The impact of HIV in Zimbabwe since the early 1980s is explored in new research published this week in the journal PNAS.

Researchers found that HIV’s impact on Zimbabwe’s population as a whole has not been quite as severe as some predicted in 1989, when a group of epidemiologists at a World Health Organisation meeting modelled its potential effects. Some of the models they created suggested that the population of Zimbabwe might start shrinking, with more people dying than being born.

The new research shows that the population of the country continues to grow. However, in the worst affected areas, HIV has reduced the level of population growth by two thirds, from 2.9% to 1.0% each year.

Sheets of highly organized epithelial cells line all the cavities and free surfaces of the body, forming barriers that control the movement of liquids and cells in the body organs. The organized structure of normal breast epithelial cells may also serve as a barrier against cancer, according to a study by University of Helsinki scientists.

Finnish researchers found that the tightly organized architecture of mammary epithelial cells is a powerful restraint against the cancer gene provoked inappropriate proliferation. Their study also links function of a tumor suppressor gene to the development of cancer gene resistant epithelial organization.

Between 5 and 10 degrees of cooling was the success criteria for the first milestone in a project involving magnetic cooling at Risø National Laboratory – Technical University of Denmark (DTU) and the first milestone has been achieved.

The figure is currently at 8.7°C; this means that a refrigerator at room temperature (20°C) can be cooled to almost 11°C, not quite enough to keep milk cold, but the project’s test setup is enough to achieve the objective of conducting research in different materials, varying operating conditions and the strength of the magnetic field.

“The setup is not the largest of its type, but the most important thing is that it ’s easy to exchange parts in the machine.

When white dwarf stars explode, they leave behind a rapidly expanding cloud of 'stardust' known as a Type Ia supernova. These exploding events, which shine billions of times brighter than our sun, are all presumed to be extremely similar, and thus have been used extensively as cosmological reference beacons to trace distance and the evolution of the Universe.

Astronomers have now – for the first time ever – provided a unique set of observations obtained with the ESO Very Large Telescope in Chile and the 10-meter Keck telescope in Hawaii, enabling them to find traces of the material that had surrounded a white dwarf star before it exploded.

NASA scientists have detected the first signs that tropical rainfall is on the rise with the longest and most complete data record available.

Using a 27-year-long global record of rainfall assembled by the international scientific community from satellite and ground-based instruments, the scientists found that the rainiest years in the tropics between 1979 and 2005 were mainly since 2001. The rainiest year was 2005, followed by 2004, 1998, 2003 and 2002, respectively.

When human heart muscle cells derived from embryonic stem cells are implanted into a rat after a heart attack, they can help rebuild the animal's heart muscle and improve function of the organ, scientists report in the September issue of Nature Biotechnology.

The researchers also developed a new process that greatly improves how stem cells are turned into heart muscle cells and then survive after being implanted in the damaged rat heart. The findings suggest that stem-cell-based treatments might one day help people suffering from heart disease, the leading cause of death in most of the world.

The study was conducted by researchers at the University of Washington School of Medicine in Seattle and at Geron Corp. in Menlo Park, Calif.