紫外辐射对栉孔扇贝精子遗传失活及形态结构的影响

报道了紫外辐射对栉孔扇贝精子遗传失活及形态结构的影响。采用光照强度为800μW/cm2·s的紫外线辐射40～50s的栉孔扇贝精子,与正常的卵子受精可以得到雌核发育的单倍体胚胎。随着辐射时间的增加,受精率明显下降,且受精卵极少发育到D形幼虫。扫描电镜观察发现,辐射后部分精子的顶体膜破裂,顶体丝伸出,辐射时间越长顶体受到的破坏越严重,证明紫外辐射可以诱导精子的顶体反应;精子的鞭毛在紫外辐射过程中也会受到破坏,随着辐射时间的增加鞭毛脱落的比例也逐渐增加。推测紫外辐射导致精子结构的破坏是受精率下降的原因之一。     

利用紫外线辐射遗传失活精子诱导虹鳟雌核发育

本试验利用紫外线辐射遗传失活精子,热休克诱导虹鳟雌核发育,确定了最佳诱导参数。结果表明,精子经紫外线照射80 s、卵受精后40 min在26℃水浴下持续处理15 min,雌核发育率最高,育成率为21.35%。利用白化体虹鳟品系金黄体色的显性性状作为鉴定雌核发育个体的依据,方法可行。     

紫外分光光度法测定饲料中的铁

饲料中铁的测定。目前多采用国标法即原子吸收光度法(AAS)。由于仪器价格昂贵，很多饲料生产企业无力购置，而常规方法又因严重的干扰问题使得测定难以进行。本文向读者推荐一种紫外分光光度法测定饲料中铁的方法，运用本方法使用国产721型或751型分光光度计可就可测定饲料原料、成品料以及预混剂中铁的     

用紫外分光光度法测定嗜水气单胞菌的浓度

研究了用紫外分光光度法测定嗜水气单胞菌（Aeromonas hydrophila）菌液浓度的可行性。随机选取东北三省嗜水气单胞菌分离株（H、J和L）接种于胰蛋白胨大豆肉汤（TSB）培养基中,培养0、3、6、9、12,及24h取样,每个样品5个平行。用紫外分光光度计（入=600nm）测定菌液OD值,同步采用10倍系列稀释法测定平皿菌落个数（CFU）。建立起H、J和L菌株OD值与CFU的回归方程式分别为：y=134．34x＋5．5206;y=135．86x＋3．1397和v：142．87x一3．7068。测定结果表明：当OD值为1时,菌液的浓度约为1．4×107CFU·mL-1。采用紫外风光光度计法测定菌液浓度时,应注意菌液浓度和培养时间的影响。     

五彩缤纷的灯鱼世界

当你面对湛蓝的天空，面对蔚蓝的大海，面对浓绿的森林和绚丽的红叶，你是否假想过；要是能把这些艳丽的色彩搬回家该有多好！那样，当你拖着港币的疲惫，从公司、从学校、从充满压力和竞争的尘世间归来，     

紫外分光光度法测定养殖区海水油类问题的探讨

目前海水增养殖区中油类监测采用的是紫外分光光度法。该方法中样品的萃取、标准曲线、分析空白等因素能够影响测定结果的准确性,通过实验数据对上述因素进行了分析探讨,总结了该方法在实验过程中需要注意的问题。     

循环水系统结合鱼菜、紫外处理对镜鲤生长及水质的影响

为探索绿色环保的循环水养殖模式,设计循环水鱼菜共生系统(鱼菜组)、紫外灯鱼菜共生系统(鱼菜紫外灯组)及循环水养殖系统(循环水组),比较三种不同处理方式对镜鲤(Cyprinuscarpio var.specularis)、叶用莴苣(Lactuca sativa var.ramosa)生长和养殖水质的影响。结果显示,鱼菜组、鱼菜紫外灯组处理对镜鲤的生长无显著影响,但会显著影响镜鲤形态学指标,鱼菜组镜鲤肠体比显著低于循环水组。体成分方面,鱼菜组全鱼粗蛋白、粗脂肪显著高于循环水组,鱼菜组肝脏粗蛋白显著低于循环水组。鱼菜紫外灯组的细菌总数显著低于鱼菜组。水质方面,鱼菜组、鱼菜紫外灯组可显著降低系统中氨氮、硝酸盐氮及总磷总氮含量,鱼菜紫外灯组硝酸盐氮、总磷及总氮含量显著高于鱼菜组。综上所述,循环水系统耦合水培蔬菜单元可改善系统水质,改善鱼体成分,并且结合紫外灯处理可降低水体细菌总数。     

我国灯诱围网产量的变化分析

根据2003～2005年我国主要渔业公司灯诱围网的生产统计数据，利用S-plus软件进行灯光围网产量的研究。研究表明，8、9月份为总产量和总网次的最高时间，6月份为总产量和总网次的最低时间；高产量和高作业网次的时间基本呈一致分布；12月份为CPUE最大时间。     

我国开发监控海洋溢油污染紫外成像技术

近日,我国采用紫外成像技术首次成功航摄到海洋溢油污染的紫外图像,验证了此项技术在可见盲紫外波段探测海洋溢油目标的可行性,为我国未来监测海洋以及内陆水体的溢油污染提供     

二氧化碳和阳光紫外辐射对坛紫菜丝状体光合生理特性的影响

为了探索大型海藻生活史丝状体阶段对于海洋酸化与紫外辐射的响应,实验选取经济海藻坛紫菜的自由丝状体作为实验材料。实验设置两个CO2浓度,正常CO2浓度(390 ppmv)和高CO2浓度(1 000 ppmv);3种辐射处理,PAR处理(仅接受可见光)、PA处理(滤除UV-B)、PAB处理(全波长辐射)。研究结果表明,高CO2显著提高了坛紫菜自由丝状体的生长速率,但高CO2处理下坛紫菜自由丝状体中藻红蛋白、藻蓝蛋白、叶绿素a、类胡萝卜素及紫外吸收物质UVACs分别降低了7.3%、9.3%、19.8%、16.5%和18.7%。高CO2处理的坛紫菜自由丝状体最大光化学效率Fv/Fm,光能利用效率(α)及最大相对电子传递速率(rETRmax)都显著高于正常CO2处理。太阳模拟器下处理的坛紫菜自由丝状体,PAR与PA处理下的抑制率,正常CO2与高CO2处理间无显著差异,然而在PAB处理下,高CO2处理的抑制率要高于正常CO2处理,这可能与其体内紫外吸收物质含量下降有关。PAR处理下的抑制率,无论是在正常CO2还是在高CO2处理下,都显著低于PA及PAB处理,而PA与PAB之间无显著差异。在未来海洋持续酸化的背景下,UV辐射的增加将会影响到坛紫菜自由丝状体的光合生理及生长。     

Effects of UV radiation on the vertical distribution of vendace [Coregonus albula (L.)] larvae in Finnish lakes

Abstract – Positively phototactic vendace larvae may be vulnerable to enhanced springtime UV levels unless they are able to avoid them. Experimental results, however, suggested that UV avoidance can exist. In this study field data from eight Finnish lakes with different characteristics were analysed. The aim of the study was to determine whether vendace larvae stayed deeper in the water column during sunny than during cloudy periods because thick cloud cover considerably reduces UV irradiance. In addition, avoidance behaviour of larvae was studied in acrylic tubes placed in a lake and under laboratory conditions. The avoidance of high UV-B exposure existed both in the littoral and pelagic zone of the lakes and in laboratory with low UV attenuation. In the lakes with high UV attenuation, avoidance behaviour did not exist. Vendace larvae may use visible light as an indirect indicator of harmful UV-B irradiance.     

UV-B辐射对三角褐指藻的膜酯脱酯化伤害

UV－B辐射对三角褐指藻的生长有明显的抑制效应，其96h半抑制剂量（96h EC50）为1.91J/m^2。进一步的结果表明，UV－B辐射增强能够引起藻细胞活性氧含量的增加，从而导致三角褐指藻的膜酯脱酯化伤害。     

紫外辐射对浒苔游孢子附着、萌发和幼苗生长的影响

为了探讨绿潮藻浒苔游孢子对紫外线(UVR)的敏感性,研究了相对于有效光辐射(PAR,P)增加UVA辐射(PAR+UVA,PA)和全波长辐射(PAR+UVA+UVB,PAB)对浒苔游孢子的光合效率、附着、萌发和幼苗生长的影响。实验结果表明,(1)强光[900μmol/(m2·s)]下PA和PAB辐射对浒苔游孢子的最大光化学效率(Fv/Fm)具有明显抑制作用,且辐射时间越长抑制作用越大。强光下PA和PAB辐射15、30、60min导致浒苔游孢子最大光化学效率分别下降为28.4%、42.4%、36.5%、52.1%、64.4%、54.5%;(2)游孢子在15min辐射期间的附着率分别为50.0%(P)、44.9%(PA)和23.9%(PAB),紫外辐射尤其是UVB显著抑制(延迟)了游孢子的附着(P<0.05),但对24h后游孢子的总附着率没有显著影响。不同辐射处理和处理时间之间存在显著交互作用(P<0.05);(3)阳光下PA和PAB对孢子萌发具有显著抑制作用,第3天PA和PAB处理的游孢子萌发率分别为P处理的57.0%和39.1%,游孢子的萌发存活决定于最初的3d,3d后的紫外辐射对幼苗的存活没有显著影响(P>0...     

鱿钓船水上集鱼灯的光照度分布及钓捕效果分析

根据2003年10月在印度洋鸢乌贼渔场中鱿钓船周围某一断面水中光照度的实测数据和渔获生产统计数据,对金属卤化物灯和高压钠灯的光照度分布及其钓捕效果进行了比较分析。在120盏×2kW金属卤化物灯作用下,在距船舷3.0m的垂直断面,其水深5m内的光照度多在100lx以上,10lx的等光照度曲线在20m水层左右,0.01lx的等光照度曲线在55m水层附近。但在20盏×500W高压钠灯作用下,在距船舷3.0m的垂直断面,其海面的平均光照度为3lx左右,0.01lx的等光照度曲线在20m水层附近。以一些头足类的适宜光照度(0.01～10lx)为例,其在该照度范围内的水体体积仅为120盏×2kW金属卤化物灯作用下的1/5左右。这说明采用高压钠灯可以使鱿鱼聚集密度增大,钓捕深度变浅,从而提高渔获效率,且其平均产量比采用高压钠灯前高1～3倍。另外,研究表明大型专业鱿钓船钓捕鸢乌贼时的最适集鱼灯功率为112～160kW,鸢乌贼的最适光照度为0.01lx左右。     

UV-B辐射对三角褐指藻DNA伤害的研究

运用生态毒理学和生物化学的方法研究了紫外线对三角褐指藻DNA的伤害作用。结果表明，低剂量的UV-B辐射对三角褐指藻的生长有促进作用，而高剂量的UV-B辐射则有抑制作用。随着UV-B辐射剂量的增加，三角褐指藻DNA损伤程度加剧。而UV-B辐射处理解除后，DNA的损伤可明显恢复。说明DNA的损伤可在一定程度上指示海洋微藻受UV-B辐射伤害的程度。     

The implications of solar UV radiation exposure for fish and fisheries

Ultraviolet radiation (UVR) possesses three important properties that combine to make it a potent environmental force. These include the potential to induce damage: UVR carries more energy per photon than any other wavelength reaching the Earth’s surface. Such highly energetic photons are known to damage many biological molecules, such as DNA and proteins. In addition, they can initiate a series of redox reactions to form reactive oxygen species (ROS), which cause oxidative stress to cells and tissues. The second property is ubiquity: owing to their dependence on light, primary producers and most visual predators, such as fish, are also necessarily exposed to damaging levels of UVR. Thirdly, the combined effect of UVR and additional environmental factors may result in synergistic effects, such as the photoactivation of organic pollutants and photosensitisation. In natural environments, the concentration of dissolved organic matter (DOM) and habitat depth are the two main factors controlling the degree of UVR exposure experienced by fish. Additional factors include vegetation coverage, particulate materials in suspension, pH and hydrological characteristics, and site location (latitude, elevation). The range of potential effects on fish includes direct DNA damage resulting in embryo and larval mortality, and adult and juvenile sunburn, as well as indirect oxidative stress, phototoxicity and photosensitisation.     

Effect of ultraviolet (UV) radiation on the abundance and respiration rates of probiotic bacteria

Effects of ultraviolet radiation (UV) on probiotic bacteria (Bacillus subtilis and B. licheniformis) were tested in two experiments, with the following treatments: (i) UV treatment – using fluorescent and UV‐lamps and (ii) Control – CTRL, using fluorescent lamps. Bacterial abundance and respiration were evaluated every 24 h for 3 days for Experiment 1, and at 0, 6 and 24 h for Experiment 2. In the Experiment 1, total UV dose was 4 336.41 mW cm^?2. UV treatment presented small respiration rates only on day 3, while in the CTRL oxygen consumption was always high. On all days, the abundance of the Bacilli exposed to UV was significantly smaller than that of the CTRL. The second experiment, with total UV dose of 1 445.47 mW cm^?2, presented oxygen consumption in the UV treatment only during the first 6 h. In the CTRL, oxygen consumption increased from the beginning due to the bigger abundance Bacilli cells. Small coccus‐shaped bacteria ocurred in the UV treatment of both experiments. It may be concluded that exposure to UV, normally used for water disinfection, can inactivate probiotic bacteria.