UScholar Works
 
Filters: Date: "1999" School Or College: "College of Science" Collection: "ir_uspace"
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CreatorTitleDescriptionSubjectDate
1 Ailion, David Charles14N study of the role of N-D---O bonds in the deuteron glass transition14N spin-lattice relaxation-time measurements in Rb0.28(ND4)0.72D2PO4 provide direct evidence for the fast exchange averaging of the "long" and "short" N-D---O hydrogen bonds between the ND4 group and the four surrounding PO4 groups. This exchange and the associated distortion of the ND4 tetrahedron...NMR; Hydrogen bonds; Spin-lattice; Relaxation-time; Deuteron glass1999
2 Seger, Jon1998 Sewall Wright Award: William Donald HamiltonThe Sewall Wright Award was established in 1991 to honor active investigators who have contributed in especially significant ways to the conceptual unification of the biological sciences. This year's recipient is William D. Hamilton of Oxford University. Beginning in the 1960s with his papers on the...Evolution; Biological; Research1999
3 Williams, Clayton C.Advances in experimental technique for quantitative two dimensional dopant profiling by scanning capacitance microscopySeveral advances have been made toward the achievement of quantitative two-dimensional dopant and carrier profiling. To improve the dielectric and charge properties of the oxide-silicon interface, a method of low temperature heat treatment has been developed which produces an insulating layer with c...Doping; Scanning capacitance microscope; SCM1999
4 Gondolo, PaoloAGAPEROS: searching for microlensing in the LMC with the pixel method. I. Data treatment and pixel light curves productionRecent surveys monitoring millions of light curves of resolved stars in the LMC have discovered several microlensing events. Unresolved stars could however signi _x000C_cantly contribute to the microlensing rate towards the LMC. Monitoring pixels, as opposed to individual stars, should be able to ...Data analysis techniques; Halo; Galaxies; Gravitational lensing; Pixel method; Large Magellanic Cloud; LMC1999
5 Gondolo, PaoloAgapeZ1: a large amplification microlensing event or an odd variable star towards the inner bulge of M31AgapeZ1 is the brightest and the shortest duration microlensing candidate event found to date in the Agape experiment. It occurred only 4200 from the centre of M31 at RA = 0h42m41:47s and Dec = 41°16'39.1" (J2000). Our photometry shows that the half intensity duration of the event is 5.3 days and ...AgapeZ1; Galaxy; Halo; Cosmology; Gravitational lensing; M31; Pixel method1999
6 Vardeny, Zeev ValentineAmplified spontaneous emission and lasing in conducting polymers and fluorescent dyes in opals as photonic crystalsSpectral narrowing of photoluminescence (PL) and evolution of sharp emission lines upon optical excitation have been observed in opals made of SiO2 spheres infiltrated with conducting polymers such as OOPPV and MDDOPPV and also fluorescent dyes such as rhodamine 6G, NK-3483, and coumarin 120. Their ...Amplified spontaneous emission; Lasing; Fluorescent dyes1999
7 Sokolsky, PierreAn analog light scattering experiment of hexagonal icelike particles. part I: experimental apparatus and test measurementsAn experimental apparatus to measure the scattering properties of hexagonal icelike particles in the analog manner at the helium neon laser wavelength of 0.633 mm has been designed and built. The instrument consists of an array of 36 highly sensitive and linear photodiode detectors that are positi...1999
8 Sokolsky, PierreAn analog light scattering experiment of hexagonal icelike particles. part II: experimental and theoretical resultsThe scattering properties of hexagonal icelike crystals as measured in the analog manner by the experimental apparatus described in Part I are presented. The crystals are made out of sodium fluoride (NaF), which has an index of refraction similar to that of water ice. The experimentally determined...1999
9 Adler, Frederick R.Balance of terror: an alternative mechanism for competitive trade-offs and its implications for invading speciesThis article uses models to propose an explanation for three observations in community ecology: the apparent overreaction of prey to attack by specialist predators, the existence of a common trade-off among components of competitive ability in communities of unrelated competitors, and the ability of...Models; Curve; Native1999
10 Olivera, Baldomero M.Block of Shaker K+ channels by ĸ-conotoxin PVIIA is state dependentĸ-conotoxin PVIIA is the first conotoxin known to interact with voltage-gated potassium channels by inhibiting Shaker-mediated currents. We studied the mechanism of inhibition and concluded that PVIIA blocks the ion pore with a 1:1 stoichiometry and that binding to open or closed channels is very d...Conotoxins; k-conotoxin PVIIA; Potassium channel blockers; Shaker K+ channels1999
11 Jorgensen, ErikCaenorhabditis elegans gene unc-25 encodes glutamic acid decarboxylase and is required for synaptic transmission but not synaptic developmentThe neurotransmitter GABA has been proposed to play a role during nervous system development. We show that the Caenorhabditis elegans gene unc-25 encodes glutamic acid decarboxylase (GAD), the GABA biosynthetic enzyme. unc-25 is expressed specifically in GABAergic neurons. Null mutations in unc-25...1999
12 Jorgensen, ErikCaenorhabditis elegans unc-49 locus encodes multiple subunits of a heteromultimeric GABA receptorIonotropic GABA receptors generally require the products of three subunit genes. By contrast, the GABA receptor needed for locomotion in Caenorhabditis elegans requires only the unc-49 gene. We cloned unc-49 and demonstrated that it possesses an unusual overlapping gene structure.1999
13 Miller, Joel StevenCollinear ferromagnetism and spin orientation in the molecule-based magnets M[N(CN)2]2 (M=Co,Ni)Zero-field unpolarized neutron powder diffraction has been used to study the low-T magnetic structure and T-dependent crystal structure of M[N(CN)2]2 (M=Co,Ni). Both compounds show collinear ferromagnetism with spin orientation along the c axis. The results provide the determination of a complete ma...Magnetic; Diffraction; Structure1999
14 Beckerle, Mary C.; Clark, Kathleen A.Conserved LIM protein that affects muscular adherens junction integrity and mechanosensory function in Caenorhabditis elegansWe describe here the molecular and functional characterization of the Caenorhabditis elegans unc-97 gene, whose gene product constitutes a novel component of muscular adherens junctions. UNC-97 and homologues from several other species define the PINCH family, a family of LIM proteins whose modula...LIM domains; Caenorhabditis elegans; UNC-97; Adherens junction; Touch neuron; Muscle development1999
15 Goller, FranzContributions of expiratory muscles to song production in zebra finchesBirdsong production requires coordinated activity of syringeal and respiratory muscles, Phonation occurs during the expiratory phase of the respiratory cycle, and expiratory muscles generate the pressure head for sound production.Phonation; Syringeal muscles; Air sac pressure1999
16 Miller, Joel StevenCrystal structure and magnetic properties of [Fe{N(CN)2}2(MeOH)2] a 2-D layered network consisting of hydrogen-bonded 1-D chainsA novel 2-D layered network structure [Fe{N(CN)2}2(MeOH)2] was synthesized and characterized by X-ray crystallography, vibrational, and magnetic susceptibility. The neutral 2-D stair-like framework consists of hydrogen-bonded infinite 1-D {Fe[N(CN)2]2} ribbons that pack in a staggered arrangement wh...Solids; Dicyanamide; Ordering1999
17 Adler, Frederick R.Departure time versus departure rate: how to forage optimally when you are stupidForagers unable to leave a patch at the optimal moment must act as constrained foragers. Extending the results of Houston and McNamara (1985), we compare a blundering forager that leaves patches at a constant rate with an unconstrained optimal forager that leaves patches at the optimal time.Blundering Foragers; Foraging; Marginal Value Theorem1999
18 Lupton, John MarkDevice model for polymer light emitting diodes: effect of temperature and oxidationWe present a temperature-dependent single carrier device model for polymer light-emitting diodes. The model includes both the injection of charge carriers over a barrier and the transport of charges across the device. To test the model, the temperature dependence of an LED based on the conjugated po...Single carrier; Temperature dependent; Poly(phenylene vinylene); Transport measurements; ITO; Disorder1999
19 Miller, Joel StevenDimetallic complexes derived from a novel dinucleating chelating symmetric triazole ligand; crystal strcutrue,magnetic properties and ESR study of Bis[μ-3,5-diacetlyamino-1,2,4-triazolato-O',N1,N2,O"]bis[nitrato)(aqua)-copper(II)]Reaction of 3,5-diacetylamino-1,2,4-triazole (Hdaat) with copper(II), nickel(II) and cobalt(II) salts yields dinuclear co-ordination compounds, which were spectroscopically characterized. The crystal and molecular structure of one of the compounds, bis[u-3,5-diacetylamino-1,2,4-triazolato-0'_x0001_,...Susceptibility; Orbitals; Compounds1999
20 Truong, ThanhDirect ab initio dynamics studies of the hydrogen abstraction reactions of hydrogen atom with fluoromethanesA direct ab initio dynamics study on the gas-phase reactions of atomic hydrogen with different fluoromethanes has been carried out. The thermal rate constants were calculated using canonical variational transition state (CVT) theory augmented by multidimensional semiclassical zero and small curvatur...Hydrogen abstraction reactions; Gas-phase reactions; Fluoromethanes; Thermal rate constants; Moller?Plesset perturbation theory; Hybrid density functional theory1999
21 Ehleringer, James R.Ecosystem physiology responses to global changeMost ecosystems exposed to double ambient C02 show higher peak season net carbon uptake than those growing at current-ambient C02. For grasslands, above-ground biomass increased by an average of 14%, although individual responses for a given system and year range from negative to +85%. The wide ran...Global change ; Ecosystem physiology; Carbon budget; Temperature; Water availability; Nitrogen deposition; Ozone1999
22 Symko, Orest GeorgeEnergy conversion using thermoacoustic devicesThermoacoustic engines offer the possibility for simple and efficient energy convmiondevices. They can be prime movers where heat produces sound or heat pumps and refrigerators where sound pump heat. An important element in such engines is the secondary thermodynamic medium, the stack which provides...Thermoacoustic devices; Thermoacoustics1999
23 Adler, Frederick R.Evolution of forager responses to inducible defensesMost theoretical and empirical investigations of inducible defenses have focused on identifying conditions that favor the evolution of inducibility by the prey species. These analyses outline the essential consequences of frequency-dependent benefits of deploying the defense, degrees of predictabili...Predation; Cues; Phenotypes1999
24 Potts, Wayne K.Evolution of mating preferences and major histocompatibility complex genesHouse mice prefer mates genetically dissimilar at the major histocompatibility complex (MHC). The highly polymorphic MHC genes control immunological self/nonself recognition; therefore, this mating preference may function to provide "good genes" for an individual's offspring. However, the evidence ...Inbreeding; Parasites; Recognition1999
25 Clayton, Dale H.Feather-busting bacteriaI ONCE HAD A COLLEAGUE who delighted in the aphorism, which he proudly coined himself, "If it's too small to see with the naked eye, it ain't there." Sadly, this view may as well be true for ornithologists who study birds only through unaided eyes, binoculars, or spotting scopes. But birds can also ...Columba livia; Columbiformes; Ectoparasites; Bacteria; Plumage1999
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