A unique set of observations, obtained with ESO's VLT, has allowed astronomers to find direct evidence for the material that surrounded a star before it exploded as a Type Ia supernova. This strongly supports the scenario in which the explosion occurred in a system where a white dwarf is fed by a red giant.

Because Type Ia supernovae are extremely luminous and quite similar to one another, these exploding events have been used extensively as cosmological reference beacons to trace the expansion of the Universe.

Volcanologist Sarah Fagents from the University of Hawaii at Manoa had an amazing opportunity to study volcanic hazards first hand, when a volcanic mudflow broke through the banks of a volcanic lake at Mount Ruapehu in New Zealand.

Fagents and colleagues were there on a National Science Foundation (NSF)-funded project to study the long-forecast Crater Lake break-out lahar at Mount Ruapehu.

A research team headed by Yadong Yin at the University of California, Riverside has created a liquid that changes its color “on demand” and can take on any color of the rainbow.

Nanoscopic particles made of tiny magnetic crystals coated with a plastic shell self-assemble in solution to form photonic crystals—semiconductors for light. When a magnetic field is applied, the optical properties of the crystals change, allowing their color to be very precisely adjusted through variation of the strength of the field.

The crystals involved are not “conventional” lattices of ions or molecules like the ones for salt. They are colloidal crystals, periodic structures that form from uniform solid particles that are finely dispersed in a liquid.

Dr. Éric A. Cohen, Director of the Human Retrovirology Research Unit at Institut de recherches cliniques de Montréal, and his team have published a discovery that could lead to the development of a new class of drugs to combat HIV.

Human immunodeficiency virus type 1 (HIV-1) causes AIDS by depleting essential immune cells called CD4+T lymphocytes in infected individuals, resulting in a compromised immune system. At the center of this process is the HIV protein, viral protein R (Vpr), which stops infected CD4+T cells from dividing and as a consequence compromises their immune function.

In addition, by arresting cell division, Vpr helps HIV to harness the infected cell’s resources to enhance viral replication.

When a strand of DNA breaks in the body's cells, it normally does not take long until it has been repaired. Now researchers at the Swedish medical university Karolinska Institutet have discovered a new mechanism that helps to explain how the cell performs these repairs.

The new results examine a phenomenon called 'cohesion', whereby two copies of a chromosome in the cell nucleus are held tightly together by a protein complex called cohesin. Cohesion fulfils an important function during cell division as the newly copied chromosomes, the sister chromatids, have to stay together until the right moment of separation. If the chromatids come apart too early, there is a risk of the daughter cells getting the wrong number of chromosomes, something that is often observed in tumor cells.

In an experiment modeled on the classic “Young’s double slit experiment” and published in the journal Nature Nanotechnology, researchers have powerfully reinforced the understanding that surface plasmon polaritons (SPPs) move as waves and follow analogous rules.

The demonstration reminds researchers and electronics designers that although SPPs move along a metal surface, rather than inside a wire or an optical fiber, they cannot magically overcome the size limitations of conventional optics.

Touted as the next wave of electronics miniaturization, plasmonics describes the movement of SPPs -- a type of electromagnetic wave that is bound to a metal surface by its interaction with surface electrons.