MI weekly selection #156
Lots of dark matter may lurk inside dwarf galaxy
Triangulum II, a dwarf galaxy that doesn’t have any star-forming regions, may harbor a vast amount of dark matter. The discovery was made while attempting to measure Triangulum II’s mass. “The total mass I measured was much, much greater than the mass of the total number of stars — implying that there’s a ton of densely packed dark matter contributing to the total mass. The ratio of dark matter to luminous matter is the highest of any galaxy we know,” said California Institute of Technology’s Evan Kirby.
Human domestication may have saved gourds from extinction
Gourds, squash and pumpkins may have survived the extinction of mastodons and other large creatures 10,000 years ago because of human domestication. As long as 30,000 years ago, large creatures weren’t deterred by the plants’ bitterness and distributed the seeds through their dung, but smaller mammals that survived the extinction didn’t care for the bitter taste. About the time mastodons died out, humans started clearing out large areas of land that offered good conditions for pumpkins and gourds to grow
Humans, marine acorn worms have a lot of genes in common
The ocean-dwelling acorn worm shares a surprising number of genes with humans. Acorn worms share about 70% of genes with humans. Humans and acorn worms share a deuterostome ancestor that lived around 500 million years ago.
Being bilingual may help stroke patients recover more easily
Being able to speak more than one language may help people recover from a stroke more easily. The results indicate that patients who are bilingual are more likely to retain normal cognitive functions following a stroke. “People with more mental activities have more interconnected brains, which are able to deal better with potential damage. Language is just one of many ways of boosting the cognitive reserve,” said study co-author Thomas Bak.
Identified gene that makes bacteria resistant to polymyxins
Researchers identified a gene that renders bacteria resistant to polymyxin antibiotics, including colistin, and scientists are calling for a halt to all use of colistin, which is widely used in livestock in many countries. The gene readily passes between bacteria, including pathogens such as E. coli and Klesbsiella pneumoniae, conferring its antibiotic-resistant properties.