Many β-lactam antimicrobials, including cephalosporins, have been used in both veterinary and human medicine in the treatment of zoonotic and infectious diseases. Especially, third-generation cephalosporins such as ceftiofur have been approved for systemic use in food-producing animals, which has resulted in the emergence of β-lactamase genes. This study aimed to investigate the occurrence of β-lactamase-producing E. coli isolated from commercial layers and characterized their antimicrobial resistance and virulence genes. Among the 85 cefotaxime (CTX)-resistant E. coli, all isolates showed resistance to at least one antimicrobial, and the rates of resistance to nalidixic acid, cephalothin, ampicillin, and cefazolin were more than 50.0%. In particular, 28 isolates were identified as containing b-lactamase genes. The extended-spectrum β-lactamase (ESBL) and plasmid-mediated AmpC genes blaCTX-M-1, blaCTX-M-14, blaCTX-M-15, and blaCMY-2 were detected in 1, 6, 5, and 4 isolates, respectively. The non-ESBL/pAmpC gene blaTEM-1 was detected in 12 isolates. The distribution of antimicrobial resistance genes in 28 β-lactamase-producing E. coli was as follows: aac(3)-II (64.3%), sul2 (32.1%), tetA (28.6%), sul1 (25.0%), cmlA gene (25.0%), and tetB (14.3%). In total, 6 virulence genes (astA, eaeA, escV, fimH, iucC, and papC) were also identified and the rates in virulence gene were as below: fimH (92.9%), iucC (25.0%), astA (21.4%), papC (10.7%), eaeA (7.1%) and escV (7.1%). Our findings suggest that antimicrobials used in commercial layer must be regulated in Korea, and comprehensive surveillance is necessary to prevent the dissemination of resistant isolates.

Amanita Pers. is a well-known monophyletic mushroom genus with a broad distribution. The genus comprises about 500 named taxa and contains deadly poisonous species, e.g. A. virosa and A. phalloides. Nonetheless, the diversity of Korean Amanita species has been underestimated. At present ca. 50 species of genus Amanita have been reported and distributed in Korea. It caused mainly three problems: 1) identification is not clarify because of the morphological investigation only; 2) poor morphological descriptions of the species; 3) absence of evidence specimens in many case of the recorded Korean Amanita species. For these reasons, the goals of the present study were to establish the accurate classification systems and to understand the diversity of Korean Amanita species. Macro-morphological characters were determined based on structures of basidiomata (universal veil on the pileus, partial veil, volva etc.), field notes and color photos of basidiocarps. Micro-morphological characters (basidiospores, basidia, composition of volval remnants on pileus and stipe base etc.) were obtained from the dried specimens after sectioning and rehydration using optical microscope. For the molecular identification, four gene regions(nrITS, nrLSU, rpb2 and tef1) were sequenced from Korean Amanita species. Among the sequenced specimens, I selected 80 specimens (which were successfully sequenced as ITS, nLSU, rpb2 and tef1) to generate the outline of Amanita phylogeny including 2 subgenera and 7 sections for determination of exact phylogenetic positions and comparison between related species. As a result of 11 data sets of each subgenus and complexes, 68 species were represented including new to Korea and candidates of new to sciences. The protein coding genes were helpful to determine the grouping within a related species and/or complex groups rather than rDNA sequences regions.

The genus Halectinosoma Vervoort, 1962 is first reported from Korean waters by the discovery of H. perforatum Itô, 1981. This species, previously recorded only from Japan, is collected from the sandy beach on the south coast of Korea, and is well distinguished from other congeners by the combination of following morphological characteristics: the elongate caudal ramus; the remarkably bilobated exopod of female P5; the small innermost seta on the distal margin of female P5 exopod; the presence of three setae on the distal exopodal segment in P4; and the presence of scale-like spinules on the ventral surfaces of urosomite. We herein provide detailed description and illustrations of this species.

Insect pollinators of the endanger orchid Cypripedium japonicum were surveyed and identified during two years, as a part of a conservation project of the orchid at Jukyeup-san and Hwaak-san (Mt.), South Korea. In total 40 individuals of 16 species in 4 families were identified. The dominant family was Halictidae, and Lasioglossum exiliceps Vachal visited the most frequently C. japonicum during the surveys. The average visiting frequency was 2.5 individuals per hour and the highest 4.3, from 12:00 – 13:00 in a day. After 15:00 insects did not visit the flowers at all. However, all of the visiting insects were found to not carry a pollinium or pollens of the orchard on their bodies; pollen carryover by any of the visiting insects did not occur at all. The orchid seems to require certain pollinators in particular body thickness due to its unique pollination mechanism. The orchid has two exit route openings, around 1 cm in diametre, where the entrapped insects can exit and an anther is situated just in front of each opening. It was inferred that a pollen carrier should be around 1 cm in body thickness. Therefore, the candidate species as the proper pollen carriers can be Tetralonia nipponensis Perez, Xylocopa appendiculata circumvolans Smith and Bombus consobrinus Dahlbom among the surveyed visitors.

Although winter rye is now widely grown as a silage crop in Korea, but silage quality of the winter rye produced from farmer's fields have not been published. Therefore, this experiment was conducted to evaluate forage quality of winter rye which was participated in Forage Quality Contest in 2008. These data were classified by resign, forage production, added inoculants, planting date, and harvest date. Difference on lactic acid of rye silage was detected in forage production (p＜0.01), however, there were no significant differences among the rye silage tested. The moisture and lactic acid were significant differences in dry matter yield of rye silage. There is all the difference between silage added inoculants and control. The pH, ash, CP, NDF and ADF of rye added with inoculants were higher t㏊n those of control silage, however, the TDN and lactic acid were increased in silage added with inoculants. The ash and CP were significant differences in planting date, but lactic acid was significant differences in harvest date. This experiment indicates t㏊t lactic acid of silage was good indicator for evaluation of rye silage. Differences in forage quality were also observed among winter rye silage. Therefore, nutritional quality as well as lactic acid is important in silage quality contest of winter rye silage.

본 연구에서는 고준위 방사성폐기물 심지층 처분시설의 규모 및 layout설정에 필요한 요소인 처분터널 및 처분공 간격에 대한 분석을 수행하였다. 이를 위하여, 기준 처분개념과 공학적 방벽 개념을 바탕으로 다양한 조건의 처분터널 및 처분공 단면을 설정하고, 단층 배치 및 복층 배치 개념 에 따른 처분동굴의 구조적, 열적 안정성을 분석하였다. 분석 결과를 바탕으로 설계에 있어서 주요한 고려인자 중의 하나인 굴착량을 감소시킬 수 있는 처분동굴 및 처분공 간격을 제안하였다. 본 연구의 결과는 심지층 처분시설 설계시 활용될 것이며, 향후, 부지에 대한 불확실성을 줄이기 위하여 정확한 부지특성 자료를 통한 상세한 분석이 필요하다.

刈取가 알팔파根瘤의 着生 및 發達과 室素固定活性에 미치는 影響을 檢討하기 위하여 圃場實驗에서는 刈取區와 非刈取區로 구분하여 時期別로 Acetylene還元法에 의하여 根瘤의 室素固定活性을 測定하였다. 養液栽培實驗에서는 地上部의 50%와 90%刈取, 花芽의 除法, 根瘤의 50%와 100% 除法등을 組合處理後 알팔파 再生과 根瘤의 着生과 發達에 미치는 影響을 檢討하였다. 1. 圃場實驗에서 根瘤의 무게는 1回刈取後 30%, 2 回刈取後 25%의 減少가 있었고

흡연 유무의 남성을 대상으로 뇌 회백질의 손상 유무를 파악 할 수 있는 확산텐서영상을 검사하여 영상을 획득 한 후 Tract-Based Spatial Statics(TBSS)방법으로 뇌 회백질 부위의 기저핵 신경섬유로의 비등방도 FA(fractional anisotropy)값을 측정 분석한 결과 모든 영역에서 흡연자가 비흡연자보다 비등방성 측정값이 낮게 관찰되었으며 FA값은 통계적으로 유의하였다. 본 연구의 측정한 FA결과 값으로 추측하자면 즉, 흡연이 뇌 회백질 기저핵의 모든 해부학적 미세 구조성 변화에 크게 영향을 미치며 신경 섬유로를 손상시키고 이와 관련된 기능적 이상에 영향을 준다고 할 수 있다.

Background : Recently, some of the previous stuies reported that was useful technique on growth and yield of organically grown ginseng transplantation in a rain shelter greenhouse. This study was conducted to investigate the optimum method of greenhouse shading for ginseng(Panax ginseng C. A. Meyer) cultivaton in the northern area of Ganwon, Korea. Methods and Results : We carried out to select optimal shade materials and light-penetrated ratio among polyethylene film with two-layered polyethylene net(PEF+PEN) and blue-white duplicated PE film(BWD-PEF) in the condition of greenhouse for ginseng cultivation. The order of light-penentrated ratio by shade meterials was PEN(75%)+PEF 〉 PEN(85%)+PEF 〉BWD-PEF(85%) 〉BWD-PEF(90%) and the order of air temperature was BWD-PEF(85%) 〉BWD-PEF(90%) 〉PEN+PEF(85%) 〉PEN+PEF(75%). The net photosynthetic rate was higher in PEN(75%)+PEF than other shading material treatments during growth season including summer high-temperature period. The root weight and yield were increased by 31.2~55.0% and 25.6~52.2%, respectively under PEN+PEF(75%) compared to other shading materials. Conclusion : We concluded that the PEN+PEF(75%) could be a good shading meterails of the greenhouse for organic 4-year-old ginseng cultivation in northern area of Gangwon, Korea.

Soybean self-sufficiency in Korea was 22.5% in year 2011, and as free trade agreement between Korea and US comes into effect, the amount of soybean importation increases. In 2012, paddy field soybean cultivation was over 0.1 million ha and it is expected to increase continuously due to rise in market price of soybean. Moreover, double cropping system including paddy field soybean is widely adopted nationwide, but studies on appropriate cultivar for this environment are insufficient. In this research, the effect of planting date and different cultivars on soybean growth and yield was investigated for three planting dates (June 20, July 5, and July 20) with 15 cultivars. According to ANOVA test, soybean yield was significantly different depending on sowing date and cultivars and interaction between sowing date and cultivars was also detected, meaning each of cultivars resulted different yield depending on sowing date. When planted on July 20, stem length, nod number, branch number and grain weight was decreased because of short growing period, resulting in yield decrease. Percentage of yield obtained from July 20 in contrast to that of June 20 showed that Pungwon, Nampung and Daepung recorded the least yield decrease and the highest yield when planted late. Evaluation of late-sowing-adaptable soybean cultivar in paddy field is now being carried on following last year.

The main nutritional problem of sorghumxsudangrass hybrid (Sorghum bicolorxSorghum sudanese) silage is low quality and palatability. This experiment was conducted to evaluate whether organic com grain and crushed rice addition of sorghumxsudangrass hybrid silage increases forage quality of the silage. The sorghumxsudangrass hybrid silages with added com grain and crushed rice were similar to conventional corn silage in moisture content. However organic sorghumxsudangrass hybrid silage had low pH values. Silage added with gain and byproduct had higher crude ash, acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents than control corn silages, while its non-fiber carbohydrate (NFC) and total digestible nutrients (TDN) showed the opposite results. Lactic acid, butyric acid and lactic percentage oftotal organic acid (UT) of sorghumxsudangrass hybrid silages were higher than those of com silage, but acetic acid was higher than control. In vitro dry matter digestibi/ity (IVDMD) of com silage was higher than other sorghum silages. Feed intake of sorghumxsudangrass hybrid silage added with crushed rice was highest among silages. Therefore, these data indicate that crushed rice and com grain added sorghumxsudangrass hybrid silage could be recommended as the most effective treatment for increasing silage quality and palatability.

We investigated the effects of temperature changes on the oxygen consumption rhythm in Japanese eels, Anguilla japonica, using an automatic intermittent flow respirometer (AIFR). The endogenous rhythm of the oxygen consumption rate (OCR) in the eels (n = 18; 44-74 cm, 145-690 g), freshly collected by bag net from estuaries, was nearly synchronous with the tidal pattern of the estuarine collection site. The magnitude of mean OCR (mOCR) of eels showed variable range of 82.2 - 116.5 ml O2 kg-1 ww h-1 under constant conditions. In case of increasing temperature from 25 to 38℃, the OCR of eels exhibited a gradually increasing trend with a rhythmic pattern until 36℃. Above 36℃, the rhythms of the OCR dampened and the OCR decreased rapidly at around 36 - 37℃. The OCR of the eels exhibited the maximum value at 38℃, and then it sharply decreased. The results suggested that the critical thermal maximum (CTM) regarding the endogenous rhythms of the eels was at around 36 - 37℃ when water temperature increased at 0.5℃/14 h following the acclimation at 25℃. In case of decreasing temperature (0.5℃/14 h) from 25 to 0℃, the OCR of the eels displayed a abrupt decrease up to 23℃, and between at 23 and 20℃, there was an agitation which showed a slight increase in the OCR with a duration of 1-2 days. Below 9℃, the OCR rhythm of the eels showed a constant state regardless of temperature decreasing. These results suggest that the Japanese eel has an upper incipient lethal temperature at 36℃, with a lower thermal limit at 9℃. The biochemical aspects of the eels influenced by water temperature need to be further studied.