2001 Image Contest Results
|Title: Nutrient Transport in Polyp Colonies
Submitted by: Rimas Surna, Ph.D
Kaunas University of Technology
||Congratulations to Dr. Surna for also winning Advanced Imaging Magazine's 2002 Solution of the Year Award for his polyp research.|
The polyp colony Hydractiniid hydroids is an ideal subject for studying nonlinear, dynamic, living systems. This model organism is easily maintained in laboratory culture, responds quickly and strongly to external stimulus, and is commonly used for immediate mutational and oncological indications. The challenge was to provide meaningful time and space variation measurements of the stolon tips to elucidate the behavior of the gastrointestinal system while monitoring colonies in real time.
Application TechniqueA series of images was acquired using the Data Translation DT3152 Framegrabber with Image-Pro Plus v4.1 software. Once the images were captured, the space representing the stolon lumen was manually outlined using Image-Pro Plus tools. A custom algorithm was written and used to trace the ectoderm and endoderm border automatically. An Image-Pro macro was created to produce lumen diameter measurements along the stolon tip in every frame. Within each frame, another macro calculated lumen volume along the stolon tip (a cross-section of the lumen was postulated round), velocity of two-directional pulsalite flow of the fluid in the lumen (with constant velocity across the lumen), and the optical density in the lumen.
The use of timed sequence files with image processing enhancement and additional highlighting of the borders as a movie provided extensive enrichment for qualitative interpretation. Nutrient particles were clearly evident and tracked. The measurements that were derived gave quantitative dimension in order to characterize colony-wide spatiotemporal dynamics of nutrient transport. These strongly nonlinear dynamic systems cannot be examined using more traditional analysis methods.
This research was supported under the joint grant awarded by the US National Research Council?s Twining Program. Dr. Surna would like to thank Professor Leo W. Buss of the Department of Ecology and Evolutionary Biology at Yale University and Professor Rimas Vaisnys of the Department of Electrical Engineering at Yale University for their support.
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