In this study direct numerical simulations are employed to investigate the effects of various parameters on laminar-flow-control capabilities narrowly spaced streaks in a supersonic boundary layer at Mach $2.0$ . Previous work by Sharma et al. ( J. Fluid Mech. , vol. 873, 2019, pp. 1072–1089) has found these streak modes, excited spanwise blowing-and-suction strip, be highly effective delaying ...

Treatment of C57Bl/6J mice with three successive doses of all-trans retinoic acid (28 mg kg-1 body weight) on 8 day, 6 h (8d,6h), 8d,12h, and 8d,18h of gestation resulted in a high incidence (79%, 31/39 fetuses) of spina bifida with myeloschisis (spina bifida aperta) in near term fetuses. Twelve hours following the last maternal dose (9d,6h), the caudal aspects of treated embryos, were abnormal...

Notch signalling is an important evolutionary conserved mechanism known to control cell fate choices through local interactions. Here, the patterns of expression of Notch-1 and -2 genes and their ligands Delta-1, Serrate-1 and -2, were established in the early blastodisc of the chicken embryo from the pre-streak to the first somite stages. Delta-1 was detected as early as the pre-streak stage i...

The location of the pre-hepatic cells which can respond to the inductive influence of the cardiac mesoderm and differentiate to the hepatic epithelium was investigated in quail embryos between the unincubated and 8-somite stages. These cells were found to exist in the whole area of the blastoderm of unincubated and prestreak stages. At the short-streak stage, just before the beginning of gastru...

The composition and synthesis of lipid have been examined in normal intima and adjacent fatty streak lesions of human arterial segments which were incubated with [2-(14)C]acetate. The incorporation of acetate into lipid was greater in fatty streaks than in normal intima. There was increased acetate incorporation into all major lipid groups in the fatty streak, with the greatest relative increas...

Three types of experiments were performed to determine the interaction between the epiblast and hypoblast for primitive streak formation: (1) Hypoblasts of blastoderms from stages XIII E.G & K to 3 H & H were separated from the epiblasts and rotated by 90 degrees counterclockwise; (2) hypoblasts from stages XIII E.G & K to 3 H & H blastoderms were rotated by 180 degrees; (3) hypoblasts were exc...

The Drosophila sprouty protein is a recently-identified intracellular modulator of FGF and EGF receptor tyrosine kinase activity which antagonises ras/MAP kinase signalling. In a differential display analysis to identify genes involved in patterning the mid/hindbrain region of the chick neural tube, we have identified a sprouty orthologue, sprouty2. Here we report expression of sprouty2 transcr...

The localized developmental expression of murine platelet-derived growth factor A (PDGF-A) was compared to that of its receptor (Pdgfra). Our in situ hybridization study included germ layers of primitive streak embryos, early axial structures (dermatome, myotome, sclerotome, floor plate), the skin and some of its derivatives (hair and mammary gland), the developing forelimb, the branchial arche...

Neuromesodermal progenitors (NMps) contribute to both the elongating spinal cord and the adjacent paraxial mesoderm. It has been assumed that these cells arise as a result of patterning of the anterior neural plate. However, as the molecular mechanisms that specify NMps in vivo are uncovered, and as protocols for generating these bipotent cells from mouse and human pluripotent stem cells in vit...

The operating characteristics of a linear-geometry (open electron drift) Hall thruster are revisited under improved vacuum conditions, in order to eliminate possible channel wall contamination from oil diffusion-pump vapors. A comparison is made between cases in which the thruster is operated with channel walls fabricated from plate diamond, and from boron nitride. These studies reveal a new op...