Alternative Breed of Three-Phase Four-Wire Shunt Compensators based on Cascaded Transformer with Single Dc-link

This paper introduces a new breed of four-wire (4W) multilevel shunt compensator to deal with either harmonic or reactive power compensation. The converter configurations are generalized for K-stages and the main benefits of proposed topologies lie on i) multilevel waveforms generation, ii) single dc-link unit and iii) modular characteristic. The configurations are based on cascaded transformers along with three-phase-bridge (TPB) converters. These converters are directly connected to the transformer primary side. A suitable PWM strategy combined with an appropriate transformer turns ratio guarantees the desirable multilevel output waveforms. The modularity feature provides simple maintenance and makes the proposed shunt active power filters (SAPFs) an attractive solution in comparison with conventional configurations. The configuration model and overall control are addressed, as well. Simulation and experimental results are presented for theoretical validation

Comparison of the genomes of two Xanthomonas pathogens with differing host specificities

The genus Xanthomonas is a diverse and economically important group of bacterial phytopathogens, belonging to the gamma-subdivision of the Proteobacteria. Xanthomonas axonopodis pv. citri (Xac) causes citrus canker, which affects most commercial citrus cultivars, resulting in significant losses worldwide. Symptoms include canker lesions, leading to abscission of fruit and leaves and general tree decline(1). Xanthomonas campestris pv. campestris (Xcc) causes black rot, which affects crucifers such as Brassica and Arabidopsis. Symptoms include marginal leaf chlorosis and darkening of vascular tissue, accompanied by extensive wilting and necrosis(2). Xanthomonas campestris pv. campestris is grown commercially to produce the exopolysaccharide xanthan gum, which is used as a viscosifying and stabilizing agent in many industries(3). Here we report and compare the complete genome sequences of Xac and Xcc. Their distinct disease phenotypes and host ranges belie a high degree of similarity at the genomic level. More than 80% of genes are shared, and gene order is conserved along most of their respective chromosomes. We identified several groups of strain-specific genes, and on the basis of these groups we propose mechanisms that may explain the differing host specificities and pathogenic processes.417688745946

Reflexões sobre as relações entre drogadição, adolescência e família: um estudo bibliográfico Reflections about the relationships among drug addiction, adolescence and family: a bibliographic review

O consumo de drogas entre adolescentes tem sido alvo de diversas pesquisas. O objetivo deste estudo foi apresentar uma sistematização dos resultados obtidos por meio de uma revisão bibliográfica envolvendo três eixos: drogadição, adolescência, família. Foram enfocados aspectos referentes ao consumo de drogas hoje e a utilização destas na adolescência, além da relação entre drogas, adolescência e família. Por meio desta revisão, observou-se que a literatura da área aponta que aspectos do funcionamento familiar podem atuar como fatores que propiciam o envolvimento dos adolescentes com substâncias psicoativas. Conclui-se pela necessidade de mais investigações buscando verificar as relações entre adolescência, drogadição e família.<br>The consumption of drugs among adolescents has been the target of several studies. The objective of this review was to present a systematization of the results obtained through a bibliographic study involving three axes: drug addiction, adolescence, family. The focus was on aspects referring to the current consumption of drugs and their use during adolescence, besides the relationship among drugs, adolescence and family. Through this study, it was observed that the literature of the area points out that aspects of the family operation can act as factors that propitiate the adolescents' involvement with psychoactive substances. It is concluded that there is need of more investigation to verify the relationships among adolescence, drug addiction and family

Comparison of the genomes of two Xanthomonas pathogens with differing host specificities

The genus Xanthomonas is a diverse and economically important group of bacterial phytopathogens, belonging to the gamma-subdivision of the Proteobacteria. Xanthomonas axonopodis pv. citri (Xac) causes citrus canker, which affects most commercial citrus cultivars, resulting in significant losses worldwide. Symptoms include canker lesions, leading to abscission of fruit and leaves and general tree decline(1). Xanthomonas campestris pv. campestris (Xcc) causes black rot, which affects crucifers such as Brassica and Arabidopsis. Symptoms include marginal leaf chlorosis and darkening of vascular tissue, accompanied by extensive wilting and necrosis(2). Xanthomonas campestris pv. campestris is grown commercially to produce the exopolysaccharide xanthan gum, which is used as a viscosifying and stabilizing agent in many industries(3). Here we report and compare the complete genome sequences of Xac and Xcc. Their distinct disease phenotypes and host ranges belie a high degree of similarity at the genomic level. More than 80% of genes are shared, and gene order is conserved along most of their respective chromosomes. We identified several groups of strain-specific genes, and on the basis of these groups we propose mechanisms that may explain the differing host specificities and pathogenic processes