Today's Globe: sharps, tomatoes, high-tech cowboy, public health numbers, silent strokes, problem child

Each week in Massachusetts homes, patients use an estimated 2 million needles to inject medication to treat diabetes, arthritis, multiple sclerosis, and other ailments. There are so many needles -- and so many more patients expected to need them -- that Massachusetts health authorities are moving to end the practice of patients depositing them with the rest of their waste.

At least 17 Massachusetts residents have been sickened by salmonella from raw tomatoes - part of a nationwide outbreak that has struck more than 750 people since April. Ken Lee, director of the Ohio State University Food Safety Center, about the possible causes of the outbreak, and what consumers should know to eat safely.

In a research project aimed at helping cattle farmers corral their herds more efficiently, a team from the Massachusetts Institute of Technology and the US Department of Agriculture has devised a way to remotely issue commands to cows.

Elena Naumova (left) is a mathematician who studies public health figures; she creates the statistics you don't want to end up as.

Routine brain scans in a group of middle-aged people showed that 10 percent had suffered a stroke without knowing it, raising their risk for further strokes and memory loss, US researchers said.

Also in Health/Science, will diet help combat inflammatory woes such as arthritis and how do a neutron star and a black hole differ?

On the op-ed page:

"Our society is at risk of raising a significant proportion of the next generation on psychotropic medications," Claudia Meininger Gold, a pediatrician in Great Barrington, writes. "To change this, a paradigm shift is needed in how we think about children, behavior, and relationships."