Washington - Scientists have created a strain of the human AIDS virus able to infect and multiply in monkeys in a step toward testing future vaccines in monkeys before trying them in people, according to a new study.
This strain of HIV, the human immunodeficiency virus, was developed by altering a single gene in the human version to allow it to infect a type of monkey called a pig-tailed macaque, the researchers said on Monday.
The genetically engineered virus, once injected into this monkey, proliferates almost as much as it does in people, but the animal ultimately suppresses it and the virus does not make it sick, they said.
Science & Technology
Critters, microbes scheduled to make a round-trip journey to Phobos
No one knows if there is life on Mars, but if all goes well with a Russian science mission later this year, there will be life on the Martian moon Phobos - for a short time anyway.
An assortment of critters and microbes are scheduled to make a round-trip journey to Phobos as passengers aboard a Russian spacecraft, scheduled to launch in October.
The mission, called Phobos-Grunt, aims to return samples of the Martian moon to Earth for analysis. It will be the first Russian-led mission to Mars since the loss of the Phobos 1 and Phobos 2 probes in 1988 and the botched launch of the Mars 96 spacecraft.
© NASA
This NASA image shows the Martian moon Phobos, believed to have once been an asteroid that was snagged by the Red Planet's gravity and then became an orbiting moon. A Russian mission to the moon will test whether living organisms can survive the ride to space and back.
This NASA image shows the Martian moon Phobos, believed to have once been an asteroid that was snagged by the Red Planet's gravity and then became an orbiting moon. A Russian mission to the moon will test whether living organisms can survive the ride to space and back.
An assortment of critters and microbes are scheduled to make a round-trip journey to Phobos as passengers aboard a Russian spacecraft, scheduled to launch in October.
The mission, called Phobos-Grunt, aims to return samples of the Martian moon to Earth for analysis. It will be the first Russian-led mission to Mars since the loss of the Phobos 1 and Phobos 2 probes in 1988 and the botched launch of the Mars 96 spacecraft.
© NASA/JPL/University of Arizona
The gully system in the Promethei Terra region of Mars appears to have been carved by melt water and may be the most recent period when water was active on the planet.
The gully system in the Promethei Terra region of Mars appears to have been carved by melt water and may be the most recent period when water was active on the planet.
Planetary geologists at Brown University have found a gully fan system on Mars that formed about 1.25 million years ago. The fan offers compelling evidence that it was formed by melt water that originated in nearby snow and ice deposits and may stand as the most recent period when water flowed on the planet.
Gullies are known to be young surface features on Mars. But scientists studying the planet have struggled with locating gullies they can conclusively date. In a paper that appears on the cover of the March issue of Geology, the Brown geologists were able to date the gully system and hypothesize what water was doing there.
The gully system shows four intervals where water-borne sediments were carried down the steep slopes of nearby alcoves and deposited in alluvial fans, said Samuel Schon, a Brown graduate student and the paper's lead author.
© NASA, ESA and R. Sharples (University of Durham, U.K.))
The three pictured galaxies -- NGC 7173 (middle left), NCG 7174 (middle right) and NGC 7176 (lower right) -- are part of the Hickson Compact Group 90, named after astronomer Paul Hickson, who first catalogued these small clusters of galaxies in the 1980s. NGC 7173 and NGC 7176 appear to be smooth, normal elliptical galaxies without much gas and dust. In stark contrast, NGC 7174 is a mangled spiral galaxy, barely clinging to independent existence as it is ripped apart by its close neighbours. The strong tidal interaction surging through the galaxies has dragged a significant number of stars away from their home galaxies. These stars are now spread out, forming a tenuous luminous component in the galaxy group.
The three pictured galaxies -- NGC 7173 (middle left), NCG 7174 (middle right) and NGC 7176 (lower right) -- are part of the Hickson Compact Group 90, named after astronomer Paul Hickson, who first catalogued these small clusters of galaxies in the 1980s. NGC 7173 and NGC 7176 appear to be smooth, normal elliptical galaxies without much gas and dust. In stark contrast, NGC 7174 is a mangled spiral galaxy, barely clinging to independent existence as it is ripped apart by its close neighbours. The strong tidal interaction surging through the galaxies has dragged a significant number of stars away from their home galaxies. These stars are now spread out, forming a tenuous luminous component in the galaxy group.
About 100 million light-years away, in the constellation of Piscis Austrinus (the Southern Fish), three galaxies are playing a game of gravitational give-and-take that might ultimately lead to their merger into one enormous entity.
A new image from the Advanced Camera for Surveys on the NASA/ESA Hubble Space Telescope allows astronomers to view the movement of gases from galaxy to galaxy, revealing the intricate interplay among them.
The three pictured galaxies - NGC 7173 (middle left), NCG 7174 (middle right) and NGC 7176 (lower right) - are part of the Hickson Compact Group 90, named after astronomer Paul Hickson, who first catalogued these small clusters of galaxies in the 1980s. NGC 7173 and NGC 7176 appear to be smooth, normal elliptical galaxies without much gas and dust.
© NASA/JPL/Space Science Institute
This sequence of three images, obtained by NASA's Cassini spacecraft over the course of about 10 minutes, shows the path of a newly found moonlet in a bright arc of Saturn's faint G ring.
This sequence of three images, obtained by NASA's Cassini spacecraft over the course of about 10 minutes, shows the path of a newly found moonlet in a bright arc of Saturn's faint G ring.
NASA's Cassini spacecraft has found within Saturn's G ring an embedded moonlet that appears as a faint, moving pinprick of light. Scientists believe it is a main source of the G ring and its single ring arc.
Cassini imaging scientists analyzing images acquired over the course of about 600 days found the tiny moonlet, half a kilometer (about a third of a mile) across, embedded within a partial ring, or ring arc, previously found by Cassini in Saturn's tenuous G ring.
The finding is being announced March 3 in an International Astronomical Union circular. Images can be found HERE, HERE and HERE.
"Before Cassini, the G ring was the only dusty ring that was not clearly associated with a known moon, which made it odd," said Matthew Hedman, a Cassini imaging team associate at Cornell University in Ithaca, N.Y. "The discovery of this moonlet, together with other Cassini data, should help us make sense of this previously mysterious ring."
© ESO
Artist's impression of how the surface of Pluto might look, according to one of the two models that a team of astronomers has developed to account for the observed properties of Pluto's atmosphere, as studied with CRIRES. The image shows patches of pure methane on the surface. At the distance of Pluto, the Sun appears about 1000 times fainter than on Earth.
Artist's impression of how the surface of Pluto might look, according to one of the two models that a team of astronomers has developed to account for the observed properties of Pluto's atmosphere, as studied with CRIRES. The image shows patches of pure methane on the surface. At the distance of Pluto, the Sun appears about 1000 times fainter than on Earth.
Using ESO's Very Large Telescope, astronomers have gained valuable new insights about the atmosphere of the dwarf planet Pluto. The scientists found unexpectedly large amounts of methane in the atmosphere, and also discovered that the atmosphere is hotter than the surface by about 40 degrees, although it still only reaches a frigid minus 180 degrees Celsius.
These properties of Pluto's atmosphere may be due to the presence of pure methane patches or of a methane-rich layer covering the dwarf planet's surface.
"With lots of methane in the atmosphere, it becomes clear why Pluto's atmosphere is so warm," says Emmanuel Lellouch, lead author of the paper reporting the results.
Pluto, which is about a fifth the size of Earth, is composed primarily of rock and ice. As it is about 40 times further from the Sun than the Earth on average, it is a very cold world with a surface temperature of about minus 220 degrees Celsius!
© Journal of Cognitive Neuroscience
The neuroscience of decision-making: By examining stroke victims, researchers determined that the brain's frontal lobe controls decision-making, with abstract decisions made closer to the front and concrete decisions farther back.
The neuroscience of decision-making: By examining stroke victims, researchers determined that the brain's frontal lobe controls decision-making, with abstract decisions made closer to the front and concrete decisions farther back.
A Brown University study of stroke victims has produced evidence that the frontal lobe of the human brain controls decision-making along a continuum from abstract to concrete, from front to back.
Abstract actions can be controlled at an abstract level, such as deciding to make a sandwich, or at more concrete and specific levels, such as choosing a sequence of movements that make the sandwich.
The scientific data supports preexisting theories that abstract decisions about action take place in the front of the frontal lobe, the back portion controls the capacity for concrete decisions, and the progression from front to back forms a gradient from abstract to concrete.
The Brown researchers are among the first to show that specific areas of the frontal cortex are needed for different levels of abstract decision.
© Unknown
The excavation site near Hoo church where the body was found.
The excavation site near Hoo church where the body was found.
The skeleton, found by Faversham-based archaeologist Dr Paul Wilkinson, is thought to be from the 14th or 15th century.
It was found in unconsecrated ground under a holly tree, next to Hoo St Werburgh parish church, near Rochester.
The remains would normally be left in archives for future archaeological reference, but the vicar of Hoo, the Rev Andy Harding, has asked for the body to be returned so she can be re-buried in the church grounds.
Dr Wilkinson found the remains about six years ago after a dig requested by Simon Wright Homes, which they were obliged to perform before starting their development.
© NASA
Illustration of GRB.
Illustration of GRB.
UK astronomers, using a telescope aboard the NASA Swift Satellite, have captured information from the early stages of a gamma ray burst - the most violent and luminous explosions occurring in the Universe since the Big Bang.
Swift is able to both locate and point at gamma ray bursts (GRBs) far quicker than any other telescope, so by using its Ultraviolet/Optical Telescope (UVOT) the astronomers were able to obtain an ultraviolet spectrum of a GRB just 251 seconds after its onset - the earliest ever captured. Further use of the instrument in this way will allow them to calculate the distance and brightness of GRBs within a few hundred seconds of their initial outburst, and gather new information about the causes of bursts and the galaxies they originate from.
It is currently thought that some GRBs are caused by immense explosions following the collapse of the core of a rapidly rotating, high-mass star into a black hole, but there are still many mysteries surrounding them.
