• Title/Summary/Keyword: UNGULATE

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Unsolved Questions on the Anatomy of the Ventricular Conduction System

  • Oh, Il-Young;Cha, Myung-Jin;Lee, Tae-Hui;Seo, Jeong-Wook;Oh, Seil
    • Korean Circulation Journal
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    • v.48 no.12
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    • pp.1081-1096
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    • 2018
  • We reviewed the anatomical characteristics of the conduction system in the ventricles of human and ungulate hearts and then raised some questions to be answered by clinical and anatomical studies in the future. The ventricular conduction system is a 3-dimensional structure as compared to the 2-dimensional character of the atrial conduction system. The proximal part consisting of the atrioventricular node, the bundle of His and fascicles are groups of conducting cells surrounded by fibrous connective tissue so as to insulate from the underlying myocardium. Their location and morphological characters are well established. The bundle of His is a cord like structure but the left and right fascicles are broad at the proximal and branching at the distal part. The more distal part of fascicles and Purkinje system are linear networks of conducting cells at the immediate subendocardium but the intra-mural network is detected at the inner half of the ventricular wall. The papillary muscle also harbors Purkinje system not in the deeper part. It is hard to recognize histologically in human hearts but conducting cells as well as Purkinje cells are easily recognized in ungulate hearts. Further observation on human and ungulate hearts with myocardial infarct, we could find preserved Purkinje system at the subendocardium in contrast to the damaged system at the deeper myocardium. Further studies are necessary on the anatomical characteristics of this peripheral conduction system so as to correlate the clinical data on hearts with ventricular arrhythmias.

Disease Severities of Flue-Cured Tobacco Plants Surveyed in Korea, 2006 (2006년도 황색종 담배 병해발생 상황<단보>)

  • Yi, Young-Keun;Yim, Young-Gu
    • Journal of the Korean Society of Tobacco Science
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    • v.28 no.2
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    • pp.158-161
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    • 2006
  • Main tobacco diseases were surveyed on major flue-cured leaf tobacco fields throughout South Korea in 2006. Mosaic caused by potato virus Y and bacterial wilt caused by Ralstonia solanacearum were most severe during harvest season. During last ten years, the damage by tobacco mosaic virus was reduced but the incidence of bacterial wilt increased. These changes of the disease incidences coincide with release time of the tobacco cultivar resistant to the tobacco mosaic virus but susceptible to bacterial wilt pathogen. Wild fire(Pseudomonas syringae pv. tabaci strain ungulate) occurred severely at Kangwon province, though the symptom of wild fire with yellow halo was not observed.

Simple Assessment of Taxonomic Status and Genetic Diversity of Korean Long-Tailed Goral (Naemorhedus caudatus) Based on Partial Mitochondrial Cytochrome b Gene Using Non-Invasive Fecal Samples

  • Kim, Baek-Jun
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.2 no.1
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    • pp.32-41
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    • 2021
  • South Korea presently harbors less than 800 long-tailed gorals (Naemorhedus caudatus), an endangered species. I report for the first time on the taxonomic status and genetic diversity of the Korean species using non-invasive fecal sampling based on mitochondrial cytochrome b gene sequence analyses. To determine the taxonomic status of this species, I reconstructed a consensus neighbor-joining tree and generated a minimum spanning network combining haplotype sequences obtained from feces with a new goral-specific primer set developed using known sequences of the Korean goral and related species (e.g., Russian goral, Chinese goral, Himalayan goral, Japanese serow, etc.). I also examined the genetic diversity of this species. The Korean goral showed only three different haplotypes. The phylogenetic tree and parsimony haplotype network revealed a single cluster of Korean and Russian gorals, separate from related species. Generally, the Korean goral has a relatively low genetic diversity compared with that of other ungulate species (e.g., moose and red deer). I preliminarily showcased the application of non-invasive fecal sampling to the study of genetic characteristics, including the taxonomic status and genetic diversity of gorals, based on mitochondrial DNA. More phylogenetic studies are necessary to ensure the conservation of goral populations throughout South Korea.

Optimal Derivation Timing for Establishment of Porcine Embryonic Stem Cells (돼지 배아줄기세포 확립을 위한 최적의 유도시기)

  • Kim, Eun-Hye;Cheong, Seung-A;Yoon, Junchul David;Jeon, Yubyeol;Hyun, Sang-Hwan
    • Journal of Embryo Transfer
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    • v.28 no.1
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    • pp.1-6
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    • 2013
  • A lot of works have been dedicated to clarify the reasons why the establishment of embryonic stem cells (ESCs) from pig is more difficult than that from mouse and human. Several concomitant factors such as culture condition including feeder layer, sensitivity of cell to cell contact, definitive markers of pluripotency for evaluation of the validity and optimal timing of derivation have been suggested as the disturbing factors in the establishment of porcine ESCs Traditionally, attempts to derive stem cells from porcine embryos have depend on protocols established for mouse ESCs using inner cell mass (ICM) for the isolation and culture. And more recently, protocols used for primate ESCs were also applied. However, there is no report for the establishment of porcine ESCs. Indeed, ungulate species including pigs have crucial developmental differences unlike rodents and primates. Here we will review recent studies about issues for establishment of porcine ESCs and discuss the promise and strategies focusing on the timing for derivation and pluripotent state of porcine ESCs.

Species and Sex Identification of the Korean Goral (Nemorhaedus caudatus) by Molecular Analysis of Non-invasive Samples

  • Kim, Baek Jun;Lee, Yun-Sun;An, Jung-hwa;Park, Han-Chan;Okumura, Hideo;Lee, Hang;Min, Mi-Sook
    • Molecules and Cells
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    • v.26 no.3
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    • pp.314-318
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    • 2008
  • Korean long-tailed goral (Nemorhaedus caudatus) is one of the most endangered species in South Korea. However, detailed species distribution and sex ratio data on the elusive goral are still lacking due to difficulty of identification of the species and sex in the field. The primary aim of this study was to develop an economical PCR-RFLP method to identify species using invasive or non-invasive samples from five Korean ungulates: goral (N. caudatus), roe deer (Capreolus pygargus), feral goat (Capra hircus), water deer (Hydropotes inermis) and musk deer (Moschus moschiferus). The secondary aim was to find more efficient molecular sexing techniques that may be applied to invasive or non-invasive samples of ungulate species. We successfully utilized PCR-RFLP of partial mitochondrial cytochrome b gene (376 bp) for species identification, and sex-specific amplification of ZFX/Y and AMELX/Y genes for sexing. Three species (goral, goat and water deer) showed distinctive band patterns by using three restriction enzymes (Xbal, Stul or Sspl). Three different sexing primer sets (LGL331/335 for ZFX/Y gene; SE47/48 or SE47/53 for AMELX/Y gene) produced sex-specific band patterns in goral, goat and roe deer. Our results suggest that the molecular analyses of non-invasive samples might provide us with potential tools for the further genetic and ecological study of Korean goral and related species.

The Tresnds of Artiodactyla Researches in Korea, China and Japan using Text-mining and Co-occurrence Analysis of Words (텍스트마이닝과 동시출현단어분석을 이용한 한국, 중국, 일본의 우제목 연구 동향 분석)

  • Lee, Byeong-Ju;Kim, Baek-Jun;Lee, Jae Min;Eo, Soo Hyung
    • Korean Journal of Environment and Ecology
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    • v.33 no.1
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    • pp.9-15
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    • 2019
  • Artiodactyla, which is an even-toed mammal, widely inhabits worldwide. In recent years, wild Artiodactyla species have attracted public attention due to the rapid increase of crop damage and road-kill caused by wild Artiodactyla such as water deer and wild boar and the decrease of some species such as long-tailed goral and musk deer. In spite of such public attention, however, there have been few studies on Artiodactyla in Korea, and no studies have focused on the trend analysis of Artiodactyla, making it difficult to understand actual problems. Many recent studies on trend used text-mining and co-occurrence analysis to increase objectivity in the classification of research subjects by extracting keywords appearing in literature and quantifying relevance between words. In this study, we analyzed texts from research articles of three countries (Korea, China, and Japan) through text-mining and co-occurrence analysis and compared the research subjects in each country. We extracted 199 words from 665 articles related to Artiodactyla of three countries through text-mining. Three word-clusters were formed as a result of co-occurrence analysis on extracted words. We determined that cluster1 was related to "habitat condition and ecology", cluster2 was related to "disease" and cluster3 was related to "conservation genetics and molecular ecology". The results of comparing the rates of occurrence of each word clusters in each country showed that they were relatively even in China and Japan whereas Korea had a prevailing rate (69%) of cluster2 related to "disease". In the regression analysis on the number of words per year in each cluster, the number of words in both China and Japan increased evenly by year in each cluster while the rate of increase of cluster2 was five times more than the other clusters in Korea. The results indicate that Korean researches on Artiodactyla tended to focus on diseases more than those in China and Japan, and few researchers considered other subjects including habitat characteristics, behavior and molecular ecology. In order to control the damage caused by Artiodactyla and to establish a reasonable policy for the protection of endangered species, it is necessary to accumulate basic ecological data by conducting researches on wild Artiodactyla more.

Abundance and Occupancy of Forest Mammals at Mijiang Area in the Lower Tumen River (두만강 하류 밀강 지역의 산림성 포유류 풍부도와 점유율)

  • Hai-Long Li;Chang-Yong Choi
    • Korean Journal of Environment and Ecology
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    • v.37 no.6
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    • pp.429-438
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    • 2023
  • The forest in the lower Tumen River serves as an important ecosystem spanning the territories of North Korea, Russia, and China, and it provides habitat and movement corridors for diverse mammals, including the endangered Amur tiger (Panthera tigris) and Amur leopard (Panthera pardus). This study focuses on the Mijiang area, situated as a potential ecological corridor connecting North Korea and China in the lower Tumen River, playing a crucial role in conserving and restoring the biodiversity of the Korean Peninsula. This study aimed to identify mammal species and estimate their relative abundance, occupancy, and distribution based on the 48 camera traps installed in the Mijiang area from May 2019 to May 2021. The results confirmed the presence of 18 mammal species in the Mijiang area, including large carnivores like tigers and leopards. Among the dominant mammals, four species of ungulates showed high occupancy and detection rates, particularly the Roe deer (Capreolus pygargus) and Wild boar (Sus scrofa). The roe deer was distributed across all areas with a predicted high occupancy rate of 0.97, influenced by altitude, urban residential areas, and patch density. Wild boars showed a predicted occupancy rate of 0.73 and were distributed throughout the entire area, with factors such as wetland ratio, grazing intensity, and spatial heterogeneity in aspects of the landscape influencing their occupancy and detection rates. Sika deer (Cervus nippon) exhibited a predicted occupancy rate of 0.48, confined to specific areas, influenced by slope, habitat fragmentation diversity affecting detection rates, and the ratio of open forests impacting occupancy. Water deer (Hydropotes inermis) displayed a very low occupancy rate of 0.06 along the Tumen River Basin, with higher occupancy in lower altitude areas and increased detection in locations with high spatial heterogeneity in aspects. This study confirmed that the Mijiang area serves as a habitat supporting diverse mammals in the lower Tumen River while also playing a crucial role in facilitating animal movement and habitat connectivity. Additionally, the occupancy prediction model developed in this study is expected to contribute to predicting mammal distribution within the disrupted Tumen River basin due to human interference and identifying and protecting potential ecological corridors in this transboundary region.