Postdoctoral Scholars

[ Postdoctoral Scholars | Current and Former Graduate Students ]

Postdoctoral Scholars
	Kate Achilles C-MORE Postdoctoral Scholar University of Hawai‘i at Manoa (UH Manoa) Themes I and II. Achilles' research focuses on the diversity and abundance of diazotrophic microbes in the open ocean, denitrification in oxygen minimum zones in the water column, development of techniques for cell sorting of cyanobacteria by flow cytometry for subsequent cultivation and molecular analyses, as well as the bioavailability of iron to cyanobacteria. She is also actively working on the development of educational programs that promote awareness and interest in microbial oceanography by creating innovative curriculum modules, providing access to teacher workshops and shipboard experiences, and establishing active community outreach programs. Keywords: nitrogen fixation, cyanobacteria, bioavailability of iron, denitrification, flow cytometry, education, outreach kate.achilles@soest.hawaii.edu
	Alex Culley C-MORE Postdoctoral Scholar University of Hawai‘i at Manoa (UH Manoa) Themes I and II. Culley will use cultivation dependent and independent techniques to investigate marine virus diversity and dynamics. Specific objectives include the isolation and characterization of viruses that infect organisms of ecological importance, particularly from the open ocean, and the exploration of the population composition and structure of marine RNA virus communities, a very poorly characterized group of marine microbes. Keywords: microbial diversity, viral ecology, marine RNA virus, picorna-like virus aculley@hawaii.edu
	Solange Duhamel C-MORE Postdoctoral Scholar University of Hawai‘i at Manoa (UH Manoa) Themes I, II, and III. Duhamel is interested in the dynamics of phosphorus biogeochemistry and bioavailability and its link with C and N cycling. She is particularly interested in prokaryotes and phytoplankton P incorporation pathways (direct incorporation from DIP or indirect incorporation from DOP) and in the algal-bacterial competition for P in P-limited areas. She develops cell-specific indicators of nutritional status such as ELF-labeling (Enzyme-Labeled Fluorescence). Keywords: DIP, DOP, phosphatase, ELF, prokaryotes, phytoplankton, microscopy, flow cytometry solange@hawai.edu
	Jennifer Edmonds C-MORE Postdoctoral Scholar University of Hawai‘i at Manoa (UH Manoa) Themes I, II, and III. Edmonds is interested in how microbial community gene structure and expression influences key biogeochemical transformations of C, N, P, and S. She is currently focusing on the microbial utilization of complex dissolved organic phosphorus (DOP) compounds under conditions of P stress or starvation. Particular interest falls on the C-P lyase pathway, which may be a mechanism for aerobic methane production in the ocean water column. Keywords: diversity, ecology, mRNA, methane production, DOP jedmonds@hawaii.edu
	Alexander Eiler C-MORE Postdoctoral Scholar University of Hawai‘i at Manoa (UH Manoa) Themes I, II, and III. Eiler is interested in the life strategies of marine microbes. He will perform laboratory experiments to study the physiological and evolutionary responses of abundant groups of marine bacteria to environmental stimuli. Additionally, Eiler will pursuit to identify the key players in marine microbial communities of the North Pacific Subtropical Gyre by linking distribution patterns of bacterial groups to ecosystem functions. Guided by this statistical approach some directed efforts will be applied to isolate and characterize the identified key-microbes. Keywords: diversity, genomics, ecology, picoplankton, phylogeny, mRNA, 16S rRNA eiler@hawaii.edu
	Rachel A. Foster C-MORE Postdoctoral Scholar University of California, Santa Cruz (UCSC) Themes I, II, and IV. Foster’s research focuses on the diversity and distribution of planktonic symbioses. In particular she is most interested in diatom hosts, which harbor symbiotic cyanobacteria or cyanobionts. Diatoms with associated diazotrophs, DDAs, have been reported from all major subtropical and tropical seas, yet very little is known about the intricacies of the relationships. She is currently working on developing and applying new methodology to reveal if fixed nitrogen by the cyanobiont is in fact transferred to the host diatom. Results from Foster’s research will be directly applicable to the modeling of nitrogen exchange between host and symbiont and vice versa. Keywords: symbioses, nitrogen, diatoms, Richelia rfoster@pmc.ucsc.edu
	Nicole Goebel C-MORE Postdoctoral Scholar University of California at Santa Cruz (UCSC) Themes II and IV. Goebel’s research focuses on the the temporal and spatial variability of the community structure of marine phytoplankton communities. Statistical and numerical modeling approaches have been used in order to assess the relative contributions of three known diazotrophs (Trichodesmium, Group B, and Group A) to nitrogen fixation at Station ALOHA, and are currently used to predict the predominant primary producers within the California Current. She has also carried out growth measurements of Trichodesmium and Crocosphaera cultures in order to constrain parameterizations of modeled growth rates. Keywords: modeling, nitrogen fixation ngoebel@pmc.ucsc.edu
	Rex Malmstrom C-MORE Postdoctoral Scholar Massachusetts Institute of Technology (MIT) Themes I and II. Malmstrom is interested in the dynamics of marine cyanobacterial populations. Currently, he is investigating seasonal changes in the abundance of various subgroups of Prochlorococcus, an abundant clade of marine cyanobacteria, in the North Pacific and North Atlantic oceans. In addition, he is exploring new technologies for targeted gene expression studies of natural Prochlorococcus populations. Keywords: Prochlorococcus, genomics, transcriptomics, whole genome amplification rexrm@mit.edu
	Mar Nieto-Cid C-MORE Postdoctoral Scholar Woods Hole Oceanographic Institution (WHOI) Theme I and II. In general, Nieto-Cid is interested in the composition and fractionation of dissolved organic matter (DOM) and its role in biogeochemical cycles. Specifically, she is working on the influence of DOM fractionation on microbial consortia. She is also involved in the characterization of natural iron binding organic ligands to provide a better understanding of iron speciation in seawater and to help to integrate studies of siderophores from pure culture with microbial iron acquisition in iron limited environments. Keywords: dissolved organic matter, biogeochemical cycles, trace metal organic ligands mnietocid@whoi.edu
	Sophie Rabouille C-MORE Postdoctoral Scholar University of California at Santa Cruz (UCSC) Themes II and IV. Rabouille is interested in the influence of plankton dynamics on nutrients fluxes. She develops models of phytoplankton growth to investigate changes in metabolic activities in response to forcing conditions of the environment. In particular, she focused on the effect of metabolic constraints on nitrogen fixation in planktonic cyanobacteria; she followed their activity in relation to fluctuations of environmental variables such as irradiance and oxygen concentration. Based on the analysis of the HOT database, she also modeled the vertical segregation of high- and low-light adapted ecotypes of Prochlorococcus sp. in the North Pacific Subtropical Gyre. She is currently working on a new ecosystem model to analyze plankton diversity and dynamics in the California Current system. Keywords: plankton dynamics, light response curves, nitrogen fixation, nutrient fluxes, modeling srabouille@pmc.ucsc.edu
	Sébastien Rodrigue C-MORE Postdoctoral Scholar Massachusetts Institute of Technology (MIT) Themes I, II, and III. The work of Rodrigue focuses on Prochlorococcus, the smallest known phototroph, and the most abundant photosynthetic cell on the planet. More specifically, he studies gene regulatory networks, and develops new cultivation-independent methods to study microbial populations and sequence genomes from single-cells. Keywords: genome diversity, gene expression, single-cell approaches s_rod@mit.edu
	Angelicque White C-MORE Postdoctoral Scholar Oregon State University (OSU) Themes II, III, and IV. White’s primary research interests involve understanding how specific organisms acquire the elements necessary for growth and how different nutrient sources impact primary productivity and particle export. She is also working on the development of stochastic, optimization models which can allow for more realistic simulations of the taxonomic and biogeochemical diversity of the phytoplankton community in the upper water column of the North Pacific. Keywords: nitrogen fixation, phosphorus, model development, cyanobacterial diversity, cyanobacterial physiology, Trichodesmium awhite@coas.oregonstate.edu
	Sam Wilson C-MORE Postdoctoral Scholar University of Hawai‘i at Manoa (UH Manoa) Themes I and II. Wilson’s research focuses on the analysis of reduced gases in the open ocean including nitrous oxide, methane and dimethylsulphide. The work will investigate the production and consumption mechanisms of these trace gases in the upper water column, as well as the microbiology responsible for these processes. Keywords: methane, nitrous oxide, dimethylsulphide, reduced gases stwilson@hawaii.edu