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https://www.readbyqxmd.com/read/28650835/a-new-representation-in-pso-for-discretization-based-feature-selection
#1
Binh Tran, Bing Xue, Mengjie Zhang
In machine learning, discretization and feature selection (FS) are important techniques for preprocessing data to improve the performance of an algorithm on high-dimensional data. Since many FS methods require discrete data, a common practice is to apply discretization before FS. In addition, for the sake of efficiency, features are usually discretized individually (or univariate). This scheme works based on the assumption that each feature independently influences the task, which may not hold in cases where feature interactions exist...
June 23, 2017: IEEE Transactions on Cybernetics
https://www.readbyqxmd.com/read/28650832/committee-based-active-learning-for-surrogate-assisted-particle-swarm-optimization-of-expensive-problems
#2
Handing Wang, Yaochu Jin, John Doherty
Function evaluations (FEs) of many real-world optimization problems are time or resource consuming, posing a serious challenge to the application of evolutionary algorithms (EAs) to solve these problems. To address this challenge, the research on surrogate-assisted EAs has attracted increasing attention from both academia and industry over the past decades. However, most existing surrogate-assisted EAs (SAEAs) either still require thousands of expensive FEs to obtain acceptable solutions, or are only applied to very low-dimensional problems...
June 22, 2017: IEEE Transactions on Cybernetics
https://www.readbyqxmd.com/read/28649405/bacillus-subtilis-biofilm-development-in-the-presence-of-soil-clay-minerals-and-iron-oxides
#3
Wenting Ma, Donghai Peng, Sharon L Walker, Bin Cao, Chun-Hui Gao, Qiaoyun Huang, Peng Cai
Clay minerals and metal oxides, as important parts of the soil matrix, play crucial roles in the development of microbial communities. However, the mechanism underlying such a process, particularly on the formation of soil biofilm, remains poorly understood. Here, we investigated the effects of montmorillonite, kaolinite, and goethite on the biofilm formation of the representative soil bacteria Bacillus subtilis. The bacterial biofilm formation in goethite was found to be impaired in the initial 24 h but burst at 48 h in the liquid-air interface...
2017: NPJ Biofilms and Microbiomes
https://www.readbyqxmd.com/read/28639958/pediatric-jellyfish-envenomation-in-the-mediterranean-sea
#4
Miguel Glatstein, Dikla Adir, Bella Galil, Dennis Scolnik, Ayelet Rimon, Dikla Pivko-Levy, Christopher Hoyte
BACKGROUND: Several species of jellyfish native to the western Indian Ocean have entered the Mediterranean Sea through the Suez Canal. Since the late 1980s, each summer Rhopilema nomadica forms swarms as long as 100 km in the southeastern Levant and since the millennium aggregations of additional nonnative jellyfish have been sighted. The aim of this study was to evaluate children seen in the emergency department after jellyfish envenomations and to establish patterns of toxicity associated with this organism...
June 20, 2017: European Journal of Emergency Medicine: Official Journal of the European Society for Emergency Medicine
https://www.readbyqxmd.com/read/28637123/inhibition-of-swarming-motility-of-pseudomonas-aeruginosa-by-methanol-extracts-of-alpinia-officinarum-hance-and-cinnamomum-tamala-t-nees-and-eberm
#5
Divya Lakshmanan, Jishudas Nanda, K Jeevaratnam
Bacterial drug resistance is a challenge in clinical settings, especially in countries like India. Hence, discovery of novel alternative therapeutics has become a necessity in the fight against drug resistance. Compounds that inhibit bacterial virulence properties form new therapeutic alternatives. Pseudomonas aeruginosa is an opportunistic, nosocomial pathogen that infects immune-compromised patients. Swarming motility is an important virulence property of Pseudomonas which aids it in reaching host cells under nutrient limiting conditions...
June 15, 2017: Natural Product Research
https://www.readbyqxmd.com/read/28634487/dynamic-inertia-weight-binary-bat-algorithm-with-neighborhood-search
#6
Xingwang Huang, Xuewen Zeng, Rui Han
Binary bat algorithm (BBA) is a binary version of the bat algorithm (BA). It has been proven that BBA is competitive compared to other binary heuristic algorithms. Since the update processes of velocity in the algorithm are consistent with BA, in some cases, this algorithm also faces the premature convergence problem. This paper proposes an improved binary bat algorithm (IBBA) to solve this problem. To evaluate the performance of IBBA, standard benchmark functions and zero-one knapsack problems have been employed...
2017: Computational Intelligence and Neuroscience
https://www.readbyqxmd.com/read/28630619/a-swarm-optimization-genetic-algorithm-based-on-quantum-behaved-particle-swarm-optimization
#7
Tao Sun, Ming-Hai Xu
Quantum-behaved particle swarm optimization (QPSO) algorithm is a variant of the traditional particle swarm optimization (PSO). The QPSO that was originally developed for continuous search spaces outperforms the traditional PSO in search ability. This paper analyzes the main factors that impact the search ability of QPSO and converts the particle movement formula to the mutation condition by introducing the rejection region, thus proposing a new binary algorithm, named swarm optimization genetic algorithm (SOGA), because it is more like genetic algorithm (GA) than PSO in form...
2017: Computational Intelligence and Neuroscience
https://www.readbyqxmd.com/read/28630112/rapid-evolution-of-ovarian-biased-genes-in-the-yellow-fever-mosquito-aedes-aegypti
#8
Carrie A Whittle, Cassandra G Extavour
Males and females exhibit highly dimorphic phenotypes, particularly in their gonads, which is believed to be driven largely by differential gene expression. Typically, the protein sequences of genes upregulated in males, or male-biased genes, evolve rapidly as compared to female-biased and unbiased genes. To date, the specific study of gonad-biased genes remains uncommon in metazoans. Here, we identified and studied a total of 2,927, 2,013 and 4,449 coding-sequences (CDS) with ovary-biased, testis-biased and unbiased expression respectively in the yellow-fever mosquito Aedes aegypti The results showed that ovary-biased and unbiased CDS had higher nonsynonymous to synonymous substitution rates (dN/dS) and lower optimal codon usage (those codons that promote efficient translation) than testis-biased genes...
June 19, 2017: Genetics
https://www.readbyqxmd.com/read/28629202/a-novel-extreme-learning-machine-classification-model-for-e-nose-application-based-on-the-multiple-kernel-approach
#9
Yulin Jian, Daoyu Huang, Jia Yan, Kun Lu, Ying Huang, Tailai Wen, Tanyue Zeng, Shijie Zhong, Qilong Xie
A novel classification model, named the quantum-behaved particle swarm optimization (QPSO)-based weighted multiple kernel extreme learning machine (QWMK-ELM), is proposed in this paper. Experimental validation is carried out with two different electronic nose (e-nose) datasets. Being different from the existing multiple kernel extreme learning machine (MK-ELM) algorithms, the combination coefficients of base kernels are regarded as external parameters of single-hidden layer feedforward neural networks (SLFNs)...
June 19, 2017: Sensors
https://www.readbyqxmd.com/read/28621992/chaotic-model-for-l%C3%A3-vy-walks-in-swarming-bacteria
#10
Gil Ariel, Avraham Be'er, Andy Reynolds
We describe a new mechanism for Lévy walks, explaining the recently observed superdiffusion of swarming bacteria. The model hinges on several key physical properties of bacteria, such as an elongated cell shape, self-propulsion, and a collectively generated regular vortexlike flow. In particular, chaos and Lévy walking are a consequence of group dynamics. The model explains how cells can fine-tune the geometric properties of their trajectories. Experiments confirm the spectrum of these patterns in fluorescently labeled swarming Bacillus subtilis...
June 2, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28619941/recurring-and-triggered-slow-slip-events-near-the-trench-at-the-nankai-trough-subduction-megathrust
#11
Eiichiro Araki, Demian M Saffer, Achim J Kopf, Laura M Wallace, Toshinori Kimura, Yuya Machida, Satoshi Ide, Earl Davis
The discovery of slow earthquakes has revolutionized the field of earthquake seismology. Defining the locations of these events and the conditions that favor their occurrence provides important insights into the slip behavior of tectonic faults. We report on a family of recurring slow-slip events (SSEs) on the plate interface immediately seaward of repeated historical moment magnitude (Mw) 8 earthquake rupture areas offshore of Japan. The SSEs continue for days to several weeks, include both spontaneous and triggered slip, recur every 8 to 15 months, and are accompanied by swarms of low-frequency tremors...
June 16, 2017: Science
https://www.readbyqxmd.com/read/28618584/model-of-the-best-of-n-nest-site-selection-process-in-honeybees
#12
Andreagiovanni Reina, James A R Marshall, Vito Trianni, Thomas Bose
The ability of a honeybee swarm to select the best nest site plays a fundamental role in determining the future colony's fitness. To date, the nest-site selection process has mostly been modeled and theoretically analyzed for the case of binary decisions. However, when the number of alternative nests is larger than two, the decision-process dynamics qualitatively change. In this work, we extend previous analyses of a value-sensitive decision-making mechanism to a decision process among N nests. First, we present the decision-making dynamics in the symmetric case of N equal-quality nests...
May 2017: Physical Review. E
https://www.readbyqxmd.com/read/28613253/terpenoids-from-platostoma-rotundifolium-briq-a-j-paton-alter-the-expression-of-quorum-sensing-related-virulence-factors-and-the-formation-of-biofilm-in-pseudomonas-aeruginosa-pao1
#13
Tsiry Rasamiravaka, Jérémie Ngezahayo, Laurent Pottier, Sofia Oliveira Ribeiro, Florence Souard, Léonard Hari, Caroline Stévigny, Mondher El Jaziri, Pierre Duez
Platostoma rotundifolium (Briq.) A. J. Paton aerial parts are widely used in Burundi traditional medicine to treat infectious diseases. In order to investigate their probable antibacterial activities, crude extracts from P. rotundifolium were assessed for their bactericidal and anti-virulence properties against an opportunistic bacterial model, Pseudomonas aeruginosa PAO1. Whereas none of the tested extracts exert bacteriostatic and/or bactericidal proprieties, the ethyl acetate and dichloromethane extracts exhibit anti-virulence properties against Pseudomonas aeruginosa PAO1 characterized by an alteration in quorum sensing gene expression and biofilm formation without affecting bacterial viability...
June 14, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28613192/an-external-archive-guided-multiobjective-particle-swarm-optimization-algorithm
#14
Qingling Zhu, Qiuzhen Lin, Weineng Chen, Ka-Chun Wong, Carlos A Coello Coello, Jianqiang Li, Jianyong Chen, Jun Zhang
The selection of swarm leaders (i.e., the personal best and global best), is important in the design of a multiobjective particle swarm optimization (MOPSO) algorithm. Such leaders are expected to effectively guide the swarm to approach the true Pareto optimal front. In this paper, we present a novel external archive-guided MOPSO algorithm (AgMOPSO), where the leaders for velocity update are all selected from the external archive. In our algorithm, multiobjective optimization problems (MOPs) are transformed into a set of subproblems using a decomposition approach, and then each particle is assigned accordingly to optimize each subproblem...
June 12, 2017: IEEE Transactions on Cybernetics
https://www.readbyqxmd.com/read/28609446/are-sex-ratio-distorting-endosymbionts-responsible-for-mating-system-variation-among-dance-flies-diptera-empidinae
#15
Rosalind L Murray, Elizabeth J Herridge, Rob W Ness, Luc F Bussière
Maternally inherited bacterial endosymbionts are common in many arthropod species. Some endosymbionts cause female-biased sex ratio distortion in their hosts that can result in profound changes to a host's mating behaviour and reproductive biology. Dance flies (Diptera: Empidinae) are well known for their unusual reproductive biology, including species with female-specific ornamentation and female-biased lek-like swarming behaviour. The cause of the repeated evolution of female ornaments in these flies remains unknown, but is probably associated with female-biased sex ratios in individual species...
2017: PloS One
https://www.readbyqxmd.com/read/28607981/novel-structural-phases-and-the-electrical-properties-of-si3b-under-high-pressure
#16
Jingjing Wang, Guoliang Sun, Panlong Kong, Weiguo Sun, Cheng Lu, Feng Peng, Xiaoyu Kuang
We report a detailed theoretical study of the electronic structure, phase stability, elastic and mechanical properties of Si3B in the pressure range of 0-160 GPa by employing the crystal structure analysis by particle swarm optimization (CALYPSO) method combined with first-principles calculations. Our theoretical predictions reveal that, as the pressure increases, Si3B moves through the following sequence of phases: P3121 → C2/m → P21/m, and the corresponding transition pressures are computed to be 30 and 64 GPa, respectively...
June 21, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28607157/anaerobic-cysteine-degradation-and-potential-metabolic-coordination-in-salmonella-enterica-and-escherichia-coli
#17
Melissa Loddeke, Barbara Schneider, Tamiko Oguri, Iti Mehta, Zhenyu Xuan, Larry Reitzer
Salmonella enterica has two CutR-activated enzymes that degrade cysteine: the aerobic CdsH and an unidentified anaerobic enzyme; E. coli only has the latter. To identify the anaerobic enzyme, transcript profiling was performed from E. coli without cutR and with overexpressed cutR 37 genes showed at least a five-fold change in expression, and the cutPA (formerly yhaOM) operon had the greatest differential. Homology suggested that CutP and CutA are a cysteine transporter and an iron-sulfur-containing cysteine desulfidase, respectively...
June 12, 2017: Journal of Bacteriology
https://www.readbyqxmd.com/read/28600487/fluid-viscoelasticity-promotes-collective-swimming-of-sperm
#18
Chih-Kuan Tung, Chungwei Lin, Benedict Harvey, Alyssa G Fiore, Florencia Ardon, Mingming Wu, Susan S Suarez
From flocking birds to swarming insects, interactions of organisms large and small lead to the emergence of collective dynamics. Here, we report striking collective swimming of bovine sperm in dynamic clusters, enabled by the viscoelasticity of the fluid. Sperm oriented in the same direction within each cluster, and cluster size and cell-cell alignment strength increased with viscoelasticity of the fluid. In contrast, sperm swam randomly and individually in Newtonian (nonelastic) fluids of low and high viscosity...
June 9, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28598608/ground-state-crystal-structure-of-strontium-peroxide-predicted-from-first-principles
#19
Yanchao Wang, Sheng Wang, Yunwei Zhang, Jian Lv, Yue Chen, Weitao Zheng, Yanming Ma
It has been widely believed that SrO2, a typical alkaline earth metal peroxide, should adopt the tetrahedral CaC2-type structure (space group I4/mmm) at ambient pressure. Here we report a monoclinic structure (space group C2c), as predicted from first-principles swarm structure searching simulations, is energetically more favorable than the CaC2-type structure at ambient pressure and low temperature, while the I4/mmm structure is only stable at high pressure (>20 GPa) or elevated temperature conditions. A key difference between these structures is the distinct orientation of peroxide ions...
June 9, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28593349/transcriptomic-analysis-of-the-swarm-motility-phenotype-of-salmonella-enterica-serovar-typhimurium-mutant-defective-in-periplasmic-glucan-synthesis
#20
Arvind A Bhagwat, Lynn Young, Allen D Smith, Medha Bhagwat
Movement of food-borne pathogens on moist surfaces enables them to migrate towards more favorable niches and facilitate their survival for extended periods of time. Salmonella enterica serovar Typhimurium mutants defective in Osmoregulated periplasmic glucans (OPG) synthesis are unable to exhibit motility on moist surfaces (swarming); however, their mobility in liquid (swim motility) remains unaffected. In order to understand the role of OPG in swarm motility, transcriptomic analysis was performed using cells growing on a moist agar surface...
June 8, 2017: Current Microbiology
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