• 하천과문화
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• 제4권4호
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• pp.52-57
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• 2008

• 한국양식학회지
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• 제15권1호
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• pp.43-48
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• 2002

We investigated the gonadosomatic index (GSI), germ cell development, reproductive cycle of the Afriean lungfish Protorierus annecteus (Owen) by histological observations and morphometric data. Samples were collected from the river Orie and its flood of Nigeria, from January to December 2000. The fish is dioecious and oviparous. Monthly changes in the gonadosomatic index (GSI) showed a similar pattern to change in the mean oocyte diameter and the reproductive cycle. The reproductive period occurred from March to July-August; the spawning period was once a year between truly and August, and the main spawning occurred in August when active and voracious feeding occurred during the rainy season. In the resting (dormant) stage after spawning, fish stopped feeding and aestivated during the dry season from December to February. The reproductive cycle of the species can be divided into five successive stages, quiescent stage (March to April), developing/maturing stage (April to lune), ripe/spawning stage (July to August), post-spawning stage (September to November), and resting (dormant) stage (December to February).

• 한국양식학회지
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• 제14권2호
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• pp.73-79
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• 2001

Testicular development of the male African lungfish, Protopterus annectens (Owen) was investigated histologically. The testis was found to be an elongated structure that possessed two distinct portions: an anterior spermatogenic part that was made up of a system of testicular tubules and a posterior vesicular part that invaded the kidney tissue. Spermatogenesis can be divided into five stages; primary spermatogonia, secondary spermatogonia, spermatocyte, spermatids and spermatozoa. Based on the gonadosomatic index (GSI) and histological changes observed, the reproductive cycle can be divided onto four distinct stages: resting and quiescent (December to February), growing (March to June) ripe and spent (July to August) and postspawning (September to November). The GSI was the maximum on July when reproductive cells were mature, ripe and ready for spawning; and the minimum in August after fish spawned.

• 식품보건융합연구
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• 제6권3호
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• pp.5-21
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• 2020

Bungkang (Syzygium polyanthum) is a medium to tall plant which produces medicinal root-bark, the plant is normally found along inland river bank and produces small white flowers and fruits. Essential oils are among the most interesting components of the plant extracts consisting mostly of monoterpenoid or sesquiterpenoids. They are used as therapeutic agents in ethno, conventional, and complementary alternative medicines. Investigation and evaluation of the essential oil of Syzygium polyanthum as well as the antibacterial, antioxidant and antifungal activity was ascertained. The experiment was performed. 100 chemical constituents were obtained and two pure compound was isolated as Eugenol (1) and Farnesol (2). Significant growth inhibition of Staphylococcus aureus, (ATCCⓒ25923) Klebsiellia pneumonia (ATCCⓒ19155), Salmonella typhi (ATCCⓒ14028) and Escherichia coli (ATCC©25922) and the fungal strains Aspergillus flavin, Aspergillus niger, Candida, tropicalis, and Fusarium oxysporium was observed from the essential oil at concentration of 500 ㎍/mL. Antioxidant potential was observed to be strong of 18.42 ㎍/mL when compared to the control of 15.23 ㎍/mL. The result indicated that the oil obtained from root-bark of Syzygium polyanthum can be considered as an agent for antioxidant, antibacterial and antifungal in pharmaceutical food and cosmetic industries trails.

• Journal of Forest and Environmental Science
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• 제37권3호
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• pp.243-250
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• 2021

Information on butterflies in the Niger Delta Region is relatively scanty because monitoring of their activities and distribution has not been fully documented and these are paramount to establish their conservation protocols. The study therefore aimed at evaluating the species richness distribution pattern, and relative abundance of butterflies in the University of Port Harcourt. The University Park was purposively selected for this study. The park was stratified into three different habitat types (secondary forest, farmland, and residential/garden). A sampling of each stratum was done three times; twice in the morning between 8:00 am and 12:00 pm as well as once in the evening between 4:00 pm and 6:00 pm along a 100 m line transects for 16 months (May 2017-August 2018). Data collected were analyzed for species diversity indices, evenness, and similarity index. A total of 1,932 individual butterflies belonging to 28 species, 18 genera, and five 5 families were identified in the study area. Species diversity and evenness were higher on farmland (1-D=0.909; H'=2.615; E=0.833), and least in the residential area/gardens (1-D=0.744; H'=1.975; E=0.659). The family Nymphalidae (39.0%) had the highest number of species occurrence while Hesperidae (0.4%) had the lowest composition. Anthene larydas (24.12%) had the highest relative abundance in the entire study area, followed by Acraea serena (17.49%). The study, therefore, recommends continuous monitoring of butterfly species diversity and composition also in other regions.

• 한국음향학회지
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• 제34권1호
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• pp.1-11
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• 2015

양쯔강이나 나이저강과 같은 큰 강의 하구를 통해서 많은 담수가 흘러 들어오는 연안에서는 표층염분이 급격히 낮아져서 음속 변화에 영향을 끼친다. 본 논문에서는 우기의 동중국해 해역과 기니만에서 저염분수로 인해 생성되는 표층음파채널(SSC) 현상을 분석하였다. 동중국해는 KODC(Korea Oceanographic Data Center)의 자료를, 적도 부근의 기니만은 ARGO(Array for Real-time Geostrophic Oceanography) 자료를 사용하였다. 수집된 자료를 토대로 표층음파채널 발생동향을 살펴본 결과 동중국해에서는 10년 동안(2000 ~ 2009) 9개 정점에서 측정된 90회 자료중 표층음파채널은 32회 나타났고 그 중 염분채널은 14회 나타난 반면 기니만에서는 3년 동안(2006 ~ 2009) 20개 정점에서 측정된 20회 자료 중 모든 경우에서 표층음파채널이 발생하였으며 염분채널은 18회 나타났다. 음속구배에 영향을 주는 수온-염분의 기울기를 분석한 결과 동중국해에서는 염분과 수온 변화량 모두 크게 나타나 염분, 수온의 조합에 의한 표층음파채널이 형성되었다. 반면 기니만에서는 혼합층이 잘 발달하여 수온 변화가 적고 염분 변화량이 크게 나타나 주로 염분에 의한 표층음파채널이 형성되었다. 음향 특성 분석 결과 동중국해 정점은 채널두께가 6.5 m, 임계각은 $1.5^{\circ}$, 표층과 수온약층에서 전달손실 차는 11.5 dB로 나타났고, 기니만 정점은 채널두께가 18 ~ 24 m, 임계각은 $4.0{\sim}5.4^{\circ}$, 전달손실 차이는 21.5 ~ 27.9 dB로 나타났다. 따라서 본 연구는 큰 강의 하구나 강수량이 많은 해역에서 저염분수로 인한 음파전달 변화를 이해하기 위한 기초 자료로 활용될 수 있을 것으로 판단된다.