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A Study on National Health Benefits Expansion Policy and Its Ramifications in South Korea
Get PDFSince 1989, when South Korea achieved universal health coverage (UHC), 97.1% of the population has been covered under the NHI system with remaining 3% receiving services through the Medical Aid Program. Regardless of the sufficient population coverage, patients who require high-cost procedures still experience overwhelming costs of care due to a limited range of covered services in NHI. To compensate for the deficiency of covered services, the government has implemented the ‘Mid-term Health Benefits Expansion Security Plan’ since 2005. Despite the long-lasting implementation, this plan has been criticized for not showing any prominent evidence of reducing patients’ health spending. In addition, it has been accused of triggering providers to induce patients’ consumption of non-covered services to increase their profits against the government’s regulations towards covered services.
This study aims to provide empirical evidence on the effect of the benefits expansion policy, whether the benefits expansion policy increased healthcare expenditures and utilization and lead to supplier-induced demand (SID) for services not covered by the NHI.
We employ the Two-Part Difference-in-Differences (Two-Part DiD) estimation for analysis with the Korean Health Panel Survey (KHPS) data. We divide the DiD model into two separate equations of the probability of accessing any care and the intensity of care conditional on the initiated care to consider a high skewness with a peak at zero and heterogeneity between zero and non-zero in health claims data.
We find that the government’s benefits expansion policy reduced the patients’ total and inpatient OOP payments without significant changes in utilization. Although spending for outpatient services increased, it was statistically insignificantly associated with the policy. In this study, as the primary beneficiaries of the policy were the patients with major catastrophic diseases who essentially needed inpatient services, the policy’s benefits were mainly concentrated on inpatient services. The policy also primarily affected the reduction of health spending of patients with the highest income. Given that the policy’s purpose is to redistribute the social resources, this result might not be a desired outcome.
We find no evidence of SID for non-covered services. The absence of such an effect might result from the fact that we mainly examine the critical patients with major catastrophic diseases. By considering the necessity of care for those patients, providers did not significantly change the quantities of non-covered services to maintain their profits after the policy.
The benefits expansion policy affects to reduce patients’ health spending in terms of total and inpatient services without significant changes in utilization. However, as the policy’s benefits are mostly limited to a particular portion of patients and services, the government might need to reinforce the benefits coverage for more general patients to benefit from the policy
Characterization of Mycobacterium avium subsp. hominissuis Interactions with Host Macrophages and Multinucleated Giant Cells
Get PDFTo examine the macrophage response to M. avium, I compared inflammasome and cytosolic sensor expression and activation. My result demonstrated that virulent strains of M. avium (A5 and 104) suppress IL-1β production and induce IFN-β production in macrophages. M. avium mutants deficient at DNA export in the biofilm exhibited reduced intracellular survival and significantly higher IL-1β production than wildtype. IFN-β production appeared to be related to DNA export capability. To further characterize MGCs, we developed a novel in vitro model which is comprised of a human-derived cell line (THP-1) and cytokine stimulation (IFN-γ and TNF-α). Examination of MGCs with transmission electron microscopy uncovered increased lipid droplets and elevated autophagy. My results showed that M. avium survived and replicated in MGCs and that host lipids play a role in intracellular replication. MGC-passaged bacteria were readily phagocytosed and exhibited normal intracellular replication. The mechanism of cell exit is still unclear. The data presented in this dissertation significantly advance our understanding of the macrophage response to M. avium, and the features of MGCs, and how they interact with M. avium. Understanding these host-pathogen interactions has implications for NTM treatment. The idea that eDNA influences intracellular survival and anti-inflammatory signaling needs further study. However, DNA export genes could be a useful target for future therapies
Valuing Coastal Risk with Revealed and Stated Preference Methods
Get PDFDeveloped coastlines provide a variety of recreation opportunities to coastal residents and visitors but are also the first line of defense for oceanfront development against chronic hazards like erosion and sea level rise. In the Pacific Northwest of the United States, oceanfront homes also face an additional severe but very low frequency acute hazard: a Cascadia Subduction Zone earthquake and tsunami. These chronic and acute coastal hazards pose a challenge for policymakers because they often create conflicting interests. This dissertation is composed of two essays on issues of acute and chronic coastal risk in Oregon. The first essay investigates the impact of information shocks about tsunami risk on coastal residents’ risk perceptions, as capitalized into property prices. We use revealed preference methods to examine the coastal Oregon housing market response to three sets of tsunami risk signals: two exogenous events, a hazard planning change, and the addition of visual cues of tsunami risk in residential neighborhoods. The potential housing market impacts identified in these analyses suggest that risk signals about a high severity but low frequency acute hazard can be salient to coastal residents. These findings suggest that Oregon policymakers and emergency managers may be able to use risk signals to induce individuals to pay attention to and prepare more for a Cascadia Subduction Zone event. In the second essay, we develop a combined revealed and stated preference survey and collect survey data from Oregon households. We use this data to estimate stated preference models and measure Oregon residents’ willingness to pay for coastal erosion management conditional on differences in shoreline armoring policy for private oceanfront landowners. Results are suggestive of significant welfare gains stemming from a coastal management plan that would provide funding for sediment management to preserve safe recreation access on developed Oregon beaches. We do not find evidence of a significant difference between how much Oregon residents are willing to pay for a policy scenario where the existing shoreline armoring policy (Goal 18) is relaxed to allow more armoring of private property and a policy scenario where the existing armoring policy is maintained in its current form. Overall, these two essays contribute new information about Oregon residents’ perceptions and preferences regarding acute and chronic coastal risk. These findings can help inform policies in both emergency and resource management
Novel System Design and Operational Strategies for the Production of Biofuels and Bioproducts
Get PDFEnzymatic hydrolysis is a critical process in the conversion of lignocellulosic biomass into biofuels and biochemicals. Achieving high efficiencies and productivity during the enzymatic hydrolysis of biomass is the key for the commercially viable process. Downstream processing challenges require high product titers which in turn require the use of high solid concentrations during enzymatic hydrolysis. Challenges such as low hydrolysis efficiency, high energy consumption, poor mixing quality and high maintenance requirements at high solids concentrations necessitate operational strategies and the system design-based solutions.
This project aims to develop a system capable of processing high solids content slurry and identify the strategies for high products concentration while maintaining low energy consumption.
Fed-batch approach was used to successfully demonstrate high glucose and ethanol concentrations after hydrolysis and fermentation respectively. With 45% (w/w) solids loading of corn stover, the released glucose concentration was 205 ± 25.8 g/L at 96 hours, while ethanol concentration was 115.9 ± 6.7 g/L at 156 hours.
Various surfactant concentrations were evaluated to determine their effectiveness. The experiments were conducted in the 0–2.5% for PEG6000 using 30% solids loading of wheat straw using separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF).
The synergetic effect of combining the fed-batch method with surfactant addition was investigated. Various surfactant concentrations were evaluated to determine their effectiveness. The experiments were conducted in the 0–2.5% for PEG6000 using 30% solids loading of wheat straw using separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF). The results illustrated a significant improvement in the final glucose and ethanol titers when PEG6000 was used. However, a detailed economic analysis of the various process options indicated that the PEG concentrations <1% are preferred when using return on investment as a performance criterion.
Reactor design and configuration were comprehensively tested in this work. Horizontal reactors represent a potential solution to some of the challenges due to the ability to provide high mixing quality for high solids enzymatic hydrolysis (HSEH) with lower mixing energy requirements compared to vertical reactors. A system consisting of a horizontal reactor with a novel design of impeller that integrates the functions of helical impeller and paddlewheel was constructed. A feeding unit was built and installed on the system to control the biomass addition into the reactor. The system demonstrated its superior performance at high solids loading (40%) as measured by the final glucose and ethanol concentrations. Combining the horizontal reactor system with the surfactant (PEG 6000) addition at 0% and 1% concentrations, the glucose concentrations were 201.4 g/L and 219.7 g/L respectively. Ethanol concentrations during the SSF were 134.5 g/L with the addition of 1% PEG6000. The feeding unit was well controlled and was able to provide the required amount of biomass. Furthermore, the system was able to maintain a low level of energy consumption at 43.2 Wh/kg. Based on these results, the fed-batch approach for the SSF method with a 1%PEG 6000 is the recommended strategy for operating the novel horizontal system.
To further evaluate the system performance from economic and environmental impact perspectives, a detailed techno-economic analysis and life cycle assessment were performed. The results of the techno-economic analysis indicated a return on investment (ROI) of 12.21% when operating the system using the best scenario (fed-batch, SSF, 1% PEG600, and 72 hours). The sensitivity analysis indicated that the selling price of ethanol is the most important factor confirming the results observed by other researchers. The biomass price and plant production capacity were the next two most important factors for economic viability. The LCA results indicated that the system has lower environmental impacts in many impact categories such as GWP, acidification, ecotoxicity, and eutrophication, in addition to human health.
This research, at a fundamental level, developed technologies in the areas of biofuels and biochemicals by developing controllable reactor systems that address some of the challenges in the hydrolysis and fermentation of biomass at high solid concentrations. Based on the experimental results, the techno-economic and life cycle analysis, the proposed system design and operational strategies were found to be technically feasible and economically viable with lower impacts on the environment compared to the state-of-the-art technologies
Petrological Forensics of the Mount Sinabung, Sumatra, Indonesia Magma Reservoir before May 2016 Dome Collapse
Get PDFMount Sinabung, Sumatra, Indonesia initiated eruptive activity in 2010 with the addition of a magmatic component in 2013, after a 3 year period of quiescence. Observations of magmatic activity began with phreatomagmatic eruption starting July 2013 closely followed by extrusion of andesitic lava in December 2013. Lava effusion has persisted through the eruptive phases (December 2013 – present) with periodic dome building events with partial to complete failure of the dome and production of pyroclastic density currents (PDCs). Since a magmatic component began erupting in 2013, Mount Sinabung has been producing predominately andesite lavas that evolve in composition as the eruptive phases progress (from 57 wt% SiO2 in 2013 to 65 wt% SiO₂ in 2015). In May 2016, when the lava dome collapsed and successively generated PDCs, the resulting magmatic clasts contained intermingled enclaves. This was the first reported observation of these magmatic enclaves and were thought to be evidence for magmatic recharge that may affect eruptive style and longevity of subsequent activity.
This microanalytical forensic investigation was an effort to determine if magmatic enclaves from the May 2016 dome collapse were evidence of mafic recharge in the system. Petrographic analysis was used to for detailed textural description of the samples collected. Phase chemistry was collected on electron microprobe to discern multiple compositional populations of mineral constituents. Sample textures are highly variable are resulted in the division of the samples into four textural units: andesite host (AH), enclave type-I (ET1), enclave type-II (ET2), and enclave type-III (ET3). Mineral compositions were probed to assess if there were multiple mineral populations present and displaying exchange between the enclaves and host. These analyses found that phenocrysts in all four units were broadly similar with small deviations in plagioclase core composition and amphiboles analyzed in ET3.
Multiple geothermobarometers were employed to determine pressure and temperature conditions of pre-eruptive magmas at Mount Sinabung. Temperature estimates for Fe-Ti oxides, pyroxene, and amphibole range from ~825 to 1100 °C. Pressure estimates from pyroxene and amphibole indicate crystallization depths from ~5 to 32 km, with two main regions of crystallization occurring between ~5 to 16 km and ~24 to 32 km. Magmatic inclusions and pyroxene-rich glomerocrysts likely represent magma of a similar composition crystallizing deeper in the system. Ascent of this magma where it intermingled with the AH magma. Mingling was long enough to grew similar composition rims on plagioclase in all four units before it was erupted on the surface during dome formation. The complex data presented here builds an image of the intricate petrological processes occurring beneath Mount Sinabung and contributes to our understanding of pre-eruptive conditions at the volcano
Potential additive-manufacturing of ablative thermal protection systems
Get PDFElectrodeposition is a versatile polymer deposition technique to create nano-microscale materials using an electrical field generated from a charged droplet of solution and a grounded collector. Electrospinning or electrospraying can occur during electrodeposition, leading to the creation of nanofibers or bead-like materials depending on the process parameters. Photopolymerization of the electrodeposited solution has been used to cure the material during the flight of the charged droplets and/or produce a core-shell morphology of different polymer compositions. Acrylate monomers have been used in photopolymerization reactions due to their fast reaction time and reduction of moisture sensitivity. One drawback of acrylate monomers is the increase in oxygen-sensitivity, which requires an inert environment. The primary focus of using photopolymerization in this manuscript’s evaluation was to cure the acrylate monomers during flight, in of hopes of producing a distinct film morphology.
The purpose of this manuscript’s evaluation, which was conducted in collaboration with Nanovox, LLC on a NASA funded project, was to utilize electrospinning as a manufacturing method for the production of thermal protection systems (TPS). The main goal of this manuscript’s evaluation was to optimize the electrodeposition process. The materials’ properties obtained from the electrodeposited films were observed to determine if electrodeposition was a viable way to produce a TPS. Previous methods of manufacturing TPS are more labor intensive and expensive due to material costs. Electrospinning was investigated as an environmentally friendly alternative manufacturing technique to solve the intensive labor and material cost issues with the added benefit of possibly controlling the overall morphology of the film.
The products generated in the electrospinning process were fully cured polymer films with high thermal stability and non-porous film morphology. The most successful set-up was a vacuum chamber, which allowed for a N2 (g) rich environment with a light vacuum applied to keep the chamber gas pressure close to atmospheric. The shape of the films was determined by the distance from the collector. As the distance increased, a higherdegree of arcing was observed. The most consistent surface morphology that was observed was a non-porous film with bumpy ridges. Upon closer inspection under the SEM, the non-porous surface appeared to have droplets that were deposited in a bead-like shape rather than a fiber-like shape, which was more indicative of electrospraying, although some indication of electrospinning was observed sporadically.
A comparative analysis of the reinforced composites found few differences between the control and reinforced films due to the lack of filler deposited. Fillers are used within TPS to provide additional structural and thermal reinforcement. The fillers aid in the production of the char layer for insulation and pores in order to allow the pyrolysis gas to travel to the surface. The majority of the filler was observed to be trapped within the plastic body of the needle before reaching the metal portion when processing the electrodeposited samples. The design of the needle’s plastic body led to a reduction in the filler distribution for the reinforced composite films. The thermal behavior of the reinforcement composite films was similar to the control because the filler distribution in the composite film was uneven. The HGMB showed a slight improvement in the thermal stability and char residual from the cast samples created.
Cure-inflight electrodeposition was shown to have successfully produced a fully cured film that exhibited high thermal stability. Electrodeposition showcased its capabilities to photopolymerize the polyhedral oligomeric silsesquioxane/aliphatic urethane acrylate monomers in flight, which is a more environmentally friendly method. While some issues did arise with the production of the reinforcement composite films, overall, electrodeposition can produce a reinforced composite film
Organization, Objectives, and Procedural Outcomes: Trade-Offs Associated with Managerial Choices in Oaxacan Community Forest Enterprises
Get PDFThis paper examines four community forest enterprises (CFEs) in Oaxaca, Mexico, where CFEs have been held up as a positive example of community forestry that simultaneously addresses both conservation and development goals. CFEs are community-owned businesses that manage their forests to provide income and other benefits and may be considered “social enterprises” due to their objectives beyond profit maximization, such as the provision of local employment and public goods and services. This paper draws on a case study, and community forestry and social enterprise scholarship to explore the variation in internal organization among CFEs, the objectives members hold for their enterprises, and the way organization and differences in objectives contribute to difficult choices between increasing profits and maintaining procedural outcomes such as trust and transparency in communities. While this work demonstrates how theorized “win-wins” in community forestry can belie trade-offs, it also highlights some of the ways communities have addressed and, in some cases, mitigated such tensions
Local and Global Explanations for Deep Image Classification via Structured Attention Graphs
No full textAttention maps are popular tools of explaining the decisions of convolutional neural net-works (CNNs) for image classification. Typically, for each image of interest, a single attention map is produced, which assigns weights to pixels based on their importance to the classification. We argue that a single attention map provides an incomplete under-standing since there are often many other maps that explain a classification equally well. In this thesis, we show that there are indeed multiple relatively localized explanations for many images which can be systematically enumerated by search methods such as beam search. Based on this finding, we introduce structured attention graphs (SAGs), which compactly represent sets of attention maps for an image by capturing how different combinations of image regions impact the confidence of a classifier. We propose an approach to compute SAGs and a visualization for SAGs so that deeper insight can be gained into the classifier’s decisions. We conduct a user study comparing the use of SAGs to traditional attention maps for answering counterfactual questions about image classifications. Our results show that the users answer comparative counterfactual questions better when presented with SAGs compared to attention map baselines. Further, we extend SAGs from providing local explanations for image instances to provide global explanations for class instances that hold across sets of images. We build an interpretable nearest-neighbour classifier by agglomeratively grouping important image patches obtained from SAGs into clusters that are coherent in semantics and separable by class labels
Antibiotic Resistance in Treated Wastewater Effluent and Biosolids and Fate after Agricultural Reuse
Get PDFConventional wastewater treatment facilities using activated sludge, secondary clarifiers, and chlorine disinfection comprise a large portion of urban wastewater treatment practices in the United States. While highly adept at removing chemical, physical, and numerous biological contaminants, these treatment methods are ineffective at removing contaminants of emerging concern, such as antibiotics and antibiotic resistance genes (ARGs) from wastewater. As a result, antibiotics and ARGs, as well as any antibiotic-resistant bacteria (ARB) not inactivated during the disinfection process, can be discharged through biosolids or treated wastewater effluent (TWE) into receiving environments and pose a threat to human health. We investigated how abundances of 9 ARGs and one class 1 integron (an indicator gene for multiple resistance and horizontal gene transfer) changed in TWE over time by collecting weekly samples from February to April 2019. Analysis revealed that these genes were highly prevalent in TWE, with relative abundances (ARG copies per mL normalized to 16S rRNA copies per mL) ranging from 2.3 × 10-5 to 4.2 × 10-1 in TWE. No samples contained relative abundances of ARGs that were outliers compared to the study average. Additionally, multiple of the individual ARGs showed correlation with each other and with the class 1 integron (intI1), suggesting multi-drug resistance is a relevant concern.
In addition to environmental discharge or landfill disposal, reuse of TWE and biosolids is a current practice to combat global issues of water and fertilizer shortage. To understand the prevalence of ARGs in TWE, a second study was completed investigating the persistence of a more direct threat to human health: potentially human pathogenic ARB. While decay rates of total fecal bacterial indicators in soil have been frequently reported, very few studies have been completed comparing persistence of the antibiotic-resistant counterparts. Additionally, little is known about how the multi-drug resistance of ARB changes over time after biosolids amendment or TWE irrigation. In this study, germinated carrot seeds were planted in soils that received biosolids amendment and/or TWE irrigation. Total and antibiotic-resistant quantities of two fecal indicator bacteria (Escherichia coli and enterococci) were measured in soil weekly until harvest 77 days after planting. E. coli and enterococci were detectable in the biosolids amended soil, and E. coli was present on carrots from amended soil at harvest. No statistical difference was found between TWE irrigation and irrigation with DI water regarding concentrations in soil or on harvested carrots (p > 0.05) Concentrations of antibiotic-resistant E. coli and enterococci declined at faster rates than their total abundances. Isolated colonies of these bacteria were collected at days 0, 35, and 77 to investigate changes in multi-drug resistance. Analysis revealed that percentages of multi-drug resistant (MDR) E. coli declined significantly over time (p 0.05). These results allow for cautious optimism about reuse of TWE in terms of its impact on ARB in soil, however, the continued presence of fecal indicator bacteria in soil and on harvested carrots further demonstrates the risks associated with biosolids amendment. Difference of multi-drug resistance patterns between E. coli and enterococci isolates encourages the need for additional studies on the topic
Comparing Migratory Patterns and Survival Between Wild and Wild Fish Surrogate Juvenile Spring Chinook Salmon (Oncorhynchus tshawytscha)
Get PDFAnadromous salmonid populations in the Pacific Northwest have declined over the past 150 years. In 1999, wild spring Chinook salmon (Oncorhynchus tshawytscha) were federally listed as threatened within the Willamette Basin, OR. Currently, practices to restore wild populations in the upper Willamette Basin involve trapping wild adults at the base of high-head dams and hauling them upstream to historic spawning locations. Their resulting progeny must migrate downstream past the dams, highlighting the necessity of effective juvenile passage. Ideally, studies evaluating downstream juvenile passage structures would use wild fish, but this is often not feasible because of the large number of fish required for reliable estimates. The Wild Fish Surrogate Project at Oregon State University rears juvenile spring Chinook salmon as substitutes for wild-origin fish that are intended to behave similarly to wild ones and emulate wild juvenile migratory phenotypes in the Willamette Basin. We compared survival and movement of wild and wild fish surrogate juvenile Chinook salmon using a combination of PIT-tag detections at interrogation stations and seining recaptures in the McKenzie River Basin. We estimated survival with multi-state Cormack-Jolly-Seber models and compared survival between the two groups through time. Overall, detections and movements of wild and surrogate juveniles were similar, although wild fish surrogates tended to move earlier than their wild juvenile counterparts. Surrogate juveniles had a greater probability of movement within the upper Willamette River Basin compared to wild juveniles. This was likely due to the wild fish surrogates experiencing a novel environment and searching for suitable resources within the river system. Movement both within the upper Willamette River Basin and past Willamette Falls increased as the mean 7-day maximum temperature decreased, reflecting seasonal changes. Apparent survival differed between the two groups, and varied with maximum temperature. Surrogate fish had greater apparent survival at warmer temperatures compared to wild juveniles. This difference may have been a result of surrogate juveniles rearing at warmer temperatures prior to release and also being more likely to move downstream soon after being introduced into the McKenzie River