2014 Thin layers of nematic liquid crystal with two free surfaces show a vortex pattern if they are subjected to an electric field. In this paper, we study a characteristic inversion of the hydrodynamic flow, that occurs if a pulsed electric field is applied. Such an effect is interpreted in terms of the relaxation mechanisms of the layer. J. Physique LETTRES 42 (1981) L-347 L-351 1

Interspecific amphihaploid and amphidiploid hybrids between Nicotiana glauca Grah. (2n = 24) and N. tabacum L. (2n = 48) cultivars BY 103 and K 326 were analysed. F1 amphihaploids (2n = 36) were viable and completely self- and cross-sterile, and mostly univalents were present during meiosis (with pairing range from 0 to 5). In some meiocytes, meiotic irregularities were observed, such as sporad...

Eighteen volatile monoterpenes, which are among the major constituents of essential oils from plants, were screened for phytotoxicity to several crop and weed species. Several monoterpenes containing an oxygen function severely inhibited germination of four different annual weeds while concurrently displaying little effect on soybean germination. Soybeans varied in their sensitivity to various ...