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open access

Stability of Myosin Subfragment-2 Modulates the Force Produced by Acto-Myosin Interaction of Striated Muscle

Description: Myosin subfragment-2 (S2) is a coiled coil linker between myosin subfragment-1 and light meromyosin (LMM). This dissertation examines whether the myosin S2 coiled coil could regulate the amount of myosin S1 heads available to bind actin thin filaments by modulating the stability of its coiled coil. A stable myosin S2 coiled coil would have less active myosin S1 heads compared to a more flexible myosin S2 coiled coil, thus causing increased force production through acto-myosin interaction. The … more
Date: December 2017
Creator: Singh, Rohit Rajendraprasad
Partner: UNT Libraries
open access

Genetic Interest Assessment

Description: Genetics is becoming increasingly integrated into peoples' lives. Different measures have been taken to try and better genetics education. This thesis examined undergraduate students at the University of North Texas not majoring in the life sciences interest in genetic concepts through the means of a Likert style survey. ANOVA analysis showed there was variation amongst the interest level in different genetic concepts. In addition age and lecture were also analyzed as contributing factors t… more
Date: May 2013
Creator: Doughney, Erin
Partner: UNT Libraries
open access

Fluorescence labeling and computational analysis of the strut of myosin's 50 kDa cleft.

Description: In order to understand the structural changes in myosin S1, fluorescence polarization and computational dynamics simulations were used. Dynamics simulations on the S1 motor domain indicated that significant flexibility was present throughout the molecular model. The constrained opening versus closing of the 50 kDa cleft appeared to induce opposite directions of movement in the lever arm. A sequence called the "strut" which traverses the 50 kDa cleft and may play an important role in positioning… more
Date: August 2007
Creator: Gawalapu, Ravi Kumar
Partner: UNT Libraries
open access

Genetic and Cellular Analysis of Anoxia-Induced Cell Cycle Arrest in Caenorhabditis elegans

Description: The soil-nematode Caenorhabditis elegans survives oxygen deprivation (anoxia < 0.001 kPa of O2, 0% O2) by entering into a state of suspended animation during which cell cycle progression at interphase, prophase and metaphase stage of mitosis is arrested. I conducted cell biological characterization of embryos exposed to various anoxia exposure times, to demonstrate the requirement and functional role of spindle checkpoint gene san-1 during brief anoxia exposure. I conducted a synthetic lethal s… more
Date: December 2008
Creator: Hajeri, Vinita A.
Partner: UNT Libraries
open access

Respiratory Responses in the Freshwater Snail (Pomacea Bridgesii) are Differently Affected by Temperature, Body Mass,and Oxygen Availability

Description: Pomacea bridgesii is a snail species native to tropical and sub-tropical regions, where it usually faces variability in water, temperature and oxygen level. This study of the effect of temperature on mass-specific oxygen consumption (ṀO2) and its relation to body weight shows that the ṀO2 of juvenile snails in normoxia (18-21 kPa) acclimated at temperature of 25°C ranged from 5 to 58 µMol O2/g/h, with a mean of 41.4 ± 18.3 µMol O2/g/h (n=7). Adult snails in normoxia at 25°C show less variat… more
Date: August 2016
Creator: Frifer, Wenasa Salem
Partner: UNT Libraries
open access

Key Factors Influencing Retention Rates among Historically Underrepresented Student Groups in STEM Fields

Description: The aim of the study was to identify the factors that have an influence on the completion rates of undergraduate students in the fields of science, technology, engineering and mathematics (STEM). Using Tinto's retention rate theory as the theoretical foundation, data were collected from freshman who were enrolled in the years 2005 to 2008. Results showed gender and first-generation status were significant predictors of STEM completion and time taken to complete the degree. Institutional bias pl… more
Date: December 2018
Creator: Premraj, Divya
Partner: UNT Libraries
open access

Neurological Responses to a Glucose Diet in Caenorhabditis elegans

Description: TRPV channels play a role in both mammalian insulin signaling, with TRPV1 expression in pancreatic beta-cells, and in C. elegans insulin-like signaling through expression of OSM-9, OCR-1, and OCR-2 in stress response pathways. In response to a glucose-supplemented diet, C. elegans are know to have sensitivity to anoxic stress, exhibit chemotaxis attraction, and display reduced egg-laying rate. Transcriptome analysis reveals that glucose stimulates nervous system activity with increased transcri… more
Date: August 2017
Creator: Dumesnil, Dennis
Partner: UNT Libraries
open access

Computational Investigation of DNA Repair Enzymes: Determination and Characterization of Cancer Biomarkers and Structural Features

Description: Genomic integrity is important for living cells' correct functioning and propagation. Deoxyribonucleic acid as a molecule is a subject to chemical reactions with agents that can come from environment as well as from internal metabolism processes. These reactions can induce damage to DNA and thus compromise the genetic information, and result in disease and death of an organism. To mitigate the damage to DNA, cells have evolved to have multiple DNA repair pathways. Presented here is a computat… more
Date: May 2018
Creator: Silvestrov, Pavel
Partner: UNT Libraries
open access

Studies on actomyosin crossbridge flexibility using a new single molecule assay.

Description: Several key flexure sites exist in the muscle crossbridge including the actomyosin binding site which play important roles in the actomyosin crossbridge cycle. To distinguish between these sources of flexibility, a new single molecule assay was developed to observe the swiveling of rod about a single myosin. Myosins attached through a single crossbridge displayed mostly similar torsional characteristics compared to myosins attached through two crossbridges, which indicates that most of the tors… more
Date: May 2004
Creator: Gundapaneni, Deepika
Partner: UNT Libraries

A morphological study of the avian (Gallus domesticus) ductus arteriosi during hatching.

Description: The ductus arteriosi (DA) are two blood vessels connecting the pulmonary arteries to the descending aorta in the avian embryo. Following hatching, the DA closes, separation of the systemic and pulmonary circulation. I present the morphological changes that occur in the chicken DA during prepipping, internal pipping, external pipping, and hatching. The avian DA consists of two distinct tissue types, a proximal and a distal portion. Histological examination shows developmental differences bet… more
Access: Restricted to UNT Community Members. Login required if off-campus.
Date: May 2006
Creator: Belanger, Candace
Partner: UNT Libraries

Evaluation of virulence in wild type and pyrimidine auxotrophs of Pseudomonas aeruginosa using the eukaryotic model system Caenorhabditis elegans.

Description: The human opportunistic pathogen, Pseudomonas aeruginosa PAO1, has been shown to kill the nematode Caenorhabditis elegans. C. elegans has been a valuable model for the study of bacterial pathogenesis, and has reinforced the notion that common virulence and host defense mechanisms exist. Recently, the pyrimidine pathway was shown to regulate virulence levels. Therefore, mutations in the pyrimidine pathway of PAO1 showed decrease virulence in the nematode. When starving the nematode, bacterial… more
Access: Restricted to the UNT Community Members at a UNT Libraries Location.
Date: August 2004
Creator: Anvari, Sara
Partner: UNT Libraries

Characterization of Infection Arrest Mutants of Medicago Truncatula and Genetic Mapping of Their Respective Genes.

Description: In response to compatible rhizobia, leguminous plants develop unique plant organs, root nodules, in which rhizobia fix nitrogen into ammonia. During nodule invasion, the rhizobia gain access to newly divided cells, the nodule primordia, in the root inner cortex through plant-derived cellulose tubes called infection threads. Infection threads begin in curled root hairs and bring rhizobia into the root crossing several cell layers in the process. Ultimately the rhizobia are deposited within nodul… more
Access: Restricted to the UNT Community Members at a UNT Libraries Location.
Date: May 2005
Creator: Veereshlingam, Harita
Partner: UNT Libraries
open access

Function of the ENOD8 gene in nodules of Medicago truncatula.

Description: To elaborate on the function(s) of the ENOD8 gene in the nodules of M. truncatula, several different experimental approaches were used. A census of the ENOD8 genes was first completed indicating that only ENOD8.1 (nt10554-12564 of GenBank AF463407) is highly expressed in nodule tissues. A maltose binding protein-ENOD8 fusion protein was made with an E. coli recombinant system. A variety of biochemical assays were undertaken with the MBP-ENOD8 recombinant protein expressed in E. coli, which did … more
Date: December 2006
Creator: Coque, Laurent
Partner: UNT Libraries
open access

FLP-mediated conditional loss of an essential gene to facilitate complementation assays

Description: Commonly, when it is desirable to replace an essential gene with an allelic series of mutated genes, or genes with altered expression patterns, the complementing constructs are introduced into heterozygous plants, followed by the selection of homozygous null segregants. To overcome this laborious and time-consuming step, the newly developed two-component system utilizes a site-specific recombinase to excise a wild-type copy of the gene of interest from transformed tissues. In the first componen… more
Date: December 2007
Creator: Ganesan, Savita
Partner: UNT Libraries

A Sensitive and Robust Machine Learning-Based Framework for Deciphering Antimicrobial Resistance

Description: Antibiotics have transformed modern medicine in manifold ways. However, the misuse and over-consumption of antibiotics or antimicrobials have led to the rise in antimicrobial resistance (AMR). Unfortunately, robust tools or techniques for the detection of potential loci responsible for AMR before it happens are lacking. The emergence of resistance even when a strain lacks known AMR genes has puzzled researchers for a long time. Clearly, there is a critical need for the development of novel app… more
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Date: August 2022
Creator: Sunuwar, Janak
Partner: UNT Libraries
open access

Morphological and physiological developmental consequences of parental effects in the chicken embryo (Gallus gallus domesticus) and the zebrafish larva (Danio rerio).

Description: Cardiac, metabolic and growth response of early-stage chicken embryos to perturbations in yolk environment was investigated. Also, effects of parental hypoxia exposure on hypoxia resistance, thermal tolerance and body length of zebrafish larvae were investigated. In the first study, thyroxine, triiodothyronine and testosterone produced differential effects on heart rate and development rate of chicken embryos during the first 4 days of development. Triiodothyronine caused a dose-dependent inc… more
Date: August 2008
Creator: Ho, Dao H.
Partner: UNT Libraries
open access

Molecular and Functional Characterization of Medicago Truncatula Npf17 Gene

Description: Legumes are unique among plants for their ability to fix atmospheric nitrogen with the help of soil bacteria rhizobia. Medicago truncatula is used as a model legume to study different aspects of symbiotic nitrogen fixation. M. truncatula, in association with its symbiotic partner Sinorhizobium meliloti, fix atmospheric nitrogen into ammonia, which the plant uses for amino acid biosynthesis and the bacteria get reduced photosynthate in return. M. truncatula NPF1.7 previously called MtNIP/LATD is… more
Date: December 2013
Creator: Salehin, Mohammad
Partner: UNT Libraries
open access

Detection and Classification of Cancer and Other Noncommunicable Diseases Using Neural Network Models

Description: Here, we show that training with multiple noncommunicable diseases (NCDs) is both feasible and beneficial to modeling this class of diseases. We first use data from the Cancer Genome Atlas (TCGA) to train a pan cancer model, and then characterize the information the model has learned about the cancers. In doing this we show that the model has learned concepts that are relevant to the task of cancer classification. We also test the model on datasets derived independently of the TCGA cohort and s… more
Date: July 2023
Creator: Gore, Steven Lee
Partner: UNT Libraries
open access

The Development of Potential Therapeutic Anti-Myosin S2 Peptides that Modulate Contraction and Append to the Heart Homing Adduct Tannic Acid without Noticeable Effect on Their Functions

Description: This dissertation aimed to explore the S2 region with an attempt to modulate its elasticity in order to tune the contraction output. Two peptides, the stabilizer and destabilizer, showed high potential in modifying the S2 region at the cellular level, thus they were prepared for animal model testing. In this research, (i) S2 elasticity was studied, and the stabilizer and destabilizer peptides were built to tune contraction output through modulating S2 flexibility; (ii) the peptides were attache… more
Date: May 2021
Creator: Qadan, Motamed
Partner: UNT Libraries
open access

Effect of the Resistance Exercise-Induced Hormonal Changes on Satellite Cell Myogenic State

Description: Skeletal muscle satellite cells are important for muscle repairing and muscle mass growth. For a successful muscle regenerative process, satellite cells have to sequentially undergoing different stages of myogenic process, i.e. proliferative state and differentiation state. To support this process, the presence of different circulating factors, such as immune cells, cytokines, and hormones, at the appropriate time course is critical. Among these factors, hormones, such as testosterone, cortisol… more
Date: May 2018
Creator: Luk, Hui Ying
Partner: UNT Libraries
open access

Genetic Mechanisms for Anoxia Survival in C. Elegans

Description: Oxygen deprivation can be pathological for many organisms, including humans. Consequently, there are several biologically and economically relevant negative impacts associated with oxygen deprivation. Developing an understanding of which genes can influence survival of oxygen deprivation will enable the formulation of more effective policies and practices. In this dissertation, genes that influence adult anoxia survival in the model metazoan system, C. elegans, are identified and characterized.… more
Date: August 2008
Creator: Mendenhall, Alexander R.
Partner: UNT Libraries
open access

Identifying genetic interactions of the spindle checkpoint in Caenorhabditis elegans.

Description: Faithful segregation of chromosomes is ensured by the spindle checkpoint. If a kinetochore does not correctly attach to a microtubule the spindle checkpoint stops cell cycle progression until all chromosomes are attached to microtubules or tension is experienced while pulling the chromosomes. The C. elegans gene, san-1, is required for spindle checkpoint function and anoxia survival. To further understand the role of san-1 in the spindle checkpoint, an RNAi screen was conducted to identify gen… more
Date: May 2009
Creator: Stewart, Neil
Partner: UNT Libraries
open access

Hypoxic and hyperoxic incubation affects the ductus arteriosus in the developing chicken embryo (Gallus gallus).

Description: Developing chicken embryos have two ductus arteriosus (DA) that shunt blood away from the lungs and to the chorioallantoic membrane, the embryonic gas exchanger. In mammals, DA closure is stimulated by an increase in blood gas O2 that occurs as the animal begins to breathe with its lungs. The goal of this study was to determine the influence of O2 levels during incubation on the vascular reactivity and morphology of the O2-sensitive DA and to examine the effects of changing O2 levels during l… more
Date: December 2009
Creator: Copeland, Jennifer
Partner: UNT Libraries
open access

In vitro Cultures of Morus alba for Enhancing Production of Phytoestrogens

Description: Plant estrogens have long been associated with health benefits. The potential of tissue culture techniques for the production of several secondary metabolites has been known for many years. Tissue cultures stimulate the production or induce the biosynthesis of novel compounds not found in the mature plant. Tissue culture of Morus alba, family Moraceae, is known to contain phytoestrogens, was established on plant-hormone supplemented Murashige and Skoog (MS) medium. Petiole and the stem tissue f… more
Date: December 2009
Creator: Bakshi, Vibhu
Partner: UNT Libraries
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