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Open Access Publications from the University of California

UC Irvine Electronic Theses and Dissertations

Cover page of Information Systems for Grassroots Sustainable Agriculture

Information Systems for Grassroots Sustainable Agriculture

(2019)

Scientists widely accept that modern agriculture is unsustainable, but the best methods for addressing unsustainability are still contested (Constance, Konefal, and Hatanaka 2018). Grassroots sustainable agriculture communities have long participated in the exploration of solutions for agriculture unsustainability, and their momentum continues to grow in the technical age. Practitioners of grassroots sustainable agriculture use many information systems that were not originally built to support the design of agricultural systems. Based on ethnographic research with two grassroots sustainable agriculture communities, I show that participants’ personal and community values frequently clashed with those embedded in information systems, including ones used to look for and manage plant information. Furthermore, I demonstrate a range of information challenges that participants faced in the absence of tools designed to support their specific work. I argue that practitioners of grassroots sustainable agriculture need information systems tailored to their goals and values in order to productively address barriers to designing and building agroecosystems for their communities.

This dissertation provides an example of how to involve communities in the development of information technology artifacts and strengthen efforts to support sustainability via technological interventions. First, I engaged in two grassroots sustainable agriculture communities as a participant, experiencing their practices, values, and information challenges first hand. Then, I worked with the communities to create a plant database web application (SAGE Plant Database) that supports agroecosystem design in local contexts. Members of the communities participated in the design, development, and data population stages so that the SAGE Plant Database supports their design context and upholds their technological and holistic sustainability values. At the foundation of the database is a plant ontology grounded in the participants’ practice of designing agroecosystems. My comparative analysis of the design of the SAGE Plant Database to other databases demonstrates its relevance due to its emphasis on agroecological relationships among plants and between plants and the environment, the inclusion of ethnobotanical data, and the embedded community values. By engaging in this research, I seek to make progress towards transforming the technology-supported food system into one that furthers food security, food sovereignty, and holistic sustainability.

Cover page of A Direct Demand Model for Commuter Rail Ridership in the San Francisco Bay Area

A Direct Demand Model for Commuter Rail Ridership in the San Francisco Bay Area

(2019)

This thesis documents the development of a direct travel demand model for commuter rail in the San Francisco Bay Area. A direct demand model simultaneously estimates trip generation and attraction, which for this thesis would be trips between an origin-destination pair of stations. In the model, the number of trips assigned to an origin-destination pair of stations is dependent on land use characteristics at the origin and destination stations in combination with travel time on the network during congested peak periods and via transit. The model uses a multiplicative direct demand model to estimate ordinary least square regression parameters for the origin-destination trips. From the model form, the resultant estimated regression parameters are elasticities, and as such, can be used to postulate the effects of the selected land use characteristics and network travel times upon the number of trips made.

At both the origin and destination, the location of the station within the central business districts of the San Francisco Bay region had the largest effect on trip generation and attraction. Higher employment density at the destination and a larger number of workers per household at the origin had a positive effect on trips, while the total number of industrial workers at the destination and an increased number of two car households had a negative effect on trips. Longer travel times on transit appeared to have a positive effect on trips, yet longer travel times in congested peak periods appeared to have a negative effect on trips.

Advancing Process-Based Nonstationary Analysis of Climate Extremes: Modeling, Uncertainty Assessment and Multivariate Attribution

(2019)

Extreme weather events are inherent in climate variability and they can cause ecosystem alterations, infrastructure damages, suspension of food supply chains, and loss of lives. Today's highly populated and urbanized society is more vulnerable than ever to natural hazards and their disruptive consequences. Projected population growth and changes in climate variability are expected to exacerbate the societal and economic impact of climatic extremes. The scientific community, global organizations, and other stakeholders have all recognized the urgency of improving our understanding of both natural and human-induced climate variability.

The overarching goal of this thesis is to advance the current methods for nonstationary analysis of climatic extremes and their attributions. Here we propose a methodological framework for investigating hydroclimatic extremes over time and in response to a physical driver/covariate. The Process-based Nonstationary Extreme Value Analysis (ProNEVA) framework is unique in that it allows for incorporating a physical component into traditional frequency analysis techniques to account for observed or process-based changes in the variable of interest. The model can be used for both stationary and nonstationary analyses of extremes and includes a Graphical User Interface (GUI) for easier implementation.

We then shed light on the uncertainty inherent in the estimation of climatic extremes. We propose a generalized approach for including uncertainty information in the recurrence interval of extremes. The approach offers insights on how information about extremes should be interpreted by planners and decision-makers under conditions of uncertainty.

Using the method developed in this thesis, we show how extreme precipitation is expected to change in the future. We also highlight the importance of merging information from observations and climate model simulations for risk assessment purposes.

Finally, we outline a methodological framework for attribution of changes in multiple extremes or multiple features of an extreme event. We show the potential of copula functions for attribution of changes in both the magnitude and the dependence structure between characteristics of a natural phenomenon or, more generally, between two dependent variables.

“Fists of Iron, Fists of Yellow”: Examining Asian Performances, Resistance Work, and Yellow Peril in Marvel’s Iron Fist Netflix Series

(2019)

The Netflix superhero show Iron Fist (2017-2018) is widely known and critiqued in U.S. mainstream media for its whitewashing controversy and cultural appropriations of Asian culture. Much of the focus has been on the protagonist Danny Rand (played by white actor Finn Jones) and how the show could have been both progressively and critically better if the character had been Asian American. However, little attention has been directed to the Asian actors and actresses of Iron Fist in terms of how they contend with and resist the Orientalist legacy of the show through their performances, and how the show helps to enable their resistance work.

This paper argues that Iron Fist as a platform enables Asian Americans to use their performances as a means of negotiating their representation in Hollywood and enacting resistance against Orientalism and stereotyping. Conversely, this paper also argues that these performances and resistances are also being filtered through the Yellow Peril/Orientalist framework of the show, which troubles and complicates the representation work of Asian/Americans. To support these points, I will examine the performances of three Asian actors/actresses who play prominent roles on Iron Fist, how they conduct their resistance work, and how the show influences their resistance. Ultimately, this paper seeks to substantiate resistance work as not necessarily victories nor hopeless cases, but acts that create sites of significant and complex strategy-making, deliberation, compromise, conflict, invention, and rumination.

Cover page of Essays on Price Discrimination and Congestion Externalities in the U.S. Airline Industry

Essays on Price Discrimination and Congestion Externalities in the U.S. Airline Industry

(2019)

This dissertation contains three chapters and focuses on price discrimination and airport congestion in the U.S. airline industry.

The first chapter explores possible determinants that may affect an airline's decision to charge passengers different roundtrip fares depending on trip origin, a case of directional price discrimination. Such fare differences cannot be the result of differences in cost, as the cost of flying a roundtrip passenger does not significantly differ depending on direction. It is argued that directional fare differences result from airlines recognizing that passenger price elasticities differ between route endpoints. A price discriminating airline will then charge a higher roundtrip fare at the endpoint where the passenger price elasticity of demand is comparatively lower. Evidence is found suggesting that airlines do use differences in income to price discriminate when setting roundtrip fares. Fares are found to be $0.18-$0.43 higher on average for each $1000 difference in average per capita income between origin and destination metro areas. This finding is sensible assuming that higher incomes reduce the price elasticity of demand for air travel, with richer passengers being less sensitive to the cost of travel.

The second chapter investigates the trade-off between providing convenient flight connections for passengers and reducing airport congestion. From the passenger perspective, layovers are detrimental since the addition to total travel time relative to a nonstop itinerary is a cost incurred by the passenger. An airline is able to reduce a passenger's layover time by narrowing the gap between flights at the connecting airport. However, narrowing this flight gap has the adverse effect of increasing airport congestion. Taking these perspectives into account, it is clear that layover time influences a prospective passenger's purchasing decision and an airline's flight scheduling decision. Using published fare and itinerary data from Google Flights, this chapter provides insight into both decisions by providing empirical estimates on the value of layover time in the U.S. airline industry. Passengers are found to be compensated with a fare that is $42.74-$47.60 cheaper per hour of layover time.

The last chapter evaluates the effectiveness of slot controls (restrictions on the number of departing and arriving flights) as a congestion management policy. Utilizing the introduction of slot controls at John F. Kennedy (JFK) and Newark (EWR) airports in 2008 as a quasi-experiment, no evidence is found of a reduction in flight delays at both airports. In the months after slot controls were introduced, the average arrival delay at EWR actually increased by 7 minutes. Further, the length of Delta's departure banks (high-volume periods of departing flights) decreased by about 2 minutes at JFK while the scheduled time of EWR flights decreased by 1.5-2.2 minutes. These findings are consistent with Ater (2012), who suggested that policies aimed at reducing congestion at highly concentrated airports will only have a limited impact because dominant airlines already internalize congestion. The results highlight the need for policymakers to carefully consider how the allocation of airport slots will impact flight scheduling decisions when implementing similar policies in the future.

Cover page of Single-Nanoparticle Microscopy of DNA-Incorporated Hydrogel Nanoparticles

Single-Nanoparticle Microscopy of DNA-Incorporated Hydrogel Nanoparticles

(2019)

This dissertation is the cumulative work towards the development of bioactive hydrogel nanoparticles by way of DNA incorporation. First, a collection of orthogonal DNA sequences is fabricated and binding coefficients quantified via surface plasmon resonance imaging (SPRI). Then, using a sample sequence from the collection, the DNA is polymerized into the backbone of hydrogel nanoparticles (HNPs) to be characterized by single-nanoparticle SPRI microscopy as surface adsorption measurements to gold thin-films. The SPRI responses, Δ%RNP, from several hundred nanoparticle adsorption events are used to generate frequency distribution histograms that characterize the nanoparticle size, composition, and bioactivity through complementary DNA hybridization and enzymatic-induced hydrolysis. These analyses reveal a dependence on the base sequence to aid in the incorporation of DNA into the HNPs. Lastly, DNA incorporation is further elaborated upon by the formation of nanocomposite HNPs, wherein the magnetic nanoparticle ferrite is present during DNA-HNP formation, alluding to a preferential covalent incorporation of DNA over that of ferrite nanoparticles as characterized by SPRI microscopy.

Dietary profiles, organic food consumption, and urinary glyphosate levels in a cohort of postmenopausal women in Orange County, California

(2019)

Background: Health concerns surrounding the herbicide, glyphosate, have increased recently due to its widespread use in agriculture and lack of regular surveillance programs in the food supply. However, studying the potential association between organic food consumption, which should decrease one’s exposure to glyphosate, and human health may be complicated due to confounding by the profiles of organic food consumers. Thus, understanding organic food consumer profiles is crucial. In addition, it is unknown whether self-reported organic food consumption frequency is indicative of one’s actual exposure to glyphosate.

Objective: To identify demographic, health-related, and diet-related factors associated with organic food consumption and to determine the association between self-reported organic food consumption frequency and urinary glyphosate levels.

Method: 375 women in Orange County were ranked into three groups based on their self-reported frequency of organic food consumption. Factors associated with frequency of organic food consumption, and urinary glyphosate levels across groups were analyzed.

Results: Self-reported organic food consumption frequency was associated with education, BMI, and healthy diet. We found highest urinary glyphosate levels in the sometime organic food consumers among the three groups, but it was not statistically different. However, grain intake was positively associated with glyphosate levels in infrequent organic food consumers.

Conclusion: The organic food consumer characteristics we observed were consistent with previous findings, and must be considered as confounders when studying the potential health effects of organic food consumption. We observed associations between urinary glyphosate levels and the diet, but our study findings should be confirmed in a larger population.

Cover page of Devising Dance Theatre

Devising Dance Theatre

(2019)

ABSTRACT OF THE THESIS

Devising Dance Theatre

By

Robyn C. O’Dell

Master of Fine Arts in Dance

University of California, Irvine, 2019

Dr. Lisa Naugle, Chair

This research explores devised theatre approaches in efforts to teach and enhance the skills for contemporary modern dance students to participate in a collaborative, cross disciplinary style of performance making. Devised theatre is a contemporary theatre approach which derived from a desire to create collaboratively designed theatre and to challenge the hierarchal western theatre traditions. Collaborative approaches to theatre and dance can be traced throughout the twentieth century, with roots to post-modern dance and feminist collective theatre movements.

The training of many contemporary modern dance students is often focused on the traditional solo artists paradigm, with little emphasis on creative collaboration, although many professional contemporary choreographers do create work within a collaborative construct. As theatre, dance, and the visual arts continue to traverse and intersect with each other, practitioners grow increasingly more interested in working in a collaborative, cross disciplinary process.

Investigating my own choreographic interests to create dance theatre works, I used devised theatre methods in my process to help develop skills necessary for this style of performance. Through a four-month rehearsal process, six undergraduate dance students, one university staff member, and I embarked on a collaborative creative process to create an original devised dance theatre work, based on the short story, The Yellow Wallpaper, by Charlotte Perkins Gilman. This process-based research resulted in a performance at the Experimental Performance Laboratory Theater at the University of California, Irvine in April of 2019.

Cover page of Essays in Education and Labor Economics

Essays in Education and Labor Economics

(2019)

This dissertation examines how sex education mandates affect teenage sexual behaviors and health, how an introduction of a paid parental leave scheme affects maternal labor market outcomes, and how school-level technology investment impacts student achievement. The data used for this dissertation include publicly available student-level data, confidential micro-data from the Australian government, and publicly available school-level data from the California Department of Education. The empirical methods used in this dissertation include difference-in-difference models, and regression discontinuity models. In the first chapter, I show that state-mandated school-based sex education has no significant impact on teenage sexual behaviors, gonorrhea rates, or birth rates. In the second chapter, I develop theoretical predictions of the impact of an introduction of a paid parental leave scheme on maternal labor market outcomes in Australia, and empirically test these predictions. I find no evidence that Australia’s paid parental leave scheme impacted maternal labor market outcomes in the short-run. In the third chapter, I examine the impact of school-level technology investment on student achievement in California, and find positive effects on English test scores. I find that the effects are largest for middle schoolers, and are concentrated among the low- socioeconomic students, suggesting that technology investment can help narrow the income achievement gap.

Molecular Composition, Optical Properties, and Chemical Aging of Primary and Secondary Organic Aerosol

(2019)

Aerosols are composed of solid or liquid particles and the gases they are suspended in. Primary aerosols are directly emitted and secondary organic aerosols (SOA) are formed in the atmosphere from the oxidation of volatile organic compounds (VOCs). The molecular composition of aerosol particles determines their optical properties, and affects the radiation balance of the Earth. Organic aerosol particles largely scatter solar radiation, however, there is a subset of organic particles called brown carbon (BrC) that absorb near-ultraviolet and visible radiation from the sun. Also, adverse effects on human health from exposure to aerosols are related to their molecular composition. The molecular composition of aerosol particles can also change during atmospheric transport, for example, due to the effects of sunlight and water vapor; and this makes the optical properties and human health effects of aerosols even harder to predict.

Chapters 2 and 3 examine the composition of smoke from biomass-burning cookstoves in rural India. This was done for two fuel types (wood and dung), as well as two stoves that are common to the area, the chulha and angithi. Chapter 2 quantifies the emission factors (EFs) of VOCs and PM2.5 from these emission sources, and estimates ozone and SOA production from these emissions. The major finding was that dung fuels and angithi cookstoves significantly increase the EFs for most VOCs. In Chapter 3, the molecular composition of smoke particles are characterized using high resolution mass spectrometry techniques. We observed that particles produced from dung-burning cookstoves were more complex (in terms of numbers of components), and contained a higher fraction of nitrogen-containing molecules (by mass abundance).

Chapter 4 characterizes BrC chromophores found in aerosol particles produced by simulated wildfires during the FIREX campaign. Then, we estimate lifetimes of individual BrC chromophores as well as bulk BrC absorbance. We find that BrC absorption has lifetimes of 10 to 41 days due to photochemical aging.

Chapter 5 investigates the evaporative browning of various SOA extracts, acidified with sulfuric acid to pH=2. The optical properties were quantified for SOAs of various precursors, both anthropogenic and biogenic, and oxidants (OH, O3, NOx). The molecular composition of BrC chromophores were determined, all of which were organosulfates.

Chapter 6 explores the effect of water vapor and aerosol liquid water on the molecular composition of SOA, as it is formed and chemically aged. We have evidence that for α-pinene/OH SOA formed in the presence of ammonium sulfate seed, water likely participates in hydrolysis reactions that result in less viscous particles.

These results provide key inputs to air quality models to more accurately predict regional climate; including EFs for Indian cookstoves and lifetimes of BrC in biomass burning organic aerosol. Other observations regarding secondary BrC formation in CCN mimics and hydrolysis reactions occurring in model SOA further our understanding of the evolution and chemical processing of atmospheric aerosols.