• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.40 no.5
• /
• pp.276-281
• /
• 2007

The toxicity of two species of puffer fish, Takifugu xanthopterus and T. stictonotus, collected from coastal regions of Korea, was determined using a mouse bioassay. The highest toxin scores in the muscle, skin, fins, and testis in both species were below 50 mouse units (MU) per gram, and for each organ of both species the proportion of toxic specimens containing ${\geq}10MU/g$ was less than about 10%. In T. xanthopterus, the highest toxin levels in the liver, gallbladder, and ovary exceeded 1,000 MU/g (1,275-1,910), while less than 200 MU/g (12-136) was detected in the same organs of T. stictonotus. Therefore, the toxicities of muscle, skin, and testis in both species of puffer fish were within acceptable levels for human consumption.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.49-49
• /
• 2022

One of the major problems with sweetpotato (Ipomoea batats Lam.) is the tough thread tissue that occurs in the storage root, which has a negative impact on the sales of sweet potato because it impairs the texture during cooking and the processing quality. The fiber contents in storage roots of sweetpotato is affected by cultivation conditions and environment. To investigate the effect of fiber generation at different levels of irrigation, the sweetpoatoto "Hogammi" was transplanted in greenhouse. Sweetpotato was grown in styrofoam beds(W1605*D330*H300mm) to block moisture flowing from the outside. The irrigation was carried out as 3 levels (5,10, and 20 mm through drip irrigation facilities) at 20-day intervals. Five plants were harvested per plot at 90, 100 and 120 days after transplanting (DAT). The size of the storage root was large in the order of irrigation conditions 10mm>20mm>5mm treatment. And the longer cultivation period, the larger size of the storage root was observed. As a result of the analysis of the fiber content, it showed a tendency to decrease as the cultivation period increased (90days→120days). In addition, the fiber contents of sweetpotato harvested at 90, 100 and 120 DAT in the level of 5 mm irrigation plot were 351, 324 and 207 mg/100g, respectively, which were higher than those of other irrigation level plots. During all cultivation periods, the 10mm treatment group showed the lowest fiber content of 280, 228 and 127 mg/100g. At 20 mm irrigation level, the fiber content was less than that of 5mm irrigation level, but showed a tendency to increase compared to that of 10 mm irrigation level. These results suggested that drought stress or excessive-irrigation increases the fiber content of sweetpotato, which reduces their commercial value.

• Journal of the Korean Society of Food Culture
• /
• v.36 no.1
• /
• pp.76-83
• /
• 2021

This study investigated the effect of the addition of various levels of pig head meat (HM) as a substitute for rear leg meat (RLM) on the physico-chemical quality characteristics of non-emulsified, smoked, and cooked sausage during refrigerated storage. Sausages were prepared in four variations according to the proportion (0%, 10%, 20%, or 30%) of HM added and maintained at 4℃. Quality measurements were taken for 28 days. The sausages added with the addition of 20% and 30% HM had significantly (p<0.05) higher moisture and lower protein content compared to those without the addition of HM. The pH value during the storage period was higher (p<0.05) in the sausages to which the HM had been added than in those without HM. The sausages with 30% HM showed the lowest (p<0.05) L⁎ and b⁎ values and the highest (p<0.05) a⁎ value during the storage period. The 2-thiobarbituric acid reactive substances (TBARS) content, hardness, cohesiveness, springiness, gumminess, and chewiness of the sausages showed no significant variations with the addition of various levels of HM. These data suggest that RLM could be substituted with 30% HM because it does not negatively affect the quality of the non-emulsified sausage. However, a further study on sausages made with 100% HM instead of RLM may be needed to improve its utilization.

• Reproductive and Developmental Biology
• /
• v.37 no.1
• /
• pp.51-55
• /
• 2013

The present study was conducted to examine the effect of antioxidant treatment during parthenogenetic activation procedure on the reactive oxygen species (ROS) levels and in vitro development of porcine parthenogenetic embryos. Porcine in vitro matured oocytes were activated by a combination of electric stimulus and 2 mM 6-dimethylaminopurine (6-DAMP) before in vitro culture. During the activation period, oocytes were treated with $50{\mu}M$ ${\beta}$-mercaptoethanol (${\beta}$-ME), $100{\mu}M$ L-ascorbic acid (Vit. C) or $100{\mu}M$ L-glutathione (GSH). To examine the ROS level, porcine parthenogenetic embryos were stained in $10{\mu}M$ dichlorohydrofluorescein diacetate ($H_2DCFDA$) dye 20 h after culture, examined under a fluorescence microscope, and the fluorescence intensity (pixels) were analyzed in each embryo. The parthenogenetic embryos were cultured for 6 days to evaluate the in vitro development. The apoptosis was measured by TUNEL assay. The $H_2O_2$ levels of parthenogenetic embryos were significantly lower in antioxidant treatment groups ($26.9{\pm}1.6{\sim}29.1{\pm}1.3$ pixels/embryo, p<0.05) compared to control ($33.2{\pm}1.7$ pixels/embryo). The development rate to the blastocyst stage was increased in antioxidant treatment groups (32.0~32.5%) compared to control (26.9%, p<0.05), although, there was no difference in apoptosis among groups. The result suggests that antioxidant treatment during parthenogenetic activation procedure can inhibit the ROS generation and enhance the in vitro development of porcine parthenogenetic embryos.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2015.05a
• /
• pp.173-173
• /
• 2015

The flood water level in tidal river is determined by the joint effects of flood discharge and tidal water levels at downstream boundary. Due to the variable tidal boundary conditions, the evaluated design water levels associated with a certain flood event can be significantly different. To avoid determining of design water levels just by a certain tidal boundary condition and remove the influence of variability in boundary condition from the evaluation of design water levels, a probabilistic approach is considered in this study. This study focuses on the development of a method to evaluate the realistic design water levels in tidal river with taking into account the combined effects of river discharge and tidal level. The flood water levels are described by the joint probability of two driving forces, river discharge and tidal water levels. The developed method is applied to determine design water levels for the tidal reach of the Han River. An unsteady flow model is used to simulate the flow in the reach. To determine design water levels associated with a certain flood event, first, possible boundary conditions are obtained by sampling starting times of tidal level time series; then for each tidal boundary condition, corresponding peak water levels along the channel are computed; and finally, design water levels are determined by computing the expectations of the peak water levels. Two types of tides which are composed by different constituents are assumed (one is composed by $M_2$, and the other one is composed by $M_2$ and $M_2$) at downstream boundary, and two flood events with different maximum flood discharges are considered in this study. It is found that (a) the computed design water levels with two assumed tides have no significant difference for a certain flood event, though variability of peak water levels due to the tidal effect is considerably different; (b) tidal effect can reach to the Jamsil submerged weir and the effect is obvious in the downstream reach of the Singok submerged weir; (c) in the tidally affected reach, the variability of peak water levels due to the tidal effect is greater if the maximum flood discharge is smaller.

• Korean Journal of Agricultural Science
• /
• v.49 no.2
• /
• pp.249-257
• /
• 2022

The present study investigates the effects of different inclusion levels of a microwave-dried black soldier fly (Hermetia illucens) larvae meal (HILM) on the carcass characteristics, breast meat quality, and fatty acid profiles of leg meat in broiler chickens. A total of 150 male broilers were randomly assigned to three dietary treatment groups (10 replicates·treatment^-1 and 5 birds·replicate^-1). HILM was included at increasing levels (0, 2, and 4%; CON, 2HILM, and 4HILM, respectively) in diets formulated for three feeding phases: starter (1 - 7 d), grower (7 - 21 d), and finisher (21 - 35 d). One bird per replicate was slaughtered at d 35; the carcasses and organs were weighed, and breast and leg meats were excised for a meat analysis. A linear decrease (p < 0.01) was observed for live and carcass weights for the whole period of the experiment, with no difference between the CON and 2HILM groups. Broilers fed HILM showed no significant differences in meat quality parameters, except for an increase in yellowness (b^*) in the 2HILM and 4HILM groups compared to the CON group (p < 0.01). With an increase in the HILM inclusion level, the proportion of saturated fatty acids (SFAs) such as lauric, myristic, stearic, arachidic, and heneicosylic acids showed a linear increase (p < 0.01); however, total SFA, monounsaturated fatty acid, and polyunsaturated fatty acid did not differ among the dietary treatments. Thus, microwave-dried HILM can be considered as a possible alternative ingredient to soybean meal in broiler diets up to a 2% inclusion level.

• Journal of Animal Science and Technology
• /
• v.66 no.2
• /
• pp.374-386
• /
• 2024

To predict the apparent total tract digestibility (ATTD) of crude protein (CP) in dogs we developed an in vitro system using an in vitro digestion method and a statistical analysis. The experimental diets used chicken meat powder as the protein source, with CP levels of 20% (22.01%, analyzed CP value as dry-based), 30% (31.35%, analyzed CP value as dry-based), and 40% (41.34%, analyzed CP value as dry-based). To simulate in vivo digestive processes a static in vitro digestion was performed in two steps; stomach and small intestine. To analyze ATTD the total fecal samples were collected in eight neutered beagle dogs during the experimental period. CP digestibility was calculated by measuring CP levels in dog food, in vitro undigested fraction, and dog feces. In result, CP digestibility at both in vivo and in vitro was increased with increasing dietary CP levels. To estimate in vivo digestibility the co-relation of in vivo ATTD and in vitro digestibility was investigated statistically and a regression equation was developed to predict the CP ATTD (% = 2.5405 × in vitro CP digestibility (%) + + 151.8). The regression equation was evaluated its feasibility by using a commercial diet. The predicted CP digestibility which was calculated by the regression equation showed high index of similarity (100.16%) with that of in vivo in dogs. With that, it would be a feasible non-animal method to predict in vivo CP digestibility by using in vitro digestion method and the proposed linear regression equation in adult dogs.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.43 no.1
• /
• pp.12-17
• /
• 2010

Wild and cultured fish including olive flounder, sea bass, rock bream, yellowtail, gray mullet, gizzard shad, black rockfish, red seabream and squid were collected from a fish market located on the coast of Korea, and the antibiotic content of their muscle was investigated. Tetracycline group antibiotics were not detected in the 108 individuals of 9 species of wild fish. However, oxytetracycline (OTC) and tetracycline(TC) were detected in some samples of the 111 individuals in 7 cultured live fish species. The detected ranges of OTC and TC were ND~ 0.06 and ND~ 0.03, respectively. Five different fluoroquinolone antibiotics were also tested for, but were not detected in the wild fish species. Only small amount of criprofloxacin(ND~0.029 mg/kg) were detected in a few cultured fish samples. Oxolinic acid was not detected in either wild and cultured fish samples. Results showed that even very low levels of antibiotics could be detected by the testing methods used. Antibiotics were identified in a few fish samples but levels were far below the maximum allowable limits of the Korean Food Code, and the safety of fish being sold in markets, with regard to antibiotic levels, was confirmed.

• Korean Journal of Child Studies
• /
• v.33 no.2
• /
• pp.145-164
• /
• 2012

This study examined the effects of marital conflict and mothers' anger and depression on the behavioral problems of preschoolers. A total of 393 mothers with 3-year-old preschoolers responded to questionnaires, which included items related to marital conflict, mothers' anger and depression, and their preschoolers' behavioral problems. Data were analyzed by means of structural equation modeling. The results indicated that marital conflict had no direct effect, but there were indirect effects on preschoolers' behavioral problems caused by mothers' anger and depression. Mothers who believed that they were experiencing high levels of marital conflict revealed high levels of anger and depression and reported higher rates of behavioral problems in their children. Mothers' depression also mediated the impact of marital conflict on preschoolers' behavioral problems, but mothers' anger level apparently did not. The effects of mothers' level of depression on preschoolers' behavioral problems were the highest among all the predictors. These findings imply that both improving marital relationships and regulating mothers' anger and depression levels need to be emphasized when designing prevention and intervention programs aimed at improving the behavioral problems of preschoolers.

• Fisheries and Aquatic Sciences
• /
• v.10 no.4
• /
• pp.205-214
• /
• 2007

Surface water and sediment samples collected from the Mokpo coast of Korea were analyzed for molecular markers of organic municipal wastewaters, i.e., 11 fecal sterols including coprostanol (Cop) and nonylphenolic compounds (NPs), to characterize the main routes of these wastewaters to the coast and to assess contamination levels. Concentrations of Cop ranged from 94 to 7,568 ng/L in surface water and from 43 to 38,108 ng/g dry weight in sediments. Concentrations of NPs [nonylphenol (NP) and nonylphenol mono- and di-ethoxylates ($NP_{1-2}EOs$)] ranged from 123 to 4,729 ng/L in surface water and from 4 to 2,119 ng/ng dry weight in sediments. The levels of these compounds were much higher at stations near the rivers that pass through the urban center of Mokpo and the outfall of the wastewater treatment plant (WWTP). The spatial distribution of Cop levels was statistically similar to that of NPs (r=0.809 and 0.982 in surface water and sediments, respectively), indicating that these compounds may have similar discharge points, transport, mixing, and deposition in the study area. These results suggest that considerable amounts of organic wastewater compounds are discharged through rivers and WWTP effluent to the Mokpo coast.