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A photo of a Himba father and son.

Study of African society inspires broad thinking about human paternity, fidelity

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A new study from UCLA professor of anthropology Brooke Scelza invites geneticists and sociologists to think more broadly about human fidelity and paternity.

Scelza’s study, published in the journal Science Advances, uses data from a long-term anthropological study in Namibia with Himba pastoralists. She found that Himba have the highest recorded rate of what researchers call “extra-pair paternity.” The term refers to an instance in which a child is born to a married couple, but the husband is not the biological father.

The rate of extra-pair paternity found among Himba is 48%, far exceeding the 1% to 10% range previously thought to be typical for humans. Having children with non-marital partners was widespread among this group. A high percentage of couples (70%) had at least one child who was fathered by someone outside the marriage.

Extra-pair paternity is typically thought to occur at the expense of the husband, who is ostensibly being “tricked” into caring for a child who is not biologically his, Scelza said. However, her team shows that Himba men and women are highly accurate at detecting extra-pair paternity in their children. And Scelza contends that men not only are aware of this pattern, but they also have a system of social norms that support the practice.

A photo of a Himba father and son.

Brooke Scelza’s study found that “Himba have strong beliefs about the importance of social fatherhood, that a child is yours if it is born to your wife, regardless of paternity.” Photo Credit: Brooke Scelza/UCLA

“Himba have strong beliefs about the importance of social fatherhood, that a child is yours if it is born to your wife, regardless of paternity,” Scelza said. “Both the stigma that typically surrounds women having multiple partners and the bias that might lead to children being mistreated are markedly lower among Himba than they are in much of the rest of the world.”

It was important for researchers to collaborate closely with members of the Himba community involved in the study for ethical and logistical reasons that come up whenever paternity is at issue. For this study, Scelza and her team, in collaboration with the community, designed a novel double-blind method of analysis, so that none of the researchers was privy to both genetic data and individual-identifying information. The team received ethical approval for the study from Namibian Ministry of Home Affairs and the University of Namibia, as well as UCLA and the State University of New York’s Stony Brook University.

This research, while focusing on a small group, provides a new perspective in the study of human reproduction, Scelza said.

Generally, researchers believe that extra-pair paternity is rare among humans. Geneticists have estimated the extra-pair paternity rate in populations from the Netherlands and other European-descent communities. Historically, they have found the rate in these societies to be extremely low, from 1% to 6%.

Over the last decade, more social scientists have begun to focus on diversity and inclusivity when it comes to research samples, rather than focusing solely on people from Western societies, which has been the norm.

“Anthropologists have long emphasized the need to include diverse groups in research,” said Dr. Brenna Henn, a population geneticist formerly at Stony Brook and now at UC Davis, and co-author of the study. “Geneticists are still catching up. Our study shows that paternity rates can vary widely across different populations.”

Scelza emphasized that there is no “correct” or “moral” standard that researchers should think about when examining human reproductive behavior. In Himba culture, for example, extramarital sexual activity is common and not stigmatized.

“What we’re starting to understand and examine is how social and biological notions of paternity reflect complex suites of locally relevant norms, traditions and cultural histories,” Scelza said.

Scelza has been working with the Himba people for 10 years. A previous study published in Nature Human Behavior about infidelity also included Himba.

This article originally appeared in the UCLA Newsroom.

A photo of Michelle Craske.

Michelle Craske to share how research can inform anxiety and depression treatment

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A photo of Michelle Craske.

Michelle Craske and colleagues are studying how to integrate virtual reality into treatment for anxiety and depression. Photo Credit: Reed Hutchinson/UCLA

For more than three decades, Michelle Craske has been trying to understand what makes some people prone to anxiety and depression. She’s studied what biomarkers, behaviors and thinking patterns contribute to these conditions, and how to use that knowledge to develop better treatments.

At the 128th Faculty Research Lecture, Craske, distinguished professor of psychology in the UCLA College, will describe some of her findings and talk about how virtual reality has begun playing a role in changing patients’ mindsets for the better. The talk will be held at 3 p.m. on Wednesdsay, Feb. 19.

“Anxiety and depression are dramatically increasing in prevalence,” said Craske, who is also a professor of psychiatry and biobehavioral sciences at the David Geffen School of Medicine at UCLA and holder of the Joanne and George Miller and Family Endowed Chair. “We need to understand the engine that’s driving these conditions so we can improve our treatments.”

In the U.S., only about half of people with symptoms of anxiety or depression receive treatment. And when they do get help, treatments are only effective about half the time, said Craske, also an executive committee member for the UCLA Depression Grand Challenge, a campus-wide initiative that aims to cut the global burden of depression in half by 2050.

Much of Craske’s work on anxiety centers on the idea that people prone to anxiety disorders, which affect an estimated 18% of U.S. adults each year, anticipate threat more often than others and have difficulty inhibiting this fear. Most people feel fearful when faced with a real threat — say, a bear in front of us in the woods. But people most at risk for anxiety disorders are more likely to respond to an uncertain situation — feeling afraid in the woods even when there’s no bear, for instance.

The challenge for clinicians like Craske is to decrease this anticipation of threat. Craske uses a technique known as exposure therapy, in which a person is exposed to a situation or setting that makes them anxious, in an attempt to train their brain that it’s safe. Craske utilizes prediction error learning to explain the effects of exposure therapy and attempts to optimize such learning. The greater the element of surprise, the more the learning sticks.

“We want to design a treatment where a person says, ‘Oh, I was wrong! I really expected this to be unmanageable or even risky and it wasn’t at all,’” Craske said.

Craske’s research aims to make people with depression — or those prone to depression — more motivated to work toward and to savor rewards. This “reward sensitivity” is often dampened by depression and Craske thinks it’s an avenue for potential treatments to target. For example, in her studies of the effects of kindness and compassion on depression, she has found that training people how to more regularly engage in acts of kindness can ease their symptoms.

Craske and colleagues also are studying how to integrate virtual reality into treatment for anxiety and depression.

“We use virtual reality to help people face the situations they fear and avoid, and at other times we use virtual reality to increase their capacity for positive emotions,” she said. “By immersing themselves in positive scenes we can teach them how to anticipate and savor rewarding events and then transfer that to real life.”

In her talk, titled “Anxiety and Depression: Risk Factors and Treatment,” Craske wants to convey a sense of her scientific approach, which builds off her background as a clinical psychologist to improve psychotherapies. It will take many different perspectives, however, to solve anxiety and depression, she said. In her role with the Depression Grand Challenge, she helps build collaborations between researchers like herself and those that study psychological diseases from a genetic, molecular or neurological point of view.

Craske looks forward to presenting her research, and hopes the audience comes away from her lecture feeling hopeful about the progress that science is making on anxiety and depression.

“I am deeply honored to have been selected to give this lecture which represents the true pinnacle of my career at UCLA,” Craske said.

The Faculty Research Lecture — a UCLA tradition since 1925 — is free and open to the public and will be held at 3 p.m. on Feb. 19 in the Schoenberg Music Building. Please RSVP here if you’d like to attend.

This article originally appeared in the UCLA Newsroom.

Photo of a computer-generated 3D rendering of a flu virus.

First childhood flu helps explain why virus hits some people harder than others

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Photo of a computer-generated 3D rendering of a flu virus.

A computer-generated 3D rendering of a flu virus. Photo Credit: Dan Higgins/Courtesy of CDC/Douglas Jordan

Why are some people better able to fight off the flu than others? Part of the answer, according to a new study, is related to the first flu strain we encounter in childhood.

Scientists from UCLA and the University of Arizona have found that people’s ability to fight off the flu virus is determined not only by the subtypes of flu they have had throughout their lives, but also by the sequence in which they are been infected by the viruses. Their study is published in the open-access journal PLoS Pathogens.

The research offers an explanation for why some people fare much worse than others when infected with the same strain of the flu virus, and the findings could help inform strategies for minimizing the effects of the seasonal flu.

In addition, UCLA scientists, including Professor James Lloyd-Smith, who also was a senior author of the PLoS Pathogens research, recently completed a study that analyzes travel-related screening for the new novel coronavirus 2019-nCoV. (The research is under review; a preprint is online.)

The researchers report that screening travelers is not very effective for the 2019 coronavirus — that it will catch less than half of infected travelers, on average — and that most infected travelers are undetectable, meaning that they have no symptoms yet, and are unaware that they have been exposed. So stopping the spread of the virus is not a matter of just enhancing screening methods at airports and other travel hubs.

“This puts the onus on government officials and public health officials to follow up with travelers after they arrive, to isolate them and trace their contacts if they get sick later,” said Lloyd-Smith, a UCLA professor of ecology and evolutionary biology. Many governments have started to impose quarantines, or even travel bans, as they realize that screening is not sufficient to stop the spread of the coronavirus.

One major concern, Lloyd-Smith said, is that other countries, especially developing nations, lack the infrastructure and resources for those measures, and are therefore vulnerable to importing the disease.

“Much of the public health world is very concerned about the virus being introduced into Africa or India, where large populations exist that do not have access to advanced medical care,” he said.

The researchers, including scientists from the University of Chicago and the London School of Tropical Hygiene and Medicine, have developed a free online app where people can calculate the effectiveness of travel screening based on a range of parameters.

“Our finding concerning the effectiveness of screening for the coronavirus is not a criticism of screening practices being done by public health officials in the United States or elsewhere,” Lloyd-Smith said.

He said that the biology and epidemiology of the virus itself makes infection extremely difficult to detect in its early stages, because the majority of cases show no symptoms for five days or longer after exposure.

“My colleagues and I know there is a lot of speculation online about the coronavirus and how it spreads,” Lloyd-Smith said “People should look to trusted sources for accurate information, such as the Centers for Disease Control and Prevention, the Los Angeles County Department of Public Health, and the peer-reviewed scientific literature.”

Solving a decades-old question

The PLoS Pathogens study may help solve a problem that had for decades vexed scientists and health care professionals: why the same strain of the flu virus affects people with various degrees of severity.

A team that included some of the same UCLA and Arizona scientists reported in 2016 that exposure to influenza viruses during childhood gives people partial protection for the rest of their lives against distantly related influenza viruses. Biologists call the idea that past exposure to the flu virus determines a person’s future response to infections “immunological imprinting.”

The 2016 research helped overturn a commonly held belief that previous exposure to a flu virus conferred little or no immunological protection against strains that can jump from animals into humans, such as those causing the strains known as swine flu or bird flu. Those strains, which have caused hundreds of spillover cases of severe illness and death in humans, are of global concern because they could gain mutations that allow them to readily jump not only from animal populations to humans, but also to spread rapidly from person to person.

In the new study, the researchers investigated whether immunological imprinting could explain people’s response to flu strains already circulating in the human population and to what extent it could account for observed discrepancies in how severely the seasonal flu affects people in different age groups.

To track how different strains of the flu virus affect people at different ages, the team analyzed health records that the Arizona Department of Health Services obtains from hospitals and private physicians.

Two subtypes of influenza virus, H3N2 and H1N1, have been responsible for seasonal outbreaks of the flu over the past several decades. H3N2 causes the majority of severe cases in high-risk elderly people and the majority of deaths from the flu. H1N1 is more likely to affect young and middle-aged adults, and causes fewer deaths.

The health record data revealed a pattern: People first exposed to the less severe strain, H1N1, during childhood were less likely to end up hospitalized if they encountered H1N1 again later in life than people who were first exposed to H3N2. And people first exposed to H3N2 received extra protection against H3N2 later in life.

The researchers also analyzed the evolutionary relationships between the flu strains. H1N1 and H3N2, they learned, belong to two separate branches on the influenza “family tree,” said James Lloyd-Smith, a UCLA professor of ecology and evolutionary biology and one of the study’s senior authors. While infection with one does result in the immune system being better prepared to fight a future infection from the other, protection against future infections is much stronger when one is exposed to strains from the same group one has battled before, he said.

The records also revealed another pattern: People whose first childhood exposure was to H2N2, a close cousin of H1N1, did not have a protective advantage when they later encountered H1N1. That phenomenon was much more difficult to explain, because the two subtypes are in the same group, and the researchers’ earlier work showed that exposure to one can, in some cases, grant considerable protection against the other.

“Our immune system often struggles to recognize and defend against closely related strains of seasonal flu, even though these are essentially the genetic sisters and brothers of strains that circulated just a few years ago,” said lead author Katelyn Gostic, who was a UCLA doctoral student in Lloyd-Smith’s laboratory when the study was conducted and is now a postdoctoral fellow at the University of Chicago. “This is perplexing because our research on bird flu shows that deep in our immune memory, we have some ability to recognize and defend against the distantly related, genetic third cousins of the strains we saw as children.

“We hope that by studying differences in immunity against bird flus — where our immune system shows a natural ability to deploy broadly effective protection — and against seasonal flus — where our immune system seems to have bigger blind spots — we can uncover clues useful to universal influenza vaccine development.”

Around the world, influenza remains a major killer. The past two flu seasons have been more severe than expected, said Michael Worobey, a co-author of the study and head of the University of Arizona’s department of ecology and evolutionary biology. In the 2017–18 season, 80,000 people died in the U.S., more than in the swine flu pandemic of 2009, he said.

People who had their first bout of flu as children in 1955 — when the H1N1 was circulating but the H3N2 virus was not — were much more likely to be hospitalized with an H3N2 infection than an H1N1 infection last year, when both strains were circulating, Worobey said.

“The second subtype you’re exposed to is not able to create an immune response that is as protective and durable as the first,” he said.

The researchers hope that their findings could help predict which age groups might be severely affected during future flu seasons based on the subtype circulating. That information could also help health officials prepare their response, including decisions about who should receive certain vaccines that are only available in limited quantities.

The research was funded by the National Institutes of Health, the National Science Foundation, DARPA and the David and Lucile Packard Foundation. In 2018, the NIH’s National Institute of Allergy and Infectious Diseases announced a strategic plan to develop a universal flu vaccine.

The study’s co-authors are Rebecca Bridge of the Arizona Department of Health Services and Cecile Viboud of the Fogarty International Center at the NIH.

This article originally appeared in the UCLA Newsroom.

A photo of images of fruit flies’ eyes, wings and lymph glands.

Hundreds of UCLA students publish paper analyzing 1,000 genes involved in organ development

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A team of 245 UCLA undergraduates and 31 high school students has published an encyclopedia of more than 1,000 genes, including 421 genes whose functions were previously unknown. The research was conducted in fruit flies, and the genes the researchers describe in the analysis may be associated with the development of the brain, eye, lymph gland and wings.

The fruit fly is often the object of scientific research because its cells have similar DNA to that of human cells — so knowledge about its genes can help researchers better understand human diseases. The UCLA study should be useful to scientists studying genes involved in sleep, vision, memory and many other processes in humans.

The research is published in the journal G3: Genes, Genomes, Genetics. The study’s senior authors include researchers Cory Evans and John Olson, who taught UCLA’s Biomedical Research 10H, the course in which the studies were conducted.

“I expect this will be a highly cited paper and a valuable resource to life scientists,” said Tracy Johnson, director of UCLA’s biomedical research minor, which offers the course the students all took. “It’s inspiring to know all of this really important research came from freshmen and sophomores. It’s beautiful, high-quality research.”

A photo of images of fruit flies’ eyes, wings and lymph glands.

Visible on this page are images of fruit flies’ eyes (top), wings and lymph glands, showing which genes are active (red) or were previously active (green). (Download the full image to also see scans of the brain.) Photo credit: Cory Evans

The students studied short DNA sequences to learn how specific genes are turned on and off and understand how those genes control the functions of various cell types. Although all cells have essentially the same collection of genes, specific genes are turned on or off depending on the cells’ needs, Evans said.

Each student studied several genes, ultimately producing a total of more than 50,000 microscopic images; the researchers then posted their analysis on an online database where other scientists can study the genes’ roles.

“This shows not only which genes are turned on, but the history of which genes have been turned on,” Johnson said.

The research was conducted as part of a UCLA life sciences course that was developed in the early 2000s by Utpal Banerjee, a UCLA distinguished professor of molecular, cell and developmental biology, a Howard Hughes Medical Institute Professor and a senior author of the paper. The course received initial funding from the HHMI.

“Research on science education says that one of the best way to teach science is by having authentic research experiences embedded in a course,” said Johnson, who holds the Keith and Cecilia Terasaki Presidential Endowed Chair in the Division of Life Sciences and is an HHMI Professor. “Professor Banerjee understood years ago when he envisioned the class that students learn more by doing science. They learn how to design experiments, how to think like scientists, how to write about science and how to present their research.”

Johnson said the approach is analogous to teaching a sport. “If a kid wants to play soccer, you don’t say, ‘Don’t touch the soccer ball yet. You have to first learn all of the rules, watch other people play and read about the soccer greats, and maybe in a couple of years, we’ll let you kick the ball.’ No, bring out the soccer balls! So we need to get science students in the lab.”

The students completed two other research projects, one of which Evans expects will be published this year. In that study, the undergraduates studied the effects of turning off specific genes in fruit flies using a scientific technique called RNA interference. They then determined which of those 4,000 genes, when turned off, affect the proper development of blood cells.

“We teach students how to do research, not fly biology,” said Evans, who is now an assistant professor of biology at Loyola Marymount University. “Their science literacy is high, and they know how to evaluate evidence.”

This article originally appeared in the UCLA Newsroom.

Photo of Alain Mabanckou.

UCLA professor named one of 2019’s 100 most influential Africans

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Photo of Alain Mabanckou.

Alain Mabanckou, professor of French and Francophone studies at UCLA. Credit: UCLA

Alain Mabanckou, literature professor in the UCLA Department of French and Francophone Studies, has been named one of 2019’s 100 most influential Africans by leading politics and culture magazine, “New African.”

A renowned novelist, poet and professor, Mabanckou is recognized for his contributions to the global literary scene. Known for his novels and non-fiction writing depicting the experience of contemporary Africa and the African diaspora in France, he is among the most recognized writers of Franco African contemporary literature. His most recent novel, “Black Moses,” winner of the Hurston-Wright Legacy Award, follows the story of an orphan navigating his way through a poor and corrupt society.

The list recognizes Africans who have made large contributions to the continent and its culture, from reform-leading political figures to business pioneers and record-breaking athletes. The list includes the likes of Nobel Peace Prize winner Abiy Ahmed and Kenyan world record breaking marathon runner, Eliud Kipchoge. According to “New African,” those chosen to be on the list exemplify how African talent is impacting the world.

This article originally appeared in the UCLA Newsroom.

Photo of orbits of the G objects at the center of our galaxy

Astronomers discover class of strange objects near our galaxy’s enormous black hole

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Photo of orbits of the G objects at the center of our galaxy

Orbits of the G objects at the center of our galaxy, with the supermassive black hole indicated with a white cross. Stars, gas and dust are in the background. Photo: Anna Ciurlo, Tuan Do/UCLA Galactic Center Group

Astronomers from UCLA’s Galactic Center Orbits Initiative have discovered a new class of bizarre objects at the center of our galaxy, not far from the supermassive black hole called Sagittarius A*. They published their research in the Jan. 16 issue of the journal Nature.

“These objects look like gas and behave like stars,” said co-author Andrea Ghez, UCLA’s Lauren B. Leichtman and Arthur E. Levine Professor of Astrophysics and director of the UCLA Galactic Center Group.

The new objects look compact most of the time and stretch out when their orbits bring them closest to the black hole. Their orbits range from about 100 to 1,000 years, said lead author Anna Ciurlo, a UCLA postdoctoral researcher.

Ghez’s research group identified an unusual object at the center of our galaxy in 2005, which was later named G1. In 2012, astronomers in Germany made a puzzling discovery of a bizarre object named G2 in the center of the Milky Way that made a close approach to the supermassive black hole in 2014. Ghez and her research team believe that G2 is most likely two stars that had been orbiting the black hole in tandem and merged into an extremely large star, cloaked in unusually thick gas and dust.

“At the time of closest approach, G2 had a really strange signature,” Ghez said. “We had seen it before, but it didn’t look too peculiar until it got close to the black hole and became elongated, and much of its gas was torn apart. It went from being a pretty innocuous object when it was far from the black hole to one that was really stretched out and distorted at its closest approach and lost its outer shell, and now it’s getting more compact again.”

“One of the things that has gotten everyone excited about the G objects is that the stuff that gets pulled off of them by tidal forces as they sweep by the central black hole must inevitably fall into the black hole,” said co-author Mark Morris, UCLA professor of physics and astronomy. “When that happens, it might be able to produce an impressive fireworks show since the material eaten by the black hole will heat up and emit copious radiation before it disappears across the event horizon.”

But are G2 and G1 outliers, or are they part of a larger class of objects? In answer to that question, Ghez’s research group reports the existence of four more objects they are calling G3, G4, G5 and G6. The researchers have determined each of their orbits. While G1 and G2 have similar orbits, the four new objects have very different orbits.

Ghez believes all six objects were binary stars — a system of two stars orbiting each other — that merged because of the strong gravitational force of the supermassive black hole. The merging of two stars takes more than 1 million years to complete, Ghez said.

“Mergers of stars may be happening in the universe more often than we thought, and likely are quite common,” Ghez said. “Black holes may be driving binary stars to merge. It’s possible that many of the stars we’ve been watching and not understanding may be the end product of mergers that are calm now. We are learning how galaxies and black holes evolve. The way binary stars interact with each other and with the black hole is very different from how single stars interact with other single stars and with the black hole.”

Ciurlo noted that while the gas from G2’s outer shell got stretched dramatically, its dust inside the gas did not get stretched much. “Something must have kept it compact and enabled it to survive its encounter with the black hole,” Ciurlo said. “This is evidence for a stellar object inside G2.”

“The unique dataset that Professor Ghez’s group has gathered during more than 20 years is what allowed us to make this discovery,” Ciurlo said. “We now have a population of ‘G’ objects, so it is not a matter of explaining a ‘one-time event’ like G2.”

The researchers made observations from the W.M. Keck Observatory in Hawaii and used a powerful technology that Ghez helped pioneer, called adaptive optics, which corrects the distorting effects of the Earth’s atmosphere in real time. They conducted a new analysis of 13 years of their UCLA Galactic Center Orbits Initiative data.

In September 2019, Ghez’s team reported that the black hole is getting hungrier and it is unclear why. The stretching of G2 in 2014 appeared to pull off gas that may recently have been swallowed by the black hole, said co-author Tuan Do, a UCLA research scientist and deputy director of the Galactic Center Group. The mergers of stars could feed the black hole.

The team has already identified a few other candidates that may be part of this new class of objects, and are continuing to analyze them.

Ghez noted the center of the Milky Way galaxy is an extreme environment, unlike our less hectic corner of the universe.

“The Earth is in the suburbs compared to the center of the galaxy, which is some 26,000 light-years away,” Ghez said. “The center of our galaxy has a density of stars 1 billion times higher than our part of the galaxy. The gravitational pull is so much stronger. The magnetic fields are more extreme. The center of the galaxy is where extreme astrophysics occurs — the X-sports of astrophysics.”

Ghez said this research will help to teach us what is happening in the majority of galaxies.

Other co-authors include Randall Campbell, an astronomer with the W.M. Keck Observatory in Hawaii; Aurelien Hees, a former UCLA postdoctoral scholar, now a researcher at the Paris Observatory in France; and Smadar Naoz, a UCLA assistant professor of physics and astronomy.

The research is funded by the National Science Foundation, W.M. Keck Foundation and Keck Visiting Scholars Program, the Gordon and Betty Moore Foundation, the Heising-Simons Foundation, Lauren Leichtman and Arthur Levine, Jim and Lori Keir, and Howard and Astrid Preston.

In July 2019, Ghez’s research team reported on the most comprehensive test of Einstein’s iconic general theory of relativity near the black hole. They concluded that Einstein’s theory passed the test and is correct, at least for now.

► Watch a four-minute film about Ghez’s research

►View an animation below of the orbits of the G objects, together with the orbits of stars near the supermassive black hole. Credit: Advanced Visualization Lab, National Center for Supercomputing Applications, University of Illinois

This article originally appeared in the UCLA Newsroom.

Unearthing Easter Island’s Moai

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Two Moai are shown during excavations by Jo Anne Van Tilburg and her team at Rano Raraku quarry on Rapa Nui, better known as Easter Island. Photo credit: Easter Island Statue Project

Rapa Nui (or Easter Island, as it is commonly known) is home to the enigmatic Moai, stone monoliths that have stood watch over the island landscape for hundreds of years. Their existence is a marvel of human ingenuity — and their meaning a source of some mystery.

Ancient Rapanui carvers worked at the behest of the elite ruling class to carve nearly 1,000 Moai because they, and the community at large, believed the statues capable of producing agricultural fertility and thereby critical food supplies, according to a new study from Jo Anne Van Tilburg, director of the Easter Island Statue Project, recently published in Journal of Archaeological Science.

Van Tilburg and her team, working with geoarchaeologist and soils specialist Sarah Sherwood, believe they have found scientific evidence of that long-hypothesized meaning thanks to careful study of two particular Moai excavated over five years in the Rano Raraku quarry on the eastern side of the Polynesian island.

Van Tilburg’s most recent analysis focused on two of the monoliths that stand within the inner region of the Rano Raraku quarry, which is the origin of 95 percent of the island’s more than 1,000 Moai. Extensive laboratory testing of soil samples from the same area shows evidence of foods such as banana, taro and sweet potato.

Van Tilburg said the analysis showed that in addition to serving as a quarry and a place for carving statues, Rano Raraku also was the site of a productive agricultural area.

“Our excavation broadens our perspective of the Moai and encourages us to realize that nothing, no matter how obvious, is ever exactly as it seems. I think our new analysis humanizes the production process of the Moai,” Van Tilburg said.

Van Tilburg has been working on Rapa Nui for more than three decades. Her Easter Island Statue Project is supported in part by UCLA’s Cotsen Institute of Archaeology. Tom Wake, a Cotsen Institute colleague, analyzes small-animal remains from the excavation site. Van Tilburg also serves as director of UCLA’s Rock Art Archive.

Van Tilburg, in partnership with members of the local community, heads the first legally permitted excavations of Moai in Rano Raraku since 1955. Cristián Arévalo Pakarati, a noted Rapanui artist, is project co-director.

The soils in Rano Raraku are probably the richest on the island, certainly over the long term, Sherwood said. Coupled with a fresh-water source in the quarry, it appears the practice of quarrying itself helped boost soil fertility and food production in the immediate surroundings, she said. The soils in the quarry are rich in clay created by the weathering of lapilli tuff (the local bedrock) as the workers quarried into deeper rock and sculpted the Moai.

A professor of earth and environmental systems at the University of the South in Sewanee, Tenn., Sherwood joined the Easter Island Project after meeting another member of Van Tilburg’s team at a geology conference.

She wasn’t originally looking for soil fertility, but out of curiosity and research habit, she did some fine-scale testing of samples brought back from the quarry.

“When we got the chemistry results back, I did a double take,” Sherwood said. “There were really high levels of things that I never would have thought would be there, such as calcium and phosphorous. The soil chemistry showed high levels of elements that are key to plant growth and essential for high yields. Everywhere else on the island the soil was being quickly worn out, eroding, being leeched of elements that feed plants, but in the quarry, with its constant new influx of small fragments of the bedrock generated by the quarrying process, there is a perfect feedback system of water, natural fertilizer and nutrients.”

She said it also looks like the ancient indigenous people of Rapanui were very intuitive about what to grow — planting multiple crops in the same area, which can help maintain soil fertility.

The Moai that Van Tilburg’s team excavated were discovered upright in place, one on a pedestal and the other in a deep hole, indicating they were meant to remain there.

“This study radically alters the idea that all standing statues in Rano Raraku were simply awaiting transport out of the quarry,” Van Tilburg said. “That is, these and probably other upright Moai in Rano Raraku were retained in place to ensure the sacred nature of the quarry itself. The Moai were central to the idea of fertility, and in Rapanui belief their presence here stimulated agricultural food production.”

Van Tilburg and her team estimate the statues from the inner quarry were raised by or before A.D. 1510 to A.D.1645. Activity in this part of the quarry most likely began in A.D.1455. Most production of Moai had ceased in the early 1700s due to western contact.

The two statues Van Tilburg’s team excavated had been almost completely buried by soils and rubble.

“We chose the statues for excavation based on careful scrutiny of historical photographs and mapped the entire Rano Raraku inner region before initiating excavations,” she said.

Van Tilburg has worked hard to establish connections with the local community on Rapa Nui. The project’s field and lab teams are made up of local workers, mentored by professional archeologists and geologists.

The result of their collective efforts is a massive detailed archive and comparative database that documents more than 1,000 sculptural objects on Rapa Nui, including the Moai, as well as similar records on more than 200 objects scattered in museums throughout the world. In 1995, UNESCO named Easter Island a World Heritage Site, with most of the island’s sacred sites protected within Rapa Nui National Park.

This is the first definitive study to reveal the quarry as a complex landscape and to make a definitive statement that links soil fertility, agriculture, quarrying and the sacred nature of the Moai.

Van Tilburg and her team are working on another study that analyzes the rock art carvings that exist on only three of the Moai.

This article originally appeared in the UCLA Newsroom.

That Supermassive Black Hole in our Galaxy? It has a Friend.

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Two black holes are entwined in a gravitational tango in this artist’s conception. Photo Credit: NASA/JPL-Caltech/SwRI/MSSS/Christopher Go

Smadar Naoz is an associate professor of physics and astronomy in the UCLA College. She wrote this article for The Conversation.

Do supermassive black holes have friends? The nature of galaxy formation suggests that the answer is yes, and in fact, pairs of supermassive black holes should be common in the universe.

I am an astrophysicist and am interested in a wide range of theoretical problems in astrophysics, from the formation of the very first galaxies to the gravitational interactions of black holes, stars and even planets. Black holes are intriguing systems, and supermassive black holes and the dense stellar environments that surround them represent one of the most extreme places in our universe.

The supermassive black hole that lurks at the center of our galaxy, called Sgr A*, has a mass of about 4 million times that of our sun. A black hole is a place in space where gravity is so strong that neither particles or light can escape from it. Surrounding Sgr A* is a dense cluster of stars. Precise measurements of the orbits of these stars allowed astronomers to confirm the existence of this supermassive black hole and to measure its mass. For more than 20 years, scientists have been monitoring the orbits of these stars around the supermassive black hole. Based on what we’ve seen, my colleagues and I show that if there is a friend there, it might be a second black hole nearby that is at least 100,000 times the mass of the sun.

Supermassive black holes and their friends

Almost every galaxy, including our Milky Way, has a supermassive black hole at its heart, with masses of millions to billions of times the mass of the sun. Astronomers are still studying why the heart of galaxies often hosts a supermassive black hole. One popular idea connects to the possibility that supermassive holes have friends.

To understand this idea, we need to go back to when the universe was about 100 million years old, to the era of the very first galaxies. They were much smaller than today’s galaxies, about 10,000 or more times less massive than the Milky Way. Within these early galaxies the very first stars that died created black holes, of about tens to thousand the mass of the sun. These black holes sank to the center of gravity, the heart of their host galaxy. Since galaxies evolve by merging and colliding with one another, collisions between galaxies will result in supermassive black hole pairs – the key part of this story. The black holes then collide and grow in size as well. A black hole that is more than a million times the mass of our sun is considered supermassive.

If indeed the supermassive black hole has a friend revolving around it in close orbit, the center of the galaxy is locked in a complex dance. The partners’ gravitational tugs will also exert its own pull on the nearby stars disturbing their orbits. The two supermassive black holes are orbiting each other, and at the same time, each is exerting its own pull on the stars around it.

The gravitational forces from the black holes pull on these stars and make them change their orbit; in other words, after one revolution around the supermassive black hole pair, a star will not go exactly back to the point at which it began.

Using our understanding of the gravitational interaction between the possible supermassive black hole pair and the surrounding stars, astronomers can predict what will happen to stars. Astrophysicists like my colleagues and me can compare our predictions to observations, and then can determine the possible orbits of stars and figure out whether the supermassive black hole has a companion that is exerting gravitational influence.

Using a well-studied star, called S0-2, which orbits the supermassive black hole that lies at the center of the galaxy every 16 years, we can already rule out the idea that there is a second supermassive black hole with mass above 100,000 times the mass of the sun and farther than about 200 times the distance between the sun and the Earth. If there was such a companion, then I and my colleagues would have detected its effects on the orbit of SO-2.

But that doesn’t mean that a smaller companion black hole cannot still hide there. Such an object may not alter the orbit of SO-2 in a way we can easily measure.

The physics of supermassive black holes

Supermassive black holes have gotten a lot of attention lately. In particular, the recent image of such a giant at the center of the galaxy M87 opened a new window to understanding the physics behind black holes.

The proximity of the Milky Way’s galactic center – a mere 24,000 light-years away – provides a unique laboratory for addressing issues in the fundamental physics of supermassive black holes. For example, astrophysicists like myself would like to understand their impact on the central regions of galaxies and their role in galaxy formation and evolution. The detection of a pair of supermassive black holes in the galactic center would indicate that the Milky Way merged with another, possibly small, galaxy at some time in the past.

That’s not all that monitoring the surrounding stars can tell us. Measurements of the star S0-2 allowed scientists to carry out a unique test of Einstein’s general theory of relativity. In May 2018, S0-2 zoomed past the supermassive black hole at a distance of only about 130 times the Earth’s distance from the sun. According to Einstein’s theory, the wavelength of light emitted by the star should stretch as it climbs from the deep gravitational well of the supermassive black hole.

The stretching wavelength that Einstein predicted – which makes the star appear redder – was detected and proves that the theory of general relativity accurately describes the physics in this extreme gravitational zone. I am eagerly awaiting the second closest approach of S0-2, which will occur in about 16 years, because astrophysicists like myself will be able to test more of Einstein’s predictions about general relativity, including the change of the orientation of the stars’ elongated orbit. But if the supermassive black hole has a partner, this could alter the expected result.

Finally, if there are two massive black holes orbiting each other at the galactic center, as my team suggests is possible, they will emit gravitational waves. Since 2015, the LIGO-Virgo observatories have been detecting gravitational wave radiation from merging stellar-mass black holes and neutron stars. These groundbreaking detections have opened a new way for scientists to sense the universe.

Any waves emitted by our hypothetical black hole pair will be at low frequencies, too low for the LIGO-Virgo detectors to sense. But a planned space-based detector known as LISA may be able to detect these waves which will help astrophysicists figure out whether our galactic center black hole is alone or has a partner.

This article originally appeared in the UCLA Newsroom.

Chronic opioid treatment may raise risk of post-traumatic stress disorder, study finds

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Senior author Michael Fanselow said the research suggests that chronic opioid use increases susceptibility to developing anxiety disorders. Photo credit: Reed Hutchinson/UCLA

While opioids are often prescribed to treat people with trauma-related pain, a new UCLA-led study suggests doctors should use caution before prescribing the drug to those they believe may experience severe stress in the future, in order to reduce the risk the patient will develop PTSD.

In the study, researchers administered doses of the opioid morphine to a group of 22 mice for one week, then gave the mice relatively strong foot shocks. After the morphine wore off, the mice were given mild electric foot shocks. These mice showed a substantially longer “freezing response” than a second, control group of 24 mice that had not been given morphine. When mice recall a frightening memory, they freeze. Their heart rates and blood pressure go up, and the more frightening the memory, the more they freeze.

“While we are generally aware that drug use, such as that in the current opioid crisis, has many deleterious effects, our results suggest yet another effect — increased susceptibility to developing anxiety disorders,” said senior author Michael Fanselow, UCLA distinguished Staglin family professor of psychology and director of UCLA’s Staglin Family Music Festival Center for Brain and Behavioral Health. “As opioids are often prescribed to treat symptoms such as pain that may accompany trauma, caution may be needed because this may lead to a greater risk of developing PTSD, if exposed to further traumatic events, such as an accident, later on.”

“The foot shocks produced lasting fear and anxiety-like behaviors, such as freezing,” Fanselow said.

“Our data are the first to show a possible effect of opioids on future fear learning, suggesting that a person with a history of opioid use may become more susceptible to the negative effects of stress,” Fanselow said. “The ability of opioids to increase PTSD-like symptoms far outlasted the direct effects of the drug or withdrawal from the drug, suggesting the effect may continue even after opioid treatment has stopped.”

Fanselow’s view is if there is reason to believe a patient is likely to experience severe emotional stress after opioid treatment, then doctors should use caution about prescribing an opioid. If opioid use is medically called for, then the patient should be kept away from potentially stressful situations. So, for example, a soldier treated with opioids for pain should not be sent back into combat for a period of time, he said. The development of post-traumatic stress disorder requires some stressful experience after opioid use, he said.

The researchers also gave some of the mice morphine after the initial trauma had occurred but before exposing them to the second, mild stressor. They found that mice treated with morphine after the initial trauma did not show enhanced fear learning following exposure to the mild stressor. This finding suggests that chronic use of opioids before — but not after — a traumatic event occurs affects fear learning during subsequent stressful events.

The researchers concluded the mice given morphine were more susceptible to post-traumatic stress disorder than the control group of mice not given any opioids, and inferred that people with a history of using opioids are more susceptible to PTSD than the general population.

The study is published in Neuropsychopharmacology, an international scientific journal focusing on clinical and basic science research that advances understanding of the brain and behavior.

The research was funded by the National Institute on Drug Abuse and National Institute of Mental Health.

An opiate is a drug naturally derived from the opium poppy plant, such as heroin, morphine and codeine. Opioid is a broader term that includes opiates and any substance, natural or synthetic, that binds to the brain’s opioid receptors — which play a key role in controlling pain, rewards and addictive behaviors. Synthetic opioids include the prescription painkillers Vicodin and OxyContin, as well as fentanyl and methadone.

Substance abuse and PTSD often go hand-in-hand, Fanselow said, and people with PTSD often take drugs to self-medicate. Nearly 40% of people with PTSD also have a drug disorder.

Fanselow and colleagues reported last month that a traumatic brain injury causes changes in a brain region called the amygdala; and the brain processes fear differently after such an injury.

This article originally appeared in the UCLA Newsroom.

Picture of a valley oak tree.

One of California’s iconic tree species offers lessons for conservation

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Picture of a valley oak tree.

The valley oak, the largest oak in California, grows to over 100 feet tall and provides habitat and food for a variety of animals. Photo credit: Victoria Sork/UCLA

 

With increasing regularity, Californians are witnessing firsthand the destructive power of wildfires. But not everyone sees what happens after the flames die down, when debris is cleared, homes and lives rebuilt — and trees replanted to help nature recover.

New research led by UCLA evolutionary biologist Victoria Sork examines whether the trees being replanted in the wake of California’s fires will be able to survive a climate that is continuing to warm.

The study, which is published in the Proceedings of the Natural Academy of Sciences, focuses on California’s iconic valley oak. The research is among the first to demonstrate the potential of using genomics to inform conservation strategies — essentially giving species an evolutionary boost. The study showed that planting trees that are genetically better suited to higher temperatures makes them more likely to survive and grow to maturity.

“When we think about managing ecosystems under rapidly changing climates, we have to realize trees need to be able to survive past 50 years,” Sork said.

The paper also discovered something surprising: The valley oak, an essential component of many ecosystems in California, is already poorly adapted to its environment — even considering climate conditions in 2019.

“They actually seem to grow better in cooler climates than they’re in right now,” said Luke Browne, a postdoctoral scholar at the UCLA La Kretz Center for California Conservation Science and the study’s lead author. “They might grow better if climates were more like they were 21,000 years ago, during the last ice age.”

During the peak of the last ice age, summer temperatures were about 4 to 5 degrees Celsius colder, and ice covered most of Canada and mountainous areas of the U.S.

In the fields of conservation and land management, it is a common assumption that plants and animals are adapted to their environments — that’s how evolution and natural selection are supposed to work. The new research casts doubt on that assumption.

The study is part of an ongoing project initiated by Sork and Jessica Wright, an expert in conservation genetics at the USDA Forest Service, more than 10 years ago.

Researchers gathered 11,000 seeds from 94 locations throughout the trees’ range, which stretches from the Santa Monica Mountains to the Cascade foothills in the northern part of the state. They grew them to saplings in a greenhouse and planted them in two large experimental gardens, in Chico and Placerville, California. They tracked how well trees from different locations grew, and sequenced the genomes of their mother trees to link genetic information and growth rates.

The researchers then identified which genetic variants would be more likely to thrive as climate change continues to warm California. They predicted that, under predicted future warmer temperatures, trees containing beneficial genetic variations would have 11% higher growth rates than the average for all of the trees in the experiment, and 25% higher growth rates than the trees without the beneficial variations.

Information like that could help the U.S. Forest Service, for example, in its efforts to restore forests with species that have the best chance for long-term survival.

“Studies like this one provide valuable insights that help land managers make informed decisions on reforestation projects,” Wright said. “When planting trees in a particular location, managers have to decide where to collect the acorns.”

By 2070, average temperatures in the state are projected to be up to 4.8 degrees warmer than they were during the mid- to late 20th century.

“That’s going to have consequences for how fast these trees grow,” Browne said. “We’re at a challenging time to figure out the best way to do conservation science. This paper shows one approach we could use that takes advantage of modern genomics.”

The study did not determine why valley oaks are not well adapted to their environment. It might be because the climate has already warmed up so much, the trees’ long lifespans — up to 500 years — or some other, unknown factor.

The valley oak is the largest oak in California; it grows to over 100 feet tall, and has dark green leaves and a deeply grooved trunk. It is considered a foundational species because it provides habitat and food for a variety of animals, including squirrels, birds, deer and insects. In parts of the state, it is one of the only species of tree that exists. Valley oaks provide benefits to humans, too: filtering water and providing shady places to escape the heat.

Although it focuses on the oak, the paper has broader implications for conservation science in a changing climate — especially for species that evolve and adapt slowly. That’s what Sork and Wright were thinking when they initiated the project.

At the time, they hoped to find conservation strategies that could eventually be implemented using genetic information alone — without extensive field experiments.

“Not everyone in the world is going to be able to collect 11,000 seeds and plant them in a common garden,” Sork said.

This article originally appeared in the UCLA Newsroom.