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  Partner: UNT Libraries
 Department: Department of Biology
 Collection: UNT Theses and Dissertations
Changes in Gene Expression Levels of the Ecf Sigma Factor Bov1605 Under Ph Shift and Oxidative Stress in the Sheep Pathogen Brucella Ovis

Changes in Gene Expression Levels of the Ecf Sigma Factor Bov1605 Under Ph Shift and Oxidative Stress in the Sheep Pathogen Brucella Ovis

Date: December 2012
Creator: Kiehler, Brittany Elaine
Description: Brucella ovis is a sexually transmitted, facultatively anaerobic, intracellular bacterial pathogen of sheep (Ovis aries) and red deer (Cervus elaphus). Brucella spp. infect primarily by penetrating the mucosa and are phagocytized by host macrophages, where survival and replication occurs. At least in some species, it has been shown that entry into stationary phase is necessary for successful infection. Brucella, like other alphaproteobacteria, lack the canonical stationary phase sigma factor ?s. Research on diverse members of this large phylogenetic group indicate the widespread presence of a conserved four-gene set including an alternative ECF sigma factor, an anti-sigma factor, a response regulator (RR), and a histidine kinase (HK). The first description of the system was made in Methylobacterium extorquens where the RR, named PhyR, was found to regulate the sigma factor activity by sequestering the anti-sigma factor in a process termed "sigma factor mimicry." These systems have been associated with various types of extracellular stress responses in a number of environmental bacteria. I hypothesized that homologous genetic sequences (Bov_1604-1607), which are similarly found among all Brucella species, may regulate survival functions during pathogenesis. To further explore the involvement of this system to conditions analogous to those occurring during infection, pure cultures of ...
Contributing Partner: UNT Libraries
Changes which Occur in Components C'3 and C'4 in Guinea Pig Complement after Injection of an Antigen

Changes which Occur in Components C'3 and C'4 in Guinea Pig Complement after Injection of an Antigen

Date: 1957
Creator: Hilton, Donald Long
Description: This thesis describes an experiment involving guinea pigs' blood and the changes that occurred in the serum with the injection of an antigen. The serum was analyzed in complement titration tests.
Contributing Partner: UNT Libraries
Characterization of  Moraxella bovis Aspartate Transcarbamoylase

Characterization of Moraxella bovis Aspartate Transcarbamoylase

Access: Use of this item is restricted to the UNT Community.
Date: December 2001
Creator: Hooshdaran, Sahar
Description: Aspartate transcarbamoylase (ATCase) catalyzes the first committed step in the pyrimidine biosynthetic pathway. Bacterial ATCases have been divided into three classes, class A, B, and C, based on their molecular weight, holoenzyme architecture, and enzyme kinetics. Moraxella bovis is a fastidious organism, the etiologic agent of infectious bovine keratoconjunctivitis (IBK). The M. bovis ATCase was purified and characterized for the first time. It is a class A enzyme with a molecular mass of 480 to 520 kDa. It has a pH optimum of 9.5 and is stable at high temperatures. The ATCase holoenzyme is inhibited by CTP > ATP > UTP. The Km for aspartate is 1.8 mM and the Vmax 1.04 µmol per min, where the Km for carbamoylphosphate is 1.05 mM and the Vmax 1.74 µmol per min.
Contributing Partner: UNT Libraries
Characterization of the aspartate transcarbamoylase (ATC2) that is found in the pyrBC’ complex of  Bordetella pertussis

Characterization of the aspartate transcarbamoylase (ATC2) that is found in the pyrBC’ complex of Bordetella pertussis

Date: December 2001
Creator: Dill, Michael T
Description: An aspartate transcarbamoylase (ATCase) gene from Bordetella pertussis was amplified by PCR and ligated into pT-ADV for expression in Escherichia coli. This particular ATCase (pyrB) was an inactive gene found adjacent to an inactive dihydroorotase (DHOase) gene (pyrC'). This experiment was undertaken to determine whether this pyrB gene was capable of expression alone or if it was capable of expression only when cotransformed with a functional pyrC'. When transformed into E. coli TB2 pyrB-, the gene did not produce any ATCase activity. The gene was then co-transformed into E. coli TB2 pyrB- along with a plasmid containing the pyrC' gene from Pseudomonas aeruginosa and assayed for ATCase activity. Negative results were again recorded.
Contributing Partner: UNT Libraries
Chemical and Physiological Properties of an Antibiotic Produced by a Variant of the Penicillium Notatum-Chrysogenum Group

Chemical and Physiological Properties of an Antibiotic Produced by a Variant of the Penicillium Notatum-Chrysogenum Group

Date: 1947
Creator: Conyers, Loyd, W.
Description: The present study of the production and properties of an antibiotic was undertaken in the hope that some useful information could be contributed to a long-range investigation program being carried on at North Texas State Teachers College. This program is concerned with the production of a useful antibiotic from a variant of the Penicillium notatum-chysogenum group of molds.
Contributing Partner: UNT Libraries
The Chemical Compounds Produced by Actinomycetes and Their Relation to Tastes and Odors in a Water Supply

The Chemical Compounds Produced by Actinomycetes and Their Relation to Tastes and Odors in a Water Supply

Date: 1951
Creator: Dill, Warren S.
Description: The purpose of this problem was to determine the cause of tastes and odors in the Breckenridge water supply and to isolate and culture the organisms responsible for the offensive chemicals.
Contributing Partner: UNT Libraries
Chronic Acceleration and Osteogenesis

Chronic Acceleration and Osteogenesis

Date: August 1973
Creator: Borgens, Richard Ben
Description: The effect of excess gravity on bone-forming elements of the growing perichondrial shaft of embryonic chicks was investigated through the use of the transmission electron microscope and various cytochemical techniques.
Contributing Partner: UNT Libraries
Colonial Variations of a Mucoid Strain of Staphylococcus Aureus

Colonial Variations of a Mucoid Strain of Staphylococcus Aureus

Date: June 1963
Creator: Liston, Winston Bryan
Description: It was the purpose of the present investigation to demonstrate the selection of a variant of one strain of Staphylococcus aureus by altering certain environmental factors, and to study that variant as to biochemical activities and capsule formation.
Contributing Partner: UNT Libraries
A Comparative Study of Egg Media in the Primary Isolation of Mycobacterium Tuberculosis

A Comparative Study of Egg Media in the Primary Isolation of Mycobacterium Tuberculosis

Date: 1949
Creator: Barberousse, Loris J.
Description: The primary purpose of this investigation is not only to improve the present technique of culture of Mycobacterium tuberculosis, but also to make a comparative study of the media use, namely, Veterans Administration modification of Trudeau's medium, Lowenstein's egg medium, and that developed by the author, in order to find which, if any, of these will most easily and effectively meet the needs of the hospital laboratory.
Contributing Partner: UNT Libraries
A Comparative Study of Four Genealogies to Determine Predisposition to Cancer

A Comparative Study of Four Genealogies to Determine Predisposition to Cancer

Date: 1941
Creator: Andrew, Vivian Wilson
Description: This study was made in an effort first, to determine the mode of transmission of the inheritance of a predisposition to cancer as revealed through the analyses of four separate human genealogies, and second, to make a comparative study of the genealogies to determine whether the mode of transmission is the same.
Contributing Partner: UNT Libraries