Mammals have an exquisitely tuned sensory system that tells them whether they are smelling an orange or a rose. Like keys on a piano keyboard, each component of an odor blend strikes only one chord of olfactory neuron activation. These chords are combined to form a melody that is "heard" in the brain as distinctly citrusy or sweet and flowery.

Smell in mammals turns out to be more complex than we thought. Rather than one receptor family exclusively dedicated to detecting odors, a study in mice reports that a group of neurons surrounding the olfactory bulb use an alternative mechanism for catching scents. These "necklace" neurons, as they're called, use this newly discovered olfactory detection system to respond to odors that elicit instinctive responses, such as pheromones and the smell of seeds and nuts. Harvard researchers report the finding May 26 in Cell.

Malnourished children are most likely to die from common infections, not starvation. New experimental evidence, reviewed May 26 in Trends in Immunology, indicates that even with a healthy diet, defects in immune system function from birth could contribute to a malnourished state throughout life. Researchers speculate that targeting immune pathways could be a new approach to reduce the poor health and mortality caused by under- and overnutrition.

Through new experiments involving the famous Schrödinger cat state paradox, researchers have shown that a "quantum cat" can be both alive and dead, and in two places at once.

The results, which involve inducing a large number of photons to have matching states (or to become entangled), show the ability to manipulate complex quantum states, with applications for computation and long-distance communication. They also represent perhaps the first time scientists have been able to achieve such quantum coherence at a macroscopic scale. 

A research team co-led by a scientist at New Zealand's University of Otago has sequenced the first complete mitochondrial genome of a 2500-year-old Phoenician dubbed the "Young Man of Byrsa" or "Ariche".

This is the first ancient DNA to be obtained from Phoenician remains and the team's analysis shows that the man belonged to a rare European haplogroup -- a genetic group with a common ancestor -- that likely links his maternal ancestry to locations somewhere on the North Mediterranean coast, most probably on the Iberian Peninsula.

The findings are newly published in the prestigious international journal PLOS ONE.

Meerkats live in groups of up to 50 individuals, yet a single dominant pair will almost completely monopolise reproduction, while subordinates help to raise offspring through feeding and babysitting. Since only a small minority of individuals ever get to be dominants, competition for the breeding role is intense in both sexes and females are unusually aggressive to each other.

Within groups, subordinate females are ranked in a hierarchy based on age and weight, forming a "reproductive queue". When dominant females die, they are usually replaced by their oldest and heaviest daughter, though younger sisters sometimes outgrow their older sisters and can replace them in breeding queues.