Changhan David Lee, Ph.D.
Leonard Davis School of Gerontology
University of Southern California
USC Norris Comprehensive Cancer Center
USC Research Center for Liver Diseases
Cellular homeostasis is coordinated through communication between mitochondria and the nucleus, organelles that each possess their own genomes. Whereas the mitochondrial genome is regulated by factors encoded in the nucleus, the nuclear genome is currently not known to be actively controlled by factors encoded in the mitochondrial DNA. We previously identified a peptide encoded in the mitochondrial DNA, named MOTS-c (mitochondrial open-reading-frame of the twelve S rRNA -c). MOTS-c regulates insulin sensitivity and metabolic homeostasis in an AMPK- and SIRT1-dependent manner. Our recent studies show that MOTS-c rapidly and dynamically translocates to the nucleus to regulate the nuclear genome in response to cellular stress. Within the nucleus, MOTS-c interacts with stress-responsive transcription factors and can bind to chromatin to regulate a range of adaptive gene expression. In mice, MOTS-c expression is age- and tissue-dependent. Further, MOTS-c treatment reversed age-dependent insulin resistance and significantly improved physical capacity and metabolic homeostasis in aged mice and had a considerable impact on lifespan. In humans, a centenarian-related haplogroup in a Japanese population is linked to functional MOTS-c residue variant. Our data suggest the integration of mitochondrial and the nucleus at the genetic level and that the close intergenomic communication regulates cellular homeostasis and aging.
Host: Young Jang
Ryan Hunter, Ph.D.
Department of Microbiology and Immunology
University of Minnesota
The cystic fibrosis airways harbor complex and dynamic microbial communities whose interactions with one another and the host are recognized as major players in pulmonary decline. However, details of their in situ physiology are lacking relative to their behavior on the lab bench. This seminar will focus on two vignettes that address the spatial and temporal in situ dynamics of CF lung microbiota. The first describes a metabolic labeling approach that, when coupled with fluorescent imaging, flow cytometry and genomic approaches, can differentiate actively growing cells from those that are dormant/dead and reveal their taxonomic identities. The second will focus on the role of mucins as a nutrient source for pathogen growth in the lower airways. Specifically, we have revealed a potential role for oral-derived anaerobic bacteria, most commonly thought of as “commensal” flora, in the degradation of respiratory mucins. Mucin-derived metabolites generated through this process can then stimulate the growth and pathogenicity of Pseudomonas aeruginosa and other canonical lung pathogens. This cross-feeding relationship will be discussed in the context of lung disease establishment and progression, and its implications for medical management.
Joseph “Joe” Lachance is one of three College of Sciences junior faculty to win Georgia Tech’s 2019 CTL/BP Junior Faculty Teaching Excellence Award. Jointly supported by the Center for Teaching and Learning and BP America, the award recognizes the excellent teaching and educational innovations that junior faculty bring to campus. Lachance is an assistant professor in the School of Biological Sciences and a former Class of 1969 Teaching Fellow.
As a teacher, Lachance believes his primary role is to help students learn. To accommodate students’ different learning styles, he integrates lectures with a various activities. These can be discussions of the literature or computer simulations of real data. Because empirical datasets can be messy and complex, Lachance says, students must apply critical thinking to get meaningful results, “as opposed to just applying techniques by rote”
Two examples demonstrate the innovative spirit Lachance has brought to the teaching of population genetics and other topics in biology.
For the course Mathematical Models in Biology (BIOL 2400), Lachance organized an iterated Hawk-Dove tournament. Each round involved pairs of students choosing to be aggressive (Hawk) or cooperative (Dove). As the tournament progressed, students adapted to the behaviors of their classmates. “Not only was it fun,” Lachance says, “but the evolving strategies that arose were evidence that every student had gained a deep understanding of game theory.”
"[I]t’s my role to do the best I can to facilitate student learning. Besides, what could be more fun than having a chance to share cutting-edge details about subjects you love?”
For the course Introduction to Evolutionary Biology (BIOL 3600), Lachance hosted an evolution-themed festival, modeled after the annual film festival held by the Society for the Study of Evolution. During the semester, students produced short videos to illustrate concepts of evolutionary biology. On the penultimate class of the semester, Lachance held a film festival featuring the student projects, complete with popcorn, ballots, and a trophy for the top video.
Lachance’s passion for teaching doesn’t go unnoticed. Students note his excitement, enthusiasm, and innovation in class. “His classes have given me and my peers unique opportunities to exercise our creativity with what we are learning,” one student says.
Lachance demonstrates his care for students above and beyond what students expect, this student adds. “He goes out of his way to express his vested interest in his students’ achievements and well-being in the classroom and beyond.”
“It is an honor to be one of this year’s recipients of the CTL/BP Teaching Award,” Lachance says. “As an instructor, it’s my role to do the best I can to facilitate student learning. Besides, what could be more fun than having a chance to share cutting-edge details about subjects you love?”
Prosthetic Orthotic Research Symposium
8:00 – 9:00 am
Géza F. Kogler, PhD, CO
Program Director, Master of Science in Prosthetics and Orthotics,
Georgia Institute of Technology
The Fourth Industrial Revolution and You
Silvia Ursula Raschke, PhD
British Columbia Institute of Technology, Vancouver, Canada
9:00 – 9:15 am
9:15 – 10:15 am
Session I - Orthotics - MSPO Student Capstone Presentations
Moderator - Insueng Kang, MSME
A Test Apparatus to Quantify Orthotic Ankle Joint Torque to Determine AFO Stiffness Requirements
Dansby S, Lemmon B, Bolus N, and Kogler G
Clinical Biomechanics Laboratory
The Influence of AFO Strut Stiffness Properties on Ankle Joint Angle
Sharry RA, Hinks RS, Kogler GF, Chang Y-H
Comparative Neuromechanics Laboratory
Orthotic Interface Design of a Powered Assist Hip Exoskeleton in Subjects with Stroke
Groff A, Thai S, Kang I, Hsu J, Kogler GF, Young A
Exoskeleton and Prosthetic Intelligent Controls (EPIC) Laboratory
10:15 – 10:30 am
10:30 – 11:30 am
Session II - Prosthetics - MSPO Student Capstone Presentations
The Influence of Passive versus Powered Prosthetic Feet During Walking in Felines
Grant CN, Jeffers MK, Childers WL, Herrin, KR, Klishko AN, Dalton JF, Pitkin M, Prilutsky BI
Biomechanics and Motor Control Lab
Effect of Experimental Powered Prosthesis on Hip Kinetics
Spencer M, White B, Herrin K, Young A
Exoskeleton and Prosthetic Intelligent Controls (EPIC) Laboratory
A Self-Attaching Upper Limb Prosthetic/Orthotic Prehensile Interface
Liberatore AG, Poole AG, Hammond FL
Adaptive Robotic Manipulation (ARM) Laboratory
Motor Learning Differences Between Upper Limb Amputation Levels
Hendrix W, Lee J, Alterman B, Lewis Wheaton
Cognitive Motor Control Laboratory
11:30 – 11:45 am
BREAK – Awards Judges Convene
11:45 – 12:00 pm
Award Presentation Ceremony - Outstanding Capstone Research Award
MORE ABOUT THE KEYNOTE
Speaker: Silvia Ursula Raschke, PhD
British Columbia Institute of Technology
Dr. Silvia Raschke is a graduate of Strathclyde University where she did a PhD in Prosthetics and Orthotics with a focus on AFO design and evaluation.
She works at the British Columbia Institute of Technology in Vancouver (Canada) as an applied researcher in the MAKE+ department. Her team-based research gives voice to the end users of products by employing evidence-based practices to explore and organize how people in the community are impacted by product design and/or standards of practice, or lack thereof. Her work is both grant-based peer review work as well as industry-based collaboration. In the prosthetics and orthotics field, projects include the evaluation of prosthetic foot design, development of 3D printed foot orthotics within a direct to consumer model, novel Exoskeleton design and evaluation of 3D printed prosthetic sockets. She co-supervises both BCIT engineering students as well as students from Germany and France, bringing industry-based insights and emphasis to the projects.
She has done work in veterinary product design, including orthotics, along with performance-based research with Canadian Police Dog Services. This work has led to a current role as a team member on a collaboration with the University of Saskatchewan, and the charity Audeamus, in the development of evidence-based practices and training curriculum in the development of a Service Dog Program for Veterans and First Responders with PTSD.
Title: The Fourth Industrial Revolution and You: Critical Thinking, Flexibility, Information Gathering, Disruptive Customer Desires and “Coming Together: for a New Take on Wish Fulfillment
What does any of these things have to do with each other? Or with prosthetics and orthotics? Are you ready for this version of the future, or are you not even thinking about it?
Health care is the one sector lagging in the adoption of innovative approaches and technologies at the intersection of interdisciplinary studies that make up the Fourth Industrial Revolution. Within the health sector, prosthetics and orthotics, along with other assistive technology/rehabilitation engineering fields, are those most suited to benefiting from this disruptive change but lag far behind in embracing the potential.
Why is that?
In a recent presentation on an overview of my career and what the future holds in prosthetics and orthotics I explored the concept of shifting from asking the Why? question to always starting by asking Why not? - in particular when it comes to innovation in prosthetic and orthotics. Today I am going to take you on an expanded version of my professional journey and key points along it, as I paint a picture of the impact the
Fourth Industrial Revolution will likely have on the prosthetics and orthotics sector. A future that is exciting, disruptive, open to creative interpretation and re-invention of self but that will require a nose for critical thinking, flexibility, and openness to new ideas, ways of doing things and freedom from allowing others to define who and what you are. Are you ready?
Marta Wayne, Ph.D.
Department of Biology
University of Florida
Charles F. Baer, Ph.D.
Department of Biology
University of Florida Genetics Institute
Understanding the relative contributions of the different evolutionary forces to phenotypic evolution is a central mission of population and quantitative genetics. As a starting point, it is important to isolate the contributions of mutation from the other forces, because mutation can never be "turned off". A Mutation Accumulation (MA) experiment provides a way to quantify the cumulative effects of mutation in the (near) absence of natural selection. Then, comparison of the properties of genetic variation introduced by mutation to those of the standing genetic variation within and/or between populations provides insight into what natural selection does or does not want.
We use data from a set of C. elegans MA lines to address two fundamental questions in evolution. First, we quantify the amount of mutational input into the mutational process itself. We find that the genome-wide mutation rate evolves significantly upward over a few hundred generations of relaxed natural selection. Second, we compare two independent measures of selection acting on new spontaneous mutations, one of which is conceptually airtight but of limited utility, the other of which is conceptually suspect but of broad utility (and widely applied). Happily (or coincidentally), the two measures agree with within a factor of two. We further show that new spontaneous mutations interact synergistically, potentially explaining why we have not Died 100 Times Over. Finally, we show that the base-substitution spectrum of experimentally accumulated mutations differs significantly from the spectrum of standing rare variants. That discrepancy means either (a) that natural selection skews the spectrum, or (b) mutations accumulated in the lab do not faithfully reflect the natural spectrum. We increasingly suspect the latter.
Host: Soojin Yi, Ph.D.
Host: Francesca Storici
Turgay Akay, PhD
Department of Medical Neuroscience
To generate locomotor behavior, the nervous system must precisely regulate the timing and the strength (locomotor pattern) of multiple flexor and extensor muscle contractions controlling movement at the three joints of the hindlimb. These locomotor patterns are generated by the combined actions of a network of interconnected interneurons within the spinal cord (the central pattern generator) and sensory feedback from the periphery, but how these two components are integrated and collectively act to control movement remain obscure. Using an interdisciplinary approach including mouse genetics, in vivo electrophysiology, motion analysis, and computational methods, I will discuss recent findings in my laboratory addressing the role of proprioceptive sensory feedback in locomotor pattern generation.
About the Speaker
Turgay Akay completed an undergraduate degree in fisheries engineering at Süleyman Demirel University in Turkey. His interest in animal behaviour led him back to Germany, where he was born, to pursue a diploma degree in biology at the University of Bielefeld and a PhD at the University of Cologne’s Institute for Zoology. His PhD thesis addressed the role of sensory feedback in interjoint coordination in insect walking. Upon completing his PhD in 2002, Dr. Akay re-located to North America. Following postdoctoral stints at the University of Pennsylvania with Dr. Michael Nusbaum and University of Alberta with Dr. Keir Pearson, Dr. Akay made the move to Columbia University, where he worked with Dr. Tom Jessell and later became an associate research scientist at Columbia’s Center for Motor Neuron Biology and Disease. Already a long-time collaborator with Dalhousie’s motor neuron researchers, Dr. Akay made the move to Halifax in 2014 to join the Department of Medical Neuroscience as an Assistant Professor.
Physiology Brownbag Seminars
The Physiology Group in the School of Biological Sciences hosts Brownbag Lunchtime Seminars twice a month on Wednesdays at noon in room 1253 of the Applied Physiology Building located at 555 14th Street NW, Atlanta, GA 30318. You are welcome to bring a lunch and join us as we ruminate with us on topics in Physiology! A full listing of seminars can be found at http://pwp.gatech.edu/bmmc/physiology-brownbag-seminars-spring-2019/.
Host: Boris I. Prilutsky, Ph.D.
Bulking up to avoid being eaten may have been one reason single-celled organisms joined to form multicellular entities. That’s one of the hypotheses to explain the transition to multicellularity in the early stages of life on Earth. How and why that transition occurred is one of the major questions in the story of how life began and evolved.
Georgia Tech researchers report evidence to support this hypothesis. Watching in real time, they observed how a single-celled alga became a multicellular organism in just 50 weeks after they introduced a predator. The study was published online on Feb. 20, 2019, in Scientific Reports.
“The study showed that small single-celled organisms can evolve to become larger multicellular organisms as a way to avoid being eaten,” says Matt Herron, a senior research scientist in the School of Biological Sciences and the study’s lead author.
“Nearly every living thing has to contend with the possibility of being a meal to others,” Herron says. Complex life forms have evolved various defenses to avoid becoming someone else's dinner – such as camouflage, speed, weapons, and chemical defenses. One way to avoid being eaten is to become too big for the predators. Among microbes, one way to get bigger is to form a group of cells – in other words, to become multicellular.
All multicellular organisms evolved from unicellular ancestors. But because the evolution occurred hundreds of millions of years ago, it’s hard to know how or why it happened. Experimental evolution allows researchers to watch evolutionary change as it occurs in real time in the laboratory.
“We grew some algae with predators and some without predators,” says William Ratcliff, an assistant professor in the School of Biological Sciences and study coauthor. “After 50 weeks, we compared the two cultures. We found that some cultures grown with predators had become multicellular, but cultures grown without predators remained unicellular.”
“This could be a first step toward the kind of complex multicellularity we see in animals, plants, fungi, and seaweeds,” Herron says. “The multicellular algae that evolved in our experiment could be used to explore how they continue to evolve. For example, can these algae evolve a division of labor, with cells becoming specialized to perform different functions?”
Other authors from Georgia Tech are School of Biological Sciences Professor Frank Rosenzweig, postdoctoral researcher Kimberly Chen, technician Joshua Borin, and graduate students Jacob Boswell and Jillian Walker. Other coauthors are Charles Knox and Margarethe Boyd, of the University of Montana, Missoula.
This work was supported by the National Science Foundation, NASA, the Packard Foundation, and the John Templeton Foundation.
Depiction of algal life cycles after evolution with (B, C, and D) or without (A) predators for 50 weeks. D shows a fully multicellular life cycle, with multicellular clusters releasing multicellular propagules. (Credit: Scientific Reports)