• Korean Journal of Ecology and Environment
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• v.41 no.spc
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• pp.77-85
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• 2008

Grazing rates (GR) and pseudofaeces production (PFP) of native snail, Chinese mystery snail (Cipangopaludina chinensis malleata Reeve) on natural colonial morphs of Microcystis aeruginosa was measured. C. chinensis was collected from the upstream of the Geum River (Boryeong, Korea), where they co-habituated with Unio douglasiae and Lanceolaria acrorhyncha. The experiments were performed to evaluate the GR and PFP at different conditions such as; incubation time (1, 3, 5, 7, 9 and 11 hr), body size (3 to 6.1 cm, n=28), snail density (0.5, 1, 1.5 and 2.0 ind. $L^{-1}$) and prey concentration (168.3, 336.7, 505.0 and $673.0{\mu}g\;Chl-{\alpha}L^{-1}$). All experiments were triplicated, and conducted in transparent acrylic vessel (3L in volume). Regarding feeding time, a highest GR (0.538L $gAFDW^{-1}h^{-1}$) and PFP $(7.18mgAFDW^{-1})$ appeared at 1hr and 7hr after snail stocking, respectively. Interestingly, the snail, smaller than 4.5cm in body size, showed a wide range of GR ($-4.173{\sim}1.087L\;gAFDW^{-1}h^{-1}$) for the initial period (1 and 4hrs of stocking), compared to those greater than 4.5cm, which showed a stable FR, higher than 0.5L $gAFDW^{-1}h^{-1}$. Upon density effect, the density of 1.5 ind. $L^{-1}$ induced the most effective inhibition on Microcystis biomass with highest PFP. On the prey concentration, highest GR (0.897L $gAFDW^{-1}h^{-1}$) and PFP (3.67 mg $gAFDW^{-1}h^{-1}$) were induced at the level of $168.3{\mu}g\;Chl-{\alpha}L^{-1}$ and $673{\mu}g\;Chl-{\alpha}L^{-1}$, respectively. GR and PFP of this freshwater snail on the cyanobacterial bloom (M. aeruginosa) varied with the feeding conditions, and they were comparatively high for a short period of time less than 7hrs regardless of the stocking condition. Our results suggest that this freshwater snail has a potential to control cyanobacterial bloom when provided with suitable condition.

• Applied Biological Chemistry
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• v.8
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• pp.101-111
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• 1967

Daily doses of phenylmercuric acetate arranged in $30{\gamma}\;(group\;I)$, 3{\gamma}\;(group\;II)$ and $0.3{\gamma}\;(group\;III)$ were administered respectively to rabbits for 90 days. The chief histopathological changes in the organs and the analytical data on mercury residues in the excretion and liver were as follows. 1. Kidney: In group I, severe degrees of vacuolization and cloudy swelling were occurred in the epithelial cells of proximal convoluted tubules and severe cloudy swelling and coagulative necrosis were observed in the proximal straight tubules. There were many hyaline casts in the collecting tubules. In group II, moderate degrees of vacuolization and cloudy swelling were observed in the epithelial cells of proximal convoluted tubules and moderate cloudy swelling and coagulative necrosis were encountered in the proximal straight tubules. A little numbers of hyaline casts were located in the lumen of collecting tubules. In group III, slight degree of cloudy swelling were observed in the epithelial cells of proximal convoluted and straight tubules. 2. Liver: In group I, cloudy swelling, fatty changes and coagulative necrosis were observed in the central zone of hepatic lobules. Dissociation of hepatic cell cords was encountered. Hyperplsia of hepatic cells were remarkable in group II. No Pathological changes were observed in group III. 3. Spleen: Deposition of hemosiderin pigment was prominant in group I and small amount of the pigment was observed in group II. There were no pathological changes in group III. 4. Adrenal, colon and heart: No pathological changes were detected in all 3 groups. 5. In an average about 76.5% of mercury was excreted from group I, 85.4% from group II and 79.8% from group III. 6. Mercury content in the liver was 0.0348 g in group I, 0.00378 g and 0.00066 g in group II and group III respectively. 7. In general, as to increased mercury doses the concentration of mercury accumulation in the liver became higher, how·ever, the accumulation quantity against a total amount of mercury doses showed an adverse trend. In other word, the quantity of mercury accumulation was not increased proportionately by higher dose of mercury.

• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.861-866
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• 2023

Unlike conventional smart farms that require chemical fertilizers and large spaces, aquaponics farming, which utilizes the symbiotic relationship between aquatic organisms and crops to grow crops even in abnormal environments such as environmental pollution and climate change, is being actively researched. Different crops require different environments and nutrients for growth, so it is necessary to configure the ratio of aquatic organisms optimized for crop growth. This study proposes a method to measure the degree of growth based on area and volume using image processing techniques in an aquaponics environment. Tilapia, carp, catfish, and lettuce crops, which are aquatic organisms that produce organic matter through excrement, were tested in an aquaponics environment. Through 2D and 3D image analysis of lettuce and real-time data analysis, the growth degree was evaluated using the area and volume information of lettuce. The results of the experiment proved that it is possible to manage cultivation by utilizing the area and volume information of lettuce. It is expected that it will be possible to provide production prediction services to farmers by utilizing aquatic life and growth information. It will also be a starting point for solving problems in the changing agricultural environment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.4
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• pp.485-490
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• 2014

The aim of this study was to investigate the hypocholesterol effects of Opuntia humifusa extract in hypercholesterolemic rats. Rats (8-week-old, male) were randomly divided into four groups (n=4) as follows: N-control, normal diet; H-control, hypercholesterolemic diet; OH-1, 2% O. humifusa extract-supplemented hypercholesterolemic diet; OH-2, 4% O. humifusa extract-supplemented hypercholesterolemic diet. After 4 weeks, we observed that hypercholesterolemia induced significant increases in serum lipids (total cholesterol and LDL-cholesterol), hepatic lipids (total cholesterol and triglyceride), and hepatic function parameters (ALT, alanine aminotransferase; AST, aspartate aminotransferase) (P<0.05). Treatment with O. humifusa extract for 2 weeks normalized these indexes up to the levels of normal rats. O. humifusa extract tended to increase fecal lipid (H-control: 142.74 mg/day vs. OH-1: 214.05 mg/day; OH-2: 200.95 mg/day, P<0.05) and bile acid (H-control: 37.07 ${\mu}M/day$ vs. OH-1: 47.23 ${\mu}M/day$, OH-2: 47.93 ${\mu}M/day$, P<0.05) contents of hypercholesterolemic rats. We concluded that oral administration of O. humifusa extract effectively improved cholesterol metabolism in a hypercholesterolemic animal model induced by hypercholesterol diet.

• Analytical Science and Technology
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• v.17 no.4
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• pp.337-346
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• 2004

7-keto-dehydroepiandrosterone-acetate (7-keto-DHEA-acetate) is an anabolic steroids, and we studied basically to the metabolites of it after human dosing. We tested the matrix effect from human urine to detect the 7-keto-DHEA-acetate. And LC/ESI/MS and GC/MSD was used to detect the metabolites in dosed urine. We found the some unknown compound from dosed urine (M1, M2, M3, M4 and M5), and from these results, we supposed that these compounds have the more than 3 hydroxyl and/or ketone group. Metabolite M1 was supposed that molecular weight is 302 and 3-,17-diketone and 7-hydroxyl compound (7-OH-androstendione). Metabolite M2 was supposed that the molecular weight was same to M1 and 7-,17-diketone and 3-hydroxyl compound (7-keto-DHEA).

• Journal of Applied Biological Chemistry
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• v.64 no.1
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• pp.75-81
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• 2021

Recent gut microbiota studies have revealed the important roles of gut microbiota for our health. Increasing numbers of health functional foods have been developed every year. Development of functional food often includes ex- and in-vivo experiment to verify the beneficial effects of the functional food. To investigate effects of functional food on gut microbiota, animal models were often conducted. Beneficial effects of food can be evaluated based on how gut microbiota was shifted by food, which results in either increase in beneficial bacteria, decrease in potentially pathogenic bacteria or both. As animal experiments are generally time-consuming and laborious, we investigate how well in-vitro investigation of fecal microbiota may reflect dietary health benefits. Here, we tested 15 kinds of diets using two human subjects' fecal materials. Our results showed varying gut microbiota shifts according to diets, which suggested generally known beneficial diets (i.e. Kimchi, Chunggukjang) increased Lactobacillus and Bifidobacterium. Therefore, we suggest that in vitro fecal microbiota analysis could be used to evaluate beneficial effects of diets. Moreover, this method may be ideal to establish personalized diet.

• Journal of the Korean Chemical Society
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• v.65 no.4
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• pp.249-253
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• 2021

Litter and manure were obtained at a cow house of a livestock farm in Andondg city. We examined the change of formation of nitrogen and phosphorous from these samples and tried to suggest a more useful and realistic way for removing them. Constituent and its content of sample were identified by XRF. NO₂^-, NO₃^-, and PO₄^3- ions and NH₄⁺, T-P and T-N released from sample were analyzed using ion chromatograph and UV/Vis spectrometry, respectively. As the results of this study, the ammonia nitrogen in the early stage of cow excretion is a need to make an ammonia gas state that can be immediately volatile by increasing the pH. Nitrogen and phosphorous, the main source of nutrition in green algal bloom can be removed by transforming insoluble salts such as calcium phosphate (CaHPO₄·3H₂O) and struvite (NH₄MgPO₄·6H₂O), respectively, with addition of Ca and Mg after stimulating fermentation of manure.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.4
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• pp.223-233
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• 2010

Spatio-temporal variations of long-term water qualities (COD, SS, $Chl-{\alpha}$, N-related nutrients (TN, TDN, $NO_3^-$, $NH_4^+$), P-related nutrients (TP, TDP, $PO_4^{3-}$)) at two stations (St. SD, St. GG) in the Geumgang Reservoir were investigated from August 2001 to July 2008. Statistical methods such as t-test, factor analysis, and multi-regression analysis were applied to the water quality data in the reservoir as well as mass balances on TP. From the temporal comparisons of the water qualities between 2002 and 2007, average concentrations of $NH_4^+$, $PO_4^{3-}$, and TDP gradually decreased down by 60%, 24%, 52% in 2007. However, those of TP and $Chl-{\alpha}$ increased to 99% and 423% during the period. From the spatial comparisons between the two stations, St. GG showed higher concentrations for all of the N- and P-related nutrients than in St. SD, while opposite result for the $Chl-{\alpha}$. The factor analysis showed that "the seasonal variations of N- and P-related nutrients" were the two dominant factors occupying 49% of total variances of water qualities. Based on this result, multi-regression analysis executed for the two most influential parameters (TP and $Chl-{\alpha}$) focusing on the seasonal variations of these parameters: SS and $Chl-{\alpha}$ has contributed decisively to the concentrations of TP during the wet and dry season, respectively. On the other hand, COD and TP has been important for the $Chl-{\alpha}$ during the wet and dry season, respectively. From the established mass balances of TP loadings in the Geumgang Reservoir, Other Sources (60%) occupied the greatest contribution and Fluvial Input (38%) and Sediment (1%) during the wet season. However, both Fluvial Water (48%) and Other Sources (47%) supplied comparable amount of inputs and Sediment (5%) showed significantly increased input during the dry seasons. Recently especially during the dry winter seasons, migrating bird's excretion was estimated to contribute up to 8% of total TP input and 21% of Other Sources.

• Journal of Animal Environmental Science
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• v.13 no.1
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• pp.13-20
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• 2007

Sawdust biofiltration is an emerging bio-technology for control of ammonia emissions including compost odors from composting of biological wastes. Although sawdust is widely used as a medium for bulking agent in composting system and for microbial attachment in biofiltration systems, the performance of agitated bed composting and sawdust biofiltration are not well established. A pilot-scale composting of hog manure amended with sawdust and sawdust biofiltration systems for practical operation were investigated using aerated and agitated rectangular reactor with compost turner and sawdust biofilter operated under controlled conditions, each with a working capacity of approximately $40m^3\;and\;4.5m^3$ respectively. These were used to investigate the effect of compost temperature, seed germination rate and the C/N ratio of the compost on ammonia emissions, compost maturity and sawdust biofiltration performance. Temperature profiles showed that the material in three runs had been reached to temperature of 55 to $65^{\circ}C$ and above. The ammonia concentration in the exhaust gas of the sawdust biofilter media was below the maximum average value as 45 ppm. Seed germination rate levels of final compost was maintained from 70 to 93% and EC values of the finished compost varied between 2.8 and 4.8 ds/m, providing adequate conditions for plant growth.

• Korean Journal of Ecology and Environment
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• v.50 no.2
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• pp.266-274
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• 2017

We surveyed the habitat use and food materials of the endangered Swan Goose (Anser cygnoides) during the wintering period at the Seocheon tidal flat. The bird wintered about six months from October 2014 to early April 2015 at the flat. They showed a remarkable change in choosing their feeding habitat and prey. They stayed entirely at sedge grass patches on Songrim tidal flat during the early wintering period (October), while after November they gradually moved to Janggu bay and used rice paddy fields as well as sedge patches on the tidal flats as their feeding site. The dietary analysis showed the sedge grass (Bolboschoenus sp., Cyperaceae) was the main dietary source during the entire wintering period. Interestingly, the proportion of Cyperaceae on feces decreased slightly over wintering time, while the proportion of Fabaceae increased relatively since November. These results suggest that the Swan Geese switched their habitat and food sources in response to the change of food availability. The Seocheon tidal flat area is the important wintering site for Swan Geese and sedge grass patches in the area need to be managed as the main feeding area for the wintering Swan Geese.