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Ohne Zusammenfassung     

Scale sensitivity of synthetic long‐term vegetation time series derived through overlay of short‐term field records

Questions: Is change in cover of dominant species driving the velocity of succession or is it species turnover (1)? Is the length of the time‐step chosen in sampling affecting our recognition of the long‐term rate of change (2)1 Location: 74 permanent plots located in the Swiss National Park, SE Switzerland, ca. 1900 m a.s.l. Methods: We superimpose several time‐series from permanent plots to one single series solely based on compositional dissimilarity. As shown earlier (Wildi & Schütz 2000) this results in a synthetic series covering about 400 to 650 yr length. Continuous power transformation of cover‐percentage scores is used to test if the dominance or the presence‐absence of species is governing secondary succession from pasture to forest. The effect of time step length is tested by sub‐samples of the time series. Results: Altering the weight of presence‐absence versus dominance of species affects the emerging time frame, while altering time step length is uncritical. Where species turnover is fast, different performance scales yield similar results. When cover change in dominant species prevails, the solutions vary considerably. Ordinations reveal that the synthetic time series seek for shortest paths of the temporal pattern whereas in the real system longer lasting alternatives exist. Conclusions: Superimposing time series differs from the classical space‐for‐time substitution approach. It is a computation‐based method to investigate temporal patterns of hundreds of years fitting between direct monitoring (usually limited to decades) and the analysis of proxy‐data (for time spans of thousands of years and more).     

A bacterial clone carrying sequences coding for elongation factor EF-1 alpha from Artemia

A bacterial cDNA clone was identified carrying one third of the nucleotides coding for elongation factor EF-1 alpha from the brine shrimp Artemia. The sequence of codons corresponds with the known sequence of amino acids of EF-1 alpha in the region involved.     

A new semi-automated instrument to improve the fine needle aspiration procedure during breast lesion cell sampling

A large and increasing number of women in the western world will at some point during their life be investigated morphologically for some type of breast lesion. Fine Needle Aspiration (FNA) is one morphological method which is considered to be the fastest, cheapest and the most patient-friendly approach. However, the frequency of conclusive samples using this method varies and is often too low, especially when performed by unexperienced operators. In this study we have developed and tested a new semi-automated instrument (“CytoTest”) designed for FNA which is intended to improve the efficacy of the technique by increasing the percentage of conclusive samples. A total of 443 consecutive aspiration procedures on palpable breast lesions were performed to compare this new “CytoTest” equipment with the standard protocol using the same type of needles. We conclude that by increasing the extent and frequency of the reciprocatory motions used by an experienced sampling operator as well as enhancing the ejection pressure, the cellular yield can be increased almost three folded compared to the standard protocol. For cases with high amounts of non-diagnostic material (such as blood or cystic fluid) which were discarded, up to four times more sample could be obtained. Furthermore, the frequency of sparse samples under 1 mg was halved with use of the “CytoTest”.