Planktonic foraminiferal abundances and stable isotope ratios in middle Miocene sediments of the North Atlantic and the southwestern Pacific

A three-fold expansion of the Antarctic ice sheet at 13.60, 12.82, and 11.60 Ma has been inferred from delta18O maxima analyzed in planktonic and benthic foraminiferal tests, although accompanying changes in sea surface temperature have not been detailed. We present estimated changes in middle Miocene surface-water temperatures based on analysis of delta18O in planktonic foraminifera collected at mid-latitude Deep Sea Drilling Project sites in the North Atlantic and South Pacific oceans. We also identify periods of ice-sheet growth based on comparisons of benthic and planktonic foraminiferal delta18O values. Our results indicate: (1) a distinct cooling of the sea surface from 13.6 to 13.5 Ma immediately following a peak in ice volume at 13.6 Ma, (2) a cooling of the sea surface during a period of increasing ice volume from 13.2 to 13.0 Ma, and (3) a development of the Antarctic ice sheet during a period of cooling of the sea surface centered at 11.6 Ma.

Recent investigations on zooplankton in the Limnological Institute of the University of Freiburg, in Falkau (Germany). [Translation from: Acta cient.Venezolana 18, 94-97, 1967. ]

Histochemical experiments are conducted in order to study the interrenal cells of European brook lamprey (Lampetra planeri).

Physiology of nitrate reduction in Pseudomonas aeruginosa. [Translation from: Z.allg.Mikrobiol. 13, 83-94, 1973.]

Pseudomonas aeruginosa has for some time been known as a denitrifier. Pseudomonas aeruginosa was chosen for further studies, because P. aeruginosa occurs abundantly in Plusssee and moreover there are contradictory assertions on the gas products of denitrification by this bacteria. In experimental research the pattern of growth and gas production of Pseudomonas aeruginosa on nutrient broth was studied.

The problem of the co-existence of Arctodiaptomus bacillifer (Koelb.), Acanthodiaptomus denticornis (Wierz.) and Heterocope saliens Lill [Translation from: Memorie dell'Istituto Italiano di Idrobiologia Dott.Marco de Marchi 8 81-94, 1954]

In freshwater environments of modest size and without notable ecological structure, there is usually present only one diaptomid species. When two or more diaptomid species are present in the same habitat, generally their body dimensions are distinctly different. There are only four examples of co-existence of Arctodiaptomus bacillifer (Koelb.) and Acanthodiaptomus denticornis (Wierz.) situated at higher altitudes alpine lakes. The article discusses the results of sampling in the summer of 1953 and the problem of the co-existence of Arctodiaptomus bacillifer, Acanthodiaptomus denticornis and Heterocope saliens.

Experimental research on dormancy in Cyclops vicinus [Translation from: Naturwissenschaften 56 93-94, 1969]

Dormancy has been observed in several species of Cyclops. Animals in dormancy are characterised by almost complete inactivity of the main appendages and sluggish intestinal peristalsis. In Cyclops vicinus dormancy can take place in copepod stages III (19%), IV (78%) and V (3%) but one and the same animal only in one developmental stage. The author gives his own results between frequency of dormancy and photoperiod (20 C, 1000 lux). He concludes that dormancy in C. vicinus can be influenced by day length and can be ended prematurely by short day length.

Feeding of Gammarus lacustris Sars under different conditions of habitation [Translation from: [Trophic relations of freshwater invertebrates.] (ed. G. G. Vinberg) pp.94-98. Leningrad, Zool.Inst.AN SSSR, 1980]

The amphipod Gammarus lacustris, a regular representative of lacustrine communities, often plays a significant role in the transformation of matter and energy. The object of the present work was to clarify the quantitative side of the feeding of the amphipod under different conditions of habitation. Experimental works on determination of the rate of consumption of food and its dependence on body-weight were carried out in the summer periods 1975-1978 on three water-bodies of the Krasnoyarsk region, of different conditions of habitation for the amphipods.

对磷酸氢钙(HG2636-94)检测方法的改进建议

本文对饲料级磷酸氢钙标准(HG2636-94)检测方法中钙含量的测定、氟含量的测定存在的问题进行了探讨,并提出了解决方法.利用分散剂消除磷酸根对钙测定的干扰,EDTA直接络合滴定钙,方法快速准确;控制适当的试科量以保证氟检测结果的准确度.