Solid-phase extraction of berries’ anthocyanins and evaluation of their antioxidative properties

Solid-phase extraction (SPE) was used to obtain anthocyanin-rich extracts from five berry species: chokeberry, elderberry, black currant, blackberry and blueberry. During SPE more than 94.4% of the sugars and more than 88.5% of the acids present in the crude extracts were separated. The SPE resulted in 90–95.6% anthocyanins recovery. The antioxidative properties of the anthocyanin-rich extracts were tested by measuring their oxygen radical absorption capacity (ORAC), hydroxyl radical averting capacity (HORAC), total peroxyl radical trapping antioxidant parameter (TRAP), scavenging of nitric oxide and inhibition of lipid peroxidation. Elderberry extract revealed the highest ORAC value of 5783 μmol TE/g. Chokeberry extract was the most potent inhibitor of lipid peroxidation and had the highest TRAP value of 4051 μmol TE/g. Blueberry extract had the highest HORAC result – 1293 μmol GAE/g and was the most powerful scavenger of NO. The high antioxidant activity according to all antioxidant assays revealed opportunities to apply these preparations as antioxidants.     

jSIPRO – Analysis tool for magnetic resonance spectroscopic imaging

Magnetic resonance spectroscopic imaging (MRSI) involves a huge number of spectra to be processed and analyzed. Several tools enabling MRSI data processing have been developed and widely used. However, the processing programs primarily focus on sophisticated spectra processing and offer limited support for the analysis of the calculated spectroscopic maps. In this paper the jSIPRO (java Spectroscopic Imaging PROcessing) program is presented, which is a java-based graphical interface enabling post-processing, viewing, analysis and result reporting of MRSI data. Interactive graphical processing as well as protocol controlled batch processing are available in jSIPRO. jSIPRO does not contain a built-in fitting program. Instead, it makes use of fitting programs from third parties and manages the data flows. Currently, automatic spectra processing using LCModel, TARQUIN and jMRUI programs are supported. Concentration and error values, fitted spectra, metabolite images and various parametric maps can be viewed for each calculated dataset. Metabolite images can be exported in the DICOM format either for archiving purposes or for the use in neurosurgery navigation systems.     

Loading-unloading shear behavior of rammed earth upon varying clay content and relative humidity conditions

This paper investigates the impact of clay and moisture contents on the shear behavior of compacted earth taking into account loading-unloading cycles. Fine sand was added to a natural soil, thereby obtaining three different soils with clay contents of 35%, 26%, and 17%, respectively. A series of triaxial tests was conducted on samples previously equilibrated at three different values of relative humidity (RH). The evolution of failure strength f_c, Young's modulus E, and residual strain ε_res was investigated according to the clay content and the RH, the last two parameters being measured during the loading-unloading cycles. Firstly, the relative humidity at which the samples were fabricated and conditioned was seen to have a strong impact on the mechanical characteristics of the earthen material. An increase in RH led to a decrease in both failure strength f_c and Young’s modulus E, and an increase in plastic strain. The tendencies were found to depend on the clay content of the samples. Secondly, with an increasing stress level, a progressive decrease in Young’s modulus and an increase in residual strain ε_res (after a loading-unloading cycle) appeared. Thirdly, within the range of the investigated clay contents, both failure strength f_c and residual strain ε_res increased with an increasing clay content at constant values of RH and confining pressure, the rate of this increase being a function of the RH. Young’s modulus E was relatively insensitive to changes in the clay content, its variation being less than 20% for all cases. Finally, based on a particular definition of Bishop's effective stress, involving a specific functional form χ(s), the failure states of all the samples were observed to lie approximately on a unique failure line crossing the origin in the (p′-q) plane regardless of the matric suction and confining pressure.     

Compilation of mechanical properties for the structural analysis of solid oxide fuel cell stacks. Constitutive materials of anode-supported cells

The mechanical failure of one cell is sufficient to lead to the end of service of a solid oxide fuel cell (SOFC) stack. Therefore, there is growing interest in gaining knowledge on the mechanical properties of the cell materials for stress analysis.This study compiles available data from the literature on the mechanical properties of the most common materials used in intermediate-temperature anode-supported cells: nickel and yttria-stabilized zirconia (Ni–YSZ) anodes, YSZ electrolytes, yttria (YDC) or gadolinia-doped ceria (GDC) compatibility layers and lanthanum strontium manganite (LSM) or lanthanum strontium cobalt ferrite (LSCF) cathodes. The properties for the simulation of stresses, i.e. coefficient of thermal expansion (CTE), Young's modulus, Poisson's ratio, creep behaviour and strength are reported, with an emphasis on temperature and porosity dependence and the evolution upon aging or cycling when available. Measurements of our Ni(O)–YSZ anode material includes the CTE (oxidised and reduced state), Young's modulus and strength at room temperature (oxidised and reduced) and 1073 K (oxidised).     

Effect of tactile feedback on movement speed and precision during work-related tasks using a computer mouse

Effects of tactile feedback on movement accuracy and speed were studied. Younger and older participants performed three tasks (1, select and drag word; 2, menu navigation; 3, select and drag cell) using commercial software and a mouse with or without tactile feedback. Task time and error number were recorded. Tasks were divided according to presence or absence of tactile feedback, and participants were divided into subgroups (high, average, low) based on Task 1 performance. Overall, older participants took longer (p < .0001) and made more errors (p < .001) than younger participants. There was an effect of feedback by task in younger participants for all six outcomes (p < 0.02). At the task level, with feedback, younger participants reduced performance time (13%) and errors (24%) on Task 1. Low- and average-performance younger participants benefited most from feedback for Task 1. Older low-performance participants also benefited from feedback for Task 1. For Task 3, older participants tended to take more time and make more errors with feedback. Tactile feedback may enhance performance when feedback is event related. Older people may not integrate sensation as well as younger individuals to enhance performance. Potential applications of this research include the development of tactile feedback interfaces to facilitate computer use.     

Image Decomposition into a Bounded Variation Component and an Oscillating Component

We construct an algorithm to split an image into a sum u + v of a bounded variation component and a component containing the textures and the noise. This decomposition is inspired from a recent work of Y. Meyer. We find this decomposition by minimizing a convex functional which depends on the two variables u and v, alternately in each variable. Each minimization is based on a projection algorithm to minimize the total variation. We carry out the mathematical study of our method. We present some numerical results. In particular, we show how the u component can be used in nontextured SAR image restoration.Jean-François Aujol graduated from 1 Ecole Normale Supérieure de Cachan in 2001. He was a PHD student in Mathematics at the University of Nice-Sophia-Antipolis (France). He was a member of the J.A. Dieudonné Laboratory at Nice, and also a member of the Ariana research group (CNRS/INRIA/UNSA) at Sophia-Antipolis (France). His research interests are calculus of variations, nonlinear partial differential equations, numerical analysis and mathematical image processing (and in particular classification, texture, decomposition model, restoration). He is Assistant Researcher at UCLA (Math Department).Gilles Aubert received the These dEtat es-sciences Mathematiques from the University of Paris 6, France, in 1986. He is currently professor of mathematics at the University of Nice-Sophia Antipolis and member of the J.A. Dieudonne Laboratory at Nice, France. His research interests are calculus of variations, nonlinear partial differential equations and numerical analysis; fields of applications including image processing and, in particular, restoration, segmentation, optical flow and reconstruction in medical imaging.Laure Blanc-Féraud received the Ph.D. degree in image restoration in 1989 and the Habilitation á Diriger des Recherches on inverse problems in image processing in 2000, from the University of Nice-Sophia Antipolis, France. She is currently director of research at CNRS in Sophia Antipolis. Her research interests are inverse problems in image processing by deterministic approach using calculus of variation and PDEs. She is also interested in stochastic models for parameter estimation and their relationship with the deterministic approach. She is currently working in the Ariana research group (I3S/INRIA) which is focussed on Earth observation.Antonin Chambolle studied mathematics and physics at the Ecole normale Supérieure in Paris and received the Ph.D. degree in applied mathematics from the Université de Paris-Dauphine in 1993. Since then he has been a CNRS researcher at the CEREMADE, Université de Paris-Dauphine, and, for a short period, a researcher at the SISSA, Trieste, Italy. His research interest include calculus of variations, with applications to shape optimization, mechanics and image processing.     

Analysis of imaging properties of a vibrating thin flat mirror

Thin flat mirrors are often used in designing various optical measurement systems. Such mirrors are generally deformed by environmental conditions during measurements. A detailed theory of deformation of a thin flat mirror that oscillates harmonically in the direction of the normal to its surface is introduced in our work. The mirror is treated as a vibrating membrane, and the time-dependent effect of the mirror deformation on the properties of reflected light is studied. A relation is derived for a dynamic wave aberration. On the basis of this relation, calculation of the Strehl definition of the deformed mirror is performed both by exact integration and by approximation. The results obtained can be used for analysis of the influence of mechanical vibrations on the accuracy of optical measurement systems in various practical applications where thin flat mirrors are used.     

Prefetching and caching strategies for remote and interactive browsing of JPEG2000 images.

This paper considers the issues of scheduling and caching JPEG2000 data in client/server interactive browsing applications, under memory and channel bandwidth constraints. It analyzes how the conveyed data have to be selected at the server and managed within the client cache so as to maximize the reactivity of the browsing application. Formally, to render the dynamic nature of the browsing session, we assume the existence of a reaction model that defines when the user launches a novel command as a function of the image quality displayed at the client. As a main outcome, our work demonstrates that, due to the latency inherent to client/server exchanges, a priori expectation about future navigation commands may help to improve the overall reactivity of the system. In our study, the browsing session is defined by the evolution of a rectangular window of interest (WoI) along the time. At any given time, the WoI defines the position and the resolution of the image data to display at the client. The expectation about future navigation commands is then formalized based on a stochastic navigation model, which defines the probability that a given WoI is requested next, knowing previous WoI requests. Based on that knowledge, several scheduling scenarios are considered. The first scenario is conventional and transmits all the data corresponding to the current WoI before prefetching the most promising data outside the current WoI. Alternative scenarios are then proposed to anticipate prefetching, by scheduling data expected to be requested in the future before all the current WoI data have been sent out. Our results demonstrate that, for predictable navigation commands, anticipated prefetching improves the overall reactivity of the system by up to 30% compared to the conventional scheduling approach. They also reveal that an accurate knowledge of the reaction model is not required to get these significant improvements.     

On Total Variation Minimization and Surface Evolution Using Parametric Maximum Flows

In a recent paper Boykov et al. (LNCS, Vol. 3953, pp. 409–422, 2006) propose an approach for computing curve and surface evolution using a variational approach and the geo-cuts method of Boykov and Kolmogorov (International conference on computer vision, pp. 26–33, 2003). We recall in this paper how this is related to well-known approaches for mean curvature motion, introduced by Almgren et al. (SIAM Journal on Control and Optimization 31(2):387–438, 1993) and Luckhaus and Sturzenhecker (Calculus of Variations and Partial Differential Equations 3(2):253–271, 1995), and show how the corresponding problems can be solved with sub-pixel accuracy using Parametric Maximum Flow techniques. This provides interesting algorithms for computing crystalline curvature motion, possibly with a forcing term. A. Chambolle’s research supported by ANR project “MICA”, grant ANR-08-BLAN-0082. J. Darbon’s research supported by ONR grant N000140710810.     

An optimization algorithm inspired by social creativity systems

The need for efficient and effective optimization problem solving methods arouses nowadays the design and development of new heuristic algorithms. This paper present ideas that leads to a novel multiagent metaheuristic technique based on creative social systems suported on music composition concepts. This technique, called “Musical Composition Method” (MMC), which was proposed in Mora-Gutiérrez et?al. (Artif Intell Rev 2012) as well as a variant, are presented in this study. The performance of MMC is evaluated and analyzed over forty instances drawn from twenty-two benchmark global optimization problems. The solutions obtained by the MMC algorithm were compared with those of various versions of particle swarm optimizer and harmony search on the same problem set. The experimental results demonstrate that MMC significantly improves the global performances of the other tested metaheuristics on this set of multimodal functions.