146 research outputs found
Essays on Cigarette Regulation, Prenatal Smoking, and Cross-Border Shopping
In my dissertation, I study the impact of cigarette regulation on two main outcomes: prenatal smoking and cross-border shopping. The first chapter of my dissertation concerns how state-level cigarette tax increases affect cross-state border shopping for cigarettes. To estimate this relationship, I use high-resolution census block group-by-month cellphone tracking data from Safegraph. I estimate a Callaway and Sant’Anna (2021) difference-in-differences model that accommodates my unique setting in which the tax increases I consider become effective at different times throughout the full length of the study. The use of this data allows me to avoid measurement error that could be present in self-reported data. I find that the median census block group (CBG) sent 0.53 more cross-border shoppers per month in response to a cigarette tax increase (19% increase from the pre-tax cross-border shopping mean). Further, I show that CBGs with many low educated adults and rural CBGs send substantially more cross-border shoppers than their respective counterparts. Performing a back-of-the-envelope calculation, I estimate that cigarette tax increases before 2019 increased cigarette tax revenue leakage in 2019 by 9,084,824 in Kentucky. In sum, these results suggest that cross-border shopping remains an ongoing challenge for tobacco control policy efforts and for reducing tobacco-related disparities.
The second chapter of my dissertation, written with my committee chair, studies how cigarette taxes and indoor smoking restrictions impact the propensity and intensity of smoking by a pregnant woman (prenatal smoking). We use data from the Nation Vital Statistics System to get smoking data from almost every pregnant woman in the USA from 1995 to 2018. To reduce bias from dynamic and heterogeneous treatment effects, we estimate a modified stacked difference-in-differences model that accommodates our unique policy environment in which policies are often gradually strengthened over time and dose increases vary. We find some evidence that indoor smoking restrictions modestly decreases prenatal smoking and, contrary to previous literature, that cigarette taxes do not significantly impact prenatal smoking. Indoor smoking restrictions may be better from a health-equity perspective than cigarette taxes
Further development of an algorithm for the nonlinear stability analysis of the orbiting astronomical observatory paired-tracker control system Final report
Algorithm development for estimating domain of attraction of OAO paired-tracker equilibrium state with Liapunov function
A Quantitative Description of State-Level Taxation of Oil and Gas Production in the Continental U.S.
We provide a quantitative description of state-level taxation of oil and gas production in the Continental U.S. for 2004 to 2013. Aggregate revenues from production taxes nearly doubled in real terms over the period, reaching 2.4 per barrel or $5.5 per ton of carbon. Lastly, state-level tax rates are two-thirds higher in states excluding oil and gas wells from local property taxes, suggesting that the policies are substitutes for one another
Detection of retained microbubbles in carotid arteries with real-time low mechanical index imaging in the setting of endothelial dysfunction
ObjectivesWe sought to determine if intravenously injected microbubbles would be retained by the carotid arteries (CAs) in the setting of endothelial dysfunction (ED) using a linear transducer equipped with a low mechanical index pulse sequence scheme (PSS).BackgroundMicrobubbles normally pass freely through large and small vessels but are retained in regions with ED. New high-frequency low mechanical index PSS can potentially be utilized to image these retained microbubbles.MethodsIntravenous albumin- and lipid-encapsulated microbubbles were administered in seven pigs while imaging the CAs before and after a 20% intralipid infusion to induce hypertriglyceridemia. The degree of microbubble retention was quantified by measuring endothelial acoustic intensity (AI) after clearance of free-flowing microbubbles. Microbubble adherence was also evaluated after selective balloon injury of the CAs. The CA diameter responses to acetylcholine were quantified.ResultsAfter induction of hypertriglyceridemia, adherence of albumin-encapsulated microbubbles was visually evident in all CAs, and endothelial AI increased significantly (p < 0.001 compared with baseline). The CA responses to acetylcholine went from vasodilation at baseline to vasoconstriction during hypertriglyceridemia. Endothelial AI also increased in the balloon-stretched vessels (p < 0.01 compared with uninjured vessels) after albumin-encapsulated microbubble injection, with a ring of microbubbles selectively adhering to the injured segment. This retention was not observed with lipid-encapsulated microbubbles. Scanning electron microscopy confirmed that albumin-coated microbubbles adhered to endothelial cells.ConclusionsRetention of intravenously injected albumin microbubbles occurs in the setting of both global and regional ED in large vessels and can be noninvasively imaged with high-frequency low mechanical index PSS
The use of microbubbles to target drug delivery
Ultrasound-mediated microbubbles destruction has been proposed as an innovative method for noninvasive delivering of drugs and genes to different tissues. Microbubbles are used to carry a drug or gene until a specific area of interest is reached, and then ultrasound is used to burst the microbubbles, causing site-specific delivery of the bioactive materials. Furthermore, the ability of albumin-coated microbubbles to adhere to vascular regions with glycocalix damage or endothelial dysfunction is another possible mechanism to deliver drugs even in the absence of ultrasound. This review focuses on the characteristics of microbubbles that give them therapeutic properties and some important aspects of ultrasound parameters that are known to influence microbubble-mediated drug delivery. In addition, current studies involving this novel therapeutical application of microbubbles will be discussed
Self-assembled liposome-loaded microbubbles: The missing link for safe and efficient ultrasound triggered drug-delivery
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