Immigrants in the United States require less than half the health-care services than do native-born Americans, according to study findings published in the American Journal of Public Health.

Immigrant children get even lower levels of care, receiving 84 percent less than U.S.-born children, according to researchers at Harvard and Columbia universities and the Keck School of Medicine of the University of Southern California.

During the evaluation of competitive athletes, a history or a documentation of cardiac arrhythmias has become particularly important because arrhythmias may be the initial expression of an underlying cardiac disease or of primary electrical disorders, sometimes early manifestations of potentially life-threatening events. Cardiac arrhythmias are among the most important causes of non-eligibility to sports activities, and some arrhythmogenic diseases are three times more frequent among athletes than among sedentary subjects of the same age.

Arrhythmias, in young competitive athletes and also the elite are usually "benign" or "paraphysiological" (duo to prolonged training).

Mechanical 'artificial hearts' can be used to return severely failing hearts to their normal function, potentially removing the need for heart transplantation, according to new research.

The mechanical devices, known as Left Ventricular Assist Devices (LVADs), are currently used in patients with very severe heart failure whilst they await transplantation. The new study, published in the New England Journal of Medicine, shows that using an LVAD combined with certain drug therapies can shrink the enlarged heart and enable it to function normally once the LVAD is removed.

For the study, researchers from Imperial College London and the Royal Brompton and Harefield NHS Trust gave the full combination therapy to 15 severely ill patients. Of these 15, 11 recovered.

Astronomers using the Subaru telescope in Hawaii have looked 60 million years further back in time than any other astronomers, to find the most distant known galaxy in the universe. In doing so, they are upholding Subaru's record for finding the most distant and earliest galaxies known. Their most recent discovery is of a galaxy called I0K-1 that lies so far away that astronomers are seeing it as it appeared 12.88 billion years ago.

Demand from rich Chinese for Indian tiger pelts and parts used in traditional medicine fuels poaching and may lead to the extinction of the species in the wild, conservationists have warned.

Trade of tiger pelts from India into Chinese-ruled Tibet was flourishing despite laws banning the move, a report released in New Delhi by two conservation groups said Wednesday.

The Wildlife Protection Agency and Environment Investigation Agency estimate only 1,500 to 2,000 wild Royal Bengal Tigers are left in India.

It's a mystery why the speed and complexity of evolution appear to increase with time. For example, the fossil record indicates that single-celled life first appeared about 3.5 billion years ago, and it then took about 2.5 billion more years for multi-cellular life to evolve.