Matching Items (87)
Description
This dissertation consists of two essays. The first measures the degree to which schooling accounts for differences in industry value added per worker. Using a sample of 107 economies and seven industries, the paper considers the patterns in the education levels of various industries and their relative value added per worker. Agriculture has notably less schooling and is less productive than other sectors, while a group of services including financial services, education and health care has higher rates of schooling and higher value added per worker. The essay finds that in the case of these specific industries education is important in explaining sector differences, and the role of education all other industries are less defined. The second essay provides theory to investigate the relationship between agriculture and schooling. During structural transformation, workers shift from the agriculture sector with relatively low schooling to other sectors which have more schooling. This essay explores to what extent changes in the costs of acquiring schooling drive structural transformation using a multi-sector growth model which includes a schooling choice. The model is disciplined using cross country data on sector of employment and schooling constructed from the IPUM International census collection. Counterfactual exercises are used to determine how much structural transformation is accounted for by changes in the cost of acquiring schooling. These changes account for small shares of structural transformation in all economies with a median near zero.
ContributorsSchreck, Paul (Author) / Herrendorf, Berthold (Committee member) / Lagakos, David (Committee member) / Schoellman, Todd (Committee member) / Arizona State University (Publisher)
Created2011
Analysis of photocatalysis for precursor removal and formation inhibition of disinfection byproducts
Description
Disinfection byproducts are the result of reactions between natural organic matter (NOM) and a disinfectant. The formation and speciation of DBP formation is largely dependent on the disinfectant used and the natural organic matter (NOM) concentration and composition. This study examined the use of photocatalysis with titanium dioxide for the oxidation and removal of DBP precursors (NOM) and the inhibition of DBP formation. Water sources were collected from various points in the treatment process, treated with photocatalysis, and chlorinated to analyze the implications on total trihalomethane (TTHM) and the five haloacetic acids (HAA5) formations. The three sub-objectives for this study included: the comparison of enhanced and standard coagulation to photocatalysis for the removal of DBP precursors; the analysis of photocatalysis and characterization of organic matter using size exclusion chromatography and fluorescence spectroscopy and excitation-emission matrices; and the analysis of photocatalysis before GAC filtration. There were consistencies in the trends for each objective including reduced DBP precursors, measured as dissolved organic carbon DOC concentration and UV absorbance at 254 nm. Both of these parameters decreased with increased photocatalytic treatment and could be due in part to the adsorption to as well as the oxidation of NOM on the TiO2 surface. This resulted in lower THM and HAA concentrations at Medium and High photocatalytic treatment levels. However, at No UV exposure and Low photocatalytic treatment levels where oxidation reactions were inherently incomplete, there was an increase in THM and HAA formation potential, in most cases being significantly greater than those found in the raw water or Control samples. The size exclusion chromatography (SEC) results suggest that photocatalysis preferentially degrades the higher molecular mass fraction of NOM releasing lower molecular mass (LMM) compounds that have not been completely oxidized. The molecular weight distributions could explain the THM and HAA formation potentials that decreased at the No UV exposure samples but increased at Low photocatalytic treatment levels. The use of photocatalysis before GAC adsorption appears to increase bed life of the contactors; however, higher photocatalytic treatment levels have been shown to completely mineralize NOM and would therefore not require additional GAC adsorption after photocatalysis.
ContributorsDaugherty, Erin (Author) / Abbaszadegan, Morteza (Thesis advisor) / Fox, Peter (Committee member) / Mayer, Brooke (Committee member) / Arizona State University (Publisher)
Created2011
Description
This thesis research focuses on phylogenetic and functional studies of microbial communities in deep-sea water, an untapped reservoir of high metabolic and genetic diversity of microorganisms. The presence of photosynthetic cyanobacteria and diatoms is an interesting and unexpected discovery during a 16S ribosomal rRNA-based community structure analyses for microbial communities in the deep-sea water of the Pacific Ocean. Both RT-PCR and qRT-PCR approaches were employed to detect expression of the genes involved in photosynthesis of photoautotrophic organisms. Positive results were obtained and further proved the functional activity of these detected photosynthetic microbes in the deep-sea. Metagenomic and metatranscriptomic data was obtained, integrated, and analyzed from deep-sea microbial communities, including both prokaryotes and eukaryotes, from four different deep-sea sites ranging from the mesopelagic to the pelagic ocean. The RNA/DNA ratio was employed as an index to show the strength of metabolic activity of deep-sea microbes. These taxonomic and functional analyses of deep-sea microbial communities revealed a `defensive' life style of microbial communities living in the deep-sea water. Pseudoalteromonas sp.WG07 was subjected to transcriptomic analysis by application of RNA-Seq technology through the transcriptomic annotation using the genomes of closely related surface-water strain Pseudoalteromonas haloplanktis TAC125 and sediment strain Pseudoalteromonas sp. SM9913. The transcriptome survey and related functional analysis of WG07 revealed unique features different from TAC125 and SM9913 and provided clues as to how it adapted to its environmental niche. Also, a comparative transcriptomic analysis of WG07 revealed transcriptome changes between its exponential and stationary growing phases.
ContributorsWu, Jieying (Author) / Meldrum, Deirdre R. (Thesis advisor) / Zhang, Weiwen (Committee member) / Abbaszadegan, Morteza (Committee member) / Neuer, Susanne (Committee member) / Arizona State University (Publisher)
Created2013
Description
This dissertation consists of three essays that broadly deal with the growth and development of economies across time and space. Chapter one is motivated by the fact that agricultural labor productivity is key for understanding aggregate cross-country income differences. One important proximate cause of low agricultural productivity is the low use of intermediate inputs, such as fertilizers, in developing countries. This paper argues that farmers in poor countries rationally choose to use fewer intermediate inputs because it limits their exposure to large uninsurable risks. I formalize the idea in a dynamic general equilibrium model with incomplete markets, subsistence requirements, and idiosyncratic productivity shocks. Quantitatively, the model accounts for two-thirds of the difference in intermediate input shares between the richest and poorest countries. This has important implications for cross-country productivity. Relative to an identical model with no productivity shocks, the addition of agricultural shocks amplifies per capita GDP differences between the richest and poorest countries by nearly eighty percent. Chapter two deals with the changes in college completion in the United States over time. In particular, this paper develop a dynamic lifecycle model to study the increases in college completion and average IQ of college students in cohorts born from 1900 to 1972. I discipline the model by constructing historical data on real college costs from printed government reports covering this time period. The main finding is that that increases in college completion of 1900 to 1950 birth cohorts are due primarily to changes in college costs, which generate a large endogenous increase in college enrollment. Additionally, evidence is found that supports cohorts born after 1950 underpredicted sharp increases in the college earnings premium they eventually received. Combined with increasing college costs during this time period, this generates a slowdown in college completion, consistent with empirical evidence for cohorts born after 1950. Lastly, the rise in average college student IQ cannot be accounted for without a decrease in the variance of ability signals. This is attributed the increased precision of ability signals primarily to the rise of standardized testing. Chapter three again deals with cross-country income differences. In particular, it is concerned with the fact that cross-country income differences are primarily accounted for by total factor productivity (TFP) differences. Motivated by cross-country empirical evidence, this paper investigates the importance individuals who operate their own firms because of a lack of other job opportunities (need-based entrepreneurs). I develop a dynamic general equilibrium labor search model with with entrepreneurship to rationalize this misallocation across occupations and assess its role for understanding cross-country income differences. Developing countries are assumed to have tighter collateral constraints on entrepreneurs and lower unemployment benefits. Because these need-based entrepreneurs actually have a comparative advantage as workers, they operate smaller and less productive firms, lowering aggregate TFP in developing countries.
ContributorsDonovan, Kevin (Author) / Prescott, Edward C. (Thesis advisor) / Herrendorf, Berthold (Committee member) / Lagakos, David (Committee member) / Schoellman, Todd (Committee member) / Arizona State University (Publisher)
Created2013
Description
This dissertation consists of three essays on education and macroeconomics. The first chapter analyzes whether public education financing systems can account for large differences among developed countries in earnings inequality and intergenerational earnings persistence. I first document facts about public education in the U.S. and Norway, which provide an interesting case study because they have very different earnings distributions and public education systems. An overlapping generations model is calibrated to match U.S. data, and tax and public education spending functions are estimated for each country. The benchmark exercise finds that taxes and public education spending account for about 15% of differences in earnings inequality and 10% of differences in intergenerational earnings persistence between the U.S. and Norway. Differences in private education spending and early childhood education investments are also shown to be quantitatively important. The second chapter develops a life-cycle model to study increases in college completion and average ability of college students born from 1900 to 1972. The model is disciplined with new historical data on real college costs from printed government surveys. I find that increases in college completion for 1900 to 1950 cohorts are due primarily to changes in college costs, which generate large endogenous increases in college enrollment. Additionally, I find strong evidence that post-1950 cohorts under-predicted large increases in the college earnings premium. Modifying the model to restrict perfect foresight of the education premia generates a slowdown in college completion consistent with empirical evidence for post-1950 cohorts. Lastly, I find that increased sorting of students by ability can be accounted for by increasingly precise ability signals over time. The third chapter assesses how structural transformation is affected by sectoral differences in labor-augmenting technological progress, capital intensity, and capital-labor substitutability. CES production functions are estimated for agriculture, manufacturing, and services on post-war U.S. data. I find that sectoral differences in labor-augmenting technological progress are the dominant force behind changes in sectoral labor and relative prices. Therefore, Cobb-Douglas production functions with labor-augmenting technological change capture the main technological forces behind post-war U.S. structural transformation.
ContributorsHerrington, Christopher (Author) / Prescott, Edward C. (Thesis advisor) / Ventura, Gustavo (Thesis advisor) / Herrendorf, Berthold (Committee member) / Schoellman, Todd (Committee member) / Arizona State University (Publisher)
Created2013
Description
Bacteroides have been suggested as alternative indicators of fecal pollution since they are highly abundant in feces and are thought to have limited potential to grow in environment. However, recent literature suggests that Bacteroides can potentially survive within water distribution systems. The first objective of this study was therefore to investigate the validity of Bacteroides as a fecal indicator for drinking water through laboratory experiments and field studies. Experiments were performed using a laboratory scale PVC model water distribution system that was spiked with 109 Bacteroides. Samples were collected over the following four and analyzed by culture and molecular-based techniques. Second, field studies were performed by collecting water meters from two large chlorinated water distribution systems in central Arizona. Upon removal for repair by city personnel, meters were collected and biofilms samples were gathered within two hours. The biofilms were then analyzed using culture and molecular-based assays. The results from these studies support the hypothesis that Bacteroides DNA may be found in water distribution systems despite the difficulty of cultivating these bacterial cells. These experiments present the importance of considering biofilm interactions with fecal indicator bacteria when performing molecular assays on environmental samples, as biofilms may provide protection from high oxygen concentrations and grazing protozoa in bulk water that limit the persistence Bacteroides in the environment. Although the significance of biofilm interactions with surface or recreational waters may be small, they are likely important when considering drinking water delivered through distribution systems. The second objective of this study was to investigate alternative detection methodologies for the fecal indicator Bacteroides. In particular, this study focused on using a simplified protocol of Nucleic Acid Sequence Based Amplification (NASBA) and Thermophilic Helicase-Dependent Amplification (tHDA) to amplify the highly conserved 16s rRNA gene in the genomic DNA of fecal indicator Bacteroides. The results of this study show that the simplified NASBA procedure was not able to amplify the target, while continuous problems with tHDA exposed the methods lack of reliability. These results suggest higher reliability in the isothermal amplification methods needs to be achieved before application to environmental samples.
ContributorsDunkin, Nate (Author) / Abbaszadegan, Morteza (Thesis advisor) / Alum, Absar (Committee member) / Fox, Peter (Committee member) / Arizona State University (Publisher)
Created2012
Description
Water quality in surface water is frequently degraded by fecal contamination from human and animal sources, imposing negative implications for recreational water use and public safety. For this reason it is critical to identify the source of fecal contamination in bodies of water in order to take proper corrective actions for controlling fecal pollution. Bacteroides genetic markers have been widely used to differentiate human from other sources of fecal bacteria in water. The results of this study indicate that many assays currently used to detect human-specific Bacteroides produce false positive results in the presence of freshwater fish. To further characterize Bacteroides from fish and human, the fecal samples were cultured, speciated, and identified. As a result, forty six new Bacteroides 16S rRNA gene sequences have been deposited to the NCBI database. These sequences, along with selected animal fecal sample Bacteroides, were aligned against human B. volgatus, B. fragilis, and B. dorei to identify multi-segmented variable regions within the 16S rRNA gene sequence. The collected sequences were truncated and used to construct a cladogram, showing a clear separation between human B. dorei and Bacteroides from other sources. A proposed strategy for source tracking was field tested by collecting water samples from central AZ source water and three different recreational ponds. PCR using HF134 and HF183 primer sets were performed and sequences for positive reactions were then aligned against human Bacteroides to identify the source of contamination. For the samples testing positive using the HF183 primer set (8/13), fecal contamination was determined to be from human sources. To confirm the results, PCR products were sequenced and aligned against the four variable regions and incorporated within the truncated cladogram. As expected, the sequences from water samples with human fecal contamination grouped within the human clade. As an outcome of this study, a tool box strategy for Bacteroides source identification relying on PCR amplification, variable region analysis, human-specific Bacteroides PCR assays, and subsequent truncated cladogram grouping analysis has been developed. The proposed strategy offers a new method for microbial source tracking and provides step-wise methodology essential for identifying sources of fecal pollution.
ContributorsKabiri-Badr, Leila (Author) / Abbaszadegan, Morteza (Thesis advisor) / Bingham, Scott (Committee member) / Rock, Channah (Committee member) / Fox, Peter (Committee member) / Mclain, Jean (Committee member) / Arizona State University (Publisher)
Created2012
Description
Nanotechnology is a scientific field that has recently expanded due to its applications in pharmaceutical and personal care products, industry and agriculture. As result of this unprecedented growth, nanoparticles (NPs) have become a significant environmental contaminant, with potential to impact various forms of life in environment. Metal nanoparticles (mNPs) exhibit unique properties such as increased chemical reactivity due to high specific surface area to volume ratios. Bacteria play a major role in many natural and engineered biogeochemical reactions in wastewater treatment plants and other environmental compartments. I have evaluated the laboratory isolates of E. coli, Bacillus, Alcaligenes, Pseudomonas; wastewater isolates of E. coli and Bacillus; and pathogenic isolate of E. coli for their response to 50 & 100 nm sized Cu nanoparticles (CuNPs). Bactericidal tests, scanning electron microscopy (SEM) analyses, and probable toxicity pathways assays were performed. The results indicate that under continuous mixing conditions, CuNPs are effective in inactivation of the selected bacterial isolates. In general, exposure to CuNPs resulted in 4 to >6 log reduction in bacterial population within 2 hours. Based on the GR, LDH and MTT assays, bacterial cells showed different toxicity elicitation pathways after exposure to CuNPs. Therefore, it can be concluded that the laboratory isolates are good candidates for predicting the behavior of environmental isolates exposed to CuNPs. Also, high inactivation values recorded in this study suggest that the presence of CuNPs in different environmental compartments may have an impact on pollutants attenuation and wastewater biological treatment processes. These results point towards the need for an in depth investigation of the impact of NPs on the biological processes; and long-term effect of high load of NPs on the stability of aquatic and terrestrial ecologies.
ContributorsAlboloushi, Ali (Author) / Abbaszadegan, Morteza (Thesis advisor) / Alum, Absar (Committee member) / Fox, Peter (Committee member) / Olson, Larry (Committee member) / Arizona State University (Publisher)
Created2012
Description
Sanctuary jurisdictions are jurisdictions that do not enforce one or more aspects of federal immigration policy in regards to unauthorized immigrants. Some states maintain state-wide sanctuary policies while others are adamantly against them. Estimates of taxes that unauthorized immigrants pay and estimates of the amount of state funding that unauthorized immigrants can access (education, financial aid, corrections, and welfare) reveal that regardless of sanctuary status, unauthorized immigrants may “pay in” more than they “take out” from the system. The status of “sanctuary jurisdiction” does not appear to have much if any effect on the net state budget. However, unauthorized immigrants are able to access more welfare programs in sanctuary states.
ContributorsLattus, Anna Olivia (Author) / Herrendorf, Berthold (Thesis director) / Hobijn, Bart (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / Economics Program in CLAS (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
The Downtown ASU campus Bio 201 and 202 anatomy labs are planning on revising the method in which students are presented and evaluated on lab material for the Fall 2016 semester. The goal of this thesis project was to analyze the methods used in previous semesters in order to determine which method, if any, proved to be the most effective means of evaluation for the students. The general setup of the anatomy labs is that the students come to lab, receive that week's instruction, and then are quizzed on that week's material at the beginning of their next lab. Then roughly every five new segments there is a practical covering the cumulative information from the last five segments. Therefore it is imperative to analyze the current and previous methods of evaluation in order to find which one has the strongest correlation with an individual's quiz performance and their practical grade. Since the Fall 2014 semester three different quiz types have been used in lab while the practical has remained the same. The three different types of quizzes are written, turning point, and no quiz; in order to determine which method was most effective overall practical averages for each student was compared to their corresponding quiz average. This data was put into Excel and used to generate a graph in order to determine the r-squared values to determine which had the strongest correlation. The results showed that no matter what quiz type was used there was no statistically significant correlation between quiz performance and practical performance; in fact practical averages were nearly identical between semesters for Bio 201 and 202. However, visual analysis of the graph demonstrated that certain quiz methods did seem to be more effective than others. For Bio 201 it seemed that written quizzes were the most effective means of evaluation, while in Bio 202 the turning point quizzes were best.
ContributorsOlson, Zachary G (Author) / Kingsbury, Jeffrey (Thesis director) / Legere, Jenny (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05