3,955 research outputs found
Comparing the impacts of 2003 and 2010 heatwaves in NPP over Europe
In the last decade, Europe was stricken by two outstanding heatwaves, the 2003 event in Western Europe and the recent 2010 episode over Russia. Both extreme events were characterised by record-breaking temperatures, and widespread socio-economic impacts, including significant increments on mortality rates, decreases in crop production and in hydroelectric production. This work aims to assess the influence of both mega-heatwaves on vegetation carbon uptake, using yearly Net Primary Production (NPP) and monthly Net Photosynthesis (PsN) data derived from satellite imagery obtained from MODIS for the period 2000–2011. <br><br> In 2010, markedly low productivity was observed over a very large area in Russia, at monthly, seasonal and yearly scales, falling below 50% of average NPP. This decrease in NPP in 2010 was far more intense than the one affecting Western Europe in 2003, which corresponded to 20–30% of the average, and affected a~much larger extent. Total NPP anomalies reached −19 Tg C for the selected regions in France during 2003 and −94 Tg C for western Russia in 2010, which corresponds almost to the magnitude of total NPP anomaly during 2010 for the whole Europe. <br><br> Overall, the widespread negative PsN anomalies in both regions match the patterns of very high temperature values preceded by a long period of below-average precipitation, leading to strong soil moisture deficits, stressing the role of soil-atmosphere coupling. In the case of 2003 heatwave, results indicate a strong influence of moisture deficits coupled with high temperatures in the response of vegetation, while for the 2010 event very high temperatures appear to be the main driver of very low NPP
A Review of Noncommutative Field Theories
We present a brief review of selected topics in noncommutative field theories
ranging from its revival in string theory, its influence on quantum field
theories, its possible experimental signatures and ending with some
applications in gravity and emergent gravity.Comment: Talk presented at the XIV Mexican School on Particles and Fields,
Morelia, Mexico, November 9-11, 2010; 8 pages. V2 reference adde
Diodos emissores de luz (LEDs) e concentrações de BAP na multiplicação de bananeira cv. Grande Naine.
Non-Commutative Correction to Thin Shell Collapse in Reissner Nordstrm Geometry
This paper investigates the polytropic matter shell collapse in the
non-commutative Reissner-Nordstrm geometry. Using the Israel
criteria, equation of motion for the polytropic matter shell is derived. In
order to explore the physical aspects of this equation, the most general
equation of state, , has been used for finite
and infinite values of . The effective potentials corresponding to the
equation of motion have been used to explain different states of the matter
shell collapse. The numerical solution of the equation of motion predicts
collapse as well as expansion depending on the choice of initial data. Further,
in order to include the non-commutative correction, we modify the matter
components and re-formulate the equation of motion as well as the corresponding
effective potentials by including non-commutative factor and charge parameter.
It is concluded that charge reduces the velocity of the expanding or collapsing
matter shell but does not bring the shell to static position. While the
non-commutative factor with generic matter favors the formation of black hole.Comment: 18 pages,17 figure
Supporting emergence or reference drought tolerance phenotyping centers - drought phenotyping network.
The project developed and made useful phenotypic evaluation protocols for cereals (maize, sorghum, rice, and wheat) and legume crops (common bean and cowpea), and established phenotyping site specific experimental (SSE) areas of excellence (2) and reference (5) for drought tolerance (DT) studies according to specific climatic condition, soil physical and chemical properties, with laboratories, controlled environment target fields and greenhouses, training unit for researchers and assistants, with facilities and well defined dry season periods to assure total irrigation and soil moisture control during the drought phenotyping field trials. Overall, the project established a scientific and service network for drought tolerance phenotyping in Brazil
Sequence-based prediction for vaccine strain selection and identification of antigenic variability in foot-and-mouth disease virus
Identifying when past exposure to an infectious disease will protect against newly emerging strains is central to understanding the spread and the severity of epidemics, but the prediction of viral cross-protection remains an important unsolved problem. For foot-and-mouth disease virus (FMDV) research in particular, improved methods for predicting this cross-protection are critical for predicting the severity of outbreaks within endemic settings where multiple serotypes and subtypes commonly co-circulate, as well as for deciding whether appropriate vaccine(s) exist and how much they could mitigate the effects of any outbreak. To identify antigenic relationships and their predictors, we used linear mixed effects models to account for variation in pairwise cross-neutralization titres using only viral sequences and structural data. We identified those substitutions in surface-exposed structural proteins that are correlates of loss of cross-reactivity. These allowed prediction of both the best vaccine match for any single virus and the breadth of coverage of new vaccine candidates from their capsid sequences as effectively as or better than serology. Sub-sequences chosen by the model-building process all contained sites that are known epitopes on other serotypes. Furthermore, for the SAT1 serotype, for which epitopes have never previously been identified, we provide strong evidence - by controlling for phylogenetic structure - for the presence of three epitopes across a panel of viruses and quantify the relative significance of some individual residues in determining cross-neutralization. Identifying and quantifying the importance of sites that predict viral strain cross-reactivity not just for single viruses but across entire serotypes can help in the design of vaccines with better targeting and broader coverage. These techniques can be generalized to any infectious agents where cross-reactivity assays have been carried out. As the parameterization uses pre-existing datasets, this approach quickly and cheaply increases both our understanding of antigenic relationships and our power to control disease
The Mechanical Behavior of a 25Cr Super Duplex Stainless Steel at Elevated Temperature
Peer reviewedPostprin
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