Nature

You don’t always know what you’re saying

People’s conscious awareness of their speech often comes after they’ve spoken, not before.

If you think you know what you just said, think again. People can be tricked into believing they have just said something they did not, researchers report this week.

The dominant model of how speech works is that it is planned in advance — speakers begin with a conscious idea of exactly what they are going to say. But some researchers think that speech is not entirely planned, and that people know what they are saying in part through hearing themselves speak.

So cognitive scientist Andreas Lind and his colleagues at Lund University in Sweden wanted to see what would happen if someone said one word, but heard themselves saying another. “If we use auditory feedback to compare what we say with a well-specified intention, then any mismatch should be quickly detected,” he says. “But if the feedback is instead a powerful factor in a dynamic, interpretative process, then the manipulation could go undetected.” Read more in Nature.

Dietary fibre acts on brain to suppress appetite

Mouse study suggests that brain activity, not gut hormones, accounts for fibre’s weight-control action.

People have long been told that a diet high in fibre can help to fight obesity, but how it does so has been unclear. A study of mouse metabolism now suggests that a product of fibre fermentation may be directly affecting the hypothalamus, a region of the brain involved in regulating appetite. Read more in Nature.

Sponsor a fish and save Canada’s experimental lakes

Fans of environmental science can now play a direct role in helping Canada’s unique Experimental Lakes Area continue to do the research it has done for decades.

The International Institute for Sustainable Development, based in Winnipeg, took over running the ELA on 1 April, after the federal government eliminated funding for the decades-old environmental research facility (see ‘Test lakes face closure’ and ‘Last minute reprieve for Canada’s research lakes’). The Canadian provinces of Ontario and Manitoba have stepped in to provide money to run the facility and conduct research for the next several years, but more cash is needed to restore research at the ELA to its former levels.

So IISD has turned to the public. It launched an appeal on the crowdfunding site Indiegogo seeking contributions to expand research and make the ELA less dependent on government largesse. Read more in Nature.

The changing colour of fat

The different functions of white, brown and beige fat might yield new targets in the fight against obesity and metabolic disease.

When you think of fat in the human body, you might picture a homogenous, white substance, much like a block of lard. But researchers are learning that the role of fat in metabolism changes depending on where it is in the body, and even on the type of fat cell. Soon these differences could be harnessed to fight metabolic disorders such as diabetes and obesity. Read more in Nature.

Pests worm their way into genetically modified maize

Broadening of rootworm resistance to toxins highlights the importance of crop rotation.

Even with biotech crops, farmers still need to make use of age-old practices such as crop rotation to fight insect pests. That’s the lesson to be drawn from the latest discovery of resistance to the pest-fighting toxins added to maize — also known as corn.

According to a team led by Aaron Gassmann, an entomologist at Iowa State University in Ames, in some Iowa fields a type of beetle called the western corn rootworm (Diabrotica virgifera virgifera LeConte) has developed resistance to two of the three types of Bacillus thurinigiensis (Bt) toxin produced by genetically modified maize. Resistance to one type of Bt toxin has cropped up in the worms in recent years, but now there is a twist — the researchers have found that resistance to that type of Bt toxin also confers protection against another, more recently introduced type. Read more in Nature.

New contender for ‘fat gene’ found

Researchers may have been focusing on the wrong gene.

Scientists studying what they thought was a ‘fat gene’ seem to have been looking in the wrong place, according to research published today in Nature. It suggests instead that the real culprit is another gene that the suspected obesity gene interacts with.

In 2007, several genome studies identified mutations in a gene called FTO that were strongly associated with an increased risk of obesity and type 2 diabetes in humans. Subsequent studies in mice showed a link between the gene and body mass. So researchers, including Marcelo Nóbrega, a geneticist at the University of Chicago, thought that they had found a promising candidate for a gene that helped cause obesity. Read more in Nature.

Storm brewing over WHO sugar proposal

Industry backlash expected over suggested cut in intake.

Scientists are gearing up for a battle with the food industry after the World Health Organization (WHO) moved to halve its recommendation on sugar intake.

Nutrition researchers fear a backlash similar to that seen in 2003, when the WHO released its current guidelines stating that no more than 10% of an adult’s daily calories should come from ‘free’ sugars. That covers those added to food, as well as natural sugars in honey, syrups and fruit juice. In 2003, the US Sugar Association, a powerful food-industry lobby group based in Washington DC, pressed the US government to withdraw funding for the WHO if the organization did not modify its recommendations. The WHO did not back down, and has now mooted cutting the level to 5%. Read more in Nature.

Male scent stimulates female goats’ fertility

Current Biology, Murata et al.

Current Biology, Murata et al.

Single pheromone found to induce ovulation.

The distinctive aroma of goats does more than just make barnyards extra fragrant. Male goats can use their heady scent to make female goats ovulate simply by being near them.

Researchers had ascribed this ‘male effect’ to chemicals known as primer pheromones — a chemical signal that can cause long-lasting physiological responses in the recipient. Examples of primer pheromones are rare in mammals; the male effect in goats and sheep, and a similar effect in mice and rats, where the presence of males can speed up puberty in females, are the only known cases. But exactly what substances are at work and how has remained a mystery. Read more in Nature.

Canadian government accused of destroying environmental archives

Courtesy of Save Ocean Science.

Courtesy of Save Ocean Science.

Researchers fear that valuable documents will disappear as libraries close and merge.

Scientists in Canada are up in arms over the recent closure of more than a dozen federal science libraries run by Fisheries and Oceans Canada (DFO) and Environment Canada.

The closures were mostly completed by last autumn, but hit the headlines last week when pictures of dumpsters full of scientific journals and books began circulating online. Some of facilities that have been closed include the library at the century-old St. Andrews Biological Station in New Brunswick, which had just completed a multi-million-dollar refurbishment a year earlier, and the library at the Freshwater Institute in Winnipeg, Manitoba. The libraries housed hundred of thousands of documents on fisheries and aquatic science, such as historical fish counts and water-quality analyses. Read more in Nature.