Mexico City, Apr. 28: The World Health Organization has raised the alert level in relation to the `Swine Flu’ epidemic to Phase 4, meaning there is sustained human-to-human transmission of the virus causing outbreaks in at least one country.

On Monday, the alert was raised above Phase 3.

Putting an alert at Phases 4 or 5 signals that the virus is becoming increasingly adept at spreading among humans.

Phase 6 is for a full-blown pandemic, characterized by outbreaks in at least two regions of the world.

Geneva - World Health Organization officials reiterated Tuesday that travel restrictions would not help stem the spread of the swine influenza virus. "Border controls don't work, screenings don't work," said spokesman Gregory Hartl, speaking to reporters in Geneva. "Travel restrictions do not help."

In response to action by some countries which have banned pork from Mexico and some US states, the WHO reaffirmed that it did not recommend such moves.

Phnom Penh - Cambodian authorities Tuesday installed equipment to scan passengers for fever at Phnom Penh's international airport to stem the spread of swine flu. The World Health Organization (WHO) and the Health Ministry said there were no reported cases of the potentially deadly viral infection in the country.

Nairobi/Mogadishu - Two European aid workers employed by Medecins Sans Frontieres (MSF) who were kidnapped in Somalia over a week ago have been released, reports said Tuesday. The BBC cited militant Islamist group al-Shabaab as saying it had released the Danish nurse and Belgian doctor.

However, a regional spokeswoman for MSF in the Kenyan capital Nairobi could not immediately confirm the reports.

The pair were taken nine days ago on the way to Hudur, the capital of the Bakol region in south-west Somalia.

Washington, Apr 28 : Smoking, high blood pressure and being overweight—these are the top three preventable risk factors for premature mortality in the United States, according to a new study.

Led by researchers at the Harvard School of Public Health (HSPH), the collaborative study found that smoking is responsible for 467,000 premature deaths each year, high blood pressure for 395,000, and being overweight for 216,000.

The effects of smoking work out to be about one in five deaths in American adults, while high blood pressure is responsible for one in six deaths.

Washington, Apr 28 : Researchers from the University of California, San Diego School of Medicine have identified a protein which, when over-expressed, leads to the formation of senile plaques that cause Alzheimer’s disease.

It can be a potential new therapeutic target to block the accumulation of amyloid plaque in the brain.

"The role of the multi-domain protein, RANBP9, suggests a possible new therapeutic target for Alzheimer''s disease," said Dr David E. Kang, assistant professor of neurosciences at UC San Diego and director of this study.