Types
Multiple vortex
A multiple-vortex tornado is a type of tornado in which two or more columns of spinning air rotate about their own axes and at the same time revolve around a common center. A multi-vortex structure can occur in almost any circulation, but is very often observed in intense tornadoes. These vortices often create small areas of heavier damage along the main tornado path. This is a phenomenon that is distinct from a satellite tornado, which is a smaller tornado that forms very near a large, strong tornado contained within the same mesocyclone. The satellite tornado may appear to "orbit" the larger tornado (hence the name), giving the appearance of one, large multi-vortex tornado. However, a satellite tornado is a distinct circulation, and is much smaller than the main funnel. Waterspout
A waterspout is defined by the National Weather Service as a tornado over water. However, researchers typically distinguish "fair weather" waterspouts from tornadic (i.e. associated with a mesocyclone) waterspouts. Fair weather waterspouts are less severe but far more common, and are similar to dust devils and landspouts. They form at the bases of cumulus congestus clouds over tropical and subtropical waters. They have relatively weak winds, smooth laminar walls, and typically travel very slowly. They occur most commonly in the Florida Keys and in the northern Adriatic Sea. In contrast, tornadic waterspouts are stronger tornadoes over water. They form over water similarly to mesocyclonic tornadoes, or are stronger tornadoes which cross over water.
The provisional representation of species addressed by the resource has been indicated in the TaxBox on this page by a superscript yb beside the species name. Development of YersiniaBase was funded by the University of Malaya and the Ministry of Education, Malaysia. Pathogenesis
Y. pestis is the causative agent of plague. The disease caused by Y. enterocolitica is called yersiniosis. Yersinia may be associated with Crohns disease, an inflammatory autoimmune condition of the gut. Iranian sufferers of Crohns disease were more likely to have had earlier exposure to refrigerators at home, consistent with its unusual ability to thrive at low temperatures. Yersinia is implicated as one of the causes of reactive arthritis worldwide.Also, the genus is associated with pseudoappendicitis, which is an incorrect diagnosis of appendicitis due to a similar presentation. History
Y. pestis, the first known species, was identified in 1894 by A.E.J. Yersin, a Swiss bacteriologist, and Kitasato Shibasaburō, a Japanese bacteriologist. It was formerly described as Pasteurella pestis (known trivially as the plague-bacillus) by Lehmann and Neumann in 1896. In 1944, van Loghem reclassified the species P. pestis and P. rondentium into a new genus, Yersinia. Following the introduction of the bacteriological code, it was accepted as valid in 1980. References
External links
Yersinia Enterocolitis Mimicking Crohns Disease in a Toddler
Sweden: Pork warnings over new stomach illness
Yersinia genomes and related information at PATRIC, a Bioinformatics Resource Center funded by NIAID
YersiniaBase