999 research outputs found
Notes on Leptocampoplex cremastoides (Hymenoptera, lchneumonidae, Campopleginae), a new genus and species to the Finnish fauna
Leptocampoplex cremastoides (Holmgren, 1858) is reported as new to Finland. The taxonomy and the biology of the species is shortly reviewed
Light response of the chlorophyll fluorescence parameters and partitioning of absorbed light energy in wild type and npq4 mutant of Arabidopsis thaliana
Photoprotective thermal dissipation of absorbed light energy is measured as non-photochemical quenching (NPQ) of chlorophyll fluorescence during exposure of plants to higher light intensities. We investigated the light response behavior of chlorophyll fluorescence and energy partitioning in PSII of npq4 mutant of Arabidopsis thaliana, which is lacking of PsbS protein, to that of the wild type plants. We found that the PsbS protein appears to function not only in thermal dissipation in light via xanthophyll pigments, but also modified the allocation pattern of excitation energy absorbed in the PSII to PSII photochemistry (P), thermal dissipation in light (DL) and excess excitation (E)
Shape of an elastica under growth restricted by friction
We investigate the quasi-static growth of elastic fibers in the presence of
dry or viscous friction. An unusual form of destabilization beyond a critical
length is described. In order to characterize this phenomenon, a new definition
of stability against infinitesimal perturbations over finite time intervals is
proposed and a semi-analytical method for the determination of the critical
length is developed. The post-critical behavior of the system is studied by
using an appropriate numerical scheme based on variational methods. We find
post-critical shapes for uniformly distributed as well as for concentrated
growth and demonstrate convergence to a figure-8 shape for large lengths when
self-crossing is allowed. Comparison with simple physical experiments yields
reasonable accuracy of the theoretical predictions
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