Trisha Kesar, PT, Ph.D.
Division of Physical Therapy
Department of Rehabilitation Medicine
Emory University School of Medicine
ABSTRACT
Most stroke survivors have persistent mobility deficits that reduce community participation and quality of life. A complex array of direct and indirect connections between cortical and spinal circuits play important roles in motor control and post-stroke motor recovery. However, circuit dysfunctions underlying post-stroke impairments remain poorly understood, limiting the development of neurobiology-informed therapies. Our long-term goal is to identify key neuromotor control circuits that can be facilitated using pharmacological, regenerative, or behavioral treatments to improve walking function in stroke survivors. Ongoing studies in our lab are conducting the first comprehensive characterization of the physiology and behavioral correlates of direct and indirect descending motor pathway activity in individuals with post-stroke mobility deficits. The lateral corticospinal tract (CST) and a parallel system comprising non-CST pathways that travels indirectly (e.g. cortico-reticulo-spinal system) are both crucial for normal motor control. A cortical or sub-cortical stroke lesion can disrupt both CST and non-CST descending pathways, causing motor control impairments. Transcranial magnetic stimulation (TMS) and Hoffman reflexes have been previously used to probe corticospinal and spinal reflex circuits. However, in isolation, neither TMS nor PNS can specifically quantify activity in descending projections that modulate LMN excitability, the final common output for motor control. Short-latency facilitation (SLF) and long-latency facilitation (LLF) are neurophysiologic techniques, wherein pairing of subthreshold TMS of M1 with PNS measures the excitability of direct, fast-conducting and indirect, slower descending projections onto spinal LMNs. In this seminar, I will present preliminary results related to the use of SLF and LLF as novel indices to parse out activity in two descending systems important for post-stroke motor control.
Host: Richard Nichols, Ph.D.
Event Details
Arcadi Navarro, Ph.D.
Universitat Pompeu Fabra Barcelona
ABSTRACT
The rapid progress of medical and comparative genomics is affording new data that allow testing hypothesis related to senescence and aging, both within and across species. Recently, we studied the effects of genetic variants associated with complex human diseases appearing at different periods in life, and made observations that fitted the Mutation Accumulation and the Antagonistic Pleiotropy theories of ageing. In particular, we observed higher risk allele frequencies and large effect sizes for late-onset diseases, and detected a significant excess of early–late antagonistically pleiotropic variants. Strikingly, these variants tend to be harboured by genes related to ageing across many species.
These results prompted a set of comparative genomic studies in which, so far, we have focused on coding variation of primates and mammals and on maximum lifespan. We use two different approaches. First, we search for parallel amino-acid mutations that co-occur with increases or reductions in longevity across the primate & mammal lineages. Second, we study how changes in rates of protein evolution correlate with changes in longevity across phylogenies using phylogenetic generalized least squares. Both approaches help identifying genes and pathways related to aging and longevity and, in addition, allow for better interpretation of human longevity data coming from GWAS.
Host: Greg Gibson, Ph.D.
Event Details
Editor's note: Here is an update on the information at minute 1:36 in the video: The Center for Relativistic Astrophysics, which currently occupies the next space to be renovated, is now slated to move into the Klaus Building to form a new interdisciplinary research neighborhood focusing on astrophysics and planetary sciences.
Relentless construction in Georgia Tech makes it hard to keep track of what’s done and what’s just started. Earlier this year, the renovated first floor of the Gilbert Hillhouse Boggs building opened for business without fanfare. In the spring 2019 semester, upper-level laboratory courses in physics and biology quietly moved to spaces fashioned out of old offices and research labs.
On the outside, Boggs looks the same as it was in the 1970s, when it was built. But come in and you might exclaim, “Wow! I had no idea Boggs could look like this,” as Juan Archila says he has heard many people say. As the College of Sciences’ director of facilities and capital planning, Archila was heavily involved in the building’s makeover.
Repurposed Mingles with State-of-the-Art
The main drivers of the Boggs first-floor upgrade are safety, accessibility, and sustainability. “We now have windows between the biology labs,” Archila says. All door also have windows, “to create transparency and to promote safety and accountability.” For students with disabilities, labs now have benches that are shorter than standard.
Budget for the project was tight, Archila says. In the spirit of sustainability and economy, usable materials were reused. “We didn’t completely gut the old spaces,” Archila says. “We repurposed and moved a lot of the cabinetry.”
Amid the repurposed cabinets are state-of-the-art equipment.
“Last year we received Tech Fee Funds to purchase nine Class II Biological Safety Cabinets,” says Alison Onstine, laboratory manager in the School of Biological Sciences. Each cabinet is six feet long and can accommodate two students working side by side. These equipment expand the hands on experience for students in handling cells, as well as organisms that require Biosafety Level 2.
More equipment is forthcoming, including an ultra-low-temperature freezer for specimen preservation, fluorescent microscopes, incubators for microbial work, and additional physiology equipment.
Improvements in Learning and Instruction
Upper-level biology lab courses are now in Boggs, including genetics, microbiology, cell and molecular biology, anatomy, and physiology. Labs for advanced physics courses, as well as electronics and optics, also have moved to Boggs.
The advanced physics labs were previously taught in two small rooms in the Howey Building, says Claire Berger, a professor of the practice in the School of Physics who teaches the lab courses. In Boggs, “we have so much more space! It is clean and well-organized.
“It allows for more experiments to be set up and in better conditions. For example, the labs now have three separate dark rooms, equipped with water sinks, for the optical experiments.
“The labs are also less cluttered, therefore better in terms of safety. Because the teaching environment is less noisy, we can have one-to-one teaching on each of the individual experiments, as well as group teaching with a large, well-lit white board.”
The biology labs now in Boggs previously were taught in spaces spread across three floors of the Cherry Emerson Building. Now they are in one floor, sharing preparation rooms and equipment. “In Boggs, we have a strong nucleus that brings together the biology teaching lab community,” Onstine says.
“We have, for the first time, office spaces for teaching assistants and instructors to meet with students in close proximity to the labs,” Onstine says. “Additional benefits include two new shared equipment labs accessible to everyone, bringing our most advanced equipment within easy reach of students – including a bench-top flow cytometer, fluorescent plate readers, real-time PCR machines. These equipment spaces located between two teaching labs have promoted an open plan which we hope will create more connectivity between our core upper-level lab courses.”
With the advanced chemistry labs in the second-floor, Boggs has become an interdisciplinary space for upper-level science majors, Archila says. “People who are focused on different majors see each other. That’s when you realize that a lot of people are attacking the same problem, just from different angles. It makes sense for Georgia Tech to establish that culture from the very beginning.”
“We are fortunate to share the floor with a new neuroscience teaching lab and to be one floor away from the chemistry teaching labs,” Onstine says. She thinks this layout will foster interaction and interdisciplinary research among students of different majors.
The College of Sciences welcomes seven members of faculty who joined in 2019. They include Susan Lozier, the new dean, Betsy Middleton and John Clark Sutherland Chair, and professor in the School of Earth and Atmospheric Sciences. Six others joined the Schools of Chemistry and Biochemistry, Physics, and Psychology, as well as the Undergraduate Program in Neuroscience.
Meghan Babcock, Academic Professional, School of Psychology
Meghan Babcock earned her Ph.D. in experimental psychology from the University of Texas, Arlington, with an emphasis in social and personality psychology. As an academic professional, she is responsible for supporting undergraduate education through teaching and academic advising for all undergraduate psychology majors. She teaches undergraduate courses in psychology – including Research Methods in Psychology and Social Psychology – and manages the laboratory sections for the Research Methods course. In addition, she serves as a supervisor for undergraduate senior theses.
Marcus Cicerone, Professor, School of Chemistry and Biochemistry
Marcus Cicerone was a former group and project leader for the National Institute of Standards and Technology. His research centers on the development and application of Raman imaging approaches and the dynamics of amorphous condensed matter. His research group has logged many imaging firsts, including the first to obtain quantitative vibrational fingerprint spectra from mammalian cells using coherent Raman imaging and the first to identify specific structural proteins from coherent Raman imaging.
Glen Evenbly, Assistant Professor, School of Physics
Born in New Zealand, Evenbly earned physics degrees from the University of Auckland, in New Zealand (B.S.), and the University of Queensland, in Australia (Ph.D.). After postdoctoral work in California Institute of Technology and the University of California, Irvine, he served as an assistant professor in the University of Sherbrooke, in Canada. He researches the development and implementation of tensor network approaches for the efficient simulation of many-body systems, with additional applications to data compression and machine learning. He received the 2017 Young Scientist Prize in Computational Physics from the International Union of Pure and Applied Physics for developing new renormalization methods to study quantum systems.
Keaton Fletcher, Assistant Professor, School of Psychology
Keaton Fletcher is an industrial-organizational psychologist who studies work team leadership and associated outcomes for individuals, teams, and organizations. Specifically, he explores how a leader's differential treatment of team members can alter team dynamics, such as information sharing, trust, conflict, and cooperation, as well as individual outcomes such as health behaviors, job attitudes, and psychological and physical well-being. He examines these dynamics and implications in the field of healthcare, given the unique challenges healthcare teams face (e.g., interruptions, membership change). He also explores ways to improve leadership behaviors and workers’ well-being through training and intervention.
Joshua Kretchmer, Assistant Professor, School of Chemistry and Biochemistry
Joshua Kretchmer joined Georgia Tech after graduate and postdoctoral studies at the California Institute of Technology. He is a theoretical and computational chemist with the rare ability to combine the two important areas of electronic structure and quantum dynamics for large systems. His research focuses on developing new techniques to understand and predict the transport of charge and energy in complex environments and materials. He will apply his new techniques and insights to various applications, from chemical control in optical cavities, to light-harvesting materials, to surface catalysis.
Susan Lozier, Professor, School of Earth and Atmospheric Sciences
Susan Lozier is also the new dean and Betsy Middleton and John Clark Sutherland Chair of the College of Sciences. As dean, she will continue her research, studying the large-scale overturning circulation of the ocean, which impacts regional and global climate through the redistribution of heat. Overturning circulation – also known as the ocean conveyor belt – is also responsible for taking anthropogenic CO2 from the atmosphere and sequestering it in the deep ocean. Lozier leads the Overturning in the Subpolar North Atlantic Program (OSNAP), a National Science Foundation (NSF)-funded, international collaboration that aims “to provide a continuous record of the full-water column, trans-basin fluxes of heat, mass and freshwater in the subpolar North Atlantic.”
Alonzo Whyte, Academic Professional, Undergraduate Program in Neuroscience
After Alonzo Whyte earned his Ph.D. in from the University of St. Andrews, in Scotland, he completed an NIH-funded Fellowship in Research and Science Teaching (FIRST) at Emory University, focusing on developmental factors during adolescence that increase vulnerability to drug addiction and maladaptive decision-making. He teaches in the Principles of Neuroscience course and several upper-level neuroscience courses, in addition to coordinating the development of new experiments for the NEUR 2001 lab sections. He also provides academic advising to undergraduate neuroscience majors and serves on the Neuroscience Curriculum Committee for the management and development of neuroscience core and elective courses.
Susan Lozier began her service as the new Dean and Betsy Middleton and John Clark Sutherland Chair of the College of Sciences on September 1.
Lozier’s path to Georgia Tech is marked by excellence in research, education, and leadership, as well as the integration of scientific disciplines and a passion for mentoring. As dean, she will bring her vast experience to bear in addressing the needs of the College as she leads it to the next levels of achievement.
In the next few months, Lozier will meet with and listen to the College’s diverse constituents. “Reaching out to everyone and understanding their concerns and their vision for the College moving ahead is important to me,” she says.
Broadly, Lozier has three goals as dean:
- To strengthen the sense of community among students, alumni, faculty, research scientists/postdocs, and staff
- To elevate sciences and mathematics research and education across Georgia Tech and beyond
- To develop resources to support College of Sciences innovators in pursuing special projects, new research directions, and teaching and outreach opportunities.
About the first goal, Lozier says, “I’m very interested in making sure everybody understands that they are valued members of the College and that their contributions are highly appreciated.” She’s especially keen to bolster students’ identification with the College as their home, in addition to their natural affinity for their schools.
Of the second goal, Lozier says she wants to “immerse myself in the work of the College so I can be an effective communicator of that work, which is necessary for me to achieve my third goal,” which is to develop resources for people to advance their innovative ideas.
For more about Susan Lozier's experience, science, and other interests, read the full story here.
An interdisciplinary team of researchers at the Georgia Institute of Technology and the Institut Pasteur has received a $2.5 million National Institutes of Health (NIH) grant to advance the clinical potential of bacteria-killing viruses – also called bacteriophage, or phage.
Over the five years of the award, Joshua Weitz of the School of Biological Sciences at Georgia Tech and Laurent Debarbieux of the Institut Pasteur, in Paris, will jointly lead teams in the U.S. and France to research interactions between bacteriophage and the host’s immune response in treating acute respiratory infections caused by multi-drug-resistant bacteria.
The spread of antibiotic-resistant pathogens represents a significant public health challenge. In response, scientists and clinicians are exploring alternative ways to cure bacterial infections that cannot be treated with antibiotics. One approach is to use bacteriophage, which exclusively infect and eliminate bacteria. In a 2017 study published in Cell Host and Microbe, the teams of Weitz and Debarbieux showed that a synergy between an infected animal’s immune system and phage is essential to curing an infection.
Advancing the fundamental understanding of phage therapy will help advance its robust and reliable use in the clinic. The five-year NIH grant (1R01AI46592-01; Synergistic Control of Acute Respiratory Pathogens by Bacteriophage and the Innate Immune Response) will enable the U.S. and French teams to examine the dynamics of the synergy between phage and the immune response in treating acute respiratory infections.
“This project represents an important opportunity to integrate mathematical modeling into the foundations of phage therapy research,” Weitz says. “We look forward to extending our ongoing collaboration with the experimental phage therapy team led by Laurent Debarbieux to iteratively refine a mechanistic understanding of how phage therapy works in vivo and to develop candidate approaches to deploy phage therapy in translational settings.”
To achieve their goals, the principal investigators will combine mathematical modeling (at Georgia Tech) and animal experiments (at the Institut Pasteur). Building on their 2017 findings, the team will examine the interactions between therapeutic phage; neutrophils, which are the cells of the immune system involved in the synergy; and multi-drug-resistant Pseudomonas aeruginosa in an acute respiratory pneumonia mouse model system. The project will focus on understanding and optimizing synergistic interactions between phage and neutrophils in eliminating bacteria, even when the animal host’s immune response is impaired.
Overall, this project aims to provide a framework for advancing principles of phage ecology and innate immunology in the rational design of phage therapy for therapeutic use.
The School of Biological Sciences wants to extend a warm welcome, and a frozen treat, to our new and returning Biology Majors! The BioSci community is invited kick off the year with us at the Bio-Pop Social. Come to meet new people, enjoy King of Pops and collect a free “exclusive” Biology major t-shirt with your Buzzcard.*
In case of rain: ES&T 1st Floor Atrium
*Shirts are designed for undergraduate biology majors but are available to all members of the school. One t-shirt per person for those who don’t already have one.
Event Details
Young Jang, Ph.D.
School of Biological Sciences
Georgia Institute of Technology
ABSTRACT
Age-related loss of muscle mass and function often referred to as sarcopenia dramatically affects the quality of life in the elderly population and predisposes them to an increased risk of morbidity, disability, and mortality. As the elderly population rapidly grows in the United States, the healthcare cost to treat sarcopenia and frailty-related is projected to grow exponentially in the next decades. The etiology of sarcopenia is a multifactorial process that involves both intrinsic and extrinsic factors. However, mounting evidence from both animal and human studies suggests a decline in muscle stem cell (MuSC) function and an inability to repair/regenerate muscle following injury directly contributes to age-acquired deficits in muscle function. Although stem cell interventions and cell-based therapeutic approaches seemed promising to treat age-dependent muscle wasting, only limited success has been achieved due to extremely low donor stem cell engraftment and survival in the aged host muscle. Consequently, there is a growing need for a clinically applicable therapeutic strategy to attenuate age-related muscle loss. To overcome this challenge, we engineered a biofunctional matrix that harnesses key characteristics of native muscle microenvironment and maximizes MuSCs myogenic potential. By capitalizing MuSC delivery in the biomimetic matrix, I will discuss some of the strategies we can use to understand the mechanisms of sarcopenia and describe advanced stem cell niche-based therapy that rejuvenates aging muscle. In the second part of the presentation, I will discuss how heterochronic parabiosis, in which young and aged animals are surgically attached to share circulation, and how exposure of aged muscle, to a “youthful” systemic environment, reverse many indicators of age-related pathology and restores robust muscle regeneration after injury. I will also describe how we can leverage the organ-on-a-chip and functional biomaterials to mimic parabiosis and understand the systemic regulations of muscle aging and other muscle-wasting conditions.
Event Details
Yang Chai, D.D.S., Ph.D.
Center for Craniofacial Molecular Biology
Herman Ostrow School of Dentistry
University of Southern California
ABSTRACT
The human skull is composed of twenty-two bones connected by sutures, which are fibrous joints that contain skeletal progenitor cells. The calvarial sutures allow compression of the skull during childbirth and dramatic postnatal growth. Craniosynostosis is a common congenital defect characterized by premature suture fusion, which can cause severe outcomes including abnormal growth of the skull, increased intracranial pressure, retarded brain development and impaired neurocongnitive function. Currently, the only treatment option for infants with craniosynostosis is surgery that involves cutting the calvaria into pieces, manually reshaping them, and fixing them in place mechanically, necessitating blood transfusion and complex post-surgical care. In many cases, the calvarial bones fuse again, which requires repeated operations to relieve the constriction on the brain during the sensitive period of development in order to improve physiological function. Clearly, there is an immense need for a better approach to the treatment of craniosynostosis and prevention of re-occurrence.
Recent studies have shown that Gli1+ cells are an indispensable mesenchymal stem cell (MSC) source within the cranial sutures. Ablation of Gli1+ cells leads to fusion of all craniofacial sutures in adult mice; we have also demonstrated there is a premature loss of Gli1+ cells prior to coronal suture fusion in Twist1+/- mice, which provide an important, clinically relevant craniosynostosis model of Saethre-Chotzen syndrome. Here we took advantage of the Twist1+/- mouse model, developed an innovative scaffold combined with Gli1+ MSCs and were able to regenerate a coronal suture and improved the neurocongnitive behavior of Twist1+/- mice. This discovery provides a potential new approach for treating patients with craniosynostosis.
Supported by the NIDCR, NIH R01 DE026339; U01 DE 026914
SPEAKER BIO
Professor Chai holds the George and Mary Lou Boone Chair in Craniofacial Biology and is the associate dean of research and director of the Center for Craniofacial Molecular Biology at the Ostrow School. Chai is internationally renowned for his research into the genetics, cellular signaling, and development of cranial and facial structures, including the causes of and potential preventive measures for facial deformities such as cleft palate. Among his many honors, he has received a National Institutes of Health MERIT Award, has been elected as an American Association for the Advancement of Sciences Fellow, has received an International Association for Dental Research Distinguished Scientist Award, and has served on the editorial boards of several scientific journals. He is also an alumnus of the Ostrow School of Dentistry and is an award-winning educator and a practicing dentist at the school.
Host: Shuyi Nie, Ph.D.
