털진드기 유충 (Acari: Trombiculidae)은 쯔쯔가무시증을 전파하는 주요 매개체이다. 털진드기 유충의 발생량 은 가을철에 증가하는 것으로 알려져 있지만, 환경 및 시기에 따라 발생 패턴이 다르게 나타날 수 있어 각 지역에 대한 조사가 필요하다. 이 연구는 충남 예산의 털진드기 발생 양상을 확인하기 위해 2017년부터 2023년까지 36-51 주차 (9-12월)에 걸쳐 현장 조사를 수행하였다. 논, 밭, 수로, 초지에 5m 간격으로 털진드기 트랩을 환경별로 5개씩 설치하여 채집하였다. 그 결과 총 3,257개체로 2017년 1,104마리, 2018년 785마리, 2019년 650마리, 2020년 160마 리, 2021년 139마리, 2022년 233마리, 2023년 186마리 채집되었다. 동정 결과 5속 12종이 확인되었으며 둥근혀털 진드기(Neotrombicula tamiyai)가 1,882개체(57.78%)로 우점도가 가장 높게 나타났다. 이러한 발생 양상에 관한 연구는 매개 질환의 예방 및 관리 전략 수립에 있어 중요한 기초 자료로 활용될 수 있으므로 지속적인 연구와 모니터링이 필요할 것으로 사료된다.
This study evaluated the risk of single and combined exposure to microplastics in zebrafish (Danio rerio) through biomarkers, such as survival rate, excretion rate, and histological alterations of organ systems. The experimental groups were the control (Cont.), single microplastics exposure group (MPs, 1.83%/fish total weight (g)), the copper group (Cu, 21.6 μg L-1), and a group with combined exposure to MPs and copper (MPs*Cu). The experiment was conducted with individual exposure (7 days) for MP excretion rate analysis and group exposure (14 days) for biomarker analysis. The daily excretion rate of MPs tended to decrease in a time-dependent manner. The copper concentration in the body was not significantly different between single and combined copper exposure. The degeneration of mucous cells in the skin, capillary dilation of the gill lamella, increased intestinal mucous, hepatocyte hypertrophy, and the degeneration of glomeruli and renal tubules were observed in all exposure groups. These histological alterations showed the highest tendency in the MPs*Cu group. In this study, the changes in biomarkers were attributed to the single effect of copper or the combined effect of copper and MPs rather than being solely influenced by MPs.
To be better fit for highways, pavement systems are required to provide comfortable and safe driving and be structurally durable. Composite pavements can be an effective option as they are more durable by placing a high functional asphalt overlay on a rigid concrete base layer. In order to apply a composite pavement system to the field, it is necessary not only to develop technologies that prevent reflecting crack and deterioration of the base layer, but also to improve bonding performance of materials and ensure structural performance as a pavement system against traffic loading. In advanced countries like Japan, USA and Europe, high-functional composite pavement systems are being put into practice across new highway networks. In this study, we evaluated structural performance (rutting, reflecting crack, and deflection) by applying traffic loads of actual highways through an accelerated pavement tester (APT) of a composite pavement section made up of a quiet porous surface laid over a water-proofing layer, a continuously reinforced concrete base, and a lean concrete sub-base layer, which was developed with new pavement methods used for each layer prior to field application. The APT specimen was constructed with paving materials and equipment actually used on site in the same dimensions (W3.5m*L14m*H2m) as actual highway sections in Korea, and 3-axle double-wheel heavy load (45ton) cart type KALES(Korean Accelerated Loading and Environmental Simulator) traveling on the specimen in both directions was used to simulate traffic loading. After applying around 8,574,000 ESALs of traffic loads, no reflecting crack occurred on the asphalt surface of the composite pavement, without surface distress except for rutting. In order to examine what causes rutting of pavements, we surveyed thickness of pavements by layer and measured asphalt density.