Conditions of the human integumentary system constitute a broad spectrum of diseases, also known as dermatoses, as well as many nonpathologic states (like, in certain circumstances, melanonychia and racquet nails). While only a small number of skin diseases account for most visits to the physician, thousands of skin conditions have been described. Classification of these conditions often presents many nosological challenges, since underlying etiologies and pathogenetics are often not known. Therefore, most current textbooks present a classification based on location (for example, conditions of the mucous membrane), morphology (chronic blistering conditions), etiology (skin conditions resulting from physical factors), and so on.
The basic idea in binary morphology is to probe an image with a simple, pre-defined shape, drawing conclusions on how this shape fits or misses the shapes in the image. This simple "probe" is called structuring element, and is itself a binary image (i.e., a subset of the space or grid).
Let E be a Euclidean space or an integer grid, and A a binary image in E.
The erosion of the binary image A by the structuring element B is defined by:
where Bz is the translation of B by the vector z, i.e., , .
When the structuring element B has a center (e.g., a disk or a square), and this center is located on the origin of E, then the erosion of A by B can be understood as the locus of points reached by the center of B when B moves inside A. For example, the erosion of a square of side 10, centered at the origin, by a disc of radius 2, also centered at the origin, is a square of side 6 centered at the origin.
Acid erosion, also known as dental erosion, is a type of tooth wear. It is defined as the irreversible loss of tooth structure due to chemical dissolution by acids not of bacterial origin. Dental erosion is the most common chronic disease of children ages 5–17, although it is only relatively recently that it has been recognised as a dental health problem. There is generally widespread ignorance of the damaging effects of acid erosion; this is particularly the case with erosion due to fruit juices, because they tend to be seen as healthy. Erosion is found initially in the enamel and, if unchecked, may proceed to the underlying dentin.
The most common cause of erosion is by acidic foods and drinks. In general, foods and drinks with a pH below 5.0–5.7 have been known to trigger dental erosion effects. Numerous clinical and laboratory reports link erosion to excessive consumption of drinks. Those thought to pose a risk are soft drinks, some alcohol and fruit drinks, fruit juices such as orange juice (which contain citric acid) and carbonated drinks such as colas (in which the carbonic acid is not the cause of erosion, but citric and phosphoric acid). Additionally, wine has been shown to erode teeth, with the pH of wine as low as 3.0–3.8. Other possible sources of erosive acids are from exposure to chlorinatedswimming pool water, and regurgitation of gastric acids.
A coastline or a seashore is the area where land meets the sea or ocean, or a line that forms the boundary between the land and the ocean or a lake. A precise line that can be called a coastline cannot be determined due to the Coastline paradox.
The term coastal zone is a region where interaction of the sea and land processes occurs. Both the terms coast and coastal are often used to describe a geographic location or region; for example, New Zealand's West Coast, or the East and West Coasts of the United States. Edinburgh for example is a city on the coast of Scotland.
A pelagic coast refers to a coast which fronts the open ocean, as opposed to a more sheltered coast in a gulf or Headlands and bays/bay. A shore, on the other hand, can refer to parts of the land which adjoin any large body of water, including oceans (sea shore) and lakes (lake shore). Similarly, the somewhat related term "[Stream bed/bank]" refers to the land alongside or sloping down to a river (riverbank) or to a body of water smaller than a lake. "Bank" is also used in some parts of the world to refer to an artificial ridge of earth intended to retain the water of a river or pond; in other places this may be called a levee.
The Coast network reaches an estimated 189,000 listeners each week - many of them baby boomers and the parents of adult children. Its format is smooth, with short hourly news bulletins, succinct voice breaks, minimal ad breaks and limited clutter. Its target listener is 40 to 64 years old, has reached their highest-earning potential, owns their own home and spends disposable income on luxury items and travel. The audience is almost equally male and female, with a 52% female skew.