Millimeter interferometry provides evidence for the presence of mm to cm size ‘pebbles’ in the outer parts of disks around pre-main-sequence stars. The observations suggest that large grains are produced relatively early in disk evolution (< 1 Myr) and remain at large radii for longer periods of time (5 to 10 Myr). Simple theoretical estimates of the radial drift time of solid particles, howeve...

Elevated levels of genetic drift are hypothesized to be a dominant factor that influences genome size evolution across all life-forms. However, increased levels of drift appear to be correlated with genome expansion in eukaryotes but with genome contraction in bacteria, suggesting that these two groups of organisms experience vastly different mutational inputs and selective constraints. To dete...

Experiments have been carried out on the properties of a hollow cathode as an ion-source. The measured electron density, ion and neutral temperatures and drift velocities have been compared with predictions from the conservation laws for matter, momentum and energy. Very large exit drift velocities of ions and neutrals are observed. The magnitude and direction, against the electric field, can b...

Spray drift is one of the main sources of pesticide contamination. For this reason, an accurate understanding of this phenomenon is necessary in order to limit its effects. Nowadays, spray drift is usually studied by using in situ collectors which only allow time-integrated sampling of specific points of the pesticide clouds. Previous research has demonstrated that the light detection and rangi...

Within populations, the stochastic effect of genetic drift and deterministic effect of natural selection are potentially weakened or altered by gene flow among populations. The influence of gene flow on Lake Erie populations of the common garter snake has been of particular interest because of a discontinuous colour pattern polymorphism (striped vs. melanistic) that is a target of natural selec...

In order to evaluate new types of sensors based on the eld-e ect transistor technology, a cost-e ective measurement and control system is developed. Because some new types of transistor-based sensors are particularly prone to drift and noise, a measurement system is built around evaluating the e ect of a biasing technique known as switched biasing, which has been shown to reduce drift under cer...

Transmembrane voltage-sensitive fluorescence measurements are limited by baseline drift that can obscure changes in resting membrane potential and by motion artifacts that can obscure repolarization. Voltage-dependent shift of emission wavelengths may allow reduction of drift and motion artifacts by emission ratiometry. We have tested this for action potentials and potassium-induced changes in ...