论专家证人渎职责任

在传统的做法中，基于证人豁免原则的保护，作为专家证人出庭作证的专业人士在审判中所提供的证言不受追究。而专家证人玩忽职守责任的理论又非常具有说服力，因此在实际中，出现了对传统的背离。一种关于专家证人渎职责任的理论可能正在形成。     

A sensory source for motor variation

Suppose that the variability in our movements is caused not by noise in the motor system itself, nor by fluctuations in our intentions or plans, but rather by errors in our sensory estimates of the external parameters that define the appropriate action. For tasks in which precision is at a premium, performance would be optimal if no noise were added in movement planning and execution: motor output would be as accurate as possible given the quality of sensory inputs. Here we use visually guided smooth-pursuit eye movements in primates as a testing ground for this notion of optimality. In response to repeated presentations of identical target motions, nearly 92% of the variance in eye trajectory can be accounted for as a consequence of errors in sensory estimates of the speed, direction and timing of target motion, plus a small background noise that is observed both during eye movements and during fixations. The magnitudes of the inferred sensory errors agree with the observed thresholds for sensory discrimination by perceptual systems, suggesting that the very different neural processes of perception and action are limited by the same sources of noise.     

Into the mind of a fly

Where do animal behaviours come from and are they controlled by genes? This is the fundamental question posed by the field of neurogenetics. Pioneering work from the 1960s in Seymour Benzer's laboratory demonstrated for the first time that Drosophila melanogaster fruitflies could be mutated to obtain animals with insomnia, learning disabilities and homosexual courtship behaviours.