Scanning Electron Microscope Study of Brachysclereids of Pear (Pyrus communis L.)

The external surfaces of pear sclereids commonly are illustrated as covered with apertures. This SEAA investigation of the surface features has shown the surface to have few or no apertures. When the primary wall layer was removed the typical ramiform canal system was obvious. This observation confirms the often-ignored fact that the pitapertures of the secondary wall are not continuous with the primary wall. Hence, they do not show on the surfaces of the intact cell

Complex Langevin Simulations of QCD at Finite Density -- Progress Report

We simulate lattice QCD at finite quark-number chemical potential to study nuclear matter, using the complex Langevin equation (CLE). The CLE is used because the fermion determinant is complex so that standard methods relying on importance sampling fail. Adaptive methods and gauge-cooling are used to prevent runaway solutions. Even then, the CLE is not guaranteed to give correct results. We are therefore performing extensive testing to determine under what, if any, conditions we can achieve reliable results. Our earlier simulations at $\beta=6/g^2=5.6$, $m=0.025$ on a $12^4$ lattice reproduced the expected phase structure but failed in the details. Our current simulations at $\beta=5.7$ on a $16^4$ lattice fail in similar ways while showing some improvement. We are therefore moving to even weaker couplings to see if the CLE might produce the correct results in the continuum (weak-coupling) limit, or, if it still fails, whether it might reproduce the results of the phase-quenched theory. We also discuss action (and other dynamics) modifications which might improve the performance of the CLE.Comment: Talk presented at Lattice 2017, Granada, Spain and submitted to proceedings. 8 pages, 4 figure