Crash Anatomy Course
“I was dissecting crab legs, isolating the joint,” Mia remembers. “This particular morning I’d finally figured out how to do it without breaking the surrounding shell, and I began examining the joint structure under the microscope.”
Mia discovered that crabs have a system of what look and behave like struts in their joints, reducing the concentration of pressure by disseminating it throughout the exoskeleton.
That’s when things took an unexpected turn. “The joint was far more intricate than depicted in research papers. I’d researched the topic extensively,” she says. And so she asked Cullinane to come take a look. “I didn’t truly realize we’d found something new until Dr. C smiled, flipped through some of the scientific journals I had shown him, and told me we now had a topic for my research project. I was happy, but I didn’t realize the importance of what had just happened, or where it would lead us.” But Cullinane, who had been accustomed to teaching at the medical school level, did.
Crash anatomy course: We vertebrates, with our internal skeletal structure, have a vast network of load-distributing bones. Invertebrates lack this; arthropods, in particular, are dependent on the external cuticle and “outpocketings” to bear the stress of everyday wear and tear. What Mia discovered, and shared with readers of the May 2010 issue of Arthropod Structure & Development, is that crabs (and probably other related species as well) actually have a stress-distribution system of their own—a system of what look and behave like struts in their joints, reducing the concentration of pressure by disseminating it throughout the exoskeleton.
“Think of the ceiling of a cathedral,” Cullinane explains. “Think of the buttresses bearing the weight of the cathedral ceiling. They’re like struts—what you find within the human femur. Or, for that matter, under the chassis of your car.”
But they couldn’t be sure, not yet, how the structure worked. In order to examine it properly, Cullinane knew they needed finite element modeling capability—which engineering professor Ian Grosse, at the nearby University of Massachusetts, Amherst, could provide. Finite element modeling is a numerical technique that allows for detailed computer imaging of how structures move, revealing stress distribution and displacement that would not be obvious to the naked eye. The methodology has commonly been used in engineering; cutting-edge biologists are increasingly using it as well.
Using finite element modeling capability, Mia analyzed the crabs' stress-distribution system.
Grosse and Cullinane had never met, but their shared passion for this type of research made them natural collaborators. “I’m always interested in applying finite element analysis to new material,” Grosse said. He welcomed Mia and Cullinane into his lab, and even took it upon himself to explain to Mia the (very high-level) math behind their findings. “I was glad of that,” Cullinane happily admits. “That’s not my background.”
A High Premium on Time
After the excitement of that project, Grosse is onboard to collaborate with BIO 400 students in their next projects, and thanks to Deerfield’s close proximity to UMass and the other “Five Colleges,” Professor Grosse is happy to make the short trip to the Deerfield campus. “We have finite modeling capability here, now,” Cullinane points out. “But Professor Grosse still brings his expertise.”
Why does he bother? “Because it’s fun, of course,” laughs Grosse. “I mean, I have plenty of work to do at UMass, but seeing this methodology—that I’ve dedicated my life to—being used at the high school level? It requires special students, but this proves that with the right mentoring from teachers, this technology can become part of a high school curriculum.”
The facilities in the Koch Center don’t hurt, either. “Are you kidding me? They’re fantastic,” Grosse exclaims. “Any college would be delighted to have labs like those. I’m not sacrificing a thing when I go over there to work.”