Self-incompatibility is a widespread mechanism in flowering plants that prevents inbreeding and promotes outcrossing. The self-incompatibility response is genetically controlled by one or more ...multi-allelic loci, and relies on a series of complex cellular interactions between the self-incompatible pollen and pistil. Although self-incompatibility functions ultimately to prevent self-fertilization, flowering plants have evolved several unique mechanisms for rejecting the self-incompatible pollen. The self-incompatibility system in the Solanaceae makes use of a multi-allelic RNase in the pistil to block incompatible pollen tube growth. In contrast, the Papaveraceae system appears to have complex cellular responses such as calcium fluxes, actin rearrangements, and programmed cell death occurring in the incompatible pollen tube. Finally, the Brassicaceae system has a receptor kinase signalling pathway activated in the pistil leading to pollen rejection. This review highlights the recent advances made towards understanding the cellular mechanisms involved in these self-incompatibility systems and discusses the striking differences between these systems.
Self-incompatibility, the rejection of serf pollen, is the most widespread mechanism by which flowering plants prevent inbreeding. In Brassica, the S receptor kinase (SRK) has been implicated in the ...self-incompatibility response, but the molecular mechanisms involving SRK are unknown. One putative downstream effector for SRK is ARC1, a protein that binds to the SRK kinase domain. Here it is shown that suppression of ARC1 messenger RNA levels in the self-incompatible Brassica napus W1 line is correlated with a partial breakdown of selfincompatibility, resulting in seed production. This provides strong evidence that ARC1 is a positive effector of the Brassica self-incompatibility response.
The data processing required to extract long waves from tide-gauge data is described and applied to three diverse but typical examples: meteorologically generated long waves (rissaga), far ...infragravity waves, and tsunami. The steps are: detiding, despiking, degapping, high-pass filtering, and denoising. Orthogonal wavelet decomposition is used for despiking, high-pass filtering, and denoising. This has the advantage that it can be used for nonstationary data such as rissaga and tsunami because the basis function (the mother wavelet) is localized. The long-wave extraction method has evolved from development of real-time systems for monitoring long waves for navigation purposes. Using the technique, there are hundreds of modern tide gauges around the world (every major port has one) whose data could be used to monitor long waves that affect navigation and cause a hazard.
A simple technique to reduce the Doppler noise influence on measurements of turbulence using the Acoustic Doppler Velocimeter (ADV) is developed, and basic relationships to estimate turbulence ...characteristics using information about the Doppler noise are derived. The procedure involves, firstly, measurement of instantaneous velocities in the flow under consideration; secondly, measurement of the Doppler noise components in still water taken from the flow investigated (with the same velocity range setting that was used in turbulence measurements); and thirdly, estimation of turbulence characteristics using both sets of measurements and relationships developed in the paper. The technique was tested for three typical environments (water storage basin with silty water, laboratory flume with water containing seeding material of neutrally buoyant hollow glass spheres with a mean size around 8-10 m, and outdoor flume with natural water containing air bubbles and organic particles). It was shown that the Doppler noise can change the measured turbulence characteristics significantly, even for high-level turbulence flows.
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