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The response of the ascorbate-glutathione cycle was investigated in roots of young wheat (Triticum aestivum L.) seedlings that were deprived of oxygen either by subjecting them to root hypoxia or to entire plant anoxia and then re-aerated. Although higher total levels of ascorbate and glutathione were observed under hypoxia, only the total amount of(More)
Parasitic plants in the Scrophulariaceae develop infective root structures called haustoria in response to chemical signals released from host-plant roots. This study used a simple in vitro assay to characterize natural and synthetic molecules that induce haustoria in the facultative parasite Triphysaria versicolor. Several phenolic acids, flavonoids, and(More)
We investigate how the qualitative structure of Doppler peaks in the angular power spectrum of the cosmic microwave anisotropy is affected by basic assumptions going into theories of structure formation. We define the concepts of “coherent” and “incoherent” fluctuations, and also of “active” and “passive” fluctuations. In these terms inflationary(More)
The inflationary cosmology is analyzed from the point of view of squeezed quantum states. As noted by Grishchuk and Sidorov, the amplification of quantum fluctuations into macroscopic perturbations which occurs during cosmic inflation is a process of quantum squeezing. We carefully develop the squeezed state formalism and derive the equations that govern(More)
  • Álbrecht
  • Physical review. D, Particles and fields
  • 1993
I study the quantum mechanics of a spin interacting with an “apparatus”. Although the evolution of the whole system is unitary, the spin evolution is not. The system is chosen so that the spin exhibits loss of quantum coherence, or “wavefunction collapse”, of the sort usually associated with a quantum measurement. The system is analyzed from the point of(More)
[formula: see text] With the unambiguous structural characterization of 7,11-cyclobotryococca-5,12,26-triene 1 by NMR, a novel C30 botryococcene-related hydrocarbon skeleton bearing a midchain five-membered ring has been identified in organic-rich sediments from Lake Cadagno (Switzerland). This compound may originate from the green alga Botryococcus braunii(More)
The energy spectrum of a two-dimensional electron system in a perpendicular homogeneous magnetic field and a weak lateral superlattice potential with square symmetry is composed of Landau bands with recursive internal subband structure. The Hall conductance in the minigaps is anticipated to be quantized in integer multiples of e(2)/h that vary erratically(More)