Spectrophotometric determinations of chloroplastidic pigments in acetone, ethanol and dimethylsulphoxide

(Spectrophotometric determinations of chloroplastidic pigments in acetone, ethanol and dimethylsulphoxide). The concentration of pigment indicates a range of properties in the physiological processes of plants. A large number of procedures have been developed to measure leaf pigment content. Some of these procedures involve leaf maceration and centrifugation, while others require incubation of a leaf sample in solvent for a few minutes or hours, which makes the process laborious. The choice of the best procedure may vary according to the plant species and type of solvent used. This study compared the efficiency of three commonly used solvents (dimethylsulphoxide, ethanol and acetone) in the extraction of chlorophylls and carotenoids of five plant species and one lichen species. The results indicated that dimethylsulphoxide was more efficient at chlorophyll extraction in all of the studied species. The ethanol and acetone extracts quickly lost molecular stability. Acetone extract may also cause phaeophytinisation and reduce the chlorophyll content.(Determinações espectrofotométricas de pigmentos cloroplastídicos em acetona, etanol e dimetilsulfóxido). A concentração dos pigmentos foliares é indicativa de uma série de propriedades e processos fisiológicos. Diversas metodologias têm sido desenvolvidas para a determinação da concentração dos pigmentos foliares. Destas metodologias, algumas requerem maceração e centrifugação, enquanto outras requerem incubação das amostras foliares no solvente por alguns minutos ou horas, tornando o processo laborioso. A escolha do melhor método pode variar de espécie para espécie e do tipo de solvente utilizado. Neste sentido, testou-se a eficácia de três solventes mais comumente utilizados (dimetilsulfóxido, etanol e acetona) para a extração de clorofilas e carotenóides em cinco espécies de plantas e um líquen. Os resultados indicam que o dimetilsulfóxido possui maior eficiência na extração de clorofilas em todas as espécies estudadas. Os extratos etanólicos e cetônicos rapidamente perderam sua estabilidade. No extrato cetônico pode ocorrer, ainda, a feofitinização e a diminuição do conteúdo de clorofilas

Genomic characterization of orthobunyavirus of veterinary importance in America

During 2013, in Argentina, three new isolates of serogroup Bunyamwera virus (genus Orthobunyavirus, family Peribunyaviridae)were recovered from two horses with encephalitis, and from an aborted equine fetus. In the present study, we report the complete genome sequence, genetic characterization, and phylogenetic analysis of three new strains isolated in Argentina to clarifying their relationship within the Bunyamwera serogroup virus and to investigate the evolutionary history of viruses with segmented genomes.Fil: Tauro, Laura Beatriz. Universidad Nacional de Córdoba. Facultad de Medicina. Instituto de Virología Dr. J. M. Vanella; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: de Souza, William Marciel. Universidade de Sao Paulo; BrasilFil: Rivarola, María Elisa. Universidad Nacional de Córdoba. Facultad de Medicina. Laboratorio de Arbovirus y Arenovirus; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: de Oliveira, Rodrigo. Instituto Evandro Chagas; BrasilFil: Konigheim, Brenda Salome. Universidad Nacional de Cordoba. Facultad de Medicina. Instituto de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Patroca Silva, Sandro. Instituto Evandro Chagas; BrasilFil: Lima, Clayton. Instituto Evandro Chagas; BrasilFil: Oliveira, Layanna. Instituto Evandro Chagas; BrasilFil: Vasconcelos, Janaina M.. Instituto Evandro Chagas; BrasilFil: Ferreira Cardoso, Jedson. Instituto Evandro Chagas; BrasilFil: Vianez Júnior, João Lídio. Instituto Evandro Chagas; BrasilFil: Teixeira Nunes, Márcio Roberto. Instituto Evandro Chagas; BrasilFil: Contigiani de Minio, Marta Silvia. Universidad Nacional de Córdoba. Facultad de Medicina. Instituto de Virología Dr. J. M. Vanella; Argentin

Characterization of the Gamboa virus serogroup (Orthobunyavirus genus, Peribunyaviridae family)

Comprehensive comparative phylogenetic analyses were performed on 17 Gamboa serogroup viruses (GAMSVs) from distinct geographic regions in the Americas and other representative members of the genus Orthobunyavirus (Peribunyaviridae), based on small (S), medium (M), and large (L) open reading frame full-length and partial sequences. Genome characterization showed that the GAMSVs divide into four clades or genotypes. The GAMSVs have a genetic organization similar to other orthobunyaviruses, except that they have a larger NSm protein than other orthobunyaviruses. A serosurvey for Gamboa virus antibodies was performed in plasma from birds, other wild animals, and humans living around the Tucuruí hydroelectric dam in Pará state, northern Brazil, a known focus of GAMSV activity. Newborn chicks (Gallus gallus domesticus) were experimentally infected with a GAMSV, and the pathogenesis is described. Histopathological changes were primarily in the lungs and liver. Also, a review of the ecology of the GAMSVs in the Americas is included. In sum, this study presents the genomic and evolutionary characterization of the Gamboa group and the potential model of pathogenesis, which would be helpful for diagnostic purposes, epidemiology, and immunopathogenesis studies

Educomunicação e suas áreas de intervenção: Novos paradigmas para o diálogo intercultural

oai:omp.abpeducom.org.br:publicationFormat/1O material aqui divulgado representa, em essência, a contribuição do VII Encontro Brasileiro de Educomunicação ao V Global MIL Week, da UNESCO, ocorrido na ECA/USP, entre 3 e 5 de novembro de 2016. Estamos diante de um conjunto de 104 papers executivos, com uma média de entre 7 e 10 páginas, cada um. Com este rico e abundante material, chegamos ao sétimo e-book publicado pela ABPEducom, em seus seis primeiros anos de existência. A especificidade desta obra é a de trazer as “Áreas de Intervenção” do campo da Educomunicação, colocando-as a serviço de uma meta essencial ao agir educomunicativo: o diálogo intercultural, trabalhado na linha do tema geral do evento internacional: Media and Information Literacy: New Paradigms for Intercultural Dialogue

Stress Tolerance and Ecophysiological Ability of an Invader and a Native Species in a Seasonally Dry Tropical Forest

<div><p>Ecophysiological traits of <i>Prosopis juliflora</i> (Sw.) DC. and a phylogenetically and ecologically similar native species, <i>Anadenanthera colubrina</i> (Vell.) Brenan, were studied to understand the invasive species’ success in caatinga, a seasonally dry tropical forest ecosystem of the Brazilian Northeast. To determine if the invader exhibited a superior resource-capture or a resource-conservative strategy, we measured biophysical and biochemical parameters in both species during dry and wet months over the course of two years. The results show that <i>P. juliflora</i> benefits from a flexible strategy in which it frequently outperforms the native species in resource capture traits under favorable conditions (e.g., photosynthesis), while also showing better stress tolerance (e.g., antioxidant activity) and water-use efficiency in unfavorable conditions. In addition, across both seasons the invasive has the advantage over the native with higher chlorophyll/carotenoids and chlorophyll a/b ratios, percent N, and leaf protein. We conclude that <i>Prosopis juliflora</i> utilizes light, water and nutrients more efficiently than <i>Anadenanthera colubrina</i>, and suffers lower intensity oxidative stress in environments with reduced water availability and high light radiation.</p></div

Different physiological responses under drought stress result in different recovery abilities of two tropical woody evergreen species

ABSTRACT The effects of water deficit on physiological and biochemical variables of young plants of two tropical woody species, Pachira aquatica and Sterculia foetida, and their recovery abilities were measured. Leaf water potential, gas exchange and selected carbon metabolism components were measured in a greenhouse experiment with control, moderate and severe water deficit treatments. Under severe drought stress, gas exchange and chlorophyll fluorescence decreased in both species compared to their respective controls. After rehydration, P. aquatica and S. foetida showed a partial and full recovery of the measured variables, respectively. In addition, a decrease and an increase in photosynthetic pigments were observed for P. aquatica and S. foetida, respectively, compared to their controls. In conclusion, the two species showed differing responses regarding photosynthetic pigment content dynamics for tolerating water deficit. Individuals of P. aquatica in the severe water deficit treatment showed a decrease in pigments, which may have impaired the recovery of metabolism (gas exchange) after rehydration, while S. foetida experienced an increase, favoring a full recovery of gas exchange and biochemical metabolism after rehydration

Changes in gas exchange in native (<i>Anadenanthera colubrina)</i> and invasive (<i>Prosopis juliflora</i>) species in a tropical dry forest in Brazil across seasons: (A) stomatal conductance (g_s), (B) water potential (Ψ_l), (C) CO₂ assimilation (<i>A</i>), (D) water use efficiency (WUE = <i>A</i>/<i>E</i>), (E) transpiration (<i>E</i>).

<p>Values represent the average of replicates (n = 20±SE; invasive dry season n = 25±SE). Different letters denote statistical differences by Newman-Keul test with significance level of 5 percent between variables.</p