The physiological mechanisms underlying variation in aggression in fish remain poorly understood.One possibly confounding variable is the lack of standardization in the type of stimuli used to elicit aggression.The pr...The physiological mechanisms underlying variation in aggression in fish remain poorly understood.One possibly confounding variable is the lack of standardization in the type of stimuli used to elicit aggression.The presentation of controlled stimuli in videos,a.k.a.video playback,can provide better control of the fight components.However,this technique has produced conflicting results in animal behavior studies and needs to be carefully validated.For this,a similar response to the video and an equivalent live stimulus needs to be demonstrated.Further,different physiological responses may be triggered by live and video stimuli,and it is important to demonstrate that video images elicit appropriate physiological reactions.Here,the behavioral and endocrine responses of male Siamese fighting fish Betta splendens to a matched-for-size conspecific fighting behind a one-way mirror,presented live or through video playback,were compared.The video playback and live stimulus elicited a strong and similar aggressive response by the focal fish,with a fight structure that started with stereotypical threat displays and progressed to overt attacks.Postfight plasma levels of the androgen 11-ketotestosterone were elevated as compared to controls,regardless of the type of stimuli.Cortisol also increased in response to the video images,as previously described for live fights in this species.These results show that the interactive component of a fight and its resolution are not needed to trigger an endocrine response to aggression in this species.The study also demonstrates for the first time in a fish a robust endocrine response to video stimuli and supports the use of this technique for researching aggressive behavior in B.splendens.展开更多
H.264是ISO/IEC MPEG和ITU-TVCEG联合制定的最新的视频编码标准,其压缩性能和图像质量大大优于先前的视频编码标准。然而,Windows平台上的Windows Media Player需要第三方插件才支持H.264格式视频的播放,很多插件如ffd-show等只支持AVI...H.264是ISO/IEC MPEG和ITU-TVCEG联合制定的最新的视频编码标准,其压缩性能和图像质量大大优于先前的视频编码标准。然而,Windows平台上的Windows Media Player需要第三方插件才支持H.264格式视频的播放,很多插件如ffd-show等只支持AVI容器中的H.264播放,不支持ASF容器中的H.264视频播放。因此本文分析Windows平台的DMO等技术,利用开源程序FFMPEG,实现在Windows平台下与Windows Media Player配合的支持ASF文件容器中H.264视频回放的插件。展开更多
本文给出了一种远程视频会议系统节点设备的视频数据捕获及回放的FPGA实现。本地捕获数据在进行压缩之前,需要对每一帧中色度信号U、V、亮度信号Y以及同步信号进行分离。通过DSP EM IF接口与FPGA之间的通信,实现了捕获和回放的单片FPGA...本文给出了一种远程视频会议系统节点设备的视频数据捕获及回放的FPGA实现。本地捕获数据在进行压缩之前,需要对每一帧中色度信号U、V、亮度信号Y以及同步信号进行分离。通过DSP EM IF接口与FPGA之间的通信,实现了捕获和回放的单片FPGA设计,给出了基于FPGA的视频数据解析方法,同时也给出了DSP EM IF控制器和SDRAM控制器的FPGA实现。工程实践表明,本文的设计减少了DSP中算法软件的复杂度,提高了节点设备处理的速度,且稳定可靠。展开更多
基金supported by the Macao Science and Technology Development(FDCT)fund through projects 093/2017/A2 and 0025/2017/A2,and a postdoctoral fellowship FDCT0003/2019/APD awarded to SDC.
文摘The physiological mechanisms underlying variation in aggression in fish remain poorly understood.One possibly confounding variable is the lack of standardization in the type of stimuli used to elicit aggression.The presentation of controlled stimuli in videos,a.k.a.video playback,can provide better control of the fight components.However,this technique has produced conflicting results in animal behavior studies and needs to be carefully validated.For this,a similar response to the video and an equivalent live stimulus needs to be demonstrated.Further,different physiological responses may be triggered by live and video stimuli,and it is important to demonstrate that video images elicit appropriate physiological reactions.Here,the behavioral and endocrine responses of male Siamese fighting fish Betta splendens to a matched-for-size conspecific fighting behind a one-way mirror,presented live or through video playback,were compared.The video playback and live stimulus elicited a strong and similar aggressive response by the focal fish,with a fight structure that started with stereotypical threat displays and progressed to overt attacks.Postfight plasma levels of the androgen 11-ketotestosterone were elevated as compared to controls,regardless of the type of stimuli.Cortisol also increased in response to the video images,as previously described for live fights in this species.These results show that the interactive component of a fight and its resolution are not needed to trigger an endocrine response to aggression in this species.The study also demonstrates for the first time in a fish a robust endocrine response to video stimuli and supports the use of this technique for researching aggressive behavior in B.splendens.
文摘H.264是ISO/IEC MPEG和ITU-TVCEG联合制定的最新的视频编码标准,其压缩性能和图像质量大大优于先前的视频编码标准。然而,Windows平台上的Windows Media Player需要第三方插件才支持H.264格式视频的播放,很多插件如ffd-show等只支持AVI容器中的H.264播放,不支持ASF容器中的H.264视频播放。因此本文分析Windows平台的DMO等技术,利用开源程序FFMPEG,实现在Windows平台下与Windows Media Player配合的支持ASF文件容器中H.264视频回放的插件。
文摘本文给出了一种远程视频会议系统节点设备的视频数据捕获及回放的FPGA实现。本地捕获数据在进行压缩之前,需要对每一帧中色度信号U、V、亮度信号Y以及同步信号进行分离。通过DSP EM IF接口与FPGA之间的通信,实现了捕获和回放的单片FPGA设计,给出了基于FPGA的视频数据解析方法,同时也给出了DSP EM IF控制器和SDRAM控制器的FPGA实现。工程实践表明,本文的设计减少了DSP中算法软件的复杂度,提高了节点设备处理的速度,且稳定可靠。
