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A stormy past warns that Florida may be in store for more destructive hurricanes if scientists are right about the threat of global warming, new University of Florida research suggests.
Nearly 1,700 years ago, devastating tempests associated with sea-level rise destroyed villages of the Calusa Indians on the southwest Florida coast, near present-day Fort Myers, forcing the native fishermen to move inland to relative safety, said UF anthropologist Karen Walker.
Walker's clues to storms, sea-level rise and migration include village remains buried by storm-surge sediment, and other village deposits found at higher elevations than where they should be. In addition, the modest shells and fishbones left behind by the Indians, she said, show ecological correlations between rising sea levels and global warming periods documented in the historical record of ancient Europe.
"I think it may be a coincidence that there were major storms recorded at some of the archaeological sites that I study and that those storms happened during the warm Roman Optimum period," Walker said.
A variety of evidence points to a global episode of warming, dubbed the Roman Optimum, which occurred roughly between 200 B.C. and about A.D. 400, and a later episode, the Medieval Optimum, which took place from about A.D. 800 to A.D. 1200.
"By studying many archaeological deposits from many locations, I see a picture showing that sea-level fluctuations in Florida correlate to these climate fluctuations known from European history," she said.
Walker did her research over the past 10 years on Pine Island, Sanibel Island and other smaller islands. To document rising and falling waters, she studied radiocarbon dates, shells and fish bones, inundation deposits, elevations and other evidence.
Among the evidence, mollusk shells indicate changes in water salinity patterns, with more salty waters during sea-level rises and decreased saltiness during lowerings, she said.
A combination of storm and sea-level rise deposits overlie earlier village layers and underlie later village layers. Walker believes changes in patterns of the Indians' villages also reflect climate and sea-level change. During the Roman warming and sea-level rise, people moved their homes inland to higher ground. When climate cooled and sea level dropped, villages were built along the new, lower shoreline.
But by A.D. 800, when the Medieval warming began and sea level rose, the Calusas built massive shell mounds, suggesting they tried to get above the flood threat. "There may be other, cultural reasons why they started living on top of these huge shell mounds, but I think it's too much of a coincidence that it happens at this same time," she said.
Karen Walker, kwalker@flmnh.ufl.edu
Cathy Keen
UF Research Shows Zinc Triggers Body's Defenses
A new University of Florida study offers new evidence that zinc - the latest rage in cold remedies - may provide immediate protection against disease.
"We were startled that the response in people was so dramatic and so rapid," said Robert J. Cousins, the Boston Family professor of human nutrition in UF's Institute of Food and Agricultural Sciences. "It was amazing that the levels of the genetic material we were studying went up after only one day on zinc supplements.
"This result suggests that part of the body's protective system is very sensitive to zinc. Although more research is needed, our findings are a major step toward proving that zinc supplements can help fight infections and protect people against stress."
Cousins worked with former UF doctoral student Vicki Sullivan on the research, which was published in the Journal of Nutrition last April.
In the study, 12 men took 50-milligram zinc tablets - the typical strength available in supplements - every day for 18 days, and another 12 took a placebo. The participants' blood was drawn daily and analyzed for its ribonucleic acid, or RNA, the genetic code that tells cells to produce specific proteins.
The researchers focused on RNA that signals the body to produce a protein called metallothionein. The RNA rose the first day after participants took zinc and remained at least three times higher than it was before the study began.
The RNA levels dropped off immediately after the participants stopped taking zinc. "The body metabolizes zinc very rapidly," Cousins said. "It doesn't hold much useful zinc in reserve."
Zinc turns on metallothionein's ability to provide protection against infections, toxic chemicals and other stressors, according to earlier tests Cousins and other researchers conducted on animals.
"Our laboratory is trying to develop a sound scientific basis for saying that zinc has health benefits," said Cousins, whose research is supported by the National Institutes of Health.
Robert Cousins, cousins@gnv.ifas.ufl.edu
Chris Eversole
UF Chemists Join NASA's Astrobiology Institute
Traditional science fiction has aliens who speak some form of English or resemble humans. The problem is, chances are slim that non-terrestrial life will have such traits.
Chemists at the University of Florida hope to overcome that obstacle by figuring out what alien life might look like.
"We cannot expect the future of space exploration to be like that in Star Trek, where the aliens almost always resemble human actors," said Steven Benner, chemistry professor at UF and the principal investigator for the new Astrobiology Institute funded by NASA. "This makes it difficult to know how to recognize non-terrestrial life."
NASA and UF have teamed up with institutions such as Harvard University and UCLA to form a virtual Astrobiology Institute to study the origin and evolution of life in the galaxy.
Benner and his UF colleagues are looking for a universal feature in genetic material that also may be found in potential Martian life. Benner said DNA has evenly spaced, repeating negative electrical charges along it. These repelling charges allow the DNA molecule to be copied, an essential process in genetics. These charges could be a "universal" trait.
"While the rest of the genetic molecule will vary from life form to life form and from planet to planet," Benner said, "they will, we expect, all have the repeating, spaced electrical charges."
Benner is a member of the Mars Architecture Definition Team working at the Jet Propulsion Laboratory in Pasadena, Calif., to design a vehicle to go to Mars, collect samples and return to Earth.
Steven Benner, benner@chem.ufl.edu
Kristen Vecellio
Missing Bacterium Linked To Kidney Stones
Cystic fibrosis patients who lack a beneficial intestinal bacterium have a greatly increased likelihood of developing a condition that can lead to kidney stones, and extensive use of antibiotics may be to blame, University of Florida researchers reported in the scientific journal The Lancet.
The study is one of the first to directly link an absence of the organism, known as Oxalobacter formigenes, to the formation of the painful crystals.
Cystic fibrosis, one of the most common genetic diseases among Caucasians, afflicts about 1 in 3,200 people born each year in the United States. The so-called "thief of breath" slowly destroys patients' lungs through recurrent infections and often affects other vital organs. While kidney function is not greatly altered in these patients, kidney stones are an increasingly common complication as the life expectancy of these patients increases.
"Our study shows that cystic fibrosis patients, in general, have a very, very low frequency of colonization with this intestinal bacteria," said Ammon Peck, a professor of pathology at UF's College of Medicine. UF researchers collaborated with scientists from Alachua, Fla.-based Ixion Biotechnology Inc., Northwestern University, the University of Bonn and two German hospitals.
Of the 43 cystic fibrosis patients UF researchers studied, 19 produced too much oxalate, and all 19 lacked the bacterium, Peck said. In contrast, the few patients who were colonized - even with low levels of the organism - had normal oxalate levels. The study participants, all residing in Germany and ranging in age from 3 to 39, had cystic fibrosis and showed no signs of an intestinal malabsorption problem. Their results were compared with findings from 21 healthy volunteers ages 4 to 44.
Oxalobacter formigenes appears to break down calcium oxalate before it can form crystals that evolve into kidney stones, he said. Oxalate is found in high concentrations in many foods, including asparagus, tea, broccoli, peanut butter, spinach and chocolate.
When oxalate levels are kept low, it is easier for the body to excrete the substance through the kidneys. But if there is more oxalate than can be dissolved in the urine, the crystals settle out and form stones.
Peck and his colleagues suspect prolonged antibiotic use and other high-dose drug regimens may preclude natural colonization with the organism, or may irreversibly destroy the colonies.
Researchers reviewed study participants' medical records and discovered that, among the patients, 29 different antibiotic regimens had been used, and many patients were likely to be on other medications as well. Only one patient had not been treated with antibiotics - the only person who tested strongly positive for O. formigenes.
UF researchers recently received a $1 million grant from the National Institutes of Health to continue their study of O. formigenes, including whether kidney stones can be prevented in laboratory rats by replenishing the bacterium.
Ammon Peck, peck.pathology@mail.health.ufl.edu
Melanie Fridl Ross
Researchers Evalute Youth Smoking Habits
Fewer than a third of those who know about the state's new Truth youth anti-smoking campaign think it will cause youth smoking to decline, according to research by UF's Communications Research Center.
The Florida Department of Health awarded the center, part of UF's College of Journalism and Communications, $286,672 from the state's $11.3 billion tobacco settlement to conduct a three-pronged evaluation of the state's smoking habits and tobacco-promotion activities.
"We're very interested in what's going on in retail sales of tobacco, from stores and pricing strategy to targeting of ethnic groups," said center director Mary Ann Ferguson.
Three surveys tracked public attitudes on the tobacco industry and the Truth youth anti-smoking campaign.
The June survey found only 23 percent of adult Floridians smoke, but 53 percent have smoked at least five packs of cigarettes in a lifetime.
A majority, 58 percent, of the respondents felt tobacco companies have tried to mislead youth to get them to purchase their product, and three-fourths of the respondents agreed that "in spite of what they say, tobacco companies use advertising to attract young people."
The same survey also measured awareness of the new Truth anti-smoking campaign targeted at youth. Forty-four percent of the survey respondents were aware of the campaign, and 63 percent of those respondents like the campaign in general - with 73 percent of those same respondents liking the intent and tone of the campaign.
The second prong of the evaluation targeted tobacco sponsorship of events that attract school-age children. Six counties - Duval, Gadsden, Miami-Dade, Hendry, Brevard and Citrus - were chosen based on the demographics of their school districts: either rural or urban black, white or Hispanic.
Researchers monitored the prevalence and availability of tobacco at 174 events in these counties. The events included motor sports, music festivals, fairs and sporting events; events held at sports bars were most likely to have tobacco present.
Although only 24 events had tobacco products for sale, 62.5 percent of those events did not have readily observed regulatory or warning signs regarding tobacco sales to minors, as required by state law.
The final thrust of the research looked at tobacco advertising patterns in five types of Florida stores: gas station/convenience stores, convenience stores, drug stores, grocery stores and gas stations. Each of the 303 stores surveyed was analyzed for the presence of exterior and interior advertisements and marketing themes.
"It's quite informative to actually visit these stores," Ferguson said. "Ads covered whole buildings, fences, gas pumps, sidewalks and shopping baskets."
In 20 percent of the stores, researchers did not see regulatory signs, and signs regarding smoking risks were found in only 40 percent of the stores.
Ferguson said these study results have been presented to the Florida Pilot Program on Tobacco Control so they can re-evaluate their youth anti-smoking campaigns and mold them to combat tobacco advertising even better.
Mary Ann Ferguson, mafergus@jou.ufl.edu
Kristen Vecellio
Batter Up! Don't Blink
When Tampa Bay Devil Rays outfielder Rich Butler steps to the plate, he's waiting for the type of pitch he hits best.
"I'm always looking for a fastball," he said. "You have to. If you're expecting a fastball, you have time to adjust to a curve ball, but if you're waiting for a curve ball and the pitch is a fastball, there's no way you can hit it."
University of Florida researchers can explain why.
A team headed by Robert Singer, chairman of UF's Department of Exercise and Sport Sciences, has proved for the first time scientifically that hitters' reactions to curve balls are significantly slower than their reactions to fastballs.
"The mental activity is greater for a curve ball," Singer said. "A fastball is coming faster and you can see its path. It takes more pattern recognition to see if a curve is breaking. In terms of processing, there is a 150-millisecond difference."
In a game where fractions of a second count, the time lapse is a big one, he said.
"The fact of the matter is, at 60 feet 6 inches, a ball thrown at 90 mph takes less than half a second to cross the plate," he said. "You're talking about having less than 0.48 seconds to decide what it is, if you want to hit it and when it will cross the plate."
Singer measured the brain activities of five former collegiate baseball players while they watched videotaped pitches thrown by a collegiate pitcher. Fastballs and curve balls were randomly mixed up in each video sequence, and the participants were instructed to react to the pitch by pushing one button for a curve ball and another for a fastball.
The varying angles and speeds of the curve ball require more time for recognition than the fastball, which causes the difference in reaction times, Singer said.
"You don't have a lot of time if you're a batter," he said. "You need to pick up more information than just the fact that the ball is being thrown."
That's why mental preparation is so important in the game of baseball, Singer said. The more quickly a batter can determine the nature of the pitch, the more time he or she has to react and decide how to swing.
The key to being a better batter, Singer said, is to determine the type of pitch as quickly as possible but wait until the last possible millisecond to react. The closer a batter can come to narrowing the reaction time between a fastball and a curve ball, the better chance he or she will have of hitting the ball.
"The angles of a curve ball make it hard to determine where the ball will cross the plate, and some curve balls can be nastier than others," Butler said. "On the other hand, a fastball is coming at you at 90 mph. The brain has to register all the elements at once."
Robert Singer, rsinger@hhp.ufl.edu
Kristin Harmel
Wine From UF Grape
One Of World's Best
It's fruity, yet unassuming. Dry with a smooth and light texture. Very pleasant to the palate.
Blanc du Bois, an award-winning table wine, is knocking the socks off wine know-it-alls from California to France.
Oh yeah. And it's made in Florida.
The white wine, made from a hybrid grape developed by a University of Florida grape breeder 30 years ago, was awarded a double gold medal at the recent Indy International Wine Competition in Indianapolis.
Wine experts picked the 1997 Blanc du Bois, produced at Lakeridge Winery in Lake County, as one of the 40 best of 2,147 wines from 19 countries. The competition is the third-largest wine competition in the country, which places the Florida wine among the best vintages in the world.
"No grape that's been grown in Florida has ever come close to this," said Dennis Gray, a grape researcher with UF's Institute of Food and Agricultural Sciences. "We knew it was a good product, but this is beyond what we expected."
John Mortensen developed the initial cross breed in 1968 at the IFAS Central Florida Research and Education Center in Leesburg. Scientists were experimenting with new grapes that would stand up better to fungal disease, said Mortensen, who retired from UF in 1991.
"Our original objective wasn't to breed a grape for wine," he said. "We were making a bunch grape for fresh eating that would ripen early and was disease resistant."
What they got was a white grape with a spicy flavor that resembled a German Riesling. Robert Bates, a professor of food processing at UF, recognized the grape's wine potential and began testing it in the early '70s.
"It was a hard grape to cultivate because of disease," Bates said, "but it was a quantum leap in terms of taste."
Jeanne Burgess, a winemaker with what was then the Lafayette Vineyards in Tallahassee, also liked the grape and persuaded the UF researchers to allow her to cultivate it and produce the new dry white. The vineyard began selling the variety in 1987.
When the Tallahassee vineyard moved its operation to Clermont and opened the Lakeridge Winery in 1988, they brought the Blanc du Bois with them. Today, 20 of the 50 acres of vineyards at Lakeridge are devoted to the Blanc du Bois.
"I feel like a parent whose kid graduated from college with honors," Burgess said. "The Blanc du Bois has won a lot of awards, but none as prestigious as this. Its showing just reinforces that good wines can be made in places other than California or Central Europe."
Robert Bates, rpb@gnv.ifas.ufl.edu
Karen Meisenheimer
Gene Therapy Research Could Forestall Blindness
University of Florida researchers have designed a new genetic weapon that has been shown in laboratory animals to significantly slow progression of retinitis pigmentosa, a leading cause of inherited human blindness.
The weapon, a ribozyme manufactured in the laboratory, works by chopping up genetic messengers before they deliver the instructions of a mutant gene.
"This is the first case we know of where ribozymes have been used to correct a disease in an animal in a way that realistically could be used in humans," said Alfred S. Lewin, a professor of molecular genetics and microbiology in UF's College of Medicine. "We also believe this technique might be useful for other inherited diseases."
Lewin and William Hauswirth, a professor with dual appointments in ophthalmology and molecular genetics and microbiology, are leading a team conducting further animal studies in preparation for human clinical trials, an estimated five years away.
About 1 in 3,000 Americans has retinitis pigmentosa, a degenerative disease whose symptoms generally first appear during adolescence. As the disorder progresses, night vision, peripheral vision and ultimately all sight can be lost. Currently, there is no way to halt the deterioration.
UF's research builds on the Nobel Prize-winning discovery in other laboratories that ribonucleic acid, or RNA, can act as an enzyme, a substance that causes chemical reactions within cells. It is then known as a ribozyme.
In a cell, RNA is copied from a strand of DNA; it serves as the messenger that conveys DNA's genetic instructions to the cell's cytoplasm, where proteins are made. In retinitis pigmentosa, a mutant gene calls for the creation of a protein that damages the eye's light-sensitive rod cells.
About 40 percent of people with retinitis pigmentosa have the "autosomal-dominant" form; that is, they inherited a defective gene from one parent who has the disease, but also received a normal gene copy from the other parent. (About half the cases of retinitis pigmentosa occur with no known family history.)
The UF research targets the autosomal-dominant form of the disease in rats.
"We designed a ribozyme to cut up the messenger RNA that has the copies of the bad gene, while leaving alone the copies of the good gene," Lewin said.
The genes themselves - good and bad - are not disturbed.
The designer ribozyme was injected into lab rats, which were bred to have a disease similar to human retinitis pigmentosa.
"We have seen significant protection of the eye cells three months after injecting the ribozymes. That's a long time in a rodent's life," Lewin said. "We're now working to see if the protection lasts for six months."
UF's research has been supported by the March of Dimes, the Foundation Fighting Blindness and the National Eye Institute.
Alfred Lewin, lewin@medmicro.med.ufl.edu
Victoria White
"Spark"ling Silicon Could Speed Computers
When scientists and engineers began using silicon to make semiconductor devices more than 40 years ago, it was the first step in what would turn out to be one of the most powerful inventions of the 20th century: the computer chip.
Now, University of Florida engineers are experimenting with new silicon properties - with possible benefits ranging from dramatically accelerating computer speeds to the creation of "micro motors" thought to have potential for medical and other uses.
Rolf Hummel, a UF materials science and engineering professor, pioneered, and continues to refine, a technique called "spark processing" that causes silicon wafers to emit light and makes them magnetic, two properties they do not have naturally.
As part of the technique, first patented in 1995, researchers expose silicon wafers, thin slices of silicon used as bases for electronic components or circuits, to repeated sparks from a counter electrode in a chamber. By varying the frequency of the sparks, types of gasses in the chamber and other factors, researchers can change the silicon's structure at will. The resulting wafers have raised, porous areas with radically different electrical, optical and magnetic properties than the surrounding silicon.
Depending on the variables the researchers choose, the process can make the altered silicon capable of emitting violet, blue or yellow-green light.
This is significant because it could one day bridge a gap between optics and electronics that currently impedes faster computers, said Mike Stora, a graduate student researching spark processing for his doctorate in materials science and engineering.
Today's computers may have microprocessors capable of running at speeds of 400 megahertz, but copper wire and other electronic equipment connecting to the processor slow computing speeds to 100 megahertz, Stora said.
If the chips transmitted information through light rather than electronic signals - and the copper wire and other equipment were replaced with fiber optics and light-sensitive materials - entire computers could run at the speeds of their processors.
Hummel said light-emitting chips also could be used to speed up long-distance transmission over fiber-optic telephone lines, a technology that currently relies on periodic electronic amplification. By eliminating the copper wire and making the process entirely light-dependent, transmission speeds could become as much as 1,000 times faster, he said.
Rolf Hummel, rhumm@mse.ufl.edu
Aaron Hoover
New Water Filter Traps More Contaminants
A new filter coating developed by University of Florida engineers and biologists might have prevented the kind of contamination that sickened more than two dozen children at an Atlanta water park last summer.
"Pool filters remove only a small fraction of the bacteria in the water, so they're really dependent on the chlorine for decontamination," said Ben Koopman, a professor in UF's Department of Environmental Engineering Sciences. "By using a filter that is enhanced in some way, you gain an additional barrier."
Koopman and three professors in chemical engineering, materials science and engineering, and microbiology and cell science developed the coating as part of more than a decade of research through UF's Engineering Research Center (ERC). The Kimberly-Clark Corp. paid for some of the at-least $300,000 devoted to the research, with the ERC also contributing.
Dinesh Shah, professor of chemical engineering and director of the Center for Surface Science and Engineering, said the coating enables pool filters and other types of filters to trap bacteria, viruses and particles as small as 500 angstroms. One angstrom measures one ten-billionth of a meter. Viruses range in size from 500 to 1,000 angstroms, while the smallest bacteria measure about 10,000 angstroms, he said.
The key to the coating's effectiveness is its ability to give the filter a positive electrical charge, Shah said. Viruses, bacteria and tiny particles tend to be negatively charged, so the coating attracts the objects to the filter. The result is decontaminated water without the addition of chlorine or other chemicals, Shah said.
Laboratory tests of a coated swimming pool filter with contaminated water showed it trapped more than 90 percent of pathogens, compared with between 10 and 30 percent for the same uncoated filter, said Samuel Farrah, a professor of microbiology and cell science in UF's College of Agriculture.
Dinesh Shah, shah@che.ufl.edu
Ben Koopman, bkoop@ufl.edu
Aaron Hoover
Researchers Seek Faster Contamination Cleanup
University of Florida researchers are using alcohols and detergents to try to expedite the cleanup of some stubborn hazardous waste sites.
"We are developing and testing faster, cheaper and better cleanup technologies," said Suresh Rao, a graduate research professor in UF's Institute of Food and Agricultural Sciences and director of the university's Center for Natural Resources.
UF researchers are injecting a mixture of alcohols, detergents and water into the ground at a defunct dry cleaners in Jacksonville that is serving as a test site, said Mike Annable, a UF associate professor of environmental engineering.
Earlier tests conducted with the U.S. Environmental Protection Agency (EPA) at Hill Air Force Base in Utah from 1995 to 1997 found that the UF approach removed about 1,000 times more contaminants than flushing with water alone, currently the standard method, said Rao, also a UF Research Foundation Professor.
The Florida Department of Environmental Protection (DEP) and EPA each have provided about $200,000 for the Jacksonville project, which the environmental consulting firm Levine-Fricke-Recon of Tallahassee is conducting in cooperation with UF's colleges of agriculture and engineering. UF's Center for Solid and Hazardous Waste Management is providing $40,000.
The research holds promise for many kinds of chlorinated organic compounds - commonly used in dry-cleaning fluids and industrial solvents - which are heavier than water and tough to budge once they settle in pockets or pools underground.
The DEP is exploring innovative technologies for its dry-cleaning solvent cleanup program, which the Florida Legislature established in 1995.
"There has been a fear that using alcohols and detergents as flushing agents would further contaminate sites," Annable said. "But in the Utah project, we showed that the flushing agents didn't pose a problem, and we were able to pump all of the injected alcohols and detergents from the test area."
UF and EPA researchers also are examining how well helpful bacteria that digest toxic chemicals will perform after the alcohol flushing is completed.
Suresh Rao, pscr@gnv.ifas.ufl.edu
Chris Eversole
Ancient Environs Straight From The Horse's Mouth
Out of the mouths of long-dead animals come stories of vanished landscapes, ancient weather and the way creatures lived and died.
With a unique combination of two scientific techniques, UF paleontologist Bruce MacFadden and colleagues analyzed fossilized horse teeth to see what the animals ate and, in doing so, reconstructed Florida's environment as it existed 5 million years ago.
MacFadden's article in the Feb. 5, 1999 issue of the journal Science describes how he analyzed ratios of carbon isotopes along with scratches and pits in fossilized teeth found in Lakeland phosphate mines. He concluded that the horses ate a combination of foods befitting an ancient Florida of savannah-like grasslands interspersed with lush forests and marshy wetlands inhabited by rhinos, llamas, elephants and other exotic creatures.
"These techniques are revolutionizing our ability to understand what prehistoric animals ate," MacFadden said.
Modern grazers such as horses and zebras develop elongated (high-crowned) teeth because they eat gritty, abrasive grasses, while browsers such as deer, whose diet consists mainly of soft leafy vegetation, have short teeth, MacFadden said.
But MacFadden's research on six species of prehistoric horses that lived 5 million years ago shows that, despite all the horses having elongated teeth, they were a combination of browsers, grazers and mixed feeders.
"This is the first time we've been able to use other techniques to challenge this assertion that the height of a tooth is uniquely indicative of diet," he said.
The findings support modern ecological theory that animals who live together divide up the food supply in order to minimize competition for the same resources, he said.
Learning about changes in the diets of ancient animals is important because it provides clues about how species interacted at certain points in time, MacFadden said.
"If all the animals in a particular area were feeding on the same resources and there was a big extinction, you might suspect something about their diet affected the extinction," he said.
The findings also provide insight about ancient environments, he said.
"If you have a community of ancient animals that are all found to be grazers, then you can infer that the environment of the local habitat was grassland. If the animals are all browsers, then you can infer that there was more forest or scrub."
Leaves, fruits and soft vegetation photosynthesize carbon differently than grasses. This difference allowed MacFadden to determine what prehistoric horses ate based on chemical analysis of the carbon in fossilized teeth.
The study, supported by the National Science Foundation, also involved microscopic analysis of scratches and pits on the teeth to determine whether the horses were browsers or grazers. Because it is abrasive, grass forms scratches on the tooth enamel when chewed, while the compression of leaves forms pits on the teeth, he said.
Bruce MacFadden, bmacfadd@flmnh.ufl.edu
Cathy Keen