VictorJuiz/thesis huggingface dataset:
Essays on the Health Effects of Pollution in China

This dissertation consists of three chapters that analyze the health effects of pollution in China. The first chapter investigates the effect of air pollution on cardiovascular mortality in the urban areas of China. The second chapter estimates the effect of water pollution on infant mortality. The third chapter studies the relationship between water pollution and cancer among the elderly./nThe first chapter entitled "The Effect of Air Pollution on Cardiovascular Mortality: Evidences from the Beijing Olympic Games". I explore the exogenous air pollution variations induced by the 2008 Olympic Games to estimate the effects of air pollution on cardiovascular mortality in China. I use the regulation status during the Olympic Games as an instrument for air pollution. In the fixed-effects instrumental variable model, I find that air pollution has a robust and significant effect on cardiovascular mortality. In contrast, estimates from the conventional associational models are not robust. I estimate that decreasing current PM_10 concentration by 10% will save more than 67,000 lives (from cardiovascular diseases) in the urban areas in China each year./nChina's surface water system has been severely polluted in the process of rapid industrialization. The second chapter investigates how this water pollution affects infant mortality. I find that surface water pollution has a significant, nonlinear effect on infant mortality. As surface water quality deteriorates, infant mortality first increases and then decreases. Moderate levels of pollution are the most dangerous. People's avoidance behavior may explain the results: as water becomes more polluted people reduce the consumption of surface water. The ordered-probit selection model is applied to estimate the effects, and precipitation and wastewater dumping are used as the instruments for surface water quality./nChina also witnessed a dramatic increase in cancer rate in the past thirty years. In the third chapter, I investigate whether this high cancer rate is caused by water pollution. The difficulty in estimating the long-run health effects of pollution is that the lifetime exposure to pollution is hard to measure. However, China provides an ideal setting to estimate the long-run health effects of pollution because the Household Registration System (Hukou) effectively stopped people from migrating for many years. I focus on the elderly people (Age>60) because their mobility is extremely restricted by the System, so their life-time exposure to water pollution is more likely captured by the water quality data in recent years. I find that water pollution has large, significant, positive effects on all cancer mortality rate, digestive cancer mortality rate, urinary cancer mortality rate, liver and stomach cancer mortality rate. I also find that water pollution has no impact on cancer mortality rates for the younger adults (Age from 20-50), which may partially justify our argument that pollution exposure for the younger people cannot be accurately measured because they migrate.

Advisor: Perloff, Jeffrey M.
Ag-Ge Bi-lobed Nanoparticles: Synthesis, Structure, and Plasmonic Properties

A novel metal-semiconductor bi-lobed nanoparticle is introduced as a hybrid plasmonic nanostructure. This nanostructure, comprised of a lobe of Ag and a lobe of Ge, forms in a matrix due to phase segregation of the constituents and is thermodynamically stable at room temperature. The interface structure is imaged with high–resolution electron microscopy and found to be an incoherent interface with the {111} planes of the Ag and Ge components parallel to each other explaining the low Ag–Ge interfacial energy. The hemispherical shape of the silver fraction and the shared Ag–Ge interface produce a unique surface plasmon resonance in the visible to near infra–red range. This localized surface plasmon resonance is measured as an ensemble average using optical spectrophotometry and the resonance near 1.5 eV is assigned to the plasmon mode located at the Ag–Ge interface in agreement with numerical simulations. It is proposed that the metal surface plasmon couples to the semiconductor at the shared interface and that the magnitude of this coupling can be probed with a surface–enhanced Raman experiment. Single particle electron energy–loss spectra and energy–filtered transmission electron images elucidate the electronic transitions in the semiconductor and metal as well as localized surface plasmon modes and bulk plasmon modes for both semiconductor and metal. Pulsed laser melting of the bi-lobed structure, followed by quenching to a mixed non–equilibrium Ag–Ge phase, results in significant reduction of the measured localized surface plasmon, which demonstrates the application of an optical switch.

Advisor: Haller, Eugene E.
Gravure-printed Highly-scaled Organic Thin-film Transistors for Low-cost and Large-area Electronics

Printed electronics using recently developed solution-processed electronic materials and incorporating conventional graphic arts printing presses has been proposed as an emerging technology for low-cost large-area electronic systems on flexible substrates (e.g. disposable RFID tags, flexible displays, and various types of sensors and actuators). For more than a decade, a significant amount of research in printed electronics has been focused on the development of high mobility printable semiconductor materials. Despite the recent achievements of the high mobility semiconductor materials that surpass the performance of amorphous silicon, overall performance of printed transistors on plastic is not adequate for the proposed applications due to the large dimension of the transistors with significant parasitic capacitance, and underperforming semiconductor materials when incorporated with mass-production printing techniques./nIn this dissertation, we present a highly-scaled direct-gravure printing technique that allows sub-femtoliter scaling of printed inks, resulting in printed features as small as 4 μm while printed at high speed up to 1 m/s. By using this novel printing technique with the optimization of the high mobility organic semiconductors for the printed device fabrication processes, operation of gravure-printed inverters on plastic at frequencies above 1 MHz is achieved, which satisfies the performance requirements for most of the proposed applications. Along with the demonstration, we discuss how accurate pattern generation in various printing systems can be achieved with the knowledge of using contact angle hysteresis./nIn addition, we discuss experimental results on understanding of the origin of 1/f noise in organic thin-film transistors, which particularly affects the performance of the devices in sensor applications. Based on detailed analysis of observed non-idealities in the 1/f noise with respect to various grain sizes, operation regions, and bias conditions, we found that the trapping/de- trapping of carriers within the semiconductor is the dominant mechanism of the low-frequency noise generation in the organic thin-film transistors.

Advisor: Subramanian, Vivek
Schedulability Analysis and Verification of Real-Time Discrete-Event Systems

Cyber-physical systems are systems where there is a tight interaction between the computing world and the physical world. In spite of the significance of time in the dynamics of the physical world, real-time embedded software today is commonly built using programming abstractions with little or no temporal semantics. PTIDES (Programming Temporally Integrated Distributed Embedded Systems) is a programming model whose goal is to address this problem. It proposes a model-based design approach for the programming of distributed real-time embedded systems, in which the timing of real-time operations is specified as part of the model. This is accomplished by using as an underlying formalism a discrete-event (DE) model of computation, which is extended with real-time semantics./nWe address the schedulability question for PTIDES programs and uniprocessor platforms. A PTIDES program is schedulable if for all legal sensor inputs, there exists a scheduling of the PTIDES components that meets all the specified deadlines. The timing specifications allowed in the discrete-event formalism can be seen as a generalization of end-to-end latencies which are usually studied in the hard real-time computing literature. This results in a rather idiosyncratic schedulability problem. We first show that for a large subset of discrete-event models, the earliest-deadline-first scheduling policy is optimal. Second, we show that all but a finite part of the infinite state space of a PTIDES execution results in demonstrably unschedulable behaviors. As a result the schedulability problem can be reduced to a finite-state reachability problem. We describe this reduction using timed automata./nWe next turn to the verification problem for DE systems themselves. We study a basic deterministic DE model, where actors are simple constant-delay components, and two extensions of it: first, one where actors are not constant but introduce non-deterministic delays, and second, one where actors are either deterministic delays or are specified using timed automata. We investigate verification questions on DE models and examine expressiveness relationships between the DE models and timed automata./nFinally, we discuss extensions of this work to cover a wider range of discrete-event actors, and propose an approach to design more efficient and practical analyses for schedulability testing.

Advisor: Lee, Edward A
Moving to and through community college: Postsecondary aspirations and divergent outcomes

Community college has always been an attractive choice for many from the perspective that it offers access to higher education without the constraints typical of more elite four-year institutions. But while its egalitarian mission offers potentially unlimited second chances, the reality of persistent low attainment rates--despite investments in new initiatives and interventions--brings us back to the question of how community colleges both promote and constrain opportunities for students./nTo shed light on the viability of community college as an avenue to higher education, this study investigated the educational experiences of a group of students who transitioned directly from high school to community college in the fall of 2007. The design of the study employed multiple in-depth interviews with students over a twenty-month period. Forty youths from four high schools in two urban school districts in northern California were recruited and interviewed in the spring of 2007. Subsequent interviews were conducted over three semesters in community college. Information from informal communication with student participants and interviews with key administrators and staff at one community college district were used to contextualize formal student interviews. Together, these data revealed the opportunities and challenges a set of students experienced as they moved to and through community college./nThe experiences of participants in this study show that the college pipeline leaks very quickly, with the largest portion of attrition occurring between the first and the second semester of enrollment. Three factors emerged as key explanations for the observed patterns of community college enrollment. The first factor encompasses the institutional features specific to high schools and community college, such as counseling and academic preparation/supports, that may or may not be adequate to the task of moving students forward. The second and third factors--a student's level of academic preparedness and a student's familial and life circumstances--are individual factors that can affect the student's performance and the availability of support as she progresses through college. The results of the study indicate that the notion of college preparedness ought to be expanded, given that students' capacity to respond to challenges in college were influenced not only by college guidance experienced in high school but also by their social frames of reference.

Advisor: Grubb, Norton
Little, Judith W
The Prefrontal Cortex and Hierarchical Behavior

Every day, often without thinking about it, you create and achieve goals. These goals range in complexity from brushing your teeth in the morning, to avoiding traffic on your way to school, to figuring out how you're ever going to graduate from Berkeley. The intricate workings of your prefrontal cortex enable the planning and execution of such behaviors. For years, scientists have studied the mechanisms of simple choice behavior and learning in the form of stimulus- and action-outcome associations but the question of how increasingly complex and temporally-extended learning arises remains largely unknown. Informed by converging work from the fields of psychology and computer science, we set out to understand the computations performed at the level of single cells that may contribute to the ideation, mental maintenance, and stringing together of actions to perform a hierarchical gambling task. We recorded extracellular activity from two subjects as they performed an n¬-armed bandit task and compared and contrasted the information processed simultaneously in three distinct brain areas: the lateral prefrontal cortex, the orbitofrontal cortex, and the anterior cingulate cortex. While our data do not support the preferential processing of superordinate versus subordinate goals in prefrontal cortex, we did find many signals that may underlie hierarchical behavior. These include value and action encoding that depended on the hierarchical level, as well as encoding of past choices that could be used to chunk actions at the same level of the hierarchy. Understanding these mechanisms could help elucidate how the complex behavioral repertoire of the primate is implemented.

Advisor: Wallis, Jonathan D
Discrete Element Modeling of Impact Damage on Thermal Barrier Coatings

Natural gas turbines have become an increasingly important part of the energy landscape in the United States, currently accounting for 19% of all electricity production. Efforts to increase thermal efficiency in gas turbines has led to the adoption of highly porous ceramic thermal barrier coatings (TBCs), which are susceptible to erosion and foreign object impact damage. Despite significant investment to improve the design of TBCs, few numerical tools exist which are capable of both accurately capturing the specific failure mechanisms inherent to TBCs and iterating design parameters without the requirement for coupled experimental data./nTo overcome these limitations, a discrete element model (DEM) was created to simulate the microstructure of a TBC using a large-scale assembly of bonded particles. Acting as Lagrangian nodes, the particles can be combined to create accurate representations of TBC geometry and porosity. The inclusion of collision-driven particle dynamics and bonds derived from displacement-dependent force functions endow the microstructure model with the ability to deform and reproduce damage in a highly physical manner. Typical TBC damage mechanisms such as compaction, fracture and spallation occur automatically, without having to tune the model based on experimental observation. Therefore, the first order performance of novel TBC designs and materials can be determined numerically, greatly decreasing the cost of development./nTo verify the utility and effectiveness of the proposed damage model framework, a nanoindentation materials test simulation was developed to serve as a test case. By varying model parameters, such as the porosity of the TBC and maximum applied indenter force, nanoindentation data from more than one hundred distinct permutations was gathered and analyzed. This data was used to calculate the elastic modulus (E) and hardness (H) of the simulated microstructure, which could then be compared to known experimental material property values. A good correlation was found between the predicted properties calculated by the model and those found through experimental nanoindentation tests. Furthermore, conforming to the benefits of DEM, the model was able to accurately recreate the same material damage characteristics observed in literature, such as the onset of inelastic deformation from fracture.

Advisor: Wright, Paul K
Zohdi, Tarek I
Developing Small-Area Health and Exposure Data for the Use in Environmental Public Health Tracking

The turn of the millennium has been accompanied by a rapid growth in data collection along with an increasing ability to store, manipulate and analyze it. In tandem with this development in technology and surveillance, there has been a growing understanding of the importance of the socio-physical environment on population behavior and human health. We capitalize on this progress to develop a methodology by which we develop two macro scale datasets, one national and one state-wide, to support the efforts of the Centers for Disease Control and Prevention's Environmental Public Health Tracking Network (EPHTN) in understanding two important health risks: smoking and obesity. Moreover, we use new geographic information science techniques, spatial statistics methodologies and machine learning algorithms to gain a better understanding of the relationship between spatial patterns in physical and socio-demographic characteristics and health risks. Specifically, we address three specific aims: (1) To use current data systems to develop national small-area predictions of adult smoking and obesity for the EPHTN and research; (2) To evaluate current data systems and spatial analysis tools available to describe the within-school environment and the school-neighborhood socio-physical characteristics of California's public schools thought to influence childhood obesity, and use these to develop a comprehensive multilevel dataset for the EPHTN and research; (3) To test the utility of the dataset developed in aim 2 by applying it to an analysis used to increase the understanding of the relationship between the school environment and childhood obesity by examining the relative importance of school attributes. This analysis determines that current data collection systems provide a valuable resource which we combine for the ease of future research use. We demonstrate that using the spatial structure and socio-demographic patterns of health risks, we are able to downscale adult smoking and obesity prevalence to the ZIP code and census tract levels for the conterminous United States, and develop five-year predictions for these for the four quinquennia in the 1991-2010 time period. Lastly, we confirm the utility of the school dataset and determine through the third aim that individual demographics and the social environment seem to be the predominant determinants of childhood obesity.

Advisor: Jerrett, Michael
Live Imaging of Segmentation Clock Dynamics in Zebrafish

Segmentation is a developmental program in animals that generates semi-repetitive structures along the body axis. In vertebrates, somites are formed sequentially from the mesoderm of the extending tailbud, eventually giving rise to structures such as axial muscles and vertebrae. Somites form with great regularity, every thirty minutes in zebrafish. The periodicity of somite formation is controlled by a set of oscillating genes known as the segmentation clock. To better understand the dynamics of the clock and its role in patterning somites, I have explored its behavior through an in vivo clock reporter, her1:her1-venus. I show that individual cells in the presomitic mesoderm express oscillating clock expression, consistent with predictions made by mathematical modeling and analysis in fixed embryos. I am able to rapidly track a large number of PSM cells using novel semi-automated cell tracking and fluorescence quantification programs. Through these methods, I find that the clock oscillations are coordinated through the Notch pathway, and a loss of Notch function causes slower and desynchonized clock oscillations. I also explore the interaction of mitosis and the segmentation clock, and find the two processes are connected. Finally, I investigate the slowing of the segmentation clock in real-time, and find that oscillations in the anterior PSM are about twice the periodicity of somitogenesis. This has interesting implications for the role of the segmentation clock in patterning somites, including the potential to polarize somites. By studying the segmentation clock in real-time, I am able to better investigate and understand the mechanisms driving somitogenesis.

Advisor: Amacher, Sharon L
Advancing Health Impact Assessment: A Study of Training, Practice and New Approaches in the United States

In an era of growing interest in transdisciplinary collaboration, evidence-based decision-making, open government, and social impact strategies responding to political and economic challenges, Health Impact Assessment (HIA) is increasingly relevant. HIA sits at the juncture of a number of paradigms for democratic processes for dealing with uncertainty and adding value in decision-making. It draws from a rich history of impact assessment that has accounted for multiple bottom lines. While HIA has gained attention as a specific tool, it is also recognized as part of a suite of more ecological and equitable approaches to health. HIA developers are asking both how to make it work better, so that ultimately government will work better./nThis research examines the state of HIA in the United States. It examines the earliest efforts to train a variety practitioners across the country, acknowledging multiple opportunities for capacity-building and many influences on effective HIA practice. More importantly, it identifies a broad definition of effectiveness. Research on HIA practice builds on this, finding that practice is not fully aligned with standards but not necessarily deficient. While objectives should guide HIA processes, the research on training and practice highlights resources as a key driver. The third component of this research considers the resource constraints of public health in general and the opportunities to leverage outside resources using the paradigm of HIA./nIn moving the field forward, frameworks for community-based prevention and transdisciplinary education can inform HIA capacity-building. Evaluation of both processes and outcomes will be useful. While methodological challenges remain, the institutionalization of partnerships, processes, and indicators will support public health goals. The definition and standardization of HIA practice must be balanced with efforts to expand its utility in new areas such as community development. In such cases the HIA process and paradigm can leverage investments by estimating returns in health and social denominations. HIA also helps solve the "wrong pocket" problem by accounting for outcomes across sectors and institutions. If used wisely, HIA will be a critical component of health in all policy, sustainability agendas, and social impact strategies.

Advisor: Seto, Edmund YW
Satariano, William A