71 research outputs found
The impacts of increased heat stress events on wheat yield under climate change in China
China is the largest wheat producing country in the world. Wheat is one of the two major staple cereals consumed in the country and about 60% of Chinese population eats the grain daily. To safeguard the production of this important crop, about 85% of wheat areas in the country are under irrigation or high rainfall conditions. However, wheat production in the future will be challenged by the increasing occurrence and magnitude of adverse and extreme weather events. In this paper, we present an analysis that combines outputs from a wide range of General Circulation Models (GCMs) with observational data to produce more detailed projections of local climate suitable for assessing the impact of increasing heat stress events on wheat yield. We run the assessment at 36 representative sites in China using the crop growth model CSM-CropSim Wheat of DSSAT 4.5. The simulations based on historical data show that this model is suitable for quantifying yield damages caused by heat stress. In comparison with the observations of baseline 1996-2005, our simulations for the future indicate that by 2100, the projected increases in heat stress would lead to an ensemble-mean yield reduction of –7.1% (with a probability of 80%) and –17.5% (with a probability of 96%) for winter wheat and spring wheat, respectively, under the irrigated condition. Although such losses can be fully compensated by CO2 fertilization effect as parameterized in DSSAT 4.5, a great caution is needed in interpreting this fertilization effect because existing crop dynamic models are unable to incorporate the effect of CO2 acclimation (the growth enhancing effect decreases over time) and other offsetting forces
Intra-Aortic Clusters Undergo Endothelial to Hematopoietic Phenotypic Transition during Early Embryogenesis
Intra-aortic clusters (IACs) attach to floor of large arteries and are considered to have recently acquired hematopoietic stem cell (HSC)-potential in vertebrate early mid-gestation embryos. The formation and function of IACs is poorly understood. To address this issue, IACs were characterized by immunohistochemistry and flow cytometry in mouse embryos. Immunohistochemical analysis revealed that IACs simultaneously express the surface antigens CD31, CD34 and c-Kit. As embryos developed from 9.5 to 10.5 dpc, IACs up-regulate the hematopoietic markers CD41 and CD45 while down-regulating the endothelial surface antigen VE-cadherin/CD144, suggesting that IACs lose endothelial phenotype after 9.5 dpc. Analysis of the hematopoietic potential of IACs revealed a significant change in macrophage CFC activity from 9.5 to 10.5 dpc. To further characterize IACs, we isolated IACs based on CD45 expression. Correspondingly, the expression of hematopoietic transcription factors in the CD45(neg) fraction of IACs was significantly up-regulated. These results suggest that the transition from endothelial to hematopoietic phenotype of IACs occurs after 9.5 dpc
Collaboration patterns in patent networks and their relationship with the transfer of technology: the case study of the CSIC patents
Italian Association of Clinical Endocrinologists (AME) position statement: a stepwise clinical approach to the diagnosis of gastroenteropancreatic neuroendocrine neoplasms
Depolymerization of β-1,6-N-Acetyl-d-Glucosamine Disrupts the Integrity of Diverse Bacterial Biofilms
Polymeric β-1,6-N-acetyl-d-glucosamine (poly-β-1,6-GlcNAc) has been implicated as an Escherichia coli and Staphylococcus epidermidis biofilm adhesin, the formation of which requires the pgaABCD and icaABCD loci, respectively. Enzymatic hydrolysis of poly-β-1,6-GlcNAc, demonstrated for the first time by chromatography and mass spectrometry, disrupts biofilm formation by these species and by Yersinia pestis and Pseudomonas fluorescens, which possess pgaABCD homologues
Multiple regression analysis of a patent’s citation frequency and quantitative characteristics: the case of Japanese patents
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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