TensorAlgebraic object with geometric applicationsThe second-order Cauchy stress tensorT{\displaystyle \mathbf {T} } describes the stress experienced by a material at a given point. For any unit vector v{\displaystyle \mathbf {v} }, the product T⋅v{\displaystyle \mathbf {T} \cdot \mathbf {v} } is a vector, denoted T(v){\displaystyle \mathbf {T} (\mathbf {v} )}, that quantifies the force per area along the plane perpendicular to v{\displaystyle \mathbf {v} }.
DiffusionDiffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in Gibbs free energy or chemical potential. It is possible to diffuse "uphill" from a region of lower concentration to a region of higher concentration, as in spinodal decomposition.
MRI pulse sequenceAn MRI pulse sequence in magnetic resonance imaging (MRI) is a particular setting of pulse sequences and pulsed field gradients, resulting in a particular image appearance. A multiparametric MRI is a combination of two or more sequences, and/or including other specialized MRI configurations such as spectroscopy. Overview tableThis table does not include uncommon and experimental sequences.
AxonAn axon (from Ancient Greek: ἄξων, romanized: áxōn, lit. 'axis'; also called a nerve fiber or fibre) is a long slender projection of a nerve cell or neuron found in most animals that typically conducts electrical impulses known as action potentials away from the nerve cell body. The function of the axon is to transmit information to different neurons, muscles, and glands.
VoxelIn computing, a voxel is a representation of a value on a three-dimensional regular grid, akin to the two-dimensional pixel. Voxels are frequently used in the visualization and analysis of medical and scientific data (e.g. geographic information systems (G.I.S.)). Voxels also have technical and artistic applications in video games, largely originating with surface rendering in Outcast (1999).
Contrast (vision)Contrast is the difference in luminance or color that makes an object (or its representation in an image or display) distinguishable from a background. Human vision is more sensitive to relative differences than to absolute luminance, so perceived appearance can remain fairly stable despite large changes in illumination. The maximum contrast of an image is termed the contrast ratio or dynamic range.
TractographyIn neuroscience, tractography is a 3D modeling technique used to visually represent nerve tracts using data collected by diffusion MRI. It uses special techniques of magnetic resonance imaging (MRI) and computer-based diffusion MRI. The results are presented in two- and three-dimensional images called tractograms.
White matterWhite matter refers to areas of the central nervous system that are mainly made up of myelinated axons, also called tracts. Long thought to be passive tissue, white matter affects learning and brain functions, modulating the distribution of action potentials, acting as a relay and coordinating communication between different brain regions. White matter is named for its relatively light appearance resulting from the lipid content of myelin.
Biological membraneA biological membrane or biomembrane is a selectively permeablemembrane that separates the interior of a cell from the external environment or creates intracellular compartments by serving as a boundary between one part of the cell and another. Biological membranes, in the form of eukaryoticcell membranes, consist of a phospholipid bilayer with embedded, integral and peripheral proteins used in communication and transportation of chemicals and ions.
In vivoStudies that are in vivo (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, and plants, as opposed to a tissue extract or dead organism.
MacromoleculeA macromolecule is a "molecule of high relative molecular mass, the structure of which essentially comprises the multiple repetition of units derived, actually or conceptually, from molecules of low relative molecular mass." Polymers, which are often used in many consumer goods, are examples of macromolecules. Common macromolecules are biopolymers (RNA and DNA, proteins, and carbohydrates), polyolefins (polyethylene) and polyamides (nylon).
Tissue (biology)In biology, tissue is an assembly of similar cells and their extracellular matrix from the same embryonic origin that together carry out a specific function. Tissues occupy a biological organizational level between cells and a complete organ. Accordingly, organs are formed by the functional grouping of multiple tissues. The English word "tissue" derives from the French word "", meaning "fabric", derived from the verb “tisser”, "to weave".*As an Amazon Associate I earn from qualifying purchases.