不同流速下杂交鲟幼鱼游泳状态与活动代谢研究

为研究水流速度对杂交鲟幼鱼行为和代谢的影响,探讨游泳状态与活动代谢及相关游泳运动参数之间的关系,在26℃水温下,使用特制的鱼类游泳行为和活动代谢同步测定装置,测定了杂交鲟幼鱼在0.1、0.3、0.5 m/s三种流速和静水条件下的游泳状态、趋流率、摆尾频率和耗氧率。结果表明:随着流速的增大,杂交鲟幼鱼逆流前进和逆流静止游泳状态所占时间比例显著减少,而逆流后退所占时间比例显著增加,顺流而下时间比例有所上升。在0.0—0.3 m/s的流速范围内,杂交鲟幼鱼各个时段的平均趋流率、摆尾频率和耗氧率均随着流速的增加而增大,在0.3 m/s流速下分别达到100%﹑(2.53±0.34)Hz和(490.99±164.59)mg O2/(kg.h)。当流速增加至0.5 m/s时,在趋流率仍保持100%的情况下,其耗氧率相比0.3 m/s增加了21.86%,而摆尾频率却减小了6.70%。实验过程杂交鲟幼鱼趋流率与摆尾频率呈显著线性正相关,而摆尾频率与耗氧率在大部分时段却无相关性。随着时间的延长,各流速组杂交鲟幼鱼趋流率、摆尾频率和耗氧率呈现不同的变化趋势,其趋流率均相对稳定;但摆尾频率均随时间延长呈下降趋势,而耗氧率则在实验前9h随时间延长逐渐增加,随后趋于稳定。研究结果提示:杂交鲟幼鱼游泳状态的变化与流速有关,而反映运动强度大小的摆尾频率与活动代谢率的关系受到游泳状态的显著影响,同时也与运动代谢特征的时间变化有关。       

流速对红鳍银鲫幼鱼游泳状态的影响

在28℃水温下,采用特制的鱼类游泳行为测定装置,研究体重(125.94±13.87)g的红鳍银鲫(Barbodes schwanenfeldi)幼鱼在0.0m/s(对照组)和0.1m/s、0.3m/s、0.5m/s3种流速下的游泳行为。结果表明,从0.0～0.3m/s,红鳍银鲫幼鱼平均趋流率和摆尾频率均随着流速的增加而增大,而0.5m/s组在90min内随时间延长而下降。红鳍银鲫游泳状态明显受到所处流速的影响,在静水对照组以"逆流前进"和"顺流而下"为主,两者共占总观察时间的98%以上;各流速组均以逆流静止为主,且随着流速的增大,逆流静止所占时间比例从45.8%增加至81.3%,而逆流前进所占时间比例由24.1%减至5%以下;逆流后退所占时间比例以0.1m/s组最大,为16.4%;顺流而下的比例随着流速增大先减小后增大,3个流速组依次为13.7%、2.1%和10.9%。红鳍银鲫幼鱼的游泳速度(V)和摆尾频率(TBF)在逆流前进及逆流静止两种游泳状态下呈线性正相关,而在逆流后退和顺流而下两种状态下两者没有显著相关。     

不同流速对鱇(鱼良)白鱼游泳行为的影响

在25℃水温下,采用特制的鱼类游泳行为测定装置对实验鱼在静水和0.1、0.2和0.25 m·s-1流速下的游泳状态、游泳速度、趋流率和摆尾频率等参数进行测定,研究水流速度对鱇(鱼良)白鱼(Anabarilius grahami)游泳行为的影响.结果表明:有流速组的趋流率显著高于静水组,但不同流速组间的趋流率无显著差别;在0 ～0.2 m·s-1流速范围内,摆尾频率随流速加快而显著增大,但在0.25 m·s-1流速下40 min后摆尾频率显著低于0.2m·s-1流速组;随着流速的增大,主要游泳状态由逆流前进变为逆流静止;在有流速组,顺流而下状态所占时间比例相对其他游泳状态都较少;在逆流游泳的3种状态中,游泳速度均随流速的增加而增大,在顺流而下状态中,游泳速度和水速间无显著相关;游泳速度、摆尾频率和水流速度两两之间均存在显著的线性相关.     

流速对细鳞裂腹鱼游泳行为及能量消耗影响的研究

通过自制密封的鱼类游泳实验装置, 研究了流速对细鳞裂腹鱼游泳行为和能量消耗的影响。结果显示,细鳞裂腹鱼的摆尾频率随游泳速度的变化有明显的变化规律, 摆尾频率随着流速的增加而显著性的增加,而摆尾幅度有减小趋势, 差异性不显著。结果还表明, (26±1) ℃时, (10.60±0.54) cm 细鳞裂腹鱼的相对临界游泳速度为(11.5±0.5) BL/s, 绝对临界游泳速度为(110.28±2.02) cm/s。测定的相对临界流速较其他的鲤科鱼大,是对生存水流环境(流速0.5—1.5m/s)适应性的表现。这一结果表明鱼类的游泳能力是能够训练的。运动代谢率与相对流速的关系为, AMR = 93.08e(0.307v) + 314.33, R2= 0.994; 单位距离能耗与流速的指数关系为COT =28e (-1.03V) +6.05, R2= 0.998。流速达到8 BL/s 时, 裂腹鱼耗氧率开始下降, 从流速7 BL/s 时, (1245.57±90.97 )mg O2/(kg·h)最大, 下降到(978.78±189.38) mg O2/(kg·h)。1—7 BL/s 流速范围内, 裂腹鱼单位时间内的耗氧率随着游泳速度的增加而增加, 而且随着游泳速度的增加, 单位距离能耗(COT)逐渐减少, 最小能耗在6 倍体长流速, 0.68 m/s 时, 为(6.00±1.57) J/(kg·m), 其能量利用效率最大。       

水流对团头鲂(Megalobrama amblycephala)幼鱼游泳行为的影响

为探讨团头鲂幼鱼(Megalobrama amblycephala)游泳行为对水流的响应规律,该文通过特制鱼类游泳行为测定装置,测定了团头鲂幼鱼在25℃,0、0.1、0.2、0.3、0.4m/s流速条件下的游速、游距、转角、至中心点的距离及游泳轨迹。结果表明:随着流速的增大,个体游速、游距及转角值均相应增大。0、0.1及0.2m/s流速组间的游速、游距及转角差异均不显著(P>0.05),但显著小于0.3和0.4m/s组别,且0.3和0.4m/s流速组之间差异均不显著(P>0.05);整个时间段内,个体至中心点的距离随流速增大并未呈现明显规律性,各流速间差异不显著(P>0.05),游速与游距呈显著线性正相关,而与转角呈显著线性负相关,与至中心点的距离则无相关性;游泳轨迹随水流增大趋向复杂化。     

温度、盐度、pH和麻醉剂对长鳍篮子鱼幼鱼耗氧率的影响

采用Winkler法研究了温度、盐度、pH和麻醉剂对长鳍篮子鱼幼鱼(体长(3.325±0.205) cm,体质量(0.706±0.155) g)耗氧率的影响。结果表明：长鳍篮子鱼幼鱼耗氧率随着温度升高而增加,其回归关系可用对数函数Y=1.3819lnX-3.55(r=0.9475,P<0.01)表示,其生长的适宜温度为24 ℃～32 ℃;幼鱼耗氧率随着盐度的降低而逐渐增加,其回归关系可用线性函数Y=-0.1802X+1.7551(r=0.9837,P<0.01)来表示;在不同的pH下耗氧率有显著性差异(P<0.01),pH值在6.0时耗氧率最低,9.0时耗氧率最高;耗氧率随着丁香酚、MS-222的浓度升高而逐渐降低,各实验组的耗氧率要显著低于对照组,丁香酚和MS-222可以作为长鳍篮子鱼幼鱼运输过程中的麻醉剂。     

三种流速对卵形鲳鲹幼鱼耗氧率和排氨率的影响

【摘要】采用实验生态学方法, 研究了饥饿态下平均体重分别为(2.54±1.09) g、(24.35±7.19) g、(233.79±26.00) g、(508.98±126.61) g的卵形鲳鲹幼鱼(Trachinotus ovatus)在静水、0.1 m·s -1、0.2 m·s -1三种流速下的耗氧率和排氨率的变化。结果表明, 卵形鲳鲹体重对耗氧率和排氨率影响显著(P < 0.05)。在同一流速下, 耗氧率和排氨率分别随体重的增加而下降, 体重与两者间的回归关系符合异速方程Y=aWb。卵形鲳鲹的耗氧率和排氨率随着流速的升高均出现升高的趋势, 流速对均重为24.35 g和233.79 g卵形鲳鲹的耗氧率和排氨率影响显著(P < 0.05)。在静水条件下, 卵形鲳鲹代谢氧氮比的范围为31.36-46.32, 表明卵形鲳鲹主要以脂肪和碳水化合物为能源, 蛋白质其次。在试验流速范围内, 均重为24.35 g卵形鲳鲹幼鱼的氧氮比随着流速的升高而升高, 其他两组的氧氮比则随着流速的升高而降低。     

不同体质量和饥饿程度对红鳍东方鲀幼鱼游泳能力的影响

为了考察不同体质量和饥饿程度红鳍东方鲀(Takifugu rubripes)幼鱼的游泳能力,利用行为生态学方法测定了不同体质量(0.22—3.31 g)和饥饿天数(1d、3d、6d和9d)下红鳍东方鲀幼鱼的绝对临界游速(U_crit,cm/s)、相对临界游速(U_crit’,体长/s,BL/s)、偏好游速(U_pref,cm/s)、6个流速区域(2—36 cm/s)下停留时间百分比(P_t,%)、偏好区域平均流速(V_mean,cm/s)和总游泳距离(D_1h,m)等游泳行为指标。结果显示,体质量和饥饿显著影响红鳍东方鲀幼鱼的U_crit、U_crit’、P_t、V_mean和D_1h。随体质量增加,实验鱼的U_crit、U_pref、V_mean和D_1h均逐渐升高,而U_crit...     

卵形鲳鲹幼鱼耗氧率和排氨率的初步研究

运用封闭流水式实验方法对不同体重和放养密度的卵形鲳鲹(Trachinoms ovatus)幼鱼耗氧率和排氨率进行了初步的研究。结果表明,卵形鲳鲹幼鱼的耗氧率随着鱼体重的增加而逐渐下降,排氨率总体上也呈降低的趋势,体重对卵形鲳鲹耗氧率、排氨率的影响均达到显著水平(P0.05);光照对卵形鲳鲹幼鱼的耗氧率和排氨率影响非常显著(P0.01),幼鱼在遮光条件下的耗氧率和排氨率分别比在自然光照条件下要低25.18%～40.76%和16.28%～40.28%;随着放养密度的增加,卵形鲳鲹幼鱼的耗氧率逐渐降低,排氨率随着密度的增加呈先上升后下降的趋势,放养密度对卵形鲳鲹耗氧率、排氨率的影响均达到显著水平(P0.05)。卵形鲳鲹的耗氧率和排氨率具有明显的昼夜变化,白天的耗氧率和排氨率均高于夜间值,耗氧率的低谷值为高峰值的69.68%,排氨率的低谷值为高峰值的30.91%。卵形鲳鲹幼鱼的窒息点溶解氧含量为(0.991±0.058)mg/L。     

水流对草鱼幼鱼趋光行为的影响

为了探讨水流对鱼类趋光性的影响, 利用自制的循环水槽装置, 以草鱼(Ctenpharyngodon idellus)幼鱼为研究对象, 研究其在光照度为300 lx, 不同流速工况(0、0.1和0.2 m/s)下的趋光性行为, 同时设黑暗静水工况为对照组。结果表明: (1) 0.2 m/s的流速可完全激发草鱼幼鱼的趋流性, 使其游泳方向多数与顶流方向呈± 20°。(2)根据草鱼幼鱼在不同流速工况下随光照度衰减在水槽内的分布情况, 计算得其在3种流速工况下的光强期望值分别为: 52.45, 34.62和37.86 lx。(3)当照度为300 lx时, 静水工况下的实验鱼在水槽中呈现“两头高, 中间低”的分布情况, 并未表现出对某一光强范围的偏好行为; 在小于感应值的低流速下, 草鱼幼鱼的分布情况总体趋势与静水工况类似, 但在远离光源处的分布较多, 多呈“逆流后退”行为; 当流速值超过感应流速时, 在趋流性的作用下, 鱼类在尾部的聚集情况明显下降, 同时在水槽中的分布更加均匀, 其原有光环境的作用减弱。研究初步证明了略大于感应值的小流速所引发的草鱼趋流性即可对其光环境响应行为产生影响。     

弱背景噪声对大鼠听皮层神经元频率调谐的影响

在自然环境中,人和动物常在一定的背景噪声下感知信号声刺激,然而,关于低强度的弱背景噪声如何影响听皮层神经元对声刺激频率的编码尚不清楚.本研究以大鼠听皮层神经元的频率反应域为研究对象,测定了阈下背景噪声对79个神经元频率反应域的影响.结果表明,弱背景噪声对大鼠初级听皮层神经元的听反应既有抑制性影响、又有易化性影响.一般来说,抑制性影响使神经元的频率调谐范围和最佳频率反应域缩小,易化性影响使神经元的频率调谐范围和最佳频率反应域增大.对于少数神经元,弱背景噪声并未显著改变其频率调谐范围,但却改变了其最佳频率反应域范围.弱背景噪声对63.64%神经元的特征频率和55.84%神经元的最低阈值无显著影响.神经元频率调谐曲线的尖部比中部更容易受到弱背景噪声的影响.该研究结果有助于我们进一步理解复杂声环境下大脑听皮层对听觉信息的编码机制.     

酵母基因中转录正调控内含子序列特征的统计分析

大量实验研究显示,真核基因的许多内含子具有调控转录的功能,但是对此问题尚缺乏全面的研究.观察一些酵母基因的转录频率与基因的内含子序列后,发现一个值得注意的现象：转录频率高的基因内含子序列一般都比较长,而转录频率低的基因内含子一般都比较短.这提示高效转录基因的较长内含子中可能含有某些增强基因转录的特征性结构.于是选取两组酵母基因的内含子进行详细研究,第一组的基因具有较高的转录频率（>30）,第二组的基因转录频率较低（≤10）.对寡核苷酸（主要是四核苷酸、五核苷酸）的出现频率进行统计比较分析,探测到一批寡核苷酸,它们在第一组内含子中出现的频率显著高于在第二组内含子中出现的频率,同时也显著高于与第一组内含子相邻的外显子中的出现频率.其中一些寡核苷酸与实验研究得到的转录调控元件相同.从这批寡核苷酸在内含子和外显子序列中的分布看,高效转录基因内含子的序列结构确实有利于基因的转录.     

The effect of frequency and grounding on whole-body absorption of humans in E-polarized radiofrequency fields

The radiofrequency absorption rates of five male human volunteers have been measured from 3 to 41 MHz. The subjects were exposed at about 10 microW /cm2 inside a very large transverse electromagnetic (TEM) cell and never absorbed more than 1 W. Both the EKH and EHK orientations were employed under both free-space and grounded conditions. Absorption rates for the EKH orientation exceed those of the EHK orientation by 40% in free space, but only by 6% when grounded. The absorption rates for the grounded men vary with frequency, f, as f1.9 from 3 to 25 MHz and then level off at peak. The free-space absorption rates vary as f1.7 from 3 to 18 MHz and as f2.9 from 18 to 41 MHz. The average measured absorption rates at 10 MHz exceed the average of the standard model calculations by a factor of three (for free space) or four (grounded). The average man, when exposed grounded in an EKH orientation to the maximum permitted exposure levels under ANSI standard C95 .1-1982, will absorb 0.58 +/- 0.14 W/kg over most of the 3 to 41-MHz frequency range. This slightly exceeds the whole-body maximum of 0.40 W/kg underlying the standard.     

Masculine voices signal men's threat potential in forager and industrial societies

Humans and many non-human primates exhibit large sexual dimorphisms in vocalizations and vocal anatomy. In humans, same-sex competitors and potential mates attend to acoustic features of male vocalizations, but vocal masculinity especially increases perceptions of physical prowess. Yet, the information content of male vocalizations remains obscure. We therefore examined relationships between sexually dimorphic acoustic properties and men's threat potential. We first introduce a new measure of the structure of vocal formant frequencies, 'formant position' (Pf), which we show is more sexually dimorphic and more strongly related to height than is the most widely used measure of formant structure, 'formant dispersion', in both a US sample and a sample of Hadza foragers from Tanzania. We also show large sexual dimorphisms in the mean fundamental frequency (F0) and the within-utterance standard deviation in F0 (F0-s.d.) in both samples. We then explore relationships between these acoustic parameters and men's body size, strength, testosterone and physical aggressiveness. Each acoustic parameter was related to at least one measure of male threat potential. The most dimorphic parameters, F0 and Pf, were most strongly related to body size in both samples. In the US sample, F0 predicted testosterone levels, Pf predicted upper body strength and F0-s.d. predicted physical aggressiveness.     

自交作物群体的遗传组成分析

用数学方法推导出了自交作物群体遗传组成的分析公式。根据所推出的公式,可以计算出任何自交世代群体的基因型频率和同一表现型中各基因型的频率。对自交群体遗传组成的分析可用于质量性状的选择,确定选择时需要的有效群体大小和选出有效群体的大小,亦有助于确定选择的最佳世代。     

Radiofrequency radiation-induced calcium ion efflux enhancement from human and other neuroblastoma cells in culture

To test the generality of radiofrequency radiation-induced changes in 45Ca2+ efflux from avian and feline brain tissues, human neuroblastoma cells were exposed to electromagnetic radiation at 147 MHz, amplitude-modulated (AM) at 16 Hz, at specific absorption rates (SAR) of 0.1, 0.05, 0.01, 0.005, 0.001, and 0.0005 W/kg. Significant 45Ca2+ efflux was obtained at SAR values of 0.05 and 0.005 W/kg. Enhanced efflux at 0.05 W/kg peaked at the 13-16 Hz and at the 57.5-60 Hz modulation ranges. A Chinese hamster-mouse hybrid neuroblastoma was also shown to exhibit enhanced radiation-induced 45Ca2+ efflux at an SAR of 0.05 W/kg, using 147 MHz, AM at 16 Hz. These results confirm that amplitude-modulated radiofrequency radiation can induce responses in cells of nervous tissue origin from widely different animal species, including humans. The results are also consistent with the reports of similar findings in avian and feline brain tissues and indicate the general nature of the phenomenon.     

云南省三个地方鸡种血液淀粉酶多态性分析

采用垂直平板聚丙烯酰胺凝胶电泳法,测定了版纳斗鸡、武定鸡、尼西鸡的血液淀粉酶(Amy)。发现云南3个地方鸡种Amy-1的AA、BB型纯合子基因型频率很低, 其中尼西鸡为0,而AB型杂合子基因型频率很高,杂合子显著过量,均偏离Hardy-Weinberg平衡。在版纳斗鸡少数个体中还发现控制血液淀粉酶的另一位点Amy-2。 Abstract:Blood amylase polymorphism in 3 Yunnan local chicken breeds(Banna ganme chicken,Wuding chicken.Nixi chicken)was determined with polyacrylamide gel electrophoresis,It was found that frequen cies of both AA and BB homozygous genotype were very low,while AB heterozyote genotype frequency was very high in 3 Yunnan local chicken breeds and that Amy-1 distribution in these breeds was widely deviated from Hardy-Weinberg equilibrium proportion.We have also found that there is another locus Amy-2 which controls the amylase in a few Banna game chickens.     

Bioacoustics of the Neotropical Eneopterinae (Orthoptera,Grylloidea, Gryllidae)

In members of the cricket subfamily Eneopterinae (Orthoptera, Grylloidea), songs with powerful high-frequency (HF) harmonics have evolved, which likely represents a distinctive acoustic adaptation. In this study, we analysed or reanalysed the songs of the three eneopterine genera present in the Neotropics to evaluate whether they also possess high-amplitude HF components. We present new data and combine several lines of evidence to interpret or reinterpret the calling signals of a representative species for each genus. We used new recordings in order to detect and analyse potential HF components of the songs. Stridulatory files were measured, and stridulation was studied using high-speed video recordings. The results suggest that all eneopterine genera from the Neotropics use HFs to communicate, based on the rich harmonic content of their songs. Strikingly, the Neotropical eneopterines possess high dominant frequencies, recalling the patterns observed in the tribe Lebinthini, the most speciose tribe of the subfamily distributed in the Western Pacific region and in Southeast Asia: Ligypterus and Ponca show dominant harmonic peaks, whereas Eneoptera possesses unique features. The three species under study, however, deal differently with HFs.     

Intercorrelations and sources of variability in three mutagenicity assays: a population-based study

The purpose of this study was to evaluate the intercorrelation between three genetic assays in 112 subjects. The group was pooled from two originally separate but homogeneous subgroups of 56 persons each. Procedures included assays for hprt mutant frequencies, micronuclei in human lymphocytes, and mutations at the glycophorin A (gpa) loci. We found no statistically significant or biologically important intercorrelations among the three biomarkers. We did, however, observe significant correlations between log_e hprt mutant frequency and cloning efficiency (inverse correlation for these 2 variables), age and log_e hprt mutant frequency, an inverse relationship between cloning efficiency and age, and an important differential sex effect favoring a greater micronuclei frequency in females than males. No significant correlations between the covariates of interest and glycophorin A variant frequencies NN or NO were observed. Using multivariable linear regression, age was found to account for the majority of the variability in hprt mutant frequency (greater than sex and/or smoking); for micronuclei data, only sex contributed a statistically significant and biologically important proportion to the total variation. We conclude that despite observing no significant intercorrelations between the three assays performed simultaneously from the same individuals in a large population database, a significant correlation between age and hprt mutant frequency and an inverse association between cloning efficiency and hprt do exist; furthermore, we verified the strong differential sex-specific effect on micronucleus frequencies.     

Hardy-Weinberg定律在专科教学中的课堂设计

Hardy-Weinberg定律是群体遗传学的第一理论基石,也是现代进化论、现代优生学和群体育种的理论基础,是遗传学教学中的重难点内容,但通过合理的教学设计可帮助学生全面理解、掌握并应用该定律,为后续学习奠定基础。