UScholar Works
 
Filters: Date: "2004" School Or College: "College of Science" Collection: "ir_uspace" Type: "Text"
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CreatorTitleDescriptionSubjectDate
1 Lupton, John MarkAir-induced fluorescence bursts from single semiconductor nanocrystalsWe observe a dramatic enhancement of the fluorescence intensity from single core/shell CdSe/ZnS nanocrystals upon sudden exposure to air from an evacuated surrounding. Both the number of particles contributing to emission increases as well as the average emission intensity from a single particle, le...CdSe; ZnS; Air-induced; Fluorescence bursts2004
2 Sperry, John S.Analysis of circular bordered pit function I. Angiosperm vessels with homogenous pit membranesA model predicted pit and vessel conductivity, the air-seed pressure for cavitation, and the implosion pressure causing vessel collapse. Predictions were based on measurements from 27 angiosperm species with circular bordered pits and air-seed pressures of 0.2-11.3 MPa. Vessel implosion pressure exc...Functional wood anatomy; hydraulic architecture; plant biomechanics2004
3 Sperry, John S.Analysis of circular bordered pit function II. Gymnosperm tracheids with torus-margo pit membranesA model of xylem conduit function was applied to gymnosperm tracheids with torus-margo pit membranes for comparison with angiosperm vessels. Tracheids from 17 gymnosperm tree species with circular bordered pits and air-seed pressures from 0.8 to 11.8 MPa were analyzed. Tracheids were more reinforced...Functional wood anatomy; hydraulic architecture; plant biomechanics2004
4 Miller, Joel Steven; Epstein, Arthur J.Anomalous relaxation in a quasi-one-dimensional fractal cluster glassThe low-temperature spin glass state of the quasi-1D organic-based magnet [MnTPP]+[TCNE]- .x(1,3-C6H4Cl2) has unusually long relaxation times due to frustration induced by dipole-dipole interactions between fractal spin clusters. This long relaxation is investigated with in-field relaxation measurem...Sweep rate; Bifurcation; Magnetization2004
5 Goller, FranzBilateral syringeal contributions to song in the zebra finchAlthough central control of song production has been investigated extensively in the zebra finch (Taeniopygia guttata), much less is known about peripheral vocal motor dynamics during song.Electromyographic activity; Sound souces; Unilateral2004
6 Bohs, Lynn A.Chloroplast DNA phylogeny of Solanum sect on Las ocarpaSolanum section Lasiocarpa includes about a dozen species with a center of diversity in the NewWorld tropics. Solanum lasiocarpum and S. repandum (sometimes considered to be conspecific as S. ferox) have an Old World distribution in Asia and the Pacific Islands. Several species in this section produ...Solanum; trn; Lasiocarpa2004
7 Vardeny, Zeev Valentine; Raikh, Mikhail E.Coherent random lasing: trapping of light by the disorderRecent discovery of the coherent lasing from various disordered materials adds a new dimension to the conventional physics of light propagation in multiply scattering media. It suggests that in the situation, when the propagation of light is diffusive on average, the coherent feedback can be provid...Coherent random lasing; Coherent lasing; Disorder; Disordered materials; Random lasers; Random resonators; Power Fourier transform; Light propagation2004
8 Hultine, KevinComparison of methods to estimate Ephemeral Channel Recharge, Walnut Gulch, San Pedro River Basin, ArizonaEphemeral channel transmission loss represents an important groundwater surface water exchange in arid and semiarid regions and is potentially a significant source of recharge at the basin scale. Copyright [year] American Geophysical Union. Reproduced by permission of American Geophysical Union. ...Transport; Transmission; Balance2004
9 Vardeny, Zeev ValentineDirectional emission from asymmetric microlaser resonators of ∏-conjugated polymersA ∏-conjugated polymer film was fabricated into an asymmetric microlaser resonator having a quadrapole deformation with irregular boundaries and a Q factor of 600. At high excitation intensities above the threshold for lasing, we observed multimode laser emission spectra and directional emission a...Directional emission; Asymmetric microlaser resonators; pi-conjugated polymers; DOO-PPV; poly(dioctyloxy) phenylene vinylene2004
10 Carrier, David R.Evidence for endothermic ancestors of crocodiles at the stem of archosaur evolutionPhysiological, anatomical, and developmental features of the crocodilian heart support the paleontological evidence that the ancestors of living crocodilians were active and endothermic, but the lineage reverted to ectothermy when it invaded the aquatic, ambush predator niche. In endotherms, there i...Endothermy; ectothermy; Archosaur evolution; Archosaurs; Crocodilian heart2004
11 Miller, Joel Steven; Epstein, Arthur J.Ferrimagnetic resonance in films of vanadium [tetracyanoethanide]x, grown by chemical vapor depositionFerrimagnetic resonance (FMR) measurements in thin films of V[TCNE]x grown by chemical vapor deposition exhibit a series of sharp lines at 300 K. The orientational dependence of these lines is a result of the sample geometry provided the magnetization tracks the applied magnetic field. The FMR inten...Spin; Anisotropy; Magnetization2004
12 Ailion, David CharlesGallium and thallium NMR study of phase transitions and incomemensurability in the layered semiconductor TlGaSe2We report on the first NMR study of phase transitions and incommensurability in the layered semiconductor TlGaSe2. 69,71Ga and 205Tl NMR data from a powder sample show phase transitions at 118, 108 and around 69 K. The 69Ga and 71Ga spin-lattice relaxation times T1 are short and nearly temperature i...NMR; Atomic motion; Phase transitions; Spin-lattice; Relaxation-time2004
13 Clayton, Dale H.; Rogers, Alan R.Genetic analysis of lice supports direct contact between modern and archaic humansParasites can be used as unique markers to investigate host evolutionary history, independent of host data. Here we show that modern human head lice, Pediculus humanus, are composed of two ancient lineages, whose origin predates modern Homo sapiens by an order of magnitude (ca. 1.18 million years).Pediculus humanus; Head lice; Molecular phylogeny; Phthirus2004
14 Shapiro, Michael D.Genetic architecture of parallel armor plate reduction in threespine sticklebacksHow many genetic changes control the evolution of new traits in natural populations? Are the same genetic changes seen in cases of parallel evolution? Despite long-standing interest in these questions, they have been difficult to address, particularly in vertebrates. We have analyzed the genetic bas...Genetic changes; Plate number; Genetic mapping2004
15 Capecchi, Mario R.Hoxa11 regulates stromal cell death and proliferation during neonatal uterine developmentIncreasing evidence indicates that the Hoxa11 gene plays a critical role in the proper development of the uterus. In this report, we describe potential altered cellular processes in the developing uterus of Hoxa11 mutants. Histologic analysis demonstrates normal uterine morphology in Hoxa11 mutants ...2004
16 Voth, Gregory Alan; Sarofim, Adel F.Identification of pathways for polyaromatic growth using molecular dynamicsReaction pathways for polyaromatic growth in combustion environments are explored theoretically using molecular dynamic techniques. The reaction systems considered include cyclization reactions that involve H atom migration. Specifically we examine the absorption of acetylene on an aromatic ring rad...2004
17 Stang, Peter J.Incorporation of flexible pyridine-functionalized ligands into discrete supramolecules via coordination-driven self-assemblyFlexible, pyridine-functionalized ligands were self-assembled into discrete supramolecules of differing stoichiometries upon combination with various organoplatinum molecules. They are characterized by electrospray ionization mass spectrometry, 31P(iHI and 'H NMR. Despite its inherent flexibility, 3...Self-assembly; Coordination-driven; Transition-metal-mediated; Flexible ligands; Pyridyl ligands; Supramolecules2004
18 Potts, Wayne K.Infection-dependent phenotypes in MHC-congenic mice are not due to MHC: can we trust congenic animals?Congenic strains of mice are assumed to differ only at a single gene or region of the genome. These mice have great importance in evaluating the function of genes. However, their utility depends on the maintenance of this true congenic nature. Although, accumulating evidence suggests that congenic ...Strains; Mutations; Pathogen2004
19 Williams, Clayton C.Instability induced tunneling and repeatable charge injection to SiO2 surfaces by electrostatic force microscopyThe dynamic response and stability of a voltage biased oscillating cantilever in the proximity of an insulating sample surface is investigated. As the tip approaches the sample surface, the cantilever can jump between two different oscillation modes. The jump is detected as an abrupt increase in t...Electrostatic force microscopy; EFM; Dielectric films2004
20 Beckerle, Mary C.; Clark, Kathleen A.Integrin effector PINCH regulates JNK activity and epithelial migration in concert with Ras suppressor 1Cell adhesion and migration are dynamic pro- cesses requiring the coordinated action of multiple signaling pathways, but the mechanisms underlying signal integration have remained elusive. Drosophila embryonic dorsal closure (DC) requires both integrin function and c-Jun amino-terminal kinase (JNK) ...Epithelial sheets; PINCH2004
21 Beckerle, Mary C.Kindler syndrome protein is regulated by Transforming Growth Factor-β and involved in integrin-mediated adhesionTransforming growth factor-β1 (TGF-β1) contributes to tumor invasion and cancer progression by increasing the motility of tumor cells. To identify genes involved in TGF-β-mediated cell migration, the transcriptional profiles of human mammary epithelial cells (HMEC) treated with TGF-β were compar...Kindler syndrome; Kindlerin; Talin; Focal adhesions; FERM domain2004
22 DeTar, CarletonLattice quantum chromodynamics comes of ageThe strength of the electron-photon interaction is characterized by the fine-structure constant α ≈ 1/137.036. Because α is small, quantum electrodynamics (QED), the theory of interacting electrons and photons, can be solved to very good approximation with the traditional technology of pencil an...Quarks; Gluons; Mesons; CKM matrix2004
23 Saam, Brian; Laicher, GernotLiquid hyperpolarized 129Xe produced by phase exchange in a convection cellWe present a method for the production of liquid hyperpolarized 129Xe that employs spin-exchange optical pumping in the gas phase and subsequent phase exchange with a column of xenon liquid. A convection loop inside the sealed glass cell allows efficient transfer of magnetization between the gas an...Liquid hyperpolarized 129Xe; Phase exchange; Spin-exchange optical pumping; SEOP; NMR; Spin polarization2004
24 Miller, Joel Steven; Epstein, Arthur J.Local structural order in the disordered vanadium tetracyanoethylene room-temperature molecule-based magnetWe determined the vanadium oxidation state and local coordination environment in disordered samples of magnetic V[TCNE]x(x=2) prepared by chemical vapor deposition (CVD). Systematic studies of the x-ray absorption near-edge structure (XANES) in this material and reference compounds show that V ions ...Magnetic; Solvent; Structure2004
25 Lupton, John MarkLow-threshold polymeric distributed feedback lasers with metallic contactsOptical losses in waveguides comprising metallic contacts are thought to be a major hurdle to the realization of organic laser diodes. We demonstrate here that careful tuning of the waveguide mode in flexible distributed feedback lasers can allow lasing action to occur in organic thin films in the p...Metallic contacts; Organic laser diodes; Waveguides; Feedback lasers2004
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