8 research outputs found
The Selaginella Genome Identifies Genetic Changes Associated with the Evolution of Vascular Plants
Vascular plants appeared ~410 million years ago then diverged into several lineages of which only two survive: the euphyllophytes (ferns and seed plants) and the lycophytes (1). We report here the genome sequence of the lycophyte Selaginella moellendorffii (Selaginella), the first non-seed vascular plant genome reported. By comparing gene content in evolutionary diverse taxa, we found that the transition from a gametophyte- to sporophyte- dominated life cycle required far fewer new genes than the transition from a non-seed vascular to a flowering plant, while secondary metabolic genes expanded extensively and in parallel in the lycophyte and angiosperm lineages. Selaginella differs in post- transcriptional gene regulation, including small RNA regulation of repetitive elements, an absence of the tasiRNA pathway and extensive RNA editing of organellar genes
Simulating river discharge in a snowy region of Japan using output from a regional climate model
Snowfall amounts have fallen sharply along the eastern coast of the Sea of
Japan since the mid-1980s. Toyama Prefecture, located approximately in the
center of the Japan Sea region, includes high mountains of the northern
Japanese Alps on three of its sides. The scarcity of meteorological
observation points in mountainous areas limits the accuracy of hydrological
analysis. With the development of computing technology, a dynamical
downscaling method is widely applied into hydrological analysis. In this
study, we numerically modeled river discharge using runoff data derived by a
regional climate model (4.5-km spatial resolution) as input data to river
networks (30-arcseconds resolution) for the Toyama Prefecture. The five main
rivers in Toyama (the Oyabe, Sho, Jinzu, Joganji, and Kurobe rivers) were
selected in this study. The river basins range in area from 368 to 2720 km2. A numerical experiment using climate comparable to that at present
was conducted for the 1980s and 1990s. The results showed that seasonal
river discharge could be represented and that discharge was generally
overestimated compared with measurements, except for Oyabe River discharge,
which was always underestimated. The average correlation coefficient for
10-year average monthly mean discharge was 0.8, with correlation
coefficients ranging from 0.56 to 0.88 for all five rivers, whereas the
Nash-Sutcliffe efficiency coefficient indicated that the simulation accuracy
was insufficient. From the water budget analysis, it was possible to
speculate that the lack of accuracy of river discharge may be caused by
insufficient accuracy of precipitation simulation
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The Compact Salaginella Genome Identifies Changes in Gene Content Associated with the Evolution of Vascular Plants
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The compact Selaginella genome identifies changes in gene content associated with the evolution of vascular plants
We report the genome sequence of the nonseed vascular plant, Selaginella moellendorffii, and by comparative genomics identify genes that likely played important roles in the early evolution of vascular plants and their subsequent evolutio
Precipitation downscaling under climate change: Recent developments to bridge the gap between dynamical models and the end user
Precipitation downscaling improves the coarse resolution and poor representation of precipitation in global climate models and helps end users to assess the likely hydrological impacts of climate change. This paper integrates perspectives from meteorologists, climatologists, statisticians, and hydrologists to identify generic end user (in particular, impact modeler) needs and to discuss downscaling capabilities and gaps. End users need a reliable representation of precipitation intensities and temporal and spatial variability, as well as physical consistency, independent of region and season. In addition to presenting dynamical downscaling, we review perfect prognosis statistical downscaling, model output statistics, and weather generators, focusing on recent developments to improve the representation of space-time variability. Furthermore, evaluation techniques to assess downscaling skill are presented. Downscaling adds considerable value to projections from global climate models. Remaining gaps are uncertainties arising from sparse data; representation of extreme summer precipitation, subdaily precipitation, and full precipitation fields on fine scales; capturing changes in small-scale processes and their feedback on large scales; and errors inherited from the driving global climate model