Ug99
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Ug99 is a lineage of wheat stem rust, which is present in wheat fields in several countries in Africa and the Middle East and is predicted to spread rapidly through these regions and possibly further
Stem rust close up
Lagrangian coherent structures are distinguished surfaces of trajectories in a dynamical system that exert a major influence on nearby trajectories over a time interval of interest. The type of this i
Ug99
…ocean and air currents. This is especially important for inter-continental, intermittent spread, such as from Eastern South Africa to Western Australia. Lagrangian coherent structures can be used to predict spore movement as they are believed to play a significant role in spore movement. Although Ug99 had not reached China in 2020…
Figure 1: An invariant manifold in the extended phase space, formed by an evolving material surface.
Figure 2a: Hyperbolic LCS (attracting in red and repelling in blue) and elliptic LCS (boundaries of green regions) in a two-dimensional turbulence simulation. (Image: Mohammad Farazmand)
Figure 3: Instantaneous streamlines and the evolution of trajectories starting from the interior of one of them in a linear solution of the Navier–Stokes equation. This dynamical system is classified as elliptic by a number of frame-dependent coherence diagnostics, such as the Okubo–Weiss criterion. (Image: Francisco Beron-Vera)
Figure 4. Attracting and repelling LCSs in the extended phase space of a two-dimensional dynamical system.