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Bacteriocins are bacterial-derived peptides that exhibit antimicrobial activity and can be used as food preservatives. Here, using the indicator strain

Deep-sea microbes have received growing attention due to their contribution to biogeochemical cycles and climate change. However, related research lags due to the difficulty of collecting samples.

Determinism and stochasticity in microbial community composition decisions have attracted wide attention. However, there is no consensus on their interrelationships and relative importance, and the mechanism controlling the interaction between the two ecological processes remains to be revealed. The interaction of the two ecological processes on the continental shelf of the South China Sea was studied by performing 16S rRNA gene amplicon sequencing on 90 sediments at multiple depths in five sites. Three nearshore sites have higher microbial diversity than those two close to the shelf margin. Different microbial composition was observed between sites and microbial composition of nearshore sites was positively correlated with total nitrogen, total sulfur, total organic carbon, and dissolved oxygen, while that of offshore was positively correlated with total carbon, salinity, and photosynthetically active radiation. The null model test showed that the community composition among layers of the same site and between nearby sites was mainly dominated by the homogeneous selection, while that between distant sites was mainly affected by dispersal limitation, which indicates that geographic scale influences the interactivities of determinism and stochasticity. Our research indicates that the balance of these two ecological processes along the geographic scale is mainly determined by the dispersal ability of microbes and environmental heterogeneity between areas. The study provides new insights into how deterministic and stochastic processes shape microbial community composition on the continental shelf.

As one of the main gas fields in Chinese West-East Gas Transmission Project, cumulative gas production of Kela 2 Gas Field has been over 120 billion cubic meters since 2004. Each gas well has different gas production characteristics, water production, and pressure changes. Advanced water results in a serious non-homogeneous water invasion, and the actual gas production is much less than that in the development scheme. To further enhance the recovery of the Kela 2 Gas Field, productivity influencing factors of each gas pay interval are analyzed by using the production logging data based on geological characteristics. According to the change of the main gas pay and water production from production logging, gas wells are divided into four types, and three water invasion patterns in Kela 2 Gas Field. The causes of gas production changes and water production regime are analyzed for each type first, and then the main productivity influencing factors in gas wells are determined. The outcome shows that pressure drop, water breakthrough of gas pay layers, and different reservoir properties are the main productivity influencing factors. Through gas well classification of the Kela 2 Gas Field, the productivity influencing factors and productivity change regime are determined, which could provide grounds for further enhancing the recovery of the Kela 2 Gas Field.

Methicillin-resistant Staphylococcus aureus (MRSA) is a major human pathogen that is difficult to treat because of its resistance to several widely used antibiotics. The present study aimed to identify novel anti-MRSA bacteriocins in a prominent producer of bacteriocins, Bacillus cereus group.

For simulation of hypersonic turbulent and transitional flows at high Reynolds numbers, a gas-kinetic scheme (GKS) strongly coupled with the turbulent kinetic energy equation in shear stress transp...

As an important source, sink and pool of carbon, lake sediment plays an important role in carbon cycle. Inorganic carbon (IC) in lake sediment is abundant, however the role of inorganic carbon in lake systems in terrestrial carbon cycling remains less clear. In this paper, the spatial variations, source and transformation of IC in sediments of Lake Hulun were investigated and compared with typical lakes of Inner Mongolia Plateau by analyzing the influencing factors. The results showed that contents of total IC in surface sediment in Lake Hulun ranged from 17.2 to 66.7 mg g–1 with a mean of 42.6 mg g–1, and the pattern of spatial distribution showed obviously decreasing trend from southwest to northeast lake districts. The order size of IC fractions in surface sediment was in a sequence of EX (extracted by NaCl) < SAL (extracted by NaOH) < WAL (extracted by NH3·H2O) ⪡ SAC (extracted by HCl) < WAC (extracted by HO-NH2·HCl), the WAC and SAC fractions were the major fractions, accounted for 80% of total IC. In vertical distribution, the WAC and SAC fractions presented obviously opposite spatial distribution, indicted that these fractions could transform into each other in sediments. The ratio of IAP/Ksp in lake water ranged from 8.87 to 108.5, suggested that this lake had what it took to form the authigenic carbonate precipitation. A differential analysis study indicated that the mechanisms what made the difference of IC content in four lakes were multiple, the chemical properties and temperature of lake water, the defusion or dissolve of CO2, biomass and sediment environment were the key factors that might affect the contents of inorganic carbon in the lake sediment.

The Visualization for hyperspectral images is demanded by the ground processing system for quick view and information survey. Previous methods using band selection or dimension reduction fa...

Gas reservoir numerical simulation is an important method to optimize the development strategy of shale gas reservoirs which has been influenced by the multi-stage fracture. The regular fracture network model was used to build a conventional numerical simulation, in which it was difficult to show the true situation of fracture propagation. However, the physical parameters not only affect the production, but also influence the stimulation effect; moreover, the quality of the fracturing effect also affects the production which causes the input and out parameters to be inaccurate. To solve this problem, the process simulation must be completed from geology to engineering to gas reservoir. The main controlling factors of production are identified with geological and engineering factors such as horizontal stage length, the volume of fracturing fluid, well spacing, production allocation, and proppant mass. Therefore, on the basis of the integrated simulation method of a hydraulic fracturing network simulation and an unstructured grid high-precision numerical simulation, this paper builds an integrated numerical simulation of a shale gas reservoir coupled with geology and engineering to optimize the development strategy with production as the target. Taking four wells of a platform as an example, the EUR (estimated ultimate recovery) has increased by 25% after the optimization of the development strategy.

High permeability zones in the water-drive gas reservoir tend to act as dominant channels for formation water to invade into gas reservoir from the aquifer. The presence of high permeability zones results in uneven water flow front in reservoir and early water breakthrough in gas well, which seriously affects the gas field development. In this paper, conventional logging and production logging data are used to identify and characterize high permeability zones, so as to guide the optimization of development plan of Kela 2 gas field. A method to determine the lower limit of high permeability zones by using cumulative frequency curve of permeability distribution is proposed, and high permeability zones of 21 wells are identified. These high permeability zones account for 10–15% of the effective reservoir thickness in single wells, and they are mainly distributed in the middle of the Bashijiqike (K1bs) Formation (i.e., K1bs12, K1bs21 and K1bs22). The analysis of production logging data shows that the effective gas producing intervals only account for 29.2% of the total number of test intervals, most of which are related to high permeability zones. Further study shows that the high gas flow from the high permeability zones dominates the wellbore production profile, and the gas in low permeability zones flows vertically to the high permeability zones and horizontally to wellbore through these zones. Through the analysis of production profiles over the years and computer modelling, it is confirmed that water channelling occurred in some gas wells at the depth where the high permeability zones are located, which leads to a significant decline in production of these wells. Based on the study of distribution and behaviour characteristics of the high permeability zones, two suggestions on controlling inhomogeneous water invasion are put forward to realize the sustainable and stable production of the gas field.

Colorectal cancer (CRC) is a major health problem and third most common deaths in western world. Dietary interventions together with modified dietary style can prevent the CRC in humans. Xanthohumol (XHA), a polyphenol isolated from Humulus lupulus L. contains many beneficial effects. The aim of the study is to analyze the effect of XHA on Azoxymethane (AOM)-induced experimental CRC in rats. Levels of MDA were increased and enzymic antioxidants levels were decreased in AOM-induced rats. However, these levels were reversed upon XHA treatment. Further, the mRNA expressions of iNOS and COX-2 were also downregulated in XHA treated rats compared to AOM-induced rats. Further, we found that administration of XHA suppressed the wnt/β-catenin signaling together with modulation of apoptotic proteins Bax, Bcl-2, and caspase 3. We conclude that XHA can able to quench the free radicals, inhibits cell proliferation and induces apoptosis, thus it can be a chemopreventive/therapeutic agent against CRC.

Combinatorial optimization problems (COPs) are a class of NP-hard problems with great practical significance. Traditional approaches for COPs suffer from high computational time and reliance on expert knowledge, and machine learning (ML) methods, as powerful tools have been used to overcome these problems. In this review, the COPs in energy areas with a series of modern ML approaches, i.e., the interdisciplinary areas of COPs, ML and energy areas, are mainly investigated. Recent works on solving COPs using ML are sorted out firstly by methods which include supervised learning (SL), deep learning (DL), reinforcement learning (RL) and recently proposed game theoretic methods, and then problems where the timeline of the improvements for some fundamental COPs is the layout. Practical applications of ML methods in the energy areas, including the petroleum supply chain, steel-making, electric power system and wind power, are summarized for the first time, and challenges in this field are analyzed.

Bacteriocins have attracted increasing interest because of their potential as natural preservatives. Recent studies showed that the Bacillus cereus group is a prominent producer of bacteriocins. Using a laboratory-based screening strategy, we identified a strain in the B. cereus group, Bacillus toyonensis XIN-YC13, with antimicrobial activity against B. cereus. A novel, 70-amino-acid-long leaderless bacteriocin, toyoncin, was purified from the culture supernatant of strain XIN-YC13, and its molecular mass was found to be 7,817.1012 Da. Toyoncin shares no similarity with any other known bacteriocins, and its N-terminal amino acid is formylmethionine rather than methionine. Toyoncin shows good pH and heat stability and exhibits specific antimicrobial activity against two important foodborne pathogens, B. cereus and Listeria monocytogenes. Additionally, toyoncin exerts bactericidal activity and induces cell membrane damage. Toyoncin can also inhibit the outgrowth of B. cereus spores. Preservation assays showed that toyoncin effectively suppressed or eradicated B. cereus and L. monocytogenes in pasteurized skim milk. These results suggest that toyoncin can be used as a new biopreservative against B. cereus and L. monocytogenes in the food industry. IMPORTANCE We identified a novel leaderless bacteriocin, toyoncin, produced by B. toyonensis XIN-YC13. Toyoncin shows good pH and heat stability, and it has specific antimicrobial activity against B. cereus and L. monocytogenes (two important foodborne pathogens), likely by destroying their cell membrane integrity. Toyoncin inhibited the outgrowth of B. cereus spores and effectively inhibited or eliminated B. cereus and L. monocytogenes in a milk model system. These results indicate the potential of toyoncin as a food preservative.

More and more frequently, genomics and comparative genomics have been used as routine methods for general microbiological research. However, using several tools or even writing some scripts are required for completing a simple analysis, which is complicated for most biological researchers. To simplify the operation process, particularly for the convenience of microbiologists, here we have developed PGCGAP, a comprehensive, malleable, and easily installed prokaryotic genomic and comparative genomic analysis pipeline. PGCGAP implements genome assembly, gene prediction and annotation, genome and metagenome distance estimation, phylogenetic analysis, COG annotation, pan-genome analysis, inference of orthologous gene groups, variant calling and annotation, and screening for antimicrobial and virulence genes. Although we have tried our best to simplify the installation and usage of PGCGAP, it may be difficult for non-bioinformaticians to master it. Therefore, a protocol was created to help microbiologists without any experience in bioinformatics to establish their bioinformatics platform and perform routine analyses. This protocol shows how to choose the equipment to install a Linux subsystem on a laptop with a Windows 10 system, to install the PGCGAP and perform all analyses with an example dataset (This protocol applies to PGCGAP version 1.0.34 and later). The protocol requires a basic understanding of Linux, so an additional web page was written to help uninitiated users learn Linux and whole-genome sequencing (https://github.com/liaochenlanruo/pgcgap/wiki/Learning-bioinformatics or http://bcam.hzau.edu.cn/linuxwgs.php).

The description of cyber threat information is the basis of threat intelligence sharing. Focusing on the description of threat information, this paper analyzes the threat intelligence standards at home and abroad, summarizes the description and analysis methods of threat intelligence and their advantages and disadvantages. Finally, the direction and development trend of cyber threat intelligence research are prospected and summarized.

SummaryBacillus thuringiensis (Bt) which is a spore-forming gram-positive bacterium, has been used as the most successful microbial pesticide for decades. Its toxin genes (cry) have been successfully used for the development of GM crops against pests. We have previously developed a web-based insecticidal gene mining tool BtToxin_scanner, which has been proved to be the most important method for mining cry genes from Bt genome sequences. To facilitate efficiently mining major toxin genes and novel virulence factors from large-scale Bt genomic data, we re-design this tool with a new workflow. Here we present BtToxin_Digger, a comprehensive, high-throughput, and easy-to-use Bt toxin mining tool. It runs fast and can get rich, accurate, and useful results for downstream analysis and experiment designs. Moreover, it can also be used to mine other targeting genes from large-scale genome and metagenome data with the addition of other query sequences.Availability and ImplementationThe BtToxin_Digger codes and instructions are freely available at https://github.com/BMBGenomics/BtToxin_Digger. A web server of BtToxin_Digger can be found at http://bcam.hzau.edu.cn/BtToxin_Digger.Contactjszheng@mail.hzau.edu.cn; m98sun@mail.hzau.edu.cn.

Consumer demand for “fresh food” with no chemical preservatives has prompted researchers to pay more attention to natural antimicrobial peptides such as bacteriocins. Nisin is currently the most widely used food biopreservative among the bacteriocins; however, its applications are restricted due to its low stability at neutral and alkaline pH values. Circular bacteriocins have potent antimicrobial activity against foodborne pathogens, show exceptional stability, and have great potential to be developed as biopreservatives. Here, we take advantage of the precursor peptides of 15 reported circular bacteriocins to devise an in silico approach to identify potential circular bacteriocins in sequenced microbial genomes. A total of nearly 7,000 putative precursor peptides were identified from 86 species of bacteria and further classified into 28 groups based on their amino acid similarity. Among the groups, 19 showed low similarity (less than 50%) to any known precursor peptide of circular bacteriocins. One novel circular bacteriocin in group 11, cerecyclin, showed the highest identity (34%) to the known circular bacteriocin enterocin NKR-5-3B and was selected for verification. Cerecyclin showed antimicrobial activity against several Gram-positive bacteria, inhibited the outgrowth of Bacillus cereus spores, and did not exhibit hemolysis activity. Moreover, it showed 4-fold- to 8-fold-higher antimicrobial activity against B. cereus and Listeria monocytogenes than nisin A. Cerecyclin also had increased stability compared to nisin A under neutral or alkaline conditions. This work not only identified a promising food biopreservative but also provided a rich source for novel circular bacteriocins. IMPORTANCE Circular bacteriocins are promising biopreservatives, and it is important to identify more novel circular bacteriocins to enhance the current arsenal of antimicrobials. In this study, we used an in silico approach to identify a large number of novel circular bacteriocins and classified these bacteriocins into 28 groups rather than the 2 groups that were described in previous studies. Nineteen groups were novel and had low similarity (less than 50%) to any known precursor peptides of circular bacteriocins; this finding greatly expands the awareness of the novelty and diversity of circular bacteriocins. A novel circular bacteriocin which we named cerecyclin was identified in the B. cereus group; this circular bacteriocin had great antimicrobial activity against some foodborne pathogens and showed extreme stability. This study not only identified a promising food biopreservative but also provided a rich source for the identification of novel circular bacteriocins and the development of new biopreservatives.

In order to solve the practical application problem of the automatic target-scoring system based on computer vision under dynamic interference conditions such as flying catkins, this paper improves the traditional detection and removal methods of frame difference method and mean value method and proposes an effective flying catkins detection and removal algorithm based on time domain and brightness characteristics by fully studying the characteristics of flying catkins in target video and existing rain and snow removal algorithm. Experiments show that this method can effectively solve the problem of missed detection caused by the multiple moving states of flying catkins and realize the rapid flying catkins removal of the target video with good robustness and timeliness.

TiO2/TiOF2/{2 2 2}Ag3PO4 composite catalyst was prepared by hydrothermal method. The activity of the catalyst was investigated with tetracycline hydrochloride (TTCH) as the target pollutant. The samples were characterized by XRD, SEM, TEM, PL, BET, UV–Vis and other analytical methods. The results showed that: the compound improves the photocatalytic performance of silver phosphate; increases the specific surface area of the catalyst; reduces the forbidden band width and improves the activity under sunlight; suppresses the electron-hole recombination rate and increases the transfer efficiency of photogenerated electrons. The silver phosphate in the composite sample is in the form of tetrahedrons with exposed high-energy surfaces {2 2 2}. The degradation efficiency of 20 mg TiO2/TiOF2/Ag3PO4 composite catalyst has a catalytic rate of 86.4% for tetracycline. In the whole process, Superoxide radical ( O2−) has an important effect on the degradation activity of the composite catalyst to TTCH.

Burnett equations were originally derived in 1935 by Burnett by employing the Chapman-Enskog expansion to Classical Boltzmann equation to second order in Knudsen number Kn. Since then several variants of these equations have been proposed in the literature; these variants have differing physical and numerical properties. In this papers, we considered four such variants which are known in the literature as ‘the Original Burnett (OB) equations, the Conventional Burnett (CB)'equations, ‘the Augmented Burnett (AB)’ equations and the recently formulated by the authors ‘the Simplified Conventional (SCB) equations.’ One of the most important issues in obtaining numerical solutions of the Burnett equations is their stability under small perturbations. In this paper, we perform the linearized stability (known as the Bobylev Stability) analysis of three-dimensional Burnett equations for all the four variants (OB, CB, AB, and SCB) as far as the authors are aware for the first time in the literature on this subject. By introducing small perturbations in the steady state flow field, the trajectory curve and the variation in attenuation coefficient with wave frequency of the characteristic equation are obtained for all four variants of Burnett equations to determine their stability. The results show that the 3-D Augmented Burnett (AB) equations and the Simplified Conventional Burnett (SCB) equations are unconditionally stable under small wavelength perturbations. However, the Original Burnett (OB) and the Conventional Burnett (CB) equations are unstable when the Knudsen number becomes greater than a critical value and the stability condition worsens in 3-D when compared to the stability condition for 1-D and 2-D equations. The critical Knudsen number for 3-D OB and CB equations is 0.061 and 0.287 respectively. It should be noted that although both AB and SCB equations are unconditionally stable, SCB equations are much simpler to use numerically compared to AB equations without compromising accuracy.

PurposeThe existing literature has a lack of modeling of procedural fairness concerns in the supply chain level. This paper aims to investigate how procedural fairness concerns affect channel decisions, performance and coordination.Design/methodology/approachThis paper considers a supply chain consisting of one supplier and one retailer who have procedural fairness concerns in a classic Stackelberg game setting. The model is set in sales promotional environment. According to the existing literature, engagement is used to depict fair process. Some findings are made through analyzing respective decisions of the supplier and the retailer under the influence of procedural fairness concerns.FindingsThe results show that the channel efficiency can be improved when the retailer exhibits procedural fairness concerns, but if the aversion to unfair process exceeds a certain threshold, the retailer cannot benefit from it. Besides, the retailer profits more when he cares about distributional fairness, although the whole channel surplus can be improved by procedural fairness concerns.Originality/valueThis is the first paper to study the influences of procedural fairness concerns on supply chain decisions and channel performance. Finally, a mechanism combining a wholesale price contract with slotting allowances is proposed to coordinate the supply chain.

Bacillus thuringiensis serovar alesti was used to control caterpillars from 1970s. Here we reported the complete genome of BGSC 4C1, the type strain of this serovar. It has a circular chromosome and six plasmids. The largest plasmid pBMB267 contains five insecticidal crystal protein genes (two copies of cry1Ae, cry1Gb, cry2Ab, and a novel cry1M-type gene) and three vegetative insecticidal protein genes (a novel binary toxin gene operon vip1-vip2 and vip3Aa). Besides, the strain also has many genes encodeing virulence factors, and some secondary metabolite biosynthetic gene clusters involved in synthesis of antimicrobial peptides and bacteriocins. In addition, there is a poly γ-glutamate synthesis gene cluster, whose product is a candidate to control inflammasome-mediated disorders and potential in many other fields.

In the complex marine environment, with the continuous enrichment and development of target detection methods, massive target track data is stored and accumulated in the database, which contains a large amount of information and knowledge. It is possible to analyze and predict the behavior and intention of the target by means of target behavior law mining. Most of the existing target behavior law mining methods are based on the idea of clustering. When working in the complex environment of the sea battlefield, the working steps are complicated and the effect is poor. Therefore, in combination with situation analysis requirements and based on the idea of similar duplicate record detection, this paper proposes a mining method of maritime target behavior law by defining multi-dimensional record matching similarity (MDRS). The experimental analysis is carried out on the simulated military scene. The results show that the proposed method can accurately and effectively mine the behavior of the target.

A new high-efficiency photocatalyst Cu

In recent years, bacteriocins have attracted considerable interest for use as natural food preservatives against spoilage and pathogenic microorganisms. Recent studies have shown that the strains of Bacillus cereus group produce a range of highly diverse bacteriocins. In this study, we screened a large number of Bacillus cereus group strains and isolated one strain, Bacillus sp. Xin1, with antimicrobial activity against several food-borne pathogens. A novel circular bacteriocin, bacicyclicin XIN-1 (MW: 5848.1719 Da), was purified from the culture supernatant of Bacillus sp. Xin1. This bacteriocin exhibited high thermal stability, wide pH tolerance, and a wide range of antimicrobial activities against Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus, three important foodborne pathogens, as well as other pathogens. Bacicyclicin XIN-1 also inhibited the outgrowth of Bacillus cereus spores and did not show hemolysis activity. Bacicyclicin XIN-1 effectively inhibited or eliminated B. cereus ATTCC14579, S. aureus ATCC6538, and L. monocytogenes LM201 in skim milk. Our findings indicate that bacicyclicin XIN-1 has a remarkable potential for use as a natural food preservative in the food industry.

Root-knot nematodes (RKNs) which can infect almost all crops lead to huge economic losses in agriculture around the world. Unavailability of effective and environmentally friendly control of RKNs provides an opportunity to nematicidal bacteria. Fictibacillus phosphorivorans G25-29 is a gram-positive and spore-forming bacterium with nematicidal capability against root-knot nematodes and free-living nematode Caenorhabditis elegans. Here, we report the complete genome of F. phosphorivorans G25-29, containing a circular chromosome and encoding nine potential nematicidal factors which may contribute to its nematicidal activity.

This study aims at predicting affective states during programming using keyboard and mouse data. The article proposes and evaluates a novel set of features under programming context to predict affective states. Fourteen undergraduate participants performed three programming tasks of varying difficulties. At the completion of each task, participants reported their affective states by viewing webcam videos and screen recordings. Features extracted from keyboard and mouse logs were used to train multiple classifiers. Among trained classifiers, feedforward neural network recognized positive, neutral and negative states with 52.9% accuracy. The overall Cohen's Kappa reached 0.27. Without neutral states, the classifiers were able to differentiate positive and negative states with 74.1% accuracy and 0.48 Kappa. Our approach demonstrates improved ability of predicting self-labelled affective states of programmers from keyboard and mouse data, without using specialized sensors, and potential of emotional feedback to programmers during learning to deliver better experience.

Despite the successful application of crystal proteins (Cry) from Bacillus thuringiensis as biological control agents against insects, there is an increasing demand to identify new Cry toxins having higher toxicity and broad-spectrum activity against insects and plant-parasitic nematodes. To find novel Cry toxins, we screened 100 whole-genome sequences of B. thuringiensis Surprisingly, in addition to full Cry toxins, we found partial sequences, such as typical N-terminal or C-terminal regions with conserved domains, widely distributed among 20 strains of B. thuringiensis In order to further elucidate the functions of partial genes, here, we selected a partial sequence from strain C15, having 28% similarity with the N terminus of Cry5Ba and lacking a typical C terminus, and denoted it Cry5B-like N terminus. This fragment when coexpressed as a fusion protein with the C terminus of Cry5Ba (N-C fusion protein) produces pyramidal crystals. A recombinant N-C fusion protein having a 50% lethal concentration (LC50) of 23.7 μg/ml severely affected the life span, growth, and survival rate of nematodes. Light microscopy showed damage to the intestine of nematodes, confirming the pathogenicity of the N-C fusion protein. Last, the green fluorescent protein (GFP)-labeled mutant Caenorhabditis elegans FT63 showed significant damage to the intestine upon feeding N-C fusion toxin compared to the control. These results imply that partial genes can be a source of new Cry toxins, and further understanding about functions of partial cry genes can help in the study of the evolutionary strategy of B. thuringiensis to produce the multidomain toxins.IMPORTANCE Genomic analysis revealed that coding sequences for N termini and C termini of crystal proteins are widely distributed in B. thuringiensis We found Cry5B-like N terminus, lacking typical C terminus, was unable to be expressed in wild-type strain C15. However, its fusion with the C terminus of Cry5Ba not only was successfully expressed but also exhibited activity against the nematodes. This study provides insight into a potential source for novel Cry toxins.

Understanding the genetic basis of host shifts is a key genomic question for pathogen and parasite biology. The Bacillus cereus group, which encompasses Bacillus thuringiensis and Bacillus anthracis, contains pathogens that can infect insects, nematodes, and vertebrates. Since the target range of the essential virulence factors (Cry toxins) and many isolates is well known, this group presents a powerful system for investigating how pathogens can diversify and adapt to phylogenetically distant hosts. Specialization to exploit insects occurs at the level of the major clade and is associated with substantial changes in the core genome, and host switching between insect orders has occurred repeatedly within subclades. The transfer of plasmids with linked cry genes may account for much of the adaptation to particular insect orders, and network analysis implies that host specialization has produced strong associations between key toxin genes with similar targets. Analysis of the distribution of plasmid minireplicons shows that plasmids with orf156 and orf157, which carry genes encoding toxins against Lepidoptera or Diptera, were contained only by B. thuringiensis in the specialized insect clade (clade 2), indicating that tight genome/plasmid associations have been important in adaptation to invertebrate hosts. Moreover, the accumulation of multiple virulence factors on transposable elements suggests that cotransfer of diverse virulence factors is advantageous in terms of expanding the insecticidal spectrum, overcoming insect resistance, or through gains in pathogenicity via synergistic interactions between toxins., IMPORTANCE Population genomics have provided many new insights into the formation, evolution, and dynamics of bacterial pathogens of humans and other higher animals, but these pathogens usually have very narrow host ranges. As a pathogen of insects and nematodes, Bacillus thuringiensis, which produces toxins showing toxicity to many orders of insects and other invertebrates, can be used as a model to study the evolution of pathogens with wide host ranges. Phylogenomic analysis revealed that host specialization and switching occur at the level of the major clade and subclade, respectively. A toxin gene co-occurrence network indicates that multiple toxins with similar targets were accumulated by the same cell in the whole species. This accumulation may be one of the strategies that B. thuringiensis has used to fight against host resistance. This kind of formation and evolution of pathogens represents a different path used against multiple invertebrate hosts from that used against higher animals.

This paper examines various aspects of the design process and subsequent field test measurements of a large and complex substation grounding system. The study and measurements show that soil layering and lead interference can have a significant impact on the appropriate test location that yields the exact substation ground impedance. Applying a specific percentage rule such as the 61.8% rule for uniform soils to obtain the true ground impedance may lead to unacceptable errors for large grounding systems. This poses significant problems when attempting to validate a design based on raw test data that are interpreted using approximate methods to evaluate substation ground impedance, and determine ground potential rise (GPR), touch and step voltages. Advanced measurement methodologies and modern software packages were used to obtain and effectively analyze fall of potential test data, compute fault current distribution, and evaluate touch and step voltages for this large substation. Fault current distribution between the grounding system and other metallic paths were computed to determine the portion of fault current discharged in the grounding system. The performance of the grounding system, including its GPR and touch and step voltages, has been accurately computed and measured, taking into account the impedance of the steel material used of the ground conductors and circulating currents within the substation grounding system.

Gas or liquid flow through small channels has become more and more popular due to the micro-electro-mechanical systems (MEMS) fabrication technologies such as micro-motors, electrostatic comb-drive, micro-chromatographs, micro-actuators, micro-turbines and micro-pumps, etc. The flow conditions in and around these systems are always recognized as typical transitional regimes. Under these conditions, the mean free path of gas molecules approaches the characteristic scale of the micro-devices itself, and due to the little collisions the heat and momentum cannot equilibrate between the wall and fluids quickly. Couette flow is a simple and critical model in fluid dynamics which focuses on the mechanism of the heat transfer in shear-driven micro-cavities or micro-channels. Despite numerous work on the numerical solutions of the Couette flow, how to propose stable and accurate slip boundary conditions in rarefied flow conditions still remains to be elucidated. In this paper, converged solutions for steady-state ...

Combining plasma activation and cross-reactivity of sensor array, we have developed a plasma-assisted cataluminescence (PA-CTL) sensor array for fast sensing and discrimination of gaseous hydrocarbons, which can be potentially used for fast diagnosis of lung cancer. Based on dielectric barrier discharge, a low-temperature plasma is generated to activate gaseous hydrocarbons with low cataluminescence (CTL) activities. Extremely increased CTL responses have been obtained, which resulted in a plasma assistance factor of infinity (∞) for some hydrocarbons. On a 4 × 3 PA-CTL sensor array made from alkaline-earth nanomaterials, gaseous hydrocarbons showed robust and unique CTL responses to generate characteristic patterns for fast discrimination. Because of the difference in the component of hydrocarbons in breath, exhaled breath samples from donors with and without lung cancer were tested, and good discrimination has been achieved by this technique. In addition, the feasibility of multidimentional detection based on temperature was confirmed. It had good reproducibility and gave a linear range of 65-6500 ng/mL or 77-7700 ppmv (R > 0.98) for CH(4) with a detection limit of 33 ng/mL (38 ppmv) on MgO. The PA-CTL sensor array is simple, low-cost, thermally stable, nontoxic, and has an abundance of alkaline-earth nanomaterials to act as sensing elements. This has expanded the applications of CTL-based senor arrays and will show great potential in clinical fast diagnosis.

Currently, all the data processing strategies for functional magnetic resonance imaging (fMRI) utilize temporal informationpaying little attention to or totally ignoring frequency information. In this paper, a new method is proposed to detect the functional activation regions in the brain by using the frequency information of fMRI time series. The main idea is that the frequency entropy information (FEI) difference of fMRI data between task and control states is specified as brain activation index. The validity of the proposed FEI approach is confirmed by analyzing the result of the simulated synthesized data. Additionally, the comparison of receiver operating characteristic (ROC) curves acquired respectively from the proposed scheme, the statistical parametric mapping (SPM), and the Support Vector Machine (SVM) methods of fMRI data analysis indicate an obvious superiority of the former. In vivo fMRI studies of subjects with event-related experiment reveal that FEI method can enable the effective detection of brain functional activation.

A novel circularly polarized array designed for millimeter wave digital radar module was proposed and validated in this paper. The circularly polarized array was designed with single feeding point for easily integrating with front-end module. A new kind of medium filled circular cavity was employed as transition to connect the output of the T/R module and the feeding point of the array. TM010 mode was selected as the operating mode of the circular cavity based transition for its special field distribution. Good performance of flexibility, return-loss, axial ratio and radiation pattern were observed.

This paper presents an integrated approach for diagnosis and synthesis of production data for gas wells in Dina HPHT reservoir, where most of the production wells exhibit everlasting abnormal flow with limited analyzable data For production data diagnostics, we prove that for gas wells at high pressure stage (both reservoir pressure and wellbore flowing pressure are above 50MPa), the qg/(Ppi - Ppwf) versus tca plot for gas system can be substituted rigorously by qg/(Pi - Pwf) versus Gp/qg plot (similar form as liquid system) in Palacio-Blasingame decline type curve analysis; and for gas Flowing Material Balance (FMB) analysis, the qg/(Ppi - Ppwf) versus (qgtca)/[(Ppi - Ppwf)Cti] plot can be substituted by qg/(Pi - Pwf) versus Gg/(Pi - Pwf) plot. These reduced functions are used to generate simplified Blasingame diagnostic plot and FMB diagnostic plot for high pressure gas system. These simplified diagnostic plots, with no iterations or integrations when calculating, provide a quick and straightforward solution for instant detection of abnormal flowing data in field. In well production profile synthesis, the dependence of well OGIP on individual-well-flow-rate/reservoir-flow-rate ratio is given based on "pseudo-steady-state" flow theory in a multiwell reservoir. Interference effects are coupled into the analytical model by assigning varied OGIP in production profile synthesis, which reduce the risk of erroneous results in modeling long-term production profile for wells with limited analyzable history data and make the "generated" well behavior consistent with the multi-well-reservoir behavior.

The aim of the present study was to investigate the immune function of children with juvenile idiopathic arthritis (JIA). Flow cytometry and three-color direct immunofluorescence were used to examine cluster of differentiation (CD)3+ T-lymphocyte subsets and CD28/cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) expression in whole blood (using the no-wash method) from 36 children with JIA and 39 healthy children. During the active phase of JIA, CD28 expression on CD4+ T cells in children with JIA was significantly reduced; thus, CD4+CD28− T-cell frequency increased, suggesting that CD4+ T-cell and CD4+CD28− T-cell apoptosis was inhibited in patients with JIA. The continued survival of these immune-active T lymphocytes may promote the occurrence and development of JIA. CTLA-4 expression levels on CD4+ and CD8+ T cells in children with JIA during the active phase were significantly higher than those in normal controls. As the majority of CD4+ T cells in patients with JIA are CD28−, they cannot be inactivated by the interaction between CTLA-4 and B7, leading to continuously high levels of CTLA-4 expression on the surface of CD4+ T cells without functional effect. Hence, T lymphocytes are continuously kept in a highly activated state that is difficult to stop. During the resting phase, the CD4+ and CD8+ T-cell counts in children with JIA were similar to normal, and CD28 expression was also normal. This suggests that the frequency of CD4+CD28− T cells can be used as an indicator of the active phase of JIA. CTLA-4 expression on the surface of T cells in children with JIA during the resting phase was also similar to that in normal controls, suggesting that abnormal lymphocyte activation plays an important role in the active phase of JIA.

Burnett equations were originally derived in 1935 by Burnett by employing the Chapman-Enskog expansion to Classical Boltzmann equation to second order in Knudsen number Kn. Since then several variants of these equations have been proposed in the literature; these variants have differing physical and numerical properties. In this paper, we consider three such variants which are known in the literature as ‘the Original Burnett (OB) equations’, the Conventional Burnett (CB) equations’ and the recently formulated by the authors ‘the Simplified Conventional (SCB) equations.’ One of the most important issues in obtaining numerical solutions of the Burnett equations is their stability under small perturbations. In this paper, we perform the linearized stability (known as the Bobylev Stability) analysis of three-dimensional Burnett equations for all the three variants (OB, CB, and SCB) for the first time in the literature on this subject. By introducing small perturbations in the steady state flow field, the trajectory curve and the variation in attenuation coefficient with wave frequency of the characteristic equation are obtained for all the three variants of Burnett equations to determine their stability. The results show that the Simplified Conventional Burnett (SCB) equations are unconditionally stable under small wavelength perturbations. However, the Original Burnett (OB) and the Conventional Burnett (CB) equations are unstable when the Knudsen number becomes greater than a critical value and the stability condition worsens in 3D when compared to the stability condition for 1-D and 2-D equations. The critical Knudsen number for 3-D OB and CB equations is 0.061 and 0.287 respectively.

This paper describes the computations of hypersonic shock wave structure in a gas in rotational non-equilibrium using a newly developed simplified set of Burnett equations designated as Simplified Conventional Burnett (SCB) equations. Since the original formulation by Burnett, a number of variations to the original Burnett equations have been proposed and the differences among these variants and their merits/shortcomings have been described in the literature. A new variant is created based on the conventional Burnett equations for hypersonic flows by neglecting terms that are inversely proportional to the Mach number. This simplified set of conventional Burnett equations is linearly stable for small disturbances in contrast to the conventional Burnett equations which suffer from Bobylev instability. To simulate the rotational non-equilibrium effect in a diatomic gas, both the Navier–Stokes (NS) and the SCB equations are modified by including a rotational non-equilibrium relaxation model. The flow variables (density, translational and rotational temperature) in a typical 1-D shock at different Mach numbers (1.2, 5, and 10) in Nitrogen are computed using SCB and NS equations and are compared with the DSMC results. SCB calculations are in close agreement with the DSMC results at high Mach numbers.

Transposon mutagenesis and subsequent phenotype-driven screening have been extensively used to annotate gene function and uncover the mechanisms of biological phenomena. During this process, the resulting phenotypic differences are specifically attributable to the disrupted genes. In this study, the complementation of the mini-Tn10 transposon-disrupted gene gntP did not restore the germination ability of the Bacillus thuringiensis MT1518-1 mutant to the wild-type level. Genome sequencing identified 186 unlinked mutations on the chromosome of the mutant MT1518-1, including one frameshift mutation in the germination-related gene exsA. We randomly selected 19 mini-Tn10 mutants for high throughput genome sequencing. The sequencing data revealed that incidental mutations occurred frequently on their chromosomes, including 2343 single-nucleotide polymorphisms, three insertions and one deletion. We also found that stressful conditions are the underlying cause for the appearance of incidental mutations. Caution is warranted when attributing the observed phenotypic changes to the transposon-disrupted genes.

Plant-parasitic nematodes were found in 4 of the 12 clades of phylum Nematoda. These nematodes in different clades may have originated independently from their free-living fungivorous ancestors. However, the exact evolutionary process of these parasites is unclear. Here, we sequenced the genome sequence of a migratory plant nematode,Ditylenchus destructor. We performed comparative genomics among the free-living nematode,Caenorhabditis elegansand all the plant nematodes with genome sequences available. We found that, compared withC. elegans, the core developmental control processes underwent heavy reduction, though most signal transduction pathways were conserved. We also foundD. destructorcontained more homologies of the key genes in the above processes than the other plant nematodes. We suggest thatDitylenchusspp. may be an intermediate evolutionary history stage from free-living nematodes that feed on fungi to obligate plant-parasitic nematodes. Based on the facts thatD. destructorcan feed on fungi and has a relatively short life cycle, and that it has similar features to bothC. elegansand sedentary plant-parasitic nematodes from clade 12, we propose it as a new model to study the biology, biocontrol of plant nematodes and the interaction between nematodes and plants.

Theoretically, the sensitivity of the transfer function (TF) method to detect transformer winding deformation is greater in the higher frequency range. Although measurement based on low voltage impulse (LVI) is definitely faster than that based on swept frequency method (SFM), the analyzable frequency band is narrow due to the typical microsecond impulse. The characteristics of the nanosecond impulse in the frequency domain were studied in this paper. A test System based on Nanosecond low voltage impulse was developed to improve the detection sensitivity. A series experiments were carried out on a 5 kV/100 kVA distribution transformer. Measurement results with two different impulses were compared and de-noising methods were studied. Besides, a destructive experiment was carried out on an special laboratory winding to verify the sensitivity of the method.

Currently, kernel-based methods have drawn much attention from the field of pattern recognition as well as radar target recognition. As we all know, kernel discriminant analysis (KDA) is proved that it is a very effective tool used for dimensionality reduction and feature extraction. However, KDA also suffers from the so-called small sample size problem (SSS) which often exists in high-dimensional pattern recognition data. In order to deal with this problem, a complete KDA called kernel complete discriminant analysis (KCDA) is proposed. The new algorithm views the optimal discriminant vectors as a global transform in the feature space, and which carries out feature extraction by making full use of the discriminative information in both null space and non-null space of the within-class scatter matrix. Thus it makes KCDA a more powerful dicriminator. Experiments based on the measured airplanes database are conducted to evaluate the effectiveness of the proposed method, and the results show that it can achieve better classification performance.