Comparative performance of juvenile rainbow trout, Salmo gairdneri Richardson, fed to satiation with simulated 'standard' and 'high energy' diet formulations

Abstract. Four experimental diets were formulated to resemble practical rainbow trout, Salmo gairdneri Richardson, grower feeds based on medium and moderate lipid inclusions of 10 and 14% (standard energy levels) to relatively 'high energy' diets containing 18 and 22% lipid respectively. Each of these diets was isonitrogenous with a defined protein content of 42%. During a 10-week growth trial period, juvenile rainbow trout of initial mean weight of 10g were fed each ration to satiation. At the end of the study, there was a significant gain (P> 0.05) in the mean live weights of fish receiving the higher energy diets associated with improved feed conversion ratio (FCR) and net protein utilization (NPU). Although there was a declining trend in voluntary food intake relative to body weight with increasing dietary lipid content, this was insufficient to prevent greater deposition of body fat.
The results are discussed in relation to practical trout feeds in order to achieve a desired growth performance and acceptable body composition with intensive feeding regimes.     

Joint Acaricidal Action of Diafenthiuron and Fenbutatin-oxide Against Tetranychus cinnabarinus （Boisduval） （Acari： Tetranychidae）

[Objective]This study was conducted to obtain a new high-efficiency acaricide mixture.[Method]The synergism acaricidal of diafenthiuron and fenbutatin-oxide against carmine spider mite was investigated,and the optimal ratio of both acaricides were determined by means of co-toxicity factors and co-toxicity coefficients（CTC）.[Result]At 24 h post-treatment,the LC50values of diafenthiuron and fenbutatin-oxide against T.cinnabarinus female adults were 154.67 and 93.26 mg/L,respectively,and the synergistic mass ratios of diafenthiuron and fenbutatin-oxide ranged from 1：0.06 to 1：0.87,and the optimal diafenthiuron-to-fenbutatin-oxide ratio was 1：0.39 with the LC50and CTC of 67.87 mg/L and 188.93（CTC significantly above 100 strongly indicated synergism）,respectively,and the toxicity relative to diafenthiuron and fenbutatin-oxide was 2.28 and 1.37 times,respectively.[Conclusion]The joint acaricidal action of diafenthiuron and fenbutatin-oxide strongly indicates synergism.These findings proved scientific theoretical basis for mixing diafenthiuron and fenbutatin-oxide to control spider mites and developing a new synergisic acaricide.     

牛GDF-9基因的克隆与组织表达的分析

为了检测牛GDF-9基因mRNA在怀孕期牛生殖系统的表达情况,为GDF-9基因在雌性动物繁殖上的研究提供一定的理论依据。本试验根据GenBank中报道的牛GDF-9基因序列设计引物,从牛卵巢、输卵管、子宫、肾脏中提取RNA,采用RT-PCR技术进行cDNA扩增,扩增产物与载体pGM-T连接,转化大肠杆菌DH5α,筛选阳性克隆,测序。结果表明,已成功克隆的阳性重组子经测序鉴定其片段大小与预期大小完全一致,为264 bp。序列同源性分析比较表明,该cDNA及其推导的氨基酸序列与绵羊GDF-9cDNA和氨基酸序列同源性分别为97%和94%。以-βactin为内参照物,采用RT-PCR技术进行半定量分析,通过检测比较牛GDF-9基因在卵巢、输卵管、子宫、肾脏组织中mRNA的表达情况。结果表明,牛GDF-9基因在卵巢中表达量最高,在输卵管、子宫、肾脏中均有表达,但表达量不高。     

Germination and hyphal growth of Glomus caledonicum on water agar containing benomyl

Concentrations of benomyl greater than 10 ng ml^?1 inhibited germination and hyphal growth of the vesicular-arbuscular mycorrhizal fungus Glomus caledonicum on water agar. This effect was attributable to only the activity of methyl-2-benzimidazole carbamate, one of the two hydrolysis products of benomyl. Hyphal growth but not germination was affected by the pH of water agar buffered with 10 mm 2-(N-morpholino)ethane sulphonic acid.     

Mutations in a human ROBO gene disrupt hindbrain axon pathway crossing and morphogenesis

The mechanisms controlling axon guidance are of fundamental importance in understanding brain development. Growing corticospinal and somatosensory axons cross the midline in the medulla to reach their targets and thus form the basis of contralateral motor control and sensory input. The motor and sensory projections appeared uncrossed in patients with horizontal gaze palsy with progressive scoliosis (HGPPS). In patients affected with HGPPS, we identified mutations in the ROBO3 gene, which shares homology with roundabout genes important in axon guidance in developing Drosophila, zebrafish, and mouse. Like its murine homolog Rig1/Robo3, but unlike other Robo proteins, ROBO3 is required for hindbrain axon midline crossing.     

上海乡土树种及其在城市绿化建设中的应用

随着生态城市被列为上海市的建设发展目标,城市绿化建设被赋予了新的目标和内涵,生态林将逐渐成为城市绿化的主体,作为生态林建设基础的乡土树种也将得到更为广泛的应用.通过实地调查和资料调查,统计分析了上海市的乡土树种,共42科89属128种(含变种),可以分为常绿阔叶乔木、常绿阔叶灌木、半常绿阔叶灌木、落叶阔叶乔木、落叶阔叶小乔木和落叶阔叶灌木等6个类型.分析了乡土树种在上海绿化建设中的意义和应用现状,并对其应用进行了展望.表1参21     

披针叶黄华生物碱成分研究

采用 GC- MS联用分析技术从披针叶黄华总生物碱中分离鉴定出 12个喹喏里西啶生物碱 ,即无叶豆碱 ,N-甲基金雀花碱 ,金雀花碱 ,白羽扇豆碱 ,黄华碱 ,臭豆碱 ,N-甲醛基金雀花碱 ,Dodecahydro- 7,14 -methanodipyrido[1,2 - a:1′,2′- E][1.5 ]diazocine,Pyridine1- acetyl- 1,2 ,3,4 - tetrahydro- 5 - (2 - piperdinyl) ,7,14 -Methano- 2 H,6 H- dipyrido[1,2 - a:1′,2′- e][1,5 ]diaz,1,1- Dim ethyl- 3- (2 - nitrophenyl) ,7,14 - Methano- 4 H,6 H-dipyrido[1,2 - a:1′,2′- e][1,5 ]diaz。后 5种化合物为首次从该植物中鉴定     

The Gelation of CO(2): A Sustainable Route to the Creation of Microcellular Materials

Compounds with strong thermodynamic affinity for carbon dioxide (CO(2)) have been designed and synthesized that dissolve in CO(2), then associate to form gels. Upon removal of the CO(2), these gels produced free-standing foams with cells with an average diameter smaller than 1 micrometer and a bulk density reduction of 97 percent relative to the parent material.     

Method for estimation of ocean current velocity from satellite images

Barotropic instability waves on a shear interface propagate at the average speed of the water on the two sides. Assuming the instability to be excited by tidal oscillations, the phase speed is the wavelength divided by the tidal period. If the water is at rest on one side of the shear layer the current speed on the other side can be calculated. This method, applied to the Gulf Stream beyond Cape Hatteras as seen in satellite images, gives estimates of current speed in general agreement with in situ observations.