bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular dynamics simulation of β2‐microglobulin in denaturing and stabilizing conditions
Authors: Fogolari Federico , Corazza Alessandra , Varini Nicola , Rotter Matteo , Gumral Devrim , Codutti Luca , Rennella Enrico , Viglino Paolo , Bellotti Vittorio , Esposito Gennaro
Published: November 2010

β2‐Microglobulin has been a model system for the study of fibril formation for 20 years. The experimental study of β2‐microglobulin structure, dynamics, and thermodynamics in solution, at atomic detail, along the pathway leading to fibril formation is difficult because the onset of disorder and aggregation prevents signal resolution in Nuclear Magnetic Resonance experiments. Moreover, it is difficult to characterize conformers in exchange equilibrium. To gain insight (at atomic level) on processes for which experimental information is available at molecular or supramolecular level, molecular dynamics simulations have been widely used in the last decade. Here, we use molecular dynamics to address three key aspects of β2‐microglobulin, which are known to be relevant to amyloid formation: (1) 60 ns molecular dynamics simulations of β2‐microglobulin in trifluoroethanol and in conditions mimicking low pH are used to study the behavior of the protein in environmental conditions that are able to trigger amyloid formation; (2) adaptive biasing force molecular dynamics simulation is used to force cis‐trans isomerization at Proline 32 and to calculate the relative free energy in the folded and unfolded state. The native‐like trans‐conformer (known as intermediate 2 and determining the slow phase of refolding), is simulated for 10 ns, detailing the possible link between cis‐trans isomerization and conformational disorder; (3) molecular dynamics simulation of highly concentrated doxycycline (a molecule able to suppress fibril formation) in the presence of β2‐microglobulin provides details of the binding modes of the drug and a rationale for its effect. Proteins 2011. © 2010 Wiley‐Liss, Inc.
Kinetics of sorption‐desorption of benfuracarb insecticide in mollisols
Authors: Srivastava Anjana , Chandra Raju , Srivastava Prakash Chandra
Published: November 2010

BACKGROUND: Sorption‐desorption processes govern the movement of pesticides in soil. These processes determine the potential hazard of the pesticide in a given environment for groundwater contamination and need to be investigated.

RESULTS: In the present study, sorption‐desorption processes of benfuracarb were investigated using a batch method in two mollisols. The kinetics of benfuracarb sorption in mollisols conformed to two‐compartment (1 + 1) first‐order kinetics. The fast sorption rate constant was about 3 times higher for silt loam than for loam soil. However, the slow sorption rate constants were statistically similar for both soils. The concentration‐dependent sorption‐desorption isotherms of benfuracarb could not closely conform to the Freundlich isotherm in mollisols of high organic C content. The computed values of both the sorption (log K) and desorption (log K′) capacities were higher for silt loam than for loam soil. The desorption index (n′/n) values in the range 30.0–41.3 indicated poor reversibility of sorbed benfuracarb in mollisols.

CONCLUSION: In view of the strong sorption of benfuracarb in mollisols with only partial desorption, the possibility of the leaching of soil‐applied benfuracarb to contaminate groundwaters appears to be low. Copyright © 2010 Society of Chemical Industry
Gas‐phase synthesis of hydrodiphenylcyclopropenylium via nonclassical Favorskii rearrangement from alkali‐cationized α,α′‐dibromodibenzyl ketone
Authors: Zhao Zhi‐Xiong , Wang Hao‐Yang , Xu Chu , Guo Yin‐Long
Published: November 2010

The gas‐phase synthesis of hydrodiphenylcyclopropenylium from alkali‐cationized α,α′‐dibromodibenzyl ketone (1) via nonclassical Lewis‐acid‐induced Favorskii rearrangement has been studied by electrospray ionization/tandem mass spectrometry (ESI‐MS/MS) and theoretical methods, showing that cations [1–Br]+ by debromination from 1 and 1 · M+(M = Li or Na) by alkali‐metal cationization of 1 could convert into the protonated diphenylcyclopropenone 2 · H+ by collision‐induced dissociation in the gas phase. A concerted mechanism for the Lewis‐acid‐induced Favorskii rearrangement from alkali‐metal‐cationized α,α′‐dibromodibenzyl ketone was proposed and studied, based on mass spectrometric results and theoretical methods. Copyright © 2010 John Wiley & Sons, Ltd.
Encapsulation and Release of Molecular Cargos via Temperature‐Induced Vesicle‐To‐Micelle Transitions
Authors: Chen Qi , Schönherr Holger , Vancso G. Julius
Published: November 2010

Temperature‐induced vesicle‐to‐micelle transitions of polystyrene‐block‐poly acrylic acid (PS139‐b‐PAA17) aggregates in tetrahydrofuran (THF)/H2O solvent mixtures are studied. For a typical system with an initial concentration of PS139‐b‐PAA17 of 2 wt% and 50 vol% of H2O, the morphology of the aggregates changes from vesicles to micelles upon heating from room temperature to 45 °C. The transition temperature is found to depend on the polymer concentration as well as solvent composition. A higher polymer concentration results in a higher transition temperature. The morphological change is attributed to a change in the solvent‐polymer interactions, which results in a reduction in interfacial energy. The corresponding temperature‐induced morphological change is employed as a strategy for the reversible release and encapsulation of small molecules. The release of Rhodamine 110 bisamide above the transition temperature is observed as a result of the trypsin‐catalyzed hydrolysis of the bisamide into Rhodamine 110. Likewise, the successful encapsulation of Rhodamine 110 below the transition temperature is proven using sodium nitrite as a chemical quencher.
A study of multi‐hop cellular networks
Authors: Tam Y. Hung , Hassanein Hossam S. , Akl Selim G.
Published: November 2010

The number of cellular communication subscribers continues to grow, attesting to the great success of this technology. However, cellular networks have inherent limitations on cell capacity and coverage and shortcomings such as the dead spot and the hot spot problems. Multi‐hop cellular networks (MCNs) help enhance the cell capacity and coverage, while, at the same time, alleviating the dead spot and hot spot problems, increasing the utilization of radio resource, and reducing the power consumption of mobile terminals. In the past decade, more than a dozen of MCN architectures were proposed. In this paper, we study various types of MCN proposals. We identify and discuss the design decision factors and use these factors to classify most existing MCN proposals. Future research directions, including studies of capacity and energy consumption, and approaches addressing design issues such as cell size, routing, channel assignment, load balancing for MCNs are discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Isolation of Pichia pastoris PIR genes and their utilization for cell surface display and recombinant protein secretion
Authors: Pal Khasa Yogender , Conrad Sara , Sengul Mustafa , Plautz Sarah , Meagher Michael M. , Inan Mehmet
Published: November 2010

Proteins with internal repeats are highly conserved among budding yeasts. In this study, the isolation of two proteins with internal repeats (PIR) genes, i.e. PpPIR1 and PpPIR2, from the methylotrophic yeast Pichia pastoris has been reported. The PIR1 and PIR2 genes' open reading frames were found to contain 1068 and 972 bases, respectively. The sequence homology search showed a homologous conserved repeat of PIR yeast block (SQIGDGQIQATT) in both proteins. The PIR yeast block was present eight times in the PpPir1p and four times in the PpPir2p proteins. Both proteins showed conserved glutamine (Q) and aspartic acid (D) in the repeated sequences, indicating a possible alkali‐sensitive β1,3‐glucan ester linkage. The fusion constructs of PpPir1‐2p and enhanced green fluorescent protein (EGFP) were developed for yeast cell surface display. The immunofluorescence assay showed uniform localization of EGFP protein on the P. pastoris cell surface in all fusion constructs. Furthermore, new vectors were developed for recombinant protein secretion in P. pastoris, utilizing the pre‐pro signal of PpPir1p protein. Efficient processing of the signal sequence was observed from EGFP and human α1‐antitrypsin (AAT) fusion constructs and recombinant protein secretion was obtained in the culture supernatant. The DNA sequences of the P. pastoris PpPIR1 and PpPIR2 genes have been submitted to GenBank under Accession Nos HM446634 and HM446635, respectively. Copyright © 2010 John Wiley & Sons, Ltd.
Local and Permeating Disorder of Copper(I) Cations in Cu3BiS2Br2 and Cu4Bi3S5Br3–xClx (x = 1.19)
Authors: Heerwig Andreas , Nitsche Fabian , Ruck Michael
Published: November 2010

Melting reactions of Bi2S3, CuX (X = Cl, Br), copper, and sulfur resulted in black needles of qua‐ and quinternary copper bismuth sulfide halogenides. Cu3BiS2Br2 (I) has a melting point of 638(5) K and crystallizes in the orthorhombic space group Pnma with a = 804.50(6) pm, b = 393.27(3) pm, and c = 2253.2(2) pm at T = 293(2) K. Cu4Bi3S5Br3–xClx (x = 1.19(2)) (II) crystallizes in the monoclinic space group I2/m with lattice parameters a = 1573.7(2) pm, b = 397.52(3) pm, c = 2164.9(3) pm, and β = 95.66(1) °. Both compounds exhibit networks of thio‐halogenido‐bismuthate(III) polyhedra that join corners, edges, and faces. The copper(I) cations are spread over numerous contiguous trigonal or tetrahedral voids. In case of (II) a continuous pathway for copper ion transport along [010] is formed. The pseudo‐potential barrier for hopping of copper ions was calculated as 30 meV only.
Synthesis, Structural Characterization and Physical Properties of a New Member of Ternary Lithium Layered Compounds – Li2RhO3
Authors: Todorova Vanya , Jansen Martin
Published: November 2010

Li2RhO3was synthesized by solid state reaction and its crystal structure was refined from X‐ray powder data by the Rietveld‐method. The compound was obtained as a black powder and crystallizes in the monoclinic space groupC2/m, with unit cell parametersa= 5.1198(1),b= 8.8497(1),c= 5.1030(1) Å,β= 109.61(2) °,V= 217.80(1), andZ= 4. The structure determination shows that the oxygen atoms in Li2RhO3form an approximate cubic close packing, where all octahedral voids are occupied by Rh4+and Li+cations. The structure is closely related to the α‐NaFeO2and Li2MnO3layered structure types (layered variants of the NaCl‐type), but in Li2RhO3the lithium and rhodium atoms are partially disordered. Li2RhO3behaves as a semiconductor with rather small activation energy of 7.68 kJ·mol–1and is thermally stable up to 1273 K in argon atmosphere. According to measurements of the magnetic susceptibility in the temperature range from 2 to 330 K, Li2RhO3is paramagnetic, obeys the Curie–Weiss law at temperatures above 150 K, and has an effective magnetic moment of 1.97 μBat 300 K.
A Lua-based AOP infrastructure
Authors: Cacho Nélio , Batista Thaís , Fernandes Fabrício
Published: November 2010

In this paper we describe an aspect-oriented infrastructure to handle dynamic AOP based on the Lua language. This infrastructure is composed of AspectLua, a Lua extension that allows the declaration of aspects, and a meta-object protocol, LuaMOP, that unifies the introspective and reflective mechanisms provided by Lua. Aspects are defined in isolation using AspectLua and then they are weaved through LuaMOP. An important feature of AspectLua is to allow the association of aspects with undeclared elements of the application code (anticipated join points). Furthermore, it combines a range of features to make AOP easier and powerful.
A new approach for regularized image interpolation
Authors: El-Khamy S. E. , Hadhoud M. M. , Dessouky M. I. , Salam B. M. , Abd El-Samie F. E.
Published: November 2010

This paper presents a non-iterative regularized inverse solution to the image interpolation problem. This solution is based on the segmentation of the image to be interpolated into overlapping blocks and the interpolation of each block, separately. The purpose of the overlapping blocks is to avoid edge effects. A global regularization parameter is used in interpolating each block. In this solution, a single matrix inversion process of moderate dimensions is required in the whole interpolation process. Thus, it avoids the large computational cost due to the matrices of large dimensions involved in the interpolation process. The performance of this approach is compared to the standard iterative regularized interpolation scheme and to polynomial based interpolation schemes such as the bicubic and cubic spline techniques. A comparison of the suggested approach with some algorithms implemented in the commercial ACDSee software has been performend in the paper. The obtained results reveal that the suggested solution has a better performance as compared to other algorithms from the MSE and the edges preservation points of view. Its computation time is relatively large as compared to traditional algorithms but this is acceptable when image quality is the main concern.
Specular highlights detection and reduction with multi-flash photography
Authors: Feris Rogerio , Raskar Ramesh , Tan Kar-Han , Turk Matthew
Published: November 2010

We present a novel method to reduce the effect of specularities in digital images. Our approach relies on a simple modification of the capture setup: a multi-flash camera is used to take multiple pictures of the scene, each one with a differently positioned light source. We then formulate the problem of specular highlights reduction as solving a Poisson equation on a gradient field obtained from the input images. The obtained specular reduced image is further refined in a matting process with the maximum composite of the input images. Experimental results are demonstrated on real and synthetic images. The entire setup can be conceivably packaged into a self-contained device, no larger than existing digital cameras.
Crosscutting interfaces for aspect-oriented modeling
Authors: Chavez Christina , Garcia Alessandro , Kulesza Uirá , Sant’Anna Cláudio , Lucena Carlos
Published: November 2010

Aspect-oriented software development promotes improved separation of concerns by introducing a new modular unit, called aspect, for the modularization of crosscutting concerns. As a new kind of modular unit, aspects should have explicit interfaces that describe the way they interact with the rest of the system and how they affect other modules. This interaction can be homogeneous or heterogeneous. In this paper, we present crosscutting interfaces as a conceptual tool for dealing with the complexity of heterogeneous aspects at the design level. Crosscutting interfaces have been incorporated by the aSideML modeling language in order to enhance aspect description at the design level. Moreover, we present a modeling notation for the description of architecture-level aspects that also supports the explicit representation of crosscutting interfaces. Finally, we present two large-scale case studies we have performed using this modeling language that support our arguments in favor of crosscutting interfaces.
Infeasible paths in the context of data flow based testing criteria: Identification, classification and prediction
Authors: Vergilio Silvia Regina , Maldonado José Carlos , Jino Mario
Published: November 2010

Infeasible paths constitute a bottleneck for the complete automation of software testing, one of the most expensive activities of software quality assurance. Research efforts have been spent on infeasible paths, basically on three main approaches: prediction, classification and identification of infeasibility. This work reports the results of experiments on data flow based criteria and of studies aimed at the three approaches above. Identification, classification, and prediction of infeasible paths are revisited in the context of data flow based criteria (Potential Uses Criteria-PU). Additionally, these aspects are also addressed in the scope of integration and object-oriented testing. Implementation aspects of mechanisms and facilities to deal with infeasibility are presented taking into consideration Poketool — a tool that supports the application of the Potential Uses Criteria Family. The results and ideas presented contribute to reduce the efforts spent during the testing activity concerning infeasible paths.
Concurrent blind channel equalization with phase transmittance RBF neural networks
Authors: Loss Diego Vier , De Castro Maria Cristina Felippetto , Franco Paulo Roberto Girardello , de Castro Fernando César Comparsi
Published: November 2010

This paper presents a new complex valued radial basis function (RBF) neural network (NN) with phase transmittance between the input nodes and output, which makes it suitable for channel equalization on quadrature digital modulation systems. The new Phase Transmittance RBFNN (PTRBFNN) differs from the classical complex valued RBFNN in that it does not strictly rely on the Euclidean distance between the input vector and the center vectors, thus enabling the transference of phase information from input to output. In the context of blind channel equalization, results have shown that the PTRBFNN not only solves the phase uncertainty of the classical complex valued RBFNN but also presents a faster convergence rate.comes the abstract of the paper.
Design and FPGA prototyping of a H.264/AVC main profile decoder for HDTV
Authors: Agostini Luciano V. , Azevedo Filho Arnaldo P. , Staehler Wagston T. , Rosa Vagner S. , Zatt Bruno , Pinto Ana Cristina M. , Porto Roger Endrigo , Bampi Sergio , Susin Altamiro A.
Published: November 2010

This paper presents the architecture, design, validation, and hardware prototyping of the main architectural blocks of main profile H.264/AVC decoder, namely the blocks: inverse transforms and quantization, intra prediction, motion compensation and deblocking filter, for a main profile H.264/AVC decoder. These architectures were designed to reach high throughputs and to be easily integrated with the other H.264/AVC modules. The architectures, all fully H.264/AVC compliant, were completely described in VHDL and further validated through simulations and FPGA prototyping. They were prototyped using a Digilent XUP V2P board, containing a Virtex-II Pro XC2VP30 Xilinx FPGA. The post place-and-route synthesis results indicate that the designed architectures are able to process 114 million samples per second and, in the worst case, they are able to process 64 HDTV frames (1080×1920) per second, allowing their use in H.264/AVC decoders targeting real time HDTV applications.
MI-SBTVD: A proposal for the brazilian digital television system SBTVD
Authors: Mendes Luciano L. , Brito José Marcos C. , Cardoso Fabbryccio A. , Guimarães Dayan A. , Lima Gustavo C. , Gomes Geraldo G. R. , Arantes Dalton S. , Souza Richard D.
Published: November 2010

The objective of this paper is to present a general overview of the Innovative Modulation System Project — MI-SBTVD — developed for the Brazilian Digital TV System. The MI-SBTVD Project includes an LDPC high performance error correcting code, an advanced transmit spatial diversity and an efficient multi-carrier modulation scheme. The building blocks of the system, its characteristics and most relevant innovations are presented. The performance of the whole system under different channels is compared with the performance of the present-day Digital Television standards. The complete system was implemented in FPGA using VHDL language and rapid prototyping tools for DSP algorithms.
The Brazilian digital television system access device architecture
Authors: de Carvalho Eduardo Rodrigues , de Barros Gil Garcia , de Paula Costa Laisa Caroline , Faria Regis Rossi Alves , Nunes Rogério Pernas , de Deus Lopes Roseli , Zuffo Marcelo Knörich
Published: November 2010

In early 2003, the Brazilian government accelerated the decision process on analog to digital transition of terrestrial TV broadcast infrastructure, naming this initiative The Brazilian Digital Television System (SBTVD). This paper describes the access device architecture we have proposed for the SBTVD, as well as related issues. We focused on several requirements among which: flexibility to support the social economical diversity enabling market implementations that can vary on cost, complexity and applications; digital inclusion targeting a minimal cost architecture providing a simple access device to information and services by convergent broadcast and point-to-point telecommunication means; and scalability targets incorporating state-of-the-art technology, considering emerging services and the current legacy analog TV infrastructure available in Brazil. We cover the following specific topics: an architecture overview considering scalability, interoperability and regional and international requirements, operating system and middleware interfaces, audio and video coding formats and associate standards, technical and economical analysis, usability and user interface consistency. Finally two prototypes for the outlined access device architecture are reported.
Domain engineering to ensure flexibility on interaction laws of multi-agent systems
Authors: Carvalho Gustavo R. , Paes Rodrigo B. , Lucena Carlos J. P. , Choren Ricardo
Published: November 2010

Law enforcement approaches have been proposed to promote dependability in open multi-agent systems. Interaction laws are defined and then enforced to promote predictability. As new software demands and requirements appear, the system and its interaction laws must evolve to support those changes. The purpose of domain engineering is to produce a set of reusable assets for a family of systems, which are then used to build concrete members of the family. Flexibility is the ease with which a system or component can be modified for use in applications other than those for which it was originally designed. In this paper, we discuss how the MLaw infrastructure was designed to support interaction law evolution providing support to produce a set of reusable laws for a family of systems. As an example, we have implemented two customizable applications in the area of electronic negotiation expressed as an open system environment.
Using agents and ontologies for application development on the semantic web
Authors: Blois Marcelo , Escobar Maurício , Choren Ricardo
Published: November 2010

The Semantic Web provides access to heterogeneous, distributed information, enabling software products to mediate between user needs and the information sources available. Agents are one of the most promising technologies for the development of Semantic Web software products. However, agent-based technologies will not become widespread until there are adequate infrastructures for the development of semantic multi-agent systems (MAS). Some challenges, such as turning software agents into practical abstractions for dealing with ontologies, taking advantage of the distributed nature of the Web to create distributed agents and making a seamless integration with existing Web tools, e.g. the browser, still need to be addressed. This paper describes the main features of the SemantiCore framework, an agent infrastructure to develop semantic MAS. A look at a benchmark Semantic Web application illustrates the SemantiCore potential as an infrastructure for the deployment of semantic agent applications.
Using Augmented State Kalman filter to localize multi autonomous underwater vehicles
Authors: Botelho Silvia , Neves Renato , Taddei Lorenzo , Oliveira Vinícius
Published: November 2010

The present paper describes a system for the construction of visual maps (“mosaics”) and motion estimation for a set of AUVs (Autonomous Underwater Vehicles). Robots are equipped with down-looking camera which is used to estimate their motion with respect to the seafloor and built an online mosaic. As the mosaic increases in size, a systematic bias is introduced in its alignment, resulting in an erroneous output. The theoretical concepts associated with the use of an Augmented State Kalman Filter (ASKF) were applied to optimally estimate both visual map and the fleet position.
Negotiating and enacting contracts for business networks
Authors: Rittgen Peter
Published: November 2010

Flexibility is a major issue in business today and one answer to that is to organize work in networks of companies rather than within a single business. Cooperation between organizations is more easily established and adapted than reorganization of internal company structures. But how do we manage flexibility in such a network without sacrificing the minimum stability that is required for economic success? We suggest a method for coordinating interaction in a business network that provides three levels of flexibility: local ad-hoc change, global negotiated change and planned change. This method is based on the negotiation and enactment of process-based interorganizational contracts.
A method for model based test harness generation for component testing
Authors: Rocha Camila Ribeiro , Martins Eliane
Published: November 2010

We present a model-based testing approach that allows the automatic generation of test artifacts for component testing. A component interacts with its clients through provided interfaces, and request services from other components through its required interfaces. Generating a test artifact that acts as though it were the client of the component under test is the easiest part, and there already exists tools to support this task. But one needs also to create substitute of the server components, which is the hardest part. Although there are also tools to help with this task, it still requires manual effort. Our approach provides a systematic way to obtain such substitute components during test generation. Results of the application of the approach in a real world component are also presented.
Automatically composing reusable software components for mobile devices
Authors: White Jules , Schmidt Douglas C. , Wuchner Egon , Nechypurenko Andrey
Published: November 2010

Product-line architectures (PLAs) are an effective mechanism for facilitating the reuse of software components on different mobile devices. Mobile applications are typically delivered to devices using over-the-air provisioning services that allow a mobile phone to download and install software over a cellular network connection. Current techniques for automating product-line variant selection do not address the unique requirements (such as the need to consider resource constraints) of dynamically selecting a variant for overthe-air provisioning.

This paper presents the following contributions to product-line variant selection for mobile devices: (1) it describes how a constraint solver can be used to dynamically select a product-line variant while adhering to resource constraints, (2) it presents architectures for automatically discovering device capabilities and mapping them to product-line feature models, (3) it includes results from experiments and field tests with an automated variant selector, and (4) it describes PLA design rules that can be used to increase the performance of automated constraint-based variant selection. Our empirical results show that fast automated variant selection from a feature model is possible if certain product-line design guidelines are followed.
Common coupling as a measure of reuse effort in kernel-based software with case studies on the creation of MkLinux and Darwin
Authors: Yu Liguo
Published: November 2010

An obstacle to software reuse is the large number of major modifications that frequently have to be made as a consequence of dependencies within the reused software components. In this paper, common coupling is categorized and used as a measure of the dependencies between software components. We compared common coupling in three operating systems, Linux, FreeBSD, and Mach, and related it to the reuse effort of these systems. The measure is evaluated by studying the creation of two operating systems, MkLinux which is based on the reuse of Linux and Mach, and Darwin which is based on the reuse of FreeBSD and Mach. We conclude that the way that common coupling is implemented in Linux kernel induces large dependencies between software components, which required more effort in order to be reused to produce MkLinux, while the common coupling implemented in the Mach and FreeBSD kernels induces few dependencies between software components, which required less effort in order to be reused to produce Darwin.
Quality aware software product line engineering
Authors: Etxeberria Leire , Sagardui Goiuria , Belategi Lorea
Published: November 2010

Meeting and managing quality requirements such as performance, security… in a reuse context (software product line…) has a problematic that it is not found in single-systems. In this paper, an overview of aspects to consider is presented, including a review of existing approaches, as well as some conclusions, requirements and guidelines to address quality aspects in software product lines.
Statistical learning approaches for discriminant features selection
Authors: Giraldi Gilson A. , Rodrigues Paulo S. , Kitani Edson C. , Sato João R. , Thomaz Carlos E.
Published: November 2010

Supervised statistical learning covers important models like Support Vector Machines (SVM) and Linear Discriminant Analysis (LDA). In this paper we describe the idea of using the discriminant weights given by SVM and LDA separating hyperplanes to select the most discriminant features to separate sample groups. Our method, called here as Discriminant Feature Analysis (DFA), is not restricted to any particular probability density function and the number of meaningful discriminant features is not limited to the number of groups. To evaluate the discriminant features selected, two case studies have been investigated using face images and breast lesion data sets. In both case studies, our experimental results show that the DFA approach provides an intuitive interpretation of the differences between the groups, highlighting and reconstructing the most important statistical changes between the sample groups analyzed.
Cooperative object manipulation in collaborative virtual environments
Authors: Pinho Marcio S. , Bowman Doug A. , Freitas Carla M. Dal Sasso
Published: November 2010

Cooperative manipulation refers to the simultaneous manipulation of a virtual object by multiple users in an immersive virtual environment (VE). In this work, we present techniques for cooperative manipulation based on existing single-user techniques. We discuss methods of combining simultaneous user actions, based on the separation of degrees of freedom between two users, and the awareness tools used to provide the necessary knowledge of the partner activities during the cooperative interaction process. We also present a framework for supporting the development of cooperative manipulation techniques, which are based on rules for combining single user interaction techniques. Finally, we report an evaluation of cooperative manipulation scenarios, the results indicating that, in certain situations, cooperative manipulation is more efficient and usable than singleuser manipulation.
A Machine Learning Approach to Automatic Music Genre Classification
Authors: Silla Carlos N. , Koerich Alessandro L. , Kaestner Celso A. A.
Published: November 2010

This paper presents a non-conventional approach for the automatic music genre classification problem. The proposed approach uses multiple feature vectors and a pattern recognition ensemble approach, according to space and time decomposition schemes. Despite being music genre classification a multi-class problem, we accomplish the task using a set of binary classifiers, whose results are merged in order to produce the final music genre label (space decomposition). Music segments are also decomposed according to time segments obtained from the beginning, middle and end parts of the original music signal (time-decomposition). The final classification is obtained from the set of individual results, according to a combination procedure. Classical machine learning algorithms such as Naïve-Bayes, Decision Trees, k Nearest-Neighbors, Support Vector Machines and Multi-Layer Perceptron Neural Nets are employed. Experiments were carried out on a novel dataset called Latin Music Database, which contains 3,160 music pieces categorized in 10 musical genres. Experimental results show that the proposed ensemble approach produces better results than the ones obtained from global and individual segment classifiers in most cases. Some experiments related to feature selection were also conducted, using the genetic algorithm paradigm. They show that the most important features for the classification task vary according to their origin in the music signal.
Soundscape Design Through Evolutionary Engines
Authors: Fornari José , Maia Adolfo , Manzolli Jônatas
Published: November 2010

Two implementations of an Evolutionary Sound Synthesis method using the Interaural Time Difference (ITD) and psychoacoustic descriptors are presented here as a way to develop criteria for fitness evaluation. We also explore a relationship between adaptive sound evolution and three soundscape characteristics: keysounds, key-signals and sound-marks. Sonic Localization Field is defined using a sound attenuation factor and ITD azimuth angle, respectively (Ii, Li). These pairs are used to build Spatial Sound Genotypes (SSG) and they are extracted from a waveform population set. An explanation on how our model was initially written in MATLAB is followed by a recent Pure Data (Pd) implementation. It also elucidates the development and use of: parametric scores, a triplet of psychoacoustic descriptors and the correspondent graphical user interface.
AcMus: an open, integrated platform for room acoustics research
Authors: Queiroz Marcelo , Iazzetta Fernando , Kon Fabio , Gomes Márcio Henrique A. , Figueiredo Fábio L. , Masiero Bruno , Ueda Leo K. , Dias Luciana , Torres Mário Henrique C. , Thomaz Leandro F.
Published: November 2010

This article describes the design, implementation, and experiences with AcMus, an open and integrated software platform for room acoustics research, which comprises tools for measurement, analysis, and simulation of rooms for music listening and production. Through use of affordable hardware, such as laptops, consumer audio interfaces and microphones, the software allows evaluation of relevant acoustical parameters with stable and consistent results, thus providing valuable information in the diagnosis of acoustical problems, as well as the possibility of simulating modifications in the room through analytical models. The system is open-source and based on a flexible and extensible Java plug-in framework, allowing for cross-platform portability, accessibility and experimentation, thus fostering collaboration of users, developers and researchers in the field of room acoustics.
Portuguese corpus-based learning using ETL
Authors: Milidiú Ruy Luiz , dos Santos Cícero Nogueira , Duarte Julio Cesar
Published: November 2010

We present Entropy Guided Transformation Learning models for three Portuguese Language Processing tasks: Part-of-Speech Tagging, Noun Phrase Chunking and Named Entity Recognition. For Part-of-Speech Tagging, we separately use the Mac-Morpho Corpus and the Tycho Brahe Corpus. For Noun Phrase Chunking, we use the SNR-CLIC Corpus. For Named Entity Recognition, we separately use three corpora: HAREM, MiniHAREM and LearnNEC06.

For each one of the tasks, the ETL modeling phase is quick and simple. ETL only requires the training set and no handcrafted templates. ETL also simplifies the incorporation of new input features, such as capitalization information, which are sucessfully used in the ETL based systems. Using the ETL approach, we obtain state-of-the-art competitive performance in all six corpora-based tasks. These results indicate that ETL is a suitable approach for the construction of Portuguese corpus-based systems.
A privacy service for location-based collaboration among mobile users
Authors: Sacramento Vagner , Endler Markus , de Souza Clarisse
Published: November 2010

The potential loss of privacy due to the use of location based applications may be one of the greatest obstacles to their wider acceptance. Nevertheless, most research about privacy management to-date has not taken into consideration the complexity in the utilization of collaborative applications that may require users’ location sharing among participants. In this article, we propose a privacy service that helps users to maintain their privacy policy in a flexible and incremental way. We also carried out a qualitative evaluation study whose results illustrate several challenges that should be handled in the design of such a service.
Pre-processing for noise detection in gene expression classification data
Authors: Libralon Giampaolo Luiz , de Carvalho André Carlos Ponce de Leon Ferreira , Lorena Ana Carolina
Published: November 2010

Due to the imprecise nature of biological experiments, biological data is often characterized by the presence of redundant and noisy data. This may be due to errors that occurred during data collection, such as contaminations in laboratorial samples. It is the case of gene expression data, where the equipments and tools currently used frequently produce noisy biological data. Machine Learning algorithms have been successfully used in gene expression data analysis. Although many Machine Learning algorithms can deal with noise, detecting and removing noisy instances from the training data set can help the induction of the target hypothesis. This paper evaluates the use of distance-based pre-processing techniques for noise detection in gene expression data classification problems. This evaluation analyzes the effectiveness of the techniques investigated in removing noisy data, measured by the accuracy obtained by different Machine Learning classifiers over the pre-processed data.
Turn off the graphics: designing non-visual interfaces for mobile phone games
Authors: Valente Luis , de Souza Clarisse Sieckenius , Feijó Bruno
Published: November 2010

Mobile phones are a widespread platform for ICT applications because they are highly pervasive in contemporary society. Hence, we can think of mobile gaming as a serious candidate to being a prominent form of entertainment in the near future. However, most games (for computers, console and mobile devices) make extensive use of the visual medium, which tends to exclude visually-impaired users from the play. While mobile gaming could potentially reach many visually-impaired users, who are very familiar with this technology, currently there seems to be only very few alternatives for this community. In an attempt to explore new interactive possibilities for such users, this work presents an initial study on non-visual interfaces for mobile phone games. It is based on Semiotic Engineering principles, emphasizing communication through aural, tactile and gestural signs, and deliberately excluding visual information. Results include a number of issues that can be incorporated to a wider research agenda on mobile gaming accessibility, both for the visually-impaired and sighted.
A basic equation for population dynamics with destruction of breeding habitats and its application to outbreak of cyprinid herpesvirus 3
Authors: Yamamura Norio , Telschow Arndt , Uchii Kimiko , Kawabata Zen'ichiro
Published: November 2010

In reproduction, many animal species migrate to local habitats that are appropriate for reproduction and for growth of newly born offspring. The examples are ubiquitous among crabs, freshwater fishes, amphibians, migratory birds, and sea animals. We propose a basic equation for population dynamics of such animals, assuming that the number of offspring is proportional to the area of the local breeding habitats as a first approximation. This equation is very simple to be solved analytically, and useful for representing environmental issues of habitat destruction and degradation. According to the equation, the adult density in breeding habitats increases temporarily during habitat destruction and returns to the original density afterwards. The temporal peak value is higher for a larger proportion of area with destruction, a higher temporal rate of destruction, and a higher survival probability of the adults. In contrast, habitat degradation results simply in a decrease of the adult density in breeding habitats. Using this equation, we will discuss the vulnerability of populations to epidemic diseases due to temporal local high densities with decreasing breeding habitats by human activities, exemplifying an outbreak of cyprinid herpesvirus 3 for wild carps in Lake Biwa.
A Boundary Mixture Approach to Violations of Conditional Independence
Authors: Braeken Johan
Published: November 2010

Conditional independence is a fundamental principle in latent variable modeling and item response theory. Violations of this principle, commonly known as local item dependencies, are put in a test information perspective, and sharp bounds on these violations are defined. A modeling approach is proposed that makes use of a mixture representation of these boundaries to account for the local dependence problem by finding a balance between independence on the one side and absolute dependence on the other side. In contrast to alternative approaches, the nature of the proposed boundary mixture model does not necessitate a change in formulation of the typical item characteristic curves used in item response theory. This has attractive interpretational advantages and may be useful for general test construction purposes.
Does the Intercollegiate Specialty Examination in Urology (FRCS Urol) Assess the Breadth of the Urology Syllabus?
Authors: Payne S.R. , Pickard R.S. , O'Flynn K.J. , Winton E.P.
Published: November 2010

Introduction:

In January 2007, the Intercollegiate Specialty Board in Urology introduced its new two-part examination in urology (FRCS Urol). The new examination utilised validated tools, underpinned by a precise curriculum for the specialty, which facilitated the knowledge assessment of individuals wishing to gain entry to the Specialist Register for independent practice in urology. This study assesses whether the content of Sections 1 and 2 of the new examination covers the breadth of the ISCP curriculum in urology and secondly whether candidates find the examination acceptable.

Methods:

The six diets of the examination between January 2007 and November 2009 were studied. The content of the curriculum for urological training was analysed, as were the knowledge domains tested by the examination. Comparisons were made to correlate the effectiveness of the examination in testing various aspects of the syllabus. Subjective exit questionnaires were obtained from candidates sitting both sections of the examination. These were analysed for candidates' views about the organisation of the examinations, its coverage, appropriateness of standard and relevance to clinical practice.

Results:

There was a high level of concordance between the examination and the content of the curriculum although there was some disparity in the balance of the topics tested which might require fine-tuning. 86% of all candidates returned exit questionnaires with >90% agreeing that the examination was a fair test of knowledge. There was less agreement about the relevance of the MCQ paper to clinical practice.

Conclusion:

The post-2006 FRCS (Urol) examination is accepted as a fair test of urological knowledge by the vast majority of candidates presenting for this assessment. It also fulfils the requirements stipulated by Postgraduate Medical Education Training Board (PMETB) now General Medical Council (GMC) — Postgraduate Board for accreditation of training in the UK and Ireland. The examination is educationally valid although minor mismatches between the curriculum content and the topic areas tested would benefit from utilisation of an examination blueprint.
Phylogenetic analysis and evolution of aromatic amino acid hydroxylase
Authors: Cao Jun , Shi Feng , Liu Xiaoguang , Huang Guang , Zhou Min
Published: November 2010

A study was performed to investigate the phylogenetic relationship among AAAH members and to statistically evaluate sequence conservation and functional divergence. In total, 161 genes were identified from 103 species. Phylogenetic analysis showed that well‐conserved subfamilies exist. Exon–intron structure analysis showed that the gene structures of AAAH were highly conserved across some different lineage species, while some species‐specific introns were also found. The dynamic distribution of ACT domain suggested one gene fusion event has occurred in eukaryota. Significant functional divergence was found between some subgroups. Analysis of the site‐specific profiles revealed critical amino acid residues for functional divergence. This study highlights the molecular evolution of this family and may provide a starting point for further experimental verifications.
Plant and animal type 2B Ca2+‐ATPases: Evidence for a common auto‐inhibitory mechanism
Authors: Bonza Maria Cristina , Luoni Laura
Published: November 2010

Plant auto‐inhibited Ca2+‐ATPase 8 (ACA8) and animal plasma membrane Ca2+‐ATPase 4b (PMCA4b) are representatives of plant and animal 2B P‐type ATPases with a regulatory auto‐inhibitory domain localized at the N‐ and C‐terminus, respectively. To check whether the regulatory domain works independently of its terminal localization and if auto‐inhibitory domains of different organisms are interchangeable, a mutant in which the N‐terminus of ACA8 is repositioned at the C‐terminus and chimeras in which PMCA4b C‐terminus is fused to the N‐ or C‐terminus of ACA8 were analysed in the yeast mutant K616 devoid of endogenous Ca2+‐ATPases. Results show that the regulatory function of the terminal domain is independent from its position in ACA8 and that the regulatory domain belonging to PMCA4b is able to at least partially auto‐inhibit ACA8.
The Rabies Epidemic in Trinidad of 1923 to 1937: An Evaluation with a Geographic Information System
Authors: Mungrue Kameel , Mahabir Ron
Published: November 2010

Background

Rabies, although not preeminent among current infectious diseases, continues to afflict humans with as many as 55,000 deaths annually. The case fatality rate remains the highest among infectious diseases, and medical treatments have proven ineffective.

Objective

This study analyzes the rabies epidemic of 1929 to 1937 in Trinidad from a geographical perspective, using Geographic Information System (GIS) software as an analytical tool.

Setting

A small island developing country at a time when infectious diseases were rampant.

Methods

A review of the literature was undertaken, and data were collected on the occurrence of disease in both animal and humans populations and mapped using GIS software. Several factors identified in the literature were further explored such as land use/land cover, rainfall and magnetic declination.

Results

The bat rabies epidemic of 1923 to 1937 in Trinidad was migratory and seasonal, shifting to new locations along a definite path. The pattern of spread appears to be spatially linked to land use/land cover. The epidemic continues to present many unexplained peculiarities.

Conclusion

Despite the fact that this epidemic occurred almost 7 decades ago, the application of new tools available for public health use can create new knowledge and understanding of events. We showed that the spatial of distribution of the disease followed a distinct pathway possible due to the use of electromagnetic capabilities of bats.