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The Effects of Recreational Marijuana Dispensaries on Local Opioid Mortality
Full text linkThis study examines how recreational marijuana dispensaries in Colorado affect opioid mortality at the county level. Using a difference-in-difference model with county and year fixed effects, I estimate the impact of recreational marijuana dispensary access on fatal opioid overdoses. Additionally, I employ distance from a major roadway and border as two instrumental variables to help limit the endogeneity associated with the location of dispensaries. Previous studies have shown that medical and recreational marijuana dispensary access decreases opioid mortality at the state level. Still, no study has explored the connection between recreational marijuana dispensaries and overdoses at the county level. Using data from the CDC, Colorado Department of Revenue, US Census, and other sources, I found that under some specifications, one additional dispensary is associated with a 0.0668 to 0.0747 unit decrease in opioid mortality. However, this result was not robust under every specification. Given the worsening opioid crisis in the United States, research into alternate methods of reducing opioid mortality is critical
Implications of Antibiotic and Bacteriophage Resistance in Environmentally Isolated E. coli
Full text linkThe increasing prevalence of antibiotic-resistant bacteria is an emerging problem for humans. Clinical misuse, overuse in agricultural and food settings, and limited numbers of new antibiotics have accelerated the proliferation of antibiotic-resistant bacteria. To confront this threat, scientists must develop new therapeutics that kill these antibiotic-resistant bacteria. In this study, we used Escherichia coli to analyze antibiotic and bacteriophage susceptibility. E. coli is a common, mostly benign, enteric, gram-negative bacteria. We isolated three E. coli strains from the Hans Groot Kill, a stream that runs through Union College’s campus. We sought to assess various E. coli strains’ antibiotic resistance, susceptibility to bacteriophages, and underlying resistance mechanisms. We compared the environmental E. coli isolates to known lab strains of E. coli. Using T4 bacteriophage, a well characterized viral pathogen that carries out a lytic cycle in E. coli bacteria, we conducted modified plaque assays with the three environmental isolates and lab strains “B” and “C.” The environmental isolates were found to be highly resistant to T4 phage, while the lab strains were susceptible. We also conducted Kirby-Bauer antimicrobial disk susceptibility tests, using various gram-negative targeted drugs. We found the lab strains to be highly susceptible to all of the antibiotics, while the environmental isolates showed intermediate resistance to some of the antibiotics. Surprisingly, both environmental and lab strains were encapsulated. These patterns of resistance to phages and antimicrobial drugs suggest that environmental E. coli strains must have some mechanism for resistance that could be exploited as a novel means of treating drug-resistant infections
“Kids are 100% Behind”: The Impact of the Covid-19 Pandemic on Elementary and Secondary School Students in Massachusetts
Full text linkFor two years now, the Covid-19 pandemic has continuously impacted all aspects of our society, including K-12 education. The impact of the Covid-19 pandemic is thought to be very harmful and have long-term consequences. Understanding this impact is very important, which is why this study focuses on how the Covid-19 pandemic has impacted K-12 education, specifically how it has impacted academics and behavior while attempting to understand which groups were most impacted. This problem was approached in three different ways. Z-score changes were used to determine the changes by subgroup in the percentage of students failing to meet expectations and exceeding expectations in Massachusetts Comprehensive Assessment System (MCAS) scores for all available test scores between 2019 and 2021; linear regressions were used to determine which factors led to MCAS score changes in the average test scores, the percentage of students failing expectations, and the percentage of students exceeding expectations between 2019 and 2021 for 3rd, 6th, and 10th grade English Language Arts and Mathematics; and 32 educators from a variety of school districts across Massachusetts were interviewed to further understand the academic impact in schools and to understand how students’ behavior has been impacted as a result of the pandemic. The differences in MCAS scores by subgroup showed an increase in the number of students failing to meet expectations for all test scores and a decrease in the number of students exceeding expectations for almost all test scores between 2019 and 2021; these results also showed students of color and English Language Learner students being more impacted than White students. The linear regression results found that across different grades and subjects, different factors contributed to the change more than others, but Hispanic students were the most likely to lead to an adverse change while students from higher household incomes were the most likely to lead to a positive change. The linear regressions also showed that 6th-grade students were more impacted than 3rd and 10th-grade students and that there was more variance in Mathematics than English Language Arts test scores. Finally, the interviews showed noticeable class-based disparities in schools and a decline in students’ behavior, mental health, and social skills. Overall, the results from this study show that the Covid-19 pandemic has impacted K-12 education and that the impact was disparate, which will most likely continue to be an issue as time goes on
Single Photon Experiments using Type-I and Type-II Spontaneous Parametric Downconversion
Full text linkWe created an optical setup that detects single photons generated using Type-I spontaneous parametric down conversion (SPDC). A laser diode creates violet 405nm photons that are split into pairs of infrared 810nm photons and are detected in coincidence using a Field Programmable Gate Array (FPGA), using programs in LabVIEW for data acquisition. We found a value of ùëî2(0) to be 0.0014 ¬± 0.001, conclusively demonstrating the particle nature of light. Incorporating a Mach-Zhender interferometer will allow us to simultaneously demonstrate the wave nature through single-photon interference
Patronage, Power, and Ideology: Political Actors and Buddhism and Confucianism in China from the Tang to the Ming
Full text linkThis project shall examine the interactions of actors in the political realm of China with two ideologies, Buddhism and Confucianism, during the period ranging from the beginning of the Tang Dynasty in 618 until the end of the reign of the Emperor Yongle of the Ming Dynasty (1368-1644) in 1424. During the time period selected, several actors, both political and religious, attempted to make use of philosophical and religious traditions, these being Confucianism and Buddhism among others, to justify the political rule of either themselves or to further the political needs of their own religious tradition. Each figure was chosen primarily because he or she was a crucial political or intellectual figure for each of their dynasties; Wu Zetian and Emperor Wuzong for the Tang, Zhu Xi for the Song, Khubilai Khan for the Yuan, and the Hongwu and Yongle Emperors for the Ming. Each figure also interacted significantly, whether positively or negatively, with both Buddhism and Confucianism over the course of their careers, even in the case of the thinker Zhu Xi. Nevertheless, each figure primarily associated themselves politically and ideologically with one of the two traditions, or in the Emperor Wuzong\u27s case, the third tradition of Daoism. This project therefore examines themes of political power, patronage, ideology, religion, thought, and legitimacy within the context of Dynastic Chinese history extending from the Tang through the Early Ming
Investigating interactions of per- and polyfluoroalkyl acids with human serum albumin using an equilibrium dialysis method
No full textPer- and polyfluoroalkyl substances (PFAS) are anthropogenic compounds present in a wide range of consumer products. These chemicals have been identified as Contaminants of Emerging Concern (CECs) because they are both environmentally toxic and persistent, as well as bioaccumulative in living organisms. PFAS do not accumulate in fatty tissue but rather in predominantly protein-dense compartments, such as the liver, kidneys, and blood due to their oleophobic properties. Therefore, PFAS-protein binding studies are important in assessing their bioaccumulative potential. Human serum albumin (HSA) is the most abundant transporter protein in the human body and has been reported as a major binding protein of PFAS in the blood and as a target for bioaccumulation studies. The goal of this study is to determine PFAS-HSA protein-water distribution coefficients (KPW) for both legacy and alternative PFAS. A high-throughput equilibrium dialysis method is used under physiological conditions, coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS), to quantify KPW values for a variety of PFAS with HSA. This approach allows us to investigate relationships between PFAS structure and HSA binding. The method has been validated by quantifying log KPW values for perfluorooctanoic acid (PFOA)-HSA binding and hexafluoropropylene oxide dimer-acid (GenX)-HSA binding: 4.17 ÔøΩÔøΩ 0.04 and 3.2 ÔøΩÔøΩ 0.1, respectively. These values are in agreement with literature values for these PFAS binding to bovine serum albumin (BSA, the highly homologous analog of HSA found in cows) using an equilibrium dialysis technique. Ongoing studies are focused on applying this high-throughput equilibrium dialysis method to determine KPW values for a variety of legacy and alternative PFAS in order to investigate their relative bioaccumulative potentials and their binding strengths to HSA
Investigating the Thermodynamics and Seismic Profile of the Europan Hydrosphere through Pure-Water Modeling and Saltwater Experiments
Full text linkWe explore the properties of the hydrosphere on Europa involving both a modeling technique and experimental methods. We perform a computational analysis of the thermodynamic properties for an ideal, pure-water Europan ice shell using a Python programming framework called SeaFreeze. We create four models assuming surface temperatures of either 50 K or 140 K and ice shell thicknesses of either 3 km or 30 km. We observe mostly linear trends for the density and seismic wave velocities with respect to depth, and find that surface temperatures have the greatest effect on the models. Simultaneously, we experimentally investigate the phase diagram of different saltwater concentrations in an attempt to further constrain the ice shell properties. We determine the freezing-melting points of 5%, 10%, and 20% by-weight NaCl-water solutions under constant pressures from 0 MPa to 70 MPa. We find that increasing the salt concentration, the pressure, or both decreases the freezing point temperature with a freezing point temperature depression of about -20 °C from that of pure water at zero pressure. Based on our experimental results, we expect that adding NaCl to the pure-water computational models would cause them to have lower temperatures at the ice-water boundary, assuming saltwater has similar density and seismic wave velocity trends as pure-water. Areas of future development include continuing to explore the phase diagrams of different saltwater concentrations, including MgSO4, KCl, and varying combinations of all three salts, extending the pure-water SeaFreeze models to analyze Europa\u27s subsurface ocean layer, implementing various new techniques to make our experiments more precise, and finally applying our results to the other icy moons, such as Ganymede or Callisto
Experimental and Theoretical Analysis of Large Amplitude Motion in a Series of Aromatic Heterocycles
No full textA series of aromatic heterocyclic ethers were studied computationally, using DFT and experimentally, using chirped pulse Fourier transform microwave spectroscopy (CP-FTMW). 2-Methoxyfuran, 2-Methoxythiophene, 2-, 3-, and 4-Methoxypyridine were all studied computationally. Potential surface scans of the methoxy and methyl dihedral angles were used to characterize the internal barriers to rotation. Non covalent interaction plots were then constructed using the DFT generated wavefunctions to identify the important intramolecular interactions. CP-FTMW spectra were fit for both 2-Methoxyfuran and 2-Methoxythiophene, including several quartic centrifugal distrotion constants. Absence of observable splitting in the spectrum supports the hgh barriers to internal rotation calculated for the species. Additionally, the fitted rotational constants were compared to the DFT calculated values, which was used to verify the accuracy of the computational methods
两岸问题从三个看法来谈
Full text link现在，我们都知道两岸问题。在问题的基础上：台湾是否属于中国的一部分？当然，台湾跟中国有很大的关系。今天，每些土地都称自己“中国。”差不多四百年以前，台湾成为一个中国的殖民地。很多汉族人来台湾，带了他们的文化和语言。但是，从1895年到1945年，日本领导了台湾。这个外国的领导时期改变了台湾的历史。中国的现代政府，中华人民共和国，连一天都没治理了台湾。但是，这个问题可以造成了战争。为了懂这个问题的重要性，我们得寻找历史了解中国的身份。我们会发现台湾的政治重要性，这个问题结果的未来。这个问题对亚洲和世界的政治和和平很重要。台湾的经济，政治状态使两岸问题当作新冷战的中心。在这个文章，我会分析台湾的历史、政治、经济和国际的看法
Feasibility of Stable Isotope Analysis as a Method for Prior Ixodes scapularis Host Identification
No full textTick-borne diseases pose a prominent threat to humans by causing a wide range of symptoms and occasionally death. I am studying tick-borne disease transmission through an ecological lens, attempting to identify previous tick hosts using stable isotope analysis (SIA). A method for indirect tick host identification would be useful because our current understanding of the roles of various tick hosts might be biased by the ease of capture of some hosts compared to others. SIA of ticks collected in the wild could clarify the relative importance of various hosts or even identify new hosts that have not been previously considered, advancing our understanding of tick-borne disease transmission through host communities. To evaluate SIA as a technique for previous tick host identification, I trapped 2 species known to be important hosts for Ixodes scapularis (Black-legged Tick): Peromyscus leucopus (White-footed Mouse, n=26), and Tamias striatus (Eastern Chipmunk, n=19), and infested them with nymphal I. scapularis. For the 3-4 days that the ticks fed, the hosts consumed a diet enriched with 15N, an isotope commonly utilized for trophic level identification, to determine if that diet enrichment would be reflected in the molted tick. I chose 15N because previous research showed that δ13C, another useful isotope for studying diets, has a flexible isotopic signature that would likely change according to short-term, opportunistic deviations from a host’s typical diet. By using 15N, I hoped to find a less flexible isotopic signature to facilitate host identification to species or at least to feeding guild. The average isotopic signature of ticks feeding on hosts with a 15N-enriched diet was significantly higher than ticks collected from newly captured animals (which presumably reflect the wild diet; p\u3c 0.0001). This indicates that a short-term diet change was reflected in the molted tick. Further comparisons indicated that the host’s long-term diet is also reflected, revealing a summative quality of the δ15N signature. Our overall findings suggest that the δ15N isotopic signature is more flexible than expected and reflects dramatic short-term diet changes, nevertheless, host feeding guild identification could still be possible because the long-term diet is also represented