• 대한환경공학회지
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• 제31권10호
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• pp.893-900
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• 2009

시화호 인공습지의 유기물생산에 대한 갈대부착조류의 기여도를 평가하기 위하여 유입수의 수질특성이 다른 두 습지(반월천습지와 동화천습지)에서 4월부터 10월까지 매월 부착조류의 1차생산력을 측정하였다. 부착조류의 현존량은 반월천습지와 동화천습지에서 각각 37~3,581 mgChl.a/$m^2$surface stem(평균 655 mgChl.a/$m^2$surface stem), 87~2,093 mgChl.a/$m^2$surface stem(평균 527 mgChl.a/$m^2$surface stem)의 범위로 동화천습지에 비해 반월천습지에서 큰 값을 보였다. 반면 부착조류의 광합성효율을 나타내는 동화계수(assimilation number; AN)는 반월천습지에 비해 TN/TP 비가 작은 동화천습지에서 높았다. 두 습지로 유입되는 유입수의 TN/TP비와 AN사이에서의 음의 상관(r=0.46)으로부터 부착조류의 높은 광합성효율은 낮은 TN/TP와 관련이 있는 것으로 사료된다. 부착조류의 단위면적당 일일 1차생산력은 반월천습지에서 307~2,473 mgC/$m^2$/day, 동화천습지에서 756~2,096 mgC/$m^2$/day로 두 습지 모두 여름에 높은 값을 보였다. 두 습지의 평균 1차생산력은 반월천습지가 부착조류의 현존량이 큼에도 불구하고 1,166 mgC/$m^2$/day으로 동화천습지(1,467 mgC/$m^2$/day)에 비해 낮았다. 이는 AN 값에서 알 수 있듯이 반월천습지의 광합성효율이 동화천습지에 비해 낮았기 때문으로 판단된다. 시화호 인공습지에서 갈대부착조류에 의한 연간 총 유기물생산은 300 tonC/year(습지 전체 유기물생산의 33%)로 습지내 유기물생산에 부착조류의 기여가 큰 것으로 나타났다. 습지내 과도한 유기물생산은 습지의 수처리효율을 저하시킬 수 있으므로 수처리용 인공습지의 관리에 있어서 갈대부착조류의 역할이 고려되어야 한다.

• Animal cells and systems
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• 제3권3호
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• pp.243-246
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• 1999

A type of symbiosis was previously described from nature in which the gametophytes of Laminariales were endophytic in filamentous red algae. Here we reconstruct this symbiosis for the first time in laboratory culture using zoospores of the kelp, Undaria pinnatifida, and the red alga, Aglaothamnion oosumiense. Zoospores of U. pinnatifida readily attached to A. oosumiense. In 48 h these spores germinated and the initial germ tube penetrated into the host cell wall leaving only an empty zoospore wall outside the host. Within ten days, four to five-celled endophytic gametophytes were present. Zoospores of Laminaria religiosa which were also inoculated into cultures of A. oosumiense rarely attached to the red alga and never became endophytic. Within ten days the free-living gametophytes of L. religiosa on cover slips became fertile and produced young sporophytes. These observations demonstrate the ability of U. pinnatifida to become endophytic, and show differences in host specificity among kelp species.

• 환경영향평가
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• 제9권2호
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• pp.109-117
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• 2000

The dynamics of physico-chemical factors and biomass of epilithic attached algae was determined by bimonthly sampling in the Kyechon and Yudongchon situated in the upper part of Som River from March 1998 to February 1999. Among environmental factors, average of $NH_4$, $NO_3$, SRP and SRSi concentration ranged $8.9{\sim}86.6{\mu}g$ N/l, $663.9{\sim}2,018.1{\mu}g$ N/l, $0{\sim}15.0{\mu}g$ P/l and 1.6~2.6 mg Si/l, respectively. The contents of chlorophyll-a and organic matter per unit area, which ranged from 21.1 to 231.8 $mg/m^2$ and ranged from 5.2 to 52.6 $g/m^2$, respectively, showed very high in the spatial and temporal variations. Both were high in February and May and low in March seasonally. The fluctuation of epilithic biomass related the concentration of $NH_4$, SRP and current velocity. In relationship between biomass and current velocity, >200 and 100~200 mg chl-a/$m^2$ corresponded to <0.2 and <0.8 m/s, respectively. The evaluation of water quality with chl-a and organic matter of periphyton resulted on over eutrophic condition. Periphytic algae in a small stream were more effective as indicator of water quality than planktonic algae. More researches on periphytic algae in relation to water quality evaluation are needed.

• BMB Reports
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• 제40권5호
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• pp.644-648
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• 2007

Exposure of algae or plants to irradiance from above the light saturation point of photosynthesis is known as high light stress. This high light stress induces various responses including photoinhibition of the photosynthetic apparatus. The degree of photoinhibition could be clearly determined by measuring the parameters such as absorption and fluorescence of chromoproteins. In cyanobacteria and red algae, most of the photosystem (PS) II associated light harvesting is performed by a membrane attached complex called the phycobilisome (PBS). The effects of high intensity light (1000-4000 ${\mu}mol$ photons $m^{-2}s^{-1}$) on excitation energy transfer from PBSs to PS II in a cyanobacterium Spirulina platensis were studied by measuring room temperature PC fluorescence emission spectra. High light (3000 ${\mu}mol$ photons $m^{-2}s^{-1}$) stress had a significant effect on PC fluorescence emission spectra. On the other hand, light stress induced an increase in the ratio of PC fluorescence intensity of PBS indicating that light stress inhibits excitation energy transfer from PBS to PS II. The high light treatment to 3000 ${\mu}mol$ photons $m^{-2}s^{-1}$ caused disappearance of 31.5 kDa linker polypeptide which is known to link PC discs together. In addition we observed the similar decrease in the other polypeptide contents. Our data concludes that the Spirulina cells upon light treatment causes alterations in the phycobiliproteins (PBPs) and affects the energy transfer process within the PBSs.

• ALGAE
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• 제18권2호
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• pp.107-119
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• 2003

Neosiphonia is separated from the traditionally well known genus Polysiphonia (Rhodomelaceae, Rhodophyta) and 12 species includes in Korea. In this study, the vegetative and reproductive developments of two Neosiphonia species, N. decumbens (Segi) M.S. Kim et I.K. Lee and N. harlandii (Harvey) M.S. Kim et I.K. Lee, are reinvestigated. N. decumbens is diagnosed by following combination of the characters: plants 1-3 cm high, dwarf, decumbent, main axes indistinct, irregularly branched in dichotomous manner, and alternately or secundly ramified with wide angles above. N. harlandii is distinguished by the features: plants 4-8 cm high, usually solitary and saxicolous, erect, densely corticated at base of distinct main axes, rather irregularly alternate in branch, and with cicatrigenous branchlets developed numerously on every part of frond. The two species share typical characteristics of the genus Neosiphonia, such as a base attached by unicellular rhizoids, cut off by cross wall, pericentral cells in 4, trichoblasts moderately developed near the apex of branches, leaving persistent scar-cells, tetrasporangia arranged in a spiral series, procarps with 3-celled carpogonial branch, and spermatangial branches arising as a primary branch of trichoblast. Taxonomy of the two Neosiphonia in regard to Polysiphonia is discussed.

• ALGAE
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• 제23권1호
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• pp.83-90
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• 2008

Eelgrass beds are very productive and provide nursery functions for a variety of fish and shellfish species. Management for the conservation of eelgrass beds along the Korean coasts is critical, and requires comprehensive strategies such as vegetation mapping. We suggest a mapping method to spatial distribution and quantify of eelgrass beds using a digital echosounder. Echosounding data were collected from the northeast part of Kwangyang Bay, on the south of Korea, in March, 2007. A transducer was attached to a boat equipped with a DGPS. The boat completed a transect survey scanning whole eelgrass beds of 11.7 km2 with a speed of 1.5-2 m s-1 (3-4 knot). The acoustic reflectivity of eelgrass allowed for detection and explicit measurements of canopy cover and height. The results showed that eelgrass bed was distributed in depth from 1.19 to 3.6 m (below MSL) and total dry weight biomass of 4.1 ton with a vegetation area of 4.05 km2. This technique was found to be an effective way to undertake the patch size and biomass of eelgrass over large areas as nondestructive sampling.

• ALGAE
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• 제28권1호
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• pp.73-82
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• 2013

The genus Neosiphonia Kim and Lee 1999 contains approximately 30 species worldwide. Unidentified samples from Peru are here described as a new species, Neosiphonia ramirezii sp. nov., on the basis of morphological and molecular data. N. ramirezii sp. nov. is characterized by the presence of a limited prostrate system, well-developed erect filaments, rhizoids cut off from pericentral cells by cross walls, four pericentral cells that are completely ecorticate, scarce trichoblasts, inconspicuous scar cells, procarps with three-celled carpogonial branches, spermatangial branches developed from basal cells of forked trichoblasts, and spirally arranged tetrasporangia. Our new species is distinct from N. flaccidissima (Hollenberg) Kim et Lee, N. sphaerocarpa (Borgesen) Kim et Lee, and N. savatieri (Hariot) Kim et Lee from the Pacific temperate coast of South America and from 14 Neosiphonia species reported worldwide by having limited prostrate filaments attached by numerous rhizoids, dichotomous ("Y" shaped) branches in the main axes, and scarce trichoblasts. Phylogenetic rbcL analyses confirm the placement of the new taxon as a distinct species in the genus Neosiphonia.

• ALGAE
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• 제27권2호
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• pp.115-123
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• 2012

The establishment of algal spores plays an essential role in adult kelp distribution and abundance patterns. Sedimentation is a key variable regulating algal spore settlement and success, possibly controlling species-specific dominance $in$ $situ$. Laboratory experiments were used to determine spore attachment and survival rates of two Alaskan canopy-forming kelps, $Nereocystis$ $luetkeana$ (K. Mertens) Postels & Ruprecht and $Eualaria$ $fistulosa$ (Postels & Ruprecht) M. J. Wynne, to various types of sediment loading. Spore attachment for both species was significantly and similarly affected by three sediment treatments: suspended particles; settled sediment covering the substratum; and smothering of attached spores by settling sediment. Spore attachment decreased by approximately 90% at 420 mg sediment $L^{-1}$, the highest sediment load tested here, under all three treatments for both species. These results suggest that increases in sedimentation may constrain the success of the spore stages, but sediment does not seem to be a likely factor explaining species-specific distribution patterns. However, while sedimentation affected spores of both species similarly, timing of spore release in relation to times of maximum sediment load in the water might differ for different species, possibly explaining kelp species distribution patterns.

• ALGAE
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• 제25권4호
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• pp.197-204
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• 2010

Cytoskeletal changes were observed during cell division of the green alga Zygnema cruciatum using flourescein isothiocynate (FITC)-conjugated phallacidin for F-actin staining and FITC-anti-$\alpha$-tubulin for microtubule staining. Z. cruciatum was uninucleate with two star-shaped chloroplasts. Nuclear division and cell plate formation occurred prior to chloroplast division. Actin filaments appeared on the chromosome and nuclear surface during prophase, and the F-actin ring appeared as the cleavage furrow developed. FITC-phallacidin revealed that actin filaments were attached to the chromosomes during metaphase. The F-actin ring disappeared at late metaphase. At telophase, FITC-phallacidin staining of actin filaments disappeared. FITC-anti-$\alpha$-tubulin staining revealed that microtubules were arranged beneath the protoplasm during interphase and then localized on the nuclear region at prophase, and that the mitotic spindle was formed during metaphase. The microtubules appeared between dividing chloroplasts. The results indicate that a coordination of actin filaments and microtubules might be necessary for nuclear division and chromosome movement in Z. cruciatum.

• 생태와환경
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• 제49권2호
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• pp.130-141
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• 2016

This study was conducted to elucidate the structure of river ecosystem in the watershed of the Seom River and Hoengseong Reservoir located in Hoengseong of Kangwon Province from February to October 2007. Topics of the survey were mainly rainfall, discharge, water quality in abiotic factors and attached algae, benthic macroinvertebrates, fish, birds and mammals of flora and fauna in a biotic factors, respectively. Specifically, the Seom River could be seen as a typical flow rate of the stream is controlled to the effect of the dam. Basic water qualities were great to seasonal effects, it was relatively clean. Diatom Achnanthes, Cymbella, Gomphonema, and Navicula were distributed predominantly in the periphytic algae. Benthic macroinvertebrates were mostly aquatic insects and freshwater shellfish, the aquatic insects were abundant Ephemeroptera and Trichoptera. Freshwater fish was the dominant Zacco platypus, fish species varied toward the downstream. Birds were mainly observed in four species, and species Egretta garzetta, which was distributed in a wide area of the Seom River. In mammals, Lutra lutra of Mustelidae was identified that the number of inhabit widely. In aspects of the ecological trophic level, the Seom River was maintained at a relatively stable state in the producer and the consumer relationship. The results of this study will expected to be utilized as a useful data for understanding the structure and function of the lotic and lentic ecosystems.