• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.6
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• pp.563-574
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• 1986

The structure of gonads, gametogenesis and reproductive cycle of the jackknife clams, Solen strictus and Solen gordonis were investigated mainly by histological observation. The first species used were monthly sampled at the coastal area of Dadaepo, Pusan, Korea and Naechodo, Kunsan, Korea for one year from February 1982 to January 1983. The second species were monthly sampled at the sand beach of Dadaepo, Pusan, Korea, from February 1982 to January 1983. Sexualities of Solen strictus and Solen gordonis are dioecious, and these species are oviparous. The gonads are irregularly arranged from the subregion of mid-intestinal gland in visceral cavity to reticular connective tissue of foot. The ovary was composed of a number of small ovarian sacs and the testis was composed of several testicular lobuli which from the tubular structure. Early multiplicating oogonium was about $10{\mu}m$ in diamater. Nucleus and nucleolus, at that time, were distinct in appearance. Each of the early growing oocytes made an egg-stalk, connected to the germinal epithelium of the ovarian sac. A great number of undifferentiated mesenchymal tissue and eosinophilic granular cells are abundantly distributed in the ovarian sacs in the early development stages. With the further development of gonad, these tissue and cells gradually disappeared. Then the undifferentiated mesenchymal tissue and eosinophilic granular cells function as nutritive cells in the formation and development of the early stage germ cells. Mature oocytes were free in the lumen of ovarian sacs and gradually become round or oval. Ripe oocyte was about 80 to $90{\mu}m$ in diameter. With the further development of testis, each of the testicular lobuli formed stratified layers composed of spermatogonia, spermatocytes, spermatids and spermatozoa in groups on the germinal epithelium. After spawning, the gonad gradually degenerated, and disorganized completely. Then new differentiated tissues were rearranged next year. The annual reproductive cycle of those species could be classified into five stages; multiplicative, growing, mature, spent, degenerative and resting stage. It seems that the spawning season is closely related to the water temperature, and the spawning of Solen strictus occurs from June to July at above $20^{\circ}C$ in water temperature. The peak spawning season appeared in June at Dadaepo and in July at Kunsan, The spawning of Solen gordonis occurs from May to June with the peak spawning season in June. Percentages of the first maturity in female of Solen strictus ranging from 5.1-6.0 cm and 7.1-8.0 cm in shell length were $50\%$ and $100\%$, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.5
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• pp.644-651
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• 2005

Dietary supplement mainly made of herb and fiber was examined whether it could reduce body weight and fat, modify blood lipid concentrations and bowel habits in 30 collegians without intentional diet restriction or lifestyle change for 5 weeks. Free-living subjects were required to take diet pills 2 times daily 30 minutes before meals. Before the study began, 24 hr recall diet record and the questionnaires had been collected. Anthropometric measurements (height, weight, waist and hip circumferences, triceps and abdomen skinfold thickness, and body fat) were performed and blood samples were withdrawn before and after the study. Blood lipid fractions analyzed were total cholesterol (TC), triglyceride (TG), HDL-cholesterol and LDL-cholesterol. After the trial, body weight, body mass index, and percent ideal body weight of the subjects were reduced to mean of 0.5 kg, 0.2 and $0.9\%$, respectively (p<0.05). Percent body fat, triceps and abdomen skinfold thickness, and waist and hip circumferences were all reduced significantly except for $\%$ abdominal fat, but $\%$ body muscle mass increased from $36.5\%$ to $37.4\%$ (p=0.000). TC and TG were remarkably diminished (p<0.01) and LDL-cholesterol tended to decrease, but no change was observed in HDL-cholesterol. Bowel movements were also increased (p<0.01). In conclusion, this specific herb and fiber-rich dietary supplement reduced body weight and body fat indices, improved anthropometric indices, modified blood lipid fractions and bowel movement desirably. The study suggest that herb and fiber-rich dietary supplement might help control body weight, body fat loss and adult diseases positively.

• Journal of Korean Society of Forest Science
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• v.104 no.4
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• pp.564-577
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• 2015

The objectives of this study were to investigate the possibility of establishing a tree nursery at Saemangeum reclaimed land and to classify landscape trees based on the salt tolerance. A tree nursery (2.0 ha) was made in Gunsan Okgu area in 2012 with underground drain lines on the reclaimed land established in 2010. Salt content of the nursery soil within the 60 cm depth in 2013 was 5.13 dS/m and 8.20 dS/m for the pre-desalinated and non-desalinated lands, respectively. Thirty-six woody plant species (22 tree species and 14 shrub species at ages of 1 to 4) with a total of 3,943 individuals were planted in early April, 2013 and their growth performance was monitored until September of the same year. The average survival rate of the transplanted plants was 71.4% in late September, suggesting the high possibility of establishing a tree nursery at the reclaimed land. Based on the survival rate and tree vigor (amount of healthy leaves and crown development), the following 17 species with some salt tolerance were classified into three groups: "salt tolerant group" (3 species, Tamarix chinensis, Cudrania tricuspidata, Ilex serrata), "recommended group" (5 species, Pinus thunbergii, Albizia julibrissin, Ligustrum obtusifolium, Rosa rugosa, Pleioblatus pygmaeus), "plantable group" (9 species, Zelkova serrata, Hibiscus syriacus, Elaeagnus umbellata, Sorbus alnifolia, Sophora japonica, Metasequoia glyptostroboides, Quercus acutissima, Ulmus parvifolia, Robinia pseudoacacia). Seven tree species that had been adapted to the reclaimed land for three to four years before being transplanted to new reclaimed land in Gunsan Okgu area showed average survival rate of 98%, suggesting that pre-conditioned trees would survive well in the reclaimed land.

• Korean Journal of Ichthyology
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• v.25 no.2
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• pp.90-105
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• 2013

This study was performed to find out stomach contents of cold water fish such as Manchurian trout (Brachymystax lenok tsinlingensis) and River salmon (Oncorhynchus masou masou) in the Odae mountain area. Field survey was carried out 3 times by each season from May to October 2012 along the Gyebang stream and the Yangyang-Namdae stream at north-west mountain slope and north-east mountain slope of the Odae mountain area respectively. The result of digestive track analysis showed that food species of Manchurian trout were total individuals of 645 including 5 orders, 23 families, 39 species of benthic macroinvertebrates and 11 taxa of terrestial insects. And each IRI (Index of Relative Importance, %) value of food species by Manchurian trout was terrestial insects 37.0%, Trichoptera 36.4%, Ephemeroptera 20.0%, Diptera 3.9%, Plecoptera 2.7%, and Gordea <0.1%. While the River salmon fed on 1,186 individuals covering 4 orders, 20 families, 33 species of benthic macroinvertebrates and 6 taxa of terrestial insects including arachnid. Also IRI values by River salmon were terrestial insects including arachnid 2.7%, Ephemeroptera 52.9%, Trichoptera 27.9%, Diptera 9.4%, and Plecoptera 7.0% respectively. With these results, we might say that both Manchurian trout and River salmon is carnivorous fish which display the feeding preference to terrestial insects and benthic macroinvertebrates. As a results we could find out that the two kinds of cold water fish preferred similar habitat types and liked same order of food species in same season, however the compositions of food species for Manchurian trout and River salmon were considerably different.

• Journal of agricultural medicine and community health
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• v.36 no.1
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• pp.1-12
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• 2011

Objectives: The purpose of this study was to find out the suicide ideation of high school students in urban and rural areas, and especially to research the relationship between suicide ideation, and general characteristics, characteristics of school life, and empirical characteristics of suicide. Methods: This research targeted four urban and four rural high schools in two cities. The study subjects were 1,114 students in urban area and 968 students in rural area, total 2,082 students. The survey was conducted from July 1, 2009 to July 31, 2009. For statistical analysis, chi-square test, t-test and ANOVA were used for investigating related factors with suicide ideation in urban and rural areas, respectively, with multiple logistic regression for multivariate analysis. Results: The results showed that 38.8% of respondents had suicide ideation within 1 year. The percentage of female students (44.8%) was significantly higher than that of male students (33.4%). However, there was no significant difference between urban (38.0%) and rural area (39.9%). The significant influencing factors on suicide ideation in multiple logistic regression were gender [female student OR(odds ratio)=1.80 (95% CI 1.31-2.47) compared with male student] and grade [second year OR=1.40 (95% CI 0.98-2.00), third year OR=2.15 (95% CI 1.49-3.12) compared with first year] in urban area. Those in rural area were gender [female student OR(odds ratio)=2.71 (95% CI 1.23-2.38) compared with male student], economic deterioration [yes OR=1.81 (95% CI 1.24-2.64) compared with no], and grade [second year OR=2.80 (95% CI 1.82-4.32), third year OR=3.84 (95% CI 2.52-5.87) compared with first year]. Conclusions: This study showed about 40% of high school students had suicide ideation within 1 year. A suicide prevention program may be implemented considering factors related with suicide ideation identified in this study.

• Korean journal of applied entomology
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• v.43 no.1
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• pp.61-70
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• 2004

Environmentally sound control of Japanese lawngrass cutworm, Spodoptera depravata with Korean entomopathogenic nematodes (Heterorhabditis sp. Gyeongsan, Steinernema carpocapsae GSNI , S. glaseri Dongrae, S. longicaudum Nonsan, and S. monticolum Jiri) was evaluated in the laboratory and field. In addition, effect of turf height on the pathogenicity of entomopathogenic nematodes and density of ant (Formica japonica) and spine-tailed earwigs (Forficula scudderi) were investigated in the field. The corrected mortality of 3rd instar of S. depravata larvae was 53.3% to 66.7% 5 days later after treatment of entomopathogenic nematodes. $LC_{50}$ value of S. carpocapsae GSN1 and S. monticolum Jiri against 3rd instar of S. depravata was 6.9 and 3.9, respectively. Pathogenicity of S. carpocapsae GSN1 was different depending on larval stages, i.e., mortality of 2nd instar was the highest representing 73.3% but decreased from 3rd instar. Turf height affected pathogenicity of entomopathogenic nematodes. Mortality of 4th instar of S. depravata was 40.0% by S. carpocapsae GSN1 and 33.3% by S. monticolum Jiri, and 83.3% by fenitrothion, respectively, in the turf height of 14mm, but those were lower in 45mm. The corrected mortality of S. depravata larvae was lower at the entomopathgenic nematode plots than fenitrothion plot in the distribution field of Formica japonica. However, reduction rate of F japonica was higher in fenitrothion by 56.7% compared with 0% in S. carpocapsae GSN1 and 6.7% in S. monticolum Jiri. Turf height influenced control of S. depravate in S. carpocapsae GSN1 and fenitrothion. Control value of S. carpocapsae GSN1 was 62.2% in the turf height of 3-4cm, but not effective at all in 6-8cm and 12-14cm. However, there was not significantly different in fenitrothion plots. Forficula Scudderi was also reduced only in fenitrothion plots. Reduction rate was 100% in 3-4cm, 41.7% in 6-8cm, and 16.7% in 12-14cm, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.12
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• pp.1920-1928
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• 2014

The purpose of this study was to evaluate the importance and performance of middle school foodservice hygiene in Busan. In this study, questionnaires were administered to 1,000 students consisting of 100 students in 10 middle schools in Busan in December, 2013. The students assessed importance and performance of personal hygiene as 3.81 and 3.60 on a scale of 5.00, respectively. Males gave higher scores to importance and performance of personal hygienic than females. First grade students gave significantly higher scores than 2nd and 3rd grade students to importance and performance of personal hygienic. The mean scores of importance of foodservice hygiene were 4.47 for food hygiene, 4.25 for equipment hygiene, 4.23 for employee hygiene, and 4.19 for environment hygiene. For importance of foodservice hygiene, females gave significantly (P<0.001) higher scores than males. However, male gave significantly higher scores than females for performance of foodservice hygiene. The importance and performance grid showed important factors for personal and foodservice hygiene. 'Hand washing before eating the meal' for personal hygiene and 'cleanliness of tray' for foodservice hygiene showed the highest importance and lowest performance scores. Foodservice hygiene can be improved through customized education of students regarding meal service and food hygiene, equipment hygiene, and environment hygiene.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.4
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• pp.501-512
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• 2017

This study analyzed changes in nutrient contents of children's favorite foods between March 2010 and July 2012 after policy implementation on energy-dense and nutrient-poor (EDNP) foods based on Special Act on Safety Control of Children's Dietary Life in Korea. A total of 6,684 products in the list of children's favorite foods by the Ministry of Food and Drug Safety in March 2010 and 7,347 products in July 2012 were classified into the following three types: food products (1) manufactured or sold in 2012 as well as 2010 (n=6,174), (2) discontinued in 2012 (n=510), and (3) newly introduced in 2012 (n=1,173). Among children's favorite foods manufactured or sold in 2012 as well as 2010 (n=6,174), calories and key nutrients in sweetened ices, breads, ice creams, deep-fried noodles/noodles, ready-to-eat (RTE) foods, and pizzas were improved in comparison to those in the other food groups. However, most of the changes in calories or key nutrient contents per 100 g (or 100 mL) fell below 1 kcal or 1 g. The newly introduced candies, breads, and carbonated beverages showed slightly greater improvements in calories and key nutrient contents per 100 g (or 100 mL) than the discontinued ones in 2012. On the other hand, some negative changes were found in newly introduced chocolates and RTE foods in comparison to the discontinued ones. Overall, policy implementation on EDNP foods seemed to induce changes in nutrient contents of children's favorite foods, yet the extent of the changes was limited.

• The Korean Journal of Air & Space Law and Policy
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• v.23 no.2
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• pp.115-136
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• 2008

The development of the aviation technology is beyond the people's imagination. For example, with some exaggeration, If the autopilot engage upon take off, You will realize that you are on the centerline of the foggy JFK runway 13R after 15 hours with only once or twice of intervention. But the more aviation technology develops, the more responsible the pilot will be who has the final authority of the aviation safety. In the JAL 706 accident caused by unidentified reason, the pilot increased pitch abruptly and overrode the control from the autopilot. The result of this process made the death of a flight attendant and some injuries of a few passengers. The district court found the pilot not guilty at the first trial on the ground that the control override was not connected to the possibility of foresight and avoidance of the human death. The pilot was proved to be innocent through the analysis of the DFDR and ADAS that the override did not precede the unidentified pitch up motion. The judicial precedent related to aviation accidents in Korea requires pilots' absolute and extended care compared to the ordinarily prudent or reasonably careful behaviors in the vehicle and medical accidents. Although there is some controversy about the standard care, the care required in the actual operation of high tech aircraft by a pilot should include objective and standard care and be judged by analysis of the scientific data. Although the pilot maintained the unusual hi speed that doesn't have safety margin and descended under turbulence in case of the JAL 706 accident, the court negatived its relation to the cause of pitch up. Also, the override of the control after initial pitch up might have caused the possibility of the death and injury, but the court denied it. Because of this complex cause of the aviation accidents, it is important for a court to figure out the core reason of the event and casual relationship with the pilot Now, It is required that the judgement of negligence in the aviation accidents should include an objective care with scientific data from simulated circumstances(or a simulator) as the Japanese court not from the theory of vehicle's negligence.

• Sleep Medicine and Psychophysiology
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• v.8 no.1
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• pp.30-36
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• 2001

Object: Diurnal variation is included in the diagnostic criteria of the major depressive disorder, melancholic specifier. But there has been controversy over whether diurnal variation is an unique depressive symptoms or a symptom related to a change of sleep patterns, or that of another mechanism, when the previous studies are reviewed. We investigated the existence of diurnal variation according to the subtype of depression and whether diurnal variation is charateristic of melancholic depression or not. We also compared sleep variables according to the existence of diurnal variation. Method: We examined diurnal variation, sleep patterns, severity of depression using the Visual Analogue Mood Scale, Pittsburgh Sleep Quality Index, and Hamilton Depression Rating Scale. Patients recorded their mood state on the Visual Analogue Mood Scale twice a day, morning and evening, for diurnal variation. We divided depressive patients into two groups,-diurnal variation group and nondiurnal variation group,-and compared the mood and sleep variables using SPSS. Results: The frequency of diurnal variation is not significantly different among the subtypes of depression. Significant differences between the diurnal variation group and the nondiurnal variation group existed in middle insomnia and sleep time (p<0.05). In melancholic type, al significant difference between the diurnal variation group and the nondiurnal variation group was noticed in PSQI total, sleep latency, sleep disturbances, daytime dysfunction as well as middle insomnia and sleep time (p<0.05). Conclusions: Diurnal variation existed in other types of depression as well as melancholic type. The results showed that diurnal variation was not a specific symptom of melancholic type, and existence of diurnal variation might be related to sleep patterns.