• Restorative Dentistry and Endodontics
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• v.9 no.1
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• pp.127-132
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• 1983

The purpose of this study was to examine the sealing ability of the vitapex, when used with gutta-percha cone, as a root canal filling material. Fourty five canals from extracted human maxillary and mandibular teeth were randomly selected and instrumented in a conventional method with k-file. After instrumentation and dry the canal with paper points, the canals were divided into three groups and fifteen canals in each group were filled with the following materials; Vitapex, Vitapex in combination with gutta-percha cone, and Gutta-percha cone and Zinc-oxide Eugenol Cement. All the specimens were immersed in 2% methylenblue dye solution and the depth of dye penetration into the canals were evaluated by macroscope at the intervals of 1 day, 2days and 7days. The following results were obtained; 1. All the materials experimented showed varying degrees of dye penetration. 2. The canals filled with Vitapex and Vitapex in combination with gutta perch a cone revealed sudden increase of dye penetration with time passage compared to the canals obturated with Gutta-percha cone and Zinc-oxide eugenol cement. 3. In the canals filled with Vitapex, the mean dye penetration was 1.6mm at 1day, but the specimen exposed to the dye for 7days showed mean dye penetration of 9.2mm. 4. In the canals obturated with Vitapex and gutta-percha cone, the mean dye penetration was 2mm at 1day, 2.2mm at 2days, and 8mm at 7days.

• Journal of Marine Bioscience and Biotechnology
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• v.3 no.1
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• pp.24-30
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• 2008

Fishing in Kenya, until the discovery of Nile perch as an export commodity in the early 1990s, has basically a subsistence occupation for the lake and coastal communities. The government also did not recognize the importance of fisheries as a contributor to the macro-economy and therefore, did not pay much attention in terms of resource allocation for the development of the sector. Most fishing in Kenya is artisanal, with a little industrial fishing by prawn trawlers. The deep sea (EEZ) fishery resources are currently exploited by DWFNs through a licensing system. Only a small quantity of catch from the EEZ is landed in Kenya, primarily tuna loins for processing for export. Currently capture fisheries, mainly from Lake Victoria, earn local fishers over Kenya shillings (K Sh) 7 billion, while exports earn the country K Sh 5 billion (US$ 50 million) in foreign exchange annually. The government has been putting in place an enabling environment to promote investment activities in order to achieve economic recovery as well as for the development and sustainable use of fisheries resources in the country within the specified period. The Department's major roles are to ensure sustainable exploitation of fisheries resources; to promote aquaculture development; to assure quality and safety of fish and fishery products; and to facilitate fish marketing in order to maximize the benefits that can be derived from fisheries. The contribution of fisheries to local incomes, subsistence and food nutrition is significant, as this occurs in areas with the highest incidences of poverty in the country.

• Journal of Animal Environmental Science
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• v.16 no.3
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• pp.181-192
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• 2010

This review was performed to investigate the current researches on the welfare of rearing environments system in farming chicken, including stocking density, perch, housing system and research trend. The investigation indicated that most of the developed countries took much efforts into making appropriate regulations to improve the welfare of rearing environment about broilers and laying hens, particularly more parts in laying hens. Recently the regulations have varied a lot, to be more detailed than before. Moreover, some regulations give valuable suggestions to improve well-being of poultry industry such as additional facilities. Until now it has been known, the quality of the products will improve and the income of producers will increase along with the improvement of welfare. Therefore the relevant agencies and organizations can strengthen the belief of consumers especially the competition is so fierce today. In conclusion, improvement of poultry welfare should be carried out in the real situation and international trends to create the appropriate rules such as professional consulting and training.

• Journal of Veterinary Clinics
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• v.36 no.1
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• pp.82-84
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• 2019

A common kestrel (Falco tinnunculus) was presented with inability to stand and fly at Chungnam Wild Animal Rescue Center. The kestrel showed non-weight bearing ambulation on both legs and crepitation with no external wound. Radiographs revealed a fracture on mid-diaphysis of right tibiotarsus and a distal end fracture of left femur. Intramedullary pinning was chosen for reduction of both fractures. The right tibiotarsal fracture was corrected first, and left femur was repaired 5 days later. The kestrel was managed with a specially designed sling to prevent further iatrogenic damage for 2 weeks. Three weeks after the surgery, the kestrel was able to stand and found to perch in 4 weeks. On 5 weeks, The kestrel could fly free at outdoor aviary and was released through rehabilitation for 3 months finally.

• Korean Journal of Ecology and Environment
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• v.35 no.3 s.99
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• pp.232-236
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• 2002

In an effort to uncover the reproduction of Korean brook perch Coreoperca herzi testis anatomy and sperm morphology were studied. Fish samples were collected in the Sooypcheon river from May to October 2001. White-colored testes have wedgeshaped external morphology, and developed symmetrically in the dorsal cavity of the trunk. Isogenetic germ cells developed in the cyst located in seminiferous lobule. Each lobule showed significant asynchrony in the spermatogenic stage of the cyst. Sperm was 43 ${\mu}$m in length. The round head was 2.2 ${\mu}$m long. The middle piece developed beneath the head was 0.5 ${\mu}$m long. Tail was 40 ${\mu}$m in length. Coomassie brilliant blue (CBB) gave rise the intense staining in the apex of sperm head and middle piece, suggesting the possible development of acrosome.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.2
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• pp.170-177
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• 2018

Samples were obtained from broodstork in May, 1998, while naturally fertilized embryos were maintained and the process of skeletal development was observed from larvae and juveniles. Prelarvae immediately after hatching showed an average total length of $5.38{\pm}0.41mm$ (n=10), premaxillary and dentary were ossified, parasphenoid was ossified in the cranium, and centrum and caudal bone did not ossify. Prelarvae showed ossification with maxillary, articular and epihyal and branchiostegal rays of hyoid arch were ossified at 5 days after hatching with an average total length of $6.40{\pm}0.39mm$ (n=10). The vertebrae began to ossify in the direction of the tail, and neural spine began to ossify above the ossified vertebra. Postlarvae showed ossification of lateral ethmoid, parietal, and caudal skeleton in the cranium when the average total length was $7.30{\pm}0.12mm$ (n=10) in 8 days after hatching. At 22 days after hatching, postlarvae ossified maxillary in the cranium, and ossified endopterygoid and ectopterygoid, etc. in the palate, when the average length of $11.1{\pm}1.27mm$ (n=10). At 32 days after hatching, with the average length was $12.8{\pm}1.97mm$ (n=10), caudal skeleton had one additional epural bone ossification, resulting in ossification of a total of 3 epural bone to complete ossification of all spicules.

• Korean Journal of Veterinary Research
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• v.30 no.4
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• pp.479-485
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• 1990

This study was carried out to observe in vitro effect of praziquantel on the viability and internal organ changes of Heterophyopsis continua with light microscopy. Metacercariae were collected from the perch, Lateolabrax japonicus, by artificial digestion technique and fed to 2-week old chickens. Adult worms were recovered from the small intestines of chickens 8 days after infection. For working solutions, praziquantel was diluted with TC199 medium at the concentration of 0.01, 0.1, 1 and $10{\mu}g/ml$. To each petri dish containing 10ml of solution, 5~10 worms were introduced and incubated at $37^{\circ}C$. Motlity of worms was observed at 5, 15, 30, 60 minutes, 1, 2, 4 and 6 hours after incubation. For light microscopy, worms were fixed in 10% formalin under cover glass pressure and stained with Semichon's acetocarmine. The results were as follows: 1. In $0.01{\mu}g/ml$ praziquantel, the worms had their mobility until 6 hours post treatment. However, worms in over $0.1{\mu}g/ml$ of praziquantel contracted within 5 minutes and immobilized. 2. Intestine of the worm incubated in $0.001{\mu}g/ml$ praziquantel for 5 minutes was dilated and intestinal wall was thickened. 3. In incubated over $0.1{\mu}g/ml$ praziquantel, pharynx of the worm protruded out from oral sucker. 4. The lowest effective lethal concentration of praziquantel on H. continua was $0.1{\mu}g/ml$. The worms exposed to the drug were observed to be immobilized immediately after incubation in solutions of over $0.1{\mu}g/ml$ concentration. All of the worms in early period showed severe contraction and those in late period showed severe dilation.

• Korean Journal of Organic Agriculture
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• v.28 no.4
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• pp.643-658
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• 2020

Animal welfare has become a prominent concern around the world so that the laws and guidelines of animal welfare are being strengthened in many countries including the EU. In Korea, it is required to supplement animal welfare standards because social awareness of animal welfare has changed. This study was conducted to compare broiler welfare certification standards and improve the quality of practice. We found that broiler welfare certification standards differ among countries according to environmental and managemental differences. Standards for stocking density and perch which is considered more important for poultry welfare are similar, but there is a little difference in feed, water, litter and lighting. Therefore, we assumed that theses are able to revise standards taking into account the environment and suggested that the broiler welfare certification standard will serve as a more useful criterion if breeding conditions in Korea are considered.

• Korean Journal of Ecology and Environment
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• v.44 no.2
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• pp.172-177
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• 2011

The study sought to determine the efficient management of Korean aucha perch by estimating the potential yield (PY), which means the maximum sustainable yield (MSY) based on the optimal stock, in the mid-upper region of the Seomjin River watershed from August 2008 to April 2009. The stock assessment was conducted by the swept area method and PY was estimated by a modified fisheries management system based on the allowable biological catch. Also, the yield-per-recruit analysis (Beverton and Holt, 1957) was used to review the efficient management of resource, Coreoperca herzi. The age at first capture ($t_c$) was 1.464 age and converted body length was 7.8 cm. Concerning current fishing intensities, the instantaneous coefficient of fishing mortality (F) was estimated to be 0.061 $year^{-1}$; yield-per-recruit analysis estimated the current yield per recruit as 4.124 g with F and $t_c$. The fishing mortality of Allowable Biological Catch ($F_{ABC}$) based on the current $t_c$ and F was estimated to be 0.401 $year^{-1}$, therefore, the optimum fishing intensities could be achieved at the higher fishing intensity for Coreoperca herzi. The calculated annual stock of Coreoperca herzi was 3,048 kg, the potential yield was estimated to be 861 kg with $t_c$ and $F_{ABC}$ at the fixed current level. Using yield-per-recruit analysis, if F and $t_c$ were set at 0.643 $year^{-1}$ and 3 age, respectively, the yield per recruit would be predicted to increase 3.4-fold, from 4.12 g to 13.84 g.

• Korean Journal of Ecology and Environment
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• v.43 no.1
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• pp.82-90
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• 2010

The ecological characteristics of the Korean Aucha perch, Coreoperca herzi, were determined in order to estimate stock of the mid-upper system of the Seomjin River. The age was determined by counting the otolith annuli. The oldest fish observed in this study was 5 years old. Relationships between body length (BL) and body weight (BW) were $BW=0.0195BL^{3.08}$ ($R^2=0.966$) (p<0.01). Relationships between the otolith radius (R) and body length (BL) were BL=3.882R+1.66 ($R^2=0.944$). The von Bertalanffy growth parameters estimated from a non-linear regression method were $L_{\infty}=19.68\;cm$, $W_{\infty}=188.64\;g$, $K=0.17\;year^{-1}$ and $t_0=-1.46$ year. Therefore, growth in length of the fish was expressed by the von Bertalanffy's growth equation as $L_t=19.68$ ($1-e^{-0.17(t+1.46)}$) ($R^2=0.997$). The annual survival rate (S) was estimated to be $0.666\;year^{-1}$. The instantaneous coefficient of natural mortality (M) of estimated from the Zhang and Megrey method was $0.346\;year^{-1}$, and instantaneous coefficient of fishing mortality (F) was calculated $0.061\;year^{-1}$. From the estimates of survival rate (S), the instantaneous coefficient of total mortality(Z) was estimated to be $0.407\;year^{-1}$.