Analysis of bacterial community structures in two sewage treatment plants with different sludge properties and treatment performance by nested PCR-DGGE method

The bacterial community structures in two sewage treatment plants with different processes and performance were investigated by denaturing gradient gel electrophoresis （DGGE） of nested polymerase chain reaction （nested PCR） amplified 16S rRNA gene fragments with group-specific primers. Samples of raw sewage and treated effluents were amplified using the whole-cell PCR method, and the activated sludge samples were amplified using the extracted genomic DNA before the PCR products were loaded on the same DGGE gel for bacterial community analysis. Ammonia-oxidizing bacterial and actinomycetic community analysis were also carried out to investigate the relationship between specific population structures and system or sludge performance. The two plants demonstrated a similarity in bacterial community structures of raw sewage and activated sludge, but they had different effluent populations. Many dominant bacterial populations of raw sewage did not appear in the activated sludge samples, suggesting that the dominant bacterial populations in raw sewage might not play an important role during wastewater treatment. Although the two plants had different sludge properties in terms of settleability and foam forming ability, they demonstrated similar actinomycetic community structures. For activated sludge with bad settling performance, the treated water presented a similar DGGE pattern with that of activated sludge, indicating the nonselective washout of bacteria from the system. The plant with better ammonium removal efficiency showed higher ammonia-oxidizing bacteria species richness. Analysis of sequencing results showed that the major populations in raw sewage were uncultured bacterium, while in activated sludge the predominant populations were beta proteobacteria.

Community Structure and Value Evaluation of Local Brassicaceae Potherbs in Shiyan City

[Objectives]This study was conducted to evaluate the value of local Brassicaceae potherb resources in Shiyan City.[Methods]Seven species of local Brassicaceae edible plants resources in Shiyan City,including Cardamine hirsuta L.,Cardamine flexuosa,Cardamine impatiens L.,Capsella bursa-pastoris(Linn.),Orychophragmus violaceus(L.)O.E.Schulz,Draba nemorosa L.,Rorippa indica(L.)Hiern.,were investigated using sampling method,and their value was evaluated.[Results]①Shiyan City was rich in resources of local Brassicaceae potherbs,mostly of which grew in humid areas.②In the communities of target species,there were 20 species of plants in 19 genera of 15 families in the arbor layer,19 species of plants in 16 genera from 15 families in the shrub layer,and 58 species of plants in 51 genera from 23 families in the herbaceous layer.The tree,shrub and herb species with the highest dominance Populus simonii var.przewalskii,Robinia pseudoacacia and Chrysanthemum indicum.Local Brassicaceae potherbs in Shiyan City have high edible and medicinal value,especially Cardamine,which has strong selenium-rich ability and is worthy of vigorous development.[Conclusions]This study provides scientific basis and reference for the development and utilization of local potherbs of Brassicaceae in this area.

Schistosomiasis control in Senegal:results from community data analysis for optimizing preventive chemotherapy intervention with praziquantel

Background Over the past two decades,preventive chemotherapy(PC)with praziquantel(PZQ)is the major strategy for controlling schistosomiasis in Senegal.The objective of this analysis was to update the endemicity of schistosomiasis at community level for better targeting mass treatment with PZQ in Senegal.Methods Demographic and epidemiological data from 1610 community health areas were analyzed using the schistosomiasis community data analysis tool of Expanded Special Project for Elimination of Neglected Tropical Diseases which developed by World Health Organization/Africa Ofce(WHO/AFRO).The tool uses a WHO/AFRO decision tree for areas without epidemiological data to determine whether mass treatment should be continued at community level.Descriptive analysis was performed.Results Overall,the endemicity of 1610 community health areas were updated based on the data from the district endemicity(33.5%)and the form of Join request for selected PC medicine(40.5%).Up to 282(17.5%)and 398(24.7%)of community health areas were classifed as moderate and high endemicity.41.1%of communities were non endemic.High endemicity was more important in Tambacounda,Saint Louis,Matam,Louga and Kedougou.A change in endemicity category was observed when data was disagregted from district level to community level.Implementation units classifed non endemic were more important at community level(n=666)compared to district level(n=324).Among 540 areas previously classifed high endemic at district level,392(72.6%)remained high prevalence category,while 92(17.0%)became moderate,43(8.0%)low and 13(2.4%)non-endemics at community level.Number of implementation units requiring PC was more important at district level(1286)compared to community level(944).Number of school aged children requiring treatment was also more important at district level compared to community level.Conclusions The analysis to disaggregate data from district level to community level using the WHO/AFRO schistosomiasis sub-district data optimization tool provide an update of schistosomiasis endemicity at community level.This study has allowed to better target schistosomiasis interventions,optimize use of available PZQ and exposed data gaps.

Community Detection in Disease-Gene Network Based on Principal Component Analysis

The identification of communities is imperative in the understanding of network structures and functions.Using community detection algorithms in biological networks, the community structure of biological networks can be determined, which is helpful in analyzing the topological structures and predicting the behaviors of biological networks. In this paper, we analyze the diseasome network using a new method called disease-gene network detecting algorithm based on principal component analysis, which can be used to investigate the connection between nodes within the same group. Experimental results on real-world networks have demonstrated that our algorithm is more efficient in detecting community structures when compared with other well-known results.

Impact of climate change on dynamic of plant communities, lakes and swamps in Beijing area during Holocene period

From 400-60 cm 26 samples were obtained in an 820 cm profile at Dongganchi of Fangshan in Beijing. They provided a continuous record of vegetation and environmental changes over ca .7000 aB.P., as inferred from Spore-pollen. loss-on-ignition (LOI), and charcoal analysis,impacts of natural fire and human activities on plant communities and lakes and swamps were considered. 1) From 7000-5960 aB.P, the forest development was limited, probably in response to climate Warming. Aquatic and marsh plants began to increase, bat the lakes and swamps in some areas were limited. 2) About 5960-3390 aB.p, presumably in responded to climate warming which was warmer than that at present Aquatic plants began to become abundant,reflected the widespread development of the lakes and swamps, the climate was wet with annual precipitation higher than that at present 3) About 3390-1000 aB.P, human activities have kept to be the dominating factor in the evolution of vegetation and climatic change. Temperature decreased, and the annual precipitation rapidly reduced in Baijing area. the lakes and swamps gradually shrank back, some of them even disappeared. 4) After 1000 aB.P, there was a severe fluntuction, and early during this time, it was comparatively warm and humid, but became cool and dry later. In the meantime. human activities were intensified. agricultural activity was flourished. and large area of water field was cultivated

The short and long-term effect of polystyrene nanoplastics on nitrifying sludge at high nitrite concentrations

The effect of nanoplastics(NPs)on nitrite oxidation bacteria(NOB)community in treating high-strength wastewater remains unclear,which seriously affects the stability of nitrogen removal process.In this study,highly active nitrifying sludge was enriched and exposed to 50nm polystyrene NPs(PS-NPs)for short-term(1,100,500,and 1000 mg/L,1.5 hr)and long-term(1,10,100 mg/L,40 days)at high nitrite concentration.In contrast to previous studies,our results showed that the exposures to PS-NPs had little effect on nitrifying performances.After long-term exposure,the protein/polysaccharide ratios in extracellular polymeric substances(EPS)were positively correlated with PS-NPs concentrations(0.78–0.99).The produced reactive oxygen species(ROS)were gradually removed,and PS-NPs higher than 10 mg/L caused damage to membrane integrity.Long-term exposure for 40 days increased the community diversity and caused significant differences between the control and exposed communities.The control group were dominated by Nitrobacter and Exiguobacterium,while the exposure group was dominated by Bacillus,Mycobacterium,and Nitrospira.A noticeable shift in the NOB community from Nitrobacter(26.5%to 3.4%)to Nitrospira(1.61%to 14.27%)was observed.A KEGG analysis indicated a decrease in cell growth and death,cell motility and energy metabolism.It appeared that NOB could adapt to PS-NPs stress through enhanced secretion and removal of oxidative damage.Overall,this study provided new insights into the response mechanism of NOB to PS-NPs exposure.

Simultaneous Fe(Ⅲ) reduction and ammonia oxidation process in Anammox sludge

In recent years, there have been a number of reports on the phenomenon in which ferric iron（Fe（Ⅲ）） is reduced to ferrous iron [Fe（Ⅱ）] in anaerobic environments, accompanied by simultaneous oxidation of ammonia to NO2-, NO3-, or N2.However, studies on the relevant reaction characteristics and mechanisms are rare. Recently, in research on the effect of Fe（Ⅲ） on the activity of Anammox sludge, excess ammonia oxidization has also been found.Hence, in the present study, Fe（Ⅲ） was used to serve as the electron acceptor instead of NO2-,and the feasibility and characteristics of Anammox coupled to Fe（Ⅲ） reduction（termed Feammox） were investigated. After 160 days of cultivation, the conversion rate of ammonia in the reactor was above 80%, accompanied by the production of a large amount of NO3-and a small amount of NO2-. The total nitrogen removal rate was up to 71.8%. Furthermore,quantities of Fe（Ⅱ） were detected in the sludge fluorescence in situ hybridization（FISH） and denaturated gradient gel electrophoresis（DGGE） analyses further revealed that in the sludge, some Anammox bacteria were retained, and some microbes were enriched during the acclimatization process. We thus deduced that in Anammox sludge, Fe（Ⅲ） reduction takes place together with ammonia oxidation to NO2-and NO3-along with the Anammox process.

The role of NiFe_(2)O_(4)nanoparticle in the anaerobic digestion(AD)of waste activated sludge(WAS)

Anaerobic digestion(AD)is a promising technology for the treatment of waste activated sludge(WAS)with energy recovery.However,the low methane yield and slow methanogenesis limit its broad application.In this study,the NiFe_(2)O_(4)nanoparticles(NPs)were fabricated and applied as a conductive material to enhance the AD via promoting the direct interspecies electron transfer(DIET).The crystal structure,specific surface area,morphology and elemental composition of the as-prepared NiFe_(2)O_(4)NPs were characterized by X-ray diffraction(XRD),Brunauer-Emmett-Teller(BET),scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS).The biochemical methane potential(BMP)test was performed(lasting for 35 days)to evaluate the energy recovery in AD with the addition of the NiFe_(2)O_(4)NPs.The results illustrate that NiFe_(2)O_(4)NPs could accelerate both the hydrolysis,acidogenesis and methanogenesis,i.e.,the cumulative methane production and daily methane yield increased from 96.76±1.70 mL/gVS and 8.24±1.26 mL gVS^(-1)d^(-1)in the absence of NiFe_(2)O_(4)NPs(Group A)to 123.69±3.20 mL/gVS and 9.71±0.77 mL gVS^(-1)d^(-1)in the presence of NiFe_(2)O_(4)NPs(Group B).The model simulation results showed that both the first-order kinetic model and the modified Gompertz model can well simulate the experimental results.The hydrolysis rate constant k increased from 0.04±0.01 d^(-1)in Group A to 0.06±0.01 d^(-1)in Group B.And the maximum methane production potential and activity were both improved after adding NiFe_(2)O_(4).The microbial community analysis revealed that the microorganisms associated with hydrolysis and acidogenesis were more abundant in the presence of NiFe_(2)O_(4).And the methanogenic archaea were enriched to a larger extent,resulted in the higher methanogenesis activities via dosing NiFe_(2)O_(4).

High rate production of concentrated sulfides from metal bearing wastewater in an expanded bed hydrogenotrophic sulfate reducing bioreactor

Metallurgical wastewaters contain high concentrations of sulfate,up to 15 g L^(-1).Sulfate-reducing bioreactors are employed to treat these wastewaters,reducing sulfates to sulfides which subsequently coprecipitate metals.Sulfate loading and reduction rates are typically restricted by the total H2S concentration.Sulfide stripping,sulfide precipitation and dilution are the main strategies employed to minimize inhibition by H2S,but can be adversely compromised by suboptimal sulfate reduction,clogging and additional energy costs.Here,metallurgical wastewater was treated for over 250 days using two hydrogenotrophic granular activated carbon expanded bed bioreactors without additional removal of sulfides.H2S toxicity was minimized by operating at pH 8±0.15,resulting in an average sulfate removal of 7.08±0.08 g L^(-1),sulfide concentrations of 2.1±0.2 g L^(-1) and peaks up to 2.3±0.2 g L^(-1).A sulfate reduction rate of 20.6±0.9 g L^(-1)d^(-1) was achieved,with maxima up to 27.2 g L^(-1)d^(-1),which is among the highest reported considering a literature review of 39 studies.The rates reported here are 6e8 times higher than those reported for other reactors without active sulfide removal and the only reported for expanded bed sulfate-reducing bioreactors using H2.By increasing the influent sulfate concentration and maintaining high sulfide concentrations,sulfate reducers were promoted while fermenters and methanogens were suppressed.Industrial wastewater containing 4.4 g L^(-1) sulfate,0.036 g L^(-1) nitrate and various metals(As,Fe,Tl,Zn,Ni,Sb,Co and Cd)was successfully treated with all metal(loid)s,nitrates and sulfates removed below discharge limits.

Bacterial communities in different locations, seasons and segments of a dairy wastewater treatment system consisting of six segments

A dairy wastewater treatment system composed of the 1st segment（no aeration） equipped with a facility for the destruction of milk fat particles, four successive aerobic treatment segments with activated sludge and a final sludge settlement segment was developed. The activated sludge is circulated through the six segments by settling sediments（activated sludge） in the 6th segment and sending the sediments beck to the 1st and 2nd segments.Microbiota was examined using samples from the non-aerated 1st and aerated 2nd segments obtained from two farms using the same system in summer or winter. Principal component analysis showed that the change in microbiota from the 1st to 2nd segments concomitant with effective wastewater treatment is affected by the concentrations of activated sludge and organic matter（biological oxygen demand [BOD]）, and dissolved oxygen（DO） content. Microbiota from five segments（1st and four successive aerobic segments） in one location was also examined. Although the activated sludge is circulating throughout all the segments, microbiota fluctuation was observed. The observed successive changes in microbiota reflected the changes in the concentrations of organic matter and other physicochemical conditions（such as DO）, suggesting that the microbiota is flexibly changeable depending on the environmental condition in the segments. The genera Dechloromonas, Zoogloea and Leptothrix are frequently observed in this wastewater treatment system throughout the analyses of microbiota in this study.

Name-Face Association in Web Videos: A Large-Scale Dataset,Baselines, and Open Issues

Associating faces appearing in Web videos with names presented in the surrounding context is an important task in many applications. However, the problem is not well investigated particularly under large-scale realistic scenario,mainly due to the scarcity of dataset constructed in such circumstance. In this paper, we introduce a Web video dataset of celebrities, named WebV-Cele, for name-face association. The dataset consists of 75 073 Internet videos of over 4 000 hours,covering 2 427 celebrities and 649 001 faces. This is, to our knowledge, the most comprehensive dataset for this problem.We describe the details of dataset construction, discuss several interesting findings by analyzing this dataset like celebrity community discovery, and provide experimental results of name-face association using five existing techniques. We also outline important and challenging research problems that could be investigated in the future.

Geomorphic predictors of riparian vegetation in small mountain watersheds

Aims Hydrogeomorphic processes operating at watershed,process zone and site scales influence the distribution of riparian vegeta-tion.However,most studies examining the relationships between hydrogeomorphic processes and riparian vegetation are conducted at site scales.We quantified the relative importance of watershed,process zone and site geomorphic characteristics for predicting riparian plant community types and plant species abundances in four small mountain watersheds in central Nevada,u.Methods We mapped riparian vegetation types and identified process zones(based on dominant geomorphic process and valley fill material)within the watersheds.We sampled sites in each combination of veg-etation type and process zone(n=184 sites)and collected data on watershed scale factors,valley and stream geomorphic characteristics and on plant cover of each geomorphic surface.Plant community types were defined by cluster and indicator species analyses of plant cover data,and related to geomorphic variables using ordination analysis(nonmetric multidimensional scaling).linear mixed effects models were used to predict abundances of indicator species.Important Findings Variables describing position in the watershed(elevation,contrib-uting area)that are related to gradients of temperature,moisture and stream discharge were of primary importance in predicting plant community types.Variables describing local geomorphic setting(valley width,stream gradient,channel sediments,geomor-phic surface height)were of secondary importance,but accurately described the geomorphic setting of indicator species.The process zone classification did not include position in the watershed or channel characteristics and only predicted plant community types with unique geomorphic settings.In small mountain watersheds,predicting riparian vegetation distribution requires explicit consid-eration of scale and geomorphic context within and among water-sheds in addition to site variables.