Ben O'Shaughnessy
1006 S W Mudd, Mail Code: 4721
Phone: +1 212-854-3203
Fax: +1 212-854-3054
Email:
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Education:
Ph.D., Physics, University of Cambridge
BSc, Maths and Physics, Univ of Bristol
Research interests:
In our research we investigate: biophysics of living cells; emerging biotechnologies; living and synthetic soft matter; nanoscience and nanotechnology. Group members are mainly theorists. Jointly advised experimental students and postdocs are also welcome.
Biology. We investigate physics of cellular processes and machines such as motors powering the motion of living cells and the coupled behavior of the membrane and cytoskeleton. Using analytical and computational approaches and working in close collaboration with experimental biologists, our goal is to develop quantitative models to identify basic mechanisms and explain and predict experimental results. We are interested in actin filament growth kinetics and the role of proteins such as Arp2/3 complex and formins which cells use to regulate growth in order to produce specific cytoskeletal structures. Related issues include the forces which actin filaments exert, both individually and in bundles, and how cells coordinate many-filament dynamics for coherent motion. Another focus of our work is cell membranes: their structure and dynamics and how they interact with the cytoskeleton. Our research also addresses biotechnologies harnessing natural cellular processes, such as DNA microarrays used in gene expression and sequencing studies. Living matter is soft and charged, and our biological research is intertwined with our work on strongly charged polymers such as DNA. We have developed theories of strongly charged polymer layers and manning counterion condensation.
Nanoscience and nanotechnology. Nanoscience concerns the fabrication and properties of entirely new materials and devices employing nanoscale building blocks. Creating such new materials requires delicate organization of nano-objects. We study the directed organization of nanoparticles by soft polymeric media and the 2D and 3D material phases which result, including remarkable striped phases related to modulated phases arising in various conventional 2D molecular systems.
Other topics in soft matter. Our work on irreversibility in polymer adsorption has aimed to understand what distinguishes non-equilibrium layers from their equilibrium counterparts. We have developed theories of synthetic and biological ``living'' polymers exhibiting dynamic length distributions highly sensitive to external conditions.
Selected Publications:
D. Vavylonis, Q. Yang, and B. O'Shaughnessy, ``Actin Polymerization Kinetics, Cap Structure, and Fluctuations'' , Proc. Natl. Acad. Sci. USA 102, 8543--8548 (2005).
B. O'Shaughnessy and Q. Yang, ``Manning-Oosawa Counterion Condensation'', Phys. Rev. Lett. 94, 048302 (2005).
B.O'Shaughnessy and D.Vavylonis, ``Non-Equilibrium in Adsorbed Polymer Layers'', J. Phys.: Condens. Matter 17, R63--R99 (2005).
B. O'Shaughnessy and D. Vavylonis, ``Irreversibility and Polymer Adsorption", Phys. Rev. Lett. 90, 056103 (2003).
B. O'Shaughnessy and D. Vavylonis, ``The Ultrasensitivity of Living Polymers", Phys. Rev. Lett. 90, 118301 (2003).
J. U. Kim and B. O'Shaughnessy, ``Morphology Selection of Nanoparticle Dispersions by Polymer Media", Phys. Rev. Lett. 89, 238301 (2002).