When you fall down, get back up again.
There is great wisdom in the Japanese proverb “fall down seven times, stand up eight”, with science showing that falling over actually makes you better at motor learning.
The brain uses responses to mistakes to refine our motor skills, paying special attention to potentially dangerous ones such as slipping or stumbling. But in most laboratory-based research on motor learning, mistakes have no dangerous consequences.
In a study out of Simon Fraser University, Canada, researchers decided to add an element of risk. Participants wearing prism goggles walked until they stepped their right foot onto a target, where the goggles would warp their visual field and shift everything to the right. One group had a slippery surface hidden to the right of the target. The participants continued to slip until they learned to correctly adjust their steps to the left side. They were tested for over a week, slipping and tripping.
While the slip group and control group adjusted to the goggles at a similar rate, those in the slip group were able to perform better in new tasks, including stepping on the target with their left foot or stepping over obstacles.
This research, published in eNeuro, shows that the more challenging hurdles we face, the better we learn.
Cue Chumbawamba song…
We’ve underestimated how much trouble our reptiles are in
The International Union for Conservation of Nature’s (IUCN) Red List of Threatened Species is a globally comprehensive assessment of the extinction risk of species, and informs on policy and management. However, due to a lack of data, 28% of reptile species remain unassessed, and 14% of those assessed have been classified as data deficient (DD).
Using computer modelling techniques, an international team of scientists has been able to calculate with high accuracy the vulnerability of 4,369 reptile species currently unassessed or deemed DD by the IUCN.
Using these models, the team was able to classify species into the threatened/nonthreatened category with 90% accuracy, and predicted extinction-risk categories with 84% accuracy. While this means we can gauge the extinction risks for more species, it also means we’ve realised more reptile species are in trouble than previously thought.
“Altogether, our models predict that the state of reptile conservation is far worse than currently estimated, and that immediate action is necessary to avoid the disappearance of reptile biodiversity,” the authors conclude. “Regions and taxa we identified as likely to be more threatened should be given increased attention in new assessments and conservation planning. Lastly, the method we present here can be easily implemented to help bridge the assessment gap on other less known taxa.”
You can read more about this in PLOS Biology.
Earth’s wobble shortened ice-age cycles
Ice ages are currently occurring every 100,000 years or so, when the massive northern hemisphere ice sheets wax and wane. Prior to one million years ago, these cycles lasted only 40,000 years at a time. While scientists know that the Earth’s obliquity, which is the planet’s angle as it orbits around the Sun, is partly responsible for ice ages, they weren’t sure why the cycles became longer during the early Pleistocene.
New work, published in Science, has identified that precession, which is the Earth’s wobble as it rotates, is likely responsible for the lengthening of ice-age cycles. Much like a spinning top wobbling slightly off-centre, the angle of the wobbles means that sometimes the northern hemisphere or the southern hemisphere is closest to the sun, creating a warmer summer in one hemisphere every 10,000 years.
Using glaciation records spanning the past 1.7 million years, scientists can confirm that obliquity alone was sufficient to end a glacial cycle before the Pleistocene, with ice-sheet expansion consistently linked to a decrease in obliquity; whereas during the mid to late Pleistocene, precession became more a main player, with precession minima linked to mass ice-wasting events.
“These findings are the culmination of a major effort, involving more than 12 years of painstaking work in the laboratory to process nearly 10,000 samples and the development of a range of new analytical approaches,” says lead author Professor Stephen Barker, from Cardiff University, UK.
“Thanks to this we can finally put to rest a long-standing problem in paleoclimatology and ultimately contribute to a better understanding of Earth’s climate system.”
How to tie-dye your own cotton with acorns and rust
For thousands of years, natural materials have been used as dyes, as well as mordants, which are substances that help stick the dye to fibres.
A group of chemical engineers from the Manhattan College School of Science, US, has shown you can do your own tie-dye using acorns, which have brown-coloured tannins, and orange-coloured rust from iron as a mordant. The reaction of these two materials created a third dark-blue, almost black, colour, allowing the team to experiment with colours and designs on cotton napkins.
The napkins were wrapped in rubber bands, and soaked in an acorn dye bath, then dipped in a rust and vinegar solution. Even though all the dyeing solutions are safe to tip down the drain, the researchers used gloves, lab coats and goggles to protect their eyes and clothing from staining.
The activity, published in the Journal of Chemical Education, is a fun and environmentally friendly process for tie-dying cotton that can be done under minimal supervision. You can even tailor your DIY tie-dye to the native materials you have on hand – for example, eucalyptus leaves and bark can produce a variety of beautiful colours.
Qamariya Nasrullah holds a PhD in evolutionary development from Monash University and an Honours degree in palaeontology from Flinders University.
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