Cory Lab

7.29.10 Cory lab visiting fellow presents in the UNC-SPH Living in Color Conference

2010-07-29T08:40:00.000-07:00

Today is the first annual UNC SPH first annual Public Health Living in Color Conference to showcase the work of fellows participating in a competitive extern-ship program in the school. The Cory lab hosted Jaleesa Powell, an undergrad at UNC (pictured), as a fellow in this program for the month of July. Jaleesa presented her work comparing the fluorescent fingerprint of bottled vs. tap water in the conference poster session today. You can read more about the program and the theme here.

6.9.10 RMC at Toolik Field Station

2010-06-09T09:23:00.000-07:00

Field work season has arrived, and I am now at Toolik Field Station in the arctic region of Alaska, near the Brooks Range and Gates of the Arctic National Park to study processes controlling the fate of carbon released from thawing permafrost in the Arctic tundra and surface waters. Today's photos show the journey from Fairbanks to the field station along the famous Dalton Highway (also known as the haul road for all you ice-road- trucker fans).The drive takes about ~ 8hrs, driving anywhere from 20-50 mph on the mostly dirt-and very dirty- road, and crosses the mighty Yukon River and the Arctic Circle.

5.10.10 Group Photos!

2010-05-10T18:36:00.000-07:00

It is the end of the spring semester and we took some time to celebrate-- with photos to prove it. On Friday we sat outside at Tyler's in Durham for dinner, enjoying a perfect spring evening. Then we strolled over to the Durham Bulls Athletic Stadium to watch the Durham Bulls beat the Scranton/Wilkes-Barre Yankees. Photo (L- R (back) Rose, Brittany, Rory (front) Katie, George, Angela.
Photos below: Durham bull gets all lit up for a home run; and an awesome fireworks display following the game!

Here is the official Cory Lab in April, 2010 Group Photo (click to see larger view):

L -R: Brittany Papworth (U), George Gang (G), Ashley Mui (U), Lauren Visser (U), Katie Harrold (G), Angela Wang (G), Rory Polera (G), Rose Cory (PI).
U: undergrad G: grad PI: principal investigator

4.21.10 Singlet oxygen and dissolved organic matter

2010-04-21T09:43:00.000-07:00

Cory et al. study, from my postdoctoral work with Profs. Kris McNeill and Jim Cotner and our collaborators, is now published in ES&T. We found that singlet oxygen, a reactive oxygen species found in sunlit waters, oxidizes dissolved organic matter (DOM) to produce a range of products that appear to be less nutritious to bacteria. Check it out!!

4.21.10 Captiviating Tales of Polar Explorers

2010-04-19T06:33:00.000-07:00

R.M. Cory is participating in this event but on by then UNC Global Education Center to celebrate polar regions and polar exploration, it is part of a larger exhibit on Ice Counterpoint: Encounters in Antarctica and the Arctic. This event will feature a unique combination of history, story telling, music, art, and science. Check it out at 6pm in the Global Fedex Building on April 21.

4.18.10 EWB 6k race

2010-04-19T06:27:00.000-07:00

Congrats to all runners and participants of the Engineers Without Borders 6k race! We had perfect running weather and an excellent course around the UNC campus.

3.28.10 Grad student awards

2010-03-28T09:54:00.000-07:00

Grad student George Dang receives a travel award to attend the ASLO meeting in Santa Fe, NM this June!
Grad student Rory Polera receives an NSF EAPSI award to work with Cynthia Joll in Perth, Australia at the Curtin Water Quality Research Centre this summer on a collaborative effort to compare water reuse systems.

3.16.10 ESE Open House on March 19

2010-03-16T11:40:00.000-07:00

The Department of Environmental Sciences and Engineering (ESE) at the University of North Carolina at Chapel Hill invites prospective graduate students to attend the School-wide Graduate Program Open House on Friday, March 19th, 2010 to meet with faculty + tour the facilities and learn about the graduate programs.

3.12.10 R.M. Cory attends Arctic LTER meeting

2010-03-12T07:31:00.000-08:00

Rose attended the Arctic LTER meeting in Woods Hole, MA (3/5-3/7) to learn about the on-going research at this important field site, including the recent fire and thermokarst related disturbances, and to plan for upcoming field work there this summer with colleagues from the University of Michigan.
Pictured: R.M. Cory and B. Neilson.

3.1.10 R.M. Cory et al. fluorescence methods paper pub. online

2010-03-12T07:18:00.000-08:00

Rose and co-author's fluorescence/EEM methods paper appears online in Limnology & Oceanography: Methods.

PARAFAC Workshop in the Cory Lab March 13-14

2010-02-19T15:06:00.000-08:00

We'll be hosting a PARAFAC Workshop in the Cory Lab March 13-14 with groups from Duke and other Universities. We'll cover EEM corrections and PARAFAC using Stedmon & Bro's PARAFAC tutorial and DOMFluor Toolbox.
We may also go over excitation correction with rhodamine and Fluoromax software issues.

A tribute to the Engineers Without Borders fundraising event

2010-02-07T16:13:00.000-08:00

Last night the Daniel A. Okun chapter of Engineers Without Borders at UNC-Chapel Hill held a very successful fundraising event, which followed a day long symposium on development of small scale international projects. The event was a lot of fun and very well organized. It was a nice setting to be reminded of the nature of scope of this chapter's international and local projects, including the Rogers Rd. project which is quite literally close to my home. I was really impressed with the efforts and dedication of EWB members.

Photo: Angela Wang (center) is the EWB Vice President. Nice work Angela!!

It's all about the carbon

2010-02-07T15:09:00.000-08:00

Check out this excellent cartoon describing carbon's role in climate change: It's all about the carbon, by Robert Krulwich (Radio Lab) and Odd Todd. I like this cartoon so much because it emphasizes carbon chemistry to help explain climate change, which is the focus of much of my (R.M. Cory) past and current research. For example, one of my research objectives is to understand how the chemistry of naturally occurring organic carbon controls how and how fast it can be oxidized to CO2 by chemical and biological processes in the environment.

Grad students receive mentoring awards

2010-02-03T10:57:00.000-08:00

Congrats to graduate students Angela Wang and Rory Polera who received awards from UNC to support their efforts in mentoring undergraduate researchers who recently joined our lab. The undergraduate students are analyzing the fluorescent fingerprint of surface water, drinking water, and non-potable reclaimed water for a range of different research questions.

A New Record: 120 EEMs in One Day!

2010-01-27T17:39:00.000-08:00

I am pretty sure we set a new record for the number of excitation-emission matrices run in one day. (Side note: excitation emission matrices, or EEMs, are a tool we use measure the fluorescent fingerprint of water, which provides information on water quality). Today, Brooke H. of the Bernhardt lab at Duke collected 120 EEMs from of different urban stream samples, starting ~ 9am and finishing around 5pm. This extraordinary rate of EEM analysis was made possible by my new Fluorolog from Horiba that uses CCD detection (think digital camera), to collect a multispectral EEM in 20 SECONDS!! Compare this to the 18-30 minute EEMs collected conventionally on most other fluorometers, which adds up to ~7-8 DAYS to analyze 120 EEMs.
So, what will we do with all this free time? Probably not go to Disney Land, but instead we'll take advantage of this fast EEM capability to evaluate (1) time-sensitive samples (2) to address some questions about PARAFAC models that are only now practical with the capability to generate large datasets in a short amount of time (3) develop the EEM/PARAFAC approach to assess changes in water quality in "real time", among other pursuits.

Recent News

2009-11-30T12:38:00.000-08:00

November has been busy and rewarding.

George Dang, an MS student in my group, won a Gillings School of Global Public Health travel award. This award will help George collect samples from the Neuse River/Pamlico Sound Estuary, which is part of his MS thesis research on the relationships between dissolved organic matter (DOM) sources and water quality in this system. Congrats George!!
Rory Polera presented a poster of his research at the NC American Water Works Association annual meeting in Raleigh, NC, a pretty impressive accomplishment given that this is Rory's 1st semester in grad school!
We hosted applications specialists from Horiba Scienific who helped us learn some of the advanced capabilities of our new Fluorlog-321 instrument. The folks from Horiba also used our Fluorolog-321 to conduct demonstrations for various interested groups at UNC and beyond.

Reclaimed Water Song

2009-11-09T19:11:00.000-08:00

One bottle of water contains highly treated wastewater (reclaimed water) and the other contains drinking water (potable water). Can you tell them apart? We can! The fluorescent fingerprint of the two different water sources differs dramatically as Rory's research is demonstrating. If you don't know what reclaimed water is, let some school kids in Tuscon inform you through song. You can tell from this Ode to Reclaimed Water that water reuse is an important issue in Tuscon, Arizona.
We are testing the fluorescence approach to distinguish water sources in the new UNC reclaimed water system. UNC just won the 2009 Institution of the Year Award from the Water Reuse Association based on its new reclaimed water system. We are pretty happy to have such a nice system to test our approach in our own backyard here in Chapel Hill.

Evaluating our fluorometers

2009-11-07T10:30:00.000-08:00

Yesterday Katie and I did some tests to evaluate the performance of our new Fluorolog. This involved some "easy" number crunching. Our simple number crunching required extra attention to how we organized our data, mainly due to the different ways we can analyze sample fluorescence on the new instrument, depending on geometry or detector type (for simplicity). We analyzed the emission spectrum of quinine sulfate, a well characterized fluorophore (molecule that emits excess energy as light from its excited state). We compared our quinine sulfate emission spectrum to the emission spectrum of quinine sulfate as presented by the National Institute of Standards & Technology (NIST; specifically Velapoldi & Mielenz, 1980). The goal of this comparison is to see if our quinine sulfate spectrum overlaps perfectly with the NIST reference spectrum, generally following guidelines and recommendations in Cory et al. (L&O Methods, In Press). Typically, emission spectra collected on different instruments contain signal (intensity) that is a function of (1) the fluorophore studied (how it emits light as a function of wavelength) and (2) the response of the instrument (specific to each instrument and its components). As you can see from my illustration above, our quinine sulfate spectrum did not overlap well with the NIST reference spectrum until we removed the instrument-specific response.
Why is this important? Because we need to be able to compare our data to data collected on other instruments in different labs now and in the future. Removing instrument-specific response means that ideally, all signal is due only to the molecule(s) studied. If all labs remove instrument response, we can all confidently compare trends among labs and over time.

Fluorolog-321 has arrived

2009-11-05T20:29:00.000-08:00

A few weeks ago we received the Fluorolog-321 fluorometer from Horiba Scientific. Last week it was installed, and since then we have collected our first excitation emission matrices (EEMs) old school style with the PMT detector and also with the new CCD detector! The new CCD detector allows us to collect EEMs very quickly, from < 1 minute to ~ 2 minutes or so, depending on the paramaters used. In comparison, with similar analysis parameters on the PMT, collecting an EEM takes at least 18 minutes. Running faster scans means that we could generate enough data for a PARAFAC model (mathematical deconvolution of EEM dataset) in 1-2 days rather than the weeks or months it would take with the slower scans.
We can also do time-resolved fluorescence measurements with the fluorolog, and will be exploring this feature in the next few months.