Advanced solutions for quality-oriented multimedia broadcasting

Multimedia content is increasingly being delivered via different types of networks to viewers in a variety of locations and contexts using a variety of devices. The ubiquitous nature of multimedia services comes at a cost, however. The successful delivery of multimedia services will require overcoming numerous technological challenges many of which have a direct effect on the quality of the multimedia experience. For example, due to dynamically changing requirements and networking conditions, the delivery of multimedia content has traditionally adopted a best effort approach. However, this approach has often led to the end-user perceived quality of multimedia-based services being negatively affected. Yet the quality of multimedia content is a vital issue for the continued acceptance and proliferation of these services. Indeed, end-users are becoming increasingly quality-aware in their expectations of multimedia experience and demand an ever-widening spectrum of rich multimedia-based services. As a consequence, there is a continuous and extensive research effort, by both industry and academia, to find solutions for improving the quality of multimedia content delivered to the users; as well, international standards bodies, such as the International Telecommunication Union (ITU), are renewing their effort on the standardization of multimedia technologies. There are very different directions in which research has attempted to find solutions in order to improve the quality of the rich media content delivered over various network types. It is in this context that this special issue on broadcast multimedia quality of the IEEE Transactions on Broadcasting illustrates some of these avenues and presents some of the most significant research results obtained by various teams of researchers from many countries. This special issue provides an example, albeit inevitably limited, of the richness and breath of the current research on multimedia broadcasting services. The research i- - ssues addressed in this special issue include, among others, factors that influence user perceived quality, encoding-related quality assessment and control, transmission and coverage-based solutions and objective quality measurements

A heuristic framework for the bi-objective enhanced index tracking problem

The index tracking problem is the problem of determining a portfolio of assets whose performance replicates, as closely as possible, that of a financial market index chosen as benchmark. In the enhanced index tracking problem the portfolio is expected to outperform the benchmark with minimal additional risk. In this paper, we study the bi-objective enhanced index tracking problem where two competing objectives, i.e., the expected excess return of the portfolio over the benchmark and the tracking error, are taken into consideration. A bi-objective Mixed Integer Linear Programming formulation for the problem is proposed. Computational results on a set of benchmark instances are given, along with a detailed out-of-sample analysis of the performance of the optimal portfolios selected by the proposed model. Then, a heuristic procedure is designed to build an approximation of the set of Pareto optimal solutions. We test the proposed procedure on a reference set of Pareto optimal solutions. Computational results show that the procedure is significantly faster than the exact computation and provides an extremely accurate approximation

Ferramenta para integração de dados de recursos naturais dos biomas brasileiros.

O projeto NATDATA, sigla para Plataforma de Integração de Dados dos Recursos Naturais (MACÁRIO et al., 2011) tem como um de seus objetivos criar uma interface para o usuário final das informações sobre os recursos naturais dos biomas brasileiros, ajudando-o com um ambiente intuitivo que permita a consulta rápida e integrada a esses dados. Essa consulta permitirá que haja uma melhor orientação dos investimentos, como uma visão antecipada dos possíveis problemas que alguma região possa sofrer. Devido ao modo heterogêneo com que diversas instituições brasileiras colheram essas informações, há uma grande dificuldade em reaproveitá-las em conjunto. Com isso, o projeto NATDATA foca centralizar essa informação, tornando-a utilizável

Preliminary Observations on Zelus Obscuridorsis (Stal) (Hemiptera: Reduviidae) as Predator of the Corn Leafhopper (Hemiptera: Cicadellidae) in Argentina

Fil: Virla, Eduardo G.. Fundación M. Lillo. Instituto de Entomología. San Miguel de Tucumán; ArgentinaFil: Melo, María Cecilia. Instituto de Limnología Dr. Raúl A. Ringuelet (ILPLA). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Speranza, Stefano. Department of Agriculture, Forests, Nature and Energy. University of Tuscia; Ital

Sistema de informação para o agronegócio da cana-de-açúcar.

RESUMO: Este trabalho apresenta esforços de organização de informações e de melhoria de ferramentas de difusão pela Embrapa Informática Agropecuária, com foco no sistema agroindustrial da cana-de-açúcar. Apresenta-se a implementação de uma ferramenta WebGIS e os resultados de espacialização e organização das informações sobre empreendimentos do agronegócio. A iniciativa mostra-se promissora para adoção pela Embrapa como referência para análise do agronegócio e difusão de informações.SBIAgro 2011

Enzymatic synthesis of γ-glutamyl derivatives catalyzed by a new mutant γ-glutamyltransferase with improved transpeptidase activity

Despite their potential applicative interest as biologically active compounds and as flavor enhancers, \u3b3-glutamyl derivatives are commercially underexploited compounds. This is mainly due to the difficulties connected with their supply at a reasonable cost. As a consequence, enzymatic approaches to their preparation, based on the use of \u3b3-glutamyltransferases (GGTs), have been proposed1 to circumvent both the low-yielding extractive procedures from natural sources and the troublesome chemical synthesis, rendered uneconomical by the need of protection and deprotection steps. GGTs catalyze the transfer of a \u3b3-glutamyl moiety from a donor substrate (e.g. glutathione) to the primary amino group of an acceptor compound in a so-called transpeptidation reaction, through the formation of a \u3b3-glutamyl-enzyme intermediate. However, also the use of GGTs as biocatalysts is not free from drawbacks. In addition to the transpeptidase activity, GGTs show a non-negligible hydrolase activity towards both the donor substrate and the newly formed transpeptidation product, affording irreversibly glutamic acid.2 In our ongoing studies on bacterial GGTs, we found that the presence of the lid loop \u2013 a short amino acids sequence covering the active site in most of the known GGTs \u2013 not only affects substrate selection, but also modulates hydrolase/transpeptidase activities.3 Within the TailGluTran Project,4 aimed at the development of mutant GGTs with improved transpeptidase activity, is currently under investigation a mutant enzyme obtained by inserting the sequence of the lid loop on the structure of a GGT naturally lacking it. The mutant enzyme shows promising high transpeptidase activity with respect to wild type counterparts and represents a starting point for further modifications in the search of a suitable biocatalyst intended for preparative purposes

Synthesis of γ-glutamyl derivatives of sulfur-containing amino acids in a multigram scale via a two-step, one-pot procedure

\u3b3-Glutamyl derivatives of sulfur amino acids have been prepared in multigram scale starting from readily available starting materials. The synthesis comprises two one-pot operations, both consisting of two reactions. In the first operation, N-phtaloyl-l-glutamic acid anhydride is obtained from l-glutamic acid and phtalic anhydride. In the second one, N-phtaloyl-l-glutamic acid anhydride is used to acylate amino acids and the N-phtaloyl protecting group is removed. The described approach offers a viable entry to \u3b3-glutamyl derivatives of sulfur-containing amino acids with flavor-enhancer and nutraceutical properties

A mechanical system for tensile testing of supported films at the nanoscale

Standard tensile tests of materials are usually performed on freestanding specimens. However, such requirement is difficult to implement when the materials of interest are of nanoscopic dimensions due to problems related to their handling and manipulation. In the present paper, a new device is presented for tensile testing of thin nanomaterials, which allows tests to be carried out on specimens initially deposited onto a macroscopic pre-notched substrate. On loading, however, no substrate effects are introduced, allowing the films to be freely stretched. The results obtained from a variety of thin metal or polymeric films are very promising for the further development of this technique as a standard method for nanomaterial mechanical testin

Adaptação de ferramenta de relatório geoespacial para Zoneamento Ecológico-Econômico da Amazônia Legal.

A ferramenta "relatório", objeto deste trabalho, foi programada originalmente para realizar consultas de terras particulares no Mato Grosso do Sul, via um sistema de informação geográfica web chamado Sistema Interativo de Suporte ao Licenciamento Ambiental (Sisla). O objetivo deste trabalho é adaptá-la para uma função similar no Projeto de Zoneamento Ecológico-Econômico da Amazônia Legal (ZEEAL)