• Title/Summary/Keyword: Niche

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The Development of Climax Index by Analysis of Eco-morphological Characters for Major Deciduous Tree Species

  • Kim, Ji Hong;Chung, Sang Hoon;Lee, Jeong Min;Kim, Se Mi
    • Journal of Forest and Environmental Science
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    • v.28 no.4
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    • pp.199-204
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    • 2012
  • This study was conducted to estimate climax index by eco-morphology for major 36 tree and sub-tree species in natural deciduous forests so as to interpret seral position of each species in the forest community. Fourteen eco-morphological characters which were considered to be associated with successional gradient in the forest were selected for the study. Four levels per character for each species were given on a standardized scale of increasing climax, and the index was computed by the proportion of the sum of total scores, expressed by percent values. With calculated mean value of 54.8 for all indices, Carpinus cordata had the highest index value of 90.5, and Populus davidiana recorded the lowest of 13.2. The most climax group, greater than 70 of the index, contained only 8 species, intermediate group, between 41 to 70 of the index, had 23 species, and the most pioneer group, less than 40 of the index comprised 5 species. The result has noticed that the large number of species would take advantage of most diverse resource and niche in the intermediate stage of the sere in the forest. By cluster analysis all 36 species were subjected to be classified into several species groups which had common similar eco-morphological characteristics. The indices were additionally plotted on the two dimensional graph to recognize the positions related to the light absorption factor and reproduction factor. The climax index of tree and sub-tree species developed by this study could be applied to understand the present status of successional stage on the basis of species composition by the method of summing up the indices. And comparison of forest successional stage among various forest communities could be done by summing up the climax indices of composed species in each community. However, this kind of applied methodology should be limited to the forest of similar species composition and site condition.

Deciphering Diversity Indices for a Better Understanding of Microbial Communities

  • Kim, Bo-Ra;Shin, Jiwon;Guevarra, Robin B.;Lee, Jun Hyung;Kim, Doo Wan;Seol, Kuk-Hwan;Lee, Ju-Hoon;Kim, Hyeun Bum;Isaacson, Richard E.
    • Journal of Microbiology and Biotechnology
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    • v.27 no.12
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    • pp.2089-2093
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    • 2017
  • The past decades have been a golden era during which great tasks were accomplished in the field of microbiology, including food microbiology. In the past, culture-dependent methods have been the primary choice to investigate bacterial diversity. However, using culturein-dependent high-throughput sequencing of 16S rRNA genes has greatly facilitated studies exploring the microbial compositions and dynamics associated with health and diseases. These culture-independent DNA-based studies generate large-scale data sets that describe the microbial composition of a certain niche. Consequently, understanding microbial diversity becomes of greater importance when investigating the composition, function, and dynamics of the microbiota associated with health and diseases. Even though there is no general agreement on which diversity index is the best to use, diversity indices have been used to compare the diversity among samples and between treatments with controls. Tools such as the Shannon-Weaver index and Simpson index can be used to describe population diversity in samples. The purpose of this review is to explain the principles of diversity indices, such as Shannon-Weaver and Simpson, to aid general microbiologists in better understanding bacterial communities. In this review, important questions concerning microbial diversity are addressed. Information from this review should facilitate evidence-based strategies to explore microbial communities.

Research trends in outdoor pig production - A review

  • Park, Hyun-Suk;Min, Byungrok;Oh, Sang-Hyon
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.9
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    • pp.1207-1214
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    • 2017
  • Since the industrialization of swine production in the late 1900s, swine farms in the United States, as well as in Europe, have largely become consolidated. Pig farms became larger in size but fewer in number, with 91% of market pigs being produced by large operations with 5,000 or more pigs on-site in the US, and only 3% of the total utilized agricultural land representing organic farming. Such change in the market made it difficult for small farmers to stay competitive, forcing them to find alternative ways to reduce the cost of production and increase profit using the outdoor production system. In contrast to the indoor confinement system, outdoor production system uses pasture-based units and/or deep-bedded hoop structures that promote animal welfare and environmental sustainability with a lower capital investment. In accord with the growing concern for animal and environmental welfare and food safety by the consumers, small farmers practicing an outdoor production system are seeing increased opportunities for marketing their products in the pork niche market. Unlike the general belief that the reproductive and growth performance measures of the outdoor sows and piglets are poorer in comparison with the animals reared indoors, studies showed that there was no significant difference in the performance measures, and some traits were even better in outdoor animals. Improved reproductive and production traits can increase the sustainability of outdoor farming. Present study reviewed the recent studies comparing the performance measures, meat quality and health of indoor and outdoor animals, as well as the efforts to improve the outdoor production system through changes in management such as hut types and breed of animals.

Effects of Extracellular Matrix Protein-derived Signaling on the Maintenance of the Undifferentiated State of Spermatogonial Stem Cells from Porcine Neonatal Testis

  • Park, Min Hee;Park, Ji Eun;Kim, Min Seong;Lee, Kwon Young;Hwang, Jae Yeon;Yun, Jung Im;Choi, Jung Hoon;Lee, Eunsong;Lee, Seung Tae
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.10
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    • pp.1398-1406
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    • 2016
  • In general, the seminiferous tubule basement membrane (STBM), comprising laminin, collagen IV, perlecan, and entactin, plays an important role in self-renewal and spermatogenesis of spermatogonial stem cells (SSCs) in the testis. However, among the diverse extracellular matrix (ECM) proteins constituting the STBM, the mechanism by which each regulates SSC fate has yet to be revealed. Accordingly, we investigated the effects of various ECM proteins on the maintenance of the undifferentiated state of SSCs in pigs. First, an extracellular signaling-free culture system was optimized, and alkaline phosphatase (AP) activity and transcriptional regulation of SSC-specific genes were analyzed in porcine SSCs (pSSCs) cultured for 1, 3, and 5 days on non-, laminin- and collagen IV-coated Petri dishes in the optimized culture system. The microenvironment consisting of glial cell-derived neurotrophic factor (GDNF)-supplemented mouse embryonic stem cell culture medium (mESCCM) (GDNF-mESCCM) demonstrated the highest efficiency in the maintenance of AP activity. Moreover, under the established extracellular signaling-free microenvironment, effective maintenance of AP activity and SSC-specific gene expression was detected in pSSCs experiencing laminin-derived signaling. From these results, we believe that laminin can serve as an extracellular niche factor required for the in vitro maintenance of undifferentiated pSSCs in the establishment of the pSSC culture system.

A Study on Possibility of RO as a Local Media (지역매체로서의 중계유선방송(RO)의 가능성에 대한 연구)

  • Nam, Chong-Hoon
    • Journal of Digital Contents Society
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    • v.9 no.2
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    • pp.213-223
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    • 2008
  • This study attempted to analyze background and industrial difference of RO and SO. RO was launched for solving a problem of terrestrial broadcasting. After solving a problem of terrestrial broadcasting system, RO has played a roll as a local media. On the other hand, SO was launched by government's policy so SO has been protected and brought up by government. Because market of RO and SO is overlap and competitive, RO has been restricted by government for issuing new license and renewal of permission. Presently, environment of media has been changed very dramatically, so various niche media are needed for various customer's needs. In addition, local media are in trouble of playing a role as a public broadcasting service in Korea. Therefore, RO might be a good solution. In this study for the analysis of the user's needs a survey was conducted. This study shows possibility of RO's roll and function as a local media.

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A Study on the Costumes of stone Buddhist image in the Sokkuram Cave Temple (석굴암 불상에 나타난 법의 연구)

  • 김정진
    • Journal of the Korean Society of Costume
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    • v.50 no.7
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    • pp.47-58
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    • 2000
  • Prime Minister Kim tart-song is said to have built this cave temple in the tenth year of the reign of King Kyongdok-wang(742-765) of Unified Shilla(751). The numerous stone Buddhist images in the grotto represent the best Buddhist figure of the Unified Shilla period and of all Korea. The Sokkuram Grotto is composed of the main hall, entrance to the main chamber and antechamber in space. The main hall beyond the small antechamber is round and the ceilling is domed. Within the rotunda sits a majestic Buddha(Amitabha), 3.48m in height and 2.6m in width, carved in granite and facing east. Surrounding the main Seated Buddha are eleven-headed Avalokitesvara Bodhisattva, Manjusri Bodhisattva and the other three Buddhist images, Ten disciples, Buddhist figures in the ten Niches in relief. An eleven-headed Avalokltesvara Bodhisattva of boundless mercy is sculptured on the wall behind the main Seated Buddha. Further guarding the Buddha are ten standing Arhans of the Disciples of Buddha. Next, two Devas. one on each side, stand guard. Two Bodhisattvas are the saints who are next to the Seated Buddha in importance, also one on each side. And, There are ten niches around the dome. They contain seven seated Bodhisattvas and one Vimalakirti(the name of a famous lay disciple of the Buddha). Two niches are empty. Consequently, there are total thirty-eight Buddhist images in the Sokkuram cave temple. The Buddhist images have been reguarded as masterpieces of Buddhist art and Shilla culture of Unified Shilla in the eightth century. The Buddhist images are represented very dear, elegance and beauty of detail skill

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A study on the change of root surface irradiated by Er:YAG laser (Er:YAG laser를 조사한 치근면의 변화에 관한 연구)

  • Lee, Sang-Hyun;Kim, Young-Jun;Chung, Hyun-Ju
    • Journal of Periodontal and Implant Science
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    • v.32 no.2
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    • pp.303-314
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    • 2002
  • This study was performed to evaluate the usability of Er:YAG laser for periodontal therapy. Forty dental root slabs ($5{\times}5{\times}2mm^3$) were prepared from human periodontally diseased extracted teeth and grouped into 4 groups: 1) control (root planing only), 2) root planing and irradiated with laser at 30mJ, 3) root planing and irradiated with laser at 60mJ, and 4) root planing and irradiated with laser at 100mJ. The root slabs were embedded in resin block before laser treatment. Er:YAG laser was irradiated under water irrigation with the tip held perpendicular to the root surface in contact mode. After Er:YAG laser irradiation or planing on the root surface, morphological changes have been observed under SEM, and the micro-hardness and Ca/P ratio were compared. 1. In the Control group, the root surface showed the directional change caused by root planing instrumentation, and the presence of smear layer, and no exposure of dentinal tubule was observed. Laser irradiated group showed surface changes with rough dentin surface of niche and depression and dentinal tubule exposure by the elimination of smear layer. 2. The micro-hardness of root surface in the laser irradiated group was higher than the control group. The higher energy output was applied, the higher micro-hardness on root surface was resulted. 3. The higher energy output was applied, the higher Ca/P ratio was observed. The higher Ca/P ratio in 60mJ group and 100mJ group was statistically significantly compared to the control group and the 30mJ group. These results suggest that Er:YAG laser irradiation on the periodontally diseased root surface could remove smear layer and increase the micro-hardness on root surface and Ca/P ratio which contribute to enhance the acid resistance of periodontally treated root surface.

Investments on Pro-poor Development Projects on Goats: Ensuring Success for Improved Livelihoods

  • Devendra, C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.1
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    • pp.1-18
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    • 2013
  • The elements that determine the success of development projects on goats and the prerequisites for ensuring this are discussed in the context of the bewildering diversity of goat genetic resources, production systems, multifunctionality, and opportunities for responding to constraints for productivity enhancement. Key determinants for the success of pro-poor projects are the imperatives of realistic project design, resolution of priorities and positive impacts to increase investments and spur agricultural growth, and appropriate policy. Throughout the developing world, there exist 97% of the total world population of 921 million goats across all agroecological zones (AEZs), including 570 breeds and 64% share of the breeds. They occupy a very important biological and socioeconomic niche in farming systems making significant multifunctional contributions especially to food, nutrition and financial security, stability of farm households, and survival of the poor in the rural areas. Definitions are given of successful and failed projects. The analyses highlighted in successful projects the value of strong participatory efforts with farmers and climate change. Climate change effects on goats are inevitable and are mediated through heat stress, type of AEZ, water availability, quantity and quality of the available feed resources and type of production system. Within the prevailing production systems, improved integrated tree crops - ruminant systems are underestimated and are an important pathway to enhance C sequestration. Key development strategies and opportunities for research and development (R and D) are enormous, and include inter alia defining a policy framework, resolution of priority constraints using systems perspectives and community-based participatory activities, application of yield-enhancing technologies, intensification, scaling up, and impacts. The priority for development concerns the rainfed areas with large concentrations of ruminants in which goats, with a capacity to cope with heat tolerance, can be the entry point for development. Networks and networking are very important for the diffusion of information and can add value to R and D. Well formulated projects with clear priority setting and participatory R and D ensure success and the realisation of food security, improved livelihoods and self-reliance in the future.

Study on Online Community Media Practice: Focus On Daedeok-valley Radio (온라인 공동체 미디어(Community Media) 실천연구: 대덕밸리라디오를 중심으로)

  • Choi, Soonhee
    • The Journal of the Korea Contents Association
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    • v.17 no.6
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    • pp.39-54
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    • 2017
  • This study started from the consciousness that the community media practice studies have been confined to the traditional terrestrial broadcasting. The following research results and implications were obtained by analyzing Daedeok-valley Radio's case to elucidate characteristics of online-based community media and content production and distribution characteristics neglected in previous researches. First, online community media activities are civic/citizen media activities that capture the value of local communities, and this locality is realized through media content production and its online distribution. Second, contents of online community media link members of the community, and individuals become nodes, interacting both online and offline. Therefore, online-based citizen media activities can be utilized effectively as a means to enhance civic participation and to achieve the locality of community in online and offline spaces depending on strategies for online contents production and distribution. Utilizing online infrastructures for media content creation and distribution in Korea demonstrates potential opportunities of local online media to be considered as niche media that can increase its own sustainability.

C7 Posterior Fixation Using Intralaminar Screws : Early Clinical and Radiographic Outcome

  • Jang, Sang-Hoon;Hong, Jae-Taek;Kim, Il-Sup;Yeo, In-Sung;Son, Byung-Chul;Lee, Sang-Won
    • Journal of Korean Neurosurgical Society
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    • v.48 no.2
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    • pp.129-133
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    • 2010
  • Objective : The use of segmental instrumentation technique using pedicle screw has been increasingly popular in recent years owing to its biomechanical stability. Recently, intralaminar screws have been used as a potentially safer alternative to traditional fusion constructs involving fixation of C2 and the cervicothoracic junction including C7. However, to date, there have been few clinical series of C7 laminar screw fixation in the literature. Thus, the purpose of this study is to report our clinical experiences using C7 laminar screw and the early clinical outcome of this rather new fixation technique. Methods : Thirteen patients underwent C7 intralaminar fixation to treat lesions from trauma or degenerative disease. Seventeen intralaminar screws were placed at C7. The patients were assessed both clinically and radiographically with postoperative computed tomographic scans. Results : There was no violation of the screw into the spinal canal during the procedure and no neurological worsening or vascular injury from screw placement. The mean clinical and radiographic follow up was about 19 months, at which time there were no cases of screw pull-out, screw fracture or non-union. Complications included two cases of dorsal breech of intralaminar screw and one case of postoperative infection. Conclusion : Intralaminar screws can be potentially safe alternative technique for C7 fixation. Even though this technique cannot be used in the cases of C7 laminar fracture, large margin of safety and the ease of screw placement create a niche for this technique in the armamentarium of spine surgeons.