Consortium Chain Consensus Vulnerability and Chain Generation Mechanism

Effectively identifying and preventing the threat of Byzantine nodes to the security of distributed systems is a challenge in applying consortium chains.Therefore,this paper proposes a new consortium chain generation model,deeply analyzes the vulnerability of the consortium chain consensus based on the behavior of the nodes,and points out the effects of Byzantine node proportion and node state verification on the consensus process and system security.Furthermore,the normalized verification node aggregation index that represents the consensus ability of the consortium organization and the trust evaluation function of the verification node set is derived.When either of the two is lower than the threshold,the consortium institution or the verification node set members are dynamically adjusted.On this basis,an innovative consortium chain generation mechanism based on the Asynchronous Binary Byzantine Consensus Mechanism(ABBCM)is proposed.Based on the extended consortium chain consensus mechanism,a certain consensus value set can be combined into multiple proposals,which can realize crossdomain asynchronous message passing between multi-consortium chains without reducing the system’s security.In addition,experiments are carried out under four classical Byzantine Attack(BA)behaviors,BA1 to BA4.The results show that the proposed method can obtain better delay than the classical random Byzantine consensus algorithm Coin,effectively improving the consensus efficiency based on asynchronous message passing in the consortium chain and thus meeting the throughput of most Internet of Things(IoT)applications.

Vertical Federated Learning Based on Consortium Blockchain for Data Sharing in Mobile Edge Computing

The data in Mobile Edge Computing(MEC)contains tremendousmarket value,and data sharing canmaximize the usefulness of the data.However,certain data is quite sensitive,and sharing it directly may violate privacy.Vertical Federated Learning(VFL)is a secure distributed machine learning framework that completes joint model training by passing encryptedmodel parameters rather than raw data,so there is no data privacy leakage during the training process.Therefore,the VFL can build a bridge between data demander and owner to realize data sharing while protecting data privacy.Typically,the VFL requires a third party for key distribution and decryption of training results.In this article,we employ the consortium blockchain instead of the traditional third party and design a VFL architecture based on the consortium blockchain for data sharing in MEC.More specifically,we propose a V-Raft consensus algorithm based on Verifiable Random Functions(VRFs),which is a variant of the Raft.The VRaft is able to elect leader quickly and stably to assist data demander and owner to complete data sharing by VFL.Moreover,we apply secret sharing todistribute the private key to avoid the situationwhere the training result cannot be decrypted if the leader crashes.Finally,we analyzed the performance of the V-Raft and carried out simulation experiments,and the results show that compared with Raft,the V-Raft has higher efficiency and better scalability.

Asymmetric Consortium Blockchain and Homomorphically Polynomial-Based PIR for Secured Smart Parking Systems

In crowded cities,searching for the availability of parking lots is a herculean task as it results in the wastage of drivers’time,increases air pollution,and traffic congestion.Smart parking systems facilitate the drivers to determine the information about the parking lot in real time and book them depending on the requirement.But the existing smart parking systems necessitate the drivers to reveal their sensitive information that includes their mobile number,personal identity,and desired destination.This disclosure of sensitive information makes the existing centralized smart parking systems more vulnerable to service providers’security breaches,single points of failure,and bottlenecks.In this paper,an Improved Asymmetric Consortium Blockchain and Homomorphically Computing Univariate Polynomial-based private information retrieval(IACB-HCUPPIR)scheme is proposed to ensure parking lots’availability with transparency security in a privacy-preserving smart parking system.In specific,an improved Asymmetric Consortium Blockchain is used for achieving secure transactions between different parties interacting in the smart parking environment.It further adopted the method of Homomorphically Computing Univariate Polynomial-based private information retrieval(HCUPPIR)scheme for preserving the location privacy of drivers.The results of IACB-HCUPPIR confirmed better results in terms of minimized computation and communication overload with throughput,latency,and response time with maximized drivers’privacy preservation.Moreover,the proposed fully homomorphic algorithm(FHE)was compared against partial-homomorphic encryption(PHE)and technique without encryption and found that the proposed model has quick communication in allocating the parking slots starting with 24.3 s,whereas PHE starts allocating from 24.7 s and the technique without encryption starts at 27.4 s.Thus,we ensure the proposed model performs well in allocating parking slots with less time and high security with privacy preservation.

Research and Practice on the Construction of Municipal Industry-Education Consortium Based on the Integration of Industrial Chain,Innovation Chain,Talent Chain,and Education Chain

The construction of a municipal industry-education consortium is one of the important measures for the“one body,two wings,and five key points”reform of China’s modern vocational education system in the new era.It is of great significance for the integrated promotion of the three major national strategies of education,technology,and talent.Exploring the construction path of municipal industry-education consortia from the perspective of“four-chain integration”is essential for improving the quality of vocational education talents,comprehensively promoting local economic and social development,and serving the national strategy of revitalizing the country through science and education.The new generation of information technology industry-education consortium in Chengdu actively explores new paths of industry-education integration,science-education integration,and vocational-education integration.It has formed a“park+alliance”to establish a diversified collaborative construction and management mechanism,a“professional+industry”school-enterprise cooperation to promote industrial transformation and upgrading,a“teaching+research and development”to build an industry-university research innovation platform to empower high-quality development,and a“cultivation+employment”to explore a matrix style talent cultivation model,thus promoting regional governments,industries enterprises,and higher education institutions.Fully leveraging complementary advantages involves capitalizing on the spatial cluster effect.It requires a foundation in the education chain,guided by the industrial chain,activation of the innovation chain,establishment of a talent chain,enhancement of the value chain,and the promotion of a modern vocational education structure.This structure should align with market demand and industry structure,ultimately promoting regional economic and social development.

A Consortium Blockchain Paradigm on Hyperledger-Based Peer-to-Peer Lending System

This paper focuses on how to use consortium blockchain to improve the regulation of peer-to-peer(P2 P) lending market. The partial decentralized consortium blockchain with limited pre-set nodes can well improve transparency and security, which is suitable for financial regulation. Considering irregularities of the P2P lending market, the Hyperledger-based Peer-to-Peer Lending System(HyperP2PLS) is proposed. First elaborate the application scenario and business logic of the system, where a national P2P Lending Trading Center will be established to integrate all transactions and information of P2P lending market. Then construct the system architecture consisting of the blockchain network, HTTP server, and applications. The algorithm of implementation process and the web application for users have been well illustrated. The performance analysis shows that HyperP2PLS can guarantee the reliability, safety, transparency and efficiency.

Exploration of the key microbes and composition stability of microbial consortium GF-20 with efficiently decomposes corn stover at low temperatures

The microbial consortium GF-20(GF-20) can efficiently decompose corn stover at low temperatures. The present study explored the key microbes of GF-20 and evaluated different culture conditions on its composition stability to promote the utilization of corn stover decomposing microbes in low temperature regions. GF-20 was subcultured to the 15 th generation under different temperatures, pHs, carbon, and nitrogen sources. Then, the dynamics of fermenting pH, cellulose enzyme activities, carbohydrate concentration, and oxidation reduction potential were determined to estimate the degradation efficiency of corn stover with GF-20. Furthermore, the structural stability and functional microbes of GF-20 were identified on the basis of PCR-denaturing gradient gel electrophoresis(DGGE) profiling and principal component analysis. The results showed that the offspring of GF-20 subcultured under different temperatures(4–30°C) and pH(6.0–9.0) conditions maintained stable growth, decomposition function, and composition structure. Furthermore, consortia GF-20 had a stable composition structure, which induced GF-20 to secrete cellulose and promote substrate decomposition as corn stover and ammonium were used as sources of carbon and nitrogen, respectively. According to the PCR-DGGE profiles, the key strains of GF-20 were determined to be Bacillus licheniformis, Cellvibrio mixtus subsp. mixtus, Bacillus tequilensis, Clostridium populeti, and Clostridium xylanolyticum.

Isolation and Characteristics of a Microbial Consortium for Effectively Degrading Phenanthrene

A microbial consortium （named W4） capable of aerobic biodegradation of solid phenanthrene as the sole source of carbon and energy was isolated by selective enrichment from petroleum-contaminated soil in the Henan oilfield, China. The strains of the consortium were identified as Sphingomonas cloacae, Rhizobium sp., Pseudomonas aeruginosa and Achromobacter xylosoxidans respectively by means of genetic methods. The major metabolites of phenanthrene were analyzed by gas chromatography-mass spectrometry （GC-MS）. The biodegradation percentage of solid phenanthrene at 200 mg/L in liquid medium after 7 days of growth was greater than 99%. The degradation of phenanthrene was compared between individual predominant strains and the microbial consortium in different treatment processes. The microbial consortium showed a significant improvement of phenanthrene degradation rates in either static or shaking culture. The degradation percentage of phenanthrene by the consortium W4 decreased to some degree when C 16 coexisted, however it was hardly affected by C30. Furthermore, the ability of consortium W4 to remediate oil sludge from the Dagang oil refinery was studied by composting, and it was found that the consortium W4 could obviously remove polycyclic aromatic hydrocarbons （PAils） and paraffinic hydrocarbons. All the results indicated that the microbial consortium W4 had a promising application in bioremediation of oil-contaminated environments and could be potentially used in microbial enhanced oil recovery （MEOR）.

Microbial oxidation of refractory gold sulfide concentrate by a native consortium

A defined mesophilic consortium including an iron oxidizing bacterium and a sulfur oxidizing bacterium was constructed to evaluate its ability for bioleaching a flotation concentrate from Andacollo mine in Neuquén,Argentina.Experiments were performed in shake flasks with a pulp density of10%(w/v),using a basal salt medium containing ferrous iron at pH1.8.The leaching solutions were analyzed for pH,redox potential(using specifics electrodes),ferrous iron(by UV-Vis spectrophotometry)and metal concentrations(by atomic absorption spectroscopy).The results showed that the consortium was able to reduce the refractory behavior of the concentrate,allowing91.6%of gold recovery;at the same time,high dissolution of copper and zinc was reached.These dissolutions followed a shrinking core kinetic model.According to this model,the copper solubilization was controlled by diffusion through a product layer(mainly jarosite),while zinc dissolution did not show a defined control step.This designed consortium,composed of bacterial strains with specific physiological abilities,could be useful not only to optimize gold recovery but also to decrease the leachates metallic charge,which would be an environmental advantage.

Degradation Characteristics and Community Structure of a Hydrocarbon Degrading Bacterial Consortium

A hydrocarbon degrading bacterial consortium KO5-2 was isolated from oil-contaminated soil of Karamay in Xinjiang, China, which could remove 56.9% of 10 g/L total petroleum hydrocarbons(TPH) at 30 ℃ after 7 days of incubation, and could also remove 100% of fluorene, 98.93% of phenanthrene and 65.73% of pyrene within 3, 7 and 9 days, respectively. Twelve strains from six different genera were isolated from KO5-2 and only eight ones were able to utilize the TPH. The denaturing gradient gel electrophoresis(DGGE) was used to investigate the microbial community shifts in five different carbon sources(including TPH, saturated hydrocarbons, fluorene, phenanthrene and pyrene). The test results indicated that the community compositions of KO5-2 in carbon sources of TPH and saturated hydrocarbons, respectively, were roughly the same, while they were distinctive in the three different carbon sources of PAHs. Rhodococcus sp. and Pseudomonas sp. could survive in the five kinds of carbon sources. Bacillus sp., Sphingomonas sp. and Ochrobactrum sp. likely played key roles in the degradation of saturated hydrocarbons, PAHs and phenanthrene, respectively. This study showed that specific bacterial phylotypes were associated with different contaminants and complex interactions between bacterial species, and the medium conditions influenced the biodegradation capacity of the microbial communities involved in bioremediation processes.

Kinetics and characteristics of phenanthrene degradation by a microbial consortium

The kinetics and characteristics of phenanthrene degradation by a microbial consortium W4 isolated from Henan Oilfield were investigated. The degradation percentage of solid phenanthrene at 200 mg/L in liquid medium after 6 days of incubation was higher than 95% under the condition of 37 ℃ and 120 r/min by this microbial consortium. The degradation of phenanthrene could be fitted to a first-order kinetic model with the half-life of 1.25 days. The optimum conditions for degradation ofphenanthrene by consortium W4 were as follows： temperature about 37℃, pH from 6.0 to 7.0 and salinity about 8.0 g/L. It was concluded that microbial consortium W4 might degrade phenanthrene via both salicylic acid and o-phthalic acid pathways by analyzing products with GC-MS.

Screening of a microbial consortium with efficient corn stover degradation ability at low temperature

To speed up the degradation of corn stover directly returned to soil at low temperature, the corn stover-degrading microbial consortium GF-20, acclimated to biological decomposition in the frigid region, was successfully constructed under a long-term limiting substrate. To evaluate its potential in accelerating the decomposition of un-pretreated corn stover, the decomposing property, fermentation dynamic and the microbial diversity were analyzed. GF-20 degraded corn stover by 32% after 15-day fermentation at 10℃. Peak activities of filter paperlyase（FPA）, β-glucosidases（CB）, endoglucanases（Cx）, and cellobiohydrolases（C1） were 1.15, 1.67, 1.73, and 1.42 U m L^–1, appearing at the 6th, 3rd, 11 th, and 9th d, respectively. The p H averaged at 6.73–8.42, and the optical density（OD） value peaked at 1.87 at the 120 h of the degradation process. Cellulase, hemicellulase and lignin in corn stover were persistently degraded by 44.85, 43.85 and 25.29% at the end of incubation. Result of denaturing gradient gel electrophoresis（DGGE） profiles demonstrated that GF-20 had a stable component structure under switching the temperature and p H. The composition of the GF-20 was also analyzed by constructing bacterial 16 S r DNA clone library and fungal 18 Sr DNA-PCR-DGGE. Twenty-two bacterial clones and four fungal bands were detected and identified dominant bacteria represented by Cellvibrio mixtus subsp., Azospira oryzae, Arcobacter defluyii, and Clostridium populeti and the fungi were mainly identified as related to Trichosporon sp.

Isolation and Characterization of a Thermophilic Oil-Degrading Bacterial Consortium

In this study, a thermophilic oil-degrading bacterial consortium KO8-2 growing within the temperature range of 45--65℃ （with 55℃ being the optimum temperature） was isolated from oil-contaminated soil of Karamay in Xinjiang, China. Denaturing gradient gel electrophoresis （DGGE） showed that there were nine strains included in KO8-2, which originated from the genera of Bacillus, Geobacillus and Clostridium. They all belonged to thermophilic bacteria, and had been previously proved as degraders of at least one petroleum fraction. The crude oil degraded by KO8-2 was analyzed by infrared spectrophotometry, hydrocarbon group type analysis and gas chromatography. The results indicated that the bacterial consortium KO8-2 was able to utilize 64.33% of saturates, 27.06% of aromatics, 13.24% of resins and the oil removal efficiency reached up to 58.73% at 55 ~C when the oil concentration was 10 g/L. Detailed analysis showed that KO8-2 was able to utilize the hydrocarbon components before C19, and the n-alkanes ranging from C20--C33 were signifi- cantly degraded. The ratios of nC17/Pr and nC18/Ph were 3.12 and 3.87, respectively, before degradation, whereas after degradation the ratios reduced to 0.21 and 0.38, respectively. Compared with the control sample, the oil removal efficiency in KO8-2 composting reactor reached 50.12% after a degradation duration of 60 days.

Application of an immobilized microbial consortium for the treatment of pharmaceutical wastewater: Batch-wise and continuous studies

In the present investigation,a microbial consortium consisting of four bacterial strains was selected for the treatment of pharmaceutical industry wa stewater.The consortium was immobilized on a natural support matrixLuffa and used for the treatment of real-time pharmaceutical wastewater in batch and continuous processes.The batch process was carried out to optimize the culture conditions and monitor the enzymatic activity.An array of enzymes such as alcohol dehydrogenase,aldehyde dehydrogenase,monooxygenase,catechol 2,3-dioxygenase and hydroquinol 1,2-dioxygenase were produced by the consortium.The kinetics of the degradation in the batch process was analyzed and it was noted to be a first-order reaction.For the continuous study,an aerobic fixed-film bioreactor(AFFBR) was utilized for a period of 61 days with variable hydraulic retention time(HRT) and organic loading rate(OLR).The immobilized microbes treated the wastewater by reducing the COD,phenolic contaminants and suspended solids.The OLR ranged between(0.56±0.05) kg COD·m^(-3) d^(-1) to 3.35 kg COD·m^(-3)·d^(-1) and the system achieved an average reduction of 96.8% of COD,92.6% of phenolic compounds and 95.2% of suspended solids.Kinetics of the continuous process was interpreted by three different models,where the modified Stover Kincannon model and the Grau second-order model proved to be best fit for the degradation reaction with the constant for saturation value,k_(L) being 95.12 g·L^(-1)·d^(-1).the constant for maximum utilization of the substrate U_(max) being 90.01 g·L^(-1) d^(-1) and substrate removal constant KY was1.074 d^(-1) for both the models.GC-MS analysis confirmed that most of the organic contaminants were degraded into innocuous metabolite s.

Increased sedimentation of a Pseudomonas–Saccharomyces microbial consortium producing medium chain length polyhydroxyalkanoates

Concerns about feasibility,separability,settleability,efficiency once hampered studies on polyhydroxyalkanoates(PHAs)production,which mainly focused on single strain microorganism or activated sludge rather than artificial microbial consortia.Here,a medium chain length PHAs(mcl-PHAs)producing Pseudomonas-Saccharomyces consortium with xylose as the main substrate was studied.Mcl-PHAs accumulation increased from 12.69 mg·L^-1 to 152.3 mg·L^-1 without any optimization method.The presence of Saccharomyces cerevisiae,though in a relatively low concentration,improved the sedimentation of cell mass of the mixed culture by 60%.Reasons for better sedimentation of the consortium were complex:first,the length of Pseudomonas putida increased two to three times in the consortium;second,the positive surface charge of P.putida was neutralized by S.cerevisiae;third,the adhesion proteins on the surface of S.cerevisiae interacted with the P.putida.

Efficient degradation of lube oil by a mixed bacterial consortium

A laboratory study was performed to assess the biodegradation of lube oil in bio-reactor with 304# stainless steel as a biofilm carrier. Among 164 oil degrading bacterial cultures isolated from oil contaminated soil samples, Commaonas acidovorans Px1, Bacillus sp. Px2, Pseudomonas sp. Px3 were selected to prepare a mixed consortium for the study based on the efficiency of lube oil utilization. The percentage of oil degraded by the mixed bacterial consortium decreased slightly from 99% to 97.2% as the concentration of lube oil was increased from 2000 to 10,000 mg/L. The degradation of TDOC （total dissolved organic carbon） showed a similar tendency compared with lube oil removal, which indicated that the intermediates in degradation process hardly accumulated. Selected mixed bacterial consortium showed their edge compared to activated sludge. Scanning electron microscopy （SEM） photos showed that biofilms on stainless steel were robust and with a dimensional framework constructed by EPS （extracellular polymeric substances）, which could promote the biodegradation of hydrocarbons. The increase of biofilm followed first-order kinetics with rate of 0.216 μg glucose/（cm2·day） in logarithm phase. With analysis of Fourier transform infrared spectroscopy （FT-IR） and gas chromatography-mass spectrometry （GC-MS） combined with removal of lube oil and TDOC, mixed bacterial consortium could degrade benzene and its derivatives, aromatic ring organic matters with a percentage over 97%.

Study of a plugging microbial consortium using crude oil as sole carbon source

A microbial consortium named Y4 capable of producing biopolymers was isolated from petroleum-contaminated soil in the Dagang Oilfield, China. It includes four bacterial strains： Y4-1 （Paenibacillus sp.）, Y4-2 （Actinomadura sp.）, Y4-3 （Uncultured bacterium clone） and Y4-4 （Brevibacillus sp.）. The optimal conditions for the growth of the consortium Y4 were as follows： temperature about 46 ℃, pH about 7.0 and salinity about 20.0 g/L. The major metabolites were analyzed with gas chromatographymass spectrometry （GC-MS）. A comparison was made between individual strains and the microbial consortium for biopolymer production in different treatment processes. The experimental results showed that the microbial consortium Y4 could produce more biopolymers than individual strains, and the reason might be attributed to the synergetic action of strains. The biopolymers were observed with optical and electron microscopes and analyzed by paper chromatography. It was found that the biopolymers produced by the microbial consortium Y4 were insoluble in water and were of reticular structure, and it was concluded that the biopolymers were cellulose. Through a series of simulation experiments with sand cores, it was found that the microbial consortium Y4 could reduce the permeability of reservoir beds, and improve the efficiency of water flooding by growing biomass and producing biopolymers. The oil recovery was enhanced by 3.5% on average. The results indicated that the consortium Y4 could be used in microbial enhanced oil recovery and play an important role in bioremediation of oil polluted environments.

The Pathway of China’s Integrated Delivery System:Based on the Analysis of the Medical Consortium Policies

With the deepening of China’s health-care reform,an integrated delivery system has gradually emerged with the function of improving the efficiency of the health-care delivery system.For China’s integrated delivery system,a medical consortium plays an important role in integrating public hospitals and primary care facilities.The first medical consortium policy issued after the COVID-19 pandemic apparently placed hope on accelerating the implementation of a medical consortium and tiered health-care delivery system.This paper illustrates the possible future pathway of China’s medical consortium through retrospection of the 10-year process,changes of the series of policies,and characteristics of the policy issued in 2020.We considered that a fully integrated medical consortium would be a major phenomenon in China's medical industry,which would lead to the formation of a dualistic care pattern in China.

Stability Analysis of a Lignocellulose Degrading Microbial Consortium

An active mesophilic lignocellulose degrading microbial consortium, designated LZF-12, was bred from humus-rich soil by successive subcultivation under facultative aerobic static condition. Batch experiments were performed to investigate the structural and functional stability of lignocellulose degradation of rice straw of 10 g · L-1. The results showed that efficient degradation of rice straw(>70%) could be achieved and acetic acid concentration accounted for over 70% of total aqueous products from different generations by microbial consortium LZF-12 within 7 days. Denaturing gradient gel electrophoresis(DGGE) and sequencing of 16 S r DNA sequences amplified from the total consortium DNA representing the presence of sequences were related to those of Clostridium, Clostridium cellulolyticum, Pseudomonas, Acetivibrio and some uncultured bacteria in LZF-12. DGGE pattern profiles from different LZF-12 generations were reproducible, suggesting the relative stabilities of the microbial community structure and succession mechanism in the established consortium.

Culturing of Autoflocculating Microalgal Consortium in Continuous Raceway Pond Reactor

The goal of this study was to develop a self-settling microalgal consortium in raceway pond reactor (RPR). Experiments were carried out with cultures that developed without additional seeding, but naturally promoted by process conditions in a raceway pond reactor. The changes in microalgal communities and total biomass under nitrogen and phosphorous limitations were studied in both batch and continuous systems. At the steady state batch had the population of 46% Euglena sp., 16% Closterium sp., 14% Chlorella sp., 14% Scenedesmus sp. and 10% Ankistrodesmus sp. with a maximum biomass of 900 mg/L. In order to get self-settling microalgal consortium, the operation was changed to continuous continuous mode with the aid of a specially designed settler for daily harvest and recycling of the biomass. Grazing fauna could be controlled by managing reduced liquid and solid retention time. At steady-state condition, an autofloculating and self-settling consortium was developed which had mainly Fragilaria sp., Scenedesmus sp., and filamentous Ulothrix sp. The maximum biomass concentration obtained was 140 mg/L. The presence of neutral lipid droplets in the consortium was identified by staining with Nile Red. Development of the lipid rich consortium could be a suitable method for producing biofuel.

Development and characterization of a functional microbial consortium for crude oil degradation

Crude oil-degrading microbial consortia were enriched from three oil-contaminated sites to achieve the efficient biodegradation of crude oil,especially its refractory residues.The gravimetric method was used to analyze the degradation efficiency of the enriched consortia and changes in the fractions of the crude oil.The effects of changes in environmental factors were also studied to determine the optimal oil-reducing conditions and assess the dominant bacteria of the mixed flora.Results show that all three consortia exhibit reliable crude oil-biodegradation abilities and that their mixture results in biodegradation rate are as high as(48.0±3.5)%over 30 d of incubation.The consortium mixture can degrade 11.1%of the refractory resins,79.7%of the saturated hydrocarbons,and 45.7%of the aromatics in crude oil.Neutral pH,an incubation temperature of 30℃,and low mineral salt concentrations(0.8%to 4.0%)are optimal for crude oil biodegradation.The dominant genera in the consortium mixture include Pseudomonas,Stenotrophomonas,Brucella,Serratia,Brevundimonas,and Achromobacter.The richness and diversity of the microbial community in the consortium remain stable during crude oil degradation.Therefore,microbial enrichment from multiple sources may be performed to construct a mixed consortium for crude oil pollution bioremediation.