• Title/Summary/Keyword: different niche

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Analysis of Food Resources of 20 Endangered Fishes in Freshwater Ecosystems of South Korea using Non-metric Multidimensional Scaling and Network Analysis (비메트릭 다변량 척도법과 네트워크 분석을 통한 멸종위기 국내 담수어류 20종의 먹이원 분석)

  • Ji, Chang Woo;Lee, Dae-Seong;Lee, Da-Yeong;Park, Young-Seuk;Kwak, Ihn-Sil
    • Korean Journal of Ecology and Environment
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    • v.54 no.2
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    • pp.130-141
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    • 2021
  • By reviewing previous literature, we analyzed the food sources of 20 out of 29 endangered fish species from freshwater ecosystems in South Korea. A total of 19 studies reported that food sources of 20 endangered fish species included 20 phyla, 31 classes, 58 orders, 116 families, and 154 genera. Arthropod, insecta, diptera, and chironomidae were the most fed animal food sources according to different resolution of taxa index on phylum, class, order and family. Similarity, bacillariophyta, bacillariophyceae, naviculales, and cymbellaceae were the most fed abundant plant sources. A larger number of fish species were reliant on animal food sources than plant food sources. 18 of the endangered fish preyed on arthropods, whereas only 6 species consumed bacillariophyta. To characterize the feeding groups of the 20 fish species, a hierarchical clustering analysis and non-metric multidimensional scaling analysis were conducted. The fish species were divided into two groups: 1) insectivores and 2) planktivores. A network analysis, which associated the link between endangered fishes and food sources, also revealed the same two groups. The highest hub score of food sources was for macroinvertebrates, including diptera (0.47), ephemeroptera (0.42), and trichoptera (0.38), based on the network analysis. Niche breadth was used to calculate the diversity of the food sources. Phoxinus phoxinus (0.57) showed thehighest food source diversity among the fish species, whereas Iksookimia pacifica (0.01) showed the lowest. This study will be utilized for the conservation and restoration of the endangered fish species.

Changes in the Energy Landscape from Multi-Level Perspective: A Case Study of the Photovoltaic Module Carbon Certification System (다층적 관점에서 바라본 에너지경관의 변동: 태양광 모듈 탄소인증제를 사례로)

  • Jang, Geunyong
    • Journal of the Economic Geographical Society of Korea
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    • v.24 no.4
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    • pp.367-385
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    • 2021
  • This study examined changes in the energy landscape, focusing on the photovoltaic module carbon certification system. As the global photovoltaic market has been reorganized around Chinese companies, the South Korean government has pushed to strengthen the competitiveness of the nation's photovoltaic industry. However, a limitation remains in that the government-led effort was not sufficient to bring about dynamic changes in the energy landscape. Against this backdrop, this study explored the stages leading to the multi-level perspectives of "macro-environment, socio-technical regime, and niche" to track the process of the government and domestic photovoltaic companies as part of a socio-technical regime responding to global market changes. In particular, this study raised an issue with the conceptual discussion of multi-level perspective, which placed a particular emphasis on the rate of change at each level and the niche in which innovative experiments take place, and thus attempted to fill this gap by tracking the energy landscape that varies differently from space. These spatial discussions can track different carbon emissions coefficients and industrial characteristics for each country, and have a higher level of explanatory power for the system thus constructed. In addition, through discussions on the problems and implications of the government-led introduction of renewable energy policies, this study suggests the need to create and implement a field-oriented system.

Effects of Extracellular Signaling on the Endogenous Expression of Self-Renewal-Stimulating Factor Genes in Mouse Embryonic Stem Cells

  • Gong, Seung-Pyo;Lee, Seung-Tae
    • Reproductive and Developmental Biology
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    • v.36 no.1
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    • pp.13-19
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    • 2012
  • In order to provide the basis for developing practical mouse embryonic stem cells (mESCs) culture method, how the endogenous level of self-renewal-stimulating factor genes was altered in the mESCs by different extracellular signaling was investigated in this study. For different extracellular signaling, mESCs were cultured in 2 dimension (D), 3D and integrin-stimulating 3D culture system in the presence or absence of leukemia inhibitory factor (LIF) and transcriptional level of $Lif$, $Bmp4$ and $Wnt3a$ was evaluated in the mESCs cultured in each system. The expression of three genes was significantly increased in 3D system relative to 2D system under LIF-containing condition, while only $Wnt3a$ expression was increased by 3D culture under LIF-free condition. Stimulation of integrin signaling in mESCs within 3D system with exogenous LIF significantly up-regulated transcriptional level of $Bmp4$, but did not induce transcriptional regulation of $Lif$ and $Wnt3a$. In the absence of LIF inside 3D system, the expression of $Lif$ and $Bmp4$ was significantly increased by integrin signaling, while it significantly decreased $Wnt3a$ expression. Finally, the signal from exogenous LIF significantly caused increased expression of $Lif$ in 2D system, decreased expression of $Bmp4$ in both 2D and 3D system, and decreased expression of $Wnt3a$ in integrin-stimulating 3D system. From these results, we identified that endogenous expression level of self-renewal-stimulating factor genes in mESCs could be effectively regulated through artificial and proper manipulation of extracellular signaling. Moreover, synthetic 3D niche stimulating endogenous secretion of self-renewal-stimulating factors will be able to help develop growth factor-free maintenance system of mESCs.

A Study on Restructuring of Learner-Centered Education Environment through Participatory Design - Focusing on the 'User-Integrated Platform Project' Case - (참여디자인을 통한 학습자중심교육환경 재구조화 방향연구 - '사용자-융합플랫폼 프로젝트' 사례를 중심으로 -)

  • Yoo, Myoung-Hee
    • Journal of the Korean Institute of Educational Facilities
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    • v.27 no.2
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    • pp.35-47
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    • 2020
  • The need for communication is emphasized in decision making, design methods and processes for the educational environment that contain new curricula and learning methods. In this study, we tried to find the direction and agenda of learner-centered environment restructuring through the 'user-integrated platform' in which various subjects related to school space environment understand each other's position and overcome the barriers and prejudices of each sector. The project was planned in a 'bottom-up process' method that uncovered the singularities of the previous stage and led the main contents of the next stage. The various subjects who participated in the project shared their own experiences and different positions regarding the school space. At the workshop, the topics of the participating teams were divided into two categories. The teams in the category of the 'school culture and space' insisted innovation of 'the school culture' as a premise for the restructuring of the 'school space', and proposed schools with different interpretations of 'authority and rules of school', 'the meaning of learning and play' and 'the main character of school. The teams in the category of the 'school borders and spaces' focused on 'communication' and proposed schools containing 'emotional care of students', 'borders between schools and villages', 'village community schools', and 'interspace and niche time'. After the workshop, we were able to derive the direction and architectural strategy of the school space restructuring by analyzing the works of the participants. Through this study, we confirmed the possibility of translating user's ideas into the professional domain through careful planning, preparation, facilitation, and analysis in Participatory Design.

Effects of American Ginseng Cultivation on Bacterial Community Structure and Responses of Soil Nutrients in Different Ecological Niches

  • Chang, Fan;Jia, Fengan;Lv, Rui;Guan, Min;Jia, Qingan;Sun, Yan;Li, Zhi
    • Journal of Microbiology and Biotechnology
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    • v.32 no.4
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    • pp.419-429
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    • 2022
  • American ginseng (Panax quinquefolium L.) is a perennial herbaceous plant widely cultivated in China, Korea, the United States, and Japan due to its multifunctional properties. In northwest China, transplanting after 2-3 years has become the main mode of artificial cultivation of American ginseng. However, the effects of the cultivation process on the chemical properties of the soil and bacterial community remain poorly understood. Hence, in the present study, high-throughput sequencing and soil chemical analyses were applied to investigate the differences between bacterial communities and nutrition driver factors in the soil during the cultivation of American ginseng. The responses of soil nutrition in different ecological niches were also determined with the results indicating that the cultivation of American ginseng significantly increased the soluble nutrients in the soil. Moreover, the bacterial diversity fluctuated with cultivation years, and 4-year-old ginseng roots had low bacterial diversity and evenness. In the first two years of cultivation, the bacterial community was more sensitive to soil nutrition compared to the last two years. Proteobacteria, Actinobacteria, Gemmatimonadetes, Acidobacteria, Firmicutes, and Bacteroidetes dominated the bacterial community regardless of the cultivation year and ecological niche. With the increase of cultivation years, the assembly of bacterial communities changed from stochastic to deterministic processes. The high abundance of Sphingobium, Novosphingobium, and Rhizorhabdus enriched in 4-years-old ginseng roots was mainly associated with variations in the available potassium (AK), total phosphorus (TP), total potassium (TK), and organic matter (OM).

Interspecies comparative morphological evaluation of the corneal epithelial stem cell niche: a pilot observational study

  • Popova, Petya;Malalana, Fernando;Biddolph, Simon;Ramos, Tiago;Parekh, Mohit;Chantrey, Julian;Ahmad, Sajjad
    • Journal of Veterinary Science
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    • v.23 no.4
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    • pp.62.1-62.10
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    • 2022
  • Background: The corneal and limbal morphology relevant to corneal epithelial maintenance in ten different species was examined using histological methods. Objectives: The presence of a Bowman's layer, limbal epithelial cell, and superficial stromal morphology was examined in the following species to evaluate the differences in corneal thickness and epithelium: Java sparrows, frogs, macaws, spoonbills, red pandas, penguins, horses, Dobermans, orangutans, and humans. Methods: Corneal sections (4 ㎛) were obtained from ten ocular globes from three different animal classes: Aves, Amphibia, and Mammalia. All sections were stained with hematoxylin and eosin and periodic acid-Schiff reaction. After microscopy, all stained slides were photographed and analyzed. Results: Significant morphological differences in the corneal and limbal epithelia and their underlying stroma between species were observed. The number of corneal epithelial cell layers and the overall corneal epithelial thickness varied significantly among the species. The presence of a Bowman's layer was only observed in primates (orangutans and humans). Presumed supranuclear melanin caps were noted in four species (orangutans, macaws, red pandas, and horses) in the limbal basal epithelial layer (putative site of corneal epithelial stem cells). The melanin granules covered the apex of the cell nucleus. Conclusions: Supranuclear melanin capping has been described as a process within the epidermis to reduce the concentration of ultraviolet-induced DNA photoproducts. Similarly, there may be a relationship between limbal stem cell melanin capping as a protective mechanism against ultra-violet radiation.

The Exploration of New Business Areas in the Age of Economic Transformation : a Case of Korean 'Hidden Champions' (Small and Medium Niche Enterprises (경제구조 전환기에서 새로운 비즈니스 영역의 창출 : 강소기업의 성공함정과 신시장 개척)

  • Lee, Jangwoo
    • Korean small business review
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    • v.31 no.1
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    • pp.73-88
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    • 2009
  • This study examines the characteristics of 24 Korean hidden champions such as key success factors, core competences, strategic problems, and desirable future directions. The study categorized them into 8 types with Danny Miller's four trajectories and top manager's decision making style(rationality and passion). Danny Miller argued in his book, Icarus paradox, that outstanding firms will extend their orientations until they reach dangerous extremes and their momentum will result in common trajectories of decline. He suggested four very common success types: Craftsmen, Builders, Pioneers, Salesmen. He also suggested common trajectories of decline:Focusing(from Craftsmen to Tinkers), Venturing(from Builders to Imperialists), Inventing(from Pioneers to Escapists), Decoupling(from Salesmen to Drifts). In Korea, successful startups appear to possess three kinds of drive: Technology-drive, Vision-drive, Market-drive. Successful technology-driven firms tend to grow as craftsmen or pioneers. Successful vision-driven and market-driven ones tend to grow as builders and salesmen respectively. Korean top managers or founders seem to have two kinds of decision making style: Passion-based and Rationality-bases. Passion-based(passionate) entrepreneurs are biased towards action or proactiveness in competing and getting things done. Rationality- based ones tend to emphasis the effort devoted to scanning and analysing information to better understand a company's threats, opportunities and options. Consequently this study suggested 4*2 types of Korean hidden champions: (1) passionate craftsmen, (2) rational craftsmen, (3) passionate builders, (4) rational builders, (5) passionate pioneers, (6) rational pioneers, (7) passionate salesmen, (8) rational salesmen. These 8 type firms showed different success stories and appeared to possess different trajectories of decline. These hidden champions have acquired competitive advantage within domestic or globally niche markets in spite of the weak market power and lack of internal resources. They have maintained their sustainable competitiveness by utilizing three types of growth strategy; (1) penetrating into the global market, (2) exploring new service market, (3) occupying the domestic market. According to the types of growth strategy, these firms showed different financial outcomes and possessed different issues for maintaining their competitiveness. This study found that Korean hidden champions were facing serious challenges from the transforming economic structure these days and possessed the decline potential from their success momentum or self-complacence. It argues that they need to take a new growth engine not to decline in the turbulent environment. It also discusses how firms overcome the economic crisis and find a new business area in promising industries for the future. It summarized the recent policy of Korean government called as "Green Growth" and discussed how small firms utilize such benefits and supports from the government. Other implications for firm strategies and governmental policies were discussed.

Textile Design for Children Applying Korean Prehistoric Petroglyphs (한국 선사시대 암각화를 응용한 아동용 텍스타일 디자인 연구)

  • Jang, Kyung Ah;Park, Eun Kyung
    • Journal of the Korean Society of Costume
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    • v.64 no.2
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    • pp.135-149
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    • 2014
  • This study attempts to adapt and develop Korean prehistoric petroglyphs into textile design for children. For this purpose, literature review was conducted to understand the plasticity and symbolism expressed in Korean prehistoric petroglyphs. Also this study conducted textile design development as follows: First, the figures and faces in petroglyphs were selected because children can easily recognize them. Second, two groups of different ages (7-9 and 10-13) were allowed to freely draw the selected motifs. Third, some of the motifs created by the children were selected that show children's individuality and also keep the features of the original motifs. The children's motifs were developed into textile design using Texpro and Photoshop. Then digital textile printing and 3D mapping program were used to make pajamas (5 types), umbrellas (3 types), and simulate bedding sets (2 types) for children. This research's results are as follows: First, petroglyphs are symbolic language of human's oldest art form, and related to religious and mythical belief. Korean petroglyphs have plasticity showing the development steps in technique and expression, with various shapes such as animals, human figures, faces, masks and abstract figures. Third, children showed their interests in various human figures and faces of the petroglyphs, and it was easy to draw those motifs in their own way. Fourth, 10 design motifs were selected from the children's work and used to create textiles considering materials and colors for children. Total 10 items were made and presented. This study confirmed the usefulness of applying prehistoric petroglyphs to children's textiles designs. These designs may grow as a kind of cultural product for children who know about and like petroglyphs. They can be a niche market items too, made to order for children with individuality and who favor originality.

Characteristics and Technology Development Mode of Local Hidden Champions in Korea : How are they different? (지역 강소기업의 특성과 기술개발 방법 : 독일 강소기업과의 비교를 중심으로)

  • Huh, Moon-Goo
    • Journal of Digital Convergence
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    • v.13 no.8
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    • pp.221-234
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    • 2015
  • The purpose of this paper is to investigate the differences between successful SMEs in Korea and German hidden champions, with respect to both strategic importance and performance of major competitive dimensions, and mode of technology development. Data were collected through survey and public databases, and the sample comprises successful SMEs located in regional area in Korea. The results show that Korean hidden champions are relatively low regarding specialization of business domain and globalization while German hidden champions have positioned in global niche market. It is also found that local firms utilize technology alliances actively for technology development while German hidden champions rely heavily on internal R&D as a primary source of innovation. Based upon these results, policy directions for fostering local hidden champions were suggested.

Market Opportunities and Constraints Confronting Resource-Poor Pig Farmers in South Africa's Eastern Cape Province

  • Madzimure, James;Bovula, Ntombizodwa;Ngorora, Grace P.K.;Tada, Obert;Kagande, Shelton M.;Bakare, Archibold G.;Chimonyo, Michael
    • The Journal of Industrial Distribution & Business
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    • v.5 no.2
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    • pp.29-35
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    • 2014
  • Purpose - The study aimed to evaluate the market opportunities and constraints confronting resource-poor pig farmers in South Africa. Research design, data, and methodology - Information was collected from 292 households in three municipalities through interviews with key informants. The data collected included socio-economic characteristics, major market channels, prices for different pig classes, average weight of the pigs on sale, number of pigs sold annually, and preferred meat quality attributes. Results - In Ngqushwa, 96% of respondents sold pigs as compared to Elundini (81%) and Ntabankulu (65%). Less resource-poor households and those with market-oriented production had large herdsizes (P < 0.05) when compared to more resource-poor farmers. The probability of selling pigs was high for the backyard production system and educated farmers. For all farmers, opportunities included high pork demand, good prices, employment creation, and a niche market for organically produced indigenous pork. Constraints include disease, feed shortages for large herds, distances to formal markets, lack of training, and drugs. Conclusions - Constraints outnumbered opportunities for the resource-poor pig farmers.