Neuroscience

Scientists reverse aging process in rat brain stem cells

New research, published today in Nature, reveals how increasing brain stiffness as we age causes brain stem cell dysfunction, and demonstrates new ways to reverse older stem cells to a younger, healthier state.

Diseases, Conditions, Syndromes

New window on fibrosis

DDR1 is a receptor tyrosine kinase (RTK)—a cell surface receptor—that regulates multiple functions including the maintenance of the normal structure of tissues, but which also contributes to pathological conditions including ...

Medical research

Tumor macrophage marker offers unique target for treatment

Macrophages are white blood cells that accumulate in tumors, where they aid cancer progression. Now scientists have identified a surface protein found only on the macrophages residing in tumors, exposing a target for precise ...

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Surface

In mathematics, specifically in topology, a surface is a two-dimensional topological manifold. The most familiar examples are those that arise as the boundaries of solid objects in ordinary three-dimensional Euclidean space R3 — for example, the surface of a ball or bagel. On the other hand, there are surfaces which cannot be embedded in three-dimensional Euclidean space without introducing singularities or intersecting itself — these are the unorientable surfaces.

To say that a surface is "two-dimensional" means that, about each point, there is a coordinate patch on which a two-dimensional coordinate system is defined. For example, the surface of the Earth is (ideally) a two-dimensional sphere, and latitude and longitude provide coordinates on it — except at the International Date Line and the poles, where longitude is undefined. This example illustrates that not all surfaces admits a single coordinate patch. In general, multiple coordinate patches are needed to cover a surface.

Surfaces find application in physics, engineering, computer graphics, and many other disciplines, primarily when they represent the surfaces of physical objects. For example, in analyzing the aerodynamic properties of an airplane, the central consideration is the flow of air along its surface.

This text uses material from Wikipedia, licensed under CC BY-SA