• Journal of Chest Surgery
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• v.34 no.11
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• pp.823-830
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• 2001

Background: Paraplegia is a serious complication of thoracic or thoracoabdominal aortic operations, which is related to ischemic injury of the spinal cord induced by low perfusion pressure during cross clamping of the aorta. Ischemic preconditioning of heart or brain with reversible sublethal ischemic injury induces resistance to subsequent lethal ischemia. The aim of this study is to investigate whether ischemic tolerance could be induced by the preconditioning of the spinal cord using swine model. Material and Method: The animals were randomly assigned to three groups: sham group(n=3), control group(n=6) and pre-conditioning group(n=8). In the sham group, we performed the left thoracotomy only without any ischemic injury. In the preconditioning group, the swine received reversible spinal cord ischemic injury by aortic clamping for 20 minutes, whereas control group had no previous aortic cross- clamping. Forty-eight hours later, the aorta was clamped for 30 minutes in both groups. Neurological examination was done 24 hours later, then the animals were euthanized for histopathology and malonedialdehyde(MDA) spectrophotometry assay of the spinal cord. Result: Statistically significant difference in neurological outcome was observed between the control and preconditioning groups at 24 hours after ischemic injury. The incidence of paraplegia and severe paresis was 100% in the control group, and 62.5% in the preconditing group(p=0.028). There was no statistically significant difference in histopathology and MDA assay of the ischemic spinal cord between these two groups with borderline statistical difference in MDA assay(p=0.0745). Conclusion: In the present swine study, ischemic preconditioning could induce tolerance against 30 minute ischemic insult of the spinal cord, although the animals did not completely recover(stand-up or walk). We expect that combining this preconditioning with other currently existing protection methods might lead to a synergistic effect, which warrants further investigation.

• 한국해양학회지
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• v.30 no.5
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• pp.403-412
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• 1995

The present study was performed to determine th growth and production of Mactra veneriformis on the Songdo tidal flat off Inchon. west coast of Korea. Monthly samples were collected from Marc 1989 to September 1990. The size distributions of shell length showed unimodal patterns from March to August 1989. The binodal pattern after September 1989 indicated a recruitment of young clams during this period. The density fluctuated irregularly, but showed a decreasing pattern over time on the whole. The density of the year class 1989 increased markedly after February 1990. The growth in shell length showed three phases during a year, a fast growth phase in spring, a slow growth phase in summer and autumn, and a lag phase in winter. The annual increment in shell length reduced with age. The flesh dry weight showed a peak in late spring just before the spawning period, and another peak in autumn. The length of annuli and the back-calculated flesh dry weight were used to describe the annual growth. The growth in shell length fitted to the von Bertalanffy model and the flesh dry weight to the Gompertz model. The absolute growth rate of the shell length reduced gradually with age. The year class 1985 had the highest L, and the yeat class 1986 the lowest L. The annual growth in weight showed a typical sigmoid curve. The growth rate was maximum at the age of 2 to 3. Year classes of 1984 and 1985 had higher values of W and higher absolute growth rates than those of 1986 and 1987. Maximum absolute growth rates of 1986 and 1987 year classes were recorded at younger ages than 1984 and 1985 year classes. The annual relative growth rates of length and weight decreased exponentially with age. Biomass in flesh dry weight increased till spring and thereafter decreased progressively. Maximum biomass was 134.6g m/SUP -2/ in August 1990. The biomass of 1989 yeat class occupied highest proportion in total biomass. Annual production in flesh dry weight from March 1989 to March 1990 was 67.9 g m/SUP -2/ year/SUP -1/. Cumulative production of 1989 year class was highest among all year classes, and that of year class 1984 was lowest. The production is high in spring and autumn, and very low in summer and winter.

• Korean Journal of Ichthyology
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• v.18 no.4
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• pp.355-362
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• 2006

The age and growth of brown sole, Pleuronectes herzensteini were investigated from samples randomly collected in the East Sea of Korea from April, 2003 to March, 2004. Ages were determined from annuli in otoliths and annuli were formed between March and May once a year. Also, main spawning period were estimated between March and April, thus rings were considered as annual marks. The von Bertalanffy growth parameters estimated from a non-linear regression method were $L_{\infty}=37.2cm$, K=0.131/year, $t_0=-2.008years$ for female and $L_{\infty}=28.3cm$, K=0.177/year, $t_0=-2.135years$ for male, and the growth between female and male was different.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.499-501
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• 2000

굴을 포함한 대부분의 해양 무척추동물들은 동일종이라도 먹이조건과 온도조건에 의해 성장과 발육, 번식초기연령이나 최소번식 크기 등에 큰 차이를 보인다. 굴의 번식수단 및 생활사 를 이해하기 위해서는 번식이나 생활사에 관한 속성을 보다 수량적으로 확인하고 동시에 개체군 생태학적인 지견을 가질 필요가 있다 (윤, 1996). 대서양산 굴, Crassostre virginica에 대하여 Lee and Heffernan (1991)은 알의 지질과 단백질 조성을 밝히고 생화학적 특성을 보고하였으며, Choi et al. (1993)는 면역학적 방법을 이용하여 번식량에 대한 정량적인 연구를 보고한 바 있으나, 이와는 대조적으로 참굴 C. gigas의 알 및 번식량에 대한 연구는 미비한 실정이다. (중략)

• Korean Journal of Poultry Science
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• v.38 no.4
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• pp.305-313
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• 2011

This study was conducted to investigate the effects of housing systems on the productivity and physiological response as stress indicators in White Leghorn chickens. The chickens subjected to the conventional cages had a significantly lower viability, hen-housed egg production, egg weight and body weight compared with those to the floor pens. However, the hens housed in the conventional cages had a shorter day of the first egg and a greater egg quality compared with those housed in the floor pens. In addition, this study was also investigated to identify biological markers for assessing the physiological response of chickens under stress conditions. As biological markers, the amount of telomeric DNA was analyzed by quantitative fluorescent in situ hybridization on the nuclei of cells. The DNA damage rate of lymphocytes was also quantified by the comet assay. The amount of telomeric DNA of the lymphocytes, kidney and spleen was significantly higher in the chickens under floor pens than those under conventional cages. The DNA damage also increased in chickens raised under conventional cages, as compared to the chickens under floor pens. As results, we conclude that the chickens housed in conventional cages have a greater stressful status than those housed in floor pens.

• Korean Journal of Ichthyology
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• v.29 no.4
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• pp.235-243
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• 2017

Reproductive characteristics of Rhodeus pseudosericeus (Pisces: Acheilognathinae) was investigated at the Heukcheon (River), Yangpyeong-gun, Gyeonggi-do, Korea from January to July in 2012. This fish prefers heavily vegetated stagnant pool with Phragmites japonica and Salix koreensis and area with high proportions of sand and mud. The standard length of the population indicated that 13~22 mm group is 0-year old, 30~45 mm group is 1-year old, 45~55 mm group is 2-year old and 45~70 mm group is more than 3-year old (June in 2012). The sex ratio of female to male was 1 : 0.80. The spawning season was from March to June with water temperatures in the range $11.0{\sim}26.2^{\circ}C$. The embryos were found with no egg mass in Unio douglasiae sinuolatus and the number of those was 1~22 ($5.8{\pm}5.51$). The number of the embryos found in each of the four parts of the mussel gill was 1~9 ($2.7{\pm}2.16$) in left outer, 1~2 ($1.5{\pm}0.71$) in left outer, 1~5 ($1.8{\pm}1.79$) in left outer and 1~22 ($5.8{\pm}5.51$) in left outer.

• Korean Journal of Ichthyology
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• v.5 no.2
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• pp.184-193
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• 1993

The distribution, and length and age compositions of Johnius belengeri were studied using samples collected by an otter trawl from the five different coastal waters of Korea ; Asan Bay, Cheonsu Bay, waters off Yeongkwang and Samchonpo, and Yeongil Bay. This fish showed a high density of 1,147 individuals/$10,000m^2$ and predominated in abundance of the demersal fish in the coastal water off Yeongkwang. The mean density was 94 individuals/$10,000m^2$ in Cheonsu Bay and 8-24 individuals/$10,000m^2$ in Asan Bay and in the water off Samchonpo. Few fish were collected from Yeongil Bay. J. belengeri occurred from spring to autumn in the study area and showed a relatively high density in spring or in summer. The fish collected in spring and in summer composed of adults of age group I, II and III. Some juveniles began to occurred in the waters off Yeongkwang and Samchonpo from summer. The fish collected in autumn consisted mainly of the fish of age group 0. It implies that the adults after spawning moved out from the embayments for feeding. but the young fish stayed and grew in the embayments until late autumn when they migrated to the offshore water for wintering.

• Korean Journal of Ichthyology
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• v.20 no.1
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• pp.21-27
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• 2008

A total sample of 215 specimens of the Iksookimia koreensis was collected monthly from June 2004 to June 2005 in the Namdae stream, Cheorwon-gun, Gangwon-do, Korea. The age of every individual sample was estimated by the number of annual rings on the scales. A significant decrease of gonadosomatic index was noted between May and June reflecting the reproduction during this period. I. koreensis exhibited a strong bias to female (female : male, 1 : 0.56). The maximum age observed was 3 years old for male & female, both. The von Bertalanffy growth curves were expressed as $L_t=126.30[1-\exp\{-0.576(t+0.940)\}]$ for females and $L_t=100.19[1-\exp\{-1.119(t+0.695)\}]$ for males.Growth curve of weight was expressed as $W_t=11.567[1-\exp\{-0.576(t+0.940)\}]^{3.199}$ for females, $W_t=5.514[1-\exp\{-1.119(t+0.695)\}]^{3.199}$ for males. On the other hand, a significant difference in the growth rate between both sexes was found(i.e. females grew faster than males).

• Korean journal of applied entomology
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• v.31 no.4
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• pp.551-559
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• 1992

These studies were conducted to investigate the biological effects of buprofezin 25% WP on the adult of the brown planthopper (BPH) and its control effects on the BPH population, when buprofezin was treated on different days after the introduction of the BPH adult to the potted rice. Also age structures of the BPH population at the time of buprofezin treatment were observed. The results were as follows: Buprofezin (7.0 g a.i./l0 a) could reduce the longevity and fecundity of the newly emerged female but did not affect the biology of older female, and it did not affect the biology of the male. The larval densities at the time of buprofezin treatment was reduced to nearly zero after treatment. The higher the residual effect and the proportion of larvae at the time of buprofezin treatment were, the higher its con¬trol effect on the BPH population was. In case of buprofezin 7.0 g a.i./l0a treatment, the time interval of treatment that could show the highest control effect was about 10 days (from 18 days after the adult introduction to the adult emergence days of next generation).

• Korean journal of applied entomology
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• v.51 no.3
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• pp.235-243
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• 2012

Population dynamics of the American serpentine leafminer, Liriomyza trifolii (Burgess), were observed and modeled in order to compare the effects of air and tomato leaf temperatures inside a greenhouse using DYMEX model builder and simulator (pre-programed module based simulation programs developed by CSIRO, Australia). The DYMEX model simulator consisted of a series of modules with the parameters of temperature dependent development and oviposition models of L. trifolii were incorporated from pre-published data. Leaf surface temperatures of cherry tomato leaves (cv. 'Koko') were monitored according to three tomato plant positions (top, > 1.8 m above the ground level; middle, 0.9 - 1.2 m; bottom, 0.3 - 0.5 m) using an infrared temperature gun. Air temperature was monitored at the same three positions using a self-contained temperature logger. Data sets for the observed air temperature and average leaf surface temperatures were collected (top and bottom surfaces), and incorporated into the DYMEX simulator in order to compare the effects of air and leaf surface temperature on the population dynamics of L. trifolii. The initial population consisted of 50 eggs, which were laid by five female L. trifolii in early June. The number of L. trifolii larvae was counted by visual inspection of the tomato plants in order to verify the performance of DYMEX simulation. The egg, pupa, and adult stage of L. trifolii could not be counted due to its infeasible of visual inspection. A significant positive correlation between the observed and the predicted numbers of larvae was found when the leaf surface temperatures were incorporated into the DYMEX simulation (r = 0.97, p < 0.01), but no significant positive correlation was observed with air temperatures(r = 0.40, p = 0.18). This study demonstrated that the population dynamics of L. trifolii was affected greatly by the leaf temperatures, though to little discernible degree by the air temperatures, and thus the leaf surface temperature should be for a consideration in the management of L. trifolii within cherry tomato greenhouses.