• Korean Journal of Agricultural Science
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• v.33 no.1
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• pp.17-24
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• 2006

An experiment was conducted to investigate the effects of forced molting and egg storage time on the various egg qualities. A total of 240 ISA Brown layers (60 wk of age) were employed as the unmolted treatment (Control). Two hundred and forty ISA Brown layers, molted at the age of 55 wk, were used as a forced molting treatment (T1), and the same number and strain of layers, molted at the age of 70 wk, were also used as the another forced molting treatment (T2). A total of 120 eggs were sampled from each treatment, and divided into six sets, 20 eggs per set. These six sets were stored for 1, 3, 6, 9, 12, and 15 days at $18^{\circ}C$ temperature, respectively. Eggs from T1 were collected from laying hens at the age of 68 wk, which started molting at 60 wk of age and achieved 50% egg production at 63 wk of age. Eggs from T2 were collected from hens at 82 wk of age, which started molting at 70 wk of age and achieved 50% egg production at 78 wk of age. The eggshell strength of T1 was significantly (p<0.05) higher than the Control and T2, and the storing periods did not affect the eggshell strength at all. Neither the forced molting nor the storing periods did not exert any consistent effect on the egg weight, eggshell thickness, eggshell color and egg yolk color. The albumin heights of T1 and T2 were significantly (p<0.05) lower than the Control, and it was remarkably reduced gradually as the storage periods increased in all three treatments. The Haugh unit showed very similar trends as the albumin height, indicating that both albumin height and Haugh unit were very much related to each other. In conclusion, the forced molting improves the eggshell strength, but decreases the albumin height and Haugh unit. The storage of eggs also decreases the albumin height and Haugh unit regardless of molting.

• Korean Journal of Agricultural Science
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• v.20 no.2
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• pp.153-166
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• 1993

The experiments were conducted to improve raw milk quality during storage, the chemical composition and microbiological aspect of raw milk, milk thermized at $65^{\circ}C$ for 30 second, and $75^{\circ}C$ for 2 second stored at $5^{\circ}C$ for 4 days were investigated. The result obtained were summarized as follows : 1. During storage of raw and thermized milk, in the composition of milk fat, milk protein, lactose and total solid did not change significantly. 2. The range of pH and acidity for the raw milk were 6.73~5.94 and 0.16~0.27% respectively and those of the thermized milk were 6.79~6.62 and 0.16~0.17% respectively. The phosphatase test were negative in heated milk. 3. The composition of total nitrogen, NCN and whey protein were decreased, wherease those of NPN and casein were increased in heat treated milk. 4. The compositions of total nitrogen and casein were decreased as the storage period advanced, wherese those of NCN and NPN were increased. However, the composition of whey protein did not significantly change. 5. The number of coliform bacteria was not found in thermized milk. but were gradually increased in raw milk during storage period. 6. Raw milk had total bacteria count as $5.6{\times}10^6/ml$, psychrotrophic bacteria $1.8{\times}10^6/ml$ and thermoduric bacteria $1.6{\times}10^5/ml$, as the heat treatment increased microorganism counts decreased to milk thermized at $75^{\circ}C$, for 2 sec. $3.0{\times}10^3/ml$, $1.5{\times}10/ml$ and $2.7{\times}10^3/ml$ respectively. 7. The count of thermoduric bacteria, psychrotrophic bacteria and total bacteria were increased during storage period, and more rapidly increased in raw milk than in heat treated milk.

• Korean Journal of Agricultural Science
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• v.32 no.2
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• pp.205-214
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• 2005

The purpose of this study was to investigate the effect of ground corn as an additive to ginseng residue silages. The silages were made with corn (CS), red ginseng (GS), red ginseng residue +0.5% ground corn (GS0.5), w/w bases, red ginseng residue+1.0% ground corn (GS1.0) and red ginseng residue+silage inoculant, lactic acid bacteria (GSL). The raw materials were cut only for corn forage in 2cm length. The ginseng residue without cutting were mixed without or with additives, ground corn and inoculant, and ensiled each into two 2,000ml glass bottles. The bottles with silages were stored at a dark place at room temperature and formented for 60 days. The crude protein contents were higher for all red ginseng silages as 17.7, 18.8, 18.3 and 17.8% for GS, GS0.5, GS1.0 and GSL than that of corn silage as 8.8% (p<0.05). The calcium content were higher in GS, GS0.5, GS1.0 and GSL as 0.99, 1.13, 0.99 and 1.03% than that in CS as 0.31% (p<0.05). The pH of silages fermented for 60 days was similar each other; CS, GS, GS0.5, GS1.0 and GSL as 3.8, 3.7, 3.3, 3.5 and 3.7, respectively. However the pH of GS0.5 was the lower than that of corn silage. The total concentration of volatile fatty acids were higher for CS as 87.3 mM/dl than those of GS, GS0.5, GS1.0 and GSL as 44.7, 37.8, 46.3 and 47.2 nM/dl. However, the percentage of lactic acid concentration of ginseng silages such as GS, GS0.5, GS1.0 and GSL, 60.2, 77.2, 83.4 and 77.3% was higher than that in CS, 53.7% (p<0.05). The in vivo dry matter digestibilities for 72hr fermentation was higher in ginseng silages (GS, GS0.5, GS1.0 and GSL as 76.5, 75.8, 72.9 and 77.3%, respetively) than that in for CS as 52.1% (p<0.05). It can be concluded that silage added with ground corn (GS0.5 and GS1.0) and lactic acid inoculant were high in its quality, and the GS0.5 can be suggested as a practical method for red ginseng residues silage making.

• Korean Journal of Agricultural Science
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• v.14 no.2
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• pp.272-285
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• 1987

In order to obtain the data for the effective separation and purification of lysozyme from egg white, optimal conditions for the homogenization of egg white and lysozyme activities of some fresh hen eggs were examined. The recovery and purity of lysozyme isolated by the direct crystallization method, the adsorption with Bentonite and the batch method with Duolite were also investigated. The results obtained were summarized as follows; 1. On the homogenization of egg white, optimal stirring time and stirring rate for the measurement of the lysozyme activities were found to be 10 min. and 2,000 rpm respectively. 2. On the activities of lysozyme in the fresh hen eggs, the activities of W. Leghorn was greater than that of R. Island or Ogol fowl, and the activities of the thick white was a little greater than that of the thin white. 3. The residual lysozyme activities of the hen eggs stored at $4^{\circ}C$ was greater than that of the ones stored at $25^{\circ}C$ or $-20^{\circ}C$ over the storage periods. 4. Hen egg lysozyme recrystallized three times by the method of direct crystallization showed the recovery of 64.3% and the increase of 29 fold in specific activities. 5. By the adsorption method with bentonite, lysozyme in the egg white was adsorbed to 95.7%, and the elution rate of the ones adsorbed was 89.1%, and the increase in specific activities was 13 fold. 6. In the experiment exploying duolite as an adsorbent, Jysozyme in the egg white was obtained with the bound rate of 97%, the recovery rate of 84.8%, and was purified by 30fold.

• Korean Journal of Agricultural Science
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• v.9 no.1
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• pp.239-249
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• 1982

The outlines of superior stands, including species mixed, age classes, canopies, and ecological conditions of the stands, were examined in the forests of west Germany, Sweden, and Netherland. The establishment schemes of tree seed orchards for the production of high genetic quality seed were also investigated in the present study. 1. The meteorological conditions, abundant in precipitation and high in relative humidity, prove it to be oceanic climate characteristics in the Scandinavia located in high latitude and north-western part of Europe. The photo periodical characteristics following to day-length and the frost times determine the patterns of tree growth and distribution as well as the tree adaptability due to bud-setting and bud-flushing in Sweden forest. 2. The European forests are generally characterized by dense multistoried forest type composed of upper stories of tall tree species such as Norway spruce, fir, Scots pine and beech, lower stories of shade tolerant poles and saplings of spruce, fir, beech, and floor vegetations covered with birch, oak and hornbeam etc. 3. The single tree selection method and group shelterwood method are commonly applied for silvicultural system but shelterwood method and clearcutting method practiced partially in limited area. Badischer Femelschlagbetrieb and Bayerischer Femelschlagbetrieb are popularized to the regeneration of Schwarzwald but selection method applied in part. 4. Tree cuttings are properly limited so as not to exceed annual increment volume for the sustained yield and the preservation of ecosystem in European forest management. Land preservation and recreation function are more interested with the promotion of wood production in the forest management. 5. Careful attentions are paid to the reforestation of the introduced exotic species, such as Douglas-fir, red oak, pines from America, Japanese larch, Italian poplar etc., with concern against the insect and pest damage, and the meteorological damage. 6. Some intensive studies on tree improvement, such as selection of plus tree, selection of plus stand for seed collection, provenance trial, progeny test of clone, hybrid seed orchard for clone complexing, are performed in the countries and the great part of the seed required for reforestation are supplied from the seed orchard established in Sweden and Netherland.

• Conservation Science in Museum
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• v.22
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• pp.41-52
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• 2019

Inner walls of the stone chamber of West Ancient Tomb No. 1 and 2 in Neungsan-ri, Buyeo-gun have been inspected for possible trace of murals. Tomb No.1 has a rough surface finish of the stone wall and no traces of murals was observed in any part of the stone walls except the ceiling part of the main chamber. On the ceiling surface, there is black colored area, which showed same visual characteristics for both the surface and interior upon slight scratch of the surface, suggesting that it may not be a painted layer. In addition, this black material is not artificial stuff like black ink but is confirmed as biotite from X-ray diffraction analysis that is one of the constituents of the stone wall. In case of tomb No. 2, white material, that is confirmed as lime(calcite, CaCO3) by X-ray diffraction analysis, was observed on the wall surface of the east, west and north, suggesting possible existence of murals. The lime layers, however, are located mostly on the entrance of east wall of main chamber and the place of passage whereas they are observed only in lower parts on the other walls. It may have been formed by the inflow of soil and lime from the outside as the form of the lime layer in the east wall corresponds to the traces of soil and lime deposited from the thief pit. Furthermore, the filling material found in the gap between the stone slabs of the four directions and the ceiling was confirmed as clay soil, which is different material from the lime present on the stone wall surface. If the lime layer had been artificially constructed for the purpose of creating murals, it would have been more reasonable to use lime as well in the gap between the stone slabs of the four directions and ceiling. In this regard, we conclude that there are no murals in the Tomb No. 2 in the Neungsan-ri.

• Korean Journal of Agricultural Science
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• v.25 no.2
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• pp.168-175
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• 1998

To evaluate the storage characteristics of pheasant meat products, contents of aerobic, anaerobic and food poisoning bacteria as well as VBN were measured during storage at various temperatures. 1. During the storage Escherichia coli and food poisoning bacteria including Salmonella, Shigella and Staphylococcus were not detected from any of the pheasant meat products. 2. Total plate counts of aerobic and anaerobic bacteria increased with storage temperature, showing more than $10^6CFU/g$ of most pheasant meat products within 5~10 days of storage at $20^{\circ}C$ and $30^{\circ}C$. However, frank sausage, loin ham, pressed ham and salad showed less than $10^5CFU/g$ in 20~30 days of storage at $20^{\circ}C$. 3. When stored at $10^{\circ}C$, smoked product, electric roasted product and pressed ham showed the bacterial counts of more than $10^4CFU/g$ within 10 days of storage. Frank sausage, loin ham and salad, however, showed less than $10^3CFU/g$ in 10 days of storage at $10^{\circ}C$. 4. VBN contents of smoked product, electric roasted product and frank sausage exceeded edible limit of 20 mg%, showing more than 40 mg% and 80 mg% within 5 days and 10 days, respectively, of storage at $10^{\circ}C$. In contrast, loin ham, pressed ham and salad had the VBN of less than 20 mg% in 10 days of storage at $10^{\circ}C$. In summary, while pheasant meat products in general appear to be prone to microbial growth, loin ham and salad are thought to have a longer storage period than others, showing about 10 days of preservation at $10^{\circ}C$. Products other than loin ham and salad are suggested to be stored frozen or refrigerated at below $10^{\circ}C$.

• Korean Journal of Environment and Ecology
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• v.35 no.5
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• pp.480-489
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• 2021

Climate change poses great threats to wildlife populations by decreasing their number and destroying their habitats, jeopardizing biodiversity conservation. Asiatic salamander (Hynobiidae) species are particularly vulnerable to climate change due to their small home range and limited dispersal ability. Thus, this study used one salamander species, the Korean clawed salamander (Onychodactylus koreanus), as a model species and examined their habitat characteristics and current distribution in South Korea to predict its spatial distribution under climate change. As a result, we found that altitude was the most important environmental factor for their spatial distribution and that they showed a dense distribution in high-altitude forest regions such as Gangwon and Gyeongsanbuk provinces. The spatial distribution range and habitat characteristics predicted in the species distribution models were sufficiently in accordance with previous studies on the species. By modeling their distribution changes under two different climate change scenarios, we predicted that the distribution range of the Korean clawed salamander population would decrease by 62.96% under the RCP4.5 scenario and by 98.52% under the RCP8.5 scenario, indicating a sharp reduction due to climate change. The model's AUC value was the highest in the present (0.837), followed by RCP4.5 (0.832) and RCP8.5 (0.807). Our study provides a basic reference for implementing conservation plans for amphibians under climate change. Additional research using various analysis techniques reflecting habitat characteristics and minute habitat factors for the whole life cycle of Korean-tailed salamanders help identify major environmental factors that affect species reduction.

• Korean Journal of Breeding Science
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• v.42 no.5
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• pp.547-554
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• 2010

Low-molecular-weight glutenin subunit (LMW-GS) in common wheat (Triticum aestivum L.) is important for quality processing of bread and noodles. The objectives of this study were to clarify the composition of LMW-GSs and to identify their corresponding proteins. Using LMW-GS specific primers we cloned and characterized 43 LMW-GS genes in the wheat cultivar 'Jokyoung'. Some of these genes contain polypeptides different in size due to the presence of various deletions or insertions within repetitive and glutamine-rich domains. The comparison of deduced amino acid sequence of the LMW-GS genes in Jokyoung with that of 12 groups LMW-GSs of wheat cultivar Norin 61 showed that the deduced amino acid sequences were nearly the same to LMW-GS groups of 1, 2, 3/4, 5, 7, 10 and 11. All LMW-GS genes contain eight cysteine residues, which are conserved among all of the typical LMW-GS sequences. The relative positions of cysteine residues are also conserved, except those of the first and seventh. Based on phylogenetic analysis, the 43 sequences with the same N-terminal and C-terminal amino acid sequences were clustered in the same group. To identify the proteins containing the corresponding amino acid sequences, we determined the N-terminal amino acid sequence of 7 spots of LMW-GSs of Jokyoung separated by two-dimensional gel electrophoresis (2DE). Of them, Glu-B3 (LMW-m and LMW-s) and Glu-D3 (LMW-m) were detected in two and three spots, respectively and the others were not clear. Collectively, we classified diverse LMW-GSs and identified their corresponding protein products. These results will be helpful in breeding programs for improvement of wheat flour quality.

• Korean Journal of Environment and Ecology
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• v.33 no.2
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• pp.187-201
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• 2019

This study examined the physicochemical water quality and evaluated the ecological health in 14 sites of Geum River (upstream, mid-stream, and downstream) using the fish community distribution and guilds and eight multi-variable matrices of FAI (Fish Assessment Index) during June 2008-May 2009. The analysis of the water quality variables showed no significant variation in the upstream and mid-stream but a sharp variation due to the accumulation of organic matter from the point where the treated water of Gap and Miho streams flew. The analysis of physicochemical water properties showed that BOD, COD, TN, TP, Cond, and Chl-a tended to increase while DO decreased to cause eutrophication and algae development from the downstream where Miho and Gap stream merged. The analysis of fish community showed that the species richness index and species diversity index increased in the mid-stream area but decreased in the downstream area, indicating the stable ecosystem in the upper stream and the relatively unstable ecosystem in the downstream. The analysis of the species distribution showed that the dominant species were Zacco platypus that accounted for 20.9% of all fish species and Zacco koreanus that accounted for 13.1%. The analysis of the fish tolerance and feeding guild characteristics showed that the sensitive species, the insectivore species, and the aquatic species were dominant in the mid-stream point. On the other hand, contaminants from the sewage water treatment plant of Miho stream had a profound effect in the downstream to show the dominance of tolerant species, omnivorous species, and lentic species. Therefore, it is necessary to improve water quality by reducing the load of urban pollutants and to pay attention to the conservation and restoration of aquatic ecosystems.