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281.
282.
A. Müller K. Schneider J. Erfkamp V. Wittnebenund E. Diemann A. N. Eaton 《Die Naturwissenschaften》1988,75(12):625-627
früher: Institut für Mikrobiologie der Universität, D-3400 Göttingen 相似文献
283.
J. Schneider 《Marine Biology》1972,16(3):214-225
Three test-series were applied, which differed in regard to the basal medium (natural or artificial sea water, salinity level, addition of detergent); the culture conditions (primary cultures, subcultures, back-inoculations into basal medium without toxic metals); the criterion employed (zoospore activity, sporangia development, or dry weight of Thraustochytrium striatum Schneider). The temperature applied was 18° to 20°C. The sea water-pollen-method (MWP) proved to be the most suitable: it is simple and more sensitive than the other tests; subcultures and back-inoculations are possible without much additional work; conditions simulate nature; first results are available after 3 to 4 days. The SMS-method (enriched natural sea water of different salinities) provides additional information on salinity effects. Nine substances have been tested: (CH3COO)3Hg, HgCl2, CdCl2·H2O, ZnSO4 ·7H2O, NiSO4·7H2O, CuSO4·5H2O, CoCl2·6H2O, MnCl2 ·4H2O, and phenol. In regard to their toxicity these substances can be divided into 2 groups: Hg- and Cd-salts inhibit development down to greater dilutions than the remainder; Zn and Ni seem to yield intermediate effects. Salinity modifies the toxic effects of the test substances. In higher salinities, comparable concentrations of test substances reveal stronger inhibitory effects than in lower salinities. Detergents may augment the toxic effects, at least of CuSO4. The marine lower fungus T. striatum is a useful organism for testing biological consequences of water pollutants. 相似文献
284.
Boris M. Petrikovsky MD Phd Margaret I. Cuomo Elizabeth P. Schneider Linda J. Wyse Harris L. Cohen Martin Lesser 《黑龙江环境通报》1995,15(9):827-829
The aim was to assess the role that fetal bladder size has in the determination of fetal hydronephrosis. Forty-three fetuses were evaluated for fetal hydronephrosis in the second trimester of pregnancy. Anteroposterior measurements of the renal pelvis were obtained with a full bladder and again when the bladder emptied in each fetus. Statistical analysis was performed using the Spearman rank order correlation coefficient to assess the relationship between bladder status and renal dilation. The anteroposterior size of the fetal renal pelvis diminished from 6.8 ± 1.8 mm on a full bladder scan to 4.5 ± 1.6 mm when the bladder was emptied (P<0.001). Fifty-three per cent of the fetuses whose renal pelvic measurements were 5 mm or more on a full bladder scan had normal-appearing renal pelvises when their bladders emptied. The status of the fetal bladder should be considered when evaluating fetal hydronephrosis. 相似文献
285.
Dr. Georg Keckstein Sonja Tschurtz Volker Schneider Wolfgang Mütter Rainer Terinde Wolf-Dietrich Jonatha 《黑龙江环境通报》1990,10(1):59-65
Between October 1985 and February 1989, 49 ultrasound-guided intravascular fetal blood transfusions were performed in 16 patients (14 with rhesus (Rh) isoimmunization, 2 with non-immunologic hydrops fetalis (NIHF)). As an intra-operative complication, perivascular haematoma of the cord occurred in three patients (7 per cent). In two cases, fetal bradycardia necessitated delivery by Caesarean section at 30 and 32 weeks' gestation, respectively. In the third case, fetal bradycardia developed during transfusion, at 31 weeks' gestation, but normalized within 3 min. The baby was delivered as planned at 36 weeks of gestation, after another transfusion at 34 weeks. Dislodgement of the needle tip into perivascular tissue, caused by sudden fetal or maternal movements, is the reason for this complication. The haematoma develops as a result of delayed recognition and continuous transfusion into Wharton' s jelly. Cord haematoma may be diagnosed in time by continuous ultrasound imaging, as illustrated in case 3. To minimize the risk of needle dislodgement during transfusion, sedation of the mother and complete immobilization of the fetus by injecting a short-acting muscle relaxant into the umbilical vessel are recommended. 相似文献
286.
We appreciate the technical assistance by E. Roth, U. Sachade, H. Söchting-Mayr, M. Weyerer. We thank for support the Fonds der chemischen Industrie and the Deutsche Forschungsgemainschaft (M.W.) and the Max-PlanckGesellschaft (D.S.). 相似文献
287.
The contamination levels of different commercial herbicides and bulk reagents with the carcinogen 3,3′,4,4′-tetrachloroazobenzene (TCAB) were determined by high resolution mass spectrometry. The concentrations vary from 0.00071 to 2.8 ug/g (ppm) for the herbicides and from 0.085 to 14 ug/g for the bulk reagents. They are thus lower than those of other reports. 相似文献
288.
The common jellyfish Aurelia aurita: standing stock,excretion and nutrient regeneration in the Kiel Bight,Western Baltic 总被引:2,自引:0,他引:2
G. Schneider 《Marine Biology》1989,100(4):507-514
The population dynamics, ammonia and inorganic phosphate excretion, and nutrient regeneration of the common jellyfish Aurelia aurita was investigated from 1982 to 1984 in the Kiel Bight, western Baltic Sea. During summer 1982, medusae abundance ranged between 14 and 23 individuals 100 m-3, biomass was estimated at about 5 g C 100 m-3 and the mean final diameter of individuals was 22 cm. Abundance, based on numbers, in 1983 and 1984 was an order of magnitude lower; biomass was less than 2 g C 100 m-3 and jellyfish grew to 30 cm. During the summers of 1983 and 1984, A. aurita biomass constituted roughly 40% of that of the total zooplankton>200 m. In 1982, for which zooplankton data were lacking, it was assumed that medusae biomass was greater than that of all other zooplankton groups. Total ammonia excretion ranged between 6.5 and 36 mol h-1 individual-1, whereas inorganic phosphate release was 1.4 to 5.7 mol h-1 individual-1. Allometric equations were calculated and exponents of 0.93 for NH4–N release and 0.87 for PO4–P excretion were determined. Nitrogen and phosphorus turnover rates were 5.4 and 14.6% d-1, respectively. In 1982, the medusae population released 1 100 mol NH4–N m-2 d-1, about 11% of the nitrogen requirements of the phytoplankton. The inorganic phosphate excretion (150 mol m-2 d-1) sustained 23% of the nutrient demands of the primary producers. In the other two years the nutrient cycling of the medusae was much less important, and satisfied only 3 to 6% of the nutrient demands. It is suggested that in some years A. aurita is the second most important source of regenerated nutrients in Kiel Bight, next to sediment. 相似文献
289.
The bottlenose dolphin community of Doubtful Sound features a large proportion of long-lasting associations 总被引:4,自引:0,他引:4
David?LusseauEmail author Karsten?Schneider Oliver?J.?Boisseau Patti?Haase Elisabeth?Slooten Steve?M.?Dawson 《Behavioral ecology and sociobiology》2003,54(4):396-405
More than 12 studies of different bottlenose dolphin populations, spanning from tropical to cold temperate waters, have shown that the species typically lives in societies in which relationships among individuals are predominantly fluid. In all cases dolphins lived in small groups characterised by fluid and dynamic interactions and some degree of dispersal from the natal group by both sexes. We describe a small, closed population of bottlenose dolphins living at the southern extreme of the species' range. Individuals live in large, mixed-sex groups in which no permanent emigration/immigration has been observed over the past 7 years. All members within the community are relatively closely associated (average half-weight index>0.4). Both male–male and female–female networks of preferred associates are present, as are long-lasting associations across sexes. The community structure is temporally stable, compared to other bottlenose dolphin populations, and constant companionship seems to be prevalent in the temporal association pattern. Such high degrees of stability are unprecedented in studies of bottlenose dolphins and may be related to the ecological constraints of Doubtful Sound. Fjords are low-productivity systems in which survival may easily require a greater level of co-operation, and hence group stability. These conditions are also present in other cetacean populations forming stable groups. We therefore hypothesise that ecological constraints are important factors shaping social interactions within cetacean societies.Communicated by D. Watts 相似文献
290.