Thursday, 24 June 2010
Fin to limb evolution clue found
Fin to limb evolution clue found
Page last updated at 01:58 GMT, Thursday, 24 June 2010 02:58 UK
E-mail this to a friend Printable version By Victoria Gill
Science reporter, BBC News
The researchers discovered genes involved in fin but not limb development A study has shed light on a key genetic step in the evolution of animals' limbs from the fins of fish, scientists say.
A team of researchers identified two new genes that are important in fin development.
They report in the journal Nature that the loss of these genes could have been an "important step" in the evolutionary transformation of fins into limbs.
Marie-Andree Akimenko, from the University of Ottawa in Canada, led the research.
She and her colleagues began their study by looking at the development of zebrafish embryos. They discovered two genes that coded for proteins that were important in the structure of fins.
These proteins were components of the thread-like fibres known as "actinotrichia". These are found in fish larvae and they eventually develop into the bony fin rays of mature fish.
"We found there were no [equivalent genes] in limbs, so this suggested these may have been lost in evolution," explained Dr Akimenko.
To confirm this, they looked for - and found - the same family of genes in the genomes of elephant sharks, which are a very basal (or ancient) fish species.
This suggested that the "ancient family of genes persisted in [bony fish] and was lost when they evolved" into four-footed animals, Dr Akimenko said.
Recreating evolution
Embryo development can provide important genetic and molecular clues about evolution; many early developmental changes are believed to mirror evolutionary changes.
The embryonic fin (right) has ray-forming fibres, which are absent in the embryonic mouse limb The scientists were able to manipulate zebrafish development, to study these changes in more detail. They inactivated the newly discovered genes in a developing zebrafish embryo. When they did this, they found that it developed shorter "truncated" fins with no bony rays.
The loss of these fin rays, the scientists say, was a key step in fin-to-limb evolution.
The team then compared the development of normal zebrafish embryos with that of mouse embryos.
"When we compared fin development and limb development, the early steps are very similar," Dr Akimenko said.
"But at one point there is a divergence, and that correlates with the beginning of the expression of these genes."
Professor Jonathan Bard, a retired developmental biologist now working with the department of physiology, anatomy and genetics at Oxford University, said the findings were only a very small part of the evolutionary story.
He said that this still did not tell us about digit formation - "how the broad, multi-ray fins of fishes became transformed into the eight digits of the hand or foot plate of the first tetrapods".
"More generally," he said, "hundreds of millions of years of separate evolution divide [bony fish] and mice."
He added: "It is an interesting paper... and it will be be interesting to see what the [researchers] do next."
Wednesday, 23 June 2010
Study examines scientists' 'climate credibility'
Study examines scientists' 'climate credibility'
Page last updated at 08:47 GMT, Tuesday, 22 June 2010 09:47 UK
Most experts agreed human activity was affecting the climate system Some 98% of climate scientists that publish research on the subject support the view that human activities are warming the planet, a study suggests.
It added there was little disagreement among the most experienced scientists.
But climate sceptics questioned the findings, saying that publication in scientific journals was not a fair test of expertise.
The findings have been published in the journal Proceedings of the National Academy of Sciences.
The study's authors said they found "immense" differences in both the expertise and scientific prominence of those who supported the "primary tenets" of latest assessments made by the Intergovernmental Panel on Climate Change (IPCC) and those who were sceptical of the IPCC's findings.
In general, they added, the researchers who were convinced of the human impact on climate change had published twice as many papers as their sceptical counterparts, and were cited in other people's research two to three times more often.
Continue reading the main story It's typical of this broad-brush study to make such wide ranging claims similar to the infamous 'the debate is over'
Professor Hans von Storch
University of Hamburg
Lead author William Anderegg, from Stanford University in California, US, said the findings suggested that not all experts were equal in what they claimed.
"The researchers who are convinced (by the IPCC's assessment reports) have a lot more experience in climate research and have published a lot more papers in the scientific literature and are generally well respected in their field," he said.
"And it also demonstrates the converse that those who are sceptical of the IPCC's claims, in general, know a lot less about the climate system."
Mr Anderegg and his colleagues drew from a list of 908 researchers who had contributed to research used by the IPCC and have signed statements broadly in support of the UN body's assessments.
On the sceptical side, they chose 475 scientists from a list of 11 major sceptical declarations and open letters.
The researchers said they felt the need to carry out the survey because of the growing public perception that scientific opinion was divided on the issue following recent scandals, such as "climategate" at the UK's University of East Anglia and the use of non-peer reviewed literature in the IPCC findings.
"We really felt that the state of the scientific debate was so far removed from the state of the public discourse and we felt that a good quantitative, rigorous comparison of this would put to rest the notion that the scientists 'disagree' about global warming," Mr Anderegg told BBC News.
'Broad-brush study'
Sceptical groups, however, argued that publication in scientific journals was not a fair test of expertise.
They said that those who choose which papers to publish favoured research that supported the IPCC's view, and suggested that the new study was tautologous.
Professor Hans von Storch, from the Meteorological Institute of the University of Hamburg, said: "You have to ask yourself - which are the the tenets of (the human induced climate change) outlined by the IPCC the '"convinced" groups of scientists agree with.
"There is a core of assertions, dealing with the effect of greenhouse gases on temperature and sea level, which enjoy general agreement," Professor von Storch told BBC News.
"While others, for instance, related to the Himalaya glaciers, the changing tropical storms and their damages or the fate of Greenland, are heavy contested.
"It's typical of this broad-brush study to make such wide ranging claims similar to the infamous 'the debate is over'."
Dr Sonja Boehmer-Christiansen, from the University of Hull, UK, added: "Who judges expertise and prominence? It looks to me that the authors belong to an IPCC supporting group that must count as believers and belong to the beneficiaries of the man-made warming scare."
Tuesday, 22 June 2010
annual summer solstice.
Solstice sunrise at Stonehenge
STONEHENGE: The sun rises behind the Stonehenge monument in England, during the summer solstice shortly after 4.52am.
STONEHENGE: Revellers attend the annual summer solstice.
LONGEST DAY: Sun rises over the ancient stones at Stonehenge in Wiltshire.
SUMMER SOLSTICE: A Druid walks past the ancient standing stones at Stonehenge.
SUMMER SOLSTICE: The sun rises over the ancient stones of Stonehenge.
« Previous« PreviousNext »Next » The long and short of the Solstice Relevant offers
EuropePostcard arrives after 95 years EU to import solar power from Sahara Princess weds gym instructor Britain readies for austere budget Komorowski leads Polish election UK doctor admits he helped patients die Northern Irish police uncover large bomb in van Laura Dekker's solo sail delayed by court ruling Is BP headed for a cash crunch? French floods death toll hits 25 Thousands of New Agers and neo-pagans danced and whooped in delight as the sun rose above the ancient stone circle of Stonehenge, marking the summer solstice.
About 20,000 people crowded the prehistoric site on Salisbury Plain, Wiltshire, southern England, to see the sunrise at 4.52am following an annual all-night party.
The Heel Stone, just outside the main circle, aligns with the rising sun.
Police described the event as one of the safest in years, although 34 people were arrested for minor drug offences.
Peter Carson from English Heritage told the BBC said: "It has been quieter this year but it's been a great solstice.
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staff escape NHS hygiene rule
Muslim staff escape NHS hygiene rule
Muslim doctors and nurses are to be allowed to opt out of strict hygiene rules introduced by the NHS to restrict the spread of hospital superbugs.
Published: 12:30AM BST 11 Apr 2010
Muslim doctors and nurses are to be allowed to opt out of strict hygiene rules introduced by the NHS to restrict teh spread of hospital superbugs. Photo: MARTIN POPE
Female staff who follow the Islamic faith will be allowed to cover their arms to preserve their modesty despite earlier guidance that all staff should be "bare below the elbow".
The Department of Health has also relaxed rules prohibiting jewellery so that Sikh members of staff can wear bangles linked with their faith, providing they are pushed up the arm while the medic treats a patient.
Related Articles
Marine praised as hero by Prince Harry contracts hospital superbug MRSA
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Thomson could face legal action over norovirus outbreak
Staffordshire hospital scandal: the hidden story
Superbug hospital chief Rose Gibb sues NHS for job compensation
Fight against superbugs hampered by doctors failing to wash their handsThe Mail on Sunday reported the change had been made after female Muslims objected to being required to expose their arm below the elbow under guidance introduced by Alan Johnson when he was health secretary in 2007.
The rules were drawn up to reduce the number of patients who were falling ill, and even dying, from superbugs such as MRSA and Clostridium difficile.
Revised guidance which relaxed the requirements for some religions was published last month.
Some Muslim staff and those from other groups may be allowed to use disposable plastic over-sleeves which cover their clothes below the elbow and allow the skin to remain covered up.
Derek Butler, chairman of MRSA Action UK, said: "My worry is that allowing some medics to use disposable sleeves you compromise patient safety because unless you change the sleeves between each patient, you spread bacteria.
"Scrubbing bare arms is far more effective."
A Department of Health spokesman said: "The guidance is intended to provide direction to services in how they can balance infection control measures with cultural beliefs without compromising patient safety."
Muslim doctors and nurses are to be allowed to opt out of strict hygiene rules introduced by the NHS to restrict the spread of hospital superbugs.
Published: 12:30AM BST 11 Apr 2010
Muslim doctors and nurses are to be allowed to opt out of strict hygiene rules introduced by the NHS to restrict teh spread of hospital superbugs. Photo: MARTIN POPE
Female staff who follow the Islamic faith will be allowed to cover their arms to preserve their modesty despite earlier guidance that all staff should be "bare below the elbow".
The Department of Health has also relaxed rules prohibiting jewellery so that Sikh members of staff can wear bangles linked with their faith, providing they are pushed up the arm while the medic treats a patient.
Related Articles
Marine praised as hero by Prince Harry contracts hospital superbug MRSA
Doctors and nurses to be sacked if they do not wash their hands
Thomson could face legal action over norovirus outbreak
Staffordshire hospital scandal: the hidden story
Superbug hospital chief Rose Gibb sues NHS for job compensation
Fight against superbugs hampered by doctors failing to wash their handsThe Mail on Sunday reported the change had been made after female Muslims objected to being required to expose their arm below the elbow under guidance introduced by Alan Johnson when he was health secretary in 2007.
The rules were drawn up to reduce the number of patients who were falling ill, and even dying, from superbugs such as MRSA and Clostridium difficile.
Revised guidance which relaxed the requirements for some religions was published last month.
Some Muslim staff and those from other groups may be allowed to use disposable plastic over-sleeves which cover their clothes below the elbow and allow the skin to remain covered up.
Derek Butler, chairman of MRSA Action UK, said: "My worry is that allowing some medics to use disposable sleeves you compromise patient safety because unless you change the sleeves between each patient, you spread bacteria.
"Scrubbing bare arms is far more effective."
A Department of Health spokesman said: "The guidance is intended to provide direction to services in how they can balance infection control measures with cultural beliefs without compromising patient safety."
Friday, 18 June 2010
Ape hunters pick up new viruses
Ape hunters pick up new viruses
Chimpanzees carry viruses which can jump to humans
Two new viruses from the same family as HIV have been discovered in central Africans who hunt nonhuman primates.
Researchers say their work proves it is not unusual for potentially dangerous viruses to jump from primates to man.
They say it is important to monitor disease in bushmeat hunters closely, as any virus they contract from animals may spread to the community at large.
The study, led by the US Johns Hopkins University, is published in Proceedings of the National Academy of Sciences.
Far from being rare events, retroviruses are actively crossing into human populations
Dr Nathan Wolfe
The new viruses identified in the latest study come from a group known as the retroviruses, which are known to cause serious illnesses in humans.
They have been named Human T-lymphotropic Virus types 3 and 4 (HTLV-3 and HTLV-4).
Humans have previously been infected by HTLV-1 and HTLV-2. In most cases, infection does not produce symptoms, but it can trigger neurological problems, and even leukaemia.
Lead researcher Dr Nathan Wolfe said: "The emergence of HIV from primate origins has cost millions of lives.
"The discoveries of HTLV-3 and HTLV-4 show that, far from being rare events, retroviruses are actively crossing into human populations."
Blood samples
The research team collected and examined blood samples from more than 900 people living throughout Cameroon.
All the individuals studied reported some exposure to blood and body fluids of nonhuman primates, contact mostly due to hunting and butchering of bushmeat, and in some cases to keeping primates as pets.
Analysis of the blood samples showed that various simian (ape) viruses had infected the participants.
The two previously unknown viruses were found in two bushmeat hunters.
HTLV-3 is similar to a simian virus called STLV-3, and was most likely contracted through direct contact with a primate during hunting.
HTLV-4 does not have a known primate counterpart, making its origin less clear. The researchers believe it could have arisen through cross-species transmission from an animal carrying an unknown form of STLV.
The same team discovered another primate retrovirus - the simian foamy virus (SFV) - in bushmeat hunters last year.
Threat unclear
At this stage it is unclear whether either of the two newly discovered viruses or SFV are harmful to humans, or can be transferred from person to person.
However, the researchers say their work clearly shows that hunting provides the opportunity for viruses to jump the species barrier.
Dr Wolfe said: "Ongoing collaboration with hunters in central Africa gives us the potential to predict and prevent disease emergence.
"Given the incredible potential costs of a new human retrovirus spreading into the general population, the development of sentinel systems for forecasting disease emergence - such as long-term surveillance of hunters - should be seen as a human health imperative."
Dr Deenan Pillay, an expert in virology at University College London, UK, told the BBC News website that it had been thought few viruses jumped the species barrier.
"This research suggests that there seems to be far more transmission of a whole range of primate viruses into humans than was previously thought," he said.
"But that is not alarming in its own right. If the virus fails to replicate, or to be passed on to others, then it does not pose a threat.
"However, if cross-species transmission is such a frequent event, then all it takes is for one virus to really take hold in somebody, and be passed on to others for it to take off in humans."
Two primate species were among the seizures of bushmeat
By Mark Kinver
Science and environment reporter, BBC News
Two primate species were among the seizures of bushmeat by customs About 270 tonnes of illegal bushmeat could be passing through one of Europe's busiest airports each year, the first study of its kind estimates.
A team of researchers says the illicit trade could pose a risk to human or animal health and increase the demand for meat from threatened species.
The figure is based on seizures from searches carried out over 17 days at Charles de Gaulle airport in Paris.
The findings appear in the journal Conservation Letters.
A team of researchers from France, Cambodia and the UK said it was the "first systematic study of the scale and nature of this international trade".
"We estimate that about five tonnes of bushmeat per week is smuggled in personal baggage through Paris Roissy-Charles de Gaulle airport," they wrote.
During the 17-day study, a total of 134 passengers arriving on 29 flights from 14 African nations were searched.
Nine people were found to be carrying bushmeat, which had a combined mass of 188kg.
In total, 11 species were found - including two types of primates, two kinds of crocodiles and three rodent species - four of which were listed as protected species.
'Lucrative trade'
Co-author Marcus Rowcliffe from the Zoological Society of London (ZSL) explained why the international team of researchers decided to carry out the research.
Continue reading the main story Only a small proportion of Africa's bushmeat is exported
Calls for bushmeat ban rejected
"As no study like this had been carried out before, we really had no idea as to the volume of bushmeat coming into airports," he told BBC News.
"It was a surprise when we saw how much was arriving."
The products were not only imported for personal consumption, but were part of a lucrative organised trade with high prices indicating luxury status, Dr Rowcliffe added.
"A 4kg monkey will cost around 100 euros (£84), compared with just five euros in Cameroon," he said.
Based on the data gathered from the 29 flights covered by the study, the researchers then calculated the weekly and annual inward flow of bushmeat.
"Assuming that (the study's) rates are representative of the average weekly rate over the year, this equates to... 273 tonnes of bushmeat," they calculated.
The team suggested that there were likely to be a number of factors behind the large volume of bushmeat being imported.
"First, detecting and seizing these products is not a priority," they explained.
"Second, penalties for importing illegal meat or fish are low and rarely imposed. Third, the rewards for transporting bushmeat are potentially high."
The researchers acknowledged that the study had a short time scale and limited geographical coverage, and said that a longer and large scale survey was now required to build on the findings.
However, they added that their study did allow them to consider ways to control the trade.
They suggest offering incentives to customs officers, increasing the penalties for illegally importing the products and raising awareness among passengers that bringing such products into the EU was prohibited.
The team concluded: "The large scale of current imports makes it important to consider all options for reducing the flow of illegal meat and fish, and of bushmeat in particular."
Illegal bushmeat 'rife in Europe'
Science and environment reporter, BBC News
Two primate species were among the seizures of bushmeat by customs About 270 tonnes of illegal bushmeat could be passing through one of Europe's busiest airports each year, the first study of its kind estimates.
A team of researchers says the illicit trade could pose a risk to human or animal health and increase the demand for meat from threatened species.
The figure is based on seizures from searches carried out over 17 days at Charles de Gaulle airport in Paris.
The findings appear in the journal Conservation Letters.
A team of researchers from France, Cambodia and the UK said it was the "first systematic study of the scale and nature of this international trade".
"We estimate that about five tonnes of bushmeat per week is smuggled in personal baggage through Paris Roissy-Charles de Gaulle airport," they wrote.
During the 17-day study, a total of 134 passengers arriving on 29 flights from 14 African nations were searched.
Nine people were found to be carrying bushmeat, which had a combined mass of 188kg.
In total, 11 species were found - including two types of primates, two kinds of crocodiles and three rodent species - four of which were listed as protected species.
'Lucrative trade'
Co-author Marcus Rowcliffe from the Zoological Society of London (ZSL) explained why the international team of researchers decided to carry out the research.
Continue reading the main story Only a small proportion of Africa's bushmeat is exported
Calls for bushmeat ban rejected
"As no study like this had been carried out before, we really had no idea as to the volume of bushmeat coming into airports," he told BBC News.
"It was a surprise when we saw how much was arriving."
The products were not only imported for personal consumption, but were part of a lucrative organised trade with high prices indicating luxury status, Dr Rowcliffe added.
"A 4kg monkey will cost around 100 euros (£84), compared with just five euros in Cameroon," he said.
Based on the data gathered from the 29 flights covered by the study, the researchers then calculated the weekly and annual inward flow of bushmeat.
"Assuming that (the study's) rates are representative of the average weekly rate over the year, this equates to... 273 tonnes of bushmeat," they calculated.
The team suggested that there were likely to be a number of factors behind the large volume of bushmeat being imported.
"First, detecting and seizing these products is not a priority," they explained.
"Second, penalties for importing illegal meat or fish are low and rarely imposed. Third, the rewards for transporting bushmeat are potentially high."
The researchers acknowledged that the study had a short time scale and limited geographical coverage, and said that a longer and large scale survey was now required to build on the findings.
However, they added that their study did allow them to consider ways to control the trade.
They suggest offering incentives to customs officers, increasing the penalties for illegally importing the products and raising awareness among passengers that bringing such products into the EU was prohibited.
The team concluded: "The large scale of current imports makes it important to consider all options for reducing the flow of illegal meat and fish, and of bushmeat in particular."
Stem cell therapy 'damage' seen in kidney disease case
There are hopes that stem cell therapy can be used to tackle many diseases A new complication has been seen in a patient with kidney disease who received stem cell therapy, scientists have warned.
Stem cells were injected into the kidney, but the patient suffered tissue damage and died from an infection.
The Canadian and Thai researchers said the findings published in the Journal of the American Society of Nephrology showed caution was needed.
Experts said there was a gap between research and treatment.
Many scientists hope stem cell therapy can be used to treat a wide range of diseases.
It has been shown that it is possible to reprogram adult stem cells, taken from bone marrow, to become a range of specific cell types - including kidney cells.
Continue reading the main story We believe that this is either formed directly by the stem cells that were injected or that the stem cells caused these masses to form
Dr Duangpen Thirabanjasak,
Chulalongkorn University
And animal studies have indicated that injecting stem cells directly into organs, including the kidney, is safe.
The patient in this case had been treated by a private clinic.
Researchers from Chulalongkorn University in Bangkok, Thailand, and Paul Scott Thorner, from the University of Toronto, were involved in removing and analysing the kidney.
They found that the patient had not benefited at all from the treatment, but had actually developed tissue damage called angiomyeloproliferative lesions at the injection sites. These were found to be clusters of blood vessels and bone marrow cells.
Enthusiasm 'premature'
Dr Duangpen Thirabanjasak, from Chulalongkorn University, who led the research, said: "This type of lesion has never been described before in patients, and we believe that this is either formed directly by the stem cells that were injected or that the stem cells caused these masses to form."
And she warned that, because they had not been seen before, no-one knew how the lesions might have developed over time.
The authors conclude that their findings should serve as a warning to clinical investigators that the development of blood vessel and bone marrow masses may be a possible complication of stem cell therapy.
And they said more work was needed to identify why the masses formed, and how this could be avoided.
Writing in the journal, Andras Nagy, of Toronto's Mount Sinai Hospital, and Susan Quaggin, of the University of Toronto, said caution was needed over stem cell therapies - especially if they were being offered by unregulated private clinics.
They added: "Premature enthusiasm and protocols that are not fully vetted are dangerous and result in negative publicity for the field of stem cell research, and more importantly, may result in disastrous outcomes with no benefit to the patient.
"Although there is promise, a large gap still exists between scientific knowledge and clinical translation for safe and effective stem cell-based therapies.
Wednesday, 16 June 2010
Diabetes drugs given 'too soon'
Diabetes drugs given 'too soon'
Eating a healthy diet is a key part of diabetes control
One in three people with type 2 diabetes are given medication too soon, instead of being urged to eat better and do more exercise, a study suggests.
A study of 650 people in south west England found 36% were put on tablets within a month of being diagnosed, a Diabetes UK conference heard.
But guidelines recommend first trying lifestyle changes to control diabetes.
A Department of Health spokeswoman said medication helps people to "manage their condition".
The Royal College of GPs agreed diet and exercise should come first.
More than 400 people a day are diagnosed with type 2 diabetes in the UK.
When people are diagnosed, they're ready to make a lot of changes but if you give them a tablet, you're saying it is not their lifestyle that is the problem
Dr Rob Andrew
It is often associated with obesity, and attempts in recent years to screen people for the disease has increased the number of people being diagnosed.
In the latest study, researchers found that in many patients lifestyle management was not given a chance, despite being widely recognised as being the initial first "treatment".
Metformin is the first drug of choice, but more drugs can be added if that is not doing enough to control blood sugar levels.
The researchers found that 13% of participants were actually on two types of tablets within the first few weeks of being diagnosed with type 2 diabetes.
Study author Dr Rob Andrew, a senior lecturer at the University of Bristol, said they had not expected the figures to be quite so high.
"There is quite clear guidance that says when you're first diagnosed, you should have the opportunity to concentrate on lifestyle then if that doesn't work the next stage is metformin.
Balanced diet
"When people are diagnosed, they're ready to make a lot of changes but if you give them a tablet, you're saying it is not their lifestyle that is the problem."
He added that incentive payments to encourage GPs to reduce blood glucose levels in patients with diabetes, a lack of NHS resources for lifestyle support and a cultural attitude that people will not make the necessary changes are probably all to blame.
Simon O'Neill, from Diabetes UK, said they were concerned that in some cases medication seemed to be the first port of call.
"A healthy, balanced diet and doing physical activity should always be the foundation of good diabetes management.
"Type 2 diabetes is a progressive condition - the longer a person has diabetes, the more likely they are to need tablets, and eventually insulin.
Good diabetes care is not just about medication
Department of Health
"Even if people are on tablets, medication should not simply replace diet and physical activity."
Professor Steve Field, chairman of the Royal College of GPs, said there was probably a case of jumping in too quickly with pills.
"It is a reminder for GPs and nurses managing newly diagnosed diabetes that lifestyle advice is the most important component."
He added that in some areas of the country there was a lack of resources for supporting behavioural changes.
The Department of Health has defended its treatment of people with the condition.
A spokeswoman said: "Prescribed medication is vital to enable many people with diabetes to manage their condition on a day-to-day basis and to reduce their risk of developing complications such as heart attack and stroke."
However, she stressed that "good diabetes care is not just about medication".
"As the NICE guidelines recommend, people with type 2 diabetes should be encouraged to make lifestyle changes, such as healthy eating and increased physical activity, before starting medication," she said.
Replacing white rice with brown rice and wholemeal bread could cut the risk of diabetes by a third
White rice has a higher glycaemic index than brown rice Replacing white rice with brown rice and wholemeal bread could cut the risk of diabetes by a third, US experts say.
White rice poses a diabetes threat because it causes steep rises in blood sugar, say Harvard researchers in Archives of Internal Medicine.
Brown rice and other wholegrain foods are a healthier option as they release glucose more gradually, they say.
The study is based on questionnaires; some say the data is not robust enough to base firm conclusions on.
It may be that people who eat less white rice tend to live healthier lifestyles, for example.
'Brown is better'
In the study of nearly 200,000 US people, white rice consumption was linked to type 2 diabetes.
After adjusting for age and other diabetes risk factors, those who ate five or more 150g servings of white rice per week had a 17% increased risk of diabetes compared with people who consumed less than one serving - about a cup of rice - per month.
Although few people - only 2% - in the study ate this much white rice, the finding was significant.
The best way to prevent type 2 diabetes is by keeping active and eating a healthy balanced diet that is low in fat, salt and sugar with plenty of fruit and vegetables
Dr Victoria King
Diabetes UK
Yet eating brown rice appeared to have the opposite effect, cutting the risk of type 2 diabetes.
People who ate two or more servings of brown rice per week had an 11% reduced risk of developing the condition compared with those who ate less than one serving a month.
Based on the results, the researchers estimate that replacing 50g or one-third of a typical serving of white rice with the same amount of brown rice would lead to a 16% lower risk of type 2 diabetes.
And replacing the white rice with wholegrains, including brown rice and pasta, wholemeal bread and rolled oats, could cut the risk by more than a third.
Food composition
Dr Qi Sun and other researchers say the explanation lies in the composition of the food.
Like other wholegrain foods, brown rice is high in fibre and releases its energy slowly.
In contrast, white rice has had all the bran and some of the germ removed during milling.
This gives white rice a higher glycaemic index (GI) - a measure of how much a food raises blood sugar levels compared with the same amount of glucose or white bread.
"From a public health point of view, replacing refined grains such as white rice by whole grains, including brown rice, should be recommended to facilitate the prevention of type 2 diabetes," according to the researchers.
Experts generally recommend that at least half of carbohydrate intake should come from whole grains like brown rice.
More than 70% of the rice consumed in developed countries such as the US and UK is white.
Dr Victoria King of Diabetes UK said that, since the results were from self-reported food diaries and questionnaires, it was not possible to make conclusive recommendations on how much of certain foods, such as brown rice, might protect against type 2 diabetes at this stage.
"The best way to prevent type 2 diabetes is by keeping active and eating a healthy balanced diet that is low in fat, salt and sugar with plenty of fruit and vegetables," she said.
Sunday, 13 June 2010
Autism link with migrant parents, study finds
mengele-westof
Autism link with migrant parents, study finds
It is thought migration might "trigger" the onset of autism
Researchers have discovered that where you used to live could affect your child's chances of being autistic by up to five times.
The study looked at children whose mother had moved to the UK from outside Europe.
It showed an increased risk of autism in children whose parents had migrated from Africa, the Caribbean and Asia, the UK researchers said.
The greatest risk was for the Caribbean group, the BBC World Service reported.
Speaking on Health Check, Dr Daphne Keen, from St. George's Hospital London, said while the findings show a clear link between immigration and autism - they could not determine exactly why this was the case.
Stress factors and social isolation and so forth may operate as triggers.
Dr Daphne Keen
The research covered 428 children diagnosed with autism during a six-year period.
"We didn't find there was an increased risk in the parents who had migrated from other European countries," Dr Keen added.
"The size of the increased risk was greatest for the Caribbean group. This was at least five times.
"The risk was also very significant, but slightly less, for the African population and much lower, but still a little present, for the Asian population."
Two factors
The study took into consideration that it may just be a case of ethnicity - rather than migration - that caused the rise in cases.
However, researchers compared their results with children born of UK-born parents with Caribbean, African and Asian roots.
"We found when we analysed the two factors together, that the risk fell considerably.
HEALTH CHECK
Health Check is the weekly health programme broadcast from the BBC World Service
It is broadcast on Monday at 1032GMT and repeated at 1532GMT, 2032GMT and on Tuesday at 0132GMT
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"It seemed to suggest that immigration was the major factor, and ethnicity was just possibly a factor."
One theory is that the stress of migrating could act as a "trigger" for the disability, a factor discovered in similar studies looking at the causes of schizophrenia.
"There have been some interesting studies that seem to suggest that those sort of stress factors and social isolation and so forth may operate as triggers."
Autism link with migrant parents, study finds
It is thought migration might "trigger" the onset of autism
Researchers have discovered that where you used to live could affect your child's chances of being autistic by up to five times.
The study looked at children whose mother had moved to the UK from outside Europe.
It showed an increased risk of autism in children whose parents had migrated from Africa, the Caribbean and Asia, the UK researchers said.
The greatest risk was for the Caribbean group, the BBC World Service reported.
Speaking on Health Check, Dr Daphne Keen, from St. George's Hospital London, said while the findings show a clear link between immigration and autism - they could not determine exactly why this was the case.
Stress factors and social isolation and so forth may operate as triggers.
Dr Daphne Keen
The research covered 428 children diagnosed with autism during a six-year period.
"We didn't find there was an increased risk in the parents who had migrated from other European countries," Dr Keen added.
"The size of the increased risk was greatest for the Caribbean group. This was at least five times.
"The risk was also very significant, but slightly less, for the African population and much lower, but still a little present, for the Asian population."
Two factors
The study took into consideration that it may just be a case of ethnicity - rather than migration - that caused the rise in cases.
However, researchers compared their results with children born of UK-born parents with Caribbean, African and Asian roots.
"We found when we analysed the two factors together, that the risk fell considerably.
HEALTH CHECK
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"It seemed to suggest that immigration was the major factor, and ethnicity was just possibly a factor."
One theory is that the stress of migrating could act as a "trigger" for the disability, a factor discovered in similar studies looking at the causes of schizophrenia.
"There have been some interesting studies that seem to suggest that those sort of stress factors and social isolation and so forth may operate as triggers."
Monday, 7 June 2010
A genetically modified (GM) variety of maize banned in the EU has been sown accidentally across Germany.
Banned GM maize sown in Germany
Page last updated at 15:34 GMT, Monday, 7 June 2010 16:34 UK
GM crops are much less widespread in Europe than in the US A genetically modified (GM) variety of maize banned in the EU has been sown accidentally across Germany.
The NK603 variety has been planted in seven states. The seed supplier, US firm Pioneer Hi-Bred, called the level of contamination "minute".
It is not clear how the mistake occurred, but it could cost farmers millions of euros, as crops will now have to be destroyed.
The EU is currently reviewing its tight rules on the cultivation of GM crops.
Pioneer Hi-Bred, based in Buxtehude near Hamburg, says NK603 has been planted on "just under 2,000 hectares (4,940 acres)" of land. The environmental group Greenpeace put the area as high as 3,000 hectares.
Bavaria, Baden-Wuerttemberg and Lower Saxony are among the states where it has been sown.
Information delayed
Supporters of GM crops argue that they deliver higher yields and resistance to pests, requiring less fertiliser and pesticides.
Opponents say more scientific data is needed, arguing that their long-term genetic impact on humans and wildlife could be harmful.
They also say GM crops can enter the food chain inadvertently if they are naturally cross-pollinated with non-GM varieties.
Greenpeace says that officials knew about the contamination in early March, but that because of bureaucratic delays farmers are only now being warned.
"This is the biggest GM crop scandal in Germany to date," said a Greenpeace agriculture expert, Alexander Hissting.
Ploughing up fields
In the affected fields, up to 0.1% of the crop is contaminated with NK603 - equivalent to 100 contaminated plants per hectare, Greenpeace says.
Pioneer Hi-Bred disputes that figure. Company spokesman Mike Hall told the BBC that the level of NK603 detected in the "conventional seed" was 0.03%.
"It's highly unlikely that it's a GM trace. Anything below 0.1% could be a false positive, impossible to quantify scientifically," he said.
"In the past when they found trace amounts we removed the seed from the market. In this case they told us after it had been planted."
Stefanie Becker, spokeswoman for Lower Saxony's Environment Ministry, said that "fields will have to be ploughed up before the maize blooms - it is still possible to halt the uncontrolled spread [of the GM variety]".
She said her ministry did not get details about the distribution of the GM maize until last Friday. "We have the distributors' names, and through them the farmers will be informed," she told the BBC.
Ms Becker said the contamination affected about 2,000 hectares and originated from two sacks of seeds. It is not yet clear how the seeds got mixed up, she said.
EU divided
So far the EU has allowed only two GM crops to be cultivated - Monsanto's MON 810 maize and a type of potato harvested for starch. But Germany, like some other EU countries, banned MON 810 last year.
EU member states are divided over GM crops. Commercial GM planting takes place in Spain, Portugal and the Czech Republic. But France, Germany, Austria and Greece are among several states that have banned MON 810.
The GM maize that has spread in Germany "is not harmful to human or animal health", Ms Becker said.
The European Commission is overhauling the rules on GM crops and will present new proposals next month allowing member states more freedom to allow or ban GM varieties.
Countries would be allowed to set their own technical standards for GM farming, including buffer zones to prevent cross-pollination.
The new rules will still require approval by EU governments and the European Parliament.
WHO swine flu experts 'linked' with drug companies
WHO swine flu experts 'linked' with drug companies
Page last updated at 11:14 GMT, Friday, 4 June 2010 12:14 UK
Governments around the world stockpiled antiviral drugs Key scientists behind World Health Organization advice on stockpiling of pandemic flu drugs had financial ties with companies which stood to profit, an investigation has found.
The British Medical Journal says the scientists had openly declared these interests in other publications yet WHO made no mention of the links.
It comes as a report from the Council of Europe criticised the lack of transparency around the handling of the swine flu pandemic.
A spokesman for WHO said the drug industry did not influence its decisions on swine flu.
Guidelines recommending governments stockpile antiviral drugs were issued by WHO in 2004.
The advice prompted many countries around the world into buying up large stocks of Tamiflu, made by Roche, and Relenza manufactured by GlaxoSmithKline.
A year after the swine flu pandemic was declared, stocks are left unused in warehouses and governments are attempting to unpick contracts.
Conflict of interest
The BMJ, in a joint investigation with The Bureau of Investigative Journalism, found that three scientists involved in putting together the 2004 guidance had previously been paid by Roche or GSK for lecturing and consultancy work as well as being involved in research for the companies.
Analysis
Continue reading the main story
Fergus Walsh
Medical correspondent, BBC News
Be open. Be transparent. That seems to be the key learning point for the WHO from this joint investigation.
It is common practice for academic experts to work closely with the pharmaceutical industry, such as getting funding for drug trials, or to be paid for attending meetings.
On all clinical papers authors must publicly declare any competing interests.
So it is surely advisable that the WHO follows the same policy with its advisors.
And there is surely no logic in refusing to name the members of the emergency committee which advised the WHO about the pandemic.
To fail to do so presents an own goal to critics and conspiracy theorists.
Although the scientists involved had freely declared the links in other places and said WHO asked for conflicts of interest forms prior to expert meetings, the ties were not publically declared by WHO.
It is not clear whether these conflicts were notified privately by WHO to governments around the world, the BMJ said, and a request to see conflict of interest declarations was turned down.
In addition, membership of the "emergency committee" which advised WHO's director general Margaret Chan on declaring an influenza pandemic has been kept secret.
It means the names of the 16 committee members are known only to people within WHO, and as such their possible conflicts of interest with drug companies are unknown.
On its website, WHO says: "Potential conflicts of interest are inherent in any relationship between a normative and health development agency, like WHO, and a profit-driven industry.
"Similar considerations apply when experts advising the Organization have professional links with pharmaceutical companies.
"Numerous safeguards are in place to manage possible conflicts of interest or their perception."
Saturday, 5 June 2010
'Male menopause' idea questioned
'Male menopause' idea questioned
Doctors are divided on the idea of a male 'menopause' The "male menopause" is a myth, according to a review.
Some doctors have linked a fall in testosterone levels as men get older to symptoms such as depression and low sex drive.
But an editorial in Drug and Therapeutics Bulletin says many men reporting symptoms have normal hormone levels.
They warn against giving synthetic testosterone as it can increase the risk of prostate cancer.
Doctors are divided on the idea that men go through a well-defined "menopause".
Continue reading the main story What the paper says is that the doctor must assess the risks versus the benefits of giving testosterone
Dr Ian Banks
Men's Health Forum
Some doctors advocate the use of synthetic testosterone to relieve some of the symptoms associated with so-called male menopause such as weakness, depression and sexual problems.
But the journal says that unlike the menopause in women, where levels of the female hormone fall dramatically, testosterone levels fall by only 1 to 2% a year from the age of 40 onwards in men.
Around 80% of 60-year-olds and half of those in their 80s still have levels within the normal range.
The editorial concludes: "There is no place for testosterone therapy in older men without symptoms, or without clearly low testosterone concentrations on more than one occasion."
Risks vs benefits
Commenting on the report, Dr Ian Banks, a GP and president of the Men's Health Forum, said: "What the paper says is that the doctor must assess the risks versus the benefits of giving testosterone."
He said men seeking a "quick fix" for symptoms such as tiredness and lack of sex drive should consider lifestyle changes first.
"We've got to get the message over to resist the temptation of the quick fix and look at things such as lifestyle that you can do something about," he added.
Doctors are divided on the idea of a male 'menopause' The "male menopause" is a myth, according to a review.
Some doctors have linked a fall in testosterone levels as men get older to symptoms such as depression and low sex drive.
But an editorial in Drug and Therapeutics Bulletin says many men reporting symptoms have normal hormone levels.
They warn against giving synthetic testosterone as it can increase the risk of prostate cancer.
Doctors are divided on the idea that men go through a well-defined "menopause".
Continue reading the main story What the paper says is that the doctor must assess the risks versus the benefits of giving testosterone
Dr Ian Banks
Men's Health Forum
Some doctors advocate the use of synthetic testosterone to relieve some of the symptoms associated with so-called male menopause such as weakness, depression and sexual problems.
But the journal says that unlike the menopause in women, where levels of the female hormone fall dramatically, testosterone levels fall by only 1 to 2% a year from the age of 40 onwards in men.
Around 80% of 60-year-olds and half of those in their 80s still have levels within the normal range.
The editorial concludes: "There is no place for testosterone therapy in older men without symptoms, or without clearly low testosterone concentrations on more than one occasion."
Risks vs benefits
Commenting on the report, Dr Ian Banks, a GP and president of the Men's Health Forum, said: "What the paper says is that the doctor must assess the risks versus the benefits of giving testosterone."
He said men seeking a "quick fix" for symptoms such as tiredness and lack of sex drive should consider lifestyle changes first.
"We've got to get the message over to resist the temptation of the quick fix and look at things such as lifestyle that you can do something about," he added.
Tuesday, 1 June 2010
Friday, 28 May 2010
Wednesday, 19 May 2010
New UN climate head demands ambition and transparency
New UN climate head demands ambition and transparency
Page last updated at 14:28 GMT, Tuesday, 18 May 2010 15:28 UK
E-mail this to a friend Printable version By Steven Duke
Editor, One Planet, BBC World Service
Ms Figueres asked for "ambition, transparency and inclusiveness" The new head of the UN's climate convention has called for ambition and transparency in UN climate talks.
Christiana Figueres also told the BBC that the process used to hammer out a deal at December's Copenhagen summit was "not the most satisfactory".
The Costa Rican diplomat, who has been involved in UN climate negotiations since 1995, said she was "very honoured" to take up the post.
"It's time to make more effort, it's time to be more ambitious," she said.
Speaking to the BBC's One Planet programme, Ms Figueres added: "It is time to be more transparent and it's time to be more inclusive."
Little accord
The immediate challenge facing the new executive secretary will be to rebuild political and public support for UN negotiations, following the perceived failure to deliver a binding agreement at the Copenhagen summit.
A weaker deal - the Copenhagen Accord - was thrashed out by a select group of countries as the summit came to a stuttering end.
Admitting those accord talks were "not transparent and not inclusive enough," Ms Figueres denied that Copenhagen had been a failure, stressing climate change was now "at the top of every political agenda in every country".
The next big summit being organised by the UN Framework Convention on Climate Change (UNFCCC) will be held in Mexico at the end of the year.
Kim Carstensen, leader of the Global Climate Initiative with WWF, offered Ms Figueres the environment group's congratulations.
"She promises to be an inspiring leader who can keep a high level political dialogue going in order to secure the first critical elements of a climate treaty in Mexico," he said.
"Her background should allow her to foster trust between countries and to push for an ambitious climate deal."
Asked if it was time for the UN to look at ways to control the climate other than by enforcing tough cuts in carbon emissions, Ms Figueres re-iterated that emissions will remain the focus of her efforts.
But she did suggest it was wrong to devote all political attention to curbing harmful gases, saying efforts to help countries adapt to a changing climate had become "relegated to the side, and need to come to the centre and front".
She will take over from outgoing executive secretary Yvo de Boer in July, after the annual two weeks of negotiations between officials in Bonn.
You can hear the full interview with Ms Figueres in this week's edition of the One Planet show on the BBC World Service
Page last updated at 14:28 GMT, Tuesday, 18 May 2010 15:28 UK
E-mail this to a friend Printable version By Steven Duke
Editor, One Planet, BBC World Service
Ms Figueres asked for "ambition, transparency and inclusiveness" The new head of the UN's climate convention has called for ambition and transparency in UN climate talks.
Christiana Figueres also told the BBC that the process used to hammer out a deal at December's Copenhagen summit was "not the most satisfactory".
The Costa Rican diplomat, who has been involved in UN climate negotiations since 1995, said she was "very honoured" to take up the post.
"It's time to make more effort, it's time to be more ambitious," she said.
Speaking to the BBC's One Planet programme, Ms Figueres added: "It is time to be more transparent and it's time to be more inclusive."
Little accord
The immediate challenge facing the new executive secretary will be to rebuild political and public support for UN negotiations, following the perceived failure to deliver a binding agreement at the Copenhagen summit.
A weaker deal - the Copenhagen Accord - was thrashed out by a select group of countries as the summit came to a stuttering end.
Admitting those accord talks were "not transparent and not inclusive enough," Ms Figueres denied that Copenhagen had been a failure, stressing climate change was now "at the top of every political agenda in every country".
The next big summit being organised by the UN Framework Convention on Climate Change (UNFCCC) will be held in Mexico at the end of the year.
Kim Carstensen, leader of the Global Climate Initiative with WWF, offered Ms Figueres the environment group's congratulations.
"She promises to be an inspiring leader who can keep a high level political dialogue going in order to secure the first critical elements of a climate treaty in Mexico," he said.
"Her background should allow her to foster trust between countries and to push for an ambitious climate deal."
Asked if it was time for the UN to look at ways to control the climate other than by enforcing tough cuts in carbon emissions, Ms Figueres re-iterated that emissions will remain the focus of her efforts.
But she did suggest it was wrong to devote all political attention to curbing harmful gases, saying efforts to help countries adapt to a changing climate had become "relegated to the side, and need to come to the centre and front".
She will take over from outgoing executive secretary Yvo de Boer in July, after the annual two weeks of negotiations between officials in Bonn.
You can hear the full interview with Ms Figueres in this week's edition of the One Planet show on the BBC World Service
Wednesday, 12 May 2010
gnaw through the nuts'
By Mark Kinver
Science and environment reporter, BBC News
Agoutis are said to the only rodent able to gnaw through the nuts' outer casing A study examining the natural dispersal of Brazil nuts has suggested that intensive harvesting could threaten future regeneration of the trees.
Researchers found that large rodents quickly ate the nuts, rather than caching them, when supplies were scarce.
When supplies were plentiful, almost twice as many nuts were buried, increasing the chance of successful germination, the team added.
The findings appear in the Journal of Tropical Ecology.
The scientists from Norway, Brazil and the UK said that very little was know about the fate of Brazil nuts under natural condition, despite it being one of the most economically important non-timber crops to come out of Amazonia.
Seasonal effect
In order to get a better understanding of how the seeds were dispersed, they tracked 900 marked seeds to see how seasonal food availability affected agoutis' and acouchis' - large scatter-hoarding rodents - caching rates, dispersal distances and how long the seeds were buried before being eaten.
BRAZIL NUT TREE FACTSContinue reading the main story Can grow to 50m (164ft) high
The trees live for about 500 years
The trees' fruit have a hard case, which contains 10-25 seeds (nuts)
The seeds remain trapped, unless the case is gnawed open by agoutis
Trees located in dense tropical forests can take up to 150 years to reach maturity
"We basically found that the seasons had a very strong effect on the dispersal distances and what happened to the seeds themselves," explained Torbjorn Haugaasen, an ecologist at the Norwegian University of Life Sciences.
"During the wet season (April) - when there are a lot of other fruits in the forest - more seeds were cached for later retrieval," he added.
"In the dry season (September), on the other hand, more seeds were eaten immediately because there was not that much food around and the rodents needed to draw on the food resource.
"Seeds were also taken further away during the dry season, which suggests that the rodents saw them as a more valuable resource than during the wet season," Dr Haugaasen told BBC News.
The field study, carried out during 2006, showed that 74.4% of seeds were buried during the wet season, compared with just 38.2% during the dry season.
The team suggested that collecting too many Brazil nuts from an area could replicate "dry season" conditions for the rodents.
"Reduced seed availability due to intensive harvesting could potentially create a dry-season scenario where most seeds succumb to pre-dispersal predation, thereby adversely affecting the natural regeneration of Brazil nut trees," they wrote.
Seeds of hope
The researchers said that populations of two large rodent species were responsible for the dispersal of the Brazil nut tree seeds: agoutis and acuchis.
Up to 25 seeds, what we call Brazil nuts, are contained in the trees' fruit However, they added, only the agoutis were capable of gnawing through the hard, thick outer casing of the fruit and releasing the seeds (Brazil nuts).
Agoutis, which can weigh up to 6kg, are found throughout the same range as the Brazil nut trees in South America.
"The (trees) therefore rely almost entirely on these large terrestrial rodents for the release of their well-protected seeds," the team explained.
"Those seeds not consumed within the germination period (12-18 months) may germinate, and seeds may remain viable for at least six years."
Scatter-hoarding also benefits plants in a number of ways, such as transporting seeds away from the parent plants and increasing the probability of reaching a site more suitable for germination.
Dr Haugaasen explained that the team decided to carry out the study in order to build on the findings of a 2003 paper published in Science, which first identified the link between intensive harvesting and the lack of young Brazil nut trees.
Writing in the 2003 paper, researchers said: "Persistently harvested stands were characterised by larger (and presumably older) trees and few or no juveniles.
But, they observed: "Juveniles were most common in unharvested and lightly harvested stands."
However, Dr Haugaasen said, the people harvesting the nuts could unknowingly be contributing to the regeneration of the trees, as some nuts were accidentally dropped as they were carried out of the forest.
"We actually found seedlings along the path used by the collectors. However, this does not mean that they are all going to reach maturity because they are in (vulnerable) places."
But he warned that restricting nut collecting could prove to be counterproductive because the harvests were a key source of income for local communities.
"Alternative possibilities, such as managed planting of seedlings in natural gaps in the forest might be a better solution," he suggested.
Dr Haugaasen said that the next step for the researchers was to look at the "management implications" of their findings.
"We also need to know how the hunting of these rodents can effect the natural regeneration of these trees," he added.
"You can have a negative impact by reducing the number of these rodents.
"However, if you have a large number of seeds already buried by a rodent before it is shot, no-one else knows where those seeds are.
"So, you could arguably have a positive impact on regeneration."
Further studies on the ecology of Brazil nut trees are expected to be published in the coming 12 months
Science and environment reporter, BBC News
Agoutis are said to the only rodent able to gnaw through the nuts' outer casing A study examining the natural dispersal of Brazil nuts has suggested that intensive harvesting could threaten future regeneration of the trees.
Researchers found that large rodents quickly ate the nuts, rather than caching them, when supplies were scarce.
When supplies were plentiful, almost twice as many nuts were buried, increasing the chance of successful germination, the team added.
The findings appear in the Journal of Tropical Ecology.
The scientists from Norway, Brazil and the UK said that very little was know about the fate of Brazil nuts under natural condition, despite it being one of the most economically important non-timber crops to come out of Amazonia.
Seasonal effect
In order to get a better understanding of how the seeds were dispersed, they tracked 900 marked seeds to see how seasonal food availability affected agoutis' and acouchis' - large scatter-hoarding rodents - caching rates, dispersal distances and how long the seeds were buried before being eaten.
BRAZIL NUT TREE FACTSContinue reading the main story Can grow to 50m (164ft) high
The trees live for about 500 years
The trees' fruit have a hard case, which contains 10-25 seeds (nuts)
The seeds remain trapped, unless the case is gnawed open by agoutis
Trees located in dense tropical forests can take up to 150 years to reach maturity
"We basically found that the seasons had a very strong effect on the dispersal distances and what happened to the seeds themselves," explained Torbjorn Haugaasen, an ecologist at the Norwegian University of Life Sciences.
"During the wet season (April) - when there are a lot of other fruits in the forest - more seeds were cached for later retrieval," he added.
"In the dry season (September), on the other hand, more seeds were eaten immediately because there was not that much food around and the rodents needed to draw on the food resource.
"Seeds were also taken further away during the dry season, which suggests that the rodents saw them as a more valuable resource than during the wet season," Dr Haugaasen told BBC News.
The field study, carried out during 2006, showed that 74.4% of seeds were buried during the wet season, compared with just 38.2% during the dry season.
The team suggested that collecting too many Brazil nuts from an area could replicate "dry season" conditions for the rodents.
"Reduced seed availability due to intensive harvesting could potentially create a dry-season scenario where most seeds succumb to pre-dispersal predation, thereby adversely affecting the natural regeneration of Brazil nut trees," they wrote.
Seeds of hope
The researchers said that populations of two large rodent species were responsible for the dispersal of the Brazil nut tree seeds: agoutis and acuchis.
Up to 25 seeds, what we call Brazil nuts, are contained in the trees' fruit However, they added, only the agoutis were capable of gnawing through the hard, thick outer casing of the fruit and releasing the seeds (Brazil nuts).
Agoutis, which can weigh up to 6kg, are found throughout the same range as the Brazil nut trees in South America.
"The (trees) therefore rely almost entirely on these large terrestrial rodents for the release of their well-protected seeds," the team explained.
"Those seeds not consumed within the germination period (12-18 months) may germinate, and seeds may remain viable for at least six years."
Scatter-hoarding also benefits plants in a number of ways, such as transporting seeds away from the parent plants and increasing the probability of reaching a site more suitable for germination.
Dr Haugaasen explained that the team decided to carry out the study in order to build on the findings of a 2003 paper published in Science, which first identified the link between intensive harvesting and the lack of young Brazil nut trees.
Writing in the 2003 paper, researchers said: "Persistently harvested stands were characterised by larger (and presumably older) trees and few or no juveniles.
But, they observed: "Juveniles were most common in unharvested and lightly harvested stands."
However, Dr Haugaasen said, the people harvesting the nuts could unknowingly be contributing to the regeneration of the trees, as some nuts were accidentally dropped as they were carried out of the forest.
"We actually found seedlings along the path used by the collectors. However, this does not mean that they are all going to reach maturity because they are in (vulnerable) places."
But he warned that restricting nut collecting could prove to be counterproductive because the harvests were a key source of income for local communities.
"Alternative possibilities, such as managed planting of seedlings in natural gaps in the forest might be a better solution," he suggested.
Dr Haugaasen said that the next step for the researchers was to look at the "management implications" of their findings.
"We also need to know how the hunting of these rodents can effect the natural regeneration of these trees," he added.
"You can have a negative impact by reducing the number of these rodents.
"However, if you have a large number of seeds already buried by a rodent before it is shot, no-one else knows where those seeds are.
"So, you could arguably have a positive impact on regeneration."
Further studies on the ecology of Brazil nut trees are expected to be published in the coming 12 months
Thursday, 6 May 2010
was the Euro the eternal answer
was the Euro the eternal answer
the finances of Greece illustrate the one size fits all has issues
German stereotype ?
Who kept the U.K out of the euro
Petrol bombs were thrown at police, who responded with pepper spray and tear gas
Greece is "on the brink of the abyss", President Karolos Papoulias has warned, after three people died during protests over planned austerity measures.
"We are all responsible so that it does not take the step into the void," the president said in a statement.
It followed a day of violence during which protesters set fire to a bank, killing three employees.
Greece's government has vowed to pursue the spending cuts - a condition of its 110bn euro ($142bn; £95bn) bail-out.
"We are prepared to pay the heavy political cost," Finance Minister George Papaconstantinou told parliament during Wednesday's debate on the bill.
"We will not take a single step backwards."
The euro hit a fresh 13-month low against the dollar and European stock markets were also hit, amid concerns over Greek bail-out plans.
ANALYSIS
By Malcolm Brabant, BBC News, Athens
The situation in Athens is very tense at the moment - people are pausing and reflecting on what has happened.
Some people think that the deaths of the bank workers will have the impact of dampening down the protests because people will think that losing human lives is not worth it. But there are others who believe that this is the start of a social explosion.
This is a very volatile country.
If the outside markets look at Greece and think it is about to collapse, it may become a self-fulfilling prophecy.
In video: Reporter overcome
There are also fears Greece's debt crisis could spread to other countries.
The austerity measures - which the Greek parliament is due to vote by the end of the week - include wage freezes, pension cuts and tax rises. They aim to achieve fresh budget cuts of 30bn euros over three years, with the goal of cutting Greece's public deficit to less than 3% of GDP by 2014. It currently stands at 13.6%.
The general strike is the third to hit Greece in as many months. The protest became violent, with petrol bombs thrown at police who responded with pepper spray and tear gas.
The bodies of two women - one pregnant - and a man were found inside the Marfin bank branch on Stadiou Avenue in central Athens. They were among 20 people working there when the petrol bomb was thrown.
Most of the employees managed to escape the fumes as the flames took hold, but the three found their way blocked as they tried to escape to the roof and they suffocated.
Prime Minister George Papandreou told MPs in parliament the killings were a "murderous act".
GREEK AUSTERITY MEASURES
Public sector pay frozen till 2014
Public sector allowances cut by 20%
State pensions frozen or cut
Average retirement age up from 61 to 63
VAT increased from 19% to 23%
Taxes on fuel, alcohol and tobacco up 10%
One-off tax on profits, plus new gambling, property and green taxes
In pictures: Greece protests
Angry Greeks 'left carrying the can'
Greek economy 'to shrink by 3%'
Hewitt: Europe's days of anxiety
"Nobody has the right to violence and particularly violence that leads to murder. Violence breeds violence."
But one of the protesters told the BBC it had been the fault of the police, whose "brutality" had led to the escalation.
"It's something tragic but I think that the responsibility in the last instance lies with the government because the government unleashed a tremendous amount of police violence against a huge demonstration," Panayotis Sotiris said.
Europe future 'at stake'
Meanwhile, the German parliament has begun considering the bail-out plan for Greece. Chancellor Angela Merkel urged MPs to back the emergency loan package agreed by European finance ministers at the weekend.
What went wrong in Greece?
Greece's economic reforms that led to it abandoning the drachma in favour of the euro in 2002 made it easier for the country to borrow money.
Greece went on a debt-funded spending spree, including high-profile projects such as the 2004 Athens Olympics, which went well over budget.
It was hit by the downturn, which meant it had to spend more on benefits and received less in taxes. There were also doubts about the accuracy of its economic statistics.
Greece's economic problems meant lenders started charging higher interest rates to lend it money and widespread tax evasion also hit the government's coffers.
There have been demonstrations against the government's austerity measures to deal with its 300bn euro (£267bn) debt, such as cuts to public sector pay.
Now the government has announced that it needs to access the 30bn euros (£26bn) in emergency loans it has been offered by other EU countries.
BACK 1 of 6 NEXT It requires Germany to pay the largest proportion of the loans.
"Quite simply, Europe's future is at stake," she said.
The EU has agreed to provide 80bn euros (£69bn) in funding - of which around 22bn euros would come from Germany.
Another 30bn euros will come from the International Monetary Fund and the remainder from other eurozone members.
European Council President Herman van Rompuy said the European Union was watching events in Greece.
"We are all concerned by the Greek economic and budgetary situation, but at this moment our thoughts are with the human victims in Athens," Mr van Rompuy said
"A major programme has just been finalised. This programme is ambitious and credible in efforts that it represents towards the budgetary plan and competitiveness."
The bail-out deal is designed to prevent Greece from defaulting on its massive debt.
However, it must first be approved by some parliaments in the 15 other eurozone countries.
the finances of Greece illustrate the one size fits all has issues
German stereotype ?
Who kept the U.K out of the euro
Petrol bombs were thrown at police, who responded with pepper spray and tear gas
Greece is "on the brink of the abyss", President Karolos Papoulias has warned, after three people died during protests over planned austerity measures.
"We are all responsible so that it does not take the step into the void," the president said in a statement.
It followed a day of violence during which protesters set fire to a bank, killing three employees.
Greece's government has vowed to pursue the spending cuts - a condition of its 110bn euro ($142bn; £95bn) bail-out.
"We are prepared to pay the heavy political cost," Finance Minister George Papaconstantinou told parliament during Wednesday's debate on the bill.
"We will not take a single step backwards."
The euro hit a fresh 13-month low against the dollar and European stock markets were also hit, amid concerns over Greek bail-out plans.
ANALYSIS
By Malcolm Brabant, BBC News, Athens
The situation in Athens is very tense at the moment - people are pausing and reflecting on what has happened.
Some people think that the deaths of the bank workers will have the impact of dampening down the protests because people will think that losing human lives is not worth it. But there are others who believe that this is the start of a social explosion.
This is a very volatile country.
If the outside markets look at Greece and think it is about to collapse, it may become a self-fulfilling prophecy.
In video: Reporter overcome
There are also fears Greece's debt crisis could spread to other countries.
The austerity measures - which the Greek parliament is due to vote by the end of the week - include wage freezes, pension cuts and tax rises. They aim to achieve fresh budget cuts of 30bn euros over three years, with the goal of cutting Greece's public deficit to less than 3% of GDP by 2014. It currently stands at 13.6%.
The general strike is the third to hit Greece in as many months. The protest became violent, with petrol bombs thrown at police who responded with pepper spray and tear gas.
The bodies of two women - one pregnant - and a man were found inside the Marfin bank branch on Stadiou Avenue in central Athens. They were among 20 people working there when the petrol bomb was thrown.
Most of the employees managed to escape the fumes as the flames took hold, but the three found their way blocked as they tried to escape to the roof and they suffocated.
Prime Minister George Papandreou told MPs in parliament the killings were a "murderous act".
GREEK AUSTERITY MEASURES
Public sector pay frozen till 2014
Public sector allowances cut by 20%
State pensions frozen or cut
Average retirement age up from 61 to 63
VAT increased from 19% to 23%
Taxes on fuel, alcohol and tobacco up 10%
One-off tax on profits, plus new gambling, property and green taxes
In pictures: Greece protests
Angry Greeks 'left carrying the can'
Greek economy 'to shrink by 3%'
Hewitt: Europe's days of anxiety
"Nobody has the right to violence and particularly violence that leads to murder. Violence breeds violence."
But one of the protesters told the BBC it had been the fault of the police, whose "brutality" had led to the escalation.
"It's something tragic but I think that the responsibility in the last instance lies with the government because the government unleashed a tremendous amount of police violence against a huge demonstration," Panayotis Sotiris said.
Europe future 'at stake'
Meanwhile, the German parliament has begun considering the bail-out plan for Greece. Chancellor Angela Merkel urged MPs to back the emergency loan package agreed by European finance ministers at the weekend.
What went wrong in Greece?
Greece's economic reforms that led to it abandoning the drachma in favour of the euro in 2002 made it easier for the country to borrow money.
Greece went on a debt-funded spending spree, including high-profile projects such as the 2004 Athens Olympics, which went well over budget.
It was hit by the downturn, which meant it had to spend more on benefits and received less in taxes. There were also doubts about the accuracy of its economic statistics.
Greece's economic problems meant lenders started charging higher interest rates to lend it money and widespread tax evasion also hit the government's coffers.
There have been demonstrations against the government's austerity measures to deal with its 300bn euro (£267bn) debt, such as cuts to public sector pay.
Now the government has announced that it needs to access the 30bn euros (£26bn) in emergency loans it has been offered by other EU countries.
BACK 1 of 6 NEXT It requires Germany to pay the largest proportion of the loans.
"Quite simply, Europe's future is at stake," she said.
The EU has agreed to provide 80bn euros (£69bn) in funding - of which around 22bn euros would come from Germany.
Another 30bn euros will come from the International Monetary Fund and the remainder from other eurozone members.
European Council President Herman van Rompuy said the European Union was watching events in Greece.
"We are all concerned by the Greek economic and budgetary situation, but at this moment our thoughts are with the human victims in Athens," Mr van Rompuy said
"A major programme has just been finalised. This programme is ambitious and credible in efforts that it represents towards the budgetary plan and competitiveness."
The bail-out deal is designed to prevent Greece from defaulting on its massive debt.
However, it must first be approved by some parliaments in the 15 other eurozone countries.
Wednesday, 5 May 2010
Uganda's highest ice cap splits on Mt Margherita
Uganda's highest ice cap splits on Mt Margherita
Uganda's Rwenzori Mountains in 1987 on the left and in 2005 on the right
The ice cap on Uganda's highest peak has split because of global warming, Uganda's Wildlife Authority (UWA) says.
The glacier is located at an altitude of 5,109m (16,763ft) in the Rwenzori mountain range, near the border with the Democratic Republic of Congo.
The authorities say a crevasse has blocked access to the Margherita summit - the third-highest peak in Africa, and a popular destination with climbers.
Scientists say glaciers in the Rwenzori range could disappear within 20 years.
UWA officials said a team had been sent to the mountain to assess the extent of damage on the route to Margherita.
According to researchers, the ice cap covered 6 sq km (2 sq miles) 50 years ago. It is now less than 1 sq km.
The mountain range, which is one of the few places near the equator to have glaciers, was declared a Unesco World Heritage site in 1994.
Uganda's Rwenzori Mountains in 1987 on the left and in 2005 on the right
The ice cap on Uganda's highest peak has split because of global warming, Uganda's Wildlife Authority (UWA) says.
The glacier is located at an altitude of 5,109m (16,763ft) in the Rwenzori mountain range, near the border with the Democratic Republic of Congo.
The authorities say a crevasse has blocked access to the Margherita summit - the third-highest peak in Africa, and a popular destination with climbers.
Scientists say glaciers in the Rwenzori range could disappear within 20 years.
UWA officials said a team had been sent to the mountain to assess the extent of damage on the route to Margherita.
According to researchers, the ice cap covered 6 sq km (2 sq miles) 50 years ago. It is now less than 1 sq km.
The mountain range, which is one of the few places near the equator to have glaciers, was declared a Unesco World Heritage site in 1994.
Monday, 3 May 2010
Election: Vote battle intensifies for final three days
Election: Vote battle intensifies for final three days
Cameron denies he is 'over-confident'
Gordon Brown, David Cameron and Nick Clegg are into the final three days of election campaigning.
The Tories are ahead in the polls but not by enough to get a majority - Mr Cameron says they will campaign through the night in a final push from Tuesday.
Mr Brown said he would fight "every inch" and said "judgement and wisdom" were needed after the financial crisis.
Mr Clegg told supporters in south-east London "the sky's the limit" and they had "three days to change Britain".
The three leaders are spending the bank holiday visiting numerous seats they hope to win on 6 May.
'No complacency'
Three days before the closest election since 1992, an ICM/Guardian poll puts the Conservatives on 33%, Labour and the Lib Dems on 28% while a YouGov poll for the Sun puts the Tories on 34%, Lib Dems on 29% and Labour on 28% - which continue to point to a hung parliament.
BBC News Channel chief political correspondent Laura Kuenssberg said despite the final TV debate and Mr Brown having to apologise after being overheard calling a pensioner "bigoted", the polls had not really shifted over the past week.
In Blackpool on Monday, Mr Cameron said there was not "one ounce of complacency" in his campaign and pledged a through-the-night campaign from Tuesday night to Wednesday night, in which he is expected to meet fishermen, bakers and florists who work in the early hours of the morning.
In this country you don't inherit power, you have to earn it
Nick Clegg
Clegg warns of Tory 'arrogance'
He said he was taking "no vote for granted" and recognised that millions of people were still making up their minds.
In a message to his parliamentary candidates he said: "This is the vital time. You need to go door to door, street to street, house to house. We have a huge amount of work to do, a lot of people left to convince."
"If we get out there we can... win it and win it for our country," he said.
On Sunday he said his party had the "momentum" - and was criticised by Labour's Lord Mandelson who said Mr Cameron was "desperate to give the impression that he is home and dry" but in fact voters were "firmly resisting his soft soap campaign".
'Sky's the limit'
Addressing supporters in Blackheath, south-east London, Mr Clegg accused Mr Cameron of "breathtaking arrogance" and of "measuring up the curtains" at 10 Downing Street before the election had taken place.
Urging activists to "campaign every minute of the day", he said: "Anything can happen. The sky's the limit."
I'm going to fight every inch of the way and every second of the day
Gordon Brown
Mr Clegg said: "We have got three days in this most exciting election campaign, three days to change Britain for good. Three days to deliver the fairness... for the families and communities of Great Britain."
He acknowledged a change in Lib Dem strategy - campaigning in seats like Streatham and Lewisham that the party would not have expected to win. Mr Clegg told the BBC: "We are reaching deeper into parts of Britain that have been let down by Labour in particular for so long."
The Lib Dems have also released a list of celebrity supporters - which includes actors Colin Firth and Harry Potter star Daniel Radcliffe, satirist Armando Ianucci and campaigner Bianca Jagger.
Meanwhile Mr Brown has been joined by his own celebrity supporter, Dragons' Den entrepreneur Duncan Bannatyne, in visits to Basildon and Ipswich on Monday morning.
Equality plans
He acknowledged he was "fighting for my life" in what he described as "a post global-financial-crisis election".
He said the government needed to make the "right calls" and "judgement and wisdom" were needed while the Tories had been on the wrong side of the arguments during the economic crisis.
"It is a Labour majority government we need," he said.
"I'm going to fight every inch of the way and every second of the day to tell people in Britain that fight for the future must mean people look at our plan and what we're proposing."
The Conservatives have unveiled plans for a "contract for young people" - to guarantee them help with training and getting jobs and are setting out plans for new rules aimed at forcing listed companies to hire more female directors, proposals to close the gender pay gap and set up mentoring schemes for female and ethnic minority entrepreneurs.
Labour is concentrating on its "seasides manifesto" to boost resort towns and help them benefit from opportunities in low carbon businesses and economic regeneration.
The Lib Dems will turn their fire on the Conservatives arguing they would not reform the banks and rebuild the economy because they are "in hock to the City of London".
The three leaders will also address a CitizensUK election "assembly" of about 2,500 people in London. Each will speak for 10 minutes before taking questions from a panel about "civil society".
Cameron denies he is 'over-confident'
Gordon Brown, David Cameron and Nick Clegg are into the final three days of election campaigning.
The Tories are ahead in the polls but not by enough to get a majority - Mr Cameron says they will campaign through the night in a final push from Tuesday.
Mr Brown said he would fight "every inch" and said "judgement and wisdom" were needed after the financial crisis.
Mr Clegg told supporters in south-east London "the sky's the limit" and they had "three days to change Britain".
The three leaders are spending the bank holiday visiting numerous seats they hope to win on 6 May.
'No complacency'
Three days before the closest election since 1992, an ICM/Guardian poll puts the Conservatives on 33%, Labour and the Lib Dems on 28% while a YouGov poll for the Sun puts the Tories on 34%, Lib Dems on 29% and Labour on 28% - which continue to point to a hung parliament.
BBC News Channel chief political correspondent Laura Kuenssberg said despite the final TV debate and Mr Brown having to apologise after being overheard calling a pensioner "bigoted", the polls had not really shifted over the past week.
In Blackpool on Monday, Mr Cameron said there was not "one ounce of complacency" in his campaign and pledged a through-the-night campaign from Tuesday night to Wednesday night, in which he is expected to meet fishermen, bakers and florists who work in the early hours of the morning.
In this country you don't inherit power, you have to earn it
Nick Clegg
Clegg warns of Tory 'arrogance'
He said he was taking "no vote for granted" and recognised that millions of people were still making up their minds.
In a message to his parliamentary candidates he said: "This is the vital time. You need to go door to door, street to street, house to house. We have a huge amount of work to do, a lot of people left to convince."
"If we get out there we can... win it and win it for our country," he said.
On Sunday he said his party had the "momentum" - and was criticised by Labour's Lord Mandelson who said Mr Cameron was "desperate to give the impression that he is home and dry" but in fact voters were "firmly resisting his soft soap campaign".
'Sky's the limit'
Addressing supporters in Blackheath, south-east London, Mr Clegg accused Mr Cameron of "breathtaking arrogance" and of "measuring up the curtains" at 10 Downing Street before the election had taken place.
Urging activists to "campaign every minute of the day", he said: "Anything can happen. The sky's the limit."
I'm going to fight every inch of the way and every second of the day
Gordon Brown
Mr Clegg said: "We have got three days in this most exciting election campaign, three days to change Britain for good. Three days to deliver the fairness... for the families and communities of Great Britain."
He acknowledged a change in Lib Dem strategy - campaigning in seats like Streatham and Lewisham that the party would not have expected to win. Mr Clegg told the BBC: "We are reaching deeper into parts of Britain that have been let down by Labour in particular for so long."
The Lib Dems have also released a list of celebrity supporters - which includes actors Colin Firth and Harry Potter star Daniel Radcliffe, satirist Armando Ianucci and campaigner Bianca Jagger.
Meanwhile Mr Brown has been joined by his own celebrity supporter, Dragons' Den entrepreneur Duncan Bannatyne, in visits to Basildon and Ipswich on Monday morning.
Equality plans
He acknowledged he was "fighting for my life" in what he described as "a post global-financial-crisis election".
He said the government needed to make the "right calls" and "judgement and wisdom" were needed while the Tories had been on the wrong side of the arguments during the economic crisis.
"It is a Labour majority government we need," he said.
"I'm going to fight every inch of the way and every second of the day to tell people in Britain that fight for the future must mean people look at our plan and what we're proposing."
The Conservatives have unveiled plans for a "contract for young people" - to guarantee them help with training and getting jobs and are setting out plans for new rules aimed at forcing listed companies to hire more female directors, proposals to close the gender pay gap and set up mentoring schemes for female and ethnic minority entrepreneurs.
Labour is concentrating on its "seasides manifesto" to boost resort towns and help them benefit from opportunities in low carbon businesses and economic regeneration.
The Lib Dems will turn their fire on the Conservatives arguing they would not reform the banks and rebuild the economy because they are "in hock to the City of London".
The three leaders will also address a CitizensUK election "assembly" of about 2,500 people in London. Each will speak for 10 minutes before taking questions from a panel about "civil society".
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