• Journal of Aquaculture
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• v.13 no.4
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• pp.325-330
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• 2000

For development of all male seed production at hatchery scale, a comparative study was made on the seed production traits of supermale (IT - t) and superfemale (IT - L1 ~) Nile tilapia, Oreochromis niloticus. Supermales were crossed with normal females (XX- f) and the superfemales with normal males (XY - t ) or sex reversed males (XX- L1 t); progeny survival of these crossings and sex ratio were evaluated. Hatching success of the eggs, fertilized by the supermale was significantly lower than that by the normal male. Over 95-99 % progenies sired by crossing supermales with normal females were males, while 52-55 % progenies alone were males with the cross of normal males and normal females. Hatching success and survival of alevins were significantly higher for the progenies of the crosses between superfemales and sex reversed males than those resulting from the crosses between superfemales and normal males. However, there was no significant difference in the sex ratio among the progenies of these crosses. Therefore, crossings of superfemales with sex reversed males provide the highest percentage of survival and male progenies.

• The Korean Journal of Zoology
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• v.13 no.1
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• pp.15-20
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• 1970

The present study was undertaken in an attempt to see if the segregation frequency of a third chromosome was changed by changing the sex chromosome which were free of SD in the second chromosome. The eight genotype males having different sex chromosome constitution each were constructed by appropriate matings and the two standard laboratory stocks of Drosophila melanogaster, e and se were used as the third chromosome recessive markers for the present experiment. The results of the present investigation are given below: 1. The k values which are the proportion of the se third chromosomes recovered among progeny flies from the mating of se/e males to e females were highly signiicantly different among the four genotypes and between the two sexes,and the interaction of genotype and sex was significantly different. Thus the setregation frequency of the se third chromosome in the male, when made heterozygous with the e third chromosome, was dependent upon the sex chromosome constitution. 2. Both of the k(Woman) and the k(man) remains roughly constant among genotypes. 3. The sex ratio o the se progeny class was highly significantly heterogeneous among the four genotypes but it was homogeneous for the e progeny class. 4. The values of the k(man) and the sex ratio of the se progeny class, on the average, were higher than that of the k(Woman) and of the e progeny class, respectively. 5. Those phenomena suggest that some sort of prezygotic selection could be operating such that the combination of the e third chromosome and the Y chromosome tends to be eliminated before fertilization. This tendency argues for a re-examination of the viability estimations of Drosophila melanogaster.

• Korean Journal of Health Education and Promotion
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• v.26 no.1
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• pp.81-92
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• 2009

Objectives: This study set out to investigate the relationship among the factors of metabolic syndrome diagnosis criteria, their risk factors including general characteristics, and the distribution of the diagnosis criteria and risk among the adult residents of a rural community. Methods: Among 1,968 residents, those who had three or more of the risk factors of metabolic syndrome, which include blood pressure, blood glucose, triglyceride, abdominal obesity, and HDL-C, were categorized as the metabolic syndrome group. And their correlations were analyzed. Results: As for the risk ratio with five factors of the metabolic syndrome diagnosis criteria, it was high according to age and smoking. In addition, the results show that body fat percentage, hs-CRP, insulin, BMI, PP2, total cholesterol, and W/Ht also had much impact on increasing the risk ratio of the metabolic syndrome diagnosis criteria. It turned out that metabolic syndrome was affected by the body mass index(BMI), insulin, waist to height ratio(W/Ht), and hs-CRP. It was 2.51 times crude odds ratio that BMI over the 25kg/m2 in the ratio of the fact of metabolic syndrome and adjusted for sex odds ratio 2.50times and W/Ht was 3.31times, adjusted for sex odds ratio 3.25 times. Conclusion: BMI, W/Ht and smoking of the general characteristics seem to have close relationships with high correlations between the metabolic syndrome diagnosis criteria and the risk factors. Thus there is an urgent need to evaluate them and take interventions and monitoring measures for the clustering of risk factors.

• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.489-500
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• 1999

The fatty acid composition of muscle were investigated to compare muscle composition among the 9 domestic animals including cattle. In major domestic animals, analyzed the effects of age, part and sex of the animal on their fatty acid composition. The content of 4 types of major fatty acids of muscle was determined and calculated their ratio. Myristic acid and palmitic acid levels were high in chicken and sheep. Besides dog muscle contained a lot of stearic acid. Linoleic acid content showed evident difference in the content depending on the animal species. The ratios of linoleic acid/palmitic acid (L/P ratio) and linoleic acid/stearic acid(L/S ratio) were characteristically high in horse and pig, whereas the ratio of palmitic acid/stearic acid(P/S ratio) was $0.71{\pm}0.17$, showing very low level in dog. As for the content of stearic acid, in cattle and chicken it was higher in young animal than adults. In duck, the contents of all fatty acids and ratio were increased by the age. As for the content of fatty acids according to the part of chicken, high level was shown in thigh than in breast and wing, while there was no remarkable variation by the part in other animal. The differences in the content of myristic acid, palmitic acid and linoleic acid among some animal could be verified in muscle lipid composition. The L/P ratio which maintained certain level regardless of age, part, sex shown distinctive pattern between the species.

• Journal of Ecology and Environment
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• v.44 no.3
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• pp.178-184
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• 2020

Background: Geladas (Theropithecus gelada), endemic to Ethiopia, are distributed closely related to the escarpments and gorge systems of the country, and large populations are found in the Simien Mountain National Park. This study was conducted in Eastern Tigray, Northern Ethiopia, from February 2018 to August 2019 in order to determine population size and composition of geladas. Total count method was used to estimate the population structure of geladas. Observations of the group of geladas based on body size and morphological characteristics were used to classify age and sex categories of the population. SPSS Version 20 was used to analyze the data. Chi-square test was used to compare sex ratio of geladas and population size among the counting sites between wet and dry seasons. Results: A total of 112 and 99 individual of geladas were counted during wet and dry seasons, respectively. Of the average gelada population recorded in this study, 11.4% were adult males, 30.3% were adult females, 12.8% were sub-adult males, 25.6% were sub-adult females, and 19.9% were unidentified juveniles. However, there was no statistically significant difference among the various age and sex groups of geladas counted during wet and dry season (χ² = 2.6, DF = 4, P > 0.05). Variations of group size along seasons were observed in this study. Sex ratio of adult male to adult female was 1:2.6 and 1:2.7 during the dry and wet seasons, respectively. Conclusion: Very small gelada population size was recorded in the current study. An average of 105.5 geladas was recorded during the study period. As this is the first report of gelada population in escarpments of Eastern Tigray, population trend of the geladas cannot decide based on the current study.

• Korean journal of applied entomology
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• v.45 no.2 s.143
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• pp.169-172
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• 2006

Sex pheromone blends of large black chafer, Holotrichia parallela (Motschulasky), which consist of a major component L-isoleucine methyl ester (LIME) and a minor component (R)-(-)-linalool, showed different attractiveness depending on the mixing ratios of the two components in potato fields in South Korea. The best ratio for H. parallela attraction was 2.5:1 of LIME and (R)-(-)-linalool. The attraction ability of pheromone traps bated with 2.5:1 ratio did not drop up to 14m, but significantly decreased at 21m from H parallela release point. Korean population of H. parallela showed almost same periodical activity to sex pheromone with that reported in Japan, which showing a circabidian periodicity of 48h cycle.

• Korean Journal of Biological Psychiatry
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• v.21 no.4
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• pp.151-160
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• 2014

Objectives Prenatal testosterone is known to influence both cerebral laterality and 2nd to 4th digit ratio (2D : 4D). Epigenetic changes are thought to play some role in it. We studied sex-related differences between 2D : 4D and cerebral laterality in patients with schizophrenia and controls to examine the effects of prenatal testosterone in the development of schizophrenia. Methods Forty one men (18 schizophrenic patients and 23 controls) and 40 women (17 schizophrenic patients and 23 controls) were recruited from one psychiatric hospital in Korea. The 2D : 4D and electroencephalographic (EEG) coherence in 19 channels (66 pairs of interhemispheric coherence and 54 pairs of intrahemispheric coherence) were measured. The sex-related statistical analyses between 2D : 4D and EEG coherence in controls and patients with schizophrenia were performed using multiple regression. Results In male patients, the relationship between 2D : 4D and right intrahemispheric EEG coherence showed mainly positive correlation in delta and theta frequency bands, while it showed negative correlation in male controls. In female patients, the relationship between 2D : 4D and interhemispheric EEG coherence showed stronger positive correlation in alpha and beta frequency bands, while it showed weaker positive correlation in female controls. Conclusions Low prenatal testosterone may play certain roles in altered correlation between 2D : 4D and cerebral laterality in schizophrenia and the development of schizophrenia by epigenetic mechanism.

• Korean Journal of Head & Neck Oncology
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• v.37 no.1
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• pp.11-16
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• 2021

Background/Objectives: To analyze changes in the incidence of thyroid cancer for Korean population using big data from the National Health Insurance Service. Materials & Methods: Sample cohort database between January 2004 and December 2013 with 1,000,000 cases for each year was enrolled in this study. Thyroid cancer incidence was analyzed by sex, age and by region. Public health insurance payment was used to reflect socioeconomic status. Results: The incidence of thyroid cancer in Korea increased for 10 years annually. There are 3 times increasing in the incidence rate of thyroid cancer from 2004, 0.03% to 2013, 0.09%. The sex ratio in the incidence rate of thyroid cancer was male : female = 1:7.2 in 2004 and male : female = 1:3.6 in 2013 that suggest decreased gap between the sex ratio. Between 2004 and 2010, the incidence rates of those in their 40s were found to be the highest, whereas the incidence rates for those in their 50s were found to be highest from 2011 and thereafter. Every year the high socioeconomic status group showed a higher incidence of thyroid cancer than low socioeconomic status group. Some specific region showed continuous high incidence of thyroid cancer, not all city and state. Conclusion: The incidence rate of thyroid cancer for 10 years had special feature by sex, age, socioeconomic status and especially by region. This results will be a barometer for further epidemiologic study about the incidence of thyroid cancer for Korean population

• Journal of Ecology and Environment
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• v.42 no.4
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• pp.292-297
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• 2018

Background: Gelada baboon is one of the endemic mammals of Ethiopia residing in different highlands. The population structure and habitat use of gelada baboon in Wof-Washa particularly Gosh Meda area was investigated from September 2016 to August 2017. Total counting method was used to collect data on the population status by dividing the study area in to four blocks, namely, Kundi, Arbgebeya, Goshber, and Goshmeda. Data were analyzed using SPSS software. The age-sex category and the numbers of geladas found within the different blocks were analyzed using one-way ANOVA, and paired t test was also used to analyze the pair wise comparison of the different age and sex categories during both dry and wet seasons. Results: A total of 435 and 471 gelada baboons were counted during the wet and dry seasons, respectively. The maximum group size consisted of 178 individuals whereas the minimum group size contained 53 individuals. Out of the total population adult females accounted for 54.7% in the wet and 54.56% in the dry seasons. There was a significant difference among the age-sex categories in both the wet ($F_{2432}=630$, P < 0.05) and dry ($F_{2468}=696.6$, P < 0.05) seasons. The male to female ratio was 1:5.7 during wet season and 1:5.8 during dry season. So that the population will have a better chance to increase in the study area. Conclusion: Wof-Washa Forest could be a good site for eco-tourism activities due to the presence of endemic animals and its scenic beauty. However, the quality of the habitat is decreasing due to livestock grazing, agricultural expansion, and invasion of exotic plants species. Therefore, appropriate conservation measures should be implemented to conserve gelada baboon in particular and other wildlife resources in general.

• Fisheries and Aquatic Sciences
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• v.4 no.4
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• pp.208-218
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• 2001

We have investigated the gonad index (GI), gonadal development, reproductive cycle, first sexual maturity, sex ratio, the number of spawned eggs and spawning frequency of the Manila clam, Ruditapes philippinarum. Samples were collected from the intertidal zone of Komso Bay, Korea from January to December in 1999. Monthly changes in the gonad index (GI) and condition index showed a similar pattern in the reproductive cycle. The spawning period was once a year between early June and early October, there was a spawning peak between July and August when seawater temperature was over $20^{\circ}C$. The reproductive cycle of this species can be categorized into five successive stages; early active (February to March), late active (April to May), ripe (April to August), partially spawned (June to October), and spent/inactive stage (August to March). Percentages of first sexual maturity of female and male clams of l5.1-20.0mm in shell length were $56.3\%$ and $60.0\%$, respectively, and $100\%$ for the clams >25. mm. The sex ratio of individuals >15.1 mm in shell length was about 1:1 $(\chi^2= 0.02,\;p>0.05)$. Number of the eggs released from each clam by the induction increased as the size of clam in terms of shell length increased. Mean number of the eggs from the second induction of the spawning was $75.35-84.30\%$ $(average\;79.81\%)$ of the number of the eggs released in the first spawning. Our data indicated that R. philippinarum in Komso Bay has one major spawning peak with over two minor spawning, and the interval of each spawning was estimated to be approximately 15-17 (average 16.5) days.