Related Experiment Video

Updated: Jul 9, 2026

Generating Strictly Controlled Stimuli for Figure Recognition Experiments
05:39

Generating Strictly Controlled Stimuli for Figure Recognition Experiments

Published on: March 18, 2019

Positional signalling and specification of digits in chick limb morphogenesis

C Tickle, D Summerbell, L Wolpert

    Nature
    |March 20, 1975
    PubMed
    Summary

    Limb development relies on positional information gradients. Grafting boundary regions along the anteroposterior axis alters digit patterns, supporting a morphogen diffusion model.

    More Related Videos

    Experimental Methods to Study Human Postural Control08:12

    Experimental Methods to Study Human Postural Control

    Published on: September 11, 2019

    Lower-Limb Biomechanical Characteristics Associated with Unplanned Gait Termination Under Different Walking Speeds05:52

    Lower-Limb Biomechanical Characteristics Associated with Unplanned Gait Termination Under Different Walking Speeds

    Published on: August 25, 2020

    Related Concept Videos

    Rules for Significant Figures01:44

    Rules for Significant Figures

    In any measurement, the precision of the measuring tool is an essential factor. An ordinary ruler, for example, can measure length to the closest millimeter; a caliper, on the other hand, can measure length to the nearest 0.01 mm. As a result, the caliper is a more precise measurement tool because it can measure extremely minute changes in length. The measurements will be more accurate if the measuring tool is more precise.
    It should be emphasized that when we represent measured values, the...
    Sign Convention01:30

    Sign Convention

    When analyzing a beam subjected to various loads, it is crucial to understand the internal forces and moments generated within the structure. These internal forces can be broadly classified into normal forces, shear forces, and bending moments. To determine these forces and moments, we use the method of sections and apply a specific sign convention based on their direction and the side of the section being analyzed.
    The normal force acts perpendicular to the beam's cross-section and can cause...
    Signal and System01:26

    Signal and System

    A signal x(t) is a set of data or a time function representing a variable of interest. Signals typically convey information about a phenomenon, such as atmospheric temperature, humidity, human voice, television images, a dog's bark, or birdsongs. More generally, a signal can be a function of more than one independent variable. For instance, images depend on horizontal and vertical positions and can be regarded as two-dimensional signals. However, this text will focus on one-dimensional signals...
    Even and Odd Signals01:17

    Even and Odd Signals

    An even signal, whether in continuous-time or discrete-time, is defined by its symmetry with its time-reversed version. Mathematically, this is represented as
    Signal Flow Graphs01:18

    Signal Flow Graphs

    Signal-flow graphs offer a streamlined and intuitive approach to representing control systems, providing an alternative to traditional block diagrams. These graphs use branches to symbolize systems and nodes to represent signals, effectively illustrating the relationships and interactions within the system.
    In a signal-flow graph, branches denote the system's transfer functions, while nodes represent the signals. The direction of signal flow is indicated by arrows, with the corresponding...
    Transformations of Functions III01:20

    Transformations of Functions III

    Transformations modify the graphical representation of a function without changing its fundamental form. One common transformation is reflection, which flips the graph across a designated axis. When the vertical coordinates of all points are multiplied by the negative one, the entire graph is mirrored over the horizontal axis. This transformation reverses the vertical orientation of peaks and troughs, akin to signal inversion in electrical systems, where a waveform is flipped, but the timing of...