Three Essays on Urban Policies

This dissertation contains three chapters that examine urban policies. The first chapter considers the impacts of a new card fee for prepaid transit cards in New York City. Since 1998, the New York City Metropolitan Transportation Authority (MTA) system has used prepaid cards (MetroCards) to collect subway and bus fares. In 2013, the MTA imposed a $1 card fee (surcharge) on new MetroCard purchases. Using a novel dataset with transaction-level deposit and card use information, I show that the fee caused riders to put more money on new MetroCard purchases, particularly those in low-income neighborhoods and those who used cash or debit (rather than credit) cards. As a result, the net monthly outstanding balance from transit card deposits increased dramatically, with riders lending an extra$150 million, on an annual basis, to the MTA. Moreover, over $20 million of the increased balances in the first year were never redeemed and escheated to the MTA when these cards expired. The leading explanation highlights the importance of the cost of effort to remember to carry the same card. I pose a structural model to calibrate the effect of a new card fee. Counterfactual simulation predicts that a new card fee of$4.35 will maximize the MTA's profit. These findings have implications for fiscal policy designs and fee structures of prepaid card industry. The second chapter examines the causal effects of local access to alcohol on birth outcomes. After the repeal of National Prohibition in 1933, 30 states gave counties and municipalities the local option to continue alcohol restrictions. Citizens set alcohol control policies in their communities through jurisdiction-wide elections (i.e., local option elections). Currently, 10% of U.S. communities maintain a ban on some or all alcohol sales. Assessing the impact of local access to alcohol on alcohol-related outcomes such as birth weight, drinking under the influence, alcohol-related crimes, and so on is complicated by the potential non-random selection of liquor laws. I examine the causal effects of local access to alcohol on birth outcomes by comparing municipalities where referenda on legalizing liquor sales passed and failed by narrow margins. My results indicate that municipalities which were studied experienced higher incidence of low birth weight after legalizing the local sale of alcohol to the general public. The incidence of low birth weight rose by 4.5% for babies born within two years after the elections. The third chapter measures the deleterious effect of institutional discrimination on health. Interest in the impact of institutional discrimination on health outcomes has increased dramatically. Since research has mostly been done in the western context where social segregation has already been established, it is difficult to isolate the effect of initial social segregation on health outcomes. In this chapter, I examine the causal effect of institutional discrimination on health by exploiting a 1964 change in household registration system (hukou) in China, which caused a nationwide discrimination against rural dwellers. The 1964 change in the hukou system started to put tight control on domestic migration. Thereafter, movement from rural to urban areas became virtually impossible. Following the 1964 change in hukou policy, the fraction of urban hukou residents suddenly fell from over 50% to about 40%. I use this discontinuity in the proportion of urban hukou residents to identify the causal effect of institutional discrimination anchored in the hukou system on health. The regression-discontinuity (RD) design estimates suggest that urban hukou citizens have much better chances of being in good health. The deleterious effect of rural hukou on health possibly works through mechanisms of labor disparity, limited access to healthcare, and deprivation of quality education

Gut Microbiota Correlates With Clinical Responsiveness to Erythropoietin in Hemodialysis Patients With Anemia

The main treatment for renal anemia in end-stage renal disease (ESRD) patients on hemodialysis is erythropoiesis (EPO). EPO hyporesponsiveness (EH) in dialysis patients is a common clinical problem, which is poorly understood. Recent searches reported that gut microbiota was closely related to the occurrence and development of ESRD. This study aims to explore the changes in gut microbiota between ESRD patients with different responsiveness to EPO treatment. We compared the gut microbiota from 44 poor-response (PR) and 48 good-response (GR) hemodialysis patients treated with EPO using 16S rDNA sequencing analysis. The results showed that PR patients displayed a characteristic composition of the gut microbiome that clearly differed from that of GR patients. Nine genera (Neisseria, Streptococcus, Porphyromonas, Fusobacterium, Prevotella_7, Rothia, Leptotrichia, Prevotella, Actinomyces) we identified by Lasso regression and ROC curves could excellently predict EH. In contrast, five genera (Faecalibacterium, Citrobacter, Bifidobacterium, Escherichia–Shigella, Bacteroides) identified by the same means presented a protective effect against EH. Analyzing the correlation between these biomarkers and clinical indicators, we found that gut microbiota may affect response to EPO through nutritional status and parathyroid function. These findings suggest that gut microbiota is altered in hemodialysis patients with EH, giving new clues to the pathogenesis of renal anemia

Assessing the quality of primary healthcare for diabetes in China: multivariate analysis using the China Health and Retirement Longitudinal Study (CHARLS) Database

Objective To assess the quality of primary healthcare (PHC) for patients with diabetes in China from 2011 to 2015.Setting This study analysed data on 1006, 1472 and 1771 participants with diabetes who were surveyed in 2011, 2013 and 2015, respectively, in the China Health and Retirement Longitudinal Study, a nationally representative survey conducted in 29 provinces of China.Outcome measures The study measured the proportions of patients with diabetes who received diabetes-related health education, examinations and treatments, as well as the hospital admission rate due to diabetes of these patients. Multilevel logistic regression was used to adjust sociodemographic variables.Results According to the multivariate analysis, the proportion of patients who received diabetes-related health education decreased significantly (OR=0.74, 95% CI 0.61 to 0.90), and the proportion of those receiving examinations and treatments remained unchanged from 2011 to 2015. Diabetes-related hospitalisation increased from 4.01% in 2011 to 6.08% in 2013 (OR=1.47, 95% CI 0.97 to 2.22), and recurrent hospitalisations increased from 18.87% in 2011 to 28.45% in 2015 (OR=1.78, 95% CI 1.44 to 2.20). The proportions of patients with diabetes-related and recurrent hospitalisations in western China were higher than those in the east (OR=1.80, 95% CI 1.13 to 2.87; OR=1.92, 95% CI 1.50 to 2.45).Conclusions Nationally, the analysis of patient-reported process and outcome indicators cannot confirm that the quality of PHC has improved in China during 2011–2015. Regional disparities in primary diabetes care require urgent resource allocation to western China. Establishing a national quality registry for PHC, which transparently reports outcomes by region and social-economic position, is essential for countries sharing the challenge of improving both quality and equity of PHC

Spatial Distribution and Influencing Factors of Chinese Time-Honored Catering Brands in the Five Northwestern Provinces

The Chinese Time-honored Catering Brands (CTCBs) in the five northwestern provinces are the accumulation of culture in the northwest of China and have precious value. Their formation and development process have their own characteristics and rules. In order to clarify the spatial distribution characteristics and influencing factors of CTCBs in these provinces, this study uses geolocated social media data (the data of the CTCBs’ directory, location, and per capita consumption level), and applies statistical analysis, kernel density analysis, standard deviational ellipse, and buffer analysis to analyze the spatial distribution characteristics and influencing factors of CTCBs in the five northwestern provinces. The results show that: (1) the spatial development intensity of CTCBs is relatively strong in their original place, and their spatial distribution is uneven. The overall distribution is in the northwest-southeast direction, with strong agglomeration, and tends to be scattered in the periphery of the agglomeration area. There are some areas with higher concentrations distributed in the form of patches. (2) The number and spatial distribution of old brands with different grades and tastes have different characteristics. (3) The spatial distribution pattern of CTCBs is formed under a variety of factors, such as historical and traditional culture, regional traffic conditions and urban development patterns, etc

Spatial–Temporal Distribution of Tropospheric Specific Humidity in the Arid Region of Northwest China

Based on the atmospheric temperature and dew point temperature difference series of mandatory levels in the arid region of northwest China, we calculated the specific humidity of stations at 200, 300, 400, 500, 700, and 850 hPa and analyzed the spatial and temporal distribution. The specific humidity of radiosonde is compared with two sets of reanalysis data (ERA-interim from European Centre for Medium Range Weather Forecasts and Modern Era Retrospective Analysis for Research and Applications: MERRA-2). The annual specific humidity and summer specific humidity show a positive trend in the vertical atmospheric levels during the period 1958–2018. Taking the middle of the 1980s and 2002 as boundaries, the selected levels show the trend of “declining-gentle rising-fluctuation rising”. The maximum specific humidity is observed at the level of 850–700 hPa during the warm months of the year, and the most vertical expansion in specific humidity is in July. In terms of spatial distribution, the specific humidity is greatly influenced by the topography and underlying surface at lower levels. The characteristics of spatial distribution of the trend are well described by the two sets of reanalysis data in the middle and upper levels, but there are some deficiencies in depicting the trend in the lower levels

Visualization and Comparison of the Level of Apurinic/Apyrimidinic Endonuclease 1 in Live Normal/Cancerous and Neuron Cells with a Fluorescent Nanoprobe

As a major apurinic/apyrimidinic endonuclease and a redox signaling protein in human cells, APE1 plays a crucial role in cellular function and survival. The relationship between alterations of APE1 expression and subcellular localization and the initiation, development and treatment of various cancers has received extensive attention. However, comparing the in-vivo activity of APE1 in normal and cancerous breast live cells remains challenging due to the low efficiency of commonly used liposome transfection methods in delivering DNA substrate probes into human normal breast epithelial cells (MCF-10A). In this work, we develop a DNA/RNA hybrid-based small magnetic fluorescent nanoprobe (25 ± 3 nm) that can be taken up by various live cells under magnetic transfection. The D0/R-nanoprobe demonstrates an outstanding specificity toward APE1 and strong resistance to the cellular background interference. Using this nanoprobe, we are not only able to visualize the intracellular activity of APE1 in breast ductal carcinoma (MCF-7) live cells, but also demonstrate the APE1 activity in MCF-10A live cells for the first time. The method is then extended to observe the changes in APE1 levels in highly metabolically active neuroendocrine cells under normal conditions and severe attacks by reactive oxygen species in real-time. The fluorescent nanoprobe provides a useful tool for studying the dynamic changes of intracellular APE1 in normal or cancerous live cells. It also displays the potential for visible and controllable release of miRNA drugs within live cells for therapeutic purposes