Matching Items (112)
Description
With global environmental systems under increasing Anthropogenic influence, conservationists and environmental managers are under immense pressure to protect and recover the world’s imperiled species and ecosystems. This effort is often motivated by a sense of moral responsibility, either to nature itself, or to the end of promoting human wellbeing over the long run. In other words, it is the purview of environmental ethics, a branch of applied philosophy that emerged in the 1970s and that for decades has been devoted to understanding and defending an attitude of respect for nature, usually for its own sake. Yet from the very start, environmental ethics has promoted itself as contributing to the resolution of real-world management and policy problems. By most accounts, however, the field has historically failed to deliver on this original promise, and environmental ethicists continue to miss opportunities to make intellectual inroads with key environmental decisionmakers. Inspired by classical and contemporary American philosophers such as Charles Sanders Peirce, William James, John Dewey, and Richard Rorty, I defend in this dissertation the virtues of a more explicitly pragmatic approach to environmental ethics. Specifically, I argue that environmental pragmatism is not only commensurate with pro-environmental attitudes but that it is more likely to lead to viable and sustainable outcomes, particularly in the context of eco-social resilience-building activities (e.g., local experimentation, adaptation, cooperation). In doing so, I call for a recasting of environmental ethics, a project that entails: 1) a conceptual reorientation involving the application of pragmatism applied to environmental problems; 2) a methodological approach linking a pragmatist environmentalism to the tradition and process of adaptive co-management; and 3) an empirical study of stakeholder values and perspectives in conservation collaboratives in Arizona. I conclude that a more pragmatic environmental ethics has the potential to bring a powerful set of ethical and methodological tools to bear in real-world management contexts and, where appropriate, can ground and justify coordinated conservation efforts. Finally, this research responds to critics who suggest that, because it strays too far from the ideological purity of traditional environmental ethics, the pragmatic decision-making process will, in the long run, weaken rather than bolster our commitment to conservation and environmental protection.
ContributorsRojas, Christopher A (Author) / Minteer, Ben A (Thesis advisor) / Carr Kelman, Candice (Committee member) / Kinzig, Ann (Committee member) / Schoon, Michael (Committee member) / Arizona State University (Publisher)
Created2019
Description
Massive glycerol cluster ions with many charges (~ 106 Da, ~ ±100 charges) have been generated by electrospray to bombard biomolecules and biological sample surfaces. The low impact energy per nucleon facilitates intact sputtering and ionization of biomolecules which can be subsequently imaged. Various lipids, peptides and proteins have been studied. The primary cluster ion source has been coupled with an ion-microscope imaging mass spectrometer (TRIFT-1, Physical Electronics). A lateral resolution of ~3µm has been demonstrated, which is acceptable for sub-cellular imaging of animal cells (e.g. single cancer cell imaging in early diagnosis). Since the available amount of target molecules per pixel is limited in biological samples, the measurement of useful ion yields (ratio of detected molecular ion counts to the sample molecules sputtered) is important to determine whether enough ion counts per pixel can be obtained. The useful ion yields of several lipids and peptides are in the 1-3×10-5 range. A 3×3 µm2lipid bilayer can produce ~260 counts/pixel for a meaningful 3×3 µm2 pixel ion image. This method can probably be used in cell imaging in the future, when there is a change in the lipid contents of the cell membrane (e.g. cancer cells vs. normal cells).
ContributorsZhang, Jitao (Author) / Williams, Peter (Thesis advisor) / Hayes, Mark (Committee member) / Nelson, Randall (Committee member) / Arizona State University (Publisher)
Created2015
Description
Yersinia enterocolitica is a major foodborne pathogen found worldwide that causes approximately 87,000 human cases and approximately 1,100 hospitalizations per year in the United States. Y. enterocolitica is a very unique pathogen with the domesticated pig acting as the main animal reservoir for pathogenic bio/serotypes, and as the primary source of human infection. Similar to other gastrointestinal infections, Yersinia enterocolitica is known to trigger autoimmune responses in humans. The most frequent complication associated with Y. enterocolitica is reactive arthritis - an aseptic, asymmetrical inflammation in the peripheral and axial joints, most frequently occurring as an autoimmune response in patients with the HLA-B27 histocompatability antigen. As a foodborne illness it may prove to be a reasonable explanation for some of the cases of arthritis observed in past populations that are considered to be of unknown etiology. The goal of this dissertation project was to study the relationship between the foodborne illness -Y. enterocolitica, and the incidence of arthritis in individuals with and without contact with the domesticated pig.
ContributorsBrown, Starletta (Author) / Hurtado, Ana M (Thesis advisor) / Chowell-Puente, Gerardo (Committee member) / Hill, Kim (Committee member) / Arizona State University (Publisher)
Created2015
Description
Cell heterogeneity is widely present in the biological world and exists even in an isogenic population. Resolving the protein heterogeneity at the single cell level is of enormous biological and clinical relevance. However, single cell protein analysis has proven to be challenging due to extremely low amount of protein in a single cell and the huge complexity of proteome. This requires appropriate sampling and sensitive detection techniques. Here, a new approach, microfluidics combined with MALDI-TOF mass spectrometry was brought forward, for the analysis of proteins in single cells. The detection sensitivity of peptides as low as 300 molecules and of proteins as low as 10^6 molecules has been demonstrated. Furthermore, an immunoassay was successfully integrated in the microfluidic device for capturing the proteins of interest and further identifying them by subsequent enzymatic digestion. Moreover, an improved microfluidic platform was designed with separate chambers and valves, allowing the absolute quantification by employing iTRAQ tags or an isotopically labeled peptide. The study was further extended to analyze a protein in MCF-7 cell lysate. The approach capable of identifying and quantifying protein molecules in MCF-7 cells is promising for future proteomic studies at the single cell level.
ContributorsYang, Mian (Author) / Ros, Alexandra (Thesis advisor) / Hayes, Mark (Committee member) / Nelson, Randall (Committee member) / Arizona State University (Publisher)
Created2016
Description
Extraordinary medical advances have led to significant reductions in the burden of infectious diseases in humans. However, infectious diseases still account for more than 13 million annual deaths. This large burden is partly due to some pathogens having found suitable conditions to emerge and spread in denser and more connected host populations, and others having evolved to escape the pressures imposed by the rampant use of antimicrobials. It is then critical to improve our understanding of how diseases spread in these modern landscapes, characterized by new host population structures and socio-economic environments, as well as containment measures such as the deployment of drugs. Thus, the motivation of this dissertation is two-fold. First, we study, using both data-driven and modeling approaches, the the spread of infectious diseases in urban areas. As a case study, we use confirmed-cases data on sexually transmitted diseases (STDs) in the United States to assess the conduciveness of population size of urban areas and their socio-economic characteristics as predictors of STD incidence. We find that the scaling of STD incidence in cities is superlinear, and that the percent of African-Americans residing in cities largely determines these statistical patterns. Since disparities in access to health care are often exacerbated in urban areas, within this project we also develop two modeling frameworks to study the effect of health care disparities on epidemic outcomes. Discrepant results between the two approaches indicate that knowledge of the shape of the recovery period distribution, not just its mean and variance, is key for assessing the epidemiological impact of inequalities. The second project proposes to study, from a modeling perspective, the spread of drug resistance in human populations featuring vital dynamics, stochasticity and contact structure. We derive effective treatment regimes that minimize both the overall disease burden and the spread of resistance. Additionally, targeted treatment in structured host populations may lead to higher levels of drug resistance, and if drug-resistant strains are compensated, they can spread widely even when the wild-type strain is below its epidemic threshold.
ContributorsPatterson-Lomba, Oscar (Author) / Castillo-Chavez, Carlos (Thesis advisor) / Towers, Sherry (Thesis advisor) / Chowell-Puente, Gerardo (Committee member) / Arizona State University (Publisher)
Created2014
Description
Urban scaling analysis has introduced a new scientific paradigm to the study of cities. With it, the notions of size, heterogeneity and structure have taken a leading role. These notions are assumed to be behind the causes for why cities differ from one another, sometimes wildly. However, the mechanisms by which size, heterogeneity and structure shape the general statistical patterns that describe urban economic output are still unclear. Given the rapid rate of urbanization around the globe, we need precise and formal mathematical understandings of these matters. In this context, I perform in this dissertation probabilistic, distributional and computational explorations of (i) how the broadness, or narrowness, of the distribution of individual productivities within cities determines what and how we measure urban systemic output, (ii) how urban scaling may be expressed as a statistical statement when urban metrics display strong stochasticity, (iii) how the processes of aggregation constrain the variability of total urban output, and (iv) how the structure of urban skills diversification within cities induces a multiplicative process in the production of urban output.
ContributorsGómez-Liévano, Andrés (Author) / Lobo, Jose (Thesis advisor) / Muneepeerakul, Rachata (Thesis advisor) / Bettencourt, Luis M. A. (Committee member) / Chowell-Puente, Gerardo (Committee member) / Arizona State University (Publisher)
Created2014
Description
This dissertation consists of three substantive chapters. The first substantive chapter investigates the premature harvesting problem in fisheries. Traditionally, yield-per-recruit analysis has been used to both assess and address the premature harvesting of fish stocks. However, the fact that fish size often affects the unit price suggests that this approach may be inadequate. In this chapter, I first synthesize the conventional yield-per-recruit analysis, and then extend this conventional approach by incorporating a size-price function for a revenue-per-recruit analysis. An optimal control approach is then used to derive a general bioeconomic solution for the optimal harvesting of a short-lived single cohort. This approach prevents economically premature harvesting and provides an "optimal economic yield". By comparing the yield- and revenue-per-recruit management strategies with the bioeconomic management strategy, I am able to test the economic efficiency of the conventional yield-per-recruit approach. This is illustrated with a numerical study. It shows that a bioeconomic strategy can significantly improve economic welfare compared with the yield-per-recruit strategy, particularly in the face of high natural mortality. Nevertheless, I find that harvesting on a revenue-per-recruit basis improves management policy and can generate a rent that is close to that from bioeconomic analysis, in particular when the natural mortality is relatively low.
The second substantive chapter explores the conservation potential of a whale permit market under bounded economic uncertainty. Pro- and anti-whaling stakeholders are concerned about a recently proposed, "cap and trade" system for managing the global harvest of whales. Supporters argue that such an approach represents a novel solution to the current gridlock in international whale management. In addition to ethical objections, opponents worry that uncertainty about demand for whale-based products and the environmental benefits of conservation may make it difficult to predict the outcome of a whale share market. In this study, I use population and economic data for minke whales to examine the potential ecological consequences of the establishment of a whale permit market in Norway under bounded but significant economic uncertainty. A bioeconomic model is developed to evaluate the influence of economic uncertainties associated with pro- and anti- whaling demands on long-run steady state whale population size, harvest, and potential allocation. The results indicate that these economic uncertainties, in particular on the conservation demand side, play an important role in determining the steady state ecological outcome of a whale share market. A key finding is that while a whale share market has the potential to yield a wide range of allocations between conservation and whaling interests - outcomes in which conservationists effectively "buy out" the whaling industry seem most likely.
The third substantive chapter examines the sea lice externality between farmed fisheries and wild fisheries. A central issue in the debate over the effect of fish farming on the wild fisheries is the nature of sea lice population dynamics and the wild juvenile mortality rate induced by sea lice infection. This study develops a bioeconomic model that integrates sea lice population dynamics, fish population dynamics, aquaculture and wild capture salmon fisheries in an optimal control framework. It provides a tool to investigate sea lice control policy from the standpoint both of private aquaculture producers and wild fishery managers by considering the sea lice infection externality between farmed and wild fisheries. Numerical results suggest that the state trajectory paths may be quite different under different management regimes, but approach the same steady state. Although the difference in economic benefits is not significant in the particular case considered due to the low value of the wild fishery, I investigate the possibility of levying a tax on aquaculture production for correcting the sea lice externality generated by fish farms.
The second substantive chapter explores the conservation potential of a whale permit market under bounded economic uncertainty. Pro- and anti-whaling stakeholders are concerned about a recently proposed, "cap and trade" system for managing the global harvest of whales. Supporters argue that such an approach represents a novel solution to the current gridlock in international whale management. In addition to ethical objections, opponents worry that uncertainty about demand for whale-based products and the environmental benefits of conservation may make it difficult to predict the outcome of a whale share market. In this study, I use population and economic data for minke whales to examine the potential ecological consequences of the establishment of a whale permit market in Norway under bounded but significant economic uncertainty. A bioeconomic model is developed to evaluate the influence of economic uncertainties associated with pro- and anti- whaling demands on long-run steady state whale population size, harvest, and potential allocation. The results indicate that these economic uncertainties, in particular on the conservation demand side, play an important role in determining the steady state ecological outcome of a whale share market. A key finding is that while a whale share market has the potential to yield a wide range of allocations between conservation and whaling interests - outcomes in which conservationists effectively "buy out" the whaling industry seem most likely.
The third substantive chapter examines the sea lice externality between farmed fisheries and wild fisheries. A central issue in the debate over the effect of fish farming on the wild fisheries is the nature of sea lice population dynamics and the wild juvenile mortality rate induced by sea lice infection. This study develops a bioeconomic model that integrates sea lice population dynamics, fish population dynamics, aquaculture and wild capture salmon fisheries in an optimal control framework. It provides a tool to investigate sea lice control policy from the standpoint both of private aquaculture producers and wild fishery managers by considering the sea lice infection externality between farmed and wild fisheries. Numerical results suggest that the state trajectory paths may be quite different under different management regimes, but approach the same steady state. Although the difference in economic benefits is not significant in the particular case considered due to the low value of the wild fishery, I investigate the possibility of levying a tax on aquaculture production for correcting the sea lice externality generated by fish farms.
ContributorsHuang, Biao (Author) / Abbott, Joshua K (Thesis advisor) / Perrings, Charles (Thesis advisor) / Gerber, Leah R. (Committee member) / Muneepeerakul, Rachata (Committee member) / Schoon, Michael (Committee member) / Arizona State University (Publisher)
Created2014
Description
The increased number of novel pathogens that potentially threaten the human population has motivated the development of mathematical and computational modeling approaches for forecasting epidemic impact and understanding key environmental characteristics that influence the spread of diseases. Yet, in the case that substantial uncertainty surrounds the transmission process during a rapidly developing infectious disease outbreak, complex mechanistic models may be too difficult to be calibrated quick enough for policy makers to make informed decisions. Simple phenomenological models that rely on a small number of parameters can provide an initial platform for assessing the epidemic trajectory, estimating the reproduction number and quantifying the disease burden from the early epidemic phase.
Chapter 1 provides background information and motivation for infectious disease forecasting and outlines the rest of the thesis.
In chapter 2, logistic patch models are used to assess and forecast the 2013-2015 West Africa Zaire ebolavirus epidemic. In particular, this chapter is concerned with comparing and contrasting the effects that spatial heterogeneity has on the forecasting performance of the cumulative infected case counts reported during the epidemic.
In chapter 3, two simple phenomenological models inspired from population biology are used to assess the Research and Policy for Infectious Disease Dynamics (RAPIDD) Ebola Challenge; a simulated epidemic that generated 4 infectious disease scenarios. Because of the nature of the synthetically generated data, model predictions are compared to exact epidemiological quantities used in the simulation.
In chapter 4, these models are applied to the 1904 Plague epidemic that occurred in Bombay. This chapter provides evidence that these simple models may be applicable to infectious diseases no matter the disease transmission mechanism.
Chapter 5, uses the patch models from chapter 2 to explore how migration in the 1904 Plague epidemic changes the final epidemic size.
The final chapter is an interdisciplinary project concerning within-host dynamics of cereal yellow dwarf virus-RPV, a plant pathogen from a virus group that infects over 150 grass species. Motivated by environmental nutrient enrichment due to anthropological activities, mathematical models are employed to investigate the relevance of resource competition to pathogen and host dynamics.
Chapter 1 provides background information and motivation for infectious disease forecasting and outlines the rest of the thesis.
In chapter 2, logistic patch models are used to assess and forecast the 2013-2015 West Africa Zaire ebolavirus epidemic. In particular, this chapter is concerned with comparing and contrasting the effects that spatial heterogeneity has on the forecasting performance of the cumulative infected case counts reported during the epidemic.
In chapter 3, two simple phenomenological models inspired from population biology are used to assess the Research and Policy for Infectious Disease Dynamics (RAPIDD) Ebola Challenge; a simulated epidemic that generated 4 infectious disease scenarios. Because of the nature of the synthetically generated data, model predictions are compared to exact epidemiological quantities used in the simulation.
In chapter 4, these models are applied to the 1904 Plague epidemic that occurred in Bombay. This chapter provides evidence that these simple models may be applicable to infectious diseases no matter the disease transmission mechanism.
Chapter 5, uses the patch models from chapter 2 to explore how migration in the 1904 Plague epidemic changes the final epidemic size.
The final chapter is an interdisciplinary project concerning within-host dynamics of cereal yellow dwarf virus-RPV, a plant pathogen from a virus group that infects over 150 grass species. Motivated by environmental nutrient enrichment due to anthropological activities, mathematical models are employed to investigate the relevance of resource competition to pathogen and host dynamics.
ContributorsPell, Bruce (Author) / Kuang, Yang (Thesis advisor) / Chowell-Puente, Gerardo (Committee member) / Nagy, John (Committee member) / Kostelich, Eric (Committee member) / Gardner, Carl (Committee member) / Arizona State University (Publisher)
Created2016
Description
Prior to the COVID-19 global pandemic, ecotourism represented the tourism industry’s fastest growing segment with projections estimating that ecotourism would become the world’s largest tourism type by 2030. While the tourism industry will need several years to rebound, if historic trends tell us anything, it is that ecotourism will continue to represent a large portion of the overall industry and will continue to grow at a rate that outpaces all other tourism types. In theory, ecotourism promotes sustainable socioeconomic development while also minimizing negative environmental impacts. Unfortunately, research suggests that this is not always true, and many examples exist of ecotourism causing more harm than good. In order to combat these potential negative impacts, the ecotourism industry has become increasingly reliant on ecotourism certification programs to act as an assessment tool that identifies ecotourism’s best practitioners while minimizing false advertising present within the industry. Despite these beliefs in the efficacy of certification, there is a lack of empirical research to actually support certification as an effective assessment tool. Furthermore, little research has been conducted that assesses the impacts that certification itself has on ecotourism businesses (both certified and uncertified) and the local communities dependent on ecotourism.
My dissertation employs a mixed methods design and combines qualitative and quantitative research methods spanning multiple geographic scales to develop an understanding of certification programs as they exist today and to discern the impacts that certification itself may cause for all those either directly or indirectly involved in ecotourism. My findings ultimately suggest that certification reform is needed if certification programs are expected to be the assessment tool ecotourism experts claim them to be. Specifically, as certification exists presently, there is: no universal guideline or standard for existing certification programs to follow, a disconnect between the advertised benefits certification offers and the actual benefits received, and a lack of market penetration both amongst ecotourists and ecotourism businesses. Each of these must be addressed before certification can live up to its full potential. Furthermore, I found that certification may impact community socioeconomic dynamics, particularly by creating or exacerbating community wealth distribution.
My dissertation employs a mixed methods design and combines qualitative and quantitative research methods spanning multiple geographic scales to develop an understanding of certification programs as they exist today and to discern the impacts that certification itself may cause for all those either directly or indirectly involved in ecotourism. My findings ultimately suggest that certification reform is needed if certification programs are expected to be the assessment tool ecotourism experts claim them to be. Specifically, as certification exists presently, there is: no universal guideline or standard for existing certification programs to follow, a disconnect between the advertised benefits certification offers and the actual benefits received, and a lack of market penetration both amongst ecotourists and ecotourism businesses. Each of these must be addressed before certification can live up to its full potential. Furthermore, I found that certification may impact community socioeconomic dynamics, particularly by creating or exacerbating community wealth distribution.
ContributorsDavila, Ryan (Author) / Kinzig, Ann (Thesis advisor) / Perrings, Charles (Committee member) / Collins, James (Committee member) / Schoon, Michael (Committee member) / Buzinde, Christine (Committee member) / Arizona State University (Publisher)
Created2020
Description
Climate adaptation has not kept pace with climate impacts which has formed an adaptation gap. Increasingly insurance is viewed as a solution to close this gap. However, the efficacy and implications of using insurance in the climate adaptation space are not clear. Furthermore, past research has focused on specific actors or processes, not on the interactions and interconnections between the actors and the processes. I take a complex adaptive systems approach to map out how these dynamics are shaping adaptation and to interrogate what the insurance climate adaptation literature claims are the successes and pitfalls of insurance driving, enabling or being adaptation. From this interrogation it becomes apparent that insurance has enormous influence on its policy holders, builds telecoupling into local adaptation, and creates structures which support contradictory land use policies at the local level. Based on the influence insurance has on policy holders, I argue that insurance should be viewed as a form of governance. I synthesize insurance, governance and adaptation literature to examine exactly what governance tools insurance uses to exercise this influence and what the consequences may be. This research reveals that insurance may not be the exemplary adaptation approach the international community is hoping for. Using insurance, risk can be reduced without reducing vulnerability, and risk transfer can result in risk displacement which can reduce adaptation incentives, fuel maladaptation, or impose public burdens. Moreover, insurance requires certain information and legal relationships which can and often do structure that which is insured to the needs of insurance and shift authority away from governments to insurance companies or public-private partnerships. Each of these undermine the legitimacy of insurance-led local adaptation and contradict the stated social justice goals of international calls for insurance. Finally, I interrogate the potential justice concerns that emerged through an analysis of insurance as a form of adaptation governance. Using a multi-valent approach to justice I examine a suite of programs intended to support agricultural adaptation through insurance. This analysis demonstrates that although some programs clearly attempted to consider issues of justice, overall these existing programs raise distributional, procedural and recognition justice concerns.
ContributorsLueck, Vanessa (Author) / Klinsky, Sonja (Thesis advisor) / Schoon, Michael (Thesis advisor) / Eakin, Hallie (Committee member) / Arizona State University (Publisher)
Created2020