“This gives us a new way of studying light-matter interactions,” said Valeria Kleiman, a UF associate professor of chemistry. “It enables us to study not just how the molecule reacts, but actually to change how it reacts, so we can test different energy transfer pathways and find the most efficient one.”

Kleiman is the principal investigator in the research featured in a paper set to appear Friday in the journal Science.

Her work focuses on molecules known as dendrimers whose many branching units make them good energy absorbers. The amount of energy the synthetic molecules can amass and transfer depends on which path the energy takes as it moves through the molecule. Kleiman and three co-authors are the first to gain control of this process in real time. The team demonstrated that it could use phased tailored laser pulses — light whose constituent colors travel at different speeds — to prompt the energy to travel down different paths.

“What we see is that we control where the energy goes by encoding different information in the excitation pulses,” Kleiman said.

Researchers who now test every new molecular structure for its energy storage and transfer efficiency may be able to use what Kleiman called a new spectroscopic tool to quickly identify the most promising structures for photovoltaic devices.

“Imagine you want to go from here to Miami, and the road is blocked somewhere,” she said. “With this process, we’re able to say, ‘Don’t take that road, follow another one instead.’”

The other authors of the Science paper are Daniel Kuroda, C.P. Singh and Zhonghua Peng. The research was supported by UF and the National Science Foundation.

People who don’t achieve workout milestones such as losing fat, gaining strength or boosting cardiovascular fitness feel just as good about their bodies as their more athletic counterparts, said Heather Hausenblas, a UF exercise psychologist. Her study is published in the September issue of the Journal of Health Psychology.

“You would think that if you become more fit that you would experience greater improvements in terms of body image, but that’s not what we found,” she said. “It may be that the requirements to receive the psychological benefits of exercise, including those relating to body image, differ substantially from the physical benefits.”

The study by Hausenblas and graduate student Anna Campbell is the first to systematically analyze the wide-ranging effects of exercise on body image by examining all intervention studies on the subject until June 2008. From the 57 publications, the researchers found conclusively that exercise buffed up the way people see their bodies regardless of the actual benefits, but the results varied.

Negative body image has grown to almost epidemic proportions in the past 20 years, with as many as 60 percent of adults in national studies saying they don’t like the way their bodies look, Hausenblas said.

Americans spend billions of dollars a year for products designed to change their body size and shape, including diet pills and various cosmetic procedures, she said.

“Body dissatisfaction is a huge problem in our society and is related to all sorts of negative behavior including yo-yo dieting, smoking, taking steroids and undergoing cosmetic surgery,” she said. “It affects men and women and all ages, starting with kids who are as young as five years old saying they don’t like how their bodies look.”

The psychological advantages of exercise have been less explored, including the reduction of depression or confidence in body image, compared with the well-researched and understood physical benefits, she said.

The study found no difference in body image improvement between people who met the American College of Sports Medicine guidelines by exercising at least 30 minutes a day five days a week and those who did not, Hausenblas said. The guidelines are considered the minimum amount of exercise needed to receive the health related benefits of physical activity, she said.

“We would have thought that people exercising this amount would have felt better about their bodies than those who did not work out as much,” she said.

In other results, the study showed slightly larger benefits from exercise in terms of improving body image for women than men, Hausenblas said.

“We believed the gap would be much bigger, but what could be coming into play is the rise of body image issues among men,” she said. “We’re seeing more media portrayals of the ideal physique for men rather than the overriding emphasis on women we did in the past.”

Age presented another difference, with older people most likely to report enhanced body images from exercise, Hausenblas said. The gap may be explained by the older generation having more concerns about their body image than young people, who tend to exercise more, she said.

While the frequency of exercise mattered for boosting body perceptions, there were no differences for the duration, intensity, length or type of exercise, the study found.

“People who say they have high body dissatisfaction tend to exercise the least, so we wanted to take it a step further and see whether exercise causes people’s body image to improve,” she said.

Kathleen Martin Ginis, a kinesiology professor at McMaster University in Ontario, Canada, and exercise expert, praised the research. “This is an important study because it shows that doing virtually any type of exercise, on a regular basis, can help people feel better about their bodies,” she said. “With such a large segment of the population dissatisfied with their physiques, it’s encouraging to know that even short, frequent bouts of lower intensity exercise can improve body image.”

Writing in the September issue of AIDS, a research team led by scientists at the University of Florida explained why two subtypes of HIV-1 — the virus that causes acquired immunodeficiency syndrome, or AIDS — held steady at relatively low levels for more than 50 years in west central Africa before erupting as an epidemic in east Africa in the 1970s.

Essentially, the explanation for the HIV explosion — obscured until now — involves the relative ease with which people can travel from city to city in east Africa as opposed to the difficulties faced by people living in the population centers of the Democratic Republic of Congo, the point where HIV emerged from west central Africa in its spread to the east.

Later, as the epidemic raged in the east, cities in the Democratic Republic of Congo — a vast country almost as big as all of Western Europe — remained disconnected and isolated, explaining why the virus affected only about 5 percent of the country’s population, a level that has not changed much since the 1950s.

“We live in a world that is more interconnected every day, and we have all seen how pathogens such as HIV or the swine flu virus can arise in a remote area of the planet and quickly become a global threat,” said Marco Salemi, an assistant professor of pathology, immunology, and laboratory medicine at the UF College of Medicine and senior author of the study. “Understanding the factors that can lead to a full-scale pandemic is essential to protect our species from emerging dangers.”

Investigators used databases, including GenBank from the National Center for Biotechnology Information, as well as actual DNA samples, including samples recently collected in Uganda — the vicinity where HIV entered east Africa — to follow the virus’ molecular footprints since its emergence in the 1920s.

“HIV mutates rapidly,” said Rebecca Gray, a postdoctoral associate in the department of pathology, immunology and laboratory medicine. “This is a successful strategy for the virus, because it evolves quickly and develops drug resistance. But we can use these changes in the genome to follow it over time and develop a history of its progress.”

Researchers wanted to know why, the virus smoldered during the 1950s and 1960s, before spreading like wildfire through east Africa in the 1970s.

A fateful piece of the puzzle came in the form of geographic information system data, which uses satellite imagery and painstakingly takes into account the availability and navigability of roads between population centers, transportation modes, elevation, climate, terrain and other factors that influence travel.

“We were able to use geographic data to interpret the genetic data,” said Andrew J. Tatem, an assistant professor of geography in the College of Liberal Arts and Sciences and a member of UF’s Emerging Pathogens Institute. “Genetic data showed once HIV moved out of the Democratic Republic of Congo, it expanded fast and moved rapidly across Uganda, Kenya and Tanzania, all while staying at low levels in the DRC. What was happening was the virus was circulating at stable levels in the urban centers of the DRC, but these centers were isolated. Once it hit east Africa, connectivity between population centers combined with better quality transportation networks, and higher rates of human movement caused HIV to spread exponentially.”

HIV was prevalent in about 15 percent of the population in Kenya in 1997, although it has since dropped to about 7 percent, according to the Kaiser Family Foundation. As of 2007, an estimated 22 million people were living with HIV/AIDS in sub-Saharan Africa. About 1.1 million Americans have HIV or AIDS, and an estimated 5.1 million people in India are HIV-positive. In Eastern Europe, HIV infections more than doubled from 420,000 in 1998 to 1 million in 2001.

“If we can predict the specific routes of an epidemic, we can find the geographic regions more at risk and target these areas with medical intervention and strategies for prevention,” Salemi said. “In terms of health-care applications, coupling genetic analysis with geographic information systems can give us a powerful tool to understand the spread of pathogens and contain emerging epidemics.”

Working with Maureen M. Goodenow, the Stephany W. Holloway university chair for AIDS research at the UF College of Medicine, UF researchers collaborated with an array of scientists hailing from the National Institute of Allergy and Infectious Diseases, the Rakai Health Sciences Program and Makerere University of Uganda, and the Johns Hopkins University. They refer to the combination of techniques that led to the discovery as “landscape phylodynamics.”

“It is the first study that has given us a clear picture of epidemic history of HIV in east Africa, including the geographic routes and the time scale that it occurred,” said Oliver Pybus, a researcher in the department of zoology at Oxford University who did not participate in the study. “Genetic analysis of the HIV genome provides the family tree of the virus, combined with spatial analysis of high-resolution data of land use, topology and other factors. There is a huge potential in doing that kind of analysis, but it requires a rare combination of specialists in different fields to come together.”

But it was a far more modest observatory, located just above sea level in rural Levy County and just down the road from the UF campus, that proved key to a new discovery about what one astronomer termed “one of the weirdest” planets outside our solar system.

Three UF astronomers are among the authors of a paper that will appear Thursday in Astrophysical Journal, the leading journal in astronomy, pinning down the extravagantly unusual orbit of HD 80606b, a Jupiter-sized planet nearly 200 light years away. The astronomers made observations of the planet eclipsing its star from a 41-year-old telescope at the department’s Rosemary Hill Observatory 30 miles west of Gainesville in Bronson.

“Really, the critical data came from Florida and Indiana, because they were in the right place at the right time, and the weather was OK,” said Josh Winn, an assistant professor of physics at the Massachusetts Institute of Technology and the lead author of the paper.

The weather was OK – but just barely. Knicole Colón, a UF astronomy doctoral student who made the observations with UF associate scientist and Rosemary Hill director Francisco Reyes, said the two were blessed with cooperative clouds.

“It was fairly cloudy, and we were somewhat disappointed,” she said. “But it turned out that throughout the night, there was a hole in the cloud cover, right where our star was.”

The Rosemary Hill Observatory was founded in 1967 on an 80-acre site in Levy County less than 140 feet above sea level. It has two telescopes, the larger of which is a 30-inch Tinsley reflecting telescope. Although faculty members and graduate students have used that telescope and its 18-inch companion for research, they serve mainly as teaching tools. For research, astronomers often travel to remote mountaintops where larger, more sophisticated telescopes can capture light from far more distant stars at much finer resolutions — now including the largest of them all, the 34.1-foot Gran Telescopio Canarias, perched at 7,874 feet above sea level on a mountaintop in Spain’s Canary Islands.

The events of the night of June 4, 2009, however, proved that small, simple telescopes can still play starring roles.

On that night, Reyes and Colón joined teams at about a dozen different observatories spread from Massachusetts to Hawaii to observe the planet eclipse its host star, HD 80606.

Astronomers noticed the eclipse for the first time in late February, but they only managed to observe the very end of it. The planet completes one orbit around its star every 111 days, so the next chance for observation came on June 4. The eclipse lasts nearly 12 hours, yet any single observatory can only observe it for a short time between twilight and when the planet and star disappear below Earth’s horizon. As a result, 25 astronomers worked together, relay-race fashion east to west, to capture the event.

Colón said she, Reyes and UF astronomy assistant professor Eric Ford spent several days testing and readying the Rosemary Hill telescope. However, the weather had been poor for weeks, and prospects didn’t look good. On the appointed night, it was too cloudy at the first observatory, in Massachusetts, for successful observations. The Florida observatory was next.

Colón said that despite widespread clouds, she and Reyes located a reference star and zeroed in on HD 80606 just in time for the beginning of the eclipse. The team caught only part of the event, but the next observatory, in Indiana, was able to pick up soon after. All told, six observatories gathered about six hours of observations, capturing more than half of the eclipse. Although most were small, they included the 31-foot Keck I telescope in Hawaii. Ford participated remotely in those observations from Berkeley, Calif.

When Colón uses the Gran Telescopio Canarias, she submits her requirements for observation, then awaits the results from astronomers at the telescope. The Rosemary Hill observations were completely different.

“You are staring at a star as a planet crosses in front of it, which is pretty amazing,” she said. “It’s definitely a unique experience that you can’t get from the remote observing that I do.”

Most planets orbit their stars in a more or less circular shape. But HD 80806b’s orbit is an elongated ellipse, as though someone had grabbed its orbit and squeezed. Astronomers were unsure of the cause of this comet-like orbit, but the leading theory was a companion star’s gravitational pull. By combining their observations of the eclipse, the team demonstrated the planet’s orbit is not aligned with the star’s rotation, which suggests this theory is probably correct, Winn said.

A team led by astronomy professor Stephen Eikenberry late last week captured the first images of the cosmos ever made with a UF-designed and built camera/spectrometer affixed to the Gemini South telescope in Chile. The handful of “first light” images include a yellow and blue orb-like structure that depicts our Milky Way galaxy, home to thousands of black holes – including, at its core, a “supermassive” black hole thought to be as massive as 4 million suns put together.

“We plan to use this instrument to provide the first accurate tracking of the growth and evolution of this black hole over the last 4 billion years,” Eikenberry said.

Installation of the instrument, called FLAMINGOS-2, caps a seven-year, $5 million effort involving 30 UF scientists, engineers, students and staff. Once the instrument is scientifically tested — a process expected to last around six months — it will support a range of new science. Astronomers will use FLAMINGOS-2 (FLAMINGOS is short for the Florida Array Multi-object Imaging Grism Spectrometer) to hunt the universe’s first galaxies, view stars as they are being born, reveal black holes and investigate other phenomena.

“Achieving first light is a great achievement and important milestone,” said Nancy Levenson, deputy director of the Gemini Observatory.

The 8-meter Gemini South telescope in the Chilean Andes is one of only about a dozen 8- to 10-meter telescopes worldwide. All require technologically sophisticated instruments to interpret the light they gather. FLAMINGOS-2 “sees” near-infrared or heat-generated light beyond the range of human vision. It can reveal objects invisible to the eye, such as stars obscured by cosmic dust, or objects so far away they have next to no visible light

The instrument joins other near-infrared imagers installed on other large telescopes. But it is unusual in its ability to also act as a spectrometer, dividing the light into its component wavelengths. Astronomers analyze these wavelengths to figure out what distant objects are made of, how hot or cold they are, their distance from Earth, and other qualities.

Uniquely, FLAMINGOS-2 can take spectra of up to 80 different objects simultaneously, speeding astronomers’ hunt for old galaxies, black holes or newly forming stars and planets.

“At a cost of $1 per second for operating the Gemini telescope, it will make a huge gain in the scientific productivity and efficiency of the observatory,” Eikenberry said. “What would take an entire year previously can now be done in four nights. This is a real game changer.”

Astronomers compete heavily for time on the world’s largest telescopes, often waiting months or years for the opportunity to make observations. Eikenberry said his FLAMINGOS-2 agreement with Gemini South entitles him to at least 25 nights of observations. He will use the time to contribute to three large studies, or surveys, of the sky headed by UF astronomers.

The first is aimed at learning more about the thousands of black holes and neutron stars at the Milky Way’s center. The second will probe the formation and evolution of galaxies across time, while the third will investigate the birth of new stars.

Levenson said the Gemini telescopes are well-known for their excellent image quality. With its wide large field of view and ability examine dozens of objects at once, FLAMINGOS-2 is a good match with the Gemini South telescope.

“The center of our Milky Way galaxy is a very dusty, very crowded environment, so infrared measurements and the ability to separate the fine details of the different stars and other objects are very important,” she said.

FLAMINGOS-2’s debut comes less than two months after UF astronomers helped inaugurate the Gran Telescopio Canarias, the world’s largest telescope, in Spain’s Canary Islands. UF, which owns a 5 percent share of the 10-meter telescope, is the only participating U.S. institution.

The Gemini Observatory is the lead sponsor of FLAMINGOS-2 and the source of the $5 million for design and construction. The original FLAMINGOS, a smaller prototype that pioneered the approach used successfully in the larger version, was designed and built by the late UF astronomy professor Richard Elston. Elston was at work on the early stages of FLAMINGOS-2 when he died of cancer in 2004 at age 43.

The Gemini Observatory, which operates twin 8-m telescopes located in Chile in Hawaii, is an international collaboration supported in part by the National Science Foundation.

Reed, an associate curator of mammalogy at the university’s Florida Museum of Natural History, will use the five-year, $934,498 grant to trace the evolutionary history of lice, and he hopes the study will shed light on human migration, development and evolution.

“Parasitic lice have evolved alongside, but much faster than their human hosts,” Reed said. “The lice have given researchers a more detailed look at the process of species migration and evolution.”

The study also will analyze genetic similarities between the evolution of lice and humans as they have evolved over time. Reed said human and chimpanzee lice branched from a single evolutionary line at about the same time their hosts did and the study will use DNA sequencing data to more closely examine other similarities between the two types of lice.

The study will require samples from around the world, collected with the help of medical professionals. The grant also provides funding to support a postdoctoral fellow, two graduate students and up to 10 undergraduates, and includes a training program to teach UF graduate students how to communicate their research to lay audiences.

“Scientists often lack the skills needed to translate their technical research findings into information that is relevant to a broad public audience, “which is why we are creating this graduate opportunity,” Reed said. “Being able to employ both graduate and undergraduate students is a real benefit to the department and the university.”

The research opportunities will provide training in skills such as collecting specimens, working in the molecular lab and conducting genetic analysis, allowing students to enter the work force with specialized skills.

Human lice have been a nuisance for centuries. The rapid changes that make lice ideal candidates for a study centered on evolutionary processes also play havoc on everyday life among the general human population.

Head lice in school children, one common form of parasitic lice, have built a resistance to insecticidal shampoos in developed countries, which is why their numbers are increasing in the U.S. In underdeveloped countries where insecticidal treatments are not widely used, lice are still susceptible and easily controlled with existing medicines, Reed said.

The grant also includes the purchase of a high definition imaging system to document, compare and study specimens collected worldwide for the project.

The National Science Foundation is an independent federal agency created by Congress in 1950 and currently funds about 20 percent of all federally supported research at U.S. colleges and universities. NSF creates about 10,000 new awards each year including the Faculty Early Career Development Award, which is given to researchers who exemplify the teacher-researcher role.

An analysis of data from the Laser Interferometer Gravitational-Wave Observatory Scientific Collaboration, or LIGO, and the Virgo Collaboration has set the most stringent limits yet on the amount of gravitational waves that could have come from the Big Bang in the gravitational wave frequency band where LIGO can observe. In doing so, scientists have put new constraints on the details of how the universe looked in its earliest moments.

“Gravitational waves are the only way to directly probe the universe at the moment of its birth; they’re absolutely unique in that regard,” said David Reitze, a UF professor of physics and the spokesperson for the LIGO Scientific Collaboration. “We simply can’t get this information from any other type of astronomy. This is what makes this result in particular, and gravitational-wave astronomy in general, so exciting.”

The research is set to appear in the Aug. 20 issue of the journal Nature. Seventeen UF faculty members, postdoctoral associates and graduate students join the paper’s authors.

Much like it produced the cosmic microwave background, the Big Bang is believed to have created a flood of gravitational waves — ripples in the fabric of space and time — that carry information about the universe as it was immediately after the Big Bang. These waves would be observed as the “stochastic background,” analogous to a superposition of many waves of different sizes and directions on the surface of a pond. The amplitude of this background is directly related to the parameters that govern the behavior of the infant universe.

Earlier measurements of the cosmic microwave background have placed the most stringent upper limits of the stochastic gravitational wave background at very large distance scales and low frequencies. The new measurements by LIGO directly probe the gravitational wave background in the first minute of its existence, at time scales much shorter than accessible by the cosmic microwave background.

The research also constrains models of cosmic strings, objects that are proposed to have been left over from the beginning of the universe and subsequently stretched to enormous lengths by the universe’s expansion. These strings, some cosmologists say, can form loops that produce gravitational waves as they oscillate, decay and eventually disappear.

Gravitational waves carry with them information about their violent origins and about the nature of gravity that cannot be obtained by conventional astronomical tools. The existence of the waves was predicted by Albert Einstein in 1916 in his general theory of relativity. The LIGO and GEO instruments have been actively searching for the waves since 2002; the Virgo interferometer joined the search in 2007.

The UF LIGO research group built one of the most important and complex parts of the gravitational wave detector, the input optics, said David Tanner, a UF professor of physics. The input optics takes light from the laser, shapes the beam into an ideal form, and directs it to the interferometer at the heart of the gravitational wave detector. UF scientists are working to design and build a second version of the input optics for a major upgrade to LIGO scheduled to go on line in three to four years.

“UF also plays important role in analysis of LIGO data, including searches for sharp bursts of gravitational waves, and for the stochastic background of gravitational waves … the subject of the just published paper,” Tanner wrote in an e-mail.

The authors of the new paper report that the stochastic background of gravitational waves has not yet been discovered. But the nondiscovery of the background described in the Nature paper already offers its own brand of insight into the universe’s earliest history.

The analysis used data collected from the LIGO interferometers in Hanford, Wash., and Livingston, La. Each of the L-shaped interferometers uses a laser split into two beams that travel back and forth down long interferometer arms. The two beams are used to monitor the difference between the two interferometer arm lengths.

“Since we have not observed the stochastic background, some of these early-universe models that predict a relatively large stochastic background have been ruled out,” said Vuk Mandic, assistant professor at the University of Minnesota and the head of the group that performed the analysis. “We now know a bit more about parameters that describe the evolution of the universe when it was less than one minute old.”

The success in repairing a damaged layer of retinal cells in mice implies that blood stem cells taken from bone marrow can be programmed to restore a variety of cells and tissues, including ones involved in cardiovascular disorders such as atherosclerosis and coronary artery disease.

“To our knowledge, this is the first report using targeted gene manipulation to specifically program an adult stem cell to become a new cell type,” said Dr. Maria B. Grant, a professor of pharmacology and therapeutics at UF’s College of Medicine. “Although we used genes, we also suggest you can do the same thing with drugs — but ultimately you would not give the drugs to the patient, you would give the drugs to their cells. Take the cells out, activate certain chemical pathways, and put the cells back into the patient.”

In a paper slated to appear in the September issue of the journal Molecular Therapy, scientists describe how they used a virus carrying a gene that gently pushed cultured adult stem cells from mice toward a fate as retinal cells. Only after the stem cells were reintroduced into the mice did they completely transform into the desired type of vision cells, apparently taking environmental cues from the damaged retinas.

After studying the cell-transformation process, scientists were able to bypass the gene manipulation step entirely and instead use chemical compounds that mirrored environmental conditions in the body, thus pointing the stem cells toward their ultimate identities as vision cells.

“First we were able to show you can overexpress a protein unique to a retinal cell type and trick the stem cell into thinking it is that kind of cell,” said Grant, who collaborated with Edward Scott, the director of the Program in Stem Cell Biology and Regenerative Medicine at UF’s McKnight Brain Institute. “As we proceeded, we found we could activate the stem cells by mimicking the body’s natural signaling channels with chemicals. This implies a whole new field of stem cell research that uses drug manipulation rather than genetic manipulation to send these immature cells along new pathways.”

Scientists chose to build retinal pigment epithelial cells, which form the outer barrier of the retina. In addition to being very specialized and easy to identify, RPE cells are faulty in many retinal diseases, including age-related macular degeneration, which affects nearly 2 million people in the United States, and some forms of blindness related to diabetes.

“This work applies to 85 percent of patients who have age-related macular degeneration,” Grant said. “There are no therapies for this devastating disease.”

The work was supported by the National Eye Institute. Researchers removed blood stem cells from the bone marrow of mice, modified the cells in cultures, and injected them back into the animals’ circulatory systems. From there, the stem cells were able to home in on the eye injury and become retinal cells.

At 28 days after receiving the modified stem cells, mice that had previously demonstrated no retinal function were no different than normal mice in electrical measures of their response to light.

Grant and UF have patented some technology involved in the research.

The inauguration of the Gran Telescopio Canarias — with its 10.4-meter diameter mirror, the telescope has more light-collecting area than any other — is scheduled for July 24 in Spain’s Canary Islands. Officials and astronomers from the University of Florida, the only U.S. institution that is part of the project, will join more than 500 astronomers, journalists and celebrities in a ceremony presided over by Spain’s King Juan Carlos I and Queen Sofia.

“The completion and inauguration of the GTC is a huge milestone for astronomy and for the University of Florida in collaboration with its partners in Spain and Mexico,” UF Provost Joe Glover said. “We look forward to our astronomers playing a central role in the major discoveries this uniquely powerful telescope will enable.”

Perched 7,874 feet above sea level on a mountain on the island of La Palma, the GTC has 6 square meters more light collecting area than any of the roughly one dozen 8- to 10-meter telescopes worldwide. With a mirror composed of 36 hexagonal segments thought to have the smoothest surfaces ever made, it is also the world’s most technologically advanced optical telescope. Sensors keep the mirrors aligned to counteract the force of gravity, with the result that they act as a single surface, even as the telescope is rotated and aligned in place.

Spain owns 90 percent, Mexico 5 percent and UF 5 percent of the telescope under construction since 2000. UF contributed $5 million toward the $180 million project — and its astronomers designed and built one of the first two astronomical instruments for the telescope, a multimillion dollar heat-sensing camera called CanariCam.

Stan Dermott, chairman of UF’s astronomy department, said the GTC’s size and technical attributes enable it not only to gather more light than any other telescope, but also resolve the light into sharper and clearer focus. For astronomers, he said, those capabilities make it a powerful tool to study cosmic origins – the early days of the universe and the very early moments in the mysterious births of stars, planets and galaxies.

“The interpretation of the structure of the disks where new planets form is highly dependent on the quality of the image,” he said, adding that the GTC also will enable the discoveries of new planets, possibly including the first habitable planet.

The telescope gathers the light, but only astronomical instruments can reveal the mysteries it contains. The car engine-sized CanariCam, built at UF but now in La Palma and expected to become operational next year, “sees” the infrared light — the invisible light that accompanies heat — emitted by stars and planets as they form in space. It also sees the light that, in its visible form, is obscured by the dust clouds and gas in space.

CanariCam is unique among mid-infrared cameras in its ability to determine the direction of polarized light and accomplish coronagraphy, which blocks the bright light of stars to make faint planets nearby more visible. Those abilities will help it reveal cool planets and more about the role of magnetic fields in planet and star formation, said Charles Telesco, UF astronomy professor and the principal investigator on the CanariCam project.

UF astronomer Eric Ford became one of the first astronomers worldwide to use the GTC earlier this year. Dermott said he anticipates that about 60 astronomy faculty, graduate students, postdoctoral associates and others — most of the members of the department — will become involved with GTC-related observations or research. He stressed that access to such a prominent telescope is key to success in astronomical research.

“All the objects we study are remote, and you have to get your information from looking at images,” he said. “If the competition has a better image than you, you are basically out of business. So having the GTC puts our students and faculty on the front line.”

There is far more demand for the world’s largest telescopes than available nights, with the result that most astronomers get far less time than they want — and in some years, none at all. UF’s part ownership of the GTC means that its astronomers are guaranteed 20 nights each year. UF’S instrument-building program will result in additional nights, as will UF astronomers’ collaborations with Mexican and Spanish astronomers, Dermott said.

More photos are available at http://www.iac.es/gtcinauguracion/prensa.php?op1=4&lang=en

In a paper appearing this week in the online edition of the Proceedings of the National Academy of Sciences, UF biology professor Brian McNab concludes that contrary to common belief, dinosaurs didn’t attain their colossal body sizes because they had more food to eat. Instead, McNab says, like Popeye with his spinach-induced bulging muscles, dinosaurs simply converted more of the energy in their food to body mass.

“Dinosaurs used energy in a different way than mammals use it. Mammals use much of their energy for body maintenance, temperature regulation and activity, and less of it for growth,” McNab says. “Dinosaurs used more energy for growth and less for maintenance.”

McNab argues that the conifers, ferns and other prehistoric plants that proliferated during the Mesozoic era ending 65 million years ago largely constituted “garbage food” that required a lot of energy to digest and provided little energy in return. Despite this limitation, dinosaurs were able to grow as much as eight times bigger than modern mammals, with the largest herbivores reaching weights of 40 to 80 tons or more – six to eight times an elephant’s weight of about 7 tons. (A large rhinoceros relative that lived in the Miocene weighed 11 to 15 tons and was the largest terrestrial mammal.)

Most of today’s herbivorous mammals can eat grasses, which were not present in the Mesozoic, and are a high-energy, more readily digestible forage, McNab noted. At the other end of the scale, plankton have a high energy content and are easy to digest, which is why the largest whales can reach weights of 160 tons, eclipsing the sizes of even the largest dinosaurs, he said.

McNab says dinosaurs attained their gigantic proportions because their biology apparently combined characteristics of modern warm-blooded and cold-blooded animals. On the one hand, they could regulate their own body temperature because of their large size and small relative surface area, he concludes. On the other, their metabolic rates were only about a quarter of those of mammals, but four times those of most reptiles.

Among modern animals, McNab says, those whose metabolisms most closely match those of dinosaurs are the varanid lizards, which include the Komodo dragon and other Monitor lizards.

“If you extrapolate varanid lizards’ metabolic rate up the metabolic rates of elephants, you get an animal that weighs 60 to 80 tons,” he says. “That’s the size of the biggest dinosaurs, the sauropods.”

But it turns out that remarkable ability isn’t so mysterious after all — suggesting that researchers could learn how to replicate it in people.

Scientists had long credited the diminutive amphibious creature’s outsized capabilities to “pluripotent” cells that, like human embryonic stem cells, have the uncanny ability to morph into whatever appendage, organ or tissue happens to be needed or due for a replacement.

But in a paper set to appear Thursday in the journal Nature, a team of seven researchers, including a University of Florida zoologist, debunks that notion. Based on experiments on genetically modified axolotl salamanders, the researchers show that cells from the salamander’s different tissues retain the “memory” of those tissues when they regenerate, contributing with few exceptions only to the same type of tissue from whence they came.

Standard mammal stem cells operate the same way, albeit with far less dramatic results — they can heal wounds or knit bone together, but not regenerate a limb or rebuild a spinal cord. What’s exciting about the new findings is they suggest that harnessing the salamander’s regenerative wonders is at least within the realm of possibility for human medical science.

“I think it’s more mammal-like than was ever expected,” said Malcolm Maden, a professor of biology, member of the UF Genetics Institute, and author of the paper. “It gives you more hope for being able to someday regenerate individual tissues in people.”

Also, the salamanders heal perfectly, without any scars whatsoever, another ability people would like to learn how to mimic, Maden said.

Axolotl salamanders, originally native to only one lake in central Mexico, are evolutionary oddities that become sexually reproducing adults while still in their larval stage. They are useful scientific models for studying regeneration because, unlike other salamanders, they can be bred in captivity and have large embryos that are easy to work on.

When an axolotl loses, for example, a leg, a small bump forms over the injury called a blastema. It takes only about three weeks for this blastema to transform into a new, fully functioning replacement leg — not long considering the animals can live 12 or more years.

The cells within the blastema appear embryonic-like and originate from all tissues around the injury, including the cartilage, skin and muscle. As a result, scientists had long believed these cells were pluripotential — meaning they came from a variety of sites and could make a variety of things once functioning in their regenerative mode.

Maden and his colleagues at two German institutions tested that assumption using a tool from the transgenic kit: the GFP protein. When produced by genetically modified cells, GFP proteins have the useful quality of glowing livid green under ultraviolet light. This allows researchers to follow the origin, movement and destination of the genetically modified cells.

The researchers experimented on both adult and embryonic salamanders.

With the embryos, the scientists grafted transgenic tissue onto sites already known to develop into certain body parts, then observed how and where the cells organized themselves as the embryo developed. This approach allowed them to see, literally, what tissues the transgenic tissue made. In perhaps the most vivid result, the researchers grafted GFP-modified nerve cells onto the part of the embryo known to develop into the nervous system. Once the creatures developed, ultraviolet light exams of the adults revealed the GFP cells stretched only along nerve pathways — like glowing green strings throughout the body

With the adults, they took tissue from specific parts or organs from transgenic GFP-producing axolotls, grafted it onto normal axolotls, then cut away a chunk of the grafted tissue to allow regeneration. They could then determine the fate of the grafted green cells in the emerging blastema and replacement tissue.

The researchers’ main conclusion: Only ‘old’ muscle cells make ‘new’ muscle cells, only old skin cells make new skin cells, only old nerve cells make new nerve cells, and so on. The only hint that the axolotl cells could revamp their function came with skin and cartilage cells, which in some circumstances seemed to swap roles, Maden said.

Maden said the findings will help researchers zero in on why salamander cells are capable of such remarkable regeneration. “If you can understand how they regenerate, then you ought to be able to understand why mammals don’t regenerate,” he said.

Maden said UF researchers will soon begin raising and experimenting on transgenic axolotls at UF as part of the The Regeneration Project, an effort to treat human brain and other diseases by examining regeneration in salamanders, newts, starfish and flatworms.

The analysis of a well-preserved skull from 54 million years ago contradicts some common assumptions about brain structure and evolution in the first primates. The study also narrows the possibilities for what caused primates to evolve larger brain sizes. The study is scheduled to appear online the week of June 22 in the Proceedings of the National Academy of Sciences.

The skull belongs to a group of primitive primates known as Plesiadapiforms, which evolved in the 10 million years between the extinction of the dinosaurs and the first traceable ancestors of modern primates. The 1.5-inch-long skull was found fully intact, allowing researchers to make the first virtual mold of a primitive primate brain.

“Most explanations on the evolution of primate brains are based on data from living primates,” said lead author Mary Silcox, an anthropologist at the University of Winnipeg and research associate at UF’s Florida Museum of Natural History. “There have been all these inferences about what the brains of the earliest primates would look like, and it turns out that most of those inferences are wrong.”

Researchers used CT scans to take more than 1,200 cross-sectional X-ray images of the skull, which were combined into a 3-D model of the brain.

“A large and complex brain has long been regarded as one of the major steps that sets primates apart from the rest of mammals,” said Florida Museum vertebrate paleontologist and study co-author Jonathan Bloch. “At our very humble beginnings, we weren’t so special. That happened over tens of millions of years.”

The animal, Ignacius graybullianus, represents a side branch on the primate tree of life, Bloch
said. “You can think of it as a cousin of the main line lineage that would have given rise ultimately to us.”

In previous research, Bloch and Silcox established that Plesiadapiforms were transitional species. Ignacius was similar to modern primates in terms of its diet and tree-dwelling but did not leap from tree to tree like modern fast-moving primates.

In many ways, the early primate behaved like living primates but with a brain that was one-half to two-thirds the size of the smallest modern primates. This means that factors such as tree-dwelling and fruit-eating can be eliminated as potential causes for primates evolving larger brain sizes, Silcox said, because “the smaller brained Ignacius was already doing those things.”

The mold suggests a “startling combination” of features in the early primate that requires a rethinking of primate brain evolution, said Florida State University anthropologist Dean Falk, who was not involved in the study.

“Hypotheses about early primate brain evolution often link keen smell with nocturnal insect-eating, and a more recently evolved increase in visual processing with fruit-eating in arboreal habitats,” Falk said.

The move to larger brain size occurred during an evolutionary burst that happened 10 million years after the extinction of the dinosaurs. At that point, visual features in the brain became much more prominent while the olfactory bulbs became proportionately smaller.

More than likely, Bloch said, this change in brain structure and size was related to primates living in closed canopy forests that brought trees closer together and allowed for more leaping. But answering that will require the discovery and analysis of new fossils.

Changes in brain size and brain structure in the early stages of primate evolution have generated enormous debates for decades. But until now, fossil evidence has been lacking.

Many models of the ancestral primate brain are based on tree shrews, which come from southeast Asia and are distantly related to humans. But with some 70 million years of evolution between them and humans, “it turns out tree shrew brains are not a good model,” Silcox said.

The team headed by Eric Ford, an assistant professor of astronomy, used the Canary Islands-based GTC to observe a known star and its Jupiter-sized orbiting planet as part of an effort aimed in part at learning how planets contract in size as their stars age. With analysis of the data from the observations now under way, the team also hoped to glean insights about how to tune the GTC’s capabilities to study not only huge, gaseous Jupiter-size planets but also Neptune-sized or “super-Earth”-sized planets that could be closer in composition to Earth.

“The excellent site and large size of the GTC plus the unique filtering capabilities of its detectors will allow astronomers to minimize the effects of Earth’s atmosphere,” Ford said. “By repeatedly measuring the color of exoplanets’ host stars, astronomers can study the atmospheres of exoplanets — and distinguish small planets from other phenomena such as large star spots or binary stars.”

The UF team’s late-May observations were among several announced earlier this week by the Instituto de Astrofisica de Canarias that marked the long-awaited scientific debut of the GTC, first launched in 2000 on the island of La Palma, and only recently completed. UF contributed $5 million to the roughly $180 million telescope and owns a 5 percent share – the only U.S. institution with an ownership stake in the telescope. The Spanish government owns 90 percent, with Mexico owning the remaining 5 percent.

The GTC’s unique 34.1-foot primary mirror, composed of 36 hexagonal segments, gives it unparalleled abilities to see deep into the universe and examine distant objects in great detail. The telescope is equally notable for the ultra-precise computer control of its mirror segments — control that makes possible more finely detailed images than achievable with other telescopes. Its size and controllability makes the GTC powerful enough to detect an ordinary candle from 20,000 miles away — and resolve the width of its flame from six miles away.

UF astronomers say they will use the telescope to learn more about what occurred in the earliest years of the universe, how stars, planets and galaxies come into being, and to discover and learn more about planets outside our solar system.

“We made this investment because we want our excellent faculty and students to have as much opportunity as possible for top-class research,” said Stan Dermott, chairman of the astronomy department. “In astronomy, that requires access to the best facilities.”

Ford, graduate student Knicole Colón, and postdoctoral associates Brian Lee and Suvrath Mahadven, tapped a Spanish-built astronomical instrument, OSIRIS, to gather the data on the extrasolar star, HAT-P-3, and its planet, HAT-P-3b.

However, A UF-designed and built instrument, CanariCam, is anticipated to be the second instrument installed on the GTC. Among other goals, CanariCam will explore origins and early evolution of planetary systems by imaging the protoplanetary disks where planets are born. UF astronomers also made significant contributions to a third instrument expected to be installed on the GTC known as FRIDA.

“The University of Florida is a partner not just in the observing sense,” Dermott said. “We are also a partner in the sense of being the major builder of instruments for the telescope.”

The GTC’s first, ceremonial observations occurred in 2007, before the telescope’s mirror was complete. A formal inauguration is planned for July 24 on the island of La Palma. King Juan Carlos I and Queen Sofia of Spain will preside over the ceremony.

Now, a team of University of Florida chemists is the latest to report a new mechanism to transform light straight into motion – albeit at a very, very, very tiny scale.

In a paper expected to appear soon in the online edition of the journal Nano Letters, the UF team reports building a new type of “molecular nanomotor” driven only by photons, or particles of light. While it is not the first photon-driven nanomotor, the almost infinitesimal device is the first built entirely with a single molecule of DNA — giving it a simplicity that increases its potential for development, manufacture and real-world applications in areas ranging from medicine to manufacturing, the scientists say.

“It is easy to assemble, has fewer parts and theoretically should be more efficient,” said Huaizhi Kang, a doctoral student in chemistry at UF and the first author of the paper.

The scale of the nanomotor is almost vanishingly small.

In its clasped, or closed, form, the nanomotor measures 2 to 5 nanometers — 2 to 5 billionths of a meter. In its unclasped form, it extends as long as 10 to 12 nanometers. Although the scientists say their calculations show it uses considerably more of the energy in light than traditional solar cells, the amount of force it exerts is proportional to its small size.

But that won’t necessarily limit its potential.

In coming years, the nanomotor could become a component of microscopic devices that repair individual cells or fight viruses or bacteria. Although in the conceptual stage, those devices, like much larger ones, will require a power source to function. Because it is made of DNA, the nanomotor is biocompatible. Unlike traditional energy systems, the nanomotor also produces no waste when it converts light energy into motion.

“Preparation of DNA molecules is relatively easy and reproducible, and the material is very safe,” said Yan Chen, a UF chemistry doctoral student and one of the authors of the paper.

Applications in the larger world are more distant. Powering a vehicle, running an assembly line or otherwise replacing traditional electricity or fossil fuels would require untold trillions of nanomotors, all working together in tandem — a difficult challenge by any measure.

“The major difficulty lies ahead,” said Weihong Tan, a UF professor of chemistry and physiology, author of the paper and the leader of the research group reporting the findings. “That is how to collect the molecular level force into a coherent accumulated force that can do real work when the motor absorbs sunlight.”

Tan added that the group has already begun working on the problem.

“Some prototype DNA nanostructures incorporating single photo-switchable motors are in the making which will synchronize molecular motions to accumulate forces,” he said.

To make the nanomotor, the researchers combined a DNA molecule they created in the lab with azobenzene, a chemical compound that responds to light. A high-energy photon prompts one response; lower energy another.

To demonstrate the movement, the researchers attached a fluorophore, or light-emitter, to one end of the nanomotor and a quencher, which can quench the emitting light, to the other end. Their instruments recorded emitted light intensity that corresponded to the motor movement.

“Radiation does cause things to move from the spinning of radiometer wheels to the turning of sunflowers and other plants toward the sun,” said Richard Zare, distinguished professor and chairman of chemistry at Stanford University. “What Professor Tan and co-workers have done is to create a clever light-actuated nanomotor involving a single DNA molecule. I believe it is the first of its type.”

The National Institutes of Health and the National Science Foundation funded the research. The other coauthors of this paper are Haipeng Liu, Joseph A. Phillips, Zehui Cao, Youngmi Kim, Zunyi Yang and Jianwei Li.

Led by Florida Museum of Natural History vertebrate paleontologist Larisa DeSantis, researchers examined fossil teeth from mammals at two sites representing different climates in Florida: a glacial period about 1.9 million years ago and a warmer, interglacial period about 1.3 million years ago. The researchers found that interglacial warming resulted in dramatic changes to the diets of animal groups at both sites. The study appears in the June 3 issue of PLoS ONE.

“When people are modeling future mammal distributions, they’re assuming that the niches of mammals today are going to be the same in the future,” DeSantis said. “That’s a huge assumption.”

Co-author Robert Feranec, curator of vertebrate paleontology at the New York State Museum, said scientists cannot predict what species will do based on their current ecology.

“The study definitively shows that climate change has an effect on ecosystems and mammals, and that the responses are much more complex than we might think,” Feranec said.

The two sites in the study, both on Florida’s Gulf Coast, have been excavated quite extensively, DeSantis said. During glacial periods, lower sea levels nearly doubled Florida’s width, compared with interglacial periods. But because of Florida’s low latitude, no ice sheets were present during the glacial period. Despite the lack of glaciers in Florida, the two sites show dramatic ecological changes occurred between the two periods.

Both sites include some of the same animal groups, allowing DeSantis, Feranec and Bruce MacFadden, Florida Museum curator of vertebrate paleontology, to clarify how mammals and their environments responded to interglacial warming.

The research examined carbon and oxygen isotopes within tooth enamel to understand the diets of medium to large mammals, including pronghorn, deer, llamas, peccaries, tapirs, horses, mastodons, mammoths and gomphotheres, a group of extinct elephant-like animals.

Differences in how plants photosynthesize give them distinct carbon isotope ratios. For example, trees and shrubs process carbon dioxide differently than warm-season grasses, resulting in different carbon isotope ratios. These differences are incorporated in mammalian tooth enamel, allowing scientists to determine the diets of fossil mammals. Lower ratio values suggest a browsing diet (trees and shrubs) while a higher ratio suggests a grazing diet (grasses).

Animals at the glacial site were predominantly browsing on trees and shrubs, while some of those same animals at the warmer interglacial site became mixed feeders that also grazed on grasses. Increased consumption of grasses by mixed feeders and elephant-like mammals indicates Florida’s grasslands likely expanded during interglacial periods.

Tooth enamel locks in the chemical signatures of the plants and water an animal consumes, allowing paleontologists to understand the diets and associated climate of fossil specimens that are millions of years old. To find these signatures, researchers run samples of tooth enamel through a mass spectrometer.

DeSantis and her collaborators analyzed enamel samples from 115 fossil teeth. For two of the specimens she took serial samples, small samples that run perpendicular to the growth axis and give insight into how the diet and climate changed over a specific period of time.

“That’s one of the cool things about using mammal teeth,” she said. “We can actually look at how variable the climate was within a year, millions of years ago.”

The study highlights the importance of the fossil record in understanding long-term ecological responses to changes over time, DeSantis said. While ecological studies of modern impacts can cover only limited spans of time, “this study emphasizes the importance of using the fossil record to look at how mammals and other animals responded to climate change in the past, also helping us gain a better understanding of how they might respond in the future.”