Discovered: Men and women heal differently; doubling up on algebra improves learning; ears are flawed; revising financial statements indicates poor governance.

Men and women heal differently. For decades, the field of medicine has operated under the assumption that research based on male subjects can be applied to females as well. But as group of German researchers have compiled evidence that symptoms of illness can dramatically differ between men and women. Take heart disease: "Typically perceived as a male illness, cardiovascular disease often displays markedly different symptoms among women. While a constricted chest and pain that radiates through the left arm are standard signs of heart attack in men, in women the usual symptoms are nausea and lower abdominal pain." The evidence could influence the way studies are carried out, since "medical researchers still know very little about gender-specific differences in illness." [Clinical Chemistry and Laboratory Medicine]

Doubling up on algebra improves learning. Ten years ago, the head of Chicago Public Schools instituted an extended period for instruction among 9th graders studying algebra, in hopes that doubling the length of a class would lead to better test scores. It seems to have worked, according to a study that tracked the success of the students who took the doubly long classes: "Double-dosing had an immediate impact on student performance in algebra, increasing the proportion of students earning at least a B by 9.4 percentage points, or more than 65 percent." The impact extended even further, increasing the rates of high school graduation and college enrollment among students who doubled up. [Education Next]

Ears are flawed. The portion of our ear called the middle ear, made up of three bones which transfer waves of sound striking the ear drum to the fluid of the cochlea, is rather flawed, a London-based developmental biologist says. Due to the way ears are formed in the early stages of life, they're especially prone to infection — to say nothing of their sensitivity to even slight differences in barometric pressure. (Our ears continue to pop on the L train as it passes beneath the East River.) Ear tissue "isn’t great at forming barrier linings. Its patch in the middle ear tends to flake off when infected. And it doesn’t form the forest of protective hairlike cilia that sweeps away debris in the rest of the middle ear." [Science News]

Revised financial statements indicates poor governance. We're looking at you, Groupon. After tracking the performance of companies that had to revise past financial statements, researchers at Concordia University in Canada discovered that such revisions tend to indicate that the company is managed poorly. "Restated companies were more likely to replace their presidents, CEOs, CFOs and/or external auditors, and to increase the number and proportion of unrelated directors and audit committee members," the researchers found. This, of course, bears out in American companies, too. Andrew Mason, the eccentric CEO of Groupon, resigned at the beginning of this month, a year after the company had to revise its fourth quarter results. [Journal of Corporate Finance]