Researchers: Mark Brenner, brenner@ufl.edu, 352-392-7226, Jason Curtis, curtisj@ufl.edu
PIO: Rachel Wayne, 352-872-2620

The lowlands of Mexico and Guatemala experienced widespread deforestation by the Maya beginning about 4,000 years ago. The region has never fully recovered. Ancient Maya environmental impact provides a case study for the long-term effects of deforestation, and according to a new Nature Geoscience study published today, the implications for current tropical deforestation are far-reaching.

The lowlands of the Yucatan Peninsula were occupied and heavily used by the Maya at the height of their civilization. Contrary to popular belief, “the Maya did not live in complete harmony with the environment, and there is ample pollen evidence throughout the region for severe deforestation over a protracted period of about 2,000 years,” says study co-author Mark Brenner, Professor of Geological Sciences and Director of the Land Use and Environmental Change Institute (LUECI) at the University of Florida.

Carbon sinks are realms in which carbon is sequestered in soil and biomass. Large-scale disruptions of the reservoirs, such as through deforestation, destabilize the sinks, leading to buildups of atmospheric carbon and potential climate effects. In turn, plant life reflects such changes and thereby provides a historical record of fluctuations in carbon storage. This study is the first to focus on soil carbon dynamics in response to protracted land use and suggests that extensive deforestation had dire consequences on agriculture and the availability of potable water. “The findings have relevance today,” said Brenner. “Modern tropical forest loss will likely have longstanding impacts on soil carbon stocks in the future, and there is evidence that abrupt climate changes can have devastating effects on agricultural output.”

The team measured radiocarbon in plant waxes collected from sediment cores obtained from the bottom of lakes in the affected region. The ages of waxes provide insights into the carbon cycle in terrestrial ecosystems. By calculating the age difference between waxes and terrestrial macrofossils (e.g. seeds, charcoal) from the same sediment level in which they were buried, the scientists could assess the persistence of soil carbon over time. The study found that Maya deforestation effectively reduced the transit time by 70 to 90 percent—essentially stripping the soil of its carbon-storage potential.

In the mid-1990s, the UF team of David Hodell, Mark Brenner, and then-PhD student Jason Curtis used lake sediment cores from the Maya Lowlands to explore past climate of the region. They discovered that a series of severe droughts were temporally correlated with the mysterious 9th-century Classic Maya “collapse.” In 2007, they were approached by late Yale professor Mark Pagani and his graduate student Peter Douglas, the lead author of the present study, who were using leaf waxes to study paleoclimate and wanted to run samples from the Maya Lowlands lake cores. “Direct radiocarbon dating of leaf wax molecules and macrofossils from the same sediment depths revealed the fact that the leaf waxes, part of the soil carbon stock, are retained for long periods of time in the watershed,” said Brenner. “That finding led to the present study and the discovery that ancient Maya deforestation accelerated the export of carbon from local soils. That is, vegetation loss shortened the carbon storage time.”

Numerous descendants of the Classic Maya still occupy parts of Mexico and Central America. However, the natural environment in which the ancient Maya lived has not fully recovered from the effects of their agricultural practices, says Brenner.

UF zoologists discover a mysterious disappearance of seabirds on a Florida key.

Contact: Mark Sandfoss
mrsandfo@ufl.edu
513-314-4125
Harvey Lillywhite
hblill@ufl.edu

Mysteriously vanished waterbirds. Cannibalistic snakes. An island with no freshwater except for rainfall. It may sound like a Crichton novel or SyFy original movie, but it’s the reality of Seahorse Key, part of the Gulf Coast Cedar Keys that University of Florida biologists have been researching since the 1930s, when the renowned late zoologist Archie Carr first began studying the unusually large cottonmouth population there.

Cottonmouths are the world’s only semi-aquatic viper and also one of the few snakes that eat carrion. Unlike many other Florida snakes that eagerly consume bird eggs and hatchlings, cottonmouths enjoy a more pescatarian diet, which made them a great neighbor for the birds that nested on the keys. Birds are notoriously messy eaters and, on Seahorse Key, pelicans, cormorants, and other waterbirds made a smorgasbord of fish scraps for the cottonmouths, that also ate the rats lurking around the nests in hopes of snatching an egg or two.

This beneficial arrangement collapsed when the birds suddenly abandoned their nests. In the western part of Seahorse Key, where most of the rookeries were, cottonmouths have struggled ever since, limited to the occasional stranded fish or forced to eat each other. So discovered Mark Sandfoss, UF zoology doctoral student, who was two years into his research on waterbird–cottonmouth mutualism in the Cedar Keys, only to discover that one party was vanishing. In April 2015, the birds abandoned their rookeries on Seahorse Key for reasons still unknown, and as Sandfoss continued to capture, tag, and track the snakes, he found that many of them were small, weak, and dying. The research was published on Nov. 6, 2017, in the Journal of Zoology.

Sandfoss is a mentee of UF biology professor Harvey Lillywhite, who was director of Seahorse Key Marine Laboratory from 1998 to 2012 and who has studied the cottonmouths for almost two decades. “I knew, and was curious about, the dense population of cottonmouths on Seahorse Key for years,” said Lillywhite. “In 1998, I became the director of the Seahorse Key Marine Laboratory and decided to conduct a research program there to better familiarize myself with the island.”

Eleven years prior to Sandfoss beginning his research, Lillywhite and his student and eventual postdoc, Coleman Sheehy, published their observations of the island cottonmouths’ intense foraging behavior, especially below the rookeries. At that time, they noticed that drought was affecting the birds, and therefore the snakes. However, decades of literature showed that the Cedar Keys experienced natural cycles of inhabitation. The total abandonment of the Seahorse Key rookery was unprecedented, but presented what Sandfoss calls a “natural experiment.” What would become of the Seahorse Key cottonmouths?

Over the years, Lillywhite and Sheehy, now the herpetology collection manager at the Florida Museum of Natural History, have continued their annual check-ups of the snakes. Sandfoss was intrigued by their work and cites Lillywhite’s lab as his primary reason for coming to UF.

Cottonmouths (genus Agkistrodon), also called water moccasins, have a broad geographic range, making them a common fright in 16 states. Despite their scare tactic— a threatening gape that shows the white interior of their mouth, hence their name — incidence of human bites is low, and they are not particularly aggressive. They present little danger to humans, said Sandfoss, and “they’re really cool — and nice.” They’re especially so in Seahorse Key, where many have become accustomed to being approached and handled. In Florida, all cottonmouths are the species A. conanti, recently upgraded from a subspecies. (Interestingly, the type specimen for the species description was found just seven miles outside Gainesville.) Fairly tolerant of saltwater, the cottonmouths were able to populate Florida’s barrier islands. Unfortunately, they are not strong oceanic swimmers, and although their island lifestyle is no longer as blissful as it was, they are not well equipped to migrate.

Many snakes are ovivoric (egg-eating) and especially so on islands, where resources are scarce, but the Cedar Keys featured a remarkable symbiotic relationship. Typically, in island ecosystems with both birds and snakes, snakes prey upon the birds, explained Lillywhite. However, at Seahorse Key, the birds feed the snakes in a different way — their table scraps, so to speak. Sandfoss was entranced by the research potential of the Cedar Keys’ denizens: “The behavior and biology of the cottonmouths that survive on these islands is fascinating. It is truly a unique system.”

Although snakes are generally evolved to handle long periods without sustenance, the nesting season had lasted March to November in Seahorse Key, providing a long-term source of energy for the cottonmouths. Despite A. conanti’s guts of steel and exploratory feeding, starvation is still a real possibility and, if not fatal, detrimental to reproductive efforts in a species that bears live young.

Those live young get a taste for their prey in the early days of life, and in the western part of Seahorse Key, where birds bestowed a regular rain of fish detritus upon them, the young quickly lived up to their scientific name, derived from Latin for “fish eater.” Previous research by Lillywhite and Sheehy shows that although cottonmouths won’t turn their nose up at unfamiliar prey, they do develop a palate. On the eastern part of Seahorse Key, where fewer birds roosted before the 2015 abandonment, cottonmouths seem to have adapted to a less fishy diet, and therefore were not as negatively affected by the birds’ departure.

The nearby Snake Key seems to have fared better, although less research has been done there. “Now that bird nesting is occurring on Snake Key and not Seahorse Key we are interested to see how Snake Key cottonmouths will fare as a population,” said Sandfoss. “We suspect that the Snake Key population will receive some positive benefits from the presence of the nesting waterbirds.” The team plans to continue monitoring the keys and tracking the cottonmouth population. Meanwhile, Sandfoss, who received the 2017–18 Seahorse Key Fellowship, is tackling the question of how snakes subsist in an environment virtually free of freshwater — another characteristic of these unusual, island-dwelling snakes. Clearly, life finds a way in the Cedar Keys.

See photos and more on Exposure.

LIGO and Virgo Detect Gravitational Waves from Neutron Star Collision for the First Time

Contacts:

Guenakh Mitselmakher, 352-871-1663;

Stephen S. Eikenberry, 352-514-7632;

Imre Bartos, 917-455-6264;

David Tanner, 352-318-3985

 

Neutron stars are dead stars collapsed into the densest form of matter known to humans, with a teaspoon of neutron star matter weighing a billion tons, and their collision creates a swath of galactic debris. Decades ago, stargazing scientists formed plans to detect signals from this debris. Now, in the new era of aptly named “multi-messenger astronomy,” two international projects have achieved this goal: On August 17 of this year, the Laser Interferometer Gravitational-Wave Observatory (LIGO)’s two U.S.-based interferometers and the Virgo Collaboration’s Italy-based interferometer detected for the first time gravitational waves — ripples in space-time traveling at the speed of light — from the collision and subsequent merger of two neutron stars. The detection occurred just three days after yet another “chirp” from colliding black holes.

This is LIGO’s fifth significant detection of gravitational waves from a catastrophic cosmic event, but the first detection from a kilonova. The Aug. 14 and 17 chirps were the first for Virgo. LIGO sent an alert to about a hundred observatories around the world, sparking a six-hour hunt for light and other emissions within a banana-shaped band of cosmic signals from the event. At an unprecedented scale of international, interdisciplinary collaboration, 60 observatories confirmed that the ripple of gravitational waves were indeed from a kilonova. A broad range of so-called cosmic messengers (gravitational waves, gamma-rays, X-rays, light, radio waves) have been recorded from the collision, marking the beginning of what astronomers refer to as “multi-messenger astronomy.”

Gravitational waves carry information on the acceleration of heavy objects, such as what occurs during the merger of two neutron stars or black holes. In this case, they told scientists that the neutron-star merger occurred about 120 million light years from Earth, closer than scientists’ previous expectations. The discovery was almost simultaneous with a sharp burst of gamma rays observed by two orbiting satellites, Fermi and INTEGRAL.

Neutron star mergers were one of the original motivations for constructing the LIGO detectors, an endeavor that began half a century ago and became the biggest project the National Science Foundation ever funded. In the Advanced LIGO project stage, the interferometers heard the first chirp of gravitational waves from merging black holes in September 2015. The discovery, announced last February, heralded the beginning of gravitational-wave astronomy and earned the LIGO Scientific Collaboration much acclaim.

Scientists in the LIGO Scientific Collaboration, of which UF is a founding member, and elsewhere are using their observations of the neutron-star merger to study the universe as well as the fundamental laws of nature. Currently, gravitational-wave detectors have 232 institutions and about 1600 scientists as members. UF has made key contributions to these studies across the entire scope of the project. Physicists now better understand how extremely energetic photons are produced in outer space. LIGO enables scientists to study the expansion of the universe in unprecedented ways by comparing the observed gravitational waves to what is known about the distant galaxy in which the merger happened more than 100 million years ago. Physicists are also increasing their understanding of how matter behaves at densities greater than that of the atomic nucleus.

UF made seminal contributions to infrared and optical observations of emissions from the debris around the merged neutron stars. Led by Steve Eikenberry of UF Astronomy, UF built the FLAMINGOS2 instrument, a near-infrared imaging spectrograph installed in the Gemini-South 8-meter telescope. FLAMINGOS2 detected the infrared emission 12 hours after the chirp took place and helped confirm the signal, which was characteristic of a kilonova.

In addition, newly appointed UF Physics faculty member Imre Bartos plays a leading role in searches for neutrinos from the merger, probing emission mechanisms at extreme energies. “Neutrinos are notoriously hard to detect, so we use IceCube, a billion-ton detector deep in the ice under the South Pole in Antarctica,” said Bartos. “No extra neutrinos were seen from this event, but even this allows us to set limits on what happened following the merger.”

UF became the third university to join LIGO after Caltech and MIT. The UF-LIGO team in the Department of Physics has spearheaded the design and construction of crucial components of the LIGO observatories and was responsible for the input optics (IO) of both the initial and the Advanced LIGO detectors. The IO is one of the most complex parts of the detector, and many key components were fabricated at UF. Florida also made significant contributions to the optical design of the main interferometer. The team working on these efforts includes Guido Mueller, David Reitze, David Tanner, Paul Fulda, and John Conklin. Hai-Ping Cheng leads the computational effort to reduce thermal noise in the detector.

UF’s Sergey Klimenko and Guenakh Mitselmakher developed the algorithm that discovered the first gravitational-wave signal in LIGO data on September 14, 2015. The UF algorithm is now being used to study the fate of the neutron stars after they merged.

The discovery was published on Oct. 16, 2017 in the Astrophysical Journal Letters (PDF).

This year’s Physics Nobel Prize was awarded to three scientists who were instrumental in the construction of LIGO and the first direct observation of gravitational waves, published last year. This award was given independently of the discovery of the neutron star collision.

LIGO is funded by the NSF and operated by Caltech and MIT, which conceived of LIGO and led the Initial and Advanced LIGO projects. Financial support for the Advanced LIGO project was led by the NSF with Germany (Max Planck Society), the U.K. (Science and Technology Facilities Council) and Australia (Australian Research Council) making significant commitments and contributions to the project. More than 1,200 scientists and some 100 institutions from around the world participate in the effort through the LIGO Scientific Collaboration, which includes the GEO Collaboration and the Australian collaboration OzGrav. Additional partners are listed at http://ligo.org/partners.php. The list of UF senior LIGO members is Guenakh Mitselmakher (PI), David Tanner, David Reitze (LIGO Executive Director), Sergey Klimenko, Guido Mueller, Bernard Whiting, Steve Eikenberry, Hai-Ping Cheng, John Conklin, and Imre Bartos.

The Virgo Collaboration comprises more than 280 physicists and engineers belonging to 20 different European research groups: six from Centre National de la Recherche Scientifique (CNRS) in France; eight from the Istituto Nazionale di Fisica Nucleare (INFN) in Italy; two in the Netherlands with Nikhef; the MTA Wigner RCP in Hungary; the POLGRAW group in Poland; Spain with the University of Valencia; and the European Gravitational Observatory, EGO, the laboratory hosting the Virgo detector near Pisa in Italy, funded by CNRS, INFN, and Nikhef.

See this story with rich media on Exposure.

Anthropological analysis of shark bites provides a new standard for forensic science.

Although the fear of sharks has persisted for centuries and shows no sign of cessation, a great white is the least of Floridians’ risks in the water. Now, UF forensic anthropologists and the Florida Museum’s shark expert have joined forces to use sharks’ behavior to help forensic scientists determine cause of death for those who perish at sea. A paper published in the Journal of Forensic Sciences in May 2017 analyzes six cases in which human remains were recovered from the oceans around Florida.

The C.A. Pound Human Identification Laboratory does forensic casework for any agencies and professionals who need the identity and cause of death for human remains. When Allysha Winburn, PhD ’17, and Michala Stock, PhD candidate and alumni fellow, were assigned a case involving a partial skeleton recovered from Florida’s Atlantic Coast, they discovered what appeared to be shark bites on the bones. “I thought, hey, we have a shark specialist here. Let’s call the shark specialist!” recalls Winburn, referring to George Burgess of the Florida Museum of Natural History. Their examination led them to conclude that a bull or tiger shark had likely scavenged on the adrift remains. They applied anthropological analysis to five other cases documented in forensic literature and crafted some guidelines to help investigators and medical examiners determine two things for bodies found in the ocean: Shark attack or no? If shark, predation or scavenging?

Allysha Winburn, PhD candidate, examines remains.

“Sharks seem scary, but in the ocean, you’re more likely to die another way.” – Allysha Winburn

“Sharks seem scary, but in the ocean, you’re more likely to die another way,” Winburn says, echoing the sentiment expressed by shark experts everywhere, including Burgess. With each news report of a shark attack, galeophobia (fear of sharks) surges again, while game fishing of sharks and overfishing of their food supply continue to decimate their populations. It’s no surprise that sharks scavenge on human victims of boating accidents; however, most shark species, with the notable exception of tiger sharks, apparently don’t care for the taste.

Winburn, a former bioarchaeologist, is excited about the prospects of the paper. “I hope the findings will be used whenever shark-scavenged remains are found,” she says. Some hallmarks include parallel gouging in the bones with striations that indicate serrated teeth that indicate a marine carnivore (terrestrial ones usually have smooth teeth), compression fractures that indicate a powerful jaw, and torsion patterning that reflect sharks’ twisting form as they bite.

young woman in lab coat using tool to measure human skull Michala Stock, Alumni Fellow at the Pound Lab, measures a skull.

 

“It feels meaningful to have a very specialized skillset that can be deployed to help people to rest.” – Michala Stock

Both Winburn and Stock are NYU alumni; other than that, their collaboration the nexus of forensic anthropology and shark research was fortuitous. Stock arrived at UF four years ago after completing her Master’s at NYU. A former professional dancer and the daughter of a physician, Stock naturally was intrigued by the human form and how the skeleton shapes physicality. Her dissertation research examines how human sexual dimorphism emerges during childhood development of the skeleton.

Winburn, who arrived at UF seven years ago to switch careers after seeing how forensic anthropologists helped identify Katrina victims, tackles the questions of the aging skeleton from the other end, studying whether physical stress such as intensive exercise exacerbates age-related changes in the hip joint. Her findings suggest that the acetabulum — the pelvis side of the hip joint — is an accurate marker of age.

Together, they’re providing scientific standards for identifying human remains, as part of a relatively small academic community. They are only 400–500 practitioners of forensic anthropology in the United States, explains Winburn. “It’s not glamorous … it’s dirty, thankless and psychologically difficult field,” she says. “So if you have the skillset and mindset to do it — do it.” She points out that many cold-case victims are from minority or marginalized populations. “If we can be the voice for those people, then let’s be the voice for those people,” she says. Stock adds, “It feels meaningful to have a very specialized skillset that can be deployed not only to help people to rest, but to bring information and closure to the people remaining.”

Both are quite familiar with the gravitas of their discipline. After pursuing forensic anthropology, Winburn joined the renewed excavation of the ruins of the World Trade Center in 2007. Eight years later, Stock worked on a later phase of the project. “Every anthropologist and archaeologist from the Tri-State Area was employed to sift through [and identify] those remains,” Winburn says.

The field has been growing thanks to the popularity of Kathy Reichs’ semi-autobiographical novels about forensic anthropologist Temperance Brennan, and her TV counterpart of the same name, nicknamed “Bones.” Winburn is appreciative of pop culture’s portrayal, even if it’s not as glamorous, “if it brings people into the field.” She and Stock are less impressed by the scientific accuracy — or lack thereof — of shark research in recent shark movies. “Sharknado?!” laughs Stock.

Of course, in forensic anthropology, sharks are less the villains and moreso the bystanders — and sometimes, a clue. Thanks in part to Winburn, Stock, and Burgess’ research, the shark standards are being set for forensic science to find out the tooth — er, truth.

See this story as part of a three-story series about the intersections among the studies of humans, sharks, and their relationship.

UF psychologist Lori Knackstedt studies an antibiotic that may cure cocaine addiction.

Lori Knackstedt, professor of psychology, is seven years deep into research that’s yielded some surprising results: in cocaine-addicted rats, an antibiotic reduces their drug-seeking behavior and may prevent relapse. The drug Ceftriaxone appears to increase reuptake of glutamate, a neurotransmitter that regulates dopamine, the crux of the reward system. Knackstedt’s team wonders why.

Her latest paper, published online May 11 in the Journal of Neuroscience, has identified novel mechanisms of how Ceftriaxone (abbreviated “Cef”) reduces cocaine seeking. However, they also found that Cef is not directly increasing gene expression of two key glutamate transporters, GLT-1 and xCT. “We do find that this antibiotic changes things in the brain,” she says. “We’re just not sure how it’s doing it.”

Knackstedt’s fascination with behavior motivates her research. Her neurobiological approach stems from her undergraduate education in biology, where a neuroscience course piqued her interest in how cellular brain processes affect behavior. Now, she’s concerned with the practical aspects of behavior modification. The Ceftriaxone research examines how an antibiotic is disrupting the reward pathway in the nucleus accumbens — the reward center of the brain — and now that they know it’s not acting directly on DNA, the team is one step closer to understanding how Cef reduces excess glutamate that supports continued addiction and encourages patients to relapse.

Next, the team will expand their perspective beyond the nucleus accumbens, but that requires a broader approach: proteomics, a portmanteau of “protein genomics,” involves the use of a mass spectrometer to analyze tissue. An emerging body of research shows that “listen to your gut” has some neuroscience behind it; a reduced gut microbiome has been linked to cocaine relapse, as well as anxiety and depressive disorders. Cephalosporin antibiotics such as Cef have been shown to reduce these behaviors, but their role in the gut–brain axis is not well understood.

Nevertheless, overuse of antibiotics has its own set of side effects. Thus, Knackstedt’s side project is to get the best of both worlds: “I’m interested in developing a drug with reduced side effects to treat addictive behaviors,” she says. “Ceftriaxone is a real contender.”

See this story and learn more about the neurobiology of addiction on Exposure.

UF’s David Blackburn unlocks the frog Tree of Life.

Among UF’s renowned team of extinction experts is David Blackburn, whose appreciation for frogs has led to his work on a groundbreaking new study. A paper published in July in the Proceedings of the National Academy of Sciences shows that although frogs have been around for longer than dinosaurs, most of the world’s 6,700-plus living species of frogs evolved after a mass extinction 66 million years ago made way for new biodiversity.

Perhaps best known among mass extinctions, if not actually the most devastating, is the one that killed the dinosaurs. This event, called the Cretaceous–Tertiary extinction (K–T for short, to remind you that “Cretaceous” has a hard C), or more precisely the Cretaceous–Paleogene (K–Pg) extinction, caused a global die-off of 75 percent. Evolutionarily, these closed doors allowed others to open. Frogs, a highly adaptive type of creature, occupied many new niches, especially those created by a bloom of angiosperms, or flowering plants. Frogs took to the trees, which well suited their reproductive and self-defense needs.

This new analysis shows that the frog family tree’s new crop of branches spread out from the extinction event between the Cretaceous and Paleogene periods — the K–Pg boundary, formerly called K–T — not 100 million years ago. The results were surprising to both the researchers and the scientific community, because previous mitochondrial DNA analysis traced major extant frog lineages to about 35 million years earlier than the K–T extinction, in the middle of the Mesozoic era.

Frogs also took on very different forms, with some retaining the commonly known tadpole stage and others evolving direct development, in which minuscule frogs hatch out of the eggs. They now occupy a wide range of habitats, from semi-arid regions of Africa to the super-humid South American rainforests, from clumps of leaves on the forest floor to the tops of trees.
David Blackburn is the Associate Curator of Herpetology at the Florida Museum of Natural History and an Affiliate Professor of Biology in the College of Liberal Arts and Sciences. He also is part of the Tropical Conservation and Development program, the School of Natural Resources and Environment, and the Center for African Studies.

Visit the Blackburn Lab website.
See this story and photography at Exposure.

LIGO detects third set of gravitational waves from colliding black holes. UF physicists have played a key role in these detections.

UF’s team of physicists working on the Advanced LIGO project are continuing their trend of cosmic discoveries. On January 4, 2017, gravitational waves were detected by both of the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, La., and Hanford, Wash. This is the third gravitational wave event identified by the LIGO Scientific Collaboration and the Virgo collaboration. The previous detections occurred on September 14, 2015 and December 26, 2015.

The latest detection is especially exciting. Like the previous two gravitational-wave events, this one was produced by black holes that collided and merged. However, “this merger happened 3 billion years ago and it is the most distant of all confirmed events that were detected by LIGO so far,” explained University of Florida Professor of Physics Sergey Klimenko. “Like the others, within a second, it turned the energy of about two solar masses into gravitational radiation.”

The event was unambiguously identified by three independent search algorithms — one of which, Coherent WaveBurst, was developed at the University of Florida by a group of researchers led by Klimenko and fellow faculty member Professor Guenakh Mitselmakher.

The University of Florida has been an important part of the LIGO project since 1996, when UF Physics faculty began development of Coherent WaveBurst, as well as the input optics, one of the most complicated components of the LIGO detector.

Gravitational waves carry information about their origins and about the nature of gravity that cannot otherwise be obtained, and physicists have concluded that the gravitational waves, like those LIGO previously detected, were produced during the final second of the merger of two black holes — 31 and 19 times the mass of our sun — to produce a single, more massive spinning black hole that is 48 times the mass of the sun.

“Advanced LIGO continues to reward us with observations of absolutely spectacular signals from the collisions of black holes. These highly energetic events are telling us about the nature of space and time,” says David Tanner, a University of Florida professor who, together with Professor Guido Mueller, has led development and construction of the LIGO input optics.

One of the most remarkable features of all gravitational wave detections so far is that the signals arise from binary black hole systems, with masses in a range that was completely unexpected. “This is very exciting,” said UF Professor of Physics Bernand Whiting, “especially because less than two years ago, we did not know of their existence, and we are now beginning to [develop] models of their formation.”

The LIGO Laboratory is funded by the National Science Foundation and operated by Caltech and MIT, which conceived and built the Observatory. LIGO research is carried out by the LIGO Scientific Collaboration (LSC), a group of more than 1000 scientists from universities around the United States and in 14 other countries. More than 90 universities and research institutes in the LSC develop detector technology and analyze data; approximately 250 students are strong contributing members of the collaboration. The LSC detector network includes the LIGO interferometers and the GEO600 detector.

See this story on Exposure.

UF biology alumnus to speak at TED in Tanzania.

Marine biologist and UF Biology alumnus Mike Gil PhD’15 has been named a TED Fellow and is one of 21 international experts who will attend and speak at this year’s TEDGlobal, TED’s annual conference, which will take place in Arusha, Tanzania in August. “I’m truly honored by the distinction,” says Gil.

Gil shares his research stories on his vlog for his nonprofit SciAll.org, through which he endeavors to debunk myths and inspire interest in marine biology among the world community. The vlog includes funny moments such as fish attempting to eat his camera, scenes of adventure such as underwater footage of whales and turtles, and Gil’s direct-to-camera discussions of science careers, the nature of scientific inquiry, and how to become a marine biology. Through these videos, Gil reflects upon his own journey as a scientist while presenting science as a source of wonder and understanding.

“Humans affect ecosystems that we, as a society, have come to rely heavily upon,” he says. “I think this is among the most pressing research topics of our time.” His major research projects have revolved around the effects of human activity, especially pollution, on marine environments. At the University of Florida, his dissertation project examined nutrient pollution in coral reefs caused by nitrogen-loaded industrial and agricultural runoff. Much like when you don’t clean your fish tank, nutrient pollution can lead to algae blooms that choke coral reefs.

Gil’s recent cover story of the Proceedings of the National Academy of Sciences also touched on the algae problem. In the paper, he explains how fish eat socially and, by eating algae, help protect coral reefs. However, overfishing decimates fish populations and makes this social eating — and thus overall eating — less likely and algae takeovers more likely.

In 2012, Gil set sail on the SSV Robert C. Seamans on a research cruise with the Sea Education Association. Their itinerary took Gil through the North Pacific Subtropical Gyre, one of several such vortices in the world’s oceans that draws oceanic debris — especially plastics — into clumps that provide refuge for various species. Gil counted organisms living among the debris he pulled aboard and studied barnacle-made structures that constituted microbiomes on the plastic debris. His findings were published in Scientific Reports on Jan. 27, 2016. In a collaborative project with fellow UF Biology graduate Joseph Pfaller PhD’16, to whom Gil provided data about the mating pairs of oceanic crabs (Planes minutus) that he found on the debris, they offered evidence for a new spatial-behavioral model of symbiosis.

Gil says that his primary drive as a biologist is to study ecosystem resilience, i.e. the ability of an ecosystem to adapt to external stressors, especially anthropogenic factors, to help inform conservation efforts for future generations’ well-being. “To make the world aware of these answers will determine the future of our species (including our children, grandchildren, great grandchildren, and so on),” he says. “Fortunately, there is a simple, objective process that we can use to answer these questions, and it is called science.”

In addition to being a science educator and communicator, Gil is currently a National Science Foundation (USA) Postdoctoral Research Fellow at the University of California, Davis.

TED has taken note of his double-edged approach to science and saving the world, stating: “We choose Fellows based on remarkable achievement, their strength of character and on their innovative approach to solving the world’s tough problems.”

“Ever wonder if true adventure still exists in this world?” asks SciAll.org’s tagline. Thanks to Mike Gil, we don’t have to.

Professor of Anthropology Richard Kernaghan receives an ACLS fellowship for new book project.

Richard Kernaghan, assistant professor of anthropology at UF, has received a fellowship from the American Council of Learned Societies to pursue his new book project, Semblance in Terrain: On the Legal Topographies of Postwar, in Peru’s Upper Huallaga Valley. Expanding upon the work of his previous book, Coca’s Gone, Kernaghan draws on his more than 20 years of experience in a region historically linked to the Andean cocaine trade. Semblance in Terrain examines how following the military defeat of the Maoist Shining Path insurgency, new relations between physical geography, territory and rural transit emerge, while carrying forth traces of political violence.

To simply write about the largely “undocumented” history of the Huallaga Valley does not illuminate its transformation through the milieu of war, development, and daily life. Nor does anthropology benefit from secondary glances at bureaucratic charts or casual histories — which barely exist for the Huallaga Valley, anyway — or histories devoid of spatial and behavioral shifts. To tell a fuller story of the Valley, Kernaghan combines the methods of ethnography, historical inquiry, and photography.

Richard Kernaghan with river behind him
Richard Kernaghan in the field

 

Kernaghan began his research on Peru in 1995 as part of his doctoral studies at Columbia University, and he’s been returning to the Huallaga Valley ever since to conduct fieldwork. “When I made my initial visit in the mid-1990s, the military conflict was still unfolding,” he says. One of the most striking features of everyday life in the Huallaga of those years was how the valley’s rural expanses seemed at once politically remote and charged with danger. “Early on, it was hard to travel in the countryside for more than very brief visits,” he recalls. On the main road, the likelihood of insurgent ambushes and the wide-distribution of military checkpoints frequently interrupted transit. News spread through rumors swirling with flimsy accounts and unfettered hype, affirming the apparent danger. And yet Kernaghan says the stories people told of their own experiences were what he found most remarkable. “It was stunning — the ways they could combine deep-seated dread with moments of wonder or surprising turns of fate,” he says. As they shared accounts of prior events, they also told of what was transpiring in the countryside, conveying concrete advice about where it was not yet safe to go. In so doing they illuminated and re-enforced territorial practices — a crucial aspect of what Kernaghan’s new book explores.

Semblance in Terrain describes how attention to rural mobility in the wake of a counter-insurgency war can serve as a critical lens for reading and registering histories of violence. During his ethnographic research for the book, Kernaghan accompanied people who have spent their lives shuttling others around the valley in rafts, canoes, pickup trucks or three-wheeled auto rickshaws. His project description says it most succinctly: “I track transformations of rural routes, spatial prohibitions, and land ownership by analyzing the personal histories and material practices of current and former transportation workers (transportistas).” Despite its war-time military importance, the Huallaga Valley has not figured prominently in scholarly studies of Peru’s internal conflict. Literature on this region tends to be policy-oriented and relatively removed from the everyday experiences of the area’s longtime residents. Kernaghan contends that the voices and accounts of transportistas not only deserve to be heard, but also that without them, territorial transformations of the post-war era cannot be understood.

As the conflict has waned, new legal conditions have emerged — these have made it easier for to document how the new road construction and the expansion of rural mobilities have altered local topographies in visible yet unappreciated ways. Scenes of transportistas and their vehicles fill a new special digital collection at UF’s Smathers Libraries. Comprising almost 250 photographs and video clips, the collection constitutes an important part of his ethnographic work. In a core practice of visual anthropology, Kernaghan is creating conversation between both the photographic memories and the verbal images transmitted through the accounts of transportistas. “By setting different kinds of images side by side, I show that war does not end by ending,” says Kernaghan in his project description.

Kernaghan will finish the book, which is about halfway done, over the next year with support from the fellowship. It will be published by Stanford University Press, which also published Coca’s Gone.

See this article and additional photography on Exposure.

UF researchers conduct first implicit bias research on environmentalist attitudes and behaviors.

UF Assistant Professor of Psychology Kate Ratliff and graduate researcher Liz Redford have published the first study using implicit measures of attitudes toward environmentalists. The paper was published on March 28 in the Journal of Environmental Psychology. Their research, conducted in collaboration with Jenny Howell, assistant professor of psychology at Ohio University, suggests that people’s implicit attitudes towards environmentalists aren’t as favorable towards environmentalists as they say they are.

Combining data from Project Implicit, which offers online implicit association tests (IATs) to the global community, with data from on-campus research, the researchers found that implicit attitudes about the prototypical environmentalist better predicted environmentally friendly behavior, such as recycling or carpooling, than explicit attitudes. However, explicit attitudes are inflated compared to implicit ones, as people manage their impressions by emphasizing their “green” philosophy, even if they don’t walk the talk.

Kate Ratliff standing in front of bulletin board
Kate Ratliff in her office

“Humans are incredibly social,” said Ratliff. “We care about what others think of us, and these results suggest that we’re more likely to engage in behavior that is good for the environment if we believe that we’ll get positive regard — from ourselves or others — for doing so.” This phenomenon, called social desirability bias, can be mitigated by using IATs, which require rapid responses that leave no room for higher-level thinking.

The IATs and speeded self-reports assessed respondents’ evaluations of environmentalists in five positive and negative dimensions: attractiveness, fun, cool, intelligence, and “judgmentalness.” For the first three dimensions, respondents’ implicit attitudes weren’t as favorable toward environmentalists as their explicit values, perhaps because people have internalized negative societal attitudes, even if they say they think environmentalism is “cool.”

“Even if we think it’s important to eat vegetarian, for example, we might not do so if we have negative views of the typical vegetarian,” said Ratliff. However, implicit attitudes better predicted environmentally friendly behavior than did explicit attitudes. The exception was on the intelligence value, for which both implicit and explicit attitudes predicted green behavior.

Interestingly, on the “judgmentalness” dimension, implicit and explicit attitudes were equally favorable, and self-reported green behavior was not predicted by those attitudes. However, for those with less positive explicit attitudes, implicit attitudes were linked to less green behavior. That is, how people behave has a lot to do with implicit, automatic evaluations of groups associated with the behaviors in question.