Probleme der Erweiterung der Prüfverteilungen des Maximum-Modulus-Testes und des DUNNETT-Testes

SCHULZ (1976) gave formulas for the approximate computation of the percentage points needed for the comparison of sample means by the Maximum-Modulus-Test resp. by the DUNNETT-Test. Our investigation shows that these formulas are also practicable if the number of the mean differences k is greater than 20. The maximum difference between the exact values and the approximate values of the percentage points amounts to 0,05 in the case of the Maximum-Modulus-Test with k >20 and degrees of freedom v > k for a level of error a = 0,05 resp. a = 0,01. In the case of the DUNNETT-Test this maximum difference amounts to 0,02 for 20 < k < 50 and a = 0,05. Besides it can be here supposed that the approximate percentage points are also practicable for both k >50, a = 0,05 and k >20, a = 0,01.     

Volumen und Proteinsynthese der Kerne des Stratum Basale in der Stumpfepidermis während des Wundverschlusses nach Amputation der Vorderextremität bei Triturus vulgaris

After injection of tritiated phenylalanine, microautoradiographs of longitudinal sections of the stumps of the forelegs of Triturus vulgairs 1 hour, 2, 3 and 9 hours after amputation and also of the opposite limb (reference) were prepared for quantitative measurements. The epidermal tissue (stratum basale) was examined with regard to proximo-distal changes of nuclear volume and protein synthesis. In the stratum basale of the stump the values for the parameters examined were similar to those of the reference limbs 1h and 2h after amputation, but 3h and 9h after amputation areas of increased nuclear volume were observed as well as an increased rate of protein synthesis per unit of nuclear volume. Protein synthesis in the epidermis of the stump was extremely low 1h after amputation. Protein synthesis in the reference epidermis was also reduced at this time, but then increased although the nuclear volume remained constant.     

Rolle der einzelnen Komponenten des Cellulasekomplexes bei der Hydrolyse unlöslicher Cellulose

The kinetics of the hydrolysis of microcrystalline cellulose (MC) by a Trichoderma reesei cellulase complex and by the individual endoglucanase (pI 4.4–5.2) and cellobiohydrolase (pI 4.0–4.2) has been studied. A flow chart for the enzymatic hydrolysis of the cellulose has been revealed, which formed a basis for a computer simulation of the kinetic regularities observed. As a result of it, the values of the catalytic rate constants for the individual stages of the enzymatic degradation of MC have been calculated. Then, the synergistic behaviour of endoglucanase and cellobiohydrolase in the hydrolysis of MC has been described both quantitatively and graphically. The relative efficiency of the individual stages for the MC hydrolysis in terms of glucose and cellobiose formation for cellulase complexes of various composition has been calculated. It was quantitatively shown that cellobiohydrolase plays the key role in the MC hydrolysis by T. reesei cellulase preparations, because it gives up to 80% glucose and up to 80–90% cellobiose in the presnce of endoglucanase which in turn plays a relatively minor role in a direct formation of both soluble products of the hydrolysis.     

Die klimatischen Bedingungen des Areals der Dunklen Taiga und der sommergrünen Breitlaubwälder

Die heutige Verbreitung der Vegetationsformationen der Dunklen Taiga und des sommergrünen Breitlaubwaldes läßt sich auch im Detail weitgehend durch die aktuellen Klimafaktoren erklären. Auch das Ausfallen des Gürtels der sommergrünen Laubwälder in Nordwestamerika steht damit im Einklang. Das Fehlen ozeanischer Lorbeer-Nadelwälder im atlantischen Europa hat seine Ursache dagegen im historisch bedingten Artenpotential. Das klimatisch-potentielle europäische Areal dieser Wälder wird von sommergrünen Breitlaubwäldern ausgefüllt. Die klimatischen Areale der Dunklen Taiga bzw. der sommergrünen Breitlaubwälder stimmen gut mit den Arealen der beiden Sektionen von Circaea überein, die damit ein Beispiel für eine charakteristisch taxonomisch-geographische Sippendifferenzierung geben.     

Untersuchungen über endophytische Pilze der Rebe unter besonderer Berücksichtigung des Gefäßsystems der Unterlage

Investigations on endophytic fungi of grapevine with special emphasis on the vascular system of rootstocks In three vegetation periods endophytic fungi from rootstocks of grafted grapevines were isolated, and their influence on the host-plant was determined. Before grafting (pre-nursery) about 40 to 50% of grapevines were colonized by endophytic fungi; in grafted material after growing in a nursery this rate increased up to 50 to 90% (post-nursery). Most of these fungi are Deuteromycetes, especially Moniliales and Coelomycetes. Only a few Ascomycetes were found. The spectrumof fungi differs, mainly depending on the season (pre- and post-nursery), but less on the variety and year of sampling. Contradictory results from investigations of the relationship between the isolated fungi and the vitality of grafted grapevines were found, however the endophytes clearly showed no pathogenic character. On the contrary in some cases a higher vitality of the grapevines correlated with presence of endophytes.