Tracking dynamics of functional brain networks using dense EEG

International audienceCognition is formed from networks between functionally specific but distributed brain regions. A very challenging issue in cognition is how to precisely track brain networks at very short temporal scales (often very short <1s). So far, very few studies have addressed this problem as it requires high temporal and spatial resolution simultaneously. Due to its excellent temporal resolution, Electroencephalography (EEG) is a key neuroimaging technique to access real-time information flow among large scale neuronal networks. Here, we propose a new method based on EEG source connectivity to map large-scale networks at high temporal (in the order of ms) and spatial (~1000 regions of interest) resolution. We show clear evidence of the ability of EEG source connectivity to track brain networks with high time/space resolutions during picture naming task. Our results reveal that the cognitive process can be decomposed into a sequence of transiently-stable and partially-overlapping networks. Our qualitative and quantitative observations show that the identified brain networks are in accordance with results reported in the literature regarding involved brain areas during the analyzed task

Produção de mudas de araucária em tubetes.

bitstream/CNPF-2009-09/43530/1/com_tec201.pd

I Miss That Mississippi Miss That Misses Me

https://digitalcommons.library.umaine.edu/mmb-vp/3176/thumbnail.jp

Miniestaquia de Grevillea robusta A. Cunn. a partir de propágulos juvenis.

O presente estudo teve como objetivo avaliar a sobrevivência e a produtividade de minicepas no sistema de tubetes e o efeito do ácido indolbutírico (AIB) no enraizamento de miniestacas de Grevillea robusta. O experimento foi conduzido em Colombo, PR, com minicepas formadas partindo de mudas obtidas de sementes, as quais foram cultivadas no sistema de tubetes, durante o período de um ano. A sobrevivência das minicepas, após 15 coletas, foi de 100% com produtividade média de 1,7 miniestacas por minicepa e 4030 miniestacas por metro quadrado ao ano. As taxas médias de enraizamento foram 83, 79, 75 e 72% para os tratamentos com 0, 1000, 2000 e 4000 mg L-1 de AIB respectivamente, sendo os melhores níveis obtidos sem aplicação exógena de AIB. Com base nesses resultados, conclui-se que a miniestaquia de propágulos juvenis é uma opção para produção de mudas de Grevillea robusta durante o ano inteiro, sem a necessidade de aplicações de reguladores de crescimento, além de ser uma importante ferramenta para adaptação dos protocolos de propagação vegetativa em materiais adultos selecionados

Indução de brotações basais e estaquia de Araucaria angustifolia (Bert.) O. Ktze.

Resumo

Produção de mudas de corticeira-do-mato por miniestaquia a partir de propágulos juvenis.

bitstream/CNPF-2009-09/43377/1/com_tec130.pd

Persistence, seasonal dynamics and pathogenic potential of Vibrio communities from pacific oyster hemolymph

Bacteria of the genus Vibrio occur at a continuum from free-living to symbiotic life forms, including opportunists and pathogens, that can contribute to severe diseases, for instance summer mortality events of Pacific oysters Crassostrea gigas. While most studies focused on Vibrio isolated from moribund oysters during mortality outbreaks, investigations of the Vibrio community in healthy oysters are rare. Therefore, we characterized the persistence, diversity, seasonal dynamics, and pathogenicity of the Vibrio community isolated from healthy Pacific oysters. In a reciprocal transplant experiment we repeatedly sampled hemolymph from adult Pacific oysters to differentiate population from site-specific effects during six months of in situ incubation in the field. We characterized virulence phenotypes and genomic diversity based on multilocus sequence typing in a total of 70 Vibrio strains. Based on controlled infection experiments we could show that strains with the ability to colonize healthy adult oysters can also have the potential to induce high mortality rates on larvae. Diversity and abundance of Vibrio varied significantly over time with highest values during and after spawning season. Vibrio communities from transplanted and stationary oysters converged over time, indicating that communities were not population specific, but rather assemble from the surrounding environment forming communities, some of which can persist over longer period

Integrating Environmental, Molecular, and Morphological Data to Unravel an Ice-age Radiation of Arctic-alpine Campanula in Western North America

Many arctic-alpine plant genera have undergone speciation during the Quaternary. The bases for these radiations have been ascribed to geographic isolation,abiotic and biotic differences between populations, and/or hybridization andpolyploidization. The Cordilleran Campanula L. (Campanulaceae Juss.), a monophyletic clade of mostly endemic arctic-alpine taxa from western North America, experienced a recent and rapid radiation. We set out to unravel the factors that likely influenced speciation in this group. To do so, we integrated environmental, genetic, and morphological datasets, tested biogeographic hypotheses, and analyzed the potential consequences of the various factors on the evolutionary history of the clade. We created paleodistribution models to identify potential Pleistocene refugia for the clade and estimated niche space for individual taxa using geographic and climatic data. Using 11 nuclear loci, we reconstructed a species tree and tested biogeographic hypotheses derived from the paleodistribution models. Finally, we tested 28 morphological characters, including floral, vegetative, and seed characteristics, for their capacity to differ- entiate taxa. Our results show that the combined effect of Quaternary climatic variation, isolation among differing environments in the mountains in western North America, and biotic factors influencing floral morphology contributed to speciation in this group during the mid-Pleistocene. Furthermore, our biogeographic analyses uncovered asynchronous consequences of interglacial and glacial periods for the timing of refugial isolation within the southern and northwestern mountains, respectively. These findings have broad implications for understanding the processes promoting speciation in arctic-alpine plants and the rise of numerous endemic taxa across the region