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.

An international team of scientists has identified a common phenomenon in galaxies that could explain why huge numbers of them turn into cosmic graveyards.

Galaxies begin their existence as lively and colourful spiral galaxies, full of gas and dust, and actively forming bright new stars. However, as galaxies evolve, they quench their star formation and turn into featureless deserts, devoid of fresh new stars, and generally remain as such for the rest of their evolution. But the mechanism that produces this dramatic transformation and keeps galaxies turned off, is one of the biggest unsolved mysteries in galaxy evolution.

In an article published online ahead of print on May 25, 2016 in Nature, investigators at the Medical University of South Carolina (MUSC) report that, during sensory stimulation, increases in blood flow are not precisely "tuned" to local neural activity, challenging the long-held view that vascular and local neural responses are tightly coupled.

Many brain-imaging techniques that rely on changes in the flow and oxygenation of blood--including functional magnetic resonance imaging (fMRI)--assume that vascular changes reflect a proportional change in local neural activity.

During and after chemotherapy, many cancer patients describe feeling a mental fog, a condition that has been dubbed "chemo brain." Why this happens is unclear, but researchers have found a new clue to understanding this syndrome. A study in the journal ACS Chemical Neuroscience reports that chemotherapy in rats affects their chemical messengers dopamine and serotonin, which are associated with cognition.

COLUMBIA, Mo. (May 25, 2016) - Approximately half of patients hospitalized with traumatic brain injuries are anemic, according to recent studies, but anemia's effects on the recovery of these patients is not clear. Now, researchers from the University of Missouri School of Medicine have found evidence that anemia can negatively influence the outcomes of patients with traumatic brain injuries.

When it comes to mating, male animals show off the flashiest of ornaments to convince females of their suitability. A peacock's ornate tail may be the best-known example of a mate-attracting ornament, but a new study finds that peacock tails have nothing on a tail of another kind. Sperm tails in fruit flies are the most extreme ornament ever described.