Events Archive

Jan
30
2012
Ion and nanodrop injection from Taylor cones into gases and liquids
Jan
25
2012
Formulate Biological Sensory Adaptation
Jan
23
2012
Spiral waves and the heart: a physics approach to the study and control of the complex spatiotemporal organization of cardiac arrhythmias
The heart is an electro-mechanical system in which, under normal conditions, electrical waves propagate in a coordinated manner to initiate an efficient contraction. In pathologic states, propagation can destabilize and exhibit period-doubling bifurcations that can result in both quasiperiodic and spatiotemporally chaotic oscillations. In turn, these oscillations can lead to single or multiple rapidly rotating spiral or scroll waves that generate complex spatiotemporal patterns of activation that inhibit contraction and can be lethal if untreated. Despite much study, little is known about the actual mechanisms that initiate, perpetuate, and terminate...
Jan
18
2012
Body sculpting: Tissue mechanics in development and regeneration
Embryogenesis and regeneration are among the most striking and beautiful phenomena in nature. For a physicist, this brings together many major themes—pattern formation, information processing, the mechanics of complex fluid-like materials—that are essential for our understanding of life more broadly. In my talk I will give two examples on the important role of tissue mechanics for these phenomena. First, I will discuss how a macroscopic tissue property, specifically tissue surface tension, is connected to the properties of the constituent cells, such as cortical tension and adhesion. I will directly compare theoretical...
Jan
12
2012
Certainty And Uncertainty In Dark Matter Searches
Departing from the context of CoGeNT and COUPP, two direct searches for WIMP dark matter, we will inspect the recent landscape of anomalies observed by these and several other detectors. The aim of this talk is to communicate an appreciation for the subtleties inherent to experimental efforts in this field, and for the considerable difficulties that await for those trying to make sense of WIMP search observations (or lack thereof).
Jan
09
2012
Nobel Prize in Chemistry 2011: Dan Shechtman and the discovery of quasicrystals
Dec
15
2011
Verifying the no-hair property of massive compact objects with intermediate-mass-ratio inspirals in Advanced LIGO
The detection of gravitational waves from the inspiral of a neutron star or stellar-mass black hole into an intermediate-mass black hole (IMBH) promises an entirely new look at strong field gravitational physics. Gravitational waves from these intermediate-mass-ratio inspirals (IMRIs), systems with mass ratios from 10:1 to 100:1, may be detectable at rates of up to a few tens per year and will encode a signature of the central body's spacetime. Direct observation of the spacetime will allow us to use the "no-hair" theorem of general relativity to determine if the IMBH is a Kerr black hole (or some more exotic object, e.g. a boson star). In this talk, I will discuss the...
Dec
15
2011
Nanoscale Switching Behavior and Electronic Properties of Ultrathin Ferroelectric Structures
Dec
07
2011
"The biggest little molecules in Nature"
This colloquium will discuss recent theoretical predictions and experimental confirmation of two unusual classes of ultra-long-range molecules. One class involves a highly-excited Rydberg electron that manages to bind a distant ground state atom at thousands of Bohr radii. The other class involves the bizarre Efimov effect for three or four ground state atoms with resonant interactions. Implications for the behavior of ultracold quantum gases will be addressed.
Dec
07
2011
Analyzing 3-D stochastic dynamics in live cells
Advances in microscopy have enabled measurements in living cells, but there is a wealth of biologically relevant dynamical information contained in experimental data that has not been utilized.  Existing analysis methods either coarse grain too much or cannot overcome some technical challenges inherent to in vivo measurements. The importance of more fully utilizing information “hidden” in noisy 3D in vivo measurements will be emphasized in several problems.  In this talk, I demonstrate how recent advances in time series analysis can be used to estimate stochastic differential equations (SDEs) and construct hypothesis tests checking the...

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