Past Events

  • Math-Bio seminar: "Decoding of pairwise coalescent times and detection of recent adaptation in biobank-scale SNP array data sets"

    318 Carolyn Lynch Laboratory

    Pier Francesco Palamara (Harvard School of Public Health)

    Coalescent hidden Markov models (HMM) such as the pairwise sequentially Markovian coalescent (PSMC, Li and Durbin, 2010) enable estimating the locus-specific posterior distribution of the time to most recent common ancestor (TMRCA) of a pair of haploid chromosomes when high-coverage sequencing data is available. I will present the “ascertained sequentially Markovian coalescent” (ASMC), a coalescent HMM that can be used to accurately estimate locus-specific TMRCA probabilities in widely available SNP array data.

  • Condensed Matter Seminar: "Geometry, frustration and force production in bacterial biopolymers"

    David Rittenhouse Laboratory, A4

    Ajay Gopinathan (University of California, Merced)

    Filamentous biopolymers in bacteria are involved in a variety of critical processes including templating cell growth, segregating genetic material and force production during motility and cell division. In this talk, I will discuss how a few of these systems translate biopolymer structure at multiple scales into physical function. At the molecular scale, the filamentous bacterial protein FtsZ converts chemical energy into mechanical constriction during cell division, but without the aid of any motor proteins.

  • Math-Bio seminar: "Mutations, genetic identity, and data granularity"

    318 Carolyn Lynch Laboratory

    Jun Li (University of Michigan)

    I will talk about two studies where new insights are gained after we work on a different level of data granularity. First, in collaboration with Sebastian Zoellner we analyzed ~36 million extremely rare variants (defined as singletons in ~4,000 individuals) uniformly ascertained in an as yet unpublished whole-genome sequencing dataset. Our goal is to estimate mutation rate variation across the genome, and to identify genomic and sequence-based predictors of such variation.

  • High Energy Seminar: "The Re-emergance of Spontaneously Broken Space-time Symmetries without Goldstones or Inverse Higgs"

    DRL 2N36

    Ira Rothstein (Carnegie Mellon)

    In this talk I will discuss how broken space-time symmetries can emerge in the IR after being spontaneously broken in the UV, even though there may be no Goldstone bosons. Given that there has been a large body of work on trying to get space-time symmetry (e.g. Lorentz) to be emergent in the IR via an RG attractive basin, this may seem like a very surprising and non-generic result.

  • Condensed Matter Seminar: "Invisibility, polarized light, and the eyes of giant squid: three tales of biological optics from the deep sea"

    David Rittenhouse Laboratory, A4

    Sonke Johnsen, Duke University


    David Rittenhouse Laboratory, A4

    Zoltan Haiman (Columbia University)


  • Advances in Biomedical Optics: "Theranostics Towards Point of Care Applications"

    Donner Auditorium, Basement, Donner Building, 3400 Spruce St.

    Israel Gannot (Johns Hopkins University and Tel-Aviv University)

    My lab has been active developing Theranostics methods that utilize the advantages of different modalities for a synergetic combination for optimized clinical treatment. A main theme of the lab is bringing the treatment to a point of care setting and preferably in outpatient clinics and even at home. We believe in a low cost, portable yet very powerful solutions to deliver good and effective healthcare treatment to various areas around the globe and in remote rural locations where high end very expensive instrumentations and methodologies are not affordable.

  • High Energy Seminar: "Large N Tensor Models"

    David Rittenhouse Laboratory, 2N36

    Igor Klebanov (Princeton University)

    We review the double line notation for the Feynman diagram expansion of N by N matrix models. In the ‘t Hooft large N limit only the planar diagrams survive, and the dual graphs may be thought of as discretized random surfaces. We proceed to theories where the dynamical degrees of freedom are rank-3 tensors with distinguishable indices, each of which takes N values. Their Feynman diagrams may be drawn using colored triple lines (red, blue, green), while the dual graphs are made out of tetrahedra glued along their triangular faces.

  • Diversity and Inclusion in Physics :"Women in Physics: Understanding and Overcoming Biases and Barriers"

    David Rittenhouse Laboratory, A4

    Amy Graves (Swathmore)

    Physics is phenomenally successful at taking data on sexless, raceless objects and transforming that information into mathematical laws with highly accurate predictive power. Why, therefore, should gender be an issue among physicists – so that there is a paucity of women in physics, at all professional levels and in virtually all nations? It is a tenet of gender studies that one should avoid attributing complicated effects to a single cause. (Gender studies is a field guaranteed to annoy the physicist.

  • Condensed Matter Seminar: "Metal chalcogenide semiconductors: Synthesis, electronic structure, light-matter interactions"

    David Rittenhouse Laboratory, A4

    Peter Sutter, University of Nebraska

    Metal chalcogenides have received attention as two-dimensional (2D) materials beyond graphene. Semiconducting chalcogenides are particularly attractive since they exhibit novel physics such as strongly bound excitons and valley polarization, and may enable next-generation electronics benefiting from confinement, high carrier mobility, flexibility and bendability. While transition metal dichalcogenides (particularly MoS2) have been investigated as prototype systems, other materials, especially those incorporating normal metals or metalloids, remain much less studied.