• Journal of Aquaculture
• /
• v.4 no.1
• /
• pp.31-66
• /
• 1991

This paper deals with the reproductive ecology e.g., number of the pre-spawning moults, morphological characteristics of the pre-spawning moult the common moult, daily ration druing a molting cycle mating behavior, structures of spermatozoa and spermatophore, structure of vas deferens, mechanisms of the oviposition and brooding into the egg-chambers, a suitable time for the artificial mating and fertilization, time sequence of the oviposition and brooding into egg-chambers from the copulation, responses to temperature and chlorinity on the egg development and hatching, effect of temperatures on duration of egg development, physical mechanism of the egg hatching, to make an attempt for the artificial spawning and brooding to establish a suitable system of the artificial seedling-production for the aquaculture. 1. Females molted commonly $8{\~}10$ times at an interval of $17{\~}18$ days at $28^{\circ}C,\;3.26\~4.35\%_{\circ}$ while the prespawning moltings were $4{\~}5$ times at an interval of $13{\~}14$ days. The suitable state for artificial copulation was within 14 hours elapsed from the prespawning moltings (most suitable state was within 8 hours). Males discharged a gelatinous spermatophore and placed it on the females sternum during copulation. Oviposition was seen $6{\~}17$ hours after copulation. External fertilization was considered to take place at oviposition. Fertilized eggs held in egg-chambers forming between pleopods were about $5000{\~}6000$ in females those sizes about 6.5 cm in body length. 2. Eggs immediately after oviposition were elliptic shape, measuring $0.58{\times}0.48$ mm up to hatching. Their sizes increased with egg development and finally reached $0.85{\times}0.54$ mm up to hatching. The relationship between the long axis of the egg(Y in U) and days elapsed(X) was expressed as Y= 5.60194 + 0.007358X. The eggs performed superficial cleavage and their cleavage furrows became visible at the 4-daughter-nucleus stage. The eggs showed normal development up to hatching at water temperature range of $22{\~}30^{\circ}C$ (optimum temperature : $26{\~}28^{\circ}C$) and at chlorinity range of $0.00\~6.64\%_{\circ}$ (optimun chlorinity : $2.21{\%}_{\circ}$). The relationship between incubation period (Y in days) and water temperature(X in $^{\circ}C$) could be expressed as Y= 50.803-1.3555X. The eggs hatched $12{\~}13$ days after oviposition at $28.0{\~}28.6^{\circ}C$ 3. The pre-spawning moltings were appreciably different in the morphologic structure from those of common moltings. Breeding setae and dresses were formed on the thoracic regions, abdominal epimerae and the bases of the first to fourth pleopods in order to prepare and support oviposition, transfering and supporting eggs in egg-chambers up to hatching. These supplementary breeding organs were observed only at reproductive seasons.

• Journal of Nutrition and Health
• /
• v.48 no.6
• /
• pp.507-518
• /
• 2015

Purpose: The aim of this study was to examine the association of food security with the total and individual flavonoid intakes among Korean adults. Methods: Study subjects were 13,454 men and 19,563 women aged 19 years and older who participated in the 2007~2012 Korea National Health and Nutrition Examination Survey. Subjects were classified into food-secure and food-insecure groups using the answers to a self-reported question on food sufficiency of subjects' household. The total and individual flavonoid intakes were calculated by linking 24-h dietary recall data of subjects with a flavonoid database. Mean differences in dietary outcomes by food security status, and major food sources of total flavonoids were examined. Results: In this cross-sectional study, 5.8% of male adults and 6.6% of female adults were in food insecure households. Mean daily intakes of total flavonoids, flavonols, flavones, flavanones, flavan-3-ols, isoflavones, and proanthocyanidins were significantly lower in food-insecure groups than food-secure groups among both male and female adults. The differences were maintained in total flavonoids, flavones, flavanones, and flavan-3-ols after adjusting for total energy intake. Mean intakes of fruits and vegetables were significantly lower in food-insecure groups and the total flavonoid intake from fruits and vegetables was also significantly lower in food-insecure groups. The major food sources of total flavonoids were apples (20.7%), mandarines (12.0%), and tofu (11.5%) in the food-secure group, and apples (14.9%), tofu (13.3%), and mandarines (12.6%) in the food-insecure group. Conclusion: This study showed that food insecurity was associated with lower intakes of flavonoids and reduced intakes of fruits and vegetables in a representative Korean population.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.36 no.6
• /
• pp.91-101
• /
• 2009

In this study, the landscape of Insa-dong was interpreted from the viewpoint of a social construction of landscape, which regards the dynamic process of landscape change as more important than landscape visibility. This viewpoint also regards landscape as the result of its interaction with certain actors. From a review of previous studies on the same subject, it was found that the physical environment, institutions, and images are essential factors influencing landscape change. Insa-dong, which was Kwanindaing and Daesadong during the Joseon Dynasty, acquired symbolic meaning as a traditional area during the Japanese colonial period because of its many antique shops and Korean-style buildings. In 1970, the establishment of modern galleries in the district added to its image as a haven of the traditional Korean culture. Insa-dong thus eventually came to be referred to as "the street of traditional culture" by the people of Korea. Thanks to global festivals like the Asian Games, the Olympics, and the World Cup, Insa-dong's reputation as a cultural tourist destination has become stronger as these festivals created a need for a place in Korea where the country's traditional culture can be showcased to foreign tourists. After the mid-1990s, the merchants of Insa-dong began to cash in on the district's image as a showcase of traditional Korean culture due to the economic depression that emerged then. The people of Insa-dong and those outside it, however, came to feel that this trend damaged the district's image. Therefore, the people of Insa-dong and the district's local government started a movement to restore the aesthetic value and symbolic meaning of the district's landscape. This effort induced institutional change. Insa-dong used to be a natural haven of traditional Korean culture. Its landscape has recently been reconstructed so that this image could be restored. This process was made possible by the active interaction of diverse people: merchants, users, administrators, and NGOs.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.34 no.s02
• /
• pp.13-33
• /
• 1989

Agroclimate should be analyzed and evaluated accurately to make better use of available chimatic resources for the establishment of optimum cropping systems. Introducing of appropriate cultivars and their cultivation techniques into classified agroclimatic zone could contribute to the stability and costs of crop production. To classify the agroclimatic zones, such climatic factors as temperature, precipitation, sunshine, humidity and wind were considered as major influencing factors on the crop growth and yield. For the classification of rice agroclimatic zones, precipitation and drought index during transplanting time, the first occurrence of effective growth temperature (above 15$^{\circ}C$) and its duration, the probability of low temperature occurrence, variation in temperature and sunshine hours, and climatic productivity index were used in the analysis. The agroclimatic zones for rice crop were classified into 19 zones as follows; (1) Taebaek Alpine Zone, (2) Taebaek Semi-Alpine Zone, (3) Sobaek Mountainous Zone, (4) Noryeong Sobaek Mountainous Zone, (5) Yeongnam Inland Mountainous Zone, (6) Northern Central Inland Zone, (7) Central Inland Zone, (8) Western Soebaek Inland Zone, (9) Noryeong Eastern and Western Inland Zone, (10) Honam Inland Zone, (ll) Yeongnam Basin Zone, (12) Yeongnam Inland Zone, (13) Western Central Plain Zone, (14) Southern Charyeong Plain Zone, (15) South Western Coastal Zone, (16) Southern Coastal Zone, (17) Northern Eastern Coastal Zone, (18) Central Eastern Coastal Zone, and (19) South Eastern Coastal Zone. The classification of agroclimatic zones for cropping systems was based on the rice agroclimatic zones considering zonal climatic factors for both summer and winter crops and traditional cropping systems. The agroclimatic zones were identified for cropping systems as follows: (I) Alpine Zone, (II) Mountainous Zone, (III) Central Northern Inland Zone, (IV) Central Northern West Coastal Zone, (V) Cental Southern West Coastal Zone, (VI) Gyeongbuk Inland Zone, (VII) Southern Inland Zone, (VIII) Southern Coastal Zone, and (IX) Eastern Coastal Zone. The agroclimatic zonal characteristics of climatic disasters under rice cultivation were identified: as frequent drought zones of (11) Yeongnam Basin Zone, (17) North Eastern Coastal Zone with the frequency of low temperature occurrence below 13$^{\circ}C$ at root setting stage above 9.1％, and (2) Taebaek Semi-Alpine Zone with cold injury during reproductive stages, as the thphoon and intensive precipitation zones of (10) Hanam Inland Zone, (15) Southern West Coastal Zone, (16) Southern Coastal Zone with more than 4 times of damage in a year and with typhoon path and heavy precipitation intensity concerned. Especially the three east coastal zones, (17), (18), and (19), were subjected to wind and flood damages 2 to 3 times a year as well as subjected to drought and cold temperature injury.

• Journal of Animal Science and Technology
• /
• v.45 no.3
• /
• pp.387-396
• /
• 2003

This experiment was carried out to compare the effects of feeding commercial formula feed and rice straw separately (control) versus a total mixed ration (TMR) on productivity of Hanwoo steers in late stage of fattening and on ruminal fermentation characteristics and digestibilities. Ruminal digesta from the cannulated cattle were sampled at 0, 1, 2, 3, 5, 8 hour after feeding. The steers fed TMR consumed 7.4kg per day and there was no difference between feeding systems. Daily weight gain was not significantly (P>0.05) between feeding systems, however, TMR group showed lower daily gain than control group. The amount of feed consumption per kg weight gain was higher in TMR group than control group (10.5kg and 9.7kg, respectively), resulting in a greater efficiency of feed utilization for gain. In the result of appearance rates of quality grade A were 33% higher for TMR group than those in control group. Appearance rates of grade 1 showed 56% and 75% when fed the control and TMR, respectively. Digestibilities of dry matter, crude protein, crude fiber and gross energy for TMR treatment were significantly higher (P<0.01) than those of control. Prior to feeding (0 h) and each subsequent hour, the TMR resulted in higher rumen pH (P<0.05) when compared with control ration. The concentration of NH3-N for TMR treatment maintained at higher level up to 8hr after feeding, especially increased up to 28.2mg/$d\ell$ during 1-2 hour which was two times (P<0.05) more than control. The amount of total VFA showed same trends between feeding systems. However, the ratios of branched chained fatty acid such as iso-butyric acid and iso-valeric acid for TMR treatment were significantly(P<0.01) higher than control for 3-5hr. Results showed that TMR in these trials is effective feeding system for fattening Hanwoo steers in the respect of ruminal characteristics, total tract digestibility and productivities.

• Journal of Animal Science and Technology
• /
• v.53 no.1
• /
• pp.43-50
• /
• 2011

An investigation was done to evaluate the effects of adding green tea probiotics, Alisma canaliculatum probiotics and fermented Kelp meal on the growth performance and immune response in sows and piglets. A total of 32 pregnant sows were assigned to 4 treatments in 8 replications with 1 sow as a replicate in this experiment from 2 months before parturition to 28 days after parturition. Three hundred nineteen (319) piglets were produced from experimental sows after parturition. The dietary treatments were CON group (without antibiotics), GTP (basal+green tea probiotics, 0.5% of the diet), ACP group (basal + Alisma canaliculatum probiotics, 0.5% of the diet) and FKM group (basal+fermented Kelp meal, 0.5% of the diet). Litter size and body weight at birth and weaning size and body weight at weanling in piglets were greater in additives group compared to CON group but no statistical differences were found (P>0.05). Diarrhea score showed a decreasing tendency with three additives groups compared to CON group. The lymphocytes in blood of sows fed ACP and FKM group were significantly higher compared to CON group (P<0.05), and the MID of GTP and FKM group were significantly lower compared to CON group (P<0.05). The serum IgG concentration in sows tended to increase with additives groups compared to CON group and the serum IgA and IgM concentration in GTP and FKM group were significantly higher compared to ACP group (P<0.05). The cortisol levels showed a decreasing tendency in additives groups without statistical differences among the groups (P>0.05). Based on these observations, it can be inferred that the GTP and FKM may have such efficacy as antibiotics in growing pigs.

• Korean Journal of Poultry Science
• /
• v.38 no.1
• /
• pp.21-28
• /
• 2011

This study was conducted to investigate the effect of dietary supplement of Alisma canaliculatum and Viscum album on the growth performance and immune response of broiler chickens. One hundred and forty Ross broiler chicks (1 day old) were assigned to 4 treatments in 5 replications with 7 birds per replication. The dietary treatments were NC group (without antibiotics), PC group (basal + 50 ppm Oxytetracycline), AC group (basal + Alisma canaliculatum 0.5%), and VA group (basal + Viscum album 0.5%). The results revealed that body weight gain and feed intake were not significantly different among the treatments. Addition of AC to the diet showed significantly higher feed conversion ratios than the VA addition diet and other treatments (p<0.05). The concentration of linolenic acid, ${\alpha}$-linolenic acid and arachidonic acid in the AC and VA treatment were relatively higher than that in the antibiotic treatment, while there was no difference in the concentration of SFA, USFA, and USFA/SFA. The serum IgG concentration in chickens tended to increase in the AC and VA treatment groups compared to NC group. The IL2 concentration in AC and VA groups was significantly higher than in other group (p<0.05). IL6 was not detected, however. GOT, GPT, and T-billirubin in the VA group were significantly higher than in other groups (p<0.05). Thus, the VA additives can result in the damage of liver and kidney. In conclusion, the dietary supplement of a 0.5% of AC and VA showed a similar growth performance and increased immunity response comparable to supplementing a 50 ppm Oxytetracycline. Therefore, it can be said that the AC and VA are possible alternates of antibiotics.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.35 no.1
• /
• pp.50-56
• /
• 2015

Italian ryegrass is generally cultivated by a winter forage in a paddy field, the harvest season overlaps with rice transplantion in some cases. In addition, farmers can miss the optimal seedtime for Italian ryegrass because of the rainy season. Therefore, this research was conducted between October 2012 and June 2013 in Kwangjin, Korea to examine the effect of spring-seeding on the yields and quality of Italian ryegrass for the determination of an alternative if the optimal seedtime is missed. This trial consists of four different seeding dates (15 February, 25 February, 5 March, and 15 March) and three varieties (Kowinmaster, Kowinearly, and Green farm). The Italian ryegrass varieties "Kowinmaster," "Kowinearly," and "Green farm" were sown on February 15. The heading date of each variety showed from May 12 to May 9 and interval time of five days but the Treatment of March 15 planting date showed three days interval. The Kowinmaster variety, planted on February 15, was 93.0 cm taller on March 15 with a height of 105.7 cm. The Kowinearly and Green farm varieties planted on February 15 were of a similar height on February 25 and received a poor lodging score when planted quickly. The dry matter (DM) yield of the Kowinearly planted on February 15 was high but that of Green farm was low at 6,609 kg/ha and a difference was not shown between the varieties. The DM yield was different for those varieties planted on February 15 and March 15 (P<0.05). The crude protein content (CPC) of those varieties planted on February 15 showed an average of 8.8%, while those that were planted on March 15 showed an average that was about 2.3% higher at 11.1%; furthermore, the latter also showed lower acid detergent fiber (ADF) and total digestible nutrient (TDN) contents, by 2.1% and 1.5%, respectively. The relative feed value was about 5.9% higher, depending on the seeding date, as well as being slower and showing less difference between the varieties. According to this study, Italian ryegrass planted in a paddy field of the southern region of Korea on February 25 will produce a high-quantity yield with nutritive value.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.39 no.4
• /
• pp.207-215
• /
• 2019

This study was conducted to establish spring sowing techniques in preparation for the impacts of climate change on sowing time and wintering rates of winter forage crops such as barley, oat and IRG. Oat showed the highest yield in 2017 which had relatively dry climate condition. And when sowing in late Febrnary 2017 yielding 9,408kg/ha were obtained, yielding 4,011kg/ha more than IRG's sown in the same period. In 2018 which had relatively wet climate condition, four barley species decreased in the production from the previous year. Oat also had decreased by 70% from 9,408kg/ha to 2,851kg/ha. On the other hand, IRG maintained the production in the mid-5,000kg/ha range. It was also found that IRG had the least variability due to external influences regardless of seeding period for 2 years. Mixed sowing with IRG and oat in 50:50 ratio was the highest dry matter, 6,584kg/ha, and IRG was 18.5% and Oat was 2.3 times higher than single planting.

• Korean Journal of Ecology and Environment
• /
• v.33 no.2 s.90
• /
• pp.109-118
• /
• 2000

The dynamics of inorganic nutrients and phytoplankton population were examined at eight stations of Shihwa Reservoir, which situated near the cities newly constructed and the industrial complex of West-sea in Korea, from January to December 1999. Among environmental factors, average concentration of $NH_4$, SRP and SRSi were $522.7\;{\mu}g\;N/l$, $9.8\;{\mu}g\;N/l$ and $0.26\;{\mu}g\;Si/l$, respectively. Water quality was extremely deteriorated by a great amount of pollutants load into inner reservoir after the event of rainfall. Nutrients concentration was suddenly decreased toward the lower part. While $NO_3$ concentration did not much varied among stations, but it was relatively high in winter season. Chlorophyll-a concentration was high at the upper part of the reservoir, with average of $37.2\;{\mu}/l$, and closely related to the fluctuation of $NH_4$, SRP and SRSi concentrations. The phytoplankton development in the water column was dominated by diatom (autumn), prasinoid (winter) and dinoflagellate (summer). Dominant phytoplankton were composed to Skeletonema costatum of diatom, Prorocentrum minimum of dinoflagellate, Chroomonas spp. of cryptomonad, Eutreptiella gymnastica of euglenoid and Pyramimonas spp. of prasinoid. The large bloom of phytoplankton at the upper zone of the Shihwa Reservoir after inflow of a seawater were consistently observed. In consequence, water quality management of the inlet stream was assessed to be very important and urgent.