March 18, 2014
Deer Hunting Science May One Day Help Diabetics
April Flowers for redOrbit.com - Your Universe Online
A deer hunter's worst enemy is body odor because it alerts prey animals that a predator is near. The science behind suppressing body odor to give hunters an edge, however, could help researchers develop a life-saving device for diabetes patients, according to a study presented at the 247th National Meeting & Exposition of the American Chemical Society (ACS) this week.
"The scent of a single person is a complex mixture of hundreds of compounds given off by bacteria, which live in our bodies and on our skin," said Shamitha Dissanayake, a Mississippi State University graduate student who gave the presentation. The human body itself also creates scent compounds that are emitted through the skin and breath when it breaks down molecules to make energy.
The scent compounds, called volatile organic compounds (VOCs), evaporate easily in the air. Dissanayake worked with Todd Mlsna, PhD — Associate Professor of Analytical Chemistry and head of the laboratory — to figure out the best way to collect and analyze VOCs from body and breath odor.
The final goal of Dissanayake and Mlsna's research is to use VOC detection for monitoring and diagnosing diseases. Their expertise, however, led to a unique collaboration with Bronson Strickland, PhD, MSU Associate Extension Professor in Wildlife Ecology and Management.
"The hunting community, the deer hunters in this case, are always looking for ways to beat the deer, so to speak, in terms of scent control," Strickland said. "A deer's sense of smell, like a dog's, can be anywhere from five hundred to a thousand times more acute than a human's."
The researchers say that figuring out which specific ingredients of body odor spook deer is challenging for several reasons. Every person gives off a unique scent, and that scent can vary depending on what food and drink they ingest, and how they exercise and rest. They collected body odor samples from 65 subjects to begin addressing these challenges. Over a four hour test period, the participants wore either an untreated T-shirt, or a T-shirt treated with a commercial spray designed to eliminate or mask a hunter's body odor. Eliminating body odor was once achieved with natural products such as skunk urine. For this experiment, the researchers chose four products out of dozens on the market.
"It was a big challenge to handle such a complex data set with so many variables," he said.
A mathematician was recruited to tailor a data-crunching program for the study's needs. This analysis showed that the sprays worked by greatly reducing the levels of 29 key compounds, either by killing the responsible bacteria, binding to the chemicals or converting them into less volatile compounds. The research will continue by seeing how deer react to each of these 29 candidates.
The team found that the techniques and analytical instruments they used to investigate deer-alerting odors overlapped significantly with their methods in another area of the lab's research: diabetes alert dogs.
Type 1 diabetes, also known as juvenile diabetes, is a condition in which the body does not produce insulin, with an estimated 3 million affected in the US. As a patient's blood sugar rises or falls, they emit a different set of VOCs in their breath, which animal trainers have taught dogs to smell. Such changes can cause a number of symptoms including seizures. Some patients have already been saved hundreds of visits to the hospital by the keen sense of smell dogs possess. Such dogs are expensive, however. They require a lot of care, and they can become fatigued. The researchers hope to translate their work into a portable electronic nose to do the work of the dogs', without rest.
"It's exciting to work in this field," Mlsna said. "We now have the combination of the analytical power and the computing power to really make sense of all these complicated data."