Have Global Temperatures Reached a Tipping Point?

Adverse trends in male reproductive health: we may have reached a crucial ‘tipping point’

Healthy men produce an enormous number of sperms, far more than necessary for conception. However, several studies suggest that semen samples where the concentration of sperms is below 40 mill/mL may be associated with longer time to pregnancy or even subfertility, and specimens where the concentration of sperms is below 15 mill/mL may carry a high risk of infertility. Historic data from the 19...

The future of employment-based health benefits: have employers reached a tipping point?

The 30-year war on AIDS: have we reached the tipping point?

I is truly an honor to receive the Thomas Parran Award, and I wish to express my deep thanks and gratitude to the American Sexually Transmitted Diseases Association and the Thomas Parran Award Committee for selecting me to receive this prestigious award. I would like to recognize the support of my colleagues who provided mentorship and guidance to me throughout my career. My lifelong interest i...

Demand for Preexposure Prophylaxis Reached a Tipping Point in the Usa

Recent findings PrEP demand has reached a tipping point in the USA and is increasing rapidly. Although the primary benefit of PrEP use is biological, to reduce risk of HIV infection, PrEP users often express an alternative set of social and emotional benefits that are provided by PrEP. These collateral benefits of PrEP have salience, affect, and are experienced in the present, which are compell...

Does the Arctic sea ice have a tipping point?

[1] Two IPCC fourth assessment report climate models have Arctic Ocean simulations that become sea-ice-free year around in 1%/year CO2 increase to quadrupling experiments. These runs are examined for evidence of accelerated climate change associated with the removal of sea ice, particularly due to increasing surface albedo feedback. Both models become seasonally ice-free at an annual mean polar...