Key Points Question What factors are associated with self-reported psychological distress among school-aged children and adolescents during the COVID-19 pandemic? Findings In this cross-sectional study including 1 199 320 children and adolescents, the prevalence of self-reported psychological distress was 10.5%. Students who never wore a face mask were at higher risk for psychological distress compared with students who wore a face mask frequently, as were students who spent less than 0.5 hours exercising compared with students who spent more than 1 hour in exercising. Meaning These findings suggest that the prevalence of self-reported psychological distress among school-aged children and adolescents during the COVID-19 pandemic was relatively high.

Elevated global temperatures and increased concentrations of carbon dioxide (CO2) in the atmosphere associated with climate change will exert profound effects on rice cropping systems, particularly on their greenhouse gas emitting potential. Incorporating biochar into paddy soil has been shown previously to reduce methane (CH4) emission from paddy rice under ambient temperature and CO2. We examined the ability of rice straw-derived biochar to reduce CH4 emission from paddy soil under elevated temperature and CO2 concentrations expected in the future. Adding biochar to paddy soil reduced CH4 emission under ambient conditions and significantly reduced emissions by 39.5% (ranging from 185.4 mg kg−1 dry weight soil, dws season−1 to 112.2 mg kg−1 dws season−1) under simultaneously elevated temperature and CO2. Reduced CH4 release was mainly attributable to the decreased activity of methanogens along with the increased CH4 oxidation activity and pmoA gene abundance of methanotrophs. Our findings highlight the valuable services of biochar amendment for CH4 control from paddy soil in a future that will be shaped by climate change.

As a potent greenhouse gas with a greenhouse warming potential 28 times that of carbon dioxide over a time scale of 100 years, methane has been proven to be useful as an electron donor for the removal of various contaminants, e.g., nitrate, nitrite, perchlorate, and chromate, from contaminated water. However, microbial bromate reduction supported by methane has not been reported so far. Here, a lab-scale membrane biofilm reactor (MBfR) was set up to explore the feasibility of bromate reduction driven by methane under oxygen-limiting conditions. Long-term operational performance demonstrated that a complete reduction of bromate (BrO 3 − ) to bromide (Br − ) could be achieved, with 100% bromate removal efficiency under a volume loading of 1 mg of Br L −1 day −1 . Volatile fatty acids (VFAs) were produced in the reactor (concentrations ranging from 1.81 to 27.9 mg/ L) under oxygen-limiting conditions. High-throughput 16S rRNA gene sequencing indicated that Methanosarcina became the only dominate methane-oxidizing microorganism, and the abundance of Dechloromonas increased from 0.9 to 18.0% after they had been fed bromate. It is hypothesized that under oxygen-limiting conditions methane is oxidized into VFAs, which might be used to reduce bromate by dissimilatory bromate-reducing bacteria (likely Dechloromonas). This study offers a potential technology for bromate removal using a methane-based MBfR.

Reduction in methane emissions to the Earth’s atmosphere is a critical strategy for tackling climate change. It is well established that anaerobic oxidation of methane (AOM) associated with sulfate reduction...

Anaerobic microorganisms are thought to play a critical role in regulating the flux of short-chain gaseous alkanes (SCGAs; including ethane, propane and butane) from terrestrial and aquatic ecosystems to the atmosphere. Sulfate has been confirmed to act as electron acceptor supporting microbial anaerobic oxidation of SCGAs, yet several other energetically more favourable acceptors co-exist with these gases in anaerobic environments. Here, we show that a bioreactor seeded with biomass from a wastewater treatment facility can perform anaerobic propane oxidation coupled to nitrate reduction to dinitrogen gas and ammonium. The bioreactor was operated for more than 1000 days, and we used 13C- and 15N-labelling experiments, metagenomic, metatranscriptomic, metaproteomic and metabolite analyses to characterize the microbial community and the metabolic processes. The data collectively suggest that a species representing a novel order within the bacterial class Symbiobacteriia is responsible for the observed nitrate-dependent propane oxidation. The closed genome of this organism, which we designate as ‘Candidatus Alkanivorans nitratireducens’, encodes pathways for oxidation of propane to CO2 via fumarate addition, and for nitrate reduction, with all the key genes expressed during nitrate-dependent propane oxidation. Our results suggest that nitrate is a relevant electron sink for SCGA oxidation in anaerobic environments, constituting a new microbially-mediated link between the carbon and nitrogen cycles.

Conversion of rice straw into biochar for soil amendment appears to be a promising method to increase long-term carbon sequestration and reduce greenhouse gas (GHG) emissions. The stability of biochar in paddy soil, which is the major determining factor of carbon sequestration effect, depends mainly on soil properties and plant functions. However, the influence of plants on biochar stability in paddy soil remains unclear. In this study, bulk and surface characteristics of the biochars incubated without rice plants were compared with those incubated with rice plants using a suite of analytical techniques. Results showed that although rice plants had no significant influence on the bulk characteristics and decomposition rates of the biochar, the surface oxidation of biochar particles was enhanced by rice plants. Using 13C labeling we observed that rice plants could significantly increase carbon incorporation from biochar into soil microbial biomass. About 0.047% of the carbon in biochar was incorporated into the rice plants during the whole rice growing cycle. These results inferred that root exudates and transportation of biochar particles into rice plants might decrease the stability of biochar in paddy soil. Impact of plants should be considered when predicting carbon sequestration potential of biochar in soil systems.

Understanding the recovery of anaerobic ammonium-oxidizing (anammox) bacteria after inhibition by dissolved oxygen (DO) is critical for the successful applications of anammox-based processes. Therefore, the effects of oxygen exposure (2 mg L –1 DO for 90 min) and subsequent recovery treatments [N2 purging or nano zero-valent iron (nZVI) addition] on the activity and gene expression in a Kuenenia stuttgartiensis enrichment culture were examined. Combining the self-organizing map clustering and enrichment analysis, we proposed the oxidative stress response of anammox bacteria based on the existing concepts of oxidative stress in microbes: the DO exposure triggered a stringent response in K. stuttgartiensis, which downregulated the transcription levels of genes involved in the central metabolism and diverted energy to a flagellar assembly and metal transport modules; these changes possibly promoted survival during the inhibition of anammox activity. According to the cotranscription with central catabolism genes, putative reactive oxygen species (ROS) scavenger genes (kat and sod) were presumed to detoxify the anammox intermediates rather than ROS. In addition, both activity and mRNA profiles with appropriate amount of nZVI addition (5 and 25 mg L–1) were close to that of control, which proved the effectiveness of nZVI addition in anammox recovery. These results would be relevant to the physio-biochemistry development of anammox bacteria and further enhancement of nitrogen removal in wastewater treatment.

No abstract