Ruminant cows and sheep account for a major proportion of the methane produced around the world - an estimated 20 percent of global methane emissions stem from ruminants.

In the atmosphere, methane is a shorter-term problem than CO2 but has 23X the warming effect  – that's why researchers are looking for ways of reducing methane production. Comparatively little is known about the methane production of other animal species, but one thing seems to be clear: Ruminants produce more of the gas per amount of converted feed than other herbivores.

The La Brea Tar Pits in California are known for saber-toothed cats and mastodons but they also have insects. Recent examination of fossil leafcutter bee nest cells, led by Anna Holden of Natural History Museum of Los Angeles County and colleagues, reveal insights into the habitat and climate at the La Brea Tar Pits toward the last Ice Age. 

Holden conducted the study with bee specialists Jon B. Koch and Dr. Terry Griswold from Utah State University, paleobotanist Dr. Diane M. Erwin, from the University of California Berkeley, and Justin Hall from NHM, who used micro CT scans to reconstruct images of the nest cells and bees.

Older people without dementia but who are starting to have memory and thinking problems may have a lower risk of dying from cancer, according to a paper in Neurology. People with dementia are less likely to develop cancer also.

The study involved 2,627 people age 65 and older in Spain who did not have dementia at the start of the study. They took tests of memory and thinking skills at the start of the study and again three years later, and were followed for an average of almost 13 years. The participants were divided into three groups: those whose scores on the thinking tests were declining the fastest, those whose scores improved on the tests, and those in the middle.

Speculation goes that part of the problem for the RMS Titanic, which set out on its maiden voyage 102 years ago today, was bad luck; an exceptional number of icebergs.

Not really, according to a new analysis. There are more icebergs now.

Previously it had been suggested that the seas which sank the famous cruise ship had an exceptional number of icebergs, caused by lunar or solar effects, but using data on iceberg locations dating back to 1913 – recorded to help prevent a repeat of the Titanic – they have shown that 1912 was a significant ice year but not extreme.

The reconstruction of an extinct meat-eating marsupial's skull, Nimbacinus dicksoni, suggests that it may have had the ability to hunt vertebrate prey exceeding its own body size, according to results published April 9, 2014, in the open access journal PLOS ONE by Marie Attard from the University of New England together with colleagues from the University of New South Wales.

Growing agave and other carefully chosen plants amid photovoltaic panels could allow solar farms not only to collect sunlight for electricity but also to produce crops for biofuels, at least according to computer models.