404 results on '"Park, Ji-Hyung"'
Search Results
202. Detrital control on the release of dissolved organic nitrogen (DON) and dissolved inorganic nitrogen (DIN) from the forest floor under chronic N deposition
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Park, Ji-Hyung, primary and Matzner, Egbert, additional
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- 2006
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203. Biogeochemical pools and fluxes of carbon and nitrogen in a maritime tundra near penguin colonies along the Antarctic Peninsula
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Park, Ji-Hyung, primary, Day, Thomas A., additional, Strauss, Sarah, additional, and Ruhland, Christopher T., additional
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- 2006
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204. Tc-99m ECD SPECT and FDG PET in Partial Status Epilepticus Resulting From Cerebral Sparganosis
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Kim, Jinkwon, primary, Park, Ji-Hyung, additional, Ryu, Young-Hoon, additional, and Lee, Kyung-Yul, additional
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- 2006
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205. The effect of active encouragements of situated public display with interactive quiz.
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Lee, Joong Ho, Yoon, Hae Cheol, and Park, Ji Hyung
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- 2013
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206. Winter-Time Climatic Control on Dissolved Organic Carbon Export and Surface Water Chemistry in an Adirondack Forested Watershed
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Park, Ji-Hyung, primary, Mitchell, Myron J., additional, and Driscoll, Charles T., additional
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- 2005
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207. A case of reversible postpartum cytotoxic edema in preeclampsia
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Na, Sang-Jun, primary, Hong, Ji-Man, additional, Park, Ji-Hyung, additional, Chung, Tae-Sub, additional, and Lee, Kyung-Yul, additional
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- 2004
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208. CheMO.
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Song, Kyohyun, Kim, Gunhee, Han, Inkyu, Lee, Jeongyoung, Park, Ji-Hyung, and Ha, Sungdo
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- 2011
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209. Touch-Bookmark.
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Yoon, Dongwook, Cho, Yongjun, Yeom, Kiwon, and Park, Ji-Hyung
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- 2011
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210. Impacts of changing climate and atmospheric deposition on N and S drainage losses from a forested watershed of the Adirondack Mountains, New York State
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Park, Ji‐Hyung, primary, Mitchell, Myron J., additional, McHale, Patrick J., additional, Christopher, Sheila F., additional, and Meyers, Tilden P., additional
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- 2003
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211. I-Grabber.
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Abednego, Martha, Lee, Joong-Ho, Moon, Won, and Park, Ji-Hyung
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- 2009
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212. Development of A Methodology for An Approximate Life Cycle Assessment
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Park, Ji-Hyung, primary and Seo, Kwang-Kyu, additional
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- 2002
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213. Erratum to “Resource control on the production of dissolved organic carbon and nitrogen in a deciduous forest floor” [Soil Biol Biochem 34(3) (2002) 813–822]
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Park, Ji-Hyung, primary, Kalbitz, Karsten, additional, and Matzner, Egbert, additional
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- 2002
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214. Resource control on the production of dissolved organic carbon and nitrogen in a deciduous forest floor
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Park, Ji-Hyung, primary, Kalbitz, Karsten, additional, and Matzner, Egbert, additional
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- 2002
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215. The Effect of Initial Serum Neuron-Specific Enolase Level on Clinical Outcome in Acute Carotid Artery Territory Infarction
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Oh, Seung Hun, primary, Lee, Jin Goo, additional, Na, Sang Jun, additional, Park, Ji Hyung, additional, and Kim, Won Joo, additional
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- 2002
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216. Prediction of the life cycle cost using statistical and artificial neural network methods in conceptual product design
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Seo, Kwang-Kyu, primary, Park, Ji-Hyung, additional, Jang, Dong-Sik, additional, and Wallace, David, additional
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- 2002
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217. An Approach of Information Extraction from Web Documents for Automatic Ontology Generation.
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Hao, Yue, Liu, Jiming, Wang, Yu-Ping, Cheung, Yiu-ming, Yin, Hujun, Jiao, Licheng, Ma, Jianfeng, Jiao, Yong-Chang, Yeom, Ki-Won, and Park, Ji-Hyung
- Abstract
We examine an automated mechanism, which allows users to access this information in a structured manner by segmenting unformatted text records into structured elements, annotating these documents using XML tags and using specific query processing techniques. This research is the first step to make an automatic ontology generation system. Therefore, we focus on the explanation how we can automatically extract structure when seeded with a small number of training examples. We propose an approach based on Hidden Markov Models to build a powerful probabilistic model that corroborates multiple sources of information including, the sequence of elements, their length distribution, distinguishing words from the vocabulary and an optional external data dictionary. We introduce two different HMM models for information extraction from different sources such as bibliography and Call for Papers documents as a training dataset. The proposed HMM learn to distinguish the fields, and then extract title, authors, conference / journal names, etc. from the text. [ABSTRACT FROM AUTHOR]
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- 2005
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218. Water extract of Magnolia officinaliscortex inhibits osteoclastogenesis and bone resorption by downregulation of nuclear factor of activated T cells cytoplasmic 1
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Shim, Ki-Shuk, Kim, Taesoo, Ha, Hyunil, Lee, Chung-Jo, Lee, Bohyoung, Kim, Han Sung, Park, Ji Hyung, and Ma, Jin Yeul
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Magnolia officinaliscortex has been traditionally used to treat stomach and intestine diseases in traditional Korean medicine. In this study, we investigated the effect of water extract of M. officinaliscortex (WEMC) on osteoclast differentiation and function.
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- 2015
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219. Response of plants and the dominant microarthropod, Cryptopygus antarcticus, to warming and contrasting precipitation regimes in Antarctic tundra.
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Day, Thomas A., Ruhland, Christopher T., Strauss, Sarah L., Park, Ji-Hyung, Krieg, Michelle L., Krna, Matthew A., and Bryant, David M.
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PLANT reproduction ,ARTHROPODA ,COLLEMBOLA ,TUNDRA ecology ,METEOROLOGICAL precipitation ,PLANT biomass - Abstract
We examined the influence of warming and supplemental precipitation on plant production and abundance of the dominant microarthropod, the springtail Cryptopygus antarcticus (Collembola), in tundra dominated by the vascular plants Colobanthus quitensis and Deschampsia antarctica along the Antarctic Peninsula. Tundra cores were placed in plots near Palmer Station where they were warmed with infrared heaters in combination with receiving supplemental precipitation. Diel canopy air and soil temperatures and air vapor pressure deficits in warmed plots were elevated 0.8 °C, 2.2 °C and 0.13 kPa, respectively. After two growing seasons, total aboveground plant production was greater under warming as a result of enhanced production by C. quitensis, which more than offset declines in moss biomass. Total aboveground plant production was also greater under supplemental precipitation primarily as a result of enhanced moss production. Total aboveground plant production was greatest under the combination of warming and supplemental precipitation, primarily as a result of enhanced C. quitensis production. C. antarcticus were more abundant in cores receiving supplemental precipitation and there was a strong treatment interaction; these springtails were most abundant in warmed cores receiving supplemental precipitation. Over 50% of the variability in the abundance of C. antarcticus could be explained by differences in aboveground plant biomass. However, plant production did not appear directly responsible for differences in C. antarcticus abundance; when we examined C. antarcticus abundance per unit of aboveground plant biomass, differences in its abundance among treatments were still apparent implying these differences were not the direct result of plant biomass. The responses of C. antarcticus were consistent with its known moisture and thermal preferences, suggesting that abiotic factors played a dominant role in controlling its abundance. Precipitation regime had large impacts on warming responses and these were species specific, illustrating the importance of future precipitation regimes in predicting system responses to warming. [ABSTRACT FROM AUTHOR]
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- 2009
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220. Teaching NeuroImages: Vertebral artery compression by head tilt around the roll axis diagnosed by transcranial Doppler.
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Park, Ji-Hyung, Song, Joomee, Shin, Jaewon, Jang, Hyun-soon, and Seo, Woo-Keun
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- 2018
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221. Localized Pollution Impacts on Greenhouse Gas Dynamics in Three Anthropogenically Modified Asian River Systems
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Begum, Most Shirina, Bogard, Matthew J., Butman, David E., Chea, Eliyan, Kumar, Sanjeev, Lu, Xixi, Nayna, Omme K., Ran, Lishan, Richey, Jeffrey E., Tareq, Shafi M., Xuan, Do Thi, Yu, Ruihong, and Park, Ji‐Hyung
- Abstract
Despite growing research on greenhouse gas (GHG) emissions from inland waters, few systematic efforts have been made to assess the regional‐scale GHG emissions from Asian rivers under increasing anthropogenic stress. We examined factors controlling longitudinal and seasonal variations in the partial pressure of CO2(pCO2), and CH4and N2O concentrations in the Ganges, Mekong, and Yellow River by simultaneously measuring gas concentrations and stable C isotopes, and optical properties of dissolved organic matter (DOM) from 2016 to 2019. The levels of pCO2and CH4were distinctively higher in polluted tributaries and affected reaches of the Ganges and Mekong than in the Yellow River. The highest levels of N2O were found in the Ganges, followed by the Yellow River and Mekong. Across these basins, dry‐season mean concentrations of CO2, CH4, and N2O were 1.6, 2, and 7 times higher than those measured in the monsoon season, respectively. This seasonality was consistent with that of δ13C‐CO2, while δ13C‐CH4showed an opposite pattern. GHG concentrations exhibited significant positive relationships with DOM concentrations and optical properties including fluorescence index and protein‐like fluorescence, implying the contribution of anthropogenic, labile DOM to production of GHGs in the polluted reaches. Graphical mixing models of δ13C‐CO2and δ13C‐CH4support the stronger impact of wastewater on the Ganges and Mekong than on the Yellow River. The overall results suggest that neglecting localized pollution impacts on GHG emissions from increasingly urbanized river basins can result in a substantial underestimation of global riverine GHG emissions. Rapid urbanization and poor wastewater infrastructure are turning many large rivers in Asia into significant sources of greenhouse gases (GHGs). We examined controlling factors for the concentrations of CO2, CH4, and N2O in the Ganges, Mekong, and Yellow River by simultaneously measuring gas concentrations and stable carbon isotopes, and optical properties of dissolved organic matter (DOM). The concentrations of CO2and CH4were distinctively higher in polluted tributaries and affected sections of the Ganges and Mekong than in the Yellow River. N2O concentration was highest in the Ganges, followed by the Yellow River and Mekong. Across these basins, the concentrations of the three gases were generally higher during dry periods than in the monsoon season. GHG concentrations were positively related to DOM optical properties indicating the contribution of easily degradable DOM from pollution sources. The stable carbon isotope ratios of CO2and CH4support the stronger impact of wastewater on the Ganges and Mekong than on the Yellow River. The overall results suggest that neglecting local pollution impacts on GHG emissions from increasingly urbanized river basins can result in a substantial underestimation of global riverine GHG emissions. High CO2, CH4, and N2O concentrations in urbanized river reaches reflect influences from local tributaries carrying wastewaterSeasonality in stable C isotopes and dissolved organic matter properties corresponds to higher dry‐season greenhouse gas concentrations than in the monsoonStable C isotopes and their relationships with CO2and CH4concentrations support localized wastewater effects on urbanized rivers High CO2, CH4, and N2O concentrations in urbanized river reaches reflect influences from local tributaries carrying wastewater Seasonality in stable C isotopes and dissolved organic matter properties corresponds to higher dry‐season greenhouse gas concentrations than in the monsoon Stable C isotopes and their relationships with CO2and CH4concentrations support localized wastewater effects on urbanized rivers
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- 2021
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222. A process net model approach for multiple process plans
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Park, Ji-Hyung and Kang, Min-Hyoung
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A process planning system that generates alternative process plans offers multiple process plans for a part, thereby providing the flexibility to cope with changes in shop floor status. In this paper, we introduce the concept of a process net as a model for the generation of alternative process plans. We also show the usefulness of the process net model in generating alternative process plans by implementing the developed system to construct process nets, and devising an algorithm to generate alternative process plans for rotational parts.
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- 1998
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223. Prevalence of fragile X‐associated tremor/ataxia syndrome: A survey of essential tremor patients with cerebellar signs or extrapyramidal signs.
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Park, Ji‐Hyung, Jang, Wooyoung, Youn, Jinyoung, Ki, Chang‐Seok, Kim, Byoung Joon, Kim, Hee‐Tae, Louis, Elan D., and Cho, Jin Whan
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ESSENTIAL tremor , *TREMOR , *MAGNETIC resonance imaging , *ASIAN studies - Abstract
Objectives: In screening studies of Western patients with cerebellar dysfunction, FMR1 premutations have been detected. A screening study of East Asian patients with presumed essential tremor (ET) did not detect these mutations, possibly because the ET patients did not closely mimic the phenotype of fragile X‐associated tremor/ataxia syndrome (FXTAS). The aim of this study was to estimate the prevalence of FMR1 premutations in a carefully recruited group of ET patients with additional phenotypic features of FXTAS. Materials and Methods: From April 2014 to April 2018, we prospectively recruited patients with ET diagnoses from three tertiary care centers. Demographic and clinical data were collected, as well as data on presence of cerebellar signs and extrapyramidal signs (EPS). Tremor, cerebellar signs, and EPS were evaluated using appropriate clinical rating scales. For ET patients with additional cerebellar signs or EPS, FMR1 mutation analysis and brain magnetic resonance imaging were performed. Results: Six hundred and three ET patients were recruited. Cerebellar signs or EPS were present in 168 (27.9%) of 603. FMR1 CGG repeat analysis was performed in 74 of 168 patients. Fifty‐two of 74 had cerebellar signs only, three had EPS only, and 19 had both neurologic abnormalities. Two patients had a FMR1 premutation and fulfiled both clinical and radiological criteria of FXTAS. Conclusions: Two (2.7%) of 74 patients with presumed ET and additional neurological features were discovered to have FXTAS. The possibility of FXTAS should be considered in patients with ET who exhibit mild cerebellar signs or EPS. [ABSTRACT FROM AUTHOR]
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- 2019
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224. Seasonal and spatial changes in sediment origin, indicated by the isotopic fatty acid fingerprint of suspended river sediments from South Korea and Switzerland.
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Birkholz, Axel, Meusburger, Katrin, Lavrieux, Marlène, Park, Ji-Hyung, and Alewell, Christine
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- 2019
225. Comparison of gait parameters between drug-naïve patients diagnosed with multiple system atrophy with predominant parkinsonism and Parkinson's disease.
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Na, Boo Suk, Ha, Jongmok, Park, Ji-Hyung, Ahn, Jong Hyeon, Kim, Minkyeong, Kim, Ji Sun, Kim, Hee-Tae, Cho, Jin Whan, and Youn, Jinyoung
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MULTIPLE system atrophy , *PARKINSON'S disease , *PARKINSONIAN disorders , *ORTHOSTATIC hypotension , *BODY weight , *DISEASE duration - Abstract
Introduction: Even though gait symptoms are prominent in patients diagnosed with multiple system atrophy with predominant parkinsonism (MSA-P) compared with Parkinson's disease (PD), the gait patterns of MSA-P were not clearly elucidated. We investigated postural instability and gait disturbances in MSA-P compared with PD.Methods: We enrolled 34 drug-naïve patients with PD and 26 with MSA-P, and 18 normal controls in this study. Parkinsonism was evaluated by the Unified Parkinson's disease rating scale (UPDRS) part 3 and cognition was assessed with mini-mental status exam (MMSE). All the enrolled subjects underwent Pedoscan and GAITRite to objectively measure postural stability and gait. We compared the results of posturography and gait analysis among 3 groups, and performed correlation analysis of gait parameters with MMSE, UPDRS part 3 and posturography results.Results: No difference was detected in demographic and clinical variables, except tremor sub-score of UPDRS part 3, urinary symptoms and orthostatic hypotension. MSA-P patients showed larger total anterior-posterior and lateral movement of centre of pressure (COP), and widened base of support than PD patients. In correlation analysis, MMSE score, axial sub-score of UPDRS part 3 and lateral movement of COP were correlated with gait parameters in PD patients, while only axial sub-score was associated in MSA-P patients after controlling for age, sex, height, body weight, education year, and disease duration.Conclusion: Even at an early stage, MSA-P patients demonstrated more postural instability and gait disturbance compared with PD patients, and the related factors with gait disturbance in PD and MSA-P might be different. [ABSTRACT FROM AUTHOR]- Published
- 2019
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226. Human-demonstration based approach for grasping unknown objects.
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Kim, Hyoungnyoun, Han, Inkyu, Kim, Shin-Jung, You, Bum-Jae, and Park, Ji-Hyung
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This video presents a grasp planning of multiple robots via learning by human demonstration. In order to make a robot grasp an unknown object, the robot is required to figure out an appropriate grasping skill such as grasping points and approaching directions for the target object. After a shape of an unknown object has been reconstructed, the robot learns a natural and intuitive grasping skill by human demonstration. [ABSTRACT FROM PUBLISHER]
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- 2011
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227. Environmental co-limitation on temperature responses of greenhouse gas production in floodplain sediments.
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Zhumabieke, Maidina, Huh, Jinhee, Lee, Hyunji, and Park, Ji-Hyung
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GREENHOUSE gases , *DISSOLVED organic matter , *CONSTRUCTED wetlands , *WATERSHEDS , *FLOODPLAINS - Abstract
Despite the rising interest in understanding how climate change could affect the emissions of greenhouse gases (GHGs) from river systems, including floodplains, we still lack a mechanistic understanding of how changing environmental conditions, such as moisture and nutrient availability, limit the temperature responses of GHG production in floodplain sediments. To examine the environmental co-limitations on the temperature responses of three major GHGs (CO2, CH4, and N2O) produced in floodplain sediments, sediments from a constructed wetland on the floodplain of the lower Han River were incubated for 24 d at four temperatures spanning 4–28 ℃, under three conditions (closed, open/wetting, and open/drying). The net production of all three GHGs exhibited nonlinear temperature responses with gas-specific patterns and magnitudes of response varying over the incubation period. During the later incubation phase, positive temperature responses were weakened for the net production of CO2 and CH4 in the dried treatments, whereas a similar weakening occurred for N2O production in the wet treatments. This, combined with incubation-induced changes in dissolved organic carbon and its fluorescence components, indicated the lack or excess of moisture and associated changes in O2 and organic carbon availability as critical co-limiting factors for the temperature responses of GHG production. Warming decreased δ13C in the CH4 emitted from wet and hypoxic sediments, implying a stronger warming effect on CH4 production over oxidation. Unlike many studies assuming a consistent relationship between temperature and GHG production in sediments irrespective of other environmental conditions, our results suggest that warming effects on the GHG emissions from floodplain sediments would depend on the balance between gas production and consumption under the prevailing constraints of moisture, O2, and labile carbon availability. [ABSTRACT FROM AUTHOR]
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- 2024
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228. Seasonal shifts in diurnal variations of pCO2 and O2 in the lower Ganges River.
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Haque, Md. Morshedul, Begum, Most Shirina, Nayna, Omme K., Tareq, Shafi M., and Park, Ji‐Hyung
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ATMOSPHERIC carbon dioxide , *DISSOLVED organic matter , *SEASONS , *PARTIAL pressure - Abstract
High‐frequency, paired measurements of the partial pressure of CO2 (pCO2) and dissolved O2 were combined with dissolved organic matter (DOM) characterization to investigate diurnal (7:00–19:00) and seasonal variations in CO2 dynamics in the lower Ganges River. Diurnal variations in pCO2 shifted seasonally, concurring with changes in DOM optical properties, biodegradable DOM, and O2 departures from atmospheric equilibrium (ΔO2). Increased pCO2 and CO2 flux (FCO2) in August–September corresponded to monsoonal floods carrying more terrestrial materials. Lower dry‐season pCO2 and FCO2 concurred with higher ΔO2, and exhibited strong relationships with DO and pH, indicating a dominant influence of phytoplankton production. Despite large variations in pCO2, the year‐long positive FCO2 implied that the lower Ganges acted as a CO2 source, reaching 122 mmol m−2 d−1. Increasing hydrologic variability and pollution in the Ganges Basin can amplify pCO2 variations linked to seasonal shifts in terrestrial inputs and phytoplankton production. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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229. NUDT15 intermediate metabolisers are associated with lower loss of response in paediatric Crohn's disease patients treated by combination treatment with infliximab and azathioprine.
- Author
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Kim, Eun Sil, Choi, Sujin, Choi, So Yoon, Park, Ji Hyung, Choe, Byung‐Ho, Lee, Soo‐Youn, Kim, Mi Jin, Choe, Yon Ho, and Kang, Ben
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AZATHIOPRINE , *CHILD patients , *INFLIXIMAB , *PEDIATRICS , *DISEASE remission , *INFLAMMATORY bowel diseases - Abstract
Summary: Background: NUDT15 polymorphisms are associated with leukopenia during treatment with thiopurines. However, data regarding its effect on treatment outcomes are scarce. Aims: To investigate the outcomes between NUDT15 normal and intermediate metabolisers in paediatric patients with Crohn's disease (CD) treated with a combination therapy of infliximab (IFX) and azathioprine (AZA). Methods: In this retrospective observational study, 143 patients categorised into the NUDT15 normal and intermediate metaboliser groups were compared based on clinical remission (CR), biochemical remission (BR), mucosal healing (MH) at 1 year treatment, IFX trough levels (TLs), antibodies to IFX (ATIs), 6‐thioguanine nucleotide (6‐TGN) levels, loss of response (LOR) and IFX durability. Results: No significant differences were observed between the groups in CR, BR, MH at 1 year, whereas IFX TLs and ATIs and 6‐TGN levels were comparable. However, LOR (6.5% vs 27.7%, P = 0.025) was significantly lower and IFX durability significantly higher (96.8% vs 80.4% P = 0.027) in the intermediate group. Multivariable Cox proportional hazard regression analysis showed that ATI positivity (hazard ratio (HR): 4.76, 95% CI: 2.25‐10.07, P < 0.001) and the NUDT15 metaboliser group was associated with LOR (HR: 0.18, 95% CI: 0.04‐0.76, P = 0.019). The Kaplan‐Meier survival curves showed that the LOR‐free survival rate was significantly lower in normal metabolisers (log‐rank test P = 0.009). Conclusion: NUDT15 intermediate metabolisers were associated with lower LOR in paediatric patients with CD treated with IFX and AZA combination therapy. This finding may partially explain the longer durability of IFX in Korean children than their counterparts in Western countries. [ABSTRACT FROM AUTHOR]
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- 2022
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230. Synergistic effects of urban tributary mixing on dissolved organic matter biodegradation in an impounded river system.
- Author
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Begum, Most Shirina, Jang, Inae, Lee, Jung-Min, Oh, Han Bin, Jin, Hyojin, and Park, Ji-Hyung
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Dams and wastewater may greatly perturb riverine fluxes of dissolved organic matter (DOM) and CO 2 , yet little is known about the relationships between altered DOM quality and CO 2 emission in eutrophic impounded river systems. A basin-wide field survey of surface water CO 2 and dissolved organic carbon (DOC) was combined with laboratory incubations to examine how dams and urban tributaries delivering treated wastewater influence longitudinal patterns in DOM properties and CO 2 along the impounded Han River traversing Seoul metropolitan area. Fluorescent DOM indices including parallel factor analysis (PARAFAC) components were used to characterize DOM in relation to biodegradable DOC (BDOC). Compared with distinct downstream increases in DOC and CO 2 , BDOC concentration and its proportion in DOC (%BDOC) were highly variable along the mainstem and peaked at urban tributaries. Longitudinal increases in fluorescence index (FI), biological index (BIX), and two PARAFAC components (C2 and C3) contrasted with general decreases in humification index (HIX) and C1, reflecting increasing downstream inputs of anthropogenic DOM. During a 5-day incubation employing continuous CO 2 measurements, the cumulative production of CO 2 in the mainstem water mixed with urban tributary water was significantly higher than the level expected for conservative mixing of the two samples, indicating a synergistic enhancement of DOM biodegradation. Molecular formulas identified by Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS) revealed more consumed molecules in the mainstem water and more newly produced molecules in the tributary water over the 5-day incubation, implying abundant labile components in the mainstem water discharged from the upstream dam and highly processed tributary DOM limited in immediately biodegradable organic materials. Downstream increases in CO 2 and DOC along the Han River, combined with the synergistic effect observed in the mixed water, suggest that mixing wastewater-derived DOM with labile autochthonous DOM can enhance CO 2 production in the river system perturbed by impoundment and wastewater. Unlabelled Image • Field survey was combined with lab incubations to study human impact on river carbon. • Dissolved organic matter and CO 2 vary along impounded river with wastewater influence. • Urban tributary mixing enhances organic matter degradation and CO 2 in impounded river. • FT-ICR-MS detects organic matter degradation in impounded river and urban tributary. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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231. A multi-radionuclide approach to evaluate the suitability of 239 + 240Pu as soil erosion tracer.
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Meusburger, Katrin, Mabit, Lionel, Ketterer, Michael, Park, Ji-Hyung, Sandor, Tarjan, Porto, Paolo, and Alewell, Christine
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RADIOISOTOPES , *SOIL erosion , *PLUTONIUM , *PARTICLE size determination , *ENVIRONMENTAL testing - Abstract
Fallout radionuclides have been used successfully worldwide as tracers for soil erosion, but relatively few studies exploit the full potential of plutonium (Pu) isotopes. Hence, this study aims to explore the suitability of the plutonium isotopes 239 Pu and 240 Pu as a method to assess soil erosion magnitude by comparison to more established fallout radionuclides such as 137 Cs and 210 Pb ex . As test area an erosion affected headwater catchment of the Lake Soyang (South Korea) was selected. All three fallout radionuclides confirmed high erosion rates for agricultural sites (> 25 t ha − 1 yr − 1 ). Pu isotopes further allowed determining the origin of the fallout. Both 240 Pu/ 239 Pu atomic ratios and 239 + 240 Pu/ 137 Cs activity ratios were close to the global fallout ratio. However, the depth profile of the 239 + 240 Pu/ 137 Cs activity ratios in undisturbed sites showed lower ratios in the top soil increments, which might be due to higher migration rates of 239 + 240 Pu. The activity ratios further indicated preferential transport of 137 Cs from eroded sites (higher ratio compared to the global fallout) to the depositional sites (smaller ratio). As such the 239 + 240 Pu/ 137 Cs activity ratio offered a new approach to parameterize a particle size correction factor that can be applied when both 137 Cs and 239 + 240 Pu have the same fallout source. Implementing this particle size correction factor in the conversion of 137 Cs inventories resulted in comparable estimates of soil loss for 137 Cs and 239 + 240 Pu. The comparison among the different fallout radionuclides highlights the suitability of 239 + 240 Pu through less preferential transport compared to 137 Cs and the possibility to gain information regarding the origin of the fallout. In conclusion, 239 + 240 Pu is a promising soil erosion tracer, however, since the behaviour i.e. vertical migration in the soil and lateral transport during water erosion was shown to differ from that of 137 Cs, there is a clear need for a wider agro-environmental testing. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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232. Combining asymmetrical flow field-flow fractionation with on- and off-line fluorescence detection to examine biodegradation of riverine dissolved and particulate organic matter.
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Lee, Sang Tak, Yang, Boram, Kim, Jin-Yong, Park, Ji-Hyung, and Moon, Myeong Hee
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ASYMMETRY (Chemistry) , *FLUID flow , *FLUORESCENCE , *FIELD-flow fractionation , *BIODEGRADATION , *PARTICULATE matter , *ULTRAVIOLET radiation - Abstract
This study demonstrated that asymmetrical flow field-flow fractionation (AF4) coupled with on-line UV and fluorescence detection (FLD) and off-line excitation-emission matrix (EEM) fluorescence spectroscopy can be employed to analyze the influence of microbial metabolic activity on the consumption and production of freshwater organic matter. With the AF4 system, organic matter is on-line enriched during a focusing/relaxation period, which is an essential process prior to separation. Size-fractionated chromophoric and fluorophoric organic materials were simultaneously monitored during the 30-min AF4 separation process. Two fractions of different sizes (dissolved organic matter (DOM) and particulate organic matter (POM)) of freshwater samples from three locations (up-, mid-, and downstream) along the Han River basin of Korea were incubated with the same inoculum for 14 days to analyze fraction-specific alterations in optical properties using AF4-UV-FLD. A comparison of AF4 fractograms obtained from pre- and post-incubation samples revealed that POM-derived DOM were more susceptible to microbial metabolic activity than was DOM. Preferential microbial consumption of protein-like DOM components concurred with enhanced peaks of chromophoric and humic-like fluorescent components, presumably formed as by-products of microbial processing. AF4-UV-FLD combined with off-line identification of microbially processed components using EEM fluorescence spectroscopy provides a powerful tool to study the relationship between microbial activity and composition as well as biodegradability of DOM and POM-derived DOM from different origins, especially for the analysis of chromophoric and fluorophoric organic matter that are consumed and produced by microbial metabolic activity. The proposed AF4 system can be applied to organic matter in freshwater samples having low concentration range (0.3–2.5 ppm of total organic carbon) without a pre-concentration procedure. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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233. Downstream alteration of the composition and biodegradability of particulate organic carbon in a mountainous, mixed land-use watershed.
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Jung, Byung-Joon, Jeanneau, Laurent, Alewell, Christine, Kim, Bomchul, and Park, Ji-Hyung
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COLLOIDAL carbon , *BIODEGRADATION of carbon compounds , *CHEMICAL amplification , *LAND use , *NUCLEAR magnetic resonance , *CARBON isotopes , *WATERSHEDS - Abstract
Despite increasing recognition of storm-induced organic carbon (C) export as a significant loss from the terrestrial C balance, little is known about the biodegradation and chemical transformation of particulate organic carbon (POC) in mountainous river systems. We combined analyses of C isotopes, solution-state H NMR, and lipid biomarkers with biodegradable dissolved organic C (BDOC) measurements to investigate downstream changes of POC composition and biodegradability at a mountainous, mixed land-use watershed in South Korea. Water and suspended sediment (SS) samples were collected in a forested headwater stream, a downstream agricultural stream, and two downstream rivers during peak flow periods of four storm events, using either sequential grab sampling from the headwater stream to the most downstream river within a few hours around the peak flow or sediment samplers deployed during the whole storm event. DOC concentrations exhibited relatively small changes across sites, whereas POC concentrations were highest in the agricultural stream, and tapered along downstream reaches. The δC and δN of SS in the agricultural stream were distinct from up- and downstream signatures and similar to those for erosion source soils and lake bottom sediment, although increases in radiocarbon age indicated continuous compositional changes toward the lake. H NMR spectra of SS and deposited sediment exhibited downstream decreases in carbohydrates and lignin but enrichment of organic structures related to microbial proteins and plant wax. The downstream sediments had more microbial n-alkanes and lipid markers indicating anthropogenic origin such as coprostanol compared to the forest soil n-alkanes dominated by plant wax. While the BDOC concentrations of filtered waters differed little between sites, the BDOC concentrations and protein- to humic-like fluorescence ratios of DOC leached from SS during a 13-day incubation were higher in downstream rivers, pointing to contribution of labile POC components to the enhanced biodegradation. Overall, inputs of microbial and anthropogenic origin, in interplay with deposition and mineralization, appear to substantially alter POC composition and biodegradability during downstream transport, raising a question on the conventional view of mountainous river systems as a passive conduit of storm pulses of POC. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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234. Reassessing riverine carbon dioxide emissions from the Indian subcontinent.
- Author
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Nayna, Omme K., Sarma, Vedula V.S.S., Begum, Most Shirina, Hartmann, Jens, Kumar, Sanjeev, Tareq, Shafi M., and Park, Ji-Hyung
- Published
- 2022
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235. Monsoonal-type climate or land-use management: Understanding their role in the mobilization of nitrate and DOC in a mountainous catchment.
- Author
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Bartsch, Svenja, Peiffer, Stefan, Shope, Christopher L., Arnhold, Sebastian, Jeong, Jong-Jin, Park, Ji-Hyung, Eum, Jaesung, Kim, Bomchul, and Fleckenstein, Jan H.
- Subjects
- *
MONSOONS , *CLIMATE change , *LAND use , *NITRATES , *WATERSHEDS , *ENVIRONMENTAL engineering , *AQUIFERS - Abstract
Highlights: [•] DOC dynamics in 1st order forested streams controlled by monsoonal climate. [•] DOC dynamics in higher order agricultural streams driven by rice paddy water inputs. [•] Monsoonal climate controls river-aquifer exchange dynamics. [•] Frequent hydraulic gradient reversals are specific to the monsoonal climate. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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- View/download PDF
236. A weighted, multi-method approach for accurate basin-wide streamflow estimation in an ungauged watershed.
- Author
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Shope, Christopher L., Bartsch, Svenja, Kim, Kiyong, Kim, Bomchul, Tenhunen, John, Peiffer, Stefan, Park, Ji-Hyung, Ok, Yong Sik, Fleckenstein, Jan, and Koellner, Thomas
- Subjects
- *
GEOLOGICAL basins , *ACCURACY , *STREAMFLOW , *HYDROLOGY , *MONSOONS , *SPATIOTEMPORAL processes , *RUNOFF - Abstract
Highlights: [•] Decreased uncertainty with distributed, weighted, multi-method discharge estimates. [•] High baseflow at upper elevations, while low elevations are mainly runoff driven. [•] Scale-dependent river discharge suggests ergodic behavior in complex watersheds. [•] Spatiotemporal discharge estimates necessary for accurate basin-wine partitioning. [•] A single annual monsoonal event typically alters streambed characteristics. [Copyright &y& Elsevier]
- Published
- 2013
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237. Storm pulses and varying sources of hydrologic carbon export from a mountainous watershed
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Jung, Byung-Joon, Lee, Hyun-Ju, Jeong, Jong-Jin, Owen, Jeffrey, Kim, Bomchul, Meusburger, Katrin, Alewell, Christine, Gebauer, Gerhard, Shope, Christopher, and Park, Ji-Hyung
- Subjects
- *
SOIL erosion , *SOIL leaching , *MOUNTAIN watersheds , *CLIMATE change , *SUSPENDED sediments , *AGRICULTURAL pollution , *HYDROLOGY , *SOIL mineralogy , *RAINFALL , *CARBON in soils - Abstract
Summary: Although soil erosion and leaching can transfer a substantial portion of the annual terrestrial carbon (C) increment to aquatic systems, little is known about rapid changes in the amount and characteristics of soil organic C exported from mountainous watersheds during storm events. To trace short-term changes in sources and characteristics of soil organic C exported during storm events, we investigated storm-induced changes in concentrations of particulate and dissolved organic C (POC and DOC) and the stable isotope composition of suspended sediment (SS) in a mountainous, mixed land-use watershed in northern South Korea. Biweekly stream sampling in a headwater forest stream and a watershed outlet receiving agricultural runoff showed that concentrations of SS and POC were higher in the watershed outlet. In both the forest stream and outlet, POC concentrations were lower than DOC concentrations during baseflow, but increased rapidly with rising discharge during intense storms, resulting in higher peak POC concentrations than peak DOC concentrations. When δ 13C and δ 15N were compared between SS and potential source soils during three storm events, SS δ 13C and δ 15N in the forest stream were similar to forest floor δ 13C and δ 15N. SS δ 13C and δ 15N in the watershed outlet reflected the contribution from forest and cropland mineral soils during peak flow, with sand-size SS displaying increasing δ 13C and δ 15N with rising rainfall intensity. The results suggest that storm pulses of POC can be a transient, but dominant pathway of hydrologic C export overwhelming DOC export and that POC sources and characteristics can rapidly change corresponding to varying rainfall intensity. [Copyright &y& Elsevier]
- Published
- 2012
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238. Phytoplankton nutrient use and CO2 dynamics responding to long-term changes in riverine N and P availability.
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Kim, Dohee, Lim, Ju-Hee, Chun, Yewon, Nayna, Omme Kulsum, Begum, Most Shirina, and Park, Ji-Hyung
- Subjects
- *
PHYTOPLANKTON , *DISSOLVED organic matter , *CARBON dioxide , *ALGAL blooms , *WATER quality , *TIME series analysis - Abstract
• A 25-year time series shows recent increases in N/P driven by decreasing P levels. • Harmful algal blooms concur with short-term changes in P, N/P, and temperature. • Cyanobacterial dominance lowers phytoplankton P use efficiency at low N/P. • CO 2 relationship with N/P or Chl a indicates phytoplankton biomass as a CO 2 source. Long-term trends in riverine nutrient availability have rarely been linked to both phytoplankton composition and functioning. To explore how the changing availability of N and P affects not only phytoplankton abundance and composition but also the resource use efficiency of N, P, and CO 2 , a 25-year time series of water quality in the lower Han River, Korea, was combined with additional measurements of riverine dissolved organic carbon (DOC) and CO 2. Despite persistent eutrophication, recent decreases in P relative to N have been steep in the lowest reach, increasing the annual mean mass ratio of N to P (N/P) from 24 (1994–2015) to 65 (2016–2018). While Chl a and cyanobacterial abundance exhibited overall positive and inverse relationships with P concentrations and N/P, respectively, severe harmful algal blooms (HABs) concurred with short-term increases in P and temperature. Microcystis often dominated HABs at low N/P that usually favors N-fixing cyanobacteria such as Anabaena. In the middle and lower reaches, phytoplanktonic P use efficiency was typically lower at low N/P. V-shaped relationships between N/P and CO 2 concentrations, together with longitudinal upward shifts in the inverse relationship between Chl a and CO 2 , implied that eutrophication-enhanced phytoplankton biomass could turn into a significant source of CO 2. after passing a threshold. The combined results suggest that cyanobacterial dominance co-limited by P availability and temperature can lower planktonic P use efficiency, while enhancing riverine CO 2 emissions at low N/P ratios. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2021
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239. Temperature control on wastewater and downstream nitrous oxide emissions in an urbanized river system.
- Author
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Chun, Yewon, Kim, Dohee, Hattori, Shohei, Toyoda, Sakae, Yoshida, Naohiro, Huh, Jinhee, Lim, Ju-Hee, and Park, Ji-Hyung
- Subjects
- *
TEMPERATURE control , *WATERSHEDS , *NITROUS oxide , *SEWAGE disposal plants , *ISOINDOLE , *WATER quality , *HYPOXIA (Water) - Abstract
• N 2 O concentrations and isotopes reveal winter surges in wastewater and affected river • Low temperature lowers performance of wastewater N removal producing more N 2 O • Low temperature enhances N 2 O production via denitrification in hypoxic sediment Although eutrophic urban rivers receiving loads of wastewater represent an important anthropogenic source of N 2 O, little is known as to how temperature and other environmental factors affect temporal variations in N 2 O emissions from wastewater treatment plants (WWTPs) and downstream rivers. Two-year monitoring at a WWTP and five river sites was complemented with available water quality data, laboratory incubations, and stable isotopes in N 2 O and NO 3 − to explore how wastewater effluents interact with seasonal changes in environmental conditions to affect downstream metabolic processes and N 2 O emissions from the lower Han River traversing the megacity Seoul. Water quality data from four WWTPs revealed significant inverse relationships between water temperature and the concentrations or fluxes of total N (TN) in effluents. Increased TN fluxes at low temperatures concurred with N 2 O surges in WWTP effluents and downstream rivers, counteracting the long-term decline in TN fluxes resulting from enhanced wastewater treatments. Incubation experiments with river water and sediment, in isolation or combined, implied the hypoxic winter sediment as a large source of N 2 O, whereas the anoxic summer sediment produced a smaller amount of N 2 O only when it was added with oxic water. For both WWTP effluents and downstream rivers, bulk isotope ratios and intramolecular distribution of 15N in N 2 O distinctly differed between summer and winter, indicating incomplete denitrification in the hypoxic sediment at low temperatures as a primary downstream source adding to WWTP-derived N 2 O. Winter surges in wastewater TN and sediment N 2 O release highlight temperature variability as an underappreciated control over anthropogenic N 2 O emissions from increasingly urbanized river systems worldwide. Image, graphical abstract [ABSTRACT FROM AUTHOR]
- Published
- 2020
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240. Ultra-Low Level Somatic Mutations and Structural Variations in Focal Cortical Dysplasia Type II.
- Author
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Kim JH, Park JH, Lee J, Park JW, Kim HJ, Chang WS, Kim DS, Ju YS, Aronica E, and Lee JH
- Subjects
- Humans, TOR Serine-Threonine Kinases genetics, Mutation genetics, Focal Cortical Dysplasia, Epilepsy genetics
- Abstract
Objective: Brain somatic mutations in mTOR pathway genes are a major genetic etiology of focal cortical dysplasia type II (FCDII). Despite a greater ability to detect low-level somatic mutations in the brain by deep sequencing and analytics, about 40% of cases remain genetically unexplained., Methods: We included 2 independent cohorts consisting of 21 patients with mutation-negative FCDII without apparent mutations on conventional deep sequencing of bulk brain. To find ultra-low level somatic variants or structural variants, we isolated cells exhibiting phosphorylation of the S6 ribosomal protein (p-S6) in frozen brain tissues using fluorescence-activated cell sorting (FACS). We then performed deep whole-genome sequencing (WGS; >90×) in p-S6
+ cells in a cohort of 11 patients with mutation-negative. Then, we simplified the method to whole-genome amplification and target gene sequencing of p-S6+ cells in independent cohort of 10 patients with mutation-negative followed by low-read depth WGS (10×)., Results: We found that 28.6% (6 of 21) of mutation-negative FCDII carries ultra-low level somatic mutations (less than 0.2% of variant allele frequency [VAF]) in mTOR pathway genes. Our method showed ~34 times increase of the average mutational burden in FACS mediated enrichment of p-S6+ cells (average VAF = 5.84%) than in bulky brain tissues (average VAF = 0.17%). We found that 19% (4 of 21) carried germline structural variations in GATOR1 complex undetectable in whole exome or targeted gene sequencing., Conclusions: Our method facilitates the detection of ultra-low level somatic mutations, in specifically p-S6+ cells, and germline structural variations and increases the genetic diagnostic rate up to ~80% for the entire FCDII cohort. ANN NEUROL 2023;93:1082-1093., (© 2023 American Neurological Association.)- Published
- 2023
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- View/download PDF
241. Basin-specific pollution and impoundment effects on greenhouse gas distributions in three rivers and estuaries.
- Author
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Park JH, Lee H, Zhumabieke M, Kim SH, Shin KH, and Khim BK
- Subjects
- Humans, Estuaries, Carbon Dioxide, Methane analysis, Environmental Monitoring, Nitrous Oxide analysis, Greenhouse Gases analysis, Air Pollutants analysis
- Abstract
Large uncertainties exist regarding the combined effects of pollution and impoundment on riverine greenhouse gas (GHG) emissions. It has also been debated whether river eutrophication can transform downstream estuaries into carbon sinks. To assess human impacts on the riverine and estuarine distributions of CO
2 , CH4 , and N2 O, two source-to-estuary surveys along three impounded rivers in Korea were combined with multiple samplings at five or six estuarine sites. The basin-wide surveys revealed predominant pollution effects generating localized hotspots of riverine GHGs along metropolitan areas. The localized pollution effect was pronounced in the lower Han River and estuary adjacent to Seoul, while the highest GHG levels in the upper Yeongsan traversing Gwangju were not carried over into the faraway estuary. CH4 levels were elevated across the eutrophic middle Nakdong reaches regulated by eight cascade weirs in contrast to undersaturated CO2 indicating enhanced phytoplankton production. The levels of all three GHGs tended to be higher in the Han estuary across seasons. Higher summer-time δ13 C-CH4 values at some Nakdong and Yeongsan estuarine sites implied that temperature-enhanced CH4 production may have been dampened by increased CH4 oxidation. Our results suggest that the location and magnitude of pollution sources and impoundments control basin-specific longitudinal GHG distributions and estuarine carryover effects, warning against simple generalizations of eutrophic rivers and estuaries as carbon sinks., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have influenced the work reported in this study., (Copyright © 2023 Elsevier Ltd. All rights reserved.)- Published
- 2023
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- View/download PDF
242. Optical and molecular indices of dissolved organic matter for estimating biodegradability and resulting carbon dioxide production in inland waters: A review.
- Author
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Begum MS, Park JH, Yang L, Shin KH, and Hur J
- Subjects
- Anthropogenic Effects, Biodegradation, Environmental, Coloring Agents, Dissolved Organic Matter, Carbon Dioxide
- Abstract
Biodegradable dissolved organic carbon (BDOC) constitutes the most labile fraction of dissolved organic matter (DOM), which also functions as a source of CO
2 emissions from inland waters. However, no systematic review is available on DOM indicators of BDOC and CO2 production potential. Optical and molecular indices can be used to track small changes in DOM composition during biodegradation. In this review, we identified four different methods for measuring BDOC together with their strengths and limitations. In addition, we discuss the potential of using documented optical indices based on absorption and fluorescence spectroscopy and molecular indices based on Fourier transform ion cyclotron mass spectrometry as proxies for estimating BDOC and biodegradation-induced CO2 production based on previously reported relationships in the literature. Many absorbance- and fluorescence-based indices showed inconsistent relationships with BDOC depending on watershed characteristics, hydrology, and anthropogenic impacts. Nevertheless, several indices, including specific UV absorbance at 254 nm (SUVA254 ), humification index (HIX), and terrestrial humic-like fluorescent DOM (FDOM) components, tended to have negative relationships with BDOC in tropical and temperate watersheds under baseflow or drought periods. Protein-like FDOM exhibited the strongest correlation with BDOC in different systems, except during storms and flood events. Despite the limited number of studies, DOM molecular indices exhibited consistent relationships with BDOC, suggesting that the relative abundance of aliphatic formulas and the molecular lability index could act as reliable proxies. The DOM optical indices explain up to 96% and 78% variability in BDOC and CO2 , respectively; nonetheless, there were limited studies on molecular indices, which explain up to 74% variability in BDOC. Based on literature survey, we recommend several sensitive indices such as SUVA254 , HIX, and terrestrial humic- and protein-like FDOM, which could be useful indicators of BDOC and dissolved CO2 in inland water. Future research should incorporate a wider range of geographic regions with various land use, hydrology, and anthropogenic disturbances to develop system- or condition-specific DOM optical or molecular proxies for better prediction of BDOC and CO2 emissions., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)- Published
- 2023
- Full Text
- View/download PDF
243. Generalised autonomic failure as a prognostic factor in systemic light-chain (AL) amyloidosis.
- Author
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Kwon S, Jeong WK, Park JH, Kim J, Cho EB, Seok JM, Kim SJ, Kim K, Jeon ES, Min JH, and Kim BJ
- Subjects
- Humans, Female, Prognosis, Kaplan-Meier Estimate, Proportional Hazards Models, Immunoglobulin Light-chain Amyloidosis complications, Immunoglobulin Light-chain Amyloidosis diagnosis, Amyloidosis complications
- Abstract
Background: In the present study, it was investigated whether autonomic dysfunction could predict prognosis in light-chain (AL) amyloidosis patients., Patients and Methods: Seventy-two patients with biopsy-proven AL amyloidosis were included and underwent an autonomic function test (AFT) between January 2016 and June 2019. Autonomic failure was evaluated using the Composite Autonomic Severity Score (CASS). Survival curves and the three-year overall survival (OS) rate were estimated using the Kaplan-Meier curve, and the Cox proportional hazards regression method was used to evaluate the variables that influenced survival., Results: Autonomic dysfunction was observed in 69 (96%) patients with AL amyloidosis, and the three-year OS rate was 67%. Generalised autonomic failure (GAF) was observed in 31 (43%) patients. In the Kaplan-Meier curve, the three-year OS rates in patients with sudomotor dysfunction or GAF were lower than that in control patients (35 vs. 84%, and 33 vs. 81%, respectively). In Cox proportional hazards regression model, female, bone marrow plasma cell percentage, left ventricular systolic dysfunction, and GAF were significant independent variables associated with survival., Conclusion: The results of this study indicate that GAF on the AFT is an independent adverse prognostic factor for survival in AL amyloidosis patients.
- Published
- 2022
- Full Text
- View/download PDF
244. Comparison between Pediatric Crohn's Disease and Ulcerative Colitis at Diagnosis in Korea: Results from a Multicenter, Registry-Based, Inception Cohort Study.
- Author
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Park S, Kang B, Kim S, Choi S, Suh HR, Kim ES, Park JH, Kim MJ, Choe YH, Lee YJ, Park JH, Ryoo E, Koh H, and Choe BH
- Subjects
- Child, Humans, Male, Female, Young Adult, Adult, Cohort Studies, Republic of Korea epidemiology, Registries, Colitis, Ulcerative diagnosis
- Abstract
Background/aims: We aimed to compare the differences in pediatric Crohn's disease (CD) and ulcerative colitis (UC) at diagnosis in Korea., Methods: This was a multicenter, registry-based, inception cohort study conducted at five centers in Korea between 2013 and 2017. Baseline demographics, clinical characteristics, and results from laboratory, endoscopic, radiologic examinations were compared between pediatric CD and UC patients who were <19 years old at diagnosis., Results: A total 307 patients were included (227 CD [73.9%] and 80 UC [26.1%]). The male to female ratio was 2.49:1 for CD, and 1.49:1 for UC (p=0.019). Median age at diagnosis was 14.4 years (interquartile range, 12.4 to 16.2) for CD, and 14.4 years (interquartile range, 11.7 to 16.5) for UC (p=0.962). Hematochezia was the only dominant symptom in UC patients compared to CD patients (86.2% vs 30.8%, p<0.001). White blood cell counts, platelet counts, erythrocyte sedimentation rate, and C-reactive protein levels were significantly higher, and serum albumin level was significantly lower in CD patients than in UC patient. Anti- Saccharomyces cerevisiae antibody was positive in 44.5% and 16.2% of CD and UC patients, respectively (p<0.001), and antineutrophil cytoplasmic antibody was positive in 15.0% and 58.8% of CD and UC patients, respectively (p<0.001). Terminal ileal involvement was prominent in CD, while rectal involvement was more prominent in UC. Small bowel involvement and perianal perforating diseases were also more prominent in CD., Conclusions: This is the first a multicenter study in Korea to compare the differences between pediatric CD and UC at diagnosis in Korea. A large-scale, national study is expected to better clarify these findings in the future.
- Published
- 2022
- Full Text
- View/download PDF
245. Does Medicaid expansion influence county health spending? A case of New York counties.
- Author
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Noh S and Park JH
- Subjects
- Humans, Local Government, New York, Uncompensated Care, United States, Health Expenditures, Medicaid
- Abstract
We investigated the impacts of Medicaid expansion on New York county total health spending and specifics of health spending, including health services, public health facilities and public health administration. Little research considered the financial effect of Medicaid expansion on local governments while well reported are its influences on uninsured rates and health services utilization. New York counties have contributed to health in their boundaries by providing or funding public health services, and supporting a part of the non-federal share of Medicaid expenditures and uncompensated care. Medicaid expansion can reduce the size of county expenditures for health by enrolling more previously uninsured population in the program and offering more generous federal funding for the expanded Medicaid. We offer empirical evidence that Medicaid expansion was associated with reduced county health spending.
- Published
- 2022
- Full Text
- View/download PDF
246. Behavioral Reserve in Behavioral Variant Frontotemporal Dementia.
- Author
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Kim SH, Kim YJ, Lee BH, Lee P, Park JH, Seo SW, and Jeong Y
- Abstract
"Reserve" refers to the individual clinical differences in response to a neuropathological burden. We explored the behavioral reserve (BR) and associated neural substrates in 40 participants with behavioral variant frontotemporal dementia (bvFTD) who were assessed with the frontal behavioral inventory (FBI) and magnetic resonance imaging. Because neuroimaging abnormality showed a high negative correlation with the FBI negative (but not positive) symptom scores, we developed a linear model only to calculate the nBR (BR for negative symptoms) marker using neuroimaging abnormalities and the FBI score. Participants were divided into high nBR and low nBR groups based on the nBR marker. The FBI negative symptom score was lower in the high nBR group than in the low nBR group having the same neuroimaging abnormalities. However, the high nBR group noted a steeper decline in cortical atrophy and showed less atrophy in the left frontotemporal cortices than the low nBR group. In addition, the fractional anisotropy (FA) values were greater in the high nBR than in the low nBR group, except in the sensory-motor and occipital areas. We identified an nBR-related functional network composed of bilateral frontotemporal areas and the left occipital pole. We propose the concept of BR in bvFTD, and these findings can help predict the disease progression., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Kim, Kim, Lee, Lee, Park, Seo and Jeong.)
- Published
- 2022
- Full Text
- View/download PDF
247. Pediatric Crohn's disease with severe morbidity manifested by gastric outlet obstruction: two cases report and review of the literature.
- Author
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Kim ES, Park JH, Choe YH, and Kim MJ
- Abstract
Crohn's disease (CD) presenting as gastric outlet obstruction is rare but serious clinical presentation of CD causing severe morbidity. However, there have been few case reports concerning this disorder in East Asian children and adolescents. The current case report describes 2 pediatric patients with CD who had had gastric outlet obstruction as an initial symptom of CD. Two pediatric patients developed postprandial vomiting, bloating, and unintentional weight loss. The upper endoscopy result indicated that there was pyloric obstruction with mucosal edema, inflammation and ulcers. The serologic test and colonoscopy results suggested CD. These patients were treated with infliximab, and endoscopic balloon dilation without surgery and showed remarkable improvement in obstructing symptoms with maintaining clinical and biochemical remission. This case report elucidates the benefits of early intervention using infliximab and endoscopic balloon dilation to improve gastric outlet obstruction and achieve baseline recovery in patients with upper gastrointestinal B2 phenotype of CD.
- Published
- 2021
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- View/download PDF
248. State strategies to address medicaid prescription spending: negotiated pricing vs price transparency.
- Author
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Noh S, Janousek CL, and Park JH
- Subjects
- Drug Costs, Patient Protection and Affordable Care Act, Reimbursement Mechanisms, State Government, United States, Cost Control methods, Costs and Cost Analysis, Managed Care Programs economics, Medicaid economics, Prescription Drugs economics
- Abstract
This research longitudinally examines the association between levels of state Medicaid prescription spending and the state strategies intended to constrain cost increases: the negotiated pricing strategy, as indicated by state rebate programs, and the price transparency strategy, as indicated by state operation of All-Payer Claims Databases. The findings demonstrate evidence that state Medicaid prescription spending is influenced by the negotiated pricing strategy, especially Managed Care Organization (MCO) rebates under the Patient Protection and Affordable Care Act, but not influenced by the price transparency strategy. State decisions for MCO rebates, such as carving prescription benefits into managed care benefits, were effective in containing levels of Medicaid prescription spending over time, while other single- and multi-state rebate programs were not. Based on these findings, state policymakers may consider utilizing the MCO rebate program to address increases in Medicaid prescription spending.
- Published
- 2021
- Full Text
- View/download PDF
249. Variability of water quality and metal pollution index in the Ganges River, Bangladesh.
- Author
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Haque MM, Niloy NM, Nayna OK, Fatema KJ, Quraishi SB, Park JH, Kim KW, and Tareq SM
- Subjects
- Bangladesh, Environmental Monitoring, Humans, Rivers, Water Quality, Metals, Heavy analysis, Water Pollutants, Chemical analysis
- Abstract
The Ganges River is one of the biggest transboundary streams in the Indian sub-continent. The significant part of this waterway channel drains one of the most densely populated areas on the planet so it is unequivocally influenced by human activities. Unprecedented high-temporal-resolution samples were collected for investigating the seasonal variability of water quality. Water quality index (WQI) reveals large seasonal variation among three major seasons and also indicates that the river water is not suitable for drinking and other household uses. The dominant water facies is bicarbonate (HCO
3 - ). The water quality indices, %Na, Kelley's ratio (KR), sodium adsorption ratio (SAR), and magnesium adsorption ratio (MAR), reveal that the water is appropriate for irrigation. The permeability index (PI) indicated that the water is moderate to poorly useable for agricultural purposes. Heavy metals concentrations demonstrated significant seasonal variations with high concentrations during the monsoon due to flushing of pollutants from catchment areas by intense monsoonal precipitations. In addition, local activities such as oil spills from the boat, vehicle washing water, and agricultural runoff may also added pollutants. The single-factor pollution index (Ii) and Nemerow pollution index (Ni) exhibits minor pollution. The values of heavy metal pollution index (HPI) are far below than the critical limit (100) for the studied month, although relatively higher HPI values found for April, August, and November than other months might come from domestic wastes and agricultural activities. The heavy metal evaluation index (HEI) values of all the months indicated a low degree of pollution. Even though the river water pollution level is low, the authority should take proper management and monitoring strategy for sustainable use.- Published
- 2020
- Full Text
- View/download PDF
250. Bilateral subthalamic deep brain stimulation is an effective and safe treatment option for the older patients with Parkinson's disease.
- Author
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Kim M, Cho KR, Park JH, Ahn JH, Cho JW, Park S, Lee JI, and Youn J
- Subjects
- Adult, Aged, Aging, Female, Humans, Levodopa therapeutic use, Male, Middle Aged, Parkinson Disease physiopathology, Subthalamic Nucleus surgery, Treatment Outcome, Brain surgery, Deep Brain Stimulation methods, Parkinson Disease therapy
- Abstract
Objectives: We aimed to provide evidence that subthalamic nucleus (STN) deep brain stimulation (DBS) is an effective and safe treatment option for older patients with Parkinson's disease (PD)., Patients and Methods: Bilateral STN DBS was performed in 55 patients with PD from 2012 to 2016 at Samsung Medical Center. We divided them into two groups based on the age at DBS: younger group (<65 years, n = 38) and older group (≥65 years, n = 17). For evaluating effectiveness, we compared pre- and post-DBS Unified Parkinson's Disease Rating Scale (UPDRS) part 3 and 4 scores and levodopa equivalent daily dose (LEDD) between the two groups. Additionally, surgery-related complications in each group were assessed., Results: The mean age of the younger group was 56.7 ± 5.7 and that of the older group was 68.5 ± 2.9. More female patients underwent STN DBS in the younger group, but there were no differences in baseline characteristics. In terms of effectiveness, UPDRS part 3 and 4 scores and LEDD significantly improved 6 months after DBS in both groups. In terms of safety, 1 complication was observed in the younger group (2.6%), while 2 complications, including 1 subject with intracerebral hemorrhage, were observed in the older group (11.8%, p = 0.225)., Conclusion: Based on our results, STN DBS can be applied in well-selected older patients with PD as well as in younger patients. However, despite the lack of statistical significance, more attention should be paid on surgical complications in the older group., (Copyright © 2018 Elsevier B.V. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
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