6 ms·

Southeastern Brazil sits most directly under the SAA, which increases background levels of ionizing radiation for those in the geographic area. If there existe

by ackfoo 11y ago

Southeastern Brazil sits most directly under the SAA, which increases background levels of ionizing radiation for those in the geographic area. If there existed a map of these Li-Fraumeni variant cases, which it seems there does not, it would be interesting to compare that with the position of the SAA. It seems reasonable that a P53 mutation combined with higher background radiation would lead to increased cancer risk in those with the mutation, so the location in southeast Brazil seems like it might not be a coincidence. One also has to wonder if the P53 mutation itself is an artifact of high-Z exposure, even though it looks to be identical in all cases, but the genetics may rule that out. It may be that the Brazilian Li-Fraumeni variant situation gives us our only model of cancer risk in a low geomagnetic field environment, which is very interesting for human space exploration.

dekhn 11y ago
It's more likely the P53 mutation came from a Founder (individual who had the mutation quite some time ago) that passed it on to many individuals. Whether that original mutation was caused by a higher than average level of ionizing radiation is entirely speculative. This does not rule out increased cancer rates due to unrepaired ionizing radiation damage that went unrepaired to mutant P53, although that is also pretty speculative (I mean, it's a known fact that happens, but it's also not particularly necessary to explain the observations here). The part about cancer risk models and geomagnetic fields and space exploration are a tangent, and not even a relevant or scientifically plausible one.
barking 11y ago
SAA = South Atlantic Anomaly https://en.wikipedia.org/wiki/South_Atlantic_Anomaly https://en.wikipedia.org/wiki/South_Atlantic_Anomaly I'd never heard of it before
magic_beans 11y ago
What does SAA mean? All I get from google is South African Airways...
dredmorbius 11y ago
The South Atlantic Anomaly (SAA -- please define your acronyms) was also the focus of the high altitude ("space bomb") nuclear explosion tests of Operation Argus: https://en.wikipedia.org/wiki/Operation_Argus https://en.wikipedia.org/wiki/Operation_Argus a series of United States nuclear weapons tests and missile tests secretly conducted during August and September 1958 over the South Atlantic Ocean. They were performed by the Defense Nuclear Agency, in conjunction with the Explorer 4 space mission.... The tests were proposed by Nicholas Christofilos of what was then the Livermore branch of the Lawrence Radiation Laboratory (now Lawrence Livermore National Laboratory) as a means to verify the Christofilos effect, which argued that high-altitude nuclear detonations would create a radiation belt in the extreme upper regions of the Earth's atmosphere. Such belts would be similar in effect to the Van Allen radiation belts. Such radiation belts were viewed as having possible tactical use in war. Prior to Argus, Hardtack Teak had shown disruption of radio communications from a nuclear blast, though this was not due to the creation of radiation belts.... Due to the South Atlantic Anomaly, the Van Allen radiation belt is closer to the Earth's surface at that location. The (extreme) altitude of the tests was chosen so as to prevent personnel involved in the test from being exposed to any ionizing radiation. This and other space-based testing destroyed several satellites, including the first communications satellite, Telstar, which failed after only seven months. https://en.wikipedia.org/wiki/Telstar https://en.wikipedia.org/wiki/Telstar A memo concerning the failure of a British satellite, Ariel-1, recently surfaced and was reported by the BBC: http://www.bbc.com/future/story/20150910-the-nuke-that-fried-satellites-with-terrifying-results http://www.bbc.com/future/story/20150910-the-nuke-that-fried...

by ackfoo 11y ago

dekhn 11y ago

It's more likely the P53 mutation came from a Founder (individual who had the mutation quite some time ago) that passed it on to many individuals. Whether that original mutation was caused by a higher than average level of ionizing radiation is entirely speculative. This does not rule out increased cancer rates due to unrepaired ionizing radiation damage that went unrepaired to mutant P53, although that is also pretty speculative (I mean, it's a known fact that happens, but it's also not particularly necessary to explain the observations here). The part about cancer risk models and geomagnetic fields and space exploration are a tangent, and not even a relevant or scientifically plausible one.

barking 11y ago

SAA = South Atlantic Anomaly https://en.wikipedia.org/wiki/South_Atlantic_Anomaly https://en.wikipedia.org/wiki/South_Atlantic_Anomaly I'd never heard of it before

magic_beans 11y ago

What does SAA mean? All I get from google is South African Airways...

dredmorbius 11y ago

The South Atlantic Anomaly (SAA -- please define your acronyms) was also the focus of the high altitude ("space bomb") nuclear explosion tests of Operation Argus: https://en.wikipedia.org/wiki/Operation_Argus https://en.wikipedia.org/wiki/Operation_Argus a series of United States nuclear weapons tests and missile tests secretly conducted during August and September 1958 over the South Atlantic Ocean. They were performed by the Defense Nuclear Agency, in conjunction with the Explorer 4 space mission.... The tests were proposed by Nicholas Christofilos of what was then the Livermore branch of the Lawrence Radiation Laboratory (now Lawrence Livermore National Laboratory) as a means to verify the Christofilos effect, which argued that high-altitude nuclear detonations would create a radiation belt in the extreme upper regions of the Earth's atmosphere. Such belts would be similar in effect to the Van Allen radiation belts. Such radiation belts were viewed as having possible tactical use in war. Prior to Argus, Hardtack Teak had shown disruption of radio communications from a nuclear blast, though this was not due to the creation of radiation belts.... Due to the South Atlantic Anomaly, the Van Allen radiation belt is closer to the Earth's surface at that location. The (extreme) altitude of the tests was chosen so as to prevent personnel involved in the test from being exposed to any ionizing radiation. This and other space-based testing destroyed several satellites, including the first communications satellite, Telstar, which failed after only seven months. https://en.wikipedia.org/wiki/Telstar https://en.wikipedia.org/wiki/Telstar A memo concerning the failure of a British satellite, Ariel-1, recently surfaced and was reported by the BBC: http://www.bbc.com/future/story/20150910-the-nuke-that-fried-satellites-with-terrifying-results http://www.bbc.com/future/story/20150910-the-nuke-that-fried...