Matching Items (129)
Description
ABSTRACT Water resources in many parts of the world are subject to increasing stress because of (a) the growth in demand caused by population increase and economic development, (b) threats to supply caused by climate and land cover change, and (c) a heightened awareness of the importance of maintaining water supplies to other parts of the ecosystem. An additional factor is the quality of water management. The United States-Mexican border provides an example of poor water management combined with increasing demand for water resources that are both scarce and uncertain. This dissertation focuses on the problem of water management in the border city of Ciudad Juarez, Chihuahua. The city has attracted foreign investment during the last few decades, largely due to relatively low environmental and labor costs, and to a range of tax incentives and concessions. This has led to economic and population growth, but also to higher demand for public services such as water which leads to congestion and scarcity. In particular, as water resources have become scarce, the cost of water supply has increased. The dissertation analyzes the conditions that allow for the efficient use of water resources at sustainable levels of economic activity--i.e., employment and investment. In particular, it analyzes the water management strategies that lead to an efficient and sustainable use of water when the source of water is either an aquifer, or there is conjunctive use of ground and imported water. The first part of the dissertation constructs a model of the interactive effects of water supply, wage rates, inward migration of labor and inward investment of capital. It shows how growing water scarcity affects population growth through the impact it has on real wage rates, and how this erodes the comparative advantage of Ciudad Juarez--low wages--to the point where foreign investment stops. This reveals the very close connection between water management and the level of economic activity in Ciudad Juarez. The second part of the dissertation examines the effect of sustainable and efficient water management strategies on population and economic activity levels under two different settings. In the first Ciudad Juarez relies exclusively on ground water to meet demand--this reflects the current situation of Ciudad Juarez. In the second Ciudad Juarez is able both to import water and to draw on aquifers to meet demand. This situation is motivated by the fact that Ciudad Juarez is considering importing water from elsewhere to maintain its economic growth and mitigate the overdraft of the Bolson del Hueco aquifer. Both models were calibrated on data for Ciudad Juarez, and then used to run experiments with respect to different environmental and economic conditions, and different water management options. It is shown that for a given set of technological, institutional and environmental conditions, the way water is managed in a desert environment determines the long run equilibrium levels of employment, investment and output. It is also shown that the efficiency of water management is consistent with the sustainability of water use and economic activity. Importing water could allow the economy to operate at higher levels of activity than where it relies solely on local aquifers. However, at some scale, water availability will limit the level of economic activity, and the disposable income of the residents of Ciudad Juarez.
ContributorsGarduno Angeles, Gustavo Leopoldo (Author) / Perrings, Charles (Thesis advisor) / Holway, Jim (Thesis advisor) / Aggarwal, Rimjhim (Committee member) / Arizona State University (Publisher)
Created2011
Description
Fluoroquinolone antibiotics have been known to cause severe, multisystem adverse side effects, termed fluoroquinolone toxicity (FQT). This toxicity syndrome can present with adverse effects that vary from individual to individual, including effects on the musculoskeletal and nervous systems, among others. The mechanism behind FQT in mammals is not known, although various possibilities have been investigated. Among the hypothesized FQT mechanisms, those that could potentially explain multisystem toxicity include off-target mammalian topoisomerase interactions, increased production of reactive oxygen species, oxidative stress, and oxidative damage, as well as metal chelating properties of FQs. This review presents relevant information on fluoroquinolone antibiotics and FQT and explores the mechanisms that have been proposed. A fluoroquinolone-induced increase in reactive oxygen species and subsequent oxidative stress and damage presents the strongest evidence to explain this multisystem toxicity syndrome. Understanding the mechanism of FQT in mammals is important to aid in the prevention and treatment of this condition.
ContributorsHall, Brooke Ashlyn (Author) / Redding, Kevin (Thesis director) / Wideman, Jeremy (Committee member) / Borges, Chad (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Cancer claims hundreds of thousands of lives every year in US alone. Finding ways for early detection of cancer onset is crucial for better management and treatment of cancer. Thus, biomarkers especially protein biomarkers, being the functional units which reflect dynamic physiological changes, need to be discovered. Though important, there are only a few approved protein cancer biomarkers till date. To accelerate this process, fast, comprehensive and affordable assays are required which can be applied to large population studies. For this, these assays should be able to comprehensively characterize and explore the molecular diversity of nominally "single" proteins across populations. This information is usually unavailable with commonly used immunoassays such as ELISA (enzyme linked immunosorbent assay) which either ignore protein microheterogeneity, or are confounded by it. To this end, mass spectrometric immuno assays (MSIA) for three different human plasma proteins have been developed. These proteins viz. IGF-1, hemopexin and tetranectin have been found in reported literature to show correlations with many diseases along with several carcinomas. Developed assays were used to extract entire proteins from plasma samples and subsequently analyzed on mass spectrometric platforms. Matrix assisted laser desorption ionization (MALDI) and electrospray ionization (ESI) mass spectrometric techniques where used due to their availability and suitability for the analysis. This resulted in visibility of different structural forms of these proteins showing their structural micro-heterogeneity which is invisible to commonly used immunoassays. These assays are fast, comprehensive and can be applied in large sample studies to analyze proteins for biomarker discovery.
ContributorsRai, Samita (Author) / Nelson, Randall (Thesis advisor) / Hayes, Mark (Thesis advisor) / Borges, Chad (Committee member) / Ros, Alexandra (Committee member) / Arizona State University (Publisher)
Created2012
Description
Environmental agencies often want to accomplish additional objectives beyond their central environmental protection objective. This is laudable; however it begets a need for understanding the additional challenges and trade-offs involved in doing so. The goal of this thesis is to examine the trade-offs involved in two such cases that have received considerable attention recently. The two cases I examine are (1) the protection of multiple environmental goods (e.g., bundles of ecosystem services); and (2) the use of payments for ecosystem services as a poverty reduction mechanism. In the first case (chapter 2), I build a model based on the fact that efforts to protect one environmental good often increase or decrease the levels of other environmental goods, what I refer to as "cobenefits" and "disbenefits" respectively. There is often a desire to increase the cobenefits of environmental protection efforts in order to synergize across conservation efforts; and there is also a desire to decrease disbenefits because they are seen as negative externalities of protection efforts. I show that as a result of reciprocal externalities between environmental protection efforts, environmental agencies likely have a disincentive to create cobenefits, but may actually have an incentive to decrease disbenefits. In the second case (chapter 3), I model an environmental agency that wants to increase environmental protection, but would also like to reduce poverty. The model indicates that in theory, the trade-offs between these two goals may depend on relevant parameters of the system, particularly the ratio of the price of monitoring to participant's compliance cost. I show that when the ratio of monitoring costs to compliance cost is higher, trade-offs between environmental protection and poverty reduction are likely to be smaller. And when the ratio of monitoring costs to compliance costs is lower, trade-offs are likely to be larger. This thesis contributes to a deeper understanding of the trade-offs faced by environmental agencies that want to pursue secondary objectives of protecting additional environmental goods or reducing poverty.
ContributorsGilliland, Ted (Author) / Perrings, Charles (Thesis advisor) / Abbott, Josh K (Committee member) / Kinzig, Ann P (Committee member) / Arizona State University (Publisher)
Created2012
Description
Bacteria play a vital role in the world ecosystem, more importantly human health and disease. The capability to differentiate and identify these microorganisms serves as an important research objective. In past years, separations-based approaches have served as a way to observe and identify bacteria based on their characteristics. Gradient insulator dielectrophoresis (g-iDEP) provides benefits in identifying serotypes of a single species with precise separation. Separation of Staphylococcus epidermidis in a single g-iDEP microchannel is conducted exploiting their electrophoretic and electrokinetic properties. The cells were captured and concentrated at gates with interacting forces within the microchannel to clearly distinguish between the two strains. These results provide support for g-iDEP serving as a separating method and, furthermore, future clinical applications.
ContributorsDavis, Paige Elizabeth (Author) / Hayes, Mark (Thesis director) / Borges, Chad (Committee member) / Jones, Paul (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / T. Denny Sanford School of Social and Family Dynamics (Contributor)
Created2015-05
Description
This work examines one dimension of the effect that complex human transport systems have on the spread of Chikungunya Virus (CHIKV) in the Caribbean from 2013 to 2015. CHIKV is transmitted by mosquitos and its novel spread through the Caribbean islands provided a chance to examine disease transmission through complex human transportation systems. Previous work by Cauchemez et al. had shown a simple distance-based model successfully predict CHIKV spread in the Caribbean using Markov chain Monte Carlo (MCMC) statistical methods. A MCMC simulation is used to evaluate different transportation methods (air travel, cruise ships, and local maritime traffic) for the primary transmission patterns through linear regression. Other metrics including population density to account for island size variation and dengue fever incidence rates as a proxy for vector control and health spending were included. Air travel and cruise travel were gathered from monthly passenger arrivals by island. Local maritime traffic is approximated with a gravity model proxy incorporating GDP-per-capita and distance and historic dengue rates were used for determine existing vector control measures for the islands. The Caribbean represents the largest cruise passenger market in the world, cruise ship arrivals were expected to show the strongest signal; however, the gravity model representing local traffic was the best predictor of infection routes. The early infected islands (<30 days) showed a heavy trend towards an alternate primary transmission but our consensus model able to predict the time until initial infection reporting with 94.5% accuracy for islands 30 days post initial reporting. This result can assist public health entities in enacting measures to mitigate future epidemics and provide a modelling basis for determining transmission modes in future CHIKV outbreaks.
ContributorsFries, Brendan F (Author) / Perrings, Charles (Thesis director) / Wilson Sayres, Melissa (Committee member) / Morin, Ben (Committee member) / School of Life Sciences (Contributor) / Department of Military Science (Contributor) / Barrett, The Honors College (Contributor)
Created2015-12
Description
Background: High risk types of human papillomavirus (HPV) are known to cause cancer, including cervical (99%) and oropharyngeal cancer (70%). HPV type 16 is the most common subtype. Three antigens that are critical for integration or tumor progression are E2, E6 and E7. In this study, we developed a systematic approach to identify naturally-processed HPV16-derived HLA class I epitopes for immunotherapy development. Methods: K562 cells, which lack HLA expression, were transduced with each HPV16 antigen using lentivirus and supertransfected with HLA-A2 by nucleofection. Stable cell lines expressing each antigen were selected for and maintained throughout the investigation. In order to establish a Gateway-compatible vector for robust transient gene expression, a Gateway recombination expression cloning cassette was inserted into the commercial Lonza pMAX GFP backbone, which has been experimentally shown to display high transfection expression efficiency. GFP was cloned into the vector and plain K562 cells were transfected with the plasmid by nucleofection. Results: Expression of K562-A2 was tested at various time points by flow cytometry and A2 expression was confirmed. Protein expression was shown for the transduced K562 E7 by Western blot analysis. High transfection efficiency of the pMAX_GFP_Dest vector (up to 97% GFP+ cells) was obtained 48 hours post transfection, comparable to the commercial GFP-plasmid. Conclusion: We have established a rapid system for target viral antigen co-expression with single HLA molecules for analysis of antigen presentation. Using HPV as a model system, our goal is to identify specific antigenic peptide sequences to develop immunotherapeutic treatments for HPV-associated cancers.
ContributorsVarda, Bianca Marie (Author) / Anderson, Karen (Thesis director) / Borges, Chad (Committee member) / Krishna, Sri (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
This project examines a complex issue in urban ecology: the impact of biodiversity on ecosystem services, and considers how this varies across cities. Data were gathered on multiple economic and ecological parameters for a selection of seven cities around the world and analyzed via multiple linear regression in order to assess any relationships that may be at play. Significance values were then calculated to further define the relationships between the data. Analysis found that both biophysical and socioeconomic factors affected ecosystem services, although not all hypotheses regarding these relationships were met. Conclusions indicate that this model was fairly effective in describing physical drivers of ecosystem services, but were not as clear regarding social drivers. Further study regarding social parameters' effect on ecosystem services is recommended.
ContributorsMcDannald, Lindsay JoAnne (Author) / Perrings, Charles (Thesis director) / Kinzig, Ann (Committee member) / Grimm, Nancy (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / School of Sustainability (Contributor)
Created2014-05
Description
Protein AMPylation is a recently discovered and relatively unstudied post-translational modification (PTM). AMPylation has previously been shown to play an important role in metabolic regulation and host pathogenesis in bacteria, but the recent identification of potential AMPylators across many species in every domain of life has supported the possibility that AMPylation could be a more fundamental and physiologically significant regulatory PTM. For the first time, we characterized the auto-AMPylation capability of the human protein SOS1 through in vitro AMPylation experiments using full-length protein and whole-domain truncation mutants. We found that SOS1 can become AMPylated at a tyrosine residue possibly within the Cdc25 domain of the protein, the Dbl homology domain is vital for efficient auto-AMPylation activity, and the C-terminal proline-rich domain exhibits a complex regulatory function. The proline-rich domain alone also appears to be capable of catalyzing a separate, unidentified covalent self-modification using a fluorescent ATP analogue. Finally, SOS1 was shown to be capable of catalyzing the AMPylation of two endogenous human protein substrates: a ubiquitous, unidentified protein of ~49kDa and another breast-cancer specific, unidentified protein of ~28kDa.
ContributorsOber-Reynolds, Benjamin John (Author) / LaBaer, Joshua (Thesis director) / Borges, Chad (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of Life Sciences (Contributor)
Created2014-05
Description
In this thesis, glycan nodes, the basic subunits of complex biological sugars, were studied to determine the reproducibility of gas chromatography-mass spectrometry (GC/MS) based methylation analysis of whole blood plasma by normalization using an internal standard of heavy permethylated glycans. Glycans are complex biological sugars that have a variety of applications in the human body and will display aberrant compositions when produced by cancerous cells. Thus an assay to determine their composition can be used as a diagnostic tool. It was shown that the assay may have potential use, but needs further refinement to become an improvement over current methods by analyzing the results of ratio-determination and replicate experiments.
ContributorsMiyasaki, Tyler Takeo (Author) / Borges, Chad (Thesis director) / Van Horn, Wade (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / Chemical Engineering Program (Contributor)
Created2015-05