• Asian-Australasian Journal of Animal Sciences
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• v.25 no.5
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• pp.738-748
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• 2012

One of the main goals of small, medium and large farms is to improve the reproductive performance of rabbit does. Stocks of lower productivity can be improved by crossing with intensive breeds. A better nutritional status of both foetuses and suckling kits has a positive effect on their later productivity. Overfeeding young females before first mating can lead to conditions of fattiness. Using restricted feeding or higher fibre content in the feed and changing it for a higher level ad libitum feeding about one week prior to first mating leads to longer lifespan and higher productive level. Intensive reproductive rhythm creates a negative energy balance in does : they are unable to consume enough feed (energy) for the nutritional requirements of foetus and lactation, and therefore lose most of their fat reserves. Furthermore, primiparous does also expend energy because they are still growing. Under intensive conditions, the 42-d reproductive rhythm (re-mating 11 days after parturition) is recommended. Under extensive conditions, the 18 or 25-d mating interval with 35 to 42-d weaning could be suitable. On small farms, natural mating is favoured; on large farms AI is commonly employed. The main advantage of AI is the all-in, all-out system. Hormonal (PMSG) treatment is used with AI to increase receptivity on d 11. Frequent and high level PMSG use can lead to higher anti-PMSG antibody rates. Lower level (max. 20 IU) and less frequent PMSG injection or non-hormonal alternative methods (short dam-litter separation, changing nursing method or lighting programs) are recommended for this reason.

• Journal of Korea Multimedia Society
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• v.8 no.11
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• pp.1421-1431
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• 2005

There are two methods in 3-D sound reproduction: a surround system, like 3.1 channel method and a binaural system using 2-channel method. The binaural system utilizes the sound localization principle of a human using two ears. Generally, a crosstalk between each channel of 2-channel loudspeaker system should be canceled to produce a natural 3-D sound. To solve this problem, it is necessary to trace a head movement. In this paper, we propose a new algorithm to correctly trace the head movement of a listener. The Proposed algorithm is based on the detection of face and eye. The face detection uses the intensity of an image and the position of eyes is detected by a mathematical morphology. When the head of the listener moves, length of borderline between face area and eyes may change. We use this information to the tracking of head movement. A computer simulation results show That head movement is effectively estimated within +10 margin of error using the proposed algorithm.

• Korean Journal of Agricultural Science
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• v.8 no.1
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• pp.11-17
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• 1981

The study was carried out to investigate the distribution and composition of community of Stewartia koreana in Temple Huibang and Mt. Sogri. The results obtained were as follows: 1. Within the forest floor cover species of the Temple Huibang forest, higher importance value were observed as Calamagrostis arundinacea. Sasa borealis. Lindera erythrocarpa and Lindera obtusiloba 2. In the forest floor cover species of Mt. Sogri forest, higher importance value were observed as Sasa borealis and Acer pseudo-sieboldianum var. koreanum 3. Within the floor cover species under Stewartia koreana forest, higher importance value were observed as Sasa borealis. Acer pseudo- sieboldianum var. koreanum and Calamagrostis arundinacea 4. Under shrub layer of Stewartia koreana stands, 73% of Sasa borealis and Calamagrostis arundinacea in Temple Huibang and 93% of Sasa borealis in Mt. Sogri were counted respectively as dominant species. Therefore, it might be necessary to control such dominant undergrowing species for natural reproduction of Stewartia koreana 5. In the Temple Huibang sites, by 700m Sasa borealis and 800m Calamagrostis arundinacea were grown as dominant species.

• International Journal of Highway Engineering
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• v.7 no.4 s.26
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• pp.185-202
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• 2005

In this research, to get over restrictions of a field expreiment, we modeled a planning road through the 3D Virtual Reality and achieved data about dynamic response related to sector fluctuation and about driver's visual behavior on testers' driving the Driving Simulator Car with Eye Camera. We made constant efforts to reduce the non-reality and side effect of Driving Simulator on maximizing the accord between motion reproduction and virtual reality based on data Driving Simulator's graphic module achieved by dynamic analysis module. Moreover, we achieved data of driver's natural visual behavior using Eye Camera(FaceLAB) that is able to make an expriment without such attaching equipments such as a helmet and lense. In this paper, to evaluate the level of road's safety, we grasp the meaning of the fluctuation of safety that drivers feel according to change of road geometric structure with methods of Driving Simulator and Eye Camera and investigate the relationship between road geometric structure and safety level. Through this process, we suggest the method to evaluate the road making drivers comfortable and pleasant from planning schemes.

• Development and Reproduction
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• v.2 no.1
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• pp.81-87
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• 1998

A scanning electron microscopic study on the glochidial encystment and excystment during the development of Anodonta arcaeformis flavotincta on Carassius auratus, a common natural host fish, was carried out. The glochidia were attached to the fins, buccal cavity and gills of the host fish within 30 minutes. In this study, the fins of host fish infected with the glochidia were examined in a time series. The attachment rates of the glochidia on the pectoral fins, caudal fin and pelvic fins of the host fish were 30%, 22%, and 17%, respectively. The glochidia which attached to the fish became encysted within 27 hrs. The process of encystment progressed slowly. Ti took 24 to 27 hours in the formation of the primary cyst, and after 5 to 6 days, the larvae was covered completely with the epithelial cels of the host tissues. The process of detachment of juvenile clam was observed on the 8th day after host infection. Most of the juvenile clams have sloughed from the cyst of the host within 15 days. No significant size difference was observed in the glochidia and the juvenile which were found before attachment and after detachment from the cyst of the host fish.

• Development and Reproduction
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• v.18 no.3
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• pp.173-178
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• 2014

In order to monitor the developmental features of embryos, larvae, and juveniles of Oryzias latipes (Temminck and Schlegel), Oryzias latipes was caught in river of Shinduck-dong, Yeosu-si, Jeollanam-do, on May 2011, and experiments were carried out in Ichthyology laboratory at Chonnam National University. The blastodisc step was the first level for natural spawning. The optic vesicle, Kupffer's vesicle, myotome began to appear 75 hours 57 minutes later. After blastodisc development, the pectoral fins were made at 143 hours 37 minutes and the tail was separated started at the same time. Hatching was observed at 167 hours 27 minutes after blastodisc. The total length of the hatched larvae was 4.95~5.10 mm (mean, 5.01 mm), the mouth and anus were opened. Larvae used yolk completely after 3 days after hatching. The total length larvae was 5.45~5.56 mm (mean, 5.52 mm) after 8 days after hatching, and appeared the stems for tail. The stems pectoral, anal fin were showed after 14 days and the stems dorsal, ventral fin were appeared after 19 days. For 35 days after hatching, the total length of larvae 13.95~15.30 mm (mean, 14.64 mm), and at this time, fins and body were transferred like the adult Oryzias latipes.

• Journal of Science Education
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• v.38 no.2
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• pp.231-243
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• 2014

The purpose of this study was to compare the duplication problem of achievement standards between science and other subjects in the 2009 Revised National Curriculum and to search for solutions and implications for this problem. From the results of this study, we found that the achievement standards of practical arts, social studies, physical education and ethics were overlapped with science's ones. The duplication of content elements for 'our body and health', 'living things and environment', 'biodiversity' and 'natural disaster' categories was not high, that is, their achievement standards were relatively well-differentiated and reflected the intrinsic characteristic of each subject under common topics. But, in case of 'reproduction and development' and 'world of technology' categories, the problem of duplications was serious. In order to cope with this problem, we need to consider solutions such as merging or integrating the achievement standards of related subjects. The relevant experts should conduct in-depth discussion and negotiation, and develop achievement standards more consistent with the identity of each subject.

• Journal of Embryo Transfer
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• v.15 no.2
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• pp.167-173
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• 2000

The principal objective of this study was to clone transgenic embryos in order to improve the efficiency of transgenic animal production by the combination of microinjection and nuclear transplantation techniques. Mature female New Zealand White rabbits were superovulated by eCG and hCG treatments, fllowed by natural mating. Zygotes were collected from the oviducts at 18∼22 h after hCG injection by flushing with D-PBS containing 5% fetal calf serum(FCS). Two to three picoliters of green fluorescent protein(GFP) gene wa microinjected into male pronucleus. The foreign gene-injected zygotes were cultured in TCM-199 or RD medium containing 10% FCS with a monolayer of rabbit oviductal epithelial cells in a 5% CO2 incubator. The morulae expressing GFP gene were selected and their blastomeres were separated for the use of nuclear donor. Following nuclear transplantation of fluorescence-positive morula stage blastomeres, 13 (21.3%) out of 61 fused oocytes developed to blastocyst stage and all of the cloned blastocysts expressed GFP. The results indicate that the screening of transgene in rabbit embryos by GFP detection could be a promisible method for the preselection of transgenic embryos. Also the cloning of preselected transgenic embryos by nuclear transplantatin could be efficiently applied to the multiple production of transgenic animals.

• Journal of Environmental Science International
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• v.26 no.12
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• pp.1341-1353
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• 2017

This study aimed to identify the aquatic and riparian factors associated with the presence/absence of the Eurasian otter in the Nakdong river basin, where the species is relatively more abundant than other otter species. Environmental factors and presence records were collected. Geographical Information System technology and chi-square test were used to compare environmental gradients in aquatic and riparian factors between presence and absence sites. Aquatic habitat attributes were evaluated with natural riverside sandbars and channel crossing artificial structures, the ratio of channel width to alluvial plain width, riverbed substrate, and flow diversity. Riverbank characteristics, bank materials, man-made embankment types, and land use/land cover of inland and riverside areas were selected as riparian habitat attributes. Compared to the aquatic attributes, riparian attributes were highly significant when assessing otter presence and absence sites, suggesting that conservation of suitable riparian areas to provide maternity and resting areas for otter species is essential in the Nakdong river basin. None of the aquatic attributes examined were statistically significant when evaluating otter presence or absence. These results indicate that the presence of suitable riparian area for resting and reproduction habitats is more critical to the presence of Eurasian otter than food availability in aquatic areas. To inform implementation of effective conservation actions, broad-scale factors, such as watershed attributes, would be needed to further assess habitat conditions of the Eurasian otter.

• Fisheries and Aquatic Sciences
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• v.19 no.1
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• pp.5.1-5.7
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• 2016

The study was conducted to know the cyclic changes in gonadal maturation and to investigate the developmental stages of oocytes and testicular germ cells of an air-breathing fish, Channa striata. Fish were sampled monthly from lentic and lotic environments of three geographical locations of Bangladesh from December to November and the histological analysis of their gonad was done to evaluate the objectives. The highest mean GSI was $5.95{\pm}0.20$ for female in July and $0.14{\pm}0.01$ for male also in July showing that the gonadal development reached its peak during this month. The highest mean oocyte diameter was $1257.50{\pm}24.17{\mu}m$ observed in July implying that the oocyte reached maturity in this month. Histological study of ovary revealed the evidence of early yolk granule stage and late yolk granule stage from April to July. In case of male four stages of spermatogenesis were distinguished and spermatozoa were highly abundant in June and July. So the monthly pooled values of GSI and the analysis of gonadal histology indicated that the peak breeding season of C. striata occurred in July in the lentic and lotic environments. Samples collected from lentic and lotic habitats are suggestive of no difference in the development of the gonad. The results of the present study will be useful for selective breeding programme, conservation and sustainable fishery management of C. striata in its natural habitat.