The Experts below are selected from a list of 133578 Experts worldwide ranked by ideXlab platform
Qian Zhang - One of the best experts on this subject based on the ideXlab platform.
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a Global Database of plant production and carbon exchange from Global change manipulative experiments
Scientific Data, 2020Co-Authors: Jian Song, Mengmei Zheng, Haidao Wang, Yongge Fan, Xiaojing Yue, Zhenxing Zhou, Pengshuai Shao, Hongyan Han, Lingjie Lei, Qian ZhangAbstract:Numerous ecosystem manipulative experiments have been conducted since 1970/80 s to elucidate responses of terrestrial carbon cycling to the changing atmospheric composition (CO2 enrichment and nitrogen deposition) and climate (warming and changing precipitation regimes), which is crucial for model projection and mitigation of future Global change effects. Here, we extract data from 2,242 publications that report Global change manipulative experiments and build a comprehensive Global Database with 5,213 pairs of samples for plant production (productivity, biomass, and litter mass) and ecosystem carbon exchange (gross and net ecosystem productivity as well as ecosystem and soil respiration). Information on climate characteristics and vegetation types of experimental sites as well as experimental facilities and manipulation magnitudes subjected to manipulative experiments are also included in this Database. This Global Database can facilitate the estimation of response and sensitivity of key terrestrial carbon-cycling variables under future Global change scenarios, and improve the robust projection of Global change‒terrestrial carbon feedbacks imposed by Earth System Models.
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a Global Database of plant production and carbon exchange from Global change manipulative experiments
Scientific Data, 2020Co-Authors: Jian Song, Mengmei Zheng, Haidao Wang, Yongge Fan, Xiaojing Yue, Zhenxing Zhou, Pengshuai Shao, Hongyan Han, Lingjie Lei, Qian ZhangAbstract:Numerous ecosystem manipulative experiments have been conducted since 1970/80 s to elucidate responses of terrestrial carbon cycling to the changing atmospheric composition (CO2 enrichment and nitrogen deposition) and climate (warming and changing precipitation regimes), which is crucial for model projection and mitigation of future Global change effects. Here, we extract data from 2,242 publications that report Global change manipulative experiments and build a comprehensive Global Database with 5,213 pairs of samples for plant production (productivity, biomass, and litter mass) and ecosystem carbon exchange (gross and net ecosystem productivity as well as ecosystem and soil respiration). Information on climate characteristics and vegetation types of experimental sites as well as experimental facilities and manipulation magnitudes subjected to manipulative experiments are also included in this Database. This Global Database can facilitate the estimation of response and sensitivity of key terrestrial carbon-cycling variables under future Global change scenarios, and improve the robust projection of Global change‒terrestrial carbon feedbacks imposed by Earth System Models. Machine-accessible metadata file describing the reported data: https://doi.org/10.6084/m9.figshare.12932843
Steven Y C Tong - One of the best experts on this subject based on the ideXlab platform.
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restricted sequence variation in streptococcus pyogenes penicillin binding proteins
mSphere, 2020Co-Authors: Andrew Hayes, Jake A Lacey, Jacqui Morris, Mark R Davies, Steven Y C TongAbstract:A recent clinical report has linked Streptococcus pyogenes β-lactam antibiotic resistance to mutation in the penicillin binding protein (PBP) PBP2x. To determine whether this is an isolated case or reflects a broader prevalence of mutations that might confer reduced β-lactam susceptibility, we investigated the relative frequency of PBP sequence variation within a Global Database of 9,667 S. pyogenes isolates. We found that mutations in S. pyogenes PBPs (PBP2x, PBP1a, PBP1b, and PBP2a) occur infrequently across this Global Database, with fewer than 3 amino acid changes differing between >99% of the Global population. Only 4 of the 9,667 strains contained mutations near transpeptidase active sites of PBP2x or PBP1a. The reported PBP2x T553K substitution was not identified. These findings are in contrast to those of 2,520 S. pneumococcus sequences where PBP mutations are relatively frequent and are often located in key β-lactam binding pockets. These data, combined with the general lack of penicillin resistance reported in S. pyogenes worldwide, suggests that extensive, unknown constraints restrict S. pyogenes PBP sequence plasticity. Our findings imply that while heavy antibiotic pressure may select for mutations in the PBPs, there is currently no evidence of such mutations becoming fixed in the S. pyogenes population or that mutations are being sequentially acquired in the PBPs.IMPORTANCE β-Lactam antibiotics are the first-line therapeutic option for Streptococcus pyogenes infections. Despite the Global high prevalence of S. pyogenes infections and widespread use of β-lactams worldwide, reports of resistance to β-lactam antibiotics, such as penicillin, have been incredibly rare. Recently, β-lactam resistance, as defined by clinical breakpoints, was detected in two clinical S. pyogenes isolates with accompanying mutations in the active site of the penicillin binding protein PBP2x, raising concerns that β-lactam resistance will become more widespread. We screened a Global Database of S. pyogenes genome sequences to investigate the frequency of PBP mutations, identifying that PBP mutations are uncommon relative to those of Streptococcus pneumoniae These findings support clinical observations that β-lactam resistance is rare in S. pyogenes and suggest that there are considerable constraints on S. pyogenes PBP sequence variation.
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restricted sequence variation in streptococcus pyogenes penicillin binding proteins
bioRxiv, 2020Co-Authors: Andrew Hayes, Jake A Lacey, Jacqui Morris, Mark R Davies, Steven Y C TongAbstract:A recent clinical report has linked Streptococcus pyogenes β-lactam antibiotic resistance to mutations in the Penicillin Binding Protein PBP2x. To determine whether this is an isolated case or reflects a broader prevalence of mutations that might confer reduced β-lactam susceptibility, we investigated the relative frequency of penicillin binding protein (PBP) sequence variation within a Global Database of 9,667 S. pyogenes isolates. We found that mutations in S. pyogenes PBPs (PBP2x, PBP1a, PBP1b and PBP2a) occur infrequently across this Global Database with less than 3 amino acid changes differing between >99% of the Global population. Only 4 of the 9,667 strains contained mutations near transpeptidase active sites. The reported PBP2x T553K substitution was not identified. These findings are in contrast to those of 2,520 S. pneumococcus sequences where PBP mutations are relatively frequent and are often located in key β-lactam binding pockets. These data, combined with the general lack of penicillin resistance reported in S. pyogenes worldwide, suggests that extensive, unknown, constraints restrict S. pyogenes PBP sequence plasticity. These findings imply that while heavy antibiotic pressure may select for mutations in the PBPs, there is currently no evidence of such mutations becoming fixed in the S. pyogenes population nor that mutations are being sequentially acquired in the PBPs.
Andrew Maffei - One of the best experts on this subject based on the ideXlab platform.
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An authoritative Global Database for active submarine hydrothermal vent fields
Geochemistry Geophysics Geosystems, 2013Co-Authors: Stace E. Beaulieu, Castro RodrÍguez Anibal German, Edward T. Baker, Andrew MaffeiAbstract:The InterRidge Vents Database is available online as the authoritative reference for locations of active submarine hydrothermal vent fields. Here we describe the revision of the Database to an open source content management system and conduct a meta-analysis of the Global distribution of known active vent fields. The number of known active vent fields has almost doubled in the past decade (521 as of year 2009), with about half visually confirmed and others inferred active from physical and chemical clues. Although previously known mainly from mid-ocean ridges (MORs), active vent fields at MORs now comprise only half of the total known, with about a quarter each now known at volcanic arcs and back-arc spreading centers. Discoveries in arc and back-arc settings resulted in an increase in known vent fields within exclusive economic zones, consequently reducing the proportion known in high seas to one third. The increase in known vent fields reflects a number of factors, including increased national and commercial interests in seafloor hydrothermal deposits as mineral resources. The purpose of the Database now extends beyond academic research and education and into marine policy and management, with at least 18% of known vent fields in areas granted or pending applications for mineral prospecting and 8% in marine protected areas.
Jian Song - One of the best experts on this subject based on the ideXlab platform.
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a Global Database of plant production and carbon exchange from Global change manipulative experiments
Scientific Data, 2020Co-Authors: Jian Song, Mengmei Zheng, Haidao Wang, Yongge Fan, Xiaojing Yue, Zhenxing Zhou, Pengshuai Shao, Hongyan Han, Lingjie Lei, Qian ZhangAbstract:Numerous ecosystem manipulative experiments have been conducted since 1970/80 s to elucidate responses of terrestrial carbon cycling to the changing atmospheric composition (CO2 enrichment and nitrogen deposition) and climate (warming and changing precipitation regimes), which is crucial for model projection and mitigation of future Global change effects. Here, we extract data from 2,242 publications that report Global change manipulative experiments and build a comprehensive Global Database with 5,213 pairs of samples for plant production (productivity, biomass, and litter mass) and ecosystem carbon exchange (gross and net ecosystem productivity as well as ecosystem and soil respiration). Information on climate characteristics and vegetation types of experimental sites as well as experimental facilities and manipulation magnitudes subjected to manipulative experiments are also included in this Database. This Global Database can facilitate the estimation of response and sensitivity of key terrestrial carbon-cycling variables under future Global change scenarios, and improve the robust projection of Global change‒terrestrial carbon feedbacks imposed by Earth System Models.
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a Global Database of plant production and carbon exchange from Global change manipulative experiments
Scientific Data, 2020Co-Authors: Jian Song, Mengmei Zheng, Haidao Wang, Yongge Fan, Xiaojing Yue, Zhenxing Zhou, Pengshuai Shao, Hongyan Han, Lingjie Lei, Qian ZhangAbstract:Numerous ecosystem manipulative experiments have been conducted since 1970/80 s to elucidate responses of terrestrial carbon cycling to the changing atmospheric composition (CO2 enrichment and nitrogen deposition) and climate (warming and changing precipitation regimes), which is crucial for model projection and mitigation of future Global change effects. Here, we extract data from 2,242 publications that report Global change manipulative experiments and build a comprehensive Global Database with 5,213 pairs of samples for plant production (productivity, biomass, and litter mass) and ecosystem carbon exchange (gross and net ecosystem productivity as well as ecosystem and soil respiration). Information on climate characteristics and vegetation types of experimental sites as well as experimental facilities and manipulation magnitudes subjected to manipulative experiments are also included in this Database. This Global Database can facilitate the estimation of response and sensitivity of key terrestrial carbon-cycling variables under future Global change scenarios, and improve the robust projection of Global change‒terrestrial carbon feedbacks imposed by Earth System Models. Machine-accessible metadata file describing the reported data: https://doi.org/10.6084/m9.figshare.12932843
Sebastian Riquelme - One of the best experts on this subject based on the ideXlab platform.
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a Global Database of strong motion displacement gnss recordings and an example application to pgd scaling
Seismological Research Letters, 2019Co-Authors: C J Ruhl, Diego Melgar, Jianghui Geng, Dara E Goldberg, Brendan W Crowell, Richard M Allen, Yehuda Bock, Sergio Barrientos, Sebastian RiquelmeAbstract:Displacement waveforms derived from Global Navigation Satellite System (GNSS) data have become more commonly used by seismologists in the past 15 yrs. Unlike strong‐motion accelerometer recordings that are affected by baseline offsets during very strong shaking, GNSS data record displacement with fidelity down to 0 Hz. Unfortunately, fully processed GNSS waveform data are still scarce because of limited public availability and the highly technical nature of GNSS processing. In an effort to further the use and adoption of high‐rate (HR) GNSS for earthquake seismology, ground‐motion studies, and structural monitoring applications, we describe and make available a Database of fully curated HR‐GNSS displacement waveforms for significant earthquakes. We include data from HR‐GNSS networks at near‐source to regional distances (1–1000 km) for 29 earthquakes between M_w 6.0 and 9.0 worldwide. As a demonstration of the utility of this dataset, we model the magnitude scaling properties of peak ground displacements (PGDs) for these events. In addition to tripling the number of earthquakes used in previous PGD scaling studies, the number of data points over a range of distances and magnitudes is dramatically increased. The data are made available as a compressed archive with the article.
