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A reflex arc is a neural pathway that controls a reflex. In vertebrates, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord. This allows for faster reflex actions to occur by activating spinal motor neurons without the delay of routing signals through the brain. The brain will receive the input while the ...
Purkinje images are reflections of objects from the structure of the eye. They are also known as Purkinje reflexes and as Purkinje–Sanson images. At least four Purkinje images are usually visible in the normal eye. The first Purkinje image (P1) is the reflection from the outer surface of the cornea. The second Purkinje image (P2) is the ...
The palmar grasp reflex (or grasp reflex) is a primitive and involuntary reflex found in infants of humans and most primates. When an object, such as an adult finger, is placed in an infant's palm, the infant's fingers reflexively grasp the object. [1] Placement of the object triggers a spinal reflex, resulting from stimulation of tendons in ...
1) (similar to trees as graphs) A real tree is a geodesic metric space which contains no subset homeomorphic to a circle. [1] 2) A real tree is a connected metric space which has the four points condition [2] (see figure): For all . 3) A real tree is a connected 0-hyperbolic metric space [3] (see figure). Formally,
In mathematics, Kruskal's tree theorem states that the set of finite trees over a well-quasi-ordered set of labels is itself well-quasi-ordered under homeomorphic embedding. History [ edit ] The theorem was conjectured by Andrew Vázsonyi and proved by Joseph Kruskal ( 1960 ); a short proof was given by Crispin Nash-Williams ( 1963 ).
Reflexive space. In the area of mathematics known as functional analysis, a reflexive space is a locally convex topological vector space for which the canonical evaluation map from into its bidual (which is the strong dual of the strong dual of ) is a homeomorphism (or equivalently, a TVS isomorphism ). A normed space is reflexive if and only ...
Students did not make the academic gains hoped for last school year, with test scores in key subjects showing lagging progress and in some cases further backsliding since the pandemic, according ...
Mandelbrot set with 12 encirclements. Zooming into the boundary of the Mandelbrot set. In mathematics, a fractal is a geometric shape containing detailed structure at arbitrarily small scales, usually having a fractal dimension strictly exceeding the topological dimension. Many fractals appear similar at various scales, as illustrated in ...