Importância da origem do material de propagação na qualidade da muda de videira.

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Doenças de uva.

São conhecidas na videira (Vitis spp.) dezenas de doenças consideradas de origem viral. A videira, por ser propagada vegetativamente, facilita a disseminação destes patógenos e favorece o aparecimento de doenças complexas, pelo acúmulo de diferentes vírus numa mesma planta

The Evolution of Anodic Hydrogen on High Purity Magnesium in Acidic Buffer Solution

Hydrogen evolution (HE) on anodically polarized Mg, commonly referred to as Negative Difference Effect, was studied by galvanodynamic measurements coupled with real-time gravimetric H2 volume collection, the Scanning Vibrating Electrode Technique and potentiodynamic polarization experiments. High purity Mg (99.96% Mg) electrodes were studied in chloride-free 0.1 M citric acid solution buffered at pH with the aim of determining the source of anodic HE and the role of the corrosion film on the process. In such conditions of pH, the typical dark corrosion product exhibited in neutral and alkaline solutions was not found but the HE rate still increased with increasing potential. Evidence that HE on dissolving high purity Mg is associated with the regions dominated by the anodic dissolution reaction is provided. The role of noble impurity enrichment on the electrode surface during anodic polarization and the effect of Fe re-deposition are also discussed

Elasto-mammography: Theory, Algorithm, and Phantom Study

A new imaging modality framework, called elasto-mammography, is proposed to generate the elastograms of breast tissues based on conventional X-ray mammography. The displacement information is extracted from mammography projections before and after breast compression. Incorporating the displacement measurement, an elastography reconstruction algorithm is specifically developed to estimate the elastic moduli of heterogeneous breast tissues. Case studies with numerical breast phantoms are conducted to demonstrate the capability of the proposed elasto-mammography. Effects of noise with measurement, geometric mismatch, and elastic contrast ratio are evaluated in the numerical simulations. It is shown that the proposed methodology is stable and robust for characterization of the elastic moduli of breast tissues from the projective displacement measurement

Natal and Breeding Dispersal of Bobolinks (Dolichonyx Oryzivorus) And Savannah Sparrows (Passerculus Sandwichensis) In An Agricultural Landscape

Dispersal is a key process in the metapopulation dynamics and genetic structure of spatially segregated populations. However, our knowledge of avian dispersal, particularly in migratory passerines, remains limited. We studied dispersal of Bobolinks (Dolichonyx oryzivorus) and Savannah Sparrows (Passerculus sandwichensis) to determine whether agricultural management practices affected dispersal patterns and habitat selection. From 2002 to 2006, we banded adults and nestlings on six focal hay fields and two pastures in the Champlain Valley of Vermont and New York and searched for banded birds within 1.5 km of Vermont field sites during two years. Natal dispersal distances were greater than breeding dispersal in both species, and breeding dispersal distances of Bobolinks were greater than those of Savannah Sparrows. Site fidelity was high in both species, with \u3e80% of detected adults and ~30% of detected natal dispersers returning to the same field in subsequent years. During natal dispersal, movement was random with respect to habitat quality. Adult Bobolinks dispersed to fields with annual reproductive rates greater than or equal to those of their original field; by contrast, adult Savannah Sparrows were more likely to move to or remain in low-quality habitats. During breeding dispersal, strong site fidelity took precedence over the effect of the previous year’s nest success on the probability of dispersal, particularly for Savannah Sparrows. Site fidelity has implications for management of agricultural fields because consistency of cropping patterns and cutting dates are important for maintaining populations of these species

Winter Herbage Mass Accumulation and Animals Grazing Days of Set Stocking or Cell Grazing Dairy x Beef Systems in Southwest England

Cell grazing (CG) has shown to increase the production per hectare by allowing higher stocking rates, greater grass production and higher herbage utilisation throughout the grazing season compared to set stocking (SS). Our objective was to compare the herbage growth rate during winter resting (WHGR, October/November to April) and the animals grazing days per ha (AGD-ha) of CG and SS systems grazed by dairy x beef steers. Three 1.75ha (1.5ha in 2018) plots and three 1.0ha were used for the SS and CG, respectively. Forty-two and 48 autumn born dairy x beef steer calves were split into six equal groups and randomly allocated to treatments in April 2018 and April 2020, respectively. In the second grazing seasons (2019 and 2021), the number of animals was reduced to keep stocking rates comparative to the prior year, and steers remained in the plots until finishing (October/November). Herbage mass (HM) was recorded weekly with a rising plate meter. The WHGR was estimated by subtracting the HM recorded at the end of the previous grazing season to the HM recorded at the beginning of the following season and divided by the number of days between readings. The AGD-ha was calculated by summing the days each animal grazed each area and divided by the size of the study enclosure. In three of the four years, the CG had fewer days of winter resting (157-175) than the SS (157-182), whereas the WHGR was greater in three of the four winters (average across years: 5.77 vs. 4.05 kg DM/ha per d, for CG and SS respectively). Despite the shorter winter rest, overall, the CG accumulated 37% more HM (average across years: 976 vs. 710 kg DM/ha) and had 78% more AGD-ha (1102 vs. 620 animal.d/ha) than SS. These differences do not seem to be driven by the herbage residual at the end of the grazing season but by the change in botanical composition across time