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工学教育研究部 工学科土木環境工学プログラム担当 |
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Suzuki Y., Hiroki H., Xie H., Nishiyama M., Sakamoto S.H., Uemura R., Nukazawa K., Ogura Y., Watanabe T., Kobayashi I.
International Journal of Hygiene and Environmental Health 240 2022年3月
記述言語:日本語 掲載種別:研究論文(学術雑誌) 出版者・発行元:International Journal of Hygiene and Environmental Health
On a livestock farm where antimicrobial administration and its history had been managed for prudent use of antimicrobials, we surveyed antibiotic-resistant Escherichia coli strains isolated from cow feces and the surrounding environment (i.e., rat and crow feces, and water samples from a drainage pit and wastewater processing tank) every month for 1 year. Two strains (1.7%) in cow feces were resistant to tetracycline, whereas all other strains were susceptible to all other antimicrobials. Among 136 strains isolated from cows and wild animals, only one ampicillin-resistant strain was identified. The antibiotic resistance rate in the drainage from the barn was 8.3% (10/120), and all strains showed susceptibility for 8 months of the year. Tetracycline resistance was common in all resistant strains isolated from animal feces and water samples; all tetracycline-resistant strains carried tetA. These results strongly support the proper use and management of antibiotics on farms to minimize the outbreak and spread of antibiotic-resistant bacteria.
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Plant debris are hotbeds for pathogenic bacteria on recreational sandy beaches 査読あり
Suzuki Y., Shimizu H., Kuroda T., Takada Y., Nukazawa K.
Scientific Reports 11 ( 1 ) 2021年12月
記述言語:日本語 掲載種別:研究論文(学術雑誌) 出版者・発行元:Scientific Reports
On recreational sandy beaches, there are guidelines for the management of bacterial pollution in coastal waters regarding untreated sewage, urban wastewater, and industrial wastewater. However, terrestrial plant debris on coastal beaches can be abundant especially after floods and whilst it has rarely been considered a concern, the bacterial population associated with this type of pollution from the viewpoint of public health has not been adequately assessed. In this study, microbes associated with plant debris drifting onto Kizaki Beach in Japan were monitored for 8 months throughout the rainy season, summer, typhoon season, and winter. Here we show that faecal-indicator bacteria in the plant debris and sand under the debris were significantly higher than the number of faecal bacteria in the sand after a 2015 typhoon. When we focused on specific pathogenic bacteria, Brevundimonas vesicularis and Pseudomonas alcaligenes were commonly detected only in the plant debris and sand under the debris during the survey period. The prompt removal of plant debris would therefore help create safer beaches.
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Francisco M.E., Carvajal T.M., Ryo M., Nukazawa K., Amalin D.M., Watanabe K.
Science of the Total Environment 792 2021年10月
記述言語:英語 掲載種別:研究論文(学術雑誌) 出版者・発行元:Science of the Total Environment
Background: Dengue is an endemic vector-borne disease influenced by environmental factors such as landscape and climate. Previous studies separately assessed the effects of landscape and climate factors on mosquito occurrence and dengue incidence. However, both factors concurrently coexist in time and space and can interact, affecting mosquito development and dengue disease transmission. For example, eggs laid in a suitable environment can hatch after being submerged in rain water. It has been difficult for conventional statistical modeling approaches to demonstrate these combined influences due to mathematical constraints. Objectives: To investigate the combined influences of landscape and climate factors on mosquito occurrence and dengue incidence. Methods: Entomological, epidemiological, and landscape data from the rainy season (July–December) were obtained from respective government agencies in Metropolitan Manila, Philippines, from 2012 to 2014. Temperature, precipitation and vegetation data were obtained through remote sensing. A random forest algorithm was used to select the landscape and climate variables. Afterward, using the identified key variables, a model-based (MOB) recursive partitioning was implemented to test the combined influences of landscape and climate factors on ovitrap index (vector mosquito occurrence) and dengue incidence. Results: The MOB recursive partitioning for ovitrap index indicated a high sensitivity of vector mosquito occurrence on environmental conditions generated by a combination of high residential density areas with low precipitation. Moreover, the MOB recursive partitioning indicated high sensitivity of dengue incidence to the effects of precipitation in areas with high proportions of residential density and commercial areas. Conclusions: Dengue dynamics are not solely influenced by individual effects of either climate or landscape, but rather by their synergistic or combined effects. The presented findings have the potential to target vector surveillance in areas identified as suitable for mosquito occurrence under specific climatic conditions and may be relevant as part of urban planning strategies to control dengue.
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Enhancement of sunlight irradiation for wastewater disinfection by mixing with seawater
Suzuki Y., Uno M., Nishiyama M., Nukazawa K., Masago Y.
Journal of Water and Health 19 ( 5 ) 836 - 845 2021年10月
記述言語:日本語 掲載種別:研究論文(学術雑誌) 出版者・発行元:Journal of Water and Health
There is a need for developing a simple and easy-to-maintain disinfection technique for sewage treatment for use in developing countries and disaster-affected areas. We propose a novel disinfection technology that inactivates bacteria in wastewater via sunlight irradiation under high salt concentration by mixing with seawater. The disinfection efficiency of the proposed method was quantitatively evaluated and examined using fecal indicator bacteria. When the salinity in wastewater was adjusted to 30 practical salinity units by mixing with seawater, the constant of inactivation irradiation energy Ks (m2/MJ) was 1.6-2.2-fold greater than that without seawater for total coliforms and Escherichia coli. By contrast, although enterococci were inactivated by sunlight irradiation, an increase in salinity did not enhance disinfection. On setting the irradiation energy of sunlight to 5.5 MJ/m2,.99% of the fecal indicator bacteria were inactivated. Finally, we examined the relationship between the attenuation of irradiance and water depth and accordingly proposed a design of a treatment system wherein wastewater and seawater were adequately mixed and passed via a disinfection tank under the natural flow with sunlight irradiation.
DOI: 10.2166/wh.2021.153
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Nukazawa K., Itakiyo T., Ito K., Sato S., Oishi H., Suzuki Y.
Catena 203 ( 105323 ) 2021年8月
担当区分:筆頭著者 記述言語:英語 掲載種別:研究論文(学術雑誌) 出版者・発行元:Catena
Knowledge of the provenance and transport processes of coastal sediments is central to safeguarding against coastal erosion. However, to date coastal sediments have been poorly investigated without considering complex artificial and natural attributes such as coastal structures and watershed geology of potential source rivers. In this study, mineralogical fingerprinting technique was used to track the sources of sediments along a coastline in southwest Japan with reference to sediments of outflowing rivers. The sediment samples were collected from 65 beach sites along the Miyazaki Coast and its surrounding coastal area, and five river sites nearby. To determine the size distribution and geochemical and mineralogical compositions of the sediments, grain size, X-ray fluorescence, and X-ray diffraction (XRD) analyses were performed. Subsequently, cluster analysis was used to classify mineralogically similar groups in terms of XRD peak intensity ratio. The coastal sediment clusters corresponded well to nearby riverine clusters, suggesting that the coastal sediments were primarily transported from these river watersheds, although uncertainty as contributions of oceanic flows might be involved. The concordance ascribes to the major geological classifications in the watersheds of major rivers, as well as smaller rivers flowing in the northern area (e.g., the Shimanto Supergroup and Osuzuyama Acid Rocks). In addition to the major tendency, we also observed potential effects of manmade structures on the coastal sediment prevalence; the mineralogical similarities decreased across jetties in the Hitotsuse River mouth. The vertical mineralogical distribution of the core sediment samples observed on the left and right banks of the Hitotsuse River mouth supported the general trend of uniform cluster patterns in each core sample with horizontally different clusters across the river mouth. Mineralogical analysis targeting both coastal and riverine sediments is effective for understanding the characteristics of sediment distribution, which in turn is useful for efforts devoted to protection against coastal erosion.
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宮崎県一ツ瀬川における濁水長期化 ~その原因と産官学民が連携した対策~
杉尾哲, 糠澤桂, 鈴木祥広( 担当: 編集)
パブフル 2022年2月
著書種別:学術書
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風間 聡, 小森 大輔, 峠 嘉哉, 糠澤 桂, 横尾 善之, 渡辺 一也( 担当: 分担執筆)
理工図書 2020年9月 ( ISBN:9784844608844 )
MISC 【 表示 / 非表示 】
講演・口頭発表等 【 表示 / 非表示 】
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Catchment scale modeling of riverine species diversity using hydrological simulation 招待あり 国際会議
Nukazawa K.
Guest Lecture in Water Resources Engineering Dept. Engineering Faculty, Universitas Brawijaya
開催年月日: 2022年3月19日
記述言語:英語 会議種別:口頭発表(招待・特別)
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コロイド吸着と泡沫濃縮法を利用した細胞外 DNA の超高感度検出・定量法の開発
玉井荘一郎,小椋義俊,糠澤桂,鈴木祥広
第56回日本水環境学会年会(オンライン)
開催年月日: 2022年3月16日 - 2022年3月18日
記述言語:日本語 会議種別:口頭発表(一般)
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下水処理場における ESBL 耐性大腸菌・大腸菌群の消長と ESBL 関連遺伝子の保有率変化
山田佳奈,謝暉,糠澤桂,鈴木祥広
第56回日本水環境学会年会(オンライン)
開催年月日: 2022年3月16日 - 2022年3月18日
記述言語:日本語 会議種別:口頭発表(一般)
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河川の上流から河口に至る薬剤耐性菌の菌数・菌叢の変動解析
加藤優貴,謝暉,糠澤桂,鈴木祥広
第56回日本水環境学会年会(オンライン)
開催年月日: 2022年3月16日 - 2022年3月18日
記述言語:日本語 会議種別:口頭発表(一般)
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海岸に漂着したプラスチックゴミと植物デブリに存在する細菌の菌数と細菌叢の比較
杉山航,糠澤桂,鈴木祥広
第56回日本水環境学会年会(オンライン)
開催年月日: 2022年3月16日 - 2022年3月18日
記述言語:日本語 会議種別:口頭発表(一般)
受賞 【 表示 / 非表示 】
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第55回環境工学研究フォーラム 優秀ポスター発表賞
2018年12月 土木学会
西村恵美,糠澤桂,鈴木祥広
受賞区分:国内学会・会議・シンポジウム等の賞 受賞国:日本国
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応用生態工学会第22回研究発表会 優秀ポスター研究発表賞
2018年9月 応用生態工学会
糠澤桂
受賞区分:国内学会・会議・シンポジウム等の賞 受賞国:日本国
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平成28年度建設工学研究奨励賞
2017年6月 一般財団法人建設工学研究振興会 宮崎における分布型汚濁流出モデルの開発とその利用による河川環境・生物多様性評価
糠澤桂
受賞区分:国内外の国際的学術賞 受賞国:日本国
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第21回地球環境シンポジウム 優秀講演賞
2014年9月 土木学会地球環境委員会
糠澤桂, 風間聡, 渡辺幸三
受賞区分:国内学会・会議・シンポジウム等の賞 受賞国:日本国
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平成24年度東北大学 工学研究科長賞
2013年3月 東北大学
糠澤桂
受賞国:日本国
科研費(文科省・学振・厚労省)獲得実績 【 表示 / 非表示 】
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人口減少下での中小河川の水文・環境変化と新しい管理手法の研究
研究課題/領域番号:20H00256 2020年04月 - 2024年03月
科学研究費補助金 基盤研究(A)
担当区分:研究分担者
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蚊共生細菌ボルバキアによるデング熱の生態学的制御:安心・安価な新技術の提案
研究課題/領域番号:19KK0107 2019年10月 - 2022年03月
独立行政法人日本学術振興会 科学研究費補助金 国際共同研究加速基金(国際共同研究強化(B))
担当区分:研究分担者
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インドネシア・バンドンのデング熱蚊の生態疫学:ウイルス伝播と気候変動影響の予測
2019年04月 - 2022年03月
科学研究費補助金 二国間交流事業共同研究
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流出解析に基づく流域一貫の河川生息場モデルの高度化: 流況と空間解像度に着目して
研究課題/領域番号:19K15101 2019年04月 - 2022年03月
科学研究費補助金 若手研究
担当区分:研究代表者
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健全な流砂系の回復によるサステナブル流域総合土砂管理の実証研究
2017年04月 - 2020年03月
科学研究費補助金 基盤研究(B)
担当区分:研究分担者
その他競争的資金獲得実績 【 表示 / 非表示 】
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泡沫濃縮・分離法を用いた高濁度水からの環境DNA検出手法の開発
2020年04月 - 2021年03月
民間財団等 河川基金
担当区分:研究代表者 資金種別:競争的資金
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総合土砂管理による河川生態系への影響の定量的評価手法の開発
2017年04月 - 2019年03月
民間財団等 河川基金
担当区分:研究分担者 資金種別:競争的資金
受託研究受入実績 【 表示 / 非表示 】
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宮崎県小丸川流域における治水と生態系の総合評価のためのモデル開発
2018年05月 - 2021年03月
一般受託研究
糠澤桂、鈴木祥広
担当区分:研究代表者 受託研究区分:一般受託研究
寄附金・講座・研究部門 【 表示 / 非表示 】
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工学部研究奨学寄附金
寄附者名称:西日本技術開発(株) 2020年01月
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工学部の研究のため
寄附者名称:西日本技術開発(株) 2019年01月
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工学部の研究のため
寄附者名称:西日本技術開発(株) 2018年01月
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工学部の研究のため
寄附者名称:西日本技術開発(株) 2017年01月