496 research outputs found

    Tripes (insecta: tripidae) associados ao pinhão-manso no estado do Piauí, Brasil.

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    Objetivou-se, com esse trabalho, identificar espécies de tripes associadas ao pinhão manso (Jatropha curcas L). Inspeções periódicas foram realizadas em Unidades Demonstrativas dessa cultura na Embrapa Meio-Norte para coleta e identificação de insetos. Dentre os insetos coletados, foram identificadas três espécies de tripes: Retithrips syriacus (Mayet), Heliothrips haemorrhoidalis (Bouché) e Frankliniella schultzei (Trybom), sendo o primeiro registro de ocorrência deles no estado do Piauí e em associação a J. curcas no Brasil

    Influence of the vintage, clone and rootstock on the chemical characteristics of Syrah tropical wines from Brazil.

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    In the Northeast of Brazil, vines can produce twice a year, because annual average temperature is 26ºC, with high solar radiation and water availability for irrigation. Many cultivars have been tested according to their adaptation to the climate and soil, and the main variety used for red wines is Syrah. This work aimed to evaluate five clones of Syrah, grafted on two rootstocks, in two harvests of the second semester of 2009 and 2010, according to the chemical analyses of the wines.The clones evaluated were 100, 174, 300, 470 and 525, the rootstocks were Paulsen 1103 and IAC 313 (Golia x Vitis caribeae). Grapes were harvested in November 2009 and 2010 and the yield was evaluated. Climate characteristics of each harvest was determined and correlated to the results. Wines were elaborated in glass tanks of 20 L, with alcoholic fermentation at 25ºC for seven days, then wines were pressed and malolactic fermentation was carried out at 18ºC for 20 days. The following parameters were analyzed: alcohol content, dry extract, total anthocyanins, total phenolic index. High performance liquid chromatography was used to determine tartaric, malic, lactic and citric organic acids. Results showed that wines presented different concentrations of classical analyses, phenolics and organic acids according to the harvest date, rootstocks and clones. Principal component analysis was applied on data and clusters with wine samples were formed, explaining the variability, and results are discussed

    Influence of the vintage, clone and rootstock on the chemical characteristics of Syrah tropical wines from Brazil.

    Get PDF
    In the Northeast of Brazil, vines can produce twice a year, because annual average temperature is 26ºC, with high solar radiation and water availability for irrigation. Many cultivars have been tested according to their adaptation to the climate and soil, and the main variety used for red wines is Syrah. This work aimed to evaluate five clones of Syrah, grafted on two rootstocks, in two harvests of the second semester of 2009 and 2010, according to the chemical analyses of the wines.The clones evaluated were 100, 174, 300, 470 and 525, the rootstocks were Paulsen 1103 and IAC 313 (Golia x Vitis caribeae). Grapes were harvested in November 2009 and 2010 and the yield was evaluated. Climate characteristics of each harvest was determined and correlated to the results. Wines were elaborated in glass tanks of 20 L, with alcoholic fermentation at 25ºC for seven days, then wines were pressed and malolactic fermentation was carried out at 18ºC for 20 days. The following parameters were analyzed: alcohol content, dry extract, total anthocyanins, total phenolic index. High performance liquid chromatography was used to determine tartaric, malic, lactic and citric organic acids. Results showed that wines presented different concentrations of classical analyses, phenolics and organic acids according to the harvest date, rootstocks and clones. Principal component analysis was applied on data and clusters with wine samples were formed, explaining the variability, and results are discussed

    Experimental evidence of contamination on the dynamics of shrimp populations: susceptibility to spatial isolation

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    Landscape-scale ecology comprises complex structures where a flow of energy, materials and organisms among ecosystems conditions the dynamics of populations. Several natural and anthropogenic stressors are likely to affect the landscape composition, generally leading to the rupture of ecological connectivity among populations. Although contamination is considered one of the most threatening factors for biodiversity, its impact on spatial dynamics of populations (e.g., distribution, persistence and abundance) from an eco-toxicological perspective is still unknown. In the current study, the potential effect that contamination can exert on the loss of connectivity among populations (chemically fragmented habitats) leading to population isolation was assessed. The estuarine shrimp Palaemon varians was used as model organisms and a novel version of the HeMHAS (Heterogeneous Multi-Habitat Assay System) was used to simulate spatially heterogeneous landscapes. In order to provide more ecological relevance to the study, besides copper as stressor [at low (0.5 μg/L) and high (25 μg/L) levels], other two factors were simultaneously tested: fish kairomones (as a predation signal) and food availability. Different scenarios were simulated in the HeMHAS to create heterogeneous landscapes that vary depending on the presence or absence of these stressors. The behavior observed by the population of P. varians clearly showed that the shrimp detected copper and avoided the regions with the highest levels of contamination. However, when fish kairomones were added to previously preferred regions, the behavior of shrimp populations did a radical turn: they escape the predator signals, moving towards contaminated regions, but with a clear preference for less contaminated areas. When faced whether to stay in a clean area with no food or moving through disturbed regions to colonize a clean region with food, shrimps’ populations crossed the regions, but with a more dynamic transit in the region with kairomones and no copper. These results indicate that contamination might interfere in the spatial dynamics of shrimps’ populations by: (i) triggering avoidance, (ii) preventing colonization, (iii) isolating populations and (iv) making them more susceptible to local extinction

    Experimental evidence of how contamination might modify the shrimps’ population dynamics and make them susceptible to spatial isolation

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    Contamination is likely to affect the landscape composition, usually linked to ecological fragmentation, which may impact the distribution, persistence and abundance of species. In the current study, the estuarine shrimp Palaemon varians was exposed to copper (25 and 0.5 μg/L) simultaneously to predation signal and food to evaluate the organism’s spatial distribution within a spatially heterogeneous landscape. All experimental landscapes were simulated in the Heterogeneous Multi Habitat Assay System (HeMHAS). As results, P. varians detected and avoided copper, however, predation signal shifted the response to preference over regions with conditions previously avoided, even if that meant to increase copper exposure. When confronted to move towards environments with high food availability, lower connectivity occurred among the shrimps’ populations isolated by contamination and predation risk simultaneously. This indicate that contamination might: (i) trigger avoidance in shrimps, (ii) prevent the colonisation towards foraging areas, (iii) enhance the populations’ isolation and (iv) make populations more susceptible to local extinction
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