Deep learning-based future drought prediction for the US drought monitor

Bokyung Son,Sumin Park,Jungho Im,Jaese Lee 한국기상학회 2022 한국기상학회 학술대회 논문집 Vol.2022 No.10

Isolation and Characterization of a Weizmannia coagulans Bacteriophage Youna2 and Its Endolysin PlyYouna2

Son Bokyung,Kim Youna,Yu Booyoung,Kong Minsuk 한국미생물·생명공학회 2023 Journal of microbiology and biotechnology Vol.33 No.8

Weizmannia coagulans (formerly Bacillus coagulans) is Gram-positive, and spore-forming bacteria causing food spoilage, especially in acidic canned food products. To control W. coagulans, we isolated a bacteriophage Youna2 from a sewage sludge sample. Morphological analysis revealed that phage Youna2 belongs to the Siphoviridae family with a non-contractile and flexible tail. Youna2 has 52,903 bp double-stranded DNA containing 61 open reading frames. There are no lysogenyrelated genes, suggesting that Youna2 is a virulent phage. plyYouna2, a putative endolysin gene was identified in the genome of Youna2 and predicted to be composed of a N-acetylmuramoyl-L-alanine amidase domain (PF01520) at the N-terminus and unknown function DUF5776 domain (PF19087) at the C-terminus. While phage Youna2 has a narrow host range, infecting only certain strains of W. coagulans, PlyYouna2 exhibited a broad antimicrobial spectrum beyond the Bacillus genus. Interestingly, PlyYouna2 can lyse Gram-negative bacteria such as Escherichia coli, Yersinia enterocolitica, Pseudomonas putida and Cronobacter sakazakii without other additives to destabilize bacterial outer membrane. To the best of our knowledge, Youna2 is the first W. coagulans-infecting phage and we speculate its endolysin PlyYouna2 can provide the basis for the development of a novel biocontrol agent against various foodborne pathogens.

Satellite-based Drought Forecasting: Research Trends, Challenges, and Future Directions

( Bokyung Son ),( Jungho Im ),( Sumin Park ),( Jaese Lee ) 대한원격탐사학회 2021 大韓遠隔探査學會誌 Vol.37 No.4

Drought forecasting is crucial to minimize the damage to food security and water resources caused by drought. Satellite-based drought research has been conducted since 1980s, which includes drought monitoring, assessment, and prediction. Unlike numerous studies on drought monitoring and assessment for the past few decades, satellite-based drought forecasting has gained popularity in recent years. For successful drought forecasting, it is necessary to carefully identify the relationships between drought factors and drought conditions by drought type and lead time. This paper aims to provide an overview of recent research trends and challenges for satellite-based drought forecasts focusing on lead times. Based on the recent literature survey during the past decade, the satellite-based drought forecasting studies were divided into three groups by lead time (i.e., short-term, sub-seasonal, and seasonal) and reviewed with the characteristics of the predictors (i.e., drought factors) and predictands (i.e., drought indices). Then, three major challenges-difficulty in model generalization, model resolution and feature selection, and saturation of forecasting skill improvement-were discussed, which led to provide several future research directions of satellite-based drought forecasting.

항공 LiDAR 및 RGB 정사 영상을 이용한 딥러닝 기반의 도시녹지 분류

손보경 ( Bokyung Son ),이연수 ( Yeonsu Lee ),임정호 ( Jungho Im ) 한국지리정보학회 2021 한국지리정보학회지 Vol.24 No.3

도시녹지는 도시 생태계 건강성 증진을 위한 중요한 요소이며, 건강한 도시 생태계 유지 및 관리를 위해서는 도시녹지의 공간적인 현황 파악이 필요하다. 환경부에서는 2010년 이후부터 총 41개의 분류 항목을 갖는 1m 급 해상도의 세분류 토지피복지도를 제공해오고 있으나, 가로수와 같은 도시 내 고해상도 상세 녹지 정보는 기타 초지로 분류되거나 누락되어 오고 있다. 따라서, 본 연구에서는 수원시 지역을 대상으로 1m 이하 급의 고해상도 원격탐사 자료(항공 LiDAR 및 RGB 정사영상)를 이용하여, 기존 세분류 토지피복지도에서는 나타나지 않는 고해상도의 상세 도시 녹지(수목, 관목 및 초지) 정보를 분류하고자 하였다. 분류 기법으로는 딥러닝 기반의 이미지 분할 방법인 U-Net 구조의 모델을 활용하였으며, 분류 항목의 수 및 사용하는 자료의 종류에 따라 총3가지의 모델(LRGB10, LRGB5, 및 RGB5)을 제안하고 성능을 평가하였다. 검증 지역에 대한 세 모델의 평균 전체 정확도는 각 83.40%(LRGB10), 89.44%(LRGB5), 74.76%(RGB5)이며, 항공 LiDAR와 RGB 정사영상을 함께 사용하여 총 5개의 항목(수목, 관목, 초지, 건물, 및 그 외)을 분류하는 LRGB5 모델의 성능이 가장 높게 나타났다. 수원시의 수목, 관목 및 초지 기준의 전체 녹지 현황은 각 45.61%(LRGB10), 43.47%(LRGB5), 및 44.22%(RGB5)로 나타났으며, 세 모델 모두 기존 세분류 토지피복지도와 비교하여 평균 13.40%의 도시 수목 정보를 더 제공할 수 있는 것으로 나타났다. 더불어 이러한 도시녹지 분류 결과는 향후 중분류 토지피복지도와 같은 기존 GIS 정보와의 융합을 통해 가로수 녹지 비율 현황 등 추가적인 상세 녹지 현황 정보를 제공할 수 있어, 다양한 도시녹지 연구 및 정책의 기초 자료로 활용될 수 있을 것으로 기대된다. Urban green space is an important component for enhancing urban ecosystem health. Thus, identifying the spatial structure of urban green space is required to manage a healthy urban ecosystem. The Ministry of Environment has provided the level 3 land cover map(the highest (1m) spatial resolution map) with a total of 41 classes since 2010. However, specific urban green information such as street trees was identified just as grassland or even not classified them as a vegetated area in the map. Therefore, this study classified detailed urban green information(i.e., tree, shrub, and grass), not included in the existing level 3 land cover map, using two types of high-resolution(<1m) remote sensing data(i.e., airborne LiDAR and RGB ortho imagery) in Suwon, South Korea. U-Net, one of image segmentation deep learning approaches, was adopted to classify detailed urban green space. A total of three classification models(i.e., LRGB10, LRGB5, and RGB5) were proposed depending on the target number of classes and the types of input data. The average overall accuracies for test sites were 83.40% (LRGB10), 89.44%(LRGB5), and 74.76%(RGB5). Among three models, LRGB5, which uses both airborne LiDAR and RGB ortho imagery with 5 target classes(i.e., tree, shrub, grass, building, and the others), resulted in the best performance. The area ratio of total urban green space(based on trees, shrub, and grass information) for the entire Suwon was 45.61%(LRGB10), 43.47%(LRGB5), and 44.22%(RGB5). All models were able to provide additional 13.40% of urban tree information on average when compared to the existing level 3 land cover map. Moreover, these urban green classification results are expected to be utilized in various urban green studies or decision making processes, as it provides detailed information on urban green space.

초음파 캐비테이션 현상에 의한 과황산염 활성화 연구 : 주파수, 온도의 영향

전보경(Bokyung Jun),강주민(Jumin Kang),손영규(Younggyu Son) 대한환경공학회 2022 대한환경공학회 학술발표논문집 Vol.2022 No.11

과황산염을 이용한 초음파/자외선 공정에서의 4-클로로페놀 분해 및 무기화 연구

전보경(Bokyung Jun),손영규(Younggyu Son),강주민(Jumin Kang) 대한환경공학회 2021 대한환경공학회 학술발표논문집 Vol.2021 No.11

Analgesic effect of structured anal skin care for perianal dermatitis after low anterior resection in the rectal cancer patients: prospective, single-center, open-label, therapeutic confirmatory, randomized clinical trial

Gyung Mo Son,In Young Lee,Mi Sook Yun,Jung-Hea Youn,Hong Min An,Kyung Hee Kim,Seung Mi Yeo,Bokyung Ku,Kun Hyung Kim,Myeong Suk Kwon 대한외과학회 2022 Annals of Surgical Treatment and Research(ASRT) Vol.103 No.6

Purpose: This prospective, single-center, open-label, therapeutic confirmatory, randomized clinical trial aimed to assess the alleviation of anal pain by applying structured anal skin care including skin protectants in rectal cancer patients with low anterior resection syndrome (LARS) combined with anal pain. Methods: From December 2017 to May 2020, 42 patients with LARS (scores of ≥21) and anal pain (visual analogue scale [VAS] score of ≥3) were randomly assigned and observed for 4 weeks. The conventional treatment consisted of dietary management, sitz baths, prohibition of anal scrubbing, loperamide, and dioctahedral smectite. In the anal care group, cleanser, barrier cream, and barrier spray were applied to the anal skin after defecation following the conventional treatment. The primary outcome was analgesic effect on anal pain after 2 weeks of structured treatment (anal care group) or conventional (control group). The cutoff for analgesic effect was a decrease in the anal pain score (VAS score of ≥2 or ≥30% reduction). Results: As a primary outcome, the analgesic effect was significantly higher in the anal care group (P = 0.034). The incontinence-associated dermatitis skin condition score was significantly improved in the anal care group than control group after 4 weeks (P = 0.023). There were no significant differences in LARS scores and quality of life scores between 2 groups. Conclusion: Structured anal skin care has a significant analgesic effect in reducing anal pain and improving anal skin conditions in patients with LARS after rectal cancer surgery.

Crystal Structure of LysB4, an Endolysin from Bacillus cereus-Targeting Bacteriophage B4

Hong, Seokho,Son, Bokyung,Ryu, Sangryeol,Ha, Nam-Chul Korean Society for Molecular and Cellular Biology 2019 Molecules and cells Vol.42 No.1

Endolysins are bacteriophage-derived enzymes that hydrolyze the peptidoglycan of host bacteria. Endolysins are considered to be promising tools for the control of pathogenic bacteria. LysB4 is an endolysin produced by Bacillus cereus-infecting bacteriophage B4, and consists of an N-terminal enzymatic active domain (EAD) and a C-terminal cell wall binding domain (CBD). LysB4 was discovered for the first time as an L-alanoyl-D-glutamate endopeptidase with the ability to breakdown the peptidoglycan among B. cereus-infecting phages. To understand the activity of LysB4 at the molecular level, this study determined the X-ray crystal structure of the LysB4 EAD, using the full-length LysB4 endolysin. The LysB4 EAD has an active site that is typical of LAS-type enzymes, where $Zn^{2+}$ is tetrahedrally coordinated by three amino acid residues and one water molecule. Mutational studies identified essential residues that are involved in lytic activity. Based on the structural and biochemical information about LysB4, we suggest a ligand-docking model and a putative endopeptidase mechanism for the LysB4 EAD. These suggestions add insight into the molecular mechanism of the endolysin LysB4 in B. cereus-infecting phages.

Effective removal of staphylococcal biofilms on various food contact surfaces by <i>Staphylococcus aureus</i> phage endolysin LysCSA13

Cha, Yoyeon,Son, Bokyung,Ryu, Sangryeol Elsevier 2019 Food microbiology Vol.84 No.-

<P><B>Abstract</B></P> <P>Staphylococcal biofilms are recognized as a significant problem in the food industry because of their high resistance to antibiotics, and the use of bacteriophages or endolysins has been regarded as a promising alternative to antibiotics. In this study, LysCSA13, an endolysin from <I>S. aureus</I> virulent bacteriophage CSA13, was cloned and characterized. LysCSA13 consists of an enzymatic active domain and a cell wall binding domain. LysCSA13 showed strong antimicrobial activity against staphylococcal strains at pH 7.0–9.0, 4.0–37.0 °C and in the presence of Ca<SUP>2+</SUP> and Mn<SUP>2+</SUP>. In addition, a high efficacy of LysCSA13 in removing staphylococcal biofilms was observed on various surfaces, including polystyrene, glass and stainless steel, displaying an approximately 80–90% decrease in biofilm mass. Furthermore, 300 nM of LysCSA13 effectively removed staphylococcal sessile cells formed on stainless steel and glass by 1–3 log units compared with the untreated control. Scanning electron microscopy analysis visualized the effective deformation and removal of cells embedded in the biofilm matrix. The results indicate that LysCSA13 can effectively control staphylococcal planktonic cells and biofilms regardless of the contact surface matrix and suggest the possible use of LysCSA13 as a promising biocontrol agent in various food processing environments.</P> <P><B>Highlights</B></P> <P> <UL> <LI> LysCSA13 endolysin is derived from the <I>Staphylococcus aureus</I> virulent phage CSA13. </LI> <LI> LysCSA13 is comprised of an enzymatic CHAP domain and a cell wall binding domain. </LI> <LI> It removed staphylococcal planktonic cells and biofilms on various surfaces. </LI> <LI> LysCSA13 is promising for use as a biocontrol agent. </LI> </UL> </P>

28kHz 초음파 반응기에서의 화학적 산화 반응 증진을 위한 고속혼합기법 적용 연구

강주민(Jumin Kang),전보경(Bokyung Jun),손영규(Younggyu Son) 대한환경공학회 2022 대한환경공학회 학술발표논문집 Vol.2022 No.11