keyword
MENU ▼
Read by QxMD icon Read
search

Swarm

keyword
https://www.readbyqxmd.com/read/28105808/evolution-of-the-structural-and-electronic-properties-of-medium-sized-sodium-clusters-a-honeycomb-like-na20-cluster
#1
Wei Guo Sun, Jing Jing Wang, Cheng Lu, Xin Xin Xia, Xiao Yu Kuang, Andreas Hermann
Sodium is one of the best examples of a free-electron-like metal and of a certain technological interest. However, an unambiguous determination of the structural evolution of sodium clusters is challenging. Here, we performed an unbiased structure search among neutral and anionic sodium clusters in the medium size range of 10-25 atoms, using the Crystal structure AnaLYsis by Particle Swarm Optimization (CALYPSO) method. Geometries are determined by CALYPSO structure searches, followed by reoptimization of a large number of candidate structures...
January 20, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28100305/environment-directed-activation-the-escherichia-coli-flhdc-operon-by-transposons
#2
Zhongge Zhang, Chika Kukita, Mir Zafri Humayun, Milton H Saier
The flagellar system in E. coli K12 is expressed under the control of the flhDC-encoded master regulator, FlhDC. Transposition of insertion sequence (IS) elements to the upstream flhDC promoter region up-regulates transcription of this operon, resulting in more rapid motility. Wang and Wood (2011) provided evidence that insertion of IS5 into upstream activating sites occurs at higher rates in semisolid agar media in which swarming behavior is allowed as compared with liquid or solid media where swarming cannot occur...
January 17, 2017: Microbiology
https://www.readbyqxmd.com/read/28100066/identification-of-eggs-from-different-production-systems-based-on-hyperspectra-and-cs-svm
#3
J Sun, S Cong, H Mao, X Zhou, X Wu, X Zhang
1. To identify the origin of table eggs more accurately, a method based on hyperspectral imaging technology was studied. 2. The hyperspectral data of 200 samples of intensive and extensive eggs were collected. Standard normalised variables (SNV) combined with Savitzky-Golay (SG) were used to eliminate noise, then stepwise regression (SWR) was used for feature selection. Grid search algorithm (GS), genetic search algorithm (GA), particle swarm optimisation algorithm (PSO) and cuckoo search algorithm (CS) were applied by support vector machine (SVM) to establish a SVM identification model with the optimal parameters...
January 19, 2017: British Poultry Science
https://www.readbyqxmd.com/read/28098559/lattice-boltzmann-simulations-of-the-bead-spring-microswimmer-with-a-responsive-stroke-from-an-individual-to-swarms
#4
Kristina Pickl, Jayant Pande, Harald Köstler, Ulrich Rüde, Ana-Suncana Smith
Propulsion at low Reynolds numbers is often studied by defining artificial microswimmers which exhibit a particular stroke. The disadvantage of such an approach is that the stroke does not adjust to the environment, in particular the fluid flow, which can diminish the effect of hydrodynamic interactions. To overcome this limitation, we simulate a microswimmer consisting of three beads connected by springs and dampers, using the self-developed waLBerla and <i>pe</i> framework based on the lattice Boltzmann method and the discrete element method...
January 18, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/28095487/dna-metabarcoding-of-amazonian-ichthyoplankton-swarms
#5
M E Maggia, Y Vigouroux, J F Renno, F Duponchelle, E Desmarais, J Nunez, C García-Dávila, F M Carvajal-Vallejos, E Paradis, J F Martin, C Mariac
Tropical rainforests harbor extraordinary biodiversity. The Amazon basin is thought to hold 30% of all river fish species in the world. Information about the ecology, reproduction, and recruitment of most species is still lacking, thus hampering fisheries management and successful conservation strategies. One of the key understudied issues in the study of population dynamics is recruitment. Fish larval ecology in tropical biomes is still in its infancy owing to identification difficulties. Molecular techniques are very promising tools for the identification of larvae at the species level...
2017: PloS One
https://www.readbyqxmd.com/read/28093584/phase-diagram-and-superconductivity-of-compressed-zirconium-hydrides
#6
Xiao-Feng Li, Zi-Yu Hu, Bing Huang
It is known that pressure can be applied to fundamentally alter the bonding patterns between the chemical elements. By employing an unbiased structure search method based on a particle swarm optimization (PSO) methodology, the phase diagram and crystal structures of Zr-H compounds are systematically investigated at a high pressure up to 150 GPa. Interestingly, some unexpectedly stable compounds with unusual chemical and physical properties are predicted to be formed, for example, four stable and metallic species with stoichiometries of ZrH, ZrH2, ZrH3, and ZrH6 are identified for the first time...
January 17, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28092578/experienced-gray-wolf-optimization-through-reinforcement-learning-and-neural-networks
#7
E Emary, Hossam M Zawbaa, Crina Grosan
In this paper, a variant of gray wolf optimization (GWO) that uses reinforcement learning principles combined with neural networks to enhance the performance is proposed. The aim is to overcome, by reinforced learning, the common challenge of setting the right parameters for the algorithm. In GWO, a single parameter is used to control the exploration/exploitation rate, which influences the performance of the algorithm. Rather than using a global way to change this parameter for all the agents, we use reinforcement learning to set it on an individual basis...
January 10, 2017: IEEE Transactions on Neural Networks and Learning Systems
https://www.readbyqxmd.com/read/28092573/environment-sensitivity-based-cooperative-co-evolutionary-algorithms-for-dynamic-multi-objective-optimization
#8
Biao Xu, Yong Zhang, Dunwei Gong, Yinan Guo, Miao Rong
Dynamic multi-objective optimization problems (DMOPs) not only involve multiple conflicting objectives, but these objectives may also vary with time, raising a challenge for researchers to solve them. This paper presents a cooperative co-evolutionary strategy based on environment sensitivities for solving DMOPs. In this strategy, a new method that groups decision variables is first proposed, in which all the decision variables are partitioned into two subcomponents according to their interrelation with environment...
January 16, 2017: IEEE/ACM Transactions on Computational Biology and Bioinformatics
https://www.readbyqxmd.com/read/28091933/flagellar-regulation-and-virulence-in-the-entomopathogenic-bacteria-xenorhabdus-nematophila-and-photorhabdus-luminescens
#9
Alain Givaudan, Anne Lanois
There is a complex interplay between the regulation of flagellar motility and the expression of virulence factors in many bacterial pathogens. Here, we review the literature on the direct and indirect roles of flagellar motility in mediating the tripartite interaction between entomopathogenic bacteria (Photorhabdus and Xenorhabdus), their nematode hosts, and their insect targets. First, we describe the swimming and swarming motility of insect pathogenic bacteria and its impact on insect colonization. Then, we describe the coupling between the expression of flagellar and virulence genes and the dynamic of expression of the flagellar regulon during invertebrate infection...
December 28, 2016: Current Topics in Microbiology and Immunology
https://www.readbyqxmd.com/read/28089602/particle-swarm-optimizer-for-weighting-factor-selection-in-intensity-modulated-radiation-therapy-optimization-algorithms
#10
Jie Yang, Pengcheng Zhang, Liyuan Zhang, Huazhong Shu, Baosheng Li, Zhiguo Gui
In inverse treatment planning of intensity-modulated radiation therapy (IMRT), the objective function is typically the sum of the weighted sub-scores, where the weights indicate the importance of the sub-scores. To obtain a high-quality treatment plan, the planner manually adjusts the objective weights using a trial-and-error procedure until an acceptable plan is reached. In this work, a new particle swarm optimization (PSO) method which can adjust the weighting factors automatically was investigated to overcome the requirement of manual adjustment, thereby reducing the workload of the human planner and contributing to the development of a fully automated planning process...
January 12, 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28068337/a-swarm-of-bee-research
#11
Lauren A Richardson
No abstract text is available yet for this article.
January 2017: PLoS Biology
https://www.readbyqxmd.com/read/28068291/particle-swarm-optimization-for-programming-deep-brain-stimulation-arrays
#12
Edgar Peña, Simeng Zhang, Steve Deyo, YiZi Xiao, Matthew D Johnson
OBJECTIVE: Deep brain stimulation (DBS) therapy relies on both precise neurosurgical targeting and systematic optimization of stimulation settings to achieve beneficial clinical outcomes. One recent advance to improve targeting is the development of DBS arrays (DBSAs) with electrodes segmented both along and around the DBS lead. However, increasing the number of independent electrodes creates the logistical challenge of optimizing stimulation parameters efficiently. APPROACH: Solving such complex problems with multiple solutions and objectives is well known to occur in biology, in which complex collective behaviors emerge out of swarms of individual organisms engaged in learning through social interactions...
February 2017: Journal of Neural Engineering
https://www.readbyqxmd.com/read/28065820/bioavailability-enhanced-resveramax%C3%A2-modulates-quorum-sensing-and-inhibits-biofilm-formation-in-pseudomonas-aeruginosa-pao1
#13
H S Vasavi, H V Sudeep, H B Lingaraju, K Shyam Prasad
Quorum sensing (QS), a cell-to-cell communication mechanism present in many bacterial species plays a key role in regulating the virulence factor and biofilm formation in many pathogens, which causes severe public health risk. Therefore, interfering with QS mechanism offers an attractive strategy to combat bacterial infections. In the present study, anti-QS activity of a novel resveratrol formulation, Resveramax™, was detected using Chromobacterium violaceum biosensor bioassay and the effect of Resveramax on QS-regulated phenotypes in Pseudomonas aeruginosa PAO1 was assessed by standard protocols...
January 5, 2017: Microbial Pathogenesis
https://www.readbyqxmd.com/read/28056789/evolutionary-diversification-of-pseudomonas-aeruginosa-in-an-artificial-sputum-model
#14
Emily V Davies, Chloe E James, Michael A Brockhurst, Craig Winstanley
BACKGROUND: During chronic lung infections of cystic fibrosis patients Pseudomonas aeruginosa populations undergo extensive evolutionary diversification. However, the selective drivers of this evolutionary process are poorly understood. To test the effects of temperate phages on diversification in P. aeruginosa biofilms we experimentally evolved populations of P. aeruginosa for approximately 240 generations in artificial sputum medium with or without a community of three temperate phages...
January 5, 2017: BMC Microbiology
https://www.readbyqxmd.com/read/28048204/su-g-206-04-a-method-for-realizing-phantom-calibration-and-geometry-calibration-accurately-based-on-a-geometry-evaluation-index
#15
S Yang, S Wu, H Qi, Y Xu, L Zhou
PURPOSE: For traditional geometric calibration, the calibration accuracy relies on both accuracy of geometry phantom manufacture and accuracy of ball bearings (BB) location estimation. In this work, we have developed a method to perform phantom calibration and geometry calibration iteratively and accurately in a whole procedure. METHODS: We have designed and manufactured a geometry phantom with BB and an evaluation phantom of a crystal ball contained in a cubic gel box...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048155/th-ef-brb-04-4%C3%AF-dynamic-conformal-arc-therapy-dynamic-conformal-arc-therapy-dcat-for-sbrt
#16
T Chiu, T Long, A Modiri, Z Tian, A Sawant, Y Yan, S Jiang, X Gu
PURPOSE: To develop an efficient and effective trajectory optimization methodology for 4π dynamic conformal arc treatment (4π DCAT) with synchronized gantry and couch motion; and to investigate potential clinical benefits for stereotactic body radiation therapy (SBRT) to breast, lung, liver and spine tumors. METHODS: The entire optimization framework for 4π DCAT inverse planning consists of two parts: 1) integer programming algorithm and 2) particle swarm optimization (PSO) algorithm...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047936/tu-h-bra-04-a-novel-superconducting-magnet-design-for-optimized-patient-access-and-minimal-ssd-for-use-in-a-linac-mr-hybrid
#17
S Yaghoobpour Tari, K Wachowicz, B Fallone
PURPOSE: A prototype rotating hybrid MR imaging system and linac has been developed to allow for simultaneous imaging and radiation delivery parallel to B0 . However, the design of a compact magnet capable of rotation in a small vault with sufficient patient access and a typical clinical source-to-surface distance (SSD) is challenging. This work presents a novel superconducting magnet design that allows for a reduced SSD and ample patient access by moving the superconducting coils to the side of the yoke...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047350/su-f-t-256-4d-imrt-planning-using-an-early-prototype-gpu-enabled-eclipse-workstation
#18
A Hagan, A Modiri, M Svatos, A Sawant
PURPOSE: True 4D IMRT planning, based on simultaneous spatiotemporal optimization has been shown to significantly improve plan quality in lung radiotherapy. However, the high computational complexity associated with such planning represents a significant barrier to widespread clinical deployment. We introduce an early prototype GPU-enabled Eclipse workstation for inverse planning. To our knowledge, this is the first GPUintegrated Eclipse system demonstrating the potential for clinical translation of GPU computing on a major commercially-available TPS...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047237/tu-h-campus-tep1-01-variable-beam-fractionation-for-sabr
#19
A Modiri, A Sawant
PURPOSE: In current conventionally-fractionated as well as hypofractionated 3D conformal radiotherapy (CRT), the same beam arrangement is employed from fraction to fraction. We challenge this notion and postulate that by varying the beam arrangement between fractions we can achieve greater sparing of organs at risk (OARs) while maintaining PTV coverage. We use an inverse planning strategy using a swarm intelligence-based global optimization algorithm to exploit the additional degree of freedom represented by inter-fractional variation in beam angles...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046651/mo-fg-bra-08-swarm-intelligence-based-personalized-respiratory-gating-in-lung-sabr
#20
A Modiri, P Sabouri, X Gu, R Timmerman, A Sawant
PURPOSE: Respiratory gating is widely deployed as a clinical motion-management strategy in lung radiotherapy. In conventional gating, the beam is turned on during a pre-determined phase window; typically, around end-exhalation. In this work, we challenge the notion that end-exhalation is always the optimal gating phase. Specifically, we use a swarm-intelligence-based, inverse planning approach to determine the optimal respiratory phase and MU for each beam with respect to (i) the state of the anatomy at each phase and (ii) the time spent in that state, estimated from long-term monitoring of the patient's breathing motion...
June 2016: Medical Physics
keyword
keyword
52032
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"