August 2014: Nearly time to take down our current wetland mesocosm experiment. We've been looking at the classic ecological dichotomy of pulse vs. press (single one time addition or chronic addition of a substrate or stressor) as it pertains to silver nanoparticles, an emerging contaminant. Most lab studies use high concentration pulse exposures, but actual exposures in natural ecosystems to these contaminants are expected to be low concentration and chronic. I'll be giving a talk on a subset of the results from this experiment at ESA in Sacramento on Wednesday, August 13th at 9:20, one year to the day after the start of this experiment. Good timing, eh? Then I'll be hurrying back to begin our final harvest immediately following ESA.
July 2014: Manuscript examining the plant and microbial mechanisms underlying resource ratio theory (sensu Tillman's R* theory) has been accepted at PLOS One! This was work from my time at UCSB, and was a collaboration with Stephanie Yelenik, Janneke Hille Ris Lambers, and Jonathan Levine. It was a single growing season experiment that took ~6 years to get accepted (not for lack of trying). The paper links community ecology and ecosystem ecology. I think by linking the two, it has had a heck of a time getting through review. We've learned many lessons about the benefits and perils of interdisciplinary research in the process, and the review process has made it a better paper.
July 2014:Promoted from Postdoctoral Associate to Research Scientist! My day to day responsibilities will be fairly similar (research, mentor, write, repeat), but now I have the ability to be a PI on grant applications, and teach classes here at Duke. Since Emily is in Germany for a year on sabbatical, I'll be offering her Biogeochemistry class (BIO/ENV 572) in Spring 2015.
June 2014: Had to say goodbye this month to Anna Fedders, who has been an integral part of our current wetland mesocosm experiment examining the impacts of pulse vs. chronic nanoparticle pollution. Anna is off to graduate school at University of Illinois at Urbana-Champaign and is sorely missed already!
It's been a busy year so far. A lot has happened since December, but the most important milestone is the publication ("just accepted") of our wetland mesocosm paper in ES&T. In this paper, we describe the fate, transport, and impacts of Ag added to wetland mesocosms as either AgNO3, 12 nm or 49 nm silver nanoparticles. Many thanks to my coauthors, and to everyone who helped with the experiment!
Was invited to give a talk and sit on a panel on the first day of the recent NSF-EPA-USDA Nanoscale Science and Engineering Grantees Conference in Arlington, Virginia. Good talks on measuring nanomaterials in complex environments (e.g., CNTs in biological organisms, metal and metal oxide particles in environmental media), synthesizing nanomaterials, manufacturing nanomaterials and nano-enabled products, and doing so in as sustainable a fashion as possible.
November 2013: Paper published in ES&T detailing experiments that I helped design, coordinate, and in the case of duckweed, conduct. These experiments tested the toxicity of sulfidized silver nanoparticles (dominant fate in wastewater effluent and biosolids, as well as in anaerobic sediments) to a range of different organisms.
Gave a nano-focused seminar for the UNCW Department of BIology and Marine Biology's seminar. Really enjoyed my visit and meetings with faculty and students, and ate some seminar snacks including delicious TiO2 nanoparticle-containing Oreos. Many thanks to Will White for hosting me, and everyone who made time to meet with me.
Started new round of wetland mesocosm experiments as a part of CEINT funded research. This round we're looking at the impacts of a pulse exposure (like our last experiment) as compared to chronic exposure, and weathered Ag nanoparticles (Ag2S nanoparticles) as compared to fresh nanoparticles (Ag(0) nanoparticles).
Benjamin P. Colman
Duke Biology/Center for the Environmental Implications of Nanotechnology
Research interests: Biogeochemistry, ecosystem ecology, plant microbe interactions, microbial ecology, ecotoxicology
Phone: (919) 660 - 7262
Email: benjamin.colman at duke.edu
Durham, NC 27708
124 Science Drive
Durham, NC 27708