Quantitative evaluation of multiband photographic techniques Final report

Quantitative evaluation of multiband photographic techniques using combination of black and white and color photo

Ab initio description of nonlinear dynamics of coupled microdisk resonators with application to self-trapping dynamics

Ab initio approach is used to describe the time evolution of the amplitudes of whispering gallery modes in a system of coupled microdisk resonators with Kerr nonlinearity. It is shown that this system demonstrates a transition between Josephson-like nonlinear oscillations and self-trapping behavior. Manifestation of this transition in the dynamics of radiative losses is studied.Comment: 10 pages, 5 figures, accepted for publication in Phys. Rev.

Capacity investigation of brine-bearing sands of the Frio Formation for geologic sequestration of CO2

The capacity of fluvial brine-bearing formations to sequester CO2 is investigated using numerical simulations of CO2 injection and storage. Capacity is defined as the volume fraction of the subsurface available for CO2 storage and is conceptualized as a product of factors that account for two-phase flow and transport processes, formation geometry, formation heterogeneity, and formation porosity. The space and time domains used to define capacity must be chosen with care to obtain meaningful results, especially when comparing different authors’ work. Physical factors that impact capacity include permeability anisotropy and relative permeability to CO2, brine/CO2 density and viscosity ratios, the shape of the trapping structure, formation porosity and the presence of low permeability layering.National Energy Technology LaboratoryBureau of Economic Geolog

Obese sedentary patients with dyspnoea on exertion who are at low risk for coronary artery disease by clinical criteria have a very low prevalence of coronary artery disease

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106981/1/cob12053.pd

Space Shuttle interactive meteorological data system study

Although focused toward the operational meteorological support review and definition of an operational meteorological interactive data display systems (MIDDS) requirements for the Space Meteorology Support Group at NASA/Johnson Space Center, the total operational meteorological support requirements and a systems concept for the MIDDS network integration of NASA and Air Force elements to support the National Space Transportation System are also addressed

Parallax and Kinematics of PSR B0919+06 from VLBA Astrometry and Interstellar Scintillometry

Results are presented from a long-term astrometry program on PSR B0919+06 using the NRAO Very Long Baseline Array. With ten observations (seven epochs) between 1994--2000, we measure a proper motion of 18.35 +/- 0.06 mas/yr in RA, 86.56 +/- 0.12 mas/yr in Dec, and a parallax of 0.83 +/- 0.13 mas (68% confidence intervals). This yields a pulsar distance of 1.21 +/- 0.19 kpc, making PSR B0919+06 the farthest pulsar for which a trigonometric parallax has been obtained, and the implied pulsar transverse speed is 505 +/- 80 km/s. Combining the distance estimate with interstellar scintillation data spanning 20 years, we infer the existence of a patchy or clumpy scattering screen along the line of sight in addition to the distributed electron density predicted by models for the Galaxy, and constrain the location of this scattering region to within about 250 parsecs of the Sun. Comparison with the lines of sight towards other pulsars in the same quadrant of the Galaxy permits refinement of our knowledge of the local interstellar matter in this direction.Comment: 12 pages, includes 4 figures and 3 tables, uses AASTeX 5 (included); ApJ submitte

The structure of the substrate-free form of MurB, an essential enzyme for the synthesis of bacterial cell walls

AbstractBackground: The repeating disaccharide and pentapeptide units of the bacterial peptidoglycan layer are connected by a lactyl ether bridge biosynthesized from UDP-N-acetylglucosamine and phosphoenolpyruvate in sequential enol ether transfer and reduction steps catalyzed by MurA and MurB respectively. Knowledge of the structure and mechanism of the MurB enzyme will permit analysis of this unusual enol ether reduction reaction and may facilitate the design of inhibitors as candidate next-generation antimicrobial agents.Results The crystal structure of UDP-N-acetylenolpyruvylglucosamine reductase, MurB, has been solved at 3.0 å and compared with our previously reported structure of MurB complexed with its substrate enolpyruvyl-UDP-N-acetylglucosamine. Comparison of the liganded structure of MurB with this unliganded form reveals that the binding of substrate induces a substantial movement of domain 3 (residues 219–319) of the enzyme and a significant rearrangement of a loop within this domain. These ligand induced changes disrupt a stacking interaction between two tyrosines (Tyr190 and Tyr254) which lie at the side of the channel leading to the active site of the free enzyme.Conclusion The conformational change induced by enolpyruvyl-UDP-N-acetylglucosamine binding to MurB results in the closure of the substrate-binding channel over the substrate. Tyr190 swings over the channel opening and establishes a hydrogen bond with an oxygen of the α-phosphate of the sugar nucleotide substrate which is critical to substrate binding

Loudly sing cuckoo : More-than-human seasonalities in Britain

This research was funded by a grant from the Arts and Humanities Research Council, grant number AH/E009573/1.Peer reviewedPostprin