Benthic primary production decreases internal phosphorus loading from lake sediments under light supplement.

In aquatic ecosystems, light penetrating the sediment surface in shallow lakes may regulate the internal phosphorus (P) release through benthic primary production, which subsequently affects oxidation, pH levels, and alkaline phosphatase activity in the upper sediment. To study the effects of light exposure on the P dynamics at the sediment-water interface under eutrophic conditions, a two-month mesocosm experiment was conducted in twelve cement tanks (1000 L each). The tanks were equipped with Light-Emitting Diode (LED) lights, and surface sediments collected from eutrophic Lake Nanhu (China) were exposed to four different light intensities (0, 50, 100, 200 μmol m s).

Allergic airway inflammation is differentially exacerbated by daytime and nighttime ultrafine and submicron fine ambient particles: heme oxygenase-1 as an indicator of PM-mediated allergic inflammation.

Ambient particulate matter (PM) originates from a range of sources and differs in composition with respect to season, time of day, and particle size. In this study, ambient PM samples in the ultrafine and submicrometer fine range were tested for the potential to exacerbate a murine model of allergic airway inflammation when exposure occurs solely during allergic sensitization, but not during subsequent allergen challenge. Temporally resolved and size-segregated PM samples were used to understand how summer or winter, day or night, and ambient ultrafine and submicrometer fine particle size influence PM's ability to exacerbate allergic inflammation.