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HDTV reveals brainiest octopus has no personality
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‘Bug’ prints can put Levitate cells to produce 3D tissue samples you at crime scene IRON-RICH cells that grow into in real cancer cells than in 2D The phages gobbled up the iron
CONEYL JAY / SCIENCE PHOTO LIBRARY
balls when “levitated” by magnets could provide a new way to study cancer in the lab – and to produce replacement tissue for grafts. The magnets can sculpt balls into shapes that resemble tumours and tissues growing in the body. Glauco Souza of Nano3D Biosciences in Houston, Texas, and his colleagues incubated human glioblastoma cells from brain tumours with iron oxide and bacteriophages – viruses that infect bacteria and can bind to, but not harm, mammalian cells.
oxide, attached themselves to the cells and then injected the cells with their magnetic cargo. Next the team placed the cells in a Petri dish half filled with a gel and covered it with a magnetic lid. The cells rose from the bottom of the dish in response to the magnet and clumped together at the interface between the gel and the air. After 72 hours, a sphere of cells 1 millimetre in diameter had formed. Protein expression in these glioblastoma cells more closely mimicked that
cultures of cells, indicating that this method could be used to study cancer (Nature Nanotechnology, DOI: 10.1038/ nnano.2010.23). Exposed to both air and fluid, the cells might also be used to model the lungs and test drugs for lung disease. The researchers also found they could create cell balls of different shapes by moving the lid, changing its shape and the strength of the magnet. This might allow skin and long, thin nerve grafts to be grown in the lab. DEX IMAGE/CORBIS
YOU might call it “CSI: Microbe”. Our fingers are home to a unique collection of bacteria that get left on surfaces we touch. By comparing bugs found on a person’s hand to those recovered at a crime scene, you might be able to identify the perpetrator. “There are certain situations where human DNA analysis or standard fingerprinting doesn’t work,” says Noah Fierer, a microbiologist at the University of Colorado in Boulder. His team knew that microbial communities on skin tend to be unique to the individual and change little over time. To see if these qualities could be applied to forensics, his team swabbed several computer keyboards and the fingertips of their users, then identified about 1400 different kinds of bacteria living on each, using DNA sequencing. The keyboard bacteria closely matched their owner’s fingertips (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.1000162107). In another test, Fierer’s team were able to correctly match nine computer mice with their owners. The “microbeprint” seems to be long-lasting: swabs left at room temperature for two weeks could be matched to owners. But accuracy issues mean you won’t see them used in court just yet, Fierer says.
Psychopathy is its own reward A LACK of emotion isn’t the only thing driving psychopaths: the brains of people with some psychopathic traits may overvalue the reward associated with getting what they want. In extreme cases, this may result in callous and manipulative acts. Psychopathy is a spectrum of traits including fearlessness, callousness and narcissism; people in whom a number of these traits are strong are classed as psychopaths. Brain areas involved in emotion are less active in such people, but this can’t explain other behaviour common to psychopaths, such as drug abuse. Now Joshua Buckholtz of Vanderbilt University in Nashville, Tennessee, has discovered that people who are unusually willing to manipulate others for their own ends – another psychopathic trait – have brains that are unusually rich in dopamine, a “reward” chemical that makes us seek pleasure, be it from drugs or getting what we want (Nature Neuroscience, DOI: 10.1038/ nn.2510). Buckholtz suggests that this extra reward urge could drive psychopaths to act without considering the costs of their actions – such as hurting others.
Brainy octopus lacks personality OCTOPUSES make for discerning TV viewers: they respond to highdefinition images but not traditional cathode ray images. What’s more, in the first study to trick octopuses into believing video images are real scenes, the cephalopods turn out to lack “personality” or consistent behaviour. It wasn’t possible to study octopus behaviour using video before because their eyes were not fooled by slow cathode ray images. But in this study, 31 gloomy octopuses (Octopus tetricus) reacted to 3-minute films on high-definition
TV as if they were real. They lunged forward as if to attack crabs, and cowered from other octopuses, according to Renata Pronk at Macquarie University in Sydney, Australia, and colleagues (The Journal of Experimental Biology, DOI: 10.1242/jeb.040675). The team found that the octopuses did not behave consistently from day to day – they might be bold one day and shy the next, for instance. The team say this suggests Octopus tetricus do not have personality – a trait which may allow it to adapt to its changing environment.
20 March 2010 | NewScientist | 17
‘Bug’ prints can put Levitate cells to produce 3D tissue samples you at crime scene IRON-RICH cells that grow into in real cancer cells than in 2D The phages gobbled up the iron
CONEYL JAY / SCIENCE PHOTO LIBRARY
balls when “levitated” by magnets could provide a new way to study cancer in the lab – and to produce replacement tissue for grafts. The magnets can sculpt balls into shapes that resemble tumours and tissues growing in the body. Glauco Souza of Nano3D Biosciences in Houston, Texas, and his colleagues incubated human glioblastoma cells from brain tumours with iron oxide and bacteriophages – viruses that infect bacteria and can bind to, but not harm, mammalian cells.
oxide, attached themselves to the cells and then injected the cells with their magnetic cargo. Next the team placed the cells in a Petri dish half filled with a gel and covered it with a magnetic lid. The cells rose from the bottom of the dish in response to the magnet and clumped together at the interface between the gel and the air. After 72 hours, a sphere of cells 1 millimetre in diameter had formed. Protein expression in these glioblastoma cells more closely mimicked that
cultures of cells, indicating that this method could be used to study cancer (Nature Nanotechnology, DOI: 10.1038/ nnano.2010.23). Exposed to both air and fluid, the cells might also be used to model the lungs and test drugs for lung disease. The researchers also found they could create cell balls of different shapes by moving the lid, changing its shape and the strength of the magnet. This might allow skin and long, thin nerve grafts to be grown in the lab. DEX IMAGE/CORBIS
YOU might call it “CSI: Microbe”. Our fingers are home to a unique collection of bacteria that get left on surfaces we touch. By comparing bugs found on a person’s hand to those recovered at a crime scene, you might be able to identify the perpetrator. “There are certain situations where human DNA analysis or standard fingerprinting doesn’t work,” says Noah Fierer, a microbiologist at the University of Colorado in Boulder. His team knew that microbial communities on skin tend to be unique to the individual and change little over time. To see if these qualities could be applied to forensics, his team swabbed several computer keyboards and the fingertips of their users, then identified about 1400 different kinds of bacteria living on each, using DNA sequencing. The keyboard bacteria closely matched their owner’s fingertips (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.1000162107). In another test, Fierer’s team were able to correctly match nine computer mice with their owners. The “microbeprint” seems to be long-lasting: swabs left at room temperature for two weeks could be matched to owners. But accuracy issues mean you won’t see them used in court just yet, Fierer says.
Psychopathy is its own reward A LACK of emotion isn’t the only thing driving psychopaths: the brains of people with some psychopathic traits may overvalue the reward associated with getting what they want. In extreme cases, this may result in callous and manipulative acts. Psychopathy is a spectrum of traits including fearlessness, callousness and narcissism; people in whom a number of these traits are strong are classed as psychopaths. Brain areas involved in emotion are less active in such people, but this can’t explain other behaviour common to psychopaths, such as drug abuse. Now Joshua Buckholtz of Vanderbilt University in Nashville, Tennessee, has discovered that people who are unusually willing to manipulate others for their own ends – another psychopathic trait – have brains that are unusually rich in dopamine, a “reward” chemical that makes us seek pleasure, be it from drugs or getting what we want (Nature Neuroscience, DOI: 10.1038/ nn.2510). Buckholtz suggests that this extra reward urge could drive psychopaths to act without considering the costs of their actions – such as hurting others.
Brainy octopus lacks personality OCTOPUSES make for discerning TV viewers: they respond to highdefinition images but not traditional cathode ray images. What’s more, in the first study to trick octopuses into believing video images are real scenes, the cephalopods turn out to lack “personality” or consistent behaviour. It wasn’t possible to study octopus behaviour using video before because their eyes were not fooled by slow cathode ray images. But in this study, 31 gloomy octopuses (Octopus tetricus) reacted to 3-minute films on high-definition
TV as if they were real. They lunged forward as if to attack crabs, and cowered from other octopuses, according to Renata Pronk at Macquarie University in Sydney, Australia, and colleagues (The Journal of Experimental Biology, DOI: 10.1242/jeb.040675). The team found that the octopuses did not behave consistently from day to day – they might be bold one day and shy the next, for instance. The team say this suggests Octopus tetricus do not have personality – a trait which may allow it to adapt to its changing environment.
20 March 2010 | NewScientist | 17