Sex attractant of the larch bud moth found by electroantennogram method

Zusammenfassung Mit Hilfe der Antennogramm-Methode wurdetrans-11-Tetracedenylacetat als spezifisches Attraktans für Männchen des LärchenwicklersZeiraphera diniana bestimmt. In geeigneter Konzentration ist die Attraktivität der synthetischen Substanz derjenigen virginer Weibchen ebenbürtig.

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This research was supported in part by Environmental Protection Agency Grant No. EP-00802 and by the Rockefeller Foundation.

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Contribution No. 46 of the research team for the investigation of the population dynamics of the larch bud moth, directed by Professor Dr.P. Bovey. The research was aided by the Swiss National Funds for Scientific Research.     

Electrical control of spin coherence in semiconductor nanostructures.

The processing of quantum information based on the electron spin degree of freedom requires fast and coherent manipulation of local spins. One approach is to provide spatially selective tuning of the spin splitting--which depends on the g-factor--by using magnetic fields, but this requires their precise control at reduced length scales. Alternative proposals employ electrical gating and spin engineering in semiconductor heterostructures involving materials with different g-factors. Here we show that spin coherence can be controlled in a specially designed AlxGa1-xAs quantum well in which the Al concentration x is gradually varied across the structure. Application of an electric field leads to a displacement of the electron wavefunction within the quantum well, and because the electron g-factor varies strongly with x, the spin splitting is therefore also changed. Using time-resolved optical techniques, we demonstrate gate-voltage-mediated control of coherent spin precession over a 13-GHz frequency range in a fixed magnetic field of 6 T, including complete suppression of precession, reversal of the sign of g, and operation up to room temperature.     

Use of synthetic sex attractant of larch bud mothZeiraphera diniana (Gn.) in monitoring traps under different conditions,and antagonistic action ofcis-isomere

Zusammenfassung Gummizapfen mit 1 l 10%iger Lösung vontrans-11-Tetradecenylacetat in Paraffinöl sind während 70–100 Tagen attraktiver für Männchen des Lärchenwicklers als Fallen mit je 2 virginen Weibchen der Art, die zudem alle 2 Wochen ersetzt werden müssen. Dascis-Isomer der Verbindung ist ein spezifischer Lockstoff für Männchen des WidderchensZygaena transalpina und ein starker Antagonist sowohl des natürlichen Weibchenpheromons des Lärchenwicklers wie des synthetischen Lockstoffs.

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Contribution Nr. 48 of the research team for the investigation of the population dynamics of the larch bud moth. The research was aided by a grant of the Swiss National Founds for Scientific Research.