Caffeine has no effect on submaximal running in hypoxia in low caffeine consuming males and females.

Background: Exposure to hypoxia immediately challenges a variety of physiologic systems that limit exercise capacity. Under normoxia, caffeine (CAFF) increases ventilation and subsequent oxygenation of hemoglobin (SpO2) and skeletal muscle (SmO2). CAFF improves exercise performance at altitude.

Large motherhood penalties in US administrative microdata.

Whereas previous research has described motherhood penalties in US survey data, we leverage administrative data on 811,000 quarterly earnings histories from the US Unemployment Insurance program. We analyze contexts where smaller motherhood penalties might be expected: couples where the woman outearns her male partner prior to childbearing, at firms that are headed by women, and at firms that are predominantly women. Our startling result is that none of these propitious contexts appear to diminish the motherhood penalty, and indeed, the gap often increases in magnitude over time following childbearing.

Reduced trolling on Russian holidays and daily US Presidential election odds.

Russian trolls generally supported the Trump campaign and were particularly active on Twitter 2015-2017. We find that trolling fell 35% on Russian holidays and to a lesser extent, when temperatures were cold in St. Petersburg.

Perinatal health among 1 million Chinese-Americans.

The literature on "missing girls" suggests a net preference for sons both in China and among Chinese immigrants to the West. Perhaps surprisingly, we find that newborn Chinese-American girls are treated more intensively in US hospitals: they are kept longer following delivery, have more medical procedures performed, and have more hospital charges than predicted (by the non-Chinese gender difference). What might explain more aggressive medical treatment? We posit that hospitals are responding to worse health at birth of Chinese-American girls.

Livestock plants and COVID-19 transmission.

Policy responses to the COVID-19 outbreak must strike a balance between maintaining essential supply chains and limiting the spread of the virus. Our results indicate a strong positive relationship between livestock-processing plants and local community transmission of COVID-19, suggesting that these plants may act as transmission vectors into the surrounding population and accelerate the spread of the virus beyond what would be predicted solely by population risk characteristics. We estimate the total excess COVID-19 cases and deaths associated with proximity to livestock plants to be 236,000 to 310,000 (6 to 8% of all US cases) and 4,300 to 5,200 (3 to 4% of all US deaths), respectively, as of July 21, 2020, with the vast majority likely related to community spread outside these plants.