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fractal dimension

Travis J Wiltshire, Matthew J Euler, Ty L McKinney, Jonathan E Butner
Humans are high-dimensional, complex systems consisting of many components that must coordinate in order to perform even the simplest of activities. Many behavioral studies, especially in the movement sciences, have advanced the notion of soft-assembly to describe how systems with many components coordinate to perform specific functions while also exhibiting the potential to re-structure and then perform other functions as task demands change. Consistent with this notion, within cognitive neuroscience it is increasingly accepted that the brain flexibly coordinates the networks needed to cope with changing task demands...
2017: Frontiers in Physiology
Igor Pantic, Jovana Paunovic, Danijela Vucevic, Tatjana Radosavljevic, Stefan Dugalic, Anita Petkovic, Sanja Radojevic-Skodric, Senka Pantic
Although there are numerous recent works focusing on fractal properties of DNA and chromatin, many issues regarding changes in chromatin fractality during physiological aging remain unclear. In this study, we present results indicating that in mice, there is an age-related reduction of chromatin fractal complexity in a population of spleen follicular cells (SFCs). Spleen tissue was obtained from 16 mice and fixated in Carnoy solution. The youngest animal was newborn, and each animal was exactly 1 month older than the previous...
September 18, 2017: Microscopy and Microanalysis
Christos Sachpekidis, Jens Hillengass, Hartmut Goldschmidt, Hoda Anwar, Uwe Haberkorn, Antonia Dimitrakopoulou-Strauss
A renewed interest has been recently developed for the highly sensitive bone-seeking radiopharmaceutical (18)F-NaF. Aim of the present study is to evaluate the potential utility of quantitative analysis of (18)F-NaF dynamic PET/CT data in differentiating malignant from benign degenerative lesions in multiple myeloma (MM). 80 MM patients underwent whole-body PET/CT and dynamic PET/CT scanning of the pelvis with (18)F-NaF. PET/CT data evaluation was based on visual (qualitative) assessment, semi-quantitative (SUV) calculations, and absolute quantitative estimations after application of a 2-tissue compartment model and a non-compartmental approach leading to the extraction of fractal dimension (FD)...
2017: American Journal of Nuclear Medicine and Molecular Imaging
Dinara Sobola, Ştefan Ţălu, Shahram Solaymani, Lubomír Grmela
The purpose of this work is to study the dependence of AFM-data reliability on scanning rate. The three-dimensional (3D) surface topography of the samples with different micro-motifs is investigated. The analysis of surface metrics for estimation of artifacts from inappropriate scanning rate is presented. Fractal analysis was done by cube counting method and evaluation of statistical metrics was carrying out on the basis of AFM-data. Combination of quantitate parameters is also presented in graphs for every measurement...
September 14, 2017: Microscopy Research and Technique
Ning Zhuang, Ying Zeng, Li Tong, Chi Zhang, Hanming Zhang, Bin Yan
This paper introduces a method for feature extraction and emotion recognition based on empirical mode decomposition (EMD). By using EMD, EEG signals are decomposed into Intrinsic Mode Functions (IMFs) automatically. Multidimensional information of IMF is utilized as features, the first difference of time series, the first difference of phase, and the normalized energy. The performance of the proposed method is verified on a publicly available emotional database. The results show that the three features are effective for emotion recognition...
2017: BioMed Research International
Mario E Valdés-Tresanco, Mario S Valdés-Tresanco, Pedro A Valiente, Germinal Cocho, Ricardo Mansilla, J M Nieto-Villar
The calculation of absolute binding affinities for protein-inhibitor complexes remains as one of the main challenges in computational structure-based ligand design. The present work explored the calculations of surface fractal dimension (as a measure of surface roughness) and the relationship with experimental binding free energies of Plasmepsin II complexes. Plasmepsin II is an attractive target for novel therapeutic compounds to treat malaria. However, the structural flexibility of this enzyme is a drawback when searching for specific inhibitors...
September 12, 2017: Journal of Molecular Recognition: JMR
Chunzhong Ni, Shitao Zhang, Zhong Chen, Yongfeng Yan, Yujian Li
This study describes the fractal dimensions of the spatial distributions of lineaments as an index of the complexity of faults, and the results could provide new insights into the migration of ore-bearing fluid. The Segment Tracing Algorithm method is employed to extract the lineaments in northeast Yunnan Province from a remote sensing image. Box-counting fractal and multifractal models are used to analyze the fractal and multifractal spatial distribution characteristics of the linear structures. The different directions of the linear structure fractal dimensions are similar in the study area...
September 5, 2017: Scientific Reports
M Korfanta, T Babadagli, K Develi
Surface roughness and flow rate effects on the solvent transport under miscible conditions in a single fracture are studied. Surface replicas of seven different rocks (marble, granite, and limestone) are used to represent different surface roughness characteristics each described by different mathematical models including three fractal dimensions. Distribution of dyed solvent is investigated at various flow rate conditions to clarify the effect of roughness on convective and diffusive mixing. After a qualitative analysis using comparative images of different rocks, the area covered by solvent with respect to time is determined to conduct a semi-quantitative analysis...
August 26, 2017: Journal of Contaminant Hydrology
Clara Llorens-Quintana, Maryam Mousavi, Dorota Szczesna-Iskander, D Robert Iskander
PURPOSE: To evaluate the effect of two types of daily contact lenses (delefilcon A and omafilcon A) on the tear film and establish whether it is dependent on pre-corneal tear film characteristics using a new method to analyse high-speed videokeratoscopy recordings, as well as to determine the sensitivity of the method in differentiating between contact lens materials on eye. METHODS: High-speed videokeratoscopy recordings were analysed using a custom made automated algorithm based on a fractal dimension approach that provides a set of parameters directly related to tear film stability...
August 29, 2017: Contact Lens & Anterior Eye: the Journal of the British Contact Lens Association
Junhao Peng, Elena Agliari
Fractal (or transfractal) features are common in real-life networks and are known to influence the dynamic processes taking place in the network itself. Here, we consider a class of scale-free deterministic networks, called (u, v)-flowers, whose topological properties can be controlled by tuning the parameters u and v; in particular, for u > 1, they are fractals endowed with a fractal dimension df, while for u = 1, they are transfractal endowed with a transfractal dimension d̃f. In this work, we investigate dynamic processes (i...
August 2017: Chaos
Miki U Kobayashi, Yoshitaka Saiki
A chaotic motion can be considered an irregular transition process near unstable periodic orbits embedded densely in a chaotic set. Therefore, unstable periodic orbits have been used to characterize properties of chaos. Statistical quantities of chaos such as natural measures and fractal dimensions can be determined in terms of unstable periodic orbits. Unstable periodic orbits that can provide good approximations to averaged quantities of chaos or turbulence are also known to exist. However, it is not clear what type of unstable periodic orbits can capture them...
August 2017: Chaos
Huria Ibrahim, Hiba Farah, Amal Zein Eddin, Samih Isber, Rabih Sultan
Metal electrodeposition systems display tree-like structures with extensive ramification and a fractal character. Electrolysis is not a necessary route for the growth of such dendritic metal deposits. We can grow beautiful ramification patterns via a simple redox reaction. We present here a study of silver (Ag) deposits from the reduction of Ag(+) in (AgNO3) solution by metallic copper. The experiments are carried out in discotic geometry, in a Petri dish hosting a thin AgNO3 solution film. A variety of deposited structures and patterns is obtained at different Ag(+) concentrations, yet with essentially the same fractal dimension averaged at 1...
August 2017: Chaos
Juan Ruiz de Miras, Víctor Costumero, Vicente Belloch, Joaquín Escudero, César Ávila, Jorge Sepulcre
Alzheimer's disease (AD) is a neurological disorder that creates neurodegenerative changes at several structural and functional levels in human brain tissue. The fractal dimension (FD) is a quantitative parameter that characterizes the morphometric variability of the human brain. In this study, we investigate spherical harmonic-based FD (SHFD), thickness, and local gyrification index (LGI) to assess whether they identify cortical surface abnormalities toward the conversion to AD. We study 33 AD patients, 122 mild cognitive impairment (MCI) patients (50 MCI converters and 29 MCI nonconverters), and 32 healthy controls (HC)...
August 30, 2017: Human Brain Mapping
Michael D Nieskoski, Kayla Marra, Jason R Gunn, P Jack Hoopes, Marvin M Doyley, Tayyaba Hasan, B Stuart Trembly, Brian W Pogue
The poor efficacy of systemic cancer therapeutics in pancreatic ductal adenocarcinoma (PDAC) is partly attributed to deposition of collagen and hyaluronan, leading to interstitial hypertension collapsing blood and lymphatic vessels, limiting drug delivery. The intrinsic micro-regional interactions between hyaluronic acid (HA), collagen and the spatial origins of mechanical stresses that close off blood vessels was investigated here. Multiple localized pressure measurements were analyzed with spatially-matched histochemical images of HA, collagen and vessel perfusion...
August 30, 2017: Scientific Reports
Shixiong Yi, Fangyin Dai, Cunyi Zhao, Yang Si
Enzyme-immobilized nanoparticles that are both catalysis effective and recyclable would have wide applications ranging from bioengineering and food industry to environmental fields; however, creating such materials has proven extremely challenging. Herein, we present a scalable methodology to create Candida rugosa lipase-immobilized magnetic nanoparticles (L-MNPs) by the combination of nonionic reverse micelle method and Fe3O4 nanoparticles. Our approach causes the naturally abundant and sustainable Candida rugose lipase to ordered-assemble into nanoparticles with high catalytic activity and durability...
August 29, 2017: Scientific Reports
Christopher J Newman, Roselyn Bruchez, Sylvie Roches, Marine Jequier Gygax, Cyntia Duc, Farzin Dadashi, Fabien Massé, Kamiar Aminian
PURPOSE: Upper limb assessments in children with hemiparesis rely on clinical measurements, which despite standardization are prone to error. Recently, 3D movement analysis using optoelectronic setups has been used to measure upper limb movement, but generalization is hindered by time and cost. Body worn inertial sensors may provide a simple, cost-effective alternative. METHODS: We instrumented a subset of 30 participants in a mirror therapy clinical trial at baseline, post-treatment, and follow-up clinical assessments, with wireless inertial sensors positioned on the arms and trunk to monitor motion during reaching tasks...
August 25, 2017: Child's Nervous System: ChNS: Official Journal of the International Society for Pediatric Neurosurgery
Wanfen Yip, Peng Guan Ong, Boon Wee Teo, Carol Yim-Lui Cheung, E Shyong Tai, Ching-Yu Cheng, Ecosse Lamoureux, Tien Yin Wong, Charumathi Sabanayagam
Retinal microvascular changes indicating microvascular dysfunction have been shown to be associated with chronic kidney disease (CKD) in cross-sectional studies, but findings were mixed in prospective studies. We aimed to evaluate the relationship between retinal microvascular parameters and incident CKD in an Asian population. We examined 1256 Malay adults aged 40-80 years from the Singapore Malay Eye Study, who attended both the baseline (2004-07) and the follow-up (2011-13) examinations and were free of prevalent CKD...
August 24, 2017: Scientific Reports
S R Shenoi, Payal Peshwani, Anup Garg, Rohit Moharil
BACKGROUND: The oral mucosa lining the oral cavity is composed of epithelium supported by connective tissue. The shape of the epithelial-connective tissue interface has traditionally been used to describe physiological and pathological changes in the oral mucosa. AIM: The aim is to evaluate the morphometric complexity in normal, dysplastic, well-differentiated, and moderately differentiated squamous cell carcinoma (SCC) of the oral mucosa using fractal geometry...
July 2017: Indian Journal of Dental Research: Official Publication of Indian Society for Dental Research
Hongwei Xu, Biao Dong, Qiaoqin Xiao, Xueke Sun, Xinran Zhang, Jiekai Lyu, Yudan Yang, Lin Xu, Xue Bai, Shuang Zhang, Hongwei Song
Artificial fractal structures have attracted considerable scientific interest in circulating tumor cells (CTCs) detection and capture, which plays a pivotal role in the diagnosis and prognosis of cancer. Herein, we designed a bionic TiO2 inverse opal photonic crystal (IOPC) structure for highly efficient immunocapture of CTCs by combination of a magnetic Fe3O4@C6@silane nanoparticles with anti-EpCAM (antiepithelial cell adhesion molecule) and microchannel structure. Porous structure and dimension of IOPC TiO2 can be precisely controlled for mimicking cellular components, and anti-EpCAM antibody was further modified on IOPC interface by conjugating with polydopamine (PDA)...
September 13, 2017: ACS Applied Materials & Interfaces
Rui Zhang, Shimin Liu, Yang Wang
Coalbed methane (CBM) and shale gas become two most important unconventional natural gas resources in US. The fractal dimension, known as the degree of self-similarity or irregularity, is an important parameter to quantitatively characterize gas storage capacity and gas transport properties in pores of rock matrix. In this study, two coal and two shale samples were evaluated to estimate fractal dimensions using combined small angle X-ray scattering (SAXS), small angle neutron scattering (SANS) and low-pressure N2 adsorption techniques...
August 21, 2017: Scientific Reports
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