• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.53 no.4
• /
• pp.530-537
• /
• 2020

This study compared the survival rates, growth, and fatty acid content of larval Pacific cod Gadus macrocephalus fed with rotifers raised on different enrichment diets. We used four commercial rotifer enrichment products (one domestic, ER1, and three imported, ER2, ER3 and ER4). Twelve 200-L tanks were used, with three replicates per treatment. Larvae were fed rotifers 3 times daily at a rate of 5 rotifers/ml/feeding from 7 to 21 days post-hatch. At the end of the feeding trial, the survival rate and total length of larvae fed ER3 were greater than those of larvae fed ER1, ER2, or ER4. ER3 had the highest proportions of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and polyunsaturated acid (PUFA). Partially reflecting this composition, larvae fed ER3 had the highest proportions of DHA and PUFA. These results show a positive effect of rotifer DHA and PUFA proportions on the survival and growth rates of Pacific cod larvae.

• The Journal of the Korea Contents Association
• /
• v.16 no.4
• /
• pp.301-312
• /
• 2016

The purpose of this study is the findings of the effects of the experiential consumption characteristics in the hotel business on customers' revisiting and switching Intention. Also, this study is to examine revisiting and switching intention in accordance with visit frequency. For this study, the author analyzed empirically 534 copies of questionnaires. The first finding of this study discovered that playfulness, symbolism, usefulness and aesthetics had positive effects on revisiting intention. Second, symbolism, usefulness and aesthetics had negative effects on switching intention. Especially, symbolism had more significant effect on revisiting and switching intention than other variables. And finally, visit frequency had moderating effects between the experiential consumption characteristics and revisiting intention, switching intention. The hotel companies are possible to obtain several strategic implications on the basis of this empirical results.

• Communications of Mathematical Education
• /
• v.30 no.4
• /
• pp.435-452
• /
• 2016

This study was designed to explore students' instrumentalization in relation to the van Hiele's teaching method within a technology environment using GeoGebra. To carry out the study, a total of 4 lesson units was developed based on van Hiele teaching method for two slow learners in Gyeonggi province, Korea. The results of study were as follows. Instrumentalization of students was actualized from preparation, to adaptation, and to application stages. In preparation, and adaptation stages, depending on visualization, students used a trial-and-error method a lot, however in application stage the role of GeoGebra was just to check the solution of what they conjectured. Therefore, a teacher should prepare geometric tasks according to the processes of instrumentalization based on geometric teaching method. During instrumentalization and instrumentation of users, usage scheme(US) and instrumented action scheme(IAS) should be concrete.

• Journal of the Korean Society of Food Culture
• /
• v.29 no.6
• /
• pp.659-667
• /
• 2014

Fruits are good sources of vitamins, minerals, fiber, and phytochemicals, which are known to reduce serum lipids, oxidative damage, and blood pressure as well as improve blood glucose control. The purpose of this study was to estimate nutrient quality indices of fruits by carrying out a critical analysis of pre-existing methods according to their nutritional compositions. Four methods were used to assess the nutrient indices of 26 fruits, which are frequently consumed by Koreans based on the fourth Korean National Health and Nutrition Examination Survey (2009). Naturally nutrient rich score (NNR), nutrient rich food (NRF), nutrient adequacy score (NAS), and nutrient density score (NDS) were used to calculate nutrient quality indices. The Korean Nutrition Society Food Composition database of fruits based on 100 g edible portions was used. The algorithm of each method included the mean percentage of daily values (Dietary Reference Intakes for Koreans, 2010) for particular nutrients based on consumption of 1,900 kcal/day. The relative score indicated that strawberries, kumquat, and lemon had high nutrient quality indices. In addition, mango, lemon, persimmon, strawberry, apricot, and tangerine fruits are rich in antioxidant nutrients such as ${\beta}$-carotene, vitamin C, vitamin E, and selenium. However, scores of nutrient quality indices did not imply that higher scores of particular fruits are superior. We suggest moderate seasonable consumption a variety of fruits. Our results can be used as a reference for consumers when they choose fruits.

• Journal of the Korean Society of Food Culture
• /
• v.32 no.5
• /
• pp.453-464
• /
• 2017

Vegetable soup has been reported to have anti-inflammatory, anti-oxidative and anti-cancer effects. In this study, five kinds of vegetable soup were developed using a new manufacturing process and compositional changes in raw material, and anti-cancer and immuno-stimulatory activities were evaluated. Cytotoxicity tests based on MTT assay revealed that all vegetable soups had strong inhibitory effects against CT26 mouse colon cancer cells, with soups including Solomon's seal being most effective based on comparison of $IC_{50}$ values. Apoptosis in response to vegetable soup was occurred by 3-5 fold on cancer cells compared to normal cells. Mouse splenocytes increased by 266-541% in response to addition of vegetable soup in an in vitro proliferation experiment. In co-culture with splenocytes and CT26 cancer cells, splenocytes increased by more than 280% in every vegetable soup treatment, while cancer cells decreased by about 60% and cytokines such as $IFN- {\gamma}$ and IL-12 were secreted from splenocytes in high levels only in response to vegetable soup including Solomon's seal. In conclusion, all vegetable soups developed in this study had anti-cancer effects, and vegetable soup including Solomon's seal showed the strongest anti-cancer and immuno-stimulatory effects. These results suggest that functionality of vegetable soup could be increased by changes in manufacturing processes and raw materials composition.

• Journal of the Korean Society of Food Culture
• /
• v.28 no.5
• /
• pp.438-449
• /
• 2013

During the Joseon Dynasty, medicinal foods derived from herbs were often more effective than traditional medicines. In addition, the royal family of the Joseon Dynasty believed that foods could be used as various disease treatments. Grain-based foods, especially medicinal porridges (藥粥), were most frequently used for diet therapy. We investigated various types of diet-related diseases suffered by King Injo (仁祖) as well as how the diseases were treated using medicinal porridges based on information in the SeungjeongwonIlgi (承政院日記), which is the daily record of the Royal Secretariat of the Joseon Dynasty. This study examined the SeungjeongwonIlgi of King Injo from his1st year (1623) to 27th year (1649) on a website database maintained by the National Institute of Korean History. According to the records, King Injo suffered from severe diarrhea several times due mainly to febrile disease (煩熱症) as well as abdominal dropsy (脹滿) throughout his entire life. Major diseases affecting King Injo were due to his unhealthy eating habits and psychological factors. For treatment, royal doctors prescribed around 15 medicinal porridges, including nelumbo (seed) porridge (Yeonja-juk), milk porridge (Tarak-juk), Chinese dioscorea porridge (Sanyak-juk), mungbean porridge (Nokdu-juk), perilla seed porridge (Imja-juk), adzuki-bean porridge (Pat-juk), soybean porridge (Kong-juk), Korean-leek porridge (Buchu-juk), and so on, in addition to other medical treatments. Diet therapy using medicinal porridges has been used throughout history since the Joseon Dynasty period. However, knowledge of traditional diet therapy and medicinal porridges used by monarchs in the Joseon Dynasty is insufficient. Therefore, in-depth study is needed to understand the theory of traditional medicinal foods as well as explore their application to patients in the context of modern medicine.

• Journal of the Korean Society of Food Culture
• /
• v.30 no.4
• /
• pp.395-405
• /
• 2015

Insamsokmieum (人蔘粟米飮), which is a kind of water gruels made with millet, ginseng, glutinous rice, and some minor ingredients, was frequently used as a medicinal food for the royal family, and it appeared first at the 10th year of King Sukjong's reign. We investigated Insamsokmieum through a literature review and the "SeungjeongwonIlgi(承政院日記)" of King Sukjong (肅宗) from his 1st year (1674) to 46th year (1720). We analyzed the nutritional value and efficacy of Insamsokmieum. In Oriental medicine, Insamsokmieum is prescribed mainly to treat symptoms such as nausea, languidness, and exhaustion in King Sukjong and Queen Inhyun (仁顯王后). In nutritional terms, Insamsokmieum has higher nutrition density than that of rice porridges (白粥) and has relatively high vitamin and mineral contents. Some nutrients such as leucine and glutamic acid, which are contained in the millet, are also known to help alleviate these symptoms. Whereas there have been studies on the efficacy and types of diet during the Joseon Dynasty, studies regarding nutrition characteristics are lacking. This study will demonstrate the superiority of dietary treatments of the Joseon Dynasty and their potential for application to modern nutrition.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.6
• /
• pp.853-859
• /
• 2014

The goal of this study was to evaluate the effects of cryoprotectants [dimethyl sulfoxide (DMSO), methanol, polyethylene glycol, and propylene glycol], cryoprotectant concentrations (10% and 20%), equilibration time (3, 10, and 30 min), cooling rate ($3^{\circ}$, $5^{\circ}$, $7^{\circ}$, and $10^{\circ}/min$), and straw size (0.25 and 0.5 mL) for sperm cryopreservation of tetraploid Pacific oysters. There was a significant difference among the four cryoprotectants, with 10% DMSO yielding the highest post-thaw survival and activity index of sperm. A significant relationship was observed between the cryoprotectant and its concentration. The sperm with equilibration times of 30 min yielded higher post-thaw survival and activity indices than those with 3 and 10 min equilibration times. The sperm cooled at a rate of $5^{\circ}/min$ yielded the highest post-thaw survival and activity index, and the results were significantly different from those observed for cooling at $7^{\circ}$ and $10^{\circ}/min$. Post-thaw survival and activity indices of sperm using a 0.25-mL straw were significantly higher than those using a 0.5-mL straw.

• YAKHAK HOEJI
• /
• v.55 no.2
• /
• pp.81-90
• /
• 2011

Most antineoplastic agents are nonselective in their mechanism of action, affecting noncancerous as well as cancerous cells, and resulting in acute effects such as irritation of mucous membranes and chronic effects such as genotoxicity, teratogenicity, and carcinogenicity. Healthcare workers occupationally exposed to antineoplastic agents are at risk. The present study aimed to develop and apply methods to monitor occupational exposure to antineoplastic agents, using cyclophosphamide (CP) as the model compound. To monitor environmental and biological exposure, potentially contaminated surfaces were wiped and 24 hour urine samples were collected from workers. Liquid chromatography combined with tandem mass spectrometry was performed, with a limit of detection of 0.05 ng/ml. Measurable amounts of CP were detected on 92% of the sampled surfaces, with a geometric mean of 175.22 $ng/m^2$. Despite the environmental contamination of the model compound, CP was below the detection limit in all urine samples. If workplace contamination cannot be completely avoided, it is importance to reduce exposure to the lowest possible levels. To this aim, efforts to minimize occupational exposure along with biological and environmental monitoring are required. The standardized sampling techniques, and specific and sensitive analytical methods reported in this study may be helpful in assessing occupational exposure and devising strategies to reduce exposure.

• Journal of The Korean Association of Information Education
• /
• v.22 no.1
• /
• pp.141-149
• /
• 2018

In order to analyze the educational effects of digital textbooks for elementary students, the 3~4 graded elementary students were selected and designated as panels in 2014 to conduct the longitudinal study. We conducted a questionnaire survey on students who were in grade 5 or 6 in elementary school in 2016 to evaluate their effects on cognitive domain, social domain, social domain, psychomotor domain, and learning competency. As a result, 5th grade students using the digital textbooks for 3 years showed higher educational effectiveness than 6th grade students using the digital textbooks for 2 years. In addition, the use of the digital textbooks for three years has been shown to have improved educational effectiveness in all areas except students' psychomotor domain. These educational effects were higher for students with higher scores, more times using digital textbooks, and higher teachers' smart education capacity.