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Noncovalent Crosslinking of SH1 and SH2 to Detect Dynamic Flexibility of the SH1 Helix

Description: In this experiment, fluorescent N- (1-pyrenyl) iodoacetamide modified the two reactive thiols, SH1 (Cys 707) and SH2 (Cys 697) on myosin to detect SH1-SH2 a -helix melting. The excimer forming property of pyrene is well suited to monitor the dynamics of the SH1 and SH2 helix melting, since the excimer should only form during the melted state. Decreased anisotropy of the excimer relative to the monomeric pyrene fluorescence is consistent with the disordering of the melted SH1-SH2 region in the a… more
Date: August 2000
Creator: Park, Hyunguk
Partner: UNT Libraries
open access

Inertial Conference Fusion Semiannual Report October 1999 - March 2000, Volume 1, Number 1

Description: This first issue of the ''ICF Semiannual Report'' contains articles whose diverse subjects attest to the broad technical and scientific challenges that are at the forefront of the ICF program at LLNL. The first article describes the progress being made at solving the surface roughness problem on capsule mandrels. All NIF capsule options, except machined beryllium, require a mandrel upon which the ablator is deposited. This mandrel sets the baseline sphericity of the final capsule. Problems invo… more
Date: March 1, 2000
Creator: Hammel, B. A.
Partner: UNT Libraries Government Documents Department
open access

Modern Philosophy: A Study of Knowledge [Part 1]

Description: Thesis written by a student in the UNT Honors College discussing a series of lectures pertaining to philosophy and epistemology. The intellectual contributions of various philosophers are included.
Date: Autumn 2000
Creator: Dodge, Catherine
Partner: UNT Honors College
open access

Benchmarks and models for 1-D radiation transport in stochastic participating media

Description: Benchmark calculations for radiation transport coupled to a material temperature equation in a 1-D slab and 1-D spherical geometry binary random media are presented. The mixing statistics are taken to be homogeneous Markov statistics in the 1-D slab but only approximately Markov statistics in the 1-D sphere. The material chunk sizes are described by Poisson distribution functions. The material opacities are first taken to be constant and then allowed to vary as a strong function of material tem… more
Date: August 21, 2000
Creator: Miller, D. S.
Partner: UNT Libraries Government Documents Department
open access

An Analytical Study of the Variations on the Theme of Paganini's Twenty-Fourth Caprice, Op. 1 by Busoni, Friedman, and Muczynski

Description: The purpose of this study is to analyze sets of variations on Paganini's theme by three twentieth-century composers: Ferruccio Busoni, Ignaz Friedman, and Robert Muczynski, in order to examine, identify, and trace different variation techniques and their applications. Chapter 1 presents the purpose and scope of this study. Chapter 2 provides background information on the musical form "theme and variations" and the theme of Paganini's Twenty-fourth Caprice, Op. 1. Chapter 2 also deals with the q… more
Date: May 2000
Creator: Ahn, Kwang Sun
Partner: UNT Libraries
open access

Steric and electronic effects of 1,3-disubstituted cyclopentadienyl ligands on metallocene derivatives of Cerium, Titanium, Manganese, and Iron

Description: Sterically demanding 1,3-disubstituted cyclopentadienyl ligands were used to modify the physical properties of the corresponding metallocenes. Sterically demanding ligands provided kinetic stabilization for trivalent cerium compounds. Tris(di-t-butylcyclopentadienyl)cerium was prepared and anion competition between halides and cyclopentadienyl groups which had complicated synthesis of the tris(cyclopentadienyl)compound was qualitatively examined. Bis(di-t-butylcyclopentadienyl)cerium methyl was… more
Date: May 19, 2000
Creator: Sofield, Chadwick Dean
Partner: UNT Libraries Government Documents Department
open access

Spin correlation in t{anti t} production from p{anti p} collisions at {radical}s = 1.8 TeV

Description: The Standard Model predicts that the lifetime of the top quark is shorter than the typical time scale at which hadronization process occurs, and the spin information at its production is preserved. Spin correlation of the t{anti t} system from p{anti p} collisions at the Tevatron is analyzed using 6 events in the dilepton channels collected using the D0 detector. Spin correlation factor of {kappa} > {minus} 0.25 at 68% CL is obtained from the data.
Date: June 15, 2000
Creator: Choi, Suyong
Partner: UNT Libraries Government Documents Department

Psychological and Sociodemographic Predictors of Psychological Distress in BRCA1 and BRCA2 Genetic Testing Participants within a Community Based Genetic Screening Program

Description: Mutations in BRCA1 and BRCA2, the first two breast cancer susceptibility genes identified, carry as much as an 85% lifetime risk of developing breast, ovarian or other cancers. Genetic testing for mutations in these two genes has recently become commercially available. There have been varying amounts of psychological distress noted among women with a family history of breast cancer. Distress has been observed to impact psychological functioning, activities of daily living, and the practice of b… more
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Date: August 2000
Creator: Lesniak, Karen
Partner: UNT Libraries
open access

Transition Metal Complexes of Cr, Mo, W and Mn Containing {eta}{sup 1}(S)-2,5-Dimethylthiophene, Benzothiophene and Dibenzothiophene Ligands

Description: The UV photolysis of hexanes solutions containing the complexes M(CO){sub 6} (M=Cr, Mo, W) or CpMn(CO){sub 3} (Cp={eta}{sup 5}-C{sub 5}H{sub 5}) and excess thiophene (T{sup *}) (T{sup *}=2,5-dimethylthiophene (2,5-Me{sub 2}T), benzothiophene (BT), and dibenzothiophene (DBT)) produces the {eta}{sup 1}(S)-T{sup *} complexes (CO){sub 5}M({eta}{sup 1}(S)-T{sup *}) 1-8 or Cp(CO){sub 2}Mn({eta}{sup 1}(S)-T{sup *})9-11, respectively. However, when T{sup *}=DBT, and M=Mo, a mixture of two products resu… more
Date: September 21, 2000
Creator: Reynolds, M.
Partner: UNT Libraries Government Documents Department
open access

A measurement of t{anti t} production cross section in p{anti p} collisions at {radical}s = 1.8 TeV using neural networks

Description: The authors present the results of a new measurement of the t{anti t} production cross section using e{mu} channel in p{anti p} collisions at {radical}s = 1.8 TeV. This study corresponds to an integrated luminosity of 108.3 {+-} 5.7 pb{sup {minus}1} acquired by the D0 detector during the Fermilab Tevatron Collider Run 1 (1992--1996). By using neural network techniques instead of the conventional analysis methods, the authors show that the signal acceptance can be increased by 10% (for m{sub t} … more
Date: June 16, 2000
Creator: Singh, Harpreet
Partner: UNT Libraries Government Documents Department

Empirical Evidence of Pricing Efficiency in Niche Markets

Description: Unique and proprietary data of the illiquid, one-year non cancelable for three month Bermudan swaps (1Y NC 3M swaps) and one-year non callable for three months Bermudan CDs (1Y NC 3M CDs), provides evidence of market efficiency. The 1Y NC 3M swap and 1Y NC 3M CD markets efficiently reflected unexpected economic information. The 1Y NC 3M swaption premiums also followed the European one-year into three-month (1Y into 3M) swaption volatilities. Swaption premiums were computed by pricing non-optio… more
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Date: May 2000
Creator: Koch, Sandra Idelle
Partner: UNT Libraries

Production and Characterization of a Novel Extracellular Polysaccharide Produced by Paenibacillus velaei, Sp. Nov

Description: Paenibacillus velaei, sp. nov. is a soil bacterium capable of producing an unusually large amount of exopolysaccharide (EPS). The EPS contains glucose, mannose, galactose and fucose in a molar ratio of 4:2:1:1. The molecular weight of the EPS is higher than 2x106. The viscosity of 1% EPS is 1300 cP when measured at a shear rate of 1 sec-1. Physiological parameters for optimal production of the EPS were studied and it was found that 1.4 g dry weight per 1 l of medium was produced when the bacter… more
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Date: August 2000
Creator: Sukplang, Patamaporn
Partner: UNT Libraries
open access

Synthesis and characterization of molecules for electron transfer research.

Description: Dimethoxynaphthalene (donor) and quinone (acceptor) have been chosen as a suitable redox pair and are bonded to either permethylated silane chains or corresponding permethylated alkyl chains to form Acceptor-(Bridge)-Donor molecules. The idea that the s-delocalization phenomenon of silane chains may greatly facilitate ET reactions will be tested. The starting material for the donor precursor, 4-(1,4-dimethoxynaphthyl)bromocyclohexane, was 1,4-naphthoquinone. After methylation and bromination, t… more
Date: December 2000
Creator: Xiao, Wu
Partner: UNT Libraries
open access

What insight do market participants gain from dividend increases?

Description: This study examines the reactions of market makers and investors to large dividend increases to identify the motives for dividend increases. Uniquely, this study simultaneously tests the signaling and agency abatement motivations as explanations of the impact of dividend increases on stock prices and bid-ask spreads. The agency abatement hypothesis argues that increased dividends constrict management's future behavior, abating the agency problem with shareholders. The signaling hypothesis asser… more
Date: May 2000
Creator: Ellis, R. Barry
Partner: UNT Libraries
open access

Effects of Self-Monitoring and Monetary Reward on Fluid Adherence among Adult Hemodialysis Patients

Description: The effects of a monetary reward and self-monitoring on reducing interdialytic weight gain (IWG) were compared for 6 hemodialysis patients in an outpatient setting. A single-subject experimental design (A-B-BC-B-BC) was used to examine each variable individually and in combination, with alternating phases to control for possible sequencing effects. Monetary reward (50 cents - $3) was administered in a titrated manner according to standardized criteria, ranging from 3 % and 4% of patients' dry w… more
Date: December 2000
Creator: Sonnier, Bridget L.
Partner: UNT Libraries
open access

A compact, discrete CsI(Tl) scintillator/Si photodiode gamma camera for breast cancer imaging

Description: Recent clinical evaluations of scintimammography (radionuclide breast imaging) are promising and suggest that this modality may prove a valuable complement to X-ray mammography and traditional breast cancer detection and diagnosis techniques. Scintimammography, however, typically has difficulty revealing tumors that are less than 1 cm in diameter, are located in the medial part of the breast, or are located in the axillary nodes. These shortcomings may in part be due to the use of large, conven… more
Date: Autumn 2000
Creator: Gruber, Gregory J.
Partner: UNT Libraries Government Documents Department
open access

Maximum-Sized Matroids with no Minors Isomorphic to U2,5, F7, F7¯, OR P7

Description: Let M be the class of simple matroids which do not contain the 5-point line U2,5 , the Fano plane F7 , the non-Fano plane F7- , or the matroid P7 , as minors. Let h(n) be the maximum number of points in a rank-n matroid in M. We show that h(2)=4, h(3)=7, and h(n)=n(n+1)/2 for n>3, and we also find all the maximum-sized matroids for each rank.
Date: May 2000
Creator: Mecay, Stefan Terence
Partner: UNT Libraries
open access

The Effects of Extinction on Human Performance Following Exposure to Fixed Ratio Schedules of Reinforcement

Description: This experiment examined the effects of extinction on rate of responding and several topographical and temporal measures in adult humans. Three college students were trained to type the sequence 1•5•3 on a numeric keypad on a computer. The subjects were exposed to different fixed-ratio schedules of reinforcement (FR1, FR 5, and FR10 respectively) and extinction. Subjects displayed typical schedule performances during the maintenance phase of the experiment. During extinction the performances we… more
Date: May 2000
Creator: Anderson, Richard L.
Partner: UNT Libraries

Scanning Tunneling Microscopy of Homo-Epitaxial Chemical Vapor Deposited Diamond (100) Films

Description: Atomic resolution images of hot-tungsten filament chemical-vapor-deposition (CVD) grown epitaxial diamond (100) films obtained in ultrahigh vacuum (UHV) with a scanning tunneling microscope (STM) are reported. A (2x1) dimer surface reconstruction and amorphous atomic regions were observed on the hydrogen terminated (100) surface. The (2x1) unit cell was measured to be 0.51"0.01 x 0.25"0.01 nm2. The amorphous regions were identified as amorphous carbon. After CVD growth, the surface of the epita… more
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Date: May 2000
Creator: Stallcup, Richard E.
Partner: UNT Libraries
open access

Effects of Daily Oral Injections of Quercetin on Implanted Colon-25 Tumor Growth in Balb-C Mice

Description: The effects of three oral dosages (0.4 mg, 0.8 mg, and 1.6 mg) of quercetin on Colon-25 tumors implanted in Balb-c mice were studied. The data in this study show that: (1) certain dosages of quercetin in alcohol solutions, reduces the weight, and size of implanted Colon-25 tumors in Balb-c mice, (2) these same dosages of quercetin all produce a profound neutrophilia combined with a significant lymphopenia at day 20 post-implantation, and (3) there was relatively little evidence of histological … more
Date: May 2000
Creator: Hayashi, Adam
Partner: UNT Libraries

Parents' Beliefs and Knowledge Regarding Child Development and Appropriate Early Childhood Classroom Practices

Description: The intent of this study was to assess low-income parents knowledge and beliefs regarding child development and appropriate classroom practice and to compare their responses with those obtained from a previous survey of upper-income parents (Grebe, 1998). This study group (N=21) consisted of parents or guardians with children in a federally subsidized child-care center. Results indicated a high level of knowledge regarding developmentally appropriate practice and child development. Overall, th… more
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Date: May 2000
Creator: Hughes, Tina M.
Partner: UNT Libraries
open access

Development of Trivalent Ytterbium Doped Fluorapatites for Diode-Pumped Laser Applications

Description: One of the major motivators of this work is the Mercury Project, which is a 1 kW scalable diode-pumped solid-state laser system under development at Lawrence Livermore National Laboratory (LLNL). Major goals include 100 J pulses, 10% wallplug efficiency, 10 Hz repetition rate, and a 5 times diffraction limited beam. To achieve these goals the Mercury laser incorporates ytterbium doped Sr{sub 5}(PO{sub 4}){sub 3}F (S-FAP) as the amplifier gain medium. The primary focus of this thesis is a full u… more
Date: June 21, 2000
Creator: Bayramian, A. J.
Partner: UNT Libraries Government Documents Department
open access

Experimental Study of the Spin Structure of the Neutron (3He) at low Q2: a connection between the Bjorken and Gerasimov-Drell-Hearn Sum Rules

Description: The authors have presented the motivations in gathering doubly polarized data in the quasi-elastic, resonance and DIS domains. These data were used to calculate the extended GDH integral. The comparison of this quantity with the spin dependent forward Compton amplitude {bar S}{sub 1} is of particular importance for the unification of the two strong interaction descriptions (nucleonic/hadronic vs. partonic) because {bar S}{sub 1} is the first quantity theoretically calculable in the full Q{sup 2… more
Date: October 9, 2000
Creator: Deur, Alexander
Partner: UNT Libraries Government Documents Department
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