Norman Garrick, author of one of my favorite papers on the built environment's effect on health, on why Amsterdam is so good for bikes:

1. All streets are bike streets

2. Separated cycle tracks, not bike lanes

3. When possible, go completely car free

4. Two speeds, both slow

5. Stress-free intersections

That favorite paper? Right here: Community design, street networks, and public health

“A French scientist caused a sensation in 1907 when he recounted an experiment showing that the lips of a woman kissed by a mustached man were polluted with tuberculosis and diphtheria bacteria as well as food particles and a hair from a spider’s leg.”

Is dockless bike sharing the next Uber?

FWIW, I hate the "Uber for ...." thing. But I'm told that it's interesting shorthand for investors. The part of this article I'm fascinated by is the "dockless" part. To my reading, dockless bike stations eliminate so many of the traditional obstacles of traditional bike shares. Less permitting, less infrastructure, less up front expense. I even wonder if they're the way that small- to medium-sized towns get into the bike share game. But you can't just ignore the city governments:

'Technically the dockless companies can enter a market without asking permission. They only need to leave some bikes around the city, and anyone with the app can start riding. But since bikes are portable and can be left anywhere, they’re vulnerable. An unhappy city regulator could round them up and haul them away at any time. “[This is] ask permission, not forgiveness,” Jordan says, reversing a popular Silicon Valley mantra. “It’s not like Lyft, where the cars are moving around, or Airbnb, where you don’t publish the address.”'

The fertility business is booming, especially on the sperm donor side

Up front: I'm totally, 100% on board with whatever fertility treatments people need to receive in order to reproduce. But there are soooo many weird quotes in this:

"Want your sperm donor to have a B.A. in political science? Want your egg donor to love animals? Want the genes of a Division I athlete? All of these are possible. Prospective parents overwhelmed by all the choices can leave it to the heavens and pick a donor by astrological sign."

and:

'The Seattle Sperm Bank categorizes its donors into three popular categories: “top athletes,” “physicians, dentists and medical residents,” and “musicians.”'

But some of the quotes from donors are heartbreakingly sweet:

'The donor said she was a “homebody” who loves taking pictures and being with family on the beach. Her personal goals, she wrote, include being “the best possible mom I can be for my children. I want to be ‘present’ when I am with them and invest into their lives. . . . I want my life to matter.”'

Here is the original Nature paper describing the synchronization of women's menstrual cycles