Washington, Sept 12 : While it is believed that biological and societal factors influence choice of partners, a new study has suggested that immunity traits may be more involved in selecting a mate.

The study by scientists in China, France, and the United Kingdom have shown that the Major Histocompatibility Complex (MHC), a large genomic region involved in immune response, influences mating selections and that this may be mediated by preferences based on body odor.

It was shown in some previous studies that humans have a tendency to prefer MHC-dissimilar mates, encouraging heterozygosity at MHC loci in offspring and resulting in improved immune response.

Washington, September 12: NASA’s Phoenix Mars Lander has photographed several dust devils dancing across the arctic plain and sensed a dip in air pressure as one passed near the Lander.

These dust-lofting whirlwinds had been expected in the area, but none had been detected in earlier Phoenix images.

The Surface Stereo Imager camera on Phoenix took 29 images of the western and southwestern horizon on Sept. 8, during mid-day hours of the Lander’s 104th Martian day.

Washington  - Alaska Governor Sarah Palin on Thursday said she was confident that she could take over the presidency if called upon, in her first interview since accepting the nomination to run as vice president with Republican nominee John McCain.

Palin, governor since 2006, was little-known nationally until she was named two weeks ago as McCain's running mate. She has faced questions from Democrats about whether she has the experience - especially in foreign policy - to be vice president to the 72-year- old McCain.

Washington  - Indian Prime Minister Manmohan Singh will visit Washington later this month as the US Congress begins to contemplate the approval of the landmark nuclear deal between the two countries.

President George W Bush formally submitted the nuclear cooperation agreement to Congress late Wednesday as he rushes to complete the deal before he leaves office in January.

Washington  - The Bolivian government committed a "grave error" by expelling the US ambassador to the country, a move that has "seriously damaged" relations with the United States, the State Department said Thursday.

Bolivian President Evo Morales ordered Ambassador Philip Goldberg out of his country on Wednesday, alleging the American was supporting opposition groups in five provinces seeking autonomy from La Paz.

US State Department spokesman Sean McCormack said the charges were "baseless" and that the expulsion was "unwarranted."

Washington - The US trade gap expanded more than expected to 62.2 billion dollars in July, the widest since March 2007, because of soaring oil prices, government figures showed Thursday.

The deficit grew 5.7 per cent, from 58.8 billion dollars in June, according to data released by the US Census Bureau and the US Bureau of Economic Analysis, through the Commerce Department.

This year's soaring energy prices and a 15-per-cent increase in oil imports ensured that the petroleum deficit alone was 43.4 billion dollars for the month.