Matching Items (79)
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The goal of this project was to design and create a genetic construct that would allow for <br/>tumor growth to be induced in the center of the wing imaginal disc of Drosophila larvae, the <br/>R85E08 domain, using a heat shock. The resulting transgene would be combined with other <br/>transgenes in

The goal of this project was to design and create a genetic construct that would allow for <br/>tumor growth to be induced in the center of the wing imaginal disc of Drosophila larvae, the <br/>R85E08 domain, using a heat shock. The resulting transgene would be combined with other <br/>transgenes in a single fly that would allow for simultaneous expression of the oncogene and, in <br/>the surrounding cells, other genes of interest. This system would help establish Drosophila as a <br/>more versatile and reliable model organism for cancer research. Furthermore, pilot studies were <br/>performed, using elements of the final proposed system, to determine if tumor growth is possible <br/>in the center of the disc, which oncogene produces the best results, and if oncogene expression <br/>induced later in development causes tumor growth. Three different candidate genes were <br/>investigated: RasV12, PvrACT, and Avli.

ContributorsSt Peter, John Daniel (Author) / Harris, Rob (Thesis director) / Varsani, Arvind (Committee member) / School of Molecular Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Woody plant encroachment is a worldwide phenomenon linked to water availability in semiarid systems. Nevertheless, the implications of woody plant encroachment on the hydrologic cycle are poorly understood, especially at the catchment scale. This study takes place in a pair of small semiarid rangeland undergoing the encroachment of Prosopis velutina

Woody plant encroachment is a worldwide phenomenon linked to water availability in semiarid systems. Nevertheless, the implications of woody plant encroachment on the hydrologic cycle are poorly understood, especially at the catchment scale. This study takes place in a pair of small semiarid rangeland undergoing the encroachment of Prosopis velutina Woot., or velvet mesquite tree. The similarly-sized basins are in close proximity, leading to equivalent meteorological and soil conditions. One basin was treated for mesquite in 1974, while the other represents the encroachment process. A sensor network was installed to measure ecohydrological states and fluxes, including precipitation, runoff, soil moisture and evapotranspiration. Observations from June 1, 2011 through September 30, 2012 are presented to describe the seasonality and spatial variability of ecohydrological conditions during the North American Monsoon (NAM). Runoff observations are linked to historical changes in runoff production in each watershed. Observations indicate that the mesquite-treated basin generates more runoff pulses and greater runoff volume for small rainfall events, while the mesquite-encroached basin generates more runoff volume for large rainfall events. A distributed hydrologic model is applied to both basins to investigate the runoff threshold processes experienced during the NAM. Vegetation in the two basins is classified into grass, mesquite, or bare soil using high-resolution imagery. Model predictions are used to investigate the vegetation controls on soil moisture, evapotranspiration, and runoff generation. The distributed model shows that grass and mesquite sites retain the highest levels of soil moisture. The model also captures the runoff generation differences between the two watersheds that have been observed over the past decade. Generally, grass sites in the mesquite-treated basin have less plant interception and evapotranspiration, leading to higher soil moisture that supports greater runoff for small rainfall events. For large rainfall events, the mesquite-encroached basin produces greater runoff due to its higher fraction of bare soil. The results of this study show that a distributed hydrologic model can be used to explain runoff threshold processes linked to woody plant encroachment at the catchment-scale and provides useful interpretations for rangeland management in semiarid areas.
ContributorsPierini, Nicole A (Author) / Vivoni, Enrique R (Thesis advisor) / Wang, Zhi-Hua (Committee member) / Mays, Larry W. (Committee member) / Arizona State University (Publisher)
Created2013
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Salmonella enterica is a gastrointestinal (GI) pathogen that can cause systemic diseases. It invades the host through the GI tract and can induce powerful immune responses in addition to disease. Thus, it is considered as a promising candidate to use as oral live vaccine vectors. Scientists have been making great

Salmonella enterica is a gastrointestinal (GI) pathogen that can cause systemic diseases. It invades the host through the GI tract and can induce powerful immune responses in addition to disease. Thus, it is considered as a promising candidate to use as oral live vaccine vectors. Scientists have been making great efforts to get a properly attenuated Salmonella vaccine strain for a long time, but could not achieve a balance between attenuation and immunogenicity. So the regulated delayed attenuation/lysis Salmonella vaccine vectors were proposed as a design to seek this balance. The research work is progressing steadily, but more improvements need to be made. As one of the possible improvements, the cyclic adenosine monophosphate (cAMP) -independent cAMP receptor protein (Crp*) is expected to protect the Crp-dependent crucial regulator, araC PBAD, in these vaccine designs from interference by glucose, which decreases synthesis of cAMP, and enhance the colonizing ability by and immunogenicity of the vaccine strains. In this study, the cAMP-independent crp gene mutation, crp-70, with or without araC PBAD promoter cassette, was introduced into existing Salmonella vaccine strains. Then the plasmid stability, growth rate, resistance to catabolite repression, colonizing ability, immunogenicity and protection to challenge of these new strains were compared with wild-type crp or araC PBAD crp strains using western blots, enzyme-linked immunosorbent assays (ELISA) and animal studies, so as to evaluate the effects of the crp-70 mutation on the vaccine strains. The performances of the crp-70 strains in some aspects were closed to or even exceeded the crp+ strains, but generally they did not exhibit the expected advantages compared to their wild-type parents. Crp-70 rescued the expression of araC PBAD fur from catabolite repression. The strain harboring araC PBAD crp-70 was severely affected by its slow growth, and its colonizing ability and immunogenicity was much weaker than the other strains. The Pcrp crp-70 strain showed relatively good ability in colonization and immune stimulation. Both the araC PBAD crp-70 and the Pcrp crp-70 strains could provide certain levels of protection against the challenge with virulent pneumococci, which were a little lower than for the crp+ strains.
ContributorsShao, Shihuan (Author) / Curtiss, Roy (Thesis advisor) / Arizona State University (Publisher)
Created2012
DescriptionA novel and unconventional approach for delivering a eukaryotic apoptosis factor, TNF-related apoptosis-inducing ligand (TRAIL), to cancer cells within and around necrotizing tumors by utilizing a S. Typhimurium purine requiring auxotroph as a biological vector to develop two anticancer therapies with multiple modality and broad economic feasibility.
ContributorsKoons, Andrew (Author) / Curtiss, Roy (Thesis director) / Lake, Douglas (Committee member) / Janthakahalli, Nagaraj Vinay (Committee member) / Barrett, The Honors College (Contributor)
Created2013-12
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Engineered pavements cover a large fraction of cities and offer significant potential for urban heat island mitigation. Though rapidly increasing research efforts have been devoted to the study of pavement materials, thermal interactions between buildings and the ambient environment are mostly neglected. In this study, numerical models featuring a realistic

Engineered pavements cover a large fraction of cities and offer significant potential for urban heat island mitigation. Though rapidly increasing research efforts have been devoted to the study of pavement materials, thermal interactions between buildings and the ambient environment are mostly neglected. In this study, numerical models featuring a realistic representation of building-environment thermal interactions, were applied to quantify the effect of pavements on the urban thermal environment at multiple scales. It was found that performance of pavements inside the canyon was largely determined by the canyon geometry. In a high-density residential area, modifying pavements had insignificant effect on the wall temperature and building energy consumption. At a regional scale, various pavement types were also found to have a limited cooling effect on land surface temperature and 2-m air temperature for metropolitan Phoenix. In the context of global climate change, the effect of pavement was evaluated in terms of the equivalent CO2 emission. Equivalent CO2 emission offset by reflective pavements in urban canyons was only about 13.9e46.6% of that without building canopies, depending on the canyon geometry. This study revealed the importance of building-environment thermal interactions in determining thermal conditions inside the urban canopy.

ContributorsYang, Jiachuan (Author) / Wang, Zhi-Hua (Author) / Kaloush, Kamil (Author) / Dylla, Heather (Author)
Created2016-08-22
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Members of the Delphinidae family are widely distributed across the world’s oceans. We used a viral metagenomic approach to identify viruses in orca (Orcinus orca) and short-finned pilot whale (Globicephala macrorhynchus) muscle, kidney, and liver samples from deceased animals. From orca tissue samples (muscle, kidney, and liver), we identified a

Members of the Delphinidae family are widely distributed across the world’s oceans. We used a viral metagenomic approach to identify viruses in orca (Orcinus orca) and short-finned pilot whale (Globicephala macrorhynchus) muscle, kidney, and liver samples from deceased animals. From orca tissue samples (muscle, kidney, and liver), we identified a novel polyomavirus (Polyomaviridae), three cressdnaviruses, and two genomoviruses (Genomoviridae). In the short-finned pilot whale we were able to identify one genomovirus in a kidney sample. The presence of unclassified cressdnavirus within two samples (muscle and kidney) of the same animal supports the possibility these viruses might be widespread within the animal. The orca polyomavirus identified here is the first of its species and is not closely related to the only other dolphin polyomavirus previously discovered. The identification and verification of these viruses expands the current knowledge of viruses that are associated with the Delphinidae family.

ContributorsSmith, Kendal Ryan (Author) / Varsani, Arvind (Thesis director) / Kraberger, Simona (Committee member) / Dolby, Greer (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Phage therapy has been around for more than a century, but has regained interest in the field of medicine and holds significant potential to act as a treatment against a deadly bacterial infection in various cactus species. It was discovered that bacteriophages isolated from soil samples of potato plants were

Phage therapy has been around for more than a century, but has regained interest in the field of medicine and holds significant potential to act as a treatment against a deadly bacterial infection in various cactus species. It was discovered that bacteriophages isolated from soil samples of potato plants were able to suppress Pectobacterium carotovorum, ‘Pectobacterium’ being within the family Pectobacteriaceae which contains the ‘Erwinia’ genus that causes soft rot diseases in various plants (Jones, 2012). The two scientists had co-inoculated “... the phage with the phytobacterium” (Jones, 2012) in order to suppress the growth and prevent the infection from occurring.
ContributorsFry, Danielle Elizabeth (Author) / Geiler-Samerotte, Kerry (Thesis director) / Pfeifer, Susanne (Committee member) / Varsani, Arvind (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
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Following the journey through the sewerage system, wastewater is subject to a series of purification procedures, prior to water reuse and disposal of the resultant sewage sludge. Biosolids, also known as treated sewage sludge, deemed fit for application on land, is a nutrient-rich, semisolid byproduct of biological wastewater treatment.

Following the journey through the sewerage system, wastewater is subject to a series of purification procedures, prior to water reuse and disposal of the resultant sewage sludge. Biosolids, also known as treated sewage sludge, deemed fit for application on land, is a nutrient-rich, semisolid byproduct of biological wastewater treatment. Technological progression in metagenomics has allowed for large-scale analysis of complex viral communities in a number of samples, including wastewater. Members of the Microviridae family are non-enveloped, ssDNA bacteriophages, and are known to infect enterobacteria. Members of the Genomoviridae family similarly are non-enveloped, ssDNA viruses, but are presumed to infect fungi rather than eubacteria. As these two families of viruses are not relatively documented and their diversity poorly classified, this study aimed to analyze the presence of genomoviruses and the diversity of microviruses in nine samples representative of wastewater in Arizona and other regions of the United States. Using a metagenomic approach, the nucleic acids of genomoviruses and microviruses were isolated, assembled into complete genomes, and characterized through visual analysis: a heat chart showing percent coverage for genomoviruses and a circular phylogenetic tree showing diversity of microviruses. The heat map results for the genomoviruses showed a large presence of 99 novel sequences in all nine wastewater samples. Additionally, the 535 novel microviruses displayed great diversity in the cladogram, both in terms of sub-family and isolation source. Further research should be conducted in order to classify the taxonomy of microviruses and the diversity of genomoviruses. Finally, this study suggests future exploration of the viral host, prior to entering the wastewater system.
ContributorsSchreck, Joshua Reuben (Author) / Varsani, Arvind (Thesis director) / Rolf, Halden (Committee member) / Misra, Rajeev (Committee member) / School of Film, Dance and Theatre (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
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Yellow-bellied marmots (Marmota flavivent) are semi-fossorial ground-dwelling sciurid rodents native to the western United States. They are facultatively social and live in colonies that may contain over 50 individuals. Marmot populations are well studied in terms of their diet, life cycle, distribution, and behavior, however, knowledge about viruses associated with

Yellow-bellied marmots (Marmota flavivent) are semi-fossorial ground-dwelling sciurid rodents native to the western United States. They are facultatively social and live in colonies that may contain over 50 individuals. Marmot populations are well studied in terms of their diet, life cycle, distribution, and behavior, however, knowledge about viruses associated with marmots is very limited. In this study we aim to identify DNA viruses by non-invasive sampling of their feces. Viral DNA was extracted from fecal material of 35 individual marmots collected in Colorado and subsequently submitted to rolling circle amplification for circular molecule enrichment. Using a viral metagenomics approach which included high-throughput sequencing and verification of viral genomes using PCR, cloning and sequencing, a diverse group of single-stranded (ss) DNA viruses were identified. Diverse ssDNA viruses were identified that belong to two established families, Genomoviridae (n=7) and Anelloviridae (n=1) and several others that belong to unclassified circular replication associated encoding single-stranded (CRESS) DNA virus groups (n=19). There were also circular DNA molecules extracted (n=4) that appear to encode one viral-like gene and are composed of <1545 nt. The viruses that belonged to the family Genomoviridae clustered with those in the Gemycircularvirus genus. The genomoviruses were extracted from 6 samples. These clustered with gemycircularvirus extracted from arachnids and feces. The anellovirus, extracted from one sample, identified here has a genome sequence that is most similar to those from other rodent species, lagomorphs, and mosquitos. The CRESS viruses identified here were extracted from 9 samples and are novel and cluster with others identified from avian species. This study gives a snapshot of viruses associated with marmots based on fecal sampling.
ContributorsKhalifeh, Anthony (Author) / Varsani, Arvind (Thesis director) / Kraberger, Simona (Committee member) / Dolby, Greer (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
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To date, there have been few, if any, studies evaluating the venom toxin levels in dogs that have been naturally envenomated by pit vipers. Understanding venom toxin pharmacokinetics in a clinical setting is important for a variety of reasons, including the potential to better elucidate treatment options, prognosis, and other

To date, there have been few, if any, studies evaluating the venom toxin levels in dogs that have been naturally envenomated by pit vipers. Understanding venom toxin pharmacokinetics in a clinical setting is important for a variety of reasons, including the potential to better elucidate treatment options, prognosis, and other factors associated with pit viper envenomation. In addition, dogs serve as a comparative species to humans for evaluating pit viper envenomations. This pilot study’s primary objective was to address the question of “What do we see?” in dogs presenting for rattlesnake envenomation. To answer this question, we obtained serum from envenomated dogs presenting at three veterinary clinics, then used enzyme-linked immunosorbent assay (ELISA) and western blot analysis to measure total venom and key toxins in sera. Phospholipase A2, a primary venom toxin, was identified in a few samples by the western blot, and contributed to the positive correlation between percent echinocytes in the blood and venom concentration. Medical data records were compared to venom concentrations measured using ELISA to determine whether there were any significant correlations. First, the hematological results were compared. Clotting times showed a strong positive correlation, clotting times and platelets showed a negative correlation, while echinocytes and platelets showed no correlation. When compared to venom concentration, clotting times showed a negative correlation, while age showed a positive correlation. Weight and platelets were also compared to venom concentration, but no significant correlations were found. The logistics of this study provided a real-world model where time elapsed between envenomation and hospital admission, thus giving a realistic look at what occurs in both animal and human medicine.
ContributorsNelson, Alexis (Co-author, Co-author) / DeNardo, Dale (Thesis director) / Woods, Craig (Thesis director) / Varsani, Arvind (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05