Biological Physics

Biological Physics

Biological Physicists, also known as Biophysicists, apply the principles and techniques of physics to study living things and how they function. At a macroscopic level, biophysicists are exploring how organisms develop and how they see, hear, taste, feel, think, and move. At a microscopic level, biophysicists are studying the factors controlling how cells move and interact, how they harness and process energy, and how they react to external physical stimuli. To facilitate their explorations, biophysicists develop new or improved techniques of imaging, diagnosis, and analysis, one particularly well known example being Magnetic Resonance Imaging (MRI).

Here are the researchers in Biological Physics who are able to supervise graduate students. To see a detailed profile of anyone, including contact information, click on the title bar or portrait. To see a personal research website (if available), click on the research picture.

Auditory biophysics, especially otoacoustic emissions; Tuvan throat singing; Coupled/nonlinear oscillators; Signal processing in sensory physiology.

I am primarily interested in auditory biophysics, chiefly in the context of how sound is transduced by the ear into neural impulses going to the brain. Remarkably, somehow in the process of being a very sensitive detector, the (healthy) ear generates and subsequently emits sounds that can be detected non-invasively using a sensitive microphone. These sounds, known as otoacoustic emissions (OAEs), reveal many aspects of the inner workings of the ear and also have many translational applications (e.g., clinical audiology). Our lab combines both experimental and theoretical/modeling approaches across a broad comparative framework so to help us better understand OAEs and thereby the key biophysical processes at work that allow us to hear the world around us.

Nanophotonics and materials for solar energy and biosensing applications.

Our research focuses on the materials and physical chemistry of nanostructures with potential applications ranging from solar energy conversion to bio-sensing. In particular, we are interested in synthesizing and assembling nanomaterials into 3D and 2D structures via a combination of bottom-up approach and top-down lithographic technique to derive novel optical, electrical, and chemical properties. We employ a wide range of characterization methods and various optical spectroscopies to elucidate the interplay between material properties and functions.

Networks of cameras; Single-chip electronic cameras; Integrated sensor design; Image processing methodologies.

I study biologically-inspired imaging systems, i.e., electronic camera chips and networks of cameras. My work encompasses distributed sensor systems based on insect and spider eyes, sensor swarms, clouds and "smart dust" modelled on ant colonies and schools of fish, high performance integrated sensor design, on-chip image processing methodologies, semiconductor device modelling and simulation, and radiation tolerant design and manufacturing. Applications include aircraft collision avoidance, space systems, industrial inspection, machine vision, and vision rehabilitation.

Molecular mechanisms of biological processes and disease; Cell biology, including stem cells; Drug screening; Biophysical, biomedical, and bioanalytical techniques.

I focus on understanding the molecular mechanisms of diseases, especially cancer, neurodegenerative disorders and immune disorders. To that end, my group and I develop new biophysical and bioanalytical approaches for studying and separating the chemical contents of individual cells, particularly proteins, enzymes, and DNA. We are also interested in understanding the molecular mechanisms that govern the fate of stem cells. Specifically, methods of chemical analysis are combined with advanced techniques in cell biology such as fluorescence image cytometry to study the molecular mechanisms of fundamental biological processes (cell cycle, cell differentiation, and apoptosis).

Regulation of biological transport; Cellular membranes; Ion channels; Intracellular reponses to stimuli; Electrophysiology; Signal transduction.

I study the regulation of biological transport at all levels of complexity: the whole cell, isolated membranes, and single proteins (that is, ion channels). Transport across cellular membranes defines the intracellular environment under diverse external conditions. Not only does transport control the composition of the intracellular milieu, but it also functions as a mechanism for translating external triggers (light, hormones, etc.) into intracellular responses. The tools I use are electrophysiology (multi-barrelled micropipettes to inject substances into the cell and perform current-voltage analysis, patch-clamping to measure ion channel activity), biochemistry (to characterize transport activity in vitro), and molecular biology (to clone and characterize genes encoding transport proteins). I work with a variety of model systems - algal, fungal, and plant - and focus on transport properties associated with particular transduction processes. For example, I have engaged in research on root hairs to characterize in detail the role of pressure in tip growth and its regulation by signaling cascades and ion transport.

Applied biophotonic and multimodal techniques for diagnostics and therpeutics; Remotely deployable biomedical sensors and devices.

My research centres on harnessing the power of light to study structural-functional changes in humans in the aging processes and consequently develop individualized countermeasures. Biophotonics converges optical and life sciences providing new insights into the mechanisms of pathogenesis, with the aim of developing pre-diagnostic metrics and intelligent phototherapeutic approaches for minimally invasive, real-time interventions. By targeting and tuning desired light-matter interactions, it is possible to study hallmark features of debilitating diseases such as age-related macular degeneration. Through the knowledge acquired, we derive new translational biophysical techniques to deliver powerful biomedical sensor tools, and personalized intelligent radiation therapeutics as well as dosimetry. The MiBAR Lab (Mermut integrated Biophotonics Applied Research Lab) is inspired to create remotely deployable medical devices for global health applications and space life sciences research. We can achieve this with photonic methods compatible with examining human biometrics in unusual and distant environments, such as in space, thereby enabling support of human health in deep space exploratory missions to Mars and beyond.

Protein dynamics, structure, and function, including folding; Enzymes; Microfluidics; Time-resolved mass spectrometry; Biophysical Nuclear Magnetic Resonance spectroscopy.

I am interested in protein biophysics, especially dynamics and folding. The tools of structural biology provide beautifully detailed snapshots of the lowest energy (or most readily crystallizable) protein conformation, but offer precious little in the way of dynamic information. Since many aspects of protein function (i.e., substrate binding/release, conformational changes, energy dissipation through bond vibrations, etc.) are inherently dynamic, we are working towards a detailed understanding of the dynamical modes available to proteins that are required to accurately predict their functional characteristics. We use a wide variety of techniques (e.g., microfluidics, time-resolved mass spectrometry, and Nuclear Magnetic Resonance spectroscopy) to facilitate studies of protein conformational dynamics on biologically important millisecond timescales and to characterize the dynamics underlying activity in a number of enzyme systems.

Visual cortex; Retina; Synaptic Plasticity; Learning; Perception; Information Theory; Machine Learning

I study the way the brain represents information about the outside world, and the way in which those representations are learned. My immediate goal is to build on my expertise in machine learning and sensory neuroscience to create a camera to brain translator that could restore sight to the blind, and could be used in computer vision systems. In parallel, I will develop new data science methods that will infer the brain’s learning rules from in vivo neural data, and use those methods to determine how behavioural context affects synaptic plasticity in the visual cortex. Next, I will use the brain’s learning rules to make next-generation machine learning algorithms that will be more flexible and efficient than the current state of the art. Finally, I will reveal how the interaction between different retinal ganglion cell types supports the communication of visual information from the eyes to the brain. That work may have strong implications for the development of next-generation retinal prosthetics.