Linking Light Exposure and Subsequent Sleep: A Field Polysomnography Study in Humans.

Study Objectives: To determine the effect of light exposure on subsequent sleep characteristics under ambulatory field conditions.

Methods: Twenty healthy participants were fitted with ambulatory polysomnography (PSG) and wrist-actigraphs to assess light exposure, rest-activity, sleep quality, timing, and architecture. Laboratory salivary dim-light melatonin onset was analyzed to determine endogenous circadian phase.

Resource pulses can alleviate the biodiversity-invasion relationship in soil microbial communities.

The roles of species richness, resource use, and resource availability are central to many hypotheses explaining the diversity-invasion phenomenon but are generally not investigated together. Here, we created a large diversity gradient of soil microbial communities by either assembling communities of pure bacterial strains or removing the diversity of a natural soil. Using data on the resource-use capacities of the soil communities and an invader that were gathered from 71 carbon sources, we quantified the niches available to both constituents by using the metrics community niche and remaining niche available to the invader.