Total N difference method and 15N isotope dilution methode - A comparative study on N-fixation

In the study, the 15N fixation of a number of green manure crops were studied using either the 15N dilution technique, or the simple total N difference method. The results of the two methods were not very different, and the total N difference method seemed to give as good results as the more complicated and expencive 15N dillution method

System-friendly wind power: How advanced wind turbine design can increase the economic value of electricity generated through wind power

Previous studies find that the economic value of electricity (USD/MWh) generated by wind power drops with increasing market share. Different measures can help mitigate the value drop, including electricity storage, flexible conventional plants, expansion of transmission, and demand response. This study assesses another option: a change in design of wind power plants. “Advanced” wind turbines that are higher and have a larger rotor compared to rated capacity (lower specific rating) generate electricity more constantly than “classical” turbines. Recent years have witnessed a significant shift towards such advanced technology. Our model-based analysis for Northwestern Europe shows that such design can substantially increase the spot market value of generated electricity. At a 30% penetration rate, the value of 1 MWh of electricity generated from a fleet of advanced turbines is estimated to be 15% higher than the value of 1 MWh from classical turbines. The additional value is large, whether compared to wind generation costs, to the value drop, or to the effect of alternative measures such as electricity storage. Extensive sensitivity tests indicate that this finding is remarkably robust. The increase in bulk power value is not the only advantage of advanced turbines: additional benefits might accrue from reduced costs for power grids and balancing services. To fully realize this potential, power markets and support policies need to be appropriately designed and signal scarcity investors

Die Bedeutung der Saatgutqualität für Sortenvergleiche mit Sommergerste im ökologischen Landbau

The results show that thousand grain weight, protein content of seed, seed contamination with fungi and seed emergence influenced yield potential of organically produced seeds of spring barley in variety trials under organic farming conditions during three years. Certified organic seed on average had smaller grains, lower protein content and brought 5% less yield than conventionally produced seeds of the same variety offered for trials by breeders. Different susceptibilities of the seeds for contamination with fungi influenced the ranking of varieties and seed lots additionally. The more of the previos seed quality parameters reached acceptable levels during organic seed production, the better starting point for a better yield was obtained. The results indicate that by comparing conventionally produced seeds of one variety with organically produced seeds of another variety the probability will be three times higher to handicap instead of favouring the variety tested with organic seed

Ueber ein neues signalisirendes und selbstregistrirendes Gefässbarometer

In diesem Artikel wird die Bauweise des Gefässbarometers ganz genau beschrieben. Außerdem wird auch die Funktionsweise des Geräts erläutert

Flugbrand- und Hartbrandanfälligkeit von Sommergersten unter simuliertem Befall

Fifty-five spring barley varieties from the German official varieties list were tested for their susceptibility to loose smut (Ustilago nuda) and covered smut (Ustilago hordei) under a simulation of natural infection conditions. For loose smut infection cv. ‘Lawina’ with about 5 % infected plants was used as spreader. In the trial with covered smut 1kg of seeds were shaken with 1g of spores to contaminate the surface of barley seeds before sowing. Only ‘Steffi’ stayed absolutely free from loose smut during two infection cycles at two locations. With an average of 12.6 % plants with loose smut ‘Danuta’ was the most susceptible. Most susceptible to covered smut were ‘Tunika’ with 13.2 % and hulless ‘Taiga’ with 15 % infected plants. Thirteen varieties remained free of covered smut. Among these ‘Auriga’, ‘Hendrix’, ‘Jacinta’ and ‘Sigrid’ showed a low loose smut infection with always less than 1 %. No correlation between loose and covered smut susceptibility could be detected. Under organic farming a variety with a susceptibility below 1 % under natural infection could be acceptable for maintaining seeds on farm, but for organic seed multiplication during all generations from breeding to production more loose smut resistant varieties are necessary to fulfil the demands of current seed regulations

Virtual screening for PPAR-gamma ligands using the ISOAK molecular graph kernel and gaussian processes

For a virtual screening study, we introduce a combination of machine learning techniques, employing a graph kernel, Gaussian process regression and clustered cross-validation. The aim was to find ligands of peroxisome-proliferator activated receptor gamma (PPAR-y). The receptors in the PPAR family belong to the steroid-thyroid-retinoid superfamily of nuclear receptors and act as transcription factors. They play a role in the regulation of lipid and glucose metabolism in vertebrates and are linked to various human processes and diseases. For this study, we used a dataset of 176 PPAR-y agonists published by Ruecker et al. ..