Fracking tests near Blackpool 'likely cause' of tremors

Cuadrilla's Mark Miller: "There are procedures we can put in place to practise earthquake prevention"

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• Solar tariff slash 'risks jobs'
• China urges tough atomic watchdog
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It is "highly probable" that shale gas test drilling triggered earth tremors in Lancashire, a study has found.

But the report, commissioned by energy firm Cuadrilla, also said the quakes were due to an "unusual combination of geology at the well site".

It said conditions which caused the minor earthquakes were "unlikely to occur again".

Protesters opposed to fracking, a gas extraction method, said the report "did not inspire confidence".

Six protesters from campaign group Frack Off climbed a drilling rig at one of Cuadrilla's test drilling sites in Hesketh Bank, near Southport, ahead of the report.

They oppose the controversial extraction method which pumps water and chemicals underground at high pressure to shatter rock formations and release gas, claiming it can be unsafe.

Safety concerns

A spokesman for Lancashire Police said the force was "liaising with the site owners and the protesters to bring about a peaceful resolution".

Cuadrilla suspended its shale gas test drilling in June, over fears of links to the earthquakes.

One tremor of magnitude 2.3 hit the Fylde coast on 1 April, followed by a second of magnitude 1.4 on 27 May.

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ANALYSIS

Daniel BoettcherEnvironment correspondent

Cuadrilla Resources believes there are huge reserves of natural gas in layers of shale under Lancashire.

That is based on the testing it has already done, but an important part of its exploration work was put on hold when it had to suspend hydraulic fracturing, or fracking.

Even though today's report says it is highly probable that fracking did trigger two earth tremors earlier this year, the company believes it can resume that process safely- with some modifications to the way it works.

Some environmental groups opposed to shale gas are calling for a moratorium on fracking. It's not just the process itself that they're concerned about. They say large-scale gas extraction will lead to more reliance on fossil fuels rather than alternative energy sources.

The industry argues that there is big potential for a new home-grown energy source that could reduce gas prices and also provide new jobs.

A study by The British Geological Survey placed the epicentre for each quake about 500m away from the Preese Hall-1 well, at Weeton, near Blackpool.

The Geo-mechanical Study Of Bowland Shale Seismicity report, carried out by independent experts, said the combination of geological factors that caused the quakes was rare, and would be unlikely to occur together again at future well sites.

It said: "If these factors were to combine again in the future local geology limits seismic events to around magnitude 3 on the Richter scale as a worst-case scenario."

However, it said that "even the maximum seismic event is not expected to present a risk".

Mark Miller, chief executive officer of Cuadrilla Resources, said: "We unequivocally accept the findings of the independent report and we are pleased that there is no threat to people or property in the local area from our operations.

"We are ready to put in place the early detection system that has been proposed in the report so that we can provide additional confidence and security to the local community.

"Cuadrilla is working with the local and national authorities to implement the report's recommendations so we may resume our operations."

A spokesman for Frack Off said: "This report does not inspire confidence, they should have done their research before drilling began."

He added: "Can we believe anything else the industry says when it talks about the safety of fracking?"

Protesters have called for an end to fracking. There have been concerns that potentially carcinogenic chemicals could escape during the process and find their way into drinking water sources.

'Hopelessly naive'

"The contamination of irrigation water means that everyone's food supplies could potentially be affected," the Frack Off spokesman added.

Friends of the Earth's senior climate campaigner Tony Bosworth said: "This report shows fracking for shale gas caused earth tremors in Lancashire - experience in the US shows it could also pollute air and water supplies.

"Extracting shale gas would suck vital funding away from clean and safe energy alternatives that could create thousands more UK jobs.

"An early seismic detection system won't be enough to make local people feel safe - there should be no more fracking in Britain until the health and environmental impacts are fully understood."

Doug Parr, chief scientist at Greenpeace, added: "Anyone who believes shale gas is the solution to our energy needs is being hopelessly naive.

"There are significant unknowns about the local and global impacts of fracking, illustrated by the conclusion by seismologists that recent fracking in the North West was responsible for a minor earthquake."

He said fracking was a "distraction from the real challenges" and that "real energy solutions" would be found in using renewable sources.

Nick Molho, head of energy policy at World Wildlife Fund UK, reiterated a call for a moratorium on fracking in the UK.

"These findings are worrying, and are likely to add to the very real concerns that people have about fracking and shale gas," he said.

The industry denies that shale gas is unsafe and a government committee has recommended that fracking should be allowed to go ahead.

The Department of Energy and Climate Change (DECC) said: "The implications of this report will be reviewed very carefully - in consultation with the British Geological Survey, independent experts, and the other key regulators, HSE and the Environment Agency - before any decision on the resumption of these hydraulic fracture operations is made."

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Energy Futures

• Solar tariff slash 'risks jobs'

• China urges tough atomic watchdog

• Warning over green energy spend

• Fracking protesters target tower 06 AUGUST 2011, LANCASHIRE
• Q&A: What is fracking? 02 NOVEMBER 2011, UK
• Shale gas drilling inquiry call 08 JUNE 2011, LANCASHIRE
• Small earthquake hits Lancashire 28 MAY 2011, LANCASHIRE

• British Geological Survey
• Cuadrilla
• Frack Off

Global Food Prices Remain High and Volatile Affecting Poorest Countries the Most

	Available in: Français, Español
Press Release No:2012/134/PRM
Floods in Thailand add further uncertainty. Food crisis in the Horn of Africa continues WASHINGTON, November 1, 2011–Global food prices remain high and volatile, hitting the poorest countries hardest and adding to the strains facing the global economy, according to the World Bank Group’s new Food Price Watch released ahead of the G-20 Summit in Cannes, France. While the Bank’s food price index has dropped 5 percent from its February 2011 peak and dipped marginally in September by one percent, it remains 19 percent above its September 2010 levels. “The food crisis is far from over,” said World Bank Group President Robert B. Zoellick, who has urged the G-20 to put food first. “Prices remain volatile and millions of people around the world are still suffering. The World Bank has been working closely with the French Presidency of the G-20 and our partner international organizations on actions to protect the most vulnerable from the dangers of food price volatility, while also addressing some of its root causes. Let's remember, averting crisis is not just about banks and debt. Millions of people around the world face a daily crisis of hunger and malnutrition. At Cannes, the G-20 can and should take steps to address their needs."   The Group of 20 heads of government, who are meeting in Cannes Nov. 3– 4 to discuss the global economy, are expected to endorse a package of concrete actions to improve transparency and policy coordination to detect and correct problems early; to help countries manage price volatility using sound risk management tools; to promote more productive and resilient agriculture; and to get food to the needy fast through emergency regional humanitarian food reserves and agreement not to ban exports of food for World Food Programme. As the world population reaches a staggering 7 billion people, it is more important than ever for the global community to galvanize around actions to improve food security. According to Food Price Watch, a quarterly report, recent floods in Thailand−the worst in 50 years−may add uncertainty in the short run following estimated production losses of between 16 to 24 percent of total production. In the meantime, the food crisis in the Horn of Africa continues, affecting over 13.3 million people in the region–an additional million since August, and the outlook remains frightening. The report said prices of grains rose 30 percent (September 2010–September 2011), with maize increasing by 43 percent, rice by 26 percent and wheat 16 percent. Soybean oil went up by 26 percent. Over the last quarter, however, an increase of 3 percent in the price of grains was roughly offset by a 3 percent decline in the prices of fats and oils. Volatility, which is higher in low income countries, is expected to persist in the medium term due to multiple global and domestic factors. Structural factors contributing to the volatility include rising populations and changing diets, increasingly intertwined relations between food and energy prices, and increasing production of biofuels. On the other hand, a favorable outlook on supply and stocks is likely to relieve some of the pressure on global food prices. Latest forecasts show global wheat stocks reaching a 10-year high in 2011-12, global production of maize to rise by 4 percent from increased production in Argentina, Brazil, China, Russia, and Ukraine. Global rice output is also likely to get a boost in 2011-12 due to an expected bumper harvest in India following very favorable monsoon rains. These production gains in some markets underscore the critical need to keep international markets open, to get food where it is needed, provide incentives to farmers who expand production, and avoid panic behavior created by export bans. While a troubled global economy could dampen demand and push food prices down, the effect on developing countries would be mixed−hurting food exporting countries and poor producers in rural areas, and benefiting food importers and consumers. The problem, Food Price Watchwarns, is that developing countries might have now limited resources to protect vulnerable populations following the economic crisis and stimulus spending. In addition, fears associated with the global economy may affect medium to long-term investments in agricultural research and more productive agricultural techniques, especially amid persistent volatility. Among the ongoing efforts to improve volatility-related information, the G-20 agriculture ministers introduced the Agricultural Market Information System (AMIS), officially launched in September, to increase market transparency on the short-term global food outlook, especially stocks, and to identify abnormal international market conditions in order to prompt early responses. How the World Bank Group is helping to put food first ·         In the Horn of Africa, the World Bank Group is providing $1.88 billion to save lives, improve social protection, and foster economic recovery and drought resilience. More than 13 million people are affected by the crisis. ·         A first-of-its-kind World Bank Group risk management product, provided by the International Finance Corporation (IFC), will enable up to $4 billion in protection from volatile food prices for farmers, food producers, and consumers in developing countries. ·         The Global Food Crisis Response Program (GFRP) is helping some 40 million people through $1.5 billion in support. ·         The World Bank Group is boosting its spending on agriculture to some $6 to $8 billion a year from $4.1 billion in 2008. ·         Supporting the Global Agriculture and Food Security Program (GAFSP), set up by the World Bank Group in April 2010 at G-20’s request, to assist country-led agriculture and food security plans and help promote investments in smallholder farmers. To date, six countries and the Gates Foundation have pledged about $971.5 million over the next three years, with $571 million received. ·         The World Bank Group is coordinating with UN agencies through the High-Level task Force on the Global Food Security Crisis and with NGOs. ·         The World Bank Group supports the Consultative Group for International Agriculture Research (CGIAR), which it helped to establish in 1971. In 2008, the CGIAR with the support of the World Bank and other donors launched a reform process, which culminated in the adoption of a comprehensive strategy that determines the new global research programs and a new funding model that prepares CGIAR to absorb and attract vastly more program funding, with a target annual budget of $1 billion by 2013, to which the World Bank contributes some $50 million per year. With agriculture production needing to rise some 70 percent by 2050, and with a five- to ten-year window to develop new varieties and get them to farmers, increased funding from the international community for global research is critical. Contacts:  In Washington: Alejandra Viveros, (202) 473-4306, aviveros@worldbank.org For Broadcast Requests: Natalia Cieslik, (202) 458-9369, ncieslik@worldbank.org To access Food Price Watch, please click:  http://go.worldbank.org/26VBL9Q3F0 Food Price Watch author, Jose Cuesta will take part in World Bank Live online discussion about Global Food Prices on Tuesday, November 8 at 10:00 am EST (15:00 GMT).  Participate and submit questions in advance here: http://live.worldbank.org/qa-global-food-prices-nov-2011 Visit us on Facebook: http://www.facebook.com/worldbank Be updated via Twitter: http://www.twitter.com/worldbank For our YouTube channel: http://www.youtube.com/worldbank

Archaeopteryx and the dinosaur-bird family tree 14 September 2011

Archaeopteryx and the dinosaur-bird family tree

14 September 2011

The first fossil skeleton specimen of Archaeopteryx lithographica was uncovered in 1861 and is looked after at the Natural History Museum. It shows a creature with both bird and dinosaur features.

The magpie-sized Archaeopteryx had bird and dinosaur features and helped show that birds evolved from dinosaurs. However, recent research in the journal Nature questions its position in the dinosaur-bird family tree.

Scientists know birds evolved from dinosaurs because many fossils have been found of ancient animals with both bird and dinosaur features, including the famousArchaeopteryx that lived 147 million years ago.

Painting of how Archaeopteryxmay have looked 147 million years ago © John Sibbick / Natural History Museum

Archaeopteryx had a feathered tail and wings with a flight feather arrangement just like modern birds. But it also had a long bony tail, teeth, and 3 fingers ending in claws, like dinosaurs. 

The first Archaeopteryx skeleton fossil was uncovered in 1861 in Solnhofen, Germany, and is looked after at the Natural History Museum. It provided the first evidence that helped demonstrate that modern birds descended from small meat-eating dinosaurs.

Along with researchers from all over the world, Museum scientists have studied the specimen ever since, and they have been able to reveal that it had hearing like an emu and a brain like a chicken.

Still a bird?

Close up of MuseumArchaeopteryx specimen showing the bird characteristic of a reversed perching toe. 

No other fossils of bird-like creatures older thanArchaeopteryx were known at the time, or for most of the time since this early discovery. So it became established as the earliest known bird. But is this still so?

Since the discovery of Archaeopteryx, many more fossils with combined dinosaur and bird features have been uncovered, especially in the last 10 years (with only 9 other Archaeopteryxfinds over the last 150 years).

In June, scientists revealed a new species from China that they say shows Archaeopteryx was not a bird at all.

Xing Xu from the Institute of Vertebrate Paleontology and Paleoanthropology, in Beijing, and colleagues, identified the feathered and chicken-sized Xiaotingia zhengi. It was very similar to Archaeopteryx, sharing features such as long and robust forelimbs, which the team says puts them together in the dinosaur group rather than with birds.

Museum specimen showing the fossil tail of 147-million-year-oldArchaeopteryx that shows the bird-like feather and dinosaur-like long bony tail.

Dr Paul Barrett, Museum dinosaur expertsays, ‘The June research shows just how fine the line between birds and non-avian dinosaurs really is’.

Species that have a mixture of features, and are hard to place in one group or another, are known as transitional forms, sometimes incorrectly called a ‘missing link’. Their fossils provide a record of significant steps in the evolution of new features.

Although Archaeopteryx and X. zhengi had some bird-like features, the researchers say they had more features that put them in the group Deinonychosauria, which includesMicroraptor and Velociraptor, rather than in the bird group Avialae.

So, does the whole bird family tree need re-arranging? 

Not according to Barrett. ‘Xiaotingia does not necessitate a major re-writing of early bird evolution, but shows that the evolution of many of the detailed anatomical features that changed during the origin of birds may have been slightly more complex than previously thought.’

Dr Angela Milner, Museum dinosaur expertcomments. ‘This recent research in no way diminishes the scientific and historical importance of Archaeopteryx.

‘Thomas Henry Huxley [pioneering biologist and educator] pointed out in 1868 that it was the first fossil to provide a snapshot of evolution in action between two major groups, dinosaurs and birds, and a clear demonstration that birds are the descendents of small meat-eating dinosaurs.

Another bird-like branch?

If Archaeopteryx is not a direct ancestor of birds, why does it have bird-like features and where does it sit in relation to the transition of dinosaurs to birds?

Archaeopteryx could be on another branch of the dinosaur family tree with bird-like feathers and skeletal features evolving in another closely related dinosaur group, suggests Barrett.

‘Maybe Archaeopteryx wasn't on the direct ancestral line to birds, but was part of an early experimentation in how to build a bird-like body.’

Overall bird origin picture

The overall picture of birds descending from meat-eating dinosaurs is firmly established. Now scientists need to rearrange the details of the early stages in the bird evolutionary tree.

Barrett adds, ‘As the authors of the June paper note, the evidence suggesting thatArchaeopteryx is not a bird is fairly equivocal and new analyses or new animals could very easily change this picture.

‘In reality what we now have are a set of animals incredibly close to bird origin – unsurprisingly these are very similar to each other, to birds and to other small meat-eating dinosaurs. As they are so similar, it becomes exceptionally difficult to disentangle their relationships accurately.’

Milner concludes, ‘The fact that Archaeopteryx may represent one of many early flying experiments rather than being the direct ancestor of modern birds is no surprise at all.

‘It is only now that Archaeopteryx can be assessed in the context of all the recent discoveries in China which provide so much more information.

Bacterium linked to bowel cancer

A barium X-ray can reveal the site of the tumour

 

• Bowel cancer death rates across UK
• Bowel cancer awareness 'very low'
• How to spot signs of bowel cancer

A type of bacterium known to cause dental decay and skin ulcers may also be linked to bowel cancer, scientists suspect.

Two independent research teams have now found the bug Fusobacterium in colon tumours.

It's not yet clear if the pathogen might cause cancerous changes or whether it is an incidental finding, they toldGenome Research journal.

If it is to blame, antibiotics might be able to treat it and prevent cancer.

Bowel cancer is the third most common cancer in the UK after after breast and lung.

Although the exact cause of bowel cancer is unknown, there are certain factors that increase risk, such as a strong family history of the disease and older age.

It may be that Fusobacterium infection can be added to that list, according to the experts, but they say much more work is needed to establish this.

The infection has already been linked with a gut condition called ulcerative colitis which is itself a risk factor for bowel cancer.

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Early warning signs and symptoms

• A persistent change in normal bowel habit, such as going to the toilet more often and diarrhoea, especially if you are also bleeding from your back passage
• Bleeding from the back passage without any reason, particularly over the age of 50
• A lump in your tummy or a lump in your back passage felt by your doctor
• Unexplained iron deficiency in men or in women after the menopause
• Unexplained extreme tiredness

And other cancers are known to be linked with certain bacteria and viruses - for example, HPV and cervical cancer.

The first study, led by Dr Robert Holt from Simon Fraser University in Canada, identified Fusobacterium's hallmark in RNA present in bowel cancer tumours. RNA is genetic material similar to DNA which is involved in transmitting and translating the genetic code.

The other team, led by Dr Matthew Meyerson from the Dana-Farber Cancer Institute in Boston, US, found microbial sequences of DNA indicative of Fusobacterium.

Together, they looked at more than 100 samples of healthy and cancerous bowel tissue.

Sarah Williams, of Cancer Research UK, said the research gave a clue about the environment in which bowel cancer grows, but added: "It's early days and we look forward to the results of more specific, in-depth studies.

"In the meantime, people can reduce their risk of bowel cancer by not smoking, cutting down on alcohol, keeping a healthy weight, being active, reducing the amount of red and processed meat in their diet and eating plenty of fibre."

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Related Stories

• Bowel cancer death rates across UK 12 SEPTEMBER 2011, HEALTH
• Bowel cancer awareness 'very low' 23 AUGUST 2011, HEALTH
• How to spot signs of bowel cancer 23 AUGUST 2011, HEALTH

From other news sites

• Yahoo! UK and Ireland Studies link bug to bowel cancer 8 hrs ago

• ABC News Linking Infection to Colon Cancer 10 hrs ago

• New York Times Separate Cancer Studies, but a Single Suspicion of Bacteria 12 hrs ago

• About these results

Related Internet links

• Genome Research
• Cold Spring Harbor Laboratory

Around the BBC

• BBC Health: Bowel cancer

breakthrough in Alzheimer’s research holds out hope not only of early detection of the crippling brain disease but also potential new treatments

Friday October 28 2011

Deposits of amyloid beta are found in the brains of Alzheimer’s patients

“A major breakthrough in Alzheimer’s research holds out hope not only of early detection of the crippling brain disease but also potential new treatments,” reports the Daily Express.
The headline is based on research into a peptide (small protein) called amyloid beta that is linked to Alzheimer’s disease. This protein is found in plaques (deposits) in the brains of Alzheimer’s patients and, according to one theory, is responsible for the disease. The researchers created a type of genetically modified yeast and used it to identify genes that could alter the toxic effect of amyloid beta. They found that the genes they identified also changed the toxic effect of amyloid beta in worms and rat brain cells. A further experiment in the yeast showed that amyloid beta disrupted a process called endocytosis in yeast cells. In endocytosis, cells take up and transport substances around the cell. This process also occurs in human cells, and genes involved in this process have already been identified as risk factors for Alzheimer’s disease.
This sort of research is important in working towards treatments for Alzheimer’s disease. However, this is early research and although the researchers are confident that these findings apply to humans, we will still need to wait for research using human cells before this can be confirmed. New treatments and diagnostic tools based on these findings are a long way off.

Where did the story come from?

The study was carried out by researchers from the Whitehead Institute for Biomedical Research, and a number of other American and international universities and research centres. It was funded by an HHMI collaborative Innovation Award, an NRSA fellowship, the Cure Alzheimer’s Fund, the US National Institutes of Health (NIH), the Kempe Foundation and Alzheimerfonden.
The study was published in the peer-reviewed journal Science.
Contrary to the report in the Daily Express, new diagnostic tests for Alzheimer’s and new treatments based on this research are not on the horizon. Instead, this early research investigated the reason for the toxicity of the amyloid beta protein, and whether other genes can influence it. Any practical application is probably years away.

What kind of research was this?

This was a laboratory study that involved experiments in yeast, worms and cultured rat brain cells to try to identify other genes that are involved in amyloid beta toxicity. Amyloid beta is the peptide (small protein) implicated in Alzheimer’s disease as it is found in plaques (deposits) in the brains of Alzheimer’s patients. The researchers aimed to understand further what happens during Alzheimer’s disease, and why the amyloid beta peptide is toxic.
A laboratory-based study is the only way that this type of question can be answered. In this study, the findings in yeast were validated in worms and mammalian cells. Many of the genes identified are present in humans, and mutations in the genes encoding these proteins have been linked to susceptibility to Alzheimer’s disease. The process that amyloid beta was shown to affect (endocytosis) is common to human cells. However, further research will have to be performed to confirm whether the findings hold true in humans.

What did the research involve?

The researchers decided first to test amyloid beta toxicity in modified yeast cells. To do this, they introduced into the yeast cells DNA that encoded amyloid beta. They then forced the cells to overexpress amyloid beta. They added a special targeting sequence to the end of amyloid beta so that it would move through the yeast cell in a similar way to that in which it moves through human cells. The researchers also constructed other control strains that overexpressed other proteins with similar properties. They then looked at the amyloid beta peptide that was produced, to confirm whether it behaved in a similar manner to amyloid beta in mammals.
A genetic screen was then performed using this yeast model. In this screen, strains which overexpressed every gene which codes for a protein were created. The researchers tried to identify two gene types. One, when overexpressed, could reverse the reduction in growth of yeast caused by expression of amyloid beta, so growth was increased (termed suppressors). The second could add to it, so growth of the yeast was further reduced (termed enhancers). The researchers then investigated whether equivalent genes are also present in human DNA, and whether they have been implicated in Alzheimer’s disease susceptibility.
The researchers then determined whether the modifiers of amyloid beta toxicity they identified had an effect on the viability of neurons (brain cells). To do this experiment, they used a type of worm called C. elegans, which they genetically modified so it expressed the amyloid beta peptide only in glutamatergic neurons, a particular type of neuron that is especially vulnerable in Alzheimer’s disease. The researchers chose C. elegans because it has been extensively studied, and the location and number of glutamatergic neurons is known.
The effect of one of the suppressors, PICALM, on the toxicity of amyloid beta aggregates was investigated in more detail in cultured rat neurons.
The researchers then returned to the yeast cells to investigate how PICALM may reduce the toxicity of amyloid beta.

What were the basic results?

The researchers found that overexpression of amyloid beta decreased cell growth. The overexpression of other similar proteins was less toxic, demonstrating that the amyloid beta peptide itself was responsible for the toxicity. The amyloid beta peptide that was produced was of the correct size and was localised correctly in the cell. It could also aggregate, or stick together. These amyloid beta aggregates form the amyloid plaques seen in Alzheimer’s disease.
Twenty-three suppressors, which reversed the reduced growth seen when amyloid beta was overexpressed, and 17 enhancers, which reduced growth further, were identified. Twelve of the modifiers of the effect of amyloid beta had clear human equivalents (homologues), and the researchers concentrated on these. Many of the modifiers are associated with Alzheimer’s disease susceptibility, for example the human homologue of yeast YAP1802 is PICALM, which research indicates is a risk factor for sporadic Alzheimer’s disease.
Expression of amyloid beta caused the age-dependent loss of glutamatergic neurons in C. elegans. The researchers tested the effect of overexpressing the modifiers they identified in yeast. Overexpression of C. elegans homologues of every gene they tested had a similar effect: either decreasing or increasing the loss of neurons. PICALM was found to suppress the toxicity of amyloid beta aggregates on cultured rat neurons.
Using the yeast system they created, they found that amyloid beta affects a process termed endocytosis. Endocytosis is a process by which the cell brings substances into the cell. Amyloid beta also affects how these substances are then moved around once in the cell (termed trafficking). Yeast YAP1802 and its human homologue PICALM has already been shown to be involved in endocytosis and trafficking, and overexpression of YAP1802 compensates for the effects amyloid beta has on these processes.

How did the researchers interpret the results?

The researchers conclude that throughout the diverse organisms examined in this study, “endocytosis is a critical point of vulnerability to [amyloid beta]”. They also say that the yeast model that they have created “provides a tool for identifying genetic leads, investigating their mechanisms of action, and screening for genetic and small molecule modifiers” of Alzheimer’s disease.

Conclusion

In this study, the researchers used yeast, worms and cultured rat brain cells to model the effect of amyloid beta, the peptide (small protein) implicated in Alzheimer’s disease. The researchers aimed to understand further what happens during Alzheimer’s disease, and why the amyloid beta peptide is toxic.
They created a yeast model of amyloid beta toxicity. Using this model, they identified genes that altered the effect of the amyloid beta peptide. Many of these genes had clear human equivalents, which have already been linked to Alzheimer’s disease susceptibility. The researchers then confirmed their findings by investigating the effect of amyloid beta and the modifier genes on worm neurons. They further investigated PICALM, a highly probable human Alzheimer’s disease risk factor, which had been identified during the study. They found that overexpression increased survival of rat neurons treated with amyloid beta aggregates.
Returning to the yeast model, the researchers investigated why the amyloid beta peptide was toxic, and how some of the modifiers could be changing the toxicity of amyloid beta. As several genes are involved in the update of substances from outside the cell and the movement of these substances inside the cell (processes called endocytosis and trafficking), they examined whether amyloid beta was affecting these processes, and found that it was.
This research has demonstrated that a variety of model systems can be used to explore the causes of Alzheimer’s disease. It has also provided reasons why certain genes might be genetic risk factors. Further research could help understand the process behind Alzheimer’s disease.
This sort of research is important and vital to working towards treatments for Alzheimer’s disease. However, this is early research and although the researchers are confident that these findings apply to humans, we will still need to wait for research using human cells. New treatments and diagnostic tools based on these findings are a long way off.

Links to the headlines

Genes research breakthrough on Alzheimer's. Daily Express, October 28 2011 

“Sunbeds may be even more dangerous than previously feared

Friday, 14 October 2011

“Sunbeds may be even more dangerous than previously feared

“Sunbeds may be even more dangerous than previously feared,” the Daily Mail has today reported. The newspaper said UVA rays, the main type of ultraviolet light emitted by tanning devices, has been found to cause the type of DNA damage that can lead to cancer.

The news is based on laboratory research that compared the DNA damage caused by UVA rays to that from UVB rays, which are already known to cause skin cancer. While UVB has long been linked to burning and skin cancer, UVA has previously been considered to be relatively harmless. However, this research builds on other studies that have suggested that UVA is not harmless and, like UVB, can lead to changes in the cell that increase the risk of skin cancer.
By exposing different areas of volunteers’ skin to UVA and UVB and examining skin tissue samples, the experimental study found that both could cause similar types of DNA damage, but that UVA tended to affect cells deeper in the skin. However, UVB affected cells at the surface of the skin more.
This research emphasises the need to use an appropriate-strength sunscreen that protects against both UVA and UVB. These sunscreens may be labelled as offering “broad spectrum” protection, and rated according to a five-star system in the UK. Cancer Research UK recommends that people use sunscreen of at least SPF 15 and with at least four stars to get good balanced protection across the UV spectrum.

Where did the story come from?

The study was carried out by researchers from King’s College London. It was funded by The National Institute for Health Research, the UK Medical Research Council, British Skin Foundation and the British Association for Dermatology.
It was published in the peer-reviewed, Journal of Investigative Dermatology.
The Daily Telegraph and the Daily Mail both appropriately advised that people should consider UVA protection as well as UVB when choosing a sunscreen.

What kind of research was this?

This laboratory-based research looked at how UVA rays affected skin cells. Light from the sun contains two types of ultraviolet (UV) rays, UVA and UVB. UVB has a shorter wavelength and has generally been thought of as the major carcinogen in sunlight. However, the researchers say that the action of UVA needs further consideration as there are more UVA than UVB rays in sunlight. UVA is also the predominant wavelength generated by sunbeds, and has now been classified as a carcinogen.
UVB is known to causes chemical changes to our DNA. In some cases the body’s natural DNA repair mechanisms can repair the damaged DNA, but in skin cancers these chemical changes have not been fixed and lead to harmful mutations in the DNA sequence. In skin cancers caused by UVB, there is a characteristic pattern of DNA damage that the researchers term a “UVB signature”.
UVA is also known to cause mutations, but this was previously thought to be by an indirect mechanism (i.e. causing chemical changes to other molecules in the cell that may have a knock-on effect on the DNA). However, recent experiments on cells in a lab have shown that UVA may also cause a “UVB signature” in the DNA sequence.
As recent evidence suggests that UVA may cause mutations in a similar way to UVB, this has raised doubts over the belief that UVA may be “safer” than UVB. Given this uncertainty, the researchers devised a series of experiments to see what effect comparable doses of UVA and UVB had on skin cells.

What did the research involve?

The researchers recruited 12 volunteers with healthy skin. The participants had fair, white skin that either always burns and never tans, or usually burns and tans with difficulty.
The participants were exposed to each wavelength of UV on 1 cm2 areas of previously-exposed skin on their buttocks.
Twenty-four hours later, the researchers used three participants to find the minimum doses of UVA and UVB needed to produce just-detectable redness of the skin. The participants were then given doses of UVA and UVB, which were multiples of this minimum dose (half the minimum dose, 1.5 times and 3 times). The degree of skin redness was assessed using a red skin scale.
The researchers took punch biopsies, which involved using a small tube-like device to extract a 4mm plug of skin from the exposed site. They used the biopsies to look at chemical changes to the DNA. To see how well the body could repair and reverse the DNA damage, they performed another set of biopsies on the exposure sites 3, 6, 24 and 48 hours after the UV exposure and examined the changes seen.

What were the basic results?

The researchers found that the skin became redder with increasing doses of either UVA or UVB. However, when they applied increasing multiples of the minimum dose required to cause redness, UVB caused more redness than UVA.
When the researchers looked for DNA chemical changes in skin cells immediately after exposure, they found that UVB led to more of these changes in the top layer of skin, whereas UVA led to more changes in the deeper layers of skin. They also found that as doses increased beyond the minimum dose, UVB caused more detectable chemical changes to the DNA than UVA. Although both UVA and UVB produced one particular type of DNA change, UVB caused additional chemical changes that were not found in UVA-treated cells.
The researchers then attempted to see how well the cells could repair the DNA damage caused by UV exposure. They found that the rate at which the body could repair the DNA damage was similar for damage caused by UVA and UVB. They said that by 48 hours the majority of DNA changes caused by UVA had disappeared but that there was still some DNA damage with UVB. The researchers said that this was because a higher proportion of DNA had been damaged with the UVB dose.

How did the researchers interpret the results?

The researchers say that they had demonstrated for the first time that UVA can cause DNA changes similar to some of those caused by UVB, although UVB also causes additional chemical changes not seen with UVA exposure. They said that deeper layers of skin are particularly vulnerable to UVA-induced damage and that this has implications for public health policies, particularly the need for developing measures that protect against UV light at a broader range of wavelengths.

Conclusion

This research has shown that UVA can produce some similar damage to the DNA when the skin becomes red as UVB. The research also showed that these changes may increase the risk of developing skin cancer if not repaired by the body. Previously, it was thought that UVB caused burning and was the major carcinogenic component of sunlight, while UVA was considered to be relatively harmless apart from ageing the skin.
In recent times studies, including this one, have suggested that UVA may directly cause the type of DNA damage that can lead to skin cancer. This study emphasises the importance of choosing a sunscreen that protects against both UVA and UVB (often labelled as offering ‘broad spectrum’ protection).
The charity Cancer Research UK has highlighted that there is no international measurement of UVA production, although in the UK there is a five-star system to measure UVA protection (the higher number of stars indicates a more balanced protection against UVA). Sunscreens will also contain a (sun protection factor) SPF rating. Cancer Research UK recommends that people use a sunscreen of SPF 15 or higher, with at least four stars to provide good protection against UVA and UVB. The charity also says consumers should not use sunscreen that has been open for over 12 to 18 months, but should instead buy fresh sunscreen offering appropriate protection.
Newspapers covering this research have also correctly highlighted that sunbeds may have a particularly high UVA output. The Daily Mail includes a quote that the strength of these rays can be 10 to 15 times higher than the midday sun. People using sunbeds and tanning booths should be aware that there is currently no regulation to govern the type or strength of UV rays that sunbeds give out. Even brief use may carry some risk, particularly for people who have fair features, freckles, lots of moles or damaged areas of skin. Read Are sunbeds safe? for more information.

Links To The Headlines

Tanning salons more dangerous than previously thought. The Daily Telegraph, October 7 2011
New sunbed alert: UV rays penetrate far deep into the skin than previously thought. Daily Mail, October 7 2011

Links To Science

Tewari A, Sarkany RP and Young AR. UVA1 Induces Cyclobutane Pyrimidine Dimers but Not 6-4 Photoproducts in Human Skin In Vivo. Journal of Investigative Dermatology, October 6 2011