Skin exposure to UVB light induces a skin-brain-gonad axis and sexual behavior

The quotation is from a well known paper in the field cited over 100 times according to google scholar: https://doi.org/10.1111/joim.12251

It was an observational study of 30k women over two decades, so very good statistical power.

> As compared to the highest sun exposure group, the mortality rate was doubled (2.0, 95% CI 1.6–2.5) amongst avoiders of sun exposure and increased by 40% (1.4, 95% CI 1.1– 1.7) in those with moderate exposure. We found that the assumption of proportional hazards seemed reasonable.

So at least among Swedish middle aged women, you are twice as likely to die if you avoid the sun, vs. if you are exposed more to the sun, controlling for factors like income, education, smoking, BMI, and exercise.

It was not a RCT, but then almost no studies of all cause mortality are.

A smaller case study of 500 melanoma patients (https://doi.org/10.1093/jnci/dji019) also found that "sun exposure is associated with increased survival from melanoma."

I think sudden and extreme sun exposure, i.e. "staying in an office all year and then going on the beach for 9h on vacation" definitely requires sunscreen, but consistent and moderate sun exposure at a rate that your body can tan and adjust to is probably a net positive for everything from circadian effects to mood and mortality, even accounting for skin cancer risk.

April-May in the US has following benefits:

-out of pocket maximum expenses are capped per calendar year. Typically, healthcare expenses for births happen in the latter half than former, and so you can potentially save a few thousand dollars, and even up to $17.4k (legal max). Post birth complications are plenty, and pelvic floor physical therapy does wonders. Not worrying about costs for these is a huge benefit.

-new resident doctors start in June, so you have less risk of a brand new doctor in April/May when they would have had 10 months of experience

-kid would be 6 months of age by winter season, so eligible for flu vaccine, and now Covid vaccine too during their first winter

-lots of schools have hard cutoffs at Aug 31 or around there. Birthdays before then, kid is in school, and after that, kid has to wait another year to start school. This could mean 6+ months of fewer daycare expenses, easily worth $10k

Gabriele Doblhammer and James W. Vaupel concluded that "month of birth influences adult life expectancy at ages 50+" in their paper [1] in the Proceedings of the National Academy of Sciences (PNAS).

They tracked for 30 years the mortality of all Danes who were at least 50 years old on 1 April 1968 (about 1.4 million people born before April 1918). They also analyzed about Austrians with known birth dates who died between 1988 and 1996 (about 700,000 people born before 1947) and native-born Australians who died between 1993 and 1997 (about 200,000 people born before 1948).

They found in Denmark and Austria that "adults born in autumn (October–December) live longer than those born in spring (April–June). The difference in lifespan between the spring and autumn born is twice as large in Austria (0.6 years) as in Denmark (0.3 years). ... We found the pattern in the Southern Hemisphere to be a mirror image reversal of that in the Northern Hemisphere." British born Australians were statistically closer to the Danes and Austrians.

Their analysis eliminated three hypotheses for these observations: seasonal distribution of deaths, social factors related to seasonal distribution of births, and differential infant survival. Their analysis and other studies of birth weight data led them to conclude that "seasonal differences in nutrition and disease environment early in life [in utero and infancy] could explain the relationship between month of birth and adult lifespan." Over the years, winter and spring nutrition has improved, so "the relationship between month of birth and lifespan seems to be stronger among the older birth cohorts than among the more recently born."

[1] https://www.pnas.org/doi/10.1073/pnas.041431898

Also, in mice [1].

[1]: https://mobile.twitter.com/justsaysinmice

There's similar issues with computer security and having projects reviewed before being shipped, with the classic story of people avoiding review because they didn't think they needed it at the start of their project (not that they're qualified to determine that) and by the time someone told them about it, it was "too late" and they'd miss important deadlines by going through the requisite review.

The only sane solution I've seen to that is to make everything go through security review, even if the review is a simple "we don't need to review this." If everyone knows everything needs review, it makes it very hard to forget about it and incentivizes people to involve security folks with their projects ASAP in the hopes of getting review done early on / avoiding being blocked by it.

You'll always need exceptions to the rule, so you can have some sufficiently high up VP or similar sign off on releasing things without review (and with the caveat that it's still going to get reviewed, it just won't block release), but that's a lot easier to manage than dealing with random developers deciding it for themselves.

It also helps a lot to have a culture where developers learn about security too, but just like researchers and ethics, they'll have perverse incentives to downplay/ignore risks so you still need other, differently incentivized people, to enforce "checks and balances."

It sounds like IRBs are not designed to review all or even most (animal?) experiments and I think that's unfortunate. It seems like a win for everyone if we get better ethics coverage.