• The Korean Journal of Ecology
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• 제26권4호
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• pp.165-172
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• 2003

The objectives of this study were to examine the physiological responses to ozone and to measure ozone uptake rates of Betula species exposed to relatively high concentration of pollutants. At the end of the growing season, photosynthesis, pigments contents, antioxidants (SOD and GR) and ozone uptake rates were measured or estimated at the leaves of five Betula species (Betula costata, B. davurica, B. platyphylla var. japonica, B. schmidtii and B. ermanii) exposed to 100ppb ozone concentration. On the termination of the experiment, growth effects were determined by measuring leaf area and dry weights of leaf, stem and root. Ozone treatment showed the significant reduction the leaf area and dry weight of four Betula species, except for B. ermanii. Shoot / root (SR) ratio of five species represented two different types. SR ratio of B. costata and B. davurica were lower than control, in contrast, SR ratio of B. platyphylla var. japonica, B. schimidtii and B. emani, were higher than that of control. The photosynthetic responses of five species were different in responses to ozone exposure. Four species, except for B. emanii, maintained or increased the stomatal conductance, but B. emanii decreased both stomatal conductance and photosynthesis. SOD activities of five species decreased by the ozone exposure, especially B. ermanii showed the largest reduction, GR activities of B. platyphylla var. japonica and B. schmidtii increased, B. costata and B. emanii decreased. Instantaneous ozone uptake rate was the highest at the leaves of B. ermanii and B. costata, ozone uptake per seedling was the highest at the leaf of B. schmidtii and B. emanii. It was concluded that B. costata, B. davurica and B. platyphylla var. japonica, appeared the growth reduction and visible ozone injury, were sensitive species to ozone, and B. schmidtii with the increased antioxidant activity and B. ermanii without the growth reduction were relatively resistant species to high ozone concentration at the early growing stage.

• The Plant Pathology Journal
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• 제35권4호
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• pp.321-329
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• 2019

Ascochyta blight caused by Ascochyta rabiei (Pass.) Lab. (Telomorph: Didymella rabiei) (Kov.) is one of the most important fungal diseases in chickpea worldwide. Knowledge about pathogen aggressiveness and identification resistance sources to different pathotypes is very useful for proper decisions in breeding programs. In this study, virulence of 32 A. rabiei isolates from different part of Iran were analyzed on seven chickpea differentials and grouped into six races based on 0-9 rating scale and susceptibility/resistant pattern of chickpea differentials. The least and most frequent races were race V and race I, respectively. Race V and VI showed highly virulence on most of differential, while race I showed least aggressiveness. Resistance pattern of 165 chickpea genotypes also were tested against six different A. rabiei races. ANOVA analysis showed high significant difference for isolate, chickpea genotypes and their interactions. Overall $chickpea{\times}isolate$ (race) interactions, 259 resistance responses (disease severity ${\leq}4$) were identified. Resistance spectra of chickpea genotypes showed more resistance rate to race I (49.70%) and race III (35.15%), while there were no resistance genotypes to race VI. Cluster analysis based on disease severity rate, grouped chickpea genotypes into four distinct clusters. Interactions between isolates or races used in this study, showed the lack of a genotype with complete resistance. Our finding for virulence pattern of A. rabiei and newly identified resistance sources could be considerably important for integration of ascochyta blight resistance genes into chickpea breeding programs and proper decision in future for germplasm conservation and diseases management.

• 한국수산과학회지
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• 제55권6호
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• pp.917-926
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• 2022

The green turtle Chelonia mydas has been designated as an endangered species globally due to its reduced population. Although C. mydas is not known to reproduce on the shores of the Korean peninsula, it has been listed as a protected marine species in South Korea. This study describes the first successful captive breeding of C. mydas in a commercial aquarium in South Korea and provides information on the early growth patterns of C. mydas hatched and reared in indoor facilities. C. mydas YS-B003 laid a total of 594 eggs in ten nesting events in the period December 2016-June 2017. Of these, 115 fertilized eggs from six events hatched successfully. The size of the newly hatched turtles differed significantly among nesting events. The hatchlings from the 8^th and 9^th nesting events were relatively smaller than those from the 3^rd and 5^th events. The rate of growth initially varied across the different events, but from the 1,000^th day, the inter-group variation disappeared. The present study provides useful information for future captive breeding of sea turtles in indoor facilities, which would contribute to the protection of these endangered sea turtle species.

• Journal of Mechanical Science and Technology
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• 제18권12호
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• pp.2265-2272
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• 2004

The aquaculture tank is used for breeding fish in sea water which was pumped up to land. The flow characteristics in the aquaculture were investigated with varying the tank geometry and flow rate. The numerical analysis has been employed for calculating the velocity and temperature distributions in a water tank of rectangular type. The finite volume method and SIMPLE algorithm with 3-dimensional standard $\kappa$-$\varepsilon$ turbulence model were used for the numerical analysis. For comparison with experimental results, the PIV system was applied to visualize the flow patterns quantitatively. The numerical results showed good agreements with the experimental results. The mean velocity and temperature versus aquarium depth were represented for various circulating flow rates. Especially, the aquaculture environment is recommended that the aquarium depth has to be d=0.5 m, and this case is the condition of higher velocity and temperature in winter season.

• 한국동물위생학회지
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• 제31권1호
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• pp.87-91
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• 2008

Between March and October 2007, a total of 516 blood samples from pigs in the Gyeonggi province were examined for seroprevalence against toxoplasmosis by latex agglutination test (LAT) and the detection of antigenic particles among seropositive samples by PCR. In the LAT, 118 (22.8%) were positive, and the unadjusted percentage of seroprevalence rates of breeding and fattening pigs were significant difference. Positive rate (14.1%) in the breeding pigs was much lower than that (27.8%) of the fattening pigs (p<0.001, Pearson's Chi-square test). The antibody detection rate of sows was lower than fattening pigs, i.e., 15.8% (25/158) and 26% (93/358), respectively (P=0.011, Pearson's Chi-square test). Among 118 seropositive samples by LAT, 68 (57.6%) were positive in PCR for the detection of the toxoplasma specific-DNA. There was a statistical difference in the positive PCR reaction between the raising pigs(63/93 67.7%) and sows (5/25, 20%) (P<0.01).

• The Korean Journal of Ecology
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• 제21권5_3호
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• pp.665-673
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• 1998

This study was conducted to clarified the relationship between bird community and forest structure and present the counterplan for protection and management of bird community from February 1993 to July 1995 at deciduous and coniferous forest within Mt. Nam area, Seoul, Korea. DBH distribution has not significant differences in each study site. Deciduous forest had more foliage coverage in all layers than coniferous forest. Total 41 species of birds, which were 16 species of resident, 14 species of summer visitor, 4 species of winter visitor, and 7 species of passage migrant were recrded in two study sites. Leaf use rate of birds was increased the increase of coverage. The number of breeding species and pairs, breeding density, and diversity index were greater in deciduous forest than coniferous forest. The number of species and pairs on bush-nesting and foraging guild were greater than other guilds. And the nuber of species and pairs on hole nesting guild were the fewest in nesting guild. Use rate of artificial nests for improvement of habitat quality was greater in coniferous forest than deciduous forest. Maintenance of bush layer, increase of coverage and leaf layer diversity, supply of artificial nests, management of large trees, and control of natural enemy were necessary for protection and management of bird community in Mt. nam area.

• 한국육종학회지
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• 제41권3호
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• pp.271-278
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• 2009

스트로브잣나무의 미국 6개 산지의 생장을 분석한 결과, 남쪽산지인 Georgia와 North Carolina 산지의 생장이 가장 우수하였다. 전체적인 생장의 경향은, 남쪽 산지의 생장이 우수한 반면 북쪽 산지의 생장은 상대적으로 저조하였으며, 잣나무에 비해 평균 2.4배(1.7~3.1배) 정도 재적생장이 우수하였다. 유시생장의 순위가 27년생까지 거의 변하지 않고 유지 되었으며, 이는 우수산지에 대한 조기선발 가능성이 매우 높음을 알 수 있었다.

• 한국수정란이식학회지
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• 제33권2호
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• pp.55-59
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• 2018

Ensuring timely ovulation concerning the service is valuable. A satisfactory conception rate can be achieved by making sure that ovulation occurs within 7-18 hours after artificial insemination (AI). Delayed ovulation is one of the disturbances commonly encountered in repeat breeding animals. Although demanding research, many studies have not been conducted. Therefore, we aimed to examine the relation between ovulation confirmation and conception rate in dairy cattle. The research findings showed that the signs of true estrus were bred 12 hours after the onset of estrus by AI in cattle. Also, the performance of AI on ovulation was confirmed by the presence of fluctuant Graafian follicles through rectal palpation. From the results, we confirmed that cow encountered delayed ovulation were bred again. The Conception rate in cows with confirmed ovulation was 51.9%, while for those without confirmed ovulation were 33.3%. In conclusion, the results indicate that ovulation confirmation will likely increase conception rate.

• 한국수정란이식학회지
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• 제20권2호
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• pp.79-87
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• 2005

한우 및 젖소에서 체외 수정란을 생산하여 수란 우에 이식하기 위해 도축장에서 난소를 채취하여 난자를 회수한 후 체외 성숙, 체외 수정, 체외 배양과정을 거쳐 수정란을 생산하였다. 체외 수정시 난자는 난구세포 부착 정도에 따라 난할율을 조사하였고, 한우와 젖소에서 체외수정 후 배반포율을 조사하였다. 신선 및 동결 수정란을 수란우에 각각 이식하여 산자 분만에 따른 수태율을 조사하였다. 1. 한우 난소 2,021개에서 20,387개의 난자를 회수하여 체외 수정 후 난할된 난자수는 13,541개로서 $66.4\%$의 난할율을 나타내었고, 젖소는 난소 144개에서 1,784개의 난자를 회수하여 체외 수정 후 1,113개의 난자가 난할되어 $62.4\%$의 난할율을 나타내었다. 2. 한우와 젖소에서 난구세포가 온전히 둘러싸인 난자의 율은 각각 45.0, $62.0\%$이었고 난할율은 각각 81.0, $72.0\%$이었다. 난구세포가 일부 분리된 난자의 난할율은 한우, 젖소 각각 63.5, $51.3\%$이었다. 난구세포가 완전 분리된 난자의 난할율은 한우, 젖소 각각 41.0, $41.7\%$이었다. 3. 한우와 젖소 체외수정에서 난자가 배반포로 발달된 율은 전체 난자수에 비교하여 각각 27.0, $23.0\%$이었고, 난할된 난자수에 비교하여 각각 40.6, $36.9\%$이었다. 4. 신선 수정란을 이식한 결과, 한우에서는 278두에 이식하여 159두가 산자를 분만하여 $57.2\%$, 젖소에서는 15두에 이식하여 8두가 분만함으로써 $53.3\%$의 임신율을 나타내었다. 5. 동결 수정란을 이식한 결과, 한우에서는 44두에 이식하여 18두가 산자를 분만하여 $40.9\%$, 젖소에서는 11두에 이식하여 4두가 분만함으로써 $36.4\%$의 임신율을 나타내었다.

• 한국동물위생학회지
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• 제32권4호
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• pp.369-375
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• 2009

This study was attempted to survey the prevalence of heartworm infection among 253 dogs (male 167, female 86) on the 16 breeding farms in southern Gyeongnam area in May to December 2007. The results obtained from this experiment were summarized as follows; Fifty seven (22.5%) of the 253 examined dogs were heartworms-antigen positive, while twenty five dogs were Microfilaria positive by the modified Knott's method. The regional infection rates were of 25% in Tongyeong and 21% in Goseong, and on the breeding environment aspects, infection rates were lower in rural area than urban area farms. The infection rates were higher in female (26/86, 30.2%) than male dog (31/167, 18.6%). The infection rates by breeding size of farms were 31% (11/35) at <20 head, 26%(35/135) at 20~50 head and 13% (11/82) at >50 head. The infection rates of heartworm in examined dogs at the age of <2, 2~4 and >5 were 10.7% (8/75), 26% (40/154) and 37.5% (9/24), respectively. In the microfillaria-infected 25 dogs, identified Dirofilaria immitis of 21 (84%) using PCR. The dogs infected with heartworm showed the increased number of eosinophil.