February 18, 2016 at 01:16AM

Today I Learned: 1) Apparently there are at least some plasmids that can replicate even when host protein synthesis is inhibited with antibiotics. Source: Andrey!!!!! 2) In a closed system without aeration (say, a spacesuit in space), a human will die from CO2 poisoning well before he or she runs out of oxygen. Source: The Martian. 3) The active ingredient in roundup, glyphosate, has recently been declared a probable human carcinogen by the WHO. However, there's a HUGE amount of controversy over this particular chemical. There have been a bunch of epidemiological studies on roundup, which have suggested everything from "it's harmless" to "working with it occupationally increases risk of Hodgkin's lymphoma". There is no direct evidence of glyphosate's toxicity in humans, BUT there are animal studies that suggest that it may be. More details here: http://ift.tt/1GT5TD2. It is definitely NOT acutely toxic in any real sense -- the LD50 in rodents of various kinds is on the order of grams per kg, which is pretty close to that of 70% ethanol (i.e., if you drank a bottle of it, you'd be about as likely to die as to live). (also of note: the WHO has no water guidelines for glyphosate concentration in water because they claim the lowest known health-safe dose of glyphosate is orders of magnitude above anything commonly found in drinking water)