Separation delay via hydro-acoustic control of a NACA4412 airfoil in pre-stalled conditions

We have performed large-eddy simulations of turbulent separation control via impedance boundary conditions (IBCs) on a \nacafft airfoil in near-stalled conditions. The uncontrolled baseline flow is obtained for freestream Mach numbers of $M_\infty=0.3$, chord-Reynolds numbers $Re_c = 1.5\times10^6$ and angle of attack, $\alpha=14^{\circ{}}$. Flow control is applied via imposition of complex IBCs using the time-domain implementation developed by Scalo, Bodart, and Lele, \emph{Phys. Fluids} (2015). Separation is delayed due to the enhanced mixing associated with convectively amplified spanwise-oriented Kelvin-Helmholtz (KH) rollers, generated via hydro-acoustic instabilities. The latter are the result of the interaction of the wall-normal transpiration through the impedance panel and the overlying mean background shear. The result is an alteration of the coupled instability between the separating shear layer and the vortex shedding in the wake (already present in the uncontrolled baseline flow) yielding unique wake topologies associated with different intensities for the passively generated KH vortical structures. Specifically, enhancements up to +13\% in the lift coefficients have been obtained. Results show that tuning of the resonant cavities below the natural shedding frequency is required to generate KH rollers structures with a sufficiently large entrainment diameter to encompass the full extent of the separated region, thereby enhancing mixing and promoting reattachment. Overall, the results presented in this work show that the adoption of hydro-acoustically tuned resonant panels is a promising passive control technique for boundary layer separation control

Tyrosine kinase signalling in breast cancer: Epidermal growth factor receptor and c-Src interactions in breast cancer

Both the non-receptor tyrosine kinase, c-Src, and members of the epidermal growth factor (EGF) receptor family are overexpressed in high percentages of human breast cancers. Because these molecules are plasma membrane-associated and involved in mitogenesis, it has been speculated that they function in concert with one another to promote breast cancer development and progression. Evidence to date supports a model wherein c-Src potentiates the survival, proliferation and tumorigenesis of EGF receptor family members, in part by associating with them. Phosphorylation of the EGF receptor by c-SRC is also critical for mitogenic signaling initiated by the EGF receptor itself, as well as by several G-protein coupled receptors (GPCRs), a cytokine receptor, and the estrogen receptor. Thus, c-Src appears to have pleiotropic effects on cancer cells by modulating the action of multiple growth-promoting receptors

Virtual Learning and Assessment in Rheumatology Fellowship Training: OSCE Revisited

OBJECTIVE: With the onset of the COVID-19 pandemic, an annual multi-institutional face-to-face Rheumatology Objective Structured Clinical Examination (ROSCE) was transformed into a virtual format. The educational goals of the virtual ROSCE (vROSCE) were to reproduce the educational value of the previous in-person ROSCE, providing a valuable formative assessment of rheumatology training activities encompassing the six Accreditation Council for Graduate Medical Education (ACGME) Core Competencies for fellows-in-training (FITs). This report describes the novel design, feasibility, and stakeholder value of a vROSCE. METHODS: Through an established collaboration of five rheumatology fellowship training programs, in February 2021, a vROSCE was created and conducted using a Zoom® platform. Station development included learning objectives, FIT instructions, faculty proctor instructions, and a checklist by which to provide structured formative feedback. An anonymous, optional web-based survey was sent to FIT participants to evaluate the experience. RESULTS: Twenty-three rheumatology FITs from 5 institutions successfully rotated through six stations in the vROSCE. Immediate feedback was given to each FIT using standardized rubrics structured around ACGME Core Competencies. Sixty-five percent (15/23) of FITs responded to the survey. Ninety-three percent of survey respondents agreed or strongly agreed that the vROSCE was a helpful educational activity and identified individualized opportunities for improvement. CONCLUSIONS: A vROSCE is an innovative, feasible, valuable, and well-received educational technology tool. The vROSCE enriched Rheumatology FITs\u27 education and offered collaborative learning experiences across institutions. This article is protected by copyright. All rights reserved