transductions

Transduction is the process of converting one form of energy, information, or signal into another. The term is used across disciplines to describe different but related transformations, ranging from physical energy to neural signals, and from formal mappings of strings to practical devices that sense or actuate in the world.

In biology, transduction has two common senses. Sensory transduction is the conversion of external stimuli—such as photons, sound waves, or chemical molecules—into neural signals. Signal transduction refers to the intracellular cascades that begin when a signal binds to a receptor, ultimately altering cellular activities such as gene expression, metabolism, or movement.

In microbiology, transduction is a mechanism of horizontal gene transfer mediated by bacteriophages. Generalized transduction can transfer random fragments of donor DNA, while specialized transduction can move specific genes adjacent to a phage integration site, contributing to genetic variation and the spread of traits such as antibiotic resistance.

In computer science, a transduction is a mapping from input strings to output strings produced by a transducer, for example a finite-state transducer. Transductions underlie text processing, compilation, and speech recognition. In linguistics, transduction grammars describe transformations between formal representations used for generation or translation.

In engineering and measurement, transducers convert energy or information from one form to another, such as microphones that turn sound into electrical signals or actuators that convert electrical signals into motion. The word emphasizes the reciprocal link between sensing, actuation, and the information that connects them.