• Title/Summary/Keyword: food chain

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Species Occurrence and Food Chain of Fisheries Resources, Nekton, on the Coast of Pukchon, Cheju Island 1. Species composition and diversity (제주도 북촌연안 수산자원유영생물의 출현과 먹이연쇄에 관한 연구 1. 종조성과 다양도)

  • GO You-Bong;SHIN Heau-Sub
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.21 no.3
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    • pp.131-138
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    • 1988
  • Collection of organisms for the fisheries resources community were obtained with a set net during 8 months between May, 1985 and May, 1986 on the coast of Pukchon, Cheju Island, Korea. Most of organisms, representing 36 species, were less than 20cm $(93\%)$ in length, and 130g $(91\%)$ in weight. The four most abundant species were jack mackerel, Trachurus japonicus ; squid, Todarodes pacificus : damsel fish, Chromis notatus : and rabbit fish, Siganus fuscescens, which comprised about $83\% in number and about $73\%$ of the total catch. The diversity index of the number of species and information indices for individual and catch were the highest in October and the lowest in Septemer, indicating a close relationship with the change between the species number and catch at that time. A cluster analysis of 17 species was illustrated from the similarity matrix. All of the 17 species were grouped at the 0.2 similarity level. Three groups were present at 0.60 level, whereas species in other groups were sporadic in occurrence.

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Semi-daily Variations in Populations of the Dinoflagellates Dinophysis acuminata and Oxyphysis oxytoxoides and a Mixotrophic Ciliate Prey Mesodinium rubrum in Masan Bay (마산만에서 와편모류 Dinophysis acuminata 및 Oxyphysis oxytoxoides와 먹이생물 섬모류인 Mesodinium rubrum의 단주기적 개체군 변동)

  • KIM, SUNJU;YOON, JIHAE;KIM, MIRAN;PARK, MYUNG GIL
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.20 no.3
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    • pp.151-157
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    • 2015
  • Recent laboratory studies have documented that mixotrophic dinoflagellates Dinophysis spp. and heterotrophic dinoflagellate Oxyphysis oxytoxoides share a common prey, i.e. the mixotrophic ciliate Mesodinium rubrum. Nonetheless, very little is known about the population dynamics and species interactions among these protists in natural environments. To investigate the interactions between the dinoflagellate predators and their ciliate prey in the field, we took the samples twice a day from 26 July to 28 August, 2011 at a fixed station in Masan Bay and analyzed their abundances. During this study, salinity was highly variable, ranging from 5 to 28, due to the periodic input of rainfalls to the sampling station. Water temperature was on average $26.5^{\circ}C$ until 20 August and thereafter was about $21^{\circ}C$ by the end of the sampling period. The ciliate M. rubrum occurred persistently throughout the sampling period, ranging from 13 to $492\;cells\;mL^{-1}$. Cell densities of D. acuminata and O. oxytoxoides ranged from undetectable level to $19,833\;cells\;L^{-1}$ and from undetectable level to $100,333\;cells\;L^{-1}$, respectively. The high abundance of D. acuminata mostly followed the blooming of the ciliate M. rubrum, but it often did not peak even during heavy blooms of the prey, probably due to sensitivity to large salinity fluctuation and also presumably overlapped grazing by other mixotrophic dinoflagellates. The abundance of O. oxytoxoides was detected only when water temperature was lower than $24^{\circ}C$, indicating that water temperature is an important environmental factor to control the population dynamics of the dinoflagellate species.

Fish Distribution, Compositions and Community Structure Characteristics during Juksan-Weir Construction in Yeongsan River Watershed (영산강 수계에서 죽산보 건설 중의 어류 분포.종 조성 및 군집구조 특성)

  • Ko, Dae-Geun;Choi, Ji-Woong;Lim, Byung Jin;Park, Jong Hwan;An, Kwang-Guk
    • Korean Journal of Environment and Ecology
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    • v.26 no.6
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    • pp.892-901
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    • 2012
  • The purpose of this research was to analyze fish fauna, distribution patterns, and fish community structures in the Juksan-Weir regions of upper weir(R-UW) and lower weir(R-LW), which was constructed in 2011 on Yeongsan River watershed. Our outcomes will provide valuable information in the impact analysis of weir constructions next decades, even if the current research is limited to distributions and fauna studies of fishes. The fishes observed were 8 family and 30 species in all the sites, and the number of the species in the regions of R-UW and R-LW was 23(938 individuals) and 27(1,680 individuals), respectively, indicating greater abundance in the lower region of Juksan-Weir. Most dominant species was Opsarichthys uncirostris amurensis with relative abundance of 42%, and this species had greater abundance in the R-LW(49%) than in the R-UW(30%). Coilia nasus, was the migratory fish sampled in this region and had no differences of abundance between the two regions. The extic species observed were Carassius cuvieri, Lepomis macrochirus, and Micropterus salmoides. The two formers of Carassius cuvieri(1.2%) and Lepomis macrochirus(3.7%) dominated in the R-UW, whereas Micropterus salmoides had greater dominance in the region of R-LW. According to tolerance guild analysis, the proportion of sensitive species ranged from 0.4 to 0.5%, and that of tolerant species ranged from 65% to 70%, implying a severe pollution of nutrients and organic matters in the water body. In the mean time, according to trophic guild analysis, the proportion of carnivores(57 - 77%) was evidently higher than that of insectivores(10 - 20%), indicating a dominance of the carnivores. Especially, high abundance of the bass, exotic species, may disturb the fish overall food chain, so the efficient ecosystem management may be required for the conservation of endemic species. When we examined fish data files of last 60 years, the species of Culter brevicauda, designated as endangered species, was observed firstly in our research area and the total number was 5 individuals(0.2% of the total). So, this region observed should be conserved as a protection zone and further monitoring studies should be done in the future.

The current status and control measures of BSE in the worldwide (국내, 외 광우병의 발생 현황과 대응 방안)

  • Yoo, Han-Sang
    • 한국환경농학회:학술대회논문집
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    • 2009.07a
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    • pp.273-282
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    • 2009
  • The transmissible spongiform encephalopathies (TSEs) disease group are fatal neurodegenerative disorders affecting a wide range of hosts. The group includes kuru and Creutzfeldt-Jakob disease (CJD) in humans, scrapie in sheep and goats and Bovine spongiform encephalopathy (BSE) in cattle. The exact nature of the infectious agent involved in the transmission of these diseases remains controversial. However, a central event in their pathogenesis is the accumulation in infected tissues of an abnormal form of a host-encoded protein, the prion protein (PrP). Whereas the normal cellular protein is fully sensitive to protease ($PrP^{sen}$), the disease-associated prion protein ($PrP^d$) is only partly degraded ($PrP^{res}$), its amino-terminal end being removed. BSE was first reported in the mid-80s in the UK. Ten years later, a new form of human prion disease, variant CJD (vCJD) developed in the wake of the BSE epidemic, and there is now strong scientific evidence that vCJD was initiated by the exposure of humans to BSE-infected tissues, thus indicating a zoonotic disease. However, the ban on the feeding of animal-derived proteins to ruminants, and the apparent lack of vertical transmission of BSE, have led to a decline in the incidence of the disease within cattle herd and therefore, an assumed decreased risk for human contacting vCJD. The origin of the original case(s) of BSE still remains an enigma even though three hypotheses have been raised. Hypotheses are i) sheep- or goat-derived scrapie-infected tissues included in meat and bone meal fed to cattle, ii) a previously undetected sporadic or genetic bovine TSE contaminating cattle feed or iii) originating from a human TSE through animal feed contaminated with human remains. A host cellular membrane protein ($PrP^C$), which is abundant in central nervous system tissue, appear to be conformationally altered in the diseased host into a prion protein ($PrP^{Sc}$). This $PrP^{Sc}$ is detergent insoluble and partially protease-resistant ($PrP^{res}$). The term $PrP^{res}$ is normally used to describe the protein detected after protease treatment, in techniques such as Western immunoblotting, and enzyme-linked immunosorbant assay using fresh/frozen tissue. Immunohistochemistry may performed with formalin-fixed tissues. Also, clinical signs of the BSE are one of the major diagnostic indicators. Recently, atypical forms (known as H- and L-type) of BSE have appeared in several European countries, Japan, Canada and the United States. An unusual case was also reported in a miniature zebu. The atypical BSE fall into two groups based on the relative molecular mass (Mm) of the unglycosylated $PrP^{res}$ band relative to that of classical BSE, one of the higher Mm (H-type) and the other lower (L-type). Both types have been detected worldwide as rare cases in older animals, at a low prevalence consistent with the possibility of sporadic forms of prion diseases in cattle. This raises the unwelcome possibility that vCJD could increase in the human population. Now, active surveillance program against BSE is going on in Korea. In regional veterinary service lab, ELISA is applied to screen the BSE in slaughter and confirmatory tests by Western immunoblotting and immunohistochemisty are carried out if there are positive or suspect in the screening test. Also, the ruminant feed ban is rigorously enforced. Removal of specified risk materials such as brain and spinal cord from cattle is mandatory process at slaughter to prevent the infected material from entering the human food chain.

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Mushroom consumption patterns in the capital area (수도권 도시가구의 버섯 소비양상)

  • Lee, Yun-Hae;Jeong, Gu-Hyoen;Kim, Yeon-Jin;Chi, Jeong-Hyun;Lee, Hae-Kil
    • Journal of Mushroom
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    • v.15 no.1
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    • pp.45-53
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    • 2017
  • Profitability of farmers has decreased mainly owing to low price while the gross amount of mushroom production has increased continuously in South Korea. In this regard, analyzing patterns of mushroom consumption is believed to be meaningful. We used a panel data set consisting of 667 families, from 2010 to 2015. Based on the panel data, mushroom consumption patterns of people living in city areas were examined. Multiple descriptive analysis methods and frequency analysis approaches were adopted in this study in terms of time and space dimensions, demographic properties, and purchase behaviors. The findings of this studyshow that mushroom purchase is highly dependent on seasonal events, which implies that the product consumption timing is predictable. In addition, yearly purchase amount patterns reflect that superstores have become the major mushroomtrading venues. This directly supports the need to establish supply chain capabilities for mushroom farmers so that they gain more bargaining power against enterprise-type groceries. Finally, functional features of mushroom can be linked with marketing promotion because purchase patterns demonstrate potential needs for healthcare food in mushroom categories. Based on the analyzed patterns, this paper provides insightful implications for policy makers who want to promote mushroom consumption.

Exploration of optimum conditions for production of saccharogenic mixed grain beverages and assessment of anti-diabetic activity (잡곡당화음료 제조 최적 조건 탐색 및 항당뇨 활성 평가)

  • Lee, Jae Sung;Kang, Yun Hwan;Kim, Kyoung Kon;Yun, Yeong Kyeong;Lim, Jun Gu;Kim, Tae Woo;Kim, Dae Jung;Won, Sang Yeon;Bae, Moo Hoan;Choi, Han Seok;Choe, Myeon
    • Journal of Nutrition and Health
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    • v.47 no.1
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    • pp.12-22
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    • 2014
  • Purpose: This study was conducted to establish the production conditions through optimization of the production process of beverages using Aspergillus oryzae CF1001, and to analyze volatile compounds and antidiabetic activity. Methods: The optimum condition was selected using the response surface methodology (RSM), through a regression analysis with the following independent variables gelatinization temperature (GT, $X_1$), saccharogenic time (ST, $X_2$), and dependent variable; ${\Delta}E$ value (y). The condition with the lowest ${\Delta}E$ value occurred with combined 45 min ST and $50^{\circ}C$ GT. The volatile compounds were analyzed quantitatively by GC-MS. Results: Assessment of antidiabetic activity of saccharogenic mixed grain beverage (SMGB) was determined by measurement of ${\alpha}$-glucosidase inhibition activity, and glucose uptake activity and glucose metabolic protein expression by reverse transcriptase polymerase chain reaction (RT-PCR) and western blot analysis. Results of volatile compounds analysis, 62 kinds of volatile compounds were detected in SMGB. Palmitic acid (9.534% ratio), benzaldehyde (8.948% ratio), benzyl ethyl ether (8.792% ratio), ethyl alcohol (8.35% ratio), and 2-amyl furan (4.826% ratio) were abundant in SMGB. We confirmed that ${\alpha}$-glucosidase inhibition activity, glucose uptake activity, and glucose-metabolic proteins were upregulated by SMGB treatment with concentration dependent manner. Conclusion: Saccharogenic mixed grain beverage (SMGB) showed potential antidiabetic activity. Further studies will be needed in order to improve the taste and functionality of SMGB.

Rapid Detection of Radioactive Strontium in Water Samples Using Laser-Induced Breakdown Spectroscopy (LIBS) (Laser-Induced Breakdown Spectroscopy (LIBS)를 이용한 방사성 스트론튬 오염물질에 대한 신속한 모니터링 기술)

  • Park, Jin-young;Kim, Hyun-a;Park, Kihong;Kim, Kyoung-woong
    • Economic and Environmental Geology
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    • v.50 no.5
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    • pp.341-352
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    • 2017
  • Along with Cs-137 (half-life: 30.17 years), Sr-90 (half-life: 28.8 years) is one of the most important environmental monitoring radioactive elements. Rapid and easy monitoring method for Sr-90 using Laser-Induced Breakdown Spectroscopy (LIBS) has been studied. Strontium belongs to a bivalent alkaline earth metal such as calcium and has similar electron arrangement and size. Due to these similar chemical properties, it can easily enter into the human body through the food chain via water, soil, and crops when leaked into the environment. In addition, it is immersed into the bone at the case of human influx and causes the toxicity for a long time (biological half-life: about 50 years). It is a very reductive and related with the specific reaction that makes wet analysis difficult. In particular, radioactive strontium should be monitored by nuclear power plants but it is very difficult to be analysed from high-cost problems as well as low accuracy of analysis due to complicated analysis procedures, expensive analysis equipment, and a pretreatment process of using massive chemicals. Therefore, we introduce the Laser-Induced Breakdown Spectroscopy (LIBS) analysis method that analyzes the elements in the sample using the inherent spectrum by generating plasma on the sample using pulse energy, and it can be analyzed in a few seconds without preprocessing. A variety of analytical plates for samples were developed to improve the analytical sensitivity by optimizing the laser, wavelength, and time resolution. This can be effectively applied to real-time monitoring of radioactive wastewater discharged from a nuclear power plant, and furthermore, it can be applied as an emergency monitoring means such as possible future accidents at a nuclear power plants.

A Survey of Ecological Knowledge and Information for Climate Change Adaptation in Korea - Focused on the Risk Assessment and Adaptation Strategy to Climate Change - (기후변화 적응정책 관련 생태계 지식정보 수요와 활용도 증진 방향 - 생태계 기후변화 리스크 평가 및 적응대책을 중심으로 -)

  • Yeo, Inae;Hong, Seungbum
    • Journal of Environmental Impact Assessment
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    • v.29 no.1
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    • pp.26-36
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    • 2020
  • This study aimed at investigating present research and knowledge-base on climate change adaptation in ecosystem sector and analyzed the current status of basic information on ecosystem that functions as evidence-base of climate change adaptation to deduce the suggestions for the future development for knowledge and information in biodiversity. In this perspective, a questionary survey titled as "the ecological knowledge-base and information needs for climate change adaptation" with the researchers who were engaged with adaptation studies for biodiversity in the ecosystem related-research institutes including national and 17 regional local governments-affiliated agencies in Korea. The results are as follows; current status of utilizing ecological information which supports climate change adaptation strategy, future needs for adaptation knowledge and ecological information, and activation of utilizing ecological information. The majority of respondents (90.7%) replied that the ecological information has high relevance when conducting research on climate change adaptation. However, only half of all respondents (53.2%) agreed with the real viability of current information to the adaptation research. Particularly, urgent priority for researchers was deduced as intensifying knowledge-base and constructing related information on 'ecosystem change from climate change (productivity, community structure, food chain, phenology, range distribution, and number of individuals) with the overall improvement of information contents and its quality. The respondents emphasized with the necessity of conducting field surveys of local ecosystem and constructing ecosystem inventories, advancing monitoring designs for climate change in ecosystem, and case studies for regional ecosystem changes with the guidance or guidelines for monitoring ecosystem change to enhance the quality of adaptation research and produce related information. In terms of activation for ecological information usage, national and local adaptation network should be working based on the integrated ecological platform necessary to support exchanges of knowledge and information and to expand ecosystem types in time and spatial dimension.

Studies on the Lipid Metabolism of Soybean during its Germination-(Part 2) Changes on lipoxygenase activity and fatty acid composition in soybean during germination- (대두발아(大豆發芽)중 지질대사(脂質代謝)에 관한 연구-제2보(第2報) Lipoxygenase activity 및 지방산(脂肪酸)의 변화에 관하여-)

  • Shin, Hyo-Sun
    • Applied Biological Chemistry
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    • v.17 no.4
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    • pp.247-256
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    • 1974
  • The Merit variety of soybean (Glycine max L.), harvested in 1971 was germinated in the dark at $21{\sim}25^{\circ}C$ for 10 days. The soybean sprout were divided into cotyledons and seedling axis and subjected to the determination of lipoxygenase activity and fatty acid composition of triglycerides, free fatty acids, phosholipids and crude fat fractions at two-day intervals during the germination periods. The results are summarized as follows 1) The lipoxygenase activity in cotyledons declined sharply after second day, but the activity in seedling axis inclined slightly after second day. However, the decrease of lipoxygenase activity in cotyledons coincided with decrease of linoleic and linolenic acids in cotyledons and increase of lipoxygenase activity in seedling axis coincided with increase of those acids in seedling axis. 2) The iodine value of neutral fat in cotyledons decreased continuously, but the iodine value of the neutral fat in seedling axis remained almost constant. iodine value in cotyeldons was greater than in seedling axis. 3) In the fatty acid composition of triglycerides in cotyledons, palmitic acid did not changes significantly, stearic acid increased continuously, oleic acid changed irregularly, linoleic and linolenic acids continuously decreased significantly. But in the fatty acid composition of triglycerides in seedling axis, palmitic acid remained unchanged, linoleic and linolenic acids slightly increased continuously, stearic and oleic acids changed irregularly. 4) Composition of free fatty acids in cotyledons and seedling axis changed irregularly, suggesting that all fatty acids produced by hydrolysis of triglycerides by lipase are used(or either biosynthetic Purpose or energy Production at random. 5) Fatty acids with odd-numbered carbon chain were not detected in the triglycerides and free fatty acid fractions during the germination periods, suggesting that all fatty acids are utilized as $C_2$-unit in degradation and biosynthesis. 6) The changes of fatty acids composition of Phospholipid in cotyledons and seedling axis during the germination were similar to these of triglyceride fraction.

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An Ecological Aesthetics and Symbolism of the Seonghyelsa Nahanjeon Floral Lattice with Patterns of Lotus Pond Scenery (연지(蓮池)로 본 성혈사 나한전 꽃살문양의 생태미학과 상징성)

  • Rho, Jae-Hyun;Lee, Da-Young;Choi, Seung-Hee
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.36 no.3
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    • pp.160-171
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    • 2018
  • This study aims to find an original form of temple flower decoration patterns, considering floral lattice pattern as a view element composing temple landscape. To that end, we analyzed and interpreted the form and symbol expressed in the floral lattice pattern at Nahanjeon of Seonghyel Temple at Yeongju, Gyeongsangbukdo. The front side of Nahanjeon windows shows a sculpture with 176 pure patterns in a form where two squares are in sequence. The basic concept of main front door (the inner gate of Nahanjeon) frames is considered the design language of lotus pond that symbolizes "square land" in traditional gardens. The four leaf clover and arrowhead are water plants discovered in areas nearby ponds, which are a realistic expression conforming to the water ecology of lotus pond. The lotus, which is the most important plant at the main front door, indicates purity, a non-stained state, and the world of the lotus sanctuary, which is the land of blissful happiness in Buddhism. The lotus expressed in the floral lattice pattern is spread in a diverse form, containing the features of creation and destruction, showing the landscape character of the "One Body of Buddha and Lotus". The expression of flying birds such as kingfishers and egrets is an ecologically aesthetic idea to infuse dynamism and vitality into a seemingly static aquatic ecosystem. The floral lattice pattern contains lotus pond scenery showing symbiosis of animals(i.e., dragons, frogs, crabs, fishes, egrets, wild geese, and kingfishers) and plants(i.e., four leaf clovers and arrowheads), which are symbols of relief faith for longevity, wealth, preciousness, and many sons. The pattern is not just an ecological aesthetic expression but a holistic harmony of ecological components such as growth and disappearance of lotus and its leaves, fitting habitats, symbiosis, and food chain.