61 research outputs found

    Chemical ecology of Astigmatid mites

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    Thesis--University of Tsukuba, D.Agr.(A), no. 727, 1990. 3. 2

    Genome Analysis and Expression Patterns of Odorant-Binding Proteins from the Southern House Mosquito Culex pipiens quinquefasciatus

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    Olfactory-based behaviors in mosquitoes are mediated by odorant-binding proteins (OBPs). They form a multigenic family involved in the peripheral events in insect olfaction, specifically the transport of odorants to membrane-bound odorant receptors. OBPs contribute to the remarkable sensitivity of the insect's olfactory system and may be involved in the selective transport of odorants

    Vigor and mortality of citrus progenies with potential use as rootstocks

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    Rootstocks influence certain characteristics of the scion, such as vigor, fruit yield and quality, and tolerance to biotic and abiotic factors. In conventional citrus breeding programs, hybridization is the main method used for obtaining rootstock varieties. Between Sept and Oct 2006, controlled pollinations were carried out resulting in nine progenies, totaling 461 hybrid seedlings. The female parents were the ‘Santa Cruz Rangpur’ lime (SCRL) and the ‘Sunki of Florida’ mandarin (SFM), while the male parents, in addition to this mandarin, were the ‘Indio’ and ‘Riverside’ citrandarins, the ‘Thomasville’ citrangequat (THOM), the ‘Swingle’ citrumelo, the ‘Argentina’ citrange (AGC) and the ‘Benecke’ trifoliate orange (BKTO). Fruit setting rates of these crosses were measured and the hybrids generated were planted in the field in 2008 and evaluated from 2010 to 2014, for the variables of plant mortality, visual vigor, plant height and trunk diameter. The descriptive statistics mean, variation range, coefficient of variation and Pearson skewness coefficient were calculated. Data were submitted to analysis of variance and the means of the treatments were grouped by the Scott-Knott test, both at 5 % significance. The progenies, having the ‘Sunki’ mandarin as the female parent, presented higher fruit setting rates and lower plant mortality rates than those obtained from the female parent ‘Rangpur’ lime, while zero plant mortality was observed in the SFM × BKTO cross. The crosses SCRL × SFM, SFM × BKTO, SFM × AGC and SFM × THOM have the potential to generate vigorous hybrids, resulting in rootstock varieties adapted to the landscape unit of Coastal Tableland

    Feromônio sexual sintético do minador-dos-citros em pomares brasileiros de citros

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    The objective of this work was to determine the best conditions of use of the synthetic sex pheromone of Phyllocnistis citrella Stainton for monitoring this species in citrus groves in northeastern Brazil. Pheromone doses (0.0, 0.1, 1, 10 and 100 µg) and longevity (1, 15, 29, 43 and 57-day-old lures) and trap height (0.5, 1.5 and 2.5 m), color (green, red, and white) and model influence on P. citrella males capture were evaluated. The doses of 10 and 100 µg of the synthetic sex pheromone – a 3:1 blend of (Z,Z,E)-7,11,13-hexadecatrienal and (Z,Z)-7,11-hexadecadienal –  attracted the greatest number of P. citrella males. Traps baited with these two both dosages continued to capture P. citrella males at a comparable rate for over eight weeks in citrus groves. Although there was no significant decrease in activity of both dosages until 57 days of exposure to the environment, the higher dose, as time passed, attracted significantly more P. citrella males than the lower dose. There were no significant differences in male capture in traps with synthetic sex pheromone placed at 1.5 and 2.5 m height, wich had the better results. Trap color and model did not affect male capture.O objetivo deste trabalho foi determinar as melhores condições de uso do feromônio sexual sintético de Phyllocnistis citrella Stainton para o monitoramento dessa espécie em pomares de citros no Nordeste do Brasil. Foram avaliados: doses (0,0, 0,1, 1, 10 e 100 µg), duração (1, 15, 29, 43 e 57 dias de exposição do feromônio sexual sintético), altura de instalação (0,5, 1,5 e 2,5 m), cor (verde, vermelha e branca) e modelo de armadilha na captura de machos de P. citrella. As doses de 10 e 100 µg do feromônio sintético – proporção de 3:1 da mistura de Z,Z,E-7,11,13-hexadecatrienal e (Z,Z)-7,11-hexadecadienal – atraíram o maior número de machos de P. citrella. Armadilhas contendo a mistura feromonal nessas duas doses capturaram machos de P. citrella por mais de oito semanas em pomares de citros. Embora nenhuma das duas doses tenha sofrido decréscimo na atividade por até 57 dias de exposição ao ambiente, com o passar do tempo a maior dose atraiu significativamente mais machos de P. citrella que a menor dose. Não houve diferença significativa na captura de machos nas armadilhas com o feromônio sexual instaladas a 1,5 e 2,5 m de altura, as quais apresentaram os melhores resultados. O modelo e a cor das armadilhas não afetaram a captura dos machos

    Eugenol mitigated acute lung but not spermatic toxicity of C60 fullerene emulsion in mice

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    C60 fullerene (C60) is a nano-pollutant that can damage the respiratory system. Eugenol exhibits significant anti-inflammatory and antioxidant properties. We aimed to investigate the time course of C60 emulsion-induced pulmonary and spermatic harms, as well as the effect of eugenol on C60 emulsion toxicity. The first group of mice (protocol 1) received intratracheally C60 emulsion (1.0 mg/kg BW) or vehicle and were tested at 12, 24, 72 and 96 h (F groups) thereafter. The second group of mice (protocol 2) received intratracheally C60 emulsion or vehicle, 1 h later were gavaged with eugenol (150 mg/kg) or vehicle, and experiments were done 24 h after instillation. Lung mechanics, morphology, redox markers, cytokines and epididymal spermatozoa were analyzed. Protocol 1: Tissue damping (G) and elastance (H) were significantly higher in F24 than in others groups, except for H in F72. Morphological and inflammatory parameters were worst at 24 h and subsequently declined until 96 h, whereas redox and spermatic parameters worsened over the whole period. Eugenol eliminated the increase in G, H, cellularity, and cytokines, attenuated oxidative stress induced by C60 exposure, but had no effect on sperm. Hence, exposure to C60 emulsion deteriorated lung morphofunctional, redox and inflammatory characteristics and increased the risk of infertility. Furthermore, eugenol avoided those changes, but did not prevent sperm damage

    Sensitivity of RT-PCR method in samples shown to be positive for Zika virus by RT-qPCR in vector competence studies

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    Abstract Tissue samples from mosquitoes artificially infected with Zika virus and shown to be positive by RT-qPCR were reexamined by RT-PCR. Using these samples we compared the two methods employed in virus RNA detection for vector competence studies. Results demonstrated that, albeit useful, RT-PCR gave false negatives with low viral loads (< 106 RNA copies/ml)

    Mapping land use changes resulting from biofuel production and the effect of mitigation measures

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    Many of the sustainability concerns of bioenergy are related to direct or indirect land use change (LUC) resulting from bioenergy feedstock production. The environmental and socio-economic impacts of LUC highly depend on the site-specific biophysical and socio-economic conditions. The objective of this study is to spatiotemporally assess the potential LUC dynamics resulting from an increased biofuel demand, the related greenhouse gas (GHG) emissions, and the potential effect of LUC mitigation measures. This assessment is demonstrated for LUC dynamics in Brazil towards 2030, considering an increase in the global demand for bioethanol as well as other agricultural commodities. The potential effects of three LUC mitigation measures (increased agricultural productivity, shift to second-generation ethanol, and strict conservation policies) are evaluated by using a scenario approach. The novel modelling framework developed consists of the global Computable General Equilibrium model MAGNET, the spatiotemporal land use allocation model PLUC, and a GIS-based carbon module. The modelling simulations illustrate where LUC as a result of an increased global ethanol demand (+26x10(9)L ethanol production in Brazil) is likely to occur. When no measures are taken, sugar cane production is projected to expand mostly at the expense of agricultural land which subsequently leads to the loss of natural vegetation (natural forest and grass and shrubland) in the Cerrado and Amazon. The related losses of above and below ground biomass and soil organic carbon result in the average emission of 26gCO(2-)eq/MJbioethanol. All LUC mitigation measures show potential to reduce the loss of natural vegetation (18%-96%) as well as the LUC-related GHG emissions (7%-60%). Although there are several uncertainties regarding the exact location and magnitude of LUC and related GHG emissions, this study shows that the implementation of LUC mitigation measures could have a substantial contribution to the reduction of LUC-related emissions of bioethanol. However, an integrated approach targeting all land uses is required to obtain substantial and sustained LUC-related GHG emission reductions in general

    Educação científica na perspectiva de letramento como prática social: funções, princípios e desafios

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