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8 projects in result set.
Statistical analysis of conformational ensembles
- This project provides computational tools and methods to analyze conformational ensembles of biomolecules, as well as their assemblies, such as those obtained from molecular simulations.
(A) PROTEINS: The molecular understanding of the functional regulation of proteins requires assessment of various states, including active and inactive states, as well as their interdependencies. For several proteins, their various states can be distinguished from each other on the basis of their minimum energy 3D structures. For many other proteins, like GPCRs, PDZ domains, nuclear transcription factors, heat shock proteins, T-cell receptors and viral attachment proteins, their states can be distinguished categorically from each other only when their finite-temperature conformational ensembles are considered alongside their minimum-energy structures. We are developing tools/methods for:
(A1) Direct comparison of conformational ensembles - The traditional approach to compare two or more conformational ensembles is to compare their respective summary statistics. This approach is, however, prone to artifactual bias, as data is compared after dimensionality reduction. The proper way to compare ensembles is to compare them directly with each other and prior to any dimensionality reduction. g_ensemble_comp is a tool we have developed that does just that and reports the difference between ensembles in terms of a true metric defined by the zeroth law of thermodynamics.
(A2) Prediction of allosteric signaling networks - method under development.
(B) LIPID MEMBRANES: The surface area of a lipid bilayer is related fundamentally to many other observables, such as thermal phase transitions and domain formation in mixed lipid bilayers. We have developed g_tessellate_area to compute the 3D surface area of a bilayer using Delunay tessellation. | |
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Activity Percentile: 94.66 Registered: 2015-09-15 17:52 |
Integrated Flux Balance Analysis Model of Escherichia coli
- This project includes several MATLAB scripts that simulate E. coli central metabolism and the effects of single gene deletions on metabolism using 3 approaches -- iFBA, rFBA, and ODE. The project also includes several MATLAB scripts that simulate biochemical networks using 1) integrated flux balance analysis (iFBA) -- a combined FBA, boolean regulatory, and ODE approach; 2) regulatory flux balance analysis (rFBA); and 3) ordinary differential equations (ODE). Additionally, the project includes several MATLAB and php scripts for visualizing metabolic simulations. | |
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Registered: 2008-06-11 23:27 |
C++ and Python code, distributed computing and OpenMM interfaces for simulations
- please cite: "Interplay of Protein and DNA Structure Revealed in Simulations of the lac Operon" (PLOS One 2013)
for any code related to protein-DNA modeling and
"Free Energy Monte Carlo Simulations on a Distributed Network" (Lecture Notes in Computer Science Journal for PARA 2010)
http://link.springer.com/chapter/10.1007%2F978-3-642-28145-7_1
for parallel client-server code, users of additional code should cite this web site. Code is provided as-is with no warranty and examples are provided to illustrate the usage of these modeling techniques with some sample systems. Code is the intellectual property of Luke Czapla, developer and biophysicist. Examples are provided in C/C++ and Python. | |
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Activity Percentile: 0.00 Registered: 2014-02-01 22:32 |
Dynamic Redox Regulation of IL-4 Signaling
- Incomplete reduction of oxygen during respiration results in the formation of highly reactive molecules known as reactive oxygen species (ROS) that react indiscriminately with cellular components and adversely affect cellular function. For a long time ROS were thought solely to be undesirable byproducts of respiration. Indeed, high levels of ROS are associated with a number of diseases. Despite these facts, antioxidants, agents that neutralize ROS, have not shown any clinical benefits when used as oral supplements. This paradox is partially explained by discoveries over the last two decades demonstrating that ROS are not always detrimental and may be essential for controlling physiological processes like cell signaling. However, the mechanisms by which ROS react with biomolecules are not well understood. In this work we combined biological experiments with novel computational methods to identify the most important mechanisms of ROS-mediated regulation in the IL-4 signaling pathway of the immune system. We developed a detailed computer model of the IL-4 pathway and its regulation by ROS dependent and independent methods. Our work enhances the understanding of principles underlying regulation of cell signaling by ROS and has potential implications in advancing therapeutic methods targeting ROS and their adverse effects. | |
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Activity Percentile: 0.00 Registered: 2015-10-16 21:42 |
FEBio: Finite Elements for Biomechanics
- FEBio is a nonlinear finite element solver that is specifically designed for biomechanical applications. It offers modeling scenarios, constitutive models, and boundary conditions that are relevant to many research areas in biomechanics and biophysics. All features can be used together seamlessly, giving the user a powerful tool for solving 3D problems in computational biomechanics. The software is open-source, and pre-compiled executables for Windows, Mac OS X and Linux platforms are available.
Current modeling capabilities include:
* Large deformation quasi-static and dynamic structural mechanics analysis.
* Modeling of complex structures that contain a combination of deformable and rigid parts.
* Multiphasic modeling, where the solvent can contain any number of solutes that may undergo chemical reactions.
* Fluid mechanics analysis, both steady-state and transient
* Fluid-solid interaction (FSI), which combines the powerful solid and fluid solvers.
FEBio also supports a plugin framework that can be used to easily develop new features for FEBio, including new constitutive models, boundary conditions, and even entire new physics solvers.
For more information check out the FEBio website at http://www.febio.org | |
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Registered: 2007-09-14 16:08 |
In Silico Liver (ISL) - Multi-level, multi-attribute model mechanisms
- The ISL project consists of a body of Java code used and reused for exploring hypothetical liver mechanisms. The codebase is designed to allow for multiple distinct use cases and experimental designs, some of which we've published already. The scale/resolution of focus changes depending on the use case/experiment being considered. Typically, the hypothetical mechanism is finer grained than the falsifcation/validation data available. Much of the published work focuses on intracellular mechanisms, which requires the cellular and tissue contexts to be defined according to the literature. | |
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Registered: 2014-03-17 18:37 |
Acetaminophen Induced Liver Injury
- The AILI project is a type of In-Silico Liver (ISL) project, which consists of a body of Java code used and reused for exploring hypothetical liver mechanisms. For AILI, the liver mechanisms are those that cause cellular damage, specifically necrosis, because of exposure to acetaminophen. Moreover, the model, a mouse analog, is used for virtual experimentation to explore and explain AILI phenomena, analogous to wet-lab experimentation. A recent addition to this project is studying the disconnect between in vitro and in vivo wet-lab experiments by comparing and contrasting virtual Mouse and Culture Analogs. | |
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Activity Percentile: 0.00 Registered: 2015-05-07 23:25 |
Proteolytic and non-proteolytic regulation of collective cell invasion
- Cancer cells manoeuvre through extracellular matrices (ECMs) using different invasion modes, including single cell and collective cell invasion. These modes rely on MMP-driven ECM proteolysis to make space for cells to move. How cancer-associated alterations in ECM influence the mode of invasion remains unclear. Further, the sensitivity of the two invasion modes to MMP dynamics remains unexplored. In this paper, we address these open questions using a multiscale hybrid computational model combining ECM density-dependent MMP secretion, MMP diffusion, ECM degradation by MMP and active cell motility. Our results demonstrate that in randomly aligned matrices, collective cell invasion is more efficient than single cell invasion. Although increase in MMP secretion rate enhances invasiveness independent of cell–cell adhesion, sustenance of collective invasion in dense matrices requires high MMP secretion rates. However, matrix alignment can sustain both single cell and collective cell invasion even without ECM proteolysis. Similar to our in-silico observations, increase in ECM density and MMP inhibition reduced migration of MCF-7 cells embedded in sandwich gels. Together, our results indicate that apart from cell intrinsic factors (i.e., high cell–cell adhesion and MMP secretion rates), ECM density and organization represent two important extrinsic parameters that govern collective cell invasion and invasion plasticity. | |
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Activity Percentile: 0.00 Registered: 2016-03-07 06:05 |