School of Psychology Work Science Center Distinguished Lecture Series presents Michael Ford, University of Alabama

To the extent that this assumption holds true, workers hold their employers responsible for the morality of their behavior. This presentation delves into several conditions of this aspect of the employee-organization relationship that have been previously understudied. 

Michael Ford will cover recent research on the beliefs and emotions that workers develop toward their employers at large, how quickly these can fluctuate, and implications for employee well-being and motivation. 

Then, he will present new findings on events that trigger moral emotions at work, the perceived entitativity of the organization responsible, and how employees respond to these occurrences and explain them with respect to the collective intent of the organization. 

Finally, Ford will consider future directions for research on emotions toward and trust in organizations and institutions.

About the Speaker
Michael Ford is an associate professor in the Department of Management at the Culverhouse College of Business at the University of Alabama,. He previously served on the psychology faculty at University at Albany-SUNY. 

His research focuses on the consequences of employee emotions for behavior and the impact of work-family conflict on subjective well-being.  His work has been published in psychology, management, educational, and occupational health journals. Ford is active on the editorial boards for several occupational health journals. 

In 2017, Ford received the Schmidt-Hunter Meta-Analysis Award from the Society for Industrial and Organizational Psychology.

About the Work Science Center Distinguished Lecture Series
This series seeks to foster thought-provoking discussion and ideas on the future of work and worklife by sharing evidence-based knowledge on topics relevant to improving human workforce development, employee management, and human well-being in the 21st century.

Reception to follow in the Student Success Center Hall of Success

To RSVP, please visit https://wscmichaelford.eventbrite.com

 

Event Details

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August 15, 2018 | Atlanta, GA

A car accident leaves an aging patient with severe muscle injuries that won’t heal. Treatment with muscle stem cells from a donor might restore damaged tissue, but doctors are unable to deliver them effectively. A new method may help change this.

Researchers at the Georgia Institute of Technology engineered a molecular matrix, a hydrogel, to deliver muscle stem cells called muscle satellite cells (MuSCs) directly to injured muscle tissue in patients whose muscles don’t regenerate well. In lab experiments on mice, the hydrogel successfully delivered MuSCs to injured, aged muscle tissue to boost the healing process while protecting the stem cells from harsh immune reactions.

The method was also successful in mice with a muscle tissue deficiency that emulated Duchene muscular dystrophy, and if research progresses, the new hydrogel therapy could one day save the lives of people suffering from the disease.

Inflammatory war zone

Simply injecting additional muscle satellite cells into damaged, inflamed tissue has proven inefficient, in part because the stem cells encounter an immune system on the warpath.

“Any muscle injury is going to attract immune cells. Typically, this would help muscle stem cells repair damage. But in aged or dystrophic muscles, immune cells lead to the release a lot of toxic chemicals like cytokines and free radicals that kill the new stem cells,” said Young Jang, an assistant professor in Georgia Tech’s School of Biological Sciences and one of the study’s principal investigators.

Only between 1 and 20 percent of injected MuSCs make it to damaged tissue, and those that do, arrive there weakened. Also, some tissue damage makes any injection unfeasible, thus the need for new delivery strategies. 

“Our new hydrogel protects the stem cells, which multiply and thrive inside the matrix. The gel is applied to injured muscle, and the cells engraft onto the tissues and help them heal,” said Woojin Han, a postdoctoral researcher in Georgia Tech’s School of Mechanical Engineering and the paper’s first author.

Han, Jang and Andres Garcia, the study’s other principal investigator, published their results on August 15, 2018, in the journal Science Advances. The National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health funded the research.

Hydrogel: watery nets

Hydrogels often start out as water-based solutions of molecular components that resemble crosses, and other components that make the ends of the crosses attach to each other. When the components come together, they fuse into molecular nets suspended in water, resulting in a material with the consistency of a gel. 

If stem cells or a drug are mixed into the solution, when the net, or matrix, forms, it ensnares the treatment for delivery and protects the payload from death or dissipation in the body. Researchers can easily and reliably synthesize hydrogels and also custom-engineer them by tweaking their components, as the Georgia Tech researchers did in this hydrogel. 

“It physically traps the muscle satellite cells in a net, but the cells also grab onto chemical latches we engineered into the net,” Han said.

This hydrogel’s added latches, which bond with proteins protruding from stem cells’ membranes, not only increase the cells’ adhesion to the net but also hinder them from committing suicide. Stem cells tend to kill themselves when they’re detached and free-floating. 

The chemical components and the cells are mixed in solution then applied to the injured muscle, where the mixture sets to a matrix-gel patch that glues the stem cells in place. The gel is biocompatible and biodegradable.

“The stem cells keep multiplying and thriving in the gel after it is applied,” Jang said. “Then the hydrogel degrades and leaves behind the cells engrafted onto muscle tissue the way natural stem cells usually would be.”

Stem cell breakdown

In younger, healthier patients, muscle satellite cells are part of the natural healing mechanism.

“Muscle satellite cells are resident stem cells in your skeletal muscles. They live on muscle strands like specks, and they’re key players in making new muscle tissue,” Han said.

“As we age, we lose muscle mass, and the number of satellite cells also decreases. The ones that are left get weaker. It’s a double whammy,” Jang said. “At a very advanced age, a patient stops regenerating muscle altogether.”

“With this system we engineered, we think we can introduce donor cells to enhance the repair mechanism in injured older patients,” Han said. “We also want to get this to work in patients with Duchene muscular dystrophy.”

“Duchene muscular dystrophy is surprisingly frequent,” Jang said. “About 1 in 3,500 boys get it. They eventually get respiratory defects that lead to death, so we hope to be able to use this to rebuild their diaphragm muscles.”

If the method goes to clinical trials, researchers will likely have to work around the potential for donor cell rejection in human patients.

Also READ: Punching Cancer with RNA Knuckles Wrapped in Hydrogel

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The following researchers coauthored the paper: Shannon Anderson, Mahir Mohiuddin, Shadi Nakhai, and Eunjung Shin from Georgia Tech; Isabel Freitas Amaral, and Ana Paula Pêgo from the University of Porto in Portugal, and Daniela Barros from Georgia Tech and the University of Porto. The research was funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health (awards # R21AR072287 and R01AR062368). Any opinions, findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect views of the National Institutes of Health.

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A Frontiers in Science Lecture by Seth Shostak, senior astronomer at SETI Institute

Are we alone in the universe?  The scientific hunt for extraterrestrial intelligence is now well into its fifth decade, and we still haven’t discovered any cosmic company.  Could all this mean that finding biology beyond Earth, even if it exists, is a project for the ages – one that might take centuries or longer? (SETI = search for extraterrestrial intelligence.)

New approaches and new technology for detecting sentient beings elsewhere suggest that there is good reason to expect that we could uncover evidence of sophisticated civilizations – the type of aliens we see in the movies and on TV – within a few decades.  But why now, and what sort of evidence can we expect?  And how will that affect humanity?

Also, if we do find E.T., what would be the societal impact of learning that something, or someone, is out there?

About the Speaker
Seth Shostak claims to have developed an interest in extraterrestrial life at the tender age of 10, when he first picked up a book about the Solar System. This innocent beginning led to a degree in radio astronomy. Now as senior astronomer, Shostak is an enthusiastic participant in the SETI Institute’s observing programs. 

In addition, Shostak is keen on outreach activities: interesting the public – and especially young people – in science in general, and astrobiology in particular. He’s co-authored a college textbook on astrobiology and has written three trade books on SETI. In addition, he’s published more than 400 popular articles on science including regular contributions to NBC News MACH, gives many dozens of talks annually, and is the host of the SETI Institute’s weekly science radio show, “Big Picture Science.” 

About Frontiers in Science Lectures 
Lectures in this series are intended to inform, engage, and inspire students, faculty, staff, and the public on developments, breakthroughs, and topics of general interest in the sciences and mathematics. Lecturers tailor their talks for nonexpert audiences.

Event Details

Date/Time:

A Frontiers in Science Lecture by Seth Shostak, senior astronomer at SETI Institute

Are we alone in the universe?  The scientific hunt for extraterrestrial intelligence is now well into its fifth decade, and we still haven’t discovered any cosmic company.  Could all this mean that finding biology beyond Earth, even if it exists, is a project for the ages – one that might take centuries or longer? (SETI = search for extraterrestrial intelligence.)

New approaches and new technology for detecting sentient beings elsewhere suggest that there is good reason to expect that we could uncover evidence of sophisticated civilizations – the type of aliens we see in the movies and on TV – within a few decades.  But why now, and what sort of evidence can we expect?  And how will that affect humanity?

Also, if we do find E.T., what would be the societal impact of learning that something, or someone, is out there?

About the Speaker
Seth Shostak claims to have developed an interest in extraterrestrial life at the tender age of 10, when he first picked up a book about the Solar System. This innocent beginning led to a degree in radio astronomy. Now as senior astronomer, Shostak is an enthusiastic participant in the SETI Institute’s observing programs. 

In addition, Shostak is keen on outreach activities: interesting the public – and especially young people – in science in general, and astrobiology in particular. He’s co-authored a college textbook on astrobiology and has written three trade books on SETI. In addition, he’s published more than 400 popular articles on science including regular contributions to NBC News MACH, gives many dozens of talks annually, and is the host of the SETI Institute’s weekly science radio show, “Big Picture Science.” 

About Frontiers in Science Lectures 
Lectures in this series are intended to inform, engage, and inspire students, faculty, staff, and the public on developments, breakthroughs, and topics of general interest in the sciences and mathematics. Lecturers tailor their talks for nonexpert audiences.

Event Details

Date/Time:

August 14, 2018 | Atlanta, GA

By Michael Evans, Freshman Chemistry Laboratory Coordinator, School of Chemistry and Biochemistry

This summer, 43 Georgia Tech students, four teaching assistants, and six faculty members crossed the Atlantic to participate in the Biomolecular Engineering, Science, and Technology (BEST) Study Abroad Program in Lyon, France.

Since the program began in 2012, it has attracted more than 170 students. While in Lyon, students took courses in chemistry, biology, or French at Lyon’s École Supérieure de Chimie Physique Électronique (CPE). They interacted with French students and faculty at CPE, sharing the spirit and culture of Georgia Tech with their hosts.  

Ferguson Beardsley appreciated the program’s mix of science and culture. “The BEST Program not only challenged me by placing me in another country; I also learned how to balance learning inside the classroom with learning outside of CPE,” said the second-year chemical engineering major. “It was the perfect experience to learn chemistry in a different cultural environment.”

This year, the program was sold out. College of Sciences majors made up 72% of the cohort; women made up 79%.

The program included excursions to locations of interest: the Pasteur Institute in Paris, CERN, the winemaking Beaujolais region, and a fragrance and personal care chemical company in the Provence region. Students also visited caves in the Ardeche region, which contain some of the world’s best preserved examples of prehistoric art.

Faculty included Cameron Tyson, program director; Jennifer Leavey and Brian Hammer, from the School of Biological Sciences, and Pamela Pollet and myself from the School of Chemistry and Biochemistry

It was my first time with the program. I was particularly struck by the visit to Grenoble and the nearby French Alps.

Grenoble’s cable car takes passengers from the city to the Grenoble Bastille. Overlooking the city, the old military fortress is now home to a museum, restaurant, and monument to the famous French geologists of the Alps. The Bastille is also the trailhead for hiking trails to Mount Jalla, a peak in the foothills of the French Alps. Near the summit is a monument to the mountain troops of France. Lookouts along the trail give breathtaking views of the city below.

In Paris, the group visited the resting place of French royalty, at the Cathedral of St. Denis, near the end of the no. 13 Métro line. The church contains the remains of most of the French kings and queens. Unlike Westminster Abbey in London, this church is far from the center of Paris. It evokes the image of a detached and elitist French aristocracy.

Smiling down on the unassuming sarcophagi of Marie Antoinette and Louis XVI is as satisfying as it sounds! The crypt beneath the church includes an ancient Roman cemetery containing the remains of St. Denis himself.

The BEST Study Abroad Program will resume in summer 2019. For additional information, see the BEST Lyon website or Facebook page.

October 19, 2017 | Atlanta, GA

For three years, Lynn A. Capadona’s job was to simulate a nightmare scenario for an astronaut – a fire aboard a spacecraft.

From 2012 to 2015, Capadona was chief engineer of the Spacecraft Fire Safety Demonstration Project (Saffire) at the NASA John Glenn Research Center, in Cleveland, Ohio. She designed the system that would run the fire experiments in various microgravity environments.

Studying Fire

“It was an intense few years,” Capadona says. “I did a lot of problem solving, using a balanced approach between what solutions may cost, how technically feasible they were, how they impacted a tight schedule, and at what level of risk to the mission.”

The results can affect spacecraft design. “Understanding how fire behaves in microgravity and how different materials propagate flames in space is immensely important for the development of future crew spacecraft,” Capadona says. “Especially as NASA begins to explore farther with plans for Mars exploration, the top priority is creating a safe environment for astronauts.”

The three Saffire missions accomplished their goals, she says, but “there is still so much more to learn about how fires behave in different environments, like those with reduced pressure or elevated oxygen.” Three more Saffire missions are planned for 2019.

Capadona’s problem-solving approached was honed at Georgia Tech, where she received a Ph.D. in chemistry in 2004.  “Earning a Ph.D. demands the mastery of critical thinking – and not just related to the discipline of the degree,” she says. “Devising multiple solutions to a problem is a skill I use almost daily in my job.”

As an undergraduate at Boston College, Capadona learned of Georgia Tech’s reputation. She knew that Tech’s chemistry department was doing research she had been exposed to while working on her B.S. in chemistry, which she received in 1999. But six other graduate schools were also tempting her.

What made Tech stand out from those other schools? “It just felt like I fit,” she says. When visiting Georgia Tech before committing to a graduate program, Capadona recalls, “the School of Chemistry and Biochemistry provided open access to faculty, students, and administrators. It was almost reverse-interview style. The experience with faculty and students seemed genuine. I liked the flexibilities the program provided.”

Once in the Ph.D. program, discovering that graduate school was not going to be easy undermined her confidence, she says. Working on her doctorate would wear her down before it built her back up.

Gaining Self-Knowledge

In graduate school, Capadona learned much about herself. “Georgia Tech confirmed to me that I know my strengths well,” she says. “I also know my weaknesses even better. To climb uphill battles or overcome challenges, I learned to rely heavily on my strengths. At the same time I surrounded myself with people whose strengths are my weaknesses. I’ll never have a perfectly complete skill set in every area, and I learned that’s alright.”

Even though she earned her Ph.D. in chemistry, Capadona joined NASA as a chemical engineer, and soon after she held different job titles. It all has to do with how NASA uses its talent, she says. “What I found as my career matured was that my discipline training provided me the basis to broaden out technically. That’s the way I got to do something bigger.” NASA encourages that kind of career growth and supports individuals who demonstrate the correct skills to take on higher level positions, she adds.

She credits her success at NASA also to her stint in Tech’s Technology Innovation: Generating Economic Results program, part of the Scheller College of Business. TI:GER helps researchers move technologies from lab to marketplace by matching them with non-technology partners, such as business experts and attorneys. “You learn to communicate with people who may not have the same specific training as you do,” she says. “If you can master that skill, the possibilities are endless.”

In 13 years at NASA, she has conducted research on next-generation materials, worked on technical troubleshooting teams for the Space Shuttle program, managed requirements for the Orion spacecraft, led late-phase technical efforts for a payload that’s still operating in the International Space Station, and managed the Saffire experiments. She now holds a management position with NASA’s systems engineering team.

“I am continually challenged and continually learning," she says. "Being successful in this and any of my jobs means working with a lot of different people across NASA and with outside organizations.”

She attributes her success in this aspect of her job also to Georgia Tech. The diversity of Tech’s student body, she recalls, made her well-rounded as a graduate. The experience with diversity, she says, “helped me weave different contexts, experiences, backgrounds, and opinions into everyday decision-making in my job.”

Advice to Students

Interacting with students from various backgrounds is one of Capadona’s tips to Tech students. “Take advantage of what the campus has to offer. There will never be another time in your life where your job is to learn about whatever you want. Pursue the things you like, even if they don’t come easy.

“The environment I was provided as a graduate student fostered a lot of independence, even when I thought I wasn’t ready for it,” she says. “It pushed me then, and I push myself in my career now.”

 

October 19, 2017 | Atlanta, GA

So unheard of was a discovery that researchers made in a protein associated with glaucoma that for over two years they ran it through a gauntlet of lab tests and published a new research paper on it. The tests validated what they initially saw.

It was a Y-shape. That made it an extreme oddity significant to science, and possibly someday to medicine, too, particularly in the treatment of certain types of blindness.

“A protein like this one has never been reported before. There are extremely few Y-shapes in proteins at all,” said Raquel Lieberman, who led the study. Lieberman is a structural biologist at the Georgia Institute of Technology, and an expert on myocilin, a protein sometimes implicated in a form of hereditary glaucoma.

Glaucoma is the second most common cause of blindness globally, and hereditary glaucoma is just one category of the disease. Genetic mutations in myocilin are a major cause of hereditary glaucoma, which can strike at a particularly young age, including in childhood.

'Absolutely unique'

There are other shapes in proteins that look similar to the Y, but there are key differences.

“Antibodies look a little like this, but in antibodies, separate proteins that are the products different genes fit together to make a kind of Y-shape,” Lieberman said. “This Y is encoded by one single gene sequence. That makes this absolutely unique.”

In addition to being the ostensible unicorn of protein structures, it turned out to be the central binding element of myocilin. The Y ties together major components to nail down myocilin’s overall form, overturning previous conceptions about the protein's appearance.

Myocilin and blindness

Although the Y hasn’t been particularly implicated in glaucoma, its existence could meaningfully alter the way researchers understand myocilin and how it works in the eye. When myocilin goes wrong, or “misfolds,” it makes fibrils that damage tissue called the trabecular meshwork that normally allows the fluid inside the eye to drain and relieve interior pressure.

“If you kill the cells that make this drainage work, it’s going to clog, and pressure inside the eye will increase,” said Lieberman, who is an associate professor in Georgia Tech’s School of Chemistry and Biochemistry. That pressure can kill parts of the retina or optic nerve, leading to irreversible partial or total blindness.

But though myocilin is common in many parts of our bodies, its normal, healthy role in the eye and, for that matter, what functions the protein has in the body at all are still a mystery.

“I think if we knew what this protein was doing in the trabecular meshwork, we would understand much more about glaucoma in general,” Lieberman said. “This research lets us know more about what myocilin is.”

Lieberman published her results on October 19, 2017, in the journal Structure.  The research was funded by the National Eye Institute and the National Institute of General Medical Sciences, both at the National Institutes of Health, by the National Science Foundation, and by the U.S. Department of Energy Office of Science.

Propellers come undone

The focus of studies so far has been on a part of myocilin that is the main culprit in a form of hereditary glaucoma, a protein structure called the olfactomedin domain, which Lieberman has also studied extensively. It looks like a protein propeller with five blades that surround a hole in the center.

“When a myocilin propellor misfolds, it unravels and forms amyloid fibrils (stringy abnormal proteins) that kill cells that maintain the trabecular network,” Lieberman said. "Until now, our work led us to believe that the propellers floated around individually as independent units, and not bound together in groups."

“All we knew before was that, in solution, those olfactomedins were just monomers. They didn’t seem to make up anything of a higher order, except when they unraveled into amyloid fibers, stuck together and blocked fluid flow,” Lieberman said.

Also READ: A fake virus unleashes immune system on an ugly tropical disease

Super sticky Y

The Y alters the picture.

It anchors the propellers in groups of four. Two propellers (olfactomedin domains) each appear to be connected to either tip of the Y’s branches probably by amino acid strings. With the Y, the overall myocilin looks like four pinwheels on strings tied to a slingshot.

Adding to the new discoveries: The Y itself is sticky, like glue. It’s even annoying to handle in the lab.

“It was sticking to the plastic, sticking to the glass, sticking to the membrane, to beads,” Lieberman said. “It’s super sticky. That may serve a biological function.”

Perhaps the Y fastens the propellers to surfaces. It’s not yet known. “But we think the main function is to pair and separate out these olfactomedin domains,” Lieberman said.

Revisiting misfolding

Mutations in the Y aren’t significantly associated with glaucoma. “When it mutates, it misfolds, but not in a way that causes all that cell death,” Lieberman said.

But in its normal role, the Y just might promote the speed of misfolding of the propeller protein (olfactomedin domain) that’s implicated in hereditary glaucoma. When misfolded proteins come into contact with good proteins, the misfolded ones tend to make the good ones misfold, too.

“If these propeller proteins are clustered together because of the Y, and one of them misfolds, it’s going to recruit the others,” Lieberman said. “Having them tied together in groups will only magnify the contagion.”

Slinkys make a Y

The Y-shape, also termed tripartite, is made up of what are called “coiled coils.” They’re pairs of short protein coils, a bit like two pieces of Slinky or coiled telephone cords, and they can be stretched similarly to a Slinky and then contract back in a similar way.

Coiled coils are very common in our bodies.

“Coiled coils represent three to five percent of our genome,” Lieberman said. “They’re found in muscle contraction, in molecule transport up and down neurons. Lots of extracellular proteins (proteins that function outside of cells) also have them.”

The Y’s branches are each a pair of coiled coils, each called a dimer, and in the trunk, they come together to form a group of four coiled coils called a tetramer.

Also READ: New nano-fight against #1 killer clogged arteries

Coauthors of this study were Shannon Hill, Elaine Nguyen, Rebecca Donegan, Athéna Patterson-Orazem, Anthony Hazel, and James Gumbart. The research was funded by the National Institutes of Health’s National Eye Institute (grant R01EY021205) and National Institute of General Medical Sciences (grants 9P41 GM103622 and 1S10OD018090-01); by the National Science Foundation (grant MCB-1452464); by the U.S. Department of Energy Office of Basic Energy Sciences (contract W-31-109-Eng-38). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the sponsors.

October 20, 2017 | Atlanta, GA

When supporting Georgia’s major collegiate sports teams, Phillip L. Williams has all his bases covered.

Williams, who hails from Decatur, Georgia, received his B.S. in biological sciences and chemistry from Georgia State University in 1975 and a Ph.D. in applied biology from Georgia Tech in 1988. He is the founding dean and Georgia Power Professor of Environmental Health in the College of Public Health at the University of Georgia (UGA).

Those last two academic institutions can cause Williams problems during the fall. After all, the University of Georgia is memorably name-checked in Georgia Tech’s fight song:

But if I had a son, sir, I'll tell you what he'd do—
He would yell, ‘To hell with Georgia!' like his daddy used to do.

Williams navigates diplomatically around the 127-year-old Georgia/Georgia Tech rivalry, known to fans as a Clean Old-Fashioned Hate. “My colleagues at UGA say I always side with Tech, and my Tech friends say I always favor UGA,” he says. “I guess this is because I think highly of both schools and speak positively about both of them, even if the background conversations reflect some traditional hostilities.”

Studying Toxicology, Gaining Confidence

Williams now watches games from home or from Sanford Stadium, in Athens. But in the 1980s, he spent fall weekends doing research for his doctorate. Sometimes the Georgia Tech band marched by his Cherry Emerson lab on the way to Bobby Dodd Stadium for Yellow Jacket games.

“I would think about how much fun people were having and that someday I would be in the stadium as well,” he says. Most of the time, he could only listen to the game on the radio as he worked.

In 1978, Williams joined Georgia Tech as a research technologist at the Engineering Experimental Station, now known as Georgia Tech Research Institute. While there, he realized he would need advanced training to conduct the kind of independent research that interested him. Williams went to Tech for his Ph.D. because of Tech’s reputation.

The biology program at Tech at the time was still small, he recalls. But “the faculty was distinguished and was willing to let me pursue my interest in toxicology.” Once he was in the program, it became clear that the School of Biology’s approach was much more quantitative than other institutions’, and it was intimidating at times, he says.

“My experience at Tech strengthened my confidence,” Williams says. “I realized that I could compete with some of the best students in the nation and that I had the option to pursue new areas of expertise. Later I found that I could compete with or collaborate with the best people in my profession.”

Benefits and Dangers of Chemicals

Williams turned to toxicology because he enjoyed understanding how chemicals could be helpful, such as medicines, or harmful, such as environmental pollutants.

“Some chemicals are solely harmful; they have no beneficial use for human health,” he says. “Others at certain exposures are either not harmful or may even help human health, but at higher exposures are harmful to people. Using that understanding to set human exposure limits to prevent adverse effects in exposed populations was an interesting challenge that I still enjoy studying.”

Williams’ professional stature and reputation grew. He established and continues to serve as senior editor of “Principles of Toxicology,” a popular three-volume guide to the field written and valued by experts around the world. He considers this accomplishment one of the most satisfying in his professional life.

Advice to Students

Another career highlight for Williams is the creation in 2005 of the UGA College of Public Health, where he serves as founding dean. “It is very rewarding to have established a college starting with 12 faculty members and to have seen it grow in the past 12 years to more than 900 students and 200 faculty and staff. We have a robust research agenda.”

Williams says the feat would have been difficult to achieve without his Tech training, which emphasized collaboration. As he learned from Tech, with its reputation as a demanding research institution, “the outcome is worth the difficulty.”

Many people he knew at Tech were just glad to graduate, Williams recalls. “It is hard to anticipate positive outcomes when you are in the thick of competing academically,” he reminds current Tech students. “But as the value of a Tech education becomes obvious through your successful careers, your fondness  for Tech will grow. Over time you will realize how unique Tech is and how enabling it can be.”

 

October 23, 2017 | Atlanta, GA

Imagine a tiny donut-shaped droplet, covered with wriggling worms. The worms are packed so tightly together that they must locally line up with respect to each other. In this situation, we would say the worms form a nematic liquid crystal, an ordered phase similar to the materials used in many flat panel displays. 

However, the nematic phase formed by the worms is filled with tiny regions where the local alignment is lost – defects in the otherwise aligned material. In addition, because the worms are constantly moving and changing their configuration, this nematic phase is active and far from equilibrium.

In research reported October 23 in the journal Nature Physics, scientists from the Georgia Institute of Technology and Leiden University in The Netherlands have described the results of a combined theoretical and experimental examination of such an active nematic on the surface of donut-shaped – toroidal – droplets. However, the researchers didn’t use actual worms, but an active nematic composed of flexible filaments covered with microscopic engines that are constantly converting energy into motion.

This particular active material, originally developed at Brandeis University, borrows elements of cellular machinery, with bundles of rod-like microtubules forming the filaments, kinesin motor proteins acting as the engines, and ATP as the fuel. When this activity is combined with defects, the defects come to life, moving around like swimming microorganisms to explore space – in this case, exploring the surface of the toroidal droplets. 

By studying toroidal droplets covered by this active nematic, the researchers confirmed a longstanding theoretical prediction about liquid crystals at equilibrium, first discussed by Bowick, Nelson and Travesset [Phys.Rev. E 69, 041102 (2004)] that nematic defects on the curved surface of such droplets will be sensitive to the local curvature. However, since the active nematic used in this work is far from equilibrium, the researchers also found how the internal activity changed and enriched the expectations.

“There have been predictions that say defects are very sensitive to the space they inhabit, specifically to the curvature of the space,” said Perry Ellis, a graduate student in the Georgia Tech School of Physics and the paper’s first author. “The torus is a great place to investigate this because the outside of the torus, the part that looks locally like a sphere, has positive curvature while the inner part of a torus, the part that looks like a saddle, has negative curvature.” 

“The quantity that characterizes a defect is what we call its topological charge or winding number,” said Alberto Fernandez-Nieves, a professor in Georgia Tech’s School of Physics and another of the paper’s co-authors. “It expresses how the alignment direction of the nematic liquid crystal changes as we go around the defect. This topological charge is quantized, meaning that it can only take values from a discrete set that are multiples of one-half. “

In these experiments, each defect has a topological charge of +1/2 or -1/2. To determine the charge and location of every defect, Ellis observed the toroidal droplets over time using a confocal microscope and then analyzed the resulting video using techniques borrowed from computer vision. The researchers found that even with the molecular motors driving the system out of equilibrium, the defects were still able to sense the curvature, with the +1/2 defects migrating towards the region of positive curvature and the -1/2 defects migrating towards the region of negative curvature. 

In this new work, the scientists took a step forward in understanding how to control and guide defects in an ordered material. 

“We have learned that we can control and guide partially ordered active matter using the curvature of the underlying substrate,” said Fernandez-Nieves. “This work opens opportunities to study how the defects in these materials arrange on surfaces that do not have constant curvature. This opens the door for controlling active matter using curvature.” 

An unexpected finding of the study was that the constant motion of the defects causes the average topological charge to become continuous, no longer taking only values that are multiples of one-half. 

“In the active limit of our experiments, we found that the topological charge becomes a continuous variable that can now take on any value,” said Fernandez-Nieves. “This is reminiscent of what happens to many quantum systems at high temperature, where the quantum, discrete nature of the accessible states and associated variables is lost. Instead of being characterized by quantized properties, the system becomes characterized by continuum properties.”

Ellis’ observations of the droplets compared well with those of numerical simulations done by Assistant Professor Luca Giomi and postdoctoral researcher Daniel Pearce at the Instituut-Lorentz for Theoretical Physics at the Universiteit Leiden in The Netherlands.

“Our theoretical model helped us decipher the experimental results and fully understand the physical mechanism governing defect motion,” said Pearce, “but also allowed us to go beyond the current experimental evidence.” Added Giomi: “Activity changes the nature of the interaction between defects and curvature. In weakly active systems, defects are attracted by regions of like-sign Gaussian curvature. But in strongly active systems, this effect becomes less relevant and defects behave as persistent random-walkers confined in a closed and inhomogeneous space”.

There are many examples of active systems driven by internal activity, including swimming microorganisms, bird flocks, robot swarms and traffic flows. “Active materials are everywhere, so our results aren’t limited to just this system on a torus,” Ellis added. “You could see the same behavior in any active system with defects.”

The research sets the stage for future work in active fluids. “Our results introduce a new framework to explore the mechanical properties of active fluids and suggest that partially ordered active matter can be guided and controlled via gradients in the intrinsic geometry of the underlying substrate,” the authors wrote in a summary of their paper.

This research was supported by the National Science Foundation under award 1609841 and the Netherlands Organization for Scientific Research. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the sponsoring agencies.

CITATION: Perry W. Ellis, Daniel J. G. Pearce, Ya-Wen Chang, Guillermo Goldsztein, Luca Giomi, and Alberto Fernandez-Nieves, “Curvature-induced Defect Unbinding and Dynamics in Active Nematic Toroids,” (Nature Physics, 2017). http://dx.doi.org/10.1038/nphys4276

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October 24, 2017 | Atlanta, GA

A new study from the Georgia Institute of Technology suggests that daydreaming during meetings isn’t necessarily a bad thing. It might be a sign that you’re really smart and creative.

“People with efficient brains may have too much brain capacity to stop their minds from wandering,” said Eric Schumacher, the Georgia Tech associate psychology professor who co-authored the study.

Schumacher and his students and colleagues, including lead co-author Christine Godwin, measured the brain patterns of more than 100 people while they lay in an MRI machine. Participants were instructed to focus on a stationary fixation point for five minutes. The Georgia Tech team used the data to identify which parts of the brain worked in unison.

“The correlated brain regions gave us insight about which areas of the brain work together during an awake, resting state,” said Godwin, a Georgia Tech psychology Ph.D. candidate.

“Interestingly, research has suggested that these same brain patterns measured during these states are related to different cognitive abilities.” 

Once they figured out how the brain works together at rest, the team compared the data with tests the participants that measured their intellectual and creative ability. Participants also filled out a questionnaire about how much their mind wandered in daily life.

Those who reported more frequent daydreaming scored higher on intellectual and creative ability and had more efficient brain systems measured in the MRI machine.

“People tend to think of mind wandering as something that is bad. You try to pay attention and you can’t,” said Schumacher. “Our data are consistent with the idea that this isn’t always true. Some people have more efficient brains.”

Schumacher says higher efficiency means more capacity to think, and the brain may mind wander when performing easy tasks.

How can you tell if your brain is efficient? One clue is that you can zone in and out of conversations or tasks when appropriate, then naturally tune back in without missing important points or steps.

“Our findings remind me of the absent-minded professor — someone who’s brilliant, but off in his or her own world, sometimes oblivious to their own surroundings,” said Schumacher. “Or school children who are too intellectually advanced for their classes. While it may take five minutes for their friends to learn something new, they figure it out in a minute, then check out and start daydreaming.”

Godwin and Schumacher think the findings open the door for follow-up research to further understand when mind wandering is harmful, and when it may actually be helpful.

"There are important individual differences to consider as well, such as a person's motivation or intent to stay focused on a particular task,” said Godwin. 

The paper, “Functional connectivity within and between intrinsic brain networks correlates with trait mind wandering,” is published in the journal Neuropsychologia.

The research is based upon work supported by the Office of the Director of National Intelligence, Intelligence Advanced Research Projects Activity (award number 2014-13121700006). Any opinions, findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.

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