Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Power Expended by a Constant Force

Power Expended by a Constant Force

The relationship between work done and the time taken to do it can be explained using the concept of power. For example, several sprinters in a race may have the same velocity when they reach the finish line, therefore doing the same amount of work, but the winner does it in the least amount of time. Thus, power is defined as the rate of doing work. Since work can vary as a function of time, the average power is defined as the work done during a time interval, divided by the time interval.

Common Ion Effect

Common Ion Effect

Compared with pure water, the solubility of an ionic compound is less in aqueous solutions containing a common ion (one also produced by dissolution of the ionic compound). This is an example of a phenomenon known as the common ion effect, which is a consequence of the law of mass action that may be explained using Le Châtelier’s principle. Consider the dissolution of silver iodide:

Decreasing Function

Decreasing Function

A decreasing function describes a relationship where the output consistently declines as the input increases. This means that for any two input values, if one is greater than the other, the corresponding output is smaller. Mathematically, a function f is decreasing on an interval I if for every x1 < x2 in I, f (x1) > f (x2). This type of behavior is visually identified on a graph that slopes downward from left to right.The nature of a function can be analyzed by calculating...

Nuclear Power

Nuclear Power

Controlled nuclear fission reactions are used to generate electricity. Any nuclear reactor that produces power via the fission of uranium or plutonium by bombardment with neutrons has six components: nuclear fuel consisting of fissionable material, a nuclear moderator, a neutron source, control rods, reactor coolant, and a shield and containment system.
Nuclear Fuels
Nuclear fuel consists of a fissile isotope, such as uranium-235, which must be present in sufficient quantity to provide a...

Introduction to Test of Independence

Introduction to Test of Independence

In statistics, the term independence means that one can directly obtain the probability of any event involving both variables by multiplying their individual probabilities. Tests of independence are chi-square tests involving the use of a contingency table of observed (data) values.
The test statistic for a test of independence is similar to that of a goodness-of-fit test:

Hypothesis Test for Test of Independence

Hypothesis Test for Test of Independence

The test of independence is a chi-square-based test used to determine whether two variables or factors are independent or dependent. This hypothesis test is used to examine the independence of the variables. One can construct two qualitative survey questions or experiments based on the variables in a contingency table. The goal is to see if the two variables are unrelated (independent) or related (dependent). The null and alternative hypotheses for this test are:
H0: The two variables (factors)...

You might also read

Related Articles

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

Sort by

Same author

Design and Measured Assessment of a MOS-Only, Capacitorless, Miniature 64-Channel Headstage Circuit for High-Density Surface Electromyography.

Sensors (Basel, Switzerland)·2026

Same author

Concurrent control of natural and robotic limbs through a tactile-encoded brain-computer interface.

Nature communications·2026

Same author

Spiking neural network decoders of finger forces from high-density intramuscular microelectrode arrays.

Nature communications·2026

Same author

Cortical Activity Associated With Phantom Leg Movements.

IEEE transactions on neural systems and rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society·2026

Same author

A Roadmap to Navigate the Future of Neural Engineering.

Journal of neural engineering·2026

Same author

Author Correction: Implanted microelectrode arrays in reinnervated muscles allow separation of neural drives from transferred polyfunctional nerves.

Nature biomedical engineering·2026

Search research articles

Related Experiment Video

Updated: Feb 8, 2026

Power Input Measurements in Stirred Bioreactors at Laboratory Scale

Power Input Measurements in Stirred Bioreactors at Laboratory Scale

Published on: May 16, 2018

Decrease in force steadiness with aging is associated with increased power of the common but not independent input to

Anna Margherita Castronovo¹, Natalie Mrachacz-Kersting², Andrew James Thomas Stevenson²

¹Department of Bioengineering, Imperial College London , London , United Kingdom.

Journal of Neurophysiology

|July 6, 2018

Summary

Aging impairs force control due to increased low-frequency oscillations in common synaptic input to spinal motor neurons, not increased independent input. This impacts motor neuron function across the lifespan.

Keywords:

aging common synaptic input force steadiness neural drive to muscles

More Related Videos

Measurements of Waves in a Wind-wave Tank Under Steady and Time-varying Wind Forcing

Measurements of Waves in a Wind-wave Tank Under Steady and Time-varying Wind Forcing

Published on: February 13, 2018

Gait Analysis of Age-dependent Motor Impairments in Mice with Neurodegeneration

Gait Analysis of Age-dependent Motor Impairments in Mice with Neurodegeneration

Published on: June 18, 2018

Related Experiment Videos

Last Updated: Feb 8, 2026

Power Input Measurements in Stirred Bioreactors at Laboratory Scale

Power Input Measurements in Stirred Bioreactors at Laboratory Scale

Published on: May 16, 2018

Measurements of Waves in a Wind-wave Tank Under Steady and Time-varying Wind Forcing

Measurements of Waves in a Wind-wave Tank Under Steady and Time-varying Wind Forcing

Published on: February 13, 2018

Gait Analysis of Age-dependent Motor Impairments in Mice with Neurodegeneration

Gait Analysis of Age-dependent Motor Impairments in Mice with Neurodegeneration

Published on: June 18, 2018

Area of Science:

Neuroscience
Motor Control
Aging Research

Background:

Motor function declines with age due to neuromuscular changes.
The specific impact of aging on spinal motor neuron control of muscle force remains unclear.

Purpose of the Study:

To investigate how aging affects common synaptic input to tibialis anterior motor neurons.
To determine the relationship between these synaptic changes and force control accuracy.

Main Methods:

Recorded motor unit discharge times from high-density surface EMG during isometric contractions.
Analyzed coherence between motor unit spike trains to characterize synaptic input.
Correlated force steadiness with common synaptic input characteristics in 20 adults (24-75 years).

Main Results:

Decreased force steadiness with age correlated with increased low-frequency oscillations in common synaptic input.
The proportion of common input to independent noise at low frequencies increased with synaptic input variability.
Gamma band common input strength decreased with age, while interspike interval variability remained unchanged.

Conclusions:

Age-related decline in force control accuracy is linked to increased low-frequency common input fluctuations to motor neurons.
Changes in synaptic input to motor neurons across the lifespan contribute to reduced force control.
Aging alters spinal motor neuron synaptic input, impacting motor function.