CBE Seminar: "Spatial and Dynamical Control in Metabolic Engineering Using Organelle Engineering and Optogenetics"
2021-10-20 15:30 - 16:30 (America/New_York) | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
Abstract
Metabolic engineering aims to rewire cellular metabolism, typically of microorganisms, to produce fuels, chemicals, pharmaceuticals, and other valuable products from renewable resources. However, it is often challenging to achieve the titers, yields, and productivities required for commercial viability. Spatial and dynamical control of engineered metabolic pathways can greatly improve their efficiency to address this obstacle. We have developed strategies to enhance the flux and specificity of metabolic pathways by spatially compartmentalizing them in yeast mitochondria and synthetic organelles. This helps increase the local concentrations of enzymes and intermediate metabolites, prevent metabolic bottlenecks, and reduce metabolite loss to competing pathways. In addition, I will present a new strategy to dynamically control metabolic pathways using optogenetics. There are many advantages of using light to control metabolic pathways, including its orthogonality, tunability, and the ease with which it can be applied or removed instantly in any schedule to continuously manipulate metabolism throughout fermentations. I will present several optogenetic circuits we have built to control microbial growth and production with light, the impact they have on chemical production, and the strategies we have developed to overcome the limited light penetration of fermentations operating at high cell density in lab scale bioreactors. Finally, I will provide a perspective on how these technologies may come together to prescribe a new paradigm for spatial and dynamical control in metabolic engineering to improve microbial chemical production.

Singh Center for Nanotechnology 2021 Annual User Meeting
2021-10-21 08:00 - 19:30 | Glandt Forum, Singh Center for Nanotechnology, 3205 Walnut Street, Philadelphia, PA, 19104, United States

MSE Seminar: "Topological Physics: from Photons to Electrons"
2021-10-21 12:30 - 13:30 | Auditorium, LRSM Building, 3231 Walnut Street, Philadelphia, PA, 19104, United States
There are many intriguing physical phenomena that are associated with topological features — global properties that are not discernible locally. The best-known examples are quantum Hall effects in electronic systems, where insensitivity to local properties manifests itself as conductance through edge states which are insensitive to defects and disorder. In this talk, Dr. Hafezi will first discuss how similar physics can be explored with photons; specifically, how various topological models can be simulated in various photonics systems, from ring resonators to photonic crystals. He then will discuss that the integration of strong optical nonlinearity can lead to unique bosonic phenomena, such as topological frequency combs, topological source of quantum light and chiral quantum optics. These results may enable the development of classical and quantum optical devices with built-in protection for next-generation optoelectronic and quantum technologies. In the end, Dr. Hafezi will cover the topological interplay between photonic and electronic systems. Specifically, he investigates how light can create and manipulate topological states of electrons.

BE Seminar: "Phage and Robotics-Assisted Biomolecular Evolution" (Emma Chory)
2021-10-21 15:30 - 16:30 | Moore 216, 200 S. 33rd Street, Philadelphia, PA, 19104, United States
This seminar will be held live and broadcast on zoom – check email for link or contact ksas@seas.upenn.edu.
Evolution occurs when selective pressures from the environment shape inherited variation over time. Within the laboratory, evolution is commonly used to engineer proteins and RNA, but experimental constraints have limited our ability to reproducibly and reliably explore key factors such as population diversity, the timing of environmental changes, and chance. We developed a high-throughput system for the analytical exploration of molecular evolution using phage-based mutagenesis to evolve many distinct classes of biomolecules simultaneously. In this talk, I will describe the development of our open-source python:robot integration platform which enables us to adjust the stringency of selection in response to real-time evolving activity measurements and to dissect the historical, environmental, and random factors governing biomolecular evolution. Finally, I will talk about our many on-going projects which utilize this system to evolve previously intractable biomolecules using novel small-molecule substrates to target the undruggable proteome.

GRASP on Robotics: "The Importance of Pneumatic Actuation in Adaptive Robotic Devices"
2021-10-22 10:30 - 11:45
Abstract: Soft pneumatic actuators have become a popular implement in modern robotic systems due to their intrinsic mechanical compliance, which affords researchers levels of robustness and adaptability that can be difficult to achieve in rigid-body, motor-driven devices. However, with the physical advantages of these versatile actuators come significant challenges in sensing, feedback control, and sustainable, portable powering that can limit their feasibility in real-world applications. This talk will highlight the engineering challenges of pneumatic actuation within the context of ongoing robotics research efforts in the ARM Lab, including the development of a soft, EMG-controlled robotic knee exoskeleton. The implications of new pneumatic actuation approaches on the future of smart, wearable human augmentation systems will also be discussed.

PICS Colloquium: "Kinetic theory for superparameterization of sea ice dynamics"
2021-10-22 14:00 - 15:00 | PICS Conference Room 534 – A Wing , 5th Floor, 3401 Walnut Street, Philadelphia, PA, 19104, United States
Arctic sea ice comprises of many ice floes whose dynamics is driven by oceanic/atmospheric currents and floe-floe interaction. Models of the effective sea ice dynamics at large scales typically employ hydrodynamic equations of motion, such as mass and momentum conservation, with complex constitutive laws attempting to capture the rheology of sea ice as a continuum. Although hydrodynamic sea ice models have enjoyed some successes, they have well-documented limitations in capturing phenomena such as fracture and lead formation, which are direct manifestation of the granular nature of sea ice.
In this talk, we describe a framework that generalizes hydrodynamic models for sea ice using a mesoscopic (kinetic) description that systematically couples macro-scale PDEs with small-scale particle methods. This framework employs a time-dependent probability distribution over floe position and velocity, evolving according to the Boltzmann equation. The mass density and momentum (computed by integrating over the velocity coordinate) evolve according to the same macro-scale hydrodynamic equations used in previous models. However, rather than requiring an effective rheology, kinetic models of the collisions between co-located ice particles determine the small-scale evolution of the conditional density and influence the macro-scale dynamics. To simulate this system efficiently, we construct a two-tiered numerical method that employs finite element methods to solve the macro-scale PDEs and a particle method to evolve the conditional density over the velocity coordinate. We illustrate the framework with idealized numerical experiments demonstrating that it can naturally reproduce phenomena such as ice breakup under a divergent flow.

CBE PhD Dissertation Defense | “Process Development and Modeling for the Advancement of Direct Air Capture Technologies"
2021-10-25 15:00 - 17:00 | Zoom – Email CBE for link
Abstract:
“As the catastrophic effects of climate change are felt throughout our global society, we must take immediate action. A portfolio of climate solutions must include both deep and robust decarbonization, and systems to remove carbon dioxide directly from the atmosphere. One promising suite of carbon removal technologies is Direct Air Capture (DAC). DAC refers to engineered systems that pull CO2 from air, capturing it in a near-pure form. The captured CO2 can be stored geologically (resulting in a reduction of atmospheric CO2 concentrations), or otherwise utilized. This Dissertation focuses on development and deployment of DAC technologies first by exploring the current DAC landscape, then by proposing a novel DAC process using earth-abundant minerals.

The current landscape of DAC includes two main approaches: solid sorbent and liquid solvent. Each DAC approach has advantages and challenges, including energy usage, specialty chemical demand, and land area requirements. Here, each approach is outlined, and suggestions are provided to accelerate industrial deployment. Additionally, the effect of different dedicated energy infrastructure to power solvent-based DAC is evaluated, including both fossil and renewable energy resources and quantifying the effect of energy-related emissions on the amount of carbon net removed from air. A technoeconomic tool is also presented which allows for a high-level cost estimate of DAC based on available information. The tool can be utilized by investors to evaluate key aspects of DAC technologies and determine which innovations result in significant cost reductions.

An ambient oxide looping process is proposed as a novel approach to DAC. The process uses earth-abundant minerals (limestone, magnesite) to produce reactive oxides (calcium oxide, magnesium oxide) that react with the CO2 in air. Investigation into the economics of the process indicates it could be less expensive per ton of CO2 removed than other DAC technologies. To understand the process viability, a series of experiments characterize industrially available calcium and magnesium oxide and hydroxide feedstocks. These experiments probe the physical properties of these materials and different aspects of engineering optimization, including material depth and rate enhancement as a function of both relative humidity and direct water addition to the system. “

MEAM Seminar: “Robotics Goes Soft: Challenges and Achievements, for New Robotics Scenarios”
2021-10-26 10:00 - 11:30 | Zoom – Email MEAM for Link, peterlit@seas.upenn.edu
Largely inspired by the observation of the role of soft tissues in living organisms, the use of soft materials for building robots is recognized as one of the current challenges for pushing the boundaries of robotics technologies and building robotic systems for service tasks in natural environments. The study of living organisms sheds light on principles that can be fruitfully adopted to develop additional robot abilities or to facilitate more efficient accomplishment of tasks, because living organisms exploit soft tissues and compliant structures to move effectively in complex natural environments.
Widely growing worldwide, soft robotics has produced already interesting achievements in terms of technologies for actuation, sensing, control, and many more. In addition to allowing more applications for robots, soft robotics technologies are enabling robot abilities that were not possible before, like morphing, stiffening, growing, self-healing, evolving. They open up new scenarios for robotics that brings towards more life-like robots, effectively and efficiently adaptable to their environments and tasks.

ODEI Spotlight: Diversity Lecture Series at Penn, "Addressing a More Complex and Encompassing Understanding of Identity"
2021-10-27 12:00 - 13:00
Speaker: Melissa E. Sanchez, Ph.D.
Center for Research in Feminist, Queer, and Transgender Studies
Topic: Addressing a More Complex and Encompassing Understanding of Identity
Date: Wednesday, October 27, 2021
Time: 12 Noon to 1:00 PM
Link: : https://upenn.zoom.us/j/93398784741?pwd=[REDACTED]

Fall 2021 GRASP SFI: “Physics-inspired learning for discontinuous contact dynamics”
2021-10-27 15:00 - 16:00 | Levine 307, 3330 Walnut Street, Philadelphia, PA, 19104, United States
*This will be a HYBRID Event with in-person attendance in Levine 307 and Virtual attendance via Zoom here…
Frictional contact is the core underlying behavior of robot locomotion and manipulation, and its nearly-discontinuous dynamics make planning and control challenging even when an accurate model of the robot is available. In this talk, I will first present empirical evidence that learning an accurate model in the first place can be confounded by contact, as modern deep learning approaches are not designed to capture this non-smoothness. Second, I will discuss ContactNets, our approach which circumvents this conflict via a smooth, implicit encoding of discontinuity as signed distance functions and contact-frame Jacobians.

ODEI Spotlight: Society of Women Engineers GSK Info Session
2021-10-27 18:00 - 19:00
Society of Women Engineers GSK Info Session
Wednesday, October 27 from 6-7 PM

GSK is hosting an information session for students of all grade levels! GSK is hiring for the Internship and Co-Op Program, and the Future Leaders Program! If you are interested in applying what you are learning in your current classes in real-life work scenarios, an internship or co-op is the perfect opportunity for you to do so! If you are coming up on graduation, the Future Leaders Program is a rotational training program that will provide you with the skills you need to succeed!

Join us to learn more about GSK’s programs, and what it is like to work here. We look forward to seeing you there!

When: October 27 at 6 PM
Where: Microsoft Teams (tinyurl.com/swe-gsk)

ESE Fall Colloquium Seminar - "Transforming Ideas to Reality: Emerging Nanotechnologies from the “Lab” to the “Fab”"
2021-10-28 10:30 - 11:30 | Raisler Lounge (Room 225), Towne Building, 220 South 33rd Street, Philadelphia, PA, 19104, United States
Emerging nanotechnologies promise to enable a wide-range of next-generation applications – from energy-efficient computing to personalized healthcare. Yet many emerging nanotechnologies face substantial inherent imperfections and variations that have rendered making working systems – and therefore the next-generation applications they promise to enable – infeasible. In this talk, I will describe how by computing advances across the entire stack – from nanomaterial synthesis to new processing techniques, circuit design methodologies, architectures, and novel systems – these challenges can be overcome to realize the first large-scale and complex electronic systems leveraging beyond-silicon emerging nanotechnologies. As a case-study, I will describe the journey of transforming carbon nanotubes from an interesting scientific nanomaterial in academic labs into the foundation for realizing novel systems and applications that can impact our daily lives, such as the first beyond-silicon microprocessor for energy-efficient computing and novel diagnostic tools for rapid and accurate disease diagnostics. I will conclude by describing how these emerging nanotechnologies are currently being transferred from the “lab” to multiple commercial “fabs”, promising a new and exciting age for electronics and the systems and applications they can enable.

MSE Grace Hopper Lecture: "Optics on the Nanoscale: Conquering Absorption with Nonlinear Optics"
2021-10-28 12:30 - 13:30 | Auditorium, LRSM Building, 3231 Walnut Street, Philadelphia, PA, 19104, United States
Optical nanostructures enable molding the flow of light on the subwavelength scale rendering possible the realization of compact, cost-effective, flat and highly efficient optical components for imaging, spectroscopy, sensing, and communications. From the fundamental science viewpoint, light-matter interactions at the nanoscale reveal themselves in new and often unexpected ways. In fact, the usual linear and nonlinear macroscopic theories that describe the behavior of the electromagnetic field merit revision. From the applications viewpoint, miniaturized, tunable and reconfigurable functionalities implemented on a chip are of paramount importance. Here, we reassess dielectric materials such as chalcogenides as promising candidates for science and applications in wavelength ranges once thought to be hostile to the propagation of light. We show that, in fact, these materials constitute new, excellent contenders for developing new, multi-functional nanophotonic devices due to their high linear refractive indices, strong nonlinear response, and fast switching speeds. To date, applications of these glasses have been limited to wavelength ranges where absorption meticulously avoided, for example, above 500nm for As2S3: high absorption at visible and ultraviolet wavelengths manifests itself through the large imaginary parts of the dielectric constants. However, we demonstrate that, as counterintuitive as it may appear, highly nonlinear, properly nanostructured chalcogenide glass, transparent in the mid- and near-infrared, can also be used to generate third harmonic frequencies in the visible and ultraviolet part of the spectrum, despite the presence of strong material absorption in this range. Such third-harmonic generation can be tuned and further enhanced using stacked metasurfaces and various mechanisms of local field enhancement, including Mie and quasi-bound states in continuum resonances.

BE Seminar: "Systems-level Analyses of the Human Gut Microbiome" (Ilana Lauren Brito)
2021-10-28 15:30 - 16:30 | Moore 216, 200 S. 33rd Street, Philadelphia, PA, 19104, United States
This seminar will be held live and broadcast on zoom – check your email for the link or contact ksas@seas.upenn.edu.
A major question regarding the human gut microbiota is: by what mechanisms do our most intimately associated organisms affect human health? In this talk, I will present several systems-level approaches that we have developed to address this fundamental question. My lab has pioneered methods that leverage protein-protein interactions to implicate bacterial proteins in human pathways linked to disease, revealing for the first time a network of interactions that affect diseases such as colorectal cancer, inflammatory bowel disease, type 2 diabetes and obesity that can be mined for novel therapeutics and therapeutic targets. I will present novel methods that that enable deeper insight into the transcriptome of organisms within our guts and their spatial localization. Finally, I will shift to the problem of the spread of antibiotic resistance, in which the gut microbiota are implicated. Pathogens become multi-drug resistance by acquiring resistance traits carried by the gut microbiota. Studying this process in microbiomes is inherently difficult using current methods. I will present several methods that enable tracking of genes within the microbiome and computational tools that predict the network of gene transfer between bacteria. Overall, these systems-level tools provide deep insight into the knobs we can turn to engineer outcomes within the microbiome that can improve human health.

GRASP on Robotics: "Planning on Graphs of Convex Sets"
2021-10-29 10:30 - 11:45 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
*This will be a HYBRID Event with in-person attendance in Wu & Chen Auditorium and Virtual attendance via Zoom Webinar here.
Motivated by the challenging problems in planning and control through contact, our group has been working to connect more deeply the motion planning formulations we often use in robotics with a different lineage of algorithms and results in combinatorial optimization. What we’ve found surprised me: I feel that we’ve been formulating our mixed-integer motion planning problems incorrectly, and that there are better formulations that can lead to dramatically faster solve times and tighter convex relaxations. I’d like to tell you that story, through the lens of optimization-based collision-free motion planning. This is joint work with Tobia Marcucci, Jack Umenberger, and Pablo Parrilo. I’ll also briefly describe a few other ongoing projects in robotic manipulation, and promise to show some robot videos.

BE Doctoral Dissertation Defense: "Mechano-regulation of meniscus development and maturation" (Tonia Tsinman)
2021-10-29 11:00 - 13:00 | https://upenn.zoom.us/j/96715197752
The Department of Bioengineering at the University of Pennsylvania and Dr. Rob Mauck are pleased to announce the Doctoral Dissertation Defense of Tonia Tsinman.

Title: “Mechano-regulation of meniscus development and maturation”

Date: October 29, 2021
Time: 11:00am

The public is welcome to attend via zoom at the following link: https://upenn.zoom.us/j/98160257924

PICS Colloquium: "A model for external aerodynamics based on building-block flows"
2021-10-29 14:00 - 15:00 | PICS Conference Room 534 – A Wing , 5th Floor, 3401 Walnut Street, Philadelphia, PA, 19104, United States
Abstract: A wall model for large-eddy simulation is proposed by devising the flow as a collection of building blocks, whose information enables the prediction of the stress as the wall. The core assumption of the model is that simple canonical flows (such as turbulent channel flows, boundary layers, pipes, ducts, speed bumps, etc) contain the essential flow physics to devise accurate models. Three types of building block units are used to train the model, namely, turbulent channel flows, turbulent ducts, and turbulent boundary layers with separation. The approach is implemented using two interconnected artificial neural networks: a classifier, which identifies the contribution of each building block in the flow; and a predictor, which estimates the wall stress via non-linear combinations of building-block units. The output of the model is accompanied by the confidence in the prediction. The latter aids the detection of areas where the model underperforms, such as flow regions that are not representative of the building blocks used to train the model. The model is validated in a realistic aircraft geometry from NASA Juncture Flow Experiment, which is representative of external aerodynamic applications with trailing-edge separation.

CBE PhD Dissertation Defense | “3D-stiffness Microenvironment Leads to Nuclear Envelope Rupture, DNA Damage, and Genome Variation”
2021-11-01 10:00 - 12:00 | Levine 307, 3330 Walnut Street, Philadelphia, PA, 19104, United States
Abstract:
“Solid tumor cells grow in a stiff microenvironment with dense extracellular matrix (ECM) and condensed packing of adjacent cells. Tumor cells are capable of migrating through constricted pores formed by ECM or surrounded by other cells, and the nuclear envelope can break with repair factor mislocalization, further leading to DNA damage and genetic changes, or even accumulated to be genomic variations. Cell division, likewise, is confined by a stiff niche of adjacent cells and extracellular matrix, and such confinement has been reported to cause chromosome mis-segregation. The chromosome-loss live cell reporter system was developed to prove that cells undergoing specific types of chromosome missegregation can survive and maintain heritability, resulting in permanent genomic variations. Mitotic cells under in vitro confinement and in vivo conditions exhibit more abnormal division and more fluorescence-null reporter-negative cells, for both cancer and normal types. Confinement and SAC inhibition both lead to chromosome mis-segregation but do not superimpose, and Topoisomerase IIa plays an essential role in cells to survive after confined mitosis. Myosin II was found to lead to increased nuclear envelope rupture and, therefore, more DNA damage, while it protects mitotic cell rounding within 3D confined environments, since the increase of reporter-negative cells was observed after Myosin II knockdown. “

PSOC@Penn Seminar: Cindy Reinhart King
2021-11-01 12:00 - 13:00 | Raisler Lounge (Room 225), Towne Building, 220 South 33rd Street, Philadelphia, PA, 19104, United States
Room: Towne 225/Raisler Lounge
For zoom link, contact manu@seas.upenn.edu.

MEAM Seminar: "Designing Robotic Systems with Collective Embodied Intelligence"
2021-11-02 10:00 - 11:30 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
Natural swarms exhibit sophisticated colony-level behaviors with remarkable scalability and error tolerance. Their evolutionary success stems from more than just intelligent individuals, it hinges on their morphology, their physical interactions, and the way they shape and leverage their environment. Mound-building termites, for instance, are believed to use their own body as a template for construction; the resulting dirt mound serves, among other things, to regulate volatile pheromone cues which in turn guide further construction and colony growth. Throughout this talk I will argue how we can leverage the same principles to achieve greater performance in robot collectives, by paying attention to the interplay between control and hardware, as well as direct- and environmentally-mediated coordination between robots. I will exemplify the strength and challenges of this approach through cell-inspired, soft, single- and multi-robot systems for exploration; micro-scale robots for bio-medical applications; termite-inspired multi-robot systems for construction- and excavation; and bio-hybrid systems for agricultural monitoring.

ESE Grace Hopper Lecture - "A Communications Perspective on Digital Privacy"
2021-11-02 11:00 - 12:00 | Raisler Lounge (Room 225), Towne Building, 220 South 33rd Street, Philadelphia, PA, 19104, United States
Many of the activities in cyberspace, from social networking to the use of mobile apps, leave digital footprints compromising the users’ privacy. As digital tracking technologies become more sophisticated and pervasive, there is a need to understand and quantify the users’ privacy risk, that is, what is the likelihood that users in cyberspace can be uniquely identified from their activities?
In this talk, we focus on de-anonymization attacks, where publicly and privately available information about users, represented as connectivity graphs, are leveraged to compromise user identities. We model the de-anonymization attack as a graph matching problem in which we have two correlated stochastic graphs the first of which has labeled vertices, whereas the second one is unlabeled. The goal is to recover the labels of the second graph by using the correlation structure. We explore how graph matching can be posed as a communications problem, and tools from information theory, communication theory and probability can be used to derive theoretical guarantees and algorithms for graph matching, thereby providing a framework for quantifying the privacy risk of users in the cyberspace.

CIS Seminar: "Sketching Algorithms"
2021-11-02 15:30 - 16:30 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
Abstract:
A “sketch” is a data structure supporting some pre-specified set of queries and updates to a database while consuming space substantially (often exponentially) less than the information theoretic minimum required to store everything seen, and thus can also be seen as some form of functional compression. A “streaming algorithm” is simply a data structure that maintains a sketch dynamically as data is updated. The advantages of sketching include less memory consumption, faster algorithms, and reduced bandwidth requirements in distributed computing environments. Despite decades of work in the area, some of the most basic questions still remain open or were only resolved recently. In this talk, I survey recent results across a variety of sketching topics.

ODEI Spotlight: Trauma Informed Care and LGBT Health
2021-11-02 19:00 - 20:00 | LGBT Center – 3907 Spruce Street, 3907 Spruce Street, Philadelphia, United States
Stephanie Tillman, CNM — the Feminist Midwife — will discuss LGBT health through the lens of trauma informed care. Registration required, more info TBA. Find full details on the event page here.

Fall 2021 GRASP SFI: "Studying Bias and Representation in Sociotechnical Systems"
2021-11-03 15:00 - 16:00
*This will be a HYBRID Event with in-person attendance in Levine 307 and Virtual attendance via Zoom here…
Algorithms play a central role in our lives today, mediating our access to civic engagement, social connections, employment opportunities, news media and more. While the sociotechnical systems deploying these algorithms—search engines, social networking sites, and others—have the potential to dramatically improve human life, they also run the risk of reproducing or intensifying social inequities and tensions. In my research, I ask whether and how these systems are biased and how those biases impact users, towards the aim of building better ones. In this talk, I will describe my work conducting algorithm audits and randomized controlled user experiments to study representation and bias, touching on examples including my recent audits of gender and racial representation in image search results and partisan political media in web search. I will conclude by discussing my most recent work building tools to extend such audits into new domains and make them more accessible and sustainable for researchers.

Homecoming 2021: Penn Engineering Update and "Engineering living biology with nanomachines"
2021-11-03 17:00 - 18:00
This special event is part of the virtual programming for Penn Homecoming 2021 and is open to all alumni, parents, and friends. Nemirovsky Family Dean and Professor Vijay Kumar will give a State of the School Update including an overview of the newly established Center for Precision Engineering for Health, which will bring together researchers spanning multiple scientific fields to develop novel therapeutic biomaterials.
Dean Kumar’s update will be followed by a presentation, “Engineering living biology with nanomachines,” by Jennifer E. Phillips-Cremins, Associate Professor and Dean’s Faculty Fellow in Bioengineering and Genetics, and Marc Miskin, Assistant Professor in Electrical and Systems Engineering, with a moderated Q&A session.
Register here. After registration, attendees will receive a link to view the live discussion the day prior to the event.

MSE Seminar: "Lansdcapes of Glass"
2021-11-04 12:30 - 13:30 | Auditorium, LRSM Building, 3231 Walnut Street, Philadelphia, PA, 19104, United States
If cooled sufficiently quickly, the disorder of a liquid can be “quenched” or locked in place; the resulting amorphous solid is glass. Although it appears to be solid on human timescales, glass continues to creep due to thermal vibrations at the molecular scale. Consider now a pile of sand; it too is a disordered system, but the grains are too massive for such thermal effects to be relevant. Yet, soils in nature relentlessly creep, on hillslopes below the angle of repose. The unchallenged dogma is that this creep is driven by churning of soil by (bio)physical disturbances. River-bed sediments also creep, at flows below the threshold of motion, though this has received far less attention. In this talk Dr. Jerolmack focuses on recent work from his group and others that examines the origins of granular creep in hillslope and river systems, and the consequences of these findings for understanding actual landscapes. Our observations, arising from first-of-their-kind experiments and simulations, reveal surprises for both materials and geology. First, gravity-driven granular creep occurs with minimal disturbance, with rates and styles comparable to field observations. Second, this creep shares deep similarities with the behavior of glass, suggesting that mechanical disturbance in granular systems plays a role akin to thermal fluctuations in molecular systems. Third, fluid-driven creep in rivers has similar behavior to gravity-driven soil creep on hillsides. In both cases this creep acts to “harden” the bed, by compaction and the creation of structures that resist motion. Thus, sediment beds maintain a memory of their history of forcing, that dicates the threshold for landsliding (hillslopes) or entrainment (rivers). The upshot is that Earth’s landscapes appear to be glassy, and that viewing the Earth’s surface as a soft-matter landscape yields (pun intended) new insights with practical consequences.

ODEI Spotlight: Critical Race Theory and DEI: From Theory to Practice
2021-11-04 17:30 - 19:00 | https://upenn.zoom.us/j/96715197752
The African-American Resource Center & Office of Affirmative Action Presents:

Critical Race Theory and DEI: From Theory to Practice
Join us as we examine the language switch from Critical Race Theory to Diversity Equity and Inclusion,
and what each term means and what DEI means and looks like at Penn.

Zoom Link:
http://upenn.zoom.us/j/7443577924

Panelists:
Beverly A. Crawford, Director of Diversity and Inclusion, Department of Preventive and Restorative Sciences
Captain W. Nicole McCoy, Commanding Officer of Diversity, Equity, and Inclusion, Public Safety
Monica Monroe, Associate Dean for Equity & Inclusion, Carey Law School

Moderator:
Valerie Dorsey Allen, Director, African-American Resource Center

Keynote Speaker:
Chaz L. Howard, Penn’s Vice President for Social Equity and Community

GRASP on Robotics: "Event-based Neuromorphic Perception and Computation: The Future of Sensing and AI"
2021-11-05 10:30 - 11:45 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
*This will be a HYBRID Event with in-person attendance in Wu & Chen Auditorium and Virtual attendance via Zoom Webinar here.
There has been significant research over the past two decades in developing new systems for spiking neural computation. The impact of neuromorphic concepts on recent developments in optical sensing, display and artificial vision is presented. State-of-the-art image sensors suffer from severe limitations imposed by their very principle of operation. These sensors acquire the visual information as a series of ’snapshots’ recorded at discrete point in time, hence time-quantized at a predetermined frame rate, resulting in limited temporal resolution, low dynamic range and a high degree of redundancy in the acquired data. Nature suggests a different approach: Biological vision systems are driven and controlled by events happening within the scene in view, and not — like image sensors — by artificially created timing and control signals that have no relation whatsoever to the source of the visual information. Translating the frameless paradigm of biological vision to artificial imaging systems implies that control over the acquisition of visual information is no longer being imposed externally to an array of pixels but the decision making is transferred to the single pixel that handles its own information individually. It is demonstrated that bio-inspired vision systems have the potential to outperform conventional, frame-based vision acquisition and processing systems in many application fields and to establish new benchmarks in terms of redundancy suppression/data compression, dynamic range, temporal resolution and power efficiency to realize advanced functionality like 3D vision, object tracking, motor control, visual feedback loops and even allow us to rethink our current paradigm of computation. The ultimate goal is to develop brain-inspired general purpose computation architectures that can breach the current bottleneck introduced by the von Neumann architecture.

PICS Colloquium: "From atoms to emergent mechanisms with information bottleneck and diffusion probabilistic models"
2021-11-05 14:00 - 15:00 | Zoom – email kathom@seas.upenn.edu
Abstract: The ability to rapidly learn from high-dimensional data to make reliable predictions about the future is crucial in many contexts. This could be a fly avoiding predators, or the retina processing terabytes of data guiding complex human actions. Modern day artificial intelligence (AI) aims to mimic this fidelity and has been successful in many domains of life. It is tempting to ask if AI could also be used to understand and predict the emergent mechanisms across timescales for complex molecules with millions of atoms. In this talk I will show that certain flavors of AI can indeed help us understand generic molecular structure and dynamics, and also predict it even in situations with arbitrary long memories. However this requires close integration of AI with old and new ideas in statistical mechanics. I will talk about such methods developed by my group (1-3) using information bottleneck, denoising probabilistic models and long short-term memory networks, focusing on the first one or two frameworks in interest of time. I will demonstrate the methods on different problems, where we predict mechanisms at timescales much longer than milliseconds while keeping all-atom/femtosecond resolution. These include ligand dissociation from flexible protein/RNA and crystal nucleation with competing polymorphs.
References:
1. Wang, Y., Ribeiro, J.M.L. & Tiwary, P. Past–future information bottleneck for sampling molecular reaction coordinate simultaneously with thermodynamics and kinetics. Nat. Commun. 10, 3573 (2019).
2. Wang, Y., & Tiwary, P. Denoising diffusion probabilistic models for replica exchange. arXiv preprint arXiv:2107.07369 (2021).
3. Tsai, S.T, Kuo, E.J. & Tiwary, P. Learning Molecular Dynamics with Simple Language Model built upon Long Short-Term Memory Neural Network. Nat. Commun. 11, 5115 (2020).

PSOC@Penn Seminar: "High-throughput multi-dimensional T cell profiling enabled systems immunology" (Ning Jenny Jiang)
2021-11-08 12:00 - 13:00 | Raisler Lounge (Room 225), Towne Building, 220 South 33rd Street, Philadelphia, PA, 19104, United States
