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1.
BMC Microbiol ; 24(1): 123, 2024 Apr 15.
Article En | MEDLINE | ID: mdl-38622504

BACKGROUND: Rhizosphere microorganisms are vital in plants' growth and development and these beneficial microbes are recruited to the root-zone soil when experiencing various environmental stresses. However, the effect of white grub (Maladera verticalis) larvae feeding on the structure and function of rhizosphere microbial communities of aerobic rice (Oryza sativa L.) is unclear. RESULTS: In this study, we compared physicochemical properties, enzyme activities, and microbial communities using 18 samples under healthy and M. verticalis larvae-feeding aerobic rice rhizosphere soils at the Yunnan of China. 16 S rRNA and ITS amplicons were sequenced using Illumina high throughput sequencing. M. verticalis larvae feeding on aerobic rice can influence rhizosphere soil physicochemical properties and enzyme activities, which also change rhizosphere microbial communities. The healthy and M. verticalis larvae-feeding aerobic rice rhizosphere soil microorganisms had distinct genus signatures, such as possible_genus_04 and Knoellia genera in healthy aerobic rice rhizosphere soils and norank_f__SC - I-84 and norank_f__Roseiflexaceae genera in M. verticalis larvae-feeding aerobic rice rhizosphere soils. The pathway of the metabolism of terpenoids and polyketides and carbohydrate metabolism in rhizosphere bacteria were significantly decreased after M. verticalis larvae feeding. Fungal parasite-wood saprotroph and fungal parasites were significantly decreased after M. verticalis larvae feeding, and plant pathogen-wood saprotroph and animal pathogen-undefined saprotroph were increased after larvae feeding. Additionally, the relative abundance of Bradyrhizobium and Talaromyces genera gradually increased with the elevation of the larvae density. Bacterial and fungal communities significantly correlated with soil physicochemical properties and enzyme activities, respectively. CONCLUSIONS: Based on the results we provide new insight for understanding the adaptation of aerobic rice to M. verticalis larvae feeding via regulating the rhizosphere environment, which would allow us to facilitate translation to more effective measures.


Oryza , Animals , Oryza/microbiology , Larva , Rhizosphere , China , Bacteria , Soil/chemistry , Soil Microbiology
2.
Environ Res ; 251(Pt 2): 118746, 2024 Mar 19.
Article En | MEDLINE | ID: mdl-38513751

Understanding the relative role of dispersal dynamics and niche constraints is not only a core task in community ecology, but also becomes an important prerequisite for bioassessment. Despite the recent progress in our knowledge of community assembly in space and time, patterns and processes underlying biotic communities in alpine glacierized catchments remain mostly ignored. To fill this knowledge gap, we combined the recently proposed dispersal-niche continuum index (DNCI) with traditional constrained ordinations and idealized patterns of species distributions to unravel community assembly mechanisms of different key groups of primary producers and consumers (i.e., phytoplankton, epiphytic algae, zooplankton, macroinvertebrates, and fishes) in rivers in the Qinghai-Tibet Plateau, the World's Third Pole. We tested whether organismal groups with contrasting body sizes differed in their assembly processes, and discussed their applicability in bioassessment in alpine zones. We found that community structure of alpine river biotas was always predominantly explained in terms of dispersal dynamics and historical biogeography. These patterns are most likely the result of differences in species-specific functional attributes, the stochastic colonization-extinction dynamics driven by multi-year glacier disturbances and the repeated hydrodynamic separation among alpine catchments after the rising of the Qilian mountains. Additionally, we found that the strength of dispersal dynamics and niche constraints was partially mediated by organismal body sizes, with dispersal processes being more influential for microscopic primary producers. Finding that zooplankton and macroinvertebrate communities followed clumped species replacement structures (i.e., Clementsian gradients) supports the notion that environmental filtering also contributes to the structure of high-altitude animal communities in glacierized catchments. In terms of the applied fields, we argue that freshwater bioassessment in glacierized catchments can benefit from incorporating the metacommunity perspective and applying novel approaches to (i) detect the optimal spatial scale for species sorting and (ii) identify and eliminate the species that are sensitive to dispersal-related processes.

3.
Eur J Med Res ; 28(1): 399, 2023 Oct 05.
Article En | MEDLINE | ID: mdl-37794519

BACKGROUND: For patients with locally advanced nasopharyngeal cancer (LA-NPC), concurrent chemoradiotherapy (CCRT) is the standardized treatment. However, whether a weekly or triweekly cisplatin regimen should be used during CCRT is controversial. Therefore, we conducted this meta-analysis to explore differences in the effects and toxicities of the two regimens. METHODS: We searched PubMed, Embase, and the Cochrane Library (until June 10, 2022). We evaluated overall survival (OS), distant metastasis-free survival (DMFS), locoregional recurrence-free survival (LRFS), disease-free survival (DFS) and grade ≥ 3 adverse events. The effect indices were hazard ratios (HRs) and odds ratios (ORs), and Review Manager software 5.4 (RevMan 5.4) was used for computations. RESULTS: We identified 7 studies in our analysis. There was no significant difference in OS (HR = 1.00, 95% CI 0.73-1.38, P = 0.99), DMFS (HR = 0.84, 95% CI 0.58-1.22, P = 0.36), LRFS (HR = 0.91, 95% CI 0.63-1.32, P = 0.62) or DFS (HR = 0.93, 95% CI 0.56-1.56; P = 0.78) between the weekly and triweekly cisplatin regimens. We found that the weekly cisplatin regimen was more likely to cause grade ≥ 3 hematological toxicity events than the triweekly cisplatin regimen. In addition, subgroup analyses revealed that patients undergoing CCRT and CCRT plus adjuvant chemotherapy (AC) had similar OS or DFS. CONCLUSION: Weekly and triweekly cisplatin regimens had similar efficacy for LA-NPC. The triweekly regimen may replace the weekly regimen for LA-NPC because of lower toxicity. Larger data accumulation and more multicenter clinical trials may be needed to verify these results.


Cisplatin , Nasopharyngeal Neoplasms , Humans , Cisplatin/adverse effects , Nasopharyngeal Neoplasms/drug therapy , Nasopharyngeal Carcinoma/drug therapy , Chemoradiotherapy/adverse effects , Disease-Free Survival , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Multicenter Studies as Topic
4.
Zhen Ci Yan Jiu ; 48(10): 969-976, 2023 Oct 25.
Article En, Zh | MEDLINE | ID: mdl-37879946

OBJECTIVES: To observe the therapeutic effect of electroacupuncture (EA) on neurogenic urinary retention rats, so as to explore the underlying mechanism of EA in treating neurogenic urinary retention by focusing on 3-phosphoinositide-dependent protein kinase 1 (PDK1)/protein kinase B (Akt)/hyperpolarization activated cyclic nucleotide-gated cation channel 4 (HCN4) pathway. METHODS: Female SD rats were randomly divided into sham operation, model, EA, PDK1 inhibitor, HCN4 blocker and EA + HCN4 blocker groups, with 20 rats in each group. The model of sacral spinal cord injury was established by modified Hassan Shaker spinal cord transection method. EA (2 Hz/15 Hz, 0.5 mA) was applied to "Zhongji" (CV3) and "Zhongliao" (BL33) for 20 min, once daily for 10 days. Rats of the PDK1 inhibitor group received intraperitoneal injection of OSU-03012 (20 mg/kg), and rats of the HCN4 blocker group received intraperitoneal injection of ivabradine (10 mg/kg), both once every other day for 10 days. The urodynamic indexes of rats were detected by multi-channel physiological recorder;muscle strip test was used to detect detrusor excitability;the morphological changes of bladder were observed by HE staining. Immunofluorescence double staining was used to detect the co-expression of HCN4 and C-Kit, a specific marker of interstitial cells of Cajal in bladder. Western blot was used to detect the expression of PDK1/Akt/HCN4 pathway proteins in bladder tissue and heat shock protein 27 (HSP27), a protein related to bladder contraction function. RESULTS: Compared with the sham operation group, the rats in the model group showed urinary dysfunction, decreased leak point pressure, isolated detrusor spontaneous contraction frequency, fluorescence intensity of C-Kit positive cells, HCN4+/C-Kit+ co-expression, HCN4 and p-HSP27/HSP27 protein expression in bladder tissue (P<0.05), and increased maximum bladder capacity and comp-liance, minimum tension during contraction of isolated detrusor, PDK1 and p-Akt/Akt protein expression in bladder tissue (P<0.05). Meanwhile, the above index were all reversed after EA and PDK1 inhibitor intervention (P<0.05). In comparison with the EA group, the rats had severe urinary dysfunction, the urine leakage point pressure, spontaneous contraction frequency, fluorescence intensity of C-Kit positive cells, the co-expression of HCN4+/C-Kit+, and the protein expression of HCN4 and p-HSP27/HSP27 were decreased (P<0.05), the maximum bladder capacity and compliance, the minimum tension during contraction of isolated detrusor, and the protein expression of PDK1 and p-Akt/Akt in bladder tissue were increased (P<0.05) in both HCN4 blocker and EA+HCN4 blocker groups. HE staining showed exfoliated bladder epithelium and disordered layers, vacuolization of bladder wall cells, with infiltration of neutrophils in mucosal and muscular layers in the model group, which were relatively milder in the EA and PDK1 inhibitor groups, but worse in the HCN4 blocker and EA + HCN4 blocker groups. CONCLUSIONS: EA can improve the urinary dysfunction in rats with neurogenic urinary retention, which may be related to its effect in inhibiting the activation of PDK1/Akt pathway, promo-ting HCN4-mediated detrusor excitatory contraction and urinary electrical signal activation.


Electroacupuncture , Spinal Cord Injuries , Urinary Retention , Animals , Female , Rats , HSP27 Heat-Shock Proteins/metabolism , Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels/genetics , Potassium Channels , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-akt/metabolism , Rats, Sprague-Dawley , Spinal Cord Injuries/therapy
5.
Eur Arch Otorhinolaryngol ; 280(7): 3097-3106, 2023 Jul.
Article En | MEDLINE | ID: mdl-37079074

BACKGROUND: Concurrent chemoradiotherapy has long been a standardized therapy for localized advanced nasopharyngeal cancer. It is widely used in clinical applications. In contrast, NCCN guidelines highlight that the efficacy of concurrent chemoradiotherapy for stage II nasopharyngeal cancer in the new era of intensity-modulated radiotherapy has not been defined. Thus, we systematically reviewed the significance of concurrent chemoradiotherapy for stage II nasopharyngeal cancer. METHODS: We searched the relevant literature in PubMed, EMBASE, and Cochrane, extracting relevant data from the searched literature. The main items extracted were hazard ratios (HRs), risk ratios (RRs) and 95% confidence intervals (CIs). When the HR could not be extracted from the literature, we used Engauge Digitizer software for extraction. Data analysis was accomplished using the Review Manager 5.4 tool. RESULTS: Our study included seven articles involving 1633 cases of stage II nasopharyngeal cancer. The survival outcomes were overall survival (OS) (HR = 1.03, 95% CI (0.71-1.49), P = 0.87), progression-free survival (PFS) (HR = 0.91, 95% CI (0.59-1.39), P = 0.66), distant metastasis-free survival (DMFS) (HR = 1.05, 95% CI (0.57-1.93), P = 0.87), local recurrence-free survival (LRFS) (HR = 0.87, 95% CI (0.41-1.84), P = 0.71, P > 0.05), and locoregional failure-free survival (LFFS) (HR = 1.18, 95% CI (0.52-2.70), P = 0.69). CONCLUSIONS: In the era of intensity-modulated radiotherapy, concurrent chemoradiotherapy and radiotherapy alone have the same survival benefits, and concurrent chemoradiotherapy increases acute hematological toxicity. Subgroup analysis showed that for people with N1 nasopharyngeal cancer at risk of distant metastases, concurrent chemoradiotherapy and radiotherapy alone also had equal survival benefits.


Nasopharyngeal Neoplasms , Radiotherapy, Intensity-Modulated , Humans , Nasopharyngeal Carcinoma/pathology , Nasopharyngeal Neoplasms/pathology , Disease-Free Survival , Chemoradiotherapy , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Retrospective Studies
6.
Sci Total Environ ; 874: 162387, 2023 May 20.
Article En | MEDLINE | ID: mdl-36848991

Anthropogenic disturbances have become one of the primary causes of biodiversity decline in freshwater ecosystems. Beyond the well-documented loss of taxon richness in increasingly impacted ecosystems, our knowledge on how different facets of α and ß diversity respond to human disturbances is still limited. Here, we examined the responses of taxonomic (TD), functional (FD) and phylogenetic (PD) α and ß diversity of macroinvertebrate communities to human impact across 33 floodplain lakes surrounding the Yangtze River. We found that most pairwise correlations between TD and FD/PD were low and non-significant, whereas FD and PD metrics were instead positively and significantly correlated. All facets of α diversity decreased from weakly to strongly impacted lakes owing to the removal of sensitive species harboring unique evolutionary legacies and phenotypes. By contrast, the three facets of ß diversity responded inconsistently to anthropogenic disturbance: while FDß and PDß showed significant impairment in moderately and strongly impacted lakes as a result of spatial homogenization, TDß was lowest in weakly impacted lakes. The multiple facets of diversity also responded differently to the underlying environmental gradients, re-emphasizing that taxonomic, functional and phylogenetic diversities provide complementary information on community dynamics. However, the explanatory power of our machine learning and constrained ordination models was relatively low and suggests that unmeasured environmental features and stochastic processes may strongly contribute to macroinvertebrate communities in floodplain lakes suffering from variable levels of anthropogenic degradation. We finally suggested guidelines for effective conservation and restoration targets aimed at achieving healthier aquatic biotas in a context of increasing human impact across the 'lakescape' surrounding the Yangtze River, the most important being the control of nutrient inputs and increased spatial spillover effects to promote natural metasystem dynamics.


Anthropogenic Effects , Ecosystem , Humans , Rivers , Phylogeny , Biodiversity , Lakes
7.
Ecol Evol ; 12(12): e9631, 2022 Dec.
Article En | MEDLINE | ID: mdl-36532136

Accurate assessment of life history and population ecology of widespread species in ultra-eutrophic freshwater lakes is a prerequisite for understanding the mechanisms by which widespread species respond to eutrophication. Freshwater pulmonate (Radix swinhoei) is widespread and abundant in many eutrophic water bodies in Asia. Despite its key roles in eutrophic lake systems, the information on life history and population ecology of R. swinhoei is lacking, especially in ultra-eutrophic freshwater plateau lakes. Here, we conducted a 1-year survey of R. swinhoei with monthly collections to measure the life history traits (life span and growth), annual secondary production, and population size structure of R. swinhoei in nearshore regions with a high seasonally variation of nutrients in Lake Dianchi, a typic hypereutrophic plateau lake in Southwest China. Our results showed that R. swinhoei had the highest biomass in autumn and had the lowest in winter. Its maximum potential life span was 2.5 years, with three recruitment periods (November, March, and July) within a year. Its annual secondary production and P/B ratio were 137.19 g WW/m2 and 16.05, respectively. Redundancy analysis showed that eutrophication-related environmental factors had weak correlations with population size structure of R. swinhoei. Our results suggested that R. swinhoei is a typical r-strategist with high secondary production and thrive in eutrophic environment. Our study can help better understand the mechanisms for widespread species to survive eutrophication and could also be relevant for biodiversity conservation and management of eutrophic ecosystems.

8.
J Environ Manage ; 320: 115885, 2022 Oct 15.
Article En | MEDLINE | ID: mdl-36056492

Lateral hydrological connectivity (LHC) is a key process in maintaining aquatic biodiversity in river floodplain ecosystems. However, the effects of LHC loss on aquatic biodiversity are rarely studied. Here, we evaluated, for the first time, the responses of multiple facets (i.e., taxonomic, functional and phylogenetic) of alpha and beta diversity of freshwater molluscs to the LHC loss in 23 floodplain lakes in the Yangtze River Basin in China. Our results showed that taxonomic and functional alpha diversities were all significantly higher in connected lakes (CLs) than in disconnected lakes (DLs), whereas phylogenetic alpha diversity (Δ+) was lower in CLs than in DLs. For beta diversity facets, taxonomic (Tßsor) and phylogenetic (Pßsor) dissimilarities were slightly more contributed by the turnover component or equally contributed by the turnover and nestedness-resultant components both in CLs and DLs. Instead, functional beta diversity (Fßsor), generally showing much lower values than Tßsor and Pßsor, was mainly contributed by the nestedness-resultant component (76.6-84.0%), especially in DLs. We found that only functional dissimilarities were significantly higher in DLs than CLs, indicating a high level of functional diversity loss without replacement of species possessing traits sensitive to hydrological disconnection (i.e., large body size, lamellibranch body form, filter feeding, ovoviviparity and burrowing habits). In general, lake area, hydrological connectivity, aquatic vegetation coverage and nutrient levels (TN and TP) played important roles in structuring variation in molluscan alpha and beta diversities, although the three diversity facets responded to different environmental factors. Our results suggest that loss of connectivity to the mainstem river has negative impacts on molluscan assemblages in floodplain lakes. More importantly, as taxonomic, functional and phylogenetic diversities responded somewhat differently to the loss of hydrological connectivity, all of these biodiversity facets should be better incorporated into aquatic biodiversity assessment and conservation programs in large river floodplains.


Biodiversity , Ecosystem , Hydrology , Lakes , Phylogeny , Rivers
9.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 47(4): 488-496, 2022 Apr 28.
Article En, Zh | MEDLINE | ID: mdl-35545344

OBJECTIVES: Electroacupuncture can enhance autophagic flow, promote neuronal regeneration, axonal and myelin remodeling to achieve the protection of spinal cord injury, but its role in neurogenic urine retention is not completely clear. This study aims to investigate whether the mechanism of electroacupuncture in the treatment of neurogenic urine retention is through autophagy mediated by adenosine monophosphate activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway. METHODS: A rat model of neurogenic urine retention after sacral spinal cord injury was established. The rats with successful model were randomly divided into a model group, an electroacupuncture group (electro-acupuncture for Ciliao, Zhongji, and Sanyinjiao by electronic stimulation, once a day, 20 min each time for 7 days), and an electroacupuncture+AMP-activated protein kinase (AMPK) inhibitor group (on the basis of the treatment of electroacupuncture group, 100 µg of AMPK inhibitor compound C was injected intramuscularly around the L2-3 intervertebral space on the 1st and 4th day). The normal group did not receive any treatment. The maximum bladder volume, bladder basal pressure, leak point pressure, and bladder compliance were recorded by multi-channel physiological recorder; the morphology of bladder tissue was observed by HE staining; autophagy was observed under transmission electron microscope; the expressions of LC3II and Beclin1 protein were observed by immunofluorescence staining; the protein levels of AMPK, phosphorylated-AMPK (p-AMPK), mTOR, phosphorylated-mTOR (p-mTOR), microtubule associated protein 1 light chain 3 (LC3) II and Beclin1 in bladder tissue were detected by Western blotting. RESULTS: Compared with the normal group, the maximum bladder capacity, leak point pressure, bladder compliance, p-AMPK, LC3II, Beclin1 protein expressions in the bladder tissue of the model group increased, and the p-mTOR protein expressions were decreased (all P<0.05); compared with the model group, the maximum bladder capacity, bladder compliance, p-mTOR protein expression in the bladder tissue of the electroacupuncture group were decreased, and the p-AMPK, LC3II, and Beclin1 protein expressions were increased (all P<0.05); compared with the electroacupuncture group, the maximum bladder capacity, bladder compliance, p-mTOR protein expression in the bladder tissue of the electroacupuncture+AMPK inhibitor group were increased, the p-AMPK, LC3II, and Beclin1 protein expressions were decreased (all P<0.05). In the model group, the bladder became larger, with unclear and varying degrees of degeneration, severe tissue damage and autophagosome appeared; the bladder of the electroacupuncture group was smaller than that of the model group, and all levels were clearly visible with autophagy bodies; the layers were slightly disordered and damaged in the electroacupuncture + AMPK inhibitor group. CONCLUSIONS: Electroacupuncture can activate autophagy through AMPK/mTOR pathway, thereby reducing neurogenic urine retention caused by spinal cord injury.


Electroacupuncture , Spinal Cord Injuries , AMP-Activated Protein Kinases , Animals , Autophagy , Beclin-1 , Mammals , Rats , Rats, Sprague-Dawley , TOR Serine-Threonine Kinases
10.
Environ Sci Pollut Res Int ; 29(46): 69875-69887, 2022 Oct.
Article En | MEDLINE | ID: mdl-35578083

Although environmental filtering and spatial structuring are commonly regarded as two key factors shaping community dynamics, their relative contribution remains unknown for numerous aquatic ecosystems, particularly highly dynamic floodplain lakes. This issue is here addressed by examining the seasonal metacommunity dynamics of freshwater fishes in Lake Dongting, a large subtropical lake of the middle Chang-Jiang basin in southern China. Physicochemical variables and fish assemblages were recorded at 20 sampling sites during the wet, normal, and dry seasons. Distance-based redundancy analysis and associated variation partitioning were used to examine the relative role of environmental variables and spatial factors in fish community assembly in each season. Analysis results demonstrated that the relative contribution of environmental filtering and spatial structuring varied depending on environmental features and the extent of hydrological connectivity in different seasons. Intensified physicochemical parameters in the dry season convinced the enhanced environmental filtering, whereas high hydrological connectivity in the wet season favored the stronger spatial process. Specifically, the community assembly processes were temporally dynamic; spatial structuring (or mass effects), resulting from excessively high dispersal rates, was dominant during the flooding season, and environmental filtering was stronger than spatial structuring (or dispersal limitation) during the non-flooding season. These findings highlight the importance of conserving local habitats of Lake Dongting during the dry and normal seasons, and maintaining of the flood pulse of the lake and its natural variability during the wet season. Apparently, the construction of a water-level regulation project at the Chenglingji Channel, the outlet watercourse of Lake Dongting, is not supported because it will change the flood pulse of this lake and thus impact habitat heterogeneity or variability.


Ecosystem , Lakes , Animals , China , Fishes , Seasons , Water
11.
Org Lett ; 24(15): 2883-2888, 2022 04 22.
Article En | MEDLINE | ID: mdl-35420435

A Mannich reaction of deprotonated, highly enantioenriched α,α-disubstituted N-tert-butanesulfinyl ketimines with isatin-derived ketimines was developed to prepare 3-amino-3-substituted oxindoles bearing an acyclic quaternary stereogenic carbon substituted with two sterically similar groups. The excellent stereocontrol of the deprotonation enabled the formation of metalloenamine intermediates with stereodefined geometry, while the precise facial selectivity of the C-C bond formation allowed the construction of contiguous quaternary and tetrasubstituted stereocenters with excellent stereoselectivity.


Isatin , Carbon/chemistry , Catalysis , Isatin/chemistry , Oxindoles , Stereoisomerism
12.
Sci Total Environ ; 825: 153940, 2022 Jun 15.
Article En | MEDLINE | ID: mdl-35183628

Conversion of forests to urban land-use in the processes of urbanization is one of the major causes of biotic homogenization (i.e., decline in beta diversity) in freshwater ecosystems, threating ecosystem functioning and services. However, empirical studies exploring urban land-use shaping patterns of taxonomic and functional beta diversities and their components in subtropical urban rivers are limited. Here, by leveraging data for 43 sampling sites from urban and forest rivers in Shenzhen, a megacity showing rapid urbanization, we determined the spatio-temporal dynamics and associated drivers of taxonomic and functional beta diversities of river macroinvertebrates. Our results showed that, from the forest to urban rivers, taxonomic beta diversity (wet: 32.9%; dry: 17.1%) declined more significantly than functional beta diversity (wet: 17.4%; dry: 9.5%) in different seasons. We further found that these compositional changes were largely driven by decreased roles of species/traits replacement. Although replacement was also dominant for taxonomic beta diversity (60.4%-68.4%) in two sets of rivers, richness difference contributed more to functional beta diversity in the urban river (52.6%-60.5%). Both deterministic and stochastic processes simultaneously affected beta diversity, with stochastic processes being more important in the urban (3.0-19.0%) than forest rivers (0.0%-3.0%). Besides, db-RDA and variation partitioning results showed that local-scale environmental variables explained considerably large fractions of variation in beta diversity. We hence recommended that biodiversity conservation should focus on improving and restoring local environmental conditions. Despite no significant seasonal differences in beta diversity were detected in this study, we found that the roles of deterministic (i.e., local-scale and land-use variables) and stochastic processes varied considerately across seasons. This result highlights the viewpoint that urban river biodiversity monitoring should go beyond one-season snapshot surveys. As the ongoing trend of urbanization in developing countries, the findings of this study are relevant in guiding urban river environmental monitoring, biodiversity conservation and land-use planning.


Ecosystem , Rivers , Biodiversity , Forests , Urbanization
13.
Environ Pollut ; 292(Pt A): 118330, 2022 Jan 01.
Article En | MEDLINE | ID: mdl-34634398

River floodplain ecosystems host one of the highest freshwater molluscan biodiversity on Earth. However, multiple human disturbances, such as loss of hydrological connectivity and deterioration of water quality, are seriously threatening most floodplain lakes throughout the world. Given the high imperilment rate of freshwater molluscs but the scarcity of studies examining the anthropogenic effects on this fauna, we test the response of mollusc assemblages to river-lake disconnection and eutrophication in 30 lakes in the Yangtze River floodplain, China. The species richness of entire Mollusca, Gastropoda and Bivalvia and 6 dominant families were all much lower at disconnected lakes than that in connected lakes, and decreased with increasing water eutrophication. The assemblage structure differed significantly among four lake groups for datasets based on entire Mollusca, Gastropoda and Bivalvia, indicating the serious impacts of hydrological disconnection and eutrophication. Moreover, the connected lakes showed significantly lower values of average taxonomic distinctness (Δ+) but higher values of variation in taxonomic distinctness (Λ+) than disconnected lakes. Such variations were triggered by the extirpation of congeneric and endemic species (mainly from families Unionidae and Viviparidae), which giving a waring of the loss of mollusc endemism in this region. In general, the present study showed that river-lake disconnection and deterioration of water quality resulted in serious biodiversity declines of both gastropods and bivalves in the Yangtze River floodplain lakes. A systematic approach including restoration of river-lake connectivity and habitats and improvement of water quality should be implemented in the conservation planning in this large river floodplain.


Lakes , Unionidae , Animals , China , Ecosystem , Eutrophication , Humans , Rivers
15.
Front Psychol ; 12: 671232, 2021.
Article En | MEDLINE | ID: mdl-34335383

In this paper we investigate the relationship between chief executive officer (CEO) empowering leadership and corporate entrepreneurship. In addition, the mediating role of information elaboration in top management teams (TMTs) and the moderating role of environmental dynamism are examined. Drawing on the information exchange/sharing perspective, we hypothesize that CEO empowering leadership has a positive effect on corporate entrepreneurship, and TMT information elaboration mediates the relationship above. Furthermore, we find that environmental dynamism positively moderates the relationship between empowering leadership and information elaboration, and negatively moderates the relationship between information elaboration and corporate entrepreneurship. Data from a sample of Chinese firms provide empirical evidence in support of these hypotheses.

16.
Environ Sci Pollut Res Int ; 28(32): 44339-44353, 2021 Aug.
Article En | MEDLINE | ID: mdl-33847890

Expansion of agricultural and urban areas and intensification of catchment land-use increasingly affect different facets of biodiversity in aquatic communities. However, understanding the responses of taxonomic and functional diversity to specific conversion from natural forest to agriculture and urban land-use remains limited, especially in subtropical streams where biomonitoring programs and using functional traits are still under development. Here, we conducted research in a subtropical stream network to examine the responses of macroinvertebrate taxonomic and functional diversity to different types of land-use in central China. Our results showed that medium body size, univoltine, gill respiration, and slow seasonal development were much higher in natural forest sites, while certain traits related to strong resilience and resistance (e.g., small body size, fast seasonal development, bi-or multivoltine, abundant occurrence in drift, sprawler) dominated in high-intensity agriculture and urbanization sites. We further found that land-use compromised water quality (e.g., increases in total phosphate, conductivity and water temperature) and habitat conditions (e.g., high proportion of sand and silt, gravel, and channel width) accounted for the changes in trait composition based on a combination of RLQ and fourth-corner analysis. Moreover, natural forest sites presented relatively high values of functional richness than other land-use, demonstrating the importance of natural forest maintenance to promote high levels of functional diversity. However, taxonomic diversity indexes showed higher sensitivity to distinguish different types of land-use compared to functional diversity measures. Even so, given that certain trait categories showed significant relationships with specific local environmental stressors, trait-based approaches can provide reliable evidence to diagnose the cause of impairment and complement the results of the taxonomic-based approaches. Our findings support the idea that taxonomic and functional approaches should be integrated in river restoration and land-use management.


Invertebrates , Rivers , Animals , Biodiversity , Ecosystem , Environmental Monitoring
17.
Environ Sci Pollut Res Int ; 28(29): 38573-38583, 2021 Aug.
Article En | MEDLINE | ID: mdl-33738738

It is generally recognized that dispersal mode can affect the relative role of environmental and spatial factors in structuring biotic communities. Disentangling the effects of dispersal mode on metacommunity structuring is essential to understanding the mechanisms of community assembly. Despite high seasonal variation in assemblage structure and phenological features of lotic macroinvertebrates, few studies examined the seasonal changes in the relative contribution of environmental and spatial processes. Here, we used two-season (spring and autumn) investigation data to link dispersal mode with local environmental and spatial factors that regulate macroinvertebrate metacommunity in a Chinese high-mountain stream network. Our aims were (1) to disentangle the relative role of environmental and spatial processes on structuring macroinvertebrate with different dispersal ability (aquatic passive: AqPa, terrestrial passive: TePa, and terrestrial active: TeAc) and (2) to determine seasonal shifts in metacommunity structuring processes. We found that assemblages of TeAc (with highest dispersal capacity) in both seasons were influenced more by environmental filtering than spatial structuring, whereas assemblages of TePa were mainly determined by spatial processes. Unexpectedly, AqPa group showed low spatial control in both seasons, probably due to their underestimated dispersal capacity via animal vector. The relative role of environmental and spatial factors was broadly stable across two seasons for AqPa and TeAc groups, but the TePa showed seasonal differences in the relative role of spatial factors, because of their seasonally changing dispersal capacity. In summary, our study emphasizes the use of dispersal mode for understanding metacommunity structuring mechanisms.


Ecosystem , Rivers , Animals , Biodiversity , Biota , China , Seasons
18.
Environ Pollut ; 269: 116059, 2021 Jan 15.
Article En | MEDLINE | ID: mdl-33307396

Effects of commercial sand mining on aquatic diversity are of increasing global concern, especially in parts of some developing countries. However, understanding of this activity on the diversity of macroinvertebrates remains focused on the α component of species diversity, rather than community functioning. Thus, there remains much uncertainty regarding how each component of taxonomic (TD) and functional (FD) diversity respond to the activity both in freshwater and marine environments. Here, we assessed the effect of sand dredging on α, ß and γ components of TD and FD during different dredging periods based on the response of macroinvertebrate communities over 4 years in the second largest freshwater lake in China. After three years of active dredging, substantial reductions in each component (α, ß and γ) of TD and FD were observed within the dredged area. Moreover, after one year of natural recovery, a distinct restoration was observed with an obvious return in multiple facets of TD and FD indices. No such changes were observed within the adjacent and reference areas. Decreases in the multiple components of TD and FD within the dredged area were most likely associated with the direct extraction of substrate and associated benthic fauna and indirect variations of the water and sediment environment (e.g., increases in water depth and decreases in %Clay). Furthermore, dispersal processes and mass effects mainly contributed to the maintenance of TD and FD during the dredged and recovery stages. In addition, the fast recovery of TD and FD was also related to the simple taxonomic structure and highly connected nature of the study area. Our results suggest that a more precise experimental design (BACI) should be pursued to avoid potentially confounding effects (e.g., natural disturbance) because the sensitivity of diversity indices depends upon different experimental designs. Moreover, measurement of the impacts of sand dredging on macroinvertebrate diversity can be undertaken within a rigorous framework for better understanding the patterns and processes of each component of TD and FD under the sand dredging disturbance.


Biodiversity , Sand , China , Environmental Monitoring , Lakes , Mining
19.
Sci Total Environ ; 758: 143630, 2021 Mar 01.
Article En | MEDLINE | ID: mdl-33218801

Environmental heterogeneity and dispersal limitation are important drivers of beta diversity; however, their relative influence on the two fundamental components of beta diversity (i.e., species replacement and richness difference) has not been fully examined in montane streams. Here, we examined the relative importance of local environmental gradients and three physical distance matrices (i.e., overland, watercourse and cost distances) on beta diversity and its two components for a macroinvertebrate metacommunity in a stream network. To provide additional insights into community assembly, we also analysed variation in two deconstructed sub-communities based on dispersal ability (i.e., weak and strong dispersers). Both environmental filters and physical distances (dispersal limitation) drove patterns of overall beta diversity, with the former generally prevailing over the latter. Species replacement components showed stronger correlations with environmental gradients than physical distances, while the opposite is true for the richness difference components. Overland distances were generally more important than cost and watercourse distances for community dissimilarity of stream macroinvertebrates, implying that lateral dispersal out of stream corridors through flight was the major dispersal route in the studied steam network. As expected, community dissimilarity of strong dispersers was primarily shaped by environmental filtering, while community dissimilarity of weak dispersers was associated with the joint effects of environmental filtering and dispersal limitation. Our findings demonstrate that partitioning overall dissimilarity into species replacement and richness difference provides more insights into the processes driving spatial variability in biological communities compared with the utilization of total beta diversity alone. Our results support the notion that maintaining environmental heterogeneity and natural connectivity of stream networks should be effective measures to conserve regional biodiversity.


Ecosystem , Rivers , Biodiversity , Biota
20.
Exp Ther Med ; 20(6): 232, 2020 Dec.
Article En | MEDLINE | ID: mdl-33149786

Effect of revascularization in the treatment of thromboangiitis obliterans (TAO) and the predictive value of serum vascular endothelial growth factor (VEGF), interleukin-1 (IL-1) and tumor necrosis factor-α (TNF-α) of risk factors of amputation were investigated. From April 2012 to August 2015, a total of 117 patients with TAO admitted to the First Hospital of Lanzhou University were selected. Patients treated with revascularization combined with prostaglandin sodium and cilostazol were enrolled in group A (67 patients), and patients treated with sodium and cilostazol were enrolled in group B (50 patients). The clinical efficacy was evaluated by calculating the intermittent claudication distance and the ankle brachial index (ABI) of patients. The occurrence probability of nausea and vomiting, skin pruritus, abdominal pain, coagulation abnormalities and amputation were recorded. The concentration of serum VEGF, IL-1 and TNF-α were measured using enzyme-linked immunosorbent assay (ELISA). After treatment, the intermittent claudication distance, ABI and efficiency of group A was markedly higher than that of group B (P<0.05). After treatment, serum VEGF concentration in group A was clearly higher than that in group B (P<0.05), and IL-1 and TNF-α levels were much lower than those in group B (P<0.05). The amputation rate in group A was significantly lower than that in group B (P<0.05). Patients with amputation in both groups were enrolled in the study group (24 cases), and those without amputation were included in the control group (93 cases). The serum VEGF concentration in the study group before treatment was significantly lower than that in the control group (P<0.05), while IL-1 and TNF-α levels were significantly higher than those of the control group (P<0.05). In conclusion, pretreatment serum VEGF, IL-1 and TNF-α had a positive diagnostic value for poor prognosis of patients with amputation, and low concentration of VEGF and higher concentration of IL-1 and TNF-α are the risk factors for amputations in patients with TAO.

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