1/fα1/f^\alpha spectra in elementary cellular automata and fractal signals

We systematically compute the power spectra of the one-dimensional elementary cellular automata introduced by Wolfram. On the one hand our analysis reveals that one automaton displays $1/f$ spectra though considered as trivial, and on the other hand that various automata classified as chaotic/complex display no $1/f$ spectra. We model the results generalizing the recently investigated Sierpinski signal to a class of fractal signals that are tailored to produce $1/f^{\alpha}$ spectra. From the widespread occurrence of (elementary) cellular automata patterns in chemistry, physics and computer sciences, there are various candidates to show spectra similar to our results.Comment: 4 pages (3 figs included

Sierpinski signal generates 1/fα1/f^\alpha spectra

We investigate the row sum of the binary pattern generated by the Sierpinski automaton: Interpreted as a time series we calculate the power spectrum of this Sierpinski signal analytically and obtain a unique rugged fine structure with underlying power law decay with an exponent of approximately 1.15. Despite the simplicity of the model, it can serve as a model for $1/f^\alpha$ spectra in a certain class of experimental and natural systems like catalytic reactions and mollusc patterns.Comment: 4 pages (4 figs included). Accepted for publication in Physical Review

Statistical Communication Theory

Contains research objectives and reports on eight research projects

Statistical Communication Theory

Contains reports on nine research projects

Statistical Communication Theory

Contains reports on six research projects

Capacitive performance of graphene-based asymmetric supercapacitor

A two-electrode asymmetric supercapacitor with positive and negative electrodes was developed. The positive electrode was composed of reduced graphene oxide/zinc oxide/cobalt oxide nanostructures (RZCo) that were prepared using a one-pot hydrothermal process. Meanwhile, polypyrrole/reduced graphene oxide (PyR) was electrodeposited on a graphite sheet as the negative electrode. These electrodes were separated by a 1.0 M Na2SO4 filter membrane. The synergistic effect between the positive and negative electrode materials widened the potential window to 1.6 V, thus contributing a high energy density of 41.8 Wh/kg at 2 mV/s, which was better than that of the KEMET commercial supercapacitor (17.7 Wh/kg). At room temperature (30 °C), the RZCo//PyR asymmetric supercapacitor exhibited a retention of 87% after 800 cycles compared to a retention of only 49% at 0 °C. Although the asymmetric supercapacitor retained 86% of its original capacitance at 60 °C, it possessed a lower specific capacitance than the asymmetric supercapacitor measured at room temperature. The RZCo//PyR asymmetric supercapacitor had a larger specific capacitance and smaller IR drop (0.09 V) than the KEMET commercial supercapacitor, which has a huge IR drop (0.22 V), providing a specific capacitance of 77.7 F/g

Smoking and health-related quality of life in English general population: Implications for economic evaluations

Copyright @ 2012 Vogl et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.This article has been made available through the Brunel Open Access Publishing Fund.Background: Little is known as to how health-related quality of life (HRQoL) when measured by generic instruments such as EQ-5D differ across smokers, ex-smokers and never-smokers in the general population; whether the overall pattern of this difference remain consistent in each domain of HRQoL; and what implications this variation, if any, would have for economic evaluations of tobacco control interventions. Methods: Using the 2006 round of Health Survey for England data (n = 13,241), this paper aims to examine the impact of smoking status on health-related quality of life in English population. Depending upon the nature of the EQ-5D data (i.e. tariff or domains), linear or logistic regression models were fitted to control for biology, clinical conditions, socio-economic background and lifestyle factors that an individual may have regardless of their smoking status. Age- and gender-specific predicted values according to smoking status are offered as the potential 'utility' values to be used in future economic evaluation models. Results: The observed difference of 0.1100 in EQ-5D scores between never-smokers (0.8839) and heavy-smokers (0.7739) reduced to 0.0516 after adjusting for biological, clinical, lifestyle and socioeconomic conditions. Heavy-smokers, when compared with never-smokers, were significantly more likely to report some/severe problems in all five domains - mobility (67%), self-care (70%), usual activity (42%), pain/discomfort (46%) and anxiety/depression (86%) -. 'Utility' values by age and gender for each category of smoking are provided to be used in the future economic evaluations. Conclusion: Smoking is significantly and negatively associated with health-related quality of life in English general population and the magnitude of this association is determined by the number of cigarettes smoked. The varying degree of this association, captured through instruments such as EQ-5D, may need to be fed into the design of future economic evaluations where the intervention being evaluated affects (e.g. tobacco control) or is affected (e.g. treatment for lung cancer) by individual's (or patients') smoking status

Mucus-degrading Bacteroides link carbapenems to aggravated graft-versus-host disease

View full abstracthttps://openworks.mdanderson.org/leading-edge/1009/thumbnail.jp

Induction of vasculogenesis in breast cancer models

Recently, there have been reports of postnatal vasculogenesis in cases of ischaemia models. The aim of the present study is to provide evidence of postnatal vasculogenesis in breast-cancer–bearing mice. Based on cell surface antigen expression, we isolated endothelial precursor cells from bone marrow, peripheral blood and tumour-infiltrating cells from mice that had received six human breast cancer xenografts. In all three areas (bone marrow, peripheral blood and tumour-infiltrating cells), endothelial precursor cell population was elevated in all transplanted mice. Differentiation and migration activities of endothelial precursor cells were measured by comparing levels of the endothelial precursor cell maturation markers Flk-1, Flt-1, Tie2, VE-cadherin and CD31 among these three areas. The endothelial precursor cell population was 14% or greater in the gated lymphocyte-size fraction of the inflammatory breast cancer xenograft named WIBC-9, which exhibits a hypervascular structure and de novo formation of vascular channels, namely vasculogenic mimicry (Shirakawa et al, 2001). In vitro, bone marrow-derived endothelial precursor cells from four human breast cancer xenografts proliferated and formed multiple clusters of spindle-shaped attaching cells on a vitronectin-coated dish. The attaching cells, which incorporated DiI-labelled acetylated low-density lipoprotein (DiI-acLDL) and were negative for Mac-1. The putative bone marrow derived endothelial precursor cell subset, which was double positive of CD34 and Flk-1, and comparative bone marrow derived CD34 positive with Flk-1 negative subset were cultured. The former subset incorporated DiI-acLDL and were integrated with HUVECs. Furthermore, they demonstrated significantly higher levels of murine vascular endothelial growth factor and interleukin-8 in culture supernatant on time course by enzyme-linked immunosorbent assay. These findings constitute direct evidence that breast cancer induces postnatal vasculogenesis in vivo

Particle tracking for polydisperse sedimenting droplets in phase separation

When a binary fluid demixes under a slow temperature ramp, nucleation, coarsening and sedimentation of droplets lead to an oscillatory evolution of the phase separating system. The advection of the sedimenting droplets is found to be chaotic. The flow is driven by density differences between the two phases. Here, we show how image processing can be combined with particle tracking to resolve droplet size and velocity simultaneously. Droplets are used as tracer particles, and the sedimentation velocity is determined. Taking these effects into account, droplets with radii in the range of 4 -- 40 micrometers are detected and tracked. Based on this data we resolve the oscillations in the droplet size distribution which are coupled to the convective flow.Comment: 13 pages; 16 figures including 3 photographs and 3 false-color plot