• The Korean Journal of Malacology
• /
• v.26 no.4
• /
• pp.303-310
• /
• 2010

Rearing condition and species of microalgae on growth and survival of the sunray surf clam, Mactra chinensis larvae were investigated for artificial seedling production. The larvae of M. chinensis on higher temperature showed high growth and low survival and was grown over $230{\mu}m$ in shell length 14 days after hatching, but low growth as $151.1{\mu}m$ at $18^{\circ}C$. The larvae of M. chinensis on salinity showed highest daily growth and survival as $11.3{\mu}m$ and 65.8% at 30 psu, respectively. The optimum of water temperature and salinity for the larval rearing were $23^{\circ}C$ and 30-35 psu over 25 psu at least. The density of larval rearing was below 10 per 1 ml in rearing seawater for elevating the development rate from D-shaped to settled (metamorphosing) stage. The larvae fed the mixed diet of Isochrysis galbana, Pavlova lutheri, Isochrysis sp. (green), Chlorella ellipsoidea showed highest growth and survival. The larvae fed the single diet of I. galbana, Isochrysis sp. (green) showed high growth and survival. But the larvae fed the single diet of P. lutheri and C. ellipsoidea showed low growth and survival. The optimum diet of larvae of M. chinensis was over two species of microalgae included I. galbana, Isochrysis sp. (green) for elevating the high growth and survival.

• Journal of Sericultural and Entomological Science
• /
• v.53 no.1
• /
• pp.1-5
• /
• 2015

As increasing utilization of Tenebrio molitor for industry, establishing effective conditions of indoor mass-rearing system become more important. For this reason, the aim of this study was to identify the physiological characteristics of Tenebrio molitor in different range of temperatures, photoperiods and rearing densities for mass breeding. As a result, their egg had above 70% hatching rate at $17.5{\sim}27.5^{\circ}C$ and the egg period was shown 5~7 days in $25{\sim}35^{\circ}C$. Consequently, in the consideration of the hatching rates and egg periods, the optimal indoor temperature for rearing was $25{\sim}27.5^{\circ}C$. Furthermore, development period of larvae in mass breeding system was shorter than individual breeding system under all the conditions of temperature. Also, the pupal weight was higher in mass breeding system except for $20^{\circ}C$ and $25^{\circ}C$. Considering elasticity of demand and weight of production, the effective condition was mass-breeding system at $25^{\circ}C$. In photoperiodic condition, the shortest of larval period was 157.35 day in 14L : 10D.

• Journal of Sericultural and Entomological Science
• /
• v.42 no.1
• /
• pp.24-27
• /
• 2000

A new silkworm variety 'Yangwonjam'for both of spring and autumn rearing season is F$_1$hybrid between Jam 143, a Japanese race bred from H5R1/P8503 and Jam 144, a Chinese race from M8312/8190. This is the first both parent sex-limited larval marking variety in Korea, and which contributes to eggs production of F$_1$hybrid silkworm with saving labor. Jam 143, Japanese parent of the 'Yangwonjam'showed high GCA in pupation percentage and Jam 144, Chinese parent showed high GCA in pupation percentage and single cocoon weight. In the local adaptability test performed at 8 local areas in spring of 1998, Yangwonjam records 1% higher in pupation percentage and 5%, 4% lower in single cocoon weight, cocoon yield from 10,000 3rd molted larvae respectively than the check variety Kumokjam. Also in the resistance test against unfavorable rearing condition performed in spring of 1997, Yangwonjam records 9%, 14% lower in single cocoon weight, cocoon shell weight respectively than the check variety, but showed 1% higher in pupation percentage than check variety.

• Fisheries and Aquatic Sciences
• /
• v.14 no.2
• /
• pp.123-129
• /
• 2011

To determine whether rearing density affects the hypermelanosis on the blind side (ambicoloration) of olive flounders Paralichthys olivaceus, we reared fry with an unpigmented non-eyed (blind) side in duplicate at densities of 150 individuals/$m^2$ (commercial production density: control) and 450 individuals/$m^2$ (high density group) for 90 days in 1-t dark-green fiberglass reinforced plastics (FRP) tank. We recorded feed intake, feed conversion efficiency (FE), growth and survival, and measured the ratios of staining blind-side area (staining area) and ambicolored fish every 30 days. Daily feed intake (DFI), feed conversion efficiency (FE), growth rate, condition factors, and survival rate were calculated at the end of the experiment. Although the FE was higher in the high-density compared to the control, the two density groups showed similar feed intakes, growth, and survival. The ratio of staining area as well as the ratio of ambicolored fish significantly were significantly higher in the high-density group than in the control from days 30 to 60, but significantly increased and evened out by the end of the experiment (P<0.05). In conclusion, we determined that rearing density is not the main cause of the blind-side hypermelanosis, but found that increasing the rearing density can accelerate the ambicoloration in olive flounders.

• Child Health Nursing Research
• /
• v.13 no.4
• /
• pp.454-466
• /
• 2007

Purpose: To explore the experiences of parenting from the mothers of children with severe CHD and to develop a grounded theory about their experiences. Method: Grounded theory method guided the data collection and analysis. A purposeful sample of 16 mothers of children with severe CHD participated during the period 2003. The data were collected by semi-structured individual interviews. Results: "Raise with dignity" emerged as the core phenomenon. 'Powerlessness' came up as the central concept. The causal conditions working on powerlessness was 'living with a bomb in the heart': uncertainty and the context were 'confronting people's eyes', 'developing child's adaptability'. An intervening condition was 'forming a support system' and consequences for coping with powerlessness were 'overcome' or 'ambivalence' using the strategies for mother's positive personality, care role perception, accepting, acknowledgement, and managing the body and mind. Conclusions: In the results of this study, the mothers of children with severe CHD are continue to struggle with life during children's growth and repeated attacks of disease. They need to be provided with skills to cope with physical and mental problems in rearing the children with expertized information for the entire period of growth.

• Journal of Digital Convergence
• /
• v.11 no.10
• /
• pp.469-481
• /
• 2013

The purpose of this study was to describe working stress, child-rearing stress and parenting attitude of nurses who have preschool children. Methods: Data were collected by questionnaires from 136 nurses in three university hospital in 2011, and analyzed by the SPSS 12.0 program. Results: Nurses scored 3.48 points on average in working stress, 2.47 points in child-rearing stress, 3.61 points in parenting attitude. According to analysis on working stress depending on general demographic characteristics showed significant differences in workplace, monthly weekend duty frequency and in child-rearing stress depending on husband's age, wife's age, total income, marital period, satisfaction at relationship with husband, working career, number of children, and a person who cares for their children. According to parenting attitude depending on general demographic characteristics showed significant differences in working condition, marital period, position, working conditions, marital period, workplace, monthly weekend duty frequency. Correlations among nurses' working stress, child-rearing stress and parenting attitude, nurses' working stress had significantly correlations with parenting stress. Conclusion: Results of the study provides data on nursing interventions to relieve nurses from their working stress and child-rearing stress and to promote favorable child parenting attitude.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.31 no.2
• /
• pp.75-78
• /
• 2015

The white-spotted chafer, Protaetia brevitarsis (Coleoptera: Scarabaeidae), is an economically important insect in Korea. Traditionally, it has been regarded as a medicine for preventing liver-related diseases and suppressing liver cancer. Recently, this beetle was enlisted as a temporal food ingredient by Korean Ministry of Food and Drug Safety. Therefore, this beetle is focused as a one of the important insects that are commercially reared and sold in Korea. As the economic importance of this beetle is growing, the suitable rearing conditions are needed for more detailed investigation. In this study, we compared three temperature conditions and two food additives, rice chaff and soybean cake, for its effects on the body weight change of third instar larvae of P. brevitarsis. Temperature is a major environmental factor that has tremendous effects on rearing insects. In additions, rice chaff and soybean cake are byproducts of other agricultural activities. Therefore, it is easy to get, and the price is comparatively low. However, they still have meaningful amount of nutrients. With four different kinds of feed and three temperature conditions on the third instar larvae of beetles, the body weight change was tracked for 14 wk. We concluded that 27.5℃ is the optimal temperature to rear the third instar larvae among three temperatures (25, 27.5, and 30℃). Among four different feeds, conventional fermented oak saw dust with rice chaff and soybean cake was the best feed for larval weight gain during 14 wk. However, feed with soybean cake at 30 ℃ was the best condition for rearing P. brevitarsis larvae when temperatures and feeds were compared at the same time.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.16 no.2
• /
• pp.103-110
• /
• 1983

The main purpose of the present study is to evaluate a revolving plate type biofilter system for mass culture of eel(Anguilla japonica) based on the experimental rearing for 120 days (Oct. 1982-Feb. 1983). Water quality changes, growth efficiency of fish and fish disease treatment were critically evaluated. A revolving plate type biofilter system was designed(Fig. 1). The system consisted of a glass tank (150 l), a revolving plate biofilter and a settling tank(150 l). The biofilter consisted of 60 submerged quadriangular plates ($28{\times}37$ cm) and 30 revolving plates (32 cm diameter) for a total of 19.0 $m^2$ of surface area. The revolving plates were made to rotate 10 time per minute, The total water volume of the rearing system were 300 l, and everyday 1/3 of the total water volume were changed with freshly prepared water. In the rearing system a total of 2 kg of eel (1,500 individuals, mean weight:1.3 g) were reared fed on the pellet feed and the dough feed. The growth efficiency were much better for the pellet feed (FC: 1.79) compared to the dough feed (FC: 3.56). During the experimental rearing water quality control was satisfactory. Total ammonia concentrations were 0.38-0.59 ppm and nitrite concentration were 0.83-1.19 ppm. On the other hand alkalinity decreased from 176ppm just after the water change to 17ppm just before the water change. The low alkaline condition was compensated by the regular change of water. Epidemics of parasitic gill-flocks (Pseudodactvlogylus sp.) was observed, and they were easily eliminated by the treatment of DDVP (1.0 ppm). Trichodina sp. and Costia sp. were observed, and they were also controlled by the treatment of potassium permanganate (4.0 ppm).

• The Korean Journal of Pharmacology
• /
• v.10 no.2
• /
• pp.13-23
• /
• 1974

Results of an experiment on the general behavior of rats in order to explore the possible pharmacological actions of Panax Ginseng upon the central nervous system can be summarized as follows: 1) The rats treated with Ginseng-saponin intraperitoneally with the doses of 50 or 100 mg/kg show the decreased sleeping component and increase in lying and grooming component and walking and rearing component of general behavior. 2) There are no difference between control group and saline treated group in pattern of general behavior components. 3) In the Ginseng-saponin treated groups, the amphetamine stimulated walking and rearing component of genenarl behavior are reduced but lying and grooming component are elevated. 4) Ginseng-saponin shows very low acute toxicity in mice. The $LD_{50}$ in mice of 24 hours after intraperitoneal injection was 795 mg/kg. From the above findings, it is to suggest that the Ginseng saponin might stimulate the central nervous system but its mode of action appears to be different from that of amphetamine. And the effects of Ginseng saponin may be varied depending on various experimental situation or condition of animals.

• Journal of Families and Better Life
• /
• v.22 no.1
• /
• pp.153-167
• /
• 2004

The purpose of this study was to investigate the difficulties, conflicts, and communications between female-headed single parents and their children, their child rearing methods and attitude, and the political suggestions for the welfare in those families. The in-depth interviews were conducted for 7 women in Gyonggi-Do and Chungnam-Do on March 3-27, 2003. The interviewees were selected for the mothers whose children were enrolled either elementary schools or middle schools. The contents of interviews were receded to be analyzed by qualitative method. The results were as follows; first, female-headed single parent families were in low economic status with unstable employment condition. Secondly, women in that families were confronted with psychological problems because of their multiple roles and low income. Third, although they had a controlled child rearing method, they used much reinforcement and praise. Thirdly, they were in need of the aids for the basic life such as housings and their children's private institute expenses. Finally, they required the repealing of an existing birthright system.