Browsing OSU - Faculty and Staff Publications by Issue Date
Now showing items 61-80 of 1079
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Conjugal transfer of R68.45 and FP5 between Pseudomonas aeruginosa strains in a freshwater environment
(American Society for Microbiology, 1988-08)Recent concern over the release of genetically engineered organisms has resulted in a need for information about the potential for gene transfer in the environment. In this study, the conjugal transfer in Pseudomonas ... -
Point source terahertz optics
(AIP Publishing, 1988-10-17)We demonstrate an ultrafast 10 micro-m sized, electric dipole source of terahertz radiation closely coupled to a 1 cm spherical mirror. This optical approach has the advantages of subpicosecond response times with essentially ... -
Observation of the formation of an optical intensity shock and wave breaking in the nonlinear propagation of pulses in optical fibers
(American Physical Society, 1989-01-30)We have observed the formation of an optical intensity shock and the subsequent wave breaking in the nonlinear propagation of 1-psec pulses in an optical fiber. The wave breaking manifests itself as the appearance of ... -
Transmembrane pore size and role of cell swelling in cytotoxicity caused by Pasteurella haemolytica leukotoxin
(American Society for Microbiology, 1989-02)Pasteurella haemolytica A1 leukotoxin causes rapid (5 to 15 min) leakage of intracellular K+ and cell swelling and slower (15 to 60 min), Ca2+-dependent formation of large plasma membrane defects (~100 nm) and leakage of ... -
Pasteurella haemolytica antigens associated with resistance to pneumonic pasteurellosis
(American Society for Microbiology, 1989-03)Antigens associated with whole Pasteurella haemolytica biotype A serotype 1, a capsular arbohydrateprotein extract of the organism, and P. haemolytica leukotoxin were separated by sodium dodecyl sulfatepolyacrylamide gel ... -
Subpicosecond electrical pulse generation using photoconductive switches with long carrier lifetimes
(AIP Publishing, 1989-03-13)Using a new mechanism of electrical pulse generation, we have generated 350 fs (full width at half maximum) electrical pulses on a coplanar transmission line, fabricated on an unimplanted silicon-on-sapphire substrate. -
Comparison of the Pasteurella haemolytica A1 envelope proteins obtained by two cell disruption methods
(American Society for Microbiology, 1989-04)The French pressure cell and sonication methods of bacterial cell disruption were compared for the evaluation of surface proteins from Pasteurella haemolytica Ai. Several protein bands were quantitatively different when ... -
Observation of electromagnetic shock waves from propagating surface-dipole distributions
(American Physical Society, 1989-06-19)We have directly measured the time-dependent electromagnetic shock wave generated by an electric surface-dipole distribution propagating faster than the phase velocity in the underlying dielectric substrate. The results ... -
High-brightness terahertz beams characterized with an ultrafast detector
(AIP Publishing, 1989-07-24)We have significantly improved the emission and detection of electromagnetic beams of single-cycle 0.5 THz pulses, through the use of new dipolar antenna structures. The frequency response was extended to well beyond the ... -
Transduction of linked chromosomal genes between Pseudomonas aeruginosa strains during incubation in situ in a freshwater habitat
(American Society for Microbiology, 1990-01)Both transduction of single chromosomal loci and cotransduction of closely linked loci were observed between lysogenic and nonlysogenic strains of Pseudomonas aeruginosa in a freshwater habitat. Transductants were recovered ... -
Trichloroethylene degradation by two independent aromatic-degrading pathways in Alcaligenes eutrophus JMP134
(American Society for Microbiology, 1990-04)The bacterium Alcaligenes eutrophus JMP134(pJP4) degrades trichloroethylene (TCE) by a chromosomal phenol-dependent pathway and by the plasmid-encoded 2,4-dichlorophenoxyacetic acid pathway. The two pathways were independent ... -
Optical and electronic properties of doped silicon from 0.1 to 2 THz
(AIP Publishing, 1990-04-23)Using a source of freely propagating subpicosecond pulses of THz radiation, we have measured the absorption and dispersion of both N- and P-type, 1 ohm-cm silicon from 0.1 to 2 THz. These results give the corresponding ... -
Carrier dynamics of electrons and holes in moderately doped silicon
(American Physical Society, 1990-06-15)A time-domain spectroscopic technique, based on the generation and detection of a collimated beam of subpicosecond broadband terahertz pulses, is used to measure the absorption and dispersion of n- and p-type silicon, with ... -
THz time-domain spectroscopy of high Tc substrates
(AIP Publishing, 1990-09-03)Using the method of time-domain spectroscopy, we have measured the absorption and dispersion from 0.2 to 2 THz of the high Tc substrates, magnesium oxide, yttria-stabilized zirconia (YSZ), and lanthanum aluminate. Our ... -
Development of a rickettsia isolated from an aborted bovine fetus
(American Society for Microbiology, 1990-10)An obligate intracellular rickettsial organism isolated from an aborted bovine fetus was studied in bovine turbinate and mouse macrophage cell cultures with light and electron microscopy. Development of the organism was ... -
Far-infrared time-domain spectroscopy with terahertz beams of dielectrics and semiconductors
(Optical Society of America, 1990-10)Using the method of time-domain spectroscopy, we measure the far-infrared absorption and dispersion from 0.2 to 2 THz of the crystalline dielectrics sapphire and quartz, fused silica, and the semiconductors silicon, gallium, ... -
Ultrastructural morphology of Cowdria ruminantium in midgut epithelial cells of adult Amblyomma hebraeum female ticks
(AOSIS, 1991)Amblyomma hebraeum male and female ticks, experimentally infected as larvae with the Ball 3 stock of Cowdria ruminantium, were fed on a heartwater susceptible sheep. The initial attachment of the males was required as a ... -
Quantitation of Plasmodium falciparum sporozoites transmitted in vitro by experimentally infected Anopheles gambiae and Anopheles stephensi
(American Society of Tropical Medicine and Hygiene, 1991)The frequency and numbers of Plasmodium falciparum sporozoites transmitted in vitro and corresponding sporozoite loads were determined for experimentally infected Anopheles gambiae and An. stephensi. Geometric mean (GM) ... -
Efficient generation of 380 fs pulses of THz radiation by ultrafast laser pulse excitation of a biased metal-semiconductor interface
(AIP Publishing, 1991-01-21)We have demonstrated a new method of generating pulses of freely propagating THz electromagnetic radiation. The resulting 380 fs pulses are the shortest directly measured THz pulses in free space to date and are more ... -
Subpicosecond, freely propagating electromagnetic pulse generation and detection using GaAs:As epilayers
(AIP Publishing, 1991-04-08)Using GaAs epilayers with arsenic precipitates (GaAs:As) as the photoconductive material in a broad-band optoelectronic terahertz beam system, we have generated and detected freely propagating, subpicosecond electromagnetic ...