• Journal of Life Science
• /
• v.18 no.6
• /
• pp.789-795
• /
• 2008

To study the possible use of probiotics in fish farming, we evaluated antagonism of antibacterial strain Bacillus amyloliquefaciens H41 against the fish pathogenic bacterium Vibrio anguillarum NCMB1. The purification of growth inhibition factor produced by B. amyloliquefaciens H41 was achieved by obtaining supernatant of this bacterium. The growth inhibition factor was purified to homogeneity by 70% ammonium sulfate precipitation, DEAE-sephadex A-50 ion exchange chromatography, sephadex G-200 gel filtration column chromatography, and sephadex G-50 gel filtration column chromatography with 40.8 fold of purification and 2.9% yield. The molecular weight of the purified growth inhibition factor was 48 kDa as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The optimum pH and temperature for the growth inhibition factor were pH 7.5 and $30^{\circ}C$, respectively. The activity of growth inhibition factor was enhanced slightly by some metal ions, such as $Mg^{+2}$, $Mn^{+2}$, but was inhibited by the addition of $Co^{+2}$, $Hg^{+2}$, $Zn^{+2}$ and $Ag^{+2}$. NaCl stability of the growth inhibition factor was observed with 50% residual activity at 3% NaCl concentration. Toxicity test showed that the purified B. amyloliquefaciens H41 growth inhibition factor did not affect the live of Japanese flounder (Paralichthys olivaceus) and the effectiveness was 78% of residual lethality compared to commercial antibacterial agents.

• Korean Journal of Poultry Science
• /
• v.31 no.4
• /
• pp.245-253
• /
• 2004

This study was conducted to investigate the effects of dietary yeast culture containing rPST on growth performances and the characteristics of body compositions in broiler chickens. A total of 460 Ross male broiler chicks aged 2-day-old were fed one of five experimental diets; Control(devoid of all), TI (with $0.1\%$ antibiotics; chlorotetracycline), T2 (with $0.1\%$ rPST-yeast culture), T3 (with $0.2\%$ rPST-yeast culture) or T4 (with $0.2\%$ SC yeast culture) for 6 weeks. Feed consumption and body weights were measured weekly. At week 5 of the experiment, 10 chicks were randomly selected and sacrificed. The relative weights of each organ and the chemical composition of edible meat were measured. The enzyme activity, total cholesterol, Ca and P were also determined. Tibial weight, bone strength and chemical composition were investigated. There were no significant differences in feed intake and feed conversion ratios among the treatments throughout the experimental period. Body weight gains tended to be increased by feeding of diets containing rPST-yeast culture. The relative weight of breast muscle in T3 group was significantly higher than that of the control (P<0.05). The moisture contents of breast meat in groups fed diets containing rPST-yeast culture or SC yeast culture were significantly increased as compared with those of the control and n. However, the contents of crude protein and ether extract were not affected by feeding of rPST-yeast culture. There were no significant differences in GOT, total cholesterol, Ca and P. The relative weight and strength and proximal composition of the tibia were also not affected by dietary treatments. These results indicated that dietary rPST-yeast culture may be a valuable alternative for optimizing growth performances, particularly for improving the yield of breast muscle.

• Journal of the Korean association of regional geographers
• /
• v.20 no.2
• /
• pp.163-175
• /
• 2014

This study is to explain social capital characteristics of Filipino immigrant women at the level of neighborhood. This research targeted Filipino immigrant women in the metropolis, small town and rural area in Korea to find out the relevance of individual property and characteristics of the community and social capital of neighboring communities- school community, cathedral community, etc- through measurement of the participants' recognition. This study reveals that differences exist in the relationship between length of residence and social capital in the school community and the catholic church community. There is a significant positive relationship between length of residence and political factors in the catholic church community, thereby having a better relationship with longer period of stay, while length of residence and confidence show a negative trend in the school community, leading to less confidence. The catholic church community holds a dominant position in homogeneity, cohesion, and the amount of social capital. According to the findings, social capital 'relation' is more closely related to homogeneity of the community, 'norms' to cohesion. 'Relation and norms' and 'confidence and politics' factors are recognized similarly in both communities, thus resulting in the recognition that decision making within the community, the share of value, and observance of social norms approximate a friendly relationship among members, and satisfaction level, emotional support, and confidence among members approach politics that members can talk about their personal matters. It is noted in the research process that the symbolism of the cathedral community as a transnational circuit behavior occurs where collective culture and personal desires of Filipino immigrant women were combined with production of social capital. Filipino immigrant women's awareness of community and social capital appearing in the cathedral community show that not only residence, along with the cultural identity of Filipino immigrant women, but also collective social and cultural characteristics, such as 'family reunion' can not be overlooked. In particular, at this time when discussion and debate on the interculturalism over multiculturalism is heating up, communal spirit and social capital based on the ethnic identity are important in that they can be a crucial path to the cross-cultural interaction with our society, therefore, a study on the social capital of the ethnic community needs to be encouraged and extended to more diverse communities, to the space of the multilayered scale.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.31 no.2
• /
• pp.272-277
• /
• 1998

Filtering rates of two farming ascidians Styela clava and S. plicata, and of a farming mussel Mytilus edulis were experimentally investigated with reference to effects of water temperature and size. Absorptiometric determinations of filtering rates were carried out in a closed system with experimental animals being decreased indicate dyes neutral red. Optical density (OD) of 440 nm in path length 22 mm cell used as the indication of food particles absorption was appeared directly in proportion with the concentration of neutral red dyes. The filtering rate F is calculated by Kim's equation $F\;=\;V(1-e^{-z})$, where V is the water volume ($\ell$) in the experimental jar, and Z is the decreasing coefficient of OD as meaning of instantaneous removal speed as In $C_t\;=\;In\;C_{o}-Z{\cdot}t$, in this formula $C_t$ is OD at the time t. Filtering rate of S. clava increased as exponential function with increasing temperature while not over critical limit, and the critical temperature for filtering rate was assumed to be between $28^{\circ}C$ and $29^{\circ}C$. In case of S. plicata, the critical temperature was to be below $13^{\circ}C$, and through the temperature range $15\~25^{\circ}C$ appeared a little difference in level even though with significant. M. edulis was not appear any significant effects by water temperature less than $29^{\circ}C$. The model formula derived from the results is as below, where F is filtering rate (${\ell}/hr/animal$), T is water temperature ($^{\circ}C$), and DW is dry meat weight (g) of experimental animal. $$S.\;Clava;\;F\;=\;e xp\;(0.119\;T-4.540)\;(DW)^{0.6745},\;T<29^{\circ}C$$) $$S.\;plicata;\;F\;=\;e xp\;(A_t)\;(DW)^{0.5675},\;(13^{\circ}C $$[A_t =-8.56+0.6805\;T-0.0153\;T^2]$$ $$M.\;edulis;\;F\;=\;0.3844\;(DW)^{0.4952},\;<29^{\circ}C$$)

• KSBB Journal
• /
• v.21 no.2
• /
• pp.110-117
• /
• 2006

During routine maintenance, animal cell lines are commonly cryopreserved in growth medium containing serum with 10% DMSO. But, in case of bioprocess under the serum-free conditions, including cultivation of cell lines and producing of pharmaceuticals, the cryopreservation should be executed without serum to prevent a cross-contamination. This experiments were performed to investigate the effects of the serum-free cryopreservation on the CHO cells. To improve the survival rates of the cryopreserved CHO cells in serum-free condition, first, the effects of permeable and non-permeable additives for substitute serum on cell viability were investigated. The combination of 10% DMSO and 0.03 M raffinose in MEM-${\alpha}$ without serum indicated 76% of cell viability. However, it did not reach the survival rates(more than 95%) of the conventional cryopreservation. In the second, to evaluate the cryopreservative ability of the serum-free medium(SFM) we compared viability of the CHO cells cryopreserved in the SFMs(Sigma C5467, C4726, and C1707, JBI SF486 and PF486), the cryoprotectant(Genenmed CAN-1000) and the MEM-${\alpha}$ with serum. All solution contained 10% DMSO. As a result of the comparison, cryopreserved cells in the SFMs showed over 95% of viability and appeared predominant viability better than cryoprotectant CAN-1000. Finally, we assessed the stability of the CHO cells in the long-term cryopreservation(LTC) using SFM. Every three months, the cryopreserved CHO cells were thawed to estimate the cell viability and the recovery rates. Then, real-time RT-PCR analyzed the inserted CHO DHFR gene. All results for the LTC appeared the same stability as the serum containing cryopreservation. In the conclusion, it could be seen that the LTC in the SFM can substitute for serum using methods in the bioprocess proceeded by CHO cells for more than 18 months.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2017.04a
• /
• pp.90-90
• /
• 2017

생력화를 위한 구기자의 수확 기계화는 열악한 수확작업환경을 쾌적한 작업환경으로 개선하고 노동력 감소, 생산비 절감을 할 수 있다. 관행 손 수확과 진동 고리형 수확기 방법보다 높은 작업 능률 향상으로 영농규모의 확대 촉진 및 안정적인 영농 구조를 구축하여 재배농가의 생산비를 절감하여 경쟁력을 높일 수 있으며, 기존 인력에 의존하였던 수확작업을 기계화함으로서 전업농 및 대단위 경작이 가능하게 함으로서 국내에서 생산한 양질의 구기자를 국민에게 안정적으로 제공할 수 있다. 따라서, 본 연구는 구기자 수확작업의 생력화를 위하여 개발 보급된 수목형의 재배법 특성을 분석하고 이를 토대로 타격장치를 적용한 보행형 구기자 수확기를 개발하는데 목적이 있다. 수목형 구기자나무의 분지에 착과되어 있는 숙과를 주행하면서 탈과 할 수 있는 탈과 장치를 제작하기 위하여 타격형 탈과 장치를 3D 모델링 작업(Inventor V.11, Autodesk, USA) 후 시작기를 제작, 구기자 수확 시작기는 주행부, 타격장치, 집과부, 분지유인부로 구성하였다. 구기자 수확 시작기의 최대 높이는 형태학적 특성을 토대로 타격봉의 높이를 900 mm 이하로 제한하였으며, 조향장치의 높이는 800 mm로 하였다. 주행부는 구기자 재식 조사결과를 이용하여 고랑 폭 1,500 mm 이하에서 자유롭게 전 후진 이동이 가능하고 경사로 등을 주행 시에도 안전성을 높이기 위해 자동브레이크 기능이 있으며 타격장치의 타격 봉은 알루미늄 재질로 지름 100 mm, 길이 400 mm로 설계 제작하였으며, 구기자 분지 타격 시 분지와 타격 봉이 수직 상태로 타격이 가능하도록 제작, 집과장치는 포장의 두둑, 고랑은 일괄 표준화가 되어 있지않아 청양구기자시험장에서 측정한 재배법을 바탕으로 설계된 수집부 프레임의 적용범위는 폭 450 mm, 길이 720 mm, 높이 1,500 mm를 집과 범위로 하여 설계 제작하였다. 타격 방식을 적용한 구기자 수확기 성능평가 결과 조숙기에 30초 이상의 탈과 시 87.5 % 이상 탈과는 어려울 것으로 판단되었으며, 성숙기에는 타격시간에 관계없이 92 %의 매우 우수한 탈과율이 나타났다. 성숙기의 주행속도 48 m/h 일 때 탈과율과 집과율은 89 %, 92 %로 나타났다.단위작업시간당 최대 수확 능력은 관행작업 2.9 kg/hr, 진동고리형 수확기 5.2 kg/hr, 타격방식을 적용한 구기자 수확기는 최소 7.6 kg/hr, 최대 24.1 kg/hr로 관행작업과 비교하여 주행속도와 시기별 최소 2.6배, 최대 8.3배의 작업 성능 차이가 나타났다. 재배양식에서는 기계화 수목형이 적합한 것으로 나타났고, 타격방식을 적용한 보행형 구기자 수확기를 이용하여 수형별 시간대별 수확성능을 시험한 결과 우수한 결과가 나타났다. 이에 따라 구기자 재배 농가에 기계화수목형 재배법을 보급하고 타격방식을 적용한 구기자 수확기를 이용하면 작업환경 개선과 노동력, 인건비 절감을 통한 영농규모의 확대 촉진 및 안정적인 영농 구조로 구기자 경쟁력 제고를 할 수 있을 것으로 판단되어진다.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.18 no.4
• /
• pp.263-273
• /
• 2015

We estimated the global inflow and stock of plastic marine debris. In South Korea, we estimated that the annual inflow of plastic marine debris (72,956 tons) was about 1.4% of annual plastics consumption (5.2 million tons) in 2012. By applying this 1.4% ratio to global plastics production from 1950 to 2013, we estimated that 4.2 million tons of plastic debris entered the ocean in 2013 and that there is a stock of 86 million tons of plastic marine debris as of the end of 2013, assuming zero outflow. In addition, with a logistic model, if 4% of petroleum is turned into plastics, the final stock of plastic marine debris shall be 199 million tons at the end. As the inflow and the stock are different units of measurement, better indicators to assess the effectiveness of inflow-reducing policies are needed. And, as the pollution from plastic marine debris is almost irreversible, countermeasures to prevent it should be valued more, and stronger preventive measures should be taken under the precautionary principle. As this is a preliminary study based on limited information, further research is needed to clarify the tendency of inflow and stock of plastic marine debris.

• 대한공업교육학회지
• /
• v.45 no.1
• /
• pp.42-62
• /
• 2020

The Ministry of Education has been quick to apply National Competency Standars (NCS) to industrial sites and educational·training institutions in order to resolve discrepancies between practical affairs in industrial sites and vocational education, training & requirements. Full implementation of NCS-based curriculum in vocational education of vocational high schools has been mandatory since 2018. This research used a region-stratified sample of 350 from teachers in 'machinery' and 'machine·metal' majors in mechanical departments of vocational high schools to investigate the awareness of practical courses for metal machining among the teachers. The research results are as follows. First, a majority of the respondents indicated the availability of turning process, milling process, computer integrated manufacturing and measuring courses in mechanical departments. Second, capabilities required by the industry are considered most in selecting practical courses and competence units. Third, positive changes with the introduction of practical courses in the school education are students' practical skills improvement and satisfaction of industrial requirements. Fourth, negative changes with the introduction of practical courses in the school education are too difficult learning modules used in practical courses for students and students' difficulty in learning because of the difference between equipment in schools and industrial equipment in learning modules. Fifth, teachers' satisfaction with practical courses classes and overall conditions is above the average, and their satisfaction with the level of practical courses and bookbinding or purchase of rearranged textbooks of practical courses is below the average. Therefore, application conditions of above-mentioned representative 4 practical courses should be examined and taken care of for consistent improvement to stabilize NCS-based educational courses in mechanical departments.

• The korean journal of orthodontics
• /
• v.33 no.6 s.101
• /
• pp.437-451
• /
• 2003

The purpose of this study was to measure maximum bite force and to investigate its relationship with anteroposterior, vertical, and transverse facial skeletal measurements. From among the dental students at the College of Dentistry, forty subjects (26 male and 14 female) were selected. With two sets of strain gauge, maximum bite force at the right and left first molars and anterior teeth was measured in the morning and afternoon. After taking lateral and posteroanterior cephalograms, fifty and nineteen variables were evaluated, respectively Paired t-tests and an independent t-test were done and correlation coefficients were obtained. 1. The maximum bite force at the first molars was $68.0\pm13.9kg$. in males and $55.6\pm10.5kg$ in females (p<0.05) while the force at the anterior teeth was $8.4\pm4.9kg\;and\;1.1\pm3.4kg$ respectively (p<0.05). 2. Some tendency for a greater value of maximum bite force at the preferred side was observed but not statistically significant (p>0.05). 3. Significant difference was observed between the strong bite force group and the weak bite force group in some cephalometric and other measurements (p<0.05). N-S-Ar, S-Ar-Go, FH-Hl, IMPA and MMO showed a significant difference in posterior maximum bite force (P). N-S-Ar and FH-H1 also showed a significant difference in anterior maximum bite force (A). 4. Several cephalometric variables showed some correlation with maximum bite force (p<0.05). N-S-Ar, S-Ar-Go, UGA, FH-H6, FH-H1, body weight and MMO were significantly correlated with posterior maximum bite force (P). Go-Me, P-1 and IMPA were significantly correlated with anterior maximum bite force (A).

• The Korean Journal of Mycology
• /
• v.42 no.3
• /
• pp.191-200
• /
• 2014

Nuruk samples collected from various regions in Korea were investigated in terms of fungal contents and diversity. In measurement of colony forming unit (CFU) in Nuruk suspensions on DRBC agar, Nuruk samples MS4, MS8, and MS10 were among the highest fungal density, with $1,278.9{\pm}21.6$ (${\times}10^4$), $1,868.0{\pm}27.7$ (${\times}10^4$), and $775.1{\pm}19.2$ (${\times}10^4$) were among the samples showing the highest fungal density. CFU per 20 mg Nuruk, respectively. The majority of fungal components were yeasts, including Pichia anomala, P. kudriavzevii, Kluyveromyces marxianus, and Saccharomycopsis fibuligera, whereas Aspergillus oryzae and Rhizopus oryzae, the representative Nuruk fungi, were predominant only in the low fungal density Nuruks (MS2, MS5, and MS11). Saccharification capability of the fungal isolates was assessed by measurement of amylase activity in the culture broth. The highest amylase activity was found in A. niger and A. luchuensis, followed by S. fibuligera. A. oryzae and R. oryzae showed fair amylase activity but significantly lower than those of the three fungal species. R. oryzae was suggested to play an additional role in degradation of ${\beta}$-glucan in crop component of Nuruk since R. oryzae was the only fungus that showed ${\beta}$-glucanase activity among the fungal isolates. To confirm the safety of Nuruk, aflatoxigenicity of the isolated Aspergillus was estimated using the DNA markers norB-cypA, aflR, and omtA. All of the isolates turned out to be non-aflatoxigenic as evidenced by the deletion of gene markers, norB-cypA and aflR, and the absence of aflatoxin in the culture supernatants shown by TLC analysis.