initiating signal meaning in English

起动信号
起始信号
启动信号

During a break , he took out a pack of cigarettes , only to see a fellow initiate signal to him that smoking was " not good for him "
休息时当他拿出香烟，同修对他比手势说抽烟no good ！不好！
In conclusion , exposure of healthy subjects to traffic - related air pollution resulted in a lower airway inflammatory response with cell migration , together with signs of an initiated signal transduction in the bronchial epithelium
总之，让健康个体暴露于车辆废气中会降低有细胞迁移的气道炎症反应，同时也有迹象显示启动了支气管上皮的信号传导。