• Journal of Korean Society on Water Environment
• /
• v.28 no.6
• /
• pp.911-916
• /
• 2012

Recently, antibiotic resistant genes (ARGs) in the environment are emerging as pollutants, since these genetic contaminants can eventually be transferred to human pathogens. The aim of this study was to develop the experimental model of antibiotic resistant gene (ARG) plasmid transfer as a function of various environmental conditions. For this purpose, the multi drug resistant plasmid pB10, which is known to be originally isolated from a wastewater treatment plant, was selected as a model transfer plasmid and Escherichia coli $DH5{\alpha}$ containing pB10 was used as a model donor. Pseudomonas aeruginosa, an opportunistic pathogen, was selected as the recipient for the conjugation experiment. When the donor and recipient were exposed to various stressors including antibiotics and heavy metal as a function of the concentrations (10, 100 and, 1000 ppb), statistically increased plasmid transfer rate was observed at a concentration of 10 ppb of tetracycline and sulfamethoxazole compared to control (no antibiotic exposure). Accordingly, the developed experimental ARG model by various stressor is a promising tool for evaluating the dissemination of ARGs by micro-contaminants in aquatic environment.

• Archives of Plastic Surgery
• /
• v.36 no.6
• /
• pp.795-798
• /
• 2009

Purpose: The repair of complex chest wall defects presents a challenging problem for the reconstructive surgeon. In particular, a free flap is often required when the defect is large, in which case suitable recipient vessels must be found to insure revascularization. The authors report a case of persistent bronchopleural - cutaneous fistula developed after undergoing lobectomy for lung cancer. Methods: The defect area was repaired using a free vertical rectus abdominis muscle flap revascularized by microvascular anastomosis to the 6th intercostal pedicle. The flap obliterated the right chest cavity, closed the site of empyema drainage, and aided healing of a bronchopleural - cutaneous fistula. Results: The patient has remained healed for 14 months without any postoperative complications and recurrent infection or fistula. Conclusion: We suggest that a rectus abdominis musculocutaneus free flap and intercostal pedicle as a recipient could be a useful method for repair of chest defects.

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 2000.11a
• /
• pp.88-90
• /
• 2000

Although primordial germ cells(PGCs) have been used in the production of germline chimera, efficiency has not been satisfactory. The Present study was conducted to improve efficiency of germline chimera production using the cultured gonadal PGCs(gPGCs). Germline chimeric chickens were produced by transfer of cultured gonadal primordial germ cells from Korean Ogol Chicken (KOC) to White Leghorn (5.5-day-old) and cultured in vitro for 10 days. Approximately 200 gPGCs (2-day-old) recipient embryos from which blood had been withdrawn via the dorsal aorta prior to the injection. Recipient embryos were incubated until hatching. Germline chimerism of the chickens reaching maturity was examined by mating them with Korean Ogol Chicken. Donor-derived offspring were identified as germline chimeric chickens based on their feather color. The frequency of germline transmission of donor PGCs ranged 1.9∼60.7%. There was no difference between both sexes. Therefore, it can be concluded that efficiency of germline chimerism can be improved via using cultured gPGCs.

• Korean Journal of Animal Reproduction
• /
• v.17 no.4
• /
• pp.287-294
• /
• 1994

This study was to investigate the effects of electrofusion, activation and developmental stage of donor embryos on in vitro development of nuclear transplant bovine embryos. A single blastomere nucleus from 8-cell to morula stage embryos produced by in vitro fertilization(IVF) was transferred into a recipient oocyte enucleated at 23∼25 h after in vitro maturation(IVM) or into a recipient oocyte enucleated and cultured for 14∼15 h. In one experiment the nuclear transplant embryos were subjected to additional activation treatments. Fusion rate of nuclear transplant eggs was high at direct current(D.C) voltages of 1.0 and 1.5 kV/cm 991.5 and 93.3%, respectively), but decreased at 2.0kV/cm (81.8%). Additional activation treatments by electric pulases or 7% ethanol did not affect the cleavage and development of nuclear transplant embryos. Development of nuclear transplant embryos slightly increased by delayed nuclear transfer and fusion (42∼43 h after IVM). With this system, blastocysts were obtained from transfer of 8-cell to morula stage donor nuclei (9.6%∼2.4%). The result of this study suggests that nucleo-cytoplasmic interactins, expecially activation of ooplast are very important for the development of nuclear transplant embryos, and donor cell stage does not affect the development of nuclear transplant embryos.

• Korean Journal of Animal Reproduction
• /
• v.22 no.2
• /
• pp.153-161
• /
• 1998

This study was conducted to examine the viability of nuclear transfer bovine embryos following embryo transfer. Donor embryos were treated with nocodazole to arrest their cell-cycle-stage at mitotic(M) phase. After releasing from nocodazole blastomeres were separated and transferred into the enucleated oocytes(BC), or cultured in medium with aphidicolin. Freshly cleaved blastomeres within 1.5h after cleavage(AC) and non-cleaved ones up to 3h after releasing from nocodazole(NC) were transferred into the enucleated oocytes. Blastocysts derived from nuclear transfer were transferred to Day 7~8 recipient cows. Some blastocysts were vitrified and thawed before embryo transfer. Developmental rates to the blastocyst stage were higher in AC(18.1%, P<0.05) than BC(8.6%) and NC(5.1%). Blastocyst development slightly enhanced with aphidicolin(1~2$\mu\textrm{g}$/ml) treatment(16.9~22.6%) compared to non treated control(11.1%). Survival rate fo vitrified nuclear transfer embryos after thawing was 75%(24/32). Twnety-three vitrified nuclear transfer embryos and 3 fresh ones were transferred to 23 recipients, 6 heads were pregnant and 1 male calf(24 kg) was born from a recipient cow recevied one vitrifiedthawed nuclear transfer embryo at 277 days after embryo transfer. This result suggests that the nuclear transfer embryos can developed to term after vitrification andembryo transfer.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.41 no.3
• /
• pp.1-10
• /
• 2018

The purpose of this study is to improve effectiveness of Korea's Official Development Assistance (ODA) provided to developing countries. To do this, we analyze the efficiency of ODA provided to 38 recipient countries by Korea through data envelope analysis method. The effects of four factors including population, GDP, economic decline and poverty, and external intervention on efficiency are also investigated by utilizing tobit regression analysis. As a result of the DEA efficiency analysis, it is found that the average efficiency score of the total is about 59%. By region, the average efficiency score of Asia, Africa, Central and South America, and the East and CIS (Commonwealth of Independent States) are about 42%, 68%, 70%, and 74%, respectively. It indicates that the Asian countries are inefficient compared to countries of the other regions. It is also found that factors of population, GDP, economic decline and poverty, and external intervention have statistically significant effects on efficiency at 0.01 significance level. In the case of the population, the higher the population of the recipient country, the more negative (-) effect is on the efficiency. The other factors such as GDP, economic decline and poverty, and external intervention have positive effects on the efficiency.

• Journal of information and communication convergence engineering
• /
• v.8 no.4
• /
• pp.355-364
• /
• 2010

A session transfer method, referred to as a Recipient Serving-call session control function (S-CSCF) Assured (RSA), is proposed in order to support both session mobility and consistency in IP multimedia subsystem (IMS) based next generation network (NGN). RSA session transfer simplifies a basic session transfer operation specified in [1] by using the user agent client (UAC) like characteristics of an S-CSCF. To show its efficiency, the session transfer delay and the traffic cost of RSA session transfer are investigated and compared with those of existing session transfer applications, including Assured and Consultative session transfers, by practically considering multiple session transfer failures. It is shown that RSA session transfer can further improve user experience by reducing session transfer delay as well as traffic cost than Assured and Consultative session transfers.

• International Commerce and Information Review
• /
• v.9 no.3
• /
• pp.287-304
• /
• 2007

Determination of the time and place of dispatch and receipt of electronic messages is an important element of the operation of many rules of law, particularly the timing of formation of the contract. In this paper, I reviewed interpretation and application of time and place of dispatch and receipt of electronic records in electronic transactions under the UNCITRAL(United Nations Commission on International Trade Law) Model Law on Electronic Commerce, USA Uniform Electronic Transactions Act and Korea Electronic Transactions Act. Time of dispatch and time of receipt are effective when received. The sender has the burden to prove that the electronic record is sent successfully to the information process system of the recipient. Therefore, to safety electronic transactions, the sender needs to request a confirm notice for receipt to the recipient when the electronic record is sent like the provisions of UNCITRAL Model Law on Electronic Commerce and Korea Electronic Transactions Act. By requesting the above, the sender is able to take precautionary measures for damage according to the failure of dispatch and receipt of the electronic records.

• Korean Journal of Microbiology
• /
• v.27 no.4
• /
• pp.422-429
• /
• 1989

Auxotrophic mutant were isolated from wild types by the treatment with NTG as a mutagen, and the conditions of protoplast formation for them were established. The protoplasts of killer yeast Saccharomyces cerevisiae K52 were formed to the level of above 70% when cells grown for 20 hr in PM medium were treated with 200 unit/ml Lyticase 50,000 at $30^{\circ}C$ for 60 min after pretreatment of 50 mM 2-mercaptoethanol in 10mM potassium phosphate buffer (pH 7.5) containing EDTA and 0.6 M sorbitol for 15 min. Also, the protoplast of the recipient S. cerevisiae S 29 were formed to the level of above 85% as it was cultured to the log phase of 24 hr in PM medium under the same conditions. The fusion frequency between the protoplast of killer yeast S. cerevisiae K 52 and the protoplast of recipient S. cerevisiae S 29 was reached to $8.2\times 10^{-6}$ when the hypertonic regeneration medium embeded with the fused protoplasts after mixing the parental protoplasts to 10$^{8}$ cells/ml in SP buffer containing 20 mM $CaCl_{2}$ and 30% PEG 6,000 for 15 min at $30^{\circ}C$ were incubated.

• Journal of Embryo Transfer
• /
• v.18 no.1
• /
• pp.81-84
• /
• 2003

This study was performed to produce Hanwoo-fetal fibroblast cell clone transferred to Holstein recipient. It was coming on the parturition but didn't show parturition signs until 272 days from the embryo transfer. For the induction of normal parturition, dexamethasone (20 mg) were injected with IM on 272 day and PG $F_{2a}$ (25 mg) plus estradiol (20 mg) was injected with IM after 24hrs. Forty-eight hours after dexamethasone injection, we could find parturition signs and delivered healthy male of offspring (40 kg) about 50 hrs after it's injection. However the recipient was showed retention of afterbirth.h.