EFFECTS OF POTASSIUM ON THE POTENTIAL OF HALICYSTIS

Sea water in which sodium has been replaced by potassium produces about the same degree of negativity in Halicystis and in Valonia. With increasing dilution of this sea water up to 1 ÷ 16 the degree of negativity steadily falls off in Halicystis. This differs from the situation in Valonia where Damon finds that with increasing dilution the negativity passes through a minimum after which increasing dilution produces increasing negativity. But conditions in the two organisms differ so greatly that a comparison is of rather doubtful significance.     

氦氖激光对鱼类生长的影响

本试验采用氦氖激光(632.8nm)以不同的功率和不同功率密度,或者不同的辐照方式,辐照孔雀幼鱼(Poecilia reticulata)、尼罗罗非鱼(Oreochromis niloticus)和淡水白鲳(Ephippus orbis)。实验结果表明,He-Ne激光辐照对三种幼鱼的生长均有促进的作用,并且不同的功率和功率密度的影响是不同的,适当的激光参量会产生较佳的影响效果。     

UNDERWATER NOISE OF WHALE-WATCHING BOATS AND POTENTIAL EFFECTS ON KILLER WHALES (ORCINUS ORCA), BASED ON AN ACOUSTIC IMPACT MODEL

Underwater noise of whale-watching boats was recorded in the popular killer whale-watching region of southern British Columbia and northwestern Washington State. A software sound propagation and impact assessment model was applied to estimate zones around whale-watching boats where boat noise was audible to killer whales, where it interfered with their communication, where it caused behavioral avoidance, and where it possibly caused hearing loss. Boat source levels ranged from 145 to 169 dB re 1 μPa @ 1 m, increasing with speed. The noise of fast boats was modeled to be audible to killer whales over 16 km, to mask killer whale calls over 14 km, to elicit a behavioral response over 200 m, and to cause a temporary threshold shift (TTS) in hearing of 5 dB after 30–50 min within 450 m. For boats cruising at slow speeds, the predicted ranges were 1 km for audibility and masking, 50 m for behavioral responses, and 20 m for TTS. Superposed noise levels of a number of boats circulating around or following the whales were close to the critical level assumed to cause a permanent hearing loss over prolonged exposure. These data should be useful in developing whale-watching regulations. This study also gave lower estimates of killer whale call source levels of 105–124 dB re 1 μPa.     

白噪声对听觉脑干电反应(ABR)和耳蜗电图(ECochG)的影响

本文通过20例听力正常人和10例听力正常豚鼠研究了白噪声对耳蜗电图(ECochG)和听觉脑干电反应(ABR)的干涉作用。实验结果表明,白噪声比短声(信号)的声强级低30dB(SL)以上时,ECochG和ABR的振幅仅轻微减小。白噪声与短声的声强级相等时,ECochG与ABR的振幅和出现率会明显受到干涉而减小,甚至完全消失。但是,此时的耳蜗微音器电位(CM)并未观察到有明显的变化。这意味着白噪声对ECochG和ABR的干涉作用主要与围绕毛细胞基底部的突触产生的抑制密切相关。由于白噪声对ABR各波的干涉有些差异,所以认为这种抑制,可能既包括脑中抑制也包括侧方抑制。     

稳态白噪声对豚鼠耳蜗电位影响的研究

本工作利用面神经管慢性埋植电极在清醒动物上对噪声暴露前后听神经动作电位(AP)和微音器电位(CM) 进行了研究,结果表明:当改变测试声强和频率时CM应起始点会发生移位(CM-shift); 123dBSPL稳态白噪声暴露1小时后.AP各参数(幅值、潜伏期和阈值)均发生明显变化.而CM各参数(幅值、CM-shift和检测阈)变化则基本未达显著性.说明AP对产损伤的敏感性要高于CM另外发现噪声暴露后AP的N_2峰的恢复比N_1峰快、CM在恢复过程中会出现幅值加大现象.     

鱼类饲养对地下水中溶解态磷酸酶的影响

比较了鱼类养殖前后 ,地下水中正磷酸盐 (o P)浓度、碱性磷酸酶活性 (APA)在不同大小颗粒之间的分布、溶解态APA对pH、温度、CuSO4、ZnSO4、EDTA 2Na与表面活性剂 (CTAB与TritonX 10 0 )的应答方式及其动力学特征。养鱼之后 ,玻璃缸水中碱性磷酸酶表现出明显较高的活性 ,且以溶解态为主要存在形式 ,这种效应与鱼类的品种有关 ,溶解态APA的最大反应速度 (Vmax)与米氏常数 (Km)均明显提高 ,最适温度与pH值以及对于Zn2 的应答方式亦发生明显改变 ,颗粒结合态APA甚微或不可监测 ,藻类极少 ,故非溶解态APA的主要贡献者。因此 ,鱼类饲养与溶解态APA之间具有密切联系。养鱼缸底颗粒的蒸馏水提取液与同缸水中的溶解态APA对pH值的应答方式十分接近 ,这一结果暗示养殖产生的固体废物是溶解态APA的来源之一。     

噪声对豚鼠耳蜗电图功率谱的影响

本文对豚鼠噪声暴露后的耳蜗电图功率谱进行了分析,实验表明:噪声组豚鼠耳蜗电图功率谱150～300Hz频段能量较正常组有明显增长;500～850Hz和850～1400Hz频段能量不集中(表2).另外,噪声组耳蜗电图功率谱与标准型的相关度比正常组与标准型的相关度差(P<0.01).     

溪流大小及其空间位置对鱼类群落结构的影响

2008年10月和2009年10月分别对黄山地区阊江流域与青弋江流域1-3级浅水溪流中鱼类群落结构进行了研究,着重探讨了溪流大小及其空间位置对鱼类群落空间分布的影响。研究共捕获35种鱼类,阊江和青弋江分别为26和29种,其Jaccard相似性系数为57.1%;两流域间每样点的物种数差异显著,个体数差异极显著。在溪流级别梯度(1-3级)下,鱼类的物种数和个体数都呈上升的变动趋势,且物种数的变化相对个体数较显著。综合相关分析、逐步多元回归分析与典范相关分析的结果,阊江和青弋江中鱼类物种数的空间变化主要与下游量级相关,而个体数的空间变化主要与水宽相关。因此,阊江和青弋江1-3级浅水溪流中鱼类群落结构的空间分布格局是溪流大小和空间位置的共同作用结果,且溪流大小和空间位置分别决定鱼类的个体数与物种数的空间分布。