5,157 research outputs found

    Nova ocorrência de vespas não-polinizadoras (Hymenoptera: Chalcidoidea) em sicônios de Ficus microcarpa no Brasil

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    Ficus microcarpa is an Asian fig tree that is ornamentally cultivated. The specific pollinator, Eupristina verticillata Waterston, and the non-pollinators Walkerella microcarpae Bouček and Philotrypesis emeryi Grandi, have been reported associated to F. microcarpa in Brazil. In here we report for the first time the occurrence of Odontofroggatia ishii Wiebes and Philotrypesis taiwanensis Chen et al in F. microcarpa in Brazil. Our results suggest that P. taiwanensis and O. ishii represent a recent influx of these wasps into Brazil. Considering that ~20 fig wasp species are associated with F. microcarpa in its native area, novel occurrences can be reported in the future in Brazil.Ficus microcarpa é uma figueira asiática cultivada com finalidades ornamentais. A espécie polinizadora específica, Eupristina verticillata Waterston, e as não-polinizadoras Walkerella microcarpae Bouček e Philotrypesis emeryi Grandi, foram relatadas associadas a F. microcarpa no Brasil. No presente estudo, relatamos pela primeira vez a ocorrência de Odontofroggatia ishii Wiebes e Philotrypesis taiwanensis Chen et al em F. microcarpa no Brasil. Nossos resultados sugerem que tais vespas foram introduzidas recentemente no país. Considerando que ~20 espécies de vespas são associadas a F. microcarpa em sua região de origem, novas ocorrências poderão ser registradas no futuro no Brasil.International Foundation for Science (IFS, Sweden)FAPES

    Role of rock fragment cover on runoff generation and sediment yield in tilled vineyards.

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    The soil in conventional Mediterranean vineyards is an active and non-sustainable source of sediment and water. Lack of vegetation cover, small soil organic matter content and intense ploughing result in large rates of erosion in a millennia-old tillage system. There is a need for soil conservation strategies that enable sustainability of wine and grape production; therefore, it is essential to measure the rates and to investigate the processes and factors of soil erosion. This study evaluated factors that can reduce soil losses in traditional Mediterranean vineyards. The investigation was carried out with 96 rainfall simulation experiments at the pedon scale (0.24m2) to measure soil detachment and runoff yield under low frequency-high magnitude rainfall events of 1 hour at 55mmhour−1. On average, runoff was 40.6% of the rainfall, and the rate of soil erosion (i.e. amount of soil lost) was 71.5 g m−2. The key factor controlling erosion was the rock fragment cover. There was a clear decrease in soil losses with increased rock fragment cover on the soil surface, but an increase in surface runoff. The results of our study showed that rock fragments at the pedon scale reduced soil erosion in Mediterranean vineyards, but when a layer of embedded rock fragments developed, large rates of runoff were triggered

    Iron-mediated stabilization of soil carbon amplifies the benefits of ecological restoration in degraded lands

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    Recent observations across a 14‐year restoration chronosequence have shown an unexpected accumulation of soil organic carbon in strip‐mined areas of central Brazil. This was attributed to the rapid plant colonization that followed the incorporation of biosolids into exposed regoliths, but the specific mechanisms involved in the stabilization of carbon inputs from the vegetation remained unclear. Using isotopic and elemental analyses, we tested the hypothesis that plant‐derived carbon accumulation was triggered by the formation of iron‐coordinated complexes, stabilized into physically protected (occluded) soil fractions. Confirming this hypothesis, we identified a fast formation of microaggregates shortly after the application of iron‐rich biosolids, which was characterized by a strong association between pyrophosphate‐extractable iron and plant‐derived organic matter. The formation of microaggregates preceded the development of macroaggregates, which drastically increased soil carbon content (~140 Mg C/ha) a few years after restoration. Consistent with previous theoretical work, iron‐coordinated organic complexes served as nuclei for aggregate formation, reflecting the synergistic effect of biological, chemical, and physical mechanisms of carbon stabilization in developing soils. Nevertheless, iron was not the only factor affecting soil carbon content. The highest carbon accumulation was observed during the period of highest plant diversity (\u3e30 species; years 3–6), declining significantly with the exclusion of native species by invasive grasses (years 9–14). Furthermore, the increasing dominance of invasive grasses was associated with a steady decline in the concentration of soil nitrogen and phosphorus per unit of accumulated carbon. These results demonstrate the importance of interdependent ecological and biogeochemical processes, and the role of soil–plant interactions in determining the success of restoration efforts. In contrast with previous but unsuccessful attempts to restore mined areas through nutrient application alone, iron‐mediated stabilization of vegetation inputs favored the regeneration of a barren stable state that had persisted for over five decades since disturbance. The effectiveness of coupled organic matter and iron “fertilization,” combined with management of invasive species, has the possibility to enhance terrestrial carbon sequestration and accelerate the restoration of degraded lands, while addressing important challenges associated with urban waste disposal

    Some interesting features of new massive gravity

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    A proof that new massive gravity - the massive 3D gravity model proposed by Bergshoeff, Hohm and Townsend (BHT) - is the only unitary system at the tree level that can be constructed by augmenting planar gravity through the curvature-squared terms, is presented. Two interesting gravitational properties of the BHT model, namely, time dilation and time delay, which have no counterpart in the usual Einstein 3D gravity, are analyzed as well.Comment: Submitted to Classical and Quantum Gravit

    Hypothalamic Inhibition Of Acetyl-coa Carboxylase Stimulates Hepatic Counter-regulatory Response Independent Of Ampk Activation In Rats.

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    Hypothalamic AMPK acts as a cell energy sensor and can modulate food intake, glucose homeostasis, and fatty acid biosynthesis. Intrahypothalamic fatty acid injection is known to suppress liver glucose production, mainly by activation of hypothalamic ATP-sensitive potassium (K(ATP)) channels. Since all models employed seem to involve malonyl-CoA biosynthesis, we hypothesized that acetyl-CoA carboxylase can modulate the counter-regulatory response independent of nutrient availability. In this study employing immunoblot, real-time PCR, ELISA, and biochemical measurements, we showed that reduction of the hypothalamic expression of acetyl-CoA carboxylase by antisense oligonucleotide after intraventricular injection increased food intake and NPY mRNA, and diminished the expression of CART, CRH, and TRH mRNA. Additionally, as in fasted rats, in antisense oligonucleotide-treated rats, serum glucagon and ketone bodies increased, while the levels of serum insulin and hepatic glycogen diminished. The reduction of hypothalamic acetyl-CoA carboxylase also increased PEPCK expression, AMPK phosphorylation, and glucose production in the liver. Interestingly, these effects were observed without modification of hypothalamic AMPK phosphorylation. Hypothalamic ACC inhibition can activate hepatic counter-regulatory response independent of hypothalamic AMPK activation.8e6266

    Instituto Compartilhado: uma parceria IFRN e uma escola estadual para manutenção do projeto de inclusão digital Um Computador por Aluno (UCA)

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    O presente trabalho encontra-se sendo realizado como projeto deextensão de uma escola pública federal e tem como o objetivo principal darcontinuidade ao programa governamental Um Computador por Aluno (UCA),fazendo uma atualização e manutenção do mesmo numa escola estadual nomunicípio de Parnamirim/RN onde estão localizadas. Funcionando nasescolas públicas desde 2010, passou-se a existir necessidade de atualizar ossoftwares, treinar os usuários e realizar a manutenção das máquinas para queo uso seja satisfatório e que o programa possa trazer ainda mais benefícios.Nessa perspectiva, este trabalho visa a melhoria e a continuidade doprograma UCA

    Chemical characterisation, antioxidant and antibacterial activities of Pinus pinaster Ait. and Pinus pinea L. bark polar extracts: prospecting Forestry by-products as renewable sources of bioactive compounds

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    Agroforestry by-products have gained rising attention in recent years as they represent inexpensive and abundant raw materials that are a source of added-value chemicals, e.g., for food and pharmaceutical applications, as well as for bioenergy generation. Pinus pinaster Ait. bark extracts are consumed worldwide for their cardiovascular benefits, whilst the health potential of Pinus pinea L. bark has not yet been deeply exploited. Therefore, this study highlights the chemical characterisation of Portuguese P. pinaster Ait. and P. pinea L. bark polar extracts, via ultra-high performance liquid chromatography-diode array detection-tandem mass spectrometry (UHPLC-DAD-MSn) analysis, and their antioxidant and antibacterial activities. Quinic acid, an A-type procyanidin dimer isomer, protocatechuic acid, and quercetin were identified for the first time as P. pinea L. bark components. Moreover, this bark demonstrated a higher total content of identified polar compounds than P. pinaster Ait. bark, with quinic acid being the most abundant compound identified. Regarding antioxidant activity, the pine bark polar extracts exhibited strong reducing power and 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis-(3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) radical scavenging effects compared to natural antioxidants. Moreover, the bactericidal actions of pine bark extracts were shown against Staphylococcus aureus and Escherichia coli at a 3.13–25 mg mL−1 range. Globally, these promising insights can boost the sustainable exploitation of P. pinea L. bark, as already occurs with P. pinaster Ait. bark, for the food and biomedical fields.publishe

    Structure, computational and biochemical analysis of PcCel45A endoglucanase from <i>Phanerochaete chrysosporium </i>and catalytic mechanisms of GH45 subfamily C members

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    Abstract The glycoside hydrolase family 45 (GH45) of carbohydrate modifying enzymes is mostly comprised of β-1,4-endoglucanases. Significant diversity between the GH45 members has prompted the division of this family into three subfamilies: A, B and C, which may differ in terms of the mechanism, general architecture, substrate binding and cleavage. Here, we use a combination of X-ray crystallography, bioinformatics, enzymatic assays, molecular dynamics simulations and site-directed mutagenesis experiments to characterize the structure, substrate binding and enzymatic specificity of the GH45 subfamily C endoglucanase from Phanerochaete chrysosporium (PcCel45A). We investigated the role played by different residues in the binding of the enzyme to cellulose oligomers of different lengths and examined the structural characteristics and dynamics of PcCel45A that make subfamily C so dissimilar to other members of the GH45 family. Due to the structural similarity shared between PcCel45A and domain I of expansins, comparative analysis of their substrate binding was also carried out. Our bioinformatics sequence analyses revealed that the hydrolysis mechanisms in GH45 subfamily C is not restricted to use of the imidic asparagine as a general base in the “Newton’s cradle” catalytic mechanism recently proposed for this subfamily
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