Nitrogen (N) loading from domestic, agricultural and industrial sources can lead to excessive growth of macrophytes or phytoplankton in aquatic environment. Many studies have used stable isotope ratios to identify anthropogenic nitrogen in aquatic systems as a useful method for studying nitrogen cycle. In this study to evaluate the precision and accuracy of denitrification bacteria method (Pseudomonas chlororaphis ssp. Aureofaciens (ATCC® 13985)), three reference (IAEA-NO-3 (Potassium nitrate KNO3), USGS34 (Potassium nitrate KNO3), USGS35 (Sodium nitrate KNO3)) were analyzed 5 times repeatedly. Measured the δ15N-NO3 and δ18O-NO3 values of IAEA-NO-3, USGS 34 and USGS35 were δ15N: 4.7±0.1‰ δ18O: 25.6±0.5‰, δ15N: -1.8±0.1‰ δ18O: -27.8±0.4‰, and δ15N: 2.7±0.2‰ δ18O: 57.5±0.7‰, respectively, which are within recommended values of analytical uncertainties. Also, we investigated isotope values of potential nitrogen source (soil, synthetic fertilizer and organic-animal manures) and temporal patterns of δ15N-NO3 and δ18O-NO3 values in river samples during from May to December. δ15N-NO3 and δ18O-NO3 values are enriched in December suggesting that organic-animal manures should be one of the main N sources in those areas. The current study clarifies the reliability of denitrification bacteria method and the usefulness of stable isotopic techniques to trace the anthropogenic nitrogen source in freshwater ecosystem.

The nitrogen isotope value in both ammonium and nitrate ion were determined at 9 stations during both June and August 2016, in order to understand the origin of DIN at the Han river. δ15N-NO3 and δ15N-NH4 values in 8 stations (CP, SB, MHC, P4, SJ, SBC, P2, SC) were no significant variation. However δ15N-NO3 and δ15N-NH4 values in KK (Kyeongan stream) showed significant different in comparison with 8 stations, with an apparent increase of nitrogen isotope values. These results indicate that antropogenic nitrogen source influence on KK station. Also the δ13C and δ15N isotope ratio of phytoplankton (Diatom and Cyanobacteria) in KK (Kyeongan stream) showed heavier values, compared to other study stations. These results indicate that nitrogen isotope value in phytoplankton effects by different nitrogen source in study sites. These results suggest that the analysis of stable isotope ratios is a simple but useful tool for the identification of dissolved inorganic nitrogen origin in aquatic environments.

토마토 작물에 발생하는 B. tabaci에 대한 예찰을 위해 시설재배지뿐만 아니라 노지 재배에서도 노란색 점착 카드트랩이 주로 사용되고 있다. 그러나, 예찰트랩의 색상과 굴절되는 빛의 강도 및 환경 변화에 따라 B. tabaci 유인력은 차이를 나타내고 있다. 따라서, 온실에 발생하는 B. tabaci 성충에 대한 light 트랩의 시설 재배 지내의 이용 가능성을 평가하기 위해 white light (450- 625nm) 및 yellow light (590nm) 트랩과 광원이 장착되지 않은 트랩을 이용하여 유인 활성을 비교하였다. 본 시험결과 광원별 B. tabaci 포획밀도는 yellow light 트 랩(525 nm)에서 168±7.6(마리/트랩)로 가장 높은 유인 활성을 나타내었으며, white light 트랩에서는 106±4.6( 마리/트랩)으로 다소 낮은 개체수가 포획되었다. 그러나 대조구로 사용된 광원이 설치되지 않은 트랩의 경우 광원이 설치된 트랩보다 적은 60±4.8(마리/트랩)의 개체수가 포획되었다. 따라서, yellow light trap과 white light 트랩에서 높은 B. tabaci 성충의 유인력을 나타내었다. 이러한 결과를 바탕으로 yellow light 및 white light 트 랩이 토마토 시설 재배지에서의 B. tabaci 성충에 대한 친환경적 해충 방제법의 일환으로 적용 될 수 있을 것으로 판단되었다.

쌈채소 수경재배 시 문제가 되는 체내 질산염 함량을 효과적으로 저감시키기 위해 폐쇄형 생산시스템에서 1) 저광도(100μmol·m-2·s-1내외) 조건에서의 수확 7일 전 양액조성 방법과 2) 질산염 저감을 위한 적정 광도 및 수확 전 적정 양액결제시기를 구명하기 위해 수행하였다. 청치마상추에서 수확 7일 전 양액조성 방법 중 양액결제(양액공급 중단) 처리와 양액내 질소 공급원으로 탄산 암모늄[(NH4)2CO3]을 사용한 처리는 처리기간 동안 체내 질산염 함량을 감소시켰으나, 생체중, 엽면적 등의 생육량도 감소되었다. 하지만 100μmol·m-2·s-1조건에서 수확 7일전 양액내 NO3-N 비료를 결제하여 조성하거나 배양액 농도를 1/2배액으로 낮추어 공급함으로써 외적 품질 및 생육량의 저하없이 질산염 함량은 감소되었다. 또한 수확 전 양액결제시기 및 적정 광도를 구명하기 위해 실험을 수행한 결과, 100, 200, 및 300μmol·m-2·s-1 의 3수준의 광조건 모두 수확 7일 전 양액결제시에 체내 질산염이 가장 낮게 나타났으며, 특히 300μmol·m-2·s- 1의 광도와 수확 7일 전 양액결제 처리시 식물체내 질산염의 빠른 저감효과를 볼 수 있었으나 생육량의 감소를 가져왔다. 수확 3일 전 양액결제 처리에 의해 300μmol·m- 2·s-1 광도에서 체내 질산염 함량은 2,021ppm에서 480ppm로, 200μmol·m-2·s-1 광도에서 3,018ppm에서 1,035ppm로 감소되었으며, 외적 품질의 저하 없이 생육량이 높으면서 동시에 짧은 시간 동안 식물체내 질산염의 저감 효과를 볼 수 있었다. 수확 7일 전 양액결제 처리는 체내 질산염의 저감효과가 컸던 반면 엽중, 엽면적 등의 생육 감소를 가져왔는데, 200과 300μmol·m-2·s-1의 광조건에서 수확7일 전 양액결제시 수확 3일 전 양액결제보다 엽중은 20~35%, 엽면적은 16~31% 낮은 값을 나타내었다. 광도 및 양액결제시기에 따른 비타민 C 함량을 분석한 결과 100, 200보다 300μmol·m-2·s-1 에서 수확 3일과 5일전 양액결제 처리시 비타민 C 함량이 가장 높게 나타났다.

This study was conducted to investigate the effect of addition of lactic acid bacteria inoculants on quality of rye silage harvested at early heading stage. The nutritive values in lactic acid bacteria (LAB) inoculated group showed similar results to control. The pH of rye silage in LAB inoculation significantly decreased as compared to control (P<0.05). In addition, the content of lactic acid in LAB inoculation significantly increased (P<0.05), but the content of acetic acid in LAB treatments decreased. In addition, lactic acid bacterial counts in LAB inoculation significantly increased as compared to control (P<0.05). Therefore, we suggest that rye silage could be improved by LAB inoculation.

The present study was carried out to explore the potential effect of shading degrees on yields and nutritive values of forage in forest-grassland. This experiment was conducted this study under different natural shading at National Institute of Animal Science, Cheonan province in Korea, for 2 years (from 2015 to 2016). This experiment was consisted of four different shading degrees, such as full sunlight (control, 10% below), 25% of shading, 35% of shading, 50% of shading. Pasture species used in this study were orchardgrass ‘Kodiwin’, perenial ryegrass ‘Linn’, tall fescue ‘Purumi’, kentuky bluegrass ‘Kenblue’, and white clover ‘Ladino’. Botanical composition of orchardgrass was higher than that of perenial ryegrass, tall fescue and kentuky bluegrass. Dry matter (DM) yields of forage decreased as increasing shading degrees. DM yields of forage significantly decreased as increasing shading degrees and lots of cutting times under increasing shading degrees decreased DM yields of forage. The content of crude protein increased as increasing shading degrees and the contents of acid detergent fiber (ADF), neutral detergent fiber (NDF), the activity of total digestible nutrient (TDN) and in-vitro digestibility (IVD), and relative feed value (RFV) were similar in control and different shading. This study suggests that orchardgrass is major component for forest-grassland and establishment of orchardgrass can be improved by increasing shading degrees.

Odor emission factors (OEFs) are important parameters in characterizing odor sources, understanding emission patterns, designing abatement facilities, and providing appropriate control methods. In this study, OEFs for complex odor from grit removal chambers in publicly-owned wastewater treatment plants were determined, and the major operating conditions affecting the emission factors were investigated. In the main study site of “S” wastewater treatment plant, the averaged OEFs from the grit chamber were found to be 466.2, 162.6, and 54.7 OU/m2/min in summer, spring, and winter, respectively. OEFs from two other grit chambers in different wastewater plants were independently measured for comparison, and the values were in the same range as the OEF from S-site at a 95% confidence level. Nevertheless, the OEFs could differ depending on the types of wastewater and the sizes of wastewater treatment plants. Using the multi-variable linear regression method, correlations between OEFs and operating conditions, i.e. activities, from grit chambers were statistically analyzed. The analyses showed that operating conditions, including total suspended solids, water temperature, and temperature difference between water and air, were the most significant parameters affecting the OEF. A linear equation using these three parameters was proposed to estimate the OEF, and can be used to predict an OEF for another grit chamber, without odor measurement.

최근 지구온난화를 포함한 환경 변화는 생태계 전체에 큰 영향을 미칠 뿐만 아니라 사회, 문화, 경제적으로도막대한 영향을 미치고 있다. 기온상승과 같은 기후변화에 따라 우리나라 자연 환경이 변화하고 이와 밀접한 관련이있는 동식물상 변화 역시 예상된다. 변온동물로 종 다양성이 풍부한 나방은 분류학적 정보가 비교적 자세하고서식지 특이성이 높으며 자외선등 트랩을 이용하여 쉽고 정량적인 채집이 가능하기 때문에 환경변화를 모니터링하기에 적절하다. 우리는 2001년부터 최근까지 한반도 남부 지방을 중심으로 지리산, 무안 승달산, 제주 한라산 등지에서5월부터 10월까지 매달 1회씩 모니터링을 진행하고 있다. 이러한 모니터링을 통하여 남부지역의 나비목 종 다양성을밝혀낼 수 있었을 뿐만 아니라 환경변화에 따른 특정 개체군의 감소 또는 증가를 확인할 수 있었다. 나방 모니터링을통하여 얻었던 중요한 연구결과 뿐만 아니라 앞으로의 방향에 대해서도 논의할 계획이다.

Pig has been known to be one of the most feasible animals as a bioreactor to produce pharmaceuticals in milk and as a mediator in xenotransplantation research. Previously, we generated transgenic pigs for both purposes, which were expressing Factor 8, vWF, hTPA, and hEPO in milk, along with expression of MCP at GalT gene locus (GalT-MCP/-MCP) as well as expressing MCP at GalT gene loci with CD73 expression (GalT-MCP/+/CD73). In this study, we performed comparative analyses of sperm parameters between wild type male (WT) pig and those transgenic males to examine the effects of transgenes integrated into the pigs on motility, morphology, viability, and acrosome integrity of the spermatozoa. Our results showed that the rates of actively motile spermatozoa of WT, Factor 8, vWF, hTPA, hEPO, GalT-MCP/+/CD73, and GalT-MCP/-MCP pigs were 85.0%, 83.3%, 82.5%, 83.3%, 82.5%, 77.5%, and 78.7%, respectively. Whereas, the rates of morphologically normal spermatozoa of WT, Factor 8, vWF, hTPA, hEPO, GalT-MCP/+/CD73, and GalT-MCP/-MCP pigs were 90.0%, 80.0%, 80.0%, 83.3%, 85.0%, 91.8%, and 80.8%, respectively. In addition, the viability in spermatozoa of WT, Factor 8, vWF, hTPA, hEPO, GalT-MCP/+/CD73, and GalT-MCP/-MCP pigs were 93.9%, 82.4%, 89.9%, 83.9%, 87.4%, 92.8%, and 83.6%, respectively. The rates of spermatozoa with normal acrosome integrity in WT, Factor 8, vWF, hTPA, hEPO, GalT-MCP/+/CD73, and GalT-MCP/-MCP pigs were 98.1%, 98.6%, 98.6%, 98.7%, 98.1%, 99.5%, and 95.1%, respectively. There were no significant differences in motility, morphology, viability, and acrosome integrity of the spermatozoa among WT, Factor 8, vWF, hTPA, and hEPO, GalT-MCP/+/CD73, and GalT-MCP/-MCP pigs. These mean that neither random integration nor targeted integration of the transgene into chromosome of pig effect on characteristics of spermatozoa. Ultimately, the transgenic male pigs subjected in this study could apply to propagate their progenies for production of human therapeutic proteins and advancing the xenotransplantation research.

Pigs have been extensively used as mediators of xenotransplantation research. Specifically, the Massachusetts General Hospital (MGH) miniature pig was developed to fix major histocompatibility antigens for use in xenotransplantation studies. We generated transgenic pigs for xenotransplantation using MGH pigs. However, it has not been studied yet whether these pigs show similarity of reproductive physiological characteristics to wild types of MGH miniature pig. In this study we analyzed the estrous cycles and pregnancy characteristics of wild type (WT) and transgenic MGH miniature pigs, which were α1,3-galactosyltransferase (GalT) heterozygous and homozygous knock-out, and membrane cofactor protein (MCP) inserted in its locus, GalT-MCP/+ and GalT-MCP/-MCP pigs. Estrous cycles of WT, GalT-MCP/+ and GalT-MCP/-MCP pigs were 20.9±0.74, 20.1±1.26, and 17.3±0.87 days, respectively, and periods of estrous were 3.2±0.10, 3.1±0.12, and 3.1±0.11 days. The periods of gestation of WT, GalT-MCP/+ and GalT-MCP/-MCP pigs were 114.2±0.37, 113.3±0.67, and 115.4±0.51 days, respectively. Litter sizes of WT, GalT-MCP/+ and GalT-MCP/-MCP pigs were 4.8±0.35, 4.8±1.11 and 3.0±0.32 respectively. There were no significant differences on estrous cycle, periods of estrous and gestation, and litter size among WT, GalT-MCP/+ and GalT-MCP/-MCP pigs, meaning that GalT knock-out and additional expression MCP of the MGH miniature pig did not effect on reproduction traits. These results provide relevant information to establish breeding system for MGH transgenic pig, and for propagation of GalT-MCP/-MCP pig to supply for xenotransplantation research.

Transplantation is considered to be a very useful approach to improve human welfare and to prolong life-span. Heterologous organ transplantation using pig organs which are similar to human beings and easy to make mass-production has known as one of the alternatives. To ensure potential usage of the pig organ for transplantation application, it is essentially required to generate transgenic pig modifying immuno-related genes. Previously, we reported production of heterozygous α 1,3-galactosyltransferase (GalT) knock-out and human membrane cofactor protein (MCP) expressing pig (GalT-MCP/+), which is enforced for suppression of hyperacute and acute immunological rejection. In this study, we reported generation of homozygous pig (GalT-MCP/-MCP) by crossbreeding GalT-MCP/+ pigs. Two female founders gave birth to six of GalT-MCP/-MCP, and seven GalT-MCP/+ pigs. We performed quantitative real-time PCR, western blot, and flow cytometry analyses to confirm GalT and MCP expression. We showed that fibroblasts of the GalT-MCP/-MCP pig do not express GalT and its product Gal antigen, while efficiently express MCP. We also showed no expression of GalT, otherwise expression of MCP at heart, kidney, liver and pancreas of transgenic pig. Taken together, we suggest that the GalT-MCP/-MCP pig is a useful candidate to apply xenotransplantation study.

Experimental evaluation of torsional behavior, which is possible behavior of seismic beams of RC structures, was carried out. Concrete strength and stirrup spacing were set as experimental variables to investigate the torsional strength of RC beams. Based on the experimental results, the torsional strength of RC beams was compared and analyzed. From the experimental results, the concrete strength was caused a difference of about 30% in the torsional strength of the maximum torque of the RC beam specimen, and the stirrup spacing was found to be about 2.8 times and 5 times that of the peak torque. Therefore, this study will be an important study to understand the effect of both concrete strength and stirrup spacing for the torsional strength or torsional behavior of RC beams.