The present study was conducted to examine the effect of antioxidant treatment during parthenogenetic activation procedure on the reactive oxygen species (ROS) levels and in vitro development of porcine parthenogenetic embryos. Porcine in vitro matured oocytes were activated by a combination of electric stimulus and 2 mM 6- dimethylaminopurine (6-DAMP) before in vitro culture. During the activation period, oocytes were treated with 50 μM β-mercaptoethanol (β-ME), 100 μM L-ascorbic acid (Vit. C) or 100 μM L-glutathione (GSH). To examine the ROS level, porcine parthenogenetic embryos were stained in 10 μM dichlorohydrofluorescein diacetate (H2DCFDA) dye 20 h after culture, examined under a fluorescence microscope, and the fluorescence intensity (pixels) were analyzed in each embryo. The parthenogenetic embryos were cultured for 6 days to evaluate the in vitro development. The apoptosis was measured by TUNEL assay. The H2O2 levels of parthenogenetic embryos were significantly lower in antioxidant treatment groups (26.9±1.6～29.1±1.3 pixels/embryo, p<0.05) compared to control (33.2±1.7 pixels/embryo). The development rate to the blastocyst stage was increased in antioxidant treatment groups (32.0～32.5%) compared to control (26.9%, p<0.05), although, there was no difference in apoptosis among groups. The result suggests that antioxidant treatment during parthenogenetic activation procedure can inhibit the ROS generation and enhance the in vitro development of porcine parthenogenetic embryos.

토마토 TYLCV는 병이 발생되면 약제나 다른 방법으로 방제가 어려우므로 내병성 품종의 개발이 반드시 필요하다. 특히, TYLCV 저항성 유전자 Ty-1,2,3(부분우성)을 한 개체 내로 집적을 시켜서 저항성이 증대된 품종의 개발이 필요하다. 토마토 TYLCV 저항성 11-TY1-AV 등 7계통을 대상으로 보독인 담배가루이를 이용하여 표현형을 조사하였다. 이병성 대비(11-TY5-AV; 슈퍼썬로드)와 F3 세대 3계통 및 F2 세대 4계통을 TYLCTHV 균주를 이용하여 접종하였다. 접종 13일 후에 이병성 대비가 100% 이병증상을 나타내었으며, 이때 11-TY4-AV는 48개체 중에서 23개체가 이병되었으며, 11-TY6-AV는 42개체 중에서 14개체, 11-TY7-AV는 48개체 중에서 14개체, 11-TY8-AV는 48개체 중에서 15개체가 이병 되었다. F2 세대 4 집단 모두 p>0.05 수준에서 TYLCV 접종 후 표현형이 정상적인 유전분리비(3:1)를 보이는 것을 확인 하였다. 또, TYLCV에 저항성인 동일한 자원을 부계로 사용하더라도 모계로 어떤 것을 사용 하느냐에 따라서 저항성 정도가 다르게 나타나는 것을 확인할 수 있었다.

The Oriental White Stork (Ciconia boyciana) is a representative wetland species distributed across East Asia. The species has been declined to face the threat of species extinctions with estimation of at about 3000 individuals. In order to re-introduce the endangered storks in the field, we developed a baseline model using the program VORTEX, performed sensitivity test, and finally suggested an ideal model based on results of the sensitivity test. The baseline model predicted 12.5% extinction probability with mean time to first extinction of 82.0 year. Sensitivity test revealed that two demographic variables (first-year mortality and percent of adult female breeding) had the greatest impacts on population persistence. Thus, corrected model improved the population persistence, where the extinction probability decreased to 1.0% in 100 years by changing values of two variables within a range of applicable to the population. Our models for stork re-introduction suggest this population will be stable by improving first-year mortality and adult female fecundity.

The current standard solutions for somatic cells used for calibration of electronic somatic cell counts as reference material in raw milk are preserved with bronopol, boric acid, sodium azide, or potassium dichromate, and have a shelf-life of only up to 6 days at 4 ± 2℃. In the present study, a set of somatic cell standard solutions (SCSS) with a stability of 5 months for calibration of electronic instruments was developed. Somatic cells collected from cow’s milk and stored in a bulk tank at a dairy plant were treated with 10% formaldehyde in order to improve stability, and then separated by centrifugation. The resulting somatic cell suspension was preserved with glycerin, thimerosal, and dimethyl sulfoxide, and diluted in 3% processed skim milk solution ranging from 200,000～250,000 (low level), 350,000～ 450,000 (medium level), and 550,000～650,000 (high level) cells/㎖. Each SCSS was verified by direct microscope somatic cell counting (DMSCC), C-reader, and commercial standard samples. The average somatic cell count determined by DMSCC was 248, 214, 226 × 103 cells/㎖, 436, 382, 420 × 103 cells/㎖, and 612, 595, 609 × 103 cells/㎖. The coefficient of variation representing the repeatability of DMSCC decreased as the number of cells increased, and was <10.0% in almost all SCSS samples (range 4.6～7.1%). No statistically significant difference in somatic cell concentration was observed after storage at refrigeration temperature (2～6℃) over a period of 22 weeks (5 months). The stabilized SCSS may be useful as a reference material for determination of somatic cell count and quality control in testing of bovine raw milk.

This study was conducted to examine the optimal concentration and treatment time of antioxidants for inhibition of the ROS generation in bovine somatic cell nuclear transfer (SCNT) embryos. Bovine oocytes were activated parthenogenetically, during which oocytes were treated with various antioxidants to determine the optimal concentrations and kind of antioxidants. Determined antioxidants were applied to oocytes during in vitro maturation (IVM) and/or SCNT procedures. Finally, antioxidant-treated SCNT embryos were compared with in vitro fertilized (IVF) embryos. H2O2 levels were analyzed in embryos at 20 h of activation, fusion or insemination by staining of embryos in 10 μM 2'7'-dichlorodihydrofluorescein diacetate (H2DCFDA) dye, followed by fluorescence microscopy. H2O2 levels of parthenogenetic embryos were significantly lower in 25 μM β- mercaptoethanol (β-ME), 50 μM L-ascorbic acid (Vit. C), and 50 μM L-glutathione (GSH) treatment groups than each control group (24.0±1.5 vs 39.0±1.1, 29.7±1.0 vs 37.0±1.2, and 32.9±0.8 vs 36.3±0.8 pixels/embryo, p<0.05). There were no differences among above concentration of antioxidants in direct comparison (33.6±0.9～35.2±1.1 pixels/embryo). Thus, an antioxidant of 50 μM Vit. C was selected for SCNT. H2O2 levels of bovine SCNT embryos were significantly lower in embryos treated with Vit. C during only SCNT procedure (26.4±1.1 pixels/embryo, p<0.05) than the treatment group during IVM (29.9±1.1 pixels/embryo) and non-treated control (34.3±1.0 pixels/embryo). Moreover, H2O2 level of SCNT embryos treated with Vit. C during SCNT procedure was similar to that of IVF embryos. These results suggest that the antioxidant treatment during SCNT procedures can reduce the ROS generation level of SCNT bovine embryos.

‘Gonji-5ho’ a new variety of oyster mushroom, fitting for the bag culture, was bred by mating between monokaryons isolated from ‘Chiak-3ho’ and ‘Suhan-1ho’ . In the major characteristics of fruit body, the pilei were thick and gray and the stipes were thick and long with softness. It was great in elasticity and cohesivness of tissue as compare to Suhan-1ho. Compared to other varieties, it is suitable to growing at higher temperature. The range of optimum temperature for the mycelial growth was around 26～29℃ and that for the pinheading and growth of fruitbody was around 18～20℃. But when grown in less than 15 degree, it was become non-uniform growth, longer culture period, and uneven stipes. In the bag culture, it was required around 18 days in incubation period and 3 days in primordia formation. The fruit body was grew vital and uniform. The yield were shown by 221.4g/1kg bag.

The present study was conducted to examine the generation of reactive oxygen species (ROS) during micromanipulation procedures in bovine somatic cell nuclear transfer (SCNT) embryos. Bovine enucleated oocytes were electrofused with donor cells, activated by a combination of Ca-ionophore and 6-dimethylaminopurine culture. Oocytes and embryos were stained in dichlorodihydrofluorescein diacetate or 3'-(p-hydroxyphenyl) fluorescein dye and the H2O2 or ˙OH radical levels were measured. In vitro fertilization (IVF) was performed for controls. The samples were examined with a fluorescent microscope, and fluorescence intensity was analyzed in each oocyte and embryo. The H2O2 and ˙OH radical levels of reconstituted oocytes were increased during manipulation (37.2~49.7 and 51.0~55.2 pixels, respectively) as compared to those of mature oocytes (p<0.05). During early in vitro culture, the ROS levels of SCNT embryos were significantly higher than those of IVF embryos (p<0.05). These results suggest that the cellular stress during micromanipulation procedures can generate the ROS in bovine SCNT embryos.

The present study was conducted to examine the reactive oxygen species (ROS) generation levels in porcine parthenogenetic embryos. Porcine in vitro matured oocytes were activated by the combination of electric stimulus and 6‐ DMAP before in vitro culture. Porcine oocytes and parthenogenetic embryos were stained in 10 μM dichlorohydrofluorescein diacetate (DCF) or 10 μM hydroxyphenyl fluorescein (HPF) dye each for 30 min at 39℃. The fluorescent emissions from the samples were recoded as JPEG file and the intensity of fluorescence in oocytes and embryos were analyzed. H2O2 and ˙OH radical levels of porcine oocytes were reduced immediately after electric stimulation. However, H2O2 and ˙OH radical levels of parthenogenetic embryos were increased with time elapsed after electric stimulation from 0 h to 3 h and after DMAP culture. During in vitro culture, H2O2 and ˙OH radical levels were gradually increased from the one‐cell stage to the two‐ and four‐cell stages. The result of the present study suggests that the ROS was not increased by electric pulse in porcine embryos. Rather than it seems to be associated with the stage of development and the culture condition.

최근 국제원자력기구와 방사성폐기물 분야 주요 선도국들은 리스크 차등접근법에 따라 방사성폐기물의 분류기준을 세분화하고 있는 추세이며, 이러한 맥락에서 극저준위폐기물을 새로운 방사성폐기물 범주로서 신설하거나 이에 대한 별도의 최적 관리방안을 모색하고 있다. 국제적으로 운영 사례가 점차 증가되고 있는 주요 국가의 극저준위폐기물 전용 공학적 표층매립형 처분시설들은 방사성핵종의 격리 및 지연성능 측면에서 1960년대 주로 건설된 천층 트렌치형 중·저준위폐기물 처분시설 보다 개선된 것으로 분석되었다. 또한 주요 선도국들의 극저준위폐기물 관리방안은 규제해제 제도, 중·저준위폐기물 처분시설 및 비원자력 폐기물매립장의 활용 가능성, 사회수용성 등에 따라 차이가 있는 것으로 나타났다. 이와 관련하여, 국내에서도 향후 대형 원자력시설의 해체에 대비하여 극저준위폐기물의 최적 관리방안에 관한 종합적인 검토와 논의를 통해 리스크 차등접근법에 따른 최적화된 관리방안을 사전에 수립하고, 이를 국가 방사성폐기물 관리정책 및 관리계획의 틀 내에서 체계적으로 시행할 필요가 있다.

This article illustrates the complicated process of language socialization and literacy development with identity reformulations that Korean students face while learning English in U.S. schools. With providing a detailed and broad picture of second language literacy development across time, the article presents two research-based studies conducted at the elementary and secondary levels respectively. Despite the constant growth of the Korean population in the USA for decades, few research studies have examined the ways that newly arrived Korean students engage in language learning and literacy practice along with changes in life, language, literacy, and culture. The presented studies employed ethnographic data gathering methods and utilized methods of constant comparison, discourse analysis, and narrative analysis. The first study focuses on literate identities of second grade Korean students in the English as a Second Language (ESL) classroom. The second study explores how Korean adolescents engage in school writing practice and how they negotiate their identities in and with writing through a case study.

Plasminogen activators (PAs) are serine protease that cleave plasminogen to form the active protease plasmin and may participate in mammalian fertilization. Although correlations have been reported between reactive oxygen species (ROS) and sperm function, the relationship between PA activity and ROS is unknown. We determined the effects of ROS on sperm function and PA activities in boar spermatozoa preincubated under the X-XO system. When spermatozoa were treated with the X+XO group, a significant increase (p<0.05) was observed in the percentage of acrosome reacted spermatozoa compared with that of the control group. However, when antioxidants were added to the medium with X+XO, the rate of acrosome reaction tended to decrease. Also, a significantly lower percentage of acrosome reacted spermatozoa was observed in the X+XO+catalase group at 6 hr of incubation compared with that of X+XO group. The density of malondialdehyde (MDA) was higher in the X+XO group than in different treatment groups. In another experiment, incubation of spermatozoa in medium with X+XO was associated with a significant (p<0.05) increase in activity of tPA-PAI and tPA compared with the control group. Antioxidants decreased the increased activity of tPA-PAI and tPA by preincubation in the X-XO system. Also, a significantly lower (p<0.05) activities of tPA-PAI and tPA were observed in the X+XO+catalase group compared with the X+XO group. No significant differences, however, were observed in the activity of uPA. These results suggest that the increase of acrosome reaction by the X-XO system resulted in increase of PAs activity in the sperm incubation medium.

방사성핵종의 분포유형에 관한 정보에 기초하여 극저준위폐기물의 자체처분 적합성을 통계학적으로 해석할 수 있는 방법론을 개발하였다. 방사성핵종의 분포에 관한 정보를 알 수 없는 경우에 대해서는 널리 알려진 마코프 부등식과 체비셰프 부등식을 적용하여 방사능농도의 산술평균과 허용되는 최대 표준편차의 상관관계식을 제시하였고, 방사성핵종의 농도가 정규분포 또는 로그정규분포를 갖는 경우에 대해서는 확률밀도함수, 누적확률밀도함수 등의 통계학적 관계식을 이용하여 방사능농도의 산술평균과 허용되는 최대 표준편차의 상관관계식을 새롭게 유도하였다. 또한, 자체처분기준 100 Bq/g 및 신뢰수준 95%인 조건에 대한 사례 적용연구를 통하여 방사능농도의 산술평균과 허용되는 표준편차의 범위를 방사성핵종의 분 포유형에 따라 정량적으로 비교·제시하고, 자체처분 대상 폐기물의 방사성핵종 분포유형에 관한 정보가 확보될 경우 동일한 신뢰수준에서 자체처분이 허용될 수 있는 범위가 확장될 수 있음을 통계학적으로 입증하였다.

We investigated the microtubule dynamics, including the inheritance of donor centrosomes and the mitotic spindle assembly occurring during the first mitosis of somatic cell nuclear transfer (SCNT) embryos in pigs. SCNT embryos were fixed 15 min and 1 h after fusion in order to assess the inheritance pattern of the donor centrosome. The distribution and dynamic of the centrosome and microtubule during the first mitotic phase of SCNT embryos were also evaluated. The frequency of embryos evidencing γ‐gtubulin spots (centrosome) was 93.2% in the SCNT embryos 15 min after fusion. In the majority of the SCNT embryos (61.5%), however, no centrosome was observed 1 h after fusion. The frequency of the embryos with no or abnormal mitotic spindles 20 h after fusion was 19.6%. The γ‐gtubulin spots were detected near the nuclei of somatic cells regardless of cell cycle phase, whereas γ‐g tubulin spots in the SCNT embryos were observed only during the inter‐ganaphase transition. These results showed that the donor centrosome is inherited into the SCNT embryos, but failed to assemble the normal mitotic spindles during first mitotic phase in some SCNT embryos.

We attempted to control the maturation promoting factor (MPF) activity and investigated the subsequent reprogramming of bovine somatic cell nuclear transfer (SCNT) embryos. Serum‐starved adult skin fibroblasts were fused to enucleated oocytes treated with 2.5 mM caffeine or 150 μM roscovitine. The MPF activity, nuclear remodeling patterns, chromosome constitutions and development of SCNT embryos were evaluated. Methylated DNA of embryos was detected at various developmental stages. The MPF activity was increased by caffeine treatment or reduced by roscovitine treatment (p<0.05). Blastocyst development was higher in the caffeine‐treated groups (27.6%) than that of the roscovitine‐treated group (8.3%, p<0.05). There was no difference in the apoptotic cell index among the three groups. However, the mean cell number of blastocysts was increased in the caffeine‐treated group (p<0.05). Higher methylation levels were observed in the Day 3 embryos of the roscovitine‐treated group (50.8%), whereas lower methylation levels were noted at Day 5 in the caffeine‐treated group (12.5%, p<0.05). These results reveal that the increase in MPF activity via a caffeine‐treatment creates a more suitable condition for nuclear reprogramming after SCNT.

‘Samkang’ a new variety of oyster mushroom, fitting for the bottle culture, was bred and by mating between monokaryons isolated from MT05433 and AE1-1. In the major characteristics of fruit body, the pilei were thick and dark-gray and the pileistripes were thick and long with softness. It was great in elasticity and cohesivness of tissue as compare to chunchu-1ho. The optimum temperature for the mycelial growth was around 26~28℃ and that for the pinheading and growth of fruitbody was around 14~16℃. In the bottle culture, it was required around 26 days in incubation period and 4 days in primordia formation. The fruit body was grew vital and uniform. The yield were shown by 136.5g/bottle.

Mushroom is cultivated in many areas of the Korea as one of the major economical crops. The production areas have steadily increased approximately 3,674 ha in 2002 to 4,118 ha in 2005. Several bacteria have been known as the causal agents of certain diseases of cultivated button mushroom, Agaricus bisporus, and oyster mushroom, Pleurotus ostreatus. It is well known as bacterial diseases of the cultivated mushroom such asbrown blotch, mummy disease, bacterial pit, bacterial rot and weeping disease, ginger blotch, and drippy gill. Unknown soft rot bacterium was isolated from sunken browning symptom of cultivated oyster mushrooms grown in Korea. The symptoms are appear as a sunken browning lesions on the caps of affected mushrooms. The bacterium causes a rapid soft rot of cultivated mushrooms in comparison with brown blotch bacteria at temperatures above 25℃. From these lesions we isolated one bacterial strain (designated OM1). Inoculation of bacterial isolates into mushroom caps yielded characteristic sunken brown, watersoaked and severe soft rot symptoms, but which were indistinguishable in early stage from those of the bacterial brown blotch well known to mushroom growers. Results of Gram stain and biochemical tests identified this isolate as Burkholderia gladioli pv. agaricicola. This was confirmed by pathogenicity, physiological and biochemical characteristics, and results of an analysis of the 16S rRNA gene sequences and the fatty acids profile. This is the first report of the isolation of B. gladioli pv. agaricicola from cultivated oyster mushroom in Korea.