Reports from the 2004 Undergraduate Exhibition
Call of the Birds
"Chip-uppity, swee-ditchety!" Out of the rhododendron thicket comes the sound of a Canada warbler, piercing through the bubbling noise of a brook nearby. "Veeeer-veeer-veer-veer-veveveer" comes the descending spiral of a veery's song. An ovenbird joins in with an accelerating progression, from whisper to shout, "teacher-Teacher-TEACHer-TEACHER-TEACH!" With a little practice, it is much faster and easier to identify a bird by ear than to spot it hiding in the brush.
In central Pennsylvania, finding these songbirds all in one place is a sign of a healthy forest along a clean headwater stream, an area where brook trout swim in tiny creeks and bear and turkey cruise the surrounding hills. Penn's Woods also support a significant proportion of the world's scarlet tanagers, worm-eating warblers, and wood thrushes. Like the birds mentioned above, these species depend on a relatively undisturbed ecosystem for successful nesting. Since that typically means a mature forest, it is no coincidence that these same sites also support higher populations of native wildflowers and amphibians, and are associated with high water quality.
Blue Jay Photo by Howard Nuernberger
Follow a stream downhill, and it will usually pop out into a valley, and civilization. Here, the big contiguous forests of the mountains are replaced by a hodgepodge of land uses, from small woodlots and housing developments to corn fields and pastures. The bird communities change as well, since many species that live only in the depths of the forest are replaced by the birds of the brushy edges: cardinals and song sparrows, catbirds and titmice. The birds of the interior disappear from even the most pristine woodlots if they are too near a forest edge. Perhaps that's because edge habitats get more sunlight, which means plants grow faster, and more insects hatch. In turn, more competitive birds move in to nest, and subsequently the areas are targeted by more nest predators, from crows and blue jays to cats and raccoons.
Eventually, most streams reach a point where they are completely surrounded by a town, croplands, or a barnyard - perfect habitats for birds that have been adapting side-by-side with human agriculture and villages for thousands of years, including house sparrows, European starlings, and pigeons. These species tend to indicate the opposite of the warbler and thrush-filled forests, being most common in areas with highly fragmented or completely disturbed vegetation, very few native amphibians and wildflowers, and lots of sediment runoff into streams and rivers after every rain.
In 2000, using this correlation between birds and the landscape, Tim O'Connell, then a postdoc working at Penn State's Cooperative Wetlands Center, developed a system to quantify the "biological integrity" of a site based upon the bird species living there. Counting birds has long been my favorite hobby, and when I started taking classes at Penn State and found out about O'Connell's Bird Community Index, I saw an opportunity to turn my pleasure pursuit into scientific research. In hopes of doing a fun project over the summer, I applied for a small grant to assess the integrity of the streamside ecosystems in eastern Centre County based upon the birds living there. A local conservation group had already received a state grant for a study of the stream quality in the Upper Penns Creek Watershed, which analyzed both physical stream habitat and water quality, the latter based upon the populations of mayflies, stoneflies, and other insects living in the streams. I visited the same sites, recorded the birds I found, and analyzed my results with the Bird Community Index. Then I tested how well my results matched up with physical habitat and water quality. I was surprised to find that in the fourteen sites I examined, there was a strong correlation between bird scores and the diversity of aquatic insects. I'm in the process of looking at more sites, but these first findings suggest that indexing bird communities may do more than predict features of the terrestrial landscape. The presence or absence of certain birds may indicate the health of aquatic ecosystems as well.
Joseph Gyekis is a sophomore majoring in life sciences with honors in geography in the Eberly College of Science and the Schreyer Honors College. At the 2004 Undergraduate Exhibition, Gyekis was awarded first prize in the health and life sciences division and first prize in public scholarship for his project titled, "Bird Communities and Water Quality in the Upper Penns Creek Watershed of Central Pennsylvania." He also took the Gerard A. Hauser prize for best presentation of undergraduate research. Gyekis has worked as an intern for Research/Penn State since January 2004 and can be reached at jgyekis@psu.edu. His adviser for the project was Chris Uhl, Ph.D., professor of biology; cfu1@psu.edu.
Divorced kids don't rock the vote
When it comes to voting among youth, does divorce matter? Julianna Sandell (political science) reports that young people ages 18 to 24 who grew up in divorced families participate in the political process less than those who grew up in nuclear two-parent households. Sandell used data from the National Education Longitudinal Study, a survey of a nationally representative sample of 8th graders and their parents, teachers, and school administrators. The survey began in 1988, and included a series of follow-ups as the students moved through high school into young adulthood.
The turtles of Wekina Springs
Good news: the redbelly, stinkpot, peninsula cooter, and loggerhead musk turtles, all Florida natives, are alive and well in the lagoons of Wekina Springs State Park. Gabrielle Hrycyshya (biology) was part of a research group that collected and analyzed data for a study of these aquatic turtle species. A team of Penn State students captured and tagged the turtles, and recorded the species, sex, and size of each before releasing them. They turtles were recaptured and remeasured over a five-year period. The researchers will continue to monitor the turtles' health and track changes in the species' populations.
Tomatoes to the rescue
Lycopene - the pigment that gives tomatoes their rich, red color - could be a cancer-fighter. Holly Hantz (nutrition) and graduate student Leanne Young grew human prostrate cancer cells in flasks in the lab. The addition of lycopene to the flasks induced apoptosis, or cell death, in the cancer cells. Their conclusion, in short: diets rich in tomatoes and tomato-based foods can lower the risk of prostrate cancer. "I like the idea that you can affect your health by what you eat, instead of just popping pills," says Hantz.
What's in horse spit?
Kristin Jury (animal bioscience) took the initiative to do the research physicians and veterinarians have been requesting for years - an analysis of the types of bacteria that live in a horse's mouth. Jury sampled saliva from stallions, mares, and foals from Penn State's agricultural research farms. She placed drops of saliva from each horse on a growth medium, and allowed the bacteria in each sample to proliferate. After isolating and identifying many species of bacteria, she tested their susceptibility to a variety of antibiotics. While most species were wiped out, a few of the bacteria showed resistance to even the strongest antibiotics on the market. In addition to raising concern about bacterial resistance to antibiotics, Jury's work provides important background information for equine dentists and health care professionals, who may now use this information to effectively treat and prevent infections arising from horse bite wounds.
Chipmunk ears
Joseph Orkin (anthropology) and Kelli Welker (psychology) studied the inner ears of chipmunks, comparing the sizes of a bone no larger than an orange seed. The inner ear bone is vital to sensing gravity, keeping balance, and preventing vertigo. Orkin and Welker wanted to find out how much the size of this bone correlated with the age, weight, and height of chipmunks. They found out that the structure quickly grew to adult size in juvenile chipmunks, giving the animals the full capability for rapid movement early in life. Furthermore, most chipmunks, male or female, heavy or light, tall or short, had almost exactly the same size of inner ear, suggesting that it develops independently of other anatomical characteristics.
Exercising immunity
Natalie Hutnick (biochemistry and molecular biology) studied the concentration of antibodies in the blood of two groups of cancer patients - one involved in regular exercise, the other not. Higher levels of IFN-gamma, a molecule that indicates activity in the part of the immune system that fights cancer cells, were present in the exercise group. Over time, exercise also seemed to lower the patients' levels of Interleukin-6, a measure of inflammation in the body.
Redesigning a voice
Some of the "talking machines" used by people with speech disabilities are "about as personalized and interesting as a generic keyboard," says Jennifer Curran (speech pathology). Curran invited a group of fourth-graders to design communications aids that kindergartens who need help with their speech might like to use. The fourth-graders suggested that the machines should take on a whole new look, with personalized backgrounds and a symbolic entry system to replace the keyboard. They also suggested adding a host of big, colorful buttons that speak of emotions (happy, mad, sad), bare necessities (bathroom, food), and entertainment (music, crafts, and recorded soliloquies). Their design gave the machine a whole new purpose - not just to serve as a tool to communicate phrases, but to become a joy in life and an extension of the child's interests and needs.
The importance of iron
The offspring of iron-deficient mothers are at risk for stunted growth and cognitive impairment. Tessy Paul (premedicine) studied the early development of rats born of mothers with an iron deficiency. Paul put the rat pups through a series of tests, such as hanging on a bar, turning around and crawling uphill after being placed on a slope with their heads pointing downward, and rolling back onto their feet after being laid flat on their backs. In many cases, the iron-deficient pups were not as adept as normal rat pups. Once started on a diet that contained adequate iron, the once-deprived pups were able to restore their internal iron levels and catch up on most developmental milestones within a few weeks, Paul reports, but some effects appeared to be irreversible. Overall, her work suggests that iron supplements soon after birth might aid development.
Calories for cows
During and after pregnancy, cows' bodies are under a lot of stress. "There's a negative energy balance," says Stacey Ward (animal bioscience). "This can lead to a decrease in milk production." It can also cause ketosis, abnormally high levels of fatty acids called ketones in the bloodstream. Ketones are made when the body breaks down fat as fuel because there isn't enough glucose available. "This is what happens to people who are on the Atkins diet," Ward explains. A build-up of fatty acids can also lead to fatty liver disease.
The solution? Energy supplements before, during, and after pregnancy. "We were testing the effectiveness of an energy supplement called propylene glycol," says Ward. "Cows don't always like what's good for them," says Ward. "It doesn't taste very good so we had to mix it with cookie meal. Candy works, too. Cows like candy."
Ward monitored the health of the cows, gathering urine, blood, and milk samples. "I had to be at the dairy barns by 5 in the morning to get the milk samples," she says. Ward and fellow researchers found that the energy supplement helped to increase the cow's caloric intake, decrease the ketone bodies in their bloodstreams, and increase their milk yield.