PubMed · 11631024
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V Zimmermann. 1982. [Not Available].. https://pubmed.ncbi.nlm.nih.gov/11631024/
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Dilute soda lakes are among the world's most productive environments and are usually dominated by dense blooms of cyanobacteria. Up to now, there has been little information available on heterotrophic bacterial abundance, production, and their controlling factors in these ecosystems. In the present study the main environmental factors responsible for the control of the heterotrophic bacterial community in five shallow soda pools in Eastern Austria were investigated during an annual cycle. Extremely high cyanobacterial numbers and heterotrophic bacterial numbers up to 307 x 10(9) L(-1) and 268 x 10(9) L(-1) were found, respectively. Bacterial secondary production rates up to 738 micro g C L(-1) h(-1) and specific growth rates up to 1.65 h(-1) were recorded in summer and represent the highest reported values for natural aquatic ecosystems. The combination of dense phytoplankton blooms, high temperature, high turbidity, and nutrient concentration due to evaporation is supposed to enable the development of such extremely productive microbial populations. By principal component analysis containing the data set of all five investigated pools, two factors were extracted which explained 62.5% of the total variation of the systems. The first factor could be interpreted as a turbidity factor; the second was assigned to as concentration factor. From this it was deduced that bacterial and cyanobacterial abundance were mainly controlled by wind-induced sediment resuspension and turbidity stabilized by the high pH and salinity and less by evaporative concentration of salinity and dissolved organic carbon. Bacterial production was clustered with temperature in factor 3, showing that bacterial growth was mainly controlled by temperature. The concept of describing the turbid water columns of the shallow soda pools as "fluid sediment" is discussed.
Carl Gussenbauer (1842-1903), known for many contributions to surgery, should also be noted prominently in the list of pioneers of pancreatic surgery. His successful performance of external drainage for a pancreatic cyst in 1882 was the first planned pancreatic operation. Although pancreatic surgery had been developed in animal models during the seventeenth century, surgery of the human pancreas was practically nonexistent owing to the dismal results seen with incidental pancreatic operations done early in the nineteenth century. Gussenbauer's procedure was a significant advance, representing a safe and effective solution to the pancreatic cyst problem. Gussenbauer's external drainage procedure remained the gold standard for treating pancreatic cysts until the 1920s and was still a widely practiced therapeutic option until the 1950s. With his discipline, insight, and innovative thought, Gussenbauer initiated the modern era of pancreatic surgery.
In the pre-vaccination era, Austria had the highest recorded morbidity of tick-borne encephalitis (TBE) in Europe. The disease accounted for more than 50% of all viral meningoencephalitides in the eastern and southern parts of the country. This prompted us to start a cooperative vaccine development project in 1971 with J. Keppie from the Microbiological Research Establishment, Porton Down, England. After very satisfactory results of field studies, conducted in individuals for whom TBE was classified as occupational disease (forest workers, farmers, etc.), the killed virus vaccine (see chapter by N. Barrett in this issue), was made commercially available by Immuno AG Vienna (now Baxter Health-Care). The vaccine proved to be highly immunogenic and very well tolerated in both adults and children. After completing the series of three vaccinations seroconversion rates of >99% were recorded. In Austria, as in other European countries, TBE is now acquired for the most part during leisure activities. In view of this fact a mass vaccination campaign was initiated in 1981. Subsequently, the vaccination coverage of the Austrian population increased from 6% in 1980 to 86% in 2001, exceeding 90% in some of the high-risk areas. Data annually collected by our surveillance system show that the clinical effectiveness of the vaccine is excellent. Based on the assumption that the whole Austrian population is at risk of infection the calculated rate of protection after three doses of the vaccine is 96-98.7%. Breakthrough disease is rare and affects mainly higher age groups. Since the advent of TBE vaccination only one single case has been observed in the age group up to 20. The increasing vaccination coverage led to a more or less steady decline of TBE, drastically reducing the public health problem that the disease poses in Austria, especially in the provinces, where formerly the highest morbidity rates were observed. For example, in Carinthia, in the years 1973-1982 an average annual incidence of 155 was recorded, compared with only four annual cases in the last 4 years. The Austrian experience shows that containment of a tick-borne viral disease is feasible, provided a well-tolerated and effective vaccine is available that is widely accepted by the general population.