Science News Digest 11th July 2011
In the science news this week, the final shuttle mission docks successfully at the International Space Station, polar bears share DNA with extinct brown bears of Ireland, selective memory really does exist, and finally… new species of bacteria found in human belly buttons.
Mice and men on historic final shuttle mission
The space shuttle Atlantis has docked with the International Space Station (ISS) for the final time in the shuttle programme’s history, reports the BBC.
Atlantis looked unlikely to get off the ground last week due to bad weather conditions at Cape Canaveral. Nonetheless the launch went ahead successfully and Atlantis reached the ISS without a hitch.
The mission is taking vital supplies to the space station, ensuring the astronauts have enough to last for a year. The delivery is said to have major significance since future cargo runs will be made by robotic spacecraft from private companies.
On arrival, ISS astronauts photographed Atlantis as it did a full flip before docking in order to check for damage sustained on its journey to the space station. As Atlantis docked, commander Chris Ferguson said “It’s great to be here station, see you shortly.”
The Atlantis astronauts were not alone on their journey, being joined by 30 mice brought along as part of a study into the effect of space-flight on human bones, according to the Telegraph.
Floating in zero gravity may be a thrilling experience, but prolonged weightlessness dramatically affects the skeleton. On average, people over 20 lose bone density at a rate of one per cent per year, but this is accelerated to one per cent per month during space travel.
The mice are being monitored for levels of sclerostin, a protein which blocks bone growth. It is hoped that introducing an antibody to block sclerostin production might halt the bone wastage. This would make longer spaceflights feasible, such as missions to Mars, and may also lead to new treatments for conditions such as osteoporosis.
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Polar bears once roamed the Emerald Isle
Not only Barack Obama can claim Irish roots - today’s polar bears are direct descendants of brown bears that once roamed Ireland, reports the Guardian.
The discovery came after DNA from the remains of the extinct Irish bears was analysed by an international team of scientists. A distinct DNA sequence, exclusively passed down the female line, was found to match that of modern polars.
Variations in climate are likely to have meant that at certain points during the last 100 000 years, the territories of the two species will have overlapped. Despite the fact that polar and brown bears have pronounced physical and behavioural differences, the two appear to mate successfully when they come into contact.
The researchers found that DNA in mitochondria, the energy-producing power houses found in all cells, contained the identical sequence. Since mitochondrial DNA is only ever passed from a mother to her offspring, the researchers deduced that the ‘Eve’ of modern polar bears must have been brown.
While DNA from 17 bears found at cave sites around Ireland was analysed, only those bears which were alive during ice age periods carried the matching genetic hallmark. It is thought that polar bears may have moved into Ireland during these colder periods, and as the ice-sheets melted the two species were forced into contact.
“Environmental conditions appear to have played, and continue to play, a big part in the evolutionary history of polar bears," said Dr Ceiridwen Edwards from Oxford University. "Today's warming climate is again bringing modern polar bears into contact with brown bears in places like Canada and Alaska."
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How to forget those embarrassing moments
Psychologists have proved that selective memory really does exist, and that it is possible to train the mind to forget unwanted memories completely, according to the Telegraph.
The study, led by Gerd Waldhauser at Sweden’s Lund University, used neuroimaging to discover which brain regions were active when volunteers were trying to forget something. The researchers were even able to pinpoint the precise moment when a memory is ‘forgotten’.
Volunteers were trained to forget neutral information in a controlled environment, while undergoing an EEG scan. Characteristic activity in certain areas signalled that the volunteer was in the process of trying to forget, and it was possible to directly observe when the memory became inhibited.
There are several situations in which the mastering the ability to forget could potentially be useful. For people who suffer from depression or post-traumatic stress disorder, constantly dwelling on painful or traumatic memories can have a devastating effect on mental health.
The consequences of deliberately repressing memories are not clearly established, and while some people are able to sublimate upsetting memories into creative activities, Waldhauser warns “‘forgotten’ or repressed feelings often manifest themselves as physiological reactions”. He is careful to stress the volunteers were trained to forget neutral memories, noting that “Training to forget a traumatic event would be more complex.”
It was found that the inhibition of memory eases off after a few hours, but that the more information suppressed, the harder it becomes to retrieve it. “If the memories have been suppressed over a long period of time, they could be extremely difficult to retrieve” said Waldhauser.
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And finally… navel-gazing scientists find new bacteria in belly buttons
Forget exotic rainforests and deep ocean vents, a study at North Carolina State University has found undiscovered life lurking in human belly buttons, says the Independent.
The study, dubbed ‘Belly Button Biodiversity’, saw microbiologists take swabs from the navels of 95 intrepid volunteers. When the samples were checked against databases of known bacteria, 662 unrecognized strains were found, some of which may be species new to science.
The volunteers were asked not only for their fluff, but also details about how often they cleaned their belly button, whether they have an ‘innie’ or an ‘outie’, as well as their age, gender, and other information. Only 4 per cent of those who took part in the project had an ‘outie’, but the microbes found in both types were the same.
Project leader Jiri Hulcr observed “We’re probably the only ones studying human belly buttons on such a large scale.” In response to the question of exactly why they are studying the belly button, Hulcr replies “Because everyone has one, it’s what once connected us to our past. Yet, we barely notice it in our daily lives, to the point that few people actually wash theirs. Which is great for the bacteria.”
Participants in the study included science writer Carl Zimmer whose unwashed navel housed at least 53 types of bacteria. On receipt of his results, Zimmer wrote "Several species I've got, such as Marimonas, have only been found in the ocean before. I am particularly baffled that I carry a species called Georgenia. Before me, scientists had only found it living in the soil. In Japan."
Mice and men on historic final shuttle mission
The space shuttle Atlantis has docked with the International Space Station (ISS) for the final time in the shuttle programme’s history, reports the BBC.
Atlantis looked unlikely to get off the ground last week due to bad weather conditions at Cape Canaveral. Nonetheless the launch went ahead successfully and Atlantis reached the ISS without a hitch.
The mission is taking vital supplies to the space station, ensuring the astronauts have enough to last for a year. The delivery is said to have major significance since future cargo runs will be made by robotic spacecraft from private companies.
On arrival, ISS astronauts photographed Atlantis as it did a full flip before docking in order to check for damage sustained on its journey to the space station. As Atlantis docked, commander Chris Ferguson said “It’s great to be here station, see you shortly.”
The Atlantis astronauts were not alone on their journey, being joined by 30 mice brought along as part of a study into the effect of space-flight on human bones, according to the Telegraph.
Floating in zero gravity may be a thrilling experience, but prolonged weightlessness dramatically affects the skeleton. On average, people over 20 lose bone density at a rate of one per cent per year, but this is accelerated to one per cent per month during space travel.
The mice are being monitored for levels of sclerostin, a protein which blocks bone growth. It is hoped that introducing an antibody to block sclerostin production might halt the bone wastage. This would make longer spaceflights feasible, such as missions to Mars, and may also lead to new treatments for conditions such as osteoporosis.
----------------------------------------
Polar bears once roamed the Emerald Isle
Not only Barack Obama can claim Irish roots - today’s polar bears are direct descendants of brown bears that once roamed Ireland, reports the Guardian.
The discovery came after DNA from the remains of the extinct Irish bears was analysed by an international team of scientists. A distinct DNA sequence, exclusively passed down the female line, was found to match that of modern polars.
Variations in climate are likely to have meant that at certain points during the last 100 000 years, the territories of the two species will have overlapped. Despite the fact that polar and brown bears have pronounced physical and behavioural differences, the two appear to mate successfully when they come into contact.
The researchers found that DNA in mitochondria, the energy-producing power houses found in all cells, contained the identical sequence. Since mitochondrial DNA is only ever passed from a mother to her offspring, the researchers deduced that the ‘Eve’ of modern polar bears must have been brown.
While DNA from 17 bears found at cave sites around Ireland was analysed, only those bears which were alive during ice age periods carried the matching genetic hallmark. It is thought that polar bears may have moved into Ireland during these colder periods, and as the ice-sheets melted the two species were forced into contact.
“Environmental conditions appear to have played, and continue to play, a big part in the evolutionary history of polar bears," said Dr Ceiridwen Edwards from Oxford University. "Today's warming climate is again bringing modern polar bears into contact with brown bears in places like Canada and Alaska."
----------------------------------------
How to forget those embarrassing moments
Psychologists have proved that selective memory really does exist, and that it is possible to train the mind to forget unwanted memories completely, according to the Telegraph.
The study, led by Gerd Waldhauser at Sweden’s Lund University, used neuroimaging to discover which brain regions were active when volunteers were trying to forget something. The researchers were even able to pinpoint the precise moment when a memory is ‘forgotten’.
Volunteers were trained to forget neutral information in a controlled environment, while undergoing an EEG scan. Characteristic activity in certain areas signalled that the volunteer was in the process of trying to forget, and it was possible to directly observe when the memory became inhibited.
There are several situations in which the mastering the ability to forget could potentially be useful. For people who suffer from depression or post-traumatic stress disorder, constantly dwelling on painful or traumatic memories can have a devastating effect on mental health.
The consequences of deliberately repressing memories are not clearly established, and while some people are able to sublimate upsetting memories into creative activities, Waldhauser warns “‘forgotten’ or repressed feelings often manifest themselves as physiological reactions”. He is careful to stress the volunteers were trained to forget neutral memories, noting that “Training to forget a traumatic event would be more complex.”
It was found that the inhibition of memory eases off after a few hours, but that the more information suppressed, the harder it becomes to retrieve it. “If the memories have been suppressed over a long period of time, they could be extremely difficult to retrieve” said Waldhauser.
----------------------------------------
And finally… navel-gazing scientists find new bacteria in belly buttons
Forget exotic rainforests and deep ocean vents, a study at North Carolina State University has found undiscovered life lurking in human belly buttons, says the Independent.
The study, dubbed ‘Belly Button Biodiversity’, saw microbiologists take swabs from the navels of 95 intrepid volunteers. When the samples were checked against databases of known bacteria, 662 unrecognized strains were found, some of which may be species new to science.
The volunteers were asked not only for their fluff, but also details about how often they cleaned their belly button, whether they have an ‘innie’ or an ‘outie’, as well as their age, gender, and other information. Only 4 per cent of those who took part in the project had an ‘outie’, but the microbes found in both types were the same.
Project leader Jiri Hulcr observed “We’re probably the only ones studying human belly buttons on such a large scale.” In response to the question of exactly why they are studying the belly button, Hulcr replies “Because everyone has one, it’s what once connected us to our past. Yet, we barely notice it in our daily lives, to the point that few people actually wash theirs. Which is great for the bacteria.”
Participants in the study included science writer Carl Zimmer whose unwashed navel housed at least 53 types of bacteria. On receipt of his results, Zimmer wrote "Several species I've got, such as Marimonas, have only been found in the ocean before. I am particularly baffled that I carry a species called Georgenia. Before me, scientists had only found it living in the soil. In Japan."
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