Seminars

Upcoming Seminars / Seminars This Week

Tue 1/22/19 12 noonGerstenzang 124
Biology Faculty Candidate
John Shin (MRC Laboratory of Molecular Biology)
Using spatial proteomics to determine the content of vesicles captured by golgin tethers at the trans-Golgi
In eukaryotic cells, the conserved family of golgin long coiled-coil proteins at the Golgi apparatus function as tethers that selectively capture incoming transport vesicles to allow SNAREs on opposing membranes to assemble and drive fusion. The cargoes that define these distinct pools of transport vesicles and the trafficking machinery they use to recognise a specific golgin are poorly understood. Here, we utilise spatial proteomic techniques in mammalian cells to map discrete protein-protein interactions by proximity labelling technologies and whole-cell spatial proteomes by the Localisation of Organelle Proteins by Isotope Tagging (LOPIT) method in order to determine the content of vesicles captured by golgin-97, golgin-245 and GCC88 golgin tethers at the trans-Golgi. From this, we identify novel factors that facilitate the targeting of different transport vesicles to these golgins and comprehensively define the cargoes that define their functions.

Tue 1/22/19 1 pmGerstenzang 122
Chemistry Seminar
Emily Mevers (Harvard)
Uncovering Microbial Chemical Warfare

Wed 1/23/19 12 noonGoldsmith 226
Mathematical Biology Journal Club
Alex Hening (Tufts University)
The Competitive Exclusion Principle in Stochastic Environments
The competitive exclusion principle states that a number of species competing for a smaller number of resources cannot coexist. Even though this is a fundamental principle in ecology,it has been observed empirically that in some settings it will fail. One example is Hutchinson's 'paradox of the plankton'. This is an instance where a large number of phytoplanktonspecies coexist while competing for a very limited number of resources. Both experimental and theoretical studies have shown that in some instances (deterministic) temporal fluctuations of the environment can facilitate coexistence for competing species. Hutchinson conjectured that one can get coexistence because nonequilibrium conditions would make it possible for different species to be favored by the environment at different times. In this talk I will look at how environmental noise interacts with competitive exclusion. I will show that, contrary to Hutchinson's explanation, one can switch between two environments in which the same speciesis favored and still get coexistence.
Hosted by Profs. Jonathan Touboul and Thomas Fai and Dr. Denis Patterson

Wed 1/23/19 1 pmGerstenzang 122
Chemistry Seminar
Rose Kennedy (Princeton)
Leveraging Mechanistic Insight to Enable Catalyst-Controlled Chemo-, Regio-, and Stereoselective C–C Bond Formation

Thu 1/24/19 11 amVolen 201
Computational Neuroscience Journal Club
Paul Miller (Brandeis University)
A random-matrix theory of the number sense
Pizza will be served

Thu 1/24/19 12 noonGerstenzang 124
Biology Faculty Candidate
Qiangjun Zhou (Stanford)
Molecular Mechanism of Neurotransmitter Release: locked until the last millisecond
Synaptotagmin, complexin, and neuronal SNARE (soluble N-ethylmaleimide sensitive factor attachment protein receptor) proteins mediate evoked synchronous neurotransmitter release, but the molecular mechanisms mediating the cooperation between these molecules remain unclear. Through a combination of high-resolution structural, biochemical, cellular Cryo-ET and electrophysiological studies, Dr. Zhou showed how these proteins form the primed pre-fusion SNARE--complexin--synaptotagmin-1 complex, and proposed an unlocking mechanism that action-potential-driven Ca2+ binds to the synaptotagmin molecules to unlock the complex, allowing full zippering of the SNARE complex and triggering membrane fusion in a highly synchronized fashion. Finally, these studies also explained the high speed of Ca2+-triggered fusion -- everything is in the right place until the synaptotagmin-1 "brake" is released.

Thu 1/24/19 12 noonGoldsmith 300
Everytopic Seminar
David Lipschutz (Technion)
Synchronous oscillatory behavior for systems of coupled delay differential equations
Dynamical system models with delayed negative feedback arise in a wide variety of applications in science and engineering, ranging from models of neuronal networks to Internet rate control models. In some applications, synchronous stable periodic oscillatory behavior can be critical to the well functioning of a system; and in other applications, it can represent systemic failure. In the first part of this talk we consider a prototypical one-dimensional delay differential equation (DDE) with a negative feedback condition and we review prior work on existence, uniqueness, and stability of periodic oscillatory solutions of this DDE. In the second part of the talk we discuss synchronous periodic oscillatory solutions of a system of coupled DDEs. Interestingly, we show that under conditions where the one-dimensional system exhibits stable periodic oscillatory behavior, the stability of the synchronous periodic solution depends on the spectrum of the coupling matrix.

Pizza.
Hosted by Profs. Konstantin Matveev and Corey Bregman

Thu 1/24/19 4 pmAbelson 229
MRSEC Seminar
Jonathan Touboul (Brandeis Mathematics)
Some Topics in Mathematical Modeling of Embryonic Development
Embryonic development is one of the main historical examples of biological problems where mathematical modeling was successfully applied. From the seminal works of D'Arcy Thompson and Alan Turing, a number of models were proposed to account for embryonic differentiation, increasingly supported by experimental data. In this talk, I will review some recent developments in mathematical modeling of embryonic development.

I will start by discussing the mechanisms that control the mammalian brain development. First, we will explore the hypothesis that the non-conventional non-cell autonomous action of homeoproteins, a class of transcription factors highly expressed during, could play a role in the localization and regularity of boundaries between brain areas. At a finer scale, we will investigate the mechanisms that may control the number of neurons in the different neocortical layers. With data collected by our collaborators on various mutant mice models of microcephaly or neural cell death, we will highlight a few key mechanisms that could support homeostasis in brain's basic architecture. If time allows, we will conclude on a recent work aimed at deciphering the mechanisms supporting skin patterning in birds, with new data on five bird species and a unified model, valid across all species, and reproducing not only the final phenotype of feather patterning but also the dynamics of the establishment of the pattern.

Hosted by John Berezney

Thu 1/24/19 4:30 pmGoldsmith 317
Joint Mathematics Colloquium
Jun Zhang (University of Michigan-Ann Arbor)
Information Geometry and Entropy-Based Inference
Information Geometry is the differential geometric study of the manifold of probability models, and promises to be a unifying geometric framework for investigating statistical inference, information theory, machine learning, etc. Instead of using metric for measuring distances on such manifolds, these applications often use "divergence functions" for measuring proximity of two points (that do not impose symmetry and triangular inequality), for instance Kullback-Leibler divergence, Bregman divergence, f-divergence, etc. Divergence functions are tied to generalized entropy (for instance, Tsallis entropy, Renyi entropy, phi-entropy) and cross-entropy functions widely used in machine learning and information sciences. It turns out that divergence functions enjoy pleasant geometric properties -- they induce what is called "statistical structure" on a manifold M: a Riemannian metric g together with a pair of torsion-free affine connections D, D*, such that D and D* are both Codazzi coupled to g while being conjugate to each other. Divergence functions also induce a natural symplectic structure on the product manifold MxM for which M with statistical structure is a Lagrange submanifold. We recently characterize holomorphicity of D, D* in the (para-)Hermitian setting, and show that statistical structures (with torsion-free D, D*) can be enhanced to Kahler or para-Kahler manifolds. The surprisingly rich geometric structures and properties of a statistical manifold open up the intriguing possibility of geometrizing statistical inference, information, and machine learning in string-theoretic languages.
Hosted by Prof. An Huang

Fri 1/25/19 11:15 amRosenstiel 118
Biochemistry-Biophysics Friday Lunchtime Pizza Talks
Saskia Neher (UNC Chapel Hill)
Mechanistic Insights into the Regulation of Lipoprotein Lipase Folding and Activity
Hosted by Niels Bradshaw

Fri 1/25/19 12:30 pmGerstenzang 123
Molecular and Cell Biology & Neuroscience Student Seminars
Roshan Nanu (Lisman/Katz/Jadhav Labs)
Emmanuel Rivera-Rodriguez (Griffith Lab)

Mon 1/28/19 12 noonGerstenzang 124
Neurobiology Journal Club (Postdoc Invited Speaker)
Evan Schaffer (Columbia University)
Perceptual consistency and the neural representation of internal states
Hosted by Brandeis Postdoc Association

Mon 1/28/19 3:40 pmGerstenzang 121
Chemistry Seminar
Michael Shi (University of South Florida)
Curiosity Driven New Reactivity Discovery

Tue 1/29/19 11 amAbelson 307
String Theory Seminar
Jonathan Harper (Brandeis University)
TBA
Hosted by High Energy Theory Group

Tue 1/29/19 12:30 pmGerstenzang 121
Joint Biology/Neuroscience Colloquium
Andrew Kruse (Harvard Medical School)
Synthetic nanobodies as tools to interrogate GPCR structure and function
Hosted by Amy Lee

Tue 1/29/19 4 pmAbelson 131
Physics Department Colloquium
Robin Wordsworth (Harvard University)
TBA
Hosted by Bjoern Penning

Thu 1/31/19 11 amVolen 201
Computational Neuroscience Journal Club
Mostafizur Rahman (Harvard University)
TBA
Pizza will be served
Hosted by Shantanu Jadhav

Thu 1/31/19 12 noonGerstenzang 124
Biology Faculty Candidate
Alexandre Wilson Bisson Filho (Harvard)
Standing on the shoulders of tiny polymers - Directional motion of cytoskeletal filaments orchestrates cytokinesis in bacteria
Most bacteria have cytoskeletal proteins that self-assemble to form polymeric structures that control cell shape, cell division, and other essential cellular processes. Unlike their eukaryotic counterparts, prokaryotic filaments themselves do not seem to confer mechanical scaffold to cells but instead direct the building of macromolecular structures that will ensure cellular support. Here, I will discuss how the circumferential motion of the bacterial tubulin-like FtsZ filaments directs the processive activity of cell-wall synthesizing enzymes during cytokinesis. These treadmilling-powered FtsZ filaments dictate the rate of cytokinesis by limiting the speed in which such enzymes rotate and insert new cell wall material around the division site. Finally, I will offer my perspective on how advanced live-cell imaging can be used to investigate how evolution shaped the dynamics and function of cytoskeletal polymers in archaea, the most alien and unexplored domain of life.

Fri 2/1/19 12:30 pmGerstenzang 123
Molecular and Cell Biology & Neuroscience Student Seminars
Chloe Greppi (Garrity Lab)
Raul Ramos (Turrigiano Lab)

Mon 2/4/19 12 noonGerstenzang 124
Biology Faculty Candidate
Peri Kurshan (Stanford)
TBA

Tue 2/5/19 11 amAbelson 307
String Theory Seminar
Andrew Rolph (Brandeis University)
Hosted by High Energy Theory Group

Tue 2/5/19 12:30 pmGerstenzang 121
Joint Biology/Neuroscience Colloquium (Neuro Training Grant Speaker)
Michael Greenberg (Harvard Medical School )
How nature and nurture conspire to control brain development and function
Hosted by Ryan Kirk

Tue 2/5/19 4 pmAbelson 131
Physics Department Colloquium
TBA
TBA
Hosted by Bjoern Penning

Thu 2/7/19 11 amVolen 201
Computational Neuroscience Journal Club
Caleb Kemere (Rice University)
TBA
Pizza will be served
Hosted by Linnea Herzog

Thu 2/7/19 12 noonGerstenzang 124
Biology Faculty Candidate
Erin Barnhart (NYU and Stanford)
Cellular mechanisms for efficient coding in the Drosophila visual system
How do neurons and circuits balance functional requirements with energetic constraints in vivo? To address this question, I have developed a versatile experimental system for simultaneously measuring and manipulating neuronal activity and cellular processes in well-characterized circuits in Drosophila. In my seminar, I will describe, first, how I used this system to investigate a circuit function -- the efficient coding of a specific visual feature -- that emerges from complementary cellular and circuit mechanisms. Second, I will describe my ongoing efforts to understand how a cellular element -- the dynamic mitochondrial network -- responds to neuronal activity, thereby coordinating energy supply with demand

Fri 2/8/19 12:30 pmGerstenzang 123
Molecular and Cell Biology & Neuroscience Student Seminars
Albert Yu (Rosbash Lab)
Hillary Rodgers (Marder Lab)

Mon 2/11/19 12 noonGerstenzang 124
Biology Faculty Candidate
Xianrui Cheng (Stanford)
Signal Transmission and Pattern Formation in Xenopus Cytoplasm
Apoptosis, a physiological cell suicide program, requires a propagation mechanism to spread its initial signals from a few isolated locations to all corners of the cell. Using quantitative live imaging of Xenopus laevis eggs, oocytes, and cell-free egg extracts, we show that instead of simple diffusion, apoptotic signal is spread by self-regenerating chemical waves (called trigger waves) traveling at ~30 µm/min in the cytoplasm. Trigger waves in apoptosis arise from the same systems-level logic that gives rise to action potentials in neurons, and therefore may be a general mechanism for biological communication over millimeter to centimeter distance scales. We further demonstrate that the cytoplasm, besides transmitting biological signals, can also self-organize into cell-like compartments capable of self-replication, suggesting that the cytoplasm can robustly generate the basic spatial organization of the cell and may retain much of its distinctive functions.

Mon 2/11/19 3:40 pmGerstenzang 121
Chemistry Seminar
Natalia Shustova (University of South Carolina )
Hosted by Grace Han

Tue 2/12/19 11 amAbelson 307
String Theory Seminar
TBA
TBA
Hosted by High Energy Theory Group

Tue 2/12/19 12:30 pmGerstenzang 121
Joint Biology/Neuroscience Colloquium
Melissa Rolls (The Pennsylvania State University)
From endosomes to microtubules, neurons use their cell biology to stay healthy and recover after injury
Hosted by Bruce Goode

Tue 2/12/19 4 pmAbelson 131
Physics Department Colloquium
Gabriela González (Louisiana State University)
TBA
Hosted by Bjoern Penning

Thu 2/14/19 11 amVolen 201
Computational Neuroscience Journal Club
TBA
TBA
Pizza will be served

Thu 2/14/19 12 noonGerstenzang 124
Biology Faculty Candidate
Guillermina Ramirez-SanJuan (UCSF and Stanford)
Adding up the noise: How cilia integrate disorder to build a directed flow
To generate large-scale flows, motile cilia coordinate their activity across entire tissues. Intuitively, to build a highly directional coherent flow, cilia would be required to cover tissues completely and be all aligned exactly in parallel. In my talk I will present results showing that such precision is unnecessary. Combining quantitative measurements in the mouse airway and computational dynamics simulations I show that spatial heterogeneity is a feature of the airway epithelium across scales (from nm to mm) and explore how much variability can be tolerated before generation of global flow fails. Altogether these results provide a phase diagram linking cilia patterning and global flow, highlighting the importance of integrated approaches to understand the physiology of multi-ciliated epithelia.

Thu 2/14/19 4 pmAbelson 229
MRSEC Seminar
Dan Nguyen (Harvard Medical School)
TBA
Hosted by John Berezney

Fri 2/15/19 12:30 pmGerstenzang 123
Molecular and Cell Biology & Neuroscience Student Seminars
Nick Clark (Marr Lab)
Claire Symanski (Jadhav Lab)

Fri 2/22/19 12:30 pmGerstenzang 123
Molecular and Cell Biology & Neuroscience Student Seminars
NO PIZZA TALKS - Mid-term break

Mon 2/25/19 12 noonGerstenzang 124
Biology Faculty Candidate
Dennis Zimmermann (MIT)
Mechanoregulation of dynamic actomyosin networks at the single-molecule level
Motility, division, polarity and morphogenesis are vital cell biological processes, that are collectively facilitated by the tightly regulated spatial and temporal assembly and disassembly of the underlying actin cytoskeleton. Defects in any of these processes can cause severe developmental defects or cancer. Only more recently we have begun to appreciate that in addition to classical signal-transduction cascades, mechanical stresses play a central role in modulating the interaction of key regulatory proteins with actin filaments and controlling the dynamics of individual filaments and the entire F-actin network. In my talk I will touch upon my most recent work where by combining biomimetic single-molecule reconstitution and mathematical modeling approaches, I discovered that the actin assembly factor Formin Cdc12 can sense and respond to piconewton forces triggering its own mechano-inhibition, a phenomenon that I showed is required for proper contractile ring assembly during cytokinesis (Nature Comm. 2017). Further, I will discuss ongoing work and future research plans focussing on elucidating the molecular principles governing the mechano-chemical regulation of the cytoskeleton during cell migration and cancer cell metastasis.

Tue 2/26/19 11 amAbelson 307
String Theory Seminar
Harsha Hampapura (Brandeis University)
TBA
Hosted by High Energy Theory Group

Tue 2/26/19 12:30 pmGerstenzang 121
Joint Biology/Neuroscience Colloquium
Tom Schwarz (Boston Children’s Hospital and Harvard Medical School )
The Kinetochore Repurposed in Neuronal Synapse Formation
Hosted by Avi Rodal

Tue 2/26/19 4 pmAbelson 131
Physics Department Colloquium
Kerry Emanuel (MIT)
TBA
Hosted by Bjoern Penning

Thu 2/28/19 11 amVolen 201
Computational Neuroscience Journal Club
TBA
TBA
Pizza will be served

Thu 2/28/19 12 noonGerstenzang 124
Biology Faculty Candidate
Saurabh Kulkarni (Yale)
Control of Organelle Number and Positioning in Multiciliated Cells
How multiciliated cells (MCCs) count and position hundreds of centrioles at the apical cell surface to seed hundreds of cilia is unknown. MCCs regulate centriole number and their positioning in an apical area dependent manner. Multiple mechanical manipulations show that MCCs measure the apical area by sensing the strain on the membrane. The presence of a mechanosensitive ion channel on the apical membrane of MCCs may provide an underlying molecular mechanism.

Thu 2/28/19 4 pmAbelson 229
MRSEC Seminar
Timothy Atherton (Tufts University)
TBA
Hosted by John Berezney

Fri 3/1/19 12:30 pmGerstenzang 123
Molecular and Cell Biology & Neuroscience Student Seminars
Rey Aguilar Lopez (Goode Lab)
Mara Rue (Marder Lab)

 
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