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https://www.readbyqxmd.com/read/28430461/quantifying-the-dynamical-complexity-of-chaotic-time-series
#1
Antonio Politi
A powerful approach is proposed for the characterization of chaotic signals. It is based on the combined use of two classes of indicators: (i) the probability of suitable symbolic sequences (obtained from the ordinal patterns of the corresponding time series); (ii) the width of the corresponding cylinder sets. This way, much information can be extracted and used to quantify the complexity of a given signal. As an example of the potentiality of the method, I introduce a modified permutation entropy which allows for quantitative estimates of the Kolmogorov-Sinai entropy in hyperchaotic models, where other methods would be unpractical...
April 7, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28430108/a-network-physiology-approach-to-the-assessment-of-the-link-between-sinoatrial-and-ventricular-cardiac-controls
#2
Alberto Porta, Vlasta Bari, Beatrice De Maria, Mathias Baumert
A network physiology approach to evaluate the strength of the directed interactions among cardiac controls at sinoatrial and ventricular levels and respiration (R) is proposed. The network is composed of three nodes (i.e. sinoatrial and ventricular cardiac controls and R) and their activity is exemplified by the variability of heart period (HP), the variability of the duration of the electrical activity of the heart approximated as the temporal distance between Q-wave onset and T-wave end or apex (i.e. QTe or QTa) and thoracic movements respectively...
April 21, 2017: Physiological Measurement
https://www.readbyqxmd.com/read/28429787/heat-temperature-and-clausius-inequality-in-a-model-for-active-brownian-particles
#3
Umberto Marini Bettolo Marconi, Andrea Puglisi, Claudio Maggi
Methods of stochastic thermodynamics and hydrodynamics are applied to a recently introduced model of active particles. The model consists of an overdamped particle subject to Gaussian coloured noise. Inspired by stochastic thermodynamics, we derive from the system's Fokker-Planck equation the average exchanges of heat and work with the active bath and the associated entropy production. We show that a Clausius inequality holds, with the local (non-uniform) temperature of the active bath replacing the uniform temperature usually encountered in equilibrium systems...
April 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28429759/dual-mechanisms-of-grain-refinement-in-a-fecocrni-high-entropy-alloy-processed-by-high-pressure-torsion
#4
Wenqian Wu, Min Song, Song Ni, Jingshi Wang, Yong Liu, Bin Liu, Xiaozhou Liao
An equiatomic FeCoCrNi high-entropy alloy with a face-centered cubic structure was fabricated by a powder metallurgy route, and then processed by high-pressure torsion. Detailed microscopy investigations revealed that grain refinement from coarse grains to nanocrystalline grains occurred mainly via concurrent nanoband (NB) subdivision and deformation twinning. NB-NB, twin-NB and twin-twin interactions contributed to the deformation process. The twin-twin interactions resulted in severe lattice distortion and accumulation of high densities of dislocations in the interaction areas...
April 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28429371/design-of-a-short-non-uniform-acquisition-protocol-for-quantitative-analysis-in-dynamic-cardiac-spect-imaging-a-retrospective-123-i-mibg-animal-study
#5
Yunlong Zan, Yong Long, Kewei Chen, Biao Li, Qiu Huang, Grant T Gullberg
PURPOSE: Our previous works have found that quantitative analysis of (123) I-MIBG kinetics in the heart with dynamic single-photon emission computed tomography (SPECT) offers the potential to quantify the innervation integrity at an early stage of left ventricular hypertrophy. However, conventional protocols involving a long acquisition time for dynamic imaging reduce the animal survival rate and thus make longitudinal analysis difficult. The goal of this work was to develop a procedure to reduce the total acquisition time by selecting non-uniform acquisition times for projection views while maintaining the accuracy and precision of estimated physiologic parameters...
April 21, 2017: Medical Physics
https://www.readbyqxmd.com/read/28429157/scenes-as-micro-cultures-examining-heterogeneity-of-hiv-risk-behavior-among-gay-bisexual-and-other-men-who-have-sex-with-men-in-toronto-canada
#6
Syed W Noor, Barry D Adam, David J Brennan, David A Moskowitz, Sandra Gardner, Trevor A Hart
Using latent class analysis (LCA), we examined patterns of participation in multiple scenes, how sexual risk practices vary by scene, and psychosocial factors associated with these patterns among 470 gay, bisexual, and other men who have sex with men (GBM) recruited from Toronto. We calculated posterior probability of being in a class from participation in nine separate scenes. We used Entropy, the Bayesian information criterion and the Lo-Mendel-Rubin likelihood ratio test to identify the best fit model. Fit indices suggested a four-class solution...
April 20, 2017: Archives of Sexual Behavior
https://www.readbyqxmd.com/read/28428329/visualization-of-rna-structure-models-within-the-integrative-genomics-viewer
#7
Steven Busan, Kevin M Weeks
Analyses of the interrelationships between RNA structure and function are increasingly important components of genomic studies. The SHAPE-MaP strategy enables accurate RNA structure probing and realistic structure modeling of kilobase-length noncoding RNAs and mRNAs. Existing tools for visualizing RNA structure models are not suitable for efficient analysis of long, structurally heterogeneous RNAs. In addition, structure models are often advantageously interpreted in the context of other experimental data and gene annotation information, for which few tools currently exist...
April 20, 2017: RNA
https://www.readbyqxmd.com/read/28427899/energy-and-information-flows-in-biological-systems-bioenergy-transduction-of-v1-atpase-rotary-motor-and-dynamics-of-thermodynamic-entropy-in-information-flows
#8
REVIEW
Ichiro Yamato, Takeshi Murata, Andrei Khrennikov
We classify research fields in biology with respect to flows of materials, energy, and information. We investigate energy transducing mechanisms in biology, using as a representative the typical molecular rotary motor V1-ATPase from a bacterium Enterococcus hirae. The structures of several intermediates of the rotary motor are described and the molecular mechanism of the motor converting chemical energy into mechanical energy is discussed. Comments and considerations on the information flows in biology, especially on the thermodynamic entropy in quantum physical and biological systems, are presented in section 3 in a biologist friendly manner...
April 17, 2017: Progress in Biophysics and Molecular Biology
https://www.readbyqxmd.com/read/28427643/improving-the-enzymolysis-efficiency-of-potato-protein-by-simultaneous-dual-frequency-energy-gathered-ultrasound-pretreatment-thermodynamics-and-kinetics
#9
Yu Cheng, Yun Liu, Juan Wu, Prince Ofori Donkor, Ting Li, Haile Ma
The thermodynamics and kinetics of traditional and simultaneous dual frequency energy-gathered ultrasound (SDFU) assisted enzymolysis of potato protein were investigated to get the knowledge of the mechanisms on the SDFU's promoting efficiency during enzymolysis. The concentration of potato protein hydrolysate and parameters of thermodynamic and kinetic during traditional and SDFU assisted enzymolysis were determined. The results showed that potato protein hydrolysate concentration of SDFU assisted enzymolysis was higher than traditional enzymolysis at the hydrolysis time of 60min (p<0...
July 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28426754/assessing-environmental-attributes-and-effects-of-climate-change-on-sphagnum-peatland-distributions-in-north-america-using-single-and-multi-species-models
#10
Tobi A Oke, Heather A Hager
The fate of Northern peatlands under climate change is important because of their contribution to global carbon (C) storage. Peatlands are maintained via greater plant productivity (especially of Sphagnum species) than decomposition, and the processes involved are strongly mediated by climate. Although some studies predict that warming will relax constraints on decomposition, leading to decreased C sequestration, others predict increases in productivity and thus increases in C sequestration. We explored the lack of congruence between these predictions using single-species and integrated species distribution models as proxies for understanding the environmental correlates of North American Sphagnum peatland occurrence and how projected changes to the environment might influence these peatlands under climate change...
2017: PloS One
https://www.readbyqxmd.com/read/28426209/channel-assisted-proton-conduction-behavior-in-hydroxyl-rich-lanthanide-based-magnetic-metal-organic-frameworks
#11
Soumava Biswas, Jayita Chakraborty, Vijay Singh Parmar, Siba Prasad Bera, Nirmal Ganguli, Sanjit Konar
Two new lanthanide-based 3D metal-organic frameworks (MOFs), {[Ln(L)(Ox)(H2O)]n·xH2O} [Ln = Gd(3+) and x = 3 (1) and Dy(3+) and x = 1.5 (2); H2L = mucic acid; OxH2 = oxalic acid] showing interesting magnetic properties and channel-mediated proton conduction behavior, are presented here. Single-crystal X-ray structure analysis shows that, in complex 1, the overall structure originates from the mucate-bridged gadolinium-based rectangular metallocycles. The packing view reveals the presence the two types of hydrophilic 1D channels filled with lattice water molecules, which are strongly hydrogen-bonded with coordinated water along the a and b axes, whereas for complex 2, the 3D framework originates from a carboxylate-bridged dysprosium-based criss-cross-type secondary building block...
April 20, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28423070/the-extended-log-logistic-distribution-properties-and-application
#12
Stênio R Lima, Gauss M Cordeiro
We propose a new four-parameter lifetime model, called the extended log-logistic distribution, to generalize the two-parameter log-logistic model. The new model is quite flexible to analyze positive data. We provide some mathematical properties including explicit expressions for the ordinary and incomplete moments, probability weighted moments, mean deviations, quantile function and entropy measure. The estimation of the model parameters is performed by maximum likelihood using the BFGS algorithm. The flexibility of the new model is illustrated by means of an application to a real data set...
January 2017: Anais da Academia Brasileira de Ciências
https://www.readbyqxmd.com/read/28422874/consort-the-effect-of-intraoperative-dexmedetomidine-on-hemodynamic-responses-during-emergence-from-nasotracheal-intubation-after-oral-surgery
#13
Youn Yi Jo, Hong Soon Kim, Kyung Cheon Lee, Young Jin Chang, Youseok Shin, Hyun Jeong Kwak
BACKGROUND: Dexmedetomidine provides smooth emergence with reduced agitation. The authors hypothesized low-dose dexmedetomidine infusion might contribute to hemodynamic stability during and after nasotracheal tube extubation. METHODS: Ninety-three adult patients scheduled for oral and maxillofacial surgery were enrolled in this prospective study. Patients were randomly assigned to receive normal saline (control group, n = 31), dexmedetomidine at 0.2 μg/kg/h (DEX0...
April 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28422217/increased-substrate-affinity-in-the-escherichia-coli-l28r-dihydrofolate-reductase-mutant-causes-trimethoprim-resistance
#14
Haleh Abdizadeh, Yusuf Talha Tamer, Omer Acar, Erdal Toprak, Ali Rana Atilgan, Canan Atilgan
Dihydrofolate reductase (DHFR) is a ubiquitous enzyme with an essential role in cell metabolism. DHFR catalyzes the reduction of dihydrofolate to tetrahydrofolate, which is a precursor for purine and thymidylate synthesis. Several DHFR targeting antifolate drugs including trimethoprim, a competitive antibacterial inhibitor, have therefore been developed and are clinically used. Evolution of resistance against antifolates is a common public health problem rendering these drugs ineffective. To combat the resistance problem, it is important to understand resistance-conferring changes in the DHFR structure and accordingly develop alternative strategies...
April 19, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28422113/increased-spontaneous-meg-signal-diversity-for-psychoactive-doses-of-ketamine-lsd-and-psilocybin
#15
Michael M Schartner, Robin L Carhart-Harris, Adam B Barrett, Anil K Seth, Suresh D Muthukumaraswamy
What is the level of consciousness of the psychedelic state? Empirically, measures of neural signal diversity such as entropy and Lempel-Ziv (LZ) complexity score higher for wakeful rest than for states with lower conscious level like propofol-induced anesthesia. Here we compute these measures for spontaneous magnetoencephalographic (MEG) signals from humans during altered states of consciousness induced by three psychedelic substances: psilocybin, ketamine and LSD. For all three, we find reliably higher spontaneous signal diversity, even when controlling for spectral changes...
April 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28421267/potential-distribution-of-mountain-cloud-forest-in-michoac%C3%A3-n-mexico-prioritization-for-conservation-in-the-context-of-landscape-connectivity
#16
Camilo A Correa Ayram, Manuel E Mendoza, Andrés Etter, Diego R Pérez Salicrup
Landscape connectivity is essential in biodiversity conservation because of its ability to reduce the effect of habitat fragmentation; furthermore is a key property in adapting to climate change. Potential distribution models and landscape connectivity studies have increased with regard to their utility to prioritizing areas for conservation. The objective of this study was to model the potential distribution of Mountain cloud forests in the Transversal Volcanic System, Michoacán and to analyze the role of these areas in maintaining landscape connectivity...
April 18, 2017: Environmental Management
https://www.readbyqxmd.com/read/28419977/investigation-of-as-v-removal-from-acid-mine-drainage-by-iron-hydr-oxide-modified-zeolite
#17
Pfano Mathews Nekhunguni, Nikita Tawanda Tavengwa, Hlanganani Tutu
In this work, the synthesis of iron (hydr) oxide modified zeolite was achieved through precipitation of iron on the zeolite. The structure and surface morphology of iron (hydr) oxide modified zeolite (IHOMZ) was studied by scanning electron microscopy (SEM), coupled with an energy-dispersive X-ray spectroscopy (EDX), and Fourier transform infrared (FT-IR) spectra. The efficiency of IHOMZ was then investigated through batch technique for the extraction of As(V) from mine waste water. The optimum parameters for maximum As(V) adsorption were: an initial As(V) concentration (10 mg L(-1)), adsorbent dosage (3...
April 15, 2017: Journal of Environmental Management
https://www.readbyqxmd.com/read/28419951/can-fractal-methods-applied-to-video-tracking-detect-the-effects-of-deltamethrin-pesticide-or-mercury-on-the-locomotion-behavior-of-shrimps
#18
Bruno Mendes Tenorio, Eurípedes Alves da Silva Filho, Gentileza Santos Martins Neiva, Valdemiro Amaro da Silva, Fernanda das Chagas Angelo Mendes Tenorio, Themis de Jesus da Silva, Emerson Carlos Soares E Silva, Romildo de Albuquerque Nogueira
Shrimps can accumulate environmental toxicants and suffer behavioral changes. However, methods to quantitatively detect changes in the behavior of these shrimps are still needed. The present study aims to verify whether mathematical and fractal methods applied to video tracking can adequately describe changes in the locomotion behavior of shrimps exposed to low concentrations of toxic chemicals, such as 0.15µgL(-1) deltamethrin pesticide or 10µgL(-1) mercuric chloride. Results showed no change after 1min, 4, 24, and 48h of treatment...
April 15, 2017: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/28419171/ultrasound-texture-analysis-association-with-lymph-node-metastasis-of-papillary-thyroid-microcarcinoma
#19
Soo-Yeon Kim, Eunjung Lee, Se Jin Nam, Eun-Kyung Kim, Hee Jung Moon, Jung Hyun Yoon, Kyung Hwa Han, Jin Young Kwak
This retrospective study aimed to evaluate whether ultrasound texture analysis is useful to predict lymph node metastasis in patients with papillary thyroid microcarcinoma (PTMC). This study was approved by the Institutional Review Board, and the need to obtain informed consent was waived. Between May and July 2013, 361 patients (mean age, 43.8 ± 11.3 years; range, 16-72 years) who underwent staging ultrasound (US) and subsequent thyroidectomy for conventional PTMC ≤ 10 mm between May and July 2013 were included...
2017: PloS One
https://www.readbyqxmd.com/read/28417127/on-the-formation-of-stripe-sigma-and-honeycomb-phases-in-a-core-corona-system
#20
Harini Pattabhiraman, Marjolein Dijkstra
Using Monte Carlo simulations and free-energy calculations, we investigate the phase behaviour of a two-dimensional core-corona system. We model this system as particles consisting of an impenetrable hard core of diameter σHD surrounded by a purely repulsive soft corona of diameter δ = 1.95σHD. At low densities, we observe the spontaneous formation of a phase with a stripe texture as well as a honeycomb-like phase driven by both energy and entropy considerations. At high densities, we find that a two-dimensional analogue of the periodic sigma phase, considered as an approximant of dodecagonal quasicrystals, is energetically stabilised with respect to two distinct dodecagonal quasicrystals, namely, a square-triangle tiling and a square-triangle-shield tiling...
April 18, 2017: Soft Matter
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