Ever met someone who just wasn't into music?
They may have a condition called specific musical anhedonia, estimated to affect 3 to 5 per cent of the population.
Researchers have discovered that people with this condition showed reduced functional connectivity between cortical regions responsible for processing sound and subcortical regions related to reward.
To understand the origins of specific musical anhedonia, the international team recruited 45 healthy participants who completed a questionnaire measuring their level of sensitivity to music, and divided them into three groups of sensitivity based on their responses.
The test subjects then listened to music excerpts inside an fMRI machine while providing pleasure ratings in real-time.
To get a control for their brain response to other reward types, participants also played a monetary gambling task in which they could win or lose real money.
Using the fMRI data, the researchers found that while listening to music, specific musical "anhedonics" presented a reduction in the activity of the nucleus accumbens, a key subcortical structure of the reward network.
Yet the reduction was not related to a general improper functioning of the nucleus accumbens itself, since this region was activated when they won money in the gambling task.
The fact people could be insensible to music while still responsive to another stimulus like money suggested different pathways to reward for different stimuli - a finding that could help scientists understand how listening to music ever became rewarding.
Antibiotic spider silk for drug delivery?
After five years' work, scientists from the University of Nottingham in the UK have developed a technique to produce chemically functionalised spider silk that can be tailored to applications used in drug delivery, regenerative medicine and wound healing.
The research team has shown for the first time how "click-chemistry" can be used to attach molecules, such as antibiotics or fluorescent dyes, to artificially produced spider silk synthesised by E.coli bacteria.
The chosen molecules can be "clicked" into place in soluble silk protein before it has been turned into fibres, or after the fibres have been formed.
This means the process can be easily controlled, and more than one type of molecule can be used to "decorate" individual silk strands.
"Our technique allows the rapid generation of biocompatible, mono or multi-functionalised silk structures for use in a wide range of applications," study co-author Professor Neil Thomas said.
"These will be particularly useful in the fields of tissue engineering and biomedicine."
The weird world of pipefish
In the upside-down world of the pipefish, sexual selection appears to work in reverse, with flashy females battling for males who bear the pregnancy and carry their young to term in their brood pouch.
But new research shows even more factors appear to play a role in determining mating success.
For most species, males compete for access to females: think, a peacock's tail or a deer's antlers.
But in some species, the sex roles are reversed and males carry the brood, as in the case of pipefish and other members of the Syngnathus family, like the seahorse.
In these cases, females must compete for access to available mates, and indeed, researchers have found secondary sex traits, such as brightly coloured ornamentation, evolving in female pipefish instead of males.
Previous studies have also found that large female pipefish, able to transfer more eggs to the male's pouch, are more attractive to the males.
But, in a new study, US and Swedish researchers found the size of male pipefish matters too.
They sampled a population of broad-nosed pipefish in shallow eelgrass beds at the beginning of the breeding season and found that larger males bred first and their offspring had a better chance of surviving.
Large males with larger embryos invested more energy per embryo than smaller males, produced more newborn offspring, and their offspring survived predation better as compared to the offspring from small males.
The study suggested larger males had a clear reproductive advantage in the wild over the smaller males.
And timing was important too - if they bred earlier, they increased their chances of being able to have more pregnancies before the end of the breeding season.
The world's thinnest wire
Meanwhile, US scientists have discovered a way to use diamondoids - the smallest possible bits of diamond - to assemble atoms into the thinnest possible electrical wires, just three atoms wide.
By grabbing various types of atoms and putting them together Lego-style, the new technique could potentially be used to build tiny wires for a wide range of applications, including fabrics that generate electricity, optoelectronic devices employing both electricity and light, and superconducting materials that conduct electricity without any loss.
"What we have shown here is that we can make tiny, conductive wires of the smallest possible size, that essentially assemble themselves," said lead author Hao Yan, a postdoctoral researcher at Stanford University.
"The process is a simple, one-pot synthesis. You dump the ingredients together and you can get results in half an hour. It's almost as if the diamondoids know where they want to go."
The needle-like wires have a semiconducting core - a combination of copper and sulphur known as a chalcogenide - surrounded by the attached diamondoids, which form an insulating shell.