Neurons often exhibit considerable fluctuations in their spontaneous (stimulus-free) activity, characterized by correlation functions. Neurons also react to time-dependent stimuli described by response functions. Because the neural raison d'etre is information processing and transmission (shaped by both their fluctuation and response properties…

Microbes have evolved genetically encoded machinery enabling them to utilize the abundant redox‐active molecules and extracellular minerals. Recently, the machinery enabling these redox reactions have been leveraged for interfacing cells and biomolecules with electrical circuits for biotechnological applications in energy harvesting, chemical…

Chirality is prevalent in nature and plays a crucial role in contexts ranging from left-right symmetry breaking in animal development to shaping material properties in synthetic systems. In this talk, I will discuss how chirality can emerge in multicellular systems, and how collectives of chiral particles exhibit novel material properties such…

Neuropeptides are ubiquitous signaling molecules that underpin almost all brain functions. They mediate extrasynaptic communication in nervous systems predominantly by binding to cell surface G protein-coupled receptors (GPCRs). The number of neuropeptide pathways is diverse and peptide-activated GPCRs are widely expressed throughout the brain,…

Circadian clocks regulate the timing of various behavioral and physiological activities in most organisms on a 24-hr scale such that they are phased appropriately to external, cyclic changes in the environment. The clock neuronal network in Drosophila melanogaster is comprised of  ~150 neurons distributed bilaterally in the brain,…

Many of the physical processes in a cell consume energy, but we are only beginning to understand how these costs have influenced the course of evolution. Biology is strewn with counter-intuitively complex mechanisms whose evolutionary predecessors must have consumed significant energy resources without any clear fitness benefit. So how do such…

In recent decades, much progress has been made in understanding how genes within cells contribute to organ-specific fates or disease phenotypes. However, it is becoming more widely acknowledged that increasing understanding at the molecular scale has not been sufficient to fully grasp how tissues comprised of thousands of cells generate their…

Pseudomonas aeruginosa is an opportunistic bacterial pathogen. Most P. aeruginosa isolates are infected by a filamentous virus (phage) called Pf. At sites of infection, filamentous Pf virions accumulate where they increase mucus viscosity, promote bacterial colonization, and directly stimulate innate anti-viral immune…

Groups of cells of all kinds work together as part of multicellular behaviors ranging from collective migration to development. These behaviors are coordinated at the level of single cells, where information about other cells and the environment are encoded in intracellular signaling dynamics that then drive cellular-level behaviors. We face…

Growth is central to life, shaping physiology, ecology, and evolution. In this talk, I discuss our efforts to elucidate the causes and consequences of bacterial growth across scales. Starting from resource allocation models and the molecular and energetic demands of protein synthesis, I first introduce how bacterial cells adjust their…

Animal behaviors are complex and hierarchical spatiotemporal patterns. In the popular model organism Caenorhabditis elegans, behavioral sequences on a slower timescale emerge from ordered and flexible transitions between different motor states, such as forward movement, reversal, and turn. On a faster timescale, intricate head…

One governing principle of the microscopic world is "predictable randomness," where snapshots of a fluctuating process may appear random, but the average outcome of the process is predictable. An exciting frontier in biological physics is evaluating if predictable randomness extends to more complex, multi-component biophysical systems, such as…

Goal-reaching problems are ubiquitous in both the natural and engineered world. While learning to achieve goals is often considered an aspect of intelligence in biological systems, it is challenging to design practical algorithms for learning such behavior in high-dimensional environments. In this talk, I'll discuss recent work on contrastive…

The dynamic assembly and disassembly of the cytoskeleton can create waves and oscillations that are critical to cell migration and other important cell behaviors.  Chemical signals have been found to trigger and steer these waves, facilitating the guidance e.g. of immune cells to their target.   Here we consider the role of these…

In 1974 Purcell authored a paper “Life at Low Reynolds Number” to describe the counterintuitive world of microscopic organisms in which viscous dissipation so dominates inertia that “coasting” is impossible, and that the geometry of a path in an internal movement space dominates self-propulsion. It is typically assumed that a key difference…

Neural responses in association brain areas during cognitive tasks are heterogeneous, and the widespread assumption is that this heterogeneity reflects complex dynamics involved in cognition. However, the complexity may arise from a fundamentally different coding principle: the collective dynamics of a neural population encode simple…