“New Biosealant Can Stabilize Cartilage, Promote Healing After Injury”

New research from Robert Mauck, Mary Black Ralston Professor in Orthopaedic Surgery and Bioengineering and Director of Penn Medicine’s McKay Orthopaedic Research Laboratory, announces a “new biosealant therapy may help to stabilize injuries that cause cartilage to break down, paving the way for a future fix or – even better – begin working right away with new cells to enhance healing.” Their research was published in Advanced Healthcare Materials. The study’s lead author was Jay Patel, a former postdoctoral fellow in the McKay Lab and now Assistant Professor at Emory University and was contributed to by Claudia Loebel, a postdoctoral research in the Burdick lab and who will begin an appointment as Assistant Professor at the University of Michigan in Fall 2021. In addition, the technology detailed in this publication is at the heart of a new company (Forsagen LLC) spun out of Penn with support from the Penn Center for Innovation (PCI) Ventures Program, which will attempt to spearhead the system’s entry into the clinic. It is co-founded by both Mauck and Patel, along with study co-author Jason Burdick, Professor in Bioengineering, and Ana Peredo, a PhD student in Bioengineering.

Read the story in Penn Medicine News.

‘RNA worked for COVID-19 vaccines. Could it be used to treat cancer and rare childhood diseases?’

William H. Peranteau, Michael J. Mitchell, Margaret Billingsley, Meghana Kashyap, and Rachel Riley (Clockwise from top left)

As COVID-19 vaccines roll out, the concept of using mRNA to fend off viruses has become a part of the public dialogue. However, scientists have been researching how mRNA can be used to in life-saving medical treatments well before the pandemic.

The “m” in “mRNA” is for “messenger.” A single-stranded counterpart to DNA, it translates the genetic code into the production of proteins, the building blocks of life. The Moderna and Pfizer COVID-19 vaccines work by introducing mRNA sequences that act as a set of instructions for the body to produce proteins that mimic parts of the virus itself. This prepares the body’s immune response to recognize the real virus and fight it off.

Because it can spur the production of proteins that the body can’t make on its own, mRNA therapies also have the potential to slow or prevent genetic diseases that develop before birth, such as cystic fibrosis and sickle-cell anemia.

However, because mRNA is a relatively unstable molecule that degrades quickly, it needs to be packaged in a way that maintains its integrity as its delivered to the cells of a developing fetus.

To solve this challenge, Michael J. Mitchell, Skirkanich Assistant Professor of Innovation in the Department of Bioengineering, is researching the use of lipid nanoparticles as packages that transport mRNA into the cell. He and William H. Peranteau, an attending surgeon in the Division of General, Thoracic and Fetal Surgery and the Adzick-McCausland Distinguished Chair in Fetal and Pediatric Surgery at Children’s Hospital of Philadelphia, recently co-authored a “proof-of-concept” paper investigating this technique.

In this study, published in Science Advances, Mitchel examined which nanoparticles were optimal in the transport of mRNA to fetal mice. Although no disease or organ was targeted in this study, the ability to administer mRNA to a mouse while still in the womb was demonstrated, and the results are promising for the next stages of targeted disease prevention in humans.

Mitchel spoke with Tom Avril at The Philadelphia Inquirer about the mouse study and its implications for treatment of rare infant diseases through the use of mRNA, ‘the messenger of life.’

Penn bioengineering professor Michael J. Mitchell, the other senior author of the mouse study, tested various combinations of lipids to see which would work best.

The appeal of the fatty substances is that they are biocompatible. In the vaccines, for example, two of the four lipids used to make the delivery spheres are identical to lipids found in the membranes of human cells — including plain old cholesterol.

When injected, the spheres, called nanoparticles, are engulfed by the person’s cells and then deposit their cargo, the RNA molecules, inside. The cells respond by making the proteins, just as they make proteins by following the instructions in the person’s own RNA. (Important reminder: The RNA in the vaccines cannot become part of your DNA.)

Among the different lipid combinations that Mitchell and his lab members tested, some were better at delivering their cargo to specific organs, such as the liver and lungs, meaning they could be a good vehicle for treating disease in those tissues.

Continue reading Tom Avril’s ‘RNA worked for COVID-19 vaccines. Could it be used to treat cancer and rare childhood diseases?’ at The Philadelphia Inquirer.

Penn Engineers’ New Bioprinting Technique Allows for Complex Microtissues

by Evan Lerner

Jason Burdick, Andrew C. Daly and Matthew Davidson

Bioprinting is currently used to generate model tissues for research and has potential applications in regenerative medicine. Existing bioprinting techniques rely on printing cells embedded in hydrogels, which results in low-cell-density constructs that are well below what is required to grow functional tissues. Maneuvering different kinds of cells into position to replicate the complex makeup of an organ, particularly at organlike cell densities, is still beyond their capabilities.

Now, researchers at the School of Engineering and Applied Science have demonstrated a new bioprinting technique that enables the bioprinting of spatially complex, high-cell-density tissues.

Using a self-healing hydrogel that allows dense clusters of cells to be picked and placed in a three-dimensional suspension, the researchers constructed a model of heart tissue that featured a mix of cells that mimic the results of a heart attack.

The study was led by Jason Burdick, Robert D. Bent Professor in the Department of Bioengineering, and Andrew C. Daly, a postdoctoral researcher in his lab. Fellow Burdick lab postdoc Matthew Davidson also contributed to the study, which has been published in the journal Nature Communications.

Even without a bioprinter, groups of cells can be made to clump into larger aggregates, known as spheroids. For Burdick and colleagues, these spheroids represented a potential building block for a better approach to bioprinting.

“Spheroids are often useful for studying biological questions that rely on the cells’ 3D microenvironments or in the construction of new tissues,” says Burdick. “However, we’d like to produce even higher levels of organization by ‘printing’ different kinds of spheroids in specific arrangements and have them fuse together into structurally complex microtissues.”

Read more at Penn Engineering Today.

Penn Engineering and CHOP Researchers Identify Nanoparticles that Could Be Used in Therapeutic mRNA Delivery before Birth

by Evan Lerner

William H. Peranteau, Michael J. Mitchell, Margaret Billingsley, Meghana Kashyap, and Rachel Riley (Clockwise from top left)

Researchers at Children’s Hospital of Philadelphia and the School of Engineering and Applied Science at the University of Pennsylvania have identified ionizable lipid nanoparticles that could be used to deliver mRNA as part of fetal therapy. The proof-of-concept study, published today in Science Advances, engineered and screened a number of lipid nanoparticle formulations for targeting mouse fetal organs and has laid the groundwork for testing potential therapies to treat genetic diseases before birth.

“This is an important first step in identifying nonviral mediated approaches for delivering cutting-edge therapies before birth,” said co-senior author William H. Peranteau, MD, an attending surgeon in the Division of General, Thoracic and Fetal Surgery and the Adzick-McCausland Distinguished Chair in Fetal and Pediatric Surgery at CHOP. “These lipid nanoparticles may provide a platform for in utero mRNA delivery, which would be used in therapies like fetal protein replacement and gene editing.”

Michael J. Mitchell, Skirkanich Assistant Professor of Innovation in Penn Engineering’s Department of Bioengineering, is the other co-senior author of the study. The co-first authors are Mitchell Lab members Rachel Riley, a postdoctoral fellow, and Margaret Billingsley, a graduate student, and Peranteau Lab member Meghana Kashyap, a research fellow.

Recent advances in DNA sequencing technology and prenatal diagnostics have made it possible to diagnose many genetic diseases before birth. Some of these diseases are treated by protein or enzyme replacement therapies after birth, but by then, some of the damaging effects of the disease have taken hold. Thus, applying therapies while the patient is still in the womb has the potential to be more effective for some conditions. The small fetal size allows for maximal therapeutic dosing, and the immature fetal immune system may be more tolerant of replacement therapy.

Read the full story in Penn Engineering Today.

NB: Rachel Riley is now Assistant Professor in Biomedical Engineering at Rowan University.

BE Seminar: “High-throughput Screening of a Combinatorial CAR Co-stimulatory Domain Library” (Kyle Daniels)

Kyle Daniels, PhD

Speaker: Kyle Daniels, Ph.D.
Postdoctoral Scholar, Cellular Molecular Pharmacology
University of California, San Francisco

Date: Thursday, October 22, 2020
Time: 3:00-4:00 PM EDT
Zoom – check email for link or contact ksas@seas.upenn.edu

Title: “High-throughput Screening of a Combinatorial CAR Co-stimulatory Domain Library”

Abstract:

CAR T cells—T cells engineered to express a chimeric antigen receptor that redirects their function to a specific antigen—have proven to be an effective therapy for certain B cell cancers, but many issues remain in order to apply CAR T cells to a broader range of cancers. The activity of CAR T cells can be modulated by varying their co-stimulatory domains. Most CARs use co-stimulatory domains from natural proteins such as 41BB or CD28, each of which contains motifs that recruit unique signaling molecules and elicit a corresponding T cell response. One strategy to achieve increased control over T cell function is to engineer synthetic co-stimulatory domains composed of novel combinations of motifs from natural co-stimulatory proteins. We constructed libraries of CARs containing synthetic co-stimulatory domains and screened these library in primary human T cells for the ability to promote proliferation, degranulation, and memory formation. The results of the screens give insights into how signaling motifs dictate cell function and offer clues on how to engineer co-stimulatory domains that promote desired CAR T cell functions.

Bio:

Kyle completed his BS in Biochemistry at University of Maryland-College Park, and did undergraduate research in the lab of Dorothy Beckett where he studied ligand binding to biotin protein ligases. He did his graduate work at Duke University with Terry Oas working to understand the mechanism of coupled binding and folding in the protein subunit of B. subtilis RNase P. He is currently a postdoctoral fellow in Wendell Lim’s lab at UCSF studying how combinations of linear motifs in receptors dictate cell function. He was an HHMI undergraduate researcher, an NSF graduate research fellow, and a Damon Runyon Cancer Research Foundation postdoctoral fellow. His research interests include synthetic biology, how cells process information and make decisions, and cellular therapy. Outside of lab, he enjoys swimming, videogames, and quality time with friends.

See the full list of upcoming Penn Bioengineering fall seminars here.

Postdoctoral Fellow Linden Parkes Wins BBRF Young Investigator Grant

Linden Parkes, PhD

The Department of Bioengineering at Penn is thrilled to congratulate Linden Parkes on receiving a Brain & Behavior Research Foundation (BBRF) Young Investigator Grant for 2021-2022. This grant will support Parkes’ continued postdoctoral research under the supervision of Danielle S. Bassett, J. Peter Skirkanich Professor of Bioengineering and Electrical and Systems Engineering in the School of Engineering and Applied Science (SEAS),  Theodore D. Satterthwaite, Associate Professor of Psychiatry in the Perelman School of Medicine (PSOM), and Raquel E. Gur, the Karl and Linda Rickels Professor of Psychiatry in PSOM.

Originally from Australia, Parkes did his undergraduate B.Sc. (Hons.) in Psychology and Psychophysiology at the Swinburne University of Technology in Melbourne. He went on to receive his Ph.D. in Neuroscience from the Turner Institute for Brain and Mental Health at Monash University (also in Melbourne) under the supervision of Murat Yucel, Professor of Psychology, Alex Fornito, Professor of Psychology, and Ben Fulcher, Senior Lecturer in the School of Physics at the University of Sydney. After finishing his doctorate, Parkes moved to Philadelphia to take up a position as a postdoctoral fellow in Danielle Bassett’s Complex Systems Lab.

Parkes will use the BBRF’s support to continue his research examining the link between the symptoms of mental illness and the brain. In particular, he seeks to uncover how individual patterns of abnormal neurodevelopment link to, and predict, the emergence of psychosis symptoms through childhood and adolescence using longitudinal data. In turn, Parkes’ work will discover prognostic biomarkers for the psychosis spectrum that will help inform clinical outcome tracking.

“I am honored to have been selected for a Young Investigator Grant from the BBRF this year,” Parkes says. “This award will support me to conduct research that I believe will make real inroads into understanding the pathways that link abnormalities in neurodevelopment to the symptoms of psychosis. I feel grateful for the opportunity to complete my postdoctoral training at Penn. Penn has connected me with wonderful people who I’m sure will be lifelong mentors, colleagues, and peers.”

The BBRF Young Investigator Grants are valued at more than $10.3 million and are awarded annually to 150 of the world’s most promising young scientists to support the work of early career investigators with innovative ideas for groundbreaking neurobiological research seeking to identify causes, improve treatments, and develop prevention strategies for psychiatric disorders.

Read more about the BBRF 2020 Young Investigators here.

Penn Bioengineering Postdoc Brittany Taylor Appointed Assistant Professor at University of Florida

 

Brittany Taylor, PhD

The Department of Bioengineering is proud to congratulate Postdoctoral Researcher Brittany Taylor, PhD on her appointment as a tenure-track Assistant Professor in the J. Crayton Pruitt Family Department of Biomedical Engineering of the Herbert Wertheim College of Engineering at the University of Florida. Taylor’s appointment will begin in January 2021 after four years as a postdoc in Penn Medicine’s McKay Orthopaedic Research Laboratory where she worked under the supervision of Louis Soslowsky, Fairhill Professor in Orthopaedic Surgery and Professor in Bioengineering.

Taylor got her BS in Biomedical Engineering from the University of Virginia where she conducted research under Drs. Cato Laurencin and Edward Botchwey (the latter got his PhD in Penn Bioengineering in 2002). She went on to complete her PhD in Biomedical Engineering in 2016, studying with Dr. Joseph Freeman, in the Musculoskeletal Tissue Regeneration Laboratory at Rutgers University. During her time at Penn, she served as the Co-President of the Biomedical Postdoctoral Council, worked with the Perelman School of Medicine’s PennVIEW program on postdoctoral diversity recruitment, and spearheaded the mentoring circles program, which brings together postdoctoral researchers, graduate students, and undergraduates in informal groups that allow mentorship and learning to flow freely.

The foundation for Taylor’s research interests is a combination of her training in bone tissue engineering, bioactive biomaterials, and tendon injury and repair. Her graduate research focused on a three-dimensional biomimetic pre-vascularized scaffold that simultaneously promoted osteogenic and angiogenic differentiation of human mesenchymal stem cells in vitro and cellular infiltration and neovascularization in vivo without the addition of growth factors of cells. As a postdoctoral fellow, in addition to investigating the role of collagen type V on tendon inflammation and remodeling in a mouse patellar tendon injury model, she also elucidated the biological and mechanical implications of an implantable bilayer delivery system (BiLDS) for controlled and localized release of non-steroidal anti-inflammatory drugs (NSAIDs) to modulate tendon inflammation in a rat rotator cuff injury and repair model. This collection of work exploits the ability of these transformative technologies to provide physical and chemical regenerative cues without the use of exogenous cells; hence avoiding possible complications associated with autologous and allogeneic cell sources and simplifying the regulatory pathway towards clinical application. Taylor’s future research program at the University of Florida will focus on tailored cell-free combinatorial strategies, such as decellularized matrices, tunable delivery systems, and modified extracellular vesicles, to complement and improve the native musculoskeletal tissue regenerative and reparative process.

“Brittany has been an amazing postdoctoral fellow,” says her mentor Louis Soslowsky. “She has learned a lot and contributed to various projects in an exemplary manner. She has been a leader in many arenas here at Penn and I am so proud of what she has done so far. I look forward to following her continued accomplishments at the University of Florida! I know she’ll do great!”

In the course of her pre-faculty career, Taylor achieved an impressive list of accomplishments. She received a Postdoctoral Fellowship for Academic Diversity from the Office of the Vice Provost for Research; a Postdoctoral Enrichment Program (PDEP) award from the Burroughs Wellcome Fund; and a UNCF Bristol-Myers Squibb E.E. Just Postgraduate Fellowship. Additionally, she was named a Rising Star in Cell Mentor’s list of “100 inspiring Black scientists in America” in February 2020 and was given a Rising Star in Biomedical Science Award from MIT in 2019.

“I am grateful for the opportunity to complete my postdoctoral training at Penn,” Taylor says:

“[P]articularly in a lab that is affiliated with the Penn Bioengineering program and the Department of Orthopaedic Surgery, where I had the unique experience of addressing basic science questions using translational animal models, while utilizing my engineering background and having a direct interaction with clinicians. Additionally, I connected with some amazing people here at Penn who had a significant impact on my time at Penn, and will be lifelong friends, colleagues, and mentors.”

Congratulations Dr. Taylor from everyone at Penn Bioengineering!

Postdoctoral Researcher Yogesh Goyal Wins BWF Career Award

Yogesh Goyal, Ph.D.

The Department of Bioengineering at Penn is thrilled to congratulate Yogesh Goyal, PhD on receiving a Burroughs Wellcome Fund (BWF) Career Award at the Scientific Interface (CASI) award for 2020-2025. He is currently a Jane Coffins Child Fellow in the lab of Arjun Raj, Professor of Bioengineering.

The BWF CASI Career Awards provide $500,000 over five years to bridge advanced postdoctoral training and the first three years of faculty service; and to foster the early career development of researchers who have transitioned from physical/mathematical/computational sciences or engineering into the biological sciences, and who are dedicated to pursuing a career in academic research. Goyal is one of just eight recipients of the 2020-2025 CASI award.

Goyal did much of his schooling in Jammu and Kashmir, India, and received his undergraduate degree in Chemical Engineering at the Indian Institute of Technology, Gandhinagar. He received his PhD from Princeton University in the Department of Chemical and Biological Engineering and the Lewis-Sigler Institute for Integrative Genomics, under the joint mentorship of Stanislav Shvartsman, PhD, and Gertrud Schüpbach, PhD. After finishing his doctorate, he came to Penn Bioengineering to work in the Raj Lab for Systems Biology.

Goyal’s research work is centered around developing novel mathematical and experimental frameworks to study how a rare subpopulation of cancer cells are able to survive drug therapy and develop resistance, resulting in relapse in patients. In particular, his work will provide a view of different paths that single cancer cells take when becoming resistant, at unprecedented resolution and scale. In turn, this will help devise novel therapeutic strategies to combat the challenge of drug resistance in cancer.

“I am very excited to be a part of the community of the Burroughs Wellcome Fund CASI award past and present recipients, which also includes my postdoctoral adviser Arjun Raj, who received this award in 2008,” Goyal says. “This CASI award will help provide me with the freedom to pursue high risk research directions as I transition to faculty. I feel fortunate to be surrounded by kind and supportive colleagues in the Bioengineering Department at Penn, an environment that has been critical for my interdisciplinary journey as a scientist.”

Rooting Out Systemic Bias in Neuroscience Publishing

An interdisciplinary research team has found statistical evidence of women being under-cited in academic literature. They are now studying similar effects along racial lines.

By Izzy Lopez

Danielle Bassett, Jordan Dworkin and Perry Zurn are leading efforts to analyze systemic bias in neuroscience citations, and have suggestions for combatting it.

Scientific papers are the backbone of a research community and the citation of those papers sparks conversation in a given field. This cycle of publication and citation leads to new knowledge, but what happens when implicit discrimination in a field leads to papers by minority scholars being cited less often than their counterparts? A new team of researchers has come together to ask this question and dig into the numbers of gender and racial bias in neuroscience.

The team members include physicist and neuroscientist Danielle Bassett, J. Peter Skirkanich Professor of Bioengineering at the University of Pennsylvania, with secondary appointments in the Departments of Neurology and Psychiatry in Penn’s Perelman School of Medicine, statistician Jordan Dworkin, then a graduate student in Penn Medicine’s Department of Biostatistics, Epidemiology and Bioinformatics, and ethicist Perry Zurn, an Assistant Professor of Philosophy at American University.

Their study on gender bias, which recently appeared in Nature Neuroscience, reports on the extent and drivers of gender imbalance in neuroscience reference lists. The team has also published a perspective paper in Neuron that makes practical recommendations for improving awareness of this issue and correcting for biases.

They are now working on a second study, led by Maxwell Bertolero, a postdoctoral researcher in Bassett’s lab, that considers the extent and drivers of racial imbalances in neuroscience reference lists.

Together, Bassett, Dworkin and Zurn are using their combined research strengths to uncover the under-citation of women or otherwise minority-led papers in neuroscience and to assess its significance. This research is fundamental in highlighting a true gap in representation in research paper citations, which can have detrimental effects for women and other minorities leading science. In addition, they provide actionable steps to address the problem and build a more equitable future.

Your research team is a distinctive one. How did you come together for a study about gender discrimination in neuroscience citations?

As it turns out, there is really strong literature on issues of diversity and citation in science. Some disciplines have done field-specific investigations, such as the foundational studies in political science, international relations, and economics, but there wasn’t yet any research in neuroscience. Since biomedical sciences often have different approaches to citation, it seemed that it would be worth doing a deeper neuroscience-specific investigation to give quantitative backing to the issue of gender bias in neuroscience research.

Danielle Bassett: When Jordan and I started working together on this project, I knew it was important. To do it right, we needed to present the information in a way that made it actionable, with clear recommendations about how each of us as scientists can help address the issue. We also needed to add someone to the team with expertise in gender theory and research ethics. We especially wanted to make sure we were discussing gender bias in a way that was informed by recent advances in gender studies. That’s when we brought Perry in.

Perry Zurn: I’m a philosopher by training, with a focus on ethics and politics. Citations are both an ethical and a political issue. Citations reflect whose questions and whose contributions are recognized as important in the scholarly conversation. As such, citations can either bring in marginalized voices, voices that have been historically excluded from a conversation, or they can simply replicate that exclusion. My own field of philosophy has just as much of a problem with gender and racial diversity as STEM fields, something Dani and I have been talking about for a long time. This work seemed like a natural point of collaboration.

Describe this study and what it means for promoting gender diversity in neuroscience.

Dworkin: To understand the role of gender in citation practices, we looked at the authors and reference lists of articles published in five top neuroscience journals since 1995. We accounted for self-citations, and various potentially relevant characteristics of papers, and we found that women-led papers are under-cited relative to what would be expected if gender was not a consideration in citation behavior. Importantly, we also found that the under-citation of women-led papers is driven largely by the citation behavior of men-led teams. We also found that this trend is getting worse over time, because the field is getting more diverse while citation rates are generally staying the same.

For a very simple example, if there were 10 women and 90 men neuroscientists in 1980, then citing 10% women would be roughly proportional. But with a diversifying field, say there are now 200 women and 200 men neuroscientists and citations are still 10% women. Sure, the percentage of women cited didn’t go down, but that percentage is now vastly lower than the true percentage in the field. That’s a dramatic example, but it shows you that if we’re going to call for equality in scientific citation, the number of women-led papers on a given reference list should reflect, or even exceed, the number of available and relevant women-led papers in a field, and our work found that it does not.

Bassett: This under-citation of women scientists is a key issue because the gaps in the amount of engagement that women’s work receives could have detrimental downstream effects on conference invitations, grant and fellowship awards, tenure and promotion, inclusion in syllabi, and even student evaluations. As a result, understanding and eliminating gender bias in citation practices is vital for addressing gender imbalances in a field.

Why are citations important to gender representation in neuroscience?

Bassett: There are a lot of underrepresented scholars who have fantastic ideas and write really interesting papers but they’re not being acknowledged — and cited — in the way they deserve. And there are great role models for all the young women who are thinking about going into science, but unless the older women scientists are being cited, the younger ones will never see them. Without serious changes in the field, and a deep commitment to gender and racial diversity, many young women and minority scientists won’t stick with it, they won’t be hired, they won’t be promoted, and they won’t be put in the textbooks.

Zurn: Exactly. I think it’s important not only to think about who we’re citing as leading scientists, but also what sorts of people we’re representing as scientists at all. If you are looking at neuroscience as a field and you see predominantly white cisgender men in the research labs and the reference lists, then you begin to think that is what a neuroscientist looks like. But this homogeneity is neither representative of an increasingly diverse field like neuroscience, nor supportive of continuing efforts to diversify STEM in general. We need to expand what a scientist looks like and citations are one way to do that.

Read the full interview on the Penn Engineering blog.

Danielle Bassett also has appointments in Penn Engineering’s Department of Electrical and Systems Engineering and Penn Arts & Sciences Department of Physics and Astronomy.

Jordan Dworkin is now an Assistant Professor of Clinical Biostatistics in the Department of Psychiatry at Columbia University.

Kristin Linn, Assistant Professor of Biostatics, Russell Shinohara, Associate Professor of Biostatistics, and Erin Teich, a postdoctoral researcher in Bassett’s lab, also contributed to the study published in Nature Neuroscience. It was supported by the National Institute of Neurological Disorders and Stroke through grants R01 NS085211 and R01 NS060910, the John D. and Catherine T. MacArthur Foundation, the Alfred P. Sloan Foundation, and the National Science Foundation through CAREER Award PHY-1554488.

What do ‘Bohemian Rhapsody,’ ‘Macbeth,’ and a list of Facebook Friends All Have in Common?

New research finds that works of literature, musical pieces, and social networks have a similar underlying structure that allows them to share large amounts of information efficiently.

Examples of statistical network analysis of characters in two of Shakespeare’s tragedies. Two characters are connected by a line, or edge, if they appear in the same scene. The size of the circles that represent these characters, called nodes, indicate how many other characters one is connected to. The network’s density relates to how complete the graph is, with 100% density meaning that it has all of the characters are connected. (Image: Martin Grandjean)

 

By Erica K. Brockmeier

To an English scholar or avid reader, the Shakespeare Canon represents some of the greatest literary works of the English language. To a network scientist, Shakespeare’s 37 plays and the 884,421 words they contain also represent a massively complex communication network. Network scientists, who employ math, physics, and computer science to study vast and interconnected systems, are tasked with using statistically rigorous approaches to understand how complex networks, like all of Shakespeare, convey information to the human brain.

New research published in Nature Physics uses tools from network science to explain how complex communication networks can efficiently convey large amounts of information to the human brain. Conducted by postdoc Christopher Lynn, graduate students Ari Kahn and Lia Papadopoulos, and professor Danielle S. Bassett, the study found that different types of networks, including those found in works of literature, musical pieces, and social connections, have a similar underlying structure that allows them to share information rapidly and efficiently.

Technically speaking, a network is simply a statistical and graphical representation of connections, known as edges, between different endpoints, called nodes. In pieces of literature, for example, a node can be a word, and an edge can connect words when they appear next to each other (“my” — “kingdom” — “for” — “a” — “horse”) or when they convey similar ideas or concepts (“yellow” — “orange” — “red”).

The advantage of using network science to study things like languages, says Lynn, is that once relationships are defined on a small scale, researchers can use those connections to make inferences about a network’s structure on a much larger scale. “Once you define the nodes and edges, you can zoom out and start to ask about what the structure of this whole object looks like and why it has that specific structure,” says Lynn.

Building on the group’s recent study that models how the brain processes complex information, the researchers developed a new analytical framework for determining how much information a network conveys and how efficient it is in conveying that information. “In order to calculate the efficiency of the communication, you need a model of how humans receive the information,” he says.

Continue reading at Penn Today.