Observations from orbit have identified clay and sulfate minerals in the lower layers, indicating a wet history.

ENGADGET: NASA's Curiosity rover receives long-distance OTA update, 'brain transplant' on Mars

Though Texas increasingly looked like a broad, bragging California, full of high-tech clusters and with the white Anglo culture besieged by Latinos and Asians, Mrs Richards was well aware of the unchanging lower layers.

ECONOMIST: Ann Richards

Pipes have now been put in place in Lake Nyos and nearby Lake Monoun to siphon water from the lower layers up to the surface and allow the CO2 at the bottom of the lake to slowly bubble out, preventing a repeat of 1986 tragedy.

BBC: 1986: Hundreds gassed in Cameroon lake disaster

An ectopia is a collection of several hundred nerve cells that have pushed their way up from the lower cortical layers into the outermost one, where they are not found in normal circumstances.

ECONOMIST: Reading minds | The

Most investors even those with several million dollars to invest--are often steered to funds of funds, which have lower minimums but several layers of fees.

FORBES: Growing Pains

But those lower-energy X-rays can be further distorted by layers of gas between the black hole and the Earth, and previous spin observations have been contentious.

BBC: First glimpse of a black hole's spin

The lower thirds of the paintings, below the false ceiling, are covered by two layers of emulsion.

BBC: Evelyn Gibbs murals to be uncovered at Nottingham church

SOLACE, the body that represents senior managers in local government, voluntary turnover in the two top layers below chief executive averages 7% a year, compared with 12% lower down the organisation.

ECONOMIST: The pay is better than it was. The bureaucracy is worse