Damage to Cauliflower Coral by Monofilament Fishing Lines in Hawaii

Abstract:  Many fishing methods and gear types used in coral reefs cause physical damage to the reef substratum. Only recently have monofilament fishing lines been recognized as a cause of coral damage and death. We assessed the extent of damage caused by monofilament fishing lines to the cauliflower coral (  Pocillopora meandrina ) colonies in fished and adjacent unfished zones at seven sites in the main Hawaiian islands. We examined coral colonies for the presence or absence of fishing line and for the degree of damage (dead, no live coral surface; damaged, some dead coral surface; or intact, no dead coral surface) in nine 25-m² grids. The mean proportion of colonies entangled with fishing lines in fished zones ranged from 0.18 to 0.44. The mean proportion of dead or damaged colonies was higher in fished than adjacent unfished zones, and there was a positive linear relationship between the proportion of colonies entangled with fishing lines and the proportion of dead or damaged colonies. These results indicate that monofilament fishing lines have a negative impact on the health and survival of P. meandrina colonies. Because tourism and related recreational fishing activities are expanding rapidly in many tropical states and nations, we recommend that the degrading effects of fishing lines on corals be considered in the design and management of tourism development.     

SO2衍生物对蚕豆根尖细胞不同分裂阶段的遗传损伤

研究SO2体内衍生物-亚硫酸钠和亚硫酸氢钠混合液[c(Na2SO3):c(NaHSO3)=3:1]对蚕豆根尖细胞不同分裂时期的遗传损伤效应；结果表明：SO2衍生物（c=0.17-15.0mmolL^-1)诱发蚕豆根尖细胞遗传损伤在细胞分裂的不同阶段有不同的表现形式。间期异常主要是微核和核芽，分裂期异常包括微核，染色体断片，粘连及滞后等，研究结果表明：SO2衍生物处理组蚕豆根尖中，间期微核细胞数，分裂期具有染色体断裂，粘连或滞后的细胞数均明显多于对照组，而且易于观察分析，可以作为环境监测指标。     

常乐稀土复合肥对玉米（Zea may L.）的细胞毒性和遗传毒性效应

为了研究常乐稀土多元复合肥对主要农作物--玉米(Zea mays L.)是否产生细胞毒性和遗传毒性效应,采用不同梯度质量浓度的稀土复合肥溶液对玉米进行处理,观察其根尖生长状况,统计分析细胞死亡率、微核率、有丝分裂指数以及对细胞DNA的损伤情况.结果表明,质量浓度为10mg·L-1以下时,常乐稀土复合肥能够促进玉米根尖的生长,100mg·L-1以上时抑制根尖生长;随着试验浓度的递增,细胞死亡率、微核率、DNA损伤率逐渐上升并具有正相关性,表现出明显的剂量-效应关系,而有丝分裂指数却随着浓度的增加逐渐下降.以上结果表明,常乐稀土复合肥对玉米确有一定的细胞毒性和遗传毒性效应,其细胞毒性阈值和遗传毒性阈值皆为100mg·L-1.     

Concentration Evolution of Gas Species within a Collapsing Bubble in a Liquid Medium

In this study numerical methods are used to investigate the relationship between chemical concentration of gas species within a cavitating bubble, equilibrium radius of the gas bubble and pressure variations in the ambient liquid. For this purpose, governing equations are developed to describe the dynamic equilibrium of a bubble in a flowing fluid and mass transfer between gas and liquid phases, where it was assumed that gases undergo isothermal compression, obey the ideal gas law, Henry law. It is further assumed that the concentration of each phase within the bubble is uniform. The resulting nonlinear equations are solved using implicit Trapezoidal method with Newton iteration. Four gas species are modeled under various initial and ambient pressure variation conditions. These conditions maybe considered to represent typical cavitation events. The numerical results obtained are presented in terms of dimensionless numbers. These results indicate that chemical damage maybe an important component of cavitation surface damage, since high concentration profiles may develop within a collapsing bubble. Proposed formulation and numerical solutions are simple and cost effective to implement. The results presented in this study maybe used to benchmark experimental investigations or other more complex solutions, which are outside the scope of this study.     

湖南怀化地区96.7城市特大洪涝灾害成因分析

湖南省怀化地区地形以山地为主,该地区１９９６年７月发生了城市特大洪涝灾害,本文概述了该地区９６．７城市洪涝灾情,并以区域灾害系统论为指导,从孕灾环境、致害因子、承灾能力和人类活动的不利影响等方面,对这次灾害的成因进行了分析,认为其主要成因是：（１）易洪涝的山丘区环境;（２）９６．７降雨强度大、覆盖面广、持续时间长的异常雨情和高洪峰水位、流量的异常水情;（３）城市防洪标准低、水利水电工程防洪效益差和抗洪害意识不强等原因造成的城市防洪能力低;（４）砍伐森林、人为侵占河道和大型水库超常规蓄水等人类活动造成的不利影响。     

西江流域中部的洪涝特征及防洪减灾对策

对广西西江流域中部的洪涝特征进行了较全面的论述,并对西江流域防洪减灾提出了有效的对策。     

用改良彗星试验检测工业废水的DNA损伤作用

采用改良彗星试验直接检测了多种工业废水不所引起的Ｖ７９细胞ＤＮＡ损伤。结果表明,所测的种各工业废话水均含有ＤＮＡ损伤剂,能够诱发培养的Ｖ７９细胞ＤＮＡ链断裂,其中以制革厂不的ＤＮＡ损伤作用最强。本研究显示出改良彗星试验在综合评价各种废水遗传毒性方面具有广阔的应用前景。     

叶面喷施2,3-二巯基丁二酸对水稻幼苗镉吸收转运及抗氧化系统的影响

稻米Cd超标问题已成为社会各界广泛关注的热点问题之一,探索降低Cd向地上部转运并缓解水稻Cd胁迫的新方法,对保障食品安全具有重要意义.本研究拟通过在水稻幼苗叶面喷施2,3-二巯基丁二酸(DMSA)评估利用该重金属螯合剂降低Cd向水稻地上部转运并缓解Cd胁迫的可行性.以我国南方水稻主栽品种之一中早35幼苗为研究材料,采用水培法研究了叶面喷施不同浓度DMSA对Cd在水稻幼苗体内吸收转运的影响,同时考察了对水稻幼苗丙二醛(MDA)、谷胱甘肽(GSH)含量以及对抗氧化酶过氧化氢酶(CAT)、超氧化物歧化酶(SOD)活性的影响.结果表明,叶面喷施DMSA 0.2、 0.4和1.0 mmol·L~(-1) 4次后,水稻幼苗地上部Cd含量随着DMSA喷施浓度增加呈显著降低趋势, 3种处理浓度与对照相比分别降低22.1%、 39.7%和43.5%,但是对水稻幼苗根部Cd含量无显著影响;对地上部及根中K、Ca、Mg、Fe、Zn和Mn这6种矿质元素含量无显著影响;喷施4次DMSA后显著降低了幼苗地上部MDA和GSH含量,同时使CAT和SOD活性显著增加,有效缓解了Cd对水稻幼苗造成的胁迫效应.DMSA能抑制Cd从水稻根部向地上部转运,同时不影响对人体必需矿质营养元素的吸收和转运,具备成为水稻降Cd叶面调理剂的潜力.     

DIDP通过线粒体-Caspase途径诱导昆明小鼠肝脏损伤的研究

为探究DIDP（Di-iso-decyl phthalate,邻苯二甲酸二异癸酯）对肝脏的影响及其可能的分子机制,以昆明小鼠为研究对象,选用Res（resveratrol,白藜芦醇）为抗氧化剂,分别设置对照组,0.15、1.5、15、150 mg/（kg·d）DIDP组,Res组,150 mg/（kg·d）DIDP+Res组,灌胃染毒9 d后,对小鼠肝脏切片进行HE染色观察,并检测ROS（reactive oxygen,活性氧）、GSH（glutathione,谷胱甘肽）、MDA（malondialdehyde,丙二醛）、Cyt-C（cytochromec,细胞色素C）、Caspase-3和血清中的ALT（alanine aminotransferase,丙氨酸氨基转移酶）含量.结果表明:与对照组相比,15、150 mg/（kg·d）DIDP组小鼠血清中ALT含量极显著上升（P < 0.01）;HE染色结果显示,15、150 mg/（kg·d）DIDP组小鼠出现肝细胞水肿、肝索紊乱、肝窦以及肝中央静脉扩张等现象;15、150 mg/（kg·d）DIDP组小鼠肝脏ROS含量显著上升（P < 0.05）,GSH含量显著下降（P < 0.05）,150 mg/（kg·d）DIDP组小鼠肝脏MDA含量极显著上升（P < 0.01）;1.5、15、150 mg/（kg·d）DIDP组小鼠肝脏中c（Cyt-C）极显著上升（P < 0.01）;15、150 mg/（kg·d）DIDP组小鼠肝脏中Caspase-3表达量极显著上升（P < 0.01）.DIDP染毒剂量的增加对肝脏的各种损伤程度呈上升趋势,Res可减轻上述DIDP对肝脏造成的各种损伤.研究显示,15、150 mg/（kg·d）DIDP可诱导肝脏组织氧化应激水平上升,进而造成线粒体损伤,导致细胞凋亡,造成肝功能受损,因此,线粒体-Caspase途径可能是DIDP诱导肝脏损伤的潜在机制之一.