Feasibility study in the application of optical signal analysis to non-destructive testing of complex structures

Advantages of the large time bandwidth product of optical processing are presented. Experiments were performed to study the feasibility of the use of optical spectral analysis for detection of flaws in structural elements excited by random noise. Photographic and electronic methods of comparison of complex spectra were developed. Limitations were explored, and suggestions for further work are offered

Worldwide flight and ground-based exposure of composite materials

The long-term durability of those advanced composite materials which are applicable to aircraft structures was discussed. The composite components of various military and commercial aircraft and helicopters were reviewed. Both ground exposure and flight service were assessed in terms of their impact upon composite structure durability. The ACEE Program is mentioned briefly

Research related to measurements of atomic species in the earth's upper atmosphere Final report

Interaction kinetics of atomic oxygen and hydrogen on metal surfaces of satellite-borne mass spectrometer

Cephem Potentiation by Inactivation of Nonessential Genes Involved in Cell Wall Biogenesis of ß-Lactamase-Producing Escherichia coli

Reversal of antimicrobial resistance is an appealing and largely unexplored strategy in drug discovery. The objective of this study was to identify potential targets for “helper” drugs reversing cephem resistance in Escherichia coli strains producing β-lactamases. A CMY-2-encoding plasmid was transferred by conjugation to seven isogenic deletion mutants exhibiting cephem hypersusceptibility. The effect of each mutation was evaluated by comparing the MICs in the wild type and the mutant harboring the same plasmid. Mutation of two genes encoding proteins involved in cell wall biosynthesis, dapF and mrcB, restored susceptibility to cefoxitin (FOX) and reduced the MICs of cefotaxime and ceftazidime, respectively, from the resistant to the intermediate category according to clinical breakpoints. The same mutants harboring a CTX-M-1-encoding plasmid fell into the intermediate or susceptible category for all three drugs. Individual deletion of dapF and mrcB in a clinical isolate of CTX-M-15-producing E. coli sequence type 131 (ST131) resulted in partial reversal of ceftazidime and cefepime resistance but did not reduce MICs below susceptibility breakpoints. Growth curve analysis indicated no fitness cost in a ΔmrcB mutant, whereas a ΔdapF mutant had a 3-fold longer lag phase than the wild type, suggesting that drugs targeting DapF may display antimicrobial activity, in addition to synergizing with selected cephems. DapF appeared to be a potential FOX helper drug target candidate, since dapF inactivation resulted in synergistic potentiation of FOX in the genetic backgrounds tested. The study showed that individual inactivation of two nonessential genes involved in cell wall biogenesis potentiates cephem activity according to drug- and strain-specific patterns

The Mollusca collected by the University of Michigan-Williamson Expedition in Venezuela, Part V

http://deepblue.lib.umich.edu/bitstream/2027.42/56621/1/OP182.pd

The Mollusca collected by the University of Michigan-Walker Expedition in southern Vera Cruz, Mexico, IV

http://deepblue.lib.umich.edu/bitstream/2027.42/56574/1/OP135.pd

Land and freshwater molluscs of the Dutch Leeward Islands.

http://deepblue.lib.umich.edu/bitstream/2027.42/56591/1/OP152.pd

A new slug from Guadeloupe

http://deepblue.lib.umich.edu/bitstream/2027.42/56612/1/OP173.pd

Impact of motion along the field direction on geometric-phase-induced false electric dipole moment signals

Geometric-phase-induced false electric dipole moment (EDM) signals, resulting from interference between magnetic field gradients and particle motion in electric fields, have been studied extensively in the literature, especially for neutron EDM experiments utilizing stored ultracold neutrons and co-magnetometer atoms. Previous studies have considered particle motion in the transverse plane perpendicular to the direction of the applied electric and magnetic fields. We show, via Monte Carlo studies, that motion along the field direction can impact the magnitude of this false EDM signal if the wall surfaces are rough such that the wall collisions can be modeled as diffuse, with the results dependent on the size of the storage cell's dimension along the field direction.Comment: 7 pages, 3 figures, NIM A, in pres