. More than 45,000 putative protein-coding genes were identified. Analysis of the assembled genome revealed a whole-genome duplication event; about 8000 pairs of duplicated genes from that event survived in the Populus genome. A second, older duplication event is indistinguishably coincident with the divergence of the Populus and Arabidopsis lineages. Nucleotide substitution, tandem gene duplication, and gross chromosomal rearrangement appear to proceed substantially more slowly in Populus than in Arabidopsis. Populus has more protein-coding genes than Arabidopsis, ranging on average from 1.4 to 1.6 putative Populus homologs for each Arabidopsis gene. However, the relative frequency of protein domains in the two genomes is similar. Overrepresented exceptions in Populus include genes associated with lignocellulosic wall biosynthesis, meristem development, disease resistance, and metabolite transport.
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| 2. |
- Salojarvi, Jarkko, et al.
(författare)
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Genome sequencing and population genomic analyses provide insights into the adaptive landscape of silver birch
- 2017
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Ingår i: Nature Genetics. - : NATURE PUBLISHING GROUP. - 1061-4036 .- 1546-1718. ; 49:6, s. 904-912
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Tidskriftsartikel (refereegranskat)abstract
- Silver birch (Betula pendula) is a pioneer boreal tree that can be induced to flower within 1 year. Its rapid life cycle, small (440-Mb) genome, and advanced germplasm resources make birch an attractive model for forest biotechnology. We assembled and chromosomally anchored the nuclear genome of an inbred B. pendula individual. Gene duplicates from the paleohexaploid event were enriched for transcriptional regulation, whereas tandem duplicates were overrepresented by environmental responses. Population resequencing of 80 individuals showed effective population size crashes at major points of climatic upheaval. Selective sweeps were enriched among polyploid duplicates encoding key developmental and physiological triggering functions, suggesting that local adaptation has tuned the timing of and cross-talk between fundamental plant processes. Variation around the tightly-linked light response genes PHYC and FRS10 correlated with latitude and longitude and temperature, and with precipitation for PHYC. Similar associations characterized the growth-promoting cytokinin response regulator ARR1, and the wood development genes KAK and MED5A.
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| 5. |
- Mazur, Mikael, 1990, et al.
(författare)
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High spectral efficiency coherent superchannel transmission with soliton microcombs
- 2021
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Ingår i: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 39:13, s. 4367-4373
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Tidskriftsartikel (refereegranskat)abstract
- Spectral efficiency (SE) is one of the key metrics for optical communication networks. An important building block for its maximization are optical superchannels, channels that are composed of several subchannels with an aggregate bandwidth larger than the bandwidth of the detector electronics. Superchannels which are routed through the network as a single entity, together with flex-grid routing, allow to more efficiently utilize available bandwidth and eliminate the guard-bands between channels, thus increasing spectral efficiency. In contrast to traditional wavelength division multiplexing (WDM) channels, subchannel spacing and thus superchannel SE is governed by the linewidth and stability of the frequency spacing of the transmitter lasers. Integrated optical frequency combs, particulary the parametrically generated so-called microcombs, which provide optical lines on a fixed frequency grid are a promising solution for low power superchannel laser sources that allow to minimize the SE loss from suboptimal channel spacing. However, it is extremely challenging to realize micro-combs with sufficient line power, coherence and line spacing that is compatible with electronic bandwidths. Because the line-spacing generated by most devices is above 40 GHz, demonstrations often rely on additional electro-optic frequency shifter or divider stages to avoid digital-to-analog-converter (DAC) performance degradation when operating at high symbol rates. Here we demonstrate a 50-line superchannel from a single 22 GHz line spacing soliton microcomb. We demonstrate 12 Tb/s throughput with > 10 bits/s/Hz SE efficiency after 80 km transmission and 8 Tb/s throughput (SE > 6 bits/s/Hz) after 2100 km, proving the feasibility and benefits of generating high signal quality, broadband waveforms directly from the output of a micro-scale device with a symbol rate close to the comb repetition rate.
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| 6. |
- Mazur, Mikael, 1990, et al.
(författare)
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High spectral efficiency superchannel transmission using a soliton microcomb
- 2019
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Ingår i: IET Conference Publications. ; 2019:CP765
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Konferensbidrag (refereegranskat)abstract
- We demonstrate transmission of a 52 channel superchannel using an optimized 22.1 GHz-spaced soliton microcomb. Enabling a record spectral efficiency of >10 bits/s/Hz after 80 km and 6.1 bits/s/Hz after 3000 km using a microcomb. Our results demonstrate that chip-scale combs can achieve performance directly comparable to bulk-optic frequency combs.
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