- Email: [email protected]
Here's a more cerebral reason to lower your cholesterol
Salamander trumps Here’s a more cerebral reason to lower your cholesterol toad as Mr Universe
LYNDA RICHARDSON/CORBIS
www.newscientist.com
070210_N_InBrief.indd 15
AN UNHEALTHY western diet could harm more than just your waistline – it may also increase your risk of Alzheimer’s disease. Earlier work on mice fed high-cholesterol diets found that their brain cells produced more amyloid beta, a protein linked to Alzheimer’s. There is also evidence that taking cholesterol-lowering statins makes people less likely to develop late-onset Alzheimer’s. To better understand this link, Brett Garner of the Prince of Wales Medical Research Institute in Sydney, Australia, and his
colleagues used human and animal cells to probe how neurons regulate their levels of cholesterol. They found that “ABC proteins”, which help control cholesterol levels in arterial walls by expelling cholesterol from the immune cells called macrophages where it builds up, were also present in neurons. When the team over-expressed the genes for these proteins in hamster and human cell lines, production of amyloid beta protein fell (Journal of Biological Chemistry, vol 282, p 2851). The work also showed that an
extracellular protein called apoE is extremely good at regulating cholesterol removal from neurons. One form of the gene for apoE is already recognised as the major genetic risk factor for lateonset Alzheimer’s disease. Garner suggests that drugs that increase expression of ABC transporters might slow the progression of Alzheimer’s. Such drugs are already being used in cardiovascular research. “A lot of people think there could be converging factors involved in these diseases,” Garner says.
Stressed cows rally with a sports drink
bicarbonate and potassium chloride to water increased the weight of 39 steers by 3 per cent compared to 40 steers that drank plain water (Australian Journal of Experimental Agriculture, vol 47, p 119). Electrolyte supplements have been used before during livestock transport, but without evidence that they work or any guidance on how much to give. “The ship’s captain says, ‘Let’s give them electrolyte,’ and the stockmen go around shoving handfuls of white powder into the troughs,” says team leader David Beatty of Murdoch University in Perth, Western Australia. His team’s controlled trial showed that animals that received the supplement drank more, and kept a normal body pH, which can be disrupted by heat stress.
DANIEL GARCIA/AFP
HOP away toads, you’ve lost your title as the world’s strongest animal. That honour now passes to the giant palm salamander Bolitoglossa dofleini, whose tongue explodes outward with more instantaneous power than any other known vertebrate muscle. At 18,000 watts of power per kilogram of muscle, the salamander, from the forest floors of Central America, is nearly twice as strong as the previous champ, the Colorado river toad Bufo alvarius. The palm salamander’s strength doesn’t come from muscle power alone but from elastic tissue that researchers believe stores up energy before exploding on release. “It’s kind of like stretching out a rubber band and letting it snap back, or shooting a bow and arrow,” says biologist Stephen Deban of the University of South Florida in Tampa. High-speed video revealed that plethodontid salamanders released their tongues at a rate faster than could be achieved through muscle contraction alone. Electrodes on the tongue then showed that the muscles contract for one-fifth of a second, or about 100 times longer than the actual firing time of the muscle cells (The Journal of Experimental Biology, DOI: 10.1242/jeb.02664). Deban and his colleagues think that stretchy lengths of collagen tissue intertwined with the tongue muscles are the likely secret of the salamander’s strength.
Keep Earth cool with moon dust DESPERATE times call for desperate measures. Why not tackle global warming with a giant dust cloud positioned in space to block out the sun? The sun shield – made from dust mined from the moon – is the brainchild of Curtis Struck at Iowa State University in Ames and would be used only if governments fail to tackle the greenhouse effect. Lunar dust particles are just the right size to scatter sunlight, Struck says. If the particles are injected at two precise positions along the moon’s orbit, they will form a pair of stable clouds that would each pass in front of the sun once a month, blocking sunlight for about 20 hours each month (Journal of the British Interplanetary Society, vol 60, p 1). “If we’re facing real threats to civilisation, then you might resort to this sort of thing,” says Struck. Others have criticised the scheme on the grounds that the clouds may reflect extra light onto Earth during the periods when they are not directly in front of the sun. Struck maintains that even if this happened, there would still be an overall decrease in the sunlight reaching Earth.
WHILE there are no plans to stage cow races, electrolyte sports drinks appear to benefit the animals by reducing suffering during long sea journeys. Australia exports over 4 million cattle and sheep a year, mainly to the Middle East, but animal welfare concerns have prompted calls to ban the practice. Temperatures can soar to over 40 °C with 80 per cent humidity as ships pass through the tropics, causing the animals to become severely stressed, suffer respiratory distress, lose weight and even die. Now a study aboard a ship bound for the Middle East has found that adding measured amounts of sodium
10 February 2007 | NewScientist | 15
6/2/07 10:10:23 am
LYNDA RICHARDSON/CORBIS
www.newscientist.com
070210_N_InBrief.indd 15
AN UNHEALTHY western diet could harm more than just your waistline – it may also increase your risk of Alzheimer’s disease. Earlier work on mice fed high-cholesterol diets found that their brain cells produced more amyloid beta, a protein linked to Alzheimer’s. There is also evidence that taking cholesterol-lowering statins makes people less likely to develop late-onset Alzheimer’s. To better understand this link, Brett Garner of the Prince of Wales Medical Research Institute in Sydney, Australia, and his
colleagues used human and animal cells to probe how neurons regulate their levels of cholesterol. They found that “ABC proteins”, which help control cholesterol levels in arterial walls by expelling cholesterol from the immune cells called macrophages where it builds up, were also present in neurons. When the team over-expressed the genes for these proteins in hamster and human cell lines, production of amyloid beta protein fell (Journal of Biological Chemistry, vol 282, p 2851). The work also showed that an
extracellular protein called apoE is extremely good at regulating cholesterol removal from neurons. One form of the gene for apoE is already recognised as the major genetic risk factor for lateonset Alzheimer’s disease. Garner suggests that drugs that increase expression of ABC transporters might slow the progression of Alzheimer’s. Such drugs are already being used in cardiovascular research. “A lot of people think there could be converging factors involved in these diseases,” Garner says.
Stressed cows rally with a sports drink
bicarbonate and potassium chloride to water increased the weight of 39 steers by 3 per cent compared to 40 steers that drank plain water (Australian Journal of Experimental Agriculture, vol 47, p 119). Electrolyte supplements have been used before during livestock transport, but without evidence that they work or any guidance on how much to give. “The ship’s captain says, ‘Let’s give them electrolyte,’ and the stockmen go around shoving handfuls of white powder into the troughs,” says team leader David Beatty of Murdoch University in Perth, Western Australia. His team’s controlled trial showed that animals that received the supplement drank more, and kept a normal body pH, which can be disrupted by heat stress.
DANIEL GARCIA/AFP
HOP away toads, you’ve lost your title as the world’s strongest animal. That honour now passes to the giant palm salamander Bolitoglossa dofleini, whose tongue explodes outward with more instantaneous power than any other known vertebrate muscle. At 18,000 watts of power per kilogram of muscle, the salamander, from the forest floors of Central America, is nearly twice as strong as the previous champ, the Colorado river toad Bufo alvarius. The palm salamander’s strength doesn’t come from muscle power alone but from elastic tissue that researchers believe stores up energy before exploding on release. “It’s kind of like stretching out a rubber band and letting it snap back, or shooting a bow and arrow,” says biologist Stephen Deban of the University of South Florida in Tampa. High-speed video revealed that plethodontid salamanders released their tongues at a rate faster than could be achieved through muscle contraction alone. Electrodes on the tongue then showed that the muscles contract for one-fifth of a second, or about 100 times longer than the actual firing time of the muscle cells (The Journal of Experimental Biology, DOI: 10.1242/jeb.02664). Deban and his colleagues think that stretchy lengths of collagen tissue intertwined with the tongue muscles are the likely secret of the salamander’s strength.
Keep Earth cool with moon dust DESPERATE times call for desperate measures. Why not tackle global warming with a giant dust cloud positioned in space to block out the sun? The sun shield – made from dust mined from the moon – is the brainchild of Curtis Struck at Iowa State University in Ames and would be used only if governments fail to tackle the greenhouse effect. Lunar dust particles are just the right size to scatter sunlight, Struck says. If the particles are injected at two precise positions along the moon’s orbit, they will form a pair of stable clouds that would each pass in front of the sun once a month, blocking sunlight for about 20 hours each month (Journal of the British Interplanetary Society, vol 60, p 1). “If we’re facing real threats to civilisation, then you might resort to this sort of thing,” says Struck. Others have criticised the scheme on the grounds that the clouds may reflect extra light onto Earth during the periods when they are not directly in front of the sun. Struck maintains that even if this happened, there would still be an overall decrease in the sunlight reaching Earth.
WHILE there are no plans to stage cow races, electrolyte sports drinks appear to benefit the animals by reducing suffering during long sea journeys. Australia exports over 4 million cattle and sheep a year, mainly to the Middle East, but animal welfare concerns have prompted calls to ban the practice. Temperatures can soar to over 40 °C with 80 per cent humidity as ships pass through the tropics, causing the animals to become severely stressed, suffer respiratory distress, lose weight and even die. Now a study aboard a ship bound for the Middle East has found that adding measured amounts of sodium
10 February 2007 | NewScientist | 15
6/2/07 10:10:23 am