Institution
Pacific Northwest National Laboratory
Facility•Richland, Washington, United States•
About: Pacific Northwest National Laboratory is a facility organization based out in Richland, Washington, United States. It is known for research contribution in the topics: Catalysis & Aerosol. The organization has 11581 authors who have published 27934 publications receiving 1120489 citations. The organization is also known as: PNL & PNNL.
Topics: Catalysis, Aerosol, Mass spectrometry, Population, Ion
Papers published on a yearly basis
Papers
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TL;DR: An additional benefit from the present strategy is that the 15N-labeled peptides do not display significant isotope-dependent chromatographic shifts from their 14N- labeled counterparts, therefore improving the precision for quantitating peptide abundances.
Abstract: We describe the combined use of 15N-metabolic labeling and a cysteine-reactive biotin affinity tag to isolate and quantitate cysteine-containing polypeptides (Cys-polypeptides) from Deinococcus radiodurans as well as from mouse B16 melanoma cells. D. radiodurans were cultured in both natural isotopic abundance and 15N-enriched media. Equal numbers of cells from both cultures were combined and the soluble proteins extracted. This mixture of isotopically distinct proteins was derivatized using a commercially available cysteine-reactive reagent that contains a biotin group. Following trypsin digestion, the resulting modified peptides were isolated using immobilized avidin. The mixture was analyzed by capillary reversed-phase liquid chromatography (LC) on-line with ion trap mass spectrometry (MS) as well as Fourier transform ion cyclotron resonance (FTICR) MS. The resulting spectra contain numerous pairs of Cys-polypeptides whose mass difference corresponds to the number of nitrogen atoms present in each of t...
307 citations
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Pacific Northwest National Laboratory1, United States Geological Survey2, Smithsonian Tropical Research Institute3, Smithsonian Conservation Biology Institute4, Woods Hole Research Center5, University of Leeds6, Lawrence Berkeley National Laboratory7, University of Texas at Austin8, Northern Arizona University9, Lancaster University10, National Center for Atmospheric Research11, University of California, Berkeley12, Los Alamos National Laboratory13, Max Planck Society14, Forest Research Institute Malaysia15, Jet Propulsion Laboratory16, Empresa Brasileira de Pesquisa Agropecuária17, International Institute of Minnesota18, University of Tokyo19, Environmental Change Institute20, University of Barcelona21, Australian National University22, University of Edinburgh23, Harvard University24, University of Utah25, Oak Ridge National Laboratory26, Princeton University27
TL;DR: The state of knowledge regarding MTF tree mortality is reviewed, a conceptual framework with testable hypotheses regarding the drivers, mechanisms and interactions that may underlie increasing MTF mortality rates are created, and the next steps for improved understanding and reduced prediction are identified.
Abstract: Tree mortality rates appear to be increasing in moist tropical forests (MTFs) with significant carbon cycle consequences. Here, we review the state of knowledge regarding MTF tree mortality, create a conceptual framework with testable hypotheses regarding the drivers, mechanisms and interactions that may underlie increasing MTF mortality rates, and identify the next steps for improved understanding and reduced prediction. Increasing mortality rates are associated with rising temperature and vapor pressure deficit, liana abundance, drought, wind events, fire and, possibly, CO2 fertilization-induced increases in stand thinning or acceleration of trees reaching larger, more vulnerable heights. The majority of these mortality drivers may kill trees in part through carbon starvation and hydraulic failure. The relative importance of each driver is unknown. High species diversity may buffer MTFs against large-scale mortality events, but recent and expected trends in mortality drivers give reason for concern regarding increasing mortality within MTFs. Models of tropical tree mortality are advancing the representation of hydraulics, carbon and demography, but require more empirical knowledge regarding the most common drivers and their subsequent mechanisms. We outline critical datasets and model developments required to test hypotheses regarding the underlying causes of increasing MTF mortality rates, and improve prediction of future mortality under climate change.
306 citations
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TL;DR: In this article, a graph-theoretic DSR strategy incorporating microgrids that maximizes the restored load and minimizes the number of switching operations is presented, where a spanning tree search algorithm is applied to find the candidate restoration strategies by modeling micro-grids as virtual feeders.
Abstract: Distribution system restoration (DSR) is aimed at restoring loads after a fault by altering the topological structure of the distribution network while meeting electrical and operational constraints. The emerging microgrids embedded in distribution systems enhance the self-healing capability and allow distribution systems to recover faster in the event of an outage. This paper presents a graph-theoretic DSR strategy incorporating microgrids that maximizes the restored load and minimizes the number of switching operations. Spanning tree search algorithms are applied to find the candidate restoration strategies by modeling microgrids as virtual feeders and representing the distribution system as a spanning tree. Unbalanced three-phase power flow is performed to ensure that the proposed system topology satisfies all operational constraints. Simulation results based on a modified IEEE 37-node system and a 1069-node distribution system demonstrate the effectiveness of the proposed approach.
305 citations
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Research Triangle Park1, Foundation for Research & Technology – Hellas2, University of Washington3, University of Michigan4, National Center for Atmospheric Research5, University of East Anglia6, Colorado State University7, University of Maryland, Baltimore County8, Leibniz Association9, University of Crete10, Columbia University11, University of Illinois at Urbana–Champaign12, Nankai University13, Georgia Institute of Technology14, Tsinghua University15, Pacific Northwest National Laboratory16, McGill University17
TL;DR: This paper reviews and synthesizes the current state of knowledge on the acidity of atmospheric condensed phases, specifically particles and cloud droplets, including recommendations for estimating acidity and pH, standard nomenclature, a synthesis of current pH estimates based on observations, and new model calculations on the local and global scale.
Abstract: . Acidity, defined as pH, is a central component of aqueous
chemistry. In the atmosphere, the acidity of condensed phases (aerosol
particles, cloud water, and fog droplets) governs the phase partitioning of
semivolatile gases such as HNO3 , NH3 , HCl, and organic acids and
bases as well as chemical reaction rates. It has implications for the
atmospheric lifetime of pollutants, deposition, and human health. Despite
its fundamental role in atmospheric processes, only recently has this field
seen a growth in the number of studies on particle acidity. Even with this
growth, many fine-particle pH estimates must be based on thermodynamic model
calculations since no operational techniques exist for direct measurements.
Current information indicates acidic fine particles are ubiquitous, but
observationally constrained pH estimates are limited in spatial and temporal
coverage. Clouds and fogs are also generally acidic, but to a lesser degree
than particles, and have a range of pH that is quite sensitive to
anthropogenic emissions of sulfur and nitrogen oxides, as well as ambient
ammonia. Historical measurements indicate that cloud and fog droplet pH has
changed in recent decades in response to controls on anthropogenic
emissions, while the limited trend data for aerosol particles indicate
acidity may be relatively constant due to the semivolatile nature of the
key acids and bases and buffering in particles. This paper reviews and
synthesizes the current state of knowledge on the acidity of atmospheric
condensed phases, specifically particles and cloud droplets. It includes
recommendations for estimating acidity and pH, standard nomenclature, a
synthesis of current pH estimates based on observations, and new model
calculations on the local and global scale.
305 citations
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TL;DR: The findings support the view that competition for multiple nutrients in oligotrophic systems is extreme, but nutrient flux is sufficient to sustain microbial community activity.
Abstract: The northwestern Sargasso Sea undergoes annual cycles of productivity with increased production in spring corresponding to periods of upwelling, and oligotrophy in summer and autumn, when the water column becomes highly stratified. The biological productivity of this region is reduced during stratified periods as a result of low concentrations of phosphorus and nitrogen in the euphotic zone. To better understand the mechanisms of microbial survival in this oligotrophic environment, we used capillary liquid chromatography (LC)-tandem mass spectrometry to detect microbial proteins in surface samples collected in September 2005. A total of 2215 peptides that mapped to 236 SAR11 proteins, 1911 peptides that mapped to 402 Prochlorococcus proteins and 2407 peptides that mapped to 404 Synechococcus proteins were detected. Mass spectra from SAR11 periplasmic substrate-binding proteins accounted for a disproportionately large fraction of the peptides detected, consistent with observations that these extremely small cells devote a large proportion of their volume to periplasm. Abundances were highest for periplasmic substrate-binding proteins for phosphate, amino acids, phosphonate, sugars and spermidine. Proteins implicated in the prevention of oxidative damage and protein refolding were also abundant. Our findings support the view that competition for multiple nutrients in oligotrophic systems is extreme, but nutrient flux is sufficient to sustain microbial community activity.
305 citations
Authors
Showing all 11848 results
Name | H-index | Papers | Citations |
---|---|---|---|
Yi Cui | 220 | 1015 | 199725 |
Derek R. Lovley | 168 | 582 | 95315 |
Xiaoyuan Chen | 149 | 994 | 89870 |
Richard D. Smith | 140 | 1180 | 79758 |
Taeghwan Hyeon | 139 | 563 | 75814 |
Jun Liu | 138 | 616 | 77099 |
Federico Capasso | 134 | 1189 | 76957 |
Jillian F. Banfield | 127 | 562 | 60687 |
Mary M. Horowitz | 127 | 557 | 56539 |
Frederick R. Appelbaum | 127 | 677 | 66632 |
Matthew Jones | 125 | 1161 | 96909 |
Rainer Storb | 123 | 905 | 58780 |
Zhifeng Ren | 122 | 695 | 71212 |
Wei Chen | 122 | 1946 | 89460 |
Thomas E. Mallouk | 122 | 549 | 52593 |