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1.
Int J Mol Sci ; 25(11)2024 May 31.
Article in English | MEDLINE | ID: mdl-38892238

ABSTRACT

Flavonoids are secondary metabolites that play important roles in the resistance of plants to abiotic stress. Despite the widely reported adverse effects of lead (Pb) contamination on maize, the effects of Pb on the biosynthetic processes of flavonoids in maize roots are still unknown. In the present work, we employed a combination of multi-omics and conventional assay methods to investigate the effects of two concentrations of Pb (40 and 250 mg/kg) on flavonoid biosynthesis in maize roots and the associated molecular regulatory mechanisms. Analysis using conventional assays revealed that 40 and 250 mg/kg Pb exposure increased the lead content of maize root to 0.67 ± 0.18 mg/kg and 3.09 ± 0.02 mg/kg, respectively, but they did not result in significant changes in maize root length. The multi-omics results suggested that exposure to 40 mg/kg of Pb caused differential expression of 33 genes and 34 metabolites related to flavonoids in the maize root system, while 250 mg/kg of Pb caused differential expression of 34 genes and 31 metabolites. Not only did these differentially expressed genes and metabolites participate in transferase activity, anthocyanin-containing compound biosynthetic processes, metal ion binding, hydroxyl group binding, cinnamoyl transferase activity, hydroxycinnamoyl transferase activity, and flavanone 4-reductase activity but they were also significantly enriched in the flavonoid, isoflavonoid, flavone, and flavonol biosynthesis pathways. These results show that Pb is involved in the regulation of maize root growth by interfering with the biosynthesis of flavonoids in the maize root system. The results of this study will enable the elucidation of the mechanisms of the effects of lead on maize root systems.


Subject(s)
Flavonoids , Gene Expression Regulation, Plant , Lead , Plant Roots , Stress, Physiological , Transcriptome , Zea mays , Zea mays/genetics , Zea mays/metabolism , Zea mays/drug effects , Zea mays/growth & development , Flavonoids/biosynthesis , Flavonoids/metabolism , Plant Roots/metabolism , Plant Roots/genetics , Plant Roots/drug effects , Plant Roots/growth & development , Lead/toxicity , Lead/metabolism , Gene Expression Regulation, Plant/drug effects , Stress, Physiological/genetics , Metabolomics/methods , Metabolome/drug effects , Gene Expression Profiling/methods , Plant Proteins/genetics , Plant Proteins/metabolism
2.
J Environ Manage ; 353: 120244, 2024 Feb 27.
Article in English | MEDLINE | ID: mdl-38335599

ABSTRACT

On a global scale, the restoration of metal mine ecosystem functions is urgently required, and soil microorganisms play an important role in this process. Conventional studies frequently focused on the relationship between individual functions and their drivers; however, ecosystem functions are multidimensional, and considering any given function in isolation ignores the trade-offs and interconnectedness between functions, which complicates obtaining a comprehensive understanding of ecosystem functions. To elucidate the relationships between soil microorganisms and the ecosystem multifunctionality (EMF) of metal mines, this study investigated natural restoration of metal mines, evaluated the EMF, and used high-throughput sequencing to explore the bacterial and fungal communities as well as their influence on EMF. Bacterial community diversity and composition were more sensitive to mine restoration than fungal community. Bacterial diversity exhibited redundancy in improving N-P-K-S multifunctionality; however, rare bacterial taxa including Dependentiae, Spirochaetes, and WPS-2 were important for metal multifunctionality. Although no clear relationship between fungal diversity and EMF was observed, the abundance of Glomeromycota had a significant effect on the three EMF categories (N-P-K-S, carbon, and metal multifunctionality). Previous studies confirmed a pronounced positive association between microbial diversity and multifunctionality; however, the relationship between microbial diversity and multifunctionality differs among functions' categories. In contrast, the presence of critical microbial taxa exerted stronger effects on mine multifunctionality.


Subject(s)
Ecosystem , Microbiota , Soil , Soil Microbiology , Bacteria/genetics , Metals
3.
Sci Total Environ ; 920: 171018, 2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38378054

ABSTRACT

The mechanism through which soil microorganisms mediate carbon and nutrient cycling during mine wasteland restoration remained unknown. Using soil metagenome sequencing, we investigated the dynamic changes in soil microbial potential metabolic functions during the transition from biological soil crusts (BSC) to mixed broad-conifer forest (MBF) in a typical PbZn mine. The results showed soil microorganisms favored carbon sequestration through anaerobic and microaerobic pathways, predominantly using efficient, low-energy pathways during succession. Genes governing carbon degradation and aerobic respiration increased by 19.56 % and 24.79 %, respectively, reflecting change toward more efficient and intensive soil carbon utilization in late succession. Nitrogen-cycling genes mediated by soil microorganisms met their maximum influence during early succession (sparse grassland, SGL), leading to a respective increase of 75.29 % and 76.81 % in the net potential nitrification rate and total nitrogen content. Mantel and correlation analyses indicated that TOC, TN, Zn and Cd contents were the main factors affecting the soil carbon and phosphorus cycles. Soil AP content emerged as the primary influencer of genes associated with the nitrogen cycle. These results shed light on the dynamic shifts in microbial metabolic activities during succession, providing a genetic insight into biogeochemical cycling mechanisms and underscoring crucial factors influencing soil biogeochemical processes in mining regions.


Subject(s)
Nitrogen , Soil , Soil/chemistry , Nitrogen/analysis , Carbon/analysis , Phosphorus , Forests , Soil Microbiology
4.
Environ Sci Pollut Res Int ; 31(2): 1941-1953, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38044401

ABSTRACT

The combination of biochar and bacteria is a promising strategy for the remediation of Cd-polluted soils. However, the synergistic mechanisms of biochar and bacteria for Cd immobilization remain unclear. In this study, the experiments were conducted to evaluate the effects of the combination of biochar and Pseudomonas sp. AN-B15, on Cd immobilization, soil enzyme activity, and soil microbiome. The results showed that biochar could directly reduce the motility of Cd through adsorption and formation of CdCO3 precipitates, thereby protecting bacteria from Cd toxicity in the solution. In addition, bacterial growth further induces the formation of CdCO3 and CdS and enhances Cd adsorption by bacterial cells, resulting in a higher Cd removal rate. Thus, bacterial inoculation significantly enhances Cd removal in the presence of biochar in the solution. Moreover, soil incubation experiments showed that bacteria-loaded biochar significantly reduced soil exchangeable Cd in comparison with other treatments by impacting soil microbiome. In particular, bacteria-loaded biochar increased the relative abundance of Bacillus, Lysobacter, and Pontibacter, causing an increase in pH, urease, and arylsulfatase, thereby passivating soil exchangeable Cd and improving soil environmental quality in the natural alkaline Cd-contaminated soil. Overall, this study provides a systematic understanding of the synergistic mechanisms of biochar and bacteria for Cd immobilization in soil and new insights into the selection of functional strain for the efficient remediation of the contaminated environments by bacterial biochar composite.


Subject(s)
Cadmium , Soil Pollutants , Cadmium/analysis , Soil Pollutants/analysis , Charcoal , Soil , Bacteria
5.
Ecotoxicol Environ Saf ; 266: 115527, 2023 Nov 01.
Article in English | MEDLINE | ID: mdl-37806135

ABSTRACT

Understanding Cd-resistant bacterial cadmium (Cd) resistance systems is crucial for improving microremediation in Cd-contaminated environments. However, these mechanisms are not fully understood in plant-associated bacteria. In the present study, we investigated the mechanisms underlying Cd sequestration and resistance in the strain AN-B15. These results showed that extracellular Cd sequestration by complexation in strain AN-B15 was primarily responsible for the removal of Cd from the solution. Transcriptome analyses have shown that the mechanisms of Cd resistance at the transcriptional level involve collaborative processes involving multiple metabolic pathways. The AN-B15 strain upregulated the expression of genes related to exopolymeric substance synthesis, metal transport, Fe-S cluster biogenesis, iron recruitment, reactive oxygen species oxidative stress defense, and DNA and protein repair to resist Cd-induced stress. Furthermore, inoculation with AN-B15 alleviated Cd-induced toxicity and reduced Cd uptake in the shoots of wheat seedlings, indicating its potential for remediation. Overall, the results improve our understanding of the mechanisms involved in Cd resistance in bacteria and thus have important implications for improving microremediation.


Subject(s)
Cadmium , Soil Pollutants , Cadmium/metabolism , Pseudomonas/genetics , Pseudomonas/metabolism , Seedlings/metabolism , Iron/metabolism , Oxidative Stress , Bacteria/metabolism , Soil Pollutants/analysis , Plant Roots/metabolism
6.
Sci Total Environ ; 904: 166871, 2023 Dec 15.
Article in English | MEDLINE | ID: mdl-37683844

ABSTRACT

The drivers and mechanisms underlying succession and the spontaneous formation of plant communities in mining wasteland remain largely unknown. This study investigated the use of nature-based restoration to facilitate the recovery of viable plant communities in mining wasteland. It was found that scientific analyses of spontaneously formed plant communities in abandoned mining areas can provide insights for nature-based restoration. A chronosequence ("space for time") approach was used to establish sites representing three successional periods with six successional stages, and 90 quadrats were constructed to investigate changes in plant species and functional diversity during succession in abandoned PbZn mining areas. A total of 140 soil samples were collected to identify changes in soil properties, including plant nutrient and heavy metal concentrations. Then, this paper used structural equation models to analyze the mechanisms that drive succession. It was found that the functional diversity of plant communities fluctuated substantially during succession. Species had similar functional traits in early and mid-succession, but traits tended to diverge during late succession. Soil bulk density and soil organic matter gradually increased during succession. Total nitrogen (N), pH, and soil Zn concentrations first increased and then decreased during succession. Concentrations of Mn and Cd gradually decreased during succession. During early succession, soil organic matter was the key factor driving plant colonization and succession. During mid-succession, soil Zn functioned as an environmental filter factor limiting the rates of succession in mining wasteland communities. During late succession, soil bulk density and competition for nutrient resources contributed to more balanced differentiation among plant species. This thesis proposed that a nature-based strategy for the stabilization of abandoned mining lands could facilitate effective plant community restoration that promotes ecosystem services and functioning.


Subject(s)
Ecosystem , Metals, Heavy , China , Metals, Heavy/analysis , Plants , Soil/chemistry
7.
Chemosphere ; 340: 139770, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37562505

ABSTRACT

Globally, reducing carbon emissions and mitigating soil heavy metal pollution pose pressing challenges. We evaluated the effects of lead (Pb) and cadmium (Cd) contamination in the field over 20 years. The five treatment groups featured Pb concentrations of 40 and 250 mg/kg, Cd concentrations of 10 and 60 mg/kg, and a combination of Pb and Cd (60 and 20 mg/kg, respectively); we also included a pollution-free control group. After 20 years, soil pH decreased notably in all treatments, particularly by 1.02 in Cd10-treated soil. In addition to the increase of SOC in Cd10 and unchanged in Pb40 treatment, the SOC was reduced by 9.62%-12.98% under the other treatments. The α diversities of bacteria and fungi were significantly changed by Cd10 pollution (both p < 0.05) and the microbial community structure changed significantly. However, there were no significant changes in bacterial and fungal communities under other treatments. Cd10 pollution reduced the numbers of Ascomycota and Basidiomycota fungi, and enhanced SOC accumulation. Compared to the control, long-term heavy Cd, Pb, and Pb-Cd composite pollution caused SOC loss by increasing Basidiomycota which promoting carbon degradation, and decreasing Proteobacteria which promoting carbon fixation via the Krebs cycle. Our findings demonstrate that heavy metal pollution mediates Carbon-cycling microorganisms and genes, impacting SOC storage.


Subject(s)
Metals, Heavy , Soil Pollutants , Cadmium/analysis , Carbon/metabolism , Soil/chemistry , Lead/metabolism , Metals, Heavy/analysis , Fungi , Soil Pollutants/analysis
8.
Int J Mol Sci ; 24(11)2023 May 26.
Article in English | MEDLINE | ID: mdl-37298252

ABSTRACT

Stomata are one of the important structures for plants to alleviate metal stress and improve plant resistance. Therefore, a study on the effects and mechanisms of heavy metal toxicity to stomata is indispensable in clarifying the adaptation mechanism of plants to heavy metals. With the rapid pace of industrialization and urbanization, heavy metal pollution has been an environmental issue of global concern. Stomata, a special physiological structure of plants, play an important role in maintaining plant physiological and ecological functions. Recent studies have shown that heavy metals can affect the structure and function of stomata, leading to changes in plant physiology and ecology. However, although the scientific community has accumulated some data on the effects of heavy metals on plant stomata, the systematic understanding of the effects of heavy metals on plant stomata remains limited. Therefore, in this review, we present the sources and migration pathways of heavy metals in plant stomata, analyze systematically the physiological and ecological responses of stomata on heavy metal exposure, and summarize the current mechanisms of heavy metal toxicity on stomata. Finally, the future research perspectives of the effects of heavy metals on plant stomata are identified. This paper can serve as a reference for the ecological assessment of heavy metals and the protection of plant resources.


Subject(s)
Metals, Heavy , Soil Pollutants , Metals, Heavy/metabolism , Plants/metabolism , Environmental Pollution , Plant Physiological Phenomena , Soil Pollutants/metabolism , Soil/chemistry
9.
Ecotoxicol Environ Saf ; 250: 114498, 2023 Jan 15.
Article in English | MEDLINE | ID: mdl-36608568

ABSTRACT

The understanding of bacterial resistance to hexavalent chromium [Cr(VI)] are crucial for the enhancement of Cr(VI)-polluted soil bioremediation. However, the mechanisms related to plant-associated bacteria remain largely unclear. In this study, we investigate the resistance mechanisms and remediation potential of Cr(VI) in a plant-associated strain, AN-B15. The results manifested that AN-B15 efficiently reduced Cr(VI) to soluble organo-Cr(III). Specifically, 84.3 % and 56.5 % of Cr(VI) was removed after 48 h in strain-inoculated solutions supplemented with 10 and 20 mg/L Cr(VI) concentrations, respectively. Transcriptome analyses revealed that multiple metabolic systems are responsible for Cr(VI) resistance at the transcriptional level. In response to Cr(VI) exposure, strain AN-B15 up-regulated the genes involved in central metabolism, providing the reducing power by which enzymes (ChrR and azoR) transformed Cr(VI) to Cr(III) in the cytoplasm. Genes involved in the alleviation of oxidative stress and DNA repair were significantly up-regulated to neutralize Cr(VI)-induced toxicity. Additionally, genes involved in organosulfur metabolism and certain ion transporters were up-regulated to counteract the starvation of sulfur, molybdate, iron, and manganese induced by Cr(VI) stress. Furthermore, a hydroponic culture experiment showed that toxicity and uptake of Cr(VI) by plants under Cr(VI) stress were reduced by strain AN-B15. Specifically, strain AN-B15 inoculation increased the fresh weights of the wheat root and shoot by 55.5 % and 18.8 %, respectively, under Cr(VI) stress (5 mg/L). The elucidation of bacterial resistance to Cr(VI) has an important implication for exploiting microorganism for the effective remediation of Cr(VI)-polluted soils.


Subject(s)
Chromium , Pseudomonas , Pseudomonas/genetics , Pseudomonas/metabolism , Chromium/analysis , Bacteria/metabolism , Iron/metabolism , Biodegradation, Environmental
10.
Ecol Evol ; 12(5): e8882, 2022 May.
Article in English | MEDLINE | ID: mdl-35509610

ABSTRACT

The mechanisms governing community assembly is fundamental to ecological restoration and clarification of the assembly processes associated with severe disturbances (characterized by no biological legacy and serious environmental problems) is essential. However, a systematic understanding of community assembly in the context of severe anthropogenic disturbance remains lacking. Here, we explored community assembly processes after metal mining, which is considered to be a highly destructive activity to provide insight into the assembly rules associated with severe anthropogenic disturbance. Using a chronosequence approach, we selected vegetation patches representing different successional stages and collected data on eight plant functional traits from each stage. The traits were classified as establishment and regenerative traits. Based on these traits, null models were constructed to identify the processes driving assembly at various successional stages. Comparison of our observations with the null models indicated that establishment and regenerative traits converged in the primary stage of succession. As succession progressed, establishment traits shifted to neutral assembly, whereas regeneration traits alternately converged and diverged. The observed establishment traits were equal to expected values, whereas regenerative traits diverged significantly after more than 20 years of succession. Furthermore, the available Cr content was linked strongly to species' ecological strategies. In the initial stages of vegetation succession in an abandoned metal mine, the plant community was mainly affected by the available metal content and dispersal limitation. It was probably further affected by strong interspecific interaction after the environmental conditions had improved, and stochastic processes became dominant during the stage with a successional age of more than 20 years.

11.
Sci Total Environ ; 806(Pt 2): 150626, 2022 Feb 01.
Article in English | MEDLINE | ID: mdl-34597554

ABSTRACT

Mining is the most destructive human activity towards ecosystems through changing the terrain, substrate properties, and vegetation community structure. Vegetation succession, the theoretical basis of restoration, is influenced by site conditions and anthropogenic intervention. In order to provide general practical applications for mine restoration, it is critical to identify the optimal intervention that promotes succession, and the influence of climates. Here, we hypothesized that high-intervention contributes to positive characteristics and more successful succession, while increasing climatic severity presents negative characteristics and succession is hard to succeed. In this study, we collected 55 global studies (n = 804) on the vegetation succession of abandoned metal mines, and evaluated the ecological characteristics and successional trends under spontaneous succession and anthropogenic intervention conditions by conducting meta-analyses. Furthermore, we considered factors that may affect the vegetation succession after closing mines, including geological conditions, mining area (area of degraded land in mine field) and mining time (duration of mining operations). Species richness and evenness increased with the age of succession under low- and non- intervention conditions, while coverage increased under high-intervention, and species diversity decreased significantly with increasing mining time in cold areas. There were significant differences in succession trends under different climate types. The vegetation structure was more likely to develop towards the target vegetation in megathermal and mesothermal than in microthermal regions. We contend that a low level of intervention can help succession, while high-intervention will not. Vegetation succession can be achieved more easily with less climatic severity, and the reduction of large-scale mining processes (area and time) can increase vegetation evenness, especially for continental or microthermal regions.


Subject(s)
Ecosystem , Soil , Humans , Metals , Mining
12.
Transl Pediatr ; 10(4): 790-806, 2021 Apr.
Article in English | MEDLINE | ID: mdl-34012829

ABSTRACT

BACKGROUND: The composition of intestinal flora in Chinese and Japanese has been reported in many studies but that in infants aged 0-6 years old has not been studied yet. METHODS: The distribution characteristics of the fecal flora of infants in Beijing (n=84) and Japan (n=53) were analyzed using 16S rRNA gene sequencing analysis. RESULTS: This study showed the higher relative abundance of Erysipelotrichaceae_ UCG-003 and Anaerostipes in male group that of Ruminiclostridium, Eubacterium, Senegalimassilia and Senegalimassilia in female group, especially Senegalimassilia, which was not detected in male group. Defecation trait groups indicated significantly higher relative abundance of Bifidobacterium in abnormal bowel trait group than that in the normal group (P<0.05). The feeding groups' analysis showed significantly higher relative abundance of Bifidobacterium and Enterococcus and lower abundance of Bacteroides and Lacetospirillaceae in the breast-feeding group than that in the formula feeding and mixed-feeding groups. The relative abundance of Parasutterella and Ruminococcaceae_UCG-003 in the halitosis group was significantly higher than that in the normal group. The comparison of cold and fever group and normal group indicated significantly higher relative abundance of Erysipelatoclostridium and lower relative abundance of Lachnospiraceae _UCG-001 in the fever and cold group than that in the normal group (P<0.05). The regional comparison of intestinal flora of Beijing and Japan showed significant increase in the relative abundance of Bacillus, Lactobacillus, Prevotella, megamonas and Veillonella in the intestinal flora of 0-6 years old infants in Beijing. CONCLUSIONS: These findings improve the understanding of intestinal bacterial and viral communities of infants from the two Asian countries.

13.
Article in English | MEDLINE | ID: mdl-33198286

ABSTRACT

Previous research on antecedents to constructive deviance remains scattered and inclusive. Our study conceptualizes constructive deviance from the perspective of ethical decision making and explores its antecedents, mechanism, and conditions. Drawing on moral licensing theory and social information processing theory, we propose that group citizenship behavior facilitates moral justification and constructive deviance when environmental dynamism is high and inhibits them when it is low; and moral justification fully mediates the relationship between the interaction of group citizenship behavior and environmental dynamism and constructive deviance. With two-wave panel data collected from 339 employees in 54 groups of five service companies in retailing, finance, and tourism randomly selected from three provinces in southern China, these hypotheses are all supported empirically. Our findings broaden the antecedents and occurrence mechanism of constructive deviance through an ethical decision-making lens. Our study contributes to the moral licensing literature by enriching the sources of moral licensing in the workplace and empirically demonstrating that moral justification may function as an underlying mechanism of moral licensing.


Subject(s)
Decision Making , Morals , Workplace , China , Decision Making/ethics , Female , Group Processes , Humans , Male , Workplace/psychology , Workplace/statistics & numerical data
14.
Article in English | MEDLINE | ID: mdl-32842458

ABSTRACT

Extant research on work-related identity discrepancy mostly has probed its effects on employees' attitudes and emotions but has paid little attention to its impact on employee behaviors. Drawing on self-discrepancy theory, we examined the influencing mechanism and conditions of work-related identity discrepancy on employee innovation behavior. With data collected from 563 employees who personally experienced leadership transition in the workplace, we found that work-related identity discrepancy predicts employee innovation behavior through workplace anxiety. We also discovered that employees' personality traits-promotion regulatory focus and prevention regulatory focus in particular-can intensify or buffer the negative relationship between work-related identity discrepancy and employee innovation behavior. We further discuss the conceptual and practical implications of these findings.


Subject(s)
Anxiety/psychology , Creativity , Interpersonal Relations , Occupational Stress/psychology , Self Efficacy , Workplace/psychology , Adult , Aged , Anxiety Disorders , Cross-Sectional Studies , Female , Humans , Leadership , Male , Middle Aged , Occupations , Organizational Culture , Organizational Innovation , Social Support
15.
Article in English | MEDLINE | ID: mdl-32784824

ABSTRACT

This research investigates the role of emotional exhaustion and supervisor incivility in explaining the relationship between work-related identity discrepancy and counterproductive work behavior. Based on resource conservation theory, our study hypothesizes a moderated mediation model that work-related identity discrepancy impacts counterproductive work behavior through emotional exhaustion, and supervisor incivility is deemed as the boundary condition in the indirect effect. Drawing on a sample of 863 employees, we found support for the moderated mediation model in which the positive relationship between work-related identity discrepancy and counterproductive work behavior was mediated by emotional exhaustion, such that the mediating relationship was strengthened for new leaders with a low level of supervisor incivility and weakened for those with high level of supervisor incivility. We further discuss the theoretical and practical implications of these findings.


Subject(s)
Incivility , Workplace , Emotions , Female , Humans , Interpersonal Relations , Male , Occupations , Self Concept
16.
Sci Total Environ ; 733: 138338, 2020 Sep 01.
Article in English | MEDLINE | ID: mdl-32446044

ABSTRACT

A pilot hybrid constructed wetland (CW) planted with reeds (Phragmite australis) and rice (Oryza sativa L.) was designed to treat liquid anaerobic digestate in the Yangtze River Delta, China. The hybrid CW system was composed of four stages: two reed vegetated vertical subsurface flow beds (VSSF: U1 and U2) in sequence, followed by a reed vegetated horizontal subsurface flow bed (HSSF: U3) and a rice vegetated surface flow bed (SF: U4). The average loading rate of digestate was 3.6 m3 per day during the experimental period. The average concentrations of TN and TP in the influent were 379 ± 58 mg L-1 and 29.6 ± 9.2 mg L-1, while the average removal efficiencies of TN and TP were 94.6% and 88.4%. Both TN and TP removal efficiencies in the second VSSF containing zeolite gave the highest removal performance, in which the mass removal rates were 21.3 ± 8.0 g-N m-2 d-1 and 0.99 ± 0.69 g-P m-2 d-1, respectively. Similarly, the highest removal performance for COD was also observed in the second VSSF with a mass removal rate of 79.9 ± 72.4 g-COD m-2 d-1. On the other hand, the average CH4 and N2O fluxes were highest in the first VSSF, at 31.8 ± 12.9 mg m-2 h-1 and 3.7 ± 2.8 mg m-2 h-1, respectively. There was a significant linear relationship between CH4 flux and DOC concentration in the pore water as well as a correlation between N2O flux and TN concentration. Total GWP of the hybrid CWs, derived from CH4 and N2O emissions, was 792.4 kg CO2-eq, of which CH4 and N2O emissions accounted for 66.0% and 34.0%, respectively. Consequently, the hybrid CWs emitted on average 0.93 kg CO2-eq to remove 1 kg COD while the average EF of TNin was 0.34%, suggesting that the use of multistage hybrid CWs could be efficiency-wise and environmentally a promising strategy for anaerobic digestate treatment.


Subject(s)
Nitrous Oxide/analysis , Wetlands , Anaerobiosis , China , Methane/analysis , Nitrogen/analysis , Nutrients , Waste Disposal, Fluid
17.
Bioresour Technol ; 310: 123344, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32344238

ABSTRACT

Agricultural drainage ditches can prevent flooding and mitigate agricultural pollution; however, the performance is unsatisfactory in plateau areas like the Dianchi Lake basin. Thus, a novel double-layer ditch system (DDS) with a fibrous packing as biofilm carriers was developed to form the carrier-attached biofilms and enhance the pollutant removal. The results indicated the DDS performed better than a single-layer ditch system, and annual average removal efficiencies of TN, NO3--N, NH4+-N, TP, COD and SS were 18.61%, 17.13%, 7.74%, 11.90%, 11.95% and 23.71%, respectively. High amount and carbon, nitrogen and phosphorus contents of biofilms are favourable to pollutant removal by DDS. Although bacterial diversity of biofilms remained relatively stable throughout the year, the relative abundance of dominant assemblages varied greatly. Denitrifying microorganisms affiliated with Bacteroidetes might contribute to effective NO3--N reduction. This study demonstrates DDS performed well and provides a novel method for application of biofilm carriers in drainage ditches.


Subject(s)
Environmental Pollutants , Water , Agriculture , Biofilms , Nitrogen , Phosphorus
18.
Article in English | MEDLINE | ID: mdl-32013097

ABSTRACT

Much of the supervision incivility research has focused on the supervisor-subordinate dyad when examining the effects of supervision incivility on employee outcomes. Our study examines a trickle-down effect of supervision incivility across three hierarchical levels, i.e., from the department leader (middle manager), through group leader (supervisor), and to group members (employees), and how it affects group psychological safety. Drawing on a sample of 346 employees and 78 group leaders in 78 work groups, our research found a negative relationship between department leader incivility and group psychological safety, and that this negative relationship was mediated by group leader incivility and moderated by group leader attribution for performance-promotion or injury-initiation motives. We further discuss the theoretical and practical implications of these findings.


Subject(s)
Group Processes , Incivility , Occupational Health , Workplace/psychology , Humans , Leadership , Motivation , Social Perception
19.
Bull Environ Contam Toxicol ; 104(3): 358-365, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31975014

ABSTRACT

Variations of phytoaccumulation and tolerance in different growth stages of plant are important factors for effective removal of pollutants in phytoremediation. The present work investigated arsenic (As) accumulation, As-tolerance and the physiological tolerance mechanisms of Typha angustifolia under different As-level during the seedling, fast-growing and breeding stages. The results showed that As mainly distributed in the underground part and total As accumulation increased with growth stages. Maximum growth rates under lower As occurred in seedling stage, whereas occurred in breeding stage under higher As. T. angustifolia exhibited the highest tolerance ability under 150 mg kg-1 As and tolerance index (TI) varied from seedling to breeding stages. During seedling stage, TI was affected by plant height (Hshoot) and net photosynthesis, which control biomass production. During fast-growing stage, Hshoot and root glutathione (GSH) co-regulated plant As-tolerance. During breeding stage, physiological metabolic processes, especially GSH-mediated processes, played a critical role in improving plant As-tolerance.


Subject(s)
Acclimatization , Arsenic/analysis , Typhaceae/growth & development , Water Pollutants, Chemical/analysis , Biodegradation, Environmental , Biomass , Plant Roots/growth & development , Plant Roots/metabolism , Seedlings/growth & development , Seedlings/metabolism , Typhaceae/metabolism
20.
Comp Med ; 60(2): 142-8, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20412690

ABSTRACT

Here we sought to evaluate the possibility of using Chinese Bama miniature pig skin as a suitable animal model for human skin. Morphologic features of the skin of Bama miniature pigs resemble those of human skin, including skin layer thickness, development of a superficial vascular system, structure of the dermal-epidermal interface, and extracellular matrix. The characteristics and densities of Langerhans cells, fibroblasts, vascular endothelial cells, and mast cells were similar between Bama pig and human skin. Immunohistochemistry showed that miniature pigs and humans have the same antigenic determinants of human laminin, fibronectin, filaggrin, collagen I, collagen III, collagen IV, and keratin but not CD34, ICAM1, or S100. In addition, collagen type I from Bama miniature pig skin exhibited physicochemical characteristics resembling those of human skin, in regard to HPLC chromatography, UV spectroscopy, amino-acid composition, and SDS-PAGE analysis. Given these results, we concluded that Bama miniature pigs have great potential as a human skin model and for developing dermal substitute materials in wound repair. However, we also observed some disparities between the skin of Bama miniature pigs and humans, including pigment cell distribution, sweat gland types, and others. Therefore, further studies are needed to completely evaluate the effects of these interspecies differences on the actual application of the model.


Subject(s)
Skin/chemistry , Skin/ultrastructure , Swine, Miniature/anatomy & histology , Animals , Collagen Type I/chemistry , Collagen Type I/genetics , Collagen Type I/metabolism , Extracellular Matrix/chemistry , Extracellular Matrix/metabolism , Female , Filaggrin Proteins , Humans , Immunohistochemistry/methods , Male , Microscopy/methods , Microscopy, Electron/methods , Models, Animal , Sus scrofa , Swine , Swine, Miniature/metabolism , Wound Healing
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