Collective Almost Synchronization in Complex Networks

This work introduces the phenomenon of Collective Almost Synchronization (CAS), which describes a universal way of how patterns can appear in complex networks even for small coupling strengths. The CAS phenomenon appears due to the existence of an approximately constant local mean field and is characterized by having nodes with trajectories evolving around periodic stable orbits. Common notion based on statistical knowledge would lead one to interpret the appearance of a local constant mean field as a consequence of the fact that the behavior of each node is not correlated to the behaviors of the others. Contrary to this common notion, we show that various well known weaker forms of synchronization (almost, time-lag, phase synchronization, and generalized synchronization) appear as a result of the onset of an almost constant local mean field. If the memory is formed in a brain by minimising the coupling strength among neurons and maximising the number of possible patterns, then the CAS phenomenon is a plausible explanation for it.Comment: 3 figure

A machine learning based framework to identify and classify long terminal repeat retrotransposons

Transposable elements (TEs) are repetitive nucleotide sequences that make up a large portion of eukaryotic genomes. They can move and duplicate within a genome, increasing genome size and contributing to genetic diversity within and across species. Accurate identification and classification of TEs present in a genome is an important step towards understanding their effects on genes and their role in genome evolution. We introduce TE-LEARNER, a framework based on machine learning that automatically identifies TEs in a given genome and assigns a classification to them. We present an implementation of our framework towards LTR retrotransposons, a particular type of TEs characterized by having long terminal repeats (LTRs) at their boundaries. We evaluate the predictive performance of our framework on the well-annotated genomes of Drosophila melanogaster and Arabidopsis thaliana and we compare our results for three LTR retrotransposon superfamilies with the results of three widely used methods for TE identification or classification: REPEATMASKER, CENSOR and LTRDIGEST. In contrast to these methods, TE-LEARNER is the first to incorporate machine learning techniques, outperforming these methods in terms of predictive performance , while able to learn models and make predictions efficiently. Moreover, we show that our method was able to identify TEs that none of the above method could find, and we investigated TE-LEARNER'S predictions which did not correspond to an official annotation. It turns out that many of these predictions are in fact strongly homologous to a known TE

Literacia comunicacional: uma estratégia para as organizações na sociedade da informação

Resenha da obra- As relações públicas e a educação corporativa: uma interface possível Autora: Roseane Andrelo Editora Unesp Digital São Paulo, 2016 99 páginas Disponível em E-book: http://editoraunesp.com.br/catalogo/9788568334775,as-relacoes-publicas-e-a-educacao-corporativ

Sequence heterogeneity and phylogenetic relationships between the copia retrotransposon in Drosophila species of the repleta and melanogaster groups

Although the retrotransposon copia has been studied in the melanogaster group of Drosophila species, very little is known about copia dynamism and evolution in other groups. We analyzed the occurrence and heterogeneity of the copia 5'LTR-ULR partial sequence and their phylogenetic relationships in 24 species of the repleta group of Drosophila. PCR showed that copia occurs in 18 out of the 24 species evaluated. Sequencing was possible in only eight species. The sequences showed a low nucleotide diversity, which suggests selective constraints maintaining this regulatory region over evolutionary time. On the contrary, the low nucleotide divergence and the phylogenetic relationships between the D. willistoni/Zaprionus tuberculatus/melanogaster species subgroup suggest horizontal transfer. Sixteen transcription factor binding sites were identified in the LTR-ULR repleta and melanogaster consensus sequences. However, these motifs are not homologous, neither according to their position in the LTR-ULR sequences, nor according to their sequences. Taken together, the low motif homologies, the phylogenetic relationship and the great nucleotide divergence between the melanogaster and repleta copia sequences reinforce the hypothesis that there are two copia families

ESTIMANDO E AVALIANDO A ESTABILIDADE DO BETA EM CINCO EMPRESAS BRASILEIRAS APÓS O PLANO REAL (1994-2001)

O objetivo deste trabalho é estimar e avaliar a estabilidade do comportamento do risco sistemático de cinco empresas brasileiras de diferentes setores no período compreendido entre os anos de 1994 a 2001, utilizando-se o Capital Asset PricingModel (CAPM)

The evolutionary dynamics of the Helena retrotransposon revealed by sequenced Drosophila genomes

<p>Abstract</p> <p>Background</p> <p>Several studies have shown that genomes contain a mixture of transposable elements, some of which are still active and others ancient relics that have degenerated. This is true for the non-LTR retrotransposon <it>Helena</it>, of which only degenerate sequences have been shown to be present in some species (<it>Drosophila melanogaster</it>), whereas putatively active sequences are present in others (<it>D. simulans</it>). Combining experimental and population analyses with the sequence analysis of the 12 <it>Drosophila </it>genomes, we have investigated the evolution of <it>Helena</it>, and propose a possible scenario for the evolution of this element.</p> <p>Results</p> <p>We show that six species of <it>Drosophila </it>have the <it>Helena </it>transposable element at different stages of its evolution. The copy number is highly variable among these species, but most of them are truncated at the 5' ends and also harbor several internal deletions and insertions suggesting that they are inactive in all species, except in <it>D. mojavensis </it>in which quantitative RT-PCR experiments have identified a putative active copy.</p> <p>Conclusion</p> <p>Our data suggest that <it>Helena </it>was present in the common ancestor of the <it>Drosophila </it>genus, which has been vertically transmitted to the derived lineages, but that it has been lost in some of them. The wide variation in copy number and sequence degeneration in the different species suggest that the evolutionary dynamics of <it>Helena </it>depends on the genomic environment of the host species.</p

Multiple invasions of Gypsy and Micropia retroelements in genus Zaprionus and melanogaster subgroup of the genus Drosophila

<p>Abstract</p> <p>Background</p> <p>The <it>Zaprionus </it>genus shares evolutionary features with the <it>melanogaster </it>subgroup, such as space and time of origin. Although little information about the transposable element content in the <it>Zaprionus </it>genus had been accumulated, some of their elements appear to be more closely related with those of the <it>melanogaster </it>subgroup, indicating that these two groups of species were involved in horizontal transfer events during their evolution. Among these elements, the <it>Gypsy </it>and the <it>Micropia </it>retroelements were chosen for screening in seven species of the two <it>Zaprionus </it>subgenera, <it>Anaprionus </it>and <it>Zaprionus</it>.</p> <p>Results</p> <p>Screening allowed the identification of diverse <it>Gypsy </it>and <it>Micropia </it>retroelements only in species of the <it>Zaprionus </it>subgenus, showing that they are transcriptionally active in the sampled species. The sequences of each retroelement were closely related to those of the <it>melanogaster </it>species subgroup, and the most parsimonious hypothesis would be that 15 horizontal transfer events shaped their evolution. The <it>Gypsy </it>retroelement of the <it>melanogaster </it>subgroup probably invaded the <it>Zaprionus </it>genomes about 11 MYA. In contrast, the <it>Micropia </it>retroelement may have been introduced into the <it>Zaprionus </it>subgenus and the <it>melanogaster </it>subgroup from an unknown donor more recently (~3 MYA).</p> <p>Conclusion</p> <p><it>Gypsy </it>and <it>Micropia </it>of <it>Zaprionus </it>and <it>melanogaster </it>species share similar evolutionary patterns. The sharing of evolutionary, ecological and ethological features probably allowed these species to pass through a permissive period of transposable element invasion, explaining the proposed waves of horizontal transfers.</p

The responsibility of the organizations due to the social impact of their communication in the virtual environment

O artigo apresenta uma reflexão sobre a responsabilidade das organizações ao disseminarem seus discursos nas mídias sociais. O objetivo é demonstrar como a comunicação organizacional, diante de seu impacto social, pode dialogar sobre questões éticas que estimulem respeito na sociedade a partir das relações estabelecidas em comunidades virtuais. Para isso, foi desenvolvida uma análise de conteúdo das interações dos públicos nas campanhas da Skol e da Alezzia no Facebook.The article presents an analysis about the responsibility of organizations when disseminating their speeches in social media. The purpose is to demonstrate how organizational communication, in view of its social impact, can dialogue on ethical topics that stimulate respect in society, based on relationships established in virtual communities. Focused on that, a content analysis was developed, considering the interactions of the audiences in Skol and Alezzia campaigns on Facebook.El artículo reflexiona acerca de la responsabilidad de las organizaciones cuando diseminan sus discursos en las redes sociales online. El objetivo es demostrar cómo la comunicación organizacional, delante de su impacto social, puede dialogar sobre cuestiones éticas que estimulan respeto en la sociedad a partir de las relaciones establecidas en comunidades virtuales. Así, fue desarrollado un análisis de contenido de las interacciones de los públicos en las campañas de Skol y Alezzia en Facebook

APLICAÇÃO DE MICRODADOS DA PNAD NA DETERMINAÇÃO DAS TAXAS DE RETORNO NA EDUCAÇÃO NO ESTADO DE GOIÁS

Este estudo investiga e analisa as taxas de retorno do investimento feito em educação para o Estado de Goiás. Foram utilizando os microdados da Pesquisa Nacional porAmostragem Domiciliar (PNAD), para o ano 2001. Os resultados sugerem que os retornos esperados ao investimento em educação explicam a influência exercida pelas variáveis independentes sobre a determinação dos rendimentos. A metodologia de análise permitiu testar as hipóteses e calcular a taxa de retorno do investimento em educação utilizando a equação minceriana estendida, comprovando a relevância econômica da variável educação que consegue captar a influência do investimento em capital humano e mensurar os retornos à educação

The protist Trichomonas vaginalis harbors multiple lineages of transcriptionally active Mutator-like elements

<p>Abstract</p> <p>Background</p> <p>For three decades the <it>Mutator </it>system was thought to be exclusive of plants, until the first homolog representatives were characterized in fungi and in early-diverging amoebas earlier in this decade.</p> <p>Results</p> <p>Here, we describe and characterize four families of <it>Mutator</it>-like elements in a new eukaryotic group, the Parabasalids. These <b><it>T</it></b><it>richomonas </it><b><it>v</it></b><it>aginalis </it><it><b>Mu</b>tator- <b>l</b>ike </it><it><b>e</b>lements</it>, or <it>TvMULEs</it>, are active in <it>T. vaginalis </it>and patchily distributed among 12 trichomonad species and isolates. Despite their relatively distinctive amino acid composition, the inclusion of the repeats <it>TvMULE1</it>, <it>TvMULE2</it>, <it>TvMULE3 </it>and <it>TvMULE4 </it>into the <it>Mutator </it>superfamily is justified by sequence, structural and phylogenetic analyses. In addition, we identified three new <it>TvMULE</it>-related sequences in the genome sequence of <it>Candida albicans</it>. While <it>TvMULE1 </it>is a member of the <it>MuDR </it>clade, predominantly from plants, the other three <it>TvMULEs</it>, together with the <it>C. albicans </it>elements, represent a new and quite distinct <it>Mutator </it>lineage, which we named <it>TvCaMULEs</it>. The finding of <it>TvMULE1 </it>sequence inserted into other putative repeat suggests the occurrence a novel TE family not yet described.</p> <p>Conclusion</p> <p>These findings expand the taxonomic distribution and the range of functional motif of <it>MULEs </it>among eukaryotes. The characterization of the dynamics of <it>TvMULEs </it>and other transposons in this organism is of particular interest because it is atypical for an asexual species to have such an extreme level of TE activity; this genetic landscape makes an interesting case study for causes and consequences of such activity. Finally, the extreme repetitiveness of the <it>T. vaginalis </it>genome and the remarkable degree of sequence identity within its repeat families highlights this species as an ideal system to characterize new transposable elements.</p