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1,231 Matching Results

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(open access)

On The Use Of Models To Assess Foot-And-Mouth Disease Transmission And Control

The 2001 outbreaks of foot-and-mouth disease (FMD) in Europe (Ferguson et al. 2001a, 2001b; Bouma et al. 2003) and concern about the possibility of an intentional introduction of a devastating foreign animal disease triggered renewed interest in both theoretical and experimental research related to FMD. Theoretical models of disease transmission, which influenced the tactical decisions of the United Kingdom (UK) government during the epidemic (Taylor 2003), resulted in large numbers of uninfected animals being slaughtered. After the epidemic, the adopted control policies were sharply criticized (Kitching 2004;, Taylor 2003). Still, the role of computationaL modeling for analyzing the scope of the epidemic and devising control strategies was recognized as substantial and necessary.

Date: July 12, 2004

Creator: Kostova-Vassilevska, Tanya

Object Type: Report

System: The UNT Digital Library

(open access)

APDS: The Autonomous Pathogen Detection System

We have developed and tested a fully autonomous pathogen detection system (APDS) capable of continuously monitoring the environment for airborne biological threat agents. The system was developed to provide early warning to civilians in the event of a bioterrorism incident and can be used at high profile events for short-term, intensive monitoring or in major public buildings or transportation nodes for long-term monitoring. The APDS is completely automated, offering continuous aerosol sampling, in-line sample preparation fluidics, multiplexed detection and identification immunoassays, and nucleic-acid based polymerase chain reaction (PCR) amplification and detection. Highly multiplexed antibody-based and duplex nucleic acid-based assays are combined to reduce false positives to a very low level, lower reagent costs, and significantly expand the detection capabilities of this biosensor. This article provides an overview of the current design and operation of the APDS. Certain sub-components of the ADPS are described in detail, including the aerosol collector, the automated sample preparation module that performs multiplexed immunoassays with confirmatory PCR, and the data monitoring and communications system. Data obtained from an APDS that operated continuously for seven days in a major U.S. transportation hub is reported.

Date: October 4, 2004

Creator: Hindson, Benjamin; Makarewicz, Anthony; Setlur, Ujwal; Henderer, Bruce; McBride, Mary & Dzenitis, John

Object Type: Article

System: The UNT Digital Library

(open access)

Development of colorimetric solid Phase Extraction (C-SPE) for in-flight Monitoring of spacecraft Water Supplies

Although having recently been extremely successful gathering data on the surface of Mars, robotic missions are not an effective substitute for the insight and knowledge about our solar system that can be gained though first-hand exploration. Earlier this year, President Bush presented a ''new course'' for the U.S. space program that shifts NASA's focus to the development of new manned space vehicles to the return of humans to the moon. Re-establishing the human presence on the moon will eventually lead to humans permanently living and working in space and also serve as a possible launch point for missions into deeper space. There are several obstacles to the realization of these goals, most notably the lack of life support and environmental regeneration and monitoring hardware capable of functioning on long duration spaceflight. In the case of the latter, past experience on the International Space Station (ISS), Mir, and the Space Shuttle has strongly underscored the need to develop broad spectrum in-flight chemical sensors that: (1) meet current environmental monitoring requirements on ISS as well as projected requirements for future missions, and (2) enable the in-situ acquisition and analysis of analytical data in order to further define on-orbit monitoring requirements. Additionally, systems …

Date: December 19, 2004

Creator: Gazda, Daniel Bryan

Object Type: Thesis or Dissertation

System: The UNT Digital Library

(open access)

Perceptions and attributions of child, spousal, and elder abuse.

Although researchers have studied perceptions regarding sexually abused children, little was known about how other types of abusive events were perceived. This study examined 480 college students' abuse history and perceptions of child, spousal, and elder abuse by varying the respondent, victim, and perpetrator genders. Physical abuse, psychological abuse, and neglect were investigated. Perceptions of abusiveness, seriousness, harm, and responsibility were examined, along with the extent of identification with the victims/perpetrators. Participants viewed spousal abuse as less serious and harmful than other abuse types, especially when perpetrated against a male or by a female. Although able to recognize psychological abuse, students did not fully understand what other abuse types entailed. Individuals also showed a considerable amount of blame toward victims. Results further demonstrated important findings about how ethnic identity/orientation, religious affiliation, and history of abuse related to perceptions of abusive events.

Date: August 2004

Creator: Altman, Adrianne

Object Type: Thesis or Dissertation

System: The UNT Digital Library

(open access)

The Southwestern Historical Quarterly, Volume 107, July 2003 - April, 2004

The Texas State Historical Association Quarterly Report includes "Papers read at the meetings of the Association, and such other contributions as may be accepted by the Committee" (volume 1, number 1). These include historical sketches, biographical material, personal accounts, and other research. Index is located at the end of the volume starting on page 643.

Date: 2004

Creator: Texas State Historical Association

Object Type: Journal/Magazine/Newsletter

System: The Portal to Texas History

Religiousness, current substance use, and early risk indicators for substance abuse and dependence among nursing students.

Access: Use of this item is restricted to the UNT Community

The purposes of this study were to examine the prevalence of current substance use and early risk indicators for substance abuse and dependence, and to investigate the relationships among religiousness, current substance use, and early risk indicators among nursing students at seven Seventh-day Adventist colleges. Data for this descriptive study were collected through Efinger's Alcohol Risk Survey (EARS) (Efinger, 1984), the CAGE Questionnaire ( Ewing , 1984), and the Intrinsic/Extrinsic-Revised Scale (Gorsuch & McPherson, 1989). Participants were 241 nursing students enrolled in their first year of nursing courses at seven colleges and universities located across the United States . Findings indicated that 42% of students scored higher than the EARS mean; 24% reported current substance use; and 15% scored in the probable abuse/dependence category of CAGE. Students who reported current substance use and those scoring in the probable substance abuse/dependence category were significantly more likely to score above the EARS median. Intrinsic religiousness demonstrated a significant inverse relationship with current substance use. Significantly lower rates of current substance use were associated with higher rates of attendance at religious services. Respondents who indicated that their religion prohibited alcohol consumption reported significantly lower rates of current substance use than those who answered …

Date: December 2004

Creator: Gnadt, Bonnie

Object Type: Thesis or Dissertation

System: The UNT Digital Library

(open access)

Concentrations of Radionuclides and Trace Elements in Soils and Vegetation Around the DARHT Facility during 2004

Samples of soil, sediment, and unwashed overstory and understory vegetation were collected at four locations around the Dual-Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos National Laboratory (LANL). All samples were analyzed for concentrations of {sup 3}H, {sup 137}Cs, {sup 90}Sr, {sup 238}Pu, {sup 239,240}Pu, {sup 241}Am, {sup 234}U, {sup 235}U, {sup 238}U, Ag, As, Ba, Be, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Se, and Tl. These results, which represent five years since the start of operations, were compared with baseline statistical reference level (BSRL) data established over a four-year-long preoperational period prior to DARHT operations, and to LANL and U.S. Environmental Protection Agency Screening Action Levels (SALs). Most radionuclides and trace elements in soil, sediment, and vegetation were below BSRL values and those soils/sediments that were above BSRLs were far below SALs.

Date: October 1, 2004

Creator: Fresquez, P.R.

Object Type: Report

System: The UNT Digital Library

(open access)

Laboratory Measurements of Velocity and Attenuation in Sediments

Laboratory measurements are required to establish relationships between the physical properties of unconsolidated sediments and P- and S-wave propagation through them. Previous work has either focused on measurements of compressional wave properties at depths greater than 500 m for oil industry applications or on measurements of dynamic shear properties at pressures corresponding to depths of less than 50 m for geotechnical applications. Therefore, the effects of lithology, fluid saturation, and compaction on impedance and P- and S-wave velocities of shallow soils are largely unknown. We describe two state-of-the-art laboratory experiments. One setup allows us to measure ultrasonic P-wave velocities at very low pressures in unconsolidated sediments (up to 0.1 MPa). The other experiment allows P- and S-wave velocity measurements at low to medium pressures (up to 20 MPa). We summarize the main velocity and attenuation results on sands and sand - clay mixtures under partially saturated and fully saturated conditions in two ranges of pressures (0 - 0.1 MPa and 0.1 - 20 MPa) representative of the top few meters and the top 1 km, respectively. Under hydrostatic pressures of 0.1 to 20 MPa, our measurements demonstrate a P- and S-wave velocity-dependence in dry sands around a fourth root (0.23 …

Date: June 8, 2004

Creator: Zimmer, M A; Berge, P A; Bonner, B P & Prasad, M

Object Type: Article

System: The UNT Digital Library

(open access)

Needs of familial caregivers of cancer patients across the advanced cancer disease trajectory.

Familial caregivers are providing increasing amounts of care to advanced cancer patients. Increased understanding of caregivers' needs is vital in providing necessary support to lessen caregiver burden and comorbidity. This study examines particular information needs across a variety of specific events in the advanced cancer disease trajectory. A cross-sectional sample of 107 familial caregivers (24 current and 83 bereaved) of people with advanced cancer completed a needs assessment survey along with a measure of health information-seeking behavior. Analyses extend current research by including more specific disease-related events along the advanced cancer trajectory through bereavement. In all information categories, endorsement of wanted information differed across broad stages of Cancer Progression, Treatment, End of Life, and Post-Patient Death. For all information categories, except Dying and Spirituality, greatest information was wanted at the Cancer Progression stage. Information need also differed across specific events within broad stages. The categories of Disease/Medical and Relating to the Patient were the most endorsed at events involving patient care. Spirituality was least endorsed. At patient death, Caregiver Well-being has the highest endorsement. For events thereafter, information on Caregiver Well-being, Spirituality, Future Outlook, and Family and Close Others was most endorsed. Information needs did not differ based on age …

Date: August 2004

Creator: Bernard, Lori Lynn

Object Type: Thesis or Dissertation

System: The UNT Digital Library

(open access)

Fuel cells at the crossroads : attitudes regarding the investment climate for the US fuel cell industry and a projection of industry job creation potential.

Fuel Cells at the Crossroads examines financial community and fuel cell industry views on the investment climate for the fuel cell industry. It also explores the investment history of the US fuel cell industry and projects potential future job creation. The scope of the study included the transportation, stationary power generation and portable sectors. Interviews were conducted with industry and financial experts. The results of the interviews provide a snapshot of industry perspective just prior to President Bush's endorsement of a hydrogen economy in his 2003 State of the Union address. In April 2003, we conducted a spot check to test whether the State of the Union address had changed opinions. We found little change among the financial and investment communities, but some guarded new optimism among industry leaders. The general outlook of our sample was cautiously hopeful. There is no question, however, that the current climate is one of great uncertainty, particularly when compared with the enthusiasm that existed just a few years ago. Among other things: (1) Respondents generally believed that the energy industry will undergo profound change over the next few decades, resulting in some form of hydrogen economy. They acknowledged, however, that huge technology and cost …

Date: May 27, 2004

Creator: unknown

Object Type: Report

System: The UNT Digital Library

(open access)

An Observational Investigation of On-Duty Critical Care Nurses' Information Behavior in a Nonteaching Community Hospital

Critical care nurses work in an environment rich in informative interactions. Although there have been post hoc self-report survey studies of nurses' information seeking, there have been no observational studies of the patterns and content of their on-duty information behavior. This study used participant observation and in-context interviews to describe 50 hours of the observable information behavior of a representative sample of critical care nurses in a 20-bed critical care hospital unit. The researcher used open, in vivo, and axial coding to develop a grounded theory model of their consistent pattern of multimedia interactions. The resulting Nurse's Patient-Chart Cycle describes nurses' activities during the shift as centering on a regular alternation with the patient and the patient's chart (various record systems), clearly bounded with nursing "report" interactions at the beginning and the end of the shift. The nurses' demeanor markedly changed between interactions with the chart and interactions with the patient. Other informative interactions were observed with other health care workers and the patient's family, friends and visitors. The nurses' information seeking was centered on the patient. They mostly sought information from people, the patient record and other digital systems. They acted on or passed on most of the information …

Date: May 2004

Creator: McKnight, Michelynn

Object Type: Thesis or Dissertation

System: The UNT Digital Library

(open access)

Spectroscopic Confirmation of A Radio-Selected Galaxy Overdensity at z = 1.11

We report the discovery of a galaxy overdensity at z = 1.11 associated with the z = 1.110 high-redshift radio galaxy MG 0442+0202. The group, CL 0442+0202, was found in a near-infrared survey of z > 1 radio galaxies undertaken to identify spatially-coincident regions with a high density of objects red in I - K' color, typical of z > 1 elliptical galaxies. Spectroscopic observations from the Keck I telescope reveal five galaxies within 35'' of MG 0442+0202 at 1.10 < z < 1.11. These member galaxies have broad-band colors and optical spectra consistent with passively-evolving elliptical galaxies formed at high redshift. Archival ROSAT observations reveal a 3{sigma} detection of soft X-ray emission coincident with CL 0442+0202 at a level five times greater than expected for the radio galaxy. These data are suggestive of a rich galaxy cluster and inspired a 45 ks Chandra X-Ray Observatory observation. As expected, the radio galaxy is unresolved to Chandra, but is responsible for approximately half of the observed X-ray flux. The remaining ROSAT flux is resolved into four point sources within 15'' of the radio galaxy, corresponding to a surface density two orders of magnitude higher than average for X-ray sources at these …

Date: February 26, 2004

Creator: Stanford, S; Stern, D; Holden, B & Spinrad, H

Object Type: Article

System: The UNT Digital Library

(open access)

Nuclear data and measurement series.

It is well established that the high fluences of fast neutrons likely to be encountered in the environments of fusion reactors or fusion materials test facilities will generate substantial quantities of helium (both {sup 4}He and {sup 3}He isotopes), and that the presence of this gas in bulk material can produce serious damage in engineering structures due to swelling. The present study was undertaken to survey the current status (as of early 2004) of the available fast neutron cross section information for helium production in several major structural elements of interest for the development of fusion energy systems. The scope of this study encompasses both compiled experimental cross section data and evaluated cross sections available from major nuclear data libraries used in the analysis of fusion systems. The main conclusion from this work is that the contemporary knowledge of those individual neutron reaction cross sections important for helium production is, in general, very inadequate for the purpose of producing reliable designs for fusion reactors (e.g., ITER) and materials irradiation test facilities (e.g., IFMIF). Since the number of distinct neutron reactions that must be considered is large, and the capabilities (both experimental and theoretical) of the nuclear physics community to adequately …

Date: May 13, 2004

Creator: Smith, D. L.

Object Type: Report

System: The UNT Digital Library

(open access)

BioAerosol Mass Spectrometry: Reagentless Detection of Individual Airborne Spores and Other Bioagent Particles Based on Laser Desorption/Ionization Mass Spectrometry

Better devices are needed for the detection of aerosolized biological warfare agents. Advances in the ongoing development of one such device, the BioAerosol Mass Spectrometry (BAMS) system, are described here in detail. The system samples individual, micrometer-sized particles directly from the air and analyzes them in real-time without sample preparation or use of reagents. At the core of the BAMS system is a dual-polarity, single-particle mass spectrometer with a laser based desorption and ionization (DI) system. The mass spectra produced by early proof-of-concept instruments were highly variable and contained limited information to differentiate certain types of similar biological particles. The investigation of this variability and subsequent changes to the DI laser system are described. The modifications have reduced the observed variability and thereby increased the usable information content in the spectra. These improvements would have little value without software to analyze and identify the mass spectra. Important improvements have been made to the algorithms that initially processed and analyzed the data. Single particles can be identified with an impressive level of accuracy, but to obtain significant reductions in the overall false alarm rate of the BAMS instrument, alarm decisions must be made dynamically on the basis of multiple analyzed particles. …

Date: July 20, 2004

Creator: Steele, P T

Object Type: Thesis or Dissertation

System: The UNT Digital Library

(open access)

The Effect of Initial Conditions on the Nonlinear Evolution of Perturbed Interfaces Driven by Strong Blast Waves

In core-collapse supernovae, strong blast waves drive interfaces susceptible to Rayleigh-Taylor (RT), Richtmyer-Meshkov (RM), and Kelvin-Helmholtz (KH) instabilities. In addition, perturbation growth can result from material expansion in large-scale velocity gradients behind the shock front. Laser-driven experiments are designed to produce a strongly shocked interface whose evolution is a scaled version of the unstable hydrogen-helium interface in core-collapse supernovae such as SN 1987A. The ultimate goal of this research is to develop an understanding of the effect of hydrodynamic instabilities and the resulting transition to turbulence on supernovae observables that remain as yet unexplained. In this dissertation, we present a computational study of unstable systems driven by high Mach number shock and blast waves. Using multi-physics radiation hydrodynamics codes and theoretical models, we consider the late nonlinear instability evolution of single mode, few mode, and multimode interfaces. We rely primarily on 2D calculations but present recent 3D results as well. For planar multimode systems, we show that compressibility effects preclude the emergence of a regime of self-similar instability growth independent of the initial conditions (IC's) by allowing for memory of the initial conditions to be retained in the mix-width at all times. The loss of transverse spectral information is demonstrated, …

Date: April 27, 2004

Creator: Miles, A

Object Type: Thesis or Dissertation

System: The UNT Digital Library

(open access)

Grandview Tribune (Grandview, Tex.), Vol. 109, No. 48, Ed. 1 Friday, July 16, 2004

Weekly newspaper from Grandview, Texas that includes local, state, and national news along with advertising.

Date: July 16, 2004

Creator: Marten, Donna K.

Object Type: Newspaper

System: The Portal to Texas History

(open access)

Perceptions of Commitment

This study investigated differences in level of commitment between married and non-married individuals, effects of demographic variables by age, gender, parenting status, and ethnicity, and determines participant's awareness of and participation in the Oklahoma Marriage Initiative (OMI) were investigated. Students from a rural Oklahoma junior college completed the Perceptions of Commitment survey during spring 2004. Responses related to levels of commitment, social exchange theory, expectations, and communication were collected. T-test analysis revealed no differences in level of commitment for any of the variables investigated. Data revealed the majority of participants were unaware of OMI and had never attended a program and do not plan to in the future. Implications of this research may be useful to future investigators who are interested in the Perceptions of Commitment survey and those focusing on marriage education programs to meet the needs of targeted audiences.

Date: August 2004

Creator: Laughlin-Rickman, Sonya

Object Type: Thesis or Dissertation

System: The UNT Digital Library

(open access)

Buckingham (1907): An appreciation

Nearly a century ago, Edgar Buckingham (1907) published a seminal work on the movement of soil moisture which is part of the foundation of modern soil physics. It also constitutes a pioneering contribution in the study of multi-phase flow in porous media. A physicist, Buckingham took on an earth science issue of importance to society, and produced superb basic science as a byproduct. Buckingham impresses us with his ability to combine experiment and theory, and his capacity to intuitively explain difficult ideas to a wide audience. Science progresses both by gradual accretion of knowledge, and by sudden influx of ideas. Buckingham's contribution belongs in the latter category. After a brief, four-year rendezvous with soil science, he went on to pursue a long and distinguished career in physics with the National Bureau of Standards. This paper is an appreciation of Buckingham's contribution on soil moisture in the context of contemporary developments in diffusion theory, and the rapid growth of science in America at the turn of the twentieth century.

Date: November 17, 2004

Creator: Narasimhan, T. N.

Object Type: Article

System: The UNT Digital Library

(open access)

The Hawaiian Monk Seal in the Northwestern Hawaiian Islands, 2001

The following document reports the findings of the studies of the endangered Hawaiian monk seal during 2001 in all of its reproductive sites in the Northwestern Hawaiian Islands. This document contains information evaluating the status and trends of monk seal subpopulations; natural history traits such as survival, reproduction, growth, behavior, and feeding habits; and the success of various activities designed to facilitate population growth.

Date: April 2004

Creator: Johanos, Thea C. & Baker, Jason D.

Object Type: Report

System: The UNT Digital Library

(open access)

The Express-Star (Chickasha, Okla.), Ed. 1 Tuesday, August 10, 2004

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.

Date: August 10, 2004

Creator: Bush, Kent

Object Type: Newspaper

System: The Gateway to Oklahoma History

(open access)

The Anatomy of Academic Dishonesty: Cognitive Development, Self-Concept, Neutralization Techniques, and Attitudes Toward Cheating

This study explored the relationship between cheating among university students and their cognitive developmental levels, use of neutralization techniques, self-concept as a multifaceted cognitive construct, and attitude toward cheating. The purposes of this study were to investigate: (1) The relationships between academic dishonesty and each of the following overall independent variables: cognitive development, use of neutralization techniques, self-concept as a multifaceted cognitive construct, and attitude toward cheating, and (2) the reasons behind college student academic cheating behaviors. The study used data from anonymous, self-report surveys administered to undergraduate students in-class and at supplemental sessions. Student participation was voluntary. The study was correlational. The five hypotheses were: (1) Self-concept is significantly and negatively related to academic dishonesty; (2) Cognitive development is significantly and negatively related to academic dishonesty; (3) Attitude toward cheating is significantly and negatively related to academic dishonesty; (4) The use of neutralization techniques is significantly and positively related to academic dishonesty; (5) Cognitive development, self-concept, and attitude toward cheating will make significant contributions to the regression model for the dependent variables of academic dishonesty. The data supported the first, third, and fourth hypotheses. However, the second and fifth hypotheses were supported under certain conditions. The roles of cognitive …

Date: August 2004

Creator: Arvidson, Cody Jean

Object Type: Thesis or Dissertation

System: The UNT Digital Library