T-Matrix Calculations for Spheroidal and Crack Like Flaws

Numerical calculations are presented for the scattering of elastic (P- and S-) waves from prolate and oblate spheroids and two-dimensional, rough, crack-like flaws for various angles of incidence, observation and frequencies using the T-matrix approach

Elastic Wave Scattering by Rough Flaws and Cracks

The scattering of elastic waves by three dimensional rough flaws and cracks is analyzed using the T-matrix approach. The scattering cross section is obtained for spheroidal cavities with a periodically corrugated surface which may be used as a model for flaws with a rough surface. The dependence of the scattering cross section on the wavelength of the corrugations is studied as a function of the incident wavelength. Cracks are modelled as degenerate oblate spheroids and the scattering cross section is obtained for incident P-waves, Multiple scattering analysis of two cavities is also discussed with some numerical results

Wireless nanotechnology based system for diagnosis of neurological and physiological disorders

Methods of selecting wide host range bacteriophage capable of growing in a plurality of bacteria including pathogenic and non-pathogenic bacteria and bacteriophage selected by the methods are disclosed. Also disclosed are methods: of treating a subject infected with a pathogenic bacterium using bacteriophage and of decontaminating objects using bacteriophage; of producing vaccines; of determining bacterial viability and of improving the sensitivity of a biosensor using wide host range bacteriophages

Testing the Inverse Born Procedure for Spheroidal Voids

Previously we have shown that the inverse Born approximation allows an accurate determination of the radius of spherical flaws in Ti. Here we report the results of extending that analysis to spheroidal voids. Both oblate and prolate spheroids are considered. Using scattering amplitude generated by the T-matrix method, we find that both the major and minor axes of 2-1 spheroids are accurately determined. Inversion results using experimental data will be presented for the 2-1 oblate spheroid: a comparison of the experimental and theoretical results will be given

Cooling a nanomechanical resonator using feedback: toward quantum behavior

Nano-electro-mechanical devices are now rapidly approaching the point where it will be possible to observe quantum mechanical behavior. However, for such behavior to be visible it is necessary to reduce the thermal motion of these devices down to temperatures in the millikelvin range. Here we consider the use of feedback control for this purpose. We analyze an experimentally realizable situation in which the position of the resonator is continuously monitored by a Single-Electron Transistor. Because the resonator is harmonic, it is possible to use a classical description of the measurement process, and we discuss both the quantum and classical descriptions. Because of this the optimal feedback algorithm can be calculated using classical control theory. We examine the quantum state of the controlled oscillator, and the achievable effective temperature. Our estimates indicate that with current experimental technology, feedback cooling is likely to bring the required milliKelvin temperatures within reach

Structure and catalytic regulatory function of ubiquitin specific protease 11 N-terminal and ubiquitin-like domains

The ubiquitin specific protease 11 (USP11) is implicated in DNA repair, viral RNA replication, and TGFβ signaling. We report the first characterization of the USP11 domain architecture and its role in regulating the enzymatic activity. USP11 consists of an N-terminal "domain present in USPs" (DUSP) and "ubiquitin-like" (UBL) domain, together referred to as DU domains, and the catalytic domain harboring a second UBL domain. Crystal structures of the DU domains show a tandem arrangement with a shortened β-hairpin at the two-domain interface and altered surface characteristics compared to the homologues USP4 and USP15. A conserved VEVY motif is a signature feature at the two-domain interface that shapes a potential protein interaction site. Small angle X-ray scattering and gel filtration experiments are consistent with the USP11DU domains and full-length USP11 being monomeric. Unexpectedly, we reveal, through kinetic assays of a series of deletion mutants, that the catalytic activity of USP11 is not regulated through intramolecular autoinhibition or activation by the N-terminal DU or UBL domains. Moreover, ubiquitin chain cleavage assays with all eight linkages reveal a preference for Lys(63)-, Lys(6)-, Lys(33)-, and Lys(11)-linked chains over Lys(27)-, Lys(29)-, and Lys(48)-linked and linear chains consistent with USP11's function in DNA repair pathways that is mediated by the protease domain. Our data support a model whereby USP11 domains outside the catalytic core domain serve as protein interaction or trafficking modules rather than a direct regulatory function of the proteolytic activity. This highlights the diversity of USPs in substrate recognition and regulation of ubiquitin deconjugation