• Title/Summary/Keyword: dominant period

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Distributional Pattern of Polychaetes in the Benthic Community of the Yellow Sea (황해의 저서군집내에서 다모류의 분포유형)

  • LEE Jae-Hac
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.20 no.3
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    • pp.224-229
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    • 1987
  • The ecological studies of the benthic polychaetes of the Yellow Sea were carried out for five years from August 1982. The emphasis of the research were placed on clarification of the distributional pattern and characteristic species of environmental factors on the polychaete community. Based on the polychaete samples analysed during the study period, it was possible to divide the polychaetes into five ecological groups : 18 warm water, 22 cold water, 20 cosmopolitan, 29 endemic, and 7 amphi-pacific species, Anaitides koreana, Aglaophamus sinensis, Nephtys polyoranchia, Nephtys caeca, Glycera capitata, and Scoloplos armiger seem to be characteristic species of sand bottom, while Haploscoloplos elongatus and Ophelina aulogaster of mud bottom. A total of 6 benthic communities have been recognized from the dominant benthic fauna found. In each benthic communities, dominant and characteristic polychaete species were clarified according to their ecological types. In general, as echinoderms such as Ophiura kinbergi, Amphioplus megapomus, and Luidia quinaria are distributed widely and found in high density, their influence on the distribution of most polychaetes is clearly shown.

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On the Trophic Correlation between Tintinnids and Dinoflagellates in Masan Bay, Korea (마산만의 유종섬모충류와 와편모류간의 포식-피포식 상관관계에 대하여)

  • YOO Kwang-Il;LEE Joon-Baek
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.20 no.3
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    • pp.230-236
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    • 1987
  • The correlation between tintinnid and dinoflagellate by means of seasonal variation of standing crops was investigated at two selected stations in Masan Bay, well-known as a red tide zone in southern coastal waters of Korea, during the period from January 1981 to December 1982. The most dominant dinoflagellates mainly belonged to $20-60\;{\mu}m$ of size class, and Gymnodinium and Prorocentrum were predominant from spring to summer season. Of tintinnid, Favella spp. were most dominant and associated with dinoflagellate blooms at the same season. Especially, Favella spp. were most positively correlated with $40-60\;{\mu}m$ size class of dinoflagellate, and also represented higher multiple corrleation with outer station (St.2), comprising relatively large species of Gymonodinium and Protogonyaulax, than with inner station (St. 1), dominated by Prorocentrum blooms. Thus, the interspecific food selection by size and morphology between tintinnid including Favella and dinoflagellate is recognized and it is considered to be an important factor influenecing on the prey-predator relationship in lower trophic level in the surveyed area.

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Species Composition of Fish from Sea Grass Bed in Chuuk Lagoon, Micronesia (마이크로네시아 축 환초내 잘피밭의 어류 종조성)

  • Choi, Young-Ung;Yoon, Kon-Tak;Lee, Dae-Won;Kim, Taihun;Kim, Yoonchil;Park, Heung-Sik
    • Ocean and Polar Research
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    • v.35 no.4
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    • pp.441-452
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    • 2013
  • The fish species composition of seagrass bed in Chuuk Lagoon, Micronesia, was investigated every month from August 2009 to July 2011, using a seine net for fish caught. A total of 32 fish species belonging to 18 families under 6 orders were identified during the study period. Of these fish, Atherinomrus lacunosus, and Strongylura incise were the major dominant species representing 85.0% in total number of individuals. The number of species and individuals were high from August to December 2009, 2010. The biomass was highest in September 2010 and the diversity index was higher in September 2009, April, August 2010 and July 2011. The 14 dominant species could be divided into 2 groups of 3 individuals based on appearance patterns; (1) resident species and temporal species (9 species, e.g. Atherinomrus lacunosus), juvenile and adults living in seagrass beds and juveniles living only in seagrass beds; (2) temporal species (2 species, e.g. Hemiramphus lutkei), juveniles living only in seagrass beds; (3) temporal species (3 individuals, e.g. Caranx sexfasiatus). For some species, the appearance patterns were affected by water temperature. However, the relationships between sea currents, salinity, tide, and structure of fish assemblage remain unclear. Further studies that regularly monitor sea grass habitats are necessary to clearly understand the correlation between environmental factors and sea grass habitat use patterns in fish assemblages.

Ichthyofauna and Fish Community Structure in Namdae Stream, Yangyang, Korea (양양 남대천의 어류상과 어류군집)

  • Kim, Chi-Hong;Lee, Wan-Ok;Hong, Kwan-Eui;Lee, Cheul-Ho;Kim, Jong-Hwa
    • Korean Journal of Ichthyology
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    • v.18 no.2
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    • pp.112-118
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    • 2006
  • The ichthyofauna and fish community structure were investigated at eleven stations in Namdae stream, Yangyang during April, 2004 and March 2005 monthly. During the surveyed period thirty five species belonging to fifteen families were collected. Dominant species in number was Triboblodon hakonensis (relative abundance : 27.9%) and subdominant was Zacco koreanus (15.0%). There were five Korean endemic species including Rhynchocypris kumgangensis. Eleven species including Pungtungia herzi are first recorded in this study. There are stabilized fish community structure with dominant species R. kumgangensis in upstream, Z. koreanus and Z. platypus in midstream and T. hakonensis in downstream respectively. But, it is very worried the change of ichthyofauna in foreseeable future because of pumped storage power station construction in midstream.

A Clinical Study of According to Prevalence of Dermatoses in a Oriental Medicine Hospital of Gang-Dong Area in Seoul (서울 강동지역 소재 한방병원 피부과 내원환자의 질환 빈도에 따른 임상적 관찰)

  • Son, Byeong-Kook;Choi, In-Hwa
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.20 no.3
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    • pp.161-168
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    • 2007
  • Objective and Methods : To study the prevalence and patterns of common dermatoses and compare these to previous reports, we reviewed 128 new outpatients who visited Allergy/Derma-cosmetic Clinic at Kyung Hee Neo Medical Center in Gang-Dong area of Seoul from January to June, 2007. Results : The results of this study are summarized as follows : 1. Among the 128 outpatients, the total number of male patients were 40(31.2%) and female patients were 88(68.8%). 2. In the age distribution, the most frequently visited age groups were 10-19 years old and 20-29 years old(each 21.1%). 3. The most common dermatoses were atopic dermatitis(27.3%), acne(14.1%), allergic contact dermatitis(11.7%), other eczemas(7.8%) and seborrheic dermatitis(7.0%). 4. Among atopic dermatitis patients, the most populated age groups were 0-9 years old and 10-19 years old(each 37.1%), these results are different from past studies revealing that 0-9 years old patients are dominant. 5. Among acne patients, the most frequent age groups were 20-29 years old(50%) and 30-39 years old(27.8%), these results are different from past studies revealing that 20-29 years old and 10-19 years old patients are dominant. 6. Among Allergic contact dermatitis patients, each age group showed no difference of population. And Allergic contact dermatitis patients visited outpatients department at early stage. Conclusion : This study shows that Oriental medicine is popular especially in atopic dermatitis, acne and allergic contact dermatitis. We should investigate long-period and multi-centered study in order to know prevalence tendency of dermatoses in Oriental Medicine. And it is nessessary to research using more efficient evaluation method and treatment for these special diseases.

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What factors reduce the yield potentiality in high-yielding rice?

  • Kobata, Tohru;Yoshida, Haruka;Masiko, Uukina;Honda, Tohru;Ishi, Hibiki;Iwasaki, Hiroyuki
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.19-19
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    • 2017
  • The indica ${\times}$ japonica rice (Oryza sativa L.) cultivars released in Japan since 1980 are high-yielding. However, occasionally in these cultivars their high yield potentials cannot be realized, particularly depending on climate conditions. The objectives of this study were to identify the reason for yield instability and the critical yield component factor causing lower grain yield in these high-yielding cultivars. Standard-yield japonica, high-yielding japonica-dominant, and indica-dominant cultivars were grown in western Japan. Rough grain yield (RY) in these high-yielding cultivars ranged from 450 to $980g\;m^{-2}$, and was positively correlated with potential grain yield (PRY). By fluctuations of solar radiation, RY changed with spikelet number (SNO), and SNO was correlated with cumulative radiation during the panicle formation period of 30 days before heading. Even if higher SNO was achieved under higher radiant conditions, RY was lower than PRY. The lower grain-filling in plants bearing higher SNO resulted from a lower filling percentage of spikelets (%F, RY/PRY), and %F was strongly correlated with spikelet fertility (%S) across all cultivars. %S was highly influenced by cumulative radiation per PRY during pollen development and establishment around heading. Inhibition of assimilation by leaf removal lowered %S. Conversely, stem thinning and removal of upper panicles around heading increased %S in spikelets of the lower part of the panicle in which sterility was higher. These results suggest that limitation of assimilate-supply due to low irradiance at the spikelet-formation and flowering stages restrains the potential of the high-yielding cultivars, depending on reduction of SNO and %S, respectively.

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Profile of airborne microorganisms distributed in general offices (일반 사무실 실내공기 내 부유미생물의 분포 양상)

  • Kim, Ki Youn;Roh, Young Man;Kim, Yoon Shin;Lee, Cheol Min;Sim, In Suk
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.18 no.1
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    • pp.11-19
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    • 2008
  • Mean levels of airborne bacteria, airborne fungi, temperature, relative humidity and carbon dioxide in total 69 general offices were $426({\pm}83)\;cfu/m^3$, $234({\pm}125)\;cfu/m^3$, $25.9({\pm}1.3)\;^{\circ}C$, $57.7({\pm}8.6)\;%$, $422({\pm}38)\;ppm$, respectively. The I/O ratio of airborne bacteria and fungi was over 1 and there was no significant difference among temperature, relative humidity and carbon dioxide in total 69 general offices. In construction period, a concentration of airborne bacteria and fungi was significantly highest in general offices constructed under one year and over three years since construction, respectively (p<0.05). The concentration of airborne fungi in general offices located at basement was significantly higher than those located at ground (p<0.05). No significant difference of airborne bacteria and fungi in general offices was found regardless of installation of HVAC system (p>0.05). The dominant bacterial genera identified in general offices was Staphylococcus, followed by Micrococcus, Bacillus, and Corynebacterium while usarium, Penicillium, Aspergillus, Alternaria, Rhizopus and Mucor were identified as dominant fungal genera in general offices.

Characteristics of Bird Community in Mangyeong River Area (만경강 지역 조류군집의 특성과 관리 방안)

  • 이우신;박찬열;임신재;허위행
    • The Korean Journal of Ecology
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    • v.25 no.2
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    • pp.61-67
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    • 2002
  • This study was conducted to clarify the characteristics of bird community and habita types in Mangyeong River area from Aug. 1999 to Jun. 2000. Paddy field was the most dominant land use type. Water area, mudiflat. shrub field, urban area and green house wee also dominant land use types in study area Eighty-eight bird species were recorded during study period. Maxiamum number of species and individuals were shown as 58 species and 7,084 individuals in Oct. and Jan. respecitvely. There were low number of diving ducks and clumped pattem of waterfowl distribution of bird community in Mangyeong River area. Dabbing ducks distributed at upper reaches near Samrye Bridge, and plovers and sandpipers at lower reaches near estuary. Those results suggest that creation of pools over one meter water-depth and restoration of paddy field freld into riparian zone with diverse shrubs are required to imcrease th bird diversity in the Mangyeong rived.

Ecological Status Evaluation using Seaweed Community Structures of Taean Coastal Areas in Korea

  • Na, Yeon Ju;Kim, Ju-Hee;Kwon, Chun Jung;Choi, Han Gil;Nam, Ki Wan
    • Ocean and Polar Research
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    • v.37 no.4
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    • pp.317-325
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    • 2015
  • To evaluate the relative ecological quality of Taean coastal areas in terms of various seaweed community indices, seasonal samplings were taken at the Hakampo, Padori, Chaeseokpo, Mongsanpo and Bangpo shores from March 2006 to January 2007. A total of 105 species were identified; species richness ranged from 37~72 species spatially and from 65~75 species seasonally over the study period. Coarsely-branched seaweeds were dominant in functional group and ESG I (ecological state group I) made up 61 species (58.10%) of the identified macroalgae. The average seaweed biomass at the five study sites was $56.63g\;dry\;wt./m^2$ (range, 36.66 at Hakampo $-73.89g/m^2$ at Mongsanpo). Seaweeds were generally abundant in mid and low intertidal zone. Corallina pilulifera, Ulva australis, Sargassum thunbergii, Neorhodomela aculeata, and Symphyocladia latiuscula were the dominant species across all five study sites. Species diversity was between 1.24~2.30, while species evenness was between 0.40 and 0.61. The dominance index ranged from 0.43 at Padori to 0.64 at Mongsanpo. Given the community indices and shore descriptions, the five study sites were divided into two groups based on ecological quality: moderate (Chaeseokpo and Mongsanpo) and good (Hakampo, Padori and Bangpo).

Molecular Systematic Study of Bacterial Community Associated with Sand Dune Plants (사구식물 연관 세균 군집의 분자계통학적 연구)

  • Do, Jin-Ok;Park, Seong-Joo;Kim, Seung-Bum
    • Korean Journal of Environmental Biology
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    • v.25 no.4
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    • pp.356-362
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    • 2007
  • The rhizobacterial diversity associated with 9 native plant species inhabiting coastal sand dunes in Tae-an area, Chungnam Province, was studied using the denaturing gradient gel electrophoresis (DGGE) fingerprinting analysis over three times from October 2003 to March 2004. One dominant band commonly occurred in all of the rhizosphere samples, which was identified as that of Lysobacter enzymogenes. The other common bands included those derived from species of Pseudomonas and Bacillus. It was notable that L. enzymogenes was dominant in all of the 9 plant species and such dominance was consistent throughout the whole sampling period, which confirms the previous study by Lee et al. (2006a). The Bacillus bands were detected in all of the three samplings, and those of Pseudomonas were notable in the samples of December 2003. By the DGGE analysis alone, the significance of Lysobacter to the sand dune plants is not clear. However, considering their presence in healthy plants and the dominance in all plant species, Lysobacter may have positive roles in the survival or growth of the plants in sand dune area.