Math Sciences Colloquia - Fall 2004

All Math Sciences colloquia take place from 1:00-2:00 p.m. in 657 Rhodes Hall with food beforehand at 12:45pm.

• October 18 - Raazesh Sainudiin, Statistical Science, "Rigorous Numerical Statistics via Enclosures"
  Abstract: Sketches of an alternative family of indices, for the set of probability measures of a statistical experiment, that allows for rigorous numerical decision-making, even in the presence of finite precision in measurement of the empirical phenomenon of interest, will be given. The often overlooked "Empirical indiscernibility" of elements of the index set, usually induced by physical limits on measurement precision, as well as, any nonidentifiability inherent in the mathematical model itself around the optimal decision will be rigorously accounted for, in addition to all the usual errors associated with shadows of real computations confined to a finite screen of floating-points embedded in the reals. Applications from phylogenetics and finite mixture problems will be covered.
  Key words:  global optimization, interval analysis, automatic differentiation, Jukes and Cantor model of DNA evolution, efficient M-H sampling
• November 1 - Richard Yamada, CAM, "A formal model for RNA polymerase translocation > during transcriptional elongation of the nascent RNA chain"
  Abstract: A chemical kinetic model of the elongation dynamics of the RNA polymerase along a DNA strand is introduced. Unlike previous models that attempt to explain the motion of RNA polymerase using internal strain and stresses, we propose a chemical kinetic model which governs the discrete movement of the RNA polymerase along a DNA tether, with no consideration given to elastic effects. Complicated sequence-dependent statistics of the motion of RNA polymerase results, in this model, from a 'look-ahead' feature in which nucleotides bind reversibly to the DNA prior to being incorporated covalently into the nascent RNA chain. Results are presented for a random DNA sequence, and also for two specific DNA sequences that have been used in single molecule observations of the random walk to RNA polymerase along DNA.
  This work is joint with Prof. Charles Peskin, CIMS-NYU.
• November 8 - Michael Robinson, CAM, "Polarizing frequency of a fluid plasma antenna element"
  Abstract: This talk uses the fluid plasma model and presents an expression for the current distribution of a plasma antenna element. I then make some comments regarding the frequencies at which the antenna element is properly polarized. Although the results are valid specifically for an element in the shape of a prism, the general solution procedure will work for other geometries.
• November 15 - Deena Schmidt, CAM, "A mathematical look at two problems in DNA sequence evolution: Analysis of zinc finger genes and waiting times for regulatory sequences"