Person:

Stokes, Chris

Much remains unknown about how the nervous system of an animal generates behaviour, and even less is known about the evolution of behaviour. How does evolution alter existing behaviours or invent novel ones? Progress in computational techniques and equipment will allow these broad, complex questions to be explored in great detail. Here we present a method for tracking each leg of a fruit fly behaving spontaneously upon a trackball, in real time. Legs were tracked with infrared-fluorescent dyes invisible to the fly, and compatible with two-photon microscopy and controlled visual stimuli. We developed machine-learning classifiers to identify instances of numerous behavioural features (for example, walking, turning and grooming), thus producing the highest-resolution ethological profiles for individual flies.

Utilizing solar energy to fix carbon dioxide (CO2) with water into chemical fuels and oxygen, a mimic process of photosynthesis in nature, is becoming increasingly important but still challenged by the low selectivity and activity, especially in CO2 electrocatalytic reduction. Here we report transition metal atoms coordinated in graphene shell as active centers for aqueous CO2 reduction to carbon monoxide (CO), with high Faradaic efficiencies over 90 % under significant currents up to ~ 60 mA/mg (12 mA/cm2). Three-dimensional atom probe tomography was employed to directly identify the single Ni atomic sites in graphene vacancies. Theoretical simulations suggest that compared to metallic Ni, the Ni atomic sites present significantly different electronic structures which facilitate CO2 to CO conversion and suppress the competing hydrogen evolution reaction dramatically.