Science names HIV study 2011 Breakthrough of Year

The journal Science on Thursday chose the HPTN 052 clinical trial, an international HIV prevention trial as the 2011 Breakthrough of the Year. The study found that if HIV-infected heterosexual individuals begin taking anti-retroviral medicines when their immune systems are relatively healthy as opposed to delaying therapy until the disease has advanced, they are 96 percent less likely to transmit the virus to their uninfected partners. Findings from the trial, first announced in May, were published in the New England Journal of Medicine in August. The study was funded by the U.S. National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. "The HPTN 052 study convincingly demonstrated that anti- retroviral medications can not only treat but also prevent the transmission of HIV infection among heterosexual individuals," said NIAID Director Anthony Fauci in a statement. "We are pleased that Science recognized the extraordinary public health significance of these study results." Science's list of nine other ground-breaking scientific achievements from 2011 include: The Hayabusa Mission: After some near-disastrous technical difficulties and a stunningly successful recovery, Japan's Hayabusa spacecraft returned to Earth with dust from the surface of a large, S-type asteroid. This asteroid dust represented the first direct sampling of a planetary body in 35 years, and analysis of the grains confirmed that the most common meteorites found on Earth, known as ordinary chondrules, are born from these much larger, S-type asteroids. Unraveling Human Origins: Studying the genetic code of both ancient and modern human beings, researchers discovered that many humans still carry DNA variants inherited from archaic humans, such as the mysterious Denisovans in Asia and still-unidentified ancestors in Africa. One study this year revealed how archaic humans likely shaped our modern immune systems, and an analysis of Australopithecus sediba fossils in South Africa showed that the ancient hominin possessed both primitive and Homo-like traits. Capturing a Photosynthetic Protein: In vivid detail, researchers in Japan have mapped the structure of the Photosystem II, or PSII, protein that plants use to split water into hydrogen and oxygen atoms. The crystal-clear image shows off the protein's catalytic core and reveals the specific orientation of atoms within. Now, scientists have access to this catalytic structure that is essential for life on Earth -- one that may also hold the key to a powerful source of clean energy. Pristine Gas in Space: Astronomers using the Keck telescope in Hawaii to probe the faraway universe wound up discovering two clouds of hydrogen gas that seem to have maintained their original chemistry for two billion years after the big bang. Other researchers identified a star that is almost completely devoid of metals, just as the universe's earliest stars must have been, but that formed much later. The discoveries show that pockets of matter persisted unscathed amid eons of cosmic violence. Getting to Know the Microbiome: Research into the countless microbes that dwell in the human gut demonstrated that everyone has a dominant bacterium leading the gang in their digestive tract: Bacteroides, Prevotella or Ruminococcus. Follow-up studies revealed that one of these bacteria thrives on a high-protein diet while another prefers vegetarian fare. These findings and more helped to clarify the interplay between diet and microbes in nutrition and disease. A Promising Malaria Vaccine: Early results of the clinical trial of a malaria vaccine, known as RTS,S, provided a shot in the arm to malaria vaccine research. The ongoing trial, which has enrolled more than 15,000 children from seven African countries, reassured malaria researchers, who are used to bitter disappointment, that discovering a malaria vaccine remains possible. Strange Solar Systems: This year, astronomers got their first good views of several distant planetary systems and discovered that things are pretty weird out there. First, NASA's Kepler observatory helped identify a star system with planets orbiting in ways that today's models cannot explain. Then, researchers discovered a gas giant caught in a rare "retrograde" orbit, a planet circling a binary star system and 10 planets that seem to be freely floating in space -- all unlike anything found in our own solar system. Designer Zeolites: Zeolites are porous minerals that are used as catalysts and molecular sieves to convert oil into gasoline, purify water, filter air and produce laundry detergents. This year, chemists really showed off their creativity by designing a range of new zeolites that are cheaper, thinner and better equipped to process larger organic molecules. Clearing Senescent Cells: Experiments revealed that clearing senescent cells, or those that have stopped dividing, from the bodies of mice can delay the onset of age-related symptoms, such as cataracts and muscle weakness. Mice whose bodies were cleared of these loitering cells didn't live longer than their untreated cage-mates -- but they did seem to live better, which provided researchers with some hope that banishing senescent cells might also prolong our golden years. The complete top 10 list of 2011 scientific breakthroughs will appear in Science on Friday.