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IN BRIEF Have pincers, will grab ride on a bat
Growing corals bathe in acid, confounding expectations HERE’S a surprising twist. Acidic water may actually be a sign of healthy corals, says a new study, muddying the waters still further on our understanding of how coral reefs might react to climate change. Andreas Andersson of the Scripps Institution of Oceanography in San Diego, California, and his colleagues carefully monitored a coral reef in Bermuda for five years, and found that spikes in acidity were linked to increased reef growth (PNAS, DOI: 10.1073/pnas.150721112). “It’s completely the opposite to what we would expect in an ocean-acidification scenario,” says Andersson.
The team discovered that the coral growth itself drove up this local acidity. To build their skeletons, it seems the corals sucked alkaline carbonate out of the water, leaving it more acidic. The results complicate the question of how coral reefs will respond to climate change, which is raising the acidity of the oceans. “Do corals care about ocean pH if they have plenty of food and light? At this point, we don’t fully know the answer to that question,” says Andersson. These corals didn’t seem to mind the fluctuations in local acidity that they created, which were much bigger than those we expect to see from climate change. This may mean that corals are well equipped to deal with the lower pH levels caused by greater acidity.
Gut bugs influence cancer treatment HOW well a cancer treatment works might depend on what’s living in your gut. Mathias Chamaillard at the University of Lille, France, and his colleagues discovered that the skin cancer drug ipilimumab isn’t as effective at treating cancer in mice born without bacteria in their gut, compared with mice with normal bacteria. The drug’s effectiveness also decreased when the normal
mice were given antibiotics to wipe out their gut bacteria. Ipilimumab appears to cause a decrease in two types of gut bacteria, called Bacteroidales and Burkholderiales, suggesting these bacteria interact with the drug. The team took faecal samples from 25 people with skin cancer and tested them for levels of Bacteroidales. When they transplanted the samples into
mice without gut bacteria and gave them ipilimumab, those that received transplants containing more Bacteroidales responded better to the treatment (Science, doi.org/83s). Chamaillard believes the bacteria are influencing the immune system in a way that facilitates the drug. He now plans to test whether the profiles of bacteria living in someone’s gut can predict how well they will respond to cancer treatment.
WHAT’S a tiny invertebrate to do? Getting around can be a struggle when you’re only a few millimetres long, but the jet-setting pseudoscorpion Apatochernes vastus has the answer: hitch a ride on a bat. These arachnids have two large pincers like scorpions do, but no stinging tail. Many species use their pincers to deliver venom to small prey, including insects. But these huge appendages have another use – clinging onto larger animals. “Hitch-hiking is their best way to disperse,” says Graeme Finlayson at Massey University, New Zealand. Pseudoscorpion species around the world have been found stowing away aboard a variety of animals, and now A. vastus has been spotted travelling by bat in New Zealand (New Zealand Journal of Zoology, doi.org/833). “They just grab on to the fur and then off they go,” says Finlayson.
Cage traps light but lets liquid through PHOTONS keep out! Microscopic cages could be built to block light, while letting liquid and gas flow. Boxes can shield objects from light, but when accessing the contents, light slips through any holes you make. That’s a problem for proposed medical techniques using targeted light to control drug release. Now Ali Mirzaei of the Australian National University in Canberra and his colleagues may have a solution: “optical metacages” made from ultra-thin wires. The team simulated a wire 200 nanometres wide and found it absorbed light from up to 100 nanometres from its edge. Placing wires at intervals would make cages that stop light going in or out (Physical Review Letters, in press). 14 November 2015 | NewScientist | 17