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Breeding Ecology and Migratory Connectivity of Passerines in the World's Southernmost Forests

Description: In the extensive and remote sub-Antarctic forests of South America, birds are the dominant terrestrial vertebrates. Despite considerable efforts to understand the ecology of birds breeding in these forests, our current knowledge for many species is still incomplete. During three breeding seasons (2014 – 2017), I studied the breeding ecology of the five most abundant open-cup forest-dwelling passerines in the sub-Antarctic forest of Navarino Island, Chile (55°04′S, 67°40′W). There were differenc… more
Date: May 2021
Creator: Jara Millar, Rocio Fernanda
Item Type: Refine your search to only Thesis or Dissertation
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Capillary Permeability to Narrow-Range Macromolecular Dextrans at Normal and Hypobaric Pressures

Description: In view of its varied concepts and interpretations, and because of the discrepancies produced by the previous utilization of polydispersed dextrans, a study using extremely narrow-range molecular weight dextran fractions was initiated to reevaluate and consolidate some of the aspects of capillary permeability. A portion of the study was performed under decreased barometric pressure in order to clarify further some of the mechanisms involved in particulate transfer across the capillary endotheli… more
Date: December 1972
Creator: Norris, John Anthony
Item Type: Refine your search to only Thesis or Dissertation
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Carbon Flux in Reservoir Sediments

Description: The central objective of the study was to fractionate sedimenting organic materials according to their source (allochthonous or autochthonous) and ultimately to determine the degree of biodegradability of contributions from either source with particular reference to activities at the mud-water interface.
Date: May 1973
Creator: Newton, Charles Eugene
Item Type: Refine your search to only Thesis or Dissertation
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Cardio-Respiratory Ontogeny and the Transition to Bimodal Respiration in an Air Breathing Fish: Morphological and Physiological Development in Normoxia and Hypoxia.

Description: As selection pressures exist for not only adults, but for every life history stage, it is important to understand how environmental factors shape developing animals. Despite the significance placed on aquatic hypoxia as a driving force in the evolution of air breathing, this is the first known study to examine the effects of hypoxia on cardio-respiratory ontogeny of an air breathing fish. Blue gouramis are obligatory air breathing fish that possess a labyrinth-like structure that serves as th… more
Date: August 2009
Creator: Blank, Tara M.
Item Type: Refine your search to only Thesis or Dissertation
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Cardiovascular Fetal Programming in Quail (Colinus virginianus), An Avian Comparative Model

Description: The consequences of early embryonic insults and how they affect subsequent life reflects the emerging concept of "fetal programming". The aim of this project is to study the effects of embryonic insults as they subsequently manifest themselves in adults, with emphasis on the heart and vasculature. My experiments establish that fetal programming operates on the bobwhite quail inducing similar changes as those observed in mammalians and other birds. The quail's fast development provides reliable … more
Date: December 2016
Creator: Flores Santin, Josele R.
Item Type: Refine your search to only Thesis or Dissertation
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Cellular Biomarkers for Measuring Toxicity of Xenobiotics: Effects of PCBs on Earthworm Lumbricus Terrestris Coelomocytes

Description: The research presented herein provides information on coelomocyte (leukocyte) collection, function and immunotoxicity from polychlorinated biphenyls (PCB) in the earthworm Lumbricus terrestris. Research was undertaken as part of an overall goal to develop a well-documented and scientifically valid non-mammalian surrogate immunoassay with the earthworm Lumbricus terrestris to assess immunotoxic potential of xenobiotics. The principal objectives were to: (1) Develop an extrusion model for analyzi… more
Date: May 1991
Creator: Eyambe, George Sona
Item Type: Refine your search to only Thesis or Dissertation

Ceramide Biosynthesis and NEET Proteins Impact Development, Function, and Maintenance of the Caenorhabditis elegans Germline

Description: I used the C. elegans genetic model to examine the role of ceramide biosynthesis (sphingolipid pathway) and iron regulation and found that each process impacts germline development and function. Using a sphingolipid specific antibody mAb15B4, I found that sphingolipids are associated with germ granules (P granules) within C. elegans and zebrafish; thus, suggesting conservation of macromolecules associated with germ granules. Phenotype analysis of ceramide biosynthesis mutants in C. elegans reve… more
Access: Restricted to UNT Community Members. Login required if off-campus.
Date: August 2019
Creator: King, Skylar Dawn
Item Type: Refine your search to only Thesis or Dissertation
open access

Changes in Heterozygosity Through Time in American Standardbred and American Saddlebred Horses (1960-1990)

Description: Observed and expected heterozygosity (H) levels for ten electrophoretic blood marker loci and expected H for seven red blood cell (RBC) anitgen/antibody loci were examined for 20 years in American Standardbred and 30 years in American Saddlebred horses. Standardbreds were classed by gait, Trotter and Pacer, and evaluated separately in most analyses. 4,404 Trotters and 12,271 Pacers were found to have statistically highly significant losses of mean total observed H through time for the ten elect… more
Date: May 1992
Creator: King, Judith A. (Judith Ann), 1955-
Item Type: Refine your search to only Thesis or Dissertation
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Characteristics of Primary Cilia and Centrosomes in Neuronal and Glial Lineages of the Adult Brain

Description: Primary cilia are sensory organelles that are important for initiating cell division in the brain, especially through sonic hedgehog (Shh) signaling. Several lines of evidence suggest that the mitogenic effect of Shh requires primary cilia. Proliferation initiated by Shh signaling plays key roles in brain development, in neurogenesis in the adult hippocampus, and in the generation of glial cells in response to cortical injury. In spite of the likely involvement of cilia in these events, little … more
Date: May 2015
Creator: Bhattarai, Samip Ram
Item Type: Refine your search to only Thesis or Dissertation
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Characterization of Arthrobacter Globiformis Aspartate Transcarbamylase Concentrations of Substrates

Description: This thesis consists of one major section with two subsections. The first subsection investigates the activity of Arthrobacter globiformis aspartate transcarbamylase's specific activity with increasing concentrations of the enzyme's substrate. Dihydroorotase (DHOase) activity was also measured with increasing concentrations of the substrate dihydroorotate. The second subsection collected data in order to classify the enzyme, resulting in a classification into the category of class A ATCases … more
Date: December 2012
Creator: Wright, Jackie
Item Type: Refine your search to only Thesis or Dissertation
open access

Characterization of Aspartate Transcarbamoylase in the Archaebacterium Methanococcus Jannaschii

Description: Asparate transcarbamoylase catalyzes the first committed step in the de novo synthesis of pyrmidine nucleotides UMP, UDP, UTP, and CTP. The archetype enzyme found in Escherichia coli (310 kDa) exhibits sigmodial substrate binding kinetics with positive control by ATP and negative control with CTP and UTP. The ATCase characterized in this study is from the extreme thermophilic Archaebacterium, Methanococcus jannaschii. The enzyme was very stable at elevated temperatures and possessed activity fr… more
Date: December 1996
Creator: Stewart, John E. B. (John Edward Bakos)
Item Type: Refine your search to only Thesis or Dissertation
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Characterization of the OCT Plasmid-Encoded Mercury Resistance Genetic Locus in Pseudomonas putida

Description: A 17.1 Kb genetic element encoding for mercury resistance (OCT-Hg^r) was shown to translocate from its original location on the OCT plasmid to the resistance plasmid, RPl, in Pseudomonas putida. Analysis of RPl-Hg^r recombinant plasmids revealed that insertion of mercury resistance genes into RPl could occur at a variety of sites, with all recombinants having common EcoRI restriction fragments of 9.4, 3.8, 2.3, and 1.6 Kb, derived from the insertion. Hybridization analysis suggested the existen… more
Date: May 1989
Creator: Armbruster, Steven C. (Steven Christopher)
Item Type: Refine your search to only Thesis or Dissertation
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Characterizing Spontaneous Neurophysiological Activity with Measures of Statistical Serial Dependence: a Summary Statistic and an Extension of the Joint Interval Histogram

Description: Two measures which indicate statistical serial dependence were evaluated. The n-dimensional Average Stored Information index (ndASI) is a measure of conditional information, which compares the entropies of higher order conditional distributions to estimate average statistical serial dependence. The generalized ranked joint interval histogram (RJIH-o) is a new nonparametric graphical analysis method. It extends the joint interval histogram by depicting longer interval sequences and can be interp… more
Date: August 1994
Creator: Weil, Jon C. (Jon Christopher)
Item Type: Refine your search to only Thesis or Dissertation
open access

Characterizing the Molecular Changes of Austrofundulus limnaeus As It Develops Towards and Enters Diapause II

Description: Austrofundulus limnaeus is a species of annual killifish which inhabits ephemeral ponds in South America. The species is able to survive seasonally desiccating ponds due to their ability to produce robust embryos. The embryos of this species are capable of entering a developmental arrest, termed diapause II, which precedes the onset of drought. While in this arrested state embryos exhibit the greatest tolerance to anoxia of any characterized vertebrate at 25ºC. Furthermore, when raised at 30ºC,… more
Date: December 2015
Creator: Toni, Lee S.
Item Type: Refine your search to only Thesis or Dissertation
open access

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

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.
Date: 1947
Creator: Conyers, Loyd, W.
Item Type: Refine your search to only Thesis or Dissertation
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Chemical Composition of the Peptidoglycan of Vitreoscilla Stercoraria

Description: The peptidoglycan layer of Vitreoscilla stercoraria, ATCC 15218, was isolated from intact cells after treatment with sodium lauryl sulfate (SLS) and digestion with Pronase. Amino acid and amino sugar content was analyzed and 67% of the total present was made up of glutamic acid, alanine, diaminopimelic acid (DAP), and glucosamine in a molar ratio of 1:1.7:1:0.7. Electron microscopy of the final peptidoglycan product showed a thin, delicately folded sacculus which exhibited a morphology differen… more
Date: August 1976
Creator: Levit, Gary
Item Type: Refine your search to only Thesis or Dissertation

Chemotactic Response of Lumbricus terrestris Coelomocytes to Larval and Adult Stages of Rhabditis pellio

Description: Experiments were performed to assess the suitability of Rhabditis pellio, a nematode found in earthworms, as a challenge organism for use in development of a biomarker assay to determine the potential of chemicals to suppress the immunocompetence of the non-specific immune system. To accomplish this goal, information on the life cycle of R. pellio was determined; including effects of incubation time and temperature on growth rates; along with information on the immune response elicited in the e… more
Access: Restricted to the UNT Community Members at a UNT Libraries Location.
Date: December 1999
Creator: Medrano, Jennifer Centurion
Item Type: Refine your search to only Thesis or Dissertation
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