RESUMO

Nowadays, high-performance audio communication devices demand superior audio quality. To improve the audio quality, several authors have developed acoustic echo cancellers based on particle swarm optimization algorithms (PSO). However, its performance is reduced significantly since the PSO algorithm suffers from premature convergence. To overcome this issue, we propose a new variant of the PSO algorithm based on the Markovian switching technique. Furthermore, the proposed algorithm has a mechanism to dynamically adjust the population size over the filtering process. In this way, the proposed algorithm exhibits great performance by reducing its computational cost significantly. To adequately implement the proposed algorithm in a Stratix IV GX EP4SGX530 FPGA, we present for the first time, the development of a parallel metaheuristic processor, in which each processing core simulates the different number of particles by using the time-multiplexing technique. In this way, the variation of the size of the population can be effective. Therefore, the properties of the proposed algorithm along with the proposed parallel hardware architecture potentially allow the development of high-performance acoustic echo canceller (AEC) systems.

RESUMO

Como resultado de una investigación impulsada por la justicia, se analizaron muestras provenientes de un posiblederrame intencional de plaguicidas sobre colmenas con abejas. En los análisis realizados se utilizó GC-MS previa extracción con solventes orgánicos. Debido a dificultades iniciales en la identificación de plaguicidas sobre tres de las muestras, se procedió alreprocesamiento de los cromatogramas utilizando selección de las relaciones de masas m/z 158, 173 y 143. Utilizando esa herramienta analítica se obtuvieron los correspondientes cromatogramas, y los espectros de masas con coincidencia frente al divulgado para el producto de descomposición de bromadiolona (PDB), determinando que tanto las abejas como las colmenas habían tenido contacto con bromadiolona (3-[3-(4’-bromobifenil-4-il)- 3-hidroxi-1-fenilpropil]-4- hidroxicumarina), un anticoagulantecumarínico de utilización agraria para combatir roedores, que parece ser prácticamente no tóxico para las abejas según informes internacionales. Se observó que en la literatura no se halla propuesta una estructura química definida para el PDB, lo cual podría constituir el fundamento para encarar trabajos futuros con el fin de elucidar el comportamiento de la droga madre enel contexto del caso.

As a result of an investigation boosted by ordinary justice, samples from a probable deliberate spill of pesticide over bees and hives were analyzed. Solvent extractions and then GC-MS were used to perform the tests. Due to difficulties since the beginning in pesticide identification upon three samples, chromatograms were reprocessed using mass selection at m/z 158, 173 y 143 mass rates. The correspondent chromatograms were gathered by these analytical tool, and their mass spectrums were found coincident with the previously reported as bromadiolone decomposition product (BDP), showing that hives as well asbees had been in contact with bromadiolone (3-[3-(4’-bromobiphenyl-4-yl)- 3-hydroxy-1-phenylpropyl]-4- hydroxycoumarin) - a coumarin rodenticide (anticoagulant) for agricultural use – which seems to be, according to international reports, practically non toxic for bees. It was observed that in the literature has not been proposed a defined chemical structure for BDP, so this could bea challenge for a future research in order to clarify its behavior in a similar situation.

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RESUMO

Health effects of smoking have been studied intensely and there is substantial evidence on the harmful consequences for health that produces. In the last 20 years the effect of environmental tobacco smoke has been studied and researchers as governmentalagencies have concluded that involuntary smoking is one of the causes of lung cancer and cardiovascular illness in adults and of adverse consequences, like the syndrome of sudden death of the nursing, asthma, bronchitis and pneumonia in small children (1,2). Epidemiological questionnaires have been the usual method to determine exposition to environmental tobacco,but they present bias and low sensibility that can lead to misinterpretations of associations between exposition and illness (3,4). Cotinine, a metabolite from nicotine with a relatively short half life in plasma (about 20-30 hours), is useful as a biomarker for categorization and verification of a recent exposition (5). The goal of this work was to determine the level of exposition to environmentaltobacco smoke in a group of adolescents of the city of Mar del Plata, Argentina.

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