Plumes of discolored water of volcanic origin and possible implications for algal communities. The case of the Home Reef eruption of 2006 (Tonga, Southwest Pacific Ocean)

The Home Reef volcano (Tonga, Southwest Pacific Ocean) erupted in August 2006. Initially a submarine eruption it quickly evolved into a subaerial event upon the formation of an ephemeral island.Remote sensing data from different sensors including MODIS, ASTER, EO-1 ALI and Landsat-7 ETM+ were used to analyze the event, focusing on the plumes of discolored water, ocean chlorophyll-a concentration (OCC) and sea surface temperature.An early classification system for the plumes was devised based on spectral properties and point of origin. Plumes originated at the volcano were named Type-I and those associated to the pumice rafts Type-II.Anomalies in ocean chlorophyll-a concentration, measured using MODIS data, were analyzed and a large bloom, presumably dominated by Trichodesmium sp. was identified. The bloom, which contributed to OCC values 17 times higher than the background, was spatially and temporally coincident with a Type-I plume of discolored water. The OCC increase appears to have been caused by a combined effect of both ocean fertilizations by the subsurface volcanic plume and rising sea surface temperatures.The Home Reef event offers a good candidate for a case of ocean enrichment by a submarine volcano and highlights the need for continuous monitoring of the eruptions even after the end of the explosive, more spectacular stages.     

Component-Based Derivation of a Parallel Stiff ODE Solver Implemented in a Cluster of Computers

A component-based methodological approach to derive distributed implementations of parallel ODE solvers is proposed. The proposal is based on the incorporation of explicit constructs for performance polymorphism into a methodology to derive group parallel programs of numerical methods from SPMD modules. These constructs enable the structuring of the derivation process into clearly defined steps, each one associated with a different type of optimization. The approach makes possible to obtain a flexible tuning of a parallel ODE solver for several execution contexts and applications. Following this methodological approach, a relevant parallel numerical scheme for solving stiff ODES has been optimized and implemented on a PC cluster. This numerical scheme is obtained from a Radau IIA Implicit Runge–Kutta method and exhibits a high degree of potential parallelism. Several numerical experiments have been performed by using several test problems with different structural characteristics. These experiments show satisfactory speedup results.     

6H hexagonal structure of low loss Ba3MTiWO9 (M = Mg, Zn) dielectrics

The crystal structure of Ba₃MTiWO₉ (M = Mg, Zn) oxides has been found to be 6H hexagonal, space group P6₃/mmc, parameters of unit cell: a = 5.7943(1) Å, c = 14.1642(1) Å and a = 5.7993(1) Å, c = 14.1626(1) Å for M = Mg and Zn, respectively. The tungsten and titanium atoms are randomly distributed in pairs of face-sharing octahedra separated by octahedral layers containing magnesium or zinc. It was revealed that the structures are well ordered which is believed to result in a low dielectric loss at a microwave frequency reported for these materials.     

Development of coloured glazes for tile applications using Taguchi's method

The development of coloured glazes produced for ceramic tiles is normally based on intuitive methods, where a lot of trials are usually necessary to obtain the desired colour.The aim of this paper was to propose a new approach to develop coloured glazes produced for tile applications using Taguchi's method. With this method, the best producing conditions can be achieved by an appropriate selection of the controlled factors – the pigments – and their levels – the quantities of the pigments – to obtain the desired colour and production costs were thus reduced.Two standard colours were selected under the conditions of the customer. The experience was planned and the results were treated according to the requirements described by Taguchi's method. The trials were selected by an orthogonal array of smaller resolution. Using Taguchi's method, the number of trials was substantially reduced; consequently the production costs and the loss to society also.     

Simulation of one-layer shallow water systems on multicore and CUDA architectures

The numerical solution of shallow water systems is useful for several applications related to geophysical flows, but the big dimensions of the domains suggests the use of powerful accelerators to obtain numerical results in reasonable times. This paper addresses how to speed up the numerical solution of a first order well-balanced finite volume scheme for 2D one-layer shallow water systems by using modern Graphics Processing Units (GPUs) supporting the NVIDIA CUDA programming model. An algorithm which exploits the potential data parallelism of this method is presented and implemented using the CUDA model in single and double floating point precision. Numerical experiments show the high efficiency of this CUDA solver in comparison with a CPU parallel implementation of the solver and with respect to a previously existing GPU solver based on a shading language.     

Handwritten character recognition by parallel labelling and shape analysis

This paper introduces a shape analysis method for handwritten characters based on polygonal approximation and a recognition on the basis of parallel fuzzy labelling. At first the input character is preprocessed for pixel definition, thinning, and tail-removal, and finally it is fed into the feature extraction and character recognition stages.     

Editorial: Security and Privacy Protection for Mobile Applications and Platforms

Mobile Networks and Applications -     

Polymorphism of Alpha-Synuclein Amyloid Fibrils Depends on Ionic Strength and Protein Concentration

Protein aggregate formation is linked with multiple amyloidoses, including Alzheimer‘s and Parkinson‘s diseases. Currently, the understanding of such fibrillar structure formation and propagation is still not sufficient, the outcome of which is a lack of potent, anti-amyloid drugs. The environmental conditions used during in vitro protein aggregation assays play an important role in determining both the aggregation kinetic parameters, as well as resulting fibril structure. In the case of alpha-synuclein, ionic strength has been shown as a crucial factor in its amyloid aggregation. In this work, we examine a large sample size of alpha-synuclein aggregation reactions under thirty different ionic strength and protein concentration combinations and determine the resulting fibril structural variations using their dye-binding properties, secondary structure and morphology. We show that both ionic strength and protein concentration determine the structural variability of alpha-synuclein amyloid fibrils and that sometimes even identical conditions can result in up to four distinct types of aggregates.     

An overview of character recognition methodologies

This work presents an overview of character recognition methodologies that have evolved in this century. At first the scanning devices that are used in character recognition will be explained, then some points will be stressed on the major research works that have made a great impact in character recognition. From a methodological point of view we will present the different steps that have been employed in OCR. And finally the most important industrial character recognisers will be covered along with the character data bases that are used in testing the various algorithms.     

The construction of a simulation-based system for the developmentof powerful and realistic models and practicals for healthcareprofessionals

The aim of this paper is to examine the importance of computer-based simulation by the demonstration and study of complex systems and the presentation of essential tools and applications that can help health professionals deliver good quality practicals, which is now impeded by cost and/or technical constrains. The tools that have been developed in the framework of the Courseware Authoring for Scientific Training (COAST) project are the “modeler environment”, which is used to describe the different tools and mathematical functions available for building models, and the “simulation author environment”, which is used for building simulation sequences and providing the required tools and functions. This effort provides scientists with new technological and cost-effective means, specifically based on multimedia simulation, for preparing educational material, so as to gradually replace laboratory practicals that are gradually becoming more expensive, and improves student's understanding of complex systems