辽宁地区毛腹种蝇的生态学调查

经过1963—64年在辽宁本溪新岭对毛腹种蝇Hylemya (Chionomyia)vetula(Zett,1838)进行生态学调查的结果,说明本种主要以成蝇越冬,多在室外活动;以蛹期越夏:10月上旬最早出现(17℃),秋末初冬大批羽化,10月中旬至11月中旬形成了第一个成蝇高峰,翌年3—4月是雌蝇产卵时期,活动频繁,雌蝇数量较多,形成了第二个成蝇高峰。于5月上旬成蝇绝迹(22℃),成蝇出现季节全长为7个月。 幼虫滋生于人粪和猪粪中。成蝇取食人粪、猪粪和牛粪。因此是一种在卫生上有一定重要性的蝇种。 三龄幼虫:肛板显然大形而向两侧突出,这点有别于种蝇属(Hylemya)的各巳知常见种的幼虫形态,但易被误认为花蝇属(Anthomyia)。它同七星花蝇(Anthomyia imbrida)和横带花蝇(Anthomyia illocata)相似,但是有以下区别:(1)小锥形的腹突、副腹突显然位于亚腹突一线的背方:(2)腹垫仅具等大的小刺,中央区无较大形的棘:(3)后肛疣仅有较大的丘状隆起,没有象花蝇属已知常见种幼虫的后肛疣那样尖而明显;(4)后气门间距约为后气门直径的1—2倍。     

Isolation and genetic study of Aspergillus nidulans mutants defective in pyrimidine biosynthesis]

8 uridine-requiring pyr mutants were isolated from Aspergillus nidulans under nitrosoguanidine treatment. All the mutants are capable to grow on the medium containing 20 mkg/ml of uridine or cytidine, or 100 mkg/ml of uracil, and they do not utilize thymidine, thymine, cytosine and deoxyuridine. Their ability to grow in the presence of orotic acid demonstrates that the pyrimidine synthesis in all the mutants is blocked at stages preceding the conversion of orotic acid into orotidine monophosphate. All the pyr mutants are of nuclear nature, they are recessive and represent three complementation groups located in the VIII chromosome. Unlike U. maydis mutant, the requirement in pyrimidines does not increase the sensitivity of A. nidulans pyr mutants to UV-irradiation.     

本溪地区蚊虫初步调查

本溪地区的蚊虫过去未有过文献报告。我们于1957—1958年,在本溪地区(本溪市、本溪县)进行了蚊虫的初步调查。经两年的调查已发现的蚊种,有按蚊属1种,伊蚊属4种,库蚊属6种,共计11种。其名称如下:     

Selective method of isolating mutants sensitive to ultraviolet radiation from a culture of Rhodopseudomonas sphaeroides

The method of penicillin selection used after UV-irradiation (lambda = 254 nm) allows one to select UV-sensitive mutants (uvs-mutants) of the phototrophous bacterium Rhodopseudomonas sphaeroides induced by nitrosomethylurea with an effectiveness greater by an order of magnitude. Over 30% of the uvs-mutants obtained using this method had an elevated sensitivity not only to far-UV (F-UV, lambda = 254 nm) but also to near-UV (N-UV, lambda greater than 280 nm) UV-irradiation. No correlation was found in the degree of sensitivity to F-UV and N-UV-irradiation of the uvs-mutants. Mutants highly sensitive to the lethal action of N-UV were isolated.     

Neural mass models as a tool to investigate neural dynamics during seizures

Epilepsy is one of the most common neurological disorders and is characterized by recurrent seizures. We use theoretical neuroscience tools to study brain dynamics during seizures. We derive and simulate a computational model of a network of hippocampal neuronal populations. Each population within the network is based on a model that has been shown to replicate the electrophysiological dynamics observed during seizures. The results provide insights into possible mechanisms for seizure spread. We observe that epileptiform activity remains localized to a pathological region when a global connectivity parameter is less than a critical value. After establishing the critical value for seizure spread, we explored how to correct the effect by altering particular synaptic gains. The spreading of seizures is quantified using numerical methods for seizure detection. The results from this study provide a new avenue of exploration for seizure control.     

Oogenesis of Mozambique tilapia. II. Synthesis of RNA and development of the nucleoli

Using methods of light and electron microscopy and authoradiography, morphology and biosynthetic activity of nucleoli and RNA synthesis in developing oocytes of Tilapia mossambique were studied. In previtellogenic oocytes nucleoli are mostly composed of fibrils, while the granular component is poorly developed. 3H-uridine is poorly incorporated in their peripheral parts. With the start of vitellogenesis, fibrils and granules are seen randomly located throughout the whole volume of the nucleoli, with primary granule concentrations in their peripheral region. 3H-uridine is intensely incorporated in the whole volume of nucleoli, and the labeled RNA migrates to the cytoplasm. In early previtellogenic oocytes chromosomes are strongly labeled with 3H-uridine, and RNA quickly migrates to the cytoplasm.