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2006

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Holy Books Or Pocket Books? Class And Values In American Politics, Matthew Keaton Jan 2006

Holy Books Or Pocket Books? Class And Values In American Politics, Matthew Keaton

Electronic Theses and Dissertations

There has been much speculation recently as to the political effect that "moral values" have on Americans and much research has shown inconclusive results as far as the effect of class. This paper aims to study how class and values, including moral values and postmaterialist values, interact with politics in the United States. The analyses performed to determine these effects include crosstabulation and logistical regressions and will include data from the National Election Studies (NES). It is found that postmaterialist values have little effect on political behavior but in separate analyses, class and moral values have increasing influences on vote …

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Science Self-Efficacy In Tenth Grade Hispanic Female High School Students, Maria Miller Jan 2006

Science Self-Efficacy In Tenth Grade Hispanic Female High School Students, Maria Miller

Electronic Theses and Dissertations

Historical data have demonstrated an underrepresentation of females and minorities in science, technology, engineering, and mathematics (STEM) professions. The purpose of the study considered the variables of gender and ethnicity collectively in relationship to tenth grade Hispanic females' perception of their self-efficacy in science. The correlation of science self-efficacy to science academic achievement was also studied. Possible interventions for use with female Hispanic minority populations might help increase participation in STEM field preparation during the high school career. A population of 272 students was chosen through convenience sampling methods, including 80 Hispanic females. Students were administered a 27-item questionnaire taken …

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Public Religious Participation: A Comparison Of Three Distinct Birth Cohorts, Diane Prather Jan 2006

Public Religious Participation: A Comparison Of Three Distinct Birth Cohorts, Diane Prather

Electronic Theses and Dissertations

Research has demonstrated that many factors affect levels of religiosity in American religion. This study extends the research on the relationship between cohort membership and public religious participation and individual personal involvement. Most of the research pertaining to the effects of cohort on religiosity has been devoted to comparisons between the Depression Era and Baby Boom Cohorts. This study extends research in this area by including Generation X to the extent possible. Using the General Social Surveys, this analysis employs an age/period/cohort analytical framework to examine religious involvement. Sociodemographic variables that are associated with religiosity are included in the analysis. …

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On The Use Of Variable Coherence In Inverse Scattering Problems, Erwan Baleine Jan 2006

On The Use Of Variable Coherence In Inverse Scattering Problems, Erwan Baleine

Electronic Theses and Dissertations

Even though most of the properties of optical fields, such as wavelength, polarization, wavefront curvature or angular spectrum, have been commonly manipulated in a variety of remote sensing procedures, controlling the degree of coherence of light did not find wide applications until recently. Since the emergence of optical coherence tomography, a growing number of scattering techniques have relied on temporal coherence gating which provides efficient target selectivity in a way achieved only by bulky short pulse measurements. The spatial counterpart of temporal coherence, however, has barely been exploited in sensing applications. This dissertation examines, in different scattering regimes, a variety …

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White Opinions Of United States Immigration: Testing Rival Hypotheses, 2004, Celeste Bulkley Jan 2006

White Opinions Of United States Immigration: Testing Rival Hypotheses, 2004, Celeste Bulkley

Electronic Theses and Dissertations

Few issues in the contemporary American political and social environments are as salient and emotionally charged as the debate over immigration. The thesis tests several competing hypotheses concerning the determinants of public opinion – among white respondents – on immigration issues. These include: the contextual considerations of southern residence and proximity to large numbers of Hispanic immigrants, as well as the individual-level factors of economic insecurity, political knowledge, national identity, group pride, and racism. Using data from the 2004 American National Election Study, the thesis provides a critical test of the competing hypotheses using multivariate analysis. Furthermore, conditional relationships are …

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Applications Of Linear And Nonlinear Optical Effects In Liquid Crystals, Hakob Sarkissian Jan 2006

Applications Of Linear And Nonlinear Optical Effects In Liquid Crystals, Hakob Sarkissian

Electronic Theses and Dissertations

Liquid crystals have been a major subject of research for the past decades. Aside from the variety of structures they can form, they exhibit a vast range of optical phenomena. Many of these phenomena found applications in technology and became an essential part of it. In this dissertation thesis we continue the line to propose a number of new applications of optical effects in liquid crystals and develop their theoretical framework. One such application is the possibility of beam combining using Orientational Stimulated Scattering in a nematic liquid crystal cell. Our numerical study of the OSS process shows that normally …

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New Developments On High-Resolution Luminescence Spectroscopy And Their Application To The Direct Analysis Of Organic Pollutants, Shenjiang Yu Jan 2006

New Developments On High-Resolution Luminescence Spectroscopy And Their Application To The Direct Analysis Of Organic Pollutants, Shenjiang Yu

Electronic Theses and Dissertations

Polycyclic aromatic compounds (PACs), which comprise a complex class of condensed multi-ring benzenoid compounds, are important environmental pollutants originating from a wide variety of natural and anthropogenic sources. PACs are generally formed during incomplete combustion of pyrolisis of organic matter containing carbon and hydrogen. Because combustion of organic materials is involved in countless natural processes or human activities, PACs are omnipresent and abundant pollutants in air, soil, and water. Chemical analysis of PACs is of great environmental and toxicological importance. Many of them are highly suspect as etiological agents in human cancer. Because PACs carcinogenic properties strongly depend on molecular …

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Trends In The Selection, Evaluation, And Compensation Of University Presidents In The Florida State University System, Nancy L. Marshall Jan 2006

Trends In The Selection, Evaluation, And Compensation Of University Presidents In The Florida State University System, Nancy L. Marshall

Electronic Theses and Dissertations

Recent literature suggested that while the discussion of presidential selection, evaluation, and compensation was common to both private and public institutions, special attention was paid to public university presidents. They and their presidencies were subject to intense public debate and scrutiny. Florida's public university presidents have contended with the same issues as their counterparts in other states. However, the 2001 changes in the state's higher education governance created distinct challenges and opportunities for the 11 presidents in the Florida State University System. The purpose of this study was to analyze the trends in the selection, evaluation, and compensation of the …

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Sic-Based Optical Interferometry At High Pressures And Temperatures For Pressure And Chemical Sensing, Surendramohan Dakshinamurthy, Nathaniel R. Quick, Aravinda Kar Jan 2006

Sic-Based Optical Interferometry At High Pressures And Temperatures For Pressure And Chemical Sensing, Surendramohan Dakshinamurthy, Nathaniel R. Quick, Aravinda Kar

Faculty Bibliography 2000s

Crystalline silicon carbide is a chemically inert wide band gap semiconductor with good mechanical strength and oxidation-resistant properties at elevated temperatures, which make it a good sensor material for harsh environments such as combustion chambers and turbine systems. For such cases, optical sensors are generally superior to electrical sensors in many aspects such as responsivity, detectivity, and sensitivity. This paper presents a wireless technique for pressure and chemical sensing based on the pressure-and temperature-dependent refractive indices of silicon carbide. A helium-neon laser with a wavelength of 632.8 nm was used as a probe laser to obtain the complementary Airy pattern …

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Method Of Images In Optical Discrete Systems, Konstantinos G. Makris, Demetrios N. Christodoulides Jan 2006

Method Of Images In Optical Discrete Systems, Konstantinos G. Makris, Demetrios N. Christodoulides

Faculty Bibliography 2000s

We show that optical wave propagation in discrete boundary geometries can be effectively analyzed using the method of images. Such semi-infinite and finite discrete systems include, for example, waveguide arrays as well as coupled resonator optical waveguides. In the linear domain, the diffraction properties of one- and two-dimensional bounded array structures are considered in detail. The possibility of using the method of images to numerically investigate nonlinear semi-infinite lattices is also discussed.

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Power Circulation Via Negative Energy-Flux Wormholes In Optical Nanowaveguides, Sergiy Mokhov, Ramy El-Ganainy, Demetrios N. Christodoulides Jan 2006

Power Circulation Via Negative Energy-Flux Wormholes In Optical Nanowaveguides, Sergiy Mokhov, Ramy El-Ganainy, Demetrios N. Christodoulides

Faculty Bibliography 2000s

We show that energy circulation within a pulse is possible when it propagates in a high-contrast dielectric nanowire. This process is accomplished through electromagnetic "wormhole" regions, in which the Poynting vector associated with the guided mode is negative with respect to the direction of propagation. For demonstration purposes this mechanism is elucidated in AlGaAs and silicon nanowaveguides. The effect of dispersion on the power circulation is also considered.

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Identification And Characterization Of Rv3281 As A Novel Subunit Of A Biotin-Dependent Acyl-Coa Carboxylase In Mycobacterium Tuberculosis H37rv, Tae-Jin Oh, Jaiyanth Daniel, Hwa-Jung Kim, Tatiana D. Sirakova, Pappachan E. Kolattukudy Jan 2006

Identification And Characterization Of Rv3281 As A Novel Subunit Of A Biotin-Dependent Acyl-Coa Carboxylase In Mycobacterium Tuberculosis H37rv, Tae-Jin Oh, Jaiyanth Daniel, Hwa-Jung Kim, Tatiana D. Sirakova, Pappachan E. Kolattukudy

Faculty Bibliography 2000s

Mycobacterium tuberculosis produces a large number of structurally diverse lipids generated from the carboxylation products of acetyl-CoA and propionyl-CoA. A biotin-dependent acyl-CoA carboxylase was purified from M. tuberculosis H37Rv by avidin affinity chromatography, and the three major protein components were determined by N-terminal sequencing to be the 63-kDa alpha 3-subunit (AccA3, Rv3285), the 59-kDa beta 5-subunit (AccD5, Rv3280), and the 56-kDa beta 4-subunit (AccD4, Rv3799). A minor protein of about 24 kDa that co-purified with the above subunits was identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry to be the product of Rv3281 that is located immediately downstream of …

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Adaptive Lens Using Liquid Crystal Concentration Redistribution, Hongwen Ren, Yi-Hsin Lin, Shin-Tson Wu Jan 2006

Adaptive Lens Using Liquid Crystal Concentration Redistribution, Hongwen Ren, Yi-Hsin Lin, Shin-Tson Wu

Faculty Bibliography 2000s

An adaptive lens using electrically induced liquid crystal (LC)/monomer concentration redistribution is demonstrated. In the absence of an electric field, the LC/monomer mixture is homogeneously distributed. Application of an inhomogeneous electric field causes the LC molecules to diffuse towards the high field region and the liquid monomer towards the low field region. On the other hand, the LC molecules tend to diffuse from high to low concentration direction in order to balance the concentration change. A gradient LC concentration is thus obtained. Using the gradient LC concentration, we demonstrate a tunable-focus lens. Compared with a conventional LC lens, our lens …

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Infrared Image Scintillation: Comparison Of Modeling And Measurement, Ingmar G. E. Renhorn, Thomas Svensson, Göran Carlsson, Staffan Cronström, Glenn D. Boreman Jan 2006

Infrared Image Scintillation: Comparison Of Modeling And Measurement, Ingmar G. E. Renhorn, Thomas Svensson, Göran Carlsson, Staffan Cronström, Glenn D. Boreman

Faculty Bibliography 2000s

Atmospheric scintillation effects on point targets and small targets are studied in the middle-wave infrared (MWIR) band over a 2.5-km horizontal path. Expressions are presented for both exact numerical calculations and for a Gaussian-aperture approximation of scintillation that has an accurate analytic solution. Experimental results show that measurements of C-n(2) using a commercial NIR scintillometer allow the prediction of average scintillation levels in the MWIR when corrections are made for wavelength and dimensions of the source and receiver. The measured log-irradiance values are approximately lognormal, and are about a factor of 2 higher than would have been expected from theory. …

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Conservation Of Angular Momentum Of Light In Single Scattering, Chaim Schwartz, Aristide Dogariu Jan 2006

Conservation Of Angular Momentum Of Light In Single Scattering, Chaim Schwartz, Aristide Dogariu

Faculty Bibliography 2000s

In this paper we discuss the conservation of angular momentum of light in single scattering of circularly polarized light from a spherical, non-absorbing particle. We show that the angular momentum carried by the incident wave is distributed in the scattered waves between terms related to polarization or spin and to orbital angular momentum, respectively. We also show that, in all scattering directions, a constant ratio exists between the flux density of the total angular momentum and the intensity.

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Observation Of Discrete Quadratic Surface Solitons, Georgios A. Siviloglou, Konstantinos G. Makris, G. Makris, Robert Iwanow, Roland Schiek, Demetrios N. Christodoulides, George I. Stegeman Jan 2006

Observation Of Discrete Quadratic Surface Solitons, Georgios A. Siviloglou, Konstantinos G. Makris, G. Makris, Robert Iwanow, Roland Schiek, Demetrios N. Christodoulides, George I. Stegeman

Faculty Bibliography 2000s

We report the first observation of discrete quadratic surface solitons in self-focusing and defocusing periodically poled lithium niobate waveguide arrays. By operating on either side of the phase-matching condition and using the cascading nonlinearity, both in-phase and staggered discrete surface solitons were observed. This represents the first experimental demonstration of staggered/gap surface solitons at the interface of a semi-infinite nonlinear lattice. The experimental results were found to be in good agreement with theory.

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Raman Gain Measurements And Photo-Induced Transmission Effects Of Germanium- And Arsenic-Based Chalcogenide Glasses, Robert Stegeman, George Stegeman, Peter Delfyett Jr., Laeticia Petit, Nathan Carlie, Kathleen Richardson, Michel Couzi Jan 2006

Raman Gain Measurements And Photo-Induced Transmission Effects Of Germanium- And Arsenic-Based Chalcogenide Glasses, Robert Stegeman, George Stegeman, Peter Delfyett Jr., Laeticia Petit, Nathan Carlie, Kathleen Richardson, Michel Couzi

Faculty Bibliography 2000s

The Raman gain spectra of millimeter thick As2S3 and As24S38Se38 glasses and Ge( 23 - x) GaxSb7S( 70 - y) Se-y with x = 0 and 5 and y = 0, 2, 5 have been measured using a direct nonlinear optics technique. The pump light originated from a picosecond Nd:YAG laser operating at 1064 nm and a tunable optical parametric generator and amplifier ( OPG/OPA) was used as a source for the probe light. A peak material Raman gain coefficient of ( 155 +/- 11) x 10(-13)m/W has been measured for the As24S38Se38 glass. A reversible photodarkening effect which responds …

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Genetically Engineered Human Mesenchymal Stem Cells Produce Met-Enkephalin At Augmented Higher Levels In Vitro, Ikuko Sugaya, Tingyu Qu, Kiminobu Sugaya, George D. Pappas Jan 2006

Genetically Engineered Human Mesenchymal Stem Cells Produce Met-Enkephalin At Augmented Higher Levels In Vitro, Ikuko Sugaya, Tingyu Qu, Kiminobu Sugaya, George D. Pappas

Faculty Bibliography 2000s

We have reported that transplantation of adrenal medullary chromaffin cells that release endogenous opioid peptides into pain modulatory regions in the CNS produce significant antinociceptive effects in patients with terminal cancer pain. However, the usefulness of this procedure is minimal because the availability of human adrenal tissue is very limited. Alternative xenogeneic materials, such as porcine and bovine adrenal chromaffin cells present problems of immune rejection and possible pathogenic contamination. In an attempt to develop opioid peptide-producing cells of autologous origin, we have transfected human mesenchymal stem cells (hMeSCs) with a mammalian expression vector containing a fusion gene of green …

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Compositional Stability Of Fept Nanoparticles On Sio2/Si During Annealing, B. Yao, R. V. Petrova, R. R. Vanfleet, K. R. Coffey Jan 2006

Compositional Stability Of Fept Nanoparticles On Sio2/Si During Annealing, B. Yao, R. V. Petrova, R. R. Vanfleet, K. R. Coffey

Faculty Bibliography 2000s

The loss of Fe due to oxidation or diffusion into the substrate can prevent the successful preparation of well-ordered, stoichiometric, FePt nanoparticles. In this work we report the composition changes during annealing observed for small ( < 10 nm) FePt nanoparticles on thermally grown SiO2 layers on Si wafer substrates. Additionally, we describe the use of a controlled reducing gas mixture, Ar+H-2+H2O, to reduce the loss of Fe.

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Optical Breathers In Nonlinear Anisotropic And Dispersive Media, G. T. Adamashvili, D. J. Kaup Jan 2006

Optical Breathers In Nonlinear Anisotropic And Dispersive Media, G. T. Adamashvili, D. J. Kaup

Faculty Bibliography 2000s

Anisotropic crystals containing impurity atoms, when the principal optical axis of the uniaxial crystal and the vector of electrical dipole moment of the impurity atoms are perpendicular to each other and are directed along different crystallographic axes, are shown to have three different mechanisms of the formation of breathers depending on the direction of the wave propagation and on the symmetry of the medium. Explicit analytic expressions for the parameters of breathers and the effective nonlinear susceptibilities for extraordinary waves are obtained. All uniaxial crystals with quadratic susceptibilities can be divided into three different groups, according to the crystal classes. …

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Strehl Ratio And Scintillation Theory For Uplink Gaussian-Beam Waves: Beam Wander Effects, Larry C. Andrews, Ronald L. Phillips, Richard J. Sasiela, Ronald R. Parenti Jan 2006

Strehl Ratio And Scintillation Theory For Uplink Gaussian-Beam Waves: Beam Wander Effects, Larry C. Andrews, Ronald L. Phillips, Richard J. Sasiela, Ronald R. Parenti

Faculty Bibliography 2000s

First-order weak-fluctuation Rytov theory predicts that the longitudinal (on-axis) component of the scintillation index of an uplink collimated beam will become significantly smaller as the size of the transmitter aperture increases up to around 100 cm. However, the results of recent computer simulations are at odds with this behavior, and we believe that this discrepancy is due to the fact that the conventional Rytov theory does not correctly account for the effects of beam wander on the scintillation index. We present a theoretical structure that accurately describes far-field irradiance fluctuations caused by uncorrected beam wander. This new theory is validated …

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Thermal Transport And Grain Boundary Conductance In Ultrananocrystalline Diamond Thin Films, Maki A. Angadi, Taku Watanabe, Arun Bodapati, Xingcheng Xiao, Orlando Auciello, John A. Carlisle, Jeffret A. Eastman, Pawel Keblinski, Patrick K. Schelling, Simon R. Phillpot Jan 2006

Thermal Transport And Grain Boundary Conductance In Ultrananocrystalline Diamond Thin Films, Maki A. Angadi, Taku Watanabe, Arun Bodapati, Xingcheng Xiao, Orlando Auciello, John A. Carlisle, Jeffret A. Eastman, Pawel Keblinski, Patrick K. Schelling, Simon R. Phillpot

Faculty Bibliography 2000s

Although diamond has the highest known room temperature thermal conductivity, k similar to 2200 W/m K, highly sp(3) amorphous carbon films have k < 15 W/m K. We carry out an integrated experimental and simulation study of thermal transport in ultrananocrystalline diamond (UNCD) films. The experiments show that UNCD films with a grain size of 3-5 nm have thermal conductivities as high as k=12 W/m K at room temperature, comparable with that of the most conductive amorphous diamond films. This value corresponds to a grain boundary (Kapitza) conductance greater than 3000 MW/m(2) K, which is ten times larger than that previously seen in any material. Our simulations of both UNCD and individual diamond grain boundaries yield values for the grain boundary conductance consistent with the experimentally obtained value, leading us to conclude that thermal transport in UNCD is controlled by the intrinsic properties of the grain boundaries.

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Near-Field Characterization Of Effective Optical Interfaces, A. Apostol, D. Haefner, A. Dogariu Jan 2006

Near-Field Characterization Of Effective Optical Interfaces, A. Apostol, D. Haefner, A. Dogariu

Faculty Bibliography 2000s

The properties of many heterogeneous media depend on both the surface roughness and the local variations of the optical properties. An effective optical interface is usually invoked to describe the characteristics of such media. Using approaches specific to near-field optics, the two influences can be decoupled and a quantitative assessment of their contributions can be performed. It is also shown that a discrete random-walk model can be used to determine the magnitude of the dielectric constant fluctuations at subwavelength scales which, in turn, describe the morphology of optically inhomogeneous media.

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External Cavity Multiwavelength Semiconductor Hybrid Mode-Locked Laser Intracavity Gain Dynamics, Luis C. Archundia, Peter J. Delfyett Jr. Jan 2006

External Cavity Multiwavelength Semiconductor Hybrid Mode-Locked Laser Intracavity Gain Dynamics, Luis C. Archundia, Peter J. Delfyett Jr.

Faculty Bibliography 2000s

The intracavity gain dynamics of an external cavity semiconductor hybrid mode-locked laser is measured under multiwavelength operation. The results show a temporal skew between pulses corresponding to different wavelength channels. A measurement of the temporal evolution of the gain reveals a slow gain depletion, avoiding carrier heating and carrier cooling, and decreasing self-phase modulation effects and gain competition between wavelength channels, making multiwavelength operation possible.

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External Cavity Multiwavelength Semiconductor Mode-Locked Lasers Gain Dynamics, Luis C. Archundia, Peter J. Delfyett Jan 2006

External Cavity Multiwavelength Semiconductor Mode-Locked Lasers Gain Dynamics, Luis C. Archundia, Peter J. Delfyett

Faculty Bibliography 2000s

The gain dynamics of a semiconductor optical amplifier ( SOA) were measured using pump-probe techniques for the amplification of 750 fs pulses, 6.5 ps pulses and multiwavelength pulses, obtained from an external cavity semiconductor mode-locked laser. Furthermore, the intracavity gain dynamics of an external cavity semiconductor mode-locked laser was measured under multiwavelength operation. The experimental results show how the inherent chirp in pulses from external cavity semiconductor mode-locked lasers result in a slow gain depletion without significant fast gain dynamics. This mitigates gain competition between wavelength channels and nonlinearities in the gain media ( SOA), enabling the multiwavelength operation of …

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Characterization Of The Ifn-Gamma T-Cell Responses To Immediate Early Antigens In Humans With Genital Herpes, Ralph P. Braun, Lendon G. Payne, Lichun Dong Jan 2006

Characterization Of The Ifn-Gamma T-Cell Responses To Immediate Early Antigens In Humans With Genital Herpes, Ralph P. Braun, Lendon G. Payne, Lichun Dong

Faculty Bibliography 2000s

Background: The IFN-gamma ELISPOT assay has been used to examine the T-cell repertoire for many disease states in humans but, as yet, not genital herpes. Using overlapping synthetic peptide libraries, an IFN-gamma ELISPOT assay was established that could measure CD4 and CD8 T-cell responses to HSV-2 antigens in patients with genital herpes. Results: In unexpanded T-cells isolated from peripheral blood, CD4 responses were readily measured against four immediate early antigens (ICP0, ICP4, ICP22 and ICP27), VP22 and gD. The CD4 responses were characterized by a low number of positive cells which produced large ELISPOTs. CD4 responses had a broad specificity …

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Cellular Response Of Shewanella Oneidensis To Strontium Stress, Steven D. Brown, Madhavi Martin, Sameer Deshpande, Sudipta Seal, Katherine Huang, Eric Alm, Yungfeng Ynag, Liyou Wu, Tingfen Yan, Xueduan Liu, Adam Arkin, Karuna Chourey, Jizhong Zhou, Dorothea K. Thompson Jan 2006

Cellular Response Of Shewanella Oneidensis To Strontium Stress, Steven D. Brown, Madhavi Martin, Sameer Deshpande, Sudipta Seal, Katherine Huang, Eric Alm, Yungfeng Ynag, Liyou Wu, Tingfen Yan, Xueduan Liu, Adam Arkin, Karuna Chourey, Jizhong Zhou, Dorothea K. Thompson

Faculty Bibliography 2000s

The physiology and transcriptome dynamics of the metal ion-reducing bacterium Shewanella oneidensis strain MR-1 in response to nonradioactive strontium (Sr) exposure were investigated. Studies indicated that MR-1 was able to grow aerobically in complex medium in the presence of 180 mM SrCl2, but showed severe growth inhibition at levels above that concentration. Temporal gene expression profiles were generated from aerobically grown, mid-exponential-phase MR-1 cells shocked with 180 mM SrCl2, and analyzed for significant differences in mRNA abundance with reference to data for nonstressed MR-1 cells. Genes with annotated functions in siderophore biosynthesis and iron transport were among the most highly …

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Ultralow Noise Optical Pulse Generation In An Actively Mode-Locked Quantum-Dot Semiconductor Laser, Myoung-Taek Choi, Ji-Myung Kim, Wangkuen Lee, Peter J. Delfyett Jan 2006

Ultralow Noise Optical Pulse Generation In An Actively Mode-Locked Quantum-Dot Semiconductor Laser, Myoung-Taek Choi, Ji-Myung Kim, Wangkuen Lee, Peter J. Delfyett

Faculty Bibliography 2000s

We report excellent noise performance of an external-cavity actively mode-locked laser based on quantum-dot gain medium. Optical pulse trains with less than 7.5 fs residual timing jitter (1 Hz to 10 MHz) for a 12.8 GHz harmonically mode-locked ring laser were obtained. This result represents, to our knowledge, the lowest residual jitter reported from actively mode-locked semiconductor lasers, and shows that quantum-dot mode-locked lasers are promising as sources of ultralow noise optical pulse trains.

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Modeling Of Phase Volume Diffractive Gratings, Part 1: Transmitting Sinusoidal Uniform Gratings, Igor V. Ciapurin, Leonid B. Glebov, Vadim I. Smirnov Jan 2006

Modeling Of Phase Volume Diffractive Gratings, Part 1: Transmitting Sinusoidal Uniform Gratings, Igor V. Ciapurin, Leonid B. Glebov, Vadim I. Smirnov

Faculty Bibliography 2000s

A detailed model of the diffraction of plane and Gaussian beams on plane uniform phase Bragg gratings based on Kogelnik's theory of coupled waves is presented. The model describes transmitting gratings with arbitrary orientation in a plane-parallel plate taking into account spectral width and angular divergence of laser beams along with material dispersion of a photosensitive medium. The model results are compared with experimental data for high- efficiency Bragg gratings in a photothermorefractive (PTR) glass.

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Lasing Mechanisms In Organic Photonic Crystal Lasers With Two-Dimensional Distributed Feedback, K. Forberich, A. Gombert, S. Pereira, J. Crewett, U. Lemmer, M. Diem, K. Busch Jan 2006

Lasing Mechanisms In Organic Photonic Crystal Lasers With Two-Dimensional Distributed Feedback, K. Forberich, A. Gombert, S. Pereira, J. Crewett, U. Lemmer, M. Diem, K. Busch

Faculty Bibliography 2000s

We present a detailed experimental and theoretical investigation of the lasing characteristics of organic photonic crystal lasers. These lasers are based on strongly modulated two-dimensional polymer surface relief structures on which thin films of optically active organic materials have been deposited. We determine the in-plane photonic band structure of the corresponding quasiguided modes within an effective two-dimensional model. In addition, we calculate the total (three-dimensional) losses associated with these modes. This allows us to identify the lasing thresholds for square lattice geometries and to understand the emission pattern.

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