Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Formation of Higher-order Actin Filaments01:11

Formation of Higher-order Actin Filaments

2.8K
The polymerization of G-actin monomers into filamentous F-actin is a multi-step process. Once the F-actins are formed, they can bundle together in different arrangements to form higher-order networks and regulate cellular functions. Common examples include the formation of lamellipodia and filopodia at the cell's leading edge by actin reorganization in a migrating cell. The microvilli on the brush border epithelial cells are also formed through the F-actin network.
The high-order actin...
2.8K
First Law: Particles in Two-dimensional Equilibrium01:18

First Law: Particles in Two-dimensional Equilibrium

14.3K
Recall that a particle in equilibrium is one for which the external forces are balanced. Static equilibrium involves objects at rest, and dynamic equilibrium involves objects in motion without acceleration; but it is important to remember that these conditions are relative. For instance, an object may be at rest when viewed from one frame of reference, but that same object would appear to be in motion when viewed by someone moving at a constant velocity.
Newton's first law tells us about...
14.3K
Phase Transitions02:31

Phase Transitions

19.1K
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to...
19.1K
Phase Transitions01:21

Phase Transitions

108
A phase transition is the process in which a substance changes from one state of matter to another, like from a solid to a liquid, liquid to gas, or vice versa, at a specific temperature and under given pressure conditions. This change is spontaneous and is affected by alterations in temperature and pressure. These parameters impact the strength of the forces between molecules (intermolecular forces) in the substance.During a phase transition, both the initial and final phases of the substance...
108
Structures of Solids02:22

Structures of Solids

17.8K
Solids in which the atoms, ions, or molecules are arranged in a definite repeating pattern are known as crystalline solids. Metals and ionic compounds typically form ordered, crystalline solids. A crystalline solid has a precise melting temperature because each atom or molecule of the same type is held in place with the same forces or energy. Amorphous solids or non-crystalline solids (or, sometimes, glasses) which lack an ordered internal structure and are randomly arranged. Substances that...
17.8K
Fluid Mosaic Model01:19

Fluid Mosaic Model

14.6K
Scientists identified the plasma membrane in the 1890s and its principal chemical components (lipids and proteins) by 1915. The model for plasma membrane structure, proposed in 1935 by Hugh Davson and James Danielli, was the first model to be widely accepted in the scientific community. The model was based on the plasma membrane's "railroad track" appearance in early electron micrographs. Davson and Danielli theorized that the plasma membrane's structure resembled a sandwich...
14.6K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Switching metastable dynamics in many-body open quantum systems.

National science review·2026
Same author

Programmable Deformation of DNA Nanostructures: Mastering Size and Topology for Tailored Mechanics.

Langmuir : the ACS journal of surfaces and colloids·2026
Same author

XY Model with Persistent Noise.

Physical review letters·2026
Same author

Multiscale Insights into the Ionic-Strength Dependence of α-Synuclein Liquid-Liquid Phase Separation.

Macromolecular rapid communications·2026
Same author

Conformation and dynamics of active polymers with one end fixed.

Physical review. E·2025
Same author

Nanomaterial signatures program biomolecular condensates via triphasic separation for chemoplasticity remodeling.

Nature communications·2025

Related Experiment Video

Updated: May 4, 2026

Forming, Confining, and Observing Microtubule-Based Active Nematics
08:37

Forming, Confining, and Observing Microtubule-Based Active Nematics

Published on: January 13, 2023

2.8K

Topological structure dynamics revealing collective evolution in active nematics.

Xia-qing Shi1, Yu-qiang Ma1

  • 11] Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou 215006, China [2] National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China.

Nature Communications
|December 19, 2013
PubMed
Summary

Topological defects in active nematics exhibit irreversible dynamics and organize large-scale collective flows. Understanding these defect behaviors allows for controlling self-organization in active matter systems.

More Related Videos

Controlling Flow Speeds of Microtubule-Based 3D Active Fluids Using Temperature
08:04

Controlling Flow Speeds of Microtubule-Based 3D Active Fluids Using Temperature

Published on: November 26, 2019

6.7K
Tuning the Contractility and Deformation Modes of Active Actin-Based Assemblies In Vitro: From Two-Dimensional Active Networks to Liquid Crystal Drops
06:48

Tuning the Contractility and Deformation Modes of Active Actin-Based Assemblies In Vitro: From Two-Dimensional Active Networks to Liquid Crystal Drops

Published on: July 11, 2025

957

Related Experiment Videos

Last Updated: May 4, 2026

Forming, Confining, and Observing Microtubule-Based Active Nematics
08:37

Forming, Confining, and Observing Microtubule-Based Active Nematics

Published on: January 13, 2023

2.8K
Controlling Flow Speeds of Microtubule-Based 3D Active Fluids Using Temperature
08:04

Controlling Flow Speeds of Microtubule-Based 3D Active Fluids Using Temperature

Published on: November 26, 2019

6.7K
Tuning the Contractility and Deformation Modes of Active Actin-Based Assemblies In Vitro: From Two-Dimensional Active Networks to Liquid Crystal Drops
06:48

Tuning the Contractility and Deformation Modes of Active Actin-Based Assemblies In Vitro: From Two-Dimensional Active Networks to Liquid Crystal Drops

Published on: July 11, 2025

957

Area of Science:

  • Physics
  • Soft Matter Physics
  • Complex Systems

Background:

  • Topological defects are common in active matter systems like bacterial colonies and colloidal layers.
  • Their dynamical properties and relation to large-scale organization in active systems are not well understood.

Purpose of the Study:

  • To investigate the dynamics of topological defects in active nematics.
  • To understand how these defects influence large-scale organization and collective behavior.

Main Methods:

  • A simple model of active nematics using self-driven hard elliptic rods was employed.
  • Dynamical processes of defect excitation, annihilation, and transportation were analyzed.

Main Results:

  • Defect dynamics in active nematics differ significantly from non-active systems.
  • These dynamical processes show strong irreversibility due to the absence of detailed balance.
  • Topological defects are identified as key organizers of large-scale dynamic structures and collective flows.

Conclusions:

  • Topological defects play a crucial role in the emergent self-organization of active matter.
  • The findings provide insights into controlling active matter self-organization through topological structures.