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To assess the impact of a school start time (SST) delay on adolescent sleep health during the COVID-19 pandemic, and whether there were differences by learning modality. Data were collected from a longitudinal study evaluating sleep, education, and health among high school students in Georgia in 2020. Paired t-tests and multivariable linear regression analyses were conducted to examine changes in sleep duration and timing among 9th grade students (n = 134) and their association with the learning modality (remote vs. in-person learner). Students' school day wake times were 1.5 hours later, school night sleep duration was 1.2 hours longer, and social jetlag was 0.9 hours shorter after the school start time delay (all P <.05). The learning modality was a significant predictor of changes in sleep timing but was not associated with changes in sleep duration. Delayed school start time was associated with positive changes in adolescent sleep health during the COVID-19 pandemic. Sleep timing was affected by the learning modality, however in-person and virtual students had similar gains in sleep duration. Learning modality may be more beneficial for adolescents with early school start times to promote healthier sleep habits. [ABSTRACT FROM AUTHOR]

Manure is a leading source of methane (CH4), nitrous oxide (N2O), and ammonia (NH3) emissions, and alternative manure management practices can help society meet climate goals and mitigate air pollution. Recent studies show that biochar‐composting can substantially reduce emissions from manure. However, most studies test only one type of biochar applied at a single application rate, leading to high variation in emission reductions between studies. Here, we measured greenhouse gas and NH3 emissions during biochar‐composting of dairy manure with biochar applied at 5% or 20%, by mass, and made from walnut shells, almond shells, or almond clippings. We found little difference in emissions between biochar type. However, we found that the 20% application rates increased CH4 emissions and decreased N2O and NH3 emissions, resulting in a net reduction in global warming potential (GWP). We attribute this result to biochar increasing the formation of compost aggregates, which likely acted as anaerobic reactors for methanogenesis and complete denitrification. Biochar may have further fueled CH4 production and N2O consumption by acting as an electron shuttle within aggregates. We recommend lower application rates, as we found that the 5% treatments in our study led to a similar reduction in GWP without increasing CH4 emissions. [ABSTRACT FROM AUTHOR]