The PT article is called "Women in Physics: A Tale of Limits" by Rachel Ivie and Casey Langer Tesfaye (Feb. 2012). In 2009 and 2010, the Working Group on Women in Physics of the International Union of Pure and Applied Physics did a large international survey to determine the status of women physicists worldwide. They surveyed 15,000 women and men physicists from 130 countries, asking questions to reveal where women may be limited in their careers.
Results are given related to career-advancing activities that respondents experience. Examples are invited speaker at conferences, leader of a group, editor of a journal and serving on conference organizing committees. They gave the numbers and I couldn't resist doing my own analysis. Here is my summary plot of the ratio of women to men experiencing different activities as a function of the importance of the activity.
In an effort to reduce bias, I first ranked the importance of the listed activities without looking at the numbers. Here is my rank ordering with larger being more important. Maybe you would have different values on some, but probably not much different.
IMPORTANCE RANKING OF ACTIVITIES
1. Attended a conference abroad
2. Served on thesis or dissertation committees (not as an adviser)
3. Advised undergraduate students
4. Served on an organizing committee for a conference in your field
5. Served on committees for grant agencies
6. Conducted research abroad
7. Advised graduate students
8. Served as editor of a journal
9. Served on important committees at your institute or company
10. Gave a talk at a conference as an invited speaker
11. Acted as a boss or manager
Looking at the plot, there is a clear trend, with a few outliers, of fewer women for more important activities. The outliers may show that my ranking of importance is not reality. For example, I ranked "serving on a thesis committee" low but it did not do well on the access ration. There may be more prestige to serving on a thesis committees than I judged.
One reason for the overall correlation is probably that activities of higher importance such as invited talks and group leadership are ones that older scientists have more access to and the ratio of women to men is lower for older age.
It is important to see the numbers and understand their implications. As stated in the PT article: "We believe the results reflect an underlying reality of disadvantage and that all the sex-based differences documented here adversely affect the careers of women physicists." With knowledge of the biases, all of us can work to reduce them.