RGP - Extract Explore Magazine Volume 1 Issue 1


UF Orthodontists Study When To Treat Buck Teeth

When is the best time to get braces for ``buck teeth?'' Should children with this common problem be treated before their permanent teeth emerge, or is it better to wait until adolescence?

Orthodontists at the University of Florida College of Dentistry, with help from colleagues around the nation, hope to answer these questions as they begin the second phase of one of the nation's first federally funded orthodontic patient trials.

About 280 children are participating in the UF study, initially funded by a $900,000 grant from the National Institutes of Health in 1990. The second phase of the study, funded by a $1.1 million NIH grant, began this year.

Buck teeth, or receding chin, occurs in about one out of five children. For years, orthodontists have pursued one of two strategies in treating these children -- give no treatment until permanent teeth have emerged, usually at about 12-14 years of age, or treat in two phases: starting treatment before all permanent teeth erupt with a simple appliance to improve jaw growth, followed by the installation of full braces after all permanent teeth have erupted.

In the initial phase of UF's study, patients were randomly divided into three groups. One group used an appliance placed in the mouth that attaches to a neck band. The second group used an appliance that fits inside the mouth to guide the lower jaw into a forward position. A control group received periodic observation.

After three years of treatment or observation, the researchers made a videotape of parent and child interviews, as well as each child's face, teeth and dental records. Researchers sent copies of each child's tape to five randomly chosen orthodontists around the country, asking if the child needed treatment, if the treatment should be immediate and how difficult the case looked.

"America's orthodontists are voting on the outcome of early treatment as they score the videotapes," said Dr. Stephen Keeling, associate professor of orthodontics and principal investigator of the UF study. "If early treatment with bionators and head gear is beneficial, the treated children should be judged to require less and simpler treatment than the non-treated children."

Vicki Fooks

Crocodiles Rebound In South Florida

Endangered American crocodiles are on the rebound in southern Florida, according to a University of Florida researcher who is finding record numbers of crocodile nests, some in places where they haven't been found for nearly a century.

Record numbers of crocodile nests have been found this year in the Everglades National Park and at Florida Power and Light's Turkey Point Power Plant, said Frank Mazzotti, an assistant professor of wildlife ecology at UF's Institute of Food and Agricultural Sciences (IFAS). In addition, two crocodile nests were discovered on Cape Sable, the first time nests have been seen there since 1897. And, on Sanibel Island near Fort Myers, crocodile nests have been seen for the first time ever this year.

``What we are seeing is a marked success of crocodiles in Florida. This is an endangered species progress story,'' said Mazzotti, who works at IFAS' Broward County extension office in Davie. ``Over the last 15 years, the number of crocodiles found nesting has doubled. This nesting season is remarkable.''

Last April through August, Mazzotti and his colleagues searched known and potential nesting habitat looking for signs of crocodiles and nesting activity. Hatched eggshells or hatchlings served as evidence of thriving crocs. At Turkey Point, they found 17 nests and tagged 307 hatchlings. The previous record was 12 nests. In the Everglades, they found 21 nests.

By tagging young crocodiles, Mazzotti and his colleagues will be able to gauge long-term growth and survival rates. More than 700 crocodiles have been marked in the Everglades and more than 2,000 in south Florida, Mazzotti said.

Gray-green and "not at all cold or slimy to the touch," American crocodiles are much less aggressive than alligators, Mazzotti says. Still, he points out, "Crocs are the top predators in their system, like lions on the Serengeti."

Andrea Billups

Manure Recycling Is Olfactory Winner

A team of UF researchers has developed a process that eliminates the manure odors associated with dairy farms while recycling water, producing methane gas and maintaining the manure's fertilizer value.

"What is the cost of odor reduction?" asks Ann Wilkie, a research assistant professor in soil and water science at UF's Institute for Food and Agricultural Sciences. "It may be the cost of staying in business."

The most commonly used manure-management system in the newer dairies in Florida utilizes short-term holding ponds for flushed-manure wastewater storage, with subsequent pumping to sprayfields to supply fertilizer nutrients and irrigation water for production of forage crops.

Although effective for nutrient recycling, these systems can produce strong odors. Spreading of manure slurry on land is the single largest cause of complaints from the public.

Anaerobic digestion, a biological process in which complex organic compounds are decomposed by microorganisms in the absence of oxygen, offers a holistic solution.

When anaerobic digestion is used under controlled conditions, most of the digestible organic matter is biodegraded with a less-offensive effluent and energy byproduct, methane gas.

Using this concept, Wilkie and her graduate research assistants are developing an anaerobic digester, known as a fixed-bed reactor, for treating the dairy wastes. Unlike aerobic systems that require energy input, anaerobic treatment is energy producing.

The fixed-bed anaerobic reactor immobilizes bacteria on a matrix or medium within the reactor, thereby preventing washout of the microbial substance. Wastewater is passed through a column filled with packing, usually a honeycomb-like structure made of plastic or other material. The packing material acts as a surface for the attachment of microorganisms and also as a trap for unattached organisms. The end result is methane and carbon dioxide.

The fixed-bed anaerobic reactor is capable of treating larger volumes of wastewater than conventional systems. Where it would take conventional anaerobic digesters about 20 days to handle the waste, a fixed-bed reactor can often do the job in as little as two days. Thus the fixed-bed reactor is appropriate technology for Florida dairy farms, given the large amounts of water used.

Wilkie has been using four, 400-liter pilot plants, but is now building a full-scale plant at the IFAS Dairy Research Unit in Hague. The reactor is an 86,000-gallon steel tank, 25 feet in diameter and 23 feet tall. The plant is expected to handle the waste from a 350-cow operation.

Perhaps the biggest challenge involves the medium which makes up the honeycomb-like structure to which the bacteria cling. The problem is matching up the proper type of bacteria to the proper surface, explains Kelly J. Riedesel, one of Wilkie's graduate research assistants.

"That's where you make it work," she said. "If you don't get the cells attached, you can't treat the waste."

In addition to eliminating odor, the potential benefits from anaerobic digestion include improving water quality, improving handling and fertilizer value of the wastes and production of biogas for general farm use.

Farms, with their many pumps, fans and other devices driven by small motors, are a natural place for methane conversion and use. Methane generally is considered the second-most significant greenhouse gas, after carbon dioxide. Anaerobic digestion cuts uncontrolled methane release.

Then there is the conservation of water, a particularly precious resource in Florida. Water has numerous uses on a dairy farm, including cleaning and cooling.

Bruce Mastron

Researchers Seek Clues To Decline In Wading Birds

University of Florida researchers are working to ensure that wading birds continue to play a role in the natural charm of the Florida Everglades ecosystems.

Peter Frederick, assistant professor of wildlife ecology and conservation at UF's Institute of Food and Agricultural Sciences, said breeding populations of wading birds have been declining dramatically in the last 40 years. With funding from the Florida Department of Environmental Protection and the U.S. Fish and Wildlife Service, Frederick has been in south Florida researching the effects that contaminants, disease and water management may have on wading bird populations.

"We have seen wading bird populations decline by at least 90 percent over the last 40 years," Frederick said. "Because of a rich record of historical wading bird responses to natural events in the Everglades, we can begin understanding the effects that something like mercury can have on these populations."

Frederick has focused on the accumulation of mercury in wading birds and its possible role in their decline. Along with co-principal investigator Marilyn Spalding, assistant scientist in the Department of Pathobiology, Frederick is studying the most at-risk group for high mercury levels.

As top-level carnivores, Great Egrets accumulate mercury by eating fish that have the metal concentrated in their tissues.

"Most of the work done in the past concentrated on toxins and mortality level," Spalding said. "We believe it is important to concentrate on sub-lethal effects and the birds' health and survival."

Frederick, Spalding and two graduate students are examining the effects of mercury on Great Egret chicks, particularly on their appetite and survival. Mercury is thought to hinder the survival and growth of the birds and may contribute to the decline of the population.

They will monitor the chicks' survival through radio transmitters banded to the chicks' legs while they are still in the nest. When the chicks begin to hunt food for themselves, the transmitters will record their activity. If the transmitter's signal indicates a chick has not moved for more than 12 hours, the researchers will assume it is dead. It will be located and its tissues analyzed for any effects from mercury.

The water turnover and food intake of egret chicks is being monitored by way of radioisotopic tracers that are injected into each bird's leg. In addition, Frederick is comparing the effects of mercury on the birds' reproduction.

"Wading birds have declined 90 percent as breeding animals in the Everglades, and a large proportion of the birds out there are simply not breeding at all," Frederick said. "Mercury could play a big role in altering the ability of birds to court and come into reproductive condition."

Sylvia K. Beauchamp

Dwarf Horse Roamed Florida 18 Million Years Ago

An 18-million-year-old skeleton of a dog-sized horse -- the only one in existence -- is coming together at the University of Florida.

The dwarf horse, known as Archaeohippus, was about the size of a greyhound and weighed close to 50 pounds when it roamed Florida millions of years ago.

The skeleton of the Archaeohippus is the only one in existence and is a valuable addition to the Florida Museum of Natural History on the Gainesville campus, said Bruce MacFadden, paleontology curator. He also believes fossil horses are of prime importance in studying evolution.

"These horses from Florida allow us to better understand some of the principles of evolution that we teach in textbooks. This particular skeleton will be unique to science."

Lurel Ponjuan

Farmers Seek Success With ``Designer Fruits''

New "designer" tropical fruits may bring the sweet taste of success to south Florida farmers whose livelihood and lifestyle turned sour after thousands of acres of groves and farmland were devastated by Hurricane Andrew.

The 1992 storm tore through farming communities like Homestead, leaving behind damaged groves and family businesses. Recovery efforts in some areas included a shift in acreage from citrus groves and more traditional crops to more diverse operations, including tropical fruits.

With exotic-sounding names like mameysapote, passion fruit, papaya and guava, these new tropical fruits look as different as they sound. But they could provide an economic opportunity for hard-hit farmers and new, exciting tastes for consumers, say researchers at the University of Florida's Institute of Food and Agricultural Sciences (IFAS).

"One hundred years ago, the banana was a novelty fruit, so who knows," said Robert Degner, program director for marketing research at UF's food and resource economics department. "Now bananas are the most widely consumed fruit in the American diet."

But how many Floridians reared on oranges and grapefruits know how to prepare these different delicacies? IFAS researchers, along with growers and industry leaders, are studying both production methods and the marketing efforts of these fruits. The results should provide growers with information needed for maintaining and expanding this market opportunity and give consumers firsthand information about incorporating these tasty treats into their diets.

There are 11 primary crops now grown in the south Florida area, including lychee, mango, annona, longan and carambola, or "star fruit."

Funded by a grant through the Florida Department of Agriculture and Consumer Services and the Tropical Fruit Growers of South Florida, scientists at IFAS' Tropical Research and Education Center in Homestead are working on 12 research projects, including disease control of mango, lychee and carambola. Also three infrastructure improvement projects, such as a new 10-acre experimental grove of banana, lychee and carambola, are being established.

Sylvia K. Beauchamp

Chlorinated Compounds Target Of $2.6 Million Federal Study

Researchers at the University of Florida have launched a five-year project to study the effects of specific chemical compounds known to contaminate lakes and waterways in Florida and elsewhere in the country.

Funded by a $2.6 million grant from the National Institutes of Health, the UF group will evaluate the effects of chlorinated organic compounds resulting from the use of agricultural pesticides, industrial solvents and other widely used chemical products.

Principal investigator Margaret James, professor and chairman of medicinal chemistry in UF's College of Pharmacy, says the UF project is aimed at identifying potential health hazards posed by low-level exposure to chlorinated compounds.

"We would like to be able to reassure people about chemical contaminants that may not really be harmful," James said, "and to encourage clean-up operations for chemicals that do pose real health hazards."

She said the project includes four major components:

Morgan Marshall

UF Veterinarians To Study Drugs In Race Horses

A new study at the University of Florida College of Veterinary Medicine may help update drug-tolerance standards and ultimately benefit the horse racing industry.

"The ultimate objective of the study is to define threshold levels of commonly used medications, below which there is no effect on the horse," said Dr. Woody Asbury, Appleton Professor and chairman of the college's Department of Large Animal Clinical Sciences.

Funded by the state's Division of Pari-mutuel Wagering, the $530,000 project is a cooperative effort between UF's colleges of veterinary medicine and pharmacy.

Only three drugs -- Furosemide, Prednisolone Sodium Succinate and Phenylbutazone -- are legal for horses to have in their systems within specified levels on race day.

"In our laboratory we test random samples of blood and urine following a race, and sometimes we find prohibited substances in the specimens," said division director Deborah Miller. "According to the law, this evidence is sufficient to establish that the drug was carried in the animal while participating in the race. Whether the drug is administered on race day or not, when it shows up in the lab, the division has no choice but to call it positive on race day."

One reason why the horse racing industry now faces difficult interpretation issues with respect to drug levels is that laboratory detection methods have become more sophisticated over the years, resulting in smaller and smaller levels of medication being detected.

Further complicating the issue is the fact that standards are not uniform from state to state.

"No one will deny that you have to treat a horse when it's ill, but there's been a lot of confusion on the part of both industry regulators and veterinarians as to what effect these drugs have on a horse over time," Asbury said.

Using a state-of-the-art, high-speed treadmill, UF veterinarians began training 15 thoroughbred horses last April. The treadmill will provide for standardized exercise regimens and can be used to monitor various functions during exercise.

Once the horses reach the desired fitness level, investigators will use analyses of urine and blood to determine the rate at which certain therapeutic medications are eliminated. The tests will be performed at the division's laboratory in Tallahassee.

Sarah Carey

Research Funding Reaches Record $208.5 Million

Despite intense competition for fewer dollars, federal funding for University of Florida research projects increased 14 percent to more than $125 million during the 1994-95 fiscal year.

Overall, UF research funding from all sources increased 7.5 percent to a record $208.5 million, bolstered by dramatic increases in funding to the College of Engineering and the Health Science Center.

"It is a testament to the quality of our faculty's research that federal agencies are awarding them more money at a time when budgets are being tightened everywhere," said Karen A. Holbrook, UF's vice president for research.

The Department of Health & Human Services was by far UF's biggest sponsor, funding nearly 400 projects for $56 million, a 17.3 percent increase over 1993-94. The National Science Foundation (NSF) awarded another $13 million for more than 200 projects, up 10.3 percent over the previous year.

Several major grants stood out in 1994-95, including the NSF-sponsored Engineering Research Center for Particle Science & Technology, which accounted for $2 million of the College of Engineering's $9 million increase. The center is expected to attract $60 million in public and private funding over the 11-year life of the grant. UF's participation in a nationwide Women's Health Initiative accounted for $2.5 million of the College of Medicine's $6 million increase to $69 million.

UF also attracted more grants from private companies. This year's $20.5 million total represents a 7.4 percent increase over 1993-94. And although state support slipped by 13 percent, the state still awarded UF $34.6 million for research.

This year's figures represent a continuation of the upward trend in research funding at UF. Research awards have more than doubled in the past decade, from about $99 million in 1985-86.

Joseph Kays

NIH Awards $1.1 Million To Study Pediatric HIV

Two University of Florida researchers are trying to find out how the HIV virus is passed from mother to child and why only a small percentage of unborn children actually contract the virus.

Using a $1.1 million federal grant, researchers are beginning to unravel the complicated transmission of the virus that causes AIDS.

A central question in the study is why only 30 percent of the infected mothers transfer the disease to their unborn children. The answer could be a major breakthrough in preventing the disease, especially in Florida, where one in every 213 women is HIV positive. Currently, AIDS is the third leading cause of death in women of reproductive age in Florida.

"We want to find out why the other 70 percent of infected mothers do not transmit the virus to their infants," said Dr. Maureen Goodenow, associate professor of pathology and pediatrics at UF's College of Medicine. Goodenow is the principal investigator of a four-year grant awarded by the National Institute of Child Health and Human Development.

Goodenow and her collaborator, Dr. John Sleasman, chief of the division of immunology and allergy, are seeking to determine how babies are infected through maternal transmission.

Pediatric HIV provides a unique opportunity to study the initial stages of HIV infection because babies have been infected for such a short time, said Sleasman, who directs the Pediatric HIV Clinic at UF.

"By understanding what happens in the early phases of infection, we might be able to come up with strategies for drug therapies or vaccines to block infection," he said.

Goodenow and Sleasman already have studied 80 mother-infant pairs. They will continue to track 30 pairs each year for the next four years.

HIV primarily targets a white blood cell known as the CD-4 T-lymphocyte. Other cells in the immune system also express CD-4 -- a molecular marker appearing on a cell's surface that helps define its function. Researchers want to find out which cells with the marker are actually infected, and whether that infection is chronic or short-term.

"The question we're interested in is which blood cells are actually infected by HIV," Goodenow said. "Not all CD-4 positive cells are infected by the virus and the question is why is that?"

Melanie Fridl Ross

Engineers Look To Space For Future Semiconductors

To develop the next generation of computer semiconductors, University of Florida researchers are turning toward space.

UF researchers on the ground will team with NASA astronauts on a series of experiments aboard a space shuttle mission this spring.

It will be the second shuttle flight mission for the project, with the first occurring two years ago. With help from the astronauts, researchers from UF, Canada and Germany will grow crystals of two synthetic compounds to learn how they may be more easily produced on earth.

The project, now in its fifth year, is being led by Reza Abbaschian, chairman of UF's materials science & engineering department. A series of 12 experiments will be conducted aboard SPACEHAB, laboratory modules that fly in the shuttle cargo bay. Funding comes from NASA and industrial partners in the United States, Canada and Germany.

Researchers at UF will be keeping an eye on the experiments through a video down-link, and will be able to make changes to the experiment's parameters through Mission Control at the Johnson Space Center.

The experiments involve crystals of gallium arsenide and gallium antimonide, which are being grown in space to avoid problems caused by gravity. On the initial flight two years ago, researchers proved their technology grew nearly perfect crystals of another compound in space. Now, using that same technique, researchers will attempt to grow gallium arsenide, a synthetic compound used as a semiconducting material, which is capable of doing calculations thousands of times faster than the silicon chips commonly found in today's computers. Because it is much more expensive than silicon, however, gallium arsenide hasn't made its way into most computers and other electronics applications. The other compound to be tested is gallium antimonide, which is used for infrared detectors, optical windows and other purposes.

Growing the two compounds on Earth is more difficult and more expensive than growing silicon. Scientists hope to understand what causes the quality differences between the crystals grown on Earth and in space, so that technology on the ground can be improved.

Mission specialist astronaut Marc Garneau said the training he and fellow astronaut Andrew Thomas received at UF will help them handle any surprises when they get into space.

James Hellegaard

Chemical Birthright

A new documentary featuring University of Florida researchers looks at the controversy over chemicals known as estrogen mimickers, which many scientists contend mimic the body's natural estrogen in ways that cause serious reproductive consequences.

Common pesticides used commercially and in the home, as well as some cleaning agents and industrial compounds, are among the chemicals at the center of the furor. While the effects of estrogen mimickers on humans has yet to be established, a growing number of researchers point to problems in wildlife and laboratory animals and trends in human epidemiology as evidence of a real threat.

UF reproductive endocrinologist Louis Guillette has studied reproductive problems in alligators in several Florida Lakes. His latest findings suggest many of the problems are due to exposure to chemicals in agricultural and urban runoff.

Produced by Cari Brunelle and Brad Wasson of UF's News & Public Affairs office, "Chemical Birthright" debuted on UF's public television station, WUFT, on Feb. 27. It is expected to appear on PBS stations around the state over the next several months. Check local listings for date and time.

Computer Model Aids Everglades Restoration

It has been choked, drowned, burned and slowly killed by years of pollution. And while the river of grass known as the Florida Everglades has somehow survived this terrific onslaught, its unique complexity continues to puzzle those who seek to restore its previously thriving beauty.

Now a pioneering study seeks to provide answers to the multi-billion dollar question of how best to save one of nature's last frontiers.

A few hundred miles north of the Everglades in Gainesville, a University of Florida engineering professor and a visiting wildlife ecologist are teaming with other scientists to create a computer model that could give planners the power to predict the future.

Knowledge gained from years of work by scientists who have studied the Everglades will be integrated into a single ecosystem model by Paul Fishwick, an associate professor in UF's Department of Computer and Information Sciences, and James Sanderson, a visiting scientist in wildlife ecology and conservation. By doing so, they are creating a computer model, known as ATLSS, which may provide the key to determining whether efforts to save the Everglades will actually work.

Among the federal agencies funding the ATLSS project are the National Biological Service, the Environmental Protection Agency, the Army Corps of Engineers, the National Park Service and the Fish and Wildlife Service.

The model will integrate various other models done by researchers studying every living thing from the smallest organisms and fish to wading birds, deer and alligators. The Everglades will be broken down into 100-meter cells for the ATLSS project, far more detailed than any computer simulation ever attempted.

James Hellegaard