Soil bacterial diversity is associated with human population density in urban greenspaces

Author Posting. © The Author(s), 2018. This is the author's version of the work. It is posted here by permission of American Chemical Society for personal use, not for redistribution. The definitive version was published in Environmental Science and Technology 52 (2018): 5115–5124, doi:10.1021/acs.est.7b06417.Urban greenspaces provide extensive ecosystem services, including pollutant remediation, water management, carbon maintenance, and nutrient cycling. However, while the urban soil microbiota underpin these services, we still have limited understanding of the factors that influence their distribution. We characterized soil bacterial communities from turf-grasses associated with urban parks, streets and residential sites across a major urban environment, including a gradient of human population density. Bacterial diversity was significantly positively correlated with the population density; and species diversity was greater in park and street soils, compared to residential soils. Population density and greenspace type also led to significant differences in the microbial community composition that was also significantly correlated with soil pH, moisture and texture. Co-occurrence network analysis revealed that microbial guilds in urban soils were well correlated. Abundant soil microbes in high density population areas had fewer interactions, while abundant bacteria in high moisture soils had more interactions. These results indicate the significant influence of changes in urban demographics and land-use on soil microbial communities. As urbanization is rapidly growing across the planet, it is important to improve our understanding of the consequences of urban zoning on the soil microbiota.This study is supported by the Earth Microbiome Project (http://www.earthmicrobiome.org/) and the China Scholarship Council (http://en.csc.edu.cn/).2019-04-0

Confucianism and the altruistic behaviour in the succession of family firms: evidence from asset write-downs

ABSTRACTThis paper explores how Confucianism influences the altruistic behaviour during family firm successions. Using a sample of Chinese listed family firms which have transferred the power to family successors during 2005-2018, we find that family firms deeply influenced by Confucianism intend to take a big bath via asset write-downs in the year before the succession. Confucianism has stronger influence on altruism when the successor have closer blood relationship with the founder, when the successor is less educated, when the family have weaker control over the firm or when the firm is in a lower market position. When the board of directors is more independent or the auditor has higher reputation, the influence of Confucianism is weaker. Family firms with more asset write-downs have better short-term performance after the succession, but lower business reform and R&D inputs. These findings enrich the research on Confucianism and corporate governance of family firms

How does the relationship between multiple large shareholders affect corporate valuations? Evidence from China

This study analyzes how the relationship between non-controlling and controlling large shareholders affects corporate valuations. Using data from the Chinese market, we find that a firm\u27s value is lower when its non-controlling large shareholders have a relationship with its controlling shareholder. In addition, higher ownership stakes and board representation of relational non-controlling large shareholders are associated with lower firm value. This effect is more pronounced when the agency conflicts between the controlling and minority shareholders are greater. Our findings suggest that it is important to consider the identities of non-controlling shareholders when examining the effects of multiple large shareholders on corporate governance or firm value

The effectiveness of government stock purchase during market crash: Evidence from China

During the Chinese stock market crash in 2015, the Chinese government formed a “national team” to directly purchase stocks of more than 1000 firms. We find that the national team\u27s interventions lower the stock price crash risk for these firms; however, they also increase stock price synchronicity, transaction cost and decrease idiosyncratic information. The stabilizing role of the “national team” disappears in the long run after the crisis period. Firms with more noise traders and a lower level of investor confidence benefit more from the national team ownership, consistent with the conjecture that the national team improves market liquidity and investor confidence

Non-controlling large shareholders in emerging markets: Evidence from China

Non-controlling large shareholders play an important role in corporate governance in emerging markets where controlling shareholder expropriation is a major concern. We argue that non-controlling large shareholders are faced with two non-conflicting incentives: to take advantage of their information advantage and obtain positive abnormal returns when they trade company shares, and to serve as effective monitors and minimize controlling shareholders\u27 appropriation of company wealth. Using a sample of large shareholders\u27 selling events upon the expiration of the lockup period following the split-share structure reform in China, we find that non-controlling large shareholders successfully time the market, as shown by their positive abnormal returns when selling their shares. Their returns are higher if they have a greater information advantage. Furthermore, the positive returns of the controlling large shareholder are negatively related to non-controlling large shareholders\u27 ownership, suggesting that non-controlling large shareholders play a monitoring role and prevent controlling shareholders from looting the company. We also show that large shareholders affiliated with the controlling shareholders are not subject to as high a level of monitoring as those controlling shareholders are. Furthermore, both firm opaqueness and the severity of agency cost affect the quality of non-controlling large shareholders\u27 monitoring

Proliferation and Anti-inflammatory Effects of Tremella fuciformis Polysaccharide on Human Chondrocytes

Objective: Osteoarthritis (OA) is a prevalent chronic joint disease. The purpose of this study was to investigate the proliferative and anti-inflammatory effects of Tremella fuciformis polysaccharide on osteoarthritis cell model human chondrocyte T/C-28a2. Methods: Proliferative effect and cytotoxicity of T/C-28a2 cells treated by Tremella fuciformis polysaccharide were detected with MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide) and crystal violet staining experiment. The bone inflammation model was established by lipopolysaccharide (LPS) treatment in T/C-28a2 cells. The expression of interleukin-6 (IL-6) in cells after drug treatment was detected by enzyme-linked immunosorbent assay (ELISA) analysis. The expression of osteoprotegerin (OPG) and inflammatory factors after drug treatment was detected by Western blot analysis. In addition, reactive oxygen species (ROS) release assay was used to detect the level of oxidative stress and anti-inflammation response to cells. Results: Tremella fuciformis polysaccharide could promote proliferation of human chondrocyte T/C-28a2 without obvious cytotoxicity. After LPS was used to treat human chondrocytes to simulate the environment of bone inflammation, it was found that the treatment of Tremella fuciformis polysaccharide and chondroitin sulfate could reduce the secretion of IL-6 and inhibit the occurrence of inflammation. Further Western blot analysis showed that after treatment of Tremella fuciformis polysaccharide, expression of related osteoprotegerin (OPG) was upregulated, expression of proapoptosis-related protein Bax, extracellular signal-regulated kinase ERK-MAPK and nuclear factor κB (NF-κB) was down-regulated. ROS release experiment showed that Tremella fuciformis polysaccharide and chondroitin sulfate could inhibit intracellular ROS levels and the occurrence of inflammatory response. Conclusion: Tremella fuciformis polysaccharide exhibited the effect of inhibiting osteoarthritis, protecting cartilage tissue and resisting cell apoptosis to a certain extent. In this study, the anti-inflammatory effect of Tremella fuciformis polysaccharide and its mechanism were primarily explored, which provided the preliminary experimental basis for the development of Tremella fuciformis polysaccharide as an anti-inflammatory drug

Comparative Expression Profiling Reveals the Regulatory Effects of Dietary Mannan Oligosaccharides on the Intestinal Immune Response of Juvenile <i>Megalobrama amblycephala</i> against <i>Aeromonas hydrophila</i> Infection

Mannan oligosaccharides (MOS) are functional oligosaccharides with beneficial effects on the non-specific immunity of Megalobrama amblycephala, but systematic studies on the immunomodulatory mechanisms of MOS are still lacking. To investigate the protective mechanisms of three different levels of dietary MOS supplementation on the intestinal immunity of juvenile M. amblycephala, comparative digital gene expression (DGE) profiling was performed. In this study, 622 differentially expressed genes (DEGs) were identified, while the similar expression tendency of 34 genes by qRT-PCR validated the accuracy of the DGE analyses. Gene Ontology (GO) enrichment revealed that the DEGs were mainly enriched in two functional categories of biological process and molecular function. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the DEGs were mainly related to complement and coagulation cascades, coagulation cascades, platelet activation, natural killer cell mediated cytotoxicity, Fc gamma R-mediated phagocytosis and antigen processing and presentation. In addition, the pro-inflammatory, apoptosis and tight junction-related genes were more significantly up-regulated upon infection in the dietary MOS groups to enhance host immune functions and maintain the stability of the intestinal barrier. These results will be helpful to clarify the regulatory mechanism of MOS on the intestinal immunity of M. amblycephala and lay the theoretical foundation for the prevention and protection of fish bacterial diseases

Molecular Characterization, Expression, Evolutionary Selection, and Biological Activity Analysis of CD68 Gene from Megalobrama amblycephala

CD68 is a highly glycosylated transmembrane glycoprotein that belongs to the lysosome-associated membrane glycoprotein family and is involved in various immune processes. In this study, Megalobrama amblycephala&nbsp;CD68 (MaCD68) was cloned and characterized, and its expression patterns and evolutionary characteristics were analyzed. The coding region of MaCD68 was 987 bp, encoding 328 amino acids, and the predicted protein molecular weight was 34.9 kDa. MaCD68 contained two transmembrane helical structures and 18 predicted N-glycosylation sites. Multiple sequence alignments showed that the MaCD68 protein had high homology with other fish, and their functional sites were also highly conserved. Phylogenetic analysis revealed that MaCD68 and other cypriniformes fish clustered into one branch. Adaptive evolution analysis identified several positively selected sites of teleost CD68 using site and branch-site models, indicating that it was under positive selection pressure during evolution. Quantitative real-time reverse transcription polymerase chain reaction analysis showed that MaCD68 was highly expressed in the head kidney, spleen, and heart. After Aeromonas hydrophila infection, MaCD68 was significantly upregulated in all tested tissues, peaking at 12 h post-infection (hpi) in the kidney and head kidney and at 120 hpi in the liver and spleen, suggesting that MaCD68 participated in the innate immune response of the host against bacterial infection. Immunohistochemical and immunofluorescence analyses also showed that positive signals derived from the MaCD68 protein were further enhanced after bacterial and lipopolysaccharide treatment, which suggested that MaCD68 is involved in the immune response and could be used as a macrophage marker. Biological activity analysis indicated that recombinant MaCD68 (rMaCD68) protein had no agglutination or bactericidal effects on A. hydrophila but did have these effects on Escherichia coli. In conclusion, these results suggest that MaCD68 plays a vital role in the immune response against pathogens, which is helpful in understanding the immune responses and mechanisms of M. amblycephala