• Title/Summary/Keyword: neutral evolution

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Genetic Variation of Taenia Pisiformis Collected from Sichuan, China, Based on the Mitochondrial Cytochrome b gene

  • Yang, Deying;Ren, Yongjun;Fu, Yan;Xie, Yue;Nie, Huaming;Nong, Xiang;Gu, Xiaobin;Wang, Shuxian;Peng, Xuerong;Yang, Guangyou
    • Parasites, Hosts and Diseases
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    • v.51 no.4
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    • pp.449-452
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    • 2013
  • Taenia pisiformis is one of the most important parasites of canines and rabbits. T. pisiformis cysticercus (the larval stage) causes severe damage to rabbit breeding, which results in huge economic losses. In this study, the genetic variation of T. pisiformis was determined in Sichuan Province, China. Fragments of the mitochondrial cytochrome b (cytb) (922 bp) gene were amplified in 53 isolates from 8 regions of T. pisiformis. Overall, 12 haplotypes were found in these 53 cytb sequences. Molecular genetic variations showed 98.4% genetic variation derived from intra-region. $F_{ST}$ and Nm values suggested that 53 isolates were not genetically differentiated and had low levels of genetic diversity. Neutrality indices of the cytb sequences showed the evolution of T. pisiformis followed a neutral mode. Phylogenetic analysis revealed no correlation between phylogeny and geographic distribution. These findings indicate that 53 isolates of T. pisiformis keep a low genetic variation, which provide useful knowledge for monitoring changes in parasite populations for future control strategies.

Endovascular Stroke Therapy Focused on Stent Retriever Thrombectomy and Direct Clot Aspiration : Historical Review and Modern Application

  • Kang, Dong-Hun;Park, Jaechan
    • Journal of Korean Neurosurgical Society
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    • v.60 no.3
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    • pp.335-347
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    • 2017
  • Intravenous recombinant tissue plasminogen activator had been the only approved treatment for acute ischemic stroke since its approval in 1995. However, the restrictive time window, numerous contraindications, and its low recanalization rate were all limitations of this modality. Under those circumstances, endovascular stroke therapy went through a great evolution during the past two decades of intravenous thrombolysis. The results of the 2013 randomized trials for endovascular stroke therapy were neutral, although they were limited by insufficient imaging screening at enrollment, early-generation devices with less efficacy, and treatment delays. Huge progress was made in 2015, as there were five randomized clinical trials which all demonstrated the safety and efficacy of endovascular stroke treatment. Despite differences in detail patient enrollment criteria, all 5 trials employed key factors for good functional recovery; (1) screening with non-invasive imaging to identify the proximal occlusion and exclude a large infarct core, (2) using highly effective modern thrombectomy devices mainly with stent retriever, and (3) establishment of a fast workflow to achieve effective reperfusion. The results of those trials indicate that modern thrombectomy devices can allow for faster and more effective reperfusion, which can lead to improved clinical outcomes compared to intravenous thrombolysis alone. These advances in mechanical thrombectomy are promising in the global fight against ischemic stroke-related disability and mortality. Two current mainstreams among such mechanical thrombectomy techniques, "stent retriever thrombectomy" and "direct clot aspiration", are the topic of this review. Stent retriever thrombectomy using Solitaire and Trevo retriever will be firstly discussed. And, the commonalities and the differences between two major clot aspiration thrombectomy techniques; a direct aspiration first pass technique (ADAPT) and forced arterial suction thrombectomy (FAST), will be additionally explained. Finally, details regarding the combination of direct clot aspiration and stent retriever thrombectomy, the switching strategy and the Solumbra technique, will be described.

국내 심부 암반지하수의 수리지구화학 진화와 관련된 고농도 불소 산출 특성

  • Kim Gyeong-Ho;Yun Seong-Taek;Chae Gi-Tak;Kim Seong-Yong;Gwon Jang-Sun;Go Yong-Gwon
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2005.04a
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    • pp.101-104
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    • 2005
  • To understand the geologic and hydrogeochemical controls on the occurrence of high fluoride concentrations in bedrock groundwaters in South Korea, we examined a total of 367 hydrochemistry data obtained from deep groundwater wells (avg, depth = 600 m) that were drilled for exploitation of hot springs. The fluoride concentrations were generally very high (avg. 5.65 mg/L) and exceeded the Drinking Water Standard (1.5 mg/L) in 72% of the samples, A significant geologic control of fluoride concentrations was observed: the highest concentrations occur in the areas of granitoids and granitic gneiss, while the lowest concentrations in the areas of volcanic and sedimentary rocks. In relation to the hydrochemical facies, alkaline $Na-HCO_3$ type waters had remarkably higher F concentrations than circum-neutral to slightly alkaline $Ca-HCO_3$ type waters. The Prolonged water-rock interaction occurring during the deep circulation of groundwater in the areas of granitoids and granitic gneiss is considered most important for the generation of high F concentrations. Under such condition, fluoride-rich groundwaters are likely formed through hydrogeochemical processes consisting of the removal of Ca from groundwater via calcite precipitation and/or cation exchange and the successive dissolution of plagioclase and F-bearing hydroxyl minerals (esp. biotite). Thus, groundwaters with high pH and very high Na/Ca ratio within granitoids and granitic gneiss are likely most vulnerable to the water supply problem in relation to the enriched fluorine.

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A STUDY OF DWARF GALAXIES EMBEDDED IN A LARGE-SCALE Hɪ RING IN THE LEO I GROUP

  • KIM, MYO JIN;CHUNG, AEREE;LEE, JONG CHUL;LIM, SUNGSOON;KIM, MINJIN;KO, JONGWAN;LEE, JOON HYEOP;YANG, SOUNG-CHUL;LEE, HYE-RAN
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.517-519
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    • 2015
  • A large-scale neutral hydrogen ($H\small{I}$) ring serendipitously found in the Leo I galaxy group is 200 kpc in diameter with $M_{H\small{I}}{\sim}1.67{\times}10^9M_{\odot}$, unique in size in the Local Universe. It is still under debate where this $H\small{I}$ ring originated - whether it has formed out of the gas remaining after the formation of a galaxy group (primordial origin) or been stripped during galaxy-galaxy interactions (tidal origin). We are investigating the optical and $H\small{I}$ gas properties of the dwarf galaxies located within the gas ring in order to probe its formation mechanism. In this work, we present the photometric properties of the dwarfs inside the ring using the CFHT MegaCam $u^{\ast}$, $g^{\prime}$, $r^{\prime}$ and $i^{\prime}$-band data. We discuss the origin of the gas ring based on the stellar age and metal abundance of dwarf galaxies contained within it.

Complete Genomic Characterization of Two Beet Soil-Borne Virus Isolates from Turkey: Implications of Comparative Analysis of Genome Sequences

  • Moradi, Zohreh;Maghdoori, Hossein;Nazifi, Ehsan;Mehrvar, Mohsen
    • The Plant Pathology Journal
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    • v.37 no.2
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    • pp.152-161
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    • 2021
  • Sugar beet (Beta vulgaris L.) is known as a key product for agriculture in several countries across the world. Beet soil-borne virus (BSBV) triggers substantial economic damages to sugar beet by reducing the quantity of the yield and quality of the beet sugars. We conducted the present study to report the complete genome sequences of two BSBV isolates in Turkey for the first time. The genome organization was identical to those previously established BSBV isolates. The tripartite genome of BSBV-TR1 and -TR3 comprised a 5,835-nucleotide (nt) RNA1, a 3,454-nt RNA2, and a 3,005-nt RNA3 segment. According to sequence identity analyses, Turkish isolates were most closely related to the BSBV isolate reported from Iran (97.83-98.77% nt identity). The BSBV isolates worldwide (n = 9) were phylogenetically classified into five (RNA-coat protein read through gene [CPRT], TGB1, and TGB2 segments), four (RNA-rep), or three (TGB3) lineages. In genetic analysis, the TGB3 revealed more genetic variability (Pi = 0.034) compared with other regions. Population selection analysis revealed that most of the codons were generally under negative selection or neutral evolution in the BSBV isolates studied. However, positive selection was detected at codon 135 in the TGB1, which could be an adaptation in order to facilitate the movement and overcome the host plant resistance genes. We expect that the information on genome properties and genetic variability of BSBV, particularly in TGB3, TGB1, and CPRT genes, assist in developing effective control measures in order to prevent severe losses and make amendments in management strategies.

Biological Inspiration toward Artificial Photostystem

  • Park, Jimin;Lee, Jung-Ho;Park, Yong-Sun;Jin, Kyoungsuk;Nam, Ki Tae
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.91-91
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    • 2013
  • Imagine a world where we could biomanufacture hybrid nanomaterials having atomic-scale resolution over functionality and architecture. Toward this vision, a fundamental challenge in materials science is how to design and synthesize protein-like material that can be fully self-assembled and exhibit information-specific process. In an ongoing effort to extend the fundamental understanding of protein structure to non-natural systems, we have designed a class of short peptides to fold like proteins and assemble into defined nanostructures. In this talk, I will talk about new strategies to drive the self-assembled structures designing sequence of peptide. I will also discuss about the specific interaction between proteins and inorganics that can be used for the development of new hybrid solar energy devices. Splitting water into hydrogen and oxygen is one of the promising pathways for solar to energy convertsion and storage system. The oxygen evolution reaction (OER) has been regarded as a major bottleneck in the overall water splitting process due to the slow transfer rate of four electrons and the high activation energy barrier for O-O bond formation. In nature, there is a water oxidation complex (WOC) in photosystem II (PSII) comprised of the earthabundant elements Mn and Ca. The WOC in photosystem II, in the form of a cubical CaMn4O5 cluster, efficiently catalyzes water oxidation under neutral conditions with extremely low overpotential (~160 mV) and a high TOF number. The cluster is stabilized by a surrounding redox-active peptide ligand, and undergo successive changes in oxidation state by PCET (proton-coupled electron transfer) reaction with the peptide ligand. It is fundamental challenge to achieve a level of structural complexity and functionality that rivals that seen in the cubane Mn4CaO5 cluster and surrounding peptide in nature. In this presentation, I will present a new strategy to mimic the natural photosystem. The approach is based on the atomically defined assembly based on the short redox-active peptide sequences. Additionally, I will show a newly identified manganese based compound that is very close to manganese clusters in photosystem II.

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The Multi-door Courthouse: Origin, Extension, and Case Studies (멀티도어코트하우스제도: 기원, 확장과 사례분석)

  • Chung, Yongkyun
    • Journal of Arbitration Studies
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    • v.28 no.2
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    • pp.3-43
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    • 2018
  • The emergence of a multi-door courthouse is related with a couple of reasons as follows: First, a multi-door courthouse was originally initiated by the United States government that increasingly became impatient with the pace and cost of protracted litigation clogging the courts. Second, dockets of courts are overcrowded with legal suits, making it difficult for judges to handle those legal suits in time and causing delays in responding to citizens' complaints. Third, litigation is not suitable for the disputant that has an ongoing relationship with the other party. In this case, even if winning is achieved in the short run, it may not be all that was hoped for in the long run. Fourth, international organizations such as the World Bank, UNDP, and Asia Development Bank urge to provide an increased access to women, residents, and the poor in local communities. The generic model of a multi-door courthouse consists of three stages: The first stage includes a center offering intake services, along with an array of dispute resolution services under one roof. At the second stage, the screening unit at the center would diagnose citizen disputes, then refer the disputants to the appropriate door for handling the case. At the third stage, the multi-door courthouse provides diverse kinds of dispute resolution programs such as mediation, arbitration, mediation-arbitration (med-arb), litigation, and early neutral evaluation. This study suggests the extended model of multi-door courthouse comprised of five layers: intake process, diagnosis and door-selection process, neutral-selection process, implementation process of dispute resolution, and process of training and education. One of the major characteristics of extended multi-door courthouse model is the detailed specification of individual department corresponding to each process within a multi-door courthouse. The intake department takes care of the intake process. The screening department plays the role of screening disputes, diagnosing the nature of disputes, and determining a suitable door to handle disputes. The human resources department manages experts through the construction and management of the data base of mediators, arbitrators, and judges. The administration bureau manages the implementation of each process of dispute resolution. The education and training department builds long-term planning to procure neutrals and experts dealing with various kinds of disputes within a multi-door courthouse. For this purpose, it is necessary to establish networks among courts, law schools, and associations of scholars in order to facilitate the supply of manpower in ADR neutrals, as well as judges in the long run. This study also provides six case studies of multi-door courthouses across continents in order to grasp the worldwide picture and wide spread phenomena of multi-door courthouse. For this purpose, the United States and Latin American countries including Argentina and Brazil, Middle Eastern countries, and Southeast Asian countries (such as Malaysia and Myanmar), Australia, and Nigeria were chosen. It was found that three kinds of patterns are discernible during the evolution of a multi-door courthouse model. First, the federal courts of the United States, land and environment court in Australia, and Lagos multi-door courthouse in Nigeria may maintain the prototype of a multi-door courthouse model. Second, the judicial systems in Latin American countries tend to show heterogenous patterns in terms of the adaptation of a multi-door courthouse model to their own environments. Some court systems of Latin American countries including those of Argentina and Brazil resemble the generic model of a multi-door courthouse, while other countries show their distinctive pattern of judicial system and ADR systems. Third, it was found that legal pluralism is prevalent in Middle Eastern countries and Southeast Asian countries. For example, Middle Eastern countries such as Saudi Arabia have developed various kinds of dispute resolution methods, such as sulh (mediation), tahkim (arbitration), and med-arb for many centuries, since they have been situated at the state of tribe or clan instead of nation. Accordingly, they have no unified code within the territory. In case of Southeast Asian countries such as Myanmar and Malaysia, they have preserved a strong tradition of customary laws such as Dhammthat in Burma, and Shriah and the Islamic law in Malaysia for a long time. On the other hand, they incorporated a common law system into a secular judicial system in Myanmar and Malaysia during the colonial period. Finally, this article proposes a couple of factors to strengthen or weaken a multi-door courthouse model. The first factor to strengthen a multi-door courthouse model is the maintenance of flexibility and core value of alternative dispute resolution. We also find that fund raising is important to build and maintain the multi-door courthouse model, reflecting the fact that there has been a competition surrounding the allocation of funds within the judicial system.

Hydrochemistry and noble gas origin of hot spring waters of Icheon and Pocheon area in Korea (이천 및 포천지역 온천수의 수리화학적 특성 및 영족기체 기원)

  • Jeong, Chan-Ho;Koh, Yung-Kwon;Shin, Seon-Ho;Nagao, Keisuke;Kim, Kyu-Han;Kim, Gun-Young
    • The Journal of Engineering Geology
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    • v.19 no.4
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    • pp.529-541
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    • 2009
  • Hydrochemical, stable isotopic ($\delta^{18}O$ and dD) and noble gas isotopic analyses of seven hot spring water samples, eleven groundwater samples and six surface water samples collected from the Icheon and Pocheon area were carried out to find out hydrochemical characteristics, and to interpret the source of noble gases and the geochemical evolution of the hot spring waters. The hot spring waters show low temperature type ranging from 21.5 to $31.4^{\circ}C$ and the pH value between 6.69 and 9.21. Electrical conductivity of hot spring waters has the range from 310 to $735\;{\mu}S/cm$. Whereas the hot spring water in the Icheon area shows the geochemical characteristics of neutral pH, the $Ca-HCO_3$(or $Ca(Na)-HCO_3$) chemical type and a high uranium content, the hot spring water in the Pocheon area shows the characteristics of alkaline pH, the $Na-HCO_3$ chemical type and a high fluorine content. These characteristics indicate that the hot spring water in the Icheon area is under the early stage in the geochemical evolution, and that the hot spring water in the Pocheon area has been geochemically evolved. The $\delta^{18}O$ and ${\delta}D$ values of hot spring waters show the range of $-10.1{\sim}-8.69%o$ and from $-72.2{\sim}-60.8%o$, respectively, and these values supply the information of the recharge area of hot spring waters. The $^3He/^4He$ ratios of the hot spring waters range from $0.09\;{\times}\;10^{-6}$ to $0.65\;{\times}\;10^{-6}$ which are plotted above the mixing line between air and crustal components. Whereas the helium gas in the Icheon hot spring water was mainly provided from the atmospheric source mixing with the mantle(or magma) origin, the origin of helium gas in the Pocheon hot spring water shows a dominant crustal source. $^{40}Ar/^{36}Ar$ ratios of hot spring water are in the range of an atmosphere source.

Hydrogeochemical Evolution Related to High Fluoride Concentrations in Deep Bedrock Groundwaters, Korea (국내 심부 암반지하수에서의 고농도 불소 산출과 관련된 수리지구화학 진화)

  • Kim Kyoung-Ho;Yun Seong-Taek;Chae Gi-Tak;Kim Seong-Yong;Kwon Jang-Soon;Koh Yong-Kwon
    • Economic and Environmental Geology
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    • v.39 no.1 s.176
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    • pp.27-38
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    • 2006
  • To understand the geologic and hydrogeochemical controls on the occurrence of high fluoride concentrations in bedrock groundwaters of South Korea, we examined a total of 367 hydrochemistry data obtained from deep groundwater wells (avg. depth=600 m) that were drilled fur exploitation of hot springs. The fluoride concentrations were generally very high (avg. 5.65mg/L) and exceeded the Drinking Water Standard (1.5 mg/L) in $72\%$ of the samples. A significant geologic control of fluoride concentrations was observed: the highest concentrations occur in the areas of granitoids and granitic gneiss, while the lowest concentrations in the areas of volcanic and sedimentary rocks. In relation to the hydrochemical facies, alkaline $Na-HCO_3$ type waters had remarkably higher F concentrations than circum-neutral to slightly alkaline $Ca-HCO_3$ type waters. The prolonged water-rock interaction occurring during the deep circulation of groundwater in the areas of granitoids and granitic gneiss is considered most important for the generation of high F concentrations. Under such condition, fluoride-rich groundwaters are likely formed through hydrogeochemical processes consisting of the removal of Ca from groundwater via calcite precipitation and/or cation exchange and the successive dissolution of plagioclase and F-bearing hydroxyl minerals (esp. biotite). Thus, groundwaters with high pH and very high Na/Ca ratio within granitoids and granitic gneiss are likely most vulnerable to the water supply problem related to enriched fluorine.

Hydrochemical and Isotopic Characteristics, and Origin of Noble Gas for Low-temperature Hot Spring Waters in the Honam Area (호남지역 저온형 온천수의 수리지화학적 및 안정동위원소 특성과 영족기체의 기원에 관한 연구)

  • Jeong, Chan-Ho;Hur, Hyun-Sung;Nagao, Keisuke;Kim, Kyu-Han
    • Economic and Environmental Geology
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    • v.40 no.5
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    • pp.635-649
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    • 2007
  • Geochemical composition, stable isotopes $({\delta}^{18}O,\;{\delta}D,\;{\delta}^{34}S)$ and noble gases(He, Ne and Ar) of nine hot spring water and three groundwater for five hot springs(Jukam, Hwasun, Dokog, Jirisan, Beunsan) from the Honam area were analyzed to investigate the hydrogeochemical characteristics and the hydrogeochemical evolution of the hot spring waters, and to interpret the source of sulfur, helium and argon dissolved in the hot spring waters. The hot spring waters show low water temperature ranging from 23.0 to $30.5^{\circ}C$ and alkaline characteristics of pH 7.67 to 9.98. Electrical conductivity of hot spring waters is $153{\sim}746{\mu}S/cm$. Groundwaters in this area were characterized by the acidic to neutral pH range$(5.85{\sim}7.21)$, the wide electrical conductivity range $(44{\sim}165{\mu}S/cm)$. The geochemical compositions of hot spring and groundwaters can be divided into three water types: (1) $Na-HCO_3$ water type, (2) Na-Cl water type and (3) $Ca-HCO_3$ water type. The hot spring water of $Ca-HCO_3$ water type in early stage have been evolved through $Ca(Na)-HCO_3$ water type into $Na-HCO_3$ type in final stage. In particular, Jurim alkaline(pH 9.98) hot spring water plotted at the end point of $Na-HCO_3$ type in the Piper diagram is likely to arrive into the final stage in geochemical evolution process. Hydrogen and oxygen isotopic data of the hot spring water samples indicate that the hot spring waters originated from the local meteoric water showing latitude and altitude effects. The ${\delta}^{34}S$ value for sulfate of the hot spring waters varies widely from 0.5 to $25.9%o$. The sulfur source of most hot spring waters in this area is igneous origin. However, The ${\delta}^{34}S$ also indicates the sulfur of JR1 hot water is originated from marine sulfur which might be derived ken ancient seawater sulfates. The $^3He/^4He\;and\;^4He/^{20}Ne$ ratios of the hot spring waters range from $0.0143{\times}10^{-6}\;to\;0.407{\times}10^{-6}\;and\;6.49{\sim}584{\times}10^{-6}$, respectively. The hot spring waters are plotted on the mixing line between air and crustal components. It means that the He gas in the hot spring waters was mainly originated from crustal sources. However, the JR1 hot spring water show a little mixing ratio of the helium gas of mantle source. The $^{40}Ar/^{36}Ar$ ratios of hot spring water are in the range from $292.3{\times}10^{-6}\;to\;304.1{\times}10^{-6}$, implying the atmospheric argon source.