By Laura Husband

Astronauts may have problems with immune deficiencies while in space, a new study has found.

The study carried out at the University of Arizona in the US with mice found that weightlessness during spaceflight caused changes to genes that controlled an immune and stress response.

“Our results hint at the possibility that an astronaut’s immune system might be compromised in space,” said immunobiologist and lead researcher Ty Lesback.

Weightlessness during spaceflight causes a change to the immune system that can make astronauts ill. Image credit: NASA

The thymus gland, which plays a key part in the immune system, was compared in four mice who spent 13 days in a space shuttle with four mice who remained on the ground.

All four mice that spent time in space were found to have changes in the same 12 genes within the thymus tissue.

“The altered genes we observed were found to primarily affect signaling molecules that play roles in programmed cell death and regulate how the body responds to stress,” explained Lesback.

Programmed cell death has an important function. But cell death needs to be tightly regulated in the immune system for the process to run smoothly.

“Potentially you could get more cell death aboard a spacecraft because many of the gene changes resulted in down-regulated changes that are needed to maintain the balance,” said Lesback.

The activity levels of thousands of genes in thymus tissue from the space-flown mice and the control group had to be compared and analysed.

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Genes linked to high altitude life

Tibetans’ ability to survive at high altitude without getting sick has been linked to genes for the first time in a study published in Science.

Tibetans live in one of the highest regions of the world yet do not experience the symptoms associated with low levels of oxygen found in these high altitudes.

Scientists have found 10 genes that could explain why Tibetans living on Mountaintops don’t get sick

By comparing the genes of 31 Tibetans with a group of 90 Japanese and Chinese lowland people, scientists discovered 10 genes linked to a resistance to altitude sickness. Two of these genes have been linked to haemoglobin, the component in blood, which carries oxygen around the body.

Scientists have long known that Tibetans produce a low number of red blood cells but it is not understood how the body survives on such decreased levels of oxygen. By doing so, doctors predict it will help to understand and treat altitude sickness in mountaineers and other illnesses.

“What’s unique about Tibetans is they don’t develop high red blood cells counts,” said Professor Josef T. Prchal, a senior author on the study. “If we can understand this, we can develop therapies for human disease.”

The study was a joint collaboration between researchers at the University of Utah and Qinghai University Medical School.

Smallpox vaccine helped to curb AIDS?

Ending the worldwide smallpox vaccination may have lead to the explosive spread of HIV, scientists in a new study have suggested.

Smallpox immunisation gradually stopped between 1950s and 1970s, and since then, the rates of HIV have increased around the world.

The researchers from the study analysed white blood cells taken from people recently immunised against smallpox. They found that HIV replicated at lower levels from the vaccinated group compared with those from a control group who had not been immunised against smallpox.

According to the research, the smallpox vaccine cut HIV replication five-fold.

“There have been several proposed explanations for the rapid spread of HIV in Africa, including wars, the reuse of unsterilised needles and the contamination of early batches of polio vaccine. However, all of these have been either disproved or do not sufficiently explain the behaviour of the HIV pandemic,” said Dr Raymond Weinstein the lead researcher of the study, from the George Mason University in Virginia.

Mobile phones – no risk of brain tumours, scientists say

The largest study of mobile phone usage has found no link to suggest it increases the risk of brain tumours although the results are inconclusive, scientists report.

The study, carried out between 2000 and 2004, involved interviewing thousands of people from 13 countries about mobile phone usage and health.

The researchers compared the results from a group of patients suffering from either glioma or meningioma (types of tumour) with a similar number of health adults acting as a control group. No children took part in the study.
“Overall, this research has not shown evidence of an increased risk of developing a giloma or meningioma brain tumour as a result of using a mobile phone,” said Patricia McKinney an epidemiologist at the University of Leeds and one of the leaders of the study.

“The balance of evidence from this study, and in the previously existing scientific literature, does not suggest a causal link between mobile phone use and risk of brain tumours,” said Anthony Swerdlow, an epidemiologist at the Institute of Cancer Research and one of the leaders of the study.

Along with the other authors of the study, he warns that this does not provide assurances that there are no health risks associated with mobile phone usage: “The duration of phone use for which we yet have evidence is currently limited, however, and we have virtually no information for use of mobile phones for longer than 15 years.”

Sleep study – too much or too little

Sleeping fewer than six hours each night leads to a higher chance of dying prematurely, a new study has found. But consistently getting too much sleep may increase the risk of developing fatal illnesses the researchers found after analysing 1.3 million participants over 25 years.

“While short sleep may represent a cause of ill-health, long sleep is believed to represent more an indicator of ill-health,” said Francesco Cappuccio, leader of the Sleep, Health and Society Programme at the University of Warwick.

“Modern society has seen a gradual reduction in the average amount of sleep people take, and this pattern is more common amongst full-time workers, suggesting that it may be due to societal pressures for longer working hours and more shift-work,” added Cappuccio.

The study, a collaboration between the University if Warwick and the Federico II University Medical school in Naples, is published in the Sleep journal.

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By Paul Rodgers

It’s the headline dedicated smokers have been waiting for: their disgusting habit is good for them. At least under certain conditions, though this doesn’t mean you’d be wise to reach for a pack of Players – the benefit is far outweighed by the danger of cancer.

Smokers are less likely to develop Parkinson’s disease, a degenerative disorder of the nervous system that often affects motor skills and speech, according to researchers at the Mayo Clinic and the European Academy of Bozen/Bolzano in Italy. But the link is not a simple one. The researchers hypothesise that a genetic disposition combines with environmental factors to protect smokers from the disease.

At last, some good news about tobacco

Maurizio Facheris, a neurologist at the Institute of Genetic Medicine at Bozen/Bolzano, and his colleagues studied 1228 subjects while working as a research fellow at the Mayo Clinic. “We asked the interviewees to tell us about their relationship with smoking and then compared this data with the presence or absence of variations in the gene CYP2A6, which encodes the enzyme responsible for metabolising nicotine,” said Facheris.

One variant of the gene, when combined with smoking, considerably reduces the risk of Parkinson’s, they found, although it is not clear whether this is due to the presence of the gene variant, or by cotinine, the derivative of nicotine it produces. “If this second hypothesis is confirmed, producing a cotinine-based drug would be a means to reduce exposure to the disease”, said Facheris.

Such a drug could be one of the first to arise from the new field of pharmacogenetics, in which patients will be genetically tested before being given personalised medicines.

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By Paul Rodgers

Most creatures that use sound do so for communication, to find a mate, warn off rivals or warn of predators. Bats, and a few other creatures, such as cetaceans, use it differently. Their calls are designed to locate obstacles, prey and each other in space. Or so scientists thought.

Bats can, it turns out, distinguish between calls made by members of their own species and others, even those that are closely related and inhabit similar ecological niches, according to research by scientists at the Max Planck Institute for Ornithology (previously part of the Kaiser Wilhelm Society, which was renamed in honour of the quantum physicist after the Second World War).

Horseshoe bats can hear foreign accents.

Bats living in similar environments tend to use similar echolocation calls to orient themselves and search for food. But in a paper in this month’s American Naturalist, Maike Schuchmann and Bjorn Siemers at the institute’s facility in Seewiesen, Austria, were able to prove that echolocation calls carry more information than assumed.

Horseshoe bat species in Bulgaria were used for the behavioural experiments, in which scientists played the calls of three different species through ultrasonic speakers and analysed the animal’s responses. Both the Bulgarian bat species showed signs of being able to distinguish the calls, although the effect was clearer with calls that were in a clearly separate frequency band from their own.

Siemers reasoned that it would be advantageous for bats to get out of the way of competitively superior species in hunting grounds. And if the other species roosted in similar roosting requirements, identifying them could help the bats find new shelters. The institute’s scientists hope to do follow-up experiments to see whether either of these hypotheses explains the new-found ability.

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By Louis Jagger

Over the last few months, an unusual website has attracted thousands of viewers to discover more about one of the world’s most beautiful birds – the barn owl.

The website, Sportsman’s Paradise Online, has set up a live internet feed inside a barn owl nesting box. Viewers have watched the chicks grow from indiscriminately cute bundles of open-mouthed hunger into their current, almost fully-fledged state.

A barn owl

Another section of the website offers information about barn owls and the testimony of those who set up the camera, in San Marcos, California. Given the 59.000 Facebook shares, 4,000+ comments and 1,195 retweets, it’s safe to say that these owls have touched internet viewers in a way that few organised nature documentaries could have done.

And this nest isn’t the only one being transmitted freely across the internet. The Franklin Institute Hawk Nest cam is currently broadcasting on Ustream with a very young brood of red-tailed hawk chicks, a live chatbox full of enthused bird-lovers, and that all-important link containing more information about The Franklin Institute and its nest-observing project.

Quite what it is about birds of prey which so captures the imagination is up for debate, but on cuteness alone these unwitting internet superstars could charm their way into anyone’s precious internet routine. One might argue that this is an invasion of privacy, but as the birds are unaware of the camera, and grow up normally, it ought to be seen as an opportunity for regular people with a passing ornithological interest to inform and educate themselves upon the mysteries of avian youth. The joy of watching a helpless ball of down grow into a powerful, ruthless winged predator, live on your laptop screen, is a unique experience to say in the least.

And if you’re especially interested in this on-demand nature-viewing, the Sportsman’s Paradise Online site has a link to several other live wildlife cameras you can explore…

By Jennifer Green

Scientists working at the SLAC National Accelerator Laboratory in California announced last week that an X-ray analysis has revealed a chemical connection between birds and dinosaurs.

Placing a 150 million year old Archaeopteryx specimen labelled ‘Thermopolis’ under a bright X-ray beam, the researchers discovered that the ‘dinobird’s’ chemical remains lay hidden just below the surface of the fossil.

By analysing how hair-thin X-ray beams interacted with the fossil, then comparing it to the composition of the surrounding rock, the scientists found significantly different concentrations of several elements, proving that they belong to the animal itself.

SLAC National Accelerator Laboratory

“People have never used a technique this sensitive on Archaeopteryx before,” said SLAC physicist Uwe Bergmann, who led the study. “Because the beam is so bright, we were able to see the teeniest chemical traces that nobody thought were there.”

From this they mapped the chemical composition of Thermopolis, which was published last week in the Proceedings of National Academy of Science. The results revealed that sections of the feathers are actually real fossilised material rather than mere impressions and contain phosphorous and sulphur – chemicals that are present in modern day birds.

“We talk about the physical link between birds and dinosaurs, and now we have found a chemical link between them,” said University of Manchester geochemist Roy Wogelius, corresponding author on the paper.

“In the fields of paleontology and geology, people have studied bones for decades. But this whole idea of the preservation of trace metals and the chemical remains of soft tissue is quite exciting.”

All ten Archaeopteryx specimens that have been discovered have undergone numerous different visual analyses and scans in the past, none of which revealed the hidden dinobird’s chemical remains.

“You would think after 150 years of study, we’d know everything we need to know about this animal,” said University of Manchester paleontologist Phil Manning. “But guess what – we were wrong.”

The new technique also provides an alternative method of analysing other fossil remains, potentially revealing new information about animals that have been extinct for a very long time.

“We’re able to read so much more into these organisms now using this technology – we’re literally touching ghosts,” said Wogelius. “Chemistry is the real key in the future of paleontology. It’s a paradigm shift.”

But the method does have its limitations. Only remains that have not been removed from their surrounding rock can be analysed this way because it is necessary to establish that elements belong to a specimen and have not been transferred from foreign sources.

By Charlotte King

Studies in mice have shown that there is little genetic overlap between male and female fat cell genes.

Human men are more likely to carry extra weight around their guts, while pre-menopausal women store it in their bottoms, hips and thighs, say researchers at UT Southwestern Medical Centre, Dallas. Their studies in mice have shown that out of around 40,000 genes that code for fat in mice, only 138 are found in both male and female fat cells.

A fat and a normal mouse

Even though the studies were only carried out in mice, human and mice species both differ in the way that males and females distribute their fat. So the researchers used the mice to model humans.

“Given the difference in gene expression profiles, a female fat tissue won’t behave anything like a male fat tissue and vice versa,” says Dr. Deborah Clegg, assistant professor of internal medicine said. “The notion that fat cells between males and females are alike is inconsistent with our findings.”

Belly fat is associated with obesity-related conditions like diabetes and heart disease, so men are at a higher risk of these. But when women hit the menopause their ovarian hormone levels drop and their fat storage changes towards their waists.

Dr Clegg says that her ultimate goal is to “determine how fat tissue is affected by sex hormones and whether it would be possible to develop a ‘designer’ hormone replacement therapy that protected post-menopausal women from belly fat and related diseases such as metabolic syndrome.”

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By Laura Husband

Soldiers in action are 22 per cent more likely to be alcoholics than those not deployed but have low levels of post-traumatic stress disorder, a new study has found.

The study, carried out at King’s College London, examined the mental health effects of serving in Iraq and Afghanistan between 2003 and 2009.

Authors of the study, military expert Dr Nicola Fear and Professor of psychiatry Simon Wessely found 22 per cent of those who had served in Iraq or Afghanistan had misused alcohol.

Soldiers in action turn to the bottle.

“The Army itself encourages drinking because it numbs feelings while on the frontline,” explained Imogen Sturgeon-Clegg, a war veteran psychologist at psychological charity ‘Combat Stress’.

Deployed soldiers also developed social problems related to drinking too much including violence and relationship breakdown.

“A lot of people have problems with anger because in the army there are only two acceptable emotions: Anger and humour. Soldiers do not get a chance to talk through their experiences. They realise they’re suffering but can’t articulate it,” Sturgeon-Clegg said.

A low prevalence of post-traumatic stress disorder was found among the deployed soldiers in the study. Between 2003 and 2009 it stayed at 3 to 4 per cent.
The authors found this surprising as the wars in Iraq and Afghanistan lasted longer than expected.

But Sturgeon-Clegg argues, “Post-traumatic stress disorder has a delayed onset in war veterans and it takes an average of 14 years for them to ask Combat Stress for help. This is usually after they have had problems adjusting to civilian life.”

By Jennifer Green and Julius Goldthorpe

Japanese Knotweed causes millions of pounds worth of damage to buildings and roads in Britain every year. If attempted, eradicating the weed using traditional methods would cost around £1.5 billion pounds. But scientists have Cab International think they have come up with a natural solution, a tiny psyllid from Japan. The bug, set to be released here this year, will be the first live agent introduced in Europe to control a weed…

By Achintya Rao

Observations of a cluster of galaxies not too far from home have revealed that the cannibalistic galaxy at the centre of the cluster might be the most massive one in our local universe.

Images of Abell 3827 from the Gemini Observatory. Gemini Legacy Image: R. Carrasco et al., Gemini Observatory/AURA

The galaxy ESO 146-IG 005 at the centre of the galaxy cluster Abell 3827 has been known for over a decade to be cannibalistic, but astronomer Rodrigo Carrasco says, “The magnitude of its appetite has not been fully appreciated.” Carrasco and his colleagues at the Gemini Observatory’s South telescope in Chile used the recent discovery of the gravitational lens around the cluster to conclude that the galaxy is nearly 30 trillion times the mass of Sol, our sun.

Line diagram of light bending around a mass. Image credit: Michael Sachs

Gravitational lensing is observed when light from a distant star or galaxy bends around a closer star or galaxy, sometimes giving the illusion of being in more than once place at a time. Often, the image of the star or galaxy observed will appear elongated. The bending of light is caused by the distortion of local spacetime by a massive object (see images). These apparent images sometimes form what are called Einstein’s rings.

The gravitational lens around the cluster, located 1.4 billion light years away from us, gave astronomers a value for the mass of the central galaxy that was 10 times higher than estimates using X-rays. “Assuming our model is correct, this is by far the most massive galaxy known in our local universe,” Carrasco said.

The two background galaxies observed lie at distances of 2.7 billion light years (labelled A, in the first image) and 5.1 billion light years (labelled B) away from us.

How Einstein's rings are formed. Image credit: NASA

The results, to be published in The Astrophysical Journal Letters¹, are very important, particularly to understand the growth of elliptical galaxies. These galaxies are thought to acquire most of their mass by merging with other galaxies or by consuming them over the course of time. Cannibalistic galaxies such as ESO 146-IG 005 can grow to tremendous sizes by consuming their neighbours.

Michael West, an astronomer from the European Southern Observatory, who first observed the cannibalistic behaviour in 1998, said, “This unabashed cannibal is something of a messy eater, with the partially digested remains of at least four smaller galaxies still visible near its centre. Eventually this galaxy will grow even bigger judging by the number of nearby galaxies already within its gravitational grasp.”

1. E. R. Carrasco, P. L. Gomez, T. Verdugo, H. Lee, R. Diaz, M. Bergmann, J. E. H. Turner, B. W. Miller, & M. J. West (2010). Strong Gravitational Lensing by the Super-massive cD Galaxy in Abell
   3827 The Astrophysical Journal Letters arXiv: 1004.5410v1

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