Pauling Fellowship Alumni
James Stegen — 2011 Pauling Fellow
James Stegen received his Ph.D. from the University of Arizona in Ecology and Evolutionary Biology in 2009.
James is a member of the Fundamental & Computational Sciences Directorate's Biological Sciences Division. His research area focuses on developing ecological models of microbial communities. In particular, he is leveraging multiple ecomics technologies to describe whole community function through time and space. This data will be used to develop process-based simulation models for predicting the effects of remediation strategies and environmental change on key ecosystem functions, such as subsurface contaminant transport.
- Hurlbert AH, and JC Stegen. 2014. "When should species richness be energy-limited, and how would we know?" Ecology Letters 17(4):401-413. doi:10.1111/ele.12240
- Bailey VL, SJ Fansler, JC Stegen, and LA McCue. 2013. "Linking Microbial Community Structure to ß-Glucosidic Function in Soil Aggregates." The ISME Journal 7(10):2044-2053. doi:10.1038/ismej.2013.87
- Lindemann SR, JJ Moran, JC Stegen, RS Renslow, JR Hutchison, JK Cole, A Dohnalkova, J Tremblay, K Singh, S Malfatti, F Chen, S Tringe, H Beyenal, and JK Fredrickson. 2013. "The Epsomitic Phototrophic Microbial Mat of Hot Lake, Washington: Community Structural Responses to Seasonal Cycling." Frontiers in Microbiology 4:323. doi:10.3389/fmicb.2013.00323
- Stegen JC, X Lin, JK Fredrickson, X Chen, DW Kennedy, CJ Murray, ML Rockhold, and A Konopka. 2013. "Quantifying Community Assembly Processes and Identifying Features that Impose Them." The ISME Journal 7:2069-2079. doi:10.1038/ismej.2013.93
- Wang J, J Shen, Y Wu, C Tu, J Soininen , JC Stegen, J He, X Liu, L Zhang, and E Zhang. 2013. "Phylogenetic beta diversity in bacterial assemblages across ecosystems: deterministic versus stochastic processes." The ISME Journal 7(7):1310-1321. doi:10.1038/ismej.2013.30
- Stegen JC, X Lin, A Konopka, and JK Fredrickson. 2012. "Stochastic and Deterministic Assembly Processes in Subsurface Microbial Communities." The ISME Journal 6(9):1653-1664. doi:10.1038/ismej.2012.22
Andreas Vaskekis — 2011 Pauling Fellow
Andreas Vasdekis is an assistant professor in the Department of Physics at the University of Idaho.
Andreas received his Ph.D. from the University of St. Andrews (UK), exploring the photophysics and applications of conjugated polymers (2008). Following a short spell at the California Institute of Technology (Caltech), he became a junior scientist at the Ecole Polytechnique Fédérale de Lausanne (EPFL, Switzerland) for three years before moving to the Pacific Northwest National Laboratory.
His research interests generally lie at the interface of photonics, biophysics and materials. At PNNL, as a member of the Environmental Molecular Sciences LaboratVory, he investigated processes and interactions associated with biofuel synthesis by developing and applying precision biological measurement techniques in microfluidics.
- Vasdekis AE, MJ Wilkins, JW Grate, RT Kelly, A Konopka, SS Xantheas, and MT Chang. 2014. "Solvent Immersion Imprint Lithography." Lab on a Chip 14(12):2072-2080. doi:10.1039/C4LC00226A
- Vasdekis AE, EA Scott, S Roke, JA Hubbell, and D Psaltis. 2013. "Vesicle Photonics." Annual Review of Materials Research 43:283-305. doi:10.1146/annurev-matsci-071312-121724
- Vasdekis AE. 2013. "Single microbe trap and release in sub-microfluidics." RSC Advances 3(18):6343-6346. doi:10.1039/C3RA40369F
Susan Wiedner — 2010 Pauling Fellow
Susan Wiedner received her Ph.D. in synthetic organic chemistry from the University of Michigan Department of Chemistry. She is a past recipient of a two-year NIH funded Chemical-Biology Interface Training grant.
Susan is collaborating with the Biological Separations and Mass Spectrometry group in the Fundamental &Computational Sciences Directorate. Her research focus is on developing and integrating a subcellular chemical proteomics platform, using activity-based probes and subcellular fractionation, to facilitate the analysis of enzyme activity to promote the field of proteomics. This technology could lead to a better understanding of systems biology on the cellular level.
- Kim YM, Metz TO, Hu Z, Wiedner SD, Kim JS, Smith RD, Morgan WF, Zhang Q. "Formation of dehydroalanine from mimosine and cysteine: artifacts in gas chromatography/mass spectrometry based metabolomics." Rapid Commun Mass Spectrom. 2011 Sep 15;25(17):2561-4.
- Wiedner SD, Burnum KE, Pederson LM, Anderson LN, Fortuin S, Chauvigné-Hines LM, Shukla AK, Ansong C, Panisko EA, Smith RD, Wright AT. "Multiplexed activity-based protein profiling of the human pathogen Aspergillus fumigatus reveals large functional changes upon exposure to human serum." J Biol Chem. 2012 Sep 28;287(40):33447-59.
- Sadler NC, Angel TE, Lewis MP, Pederson LM, Chauvigné-Hines LM, Wiedner SD, Zink EM, Smith RD, Wright AT. "Activity-based protein profiling reveals mitochondrial oxidative enzyme impairment and restoration in diet-induced obese mice." PLoS One. 2012;7(10):e47996. doi:10.1371/journal.pone.0047996.
- Wiedner SD, Ansong C, Webb-Robertson BJ, Pederson LM, Fortuin S, Hofstad BA, Shukla AK, Panisko EA, Smith RD, Wright AT. "Disparate proteome responses of pathogenic and nonpathogenic aspergilli to human serum measured by activity-based protein profiling (ABPP)." Mol Cell Proteomics. 2013 Jul;12(7):1791-805. doi: 10.1074/mcp.M112.026534.
- Wiedner SD, Anderson LN, Sadler NC, Chrisler WB, Kodali VK, Smith RD, Wright AT. "Organelle-specific activity-based protein profiling in living cells." Angew Chem Int Ed Engl. 2014 Mar 10;53(11):2919-22. doi: 10.1002/anie.201309135.
Marcel Baer — 2010 Pauling Fellow
Marcel Baer is a member of the Chemical Physics and Analysis Group within Fundamental and Computational Sciences Directorate. He is working to further develop our understanding of the important molecular interactions that give rise to novel phenomena in the vicinity of hydrophobic interfaces. His focus is on utilizing and developing less computationally intensive models that contain quantum mechanics and thus can describe chemistry. The ultimate goal is to develop a systematic approach to understanding the novel chemistry of interfaces, including heterogeneous catalysts.
- Baer MD, and CJ Mundy. 2013. "An ab initio approach to understanding the specific ion effect." Faraday Discussions 160(0):89-101. doi:10.1039/C2FD20113E
- Devanathan R, NB Idupulapati, MD Baer, CJ Mundy, and M Dupuis. 2013. "Ab initio molecular dynamics simulation of proton hopping in a model polymer membrane." Journal of Physical Chemistry B 117(51):16522-16529. doi:10.1021/jp410229u
- Stern AC, MD Baer, CJ Mundy, and DJ Tobias. 2013. "Thermodynamics of Iodide Adsorption at the Instantaneous Air-Water Interface." Journal of Chemical Physics 138(11):114709. doi:10.1063/1.4794688
- Tobias DJ, AC Stern, MD Baer, Y Levin, and CJ Mundy. 2013. "Simulation and Theory of Ions at Atmospherically Relevant Aqueous Liquid-Air Interfaces." Annual Review of Physical Chemistry 64:339-359. doi:10.1146/annurev-physchem-040412-110049
- Baer MD, AC Stern, Y Levin, DJ Tobias, and CJ Mundy. 2012. "Electrochemical Surface Potential due to Classical Point Charge Models Drives Anion Adsorption to the Air-Water Interface." The Journal of Physical Chemistry Letters 3(11):1565-1570. doi:10.1021/jz300302t
- Kimmel GA, MD Baer, NG Petrik, J VandeVondele, RJ Rousseau, and CJ Mundy. 2012. "Polarization- and Azimuth-Resolved Infrared Spectroscopy of Water on TiO2(110): Anisotropy and the Hydrogen-Bonding Network." The Journal of Physical Chemistry Letters 3(6):778-784. doi:10.1021/jz3001079
- Baer MD, CJ Mundy, MJ McGrath, IFW Kuo, JI Siepmann, and DJ Tobias. 2011. "Re-Examining the Properties of the Aqueous Vapor-Liquid Interface Using Dispersion Corrected Density Functional Theory." Journal of Chemical Physics 135(12):Article No. 124712. doi:10.1063/1.3633239
- Baer MD, TV Pham, JL Fulton, GK Schenter, M Balasubramanian, and CJ Mundy. 2011. "Is Iodate a Strongly Hydrated Cation?" The Journal of Physical Chemistry Letters 2(20):2650-2654. doi:10.1021/jz2011435
- Baer MD, and CJ Mundy. 2011. "Toward an Understanding of the Speci?c Ion Effect using Density Functional Theory." The Journal of Physical Chemistry Letters 2(9):1088-1093. doi:10.1021/jz200333b
- Lewis T, B Winter, AC Stern, MD Baer, CJ Mundy, DJ Tobias, and JC Hemminger. 2011. "Dissociation of strong acid revisited: X-ray photoelectron spectroscopy and molecular dynamics simulations of HNO3 in water." Journal of Physical Chemistry B 115(30):9445-9451. doi:10.1021/jp205510q
- Lewis T, B Winter, AC Stern, MD Baer, CJ Mundy, DJ Tobias, and JC Hemminger. 2011. "Does Nitric Acid Dissociate at the Aqueous Solution Surface?" Journal of Physical Chemistry C 115(43):21183-21190. doi:10.1021/jp205842w
Grant Johnson — 2009 Pauling Fellow
Dr. Grant Johnson is a scientist in PNNL's Fundamental & Computational Science Directorate. His research is focused within the Separations, Detection, and Analysis program with Laboratory Fellow Dr. Julia Laskin.
Dr. Johnson is developing unique capabilities for the controlled preparation and characterization of alloy nanoparticles (NPs) and clusters of precise composition. His research is employing oxygen reduction as a model reaction to investigate how the size, shape, elemental composition and support-interaction of alloy nanoparticles and clusters on surfaces influence their catalytic behavior. Utilizing these capabilities and fundamental insights into structure-reactivity relationships will allow the directed design of improved alloy nanoparticles and clusters for a broad range of applications in catalysis and energy storage.
Separating the Catalysts from the Chaff
New soft landing instrument prepares pure, undamaged samples for analysis
Ligand Stripping Leads to Unique Surface Catalyst
Novel approach uses ion-molecule collisions and deposition to create sought-after material
U.S., Taiwan Team Ties Down Vanadium Catalyst in Thin Layers
Soft landing metal-based molecules and acids on a surface creates active, easy-to-separate catalyst
Getting Positive Results with Negative Ions
Scientists show new detector's abilities, including visualizing a charged particle beam
Employing Ions Allows Scientists to Precisely Design Innovative Materials
Invited review article covers basic processes and applications of ion soft-landing
Soft Landing and Particle Coverage Key to Keeping or Losing Charge on Surfaces
New results may aid rational design of materials for sustainable energy
Preparing a Homogenous Haystack
Scientists show how to prepare identical particles for analysis, eliminating the hunt
- Strong Influence of a Minor Substitution in Gold Clusters
Ligand change controls size, stability, and charge state of nanoparticles synthesized in solution
- Scientists Write Invited Review to Commemorate 60th Anniversary of Scientific Journal
Xiao Lin — 2009 Pauling Fellow
Dr. Xiao Lin is now a Professor within the School of Physics at the University of Chinese Academy of Sciences.