The refractile outer portion of the inner member of a rod or cone cell. It is located between the myoid and the outer member of the cell, and contains mitochondria. The myoid is in contact with the external limiting membrane of the retina while the outer member is next to the pigment epithelium. 2. Surface of revolution generated by rotating an ellipse about a major or minor axis.
Definition of GIS. A geographic information system (GIS) is a system designed to capture, store, manipulate, analyze, manage, and present all types of geographical data. The key word to this technology is Geography â this means that some portion of the data is spatial. In other words, data that is in some way referenced to locations on the earth.
SARS (severe acute respiratory syndrome) Overview. Severe acute respiratory syndrome (SARS) is caused by the SARS coronavirus, known as SARS CoV. Coronaviruses are common viruses linked to infections in humans and animals. There are several recognised human coronaviruses that cause mild respiratory infections, such as the common cold. However, this type of virus can also include strains that cause more severe illnesses, such as SARS. There have been two self-limiting SARS outbreaks to date, during 2002 to 2004 (see below) associated with a highly contagious and potentially life-threatening form of pneumonia.