Effects of anthropogenic noise as a source of acoustic stress in wild populations of Hippocampus guttulatus in the Ria Formosa,south Portugal

1. This study evaluated the effects of underwater noise as a source of acoustic stress in the wild populations of Hippocampus guttulatus in the Ria Formosa, south Portugal. Two different scenarios of underwater noise were tested: transient motor boat sound (63.4–127.6 dB) and constant sound produced by the motor of the boat directly above the animals (up to 137.1 dB).
2. Observations were obtained in the wild between 4 and 10 m depth throughout a 3 min period, using a video camera and a hydrophone set, and compared with a control sample.
3. A significant increase (P < 0.05) in the respiratory rate was observed in 87% of the observed fish. Opercular movements per minute (OMPM) increased from 35.7 ± 10 (control sample) to 41.2 ± 15.5 after the first minute, to 45.5 ± 13.3 after the second (both under transient sound) and to 49.7 ± 12.5 after the third (under constant sound exposure). Differences in means between the control fish and fish observed during the second (P < 0.01) and third minute of observation (P < 0.0001) were significant. Concordantly, a significant increase (P < 0.05) in the OMPM of fish observed in the first minute and the third minute was noted. In addition to the OMPM increase, 37.5% of the animals abandoned the observation location presumably in an attempt to avoid the negative sound stimuli.
4. The noise caused by boat traffic generated an immediate physiological response, expressed as an increase in OMPM, and a behavioural response resulting in site abandonment, which together can be considered as a negative impact on the seahorse populations. This work contributes to an increasing number of studies that have shown that boat traffic can induce ecological and environmental consequences to aquatic species. Future research should evaluate how navigation exclusion areas could have a positive impact on the seahorse populations inhabiting shallow coastal areas.

     

基于分数阶微分视频融合的森林烟火检测算法

森林火灾检测是国内外林业应用研究的重要课题之一。及时准确地检测到森林火灾，对于森林健康及环境安全意义重大。现有的利用视频技术检测森林火灾的方法大多针对单一波段，如可见光波段或红外波段的视频信息进行分析，然而在实际应用过程中，由于森林环境复杂，基于单一波段视频信息检测火灾的结果欠佳。现阶段，基于多个波段的森林火灾检测方法非常少。本文综合利用红外及可见光视频特征，提出了一种基于分数阶微分视频融合的森林烟火检测算法，将分数阶微分理论引入红外视频和可见光视频融合中，利用分数阶微分算子对两个波段视频进行融合，然后利用背景去除法检测融合视频中的异常帧，且对异常帧图像及其与背景帧的差分图像分别进行图像分割，最终得到检测出的森林烟火区域。采用空间频率、平均梯度、森林火灾检测准确率和森林火灾检测时间误差度4个测度对本文算法和基于区域能量融合算法、基于窗口方差融合算法、基于HSI变换融合算法进行定量分析和比较。结果表明，本文算法的融合视频的融合效果最佳，并且森林火灾检测准确率和森林火灾检测时间误差均明显优于其他3种算法，说明本文提出的算法具有较好的有效性和准确性，为森林火灾检测提供了有利的新途径。      

Analysis of sinking death using video images of the swimming performance of Pacific Bluefin tuna (Thunnus orientalis) larvae

In this study, we aimed to clarify the mechanism of sinking death during the larval stage of Pacific Bluefin tuna Thunnus orientalis by investigating the effects of swimming performance on sinking death, using a behavioral approach. Swimming performance was examined 3–9 days after hatching (DAH) under day and night light conditions in cuboid experimental tanks. Swimming behavior variables such as swimming speed and swimming angle were measured under both light conditions. Larvae in the daytime experiment and larvae with inflated swim bladders at night were distributed on the surface layer of the water column. In contrast, larvae with uninflated swim bladders at night were frequently observed swimming vertically or sinking to the bottom of the tank. Larvae with inflated swim bladders at night were always distributed beneath the surface until the next morning (survival rates were 100 %). However, larvae with uninflated swim bladders at night swam upward repeatedly and later sank to the bottom of the tank (survival rates were 60 % and 38 % at 5 and 9 DAH, respectively). Larvae with uninflated swim bladders were not always able to maintain their swimming depth by swimming until the next morning. Additionally, their swimming speed and vertical swimming frequency (ratio) depended on the illumination and swim bladder conditions. Our findings show that larvae with uninflated swim bladders at night were associated with a higher risk of sinking death. The swimming energy capacity of Pacific Bluefin tuna larvae, which indicates the total amount of the energy that enables individuals to swim throughout the night without feeding, was found to be linked to sinking death.     

A social learning video method: Identifying and sharing successful transformation knowledge for sustainable soil management in Switzerland

To enhance sustainable land use, a From Farmer to Farmer project was conducted in Switzerland (2001–2010). A multi‐stakeholder discussion group co‐produced nine videos with experienced farmers and wine producers showing sustainable soil management practices. We analysed the video audio‐visual content and drew on reflections of the co‐production process, referring to concepts of system, target and transformation knowledge, as well as on social learning. The analysis showed a broad range of means (or actions) for sustainable soil management in arable land management, fodder production and wine growing that are aligned to transformation knowledge. The research showed that farmers refer to three phases of social learning, light‐bulb moments, coping with challenges and gaining successful expertise. These are not just linear processes of individuals. Four types of social learning were found in the video analysis: (a) learning from observing actions of others, (b) sharing experiences with storytelling, (c) informal social interactions and (d) being a role model with a large social network. Videos enable transformation knowledge to be shared with peers using storytelling; this powerful narrative communication style provides credibility and respects the ‘thought style’ of the target audience group. We conclude that for successful implementation of sustainable actions, it is important to address a specific target group and share their transformation knowledge built upon system and target knowledge. The social learning video method is a viable way to enable social learning between science, administration and practice and has potential for fostering change in sustainable soil management.     

新疆天然林资源保护工程智能化监控平台建设研究

基于移动通信、地理信息和视频监控等技术建立天然林资源保护工程智能化监控平台,实现天然林资源的全面监控和管理,加强巡护人员和巡护事件的监控力度。文中介绍了视频监控技术、移动GIS技术和智能移动通信技术等研究中的关键技术。阐述平台总体框架设计以及视频监控管理子系统、天保工程森林智能移动巡护子系统和天然林资源保护巡护管理子系统的主要功能实现。     

广州南香山水库森林水文季节变化研究

为了提高森林水文研究过程中数据采集的精确性,应用现代测绘技术,包括水准测量、全站仪三维坐标测量、GNSS 卫星测量及测深仪的水深测量等,研究了广州南香山水库的库容变化规律,反演水库上游森林径流。研究结果表明：南香山一年内的降雨量分布出现类似双波浪形的变化,波峰出现在5月份和8月份,波谷出现在1月和10月;降雨量与库容增量存在线性关系,相关系数为0.9152;地表径流的大小主要与植被类型,土壤水分的饱和度及地形有密切关系。相比传统的测量方法,现代测绘技术更精确地反映了广州南香山地区森林水文的变化规律。     

变电站中的嵌入式视频监控系统的设计

嵌入式视频监控系统可实现摄像头数据的实时采集,并拥有Web服务器及网络视频服务器的功能,远程的客户端通过浏览器可实时监控远程的视频图像。本文构建了嵌入式视频监控系统的总体框架,设计了以SH4-DSP处理器SH7760为中心的嵌入式体系的硬件结构,并通过软件实现嵌入式web服务器及视频服务器。系统成功运行表明其在变电站的应用可行。     

大华丽蜾赢的筑巢和育幼行为观察与视频记录

通过直接观察和摄像机同步记录的方式．观测大华丽蜾赢[Deltapetiolata（Fabricius）]的筑巢与育幼行为，包括选址、取水、取泥、筑巢、产卵、捕虫和封口等环节。结果表明，大华丽蜾赢一天的活动时间为8：00～18：00．完成1穴需要制作和搬运15～18个泥球，单次取泥时间为33～75s，单次取水时间为15～22s。筑巢耗费1个泥球的时间为41～209s，单穴储存2～4只夜蛾幼虫；每天筑l穴，连筑8穴，每穴产卵1粒．共8粒，幼虫发育30d左右，2只破巢而出，羽化为成虫，其余被寄生而未能完成发育。同时，成功地获得了包括巢内行为在内的视频记录。     

歧管式高压射流水下洗网机的设计

文章针对深水网箱养殖过程中岸电供应不便而给网衣的水下清洗带来极大困难的问题，研制了歧管式高压射流水下洗网机，克服了高压仓式洗网机水头损失大的缺点。通过水力学计算得到歧管式高压射流水下洗网机射流压力P=5．57MPa、喷嘴孔径d=2．6mm、射流速度v=104．1m·s。和射流功率P=12．3kW、射流反冲力F=234．96N。水下洗网机的海上清洗试验表明，在工作泵满足工作压力和设计流量条件下，歧管式高压水射流水下洗网机的综合性能达到了设计要求。