How Crocodilians Know What's for Lunch

Daphne Soares stumbled onto her discovery of a previously unknown major sensory ability in alligators when she was sitting on the back of a huge bull alligator in a pickup truck, cruising through a Louisiana swamp.

"I was looking at his jaw as we rode along and thought, 'I wonder what those little spots are for?'" says the University of Maryland doctoral student, referring to the gator's "beard" of pinprick-sized holes that line the jaws of alligators and their crocodilian relatives.

Soares's question led to her discovery of what she has named "dome pressure receptors," tiny pressure-detecting mounds that give crocodilians the ability to detect the movement of prey in water. Soares estimates the receptors probably evolved about 200 million years ago in Jurassic Age predecessors that may have been the first amphibian crocodilians. Her findings appeared in the May 16 issue of the journal Nature.

While the existence of the tiny holes had been noted in earlier research and used mainly as a marker to distinguish different types of crocodilians--which include alligators, crocodiles and the slender-snouted gavial--their function and natural history had not been determined.

Soares's research shows that dome pressure receptors, or DPRs, make up a unique sensory organ that gives crocodilians the ability to detect small disturbances on the water's surface. "Crocodilians hunt at night, half-submerged in water, waiting for prey to disrupt the water surface. Their jaw rests right at the interface of air and water," Soares says. "When they're hungry, they quickly attack anything that disturbs that interface."

Using juvenile alligators, Soares determined the function of the receptors by blocking the gators' hearing and placing them in shallow water in total darkness, leaving them with no way to sense activity through their eyes, ears or noses. When the gators submerged their jaws, Soares dropped a small bit of water on the water's surface. The alligators reacted instantly, lunging and biting in the direction of the disturbance.

She then covered the DPR area of the jaw and repeated the experiment. The animals did not react. "The DPRs detected the pressure difference in the water when the surface of the water was broken," she says. "Without the DPRs, that orienting behavior is blocked."

Soares believes the DPRs might aid in other functions as well, such as communication, which often involves bellowing and slapping the water with the lower jaw. "Our findings show that the alligator is a very touch sensitive creature," she says. "Its brain is enormously devoted to DPR information." --ET

Maryland-built Solar House Shines Bright

A fully functional solar-powered house that was designed by a team of 27 undergraduate students from the University of Maryland will be showcased this fall in the nation's capital. The 800-square-foot

prototype home--entirely constructed by the students on a lot near Tawes Theatre--will be transported to the National Mall in Washington for a competition aimed at raising awareness about the viability of solar power for residential use.

Members of the Solar Decathlon team discuss design elements of their solar house.

The 2002 Solar Decathlon features student teams from 14 universities across the United States and is sponsored by the U.S. Department of Energy. During the eight-day event, only the solar energy that is generated from within the perimeter of each house can be used to provide all of the energy needs for an entire household, including power for appliances, lighting, heating and cooling, as well as the means to store energy for a home-based business and a solar-powered car. The students will be judged in 10 specific events based on their solar homes' performance.

Public awareness is also a key part of the competition, with each team developing its own Web site, providing house tours and creating printed materials to explain the design, engineering and operation of the house as well as the products and technologies used. Maryland students began brainstorming ideas for their solar house in January 2001, and were required to raise all of the funding for project, which is expected to exceed $200,000.

For updates on the solar house as well as details on the national competition, go to the Maryland Solar Decathlon Web site at www.solartech.umd.edu. --TV

Scholars Feel Chill from Executive Order on Presidential Papers

When history professor and presidential scholar Keith Olson was writing Framing Watergate, a book about the pressure conservatives applied to oust President Richard Nixon, he made use of the Nixon presidential papers. For his future book on Eisenhower and civil rights, he is looking at the papers of President Eisenhower. But if he wants to investigate the vice presidency of George H.W. Bush or the presidency of William Jefferson Clinton, an executive order signed by President George W. Bush on Nov. 1, 2001, may stand in his way.

The executive order, known as EO 13233, gives presidents, vice presidents, their representatives and relatives power over public access to the presidential papers that were previously under the authority of the Presidential Records Act of 1978. The executive order is under assault on many fronts. In Congress, Republicans eager to look over the Clinton papers and Democrats with their own agendas are drafting legislation to nullify the order. Public advocates and press organizations have filed suit to overturn it. Even the normally mild-mannered Society of American Archivists is protesting the order through op-ed pieces, journal articles, TV appearances and public discussions, saying the curtailed access violates "the very principles upon which our nation was founded."

At a panel discussion on the topic sponsored by the Student Archivists at Maryland on May 3, Tom Connors, archivist and curator of the National Public Broadcasting Archives, a unit of McKeldin Library, shared the dais with Bruce Craig, executive director of the National Coordinating Committee for the Promotion of History; and Lee Strickland, a longtime CIA attorney who holds a joint visiting professorship in the College of Information Studies and the College Park Scholars Program. All agreed that the order will have a chilling effect on scholarship.

But will the order stand? Craig says that the plaintiffs in the lawsuit may prevail, but probably not before Congress passes legislation to nullify the order, something Olson calls "not unusual. It has happened at least 200 times." The nullification could be as simple as a veto-proof one-line statement attached to a larger appropriations bill.

Connors sees the order as an expansion of a trend toward greater secrecy in government. He has represented the SAA on hearings related to former Mayor Rudolph Giuliani's refusal to allow the New York City Municipal Archives to manage his mayoral records. He is also at work on an article for Academe, the journal of the American Association of University Professors, titled "The End of Access? Government Information Policy in the G.W. Bush Era."

Connors feels the scholarly and information community can better inform the debate if it strengthens the intellectual underpinnings of its message, "We cannot rely solely on democratic sentiment or on litigation. We have to stand on something solid, a thorough analysis of the role of information in maintaining democratic society, a theory of information and democracy."--CC

Less Stressed Chickens Mean More Dollars for Poultry Growers

Research in the College of Agriculture and Natural Resources looks to produce behavioral changes in chickens that make the birds more profitable for the state's extensive broiler industry, currently ranked 7th in the nation for the number of broilers produced each year.

Assistant professor Inma Estevez studies behavioral modification in chickens.

Inma Estevez, assistant professor of animal and avian sciences, has identified behavioral changes in chickens that are directly related to the environmental design of the birds' living area. She is particularly interested in helping Maryland poultry farmers balance production and performance with the welfare of poultry raised in a commercial broiler house using high-density rearing--where up to 50,000 birds may be raised in a single chicken house. The process is a way that poultry farmers maximize net profits per unit of area, and Estevez points out that the practice is not inhumane, per se, if farmers maintain good environmental conditions and manage the birds with care. Her research, however, has shown that high-density rearing sometimes produces a level of stress in the birds that can affect their body weight, feed conversion and meat quality--all factors that can actually decrease profits for poultry farmers.

Estevez recalls that when visiting poultry farms a few years ago for other research projects, she noticed the majority of birds in the broiler houses would always gather next to the exterior walls of the buildings. Estevez later determined that the tightly packed birds would show signs of stress, such as drinking excessive amounts of water or exhibiting aggressive behavior. She then established that the birds' natural instincts were telling them to seek shelter from imagined predators by trying to "hide" under the exterior walls.

Estevez has recently conducted experiments at the Applied Poultry Research Farm, a university research station in Upper Marlboro, Md., where she placed portable partitions in the central floor area of a scale mock-up of a commercial broiler house. "It worked really, really well," she says, noting that there were immediate signs of the chickens spreading themselves evenly across the entire floor space, dramatically reducing their level of aggression and disturbances.

Commercial poultry growers are now looking closely at her research using the portable partitions, Estevez says. "We have seen productivity increases [using the walls] because the birds do not expend as much nervous energy, and that unused energy instead means healthier and better quality broilers." Her research has found that the less-stressed broilers are able to better absorb proteins, and also may reduce the nitrogen content in their excreta. This has an environmental impact when the poultry litter is ultimately removed from the broiler house and used as a ground fertilizer for crops.

Renaissance Researcher

A passion for engaging in interdisciplinary study fuels biochemist whose work has garnered three major prizes in two years.

Victor Munoz, an assistant professor of biochemistry, is obsessed with proteins--but not because he's on one of those popular diets that go heavy on the proteins and light on the carbs. Munoz's interest in proteins is much more intrinsic: He and his colleagues in the Department of Chemistry and Biochemistry are studying the fascinating and complex process of protein folding and why it sometimes goes wrong. The applications for his research could be far-reaching, as protein "misfolding" is implicated in up to 25 human illnesses, including Alzheimer's disease, certain types of diabetes and "mad cow" disease.

Proteins are the building blocks of all life. All are composed of amino acids, linked in peptide bonds. Several of these bonded peptides together form polypeptide chains, which "fold" into complex, three-dimensional shapes such as spirals, spheres and garlands. The precise folding of a protein is required in order for it to acquire biological activity and function properly. When misfolding occurs, the resulting aggregates gain toxicity as they grow.

Munoz's research centers on learning the rules that control protein folding. "If we knew the rules for protein folding, we could predict the structure of the proteins in entire genomes. We could design proteins that work better or do new things," he says. "Maybe we could even design a protein to dissolve the plastics we're filling our landfills with." Farther off, he says, are techniques that will actually predict and reverse protein misfolding in order to prevent disease.

Munoz is one of a number of researchers across the country who are studying the same problem. What makes his approach different is that he studies small portions of the protein in an attempt to understand the whole. This "hierarchical" approach to the study of protein folding replicates what actually happens in nature.

Assistant professor Victor Munoz, one of the nation's leading protein researchers, was drawn to Maryland because of the university's commitment to interdisciplinary research.

But while the idea itself is simple, in practice scientists are hindered for a very basic reason: folding of these small portions of protein occurs "even 10 times faster than one-millionth of a second." To keep pace with this speed, Munoz and his team are using laser temperature-jumping techniques to record "snapshots" at every phase of the folding. In fact, because the equipment required did not exist in their lab at Maryland to do precisely what they needed, the team custom-built an instrument for the job. "Protein folding is clearer now than it's ever been," he says. Yet there's an obstacle inherent in the technology. The laser technology allows protein folding to be recorded at speeds high enough to actually keep up with the process, but the images that emerge aren't very clear. He compares it to watching a movie on fast-forward. "Let's say there are 20 frames per second. Anything faster than that will look blurred," he says. Work is now under way to improve the resolution of these images.

Munoz's research has garnered three major prizes in the last two years: a 2002 Searle Scholar award, a 2001 Packard Fellowship and a 2000 Camille and Henry Dreyfus Scholar Fellowship. The awards have allowed him to buy much-needed equipment and hire additional researchers. The achievement is remarkable for any scientist, says Norma M. Allewell, dean of the College of Life Sciences. "Victor is on a very fast track and one of the top scientists in his age range," she says. "He is a highly creative scientist and a superb experimentalist with tremendous energy. He is not satisfied with anything less than full and accurate solutions to problems."

That energy and enthusiasm are apparent as Munoz talks about his research and its applications. When asked for a tour of his lab, he practically leaps from his chair, relishing the opportunity to show off the equipment he and his colleagues use. After a few hours with him, it's hard to imagine that science was not his first love. Yet when he was growing up in Madrid, Spain, it was art that intrigued him--the vibrant colors, the language of the artwork itself, and what it communicated to the viewer. He also had a passion for language and the written word. (In fact, he says that while some scientists find the writing process a grind, he actually enjoys that part of his work because it gives him an opportunity to "think about everything and what it means, to be precise.") What he didn't care for were math and physics. "I always thought math and physics were boring--a lot of rules," he says.

After high school, he worked and traveled for three years, trying to figure out where his ambition and interests would take him. "My parents were worried," he jokes. But he credits that time as among the most well spent of his life. When he entered the Universidad de Alcala, de Henares, he was ready to devote himself to science. There, he earned a bachelor's in biology. At the Universidad Autonoma de Madrid, he received a master's degree in biochemistry in 1991, and from the European Molecular Biology Laboratory in Heidelberg (Germany), he received a Ph.D. in 1995. That lab is one of the top molecular biology laboratories in Europe, and being there exposed him not just to top-rate science, but also to a melange of languages and cultures. It was in that setting that he became interested in biophysics.

Maybe it's because of his early disdain for rules that he refuses to be bound by the dividing lines that separate one discipline from another. His research encompasses the techniques of the molecular biologist, the protein engineer, the chemist, the physicist and the computational analyst. When Munoz came to Maryland in 2000, what thrilled him was the knowledge that many of his new colleagues shared the same belief in the benefits of interdisciplinary research. "The problem I see is that the study of science is becoming so specialized that people are in boxes, and we sometimes have a difficult time even talking to each other. From my point of view, the most interesting problems are at the boundaries," he says. "The only way to deal with them is to combine the disciplines. Now, many people are seeing the value in interdisciplinary research."