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WELLINGTON, June 7 (Xinhua) -- Scientists in New Zealand have developed a new drug to fight previously untreatable hypoxic cancer tumors, which form in areas of the body starved of oxygen.The researchers at the Auckland University have entered an agreement for the clinical development of CEN-209, which was developed over 10 years of research, said a statement from the university Tuesday.CEN-209 was designed to enhance the effectiveness of radiotherapy and chemotherapy in solid hypoxic tumors, which were resistant to standard cancer therapies, said the statement. In lung cancer patients for example, about half of tumors had hypoxic regions.The new drug worked by damaging the DNA of hypoxic cancer cells, while leaving normal, healthy tissues alone.CEN-209 was designed and created by researchers at the university's Auckland Cancer Society Research Centre (ACSRC), using computer models of drug transport within tumors to accurately predict the anti-tumor activity of the drugs."Our computer models of drug transport developed in-house allowed the synthetic chemists to test their design theories and considerably shortened the discovery process," said Associate Professor Michael Hay, who led the ACSRC research chemists."CEN-209 improves markedly on previous agents in this class in terms of its ability to penetrate tumors, and this is reflected by its improved activity in the laboratory, when combined with long or short courses of radiotherapy," said researcher Professor Bill Wilson.Under the agreement between the university's Auckland UniServices Ltd. and California-based Centella Therapeutics, Inc., a subsidiary of Varian Medical Systems, Inc., Centella will have exclusive rights to CEN-209, which it will develop and trial with Cancer Research UK.The work on CEN-209 is the culmination of a program initiated with funding from the U.S. National Cancer Institute, and more recently from the Maurice Wilkins Centre for Biodiscovery. Ongoing preclinical research on CEN-209 and a backup compound was funded by grants from the Auckland Medical Research Foundation, Genesis Oncology Trust and Health Research Council of New Zealand, said the statement.

WASHINGTON, June 15 (Xinhua) -- Using the deepest X-ray image ever taken, astronomers found the first direct evidence that massive black holes were common in the early universe, the U.S. National Aeronautics and Space Administration (NASA) said Wednesday in a statement.The discovery from NASA's Chandra X-ray Observatory shows that very young black holes grew more aggressively than previously thought, in tandem with the growth of their host galaxies.By pointing Chandra at a patch of sky for more than six weeks, astronomers obtained what is known as the Chandra Deep Field South (CDFS). When combined with very deep optical and infrared images from NASA's Hubble Space Telescope, the new Chandra data allowed astronomers to search for black holes in 200 distant galaxies, from when the universe was between about 800 million to 950 million years old."Until now, we had no idea what the black holes in these early galaxies were doing, or if they even existed," said Ezequiel Treister of the University of Hawaii, lead author of the study to appear Thursday in journal Nature. "Now we know they are there, and they are growing like gangbusters."The super-sized growth means that the black holes in the CDFS are less extreme versions of quasars -- very luminous, rare objects powered by material falling onto supermassive black holes. However, the sources in the CDFS are about a hundred times fainter and the black holes are about a thousand times less massive than the ones in quasars.The observations found that between 30 and 100 percent of the distant galaxies contain growing supermassive black holes. Extrapolating these results from the small observed field to the full sky, there are at least 30 million supermassive black holes in the early universe. This is a factor of 10,000 larger than the estimated number of quasars in the early universe."It appears we've found a whole new population of baby black holes," said co-author Kevin Schawinski of Yale University. "We think these babies will grow by a factor of about a hundred or a thousand, eventually becoming like the giant black holes we see today almost 13 billion years later."

SAN FRANCISCO, Sept. 2 (Xinhua) -- A late-season potato blight has been detected on farms in Alaska, only the fourth time the disease appear in the U.S. state since 1995, local media reported on Friday.The disease was found this week in the fields of potato producers in cities of Delta Junction and Palmer, according to the Fairbanks Daily News-Miner, Alaska's second largest daily newspaper.Farmers in both fields are working to prevent the spread of the blight, a fungus-like disease that can kill plants in the field or cause potatoes to rot in storage, the newspaper reported.Growers have been asked to kill all affected plants within 100 feet, and plant samples from both sites will be examined to identify what type of late blight is involved.Experts said that blight can be controlled through the use of fungicides, but the cool, damp weather this summer in the areas has created an ideal environment for the disease to spread.Although Alaska's potato crop is tiny compared to other U.S. states, it has been viewed as a possible global source of seed potatoes in recent years because it is largely free of disease.A local university has explored partnerships with Chinese growers to export certified seed potatoes, noted the Fairbanks Daily News-Miner report.

LOS ANGELES, June 20 (Xinhua) -- NASA's Cassini spacecraft has successfully completed its second-closest encounter with Saturn's icy moon Helene, beaming down raw images of the small moon, the Jet Propulsion Laboratory (JPL) said on Monday.At closest approach on June 18 Cassini flew within 4,330 miles (6,968 kilometers) of Helene's surface, the second closest approach to Helene of the entire mission, said JPL in Pasadena, Los Angeles.This flyby will enable scientists to finish creating a global map of Helene, so they can better understand the history of impacts to the moon and gully-like features seen on previous flybys, according to JPL.Passing from Helene's night side to the moon's sunlit side, Cassini also captured images of the Saturn-facing side of the moon in sunlight, a region that was only illuminated by sunlight reflected off Saturn the last time Cassini closely encountered with the moon in March 2010.The closest Helene encounter of the mission took place on March 10, 2010, when Cassini flew within 1,131 miles (1,820 kilometers) of the moon.The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency.JPL, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL, while the imaging team is based at the Space Science Institute in Boulder, Colorado.