Alfred001

Right, there are some studies that show no correlation and some that show a correlation. I guess we would need to do a systematic review of the literature to really know which direction the evidence is pointing to. No strong evidence does not mean no evidence. I was never claiming there is conclusive evidence. The very text you quoted says "in man, results were less clear and often conflicting," "more recent studies report on a limited correlation," "reasonably anticipated to be a human carcinogen." Like I said, it points to a potential correlation that should be investigated. Why are we prescribing a drug if the question of carcinogenic potential hasn't been settled. Now, maybe it HAS been settled, like I said, I haven't done a systematic review of the literature, maybe the null finding studies overwhelmingly outnumber the ones that show a correlation, but right now, we (meaning we on the forum discussing this) have a few studies that show a correlation and a few that don't - hardly a settled question.

That's the one! The first one. Thank you!

Well, the fact that there may be other drugs that have a suspected link with cancer is not an argument for not investigating metronidazole's suspected link. All of them should be investigated. So we have a tentative link and strong mechanistic evidence, doesn't that suggest that the link should be further investigated before the drug is prescribed en masse as we are in fact doing? I actually don't think the study would be that difficult, this drug is widely prescribed, it wouldn't be hard to find subjects to enroll, even a massive number of them, and all you need to do is match them with controls and follow them over, yes, decades, but all that means is check ins every 5-10 years to see who got cancer. But let's set this aside, I want to focus the debate on whether it makes sense to prescribe this drug given the evidence for it causing cancer. To your last paragraph, I think it's a matter of urgent concern because it has substantial (tho not conclusive) evidence for possibly causing cancer, yet we prescribe the drug widely. Is it the most urgent drug to investigate for such a link? I don't know, I make no claim with regards to that, my claim is simply that prescribing a drug with evidence for causing cancer without disproving a causal connection with an adequate study is insane. But have the studies been done? Is there an adequately powered study with adequate followup that allows us to conclusively say there is no increase in cancer risk or that it is trivially small? Or is it simply that we haven't done the studies so we don't know how much we are potentially increasing people's risk of cancer?

Can you explain?

I've been reading some studies that relate to food and some of the discuss the pH of solid foods, however I've also come across a post on Quora that says the following in response to a question about the pH of olive oil: So, if pH is a value that only applies to aqueous solutions, how come these studies I'm reading are giving pH values for solid foods?

Are you seriously this dense?

That's precisely my point. Maybe now that I've stated it for the 100th time you'll understand what I'm saying.

No, periodic acid reflux does not result in an inverse relationship with esophageal cancer and H pylori does not cause GERD. Like I said, studies show either no correlation or an inverse correlation between H pylori and Barrett's. H pylori, as it advances, causes a decrease in acid output, not an incrase, as a consequence of gastric atrophy. Yes, there are stool and breath tests for H pylori that are quite sensitive and specific. Omeprazole is a first generation PPI, there are newer and more potent drugs such as esomeprazole and rabeprazole and another drug, more potent than those, vonoprazan, which AFAIK has only been approved by the FDA for H pylori therapy, I don't think it's been approved for GERD yet, but I may be wrong on that.

#1 How can you say that when you don't know what the risk of cancer is from a 14 day course of metronidazole? Is it lower or higher than that of H pylori? H pylori raises risk of gastric cancer (it is actually inversely correlated with esophageal cancer and is not implicated in any of the other things you mentioned), which cancers does metro raise the risk of? Is it only one or multiple? The point is that we don't know, because AFAIK (and I'll be happy to be corrected on this, as I said in the OP, I've not exhaustively reviewed the literature), there has not been a large study with long followup to test for this, which is my whole point. We have evidence of a correlation with cancer, but we don't have a study to establish or refute a causal connection, yet the drug is prescribed en masse. #2 Why take the risk when you could use other antibiotics that don't have a suspected link with cancer?

So how much does a 14 day course of metronidazole, commonly used for H pylori therapy, increase a person's cancer risk? Presumably you know, since you claim the risk-reward balance breaks in favor of using metronidazole rather than alternative antibiotics that don't have a suspected cancer risk associated.

That the risk indicated by the studies I cited does not apply to short courses of treatment. Yes, but most drugs we use are not suspected to be carcinogens.

I've cited evidence of a possible correlation, you've just flatly stated there is no increased risk when the course of treatment is short, providing no evidence, even though I've already referenced a study that found "limited correlation" with a short course specifically and never mentioned a long course of metro. Additionally, there's a cohort study (Beard et al. 1988) which found the incidence of lung cancer (bronchogenic carcinoma) was significantly increased in women exposed to metronidazole, and the excess remained after an attempt to adjust for smoking. So what's your evidence for your claim?

Is anyone aware of any documentaries about competition for mates in animals? Specifically, I'm interested in the male side of the competition. So anything that deals with males competing from females, whether that's displays or this or that or battle.

Perhaps my search of the literature has been inadequate, but as best as I can tell, the situation with metronidazole is that it was conclusively demonstrated to be carcinogenic in animals, genotoxic in humans in vitro and in vivo and "reasonably anticipated to be a human carcinogen" and in spite of this, the drug continues to be in wide use with seemingly no urgency to run a study to settle the question of its carcinogenic potential in humans. Am I missing something or is this insane? You can maybe say there's no evidence of carcinogenicity in humans, but absence of evidence is not evidence that it's not carcinogenic, not if adequately powered, well designed studies haven't been done. And in fact, as shown in one of the passages I quote later, a "limited-correlation" has been found. How is it safe for humans to be taking this drug that has so strongly been suggested to be potentially carcinogenic and has not been proven not to be? Shouldn't we stop giving this to people? Again, perhaps I'm missing some significant literature? Here's what I looked at: Association of Metronidazole with Cancer: A Potential Risk Factor or Inconsistent Deductions? (2018 review article) A review on metronidazole: an old warhorse in antimicrobial chemotherapy (2019)

I was reading a collection of short stories by the Japanese writer Akutagawa and one of the stories in the collection is called Kappa, which is apparently a creature from Japanese folklore that lives in rivers and ponds and described as follows by Wikipedia: They are typically greenish in color[7] (or yellow-blue[8]), and either scaly[9][10] or slimy skinned, with webbed hands and feet, and a turtle-like carapace on their back. This reminded me of the Creature from the Black Lagoon (aka The Shape of Water creature), although I don't know whether that creature is based on folklore or just an invention of 50s b movie writers, and it also reminded me of a claim I'm often heard that many cultures across the world have dragons in their folklore even though, at the time when their dragon myth originated, these cultures couldn't have had contact. This got me wondering, could this be true of these Kappa-like river creatures as well? Are river creatures a myth that can be found in many cultures? And do they share these features of appearance that Kappa and the black lagoon creature do?

I remember seeing a long long time ago on Youtube a video with Feynman that I think was a long interview recorded for TV, rather than a documentary, but it started with Feynman drawing a picture of his wife as she poses. I remember he comments on how pretty she is and she responds with "You always say that, Richard." Does anyone know what the title of the program was?

I think that might be it, thanks!

I remember reading a long time ago what I'm pretty sure was an excerpt from a book by Feynman in which he talked about being part of a frat in college and about how in the frat there were nerdy guys and there were jocks and the jocks were teaching the nerds how to deal with girls and the nerds were helping the jocks with their school work. Does anyone know which of his books this is from?

I'm sure you've heard these claims as well, about the harmfulness of blue light emitted by computer/smartphone screens. If I have it correctly, there are two sources of supposed harm: 1. disrupts circadian rhytm Apparently, the blue light is of a color emitted by the sun, so if you use your computer/phone late at night, your body gets the impression the sun is out and this disrupts the circadian rhytm. 2. damage to some part of the eye The other claim I think I recall hearing is that the light actually does damage to some part of the eye. This may seem highly dubious at first blush, since we're exposed to blue light from other sources a lot and if there's damage being done we'd be blind already, but it may be more nuanced than that. Sunlight is harmful to us even though we're exposed to it all the time and you wouldn't want to be overexposed to it. So, is anyone familiar with what the scientific evidence says on this topic?

Fun fact: Hemingway wrote a short story (a few paragraphs, really) about the hanging of a notorious Chicago gangster Sam Cardinella (something like that), which he apparently witnessed as a newspaper reporter. Cardinella's gang had a plan where they were gonna reanimate him in the ambulance car-post hanging, but the plan was foiled. I even read somewhere that they'd apparently tried a dry run of this with another individual, IDK how credible that is, if it is it might be an example of what you're looking for, but sounds dubious.

This question was brought about by a claim I saw on Twitter Another person lower in the thread says that Feynman tested 125 at 12. Which, from what I understand, doesn't mean you'd expect him to have a higher IQ as an adult. The tests supposedly adjust for age. Anyway, is this true? Did he really test 125 and at what age?

I don't think it's the first one and it's almost certainly not the second one. Nope, wasn't the Black Swan. I don't know if this helps at all, but I learned of the book because the author appeared on the great Bloggingheads.tv website (this was many years ago) to talk about it. I'm pretty sure he was interviewed by the science writer George Johnson (who used to be a regular) on a podcast, but I can't recall the author's name.

Not that one, either. The theme of this book was more the limits of knowledge/reason. It was about questions we can't or might not be able to answer due to limitations of reason or time or what we can know. Something along those lines.

I think it wasn't exclusively math problems, it was more general and aimed at a popular audience.

Years ago, I remember hearing about a book about problems that are either unsolvable or so difficult that it would take a supercomputer millions of years to work through. I think one problem mentioned in the book is the traveling salesman. Does anyone happen to know the title, as I can't recall it.