A case study of CO2 emissions from beef and pork production in South Korea

The current study evaluated carbon dioxide (CO2) emissions from beef and pork production and distribution chains in the South Korean meat industry. Data from industrial example farms and slaughterhouses were assessed on the basis of both the guidelines from the United Kingdom’s Publicly Available Specification (PAS) 2050:2011 and the Korea Environmental Industry & Technology Institute carbon footprint calculation. The main factors for our estimations were animal feeds, manure waste, transportation, energy and water, refrigerants, and package data. Our analyses show that 16.55 kg CO2 equivalent (eq) was emitted during the production of 1 kg of live cattle. When retail yields and packing processes were considered, the CO2-eq of 1 kg of packaged Hanwoo beef was 27.86 kg. As for pigs, emissions from 1 kg of live pigs and packaged pork meat were 2.62 and 12.75 kg CO2-eq, respectively. While we gathered data from only two farms and slaughterhouses and our findings can therefore not be extrapolated to all meats produced in the South Korean meat industry, they indicate that manure waste is the greatest factor affecting ultimate CO2 emissions of packaged meats

Beyond reducing direct medical cost: examining health outcomes in tuberculosis through a difference-in-differences analysis of South Korea’s out-of-pocket payment exception policy

BackgroundUniversal health coverage and social protection are major global goals for tuberculosis. This study aimed to investigate the effects of an expanded policy to guarantee out-of-pocket costs on the treatment outcomes of patients with tuberculosis.MethodsBy linking the national tuberculosis report and health insurance data and performing covariate-adjusted propensity-score matching, we constructed data on health insurance beneficiaries (treatment group) who benefited from the out-of-pocket payment exemption policy and medical aid beneficiaries as the control group. Using difference-in-differences analysis, we analyzed tuberculosis treatment completion rates and mortality in the treatment and control groups.ResultsA total of 41,219 persons (10,305 and 30,914 medical aid and health insurance beneficiaries, respectively) were included in the final analysis (men 59.6%, women 40.4%). Following the implementation of out-of-pocket payment exemption policy, treatment completion rates increased in both the treatment and control groups; however, there was no significant difference between the groups (coefficient, −0.01; standard error, 0.01). After the policy change, the difference in mortality between the groups increased, with mortality decreasing by approximately 3% more in the treatment group compared with in the control group (coefficient: −0.03, standard error, 0.01).ConclusionThere are limitations to improving treatment outcomes for tuberculosis with an out-of-pocket payment exemption policy alone. To improve treatment outcomes for tuberculosis and protect patients from financial distress due to the loss of income during treatment, it is essential to proactively implement complementary social protection policies

Relationship between metformin use and mortality in tuberculosis patients with diabetes: a nationwide cohort study

Background/Aims To determine whether metformin, which is considered a host-directed therapy for tuberculosis (TB), is effective in improving the prognosis of patients with TB and diabetes mellitus (DM), who have higher mortality than those without DM. Methods This cohort study included patients who were registered as having TB in the National Tuberculosis Surveillance System. The medical and death records of matched patients were obtained from the National Health Information Database and Statistics Korea, respectively, and data from 2011 to 2017 were collected retrospectively. We classified patients according to metformin use among participants who used diabetes drugs for more than 28 days. The primary outcome was all-cause mortality during TB treatment. Double propensity score adjustment was applied to reduce the effects of confounding and multivariable Cox proportional hazard models were used to estimate adjusted hazard ratio (aHR) with 95% confidence interval (CI). Results The all-cause mortality rate during TB treatment was lower (9.5% vs. 12.4%, p < 0.01) in the metformin user group. The hazard of death due to all causes after double propensity score adjustment was also lower in the metformin user group (aHR 0.76, 95% CI 0.67–0.86, p < 0.01). There was no significant difference in mortality between metformin users and non-users for TB-related deaths (p = 0.22); however, there was a significant difference in the non-TB-related deaths (p < 0.01). Conclusions Metformin use in patients with TB–DM co-prevalence is associated with reduced all-cause mortality, suggesting the potential for metformin adjuvant therapy in these patients

Magnetic Field Properties inside the Jet of Mrk 421: Multiwavelength Polarimetry Including the Imaging X-ray Polarimetry Explorer

We conducted a polarimetry campaign from radio to X-ray wavelengths of the high-synchrotron-peak (HSP) blazar Mrk 421, including Imaging X-ray Polarimetry Explorer (IXPE) measurements on 2022 December 6-8. We detected X-ray polarization of Mrk 421 with a degree of $\Pi_{\rm X}$=14$\pm$1$\%$ and an electric-vector position angle $\psi_{\rm X}$=107$\pm$3$^{\circ}$ in the 2-8 keV band. From the time variability analysis, we find a significant episodic variation in $\psi_{\rm X}$. During 7 months from the first IXPE pointing of Mrk 421 in 2022 May, $\psi_{\rm X}$ varied across the range of 0$^{\circ}$ to 180$^{\circ}$, while $\Pi_{\rm X}$ maintained similar values within $\sim$10-15$\%$. Furthermore, a swing in $\psi_{\rm X}$ in 2022 June was accompanied by simultaneous spectral variations. The results of the multiwavelength polarimetry show that the X-ray polarization degree was generally $\sim$2-3 times greater than that at longer wavelengths, while the polarization angle fluctuated. Additionally, based on radio, infrared, and optical polarimetry, we find that rotation of $\psi$ occurred in the opposite direction with respect to the rotation of $\psi_{\rm X}$ over longer timescales at similar epochs. The polarization behavior observed across multiple wavelengths is consistent with previous IXPE findings for HSP blazars. This result favors the energy-stratified shock model developed to explain variable emission in relativistic jets. The accompanying spectral variation during the $\psi_{\rm X}$ rotation can be explained by a fluctuation in the physical conditions, e.g., in the energy distribution of relativistic electrons. The opposite rotation direction of $\psi$ between the X-ray and longer-wavelength polarization accentuates the conclusion that the X-ray emitting region is spatially separated from that at longer wavelengths.Comment: 17 pages, 13 figures, 4 tables; Accepted for publication in A&

Three Essays on Water Policy Design

Irrigation water is crucial for agricultural production and farmers’ livelihoods in many regions of the world. Water scarcity, however, due in part to extended droughts and groundwater depletion, is putting ever-increasing pressure on regulatory agencies to implement water conservation policies, possibly hampering farmers’ livelihoods and food supply. It is therefore imperative to implement policies that allocate scarce water resources in the most efficient way, while allowing water buyers and sellers to benefit from trading. In this dissertation, I study the design of water policies that are in use for agricultural water management in many dry regions: markets, quotas, and water pricing. A key distinction among them is that water markets constitute a decentralized allocation mechanism, while the other policies are centralized. In my first two essays, I compare two prominent market designs, namely once-a-year trading (i.e., non-recursive design) and year-round trading (i.e., recursive design). I examine the effect of these competing market designs on efficiency and distributional outcomes. I do so by accounting for two unique characteristics of irrigation water markets: 1) farmers differ in the marginal valuation of water, and 2) water is thinly traded. In my first essay, I theoretically develop a 3-seller and 3-buyer trading model and show that a recursive design can hinder efficiency when traders differ substantially in their water valuations. This is because sellers greatly increase markups, which strengthens trading frictions. Theoretical predictions from essay 1 rest on rather strong behavioral assumptions – sellers and buyers are able to identify and play a rather complicated subgame perfect Nash equilibrium. But human subjects may deviate from these due to many reasons, including bounded rationality and off-equilibrium beliefs, among others. In my second essay, I conduct a laboratory experiment with human subjects to examine the extent to which they follow theoretical predictions, and the effects of their behavior on the relative performance of competing market designs. Experimental evidence shows that subjects do deviate from predicted equilibrium, particularly when agents are highly heterogeneous. As a result, I find that some of my theoretical predictions are reversed in the laboratory. In particular, the recursive design outperforms the non-recursive design because experimental agents behave much more competitively under the recursive design than predicted by my subgame perfect Nash equilibrium. n my third essay, I empirically compare the performance of quantity and price policies, as well as a hybrid to conserve water, using observational data from Mexican farmers. A fixed cap (the policy chosen by Mexican regulators) effectively limits water consumption, but the rigidity of the cap results in substantial welfare losses due to volatile weather patterns that induce drastic fluctuations in water demand. Consequently, I study two counterfactual policies, a price policy and a hybrid that combines quantity and price policies. I find that the hybrid policy performs very well relative to its pure counterparts because it provides an intermediate level of flexibility in water consumption, preventing large losses under anomalous weather

Swept-Source-Based Chromatic Confocal Microscopy

Chromatic confocal microscopy (CCM) has been intensively developed because it can exhibit effective focal position scanning based on the axial chromatic aberration of broadband light reflected from a target. To improve the imaging speed of three-dimensional (3D) surface profiling, we have proposed the novel concept of swept-source-based CCM (SS-CCM) and investigated the usefulness of the corresponding imaging system. Compared to conventional CCM based on a broadband light source and a spectrometer, a swept-source in the proposed SS-CCM generates light with a narrower linewidth for higher intensity, and a single photodetector employed in the system exhibits a fast and sensitive response by immediately obtaining spectrally encoded depth from a chromatic dispersive lens array. Results of the experiments conducted to test the proposed SS-CCM system indicate that the system exhibits an axial chromatic focal distance range of approximately 360 &mu;m for the 770&ndash;820 nm swept wavelength range. Moreover, high-speed surface profiling images of a cover glass and coin were successfully obtained with a short measurement time of 5 ms at a single position

Stochastic Techno-Economic Analysis of Electricity Produced from Poplar Plantations in Indiana

This study evaluates the feasibility of a 100% biomass direct firing biopower plant in Indiana. As a major biomass fuel, short-rotation coppice (SRC) poplar (Populus spp.) is chosen because of its high biomass productivity. The poplar plantation yield and moisture content data were collected from an actual field trial conducted in southern Indiana (Southwest Purdue Agricultural Center, SWPAC) beginning in 2013. Biomass Bubbling Fluidized Bed (BBFB) boiler and steam-turbine technology is used as the electricity-generating unit. For the three stochastic parameters (yield, moisture content, and planting costs), we estimate the system break-even price distribution through Monte Carlo simulation. We find that the biopower plant is not economically feasible in Indiana, as the estimated system break-even price (21.1 cents/kWh) is six times higher than the current wholesale electricity price in Indiana. Given this infeasible project condition, we find a few strategies to improve system economics. First, we estimate the optimal biomass production level to lead to the least break-even price is 0.8% more than the power plant’s biomass demand, with the possibility of purchasing woodchips from the market. Second, we find that the system break-even price could be lowered by 1 cent/kWh when a woodchip market is available, compared to the non-market condition. Third, selecting excellent land (high yield and expensive land cost) mitigates the system break-even price estimation risks. However, the opportunity cost of such land likely prohibits its use. Our LCA analysis shows the net emissions of this biopower plant is negative (-1.28kg/kWh) because of the SRC carbon sequestration. Based on this net emission, a carbon tax above $90/ton CO2 equivalence can make the biopower plant competitive with other power plants (coal and natural gas) in Indiana

Insight into functionally active bacteria in nitrification following Na+ and Mg2+ exposure based on 16S rDNA and 16S rRNA sequencing

Despite increasing interests in osmoticmembrane bioreactors, the information regarding the bacterial toxicity effects of reversely transported drawsolute (RTDS) is limited. In this study, two representative draw solutes (NaCl and MgCl2) were used at different concentrations (0, 2.5, 5.0, 7.5 and 10.0 g/L) to evaluate their toxicity in a continuous nitrifying bioreactor. Notably, Mg2+ selectively inhibited the activity of ammonia-oxidizing bacteria (AOB), which decreased to 11.3% at 7.5 g-Mg2+/L. The rRNA-based analysis was more effective than the rDNA-based analysis to elucidate the relationship between active communities of nitrifying bacteria and the actual nitrifying performance. Nitrosomonas europaea, a representative AOB, was vulnerable to Mg2+ in comparison to Na+. In contrast, the dominant nitrite-oxidizing bacteria (NOB), Nitrobacter winogradskyi and Nitrolancea hollandica, maintained a relevant level of relative abundance for achieving nitrite oxidation after exposure to 10 g/L Na+ and Mg2+. This fundamental inhibition information of the draw solute can be applied to set the operational regime preventing the critical solute concentration in mixed liquor of nitrifying OMBRs. (C) 2020 Elsevier B.V. All rights reserved