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fractal dimension

Tiago M Barbosa, Wan X Goh, Jorge E Morais, Mário J Costa, David Pendergast
The aim of this study was to compare the non-linear properties of the four competitive swim strokes. Sixty-eight swimmers performed a set of maximal 4 × 25 m using the four competitive swim strokes. The hip's speed-data as a function of time was collected with a speedo-meter. The speed fluctuation (dv), approximate entropy (ApEn) and the fractal dimension by Higuchi's method (D) were computed. Swimming data exhibited non-linear properties that were different among the four strokes (14.048 ≤ dv ≤ 39.722; 0...
2016: Frontiers in Psychology
Jasmin Nurković, Ivan Zaletel, Selmina Nurković, Šefćet Hajrović, Fahrudin Mustafić, Jovan Isma, Aleksandra Jurišić Škevin, Vesna Grbović, Milica Kovačević Filipović, Zana Dolićanin
In recent years, electromagnetic field (EMF) and low-level laser (LLL) have been found to affect various biological processes, the growth and proliferation of cells, and especially that of stem cells. The aim of this study was to investigate the effects of EMF and LLL on proliferation of human adipose tissue-derived mesenchymal stem cells (hAT-MSCs) and thus to examine the impact of these therapeutic physical modalities on stem cell engraftment. hAT-MSCs were isolated from subcutaneous adipose tissue of six persons ranging in age from 21 to 56 years...
October 21, 2016: Lasers in Medical Science
B L Altshuler, E Cuevas, L B Ioffe, V E Kravtsov
We combine numerical diagonalization with semianalytical calculations to prove the existence of the intermediate nonergodic but delocalized phase in the Anderson model on disordered hierarchical lattices. We suggest a new generalized population dynamics that is able to detect the violation of ergodicity of the delocalized states within the Abou-Chakra, Anderson, and Thouless recursive scheme. This result is supplemented by statistics of random wave functions extracted from exact diagonalization of the Anderson model on ensemble of disordered random regular graphs (RRG) of N sites with the connectivity K=2...
October 7, 2016: Physical Review Letters
Leihong Zhao, Lining Yang, Hongjun Lin, Meijia Zhang, Haiying Yu, Bao-Qiang Liao, Fangyuan Wang, Xiaoling Zhou, Renjie Li
While the adsorptive fouling in membrane bioreactors (MBRs) is highly dependent of the surface morphology, little progress has been made on modeling biocake layer surface morphology. In this study, a novel method, which combined static light scattering method for fractal dimension (Df) measurement with fractal method represented by the modified two-variable Weierstrass-Mandelbrot function, was proposed to model biocake layer surface in a MBR. Characterization by atomic force microscopy showed that the biocake surface was stochastic, disorder, self-similarity, and with non-integer dimension, illustrating obvious fractal features...
October 13, 2016: Bioresource Technology
Nicolas Rouleau, Lukasz M Karbowski, Michael A Persinger
Synthetic experimental substrates are indispensable tools which can allow researchers to model biological processes non-invasively in three-dimensional space. In this study, we investigated the capacities of an electroconductive material whose properties converge upon those of the brain. An electrically conductive material composed of carbohydrates, proteins, fats, ions, water, and trace amounts of other organic compounds and minerals was classically conditioned as inferred by electrophysiological measurements...
2016: PloS One
Soya Shinkai, Tadasu Nozaki, Kazuhiro Maeshima, Yuichi Togashi
The mammalian genome is organized into submegabase-sized chromatin domains (CDs) including topologically associating domains, which have been identified using chromosome conformation capture-based methods. Single-nucleosome imaging in living mammalian cells has revealed subdiffusively dynamic nucleosome movement. It is unclear how single nucleosomes within CDs fluctuate and how the CD structure reflects the nucleosome movement. Here, we present a polymer model wherein CDs are characterized by fractal dimensions and the nucleosome fibers fluctuate in a viscoelastic medium with memory...
October 2016: PLoS Computational Biology
Cuizhen Sun, Jinwei Qiu, Zhibin Zhang, Taha F Marhaba, Yanhao Zhang
In this paper, flocculating performance and mechanisms of a new composite coagulant, poly-ferric aluminum chloride-polydimethyl diallylammonium chloride (PFAC-PD) with different OH(-)/(Fe(3+) + Al(3+)) molar ratios, were investigated for humic acid (HA)-kaolin synthetic wastewater treatment. The impact of OH(-)/(Fe(3+) + Al(3+)) molar ratios on the removal efficiencies of turbidity and dissolved organic carbon, specific UV absorbance, coagulation mechanisms and dynamics was explored during the coagulation process using composite coagulants...
October 2016: Water Science and Technology: a Journal of the International Association on Water Pollution Research
María Karina Manzo-Valencia, Laura Valdés-Santiago, Lino Sanchez-Segura, Doralinda Guzman-de-Pena
The response to exogenous addition of Naphthalene Acetic Acid potassium salt (NAA-K+ ) to Fusarium oxysporum f. sp radici-lycopersici ATCC 60095 and F. oxysporum f. sp. cubense isolated from Michoacan Mexico soil is reported. The in vitro study showed that NAA-K+ might be effective in the control of Fusarium oxysporum. Exogenous application of NAA-K+ affected both, spores and mycelium stages of the fungi. Viability testing using acridine orange and propidium iodide showed that NAA-K+ possess fungal killing properties, doing it effective in the destruction of conidia of this phytopathogenic fungi...
October 18, 2016: Journal of Agricultural and Food Chemistry
Peng Yu, Feng Huang, Qiaowei Li, Fan Lin, Pengli Zhu
OBJECTIVE: The objective of this study was to evaluate the association of the central retinal arteriolar equivalent (CRAE) and the retinal vascular fractal dimension, two quantitative parameters that reflect microcirculation, with aortic stiffness. DESIGN AND METHOD: In this cross-sectional study, we identified the cardiovascular risk factors in 2169 subjects using a health questionnaire, physical examinations and laboratory examinations. We evaluated the aortic stiffness using noninvasive brachial-ankle pulse wave velocity (baPWV) and assessed the microcirculatory alterations with CRAE and retinal vascular fractal dimension, which were measured using fundus photography and semiautomatic quantitative software, respectively...
September 2016: Journal of Hypertension
Tien Wong
The vasculature in the retina can be viewed directly and non-invasively in vivo, offers a unique perspective of the human microvasculature, and therefore the ability to understand early changes, processes, pathways and consequences of hypertension. In the past 15 years, advances in high resolution digital retinal photography and automated or semi-automated computer image software have been applied to measure and quantify a variety of retinal microvascular parameter, including retinal arteriolar and venular caliber, tortuosity, branching patterns and fractal dimensions...
September 2016: Journal of Hypertension
Nattapong Thammasan, Koichi Moriyama, Ken-Ichi Fukui, Masayuki Numao
Although emotion detection using electroencephalogram (EEG) data has become a highly active area of research over the last decades, little attention has been paid to stimulus familiarity, a crucial subjectivity issue. Using both our experimental data and a sophisticated database (DEAP dataset), we investigated the effects of familiarity on brain activity based on EEG signals. Focusing on familiarity studies, we allowed subjects to select the same number of familiar and unfamiliar songs; both resulting datasets demonstrated the importance of reporting self-emotion based on the assumption that the emotional state when experiencing music is subjective...
April 29, 2016: Brain Informatics
Luca Mesin, Davide Dardanello, Alberto Rainoldi, Gennaro Boccia
During fatiguing contractions, many adjustments in motor units behaviour occur: decrease in muscle fibre conduction velocity; increase in motor units synchronisation; modulation of motor units firing rate; increase in variability of motor units inter-spike interval. We simulated the influence of all these adjustments on synthetic EMG signals in isometric/isotonic conditions. The fractal dimension of the EMG signal was found mainly influenced by motor units firing behaviour, being affected by both firing rate and synchronisation level, and least affected by muscle fibre conduction velocity...
October 12, 2016: Medical Engineering & Physics
T Janvier, R Jennane, A Valery, K Harrar, M Delplanque, C Lelong, D Loeuille, H Toumi, E Lespessailles
OBJECTIVES: To examine whether trabecular bone texture (TBT) parameters assessed on computed radiographs could predict knee osteoarthritis (OA) progression. METHODS: This study was performed using data from the Osteoarthritis Initiative. 1647 knees in 1124 patients had bilateral fixed flexion radiographs acquired 48 months apart. Images were semi-automatically segmented to extract a patchwork of regions of interest (ROI). A fractal texture analysis was performed using different methods...
October 11, 2016: Osteoarthritis and Cartilage
Li Shi, Florent Carn, François Boué, Eric Buhler
Aggregation of nanoparticles of given size R induced by addition of a polymer strongly depends on its degree of rigidity. This is shown here on a large variety of silica nanoparticle self-assemblies obtained by electrostatic complexation with carefully selected oppositely charged biopolyelectrolytes of different rigidity. The effective rigidity is quantified by the total persistence length L_{T} representing the sum of the intrinsic (L_{p}) and electrostatic (L_{e}) polyelectrolyte persistence length, which depends on the screening, i...
September 2016: Physical Review. E
(no author information available yet)
[This corrects the article DOI: 10.1371/journal.pone.0155415.].
2016: PloS One
Chen Wang, Fook Chiong Cheong, David B Ruffner, Xiao Zhong, Michael D Ward, David G Grier
In-line holographic microscopy images of micrometer-scale fractal aggregates can be interpreted with an effective-sphere model to obtain each aggregate's size and the population-averaged fractal dimension. We demonstrate this technique experimentally using model fractal clusters of polystyrene nanoparticles and fractal protein aggregates composed of bovine serum albumin and bovine pancreas insulin.
October 5, 2016: Soft Matter
Rashmi G S Phulari, Rajendrasinh S Rathore, Trupti Pramod Talegaon
BACKGROUND: Various clinical and histological factors have helped in predicting the survival of patients with oral squamous cell carcinoma (OSCC). However, there has been a need for more specialized diagnostic and prognostic factors to avoid subjective variation among opinion. Thus, fractal dimension (FD) can be used as an index of the morphological changes that the epithelial cells undergo during their transformation into neoplastic cell. In oral cancer study, nuclear FD (NFD) can be used as a quantitative index to discriminate between normal, dysplastic and neoplastic oral mucosa...
September 2016: Journal of Oral and Maxillofacial Pathology: JOMFP
Rodrigo Echeveste, Claudius Gros
The study of balanced networks of excitatory and inhibitory neurons has led to several open questions. On the one hand it is yet unclear whether the asynchronous state observed in the brain is autonomously generated, or if it results from the interplay between external drivings and internal dynamics. It is also not known, which kind of network variabilities will lead to irregular spiking and which to synchronous firing states. Here we show how isolated networks of purely excitatory neurons generically show asynchronous firing whenever a minimal level of structural variability is present together with a refractory period...
2016: Frontiers in Computational Neuroscience
Fan Huang, Behdad Dashtbozorg, Jiong Zhang, Erik Bekkers, Samaneh Abbasi-Sureshjani, Tos T J M Berendschot, Bart M Ter Haar Romeny
The retinal fractal dimension (FD) is a measure of vasculature branching pattern complexity. FD has been considered as a potential biomarker for the detection of several diseases like diabetes and hypertension. However, conflicting findings were found in the reported literature regarding the association between this biomarker and diseases. In this paper, we examine the stability of the FD measurement with respect to (1) different vessel annotations obtained from human observers, (2) automatic segmentation methods, (3) various regions of interest, (4) accuracy of vessel segmentation methods, and (5) different imaging modalities...
2016: Journal of Ophthalmology
Auke de Vries, Anne Wesseling, Erik van der Linden, Elke Scholten
In this research we use heat-set whey protein aggregates (diameter∼200nm) as novel building blocks for structure formation in liquid oil to form oleogels. To transfer the aggregates to the oil phase, a solvent exchange procedure to sunflower oil was applied using acetone as an intermediate solvent. We found that agglomeration of the aggregates was prevented and the particle size in oil did not change from that in the initial aqueous phase. The small protein aggregates assemble into a space-spanning network, thereby providing solid-like properties to liquid oil...
September 21, 2016: Journal of Colloid and Interface Science
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