• Journal of Life Science
• /
• v.15 no.1 s.68
• /
• pp.152-159
• /
• 2005

This research was conducted to make suggestions for the promotion of research activities in the Life Sciences field, and we evaluated the research funding trend and the present status of research funding offered by KOSEF in this field. Researchers in this field have received more research funding from the group-based programme than from the individual-based programme. Also, they have received less money (per project) than did researchers in other Science and Technology fields. The portion of research funds given to the Medical Sciences fields has markedly increased year by year, whereas the portion of funding given to the Agricultural Sciences and Biological Sciences fields has decreased annually. To encourage research activities in the Life Sciences field in Korea, the following actions and systems are required: 1) formulation of a mid-and a long-term research master plan, 2) development of a database on man power in related fields, 3) activation of top-down research topics, and associated increase of individual research grants, 4) development of special national programs for basic researches in Life Sciences, 5) organization of a committee for policy and planning within related societies, and 6) system development for fair evaluation of the results of research activities.

• Journal of The Korean Association For Science Education
• /
• v.18 no.4
• /
• pp.517-523
• /
• 1998

It has been an important task that the decreased quantities of science lessons must blend with the 7th science curriculum. This study analysed the 6th and 7th science curriculum contents, and found the perspective and the problems in relation to the decreased lessons in the 7th science curriculum. The results found in the analysis of the science content system in the curriculum are as follows: first, the new science themes in the 7th content system were those appeared in the sub-themes in the 6th curriculum, so substantially scientific concepts didn't increase in the 7th. Second, the number of the terms which restricts the conceptual and contextual region of the major science themes considerably increased in the 7th curriculum. Third, Surface Lesson Quantities(SLQ), which were defined as the counted lesson number considering the quantities of science themes and the lesson decreasing rate 30% of the whole school curriculum, were inferred as 38.5% of the 6th lesson quantities. And the results found in the analysis of the sub-themes inferred from the sentences describing the science themes in each grade are as follows: Essential Lesson Quantities (ELQ), which were defined based on the sub-themes, were more than SLQ in almost themes. But, in case of the themes, 'weather' and 'ground', SLQ were much more than ELQ. The results of this study shows that it will not easy to solve the task, the decreasing lessons and phenomena-centered approach in constructing the science teaching content according to the 7th science curriculum.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.52 no.2
• /
• pp.134-140
• /
• 2019

A feeding trial was conducted to investigate the effects of dietary fish meal replacement by a blend of lysine cell mass, corn protein concentrate and poultry by-product meal on the growth and blood chemistry of the starry flounder Platichthys stellatus. The fish meal replacer (FMR) was prepared to have the same level of protein as fish meal (FM). With a commercial diet as a positive control, five experimental diets (basal, FM42, FM32, FM22 and FM12) were formulated to contain 52% protein and 10% lipid. The dietary FM levels decreased from 52% (basal) to 42, 32, 22 and 12% with concomitant increase in the FMR to 10, 20, 30, 40 and 50%, respectively. Juvenile starry flounder with an average body weight of 177.3 g were randomly distributed in each (30 fish/tank) of 18 plastic tanks ($139{\times}99{\times}54cm$). After a 45-day feeding trial, the survival rate ranged from 95.6% (FM22) to 100% (control and FM42), while the weight gain of the fish groups varied from 49.7 to 58.4 g. The results clearly revealed that starry flounder can grow well on a diet containing low FM (12%) with a high level of FMR (50%) without any adverse effects.

• Korean Journal of Food Science and Technology
• /
• v.51 no.1
• /
• pp.29-34
• /
• 2019

In this study, a commercial production stepwise method for restorative rice with high quality and microbial safety was developed. The stepwise treatment method included steaming, refrigerated aging, and low temperature drying. The soaking rice was steamed twice at $90-100^{\circ}C$, and then, the rice was aged at $0-10^{\circ}C$, frozen at $-20^{\circ}C$, and dried at low temperatures with 5 m/s wind speed at $1-20^{\circ}C$ and 85% relative humidity. Applying the three steps improved sensory qualities compared with the conventional hot air drying and made storage at room temperature for 3 months possible. Specifically, the moisture content of the restorative rice was increased to 30%, which was 4.3 times higher than the 7% of the conventional air dried rice, and the rice grain shape was well maintained. The texture and appearance of the three-step rice were significantly improved (p<0.05) in a sensory evaluation.

• Korean Journal of Food Science and Technology
• /
• v.51 no.3
• /
• pp.221-226
• /
• 2019

This study investigated the optimal amount of shell powder (0.1, 0.2, 0.3, and 0.4%) to add to rice noodles containing 20% rice flour and compared their quality characteristics to those of wheat noodles containing a commercial alkaline reagent (added at 0.4%). As the amount of shell powder was increased, the L and b values (Hunter's color) increased. The pH, turbidity, and water absorption also increased as the amount of shell powder was increased. However, when the shell powder content exceeded 0.3%, the hardness, chewiness, springiness, and tension tended to decrease below acceptable levels. This might be because the shell powder inhibited network formation. The textural properties and pH value of rice noodles containing 0.2% shell powder were similar to those of the wheat noodles. This suggests that 0.2% shell powder may be the optimal amount to add to rice noodles when used as the alkaline reagent.

• Korean Journal of Food Science and Technology
• /
• v.51 no.2
• /
• pp.114-119
• /
• 2019

Seven antimicrobial agents known to be effective in inhibiting the growth of lactic acid bacteria were applied to ensure the microbial safety of low-salted squid and myungran jeotgal with 4-6% salinity. These agents reduced the salt content by 50% compared with the conventional Jeotgal. Lactic acid bacteria such as Lactobacillus sp., Streptococcus sp., and Pediococcus sp. were commonly found to account for 80% of microbial organisms, and yeast and fungi were observed in squid and myungran jeotgal, respectively. The total bacterial counts in squid and myungran jeotgal showed 94.20 and 90.87% reduction after the addition of 0.5% (w/w) glycine. The microbial counts in squid and myungran jeotgal decreased $10^1-10^2CFU/g$ when compared with the control after 21 days at $10^{\circ}C$. Glycine was found to be an effective commercial antimicrobial agent that can be used to control bacterial count in low-salted Jeotgal without affecting sensory qualities such as overall taste and flavor.

• Korean Journal of Environmental Agriculture
• /
• v.40 no.3
• /
• pp.219-230
• /
• 2021

BACKGROUND: Biochar is a solid material converted from agricultural biomass such as crop residues and pruning branch through pyrolysis under limited oxygen supply. Biochar consists of non-degradable carbon (C) double bonds and aromatic ring that are not readily broken down by microbial degradation in the soils. Due to the recalcitrancy of C in biochar, biochar application to the soils is of help in enhancing soil carbon sequestration in arable lands that might be a strategy of agricultural sector to mitigate climate change. METHODS AND RESULTS: Data were collected from studies on the effect of biochar application on soil C content conducted in East Asian countries including China, Japan and Korea under different experimental conditions (incubation, column, pot, and field). The magnitude of soil C storage was positively correlated (p < 0.001) with biochar application rate under field conditions, reflecting accumulation of recalcitrant black C in the biochar. However, The changes in soil C contents per C input from biochar (% per t/ha) were 6.80 in field condition, and 12.58 in laboratory condition. The magnitude of increment of soil C was lower in field than in laboratory conditions due to potential loss of C through weathering of biochar under field conditions. Biochar production condition also affected soil C increment; more C increment was found with biochar produced at a high temperature (over 450℃). CONCLUSION: This review suggests that biochar application is a potential measures of C sequestration in agricultural soils. However, as the increment of soil C biochar was affected by biochar types, further studies are necessary to find better biochar types for enhanced soil C storage.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.23 no.1
• /
• pp.117-128
• /
• 2021

The skeletal muscle development of Hanwoo steer has been processed in the prenatal and postnatal periods. Bovine satellite cell located in perimysium of muscle tissues has differentially distributed in peripheral tissues. The study of postnatal development of satellite cells can help understand the genetic and functional regulation of meat characteristics. Factors affecting muscle size increase are related to the accumulation of DNA or synthesis of RNA proteins. In this study, we observed muscle development and differentiation after culturing bovine satellite cells derived from longissimus dorsi and semimembranosus regions of Hanwoo muscle tissue. In addition, RNA sequencing data were analyzed for differentially expressed genes (DEG) involved in intracellular muscle development and growth. The DEG of the two muscle tissues were compared according to 1day, 2day, 4day, and 7day. The overall gene expression level was confirmed by the heat map. Gene Ontology (GO) classification method was used to compare the expression level of gene groups affecting LD and SM development. The histology of GO was consistent with the time-cause change of LD and SM cell morphology. SM showed more active skeletal muscle development than LD. Even within the same time, SM expressed more genes than LD, thus synthesizing more muscle fibers

• Pediatric Infection and Vaccine
• /
• v.5 no.2
• /
• pp.245-257
• /
• 1998

Purpose : Although hepatitis B vaccine has been available to general population in Korea since 1983, it was difficult to compare various types of hepatitis B virus(HBV) vaccines primarily due to the differences in vaccination schedule, dosage, test methods and seropositive antibody level. In this study we reviewed the results of previous studies published in Korea, which include antibody positive rates and antibody titers of various vaccines, and examined the immunogenicity of these HBV vaccines. Methods : Studies published in medical journals, university journals concerning antibody positive rates following hepatitis B vaccination were reviewed. Inclusion criteria were those studies in which seroprotective antibody rate of 10mIU/mL or the sample ratio unit of 10 RU were used as the cut-off value and in which the test methods were RIA or ELISA. Exclusion criteria were; 1) unclear or inconsistent vaccine dosage, 2) no record of antibody titers or seroconversion rate, 3) no defined antibody rate or ratio for positive rating and 4) the vaccination schedule other than 0-1-2 months or 0-1-6 months. Results : 23 out of 52 studies were subjected for the review for seroconversion rates. 1) As for the immunogenicity in each age group, the seroconversion rates of Hepaccine(Cheil Jedang) were 85.1% in infants, 83.3% in children and 62.7% in adults, indicating higher rates in infants and children compared to adults(P<0.01). The seroconversion rates of Hepavax(Korea Green Cross) were 84.7%, 81.1% and 90.8%, indicating higher rates in infants and adults compared to children(P<0.01). 2) The seroconversion rate of Hepavax was 85.6% with 0-1-6 mo. schedule, 78.5% with 0-1-2 mo. schedule with a statistically significant difference(P<0.01). 4) There was no difference of seroconversion rates between the two doses of Hepavax, $5{\mu}g$ and $10{\mu}g$ in infants and children. 5) In adults the seroconversion rates were 62.7% with Hepaccine, 90.8% with Hepavax, and 94.8% with Engerix-B(SmithKline Beecham). Conclusion : In Korea, the incidence of chronic hepatitis B is high and changing the schedule in vaccination cannot contribute to the increase of the serocoversion rate. And in order to maximize immunogenicity, more effective vaccines as well as more proper vaccination methods should be used.

• Journal of Food Hygiene and Safety
• /
• v.24 no.4
• /
• pp.352-356
• /
• 2009

The purpose of this study was to introduce the toxicological study review to evaluate the safety of PDMS on the 69th JECFA meeting. Polydimethylsiloxane is a polymer and its ADI was established at 23rd JECFA meeting in 1979. The ADI was maintained although the specification was expanded at its 26th, 29 th, 37 th meetings. Recently, it was reported that PDMS with low molecular weight and viscosity has high absorption rate and different toxicity, so it was submitted at 69th meeting. Toxicological studies of PDMS were submitted from the sponsor and additional information is collected from a document searching. The toxicological studies were reviewed in accordance with the 'Guidelines for the preparation of toxicological working papers for the Joint FAO/WHO Expert Committee on Food Additives'. In the available acute, sub-chronic and chronic toxicity studies on PDMS, dose-related increases in incidence and severity of ocular lesions(corneal crystal, inflammation of the corneal epithelium etc.) were consistently observed after oral dosing. It seems to be a local irritant effect, but the mechanism by which the ocular lesions arose is unclear, although the lack of absorption of PDMS indicates that it is unlikely to be a direct systemic effect. Consequently, the relevance of the ocular lesions for food use of PDMS could not be determined. The ADI of PDMS was re-established from 0-1.5 mg/kg bw/day to 0-0.8 mg/kg bw/day by applying additional safety factor 2 based on its ocular toxicity. The result of 0-0.8 mg/kg bw/day is a temporary ADI until further data are provided to 2010.