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Quality Instrumentation for the Life Sciences


PP Systems offers webinars highlighting some of the important research our customers are performing. Please sign up below if a topic is of interest to you. Would you like to be notified of upcoming webinars? Simply provide your name and email below and we will be happy to notify you!

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Best Way to Perform Light Response Curves? The right protocol depends on the information you’re looking for!

The “best” way to acquire light response curves depends on the information you are trying to obtain. Complete curves can be accomplished with a little as two minutes between step changes in PPFD, but stomatal conductance values would not represent steady-state values, and sub-stomatal CO2 values would increase abnormally at low PPFDs. This may or may not present a problem, depending on the purpose of conducting the light curve.


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About James Bunce, PhD

Dr. James Bunce recently retired from the USDA-ARS in Beltsville Maryland after a 40-year career as an environmental plant physiologist. His more recent work involves predicting the impacts of global change on plant physiology. See more about Dr. Bunce below under his past webinars.

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Past Webinars

Small System Volume: Size Does Matter. | 09.16.20

Presented by Sinisha Ivans, PhD

What important factors should you consider when purchasing a leaf gas exchange system? Find out more about the popular CIRAS-3, the fastest, most accurate portable photosynthesis system on the market for high-level research.

About Sinisha Ivans

Sinisha Ivans is a Technical Sales Engineer at PP Systems, Inc. He provides high-level technical and application-related expertise and support to existing customers. He also focuses on establishing and building relationships with customers worldwide – helping them achieve their research needs. His research interests have included observing closed path systems across the Mountain West to determine water characteristics and CO2 fluxes of sagebrush, as predominant native vegetation of the region. He holds a Ph.D. in Civil and Environmental Engineering from Utah State University.

Red, Green & Blue: Misconceptions About the Photosynthetic Efficacy of Different Light Colors | 07.23.20

Presented by Marc van Iersel, PhD

Because of the relatively low leaf absorptance of green light, it is commonly believed to be inefficient in driving photosynthesis. Dr. Marc van Iersel, from the University of Georgia, will discuss how A/Ci and light-response curves were used to develop a more nuanced understanding of the interactive effects of light intensity and color with regard to photosynthesis.

About Dr. van Iersel

Dr. Marc van Iersel has been with the University of Georgia’s Department of Horticulture since 1995, where he now holds the Dooley professorship.

His research focuses on cost-effective supplemental lighting technologies in greenhouses and vertical farms.

He is the director of project LAMP, a $5M, US-based research project that brings together plant scientists, engineers, and economists to develop profitable supplemental lighting strategies.

In 2017, he co-founded Candidus, Inc. to help bring novel lighting strategies to the greenhouse industry.

Dr. van Iersel has published 130+ scientific papers and has given invited lectures about his research around the world, including in Italy, Spain, Taiwan, Kenya, Canada, Chile, and Brazil.

What, Why & How: A/Ci? | 06.24.20

Presented by James Bunce, PhD

Learn the purpose of performing non-steady-state A (Assimilation) vs. CI (Intercellular CO2) curves and how to perform and process them quickly.

About Dr. Bunce

Dr. James Bunce built his first photosynthesis system as a graduate student 48 years ago and has been performing leaf gas exchange measurements, including many A/Ci curves ever since. He recently retired from a 40-year career with the USDA-ARS in Beltsville Maryland as an environmental plant physiologist. His most recent work involves predicting impacts of global change on plant physiology.

Since his retirement, Jim has been working closely with PP Systems assisting in the development of rapid A/Ci analysis with the CIRAS-3. He has recently published two research papers utilizing that technology: Three Methods of Estimating Mesophyll Conductance Agree Regarding its CO2 Sensitivity in the Rubisco-Limited Ci Range and Variation in Responses of Photosynthesis and Apparent Rubisco Kinetics to Temperature in Three Soybean Cultivars.