• WILLARD P. GINGERICH, Ph.D., Provost and Vice President for Academic Affairs • KENNETH SUMNER, Ph.D., Acting Associate Provost for Academic Affairs • JOANNE COTE-BONANNO, Ph.D., Associate Provost for Academic Programs and Assessment • JAMES GERMAN, Ph.D., Associate Provost for Undergraduate Education • NICOLA SULLIVAN, M.B.A., Director of Administration • MARY COLON, M.A., Director, Academic ...

A series of crown ethers, 12-crown-4, 15-crown-5, 18-crown-6, and dibenzo-30-crown-10, are examined as a possible means of shifting the mobilities of peptide ions. In this approach, a crown ether is added to a solution containing a mixture of peptides and is electrosprayed into the gas phase in order to create distributions of peptide-crown complexes. The ion complexes have different mobilities...

We give a new combinatorial deenition of a sort of weak !-category originally devised by J. Baez and J. Dolan in nite dimensional cases. Our deenition is a mixture of both inductive and coinductive deenitions, and suitable for`computational category theory.'

The spatial organization of genes and chromosomes plays an important role in the regulation of several DNA processes. However, the principles and forces underlying this nonrandom organization are mostly unknown. Despite its small dimension, and thanks to new imaging and biochemical techniques, studies of the budding yeast nucleus have led to significant insights into chromosome arrangement and ...

Proteins that bind DNA so as to reduce its end-to-end length can be dissociated by application of force. The thermodynamics of this process are discussed, with special attention to the case of histones bound to DNA (i.e., a string of nucleosomes, or chromatin fiber). The histone octamer is predicted to be driven off chromatin fiber for tensions >2 piconewtons.

DNA spools, structures in which DNA is wrapped and helically coiled onto itself or onto a protein core, are ubiquitous in nature. We develop a general theory describing the nonequilibrium behavior of DNA spools under linear tension. Two puzzling and seemingly unrelated recent experimental findings, the sudden quantized unwrapping of nucleosomes and that of DNA toroidal condensates under tension...