不同声音对草鱼幼鱼负趋音性行为反应影响研究

声驱鱼技术作为辅助过鱼措施之一,承担着保证鱼类洄游顺利通过过鱼设施,继而保护鱼类资源和恢复河流连通性的重要作用。本研究采用交替播音的形式,以草鱼(Ctenopharyngodon idellus)幼鱼为研究对象进行负趋音性实验,旨在探究草鱼幼鱼面对不同声音的行为反应。实验水槽(3.6 m×1.1 m×1.0 m)布置于下牢溪周围水域,平均水深为0.5 m,平均流速为0.06 m/s。实验使用1种单频音(1 000 Hz)和5种复杂音(鱼游动声、引擎声、短吻鳄叫声、打桩声和游艇声),声压级(sound pressure level)为(117.69±2.77) dB re 1 μPa,对照组为未播放声音时草鱼的行为反应数据。结果显示,播放复杂音时,草鱼的反应次数、趋音速度、运动时间比均显著高于单频音和对照组(P<0.001),草鱼的初次反应时间、平均反应时间均显著低于单频音和对照组(P<0.001);复杂音中,受到游艇声刺激的草鱼反应次数和趋音速度最大,受到鱼游动声刺激的草鱼反应次数、趋音速度最小;复杂音中,受到游艇声刺激的草鱼初次反应时间最短,为(23.40±5.13) s;受到引擎声刺激的草鱼初次反应时间最长,为(146.00±7.82) s,显著低于其他复杂音(P<0.05);受到游艇声和打桩声刺激的草鱼平均反应时间最短,分别为(26.52±3.01) s和(28.76±4.07) s;受到鱼游动声刺激的草鱼平均反应时间最长,为(64.76±17.82) s;复杂音中,受到鱼游动声刺激的草鱼运动时间比最高,为(98.47±0.48)%;受到引擎声刺激的草鱼运动时间比最低,为(94.58±0.54)%;播放单频音时,草鱼的反应次数、初次反应时间、平均反应时间、运动时间比均与对照组无显著差异(P>0.05)。本研究表明,5种复杂音(鱼游动声、引擎声、短吻鳄叫声、打桩声和游艇声)对草鱼幼鱼具有驱赶效果。本研究在丰富鱼类负趋音性研究的同时,为实际工程中声驱鱼辅助过鱼设施的设计和优化提供了科学依据。     

A potential early clinical phenotype of necrotizing meningoencephalitis in genetically at‐risk pug dogs

BackgroundNecrotizing meningoencephalitis (NME) in the pug dogs is a fatal neuroinflammatory disease associated with rapid progression and poor response to conventional immunosuppressive therapy. Diagnosis is typically made after severe neurological abnormalities have manifested.Hypothesis/ObjectivePug dogs at genetic risk for NME might manifest neurological abnormalities before developing pathognomonic clinical signs of NME.AnimalsThirty‐six pug dogs less than 4 years of age asymptomatic for NME.MethodsProspective observational cohort study with germline genome‐wide genotyping. Neurological examinations were performed 4 weeks apart to document reproducible findings of central nervous system disease. Magnetic resonance imaging, cerebrospinal fluid analysis, and testing for infectious diseases were performed in all pugs with reproducible abnormalities detected on neurological examination.ResultsThe overall risk allele frequency in this cohort was 40%; 5 (14%) dogs were high risk, 19 (53%) dogs were medium risk, and 12 (33%) dogs were low genetic risk for NME. Reproducible abnormalities detected on neurological examination were identified in 8/24 (33%) genetically at‐risk dogs and 0/12 (0%) low risk dogs. Clinical abnormalities included multifocal spinal pain in 8/8, reduced menace response in 5/8, and lateralizing postural reaction deficits in 5/8 pugs. There was a strong association between genotype risk and the presence of this clinical phenotype (P = .03).Conclusions and Clinical ImportanceOur findings suggest the presence of a novel early clinical phenotype of NME in apparently asymptomatic genetically at‐risk pugs which might be used to plan early diagnostic and therapeutic clinical trials.     

不同干豆豆浆机制备豆浆的主要品质评价

以大豆为原料选用我国2个主导品牌的3款豆浆机(九阳精磨豆浆机、九阳无网干豆豆浆机、美的无网干豆豆浆机)制作豆浆,从蛋白质含量、蛋白质回收率、豆浆颗粒度及感官特性等方面对豆浆品质进行评价.结果表明:豆浆的蛋白含量为1.72%～2.66%,蛋白回收率为47.13%～68.66%,带有精磨器的豆浆机制备的豆浆蛋白含量及蛋白回...     

Approaches to pathogen-mediated resistance breeding against plum pox potyvirus in stone-fruit trees1

In a programme for developing systems which allow the transfer of foreign genes into apricot cultivars, we have tested cotyledons of immature embryos, somatic embryos and leaf discs. Apricot plants have been transformed, and then regenerated, with Agrobacterium tumefaciens strain LBA 4404 containing various binary plasmids: pBinGUSint, carrying the marker gene β-glucuronidase (GUS), and pBinPPVm, carrying the coat-protein gene of plum pox potyvirus (PPV). The marker gene GUS was used for visual evaluation of the efficiency of the transformation system. The coat-protein gene was used in the hope of introducing coat protein-mediated resistance to one of the most important stone-fruit pathogens in Europe and the Mediterranean area.     

Confirmation of the Prophylactic Value of Paromomycin in a Natural Outbreak of Caprine Cryptosporidiosis

Veterinary Research Communications -     

内蒙古阿拉善盟草原疯草危害调查

采用现场调查和资料收集相结合的方法，对内蒙古阿拉善盟的阿拉善左旗、阿拉善右旗和额济纳旗3个旗疯草的种类、分布、危害及防治对策进行了调查研究。结果表明：阿拉善盟有疯草7种，其中棘豆属有毒植物3种，黄芪属有毒植物4种，分布面积超过139．33万hm^2，危害最严重的是小花棘豆和变异黄芪，给当地畜牧业造成了极大的危害，并就如何综合利用疯草提出了几点措施。     

土豆淀粉废水发酵普鲁兰多糖的研究

普鲁兰多糖是一种具有重要应用价值的微生物胞外多糖。淀粉废水是加工淀粉过程中不可避免的一种产物,成份复杂,营养丰富。利用淀粉废水作为碳源制得普鲁兰多糖,不仅使多糖的生产成本降低,变废为宝,还会减少环境污染。本文通过比较实验获得用土豆淀粉废水(potato starch waste)制多糖产率高于其它碳源,并且确定最佳发酵培养基为(%):土豆淀粉废水10,KH2PO40.6 NaCL0.2(NH4)2SO40.08。     

浅谈牧草转基因育种研究进展

简要概述了牧草遗传转化方向及牧草转基因所取得的主要贡献,介绍了牧草遗传转化三种方法,并就今后的发展前景和转基因育种生物安全问题做了初步探讨。