85 research outputs found

    Observation of coherent transients in ultrashort chirped excitation of an undamped two-level system

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    The effects of Coherent excitation of a two level system with a linearly chirped pulse are studied theoretically and experimentally (in Rb (5s - 5p)) in the low field regime. The Coherent Transients are measured directly on the excited state population on an ultrashort time scale. A sharp step corresponds to the passage through resonance. It is followed by oscillations resulting from interferences between off-resonant and resonant contributions. We finally show the equivalence between this experiment and Fresnel diffraction by a sharp edge.Comment: 4 pages, 4 figures, to appear in PR

    Dye detoxification by Lentinula edodes INCQS 40220

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    Lentinula edodes belongs to the group of fungi known as ligninolytic fungi, due to its ability to degrade the aromatic structure of the lignin. Textile dyes also have aromatic structure, and after microbial degradation, some of them can be transformed into toxic compounds, when compared to the original structure, representing risk to environment and human health. Therefore, the potential of the fungus L. edodes INCQS 40220 to decolorize and to detoxify reactive red 198 (azo dye), reactive blue 214 (azo dye) and reactive blue 21 (cooper phthalocyanine dye) in a mixture (MXD), was evaluated. After 14 days of incubation, total decolorization in liquid media was obtained. The fungal treatment of MXD did not present toxic effects towards blood human cells. The genotoxicity of MXD, assessed by Comet assay, was efficiently reduced to 61% and in the Ames test presented negative response for mutagenicity for Salmonella enterica serovar Typhimurium TA97, TA98, TA100 and TA102 strains. The results indicated L. edodes INCQS 40220 efficiency on decolorization and genotoxicity reduction of a mixture of different dyes. Therefore, based on these results, obtained under laboratory conditions, L. edodes INCQS 40220 has potential for textile effluent treatment.Título PT: Detoxificação de corante por Lentinula edodes INCQS 40220Lentinula edodes pertence ao grupo de fungos conhecidos como fungos ligninolíticos, devido a sua habilidade de degradar estruturas aromáticas da lignina. Corantes têxteis também possuem estruturas aromáticas e, após a degradação microbiana, alguns destes corantes podem ser transformados em compostos tóxicos quando comparados à estrutura original, representando risco à saúde ambiental e humana. Portanto, o potencial do fungo L. edodes INCQS 40220 para descolorir e detoxificar a mistura de vermelho reativo 198 (corante azo), azul reativo 214 (corante azo) e azul reativo 21 (corante ftalocianina de cobre) foi avaliada (MXD). Após 14 dias de incubação, foi obtida descoloração total em meio líquido. O tratamento fúngico de MXD não apresentou efeitos tóxicos em células sanguíneas humanas. A genotoxicidade de MXD, avaliada por meio do Ensaio Cometa, foi eficientemente reduzida para 61% e, no teste de Ames, apresentou resposta negativa à mutagenicidade para Salmonella enterica serovar Typhimurium TA97, TA98, TA100 e TA102 strains. Os resultados indicaram eficiência de L. edodes INCQS 40220 na descoloração e redução de genotoxicidade na mistura de diferentes corantes. Portanto, com base nos resultados obtidos em condições de laboratório, L. edodes INCQS 40220 tem potencial para o tratamento de efluente têxtil

    La dinámica del contenido generado por el usuario en medios digitales de Iberoamérica y Estados Unidos

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    ES: En este trabajo se presenta un análisis comparativo del estatus o reconocimiento del CGU (contenido generado por el usuario) y de los niveles de control de la participación de los usuarios en las ediciones en línea de 24 diarios de Argentina, Colombia, México, Perú, Portugal, España, Estados Unidos y Venezuela. El estudio analiza las condiciones en las cuales los usuarios publican contenidos, tanto en términos de restricciones como del reconocimiento que reciben sus aportaciones por parte del medio informativo. "Periodismo participativo" se define como el resultado del incremento progresivo del intercambio de mensajes entre productores y consumidores en dos dimensiones: referencial y relacionalIn this paper we present a comparative analysis of UGC status and levels of control in 24 quality online mainstream newspapers from Argentina, Colombia, México, Perú, Portugal, Spain, US and Venezuela. The study addresses the conditions in which users provide content, in terms of constraint, and the recognition given by mainstream media to the users' activity. "Participatory journalism" is defined as the evolving materialization of an increase in message interchange activity between producers and consumers in two dimensions: content and relationshi

    Omics Approaches for Understanding Biogenesis, Composition and Functions of Fungal Extracellular Vesicles

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    This is the final version. Available on open access from Frontiers Media via the DOI in this recordExtracellular vesicles (EVs) are lipid bilayer structures released by organisms from all kingdoms of life. The diverse biogenesis pathways of EVs result in a wide variety of physical properties and functions across different organisms. Fungal EVs were first described in 2007 and different omics approaches have been fundamental to understand their composition, biogenesis, and function. In this review, we discuss the role of omics in elucidating fungal EVs biology. Transcriptomics, proteomics, metabolomics, and lipidomics have each enabled the molecular characterization of fungal EVs, providing evidence that these structures serve a wide array of functions, ranging from key carriers of cell wall biosynthetic machinery to virulence factors. Omics in combination with genetic approaches have been instrumental in determining both biogenesis and cargo loading into EVs. We also discuss how omics technologies are being employed to elucidate the role of EVs in antifungal resistance, disease biomarkers, and their potential use as vaccines. Finally, we review recent advances in analytical technology and multi-omic integration tools, which will help to address key knowledge gaps in EVs biology and translate basic research information into urgently needed clinical applications such as diagnostics, and immuno- and chemotherapies to fungal infections.NIHPacific Northwest National Laboratory (PNNL)CNPq/Science Without Borders Science Program, BrazilJohns Hopkins Malaria Research InstituteFAPESPCAPESCNPqMedical Research Council (MRC

    School dropout, problem behaviour and poor academic achievement : a longitudinal view of portuguese male offenders

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    This study examines school drop outs from the perspective of male adults themselves through interviews with offenders currently serving sentences. Participants were 10 Portuguese male inmates, between the ages of 19 and 46 years of age, incarcerated in two prison facilities of the Azores. Qualitative and interpretative methods were carried out using a semi-structured in-depth individual interview that was audiorecorded and conducted on the basis of a list of topics. Interview transcripts and thematic analysis were used in data treatment and analysis. The findings primarily indicate that poor academic achievement and emotional and behavioural difficulties of participants played a particular role in early school drop out. The trajectories these individuals followed within the education system presented problem behaviour, learning disabilities, and/or foster care interventions. While school drop out circumstances were apparently various, analysis showed that they were underpinned by three distinct sets of conditions generally not addressed by the education system. The analysis of the triggering factors and the maintenance dynamics of school drop outs indicated three distinct types: retention/absenteeism, life turning points and positive resolution. Implications for secondary prevention and screening practices are discussed.FCT (SFRH/ BD/ 44245/ 2008)CIEC - unidade de investigação 317 da FC
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