向挪威南部艾于德纳河中施加石灰:底栖无脊椎动物恢复的大规模试验

本研究描述了1985年向艾于德纳河溯河鱼类所在部分施加石灰后敏感的无脊椎动物的恢复情况.这条河流在1960～1970年间丧失了它的大马哈鱼种群.施加石灰的目的是产生pH＞6.0和ANC＞20μg/L的水质,并减少不稳定铝的含量.施加石灰前,在这条河中找不到像蜉蝣类的Baetis rhodanf等高度敏感的无脊椎动物.施加石灰2年后,一些敏感的无脊椎物种产生了积极的回应.河流下游有两处地点发现了B.rhodanf.在随后的5年里,一些敏感的无脊椎物种开始在施加石灰的整个河段聚集,并且数量越来越大.在向河流施加石灰10年后,出现了蜗牛Lymnaeaperegra.这个物种的扩散也非常迅速,5年后它可以在40km范围内施以石灰的的主要河流的所有调查地点被发现.在这一区域减少硫的沉降也引起了艾于德纳河未施加石灰的各支流水质的提高.施加石灰与未施加石灰的地点的比较说明了水质和敏感物种的临界限制是决定艾于德纳河动物组成的主要因素,而与水质变化的原因无关.     

Sequence analytical approach to the Upper Kimmeridgian-Lower Tithonian storm-dominated ramp deposits of the Boulonnais (Northern France). A landward time-equivalent to offshore marine source rocks

An interdisciplinary approach based on high-resolution physical stratigraphy, biostratigraphy, organic matter analysis and clay mineralogy has been applied to the mixed siliciclastic/carbonate Kimmeridgian/Tithonian deposits of the Boulonnais (north-western France). These rocks are the age-equivalents of some of the offshore marine source rocks of the North Sea and were deposited in an overall storm-dominated homoclinal ramp setting which may represent one of the most shore-proximal sediments of this age cropping out in north-western Europe. Comparison with data from the Yorkshire, Dorset, Lorraine and Aquitaine areas allows the discrimination of three major transgressive-regressive sediment packages with disconformities of interregional extent: (1) from the Baylei Zone to top Eudoxus Zone; (2) from the Autissiodorensis Zone to base Scitulus Zone; (3) from the upper Scitulus Zone to the Pectinatus Zone. The lower two regionally correlative disconformities correspond to the sequence boundaries at the top of the Eudoxus Zone and the top of the Autissiodorensis Zone, formed by high-frequency relative sea-level variations during the periods of maximum transgression of the platform. The latter disconformity (the P1 nodule bed) reflects a major tectonically induced reorganization of the north-west European intrashelf sedimentary basin, characterized by a shift in both the location of the main depocentre and the sources of sediment production.     

XII Ecdysone Workshop July 22–26, 1996 Barcelona,Spain

XII Ecdysone Workshop July 22–26, 1996 Barcelona, Spain     

A fetus with a parvovirus B19 infection and congenital anomalies

A fetus with multiple structural defects was seen at prenatal ultrasound examination. After termination of the pregnancy a bilateral cleft lip, alveolus, and palate; micrognathia; and webbed joints were seen. Fetal tissues showed indications of infection, intranuclear inclusion bodies, chronic stress, haemolysis, arterial wall damage, and profuse haemorrhage. Parvovirus B19 DNA was detected in fetal tissues by dot hybridization after polymerase chain reaction. The possibility of parvovirus B19 infection leading to congenital malformations is discussed.     

Plant development in the absence of epiphytic microorganisms

Microorganisms (bacteria, fungi) are common residents of the roots, stems and leaves of higher plants. In order to explore the dependency of plant development on the presence of epiphytic microorganisms, the achenes (seeds) of sunflower (Helianthus annuus L.) were sterilized and germinated under aseptic conditions. The sterility of the seedlings was determined with the agar impression method. In seedlings from non-sterile seeds (control) that were likewise raised in a germ-free environment, all plant organs investigated (stem, cotyledons and primary leaves) were contaminated with bacteria. Hypocotyl elongation was not affected by epiphytic microorganisms. However, the growth rates of the cotyledons and primary leaves were higher in sterile seedlings compared with the control. The implications of this differential inhibition of organ development by epiphytic bacteria that are transmitted via the outer surface of the seed coat are discussed. We conclude that epiphytes in the above-ground phytosphere are not necessary for the development of the sunflower seedling.     

First-trimester diagnosis of duodenal stenosis associated with oesophageal atresia

Duodenal stenosis associated with oesophageal atresia was diagnosed by ultrasound at 12 weeks' gestation. The diagnosis was made by recognition of a double bubble sign which was more pronounced when a vaginal transducer was used. Post-abortion autopsy confirmed the diagnosis. Oesophageal and duodenal obstruction in this case had no effect on the amount of amniotic fluid or the alpha-fetoprotein concentration since swallowing and subsequent utilization of amniotic fluid do not occur before 12 weeks of gestation.