Field observation of predation on a horsehair worm (Gordioida: Chordodidae) by a diving beetle larva Cybister brevis Aubé (Coleoptera: Dytiscidae)

2019 ◽  
Vol 22 (2) ◽  
pp. 230-232 ◽  
Author(s):  
Reiya Watanabe
Author(s):  
Selly Veronica ◽  
Nurlisa Ginting ◽  
AmyMarisa

Night tourism development comes up as an innovative strategy for tourism development in this current intense competition. There are four main elements in night tourism, namely economic, social, environmental, and night atmosphere. Berastagi is the most popular tourist destination in Karo Regency, Sumatera Utara, Indonesia, which already have night tourism destination but unfortunately undeveloped yet. Night tourism development in Berastagi must be with the local wisdom approach to maximize its benefit. Karonese as the majority ethnic of the local community in this area potential to be developed on its night tourism. This paper only analyzes the environmental and night atmosphere aspects in Berastagi’s night tourism, which based on local wisdom. Qualitative primary data from field observation and depth interview results have been analyzed by using the descriptive method. The study shows that involving local wisdom in developing the environment and night atmosphere can give the typical identity for the night tourism in Berastagi.Night Tourism


Author(s):  
Akinori OZAKI ◽  
Panitan KAEWJANTAWEE ◽  
Monton ANONGPONYOSKUL ◽  
Nguyen Van THINH ◽  
Masayoshi HARADA ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Debo Qi ◽  
Chengchun Zhang ◽  
Jingwei He ◽  
Yongli Yue ◽  
Jing Wang ◽  
...  

AbstractThe fast swimming speed, flexible cornering, and high propulsion efficiency of diving beetles are primarily achieved by their two powerful hind legs. Unlike other aquatic organisms, such as turtle, jellyfish, fish and frog et al., the diving beetle could complete retreating motion without turning around, and the turning radius is small for this kind of propulsion mode. However, most bionic vehicles have not contained these advantages, the study about this propulsion method is useful for the design of bionic robots. In this paper, the swimming videos of the diving beetle, including forwarding, turning and retreating, were captured by two synchronized high-speed cameras, and were analyzed via SIMI Motion. The analysis results revealed that the swimming speed initially increased quickly to a maximum at 60% of the power stroke, and then decreased. During the power stroke, the diving beetle stretched its tibias and tarsi, the bristles on both sides of which were shaped like paddles, to maximize the cross-sectional areas against the water to achieve the maximum thrust. During the recovery stroke, the diving beetle rotated its tarsi and folded the bristles to minimize the cross-sectional areas to reduce the drag force. For one turning motion (turn right about 90 degrees), it takes only one motion cycle for the diving beetle to complete it. During the retreating motion, the average acceleration was close to 9.8 m/s2 in the first 25 ms. Finally, based on the diving beetle's hind-leg movement pattern, a kinematic model was constructed, and according to this model and the motion data of the joint angles, the motion trajectories of the hind legs were obtained by using MATLAB. Since the advantages of this propulsion method, it may become a new bionic propulsion method, and the motion data and kinematic model of the hind legs will be helpful in the design of bionic underwater unmanned vehicles.


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