News in Brief
- Health & Medicine
Medicaid-expanding states had fewer cardiovascular deaths than other states
Counties in states with expanded Medicaid eligibility had 4.3 fewer cardiovascular deaths per 100,000 residents, on average, than if they hadn’t expanded.
- Genetics
DNA reveals ancient Siberians who set the stage for the first Americans
A previously unknown population of Ice Age people who traveled across Beringia was discovered in Russia.
- Particle Physics
Physicists have finally figured out how pentaquarks are built
The particles are made of up two smaller particles, stuck together like atoms in a molecule.
- Genetics
Almost all healthy people harbor patches of mutated cells
Even healthy tissues can build up mutations, some of which have been tied to cancer.
- Oceans
Tiny plastic debris is accumulating far beneath the ocean surface
Floating trash patches scratch only the surface of the ocean microplastic pollution problem.
- Animals
Tiny structures in dragonfish teeth turn them into invisible daggers
The teeth of deep-sea dragonfish are transparent because of nanoscale crystals and rods that let light pass through without being scattered.
- Environment
How one fern hoards toxic arsenic in its fronds and doesn’t die
To survive high levels of arsenic, a fern sequesters the heavy metal in its shoots with the help of three proteins.
- Physics
This tabletop device turns the quantum definition of a kilogram into a real mass
The mini Kibble balance will measure 10 grams to an accuracy of a few ten-thousandths of a percent.
- Climate
Thousands of birds perished in the Bering Sea. Arctic warming may be to blame
A mass die-off of puffins and other seabirds in the Bering Sea is probably linked to climate change, scientists say.
- Archaeology
Cave debris may be the oldest known example of people eating starch
Charred material found in South Africa puts energy-rich roots and tubers on Stone Age menus, long before farming began.
- Paleontology
Fossils reveal saber-toothed cats may have pierced rivals’ skulls
Two Smilodon fossil skulls from Argentina have puncture holes likely left by the teeth of rival cats.
- Anthropology
Africa’s first herders spread pastoralism by mating with foragers
DNA unveils long-ago hookups between early pastoralists and native hunter-gatherers in Africa.
