James Gross, a psychology professor at Stanford University, has a 13-year-old daughter who loves math and science. “It hasn’t occurred to her yet that’s unusual,” he says. “But I know in the next couple of years, it will.”

She’s already being pulled out of class to do advanced things with a couple of other kids, who are guys. And as someone who studies human emotion for a procession, Gross says, “I know as time goes on, she will feel increasingly lonely as a girl who’s interested in math and science, and be at risk of narrowing her choices in life before finding out how far she could have gone.’’

Gross’ concern clearly shows what has been a touchy subject in the world of science for a long time: Why are there still so few women in science, and how might that affect what we learn from research?

Women now make up half the national workforce, earn more college and graduate degrees than men, and by some estimates represent the largest single economic force in the world. Yet the gender gap in science persists, to a greater degree than in other professions, particularly in high-end, math-intensive fields such as computer science and engineering.

According to US Census Bureau statistics, women in fields commonly referred to as STEM (science, technology, engineering, mathematics) made up 7 percent of that workforce in 1970, a figure that had jumped to 23 percent by 1990. But the rise essentially stopped there. Two decades later, in 2011, women made up 26 percent of the science workforce.

Tens of thousands of ancient pictures carved into the rocks at one of France’s most important tourist sites are being gradually destroyed. Scientists and researchers fear that the 36,000 drawings on rocks in Mont Bego in the French Alps are being damaged so rapidly that they will not survive for future generations.

The mountain, believed to have once been a site for prayer and worship, has 4,000-year-old drawings cut into bare rock. They include pictures of cows, cultivated fields and various gods and goddesses. But as the popularity of the site increases, the pictures are being ruined by thoughtless graffiti (涂鸦).

Jean Clottes is the chairman of the International Committee on Rock Art. He says, “People think that because the pictures have been there so long they will always continue to be there. But if the damage continues as this rate there will be nothing left in 50 years.”

He describes seeing tourists stamping on the drawings, wearing away the rock and definition of the artwork as they do so. Some visitors, he says, even chop off parts to take home as souvenirs.

“When people think they can’t take a good enough photograph, they rub the drawings to get a clearer picture,” he said. “The drawings are polished by the weather, and if the sun is shining and the visitors can’t see them properly they simply rub them to make them look fresher.”

But experts are divided over the best way to preserve the drawings. Henry de Lumley, director of the Museum of Natural History in Paris, believes that the only way to save the site is to turn the whole mountain into a “no-go” area, preventing the public from going there except on guided tours.

Clottes disagrees. “The measure proposed by Henry de Lumley is the most severe, and while it is the most effective, it is also certain to bring about protests from people who live there,” he said. “The site was classified as a historic monument years ago by the Ministry of Culture, and we must do as much as possible to save what is there.”

Take the Money and Run

A Latin phrase beloved by every old-fashioned British schoolmaster was mens sana in corpore sano—a healthy mind in a healthy body. Greater physical activity is associated with better mental, as well as physical health. And it might also be linked to greater worker productivity, and thus faster economic growth. That is the conclusion of a new report from a European think tank—RAND.

The RAND study looks at different measures: absenteeism(when workers take time off for illness)and presenteeism(when they turn up for work but are less productive because of sickness). The latter measure was self-reported by employees, who were asked whether their work was negatively affected by health issues. The survey suggests that between 3 and 4.5 working days each year are lost as a consequence of workers being physically inactive. This is between 1.3% and 2% of annual working time. Most of this was down to presenteeism.

Another potential gain from improved fitness is reduced health-care costs. In America, where health care is often provided through employment-based systems, firms could benefit. RAND estimates that total American health savings could be $ 6 billion a year by 2025. But the study's authors conclude that if people met certain exercise targets, global GDP could be around 0.17-0.24% higher by 2050. Nothing to laugh at in a world of slowing growth.

How to encourage workers to become more active? Rewards are useful but only if they have conditions: giving all employees free gym membership does not seem to work. Another RAND Europe study examined an experiment in which workers were each given an Apple watch, payable in installment (分期付款)at a discounted price—but only to those who agreed to have their physical activity monitored. Monthly repayments depended on how much exercise they took.

If they met the targets they ended up paying 10% of the watch's list price; those who took no exercise paid the full price. This approach takes advantage of a fact that people are eager to avoid paying more. On average, those participating in the scheme undertook 30% more exercise than before.

The problem is that many people are too optimistic about their health, ignoring the risks they face. This means that participation in workplace exercise plans tends to be low, around 7% in the sample studied by RAND. Firms are not the only ones that can encourage a healthier lifestyle; friends and families are likely to be more important. But businesses can play a bigger role.

If RAND is right, this may bring them financial benefits. Company taskmasters may yet grow fond of an adapted saying: mens sana in corporate sano.

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