Humans have two generations of teeth — baby teeth that are replaced by permanent ones — and that’s it. If you need a new tooth, a dentist will give you an implant made from a material that will likely degrade faster than a natural tooth.

But scientists are looking to sharks, which lose and regrow teeth their entire lives, to understand how we might be able to regenerate our own teeth.

New research published in Scientific Reports by GARETH FRASER, a biologist at UF, and colleagues at the University of Sheffield, UK, into human and shark teeth has found similarities in their dental stem cells that shows humans have more potential to regrow teeth than previously believed.

The team found a potential connection between shark and human teeth by examining a specialized layer of thin tissue formed in early development of the vertebrate mouth called the dental lamina.

X-Ray CT Scan of the Porbeagle Shark (Lamna nasus) head, showing the rows of regenerative teeth in the jaws. Credit: Charlie Underwood, Zerina Johanson, and Gareth Fraser; Scanned at the Image and Analysis Centre, Natural History Museum, London.

Once we develop our permanent teeth, the thin tissue of the lamina undergoes normal cell death and fragments, leaving bits and pieces of the lamina. At this stage, they’re known as dental lamina rests (DLR), which were previously thought to have low odds of growing more teeth. Fraser and team research looked at these DLRs and found they contain a number of dental stem cell markers found in vertebrates like sharks that have constant tooth regeneration throughout their lives.

The research also examined tumors that appear in the jaw, called ameloblastoma, to further understand how DLRs undergo change. Ameloblastoma are assumed to come from aberrant lamina rests. The scientists are working to understand how the trigger that causes DLRs to form these tumors could be linked to tooth development and if this could eventually lead to controlled tooth growth in humans.

To view the full study, click here.

On Nov. 14, the Museum of Tolerance in Los Angeles will hold a free advance screening of the documentary “Cojot.” UF professor GAYLE ZACHMANN serves as a Producer and Historical consultant while y alumnus BOAZ DVIR is the Director and Producer.

Zachmann, a professor in the Department of Languages, Literatures, and Cultures and the Center for Jewish Studies, collaborated with Dvir (’88, MA ’08, MFA ’14), to tell the story of the late Michel Cojot-Goldberg, a Holocaust survivor who sets out to kill the Nazi who imprisoned his father and ends up playing a key role in during the 1976 Entebbe hijacking crisis.

“Although the story of an individual, the life of Cojot-Goldberg spans the second half of the 20th century and speaks to a number of different histories,” Zachmann told UF News earlier this year. “From the resistance of individuals and families, hidden children, the rise of fascism and the plight of French Jews during the occupation, to those of post-war memory, justice and modern terror.”

Developed with the help of private support, the film tells the virtually unknown story of Cojot-Goldberg, who planned to kill the infamous Nazi Klaus Barbie. Known as the “Butcher of Lyon,” Barbie personally tortured French prisoners in Lyon and played a direct role in the Holocaust, sending 7,500 Jews to concentration camps.  Barbie also imprisoned Cojot-Goldberg’s father, who was sent to Auschwitz, where he died.

Cojot-Goldberg contacted Barbie in Bolivia posing as a journalist, but once seated with Barbie could not bring himself to pull the trigger. A year later, Cojot-Goldberg then played the improbable role as a translator onboard an Air France flight from Israel to France that was highjacked by terrorists and rerouted to Entebbe, Uganda.

Cojot is an exceptionally fine film concerning the trauma of Jewish identity in France during and after the Holocaust. Spanning major events from Lyon to La Paz to Entebbe, it is well-researched, wonderfully told, and deserves a wide audience.”  NORMAN J. W. GODA, Norman and Irma Braman Professor of Holocaust Studies, and Director, UF Center for Jewish Studies, said.

The screening at the Museum of Tolerance is free and open to the public and will be followed by a discussion with Dvir and Zachmann, along with special guest Olivier Cojot-Goldberg, the son of Michel Cojot-Goldberg.

To learn more about the event and to RSVP, click here.

Using drone technology, a team of UF researchers has uncovered how an ancient Florida village played a pivotal role in pre-Columbian geopolitics.

In research led by anthropology PhD student TERRY BARBOUR, the team discovered that the settlement on Raleigh Island, located on the northern Gulf coast of Florida around 900–1200 AD, operated as a major producer of beads made from seashells. The beads, used in rituals at the time, were highly prized in communities as far from the coast as the lower Midwest.

“In form, scale and purpose, the Raleigh Island settlement has no parallel in the archaeological record of the American Southeast,” said KEN SASSAMAN, Barbour’s advisor and the co-creator of the study. Sassaman is the Hyatt and Cici Brown Professor of Florida Archaeology in the Department of Anthropology.

The researchers used drones to survey the ancient settlement in a fraction of the time traditional methods would have taken. Working with UF partners at the GatorEye Unmanned Flying Laboratory, the team equipped the drone with Light Detection and Ranging (LiDAR) scanners that quickly collected architectural details and topographic data with unprecedented resolution.

Raleigh Island rings
A drone equipped with Light Detection and Ranging quickly collected architectural details and topographic data about the Raleigh Island settlement with unprecedented resolution. The images revealed rings made of oyster shells surrounding 37 residences.

The LiDAR shed light on how the settlement — a complex of at least 37 residential spaces surrounded by 4-meter-tall ridges of oyster shells — was organized to make beads in the very place where shells were found. In several of the living spaces, the researchers’ excavations uncovered ample evidence of large-scale bead production.

The Raleigh Island settlement is one of the few coastal communities where such extensive craft production has been found.

“What we have here is a settlement at the source of this raw material at the time when marine shell was starting to become a heavily demanded social item,” Barbour said. “The fact we have strong evidence of bead manufacture at a site with equally impressive architecture to guide us in understanding how production was organized socially makes this place really special, and as of now the only place like it we are aware of.”

The findings have been published in Proceedings of the National Academy of Sciences. ­Barbour and Sassaman’s collaborators on the project were Angélica Almeyda Zambrano and Eben North Broadbent, the co-directors of GatorEye and UF’s Spatial Ecology & Conservation Lab; Ben Wilkinson, UF assistant professor of geomatics and LiDAR expert; and Richard Kanaski, an archaeologist and Regional Historic Preservation Officer for the U.S. Fish and Wildlife Service.

For Barbour, collaborating with researchers across the UF campus and beyond emphasized the wider impact of his work.

“It forces you to create a product that is not only useful and relevant to your work personally, but also to those you work with,” he said. “This has, without a doubt, been an experience that will help me as I move into the professional sphere.”

UF astronomy lecturer PAUL SELL is among an international team of researchers who have discovered one of the largest nebulae ever observed around a merging galaxy. Their findings, published in Naturereveal the importance of galactic winds in the space between galaxies.

The astronomers discovered the massive, glowing bubble of gas surrounding a galaxy they have named “Makani,” the Hawaiian word for wind. The nebula formed as galactic winds carried large amounts of metal-enriched gas into the expansive “reservoir” between galaxies, known as the circumgalactic medium.

The team, led by David Rupke of Rhodes College, observed galactic winds in a glowing halo of oxygen that reaches extreme distances — more than 20 times Makani’s stellar radius.

This huge outflow, the researchers believe, has been driven by bursts from a compact group of aging and dying stars. Merging galaxies, formed by two once-separate galaxies coming together,  produce a large number of stars in a short time within a small space. The heaviest among them quickly die, rapidly pushing gases out of the galaxy.

UF Astronomy Lecturer Paul Sell
UF Astronomy Lecturer Paul Sell

The findings help explain how metals can be displaced into the far reaches of space.

“What is also remarkable is that the aging and dying stars appear to be powerful enough on their own to do all of the work without the need for a supermassive black hole’s help,” Sell said. “However, we expect one to be buried down in the center of the merging galaxies, maybe quite literally under a lot of dust and gas.”

Sell, who worked as a researcher at the Foundation for Research & Technology at the University of Crete before coming to UF, contributed imaging from the Hubble Space Telescope and super massive black hole analysis. His collaborators also collected data from the W.M. Keck Observatory’s new Keck Cosmic Web Imager instrument and the Atacama Large Millimeter Array.

The research team has been studying a large set of similar galaxies and will be gathering further observations using some of the world’s most sensitive telescopes.

The study was supported by the National Science Foundation, NASA, Rhodes College and the Royal Society.

The giant galactic wind surrounding Makani. The colors and contour lines show the amount of light emitted by the ionized gas from different parts of the oxygen nebula. The black in the center shows the full extent of the galaxy. The axes show distance from the center of the galaxy in kiloparsecs. Figure by Gene Leung (UC San Diego)

You can read more about the researchers’ findings here.

Assistant Professor of Philosophy Duncan Purves has received a grant from the National Science Foundation (NSF) to study the ethics of using artificial intelligence to assist police officers in anticipating crime before it happens.

Assistant Professor of Philosophy Duncan Purves

Researchers from UF and California Polytechnic State University have partnered to conduct the study, with UF receiving $269,610 of the grant’s total $509,946.

Artificial intelligence can be used to predict criminal activity in advance based on past crime statistics of a particular area. By taking this historical data into account, the AI postulates the time and location of possible crimes.

The morality of “predictive policing” is subject to considerable debate, however. Those in favor of the practice believe it to be an asset to a police department, providing a safer and faster alternative to traditional police work. Critics maintain that the technology will violate the rights of those within communities targeted by the algorithm and contribute to racial bias among police officers.

Purves’ research team plans to determine an acceptable way to act on this data, taking into account the potential harm to citizens that can come from algorithm-driven police activity. Additionally, the group will consider the ethical dilemmas involved in predictive policing in general, developing equitable solutions to problems arising from the establishment and implementation of this technology.

“As algorithmic crime-fighting tools become widespread in police departments, it is crucial that ethical questions of fairness, equity, and discrimination are addressed now,” Purves said.​ “This three-year award gives me and my colleagues valuable time and resources to address overlooked ethical implications of predictive policing technologies. Among other products, we will develop a report of empirically and ethically informed best practices for use by police departments.”

The researchers hope for the study to benefit both citizens and police departments, providing insight into the most ethical way to conduct predictive policing. The findings of the study, they expect, will also apply to other uses of artificial intelligence already in areas such as in court systems and medical fields.

To learn more about this grant, click here.

University of Florida chemistry professor Adrian Roitberg will work as part of a multi-university team on a new project that has received nearly $1 million to advance molecular sciences though machine learning.

The team was awarded $994,433 by the National Science Foundation (NSF) to build an open network where molecular scientists from different institutions can contribute their data and access tools to make the most of their research.

By bringing together experimental data and molecular models through machine learning, the platform will allow users to predict how molecules interact in complex systems. The goal is to create a central, collaborative hub that will improve and accelerate the process of creating new products ranging from medicines to smart materials.

Led by principal investigator D. Tyler McQuade, a chemical and life science engineering professor at Virginia Commonwealth University (VCU), the project is among the first to be funded by the NSF initiative Convergence Accelerator, which aims to solve problems by bringing people together across disciplines.

In addition to Roitberg and McQuade, the team includes James K. Ferri, professor in the VCU Department of Chemical and Life Science Engineering, and Carol A. Parish, professor of chemistry at the University of Richmond. The companies Two Six Labs of Arlington, Virginia, and Fathom Information Design of Boston will also collaborate on the project.

The researchers plan to present their prototype in March 2020 in hopes of obtaining $5 million more in funding.

You can learn more about the project here: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1937017&HistoricalAwards=false.

In the epicenter of the Zika epidemic in northeast Brazil, 73 percent of people living in an urban slum in Salvador were infected in 2015. However, in this highly affected population, those with immunity to dengue, a genetically similar virus, had a reduced risk of infection with Zika. University of Florida epidemiologist Derek Cummings is a senior author on the first study to explore the relationship between dengue antibodies and Zika resilience. This new research, published in Science on Feb. 8, 2019, offers insights into how immunity might be conferred from dengue-infected individuals exposed to Zika. “This study is the first to demonstrate that immunity to dengue can protect against Zika infection in human populations,” said Cummings, professor of Biology and faculty in the Emerging Pathogens Institute.

Led by the Brazilian Ministry of Health, a team including Cummings, as well as scientists from the Yale School of Public Health and the University of California San Francisco, examined a cohort of 1,453 residents participating in a long-term health survey in Pau da Lima, Salvador, Brazil. The residents may have been exposed to Zika during the 2015 outbreak in northeastern Brazil. The team then examined a subset of 642 dengue-infected residents and analyzed their risk for Zika. “Even though there was protective immunity in the population, this community was heavily infected,” said Cummings. “We estimate that 73 percent of the population was infected by Zika.”

The team developed a unique assay that measured immunoglobulin G3, which responds to a key protein in Zika. Despite the study area comprising less than one-quarter of a square kilometer, the researchers found an overall attack rate of 73 percent, yet wide variation in the risk of Zika infection across short distances. Likely depending on environmental factors such as mosquito breeding grounds, rates of infection varied from a low of 29 percent to a high of 83 percent.

Out of the 642 samples, 86 percent were positive for dengue, and for those with this prior immunity to dengue, each doubling of antibody titers was associated with a 9 percent reduction in risk of Zika infection.
“Although there are pockets of susceptible populations which were not hit by Zika, the Zika pandemic has created overall high rates of immunity in the Americas, which will be a barrier for outbreaks for the next few years,” said Cummings.

The study was supported by the US National Institutes of Health (grant to the University of Florida NIAID R01 AI114703, other institutes supported by NIAID R01 AI121207, NIAID U01 AI088752, FIC R01 TW009504 and FIC R25 TW009338), Yale School of Public Health and the Brazilian Ministries of Health, Education and Science and Technology.

Surrounded by salty water, sea snakes sometimes live a thirsty existence. Previously, scientists thought that they were able to drink seawater, but recent research has shown that they need to access freshwater. A new study published in PLOS ONE on Feb. 7 and led by Harvey Lillywhite, professor of biology of the University of Florida, shows that sea snakes living where there is drought relieve their dehydration as soon as the wet season hits, and do so by obtaining freshwater from “lenses” that form on the surface of the ocean during heavy rain—events in which the salinity at the surface decreases enough for the water to be drinkable.

The yellow-bellied sea snake (Hydrophis platurus) is the only reptile in the order Squamata that lives on the open sea. It has one of the largest geographic ranges of any vertebrate species. Given its broad range and seafaring existence, during the dry season (6-7 months at the study site in Costa Rica) it has no access to freshwater. How they survive in regions of drought seems to hinge upon access to freshwater lenses, but little is known about how marine vertebrates react to or consume rainfall. “This study contributes to a fuller understanding of how pelagic sea snakes, and possibly other marine animals, avoid desiccation following seasonal drought at sea,” said Lillywhite.

The researchers captured 99 sea snakes off the coast of Costa Rica (interestingly, the snakes have never been observed in estuaries) and offered them freshwater in a laboratory environment. The team happened to be there just as six months of drought broke and the rainy season began. They found that only 13 percent of snakes captured after the rainfall began accepted the offer, compared to 80 percent of those captured before. The rainfall must have quenched their thirst.

The study continues many years of work by Lillywhite. The present paper was coauthored by Mark Sandfoss, Lillywhite’s current PhD student, Coleman Sheehy, his former student who is now the Collections Manager in Herpetology at the Florida Museum of Natural History, and then-Fulbright visiting scholar Jenna Crowe-Riddell.

“How these animals locate and harvest precipitation is important in view of the recent declines and extinctions of some species of sea snakes,” said Lillywhite. The question remains: How will climate change and its effects on precipitation impact the sea snakes?

UF professor receives NEH fellowship to research under-studied African writing traditions

Researcher: Fiona McLaughlin, 352-392-4829, fmcl@ufl.edu

Fiona McLaughlin, professor of linguistics and African languages at the University of Florida, has received a National Endowment for the Humanities Fellowship to work on a new book, Trans-Saharan Literacies: Writing across the Desert, in the 2019-2020 academic year. Only 8 percent of applicants were awarded fellowships this year. This fellowship will support McLaughlin in exploring the social consequences of two overlooked writing traditions in Africa.

The project brings a sociolinguistic perspective to two writing traditions used by populations within and adjacent to the Sahara desert to argue for the conceptualization of a trans-Saharan world of shared historical, religious, and linguistic influences. McLaughlin developed the project over the past decade as she and colleagues have identified cultural continuities across the Sahara. “I decided that looking at writing practices would contribute to reconceptualizing the Sahara and the areas directly to its north and south as a coherent cultural sphere of mutual influence rather than a barrier,” she says.

Both literature and popular conception have tended to portray the Sahara as a barrier between North Africa and sub-Saharan Africa, but McLaughlin’s work suggests that the Sahara should be conceptualized as a cultural sphere of influence, and of religious, economic and intellectual exchange, of which writing is a crucial part.

The research focuses on the everyday writing of African languages in scripts other than the Latin script, specifically the Arabic script, in a tradition known as ajami which arose in the 15th century, and tifinagh, which since the third century BCE has been used to write Berber languages such as Tashelhiyt in Morocco and Tamasheq in Mali and Niger. These vernacular literacies persisted throughout, and provided an important social function in resistance to the imposition of colonial languages. Despite their importance, these literacies have been under-studied, due in large part to colonial and postcolonial depictions of Africa as the “oral continent.”

“There are many ways in which colonialism and Western scholarship have constructed Africa, not least of which is painting it as a continent devoid of literacy before European intervention, and this is simply not accurate,” says McLaughlin.

Moreover, ajami and tifinagh are rarely counted in official surveys of literacy, meaning that we likely don’t have an accurate picture of the prevalence of written language in the region. McLaughlin’s research will break new ground by using these writing systems as a point of departure to re-conceptualize the three countries of the Maghreb (Morocco, Algeria, Tunisia), the West African Sahel (Senegal, Mali, Niger), and the Saharan country of Mauritania, as a coherent trans-Saharan sphere.

“Being awarded an NEH Fellowship allows me the precious gift of time off to concentrate on this project, and it also reaffirms to me that the project is an intellectually worthwhile one,” McLaughlin says.