• Journal of Aquaculture
• /
• v.9 no.2
• /
• pp.141-149
• /
• 1996

Effects of $17{\alpha}$-methyltestosterone ($17{\alpha}-MT$) in rearing water on sex reversal of Nile tilapia (Oreochromis niloticus) were investigated and optimum conditions as initial treatment time, concentrations and treatment durations of hormone were evaluated in this study. For the study of the optimum initial treatment time, 0 to 20-day-old fry were treated by immersion in a 500 ppb solution of $17{\alpha}-MT$. Desirable results were obtained at 12-day-old fish as $86.4\%$ of male induction rates and this frequency was obviously higher than the other age groups. Twelve-day-old fry were immersed in $17{\alpha}-MT$ solutions at concentrations of $0\~2,000$ ppb for 24 hours for the study of dose dependent relationship between sex ratios and concentrations of $17{\alpha}-MT$, Male induction rates of all treated groups were higher than $80\%$, $X^2$ values against the sex ratio of control group indicate that sex reversal has taken place effectively in all experimental groups (P<0.001). Futhermore, 500 ppb treated groups showed highest male incidence of $86.4\%$. Effects of 5 different durations (0, 12, 18, 24 and 30 hours) treated with 1,000 ppb of $17{\alpha}-MT$ were also evaluated. Male induction rate from 0 to 24 hours treated group was increased with treatment durations. However, male incidence of 30-hour treated group ($84.0\%$) was sligthly decreased compare to the 24-hour treated group ($85.2\%$). It is concluded that immersion treatment using $17{\alpha}-MT$ on O. niloticus is possible on sex reversal at low concentration of 500 ppb and short treatment durations within 24 hours with 12-old-day fry.

• Korean Journal of Ecology and Environment
• /
• v.38 no.3 s.113
• /
• pp.341-351
• /
• 2005

Ecological stream health, based on the index of biological integrity (IBI) , was evaluated at five sampling locations of Youdeung Stream during August-October 2004. For the study, we also analyzed spatial and temporal patterns of conventional water quality over tine period of 1995 ${\sim}$ 2004, using the water chemistry dataset, obtained from the Ministry of Environment, Korea. The water quality parameters used here were conductivity, total suspended solids (TSS), biochemical oxygen demand $(BOD_5)$, chemical oxygen demand $(COD_{mn})$, total nitrogen (TN), and total phosphorus (TP). The multi-metric model values averaged 27.8 in the stream and ranged 24 ${\sim}$ 32. The health condition was judged as 'Fair' to 'Poor' conditions, according to the stream health criteria of US EPA (1993). Longitudinal variation occurred from the upstream to downstream reach; largest differences in all water quality variables occurred between Site 5 and the other sites. This was mainly attributed to the impacts of wastewater treatment plants near the locations. Also, relative proportions of tolerance and omnivore species increased in downstream reaches. The model values, however, did not match the values, based on water quality parameters. We assume that this may be associated with primarily reduced water volumn during dry season in the stream along with modified physical habitat conditions.

• Korean journal of food and cookery science
• /
• v.23 no.6
• /
• pp.987-1002
• /
• 2007

This study examined Tthe cooking methods foroftraditional foods called such as Mieum, Misu, and Goeum from the from investigation of old cook books and ancient literatureis as follows. There We found were 7 types of Mieum that were cooked by mixing rice and cereals, while 3 types of Mieum were cooked by mixing cereals and herbal medicines to with thenuts. The Mieums that were cooked by mixing meat, fish, and shellfish, etc. to the herbal medicine ingredients like such as medical plants, etc were consisted of 8 types. Therefore, a total of 18 types of Mieum, Misu, and Goeum, etc were have been classified. Among the cooking methods of for Mieum, rice and grains were boiled for an extended longtime and filtered with a sieve to be used as the juicebroth. The Job's tears and millet, etc were mixed into water, or boiled after being made into a powder, soaked into water, and dried. The herbal medicine ingredients such as ginseng were boiled for an extended long time, and once the ingredients are were flown out cooked down, it the broth was filtered with asieve to be used the as a liquid extract. The meat, bone, and shellfish, etc were also boiled for a longn extended time, filtered with a sieve, and made into a juice broth to be used as a drinks from on occasion time to time. These drinks, called Mieum, Misu, and Goeum above, were healthy foods our ancestors used to enjoy for enjoyment drinking, and were also food for remedyies and sources of nutritionon. As Since the meal replacement foods to that replace meals that can be eaten right away while working and studying are needed, due to is required within the our busy schedules of in modern peoplesociety, thise literary investigation and the cooking methods for of Mieum, Misu, and Goeum, which that used to be are our traditional foods, can be are used as a basic research material for the development of convenient breakfast to meal replacements breakfast.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.22 no.5
• /
• pp.500-507
• /
• 2016

This study was undertaken to improve the survival and early life growth rates of cold-water fish by culturing rotifer (Brachionus plicatilis) with low-temperature tolerance. The enrichment experiment was carried out at different temperatures and over different time intervals. Cultivation of the rotifer at low temperatures was repeated, with the selected and cultured as the water temperature was gradually lowered from $20^{\circ}C$ to $10^{\circ}C$. Enrichment of the rotifer was completed using A, S, SCV and SCP. Enrichment was carried out after 6, 12 and 24 hours at three different temperatures (10, 15 and $20^{\circ}C$). In the growth experiments, the rotifer increased to approximately triple their original size, from $350{\pm}7.9ind./ml$ to $1,064{\pm}5.7ind./ml$ at $10^{\circ}C$ over 50 days. The fatty acid composition of the four enrichment materials was species-specific, with the highest ratios belonging to eicosapentaenoic acid (EPA, C20:5n-3) and docosahezaenoic acid (DHA, C22:6n-3) in SCP. The fatty acid composition of the rotifers was affected by the enrichment materials. The EPA (% of total fatty acid) was more than 2 % in SCP, which showed a higher ratio than the other enrichment materials. DHA was higher in S reaching 12.40 % at $15^{\circ}C$ for 24 hours. The highest levels of EPA (3.09 %) and DHA (11.65 %) were obtained after the rotifers were enriched with S at $20^{\circ}C$ for 12hours.

• Development and Reproduction
• /
• v.10 no.2
• /
• pp.97-103
• /
• 2006

Vitellogenin(Vg) is a sex specific serum protein present in sexually maturing female blood of oviparous vertebrates. Estrogen($E_2$) is a main inducer of hepatic Vg synthesis. We investigated the effects of androgen and growth hormone(GH) on regulation of Vg and estrogen receptor(ER) genes in Japanese eel. Immature eels($200{\sim}250\;g$) were given a single injection of $E_2(5{\sim}5,000\;{\mu}g/kg\;bw)$ alone, or in combination with eel recombinant GH(eGH, $1{\sim}10\;{\mu}g/kg$) or methyltestosterone(MT, $1{\sim}5\;mg/kg$) and sacrificed 10 days after the hormone treatments. Expression levels of ER and Vg genes from the liver were determined by means of reverse transcription and polymerase chain reaction(RT-PCR). Administration of $E_2$ stimulated Vg gene expression in a dose dependent manner. Levels of Vg mRNA after the injection of $E_2(500\;{\mu}g/kg)$ with MT(5mg/kg) or eGH($10\;{\mu}g/kg$) were much higher than in that of $E_2$ alone($500\;{\mu}g/kg$). Whereas, injection of either vehicle, eGH ($10\;{\mu}g/kg$) or MT(5mg/kg) alone did not induce the expression of Vg gene in the liver. ER mRNA was detected from the fish treated with vehicle alone. $E_2$ injection($5{\sim}500\;{\mu}g/kg\;bw$) increased this ER expression but dose dependent response was not clear. Addition of MT(5mg/kg) or eGH($10\;{\mu}g/kg$) did not affect $E_2-stimulated$ ER mRNA expression. This study confirms the necessity of $E_2$ as the primary factor for Vg gene expression and requirement of additional hormones such as MT or GH for the full expression of Vg mRNA, and suggests that the additive effect of MT or GH on Vg gene expression would be mediated by some unknown factors other than ER.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.16 no.3
• /
• pp.147-154
• /
• 2011

Decision making in Environmental Impact Assessment (EIA) and Consultation on the Coastal Area Utilization (CCAU) is footing on the survey reports, thus requires concrete and accurate information on the natural habitats. In spite of the importance of reporting the ecological quality and status of habitats, the accumulated knowledge and recent techniques in ecology such as the use of investigated cases and indicators/indices have not been utilized in evaluation processes. Even the EIA report does not contain sufficient information required in a decision making process for conservation and development. In addition, for CCAU, sampling efforts were so limited that only two or a few stations were set in most study cases. This hampers transferring key ecological information to both specialist review and decision making processes. Hence, setting the effective number of sampling stations can be said as a prior step for better assessment. We introduced a few statistical techniques to determine the number of sampling stations in macrobenthos surveys. However, the application of the techniques requires a preliminary study that cannot be performed under the current assessment frame. An analysis of the spatial configuration of sampling stations from 19 previous studies was carried out as an alternative approach, based on the assumption that those configurations reported in scientific journal contribute to successful understanding of the ecological phenomena. The distance between stations and number of sampling stations in a $4{\times}4$ km unit area were calculated, and the medians of each parameter were 2.3 km, and 3, respectively. For each study, approximated survey area (ASA, $km^2$) was obtained by using the number of sampling stations in a unit area (NSSU) and total number of sampling stations (TNSS). To predict either appropriate ASA or NSSU/TNSS, we found and suggested statistically significant functional relationship among ASA, survey purpose and NSSU. This empirical approach will contribute to increasing sampling effort in a field survey and communicating with reasonable data and information in EIA and CCAU.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.21 no.4
• /
• pp.217-224
• /
• 1988

Changes in lipid components of Gul-bi, salted-dried yellow corvenia, during processing and storage were studied. Raw fishes contained $6.7\%$ total lipid (TL) which consisted of $83.3\%$ neutral lipid (NL), $6.5\%$ glycolipid (GL) and $10.2\%$ phospholipid (PL), and salted-dried sample at 30 days storage contained $11.1\%$ TL which consisted of $86.1\% NL, $7.1\%$ GL and $6.8\%$ PL. The NL was mainly consisted of trigly ceride (TG), free sterol (FS), free fatty acid (FFA), and the main lipids in PL were phosphatidyl choline (PC), phosphatidly ethanolamine (PE) and sphingomyelin (SPM). The contents of TG, PC, PE decreased, while that of FFA, SPM increased during processing and storage. Total fatty acid contents of raw fish, salted sample, salted-dried sample (product) and product at 30/days of storage were 847.9, 764.0, 633.5 and 588.mg/g-lipid, respectively, taking $C_{23:0}$ as the internal standard material. Most fatty acid con tents of TL revealed a tendency to decrease during processing and storage, highly unsaturated fatty acid such as $C_{22:6},\;C_{20:5}$, decreased largely. The major fatty acids in TL, NL, GL and PL were generally $C_{16:0},\;C_{16:1},\;C_{18:1},\;C_{20:5},\;C_{22:6}. Percentage of $C_{16:1},\;C_{18:1}$ in NL and GL and GL are higher than those in PL, while $C_{22:6},\;C_{20:5},\;C_{20:4}$. Peroxide value in salted-dried sample is 121.6 meq/kg and decreased rapidly with storage period, carbonyl value and brown pigment formation showed tendency of increase during processing and storage.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.17 no.2
• /
• pp.117-124
• /
• 1984

Sarine scrap usually comprises about $40\%$ of the raw fish in processing. The purpose of this study is to establish the desirable methods for proteinaceous materials from the sardine scrap through autolysis or enzymatic digestion and to convert them into useful by-products such as sardine sauce. Sardine scrap was chopped and mixed with equal weight of water, and be hydrolyzed them by autolysis and/or by addition of commercial proteolytic enzyme and various concentrations of sodium chloride. The optimal conditions for hydrolysis of sardine scrap were revealed in temperature at $55^{\circ}C$ and 4 hours digestion with bromelain($0.4\%$) and commercial complex enzyme ($6.0\%$), and those conditions were also applicated in autolysis. The maximum hydrolyzing rate of protein and released amino nitrogen were $82.5\%,\;5.2\%$ through autolysis, $84.3\%,\;5.8\%$ by bromelain digestion and $92.5\%,\;5.9\%$ by complex enzyme, respectively. In the products prepared from sardine scrap through autolysis or bromelain digestion, hypoxanthine was dominant, as $17.4 {\mu}mole/g$, dry matter for autolysis and $16.0 {\mu}mole/g$, dry matter, for bromelain digestion among the nucleotidcs and their related compounds, respectively. The abundant free amino acids were leucine, glutamic acid, lysnie, valine and alanine. The contents of those amino acids were $51.3\%,\;48.3\%$ of the total free amino acids, respectively. And the contents of 5'-IMP and TMAO were negligible but total creatinine was developed in value from $9.2\%\;to\;10\%$ of total extracted nitrogen. The flavor of sardine sauce prepared from sardine scrap by autolysis or enzyme digestion were not inferior to that of traditional Korean soy sauce by sensory evaluation.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.17 no.4
• /
• pp.326-335
• /
• 1988

In order to increase the availability of filefish scrap, the ordinary and low salt sauce were prepared, and identified their taste compounds in their products. To process the filefish scrap sauce, chopped filefish scrap was mixed with koji, 25% brine, slat and glucose (25.0 : 65.0 : 12.5 : 7.0, w/w) and fermented at $25{\pm}4^{\circ}C$ for 120 days. The same process was also carried out to process the low salt sauce adding sorbitol, lactic acid and ethyl alcohol (7.0 : 0.7 : 9.0. w/w) instead of salt. While amino nitrogen and volatile basic nitrogen(VBN) of products were decreased, pH and reducing sugar were increased all alone the fermentation period. The major free amino acids of products at final stage of fermentation were glutamic acid, alanine, leucine, lysine and aspartic acid. And the contents of total amino acid in the ordinary and low salt sauce were 4126.6(mg/100m1 sauce), 4519.5(mg/100m1 sauce) after fermentation. Hypoxanthine was revealed as the major constituent among nucleotides and their related compounds through fermentation. Free amino acid-N in the filefish scrap sauces were from 56.3%(ordinary) to 60.7%(low salted) of extractive nitrogen. From the sensory evaluation, the quality of products from filefish scrap sauce were almost equal to sold soy sauce on the market.

• Journal of Nutrition and Health
• /
• v.49 no.3
• /
• pp.179-188
• /
• 2016

Purpose: This cross-sectional study aimed to document the dietary behaviors, dietary changes, and health status of female marriage immigrants residing in Gwangju, Korea. Methods: The survey included 92 female immigrants attending Korean language class at a multi-cultural family support center. General characteristics, health status, anthropometric data, dietary behaviors, and dietary changes were collected. Results: Mean age of subjects was 31.3 years, and home countries of subjects were Vietnam (50.0%), China (26.0%), Philippines (12.0%), and others (12.0%). Frequently reported chronic diseases were digestive diseases (13.2%), anemia (12.1%), and neuropsychiatry disorder (8.9%). Seventeen percent of the subjects was obese ($BMI{\geq}25kg/m^2$). Dietary score by Mini Dietary Assessment was 3.45 out of 5 points. Dietary scores for dairy foods, meat/fish/egg/bean intake, meal regularity, and food variety were low, and those for fried foods and high fat meat intake were also low. Thirty-three percent of subjects answered that they have changed their diet and increased their consumption of fruits and vegetables after immigration. Length of residence in Korea was positively associated with BMI and waist circumference. Length of residence tends to be positively associated with dietary changes and obesity as well as inversely associated with disease prevalence. Conclusion: The study shows that length of residence is inversely related to disease prevalence. However, this association is thought to be due to the relatively short period of residence in Korea and thus the transitional phase to adapting to dietary practices. As the length of residence increases, disease patterns related to obesity are subject to change. Healthy dietary behaviors and adaptation to dietary practices in Korea in female marriage immigrants will not only benefit individuals but also their families and social structure. Therefore, varied, long-term, and target-specific studies on female marriage immigrants are highly needed.