This report describes an application of a digital computer to the aerodynamic design and automatic control of a large wind tunnel with flexible walls. The computational problem was threefold : first, calculation of the wall shapes for a set of 'pivotal' operating speeds between M = 1 and 2"8; second, computation of the necessary movements of the set of screw jacks which flex the walls ; and fin...

This study evaluates the role of shock wave motion on the instability of the plume exiting an over-expanded, convergent-divergent nozzle. An array of wall pressure transducers was used to track the position of the shock in time, and a Pitot probe was used to obtain simultaneous measurement of the total pressure fluctuations at various points in the jet that emerges from the separation shock. An...

Steady-state components of heat conduction solutions may have very slowly convergent series for temperatures and non-convergent heat fluxes for temperature boundary conditions. Previous papers have proposed methods to remove these convergence problems. However, even more effective procedures based on insights of Morse and Feshbach are given herein. In some cases it is possible to replace poorly...

During Xenopus development, convergent extension movements mediated by cell intercalation drive axial elongation. While many genes required for convergent extension have been identified, little is known of regulation of the cytoskeleton during these cell movements. Although microtubules are required for convergent extension, this applies only to initial stages of gastrulation, between stages 10...

Convergent extension, the simultaneous narrowing and lengthening of a tissue, plays a major role in shaping and patterning the neural ectoderm in vertebrate embryos. In this paper, we characterize the cellular mechanism underlying convergent extension of the neural ectoderm in the Xenopus laevis late gastrula and neurula embryo. Neural ectoderm in X. laevis consists of two components, a superfi...

An in-house Pressure Sensitive Paint (PSP) formulation has been developed at the Aero-Physics Laboratory at the University of Manchester. The PSP uses Bathophenanthroline Ruthenium as the luminophore molecule and is incorporated in a sol-gel matrix. Excitation occurs at 400-500 nm and emission at 550-650 nm. The Stern-Volmer plot of the PSP reveals small temperature dependence, which has always...

Germline mutation in mice of the retinoic acid receptor gene RXRalpha results in a proliferative failure of cardiomyocytes, which leads to an underdeveloped ventricular chamber and midgestation lethality. Mutation of the cell cycle regulator N-myc gene also leads to an apparently identical phenotype. In this study, we demonstrate by chimera analysis that the cardiomyocyte phenotype in RXRalpha-...

Magnetization structures in magnetic materials are usually imaged dedicated Lorentz transmission electron microscopes. Compared to conventional microscopes, the field of objective lens at sample is removed by replacing with a below sample. While this modification critical for soft-magnetic whose state affected strong lens, we propose that not necessary permanent magnets such as Sm–Co and Nd–Fe–...

Convergent extension is the primary driving force elongating the anteroposterior body axis. In Xenopus, convergent extension occurs in the dorsal mesoderm and posterior neural ectoderm, and is mediated by similar molecular pathways within these tissues. In this paper, we show that activation of NF-AT, a transcription factor known to modulate multiple signaling events, inhibits convergent extens...

Convergent extension, the simultaneous extension and narrowing of tissues, is a crucial event in the formation of the main body axis during embryonic development. It involves processes on multiple scales: the sub-cellular, cellular and tissue level, which interact via explicit or intrinsic feedback mechanisms. Computational modelling studies play an important role in unravelling the multiscale ...