주변 국가인 태국, 캄보디아, 베트남, 라오스 등에서 벼멸구(Nilaparvata lugens)와 흰등멸구(Sogatella furcifera)를 채집하던 중, 벼멸구와 형태가 아주 유사한 이삭멸구(N. muiri)와 벼멸구붙이(N. bakeri), 그리고 흰등 멸구와 형태가 아주 유사한 흰등멸구붙이(S. kolophon), 피멸구(S. vibix) 그리고 애멸구(Laodelphax striatellus)가 동시에 채집이 되는 등 형태적 차이점이 거의 없어 전문가도 쉽게 구분하지 못하는 문제가 있음이 확인되었다. 따라서 형태가 유사한 상기 멸구류의 종 동정을 확실히 할 수 있는 PCR용 프라이머의 개발을 위해 벼멸구 및 흰등멸구의 미토콘드리아 내 COI 영역을 특이적으로 검출할 수 있는 프라이머 세트를 제작하고 종 동정 효과를 확인하였다.

Recently, the importance of preventive maintenance has been emerging since failures in a complex system are automatically detected due to the development of artificial intelligence techniques and sensor technology. Therefore, prognostic and health management (PHM) is being actively studied, and prediction of the remaining useful life (RUL) of the system is being one of the most important tasks. A lot of researches has been conducted to predict the RUL. Deep learning models have been developed to improve prediction performance, but studies on identifying the importance of features are not carried out. It is very meaningful to extract and interpret features that affect failures while improving the predictive accuracy of RUL is important. In this paper, a total of six popular deep learning models were employed to predict the RUL, and identified important variables for each model through SHAP (Shapley Additive explanations) that one of the explainable artificial intelligence (XAI). Moreover, the fluctuations and trends of prediction performance according to the number of variables were identified. This paper can suggest the possibility of explainability of various deep learning models, and the application of XAI can be demonstrated. Also, through this proposed method, it is expected that the possibility of utilizing SHAP as a feature selection method.

Recently, a study of prognosis and health management (PHM) was conducted to diagnose failure and predict the life of air craft engine parts using sensor data. PHM is a framework that provides individualized solutions for managing system health. This study predicted the remaining useful life (RUL) of aeroengine using degradation data collected by sensors provided by the IEEE 2008 PHM Conference Challenge. There are 218 engine sensor data that has initial wear and production deviations. It was difficult to determine the characteristics of the engine parts since the system and domain-specific information was not provided. Each engine has a different cycle, making it difficult to use time series models. Therefore, this analysis was performed using machine learning algorithms rather than statistical time series models. The machine learning algorithms used were a random forest, gradient boost tree analysis and XG boost. A sliding window was applied to develop RUL predictions. We compared model performance before and after applying the sliding window, and proposed a data preprocessing method to develop RUL predictions. The model was evaluated by R-square scores and root mean squares error (RMSE). It was shown that the XG boost model of the random split method using the sliding window preprocessing approach has the best predictive performance.

Insect antennae play important roles in finding mates and in locating food source and oviposition sites. Riptortus pedestris is an important pest of soybean and sweet persimmon in Korea. The male R. pedestris adult produce the aggregation pheromone attracting the conspecific nymphs and both sexes of adults. The pheromone was known as a cue for food finding, but the 1st instar nymph can develop to the 2nd instar without food. This phenomenon may suggest that the 1st instar nymph may have different sensilla system from other instars. Thus, we investigated the morphology and distribution of antennal sensilla and antennal response to the aggregation pheromone (AG) of each nymphal stage using Scanning Electron Microscope (SEM) and Electroantennography (EAG). As expected, first instar nymph did not have sensilla trichodea 3 (T3) and chaetica 3 (Ch3) which existed in other instar nymphs. The antennae of the 1st instar nymph did not responded to AG, with no difference from control. For further elucidation of the functions of sensilla T3 and CH3, single sensillum recording to AG will be done.

Background: Mahonia Nepalensis DC. (Hoang lien o ro), the specie of the family Berberidaceae, is widely distributed in the high mountainous areas at altitudes 1700 – 1900 m of Vietnam. It is found that the stem of Mahonia nepalensis indicated anti-inflammatory, anti-bacterial and antifungal activities and they are used particularly for the treatment of eczema, psoriasis, and other skin conditions. However, no study on the antioxidant and anti-cancer activities of Mahonia Nepalensis stem has been previously reported. The aim of this study was to evaluate anti-oxidant and anti-cancer activities of Mahonia Nepalensis stem. Methods and Results: The stem pieces of Mahonia Nepalensis were dried and extracted three times with 100% methanol. After that, the extract was suspended in distilled water and then partitioned with n-hexane, ethyl-acetate (EtOAc) and butanol (water saturated BuOH) fractions were then evaporated using a vacuum rotary evaporator. Evaluation of the anti-oxidative activity of Mahonia Nepalensis was carried out using a DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-producing system. The results revealed that the ethyl acetate fraction of M. nepalensis possessed higher potential DPPH radical scavenging activity (IC50, 81.88 ± 1.33㎍/㎖) than other fractions as well as BHT (2,6-Di-tert-Butyl-4-methylphenol) (IC50, 250.49 ± 1.60㎍/㎖). The reducing power assay was also investigated and EtOAc fraction showed higher absorbance values than other fractions. At 1.0 mg/ml concentration, EtOAc fraction showed absorbance of 1.72, be higher than Ascorbic acid. Cell viability was evaluated according to the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyl tetrazolium Bromide) assay. By MTT assay, all fractions showed a significant reduction in cell viability on COLO 205 (Human colon carcinoma cell) at the highest concentration tested (200㎍/ ㎖) with over 70% decrease in cell viability was obtained, and the highest significantly inhibiting effect occurred in butanol fraction with approximately 90% reduction in cell viability. Conclusion: We demonstrated that Mahonia Nepalensis stem extract has highly potential in anti-cancer activity. Further studies are necessary in order to explore the variety of Mahonia Nepalensis stem to be applied as a valuable natural material.

Background : Haskap berries commonly refer to fruits of Lonicera caerulea L., recognized by the Japanese aborigines as the “The elixir of life.”. Due to their recent arrival on the North American market, haskap berries have not yet been positioned among other berries and compared in terms of their phytochemical content. And haskap berries have higher ascorbic acid and anthocyanin content than other berries known for their health-promoting benefits, such as blueberries. However, no study has reported on the antioxidant and anti-cancer activity of Lonicera caerulea stem. The purpose of this study is to present the current research on the chemical content, antioxidant and anti-cancer activities of Lonicera caerulea stem. Methods and Results : The stem of Lonicera caerulea L. ware dried in the shade at room temperature and extracted with 100% methanol. The extract was suspended in deionized water and partitioned sequentially with n-hexane, chloroform, ethyl-acetate and butanol (water saturated BuOH) fractions. Antioxidant activities were measured by determination of antioxidants, DPPH (2,2-diphenyl-1-picrylhydrazyl). Cell viability was determined by the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay. All cell lines were purchased from the Korean Cell Line Bank (Seoul, Korea). All results were performed with three replications were processed statistically. By DPPH assay, the Lonicera caerulea L. the highest activity was obtained from the ethyl-acetate fraction (IC50=15.46 ㎍/㎖). By MTT assay, the chloroform fraction showed a significant growth inhibiting effect on MCF-7 (Human breast cancer, IC50=225.91 ㎍/㎖), COLO 205 (Human colon cancer, IC50=179.55 ㎍/㎖), but on AGS (Human stomach cancer) and other fractions it did not show effect. Conclusion : We demonstrated that Lonicera caerulea L. stem extract and fractions has antioxidant and antiproliferation activity in vitro. Further studies should identify the active constituents in Lonicera caerulea L stem to evaluate the potential in vitro antioxidant and antiproliferation activities of the extract.

For the study of population genetic structure with mtDNA, it is essential to measure genetic diversity at each mtDNA regions. Also, to evaluate the variation according to the each region should follow as well as to see if there are differences. In this study, we delved into the variations and dendrogram among samples of seven mtDNA regions (NDⅡ, NDⅤ, NDⅣ, NDⅣL, NDⅥ, NDⅠ, 12SrRNA) from wild Pacific abalone, Haliotis discus hannai collected in Yeosu, Korea. The region with the highest genetic variation was NDⅣ region (Haplotype diversity = 1.0000, Nucleotide diversity = 0.010823) with two to five times higher variation than the others. Furthermore, the study to see if there is a difference between the regions of samples showed that similar aspects of dendrogram in NDⅡ and NDⅠ(divergence of 90% and 87%), which forms a group with hd4, 7, 8 and 10 at bootstrap support, based on 1000 replications. Also, pair-wise FST between clusters within the regions showed high values; 0.4061 (P=0.0000), 0.4805 (P=0.0000) respectively. Therefore we can infer that it is the most efficient and accurate way to analyze the region of NDⅣ with the highest variation in addition to the regions of NDⅡ and NDⅠ, which formed clusters with high bootstrap value, for study of population genetic structure in this species.

In this study, the quality characteristics and antioxidant activity of mulberry salad dressing prepared with yam juice during storage at 5℃ for four weeks were evaluated. The salad dressing was prepared with a salad base, mulberry, omija, and yam (4:4:6:1 or 4:4:6:3). Fresh yam juice was added to the salad dressing at 0, 7, and 18% levels. After four weeks storage, the pH increased whereas the acidity decreased. As the yam concentration increased, the pH increased to 3.84 and the acidity decreased to 0.14%. The Hunter color L (lightness), b (yellowness), and a (redness) values decreased over the storage period. After four weeks storage, the viscosity increased from 83.2 to 158.5 cp according to the amount of yam juice that was added. The antioxidant activity, such as the DPPH radical scavenging activity, and the total polyphenol content of the salad dressing improved as the yam concentration increased. Moreover, according to the storage time, the peroxide value did not increase. These results show that the mulberry salad dressing to which omija and fresh yam juice were added maintained its freshness with high antioxidative activity during storage.

Estrogens are ubiquitous signaling molecules that influence nearly every cell type, and exert profound effects on embryonic development, and differentiation. Wnt pathway, which recruits β-catenin into nuclei, and activates The Wnt-dependent transcription factors, also plays an important role in embryonic development and stem cell maintenance, and differentiation. Accumulating evidences indicate that potential convergence between these two pathways in carcinoma cells. However, physiological roles of estrogens in development and differentiation of human embryonic stem cells (hESCs) are relatively unknown. Here, we demonstrated that estrogenic compounds 17α-ethinylestradiol (EE2) and genistein (GEN) significantly increased β-catenin expression in undifferentiated hESCs cultured in feeder-free media. Interestingly, GEN treatement induced an increased trend of mesendodermal gene expressions, and significantly inhibited ectodermal gene expressions (Nestin and Pax6) in embrioid body (EB). Expectantly, GEN increased epithelial-mesenchymal transition (EMT) related gene expression (Snail2, and Twist), whereas decreased E-cadherin on day 6 of EB development. Taken together, these suggest that estrogens may in part the powerful effects on normal hESC differentiation. Mechanistic studies of estrogen signaling continue to suggest novel drug targets for stem cells and will also improve screening methods of developmental toxicity.

We previously reported that purified hepatocyte-like cells derived from human embryonic stem cell (hESC) promoted the liver tissue recovery not only by cell replacement, but also by delivering proteins (secretome) that enhance endogenous host liver regeneration. In this study, we investigated possible therapeutic effects of secretomes obtained from undifferentiated hESC and mesenchymal stem cell (hMSC), and explored the underlying mechanism in a mouse model of chronic liver injury. Mice pre-intoxicated with dimethylnitrosamine (DMN) were treated with single intraperitoneal injection of secretome or medium used to support the growth of hESCs or hMSCs. Both hESC- and MSC-secretomes induced robust host liver regeneration, as determined by biochemical and histological analyses. The expression of MMP2 was significantly increased in the liver that received hESC- or hMSC-secretome, compared to control groups. In contrast, expression of α-SMA, a hallmark of activated hepatic stellate cells, was profoundly decreased after administration of both secretomes. These results suggest that hESCs and MSCs may release soluble factors that support the host tissue regeneration of chronically injured liver.