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National Atlas of the United States

Description: This is the website for the National Atlas, which provides a comprehensive, maplike view into the enormous wealth of geospatial and geostatistical data collected for the United States. It includes many detailed, interactive maps of the nation on a wide variety of subjects such as the environment, history, government, population, and climate, as well as fully documented digital cartographic datasets and articles. The website was removed from service on September 30, 2014.
Date: September 22, 2014
Creator: United States. Department of the Interior. Geological Survey
Partner: UNT Libraries Digital Projects Unit

A Correlation of the Vegetation with the Soil Types of Haskell County, Texas

Description: The problem has consisted, first, of a mapping of the soil types present in Haskell County; second, a collection of the existing vegetation of each soil type; third, an identification of the vegetation collected and observed; fourth, and lastly, a comparative study of the vegetation of each soil type in an effort to establish a correlation between the vegetation and the soil type.
Date: 1950
Creator: Tyson, Josiah William, Jr.
Partner: UNT Libraries

The Effect of the Use of Laser Video Disc on Achievement, Attitude, and Confidence of High School Biology Students

Description: The purpose of the study was to determine the effects of level III video disc instruction on high school biology students. There were three areas studied: students' achievement in biology, students' attitude toward biology, and confidence. The experimental group consisted of 70 biology students. The control group also consisted of 70 biology students. The teacher of the experimental group used level in video disc instruction to teach about invertebrates, vertebrates, human systems, and plants throughout the semester. The teachers of the control group taught the same topics during the same period using the traditional lecture method and without level III video disc instruction. Students took the Biology Achievement Test, the Purdue Master Attitude Scale, and the Confidence in Learning Inventory before and after the treatment period. A t-test on the pretest scores of the experimental group and the control group showed no significant difference between the two groups. The experimental group also took the Technology Preference Survey after the treatment period.
Date: August 1994
Creator: Garza, Federico (Federico Angel)
Partner: UNT Libraries

Effect of Three Different Types of High School Class Schedules (Traditional, Rotating Block, and Accelerated Block) on High School Biology Achievement and on Differences in Science Learning Environments

Description: This study analyzes the effect of three different high school scheduling options on the delivery of biology instruction, on student achievement, and on student perceptions of their instructional activities. Participants were biology students and teachers from twelve high schools in a north Texas urban school district of 76,000. Block classes had 11 to 18 percent less instructional time than traditional classes. Texas Biology I End-of-Course Examination achievement results for 3,195 students along with student and teacher surveys provided information on instructional activities, attitudes, and individualization. Using an analysis of variance at a j i< .01 the following results were found; student achievement was significantly different for each of the scheduled comparisons groups, test score means were not statistically significant between the scheduled comparison groups for different ethnic groups, economically disadvantaged students, and magnet students. No significant differences were found between the science learning activity index for each of the scheduled groups. Student response data when disaggregrated and reaggregrated into program groups found a statistically significant higher index of science activity at a p. < .01 for magnet students when compared to both the regular and honor students. Regular program students had a significantly higher index of individualization than honors program students. Accelerated and rotating block classes were found to hold a significantly more positive attitude about their science learning conditions than did the traditional students. These data suggest that during the first two years of block scheduling, the initial impact of block scheduling, where total time for science is reduced, results in lower student achievement scores when compared to traditionally scheduled classes. Yet, block scheduled student attitudes and perceptions about science learning are significantly more positive than the traditionally scheduled students.
Date: May 1997
Creator: Keller, Brenda J. (Brenda Jo), 1942-
Partner: UNT Libraries

Regulatory Divergence of Aspartate Transcarbamoylase from the Pseudomonads

Description: Aspartate transcarbamoylase (ATCase) was purified from 16 selected bacterial species including existing Pseudomonas species and former species reassigned to new genera. An enormous diversity was seen among the 16 enzymes with each class of ATCase being represented. The smallest class, class C, with a catalytically active homotrimer, at 100 kDa, was found in Bacillus and other Gram positive bacteria. In this report, the ATCases from the Gram negatives, Shewanella putrefaciens and Stenotrophomonas maltophilia were added to class C membership. The enteric bacteria typify class B ATCases at 310 kDa, with a dodecameric structure composed of two catalytic trimers coupled to three regulatory dimers. A key feature of class B ATCases is the dissociability of the holoenzyme into regulatory and catalytic subunits which were enzymatically active. In this report, the ATCase from Pseudomonas indigofera was added to class B ATCases. The largest class, at 480 kDa, class A, contains the fluorescent Pseudomonas including most members of the 16S rRNA homology group I. Two polypeptides are produced from overlapping pyrBC' genes. The former, pyrB, encodes a 34 kDa catalytic polypeptide while pyrC' encodes a 45 kDa dihydroorotase-like polypeptide. Two non active trimers are made from six 34 kDa chains which are cemented by six 45 kDa chains to form the active dodecameric structure. Dissociation of the holoenyzme into its separate active subunits has not been possible. In this report, the ATCases from Comamonas acidovorans and C. testosteroni, were added to the class A enzymes. An even larger class of ATCase than class A at 600 kDa was discovered in Burkholderia cepacia. Stoichiometric measurements predict a dodecamer of six 39 kDa polypeptides and six 60 kDa polypeptides. Unlike other large pseudomonads ATCases, the enzyme from B. cepacia was dissociable into smaller active forms. Both the holoenzyme and its dissociated forms were regulated by ...
Date: December 1996
Creator: Linscott, Andrea J. (Andrea Jane)
Partner: UNT Libraries

Degradation of Complex Carbon Compounds by Marine Actinomycetes

Description: The purpose of this paper is to present a comparative study of marine bacteria, molds and actinomycetes in regard to their ability to degrade certain pure and mixed complex compounds possibly occurring in the lagoon waste traps of the Texas Gulf Coast. This comparison was made using a differential oxygen uptake as the index of specific compound utilization.
Date: August 1959
Creator: Willingham, Charles Allen
Partner: UNT Libraries

Biological Indices of Stream Pollution

Description: A thorough biological survey and evaluation is a lengthy and expensive project. The number of technically trained persons required prevent its use by most public agencies. Since public health departments are the groups most frequently concerned with measuring the effects of pollution in streams, a need exists for a simplified method of sanitary survey. Recognizing this need, the Texas Health Department assigned the writer the problem of devising a method of survey which would require a field party of two and could be conducted entirely from a mobile field laboratory.
Date: August 1952
Creator: Russell, James C.
Partner: UNT Libraries

Assembly of Pseudomonas putida Aspartate Transcarbamoylase and Possible Roles of the PyrC' Polypeptide in the Folding of the Dodecameric Enzyme

Description: Aspartate transcarbamoylase (ATCase) of Pseudomonas putida consists of two different polypeptides, PyrB and PyrC' (Schurr et al, 1995). The role of the PyrC' and the assembly of PyrB and PyrC' have been studied. The ATCase made in vitro of P.putida PyrB with P.putida PyrC', and of E.coli PyrB with P.putida PyrC ' were generated under two different conditions, denaturation and renaturation, and untreated. It was found that PyrC' plays a role in the enzymatic regulation by ATP, CTP and UTP. In addition to playing a role in substrate binding, the PyrB polypeptide is also involved in effector binding (Kumar et al., manuscript in preparation). The most energetically preferred form of the P.putida WT is a dodecamer with a molecular mass of 480 kDa. The ratio between the PyrB and the PyrC' is 1:1. In studies of nucleotide binding, it was discovered that the P.putida PyrB was phosphorylated by a protein kinase in the cell extract. In the presence of 20 mM EDTA, this phosphorylation was inhibited and the inhibition could be overcome by the addition of divalent cations such as Zn2+ and Mg2+. This result suggested that the phosphorylation reaction required divalent cations. In the CAD complex of eukaryotes, phosphorylations of the CPSase and the linker region between ATCase and DHOase did not occur in the presence of UTP and it was hypothesized (Carrey, 1993) that UTP and phosphorylation(s) regulated the conformational change in the enzyme complex. Therefore, the same idea was approached with P.putida ATCase, where it was found that 1.0 mM UTP inhibited the phosphorylation of PyrB by more than 50%. These results suggested that the regulation of the conformational change of the P.putida ATCase might be similar to that of CAD. Furthermore, peptide mapping for phosphorylation sites was performed on P.putida ATCase WT, WT --11 amino acids ...
Date: May 1999
Creator: Hongsthong, Apiradee, 1970-
Partner: UNT Libraries

Morphological and Physiological Changes in Micrococcus Pyogenes Var. Aureus during Development of its Resistance to Terramycin

Description: The problem in this investigation consists of, first, the procurement of several strains of Micrococcus pyogenes var. aureus; second, the comparison of the degree and rate of development of resistance of these organisms to terramycin; and, third, to study the morphological and physiological changes which occur during the development of resistance.
Date: August 1959
Creator: Watson, Gerald T.
Partner: UNT Libraries

The evolution, applications, and statistical interpretations of DNA typing in forensic science

Description: This thesis examines the evolution, applications, and statistical interpretations of DNA typing as a tool in the field of forensic science as well as in our criminal justice system. The most controversial aspect of DNA typing involves the determination of how likely it is that two people share the same DNA profile. This involves the use of population genetics and databases of allelic frequencies as well as some assumptions about population structuring.
Date: August 1997
Creator: Schober, Cassandra C. (Cassandra Carolyn)
Partner: UNT Libraries

Morphological and immunological characterization of earthworm Lumbricus terrestris coelomocytes

Description: This research defines the morphological characteristics of the immune cells, coelomocytes, of the earthworm, Lumbricus terrestris. Such a definition of coelomocyte morphology can be correlated with immune function which will be of value in the development of a nonmammalian surrogate system to assess the immunotoxic potential of a terrestrial xenobiotics.
Date: August 1992
Creator: Hariri, Maryam Feili
Partner: UNT Libraries

Letters to the Editor

Description: Five letters written to the editor of the Journal of Near-Death Studies on the following topics: "Skepticism and Evidence of the Paranormal," "OBEs in the Blind and Encounters with the Light," "Concerning Anesthetically-Induced Frightening NDEs," "Risks of Psychomanteum Experimentation," and "Endorphins Cannot Explain All Aspects or NDEs."
Date: Winter 1998
Creator: Ellwood, Gracia Fay; Krishnan, V.; Atwater, P. M. H.; Brodsky, Beverly & Knittweis, Jim W.
Partner: UNT Libraries

Effects of 4-Chloroglutaranilic Acid on Growth and Development of Sunflower Seedlings

Description: The potential growth-regulating compound 4-chloroglutaranilic acid (CGA) was tested in whole-plant bioassay systems which utilized sunflower seedlings (Helianthus annuus, L.). Test systems included the growth of plants in soil , solid inert (Vermiculite) substrate, and hydroponic (Seed-Pak) pouches.
Date: August 1972
Creator: Larsen, Stephen P. (Stephen Page), 1933-
Partner: UNT Libraries

A Screening of Fungi for Metabolites Inhibitory to the Growth of Bloom-Forming Blue-Green Algae

Description: Since many approaches to dealing with algal blooms are inefficient, expensive, or harmful, it was concluded that a biologically-synthesized chemical agent, specifically inhibitory to pre-bloom algal cells, might prove helpful in controlling algal blooms. Fungi were chosen as the biological entities to investigate for such a chemical.
Date: December 1970
Creator: Hardcastle, Ronald V.
Partner: UNT Libraries

Considerations in Selecting, Developing, and Validating Laboratory Experience Units in General Biology for Prospective Elementary School Teachers

Description: The primary purpose of this study was to develop the considerations and techniques for the selection, development, and validation of laboratory experience units in general biology for prospective elementary school teachers. The completed laboratory experience unites developed in this study may serve as resources of activities for college instructors who teach general biology to undergraduate majors in elementary education. For purposes of this study the laboratory experience unites were centered about those principles of general biology which an elementary school teacher should understand in order to teach about plants and animals.
Date: August 1956
Creator: Syrocki, Boleslaus John, 1912-
Partner: UNT Libraries