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Was brightest supernova fuelled by stellar collision?
In brief–
JOHN KLUGE COLLECTION, VIRGINIA/WERNER FORMAN
CATS had caught the fancy of early Egyptians long before they were fully domesticated. In fact, people in Egypt began capturing and keeping wild cats – the first tentative step toward domestication – as early as 3700 BC. Archaeologists have long known that Egyptians had domesticated cats by sometime in the third millennium BC, when cats began to take on religious significance. However, little is known about the precise timing, especially in the early stages of the domestication process. A cat skeleton found in a cemetery in Hierakonpolis, an ancient settlement in southern Egypt, gives a glimpse into this distant age. It was found in a grave with at least seven baboons and a baby hippo, all of which were most likely used in some form of ritual slaughter. Potsherds in the grave date it to about 3700 BC. Based on the size of the bones, the cat appears to be Felis silvestris, the wild ancestor of the domestic cat, according to Veerle Linseele of the Catholic University of Leuven (KUL), Belgium, and colleagues. The skeleton shows healed fractures in two legs. Since no cat is likely to have survived such injuries in the wild, the researchers conclude that it most likely suffered the injuries during capture. The amount of healing suggests that the cat must have been held in captivity for at least 4 to 6 weeks before its death (Journal of Archaeological Science, DOI: 10.1016/j/jas/2007.02.019).
18 | NewScientist | 17 November 2007
Spotless starlings know how they like their eggs MALE spotless starlings care more for chicks that hatch from darker eggs than from paler eggs, suggesting they may use egg colour as an indicator of the mother’s fitness. José Javier Cuervo of the Spanish National Research Council unit in Almería and his team clipped a few feathers from 33 female spotless starlings, reducing their wingspan by 5 per cent. These females then had to expend more energy when flying to seek food. The eggs produced by these females were lighter in
colour than those produced by their unclipped counterparts, and also lighter than those of females whose feathers had been trimmed in a way that did not reduce their wingspan. In a study with different birds, the team removed the eggs from the nests and replaced them with clutches of dark or pale fake eggs. The researchers kept the real eggs in an incubator and returned them after hatching. Males that had mates with nests of dark fake eggs returned to feed the hatchlings about three
time per hour, on average, whereas those whose nests had contained pale fake eggs fed their offspring half as often. Cuervo’s team also found that offspring born from paler eggs had a weaker immune system than those born from darker eggs. The researchers suggest that the males use egg colour to figure out their mate’s fitness and, by extension, that of their offspring, and correspondingly adjust the resources they expend raising those young (The American Naturalist, in press). DISCOVERY NETWORKS
When cats first came indoors
Pile-up led to huge supernova IT WAS one of the brightest stellar explosions ever seen – the brilliance of 50 billion suns. Now two astronomers think they know what lit the fuse. In September 2006, astronomers spotted a supernova 240 million light years away. Known as 2006gy, it had exploded with a force a hundred times as powerful as a typical supernova. Since then several groups have attempted to explain what led to such a large blast, but none could explain why it appeared to be so rich in hydrogen. Now Simon Portegies Zwart and Edward van den Heuvel of the University of Amsterdam in the Netherlands suggest that dozens of massive stars – some hydrogenrich – might have crashed into each other to form a dense cluster. This would have produced a monstrous heavyweight star with the mass of more than 100 suns, they say. Unable to support its own weight after a few million years, this star would have exploded into a supernova that outshone its galaxy. If their theory is right, the dense star cluster should become visible once the supernova has faded a few years from now, say the researchers.
Can the ‘tree man’ be cured? HIS hands and feet resemble clumps of branches and his body is covered with unsightly brown welts that could pass for bark. Now Dede, who is 36 and lives near Bandung in West Java, Indonesia, has finally learned what causes the growths that have afflicted him since the age of 18 – and a possible way to treat them. After analysing samples of Dede’s tissue and blood, Anthony Gaspari at the University of Maryland Medical Center in Baltimore has discovered that they are caused by human papilloma virus (HPV) – which also causes ordinary warts.
People are normally able to clear HPV within a year. Gaspari thinks Dede is unable to because he suffers from a rare immune deficiency caused by the inheritance of two defective genes and resulting in abnormally low numbers of protective white blood cells called CD4 cells. Yet Dede has never suffered from any other illness. The strain of HPV also seems to be unusually virulent. Now that they know the cause of the growths, it may be possible to thwart the virus with extra doses of vitamin A. Gaspari says that although the condition is extremely rare, a similar case emerged earlier this year in China. The investigation into Dede’s condition will be aired on the Discovery Channel in the UK on 15 November.
www.newscientist.com
JOHN KLUGE COLLECTION, VIRGINIA/WERNER FORMAN
CATS had caught the fancy of early Egyptians long before they were fully domesticated. In fact, people in Egypt began capturing and keeping wild cats – the first tentative step toward domestication – as early as 3700 BC. Archaeologists have long known that Egyptians had domesticated cats by sometime in the third millennium BC, when cats began to take on religious significance. However, little is known about the precise timing, especially in the early stages of the domestication process. A cat skeleton found in a cemetery in Hierakonpolis, an ancient settlement in southern Egypt, gives a glimpse into this distant age. It was found in a grave with at least seven baboons and a baby hippo, all of which were most likely used in some form of ritual slaughter. Potsherds in the grave date it to about 3700 BC. Based on the size of the bones, the cat appears to be Felis silvestris, the wild ancestor of the domestic cat, according to Veerle Linseele of the Catholic University of Leuven (KUL), Belgium, and colleagues. The skeleton shows healed fractures in two legs. Since no cat is likely to have survived such injuries in the wild, the researchers conclude that it most likely suffered the injuries during capture. The amount of healing suggests that the cat must have been held in captivity for at least 4 to 6 weeks before its death (Journal of Archaeological Science, DOI: 10.1016/j/jas/2007.02.019).
18 | NewScientist | 17 November 2007
Spotless starlings know how they like their eggs MALE spotless starlings care more for chicks that hatch from darker eggs than from paler eggs, suggesting they may use egg colour as an indicator of the mother’s fitness. José Javier Cuervo of the Spanish National Research Council unit in Almería and his team clipped a few feathers from 33 female spotless starlings, reducing their wingspan by 5 per cent. These females then had to expend more energy when flying to seek food. The eggs produced by these females were lighter in
colour than those produced by their unclipped counterparts, and also lighter than those of females whose feathers had been trimmed in a way that did not reduce their wingspan. In a study with different birds, the team removed the eggs from the nests and replaced them with clutches of dark or pale fake eggs. The researchers kept the real eggs in an incubator and returned them after hatching. Males that had mates with nests of dark fake eggs returned to feed the hatchlings about three
time per hour, on average, whereas those whose nests had contained pale fake eggs fed their offspring half as often. Cuervo’s team also found that offspring born from paler eggs had a weaker immune system than those born from darker eggs. The researchers suggest that the males use egg colour to figure out their mate’s fitness and, by extension, that of their offspring, and correspondingly adjust the resources they expend raising those young (The American Naturalist, in press). DISCOVERY NETWORKS
When cats first came indoors
Pile-up led to huge supernova IT WAS one of the brightest stellar explosions ever seen – the brilliance of 50 billion suns. Now two astronomers think they know what lit the fuse. In September 2006, astronomers spotted a supernova 240 million light years away. Known as 2006gy, it had exploded with a force a hundred times as powerful as a typical supernova. Since then several groups have attempted to explain what led to such a large blast, but none could explain why it appeared to be so rich in hydrogen. Now Simon Portegies Zwart and Edward van den Heuvel of the University of Amsterdam in the Netherlands suggest that dozens of massive stars – some hydrogenrich – might have crashed into each other to form a dense cluster. This would have produced a monstrous heavyweight star with the mass of more than 100 suns, they say. Unable to support its own weight after a few million years, this star would have exploded into a supernova that outshone its galaxy. If their theory is right, the dense star cluster should become visible once the supernova has faded a few years from now, say the researchers.
Can the ‘tree man’ be cured? HIS hands and feet resemble clumps of branches and his body is covered with unsightly brown welts that could pass for bark. Now Dede, who is 36 and lives near Bandung in West Java, Indonesia, has finally learned what causes the growths that have afflicted him since the age of 18 – and a possible way to treat them. After analysing samples of Dede’s tissue and blood, Anthony Gaspari at the University of Maryland Medical Center in Baltimore has discovered that they are caused by human papilloma virus (HPV) – which also causes ordinary warts.
People are normally able to clear HPV within a year. Gaspari thinks Dede is unable to because he suffers from a rare immune deficiency caused by the inheritance of two defective genes and resulting in abnormally low numbers of protective white blood cells called CD4 cells. Yet Dede has never suffered from any other illness. The strain of HPV also seems to be unusually virulent. Now that they know the cause of the growths, it may be possible to thwart the virus with extra doses of vitamin A. Gaspari says that although the condition is extremely rare, a similar case emerged earlier this year in China. The investigation into Dede’s condition will be aired on the Discovery Channel in the UK on 15 November.
www.newscientist.com