Health & Science

A Viking Wonder Woman

Historical accounts of female Viking warriors are often discounted as myths. But new DNA tests of a warrior buried in Sweden more than 1,000 years ago provide the first genetic evidence that some women held powerful, high-status positions in Viking culture. The 10th-century grave site, which was uncovered in the 1880s, contained a sword, arrows, a battle knife, a spear, shields, and two horses. The Viking, who stood 5-foot-6, was also buried with a set of game pieces—an indication of the deceased’s expertise in battle tactics. The archaeologists who uncovered the grave 130 years ago assumed it belonged to a high-ranking male warrior. “I think that’s a mistake that archaeologists make quite often,” archaeologist Becky Gowland tells The Guardian. “When we do that, we’re just reproducing the past in our image.” A recent DNA analysis revealed that the Viking leader lacked a Y chromosome— confirming that “he” was actually a “she.”

The extinction of parasites

Climate change could wipe out up to onethird of the Earth’s 3.5 million known parasite species over the next 53 years. That might sound like a good thing, but scientists warn that the extinction of pests such as tapeworms, fleas, and ticks could dramatically alter the delicate balance of ecosystems around the world, The New York Times reports. An international team of scientists mapped the global distribution and habitats of 457 different species of parasites and analyzed how climate change could affect them. Up to 30 per cent of parasite species, they concluded, may be extinct by 2070. A mass die-off could produce many undesirable consequences: Where parasites help control their hosts’ populations, those populations could grow out of control, the way deer did when wolves left their habitats. Other parasites might flourish in the absence of competition. Still others could migrate to new ecosystems, invading new species. An example: the mosquitoes that carry the Zika virus spreading north into the U.S. Colin Carlson, lead author of the study, said parasites are “a huge and important part of ecosystems,” and warned that extinctions will hav e consequences we can’t foresee.

Yoga’s brain boost

Yoga and meditation are becoming increasingly mainstream activities in the U.S., and new research helps explain why. Daily sessions of either practice can have dramatic effects on brain function. Scientists asked 31 healthy people to engage in 25 minutes of hatha yoga, mindfulness meditation, and quiet reading in random order. Mental tasks completed before and after each session found that yoga and meditation led to greater improvements in the participants’ energy level, mood, executive function, and ability to control thoughts and emotions. “Hatha yoga and mindfulness meditation both focus the brain’s conscious processing power on a limited number of targets, like breathing and posing, and also reduce processing of nonessential information,” the study’s co-author, Peter Hall, tells ScienceDaily.com. That mental training, he said, apparently enables people “to focus more easily on what they choose to attend to in everyday life.”

Health scare of the week

The toxins in tattoos

Tiny toxic particles from tattoo ink can travel through the body and accumulate in the lymph nodes, which could have longterm health consequences, according to a new study. In addition to pigments, tattoo ink contains molecules from preservatives and contaminants such as nickel, chromium, manganese, and cobalt. To track where these molecules go, scientists targeted one of the most common ingredients of tattoo ink: titanium dioxide, a white pigment that is often mixed with other colors. The researchers used X-ray fluorescence to analyze the lymph nodes of four deceased people who’d had tattoos. Lymph nodes serve a critical role in the immune system, filtering toxins and cancer cells and storing immune cells that fight infection. The tests confirmed the accumulation of titanium dioxide nanoparticles in lymph nodes, which suggests contaminants collect in them, too, Smithsonian.com reports. It’s unknown how deposits of microscopic contaminants could affect the lymph nodes and the immune system. “When someone wants to get a tattoo, they are often very careful in choosing a parlor where they use sterile needles,” says the study’s co-author, Hiram Castillo. “No one checks the chemical composition of the colors, but our study shows that maybe they should.”

NASA, Hjalmar Stolpe/Evald Hansen, Newscom ■