In popular legend, Lucrezia Borgia, Duchess of Ferrara (1480- 1519), stands falsely accused of poisoning her second husband. Victor Hugo portrayed her in thinly veiled fiction as a tragic femme fatale. Buffalo Bill named his gun after her.
But new research by USC historian Diane Yvonne Ghirardo reveals that the only sister of Machiavelli's Prince was less interested in political intrigue than in running a business, undertaking massive land development projects that "stand alone in the panorama of early sixteenth-century projects, not only those initiated by women," Ghirardo says.
Forced by an economic downturn to cut expenses and become an entrepreneur, the illegitimate daughter of Pope Alexander VI would control between 30,000 and 50,000 acres in northern Italy within six years.
"This is a classic case of seeing only what you're looking for and not getting the whole picture," Ghirardo says of the centuries-old mystery surrounding how Lucrezia accumulated her vast personal wealth. Ghirardo notes that historians have long dismissed Lucrezia as stupida because no record exists of her collecting art or antiquities.
"The information was there in the archives, but because she was a woman, scholars only looked at transactions for clothes, for jewelry, or for works of art. Nobody looked at the other entries in the account registers," says Ghirardo of the research project that took her more than seven years.
Science & Technology
Now, a pair of Scripps Research Institute scientists has taken a significant step toward answering that question. The scientists have synthesized for the first time RNA enzymes that can replicate themselves without the help of any proteins or other cellular components, and the process proceeds indefinitely.
The work was published on Thursday, January 8, 2008, in Science Express, the advanced, online edition of the journal Science.
In the modern world, DNA carries the genetic sequence for advanced organisms, while RNA is dependent on DNA for performing its roles such as building proteins. But one prominent theory about the origins of life, called the RNA World model, postulates that because RNA can function as both a gene and an enzyme, RNA might have come before DNA and protein and acted as the ancestral molecule of life. However, the process of copying a genetic molecule, which is considered a basic qualification for life, appears to be exceedingly complex, involving many proteins and other cellular components.
The work was published on Thursday, January 8, 2008, in Science Express, the advanced, online edition of the journal Science.
In the modern world, DNA carries the genetic sequence for advanced organisms, while RNA is dependent on DNA for performing its roles such as building proteins. But one prominent theory about the origins of life, called the RNA World model, postulates that because RNA can function as both a gene and an enzyme, RNA might have come before DNA and protein and acted as the ancestral molecule of life. However, the process of copying a genetic molecule, which is considered a basic qualification for life, appears to be exceedingly complex, involving many proteins and other cellular components.
© Geological Society of America
Small rocks, known as clasts, are spaced evenly apart rather than being clumped together in this Spirit rover image of the plain around Mars's Lahontan Crater. The image shows a region of terrain about 50 cm wide.
Small rocks, known as clasts, are spaced evenly apart rather than being clumped together in this Spirit rover image of the plain around Mars's Lahontan Crater. The image shows a region of terrain about 50 cm wide.
Photos from NASA's Spirit rover show small rocks spaced so evenly on the surface that it seems as if they must have been carefully arranged by order-loving Martians. But with no evidence of extraterrestrial landscapers, what could have created the pattern?
The wind did it, but not in an obvious way, says Jon Pelletier of the University of Arizona.
Wind storms and dust devils rage across Mars, so it's logical to suspect they blew the rocks. But the Red Planet's atmosphere is so thin that winds would have to be "10 times Hurricane Katrina" to pick up the stones, Pelletier told New Scientist. And wind-blown rocks would have no reason to stop where they were nearly equidistant from their neighbours.
© BBC News
The biofuel's developers showcased its algal origins
The biofuel's developers showcased its algal origins
The 90-minute flight by a Continental Boeing 737-800 went better than expected, a spokesperson said.
One of its engines was powered by a 50-50 blend of biofuel and normal aircraft fuel.
Wednesday's test is the latest in a series of demonstration flights by the aviation industry, which hopes to be using biofuels within five years.
Brown dwarfs, objects that are less massive than stars but larger than planets, just got more elusive, based on a study of 233 nearby multiple-star systems by NASA's Hubble Space Telescope. Hubble found only two brown dwarfs as companions to normal stars. This means the so-called "brown dwarf desert" (the absence of brown dwarfs around solar-type stars) extends to the smallest stars in the universe.
Sergio Dieterich of Georgia State University in Atlanta and team leader of the study is reporting the results January 6 at the 213th meeting of the American Astronomical Society (AAS) in Long Beach, Calif.
"We still did not find brown dwarfs around small red stars whose mass is only slightly above the hydrogen burning limit. Especially when we consider the fact that brown dwarfs binaries do exist, the fact that there are very few binaries whose components lie on different sides of the hydrogen burning limit is significant," says Dieterich.
The 233 stars surveyed are part of the RECONS (Research Consortium on Nearby Stars) survey meant to understand the nature of the sun's nearest stellar neighbors, both individually and as a population. The current primary goals are to discover and characterize "missing" members of the sample of stars within 32.6 light-years (10 parsecs) of Earth.
Sergio Dieterich of Georgia State University in Atlanta and team leader of the study is reporting the results January 6 at the 213th meeting of the American Astronomical Society (AAS) in Long Beach, Calif.
© NASA
Binary Brown Dwarf Kelu-1 This pair of NASA Hubble Space Telescope images of the binary brown dwarf Kelu-1 trace the orbital motion of the two stars over a seven-year span as photographed by the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) on Hubble. In 1998, the stars were too close together to be resolved by Hubble. By 2005, they had moved apart to a separation of 520 million miles. The projected maximum separation is 550 million miles. Binary systems allow astronomers to estimate the mass of companion objects. The brown dwarfs are 61 and 50 times the mass of Jupiter. They are therefore too small to burn as stars, but too large to have formed as planets. Based on the total estimated mass of the system, astronomers suspect there is a third brown dwarf member that has not yet been resolved.
Binary Brown Dwarf Kelu-1 This pair of NASA Hubble Space Telescope images of the binary brown dwarf Kelu-1 trace the orbital motion of the two stars over a seven-year span as photographed by the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) on Hubble. In 1998, the stars were too close together to be resolved by Hubble. By 2005, they had moved apart to a separation of 520 million miles. The projected maximum separation is 550 million miles. Binary systems allow astronomers to estimate the mass of companion objects. The brown dwarfs are 61 and 50 times the mass of Jupiter. They are therefore too small to burn as stars, but too large to have formed as planets. Based on the total estimated mass of the system, astronomers suspect there is a third brown dwarf member that has not yet been resolved.
The 233 stars surveyed are part of the RECONS (Research Consortium on Nearby Stars) survey meant to understand the nature of the sun's nearest stellar neighbors, both individually and as a population. The current primary goals are to discover and characterize "missing" members of the sample of stars within 32.6 light-years (10 parsecs) of Earth.
At least two of the extinct, ancient humans had type O blood, making them the "universal donor", according to a new genetic analysis of remains of 45,000 year old individuals.
"If you needed a blood transfusion, you could get it from these Neanderthals," says Carles Lalueza-Fox, a geneticist at Pompeu Fabra University in Barcelona, Spain, who led the study.
That's not to say all Neanderthals were type O - others may have also boasted genes for the A and B blood types, which encode enzymes that sprinkle red blood cells with two different sugar molecules, Lalueza-Fox says.
"If you needed a blood transfusion, you could get it from these Neanderthals," says Carles Lalueza-Fox, a geneticist at Pompeu Fabra University in Barcelona, Spain, who led the study.
That's not to say all Neanderthals were type O - others may have also boasted genes for the A and B blood types, which encode enzymes that sprinkle red blood cells with two different sugar molecules, Lalueza-Fox says.
A group of Dartmouth researchers has found a new function for one of the proteins involved with chromosome segregation during cell division. Their finding adds to the growing knowledge about the fundamental workings of cells, and contributes to understanding how cell function can go wrong, as it does with cancerous cells.
The researchers studied a protein called NOD, distantly related to the motor proteins that power diverse cellular activities, including intracellular transport, signaling, and cell division. They used X-ray crystallography to determine its structure, and then they used enzyme kinetics to find out how it performed. While this protein is found in fruit flies, the results are helpful in determining how related proteins work in humans.
The researchers studied a protein called NOD, distantly related to the motor proteins that power diverse cellular activities, including intracellular transport, signaling, and cell division. They used X-ray crystallography to determine its structure, and then they used enzyme kinetics to find out how it performed. While this protein is found in fruit flies, the results are helpful in determining how related proteins work in humans.
© Ray Tang/Rex Features
UK protesters demonstrate in a field of genetically modified oilseed rape
UK protesters demonstrate in a field of genetically modified oilseed rape
What would our forebears have made of test-tube babies, microwave ovens, organ transplants, CCTV and iPhones? Could they have believed that one day people might jet to another continent for a weekend break, meet their future spouse on the internet, have their genome sequenced and live to a private soundtrack from an MP3 player? Science and technology have changed our world dramatically, and, for the most part, we take them in our stride. Nevertheless, there are certain innovations that many people find unpalatable.
Leaving aside special-interest attitudes such as the fundamentalist Christian denial of evolution, many controversies over scientific advances are based on ethical concerns. In the past, the main areas of contention have included nuclear weapons, eugenics and experiments on animals, but in recent years the list of "immoral" research areas has grown exponentially. In particular, reproductive biology and medicine have become ripe for moral outrage: think cloning, designer babies, stem-cell research, human-animal hybrids, and so on. Other troublesome areas include nanotechnology, synthetic biology, genomics and genetically modified organisms or so-called "Frankenfoods".
To many scientists, moral objections to their work are not valid: science, by definition, is morally neutral, so any moral judgement on it simply reflects scientific illiteracy. That, however, is an abdication of responsibility. Some moral reactions are irrational, but if scientists are serious about tackling them - and the bad decisions, harm, suffering and barriers to progress that flow from them - they need to understand a little more and condemn a little less.
© Jet Propulsion Laboratory, NASA
Jupiter-like planets could form around twin suns.
Jupiter-like planets could form around twin suns.
In a paper published in the December 2008 issue of Astronomy and Astrophysics, astronomer Joel Kastner and his team suggest that planets may easily form around certain types of twin (or "binary") star systems. A disk of molecules discovered orbiting a pair of twin young suns in the constellation Sagittarius strongly suggests that many such binary systems also host planets.
"We think the molecular gas orbiting these two stars almost literally represents 'smoking gun' evidence of recent or possibly ongoing 'giant' (Jupiter-like) planet formation around the binary star system," says Kastner, professor at Rochester Institute of Technology's Chester F. Carlson Center for Imaging Science.
