Tuesday, August 7, 2018

The search for secrets of ancient remedies

Cassandra Quave is a world leader in the field of medical ethnobotany — studying how indigenous people used plants in their healing practices to identify promising candidates for modern drugs.

Cassandra Quave (it rhymes with “wave”) is an assistant professor in Emory’s Center for the Study of Human Health and in the School of Medicine’s Department of Dermatology. She is also a member of the Emory Antibiotic Resistance Center.

The Florida native looks at home in the sweltering heat of South Georgia, standing behind a pick-up truck parked on a dirt road that winds through a longleaf pine forest. She tilts a straw cowboy hat back from her face and waves off a flurry of gnats. Her utility belt bristles with shears and a hunting knife. The unfolded gate of the truck bed serves as her desk, as she wrangles a leafy vine of passionflower into a wooden plant press.

 “The Cherokee pounded the roots of passionflower into a poultice to draw out pus from wounds, boils and abscesses,” Quave says. “Everywhere I look in this ecosystem I see plants that have a history of medicinal use by native peoples. The resin of the pine trees all around us, the fronds from the ferns beneath them and the roots of those beautiful yellow flowers over there — black-eyed Susans — were all used to treat wounds and sores.”

Read more here about Quave's field work this summer, and the undergraduates who helped her collect plants of importance to Native Americans.

Monday, August 6, 2018

Neuroscientists team with engineers to explore how the brain controls movement

The labs of Georgia Tech's Muhannad Bakir (far left) and Emory's Samuel Sober (far right) combined forces for the project. The work will be led by post-doctoral fellows in their labs, Georgia Tech's Muneeb Zia (center left) and Emory's Bryce Chung (center right). Photos by Ann Watson, Emory Photo/Video.

By Carol Clark

Scientists have made remarkable advances into recording the electrical activity that the nervous system uses to control complex skills, leading to insights into how the nervous system directs an animal’s behavior.

“We can record the electrical activity of a single neuron, and large groups of neurons, as animals learn and perform skilled behaviors,” says Samuel Sober, an associate professor of biology at Emory University who studies the brain and nervous system. “What’s missing,” he adds, “is the technology to precisely record the electrical signals of the muscles that ultimately control that movement.”

The Sober lab is now developing that technology through a collaboration with the lab of Muhannad Bakir, a professor in Georgia Tech’s School of Electrical and Computer Engineering. The researchers recently received a $200,000 Technological Innovations in Neuroscience Award from the McKnight Foundation to create a device that can record electrical action potentials, or “spikes” within muscles of songbirds and rodents. The technology will be used to help understand the neural control of many different skilled behaviors to potentially gain insights into neurological disorders that affect motor control.

“Our device will be the first that lets you record populations of spikes from all of the muscles involved in controlling a complex behavior,” Sober says. “This technique will offer unprecedented access to the neural signals that control muscles, allowing previously impossible investigations into how the brain controls the body.”

“By combining expertise in the life sciences at Emory with the engineering expertise of Georgia Tech, we are able to enter new scientific territory,” Bakir says. “The ultimate goal is to make discoveries that improve the quality of life of people.”

A prototype of the proposed device has 16 electrodes that can record data from a single muscle. The McKnight Award will allow the researchers to scale up to a device with more than 1,000 electrodes that can record from 10 or more muscles.

The Sober lab previously developed a prototype device — electrodes attached to flexible wires — to measure electrical activity in a breathing muscle used by Bengalese finches to sing. The way birds control their song has a lot in common with human speech, both in how it is learned early in life and how it is produced in adulthood. The neural pathways for birdsong are also well known, and restricted to that one activity, making birds a good model system for studying nervous system function.

“In experiments using our prototype, we discovered that, just like in brain cells, precise spike timing patterns in muscle cells are critical for controlling behavior — in this case breathing,” Sober says. 

The prototype device, however, is basic. Its 16 electrodes can only record activity from a single muscle — not the entire ensemble of muscles involved in birdsong. In order to gain a fuller picture of how neural signals control movement, neuroscientists need a much more sophisticated device.

The McKnight funding allowed Sober to team up with Bakir. Their goal is to create a micro-scale electromyography (EMG) sensor array, containing more than 1,000 electrodes, to record single-cellular data across many muscles.

The engineering challenges are formidable. The arrays need to be flexible enough to fit the shape of small muscles used in fine motor skills, and to change shape as the muscles contract. The entire device must also be tiny enough not to impede the movement of a small animal.

“Our first step is to build a flexible substrate on the micro-scale that can support high-density electrodes,” Bakir says. “And we will need to use microchips that work in parallel with 1,000 electrodes, and then attach them to that substrate.”

To meet that challenge, the Bakir lab will create a 3D integrated circuit. “Essentially, it’s building a miniature skyscraper of electrical circuits stacked vertically atop one another,” Bakir says. This vertical design will allow the researchers to minimize the size of the flexible substrate.

“To our knowledge, no one has done what we are trying to do in this project,” Bakir says. “That makes it more difficult, but also exciting because we are entering new space.”

The Sober lab will use the new device to expand its songbird vocalization studies. And it will explore how the nervous system controls the muscles involved when a mouse performs skilled movements with its forelimbs.

An early version of the technology will also be shared with collaborators of the Sober lab at three different universities. These collaborators will further test the arrays, while also gathering data across more species.

“We know so little about how the brain organizes skilled behaviors,” Sober says. “Once we perfect this technology, we will make it available to researchers in this field around the world, to advance knowledge as rapidly as possible.”

The mission of the McKnight Foundation’s Technological Innovations in Neuroscience Award, as described on its website, is “to bring science closer to the day when diseases of the brain and behavior can be accurately diagnosed, prevented and treated.”

Singing in the brain: Songbirds sing like humans
Dopamine key to vocal learning, songbird study finds

Thursday, July 26, 2018

Templeton World Charity awards $550,000 to global STEM initiative

The Templeton World Charity Foundation awarded $550,000 to Emory mathematician Ken Ono, for a global program to identify and nurture gifted students in the areas of science, technology, engineering and math (STEM). The program, now known as the Spirit of Ramanujan STEM Talent Initiative, began in 2016 with pilot funding of $100,000 from the Templeton Foundation.

“This additional funding will allow us not only to continue the program, but to expand its mission and impact,” says Ono, Asa Griggs Candler Professor Mathematics at Emory and the vice president of the American Mathematical Society.

The pilot Spirit of Ramanujan program, or SOR, focused on finding exceptional young mathematicians, and awarded grants to 16 grade-school students from across the United States as well as from China, Egypt, India, Kenya and Qatar. SOR matched the mathematicians with mentors and the grants funded summer research and enrichment activities.

SOR will now also offer similar opportunities for individuals showing exceptional promise for STEM fields in which mathematics plays a prominent role, such as computational chemistry, computer science, electrical and computer engineering, mathematical biology, mathematical physics and statistics. Up to 30 eligible people each year will be awarded Templeton-Ramanujan Fellows Prizes (financial grants up to $5,000 per award to cover summer enrichment/research programs) or Templeton-Ramanujan Scholarly Development Prizes (educational materials such as STEM books). 

"The Spirit of Ramanujan initiative aims to break the mold and find brilliant outliers who may not be thriving in the system, so we can match them up with the resources they need," says Emory mathematician Ken Ono, one of the founders of the initiative.

“We are looking for brilliant, creative people who have ideas and abilities that will drive the future of science,” Ono says. “Young people with great promise are often outliers, so far ahead of their classes that teachers don’t know what to do with them. Genius cannot be taught, it can only be nurtured.” 

Ono founded the SOR program along with the Templeton World Charity Foundation; Expii.com, an open-source, personalized learning platform; and IFC Films and Pressman Film — producers of the 2015 biographical film, “The Man Who Knew Infinity.”

The SOR initiative was inspired by the subject of the film, Indian mathematician Srinivasa Ramanujan. A poor Hindu college dropout who was self-taught in mathematics, Ramanujan sent a letter containing some of his theories to British mathematician G.H. Hardy in 1913. Hardy was so impressed that he invited Ramanujan to Cambridge to study and collaborate. His mentorship burnished Ramanujan’s insights and brought them to a world stage. Ramanujan's work played a central role in the development of modern number theory and algebraic geometry, changing math and science forever.

Although the expanded SOR initiative is open to all ages, preference will be given to those under 32 — the age Ramanujan was when he died.

The SOR initiative invites people worldwide to solve creative mathematical puzzles via Expii.com’s Solve feature, to identify exceptional talent. The Art of Problem Solving, a web site that trains students in mathematical concepts and problem-solving techniques, is also advertising the initiative to its worldwide online community.

For more details about how to apply for an SOR grant, and the criteria for an award, visit the program’s web site: https://v1.expii.com/ramanujan

“The program is not intended to just benefit those who receive the awards,” Ono says. “We also hope they become important mathematicians and scientists who make the world a better place.”

Ono heads the SOR program, with an advisory board of other mathematicians, including Manjul Bhargava (Princetone), Olga Holtz (Berkeley), Po-Shen Loh (Carnegie Mellon) and Sujatha Ramdorai (University of British Columbia).

Sir John Templeton established the Templeton World Charity Foundation in 1996 to serve as “a global philanthropic catalyst for discoveries relating to big questions of life and the universe, in areas of science, theology, philosophy and human society.”

Templeton World Charity to fund 'Spirit of Ramanujan' fellows
Celebrating math, miracles and a movie
Mathematicians find 'magic key' to drive Ramanujan's taxi-cab number

Wednesday, July 11, 2018

Evidence reveals our fractured African roots

A range of ancient cultural artifacts found in different regions of Africa. Clear regionally distinctive material cultural styles, typically involving complex stone tools, first emerged within the Middle Stone Age.

Anthropologists are challenging the long-held view that humans evolved from a single ancestral population in one region of Africa. Instead, a scientific consortium has found that human ancestors were diverse in form and culture and scattered across the continent. These populations were subdivided by different habitats and shifting environmental boundaries, such as forests and deserts.

The journal Trends in Ecology and Evolution published the findings, which drew from studies of bones (anthropology), stones (archaeology) and genes (population genomics), along with new and more detailed reconstructions of Africa’s climates and habitats over the last 300,000 years.

Emory University anthropologist Jessica Thompson was one of 23 authors on the paper. The research was led by the Max Planck Institute for the Science of Human History in Germany and the University of Oxford in England. In the following Q&A, Thompson explains the paper and its significance.

Can you provide some background on our understanding of human evolution? 

Jessica Thompson: Even as early as 20 years ago, fossils were the main material we had to try to answer the question of where humans originated. A multi-regionalist theory hypothesized that Homo sapiens emerged in different places at the same time, evolving at the same rate across the Old World. This would mean that there was extensive gene exchange across ancient Asia, Europe and Africa, and that groups such as Neanderthals would not be a separate species but just a localized form of Homo sapiens. But it is difficult to get that level of resolution from bones alone.

By the 1990s, mitochondrial DNA analyses provided growing genetic evidence for the competing theory — that all modern humans originated in Africa and then dispersed from there around the globe. The implication of this is that groups such as the Neanderthals would actually have been different species, and that they were replaced by modern human groups dispersing from Africa.

Intense debate continued over the two theories but, by the early 2000s, it was clear that the out-of-Africa group had won. Only a small percentage of modern humans from the total population living in Africa actually left the continent, creating a genetic bottleneck in populations outside of Africa. So there is more diversity within the genomes of some living peoples in Africa today than there is, say, between an Australian aboriginal person and a Norwegian person.

As a final twist, whole-genome DNA now shows that there was some gene flow with Neanderthals as those first modern populations emerged from Africa. This could have happened several times over many thousands of years, and so a “leaky out-of-Africa” model seems to be the best fit for the data.

Jessica Thompson in the field in Malawi, where her archaeological sites are at a crossroads between southern and eastern Africa. "There, we find a long, but relatively unexplored cultural record of human behavior that goes back into the last Ice Age," she says.

How does the current paper fit into this model?

JT: While it was well established that modern humans originated in Africa, there was still the question of where in Africa. East Africa and South Africa have been strong candidates, but that could be due to the long historical bias of where fossils were being found.

Our paper takes the global idea of multi-regionalism and shrinks it down to the boundaries of Africa. The answer to where humans originated appears to be lots of places within the continent, often separated for long periods, but again with leaky boundaries. Essentially, there is not a single ancestral human population. Who we are today probably evolved as a mosaic of populations of very near modern humans who were separated by geographic and cultural boundaries but were also all interacting with one another at different points in time. Our origin story is one of lots and lots of different humans that came together and then separated and later came together again in this really confusing manner. There’s a lot of moving parts. Humans, for a very long time, have been a culturally and phenotypically diverse bunch.

What new questions does this paradigm shift bring up?

JT: Instead of seeking the origin of humans in one spot, we need to look for pieces of the puzzle in many different places. Then we can ask, what adaptations did different populations have that contributed to who we are today? How did they come to be present in the single species we are now? And, perhaps more philosophically, what are the unifying characteristics that bind us together as that species, in spite of our differences?

While we need more data from places like East Africa and South Africa, it’s apparent now that West Africa and Central Africa are also key players in the story. They’re at the crossroads for much of the continent and yet we know very little about ancient populations from those regions. I’m hoping I can contribute to that effort with my current work in Malawi, which is positioned between southern and eastern Africa. There, we find a long, but relatively unexplored cultural record of human behavior that goes back into the last Ice Age.

We also recently recovered some of the oldest DNA in Africa from a site in Malawi, which we published last year. This helped to actually show some of those ancient interactions between populations at least over the last 10,000 years or so — as well as some of the differences between them. The implications are that this kind of structure went back even farther in time, to our origins as a species.

Malawi yields oldest-known DNA from Africa
Bonding over bones, stones and beads
Have skull drill, will travel

Monday, July 9, 2018

Science on stage: Atlanta playwrights explore the human microbiome

Learning about the microbiome "is shifting my perspective of what it means to be human and an individual," says playwright Margaret Baldwin. "What bacteria are driving our dreams?"

Four Atlanta playwrights + 48 hours = four new plays at the forefront of art and science.

That’s the premise of Theater Emory’s “ 4:48,” a frenetic yet focused showcase of new works inspired by the human microbiome that will be performed July 14 at the Schwartz Center for Performing Arts.

The annual speed-writing challenge always yields compelling results, as talented local playwrights come together at Emory to quickly produce plays based on common source material. But this year, for the first time, the Playwriting Center of Theater Emory is teaming up with the Emory Center for the Study of Human Health for “4:48” — an innovative, interdisciplinary collaboration that promises to push the boundaries of both fields.

“Theater offers an exciting communication mechanism to convey cutting edge-research findings to a wide audience, while simultaneously encouraging curiosity and imagination,” says Amanda Freeman, instructor in the Center for the Study of Human Health.

The collaborators hope that this project will introduce the human microbiome — the trillions of microorganisms that live in us and on us — to a whole new audience, providing a spotlight for research that is being done right here on campus.

“I have found very few venues where new science and new art can emerge from a single exercise, so ‘4:48’ is special,” says David Lynn, Asa Griggs Candler Professor of Chemistry and Biology, one of several Emory science faculty offering support as resources for the writers.

Readings of the work developed during "4:48" begin at 4 pm on Saturday, July 14, in the Theater Lab of Schwartz Center. All readings are free and open to the public. For the schedule of readings and play titles, visit the Theater Emory website.

Click here to learn more.

Learning to love our bugs: Meet the microorganisms that help keep us healthy
Environment, the microbiome and preterm birth