Computational model predictions of level dependent changes in vowel identification with addition of rate-place cue

Author(s):  
Pranav Misra ◽  
Ananthakrishna Chintanpalli
2014 ◽  
Vol 15 (5) ◽  
pp. 823-837 ◽  
Author(s):  
Ananthakrishna Chintanpalli ◽  
Jayne B. Ahlstrom ◽  
Judy R. Dubno

2021 ◽  
Author(s):  
Keith R Carney ◽  
Akib M Khan ◽  
Shiela C Samson ◽  
Nikhil Mittal ◽  
Sangyoon J Han ◽  
...  

Cell migration is essential to physiological and pathological biology. Migration is driven by the motion of a leading edge, in which actin polymerization pushes against the edge and adhesions transmit traction to the substrate while membrane tension increases. How the actin and adhesions synergistically control edge protrusion remains elusive. We addressed this question by developing a computational model in which the Brownian ratchet mechanism governs actin filament polymerization against the membrane and the molecular clutch mechanism governs adhesion to the substrate (BR-MC model). Our model predicted that actin polymerization is the most significant driver of protrusion, as actin had a greater effect on protrusion than adhesion assembly. Increasing the lifetime of nascent adhesions also enhanced velocity, but decreased the protrusion's motional persistence, because filaments maintained against the cell edge ceased polymerizing as membrane tension increased. We confirmed the model predictions with measurement of adhesion lifetime and edge motion in migrating cells. Adhesions with longer lifetime were associated with faster protrusion velocity and shorter persistence. Experimentally increasing adhesion lifetime increased velocity but decreased persistence. We propose a mechanism for actin polymerization-driven, adhesion-dependent protrusion in which balanced nascent adhesion assembly and lifetime generates protrusions with the power and persistence to drive migration.


Author(s):  
Pras Pathmanathan ◽  
Richard A. Gray ◽  
Vicente J. Romero ◽  
Tina M. Morrison

Computational modeling has the potential to revolutionize medicine the way it transformed engineering. However, despite decades of work, there has only been limited progress to successfully translate modeling research to patient care. One major difficulty which often occurs with biomedical computational models is an inability to perform validation in a setting that closely resembles how the model will be used. For example, for a biomedical model that makes in vivo clinically relevant predictions, direct validation of predictions may be impossible for ethical, technological, or financial reasons. Unavoidable limitations inherent to the validation process lead to challenges in evaluating the credibility of biomedical model predictions. Therefore, when evaluating biomedical models, it is critical to rigorously assess applicability, that is, the relevance of the computational model, and its validation evidence to the proposed context of use (COU). However, there are no well-established methods for assessing applicability. Here, we present a novel framework for performing applicability analysis and demonstrate its use with a medical device computational model. The framework provides a systematic, step-by-step method for breaking down the broad question of applicability into a series of focused questions, which may be addressed using supporting evidence and subject matter expertise. The framework can be used for model justification, model assessment, and validation planning. While motivated by biomedical models, it is relevant to a broad range of disciplines and underlying physics. The proposed applicability framework could help overcome some of the barriers inherent to validation of, and aid clinical implementation of, biomedical models.


Author(s):  
O. E. Ruiz

Numerical simulations of the thermal inkjet (TIJ) droplet ejection process are performed. The computational approach is based on a volume of fluid (VOF) formulation. This method allows determining the coupled flow and thermal fields in the firing chamber in addition to the phase change processes that take place during the drive bubble formation, expansion, and collapse. The drive bubble pressure is a result of the phase change heat transfer during the heating pulse and is not imposed by a pressure heuristic approach. A commercially available TIJ architecture was chosen as a baseline to assess the computational model predictions of ejected droplet volume and droplet velocity during a firing cycle. These computational model predictions were compared to experimental results demonstrating an excellent agreement. The transient histories of pressure in the vapor bubble, temperature, and heat transfer rate to the fluid are analyzed to explain some of the relevant physical processes observed.


2005 ◽  
Vol 175 (2) ◽  
pp. 985-995 ◽  
Author(s):  
Fei Hua ◽  
Melanie G. Cornejo ◽  
Michael H. Cardone ◽  
Cynthia L. Stokes ◽  
Douglas A. Lauffenburger

2015 ◽  
Vol 16 (1) ◽  
Author(s):  
Robert J Flassig ◽  
Iryna Migal ◽  
Esther van der Zalm ◽  
Liisa Rihko-Struckmann ◽  
Kai Sundmacher

Sign in / Sign up

Export Citation Format

Share Document