Bristle-like integumentary structures at the tail of the horned dinosaur Psittacosaurus

A specimen of the horned dinosaur Psittacosaurus from the early Cretaceous of China is described in which the integument is extraordinarily well-preserved. Most unusual is the presence of long bristle-like structures on the proximal part of tail. We interpret these structures as cylindrical and possibly tubular epidermal structures that were anchored deeply in the skin. They might have been used in display behavior and especially if one assumes that they were colored, they may have had a signal function. At present, there is no convincing evidence which shows these structures to be homologous to the structurally different integumentary filaments of theropod dinosaurs. Independent of their homology, however, the discovery of bristle-like structures in Psittacosaurus is of great evolutionary significance since it shows that the integumentary covering of at least some dinosaurs was much more complex than has ever been previously imagined.     

The value of sonographic diagnosis of fetal malformations: Different results between indication-based and screening-based investigations

The advantages of a routine screening or indication-based ultrasound investigation during pregnancy are still under debate. This is the first study where both methods are compared in two different time periods. More malformations were diagnosed before the 24th week of gestation by means of screening-based than indication-based investigation (18 per cent vs. 5 per cent, P<0·005), and before 28 weeks in 26 per cent compared with 15 per cent respectively (P<0·01). Twenty-six per cent of all malformations were detected by means of screening-based investigations as opposed to 15 per cent by means of indication-based scans. Primary fetal malformations were also diagnosed much earlier (25 weeks vs. 30 weeks). Except for the fetal head, the detection rate of malformations was higher in nearly all other body regions of the fetus in the screening-based investigation. The most important advantage of a screening-based ultrasound investigation during pregnancy is to detect the malformations early enough in pregnancy for possible intrauterine treatment or to offer safe termination of pregnancy for the woman, at least for those anomalies that are lethal or significantly handicapping.     

Second german heavy-metal survey by means of mosses,and comparison of the first and second approach in germany and other european countries

This paper shows the geographic distribution in Germany of iron (Fe), nickel (Ni) and lead (Pb) analyzed in mosses in 1995/96 and compares it with the results of the 1990/91 pilot study within a European moss-monitoring programme. Other elements (As, Cd, Cr, Cu, Ti, V, Zn) are compared on basis of the overall element medians for Germany of the 1990/91 and 1995/96 survey. Samples of Pleurozium schreberi, Scleropodium purum, Hypnum cupressiforme and Hylocomium splendens were taken at a total of 1026 sites. In the 1995/96 monitoring campaign, 95% of the original sites of the 1990/91 study were resampled. The results from 1995/96 display local elevated values and many cases of areas affected by known sources of heavy-metal emissions. The industrialized and urban regions of Germany are shown up clearly by the 1995/96 moss-monitoring results: the Ruhr area, parts of Saarland and Baden-Württemberg, as well as areas in eastern Germany. Relatively low values for many elements were found in large areas of Lower Saxony and Bavaria. A comparison of the results of the 1990/91 and 1995/96 moss-monitoring programmes shows a fall in the concentration of the presented elements (except cadmium, copper and zinc) over the relevant period. Especially in the former GDR, chromium (Cr), iron (Fe), titanium (Ti) and vanadium (V) decreased significantly. This is, firstly, a reflection of the closure of and/or technological improvements to large power plants; secondly it is due to the fact that lignite has given way to other fuels. Vanadium (V) and nickel (Ni), typical constituents of crude oil, also show a decrease in the western part and thus document changes in the type of fuel consumed. The significant fall in lead concentration in 1995/96 as compared to 1990/91 in what used to be East and West Germany probably results from the increasing use of lead-free petrol. A comparison of the median values for 1990/91 and 1995/96 in mosses to the rate of emission of heavy metals in Germany for 1990 and 1995 shows similar trends in the case of elements such as arsenic (As), chromium (Cr), nickel (Ni), and lead (Pb). The comparison of the medians of the elements analyzed for 19 European countries indicates for most of the elements a general tendency to lower values in 1995, except for Lithuania, Netherlands, Portugal, Italy and United Kingdom.