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Fall 2001

Schedule Fall 2001

October 12, 2001
3:00 pm (Friday)

Prof. Richard H. Pratt
University of Pittsburgh

New Developments in Rayleigh and Compton Scattering

November 9, 2001
11:30 am (Friday)

Prof. D.O. Riska
Director, Helsinki Institute of Physics

The structure of the baryons

The empirical spectra of the baryons on the one hand reveal them to be formed of subnucleonic particles - quarks - but on the other hand do not have the obvious features expected on the basis of the theory for the strong interactions - quantum chromodynamics. The theoretical approach to the resolution of this paradoxical situation in terms of spontaneous breaking of chiral symmetry and effective degrees of freedom will be described. The possibility for settling some of the most open issues by experiments at the JLAB will be emphasized.

November 9, 2001
3:00 pm (Friday)

Prof. X. Nancy Xu
Old Dominion University Chemistry Department

Single-Molecule Studies of Single Living Cells

A new field of scientific research has emerged in recent years, which focuses on study of single molecules. Single-molecule detection is a way to study and characterize detailed physical and chemical properties of individual molecules. This approach allows one to look beyond the ensemble average, testing of fundamental principles and may lead to new paradigms of our thinking, and technological and methodological developments with application in a variety of research fields (e.g., medicine, biotechnology, molecular biology, material). Single living cells assemble the wide spectra of molecules and ions in a tiny compartment (~10-mm in diameter), display diverse physical and chemical reactions at all time scales and possess the most powerful and intelligent micro/nano-machinery. Therefore, single-molecule studies of single living cells present unique opportunities to overcome such overwhelming ensemble average and allow individual molecule and reaction to be singled out and explored in details for advancing the understanding of cellular function and nano-environment in complex biosystems. In this seminar, our recent development of nanoparticle probes and single-molecule dynamics microscopy for real-time monitoring of single ligand-receptor interactions on single living eukaryote cells and real-time probing of membrane pump machinery of single living bacteria cells will be discussed.