Using chaos game representation we introduce a novel and straightforward method for identifying similarities/dissimilarities between DNA sequences of the same type, from different organisms. A matrix ...is associated to each CGR pattern and the similarities result from the comparison between the matrices of the sequences of interest. Three different methods of analysis of the resulting difference matrix are considered: a 3-dimensional representation giving both local and global information, a numerical characterization by defining an
n-letter word similarity measure and a statistical evaluation. The method is illustrated by implementation to the study of albumin nucleotides sequences from eight mammal species taking as reference the human albumin.
We present a novel method for the parameter oriented analysis of mutual correlation between independent time series or between equivalent structures such as ordered data sets. The proposed method is ...based on the sliding window technique, defines a new type of correlation measure and can be applied to time series from all domains of science and technology, experimental or simulated. A specific parameter that can characterize the time series is computed for each window and a cross correlation analysis is carried out on the set of values obtained for the time series under investigation. We apply this method to the study of some currency daily exchange rates from the point of view of the Hurst exponent and the intermittency parameter. Interesting correlation relationships are revealed and a tentative crisis prediction is presented.
► Object oriented analysis of correlation of time series or equivalent structures. ► Sliding window technique applied to time series or ordered data sets. ► A new type of correlation measure is defined. ► Study of currency exchange rates using Hurst exponent and intermittency parameter.
The cell refractive index has been proposed as a putative cancer biomarker of great potential, being correlated with cell content and morphology, cell division rate and membrane permeability. We used ...digital holographic microscopy to compare the refractive index and dry mass density of two B16 murine melanoma sublines of different metastatic potential. Using statistical methods, the distribution of phase shifts within the reconstructed quantitative phase images was analyzed by the method of bimodality coefficients. The observed correlation of refractive index, dry mass density and bimodality profile with the metastatic potential of the cells was validated by real time impedance‐based assay and clonogenic tests. We suggest that the refractive index and bimodality analysis of quantitative phase image histograms could be developed as optical biomarkers useful in label‐free detection and quantitative evaluation of cell metastatic potential.
Quantitative phase images (QPIs) of digital holographic microscopy were acquired for two sublines of B16 murine melanoma cells having different metastatic potential. The cellular optical and digital signature (as refractive index, dry mass density and bimodality profile of QPIs' histograms) of these cells correlates to their metastatic potential, as proved by clonogenic and proliferation tests, and constitutes a promising label‐free biomarker of malignancy.
For Romania, as for all other ex-communist countries from Eastern Europe, the transition from the rigid centrally planned economic system to the free-market economy, fair competition based, was an ...amazing experience. From the academic standpoint, the economic reform was a huge research opportunity, as well as having extremely important practical consequences. Based on the case of Romania, the authors have developed an original, bi-dimensional matrix model of this transition process (Scarlat Model), emphasizing the typology of four basic economic systems. Managerial aspects are underlined - both for economic systems and transition process - as well as some stability considerations. Two features of the transition strategy are presented: the transition path and duration of the process. Special attention was paid to assessing the moment by when the economic transition ends. Analysis of the transition path - based on the theory of deterministic chaos (i.e. short-run predictability) - has led to interesting results: a comprehensive research on the evolution of the Romanian currency exchange over a period of sixteen years (1990-2005) revealed three intervals in the Romanian recent history of economic transition and confirmed the diagnostic of transition end. The general model is applied in the case of Romania and some interesting findings are presented, but it is also fully applicable to all Eastern European countries and not only Romania. The EU accessing process is a different type of transition - rigorously planned, regulated and monitored.
This study is proposing a semi-quantitative, unbiased "hands on - hands off" partition of the economic systems on the bases of whether they are or are not exhibiting structure as revealed by non ...linear time series analysis. The analysis is performed on the corresponding exchange rate time series with respect to the United States Dollar. The structure is related to the impact of the ongoing economic crisis upon several economic systems. By assessing the effect of the financial hit as "recession / no recession", the analysis of 26 economic systems has revealed that almost all systems suffered financial shock but not all financial shocks were followed by economic recession. The evidence of the financial shock is addressed in terms of the specific quantities of time series analysis i.e. flatness and Holder exponent. Under the assumption that the "hands on" economies are more robust against the crisis, the crossing analysis emphasizes that systems that do have such a structure could be assigned to a certain degree of centralization imprinted by an unspecified influential entity in the decision making process.
The recent devastating accident at Fukushima nuclear facilities brought into experts' attention new elements related to the issue of increased safety of the critical infrastructures. The aim of this ...paper is to approach the NPP (nuclear power plant) critical infrastructures, their lifecycle, risk analysis and management in terms of projects, project lifecycle, and project risk analysis and management. Based on the similarity identified between the NPP lifecycle and project lifecycle, it is suggested that project management principles may be applied in case of NPP projects - in addition to all specific methods for safety and risk analysis that were developed for NPPs. The managers of the NPP critical infrastructure projects must consider several risk dimensions - in addition to the nuclear safety-related risk. This paper underlines the importance of considering the cause-effect relationships between external/risk factors themselves.
This paper presents our method, which simultaneously combines automatic imaging, identification, and counting with the acquisition of morphological information for at least 1000 blood cells from ...several three-dimensional images of the same sample. We started with seeking parameters to differentiate between red blood cells that are similar but different with respect to their development stage, i.e., mature or immature. We highlight that these cells have different diffractive patterns with complementary central intensity distribution in a given plane along the propagation axis. We use the Fresnel approximation to simulate propagation through cells modeled as spheroid-shaped phase objects and to find the cell property that has the dominant influence on this behavior. Starting with images obtained in the reconstruction step of the digital holographic microscopy technique, we developed a code for automated simultaneous individual cell image separation, identification, and counting, even when the cells are partially overlapped on a slide, and accurate measuring of their morphological features. To find the centroids of each cell, we propose a method based on analytical functions applied at threshold intervals. Our procedure separates the mature from the immature red blood cells and from the white blood cells through a decision based on gradient and radius values.
We present a method that integrates the standard imaging tools for locating and detecting unlabeled nanoparticles (NPs) with computational tools for partitioning cell volumes and NPs counting within ...specified regions to evaluate their internal traffic. The method uses enhanced dark field CytoViva optical system and combines 3D reconstructions of double fluorescently labeled cells with hyperspectral images. The method allows the partitioning of each cell image into four regions: nucleus, cytoplasm, and two neighboring shells, as well as investigations across thin layers adjacent to the plasma membrane. MATLAB scripts were developed to process the images and to localize NPs in each region. Specific parameters were computed to assess the uptake efficiency: regional densities of NPs, flow densities, relative accumulation indices, and uptake ratios. The results of the method are in line with biochemical analyses. It was shown that a sort of saturation limit for intracellular NPs density is reached at high extracellular NPs concentrations. Higher NPs densities were found in the proximity of the plasma membranes. A decrease of the cell viability with increasing extracellular NPs concentration was observed and explained the negative correlation of the cell eccentricity with NPs number.
•Independent laser beams are spatially modulated as orthogonal optical modes.•The transmission is optimized by correlating the transverse intensities.•Separation and identification of modes use ...matching filter based on inner product model.•Experimental identification is performed by crossing analysis on two copies of the filtered modes.•Identification quality is quantified by Sarle's bimodality coefficient.
The study proves the concept of using a system with two inputs laser-beam, modulated independently by helical and conical phase distributions followed by their superposition in the same physical path for free space optical communications. Both phase distributions generate annular intensities with specific geometry according to the modulating parameters. The modes are multiplexed in an emission unit and propagate via laboratory free space as rings with optimized radii, without interfering, to the reading phase mask of the receiving unit. The reading mask acts as matching filter which embeds planar phase information such that to distribute the helical and conical components on mutual perpendicular directions. Identification occurs when the parameters of the reading mask match those of the input modes as predicted by a 2-dim inner product model developed here and confirmed experimentally by the occurrence of maximum intensities in the specific centers. Splitting the matrix-like diffracted beam in enabler and processing branches allows to double check and to identify the matching cases by the properties of the associated histogram without affecting subsequent signal retrieval. Crosstalk levels are examined.
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