Molecular adaptation of a leaf-eating bird: stomach lysozyme of the hoatzin

This report describes a lysozyme expressed at high levels in the stomach of the hoatzin, the only known foregut-fermenting bird. Evolutionary comparison places it among the calcium-binding lysozymes rather than among the conventional types. Conventional lysozymes were recruited as digestive enzymes twice in the evolution of mammalian foregut fermenters, and these independently recruited lysozymes share convergent structural changes attributed to selective pressures in the stomach. Biochemical convergence and parallel amino acid replacements are observed in the hoatzin stomach lysozyme even though it has a different genetic origin from the mammalian examples and has undergone more than 300 million years of independent evolution.      

A new assembly and technique for testing insecticides

A new design of insecticide testing assembly has been devised that is highly versatile in testing the efficacy, potency and interaction of insecticides and other test chemicals. The merits of the assembly and technique have been explained.     

A technique for determining the distribution of pelagic fish larvae

A technique is described for studying small scale distributional patterns of fish larvae in the pelagic region. A plankton net is mounted beneath the bows of a small boat, the contents of the net are emptied continually by a suction pump. This system has advantages over previous techniques as it allows a large number of small discrete samples to be taken over a wide area in a short space of time. Preliminary results showed the population of perch larvae in Llyn Tegid is extremely clumped and the overall abundance of the larvae decreases as samples are taken progressively further away from the south-west end of the lake.     

昆虫系统发育重建的常用方法及步骤

本文介绍了昆虫系统发育重建研究的步骤,常用方法及相关软件的使用,指出了不同研究方法的优缺点及适用范围,分析了系统发育重建存在的问题,从而为相关研究的开展提供了参考。     

A selective isolation technique for determining Chaetomium in soil

Summary It was shown that Chaetomium was isolated from four types of soil; Cinebar, Ephrata, Milville, and quartz sand, more frequently when using alcohol agar as the growth medium than it (Chaetomium) was isolated from these soils when using either Czepak's-Dox agar or peptone-dextrose agar plus rose bengal and streptomycin. This isolation method proved to be one which permits identification of the Chaetomium species without further culturing.This paper is based on work performed under United States Atomic Energy Commission Contract AT (45-1)-1830.     

A laboratory technique for examining the flight activity of insects under controlled environment conditions

A technique was developed for studying the flight activity of the, black fly,Simulium arcticum, under controlled environment conditions. Wind speed, light, temperature and humidity could be controlled and monitored in the flight chambers. Accurate measurement and recording of individual insect activity were achieved with a high-sensitivity video recording and monitoring system. The controlled-environment monitoring system is adaptable for investigations of the environmental behaviour and physiology of various insect species.     

定量测定储粮害虫胃毒作用的方法——混药薄片法

本实验制定一种定量测定储粮害虫胃毒作用的方法,命名为混药薄片法。通过试验验证饲料薄片对烟草甲Lasioderma serricorne(Fabricius)的幼虫成活率、发育历期、虫体重量、产卵量等生长发育无影响。在排除烯虫酯对烟草甲的触杀作用的前提下,将混有烯虫酯溶液的混药薄片作为饲料饲养烟草甲3龄幼虫,得到烯虫酯对烟草甲3龄幼虫的准确致死剂量为(0.46±0.03)μg。     

A technique for quantitative evaluation of ectoparasitic mites and insects of domestic animals

A modified KOH dissolution technique using Tween 80 has been developed for the diagnosis and quantitative evaluation of ectoparasitic mites and insects of veterinary importance. Fifty intact skin segments from ten different domestic animals were artificially inoculated in vitro with ten specimens each of the mitesSarcoptes scabiei, Chorioptes bovis, Psoroptes ovis andDemodex caprae and insectsHaematopinus eurysternus andBovicola bovis. Sixty-seven to 88% of the mites and 80–99% of the insects were recovered by this technique. Using this method, parasitic mites and insects were found and identified in all skin scrapings from ten naturally infested animals. Using Cook's dissolution technique in our experimental design, 63.4% ofC. bovis and 65% ofS. scabiei mites were recovered.     

A technique for measuring the susceptibility of wheat bulb fly larvae to insecticides in the laboratory

A simple assay is described for measuring the toxicity of insecticides to larvae of wheat bulb fly (Delia coarctata) in the laboratory. The method should be suitable for other small soil insect larvae that cannot be obtained in large numbers and are difficult to treat and confine. A limitation of the technique is that it works only with insecticides that are soluble enough to be toxic in aqueous solution.     

A technique for determining the shear sensitivity of mammalian cells in suspension culture

Summary A murine hybridoma was subjected to constant shear rates within a couette viscometer for periods of 15 hours. Shear effects on cells were determined by live cell counts, cell viability and by the release of the cytoplasmic enzyme lactate dehydrogenase into the culture medium. Cell damage was observed at a shear rate of 870s^-1 but not at 420s^-1.