NOTES ON THE AVAILABILITY AND CHEMICAL COMPOSITION OF WATER FROM THE GRAVEL PLAINS OF THE NAMIB-NAUKLUFT PARK

SUMMARY

Data are presented on the occurrence of a surprising number of permanent water sources on the gravel plains of the Namib-Naukluft Park, South West Africa. As a consequence, no game animal is further than ca 25 km away from the nearest watering-place. Within a broad range of ionic contents, the surface waters of the desert display a marked similarity in their chemical composition, being mainly dominated by Na⁺>Ca⁺⁺>Mg⁺⁺: Cl^?>SO₄ ^?>HCO₃ ^??CO_3- ^?. Evaporation, precipitation and rock dominance seem to be the main controlling mechanisms involved in determining the chemical composition of the waters.     

辽宁地区远古人类及其文化的初步研究

本文简略介绍了近十年来辽宁地区古人类和旧石器文化方面的研究成果,同时也初步探讨了本地区与周围地区的古人类及其文化的关系。     

适用于膜片钳研究的新生大鼠骨骼肌细胞培养

采用低浓度胰蛋白酶,较低温度下长时间搅拌及粗口径滴管分次吹打等改进方法进行新生大鼠骨骼肌细胞分散培养,能够得到较高的细胞产率。经１０ｎｍｏｌ／Ｌ秋水仙碱处理３ｄ后可得到肌球,能够适合于进行膜片钳记录,并不改变肌细胞的电生理学特性,肌球膜上有正常的Ｎａ＾＋、Ｋ＾＋和Ｎ型乙酰胆碱受体离子通道活动。本方法提供了一个较好的适用于肌细胞电生理学研究的模型。     

洛巴口蘑滤液中多糖蛋白复合物的抗肿瘤机制

从洛巴口蘑培养滤液中分离出一种具有抗肿瘤活性的多糖蛋白复合物（PSPC）。PSPC在细胞水平有能力恢复和增强带瘤鼠腹腔浸出细胞的吞噬功能和T细胞的促分裂活性。在分子水平,PSPC能恢复带瘤鼠脾细胞和腹腔浸出细胞内IFN-γ基因的表达水平。另外,PSPC能够下调带瘤鼠脾细胞内“抗细胞因子”TGF－β的表达水平。因此,PSPC的抗肿瘤机制可归咎于寄主介导的免疫调节作用。     

THE DISSOCIABILITY OF DEOXYRIBONUCLEIC ACID SYNTHESIS FROM THE DEVELOPMENT OF MULTINUCLEARITY OF MUSCLE CELLS IN CULTURE

The effects of a nitrogen mustard on both the morphology and several synthetic capacities of embryonic chick skeletal muscle cells in monolayer culture have been examined. Concentrations of nitrogen mustard which profoundly inhibit deoxyribonucleic acid synthesis specifically do not inhibit the development of multinuclearity in the contractile "ribbons" which form rapidly in culture. Nitrogen mustard affects the nuclear morphology of "fibroblast-like" and multinuclear muscle cells differentially. The mononucleated cells in treated cultures exhibit extreme nuclear enlargement which distinguishes them from the multinuclear cells as well as from both types of cells in control cultures. The nuclei of the multinuclear cells which form after nitrogen mustard treatment, however, do give evidence of having been affected by the treatment. They exhibit somewhat less uniformity of size than similar cells in control cultures. Analogous differences were described by Bodenstein (3) between potentially proliferating cells and postmitotic differentiating cells, marked nuclear enlargement being characteristic of cells in the proliferative zone. The results are more compatible with the hypothesis that multinuclearity arises through successive cell fusion than through amitotic nuclear multiplication, since it is unlikely that any form of nuclear replication could occur in the absence of DNA synthesis.     

绿僵菌产海藻糖水解酶培养条件研究

丝状真菌绿僵菌能产生一系列二糖水解酶,其中包括海藻糖水解酶。这些酶在绿僵菌对昆虫的致病过程中起着重要的作用。本文研究了不同碳源、氮源对金龟子绿僵菌Metarhizium anisopliae var. acridum菌株CQMa102产生与分解昆虫血淋巴中海藻糖等二糖相关的海藻糖水解酶活性的影响。结果表明:分别以葡萄糖、麦芽糖、蔗糖、山梨醇和可溶性淀粉为碳源,金龟子绿僵菌均可产生海藻糖水解酶,但最佳碳源是可溶性淀粉,因为由其诱导产生的海藻糖水解酶具有最高的总活性和比活性以及更多的同工酶,山梨醇次之。硝态氮(NaNO₃)作为唯一氮源时,几乎检测不出海藻糖水解酶活性,而铵态氮((NH₄)₂SO₄)或NaNO₃和有机氮(蛋白胨和酵母浸膏)混合氮源作氮源时,海藻糖水解酶活性都很高。在绿僵菌菌丝提取液和滤液的海藻糖水解酶活性比较中发现:CQMa102在多数碳源的培养基中产生的海藻糖水解酶主要分泌到培养基中,仅有少数结合在细胞壁上。     

草鱼椎骨间质细胞的培养

鱼类细胞培养不仅在病毒学及细胞生物学的研究中起重要作用,也是生物进化、发育及遗传研究的极好材料1,2.有报道指出高等脊椎动物的骨髓间质细胞具有分化成多种细胞的功能3.常用于细胞培养的鱼类组织有心、鳍、卵巢、肾及肿瘤等4,5,鱼类没有骨髓6,因此草鱼(ctenopharyngodon idellus)骨间质细胞的培养,对探讨鱼类免疫细胞分化途径、鱼类造血组织的发育及分化潜能具有重要意义。       

人参寡糖素对三七悬浮培养细胞生长的效应

从人参培养细胞的细胞壁中分离纯化到不同分子量的单体人参寡糖素。试验结果表明命名为人参寡糖素Ⅶ和人参寡糖素Ⅷ的两种寡糖素对三七悬浮培养细胞的生长具有明显的促进作用,其增长率分别为１９．３４％和１０．５８％,人参寡糖素Ⅶ的适宜浓度为５—１０ｍｇ／ｌ。在高浓度下（大于２５ｍｇ／ｌ）稍抑制培养细胞生长。在细胞培养２２天（指数生长期）后．加入１０ｍｇ／ｌ的人参寡糖素Ⅶ．然后再培养２天。其生长速率即提高,加入人参寡糖素Ⅷ后．缩短了三七细胞悬浮培养生长的延缓期．提前进入对数生长期和指数生长期,并在对数生长期和指数生长期作用最明显,因而最终收获时培养细胞的产率增加。     

灵芝—共生真菌的发酵液化学成分研究

从灵芝一共生真菌(Calcarisporium arbuscula Preuss)的发酵液中分离得到7个化合物,经波谱分析确定其结构分别为zythiostromic acid A(1),zythiostromolide(2),7,8-二甲基苯并[g]蝶啶-2,4(1H,3H)-二酮(7,8-dimethylbenzo[g]pteridine-2,4(1H,3H)-dione,3),麦角甾醇(ergosterol,4),琥珀酸(butane-dioic acid,5),狼毒甲素(5,5'-[oxybis(methylene)]bis-2-furancarboxaldehyde,6),5-羟甲基糠醛(5-hydrox-ylmethyl-2-furancarboxaldehyde,7).1,2,3首次从齿梗孢属真菌中分离得到.     

灵芝一共生真菌的发酵液化学成分研究

从灵芝一共生真菌 (CalcarisporiumarbusculaPreuss)的发酵液中分离得到 7个化合物 ,经波谱分析确定其结构分别为 :zythiostromicacidA(1) ,zythiostromolide(2 ) ,7,8 二甲基苯并 [g]蝶啶 2 ,4 (1H ,3H) 二酮 (7,8 dimethylbenzo[g]pteridine 2 ,4 (1H ,3H) dione ,3) ,麦角甾醇 (ergosterol,4 ) ,琥珀酸 (butane dioicacid ,5 ) ,狼毒甲素 (5 ,5’ [oxybis(methylene) ]bis 2 furancarboxaldehyde ,6 ) ,5 羟甲基糠醛 (5 hydrox ylmethyl 2 furancarboxaldehyde ,7)。 1,2 ,3首次从齿梗孢属真菌中分离得到。     

THE PROBLEM OF NOMENCLATURE

Whitfield, A. K. &; Blaber, S. J. M. 1978. Feeding ecology of piscivorous birds at Lake St Lucia, Part 3: Swimming birds. Ostrich 50:10-20. The diets, foraging periodicities and feeding behaviour of the Reed Cormorant Phalacrocorax africanus, Whitebreasted Cormorant Phalacrocorax carbo and White Pelican Pelecanus onocrotalus were studied at Lake St Lucia, Natal, South Africa, during 1975 and 1976. The Reed Cormorant fishes in shallow water within 100 m of the shore and mainly caught Sarotherodon mossambicus and Solea bleekeri, while the Whitebreasted Cormorant caught Mugilidae, Rhabdosargus sarba and Thryssa vitrirostris in deeper water. The diet of the White Pelican followed three distinct phases: a pre-incubation phase when the birds followed and preyed heavily on migrating Mugil cephalus shoals; an incubation and post-incubation phase when the adults flew a round trip of 200 km to the north to obtain freshwater fish, mainly cichlids, from the Pongolo pans where fishes were concentrated and densities high; and a post-fledgling phase when both adults and juveniles fed on a variety of marine species of fish in Lake St Lucia for about a month before dispersing to other areas. The feeding and breeding of Reed Cormorants and White-breasted Cormorants is discussed in relation to wind speeds, water turbidity and flooding of backwaters. The diet and long-range foraging behaviour of White Pelicans at St Lucia are compared with data from other African lakes. The breeding season of White Pelicans at St Lucia is related to availability of fish and inaccessibility of the breeding site to predators. The latter is determined by lake levels.