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Main effect models contend that perceived social support benefits mental health in the presence and the absence of stressful events, whereas stress-buffering models contend that perceived social support benefits mental health especially when individuals are facing stressful events. We tested these models of how perceived social support impacts mental health during the COVID-19 pandemic and evaluated whether characteristics of everyday social interactions statistically mediated this association – namely, (a) received support, the visible and deliberate assistance provided by others, and (b) pleasantness, the extent to which an interaction is positive, flows easily, and leads individuals to feel understood and validated. 591 United States adults completed a 3-week ecological momentary assessment protocol sampling characteristics of their everyday social interactions that was used to evaluate between-person average values and within-person daily fluctuations in everyday social interaction characteristics. Global measures of perceived social support and pandemic-related stressors were assessed at baseline. Psychiatric symptoms of depression and anxiety were assessed at baseline, at the end of each day of ecological momentary assessment, and at 3-week follow-up. Consistent with a main effect model, higher baseline perceived social support predicted decreases in psychiatric symptoms at 3-week follow-up (β = −.09, p = .001). Contrary to a stress-buffering model, we did not find an interaction of pandemic-stressors × perceived social support. The main effect of perceived social support on mental health was mediated by the pleasantness of everyday social interactions, but not by received support in everyday social interactions. We found evidence for both main effects and stress-buffering effects of within-person fluctuations in interaction pleasantness on daily changes in mental health. Results suggest the importance of everyday social interaction characteristics, especially their pleasantness, in linking perceived social support and mental health.

Widespread polybrominated diphenyl ethers (PBDEs) contamination poses risks to human health and ecosystems. Bioremediation is widely considered to be a less ecologically disruptive strategy for remediation of organohalide contamination, but bioremediation of PBDE-contaminated sites is limited by a lack of knowledge about PBDE-dehalogenating microbial populations. Here we report anaerobic PBDE debromination in microcosms established from geographically distinct e-waste recycling sites. Complete debromination of a penta-BDE mixture to diphenyl ether was detected in 16 of 24 investigated microcosms; further enrichment of these 16 microcosms implicated microbial populations belonging to the bacterial genera Dehalococcoides, Dehalogenimonas, and Dehalobacter in PBDE debromination. Debrominating microcosms tended to contain either both Dehalogenimonas and Dehalobacter or Dehalococcoides alone. Separately, complete debromination of a penta-BDE mixture was also observed by axenic cultures of Dehalococcoides mccartyi strains CG1, CG4, and 11a5, suggesting that this phenotype may be fairly common amongst Dehalococcoides. PBDE debromination in these isolates was mediated by four reductive dehalogenases not previously known to debrominate PBDEs. Debromination of an octa-BDE mixture was less prevalent and less complete in microcosms. The PBDE reductive dehalogenase homologous genes in Dehalococcoides genomes represent plausible molecular markers to predict PBDE debromination in microbial communities via their prevalence and transcriptions analysis.

Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are notorious persistent organic pollutants. However, few organohalide-respiring bacteria that harbor reductive dehalogenases (RDases) capable of dehalogenating these pollutants have been identified. Here, we report reductive dehalogenation of penta-BDEs and PCBs by

The challenge of discriminating between phylogenetically similar but functionally distinct bacterial lineages is particularly relevant to the development of technologies seeking to exploit the metabolic or physiological characteristics of specific members of bacterial genera. A computational approach was developed to expedite screening of potential genetic markers among phylogenetically affiliated bacteria.

As a group, the genus Dehalococcoides dehalogenates a wide range of organohalide pollutants, but the range of organohalide compounds that can be utilized for reductive dehalogenation differs among Dehalococcoides strains. Dehalococcoides lineages cannot be reliably disambiguated in mixed communities using typical phylogenetic markers, which often confounds bioremediation efforts. Here, we describe a computational approach to identify Dehalococcoides genetic markers with improved discriminatory resolution. Screening core genes from the Dehalococcoides pangenome for degree of similarity and frequency of 100% identity found a candidate genetic marker encoding a bacterial neuraminidase repeat (BNR)-containing protein of unknown function. This gene exhibits the fewest completely identical amino acid sequences and has among the lowest average amino acid sequence identity in the core pangenome. Primers targeting BNR could effectively discriminate between 40 available BNR sequences (in silico) and 10 different Dehalococcoides isolates (in vitro). Amplicon sequencing of BNR fragments generated from 22 subsurface soil samples revealed a total of 109 amplicon sequence variants, suggesting a high diversity of Dehalococcoides distributed in the environment. Therefore, the BNR gene can serve as an alternative genetic marker to differentiate strains of Dehalococcoides in complicated microbial communities. IMPORTANCE The challenge of discriminating between phylogenetically similar but functionally distinct bacterial lineages is particularly relevant to the development of technologies seeking to exploit the metabolic or physiological characteristics of specific members of bacterial genera. A computational approach was developed to expedite screening of potential genetic markers among phylogenetically affiliated bacteria. Using this approach, a gene encoding a bacterial neuraminidase repeat (BNR)-containing protein of unknown function was selected and evaluated as a genetic marker to differentiate strains of Dehalococcoides, an environmentally relevant genus of bacteria whose members can transform and detoxify a range of halogenated organic solvents and persistent organic pollutants, in complex microbial communities to demonstrate the validity of the approach. Moreover, many apparently phylogenetically distinct, currently uncharacterized Dehalococcoides were detected in environmental samples derived from contaminated sites.

Polybrominated diphenyl ethers (PBDEs), commonly used as flame retardants in a wide variety of consumer products, are emerging persistent pollutants and ubiquitously distributed in the environment. The lack of proper bacterial populations to detoxify these recalcitrant pollutants, in particular of higher brominated congeners, has confounded the attempts to bioremediate PBDE-contaminated sites. In this study, we report a

As a potent atmospheric greenhouse gas and a major source of ozone depletion, nitrous oxide (N

Polybrominated diphenyl ethers (PBDEs) are persistent, highly toxic, and widely distributed environmental pollutants. The microbial populations and functional reductive dehalogenases (RDases) responsible for PBDE debromination in anoxic systems remain poorly understood, which confounds bioremediation of PBDE-contaminated sites. Here, we report a PBDE-debrominating enrichment culture dominated by a previously undescribed Dehalococcoides mccartyi population. A D. mccartyi strain, designated TZ50, whose genome contains 25 putative RDase-encoding genes, was isolated from the debrominating enrichment culture. Strain TZ50 dehalogenated a mixture of pentabrominated diphenyl ether (penta-BDE) and tetra-BDE congeners (total BDEs, 1.48 μM) to diphenyl ether within 2 weeks (0.58 μM Br-/day) via ortho- and meta-bromine elimination; strain TZ50 also dechlorinated tetrachloroethene (PCE) to vinyl chloride and ethene (260.2 μM Cl-/day). Results of native PAGE, proteomic profiling, and in vitro enzymatic activity assays implicated the involvement of three RDases in PBDE and PCE dehalogenation. TZ50_0172 (PteATZ50) and TZ50_1083 (TceATZ50) were responsible for the debromination of penta- and tetra-BDEs to di-BDE. TZ50_0172 and TZ50_1083 were also implicated in the dechlorination of PCE to trichloroethene (TCE) and of TCE to vinyl chloride/ethene, respectively. The other expressed RDase, TZ50_0090 (designated BdeA), was associated with the debromination of di-BDE to diphenyl ether, but its role in PCE dechlorination was unclear. Comparatively few RDases are known to be involved in PBDE debromination, and the identification of PteATZ50, TceATZ50, and BdeA provides additional information for evaluating debromination potential at contaminated sites. Moreover, the ability of PteATZ50 and TceATZ50 to dehalogenate both PBDEs and PCE makes strain TZ50 a suitable candidate for the remediation of cocontaminated sites. IMPORTANCE The ubiquity, toxicity, and persistence of polybrominated diphenyl ethers (PBDEs) in the environment have drawn significant public and scientific interest to the need for the remediation of PBDE-contaminated ecosystems. However, the low bioavailability of PBDEs in environmental compartments typically limits bioremediation of PBDEs and has long impeded the study of anaerobic microbial PBDE removal. In the current study, a novel Dehalococcoides mccartyi strain, dubbed strain TZ50, that expresses RDases that mediate organohalide respiration of both PBDEs and chloroethenes was isolated and characterized. Strain TZ50 could potentially be used to remediate multiple cooccurring organohalides in contaminated systems.

Denitrification process in agricultural fields is a large source of nitrous oxide (N2O) emitted to the atmosphere. The rhizosphere soils tend to be the hotspots of denitrification in agricultural soils. Recent studies have reported the important role of nosZ II in eliminating N2O. However, little was known about how these more recently discovered N2O-reducing microorganisms together with other N2O-producers affected the N2O emission in agricultural rhizosphere soils. Here, we compared the potential N2O production rate, the denitrification end-product ratio, and the denitrifier communities between rhizosphere and non-rhizosphere soils of two types of crops in winter and summer. The potential activities were measured by acetylene inhibition technique. QPCR analysis was used to quantify the functional genes. High-throughput sequencing and clone library were conducted to analyze the community structure of denitrifiers. The rhizosphere soils had a higher N2O production potential but lower denitrification end-product ratio (N2O/(N2O+N2)) than the non-rhizosphere soils. The potential N2O production rate was correlated to the nirS-bacteria abundance, especially in terms of the genus Azospirillum. The N2O/(N2O+N2) ratio showed a negative correlation with both the diversity and abundance of the nosZ II-type N2O-reducers. Altogether, we propose that nirS-type N2O-producers and nosZ II-type N2O-reducers can affect the N2O emission in agricultural rhizosphere soils, and enhancement of diversity and abundance of nosZ II-type N2O-reducers may help with the N2O mitigation from upland crops.

To quickly and accurately measure psychological well-being has been a challenging task. Traditionally, this is done with self-report surveys, which can be time-consuming and burdensome. In this work, we demonstrate the use of short voice recordings on smartphones to automatically predict well-being. In a 5-day study, 35 participants used their smartphones to make short voice recordings of what they were doing throughout the day. Using these recordings, our model can predict the participants’ well-being scores with a mean absolute error of 14%, relative to the self-reported well-being (“ground truth”). Both audio and text features from the recordings, especially, MFCC and semantic features, are important for prediction accuracy. Based on the work, we provide suggestions for future research to further improve the prediction result.

Halogenated flame retardants (HFRs) have been extensively used in various consumer products and many are classified as persistent organic pollutants due to their resistance to degradation, bioaccumulation potential and toxicity. HFRs have been widely detected in the municipal wastewater and wastewater treatment solids in wastewater treatment plants (WWTPs), the discharge and agricultural application of which represent a primary source of environmental HFRs contamination. This review seeks to provide a current overview on the occurrence, fate, and impacts of HFRs in WWTPs around the globe. We first summarize studies recording the occurrence of representative HFRs in wastewater and wastewater treatment solids, revealing temporal and geographical trends in HFRs distribution. Then, the efficiency and mechanism of HFRs removal by biosorption, which is known to be the primary process for HFRs removal from wastewater, during biological wastewater treatment processes, are discussed. Transformation of HFRs via abiotic and biotic processes in laboratory tests and full-scale WWTPs is reviewed with particular emphasis on the transformation pathways and functional microorganisms responsible for HFRs biotransformation. Finally, the potential impacts of HFRs on reactor performance (i.e., nitrogen removal and methanogenesis) and microbiome in bioreactors are discussed. This review aims to advance our understanding of the fate and impacts of HFRs in WWTPs and shed light on important questions warranting further investigation.

Mingming Zhai,1,* Xi Yan,2,* Jiangzheng Liu,3 Zi Long,3 Siyan Zhao,4 Wendan Li,4 Ying Liu,4 Chunxu Hai3 1Department of Biomedical Engineering, Air Force Medical University, Xi’an, People’s Republic of China; 2Department of Dermatology, The Second Affiliated Hospital, Air Force Medical University, Xi’an, People’s Republic of China; 3Department of Toxicology, Shanxi Provincial Key Lab of Free Radical Biology and Medicine, Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Air Force Medical University, Xi’an, People’s Republic of China; 4Institute of Nuclear Biological and Chemical Defence, Beijing, People’s Republic of China*These authors contributed equally to this workCorrespondence: Chunxu HaiAir Force Medical University (AFMU), No. 169 Changle West Road, Xi’an, Shaanxi, 710032, People’s Republic of ChinaTel +86-29-84774879Email cx-hai@fmmu.edu.cnYing LiuInstitute of Nuclear Biological and Chemical Defence, No. 1, Yangfang Zhongxin North Street, Beijing, 102205, People’s Republic of ChinaEmail liuyinglyzy@163.comPurpose: The prevalence of nonalcoholic fatty liver disease (NAFLD), which has recently become known as metabolic-associated fatty liver disease (MAFLD), has risen. However, pharmacotherapies for this disease have not been approved. Electromagnetic fields (EMFs) have excellent bioeffects on multiple diseases. However, the effects of EMFs on NAFLD are unknown. This study investigated the bioeffects of EMF exposure on insulin resistance, liver redox homeostasis and hepatic steatosis in db/db mice.Methods: Animals were sacrificed after EMF exposure for 8 weeks. The fasting blood glucose and insulin levels in the serum were tested. The homeostatic model assessment of insulin resistance (HOMA-IR) was calculated by a formula. The levels of MDA, GSSG and GSH, biomarkers of redox, were assessed. The activities of CAT, SOD and GSH-Px were assessed. The body and liver weights were measured. Hepatic lipid accumulation was observed by Oil Red O staining. Hepatic CAT, GR, GSH-Px, SOD1, SOD2 and SREBP-1 expression was determined by Western blotting.Results: EMF exposure ameliorated insulin resistance and oxidative stress in the liver by downregulating the MDA and GSSG levels, increasing the reduced GSH levels, and promoting the GSH-Px levels in db/db mice. In addition, liver weight and triglyceride (TG) levels were reduced by EMF exposure. Simultaneously, EMF exposure improved hepatic steatosis by downregulating the protein expression of SREBP-1c.Conclusion: The present findings suggest that EMF exposure has positive effects in the treatment of NAFLD.Keywords: nonalcoholic fatty liver disease, electromagnetic fields, hepatic steatosis, oxidative stress, insulin resistance

Fluoroquinolone antibiotics like ofloxacin (OFL) have been frequently detected in the aquatic environment. Recently manganese-oxidizing bacteria (MOB) have attracted research efforts on the degradation of recalcitrant pollutants with the aid of their biogenic manganese oxides (BioMnOx). Herein, the degradation of OFL with a strain of MOB (Pseudomonas sp. F2) was investigated for the first time. It was found that the bacteria can degrade up to 100% of 5 μg/L OFL. BioMnOx and Mn(III) intermediates significantly contributed to the degradation. Moreover, the degradation was clearly declined when the microbial activity was inactivated by heat or ethanol, indicating the importance of bioactivity. Possible transformation products of OFL were identified by HPLC-MS and the degradation pathway was proposed. In addition, the toxicity of OFL was reduced by 66% after the degradation.