Shedding some genetically induced excess baggage may have helped the tiny Indostomus paradoxus fish thrive in freshwater and outsize its marine ancestors, according to a University of British Columbia study published in Science Express.

Measuring three to 10 centimetres long, stickleback fish originated in the ocean but began populating freshwater lakes and streams following the last ice age. Over the past 20,000 years - a relatively short time span in evolutionary terms - freshwater sticklebacks have lost their bony lateral plates, or "armour," in these new environments.

"Scientists have identified a mutant form of a gene, or allele, that prohibits the growth of armour," says UBC Zoology PhD candidate Rowan Barrett. Found in fewer than one per cent of marine sticklebacks, this allele is very common in freshwater populations.

All drugs used to treat psychosis are linked to an increased risk of stroke, and dementia sufferers are at double the risk, according to a study published on bmj.com today.

Previous research has shown that second generation (atypical) antipsychotic drugs can increase the chances of patients having a stroke. But the risk of stroke associated with first generation (typical) antipsychotics, and whether the risk differs in people with and without dementia, is not known.

Concerns about an increased risk of stroke among people taking atypical antipsychotic drugs were first raised in 2002, particularly in people with dementia. In 2004, the UK's Committee on Safety of Medicines recommended that these drugs should not be used in people with dementia, despite a lack of clear evidence.

There are no lost cities containing aliens and otherworldly technology but ancient settlements in the Amazon, now almost entirely obscured by tropical forest, were once large and complex enough to be considered "urban" as the term is commonly applied to both medieval European and ancient Greek communities, according to a paper in Science authored by anthropologists from the University of Florida and Brazil, and a member of the Kuikuro, an indigenous Amazonian people who are the descendants of the settlements' original inhabitants.

The paper also argues that the size and scale of the settlements in the southern Amazon in North Central Brazil means that what many scientists have considered virgin tropical forests are in fact heavily influenced by historic human activity. Not only that, but the settlements – consisting of networks of walled towns and smaller villages, each organized around a central plaza – suggest future solutions for supporting the indigenous population in Brazil's state of Mato Grosso and other regions of the Amazon, the paper says.

High impact activities such as jumping and skipping that can easily be incorporated into warm-ups before sports and physical education classes, have been shown to benefit bone health in adolescents. The 10 minute school-based intervention, provided twice a week for about eight months, significantly improved bone and muscle strength in healthy teenagers compared to regular warm-ups.

Physiotherapist Ben Weeks said the warm-up which included tuck jumps, star jumps, side lunges and skipping with gradually increasing complexity and repetitions, was specifically designed to apply a bone-stimulating mechanical load on the skeleton. Students worked up to about 300 jumps per session by the end of the study.

LLNL researchers care about the environment too. To keep Mother Nature safe while we blow stuff up, they have added unique green solvents (ionic liquids) to an explosive called TATB (1,3,5-triamino-2,4,6-trinitrobenzene) and improved the crystal quality and chemical purity of the material.

Most explosives belong to a general class of materials called molecular crystals, which have become important building blocks in a number of other applications ranging from drugs, pigments, agrochemicals, dyes and optoelectronics. Many of these materials, including TATB, are bound together by a strong network of hydrogen-bonds. This extended network often makes these materials nearly insoluble in common organic solvents, leading to poor quality and limited size crystals, which in turn hinders progress in many technological applications.

The advantage of using two eyes to see the world around us has long been associated solely with our capacity to see in 3-D. Now, a new study from a scientist at Rensselaer Polytechnic Institute has uncovered a truly eye-opening advantage to binocular vision: our ability to see through things.

Most animals — fish, insects, reptiles, birds, rabbits, and horses, for example — exist in non-cluttered environments like fields or plains, and they have eyes located on either side of their head. These sideways-facing eyes allow an animal to see in front of and behind itself, an ability also known as panoramic vision.

Humans and other large mammals — primates and large carnivores like tigers, for example — exist in cluttered environments like forests or jungles, and their eyes have evolved to point in the same direction. While animals with forward-facing eyes lose the ability to see what's behind them, they gain 'X-ray vision', according to Mark Changizi, assistant professor of cognitive science at Rensselaer, who says eyes facing the same direction have been selected for maximizing our ability to see in leafy environments like forests.