Fast simulation of Strehl loss due to phase aberration for the sizing of adaptive optics in laser communications system design.

An approximation is derived for the phase Strehl of an aberrated wavefront based on uncorrelated random variates. Eliminating the requirement to generate correlated variates offers an orders-of-magnitude improvement in simulation speed, while yielding accuracy that may be sufficient for the preliminary sizing of adaptive optics (AO) in laser communications system design. Examples are presented comparing the performance of several AO subsystem sizes when correcting a wavefront aberrated by Kolmogorov turbulence.

Hypokinesia and reduced dopamine levels in zebrafish lacking β- and γ1-synucleins.

α-Synuclein is strongly implicated in the pathogenesis of Parkinson disease. However, the normal functions of synucleins and how these relate to disease pathogenesis are uncertain. We characterized endogenous zebrafish synucleins in order to develop tractable models to elucidate the physiological roles of synucleins in neurons in vivo.

Evaluation of spontaneous propulsive movement as a screening tool to detect rescue of Parkinsonism phenotypes in zebrafish models.

Zebrafish models of human neuropsychiatric diseases offer opportunities to identify novel therapeutic targets and treatments through phenotype-based genetic or chemical modifier screens. In order to develop an assay to detect rescue of zebrafish models of Parkinsonism, we characterized spontaneous zebrafish larval motor behavior from 3 to 9 days post fertilization in a microtiter plate format suitable for screening, and clarified the role of dopaminergic signaling in its regulation. The proportion of time that larvae spent moving increased progressively between 3 and 9 dpf, whereas their active velocity decreased between 5 and 6 dpf as sporadic burst movements gave way to a more mature beat-and-glide pattern.

Automated measurement of zebrafish larval movement.

The zebrafish is a powerful vertebrate model that is readily amenable to genetic, pharmacological and environmental manipulations to elucidate the molecular and cellular basis of movement and behaviour. We report software enabling automated analysis of zebrafish movement from video recordings captured with cameras ranging from a basic camcorder to more specialized equipment. The software, which is provided as open-source MATLAB functions, can be freely modified and distributed, and is compatible with multiwell plates under a wide range of experimental conditions.