The highest wind speed ever measured in a tornado, which is also the highest wind speed ever recorded on the planet, is 301 ± 20 mph (484 ± 32 km/h) in the F5 Bridge Creek-Moore, Oklahoma, tornado which killed 36 people. The reading was taken about 100 feet (30 m) above the ground.Storms that produce tornadoes can feature intense updrafts, sometimes exceeding 150 mph (240 km/h). Debris from a tornado can be lofted into the parent storm and carried a very long distance. A tornado which affected Great Bend, Kansas, in November 1915, was an extreme case, where a "rain of debris" occurred 80 miles (130 km) from the town, a sack of flour was found 110 miles (180 km) away, and a cancelled check from the Great Bend bank was found in a field outside of Palmyra, Nebraska, 305 miles (491 km) to the northeast. Waterspouts and tornadoes have been advanced as an explanation for instances of raining fish and other animals. Safety
Though tornadoes can strike in an instant, there are precautions and preventative measures that can be taken to increase the chances of survival. Authorities such as the Storm Prediction Center in the United States advise having a pre-determined plan should a tornado warning be issued. When a warning is issued, going to a basement or an interior first-floor room of a sturdy building greatly increases chances of survival.
Mutations were mainly found in exons 12-22 of the intracellular TKD, including 10 missense mutations that have a single nucleotide deletion and a single codon deletion that consists of a triplet of nucleotides that have been removed causing a whole amino acid to not be coded. Additionally, three splice site mutations were identified that caused an in-frame deletion of an exon, an expressed nucleotide sequence, leading to the removal of more than 40 amino acids in the TKD.This determination has based upon genetic studies of 14 HDLS families confirming mutations in this gene. The CSF1 receptor protein primarily functions in regulation, survival, proliferation, and differentiation of microglial cells. The mechanism of microglial dysfunction due to mutations in CSF1R to the myelin loss and axonal spheroid formation remains unknown. Further research is needed to better understand disease pathogenesis. Pathology
In HDLS, there is enlargement of the lateral ventricles and marked thinning or weakening of cerebral white matter. The loss of white matter is caused by myelin loss. These changes are associated with diffuse gliosis, moderate loss of axons and many axonal spheroids.Activated or ameboid microglia and macrophages that contain myelin debris, lipid droplets and brown autofluorescent pigment granules are found in the areas with demyelination and axonal spheroids. In severely degenerated areas there are many large, reactive astrocytes filled with glial fibrils.In autopsy cases, it has been shown that white matter abnormalities are relatively confined to the cerebrum while avoiding the cerebellum and many of the major fiber tracts of the nervous system.