Caracterização química e avaliação das atividades antibacteriana, antifúngica, antimicobacteriana e citotóxica de Talinum paniculatum

In this study, the bioactivity of Talinum paniculatum was evaluated, a plant widely used in folk medicine. The extract from the T. paniculatum leaves (LE) was obtained by percolation with ethanol-water and then subjecting it to liquid-liquid partitions, yielding hexane (HX), ethyl acetate (EtOAc), butanol (BuOH), and aqueous (Aq) fractions. Screening for antimicrobial activity of the LE and its fractions was evaluated in vitro through broth microdilution method, against thirteen pathogenic and non-pathogenic microorganisms, and the antimycobacterial activity was performed through agar diffusion assay. The cytotoxic concentrations (CC90) for LE, HX, and EtOAc were obtained on BHK-21 cells by using MTT reduction assay. The LE showed activity against Serratia marcescens and Staphylococcus aureus, with Minimum Inhibitory Concentration (MIC) values of 250 and 500 µg/mL, respectively. Furthermore, HX demonstrated outstanding activity against Micrococcus luteus and Candida albicans with a MIC of 31.2 µg/mL in both cases. The MIC for EtOAc also was 31.2 µg/mL against Escherichia coli. Conversely, BuOH and Aq were inactive against all tested microorganisms and LE proved inactive against Mycobacterium tuberculosisand Mycobacterium bovisas well. Campesterol, stigmasterol, and sitosterol were the proposed structures as main compounds present in the EF and HX/EtOAc fractions, evidenced by mass spectrometry. Therefore, LE, HX, and EtOAc from T. paniculatumshowed potential as possible sources of antimicrobial compounds, mainly HX, for presenting low toxicity on BHK-21 cells with excellent Selectivity Index (SI = CC90/MIC) of 17.72 against C. albicans.Neste estudo foi avaliada a bioatividade de Talinum paniculatum, planta amplamente utilizada na medicina popular. O extrato das folhas (EF) de T. paniculatum foi obtido por percolação com etanol-água e, em seguida, submetido à partição líquido-líquido, obtendo-se as frações hexânica (HX), acetato-etílica (AcOEt), butanólica (BuOH) e aquosa (Aq). A triagem para a atividade antimicrobiana do EF e de suas frações foram avaliadas in vitro através do método de microdiluição em caldo contra treze micro-organismos patogênicos e não-patogênicos e, a atividade antimicobacteriana, foi avaliada através do teste de difusão em ágar. As concentrações citotóxicas (CC90) do EF e das frações HX e AcOEt foram obtidas sobre células da linhagem BHK-21 através do ensaio de redução do MTT. O EF mostrou atividade contra Serratia marcescens e Staphylococcus aureus, com valores de concentração inibitória mínima (CIM) de 250 e 500 µg/mL, respectivamente. Além disso, HX demonstrou excelente atividade contra Micrococcus luteus e Candida albicans com uma CIM de 31,2 µg/mL, em ambos os casos. Contra Escherichia coli, a CIM para AcOEt foi também de 31,2 µg/mL. Por outro lado, as frações BuOH e Aq foram inativas contra todos os micro-organismos testados, assim como o EF contra Mycobacterium tuberculosis e Mycobacterium bovis. Campesterol, estigmasterol e sitosterol foram as estruturas propostas como principais compostos presentes no EF e nas frações HX e AcOEt, evidenciadas através de espectrometria de massas. Portanto, o extrato da folha e as frações HX e AcOEt provenientes de T. paniculatum apresentaram potencial como possíveis fontes de compostos antimicrobianos, HX principalmente, por ter apresentado uma baixa toxicidade sobre células BHK-21 com um bom índice de seletividade (IS = CC90/MIC) de 17,72 contra C. albicans

Risk of Dengue for Tourists and Teams during the World Cup 2014 in Brazil

Abstract:Background:This year, Brazil will host about 600,000 foreign visitors during the 2014 FIFA World Cup. The concern of possible dengue transmission during this event has been raised given the high transmission rates reported in the past by this country.Methodology/Principal Findings:We used dengue incidence rates reported by each host city during previous years (2001-2013) to estimate the risk of dengue during the World Cup for tourists and teams. Two statistical models were used: a percentile rank (PR) and an Empirical Bayes (EB) model. Expected IR's during the games were generally low (<10/100,000) but predictions varied across locations and between models. Based on current ticket allocations, the mean number of expected symptomatic dengue cases ranged from 26 (PR, 10th-100th percentile: 5-334 cases) to 59 (EB, 95% credible interval: 30-77 cases) among foreign tourists but none are expected among teams. These numbers will highly depend on actual travel schedules and dengue immunity among visitors. Sensitivity analysis for both models indicated that the expected number of cases could be as low as 4 or 5 with 100,000 visitors and as high as 38 or 70 with 800,000 visitors (PR and EB, respectively).Conclusion/Significance:The risk of dengue among tourists during the World Cup is expected to be small due to immunity among the Brazil host population provided by last year's epidemic with the same DENV serotypes. Quantitative risk estimates by different groups and methodologies should be made routinely for mass gathering events. © 2014 van Panhuis et al

Evaluation of the Impacts of Biomass Burning Aerosols on the NASA GEOS Sub-Seasonal Climate Forecasts

Emission sources of trace gases and aerosol particles in the South American (SA)and African (Af) continents have a strong seasonal and space variability associated with the extensive vegetation fires activities. In both continents, during the austral winter, the fires affect mainly tropical forest and savannah-type biomes and are mostly associated with deforestation and agricultural/pasture land management. Smoke aerosol particles, on average, contribute to at least 90% of the total aerosol optical depth (AOD) in the visible spectrum in the case of the South America regional smoke. Smoke aerosols also act as cloud condensation nuclei affecting cloud microphysics properties and therefore, changing the radiation budget, hydrological cycle and global circulation patterns over disturbed areas (Kaufman, 1995; Rosenfeld, 1999; Andreae,et al., 2004; Koren et al., 2004, Zhang, 2008; Ott et al., 2010; Randles et al., 2013). This study aims to evaluate and quantify the impact of including a comprehensive emission field of biomass burning aerosol on the performance of a seasonal climate forecast system, not only regarding the AOD itself but mainly on the meteorological state variable (e.g., precipitation and temperature). To address the questions put above, we designed two numerical experiments: 1- named"AERO_CTL" which applies the Quick Fire Emissions Dataset (QFED) emissions estimated with intra-diurnal variation (hereafter, BBE), and 2- named "AERO_CLM" where the sourcee mission is based on a climatology of the QFED emissions, with only monthly variation(hereafter, BBCLIM). Hindcast simulations were produced using the Goddard Earth ObservingSystem global circulation model, version 5, sub-seasonal to seasonal (GEOS5-S2S) system with a nominal spatial resolution of 56km (Rienecker et al., 2008). In both experiments, the aerosol feedbacks from cloud developments and radiation interactions were accounted. The two experiments consisted of 4 members each and ran from June to November spanning over the years 2000 to 2015. Model performance was evaluated by calculating statistical metrics on the mean area of SA and Af. Our results demonstrated that the skill model in predicting AOD is significantly improve when BBE source emission is applied over SA, but not over the Afcontinent. Over SA, the correlation between the AERO_CTL model configuration and MERRA-2 is 0.93 (R2= 0.86, RMS=0.02, BIAS=0.01), while the AERO_CLM model presents a value of0.81 (R2= 0.65, RMS=0.04, BIAS=0.06). However, the AERO_CTL experiment better represents the inter-annual variability of the AOS in both regions. The gain of the skill in predicting the AOD by the AERO_CTL experiment is also seen in some meteorological variables. We observed an increase in the model skill in predicting the 2-meter temperature and precipitation of up to 0.3 for the AERO_CTL experiment in comparison to the AERO_CLM. AERO_CLM. According to the analyzed hindcast, we inferred that representing the BBE more realistically implies in a significant gain of skills in the seasonal climate forecasting over SA and Af continents

Padrão de visitação de Apis mellifera em cultivo de melão do tipo amarelo com e sem cobertura plástica.

Suplemento. Edição dos Anais do 52 Congresso Brasileiro de Olericultura, Salvador, jul. 2012

Comportamento de pastejo de Apis mellifera em três cultivares de meloeiro irrigado.

Suplemento. Edição dos Anais do 52 Congresso Brasileiro de Olericultura, Salvador, jul. 2012

Relationship of floral morphology and biology of yellow melon hybrids with the attractiveness of pollinators.

To increase the productivity of melon, new hybrids have been released. The aim of this study was to c ompare the differences in morphology and floral biology of two yellow melon hibrids and these could influence the attractiveness of the pollinators. The study was conducted in June 2010, at Embrapa Semiárido (Petrolina-PE), with hybrids BRS Araguaia and Tropical. To evaluate the morphology and anthesis ten flowers were selected of each floral type: hermaphrodite (H) and male (M). The floral visitors were observed simultaneously in the two hybrids, from 5h00a.m until 6h00p.m, in three non-consecutive days. In the morphology, it was found that the Tropical flowers have diameter of corolla higher in two floral types (M: x = 3.82±0.55cm, H: x = 4.74±0.52cm) compared to BRS Araguaia (M: x = 3.46±0.46cm, H: x = 3.77±0.45cm), although the differences were significant only for the hermaphrodites. The BRS Araguaia flowers presented significantly longer (p<0.05) (M: x = 2.20±0.23cm, H: x = 3.86±0.39cm) that the Tropical (M: x = 0. 96±0.30cm, H: x = 2.60±0.63cm). As for anthesis (05h30a.m.) there was no difference in relation to floral types and hybrids. The bees Apis mellifera, Xylocopa grisescens and species of Halictidae family were observed in the area. The visitation peak was recorded between 10h00a.m. and 11h00a.m. in both hybrids. Comparing the visitation in hermaphrodite flowers and production of fruit/plant, it was observed that the BRS Araguaia received more visits of A. mellifera and produced more fruit/plant (2.1) than the Tropical (1.43), indicating that the differences found in the hermaphrodite flowers may have influenced the bees behavior and thus productivity.Número Especial

Principais doenças do tomateiro no Amazonas.

Esse documento objetiva informar os técnicos da extensão rural e da iniciativa privada e, principalmente, os produtores sobre os problemas fitossanitários potenciais que podem inviabilizar o cultivo comercial do tomateiro a céu aberto nas condições tropicais úmidas, como as que prevalecem no Amazonas.bitstream/item/211514/1/Circ-Tec-75.pd

Avaliação do morfotipo, do substrato e da frequência de irrigação na produção de mudas de Oxalis psoraleoides Kunth. (Oxalidaceae).

Este trabalho teve como objetivo avaliar a infl uência do morfotipo, do substrato e da irrigação no enraizamento das estacas de Oxalis psoraleoides Kunth. (Oxalidaceae), considerada uma espécie ornamental

Avaliação de diferentes concentrações de ácido giberélico na germinação de sementes de Rhaphiodon echinus Shauer (Lamiaceae)

Rhaphiodon echinus, conhecido popularmente por beton ou falsa-menta, se destaca entre as espécies da Caatinga de potencial uso ornamental como forração de áreas. O objetivo desse estudo foi avaliar o efeito do ácido giberélico (GA3) na superação de dormência e germinação de sementes dessa espécie. Para tanto, dois experimentos foram instalados, em delineamentos inteiramente casualizados, cada qual contendo cinco tratamentos. O primeiro experimento foi composto pelos tratamentos: água destilada (T1 ? Controle I) e soluções com GA3 nas concentrações de 0,001% (T2); 0,05% (T3); 0,1% (T4) e 0,5% (T5). O segundo foi composto pelos tratamentos: água destilada (T1- Controle II) e soluções com GA3 nas concentrações de 0,5% (T2), 1% (T3), 2% (T4) e 3% (T5). As observações foram feitas diariamente anotando-se o número de sementes germinadas. Os resultados obtidos permitiram concluir que as sementes de R. echinusresponderam, positivamente aos diferentes níveis de giberelina, atingindo valor superior de germinação nas concentrações de 0,5% e 1%. O uso de giberilina além de aumentar a porcentagem de germinação, também diminuiu o tempo médio desse processoEdição Especial. 6 Workshop de Sementes e Mudas da Caatinga, Juazeiro-BA/Petrolina-PE, jul./ago. 2018