Leaf Surface Compounds and Oviposition Preference of Turnip Root Fly Delia floralis: The Role of Glucosinolate and Nonglucosinolate Compounds

The role of leaf surface compounds influencing the oviposition of the turnip root fly, Delia floralis, was investigated using bioassays and fractionation of leaf surface extracts from four Brassica genotypes. Polar leaf surface extracts contained between 65 and 175 nM/g leaf equivalent of glucosinolates. However, following fractionation it was found that nonglucosinolates were the major stimuli for D. floralis oviposition. Electrophysiological studies of leaf surface extracts and their fractions were performed by using D. radicum, the cabbage root fly, as an analytical tool. The most behaviorally active fractions contained stimulatory compound(s) that had an activity profile identical to that previously described for recently discovered nonglucosinolate compounds. The role of leaf surface chemicals in influencing antixenotic resistance to D. floralis is discussed.     

Integrated Methodology for Project Risk Management

This article presents a generic project risk management process that has been particularized for construction projects from the point of view of the owner and the consultant who may be assisting the owner. The process could also be adapted to the needs of other project participants, and many points referred to in the article can be directly applied to them. Any project risk management process must be tailored to the particular circumstances of the project and of the organization undertaking it. First, the article explains a complete or generic project risk management process to be undertaken by organizations with the highest level of risk management maturity in the largest and most complex construction projects. After that, factors influencing possible simplifications of the generic process are identified, and simplifications are proposed for some cases. Then the application to a real project is summarized. As a final validation, a Delphi analysis has been developed to assess the project risk management methodology explained here, and the results are presented.     

Der Einfluß der Kurvenform auf die Durchschlagspannung einiger Isolierstoffe

Zusammenfassung Um den Durchschlagsmechanismus einiger Isoliertsoffe zu untersuchen, werden diese an Spannungen verzerrter Kurvenformen gelegt. Für Kabelpapier ergab sich ein fast rein feldstärkebedingter Zusammenbruch, die bei den anderen Werkstoffen auftretenden Erscheinungen erlauben eine Erklärung auf Grund der wärmeelektrischen Theorie.     

Die Doppelblende

Zusammenfassung Aus der Erkenntnis heraus, da? durch eine zus?tzliche Strahleinschnürung zu der Str?mungsausbildung in einer Blende eine ?nderung der Beiwertkurvenform in Abh?ngigkeit von der Reynoldsschen Zahl eintreten kann, wird in der vorliegenden Arbeit durch Hintereinanderschalten zweier Normblenden zu einer Doppelblende eine neue Me?drossel entwickelt, die für alle praktisch wichtigen ?ffnungsverh?ltnisse eine weitgehende Unabh?ngigkeit des Beiwertes von der Reynoldsschen Zahl besitzt. VDI Herrn Prof. Dr.-Ing. e. h.Wagenbach, Darmstadt, m?chte ich an dieser Stelle für das rege Interesse und die wohlwollende F?rderung dieser Arbeit meinen herzlichsten Dank aussprechen.     

Cation-exchange separation of Group V elements: Model experiments on isolation and chemical identification of Db

A cation-exchange procedure was developed for separating Nb from Ta, Pa from Ta, and Nb, Pa, and Ta from Zr, Hf, and lanthanides in dilute HC1/HF solutions. The stability of the fluoride complexes of Group IV and V elements decreases in the following order: Nb ～ Pa > Zr > Hf > Ta. This procedure can be used in experiments on synthesis of superheavy nuclei for isolation of Db from the reaction products and for its chemical identification.     

Kommentar II

Ohne Zusammenfassung