196 Matching Results

Search Results

Advanced search parameters have been applied.

The Diagnostic Potentials of the Hewson Ratios and the Kahn Intelligence Test in Assessing Organic Brain Damage

Description: The purpose of this thesis is to explore the diagnostic potential of Hewson's ratios in evaluating the performance of selected subjects on the Wechsler scales, the Kahn Intelligence Test: Experimental Form was administered and analyzed in an attempt to develop some meaningful method of utilizing this test in diagnosis of brain disorders.
Date: June 1967
Creator: Latham, Larry L.
Partner: UNT Libraries


Description: This report covers studies of the excretion and retention of 'tracer' and toxic doses of the 11.2-day Ra{sup 223} isotope, its acute toxicity (organ weight changes, gross and microscopic pathology, and Fe{sup 59} utilization by the bone marrow), and long-term histopathological changes and alterations in the hemogram.
Date: February 21, 1958
Creator: Durbin, Patricia; Durbin, Patricia W.; Asling, C. Willet.; Jeung, Nylan; Williams, Marilyn H.; Post, James. et al.
Partner: UNT Libraries Government Documents Department

Effects of Reinforcer Magnitude on a Fixed Time Food Delivery Treatment of Pica

Description: The purpose of the current study was to examine the effects of using fixed time schedules with different magnitudes of stimulus delivery as treatment for pica. A functional assessment was conducted, which indicated that pica occurred across experimental conditions and was most frequent in the absence of social stimulation or contingencies. A competing stimulus assessment was then conducted to identify stimuli that could potentially compete with pica during NCR. Subsequently, an evaluation of the effects of reinforcer magnitude on NCR as a treatment of pica was conducted. Treatment results indicated that quantity of reinforcer increased the effectiveness of leaner schedules of reinforcer delivery; however, it was not possible to fade the temporal schedule to one that would have been useful in practice. In addition, limitations and future research are outlined.
Date: August 2010
Creator: Lyon, Nathan Scott
Partner: UNT Libraries

Prediction of Post Mortem Interval from Degradation of Endogenous Nucleotides in Human Subjects

Description: High Performance Liguid Chromatography was used to measure degradation of nucleotides in human cadavers for the purpose of prediction of post mortem interval. Endogenous nucleotides were extracted from integumentary tissue of six(6) human cadavers using six percent(6%) tricholoacetic acid. Linear regression statistical techniques were used to determine linearity of degradation of various nucleotide pools.
Date: April 1993
Creator: Williams, John Burgess
Partner: UNT Libraries

Bilingualism and Aphasia: Word Retrieval Skills in a Bilingual Anomic Aphasic

Description: This study attempted to investigate the effects of aphasia on word retrieval skills in a bilingual (Spanish-English) anomic patient. Two aspects of word finding difficulties were considered. First, an attempt was made to determine whether the patient exhibited the same degree of difficulty in both languages. Second, after the presentation of three different types of facilatory cues (initial syllable, sentence completion, translated word) the correct number of correct responses per cue were analyzed to determine whether or not the same kinds of cues were equally effective in English and in Spanish. Results indicated that word retrieval was affected to essentially the same degree in both languages, with performance in Spanish only slightly better than in English. Cue effectiveness also appeared to differ across languages.
Date: May 1984
Creator: Bond, Sandra
Partner: UNT Libraries

Complex biological and bio-inspired systems

Description: The understanding and characterization ofthe fundamental processes of the function of biological systems underpins many of the important challenges facing American society, from the pathology of infectious disease and the efficacy ofvaccines, to the development of materials that mimic biological functionality and deliver exceptional and novel structural and dynamic properties. These problems are fundamentally complex, involving many interacting components and poorly understood bio-chemical kinetics. We use the basic science of statistical physics, kinetic theory, cellular bio-chemistry, soft-matter physics, and information science to develop cell level models and explore the use ofbiomimetic materials. This project seeks to determine how cell level processes, such as response to mechanical stresses, chemical constituents and related gradients, and other cell signaling mechanisms, integrate and combine to create a functioning organism. The research focuses on the basic physical processes that take place at different levels ofthe biological organism: the basic role of molecular and chemical interactions are investigated, the dynamics of the DNA-molecule and its phylogenetic role are examined and the regulatory networks of complex biochemical processes are modeled. These efforts may lead to early warning algorithms ofpathogen outbreaks, new bio-sensors to detect hazards from pathomic viruses to chemical contaminants. Other potential applications include the development of efficient bio-fuel alternative-energy processes and the exploration ofnovel materials for energy usages. Finally, we use the notion of 'coarse-graining,' which is a method for averaging over less important degrees of freedom to develop computational models to predict cell function and systems-level response to disease, chemical stress, or biological pathomic agents. This project supports Energy Security, Threat Reduction, and the missions of the DOE Office of Science through its efforts to accurately model biological systems at the molecular and cellular level. The project's impact encompasses applications to biofuels, to novel sensors and to materials with broad use for energy or ...
Date: January 1, 2009
Creator: Ecke, Robert E
Partner: UNT Libraries Government Documents Department

Deletion of ultraconserved elements yields viable mice

Description: Ultraconserved elements have been suggested to retainextended perfect sequence identity between the human, mouse, and ratgenomes due to essential functional properties. To investigate thenecessities of these elements in vivo, we removed four non-codingultraconserved elements (ranging in length from 222 to 731 base pairs)from the mouse genome. To maximize the likelihood of observing aphenotype, we chose to delete elements that function as enhancers in amouse transgenic assay and that are near genes that exhibit markedphenotypes both when completely inactivated in the mouse as well as whentheir expression is altered due to other genomic modifications.Remarkably, all four resulting lines of mice lacking these ultraconservedelements were viable and fertile, and failed to reveal any criticalabnormalities when assayed for a variety of phenotypes including growth,longevity, pathology and metabolism. In addition more targeted screens,informed by the abnormalities observed in mice where genes in proximityto the investigated elements had been altered, also failed to revealnotable abnormalities. These results, while not inclusive of all thepossible phenotypic impact of the deleted sequences, indicate thatextreme sequence constraint does not necessarily reflect crucialfunctions required for viability.
Date: July 15, 2007
Creator: Ahituv, Nadav; Zhu, Yiwen; Visel, Axel; Holt, Amy; Afzal, Veena; Pennacchio, Len A. et al.
Partner: UNT Libraries Government Documents Department

Psychopathology and Love

Description: This study considered the relationship between psychopathology and love. Agape love was defined as spontaneous and selfless love. The hypothesis tested was that people demonstrating psychopathology would make fewer positive responses to statements reflecting love than people free of psychopathology. The MMPI was utilized to measure the presence of psychopathology. The Atkinson A Scale (developed for this study) measured agape responses. Both these instruments were administered to 102 subjects in three groups: hospital patients, seminary students, and psychology students. Mean agape scores were subjected to a one-way analysis of variance, Significant difference among the group means was detected at the p <.05 level. A Scheffe test showed hospital patients' agape scores significantly lower than scores of seminary and psychology students. The initial hypothesis was confirmed,
Date: August 1979
Creator: Atkinson, Stephen E.
Partner: UNT Libraries

Chronic Dermal Toxicity of Epoxy Resins I. Skin Carcinogenic Potency and General Toxicity

Description: Epoxy resins are a diverse class of chemicals that differ in structure, physical properties, and, presumably, biological activity. The purpose of these experiments was to compare the chronic dermal toxicity and carcinogenicity of selected commercial epoxy resins and to determine the potential for positive synergistic carcinogenic interactions between different resins. This work is an extension and continuation of a Department of Energy sponsored program to evaluate epoxy resins for potential occupational health risks. The materials examined were chosen on the basis of their interest to the U.S. government. They are representative of the manufacturer's production at the time, and therefore the data are completely valid only for the specific production period. Results of the experimental exposures will be reported in two parts. This report describes the test materials, their chemical and physical characteristics and the experimental design. General (systemic) toxicity will be evaluated and the skin carcinogenicity of the materials compared. A subsequent report will provide morphological descriptions of skin and significant internal pathology induced by the various treatments.
Date: January 16, 2001
Creator: Holland, J. M.
Partner: UNT Libraries Government Documents Department

Chlorophyll fluorescence analysis and imaging in plant stress and disease

Description: Quantitative analysis of chlorophyll fluorescence transients and quenching has evolved rapidly in the last decade. Instrumentation capable of fluorescence detection in bright actinic light has been used in conjunction with gas exchange analysis to build an empirical foundation relating quenching parameters to photosynthetic electron transport, the state of the photoapparatus, and carbon fixation. We have developed several instruments that collect video images of chlorophyll fluorescence. Digitized versions of these images can be manipulated as numerical data arrays, supporting generation of quenching maps that represent the spatial distribution of photosynthetic activity in leaves. We have applied this technology to analysis of fluorescence quenching during application of stress hormones, herbicides, physical stresses including drought and sudden changes in humidity of the atmosphere surrounding leaves, and during stomatal oscillations in high CO{sub 2}. We describe a recently completed portable fluorescence imaging system utilizing LED illumination and a consumer-grade camcorder, that will be used in long-term, non-destructive field studies of plant virus infections.
Date: December 1, 1994
Creator: Daley, P. F.
Partner: UNT Libraries Government Documents Department

Stromal-epithelial interactions in aging and cancer: Senescent fibroblasts alter epithelial cell differentiation

Description: Cellular senescence suppresses cancer by arresting cells at risk for malignant tumorigenesis. However, senescent cells also secrete molecules that can stimulate premalignant cells to proliferate and form tumors, suggesting the senescence response is antagonistically pleiotropic. We show that premalignant mammary epithelial cells exposed to senescent human fibroblasts in mice irreversibly lose differentiated properties, become invasive and undergo full malignant transformation. Moreover, using cultured mouse or human fibroblasts and non-malignant breast epithelial cells, we show that senescent fibroblasts disrupt epithelial alveolar morphogenesis, functional differentiation, and branching morphogenesis. Further, we identify MMP-3 as the major factor responsible for the effects of senescent fibroblasts on branching morphogenesis. Our findings support the idea that senescent cells contribute to age-related pathology, including cancer, and describe a new property of senescent fibroblasts--the ability to alter epithelial differentiation--that might also explain the loss of tissue function and organization that is a hallmark of aging.
Date: July 14, 2004
Creator: Parrinello, Simona; Coppe, Jean-Philippe; Krtolica, Ana & Campisi, Judith
Partner: UNT Libraries Government Documents Department

Theoretical and experimental investigations of elastic scattering spectroscopy as a potential diagnostic for tissue pathologies

Description: The spectral distribution of the diffuse reflectance of five sizes of polystyrene microspheres has been measured with an elastic scatter spectrometer designed for optical biopsy of living tissue. The microsphere sizes are representative of the suspected scattering centers in living tissue. The experiment data are discussed and interpreted in the framework of Mie scattering theory and Monte-Carlo transport analysis. Present results support the assertion that Mie theory is necessary to describe the spectral features of elastic scatter spectroscopy in tissue.
Date: April 1, 1994
Creator: Boyer, J.; Mourant, J. R. & Bigio, I. J.
Partner: UNT Libraries Government Documents Department

Use of density equalizing map projections (DEMP) in the analysis of childhood cancer in four California counties

Description: In studying geographic disease distributions, one normally compares rates of arbitrarily defined geographic subareas (e.g. census tracts), thereby sacrificing the geographic detail of the original data. The sparser the data, the larger the subareas must be in order to calculate stable rates. This dilemma is avoided with the technique of Density Equalizing Map Projections (DEMP). Boundaries of geographic subregions are adjusted to equalize population density over the entire study area. Case locations plotted on the transformed map should have a uniform distribution if the underlying disease-rates are constant. On the transformed map, the statistical analysis of the observed distribution is greatly simplified. Even for sparse distributions, the statistical significance of a supposed disease cluster can be reliably calculated. The present report describes the first successful application of the DEMP technique to a sizeable ``real-world`` data set of epidemiologic interest. An improved DEMP algorithm [GUSE93, CLOS94] was applied to a data set previously analyzed with conventional techniques [SATA90, REYN91]. The results from the DEMP analysis and a conventional analysis are compared.
Date: January 1, 1995
Creator: Merrill, D. W.; Selvin, S.; Close, E. R. & Holmes, H. H.
Partner: UNT Libraries Government Documents Department

Bence Jones proteins: Powerful tool for fundamental study of protein chemistry and pathophysiology

Description: Bence Jones proteins are typically found in patients with monoclonal plasma cell or related B-cell immunoproliferative disorders. Because of their monoclonal origin and resulting chemical homogeneity much of the fundamental information on immunoglobulin structure came initially from their analysis. Amino acid analyses of these components revealed an N-terminal variable (V) and C-terminal constant (C) domain as well as the existence within the V domain of hypervariable segments that account for the specificity and diversity of antibodies. Over the past three decades, the primary structures of hundreds of light chains (complete and partial), from human and other sources, have been determined, aligned, and archived. Bence Jones proteins and V{sub L} dimers were the crystallizable homogeneous proteins which provided much of the early three-dimensional conformational data that helped explain the structural basis of antibody function. Remarkably, a single Bence Jones protein in two solvent systems (low and high ionic strength) exhibited significant differences in the interactions of the two monomeric subunits comprising the dimer, resulting in substantial variation in the structure of the antigen combining site under the two solution conditions. This observation led to a prediction that heterogeneity of domain interactions may contribute to antibody-antigen interactions. Experimental support for this hypothesis has come from comparisons of the detailed structures of antibody-antigen complexes. The interactions at the interface of the V{sub L} dimer are a function of primary structure and solution conditions. Study of these interactions has led to new information on the relationship between protein structure and function and, as discussed below, can account for specific pathophysiological properties associated with Bence Jones proteins.
Date: December 31, 1991
Creator: Stevens, F. J.; Schiffer, M. & Solomon, A.
Partner: UNT Libraries Government Documents Department

PhyloChip microarray analysis reveals altered gastrointestinal microbial communities in a rat model of colonic hypersensitivity

Description: Irritable bowel syndrome (IBS) is a chronic, episodic gastrointestinal disorder that is prevalent in a significant fraction of western human populations; and changes in the microbiota of the large bowel have been implicated in the pathology of the disease. Using a novel comprehensive, high-density DNA microarray (PhyloChip) we performed a phylogenetic analysis of the microbial community of the large bowel in a rat model in which intracolonic acetic acid in neonates was used to induce long lasting colonic hypersensitivity and decreased stool water content and frequency, representing the equivalent of human constipation-predominant IBS. Our results revealed a significantly increased compositional difference in the microbial communities in rats with neonatal irritation as compared with controls. Even more striking was the dramatic change in the ratio of Firmicutes relative to Bacteroidetes, where neonatally irritated rats were enriched more with Bacteroidetes and also contained a different composition of species within this phylum. Our study also revealed differences at the level of bacterial families and species. The PhyloChip is a useful and convenient method to study enteric microflora. Further, this rat model system may be a useful experimental platform to study the causes and consequences of changes in microbial community composition associated with IBS.
Date: December 1, 2010
Creator: Nelson, T. A.; Holmes, S.; Alekseyenko, A. V.; Shenoy, M.; DeSantis, T.; Wu, C. H. et al.
Partner: UNT Libraries Government Documents Department

Agricultural pathogen decontamination technology-reducing the threat of infectious agent spread.

Description: Outbreaks of infectious agricultural diseases, whether natural occurring or introduced intentionally, could have catastrophic impacts on the U.S. economy. Examples of such agricultural pathogens include foot and mouth disease (FMD), avian influenza (AI), citrus canker, wheat and soy rust, etc. Current approaches to mitigate the spread of agricultural pathogens include quarantine, development of vaccines for animal diseases, and development of pathogen resistant crop strains in the case of plant diseases. None of these approaches is rapid, and none address the potential persistence of the pathogen in the environment, which could lead to further spread of the agent and damage after quarantine is lifted. Pathogen spread in agricultural environments commonly occurs via transfer on agricultural equipment (transportation trailers, tractors, trucks, combines, etc.), having components made from a broad range of materials (galvanized and painted steel, rubber tires, glass and Plexiglas shields, etc), and under conditions of heavy organic load (mud, soil, feces, litter, etc). A key element of stemming the spread of an outbreak is to ensure complete inactivation of the pathogens in the agricultural environment and on the equipment used in those environments. Through the combination of enhanced agricultural pathogen decontamination chemistry and a validated inactivation verification methodology, important technologies for incorporation as components of a robust response capability will be enabled. Because of the potentially devastating economic impact that could result from the spread of infectious agricultural diseases, the proposed capability components will promote critical infrastructure protection and greater border and food supply security. We investigated and developed agricultural pathogen decontamination technologies to reduce the threat of infectious-agent spread, and thus enhance agricultural biosecurity. Specifically, enhanced detergency versions of the patented Sandia decontamination chemistry were developed and tested against a few surrogate pathogens under conditions of relatively heavy organic load. Tests were conducted on surfaces commonly found in agricultural ...
Date: October 1, 2005
Creator: Betty, Rita G.; Bieker, Jill Marie & Tucker, Mark David
Partner: UNT Libraries Government Documents Department

Health effects of mineral dusts, Volume 28: Proceedings

Description: The processes that lead to the development of disease (or pathogenesis) by minerals very likely occur at or near the mineral-fluid interface. Thus the field of ``mineral-induced pathogenesis`` is a prime candidate for interdisciplinary research, involving mineral scientists, health scientists, petrologists, pathologists, geochemists, biochemists, and surface scientists, to name a few. This review volume and the short course upon which it was based are intended to provide some of the necessary tools for the researcher interested in this area of interdisciplinary research. The chapters present several of the important problems, concepts, and approaches from both the geological and biological ends of the spectrum. These two extremes are partially integrated throughout the book by cross-referencing between chapters. Chapter 1 also presents a general introduction into the ways in which these two areas overlap. The final chapter of this book discusses some of the regulatory aspects of minerals. A glossary is included at the end of this book, because the complexity of scientific terms in the two fields can thwart even the most enthusiastic of individuals. Individual reports have been processed separately for the database.
Date: December 31, 1993
Creator: Guthrie, G. D. Jr. & Mossman, B. T.
Partner: UNT Libraries Government Documents Department

A Comparison of Measures of Signal-To-Noise Ratio, Jitter, Shimmer, and Speaking Fundamental Frequency in Smoking and Nonsmoking Females

Description: Fifteen nonsmoking and fifteen smoking females 19 to 36 years of age were evaluated on measures of signal-to-noise ratio (SNR), jitter, shimmer, and speaking fundamental frequency (F0). The results indicated that: 1) there is a significant difference between female smokers and nonsmokers on measures of SNR, mean, and maximum F0 and, 2) there is no significant difference between female smokers and nonsmokers on measures of jitter, shimmer and minimum F0 . The SNR was found to be a powerful tool which is capable of distinguishing subtle vocal characteristics between the subject groups. It would appear that cigarette smoking may have an impact on the voice before distinct laryngeal pathologies are present.
Date: December 1991
Creator: Coy, Kelly (Kelly Bishop)
Partner: UNT Libraries

Development of a Discrete Spatial-Temporal SEIR Simulator for Modeling Infectious Diseases

Description: Multiple techniques have been developed to model the temporal evolution of infectious diseases. Some of these techniques have also been adapted to model the spatial evolution of the disease. This report examines the application of one such technique, the SEIR model, to the spatial and temporal evolution of disease. Applications of the SEIR model are reviewed briefly and an adaptation to the traditional SEIR model is presented. This adaptation allows for modeling the spatial evolution of the disease stages at the individual level. The transmission of the disease between individuals is modeled explicitly through the use of exposure likelihood functions rather than the global transmission rate applied to populations in the traditional implementation of the SEIR model. These adaptations allow for the consideration of spatially variable (heterogeneous) susceptibility and immunity within the population. The adaptations also allow for modeling both contagious and non-contagious diseases. The results of a number of numerical experiments to explore the effect of model parameters on the spread of an example disease are presented.
Date: November 1, 2000
Creator: McKenna, S.A.
Partner: UNT Libraries Government Documents Department