GM 'golden rice' boosts vitamin A

BBC NEWS | Science/Nature | GM 'golden rice' boosts vitamin A
GM 'golden rice' boosts vitamin A
By Richard Black
BBC environment correspondent

UK scientists have developed a new genetically modified strain of "golden rice", producing more beta-carotene.

The human body converts beta-carotene into vitamin A, and this strain produces around 20 times as much as previous varieties.

It could help reduce vitamin A deficiency and childhood blindness in developing countries.

The World Health Organization estimates up to 500,000 children go blind each year because of vitamin A deficiency.

Shared technology

When the original strain of golden rice emerged from laboratories in Switzerland five years ago, it was hailed by some as an instant solution.

But that original strain did not produce enough beta-carotene to ensure that children would get their daily requirement from eating normal quantities of rice.

And because of concerns about GM agriculture, it still has not been grown in field trials in Asia.

The new variety, developed at the UK laboratories of the biotechnology company Syngenta, produces much more beta-carotene.

Syngenta is making the rice available for free to research centres across Asia, who will, if they are given the go-ahead by their governments, begin field trials - probably within the next five years.

Complex issues

Not everyone believes golden rice is the best answer to Vitamin A deficiency.

Some agricultural experts and environmental groups say aiming for a balanced diet across the board would be a better solution.

"The problem is that you're trying to fix vitamin A deficiency with a narrow GM solution when the problem is much more complex," said Clare Oxborrow, from the anti-GM group Friends of the Earth.

"People who are deficient in vitamin A are also deficient in a whole host of other vitamins and minerals. What are we going to do? Are we going to genetically modify a crop to address these issues, too?

"What we should be doing is trying to support people to grow the diverse types of food that meet all their nutritional needs."

Parallel programmes

However, the Golden Rice Humanitarian Board, which is overseeing developments in the plant technology, said the crop was not intended to be the sole solution.

It said malnutrition was rooted in political, economic and cultural issues that could not be magically resolved by a single agricultural technology.

"We are trying to deal with part of the problem; we are not against supplementation, fortification, [or] small house gardens," explained Dr Jorge Mayer, the golden rice project manager.

"All this has been tried for many years and still, with all the existing programmes, with millions of dollars being invested every year - there is still a gap to be filled.

"We believe we can fill a gap and with the other programmes to try to achieve full coverage."

The latest scientific research is published in the journal Nature Biotechnology.

Les Bibittes... Global warming could trigger ant invasions

New Scientist Breaking News - Global warming could trigger ant invasions
Global warming could trigger ant invasions
22:00 21 March 2005
NewScientist.com news service
Shaoni Bhattacharya

Global warming may lead to an unexpected threat from the insect world - swarming invasions of tiny ants - suggests new research.

The study of 665 ant colonies in environments ranging from tropical rainforests to frozen tundra suggests that in warmer environments the ants' body size shrinks, on average, while the number of individuals in the colony booms.

Global warming might shrink ant workers by as much as a third, says Michael Kaspari at the University of Oklahoma, US, and the Smithsonian Tropical Research Institute in Panama, who carried out the study: "And since ant species with small workers appear to be particularly successful at invading, ant invasions - already destructive - may become more common in a warming world."

Kaspari found that worker ant and colony size varied almost 100-fold in his survey of ant colonies in 49 ecosystems in the Americas. Average nest populations varied from 63 workers in a cold temperate pine forest, to over 9000 workers in a hot, temperate desert. "The tiniest colonies are not much bigger than the inside of a Cheerio while the largest colonies can fill up a garbage can," he told New Scientist.

Worker ant size varied from the largest - the bala or bullet ant (see photo) which is about the size of an adult human thumb - to ants so small they can only be seen with a microscope. These dramatically different ants could be found co-existing in the tropics.

Kaspari says that theory suggested that body size should be bigger in the tropics, where there is more plentiful food and where the warmth enables cold-blooded creatures to perform better. But in fact, the average body size of worker ants was lower in those zones.

He suggests that higher temperature may be a "double-edged sword" when organisms are growing: "It allows you to forage, but a greater fraction of what you eat gets frittered away in metabolism." He adds that smaller organisms are also good at producing lots of offspring.

Most exciting, says Kaspari, is that "we are the first people to show that the size of an organism varies in a predictable way, and not just with latitude but based on two fundamental properties of the ecosystem - temperature and productivity".

The study shows a "massive effort" in collecting data says Francis Ratnieks, a social insect expert at the University of Sheffield, UK. He notes that some large species, like leafcutter ants, eat different foods to other ant species, and therefore may respond differently to any warming. "Leafcutter ants have tapped into a rich food source, that of fresh leaves, and their energy constraints may well be very different to those of most other ants."

Kaspari now plans to see if other organisms vary in size in such a predictable way, starting with the "brown food web" of decomposing organisms in soil.


Journal reference: Proceedings of the National Academy of Sciences (DOI: 10.1073/pnas.0407827102)

Deux pommes par jour éloignent le cancérologue

Deux pommes par jour éloignent le cancérologue
Deux pommes par jour éloignent le cancérologue

Une équipe française affirme que certains constituants de la pomme ont des propriétés qui aident à lutter contre l'apparition du cancer du colon.

Les chercheurs de l'Institut de recherche contre les cancers de l'appareil digestif (IRCAD) ont démontré que la consommation de deux pommes par jour a des effets anticancérogènes. Ils ont étudié les effets de polyphénols (composés anti-oxydants) de la pomme sur l'organisme du rat.

L'équipe a observé qu'un de ces composés inhibait la croissance des cellules et déclenchait une suite de réactions qui amènent la mort programmée (apoptose) des cellules cancéreuses.

Les scientifiques sont également heureux de constater que l'effet protecteur est obtenu avec des composés naturels à doses nutritionnelles (et non pharmaceutiques) puisque les effets anticancérogènes chez l'animal correspondent à la consommation de 2 pommes par jour chez l'humain.

Une précédente étude avait démontré que la consommation de deux pommes par jour était bonne contre le durcissement des artères.

Climate Models Reveal Inevitability of Global Warming

Science & Technology at Scientific American.com: Climate Models Reveal Inevitability of Global Warming
How to best curb greenhouse gas emissions is a hotly debated topic. But new research suggests that putting the brakes on greenhouse gas levels is not enough to slow down climate change because the ocean responds so slowly to perturbations. The study results, published today in the journal Science, indicate that even if greenhouse gas levels had stabilized five years ago, global temperatures would still increase by about half a degree by the end of the century and sea level would rise some 11 centimeters.

"Many people don't realize we are committed right now to a significant amount of global warming and sea level rise because of the greenhouse gases we have already put into the atmosphere," says study author Gerald Meehl of the National Center for Atmospheric Research (NCAR) in Boulder, Colo. "The longer we wait, the more climate change we are committed to in the future." Meehl and his NCAR colleagues ran two coupled climate models that link major components of our planet's climate and incorporate their interactions. The researchers then analyzed scenarios in which greenhouse gases continue to accumulate in the atmosphere at low, moderate and high rates. The highest rates of accumulation lead to model results that included a 3.5 degrees Celsius increase in global temperatures and a 30 centimeter rise in global sea levels.

But even without additional greenhouse gas contributions, they found, global temperature would continue to rise because of a characteristic known as thermal inertia. Water in the oceans heats and cools more slowly than air does because of its greater density, leading to a delayed response. In addition, carbon dioxide and other greenhouse gases have long atmospheric lifetimes and can affect temperatures for years after first being introduced into the atmosphere. The authors conclude that "at any given point in time, even if concentrations are stabilized, there is a commitment to future climate changes that will be greater than those we have already observed." --Sarah Graham

La médecine non traditionnelle de plus en plus populaire

La médecine non traditionnelle de plus en plus populaire: "La médecine non traditionnelle de plus en plus populaire
Mise à jour le mercredi 16 mars 2005 à 15 h 10

Un Canadien sur cinq de plus de 12 ans a consulté un spécialiste d'une médecine non traditionnelle en 2002.

Ainsi, pas moins de 5,4 millions de personnes ont déclaré avoir eu recours à des soins de santé comme la chiropractie, la massothérapie et l'acupuncture durant l'année qui a précédé l'Enquête sur la santé, menée par Statistique Canada en 2003.

La chiropratie est la plus populaire des médecines non traditionnelles. Environ 11 % de la population âgée de 12 ans et plus ont consulté un chiropraticien.

Environ 8 % ont fait appel aux services d'un massothérapeute, 2 %, d'un acupuncteur, et 2 %, d'un homéopathe ou d'un naturopathe.

Les femmes sont plus susceptibles que les hommes de déclarer une consultation de ce genre de service. Son utilisation augmente avec le revenu et le niveau de scolarité."

We're not alone -- Species list reaches half-million mark

news @ nature.com - Species list reaches half-million mark  - Researchers claim 'spectacular progress' towards logging all Earth's life.
Species list reaches half-million mark
Mark Peplow

Researchers claim 'spectacular progress' towards logging all Earth's life.

An online catalogue of all known life on Earth now has half a million species in its freely available database.

The Catalogue of Life Programme began in 2001 as a collaboration between Species 2000, a project based at the University of Reading, UK, and the Integrated Taxonomic Information System in Washington DC. The two groups each host part of the online directory.

Since then, many universities and natural history institutions have opened up their dusty card catalogues of species to contribute to the digital resource.

"The Catalogue of Life is just like the yellow pages for species," explains Paul Kirk, an expert in fungi at CABI Bioscience, a non-profit agriculture and biodiversity research organization, based at Egham, UK, that is one of the project's collaborators.

"You can't understand biodiversity without a system of communication, and it's fundamental that we have this directory of names," he says.

The catalogue is useful in any situation where researchers want to keep track of living organisms, says Kirk. For example, a definitive list of all the species within a particular genus can help with evolutionary studies.

The resource will also provide a starting point for conservation efforts in remote parts of the world where 'parataxonomists', untrained in biology, can use the catalogue as a reference to help monitor biodiversity.

Many species are known by different colloquial names in neighbouring countries, and the catalogue hopes to eliminate the confusion this causes.

Bacteria to blue whales

Biologists estimate that about 1.75 million species, from bacteria to blue whales, have already been identified on Earth. But there may be anywhere between 3 million and 12 million more yet to be discovered, says Kirk.

For each known species, the catalogue lists its different names, along with details of where it is found, the names of relevant experts, and links to other online resources.

"We need a catalogue of life, so I'm very much for it," says Charles Godfray, an evolutionary biologist at Imperial College London. "But this is just a means to an end," he adds.

More than a list

Ultimately, biologists need a catalogue that is full of information about each species, rather than a mere directory of names, he says. "What worries me is that people aren't producing those information-rich sites," says Godfray.

Other projects are attempting to create more comprehensive catalogues, he points out, such as the International Plant Names Index, based at the Royal Botanic Gardens in Kew, London.

Another promising effort is Wikispecies. Started in August 2004, this is an offshoot of the Wikimedia group, whose free online encyclopaedia is constructed by users themselves.

Biologists across the world are being invited to contribute to the Wikispecies site. "It is going well, but we are proceeding carefully to get the details right from the start," says founder Jimmy Wales.

Frank Bisby, the executive director of Species 2000, who announced the catalogue's milestone on 15 March at their annual meeting in St. Paul's Bay, Malta, says it has made "spectacular progress". The consortium aims to complete its database by the end of the decade.

Petit film drôle... Bon, pas si drôle après tout.

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Secret of fish oil's healthy effects revealed - Synthetic version could one day treat range of inflammatory diseases.

news @ nature.com - Secret of fish oil's healthy effects revealed - Synthetic version could one day treat range of inflammatory diseases.
Intéressant. Peut-être un bon exemple de médecines complémentaires? Aspirine et Omega 3!
Je crois qu'on y gagnerait à chercher du coté des biotechnologies où on pourrait produire ces Oméga 3 à partir d'algues ou de cyanobactéries ou de bactéries. Tenter d'en faire une synthèse mène presque toujours à des produits limités en terme d'efficacité et avec des effets secondaires indésirables. Martek Biosciences fabrique des DHA à partir d'algues avec un énorme succès. Les stocks de poissons ayant diminué de 90% en 150 ans, on devra penser à d'autres sources. À suivre...

Secret of fish oil's healthy effects revealed
Charlotte Schubert

Synthetic version could one day treat range of inflammatory diseases.

Fish oil's reputation as a panacea has expanded in recent years, with studies showing benefits in ailments ranging from asthma to heart disease. How it works has has been a mystery, but a new study now helps to provide the answer, and suggests that aspirin could boost the beneficial effect even further.

Many of the diseases helped by fish oils have one thing in common: chronic inflammation, in which immune cells and molecular mediators flood tissues and can create damage. This can lead, for example, to the hardening of the arteries that spurs heart attacks and strokes.

"We know that this fish oil suppresses inflammation," says Stephen Prescott, director of the Huntsman Cancer Institute at the University of Utah in Salt Lake City, and an expert on lipids and inflammation. "The question is how does it do it? People have looked for more than 20 years."

Charles Serhan at Harvard Medical School in Boston and colleagues became intrigued by the problem in 1999, after seeing a study showing that fish oil protects against cardiovascular disease.

Subjects in that study had consumed a gram of fish oil each day. "They smelled like mackerel," said Serhan. But he noticed that almost all of the subjects were also taking aspirin to prevent strokes and heart attacks. Might the two substances be working together?

Subsequent research by Serhan and his colleagues has suggested that they do. Their work in human cells and in mice showed that omega-3 fatty acids in the fish oil are converted into lipids that seem to suppress inflammation. Aspirin speeds up that conversion.

The researchers have now pinned down the effect even further by focusing on one of the lipids, called resolvin E1. First they found that healthy human volunteers fed both aspirin and fish oil had resolvin E1 in their bloodstream. Then they created a synthetic form of the lipid and tested its properties.

The lipid inhibited the migration of particular human immune cells and dramatically reduced inflammation on the skin of rabbits. Serhan and his team believe that resolvin E1 works in the body to tone down inflammation, and report their results in The Journal of Experimental Medicine1.

"This is a really attractive and interesting hypothesis at this stage," says Prescott. Raymond DuBois, a lipid researcher at Vanderbilt-Ingram Cancer Center in Nashville, Tennessee, echoes that sentiment, calling the work "a great move forward".

Serhan is now working to prove that resolvin E1 does actually help to treat disease. His unpublished data so far show that the synthetic version works in a mouse model of periodontal gum disease. Such disease is driven by inflammation, which weakens the gums and causes teeth to fall out. Resolvin E1 counteracts the process, he says.

Serhan now aims to scale up and modify the manufacture of synthetic resolvin E1 so that it can be made cheaply in bulk, and he hopes to start human trials soon.

It's a powerful substance, comments Prescott. "All you need to do is make a little bit, and bang, you have an effect."

But resolvin E1 is "just the tip of the iceberg", Serhan adds. His group is also looking at the other lipids that derive from fish oil. He suspects that each one has a part to play in orchestrating the inflammatory response. Understanding how they work could lead to the development of a range of new drugs to counteract inflammation, he predicts.
References

Arita, et al. J. Exp.l Med. 201, 713 - 722 (2005).

L'autisme droit dans les yeux

J'ai eu une expérience très étrange il y a plusieurs années avec une enfant autiste. Elle m'a regardé droit dans les yeux avec une intensité foudroyante puis elle a eu très peur. Sa frayeur était primaire et contagieuse. C'était ma première incursion dans le monde de la souffrance de l'être. J'en suis resté très bouleversé pendant des semaines, peut-être des mois.

March 07, 2005
Eye Contact Triggers Threat Response in Autistic Children

Children suffering from autism pay very little attention to faces, even those of people close to them. Indeed, this characteristic can become apparent as early as the age of one, and is often used as a developmental sign of the disease. The results of a new study provide additional insight into why autistic children avoid eye contact: they perceive faces as an uncomfortable threat, even if they are familiar.

Kim M. Dalton of the University of Wisconsin-Madison and her colleagues studied 27 autistic teenagers who looked at pictures of faces (see image) while a magnetic resonance imaging (MRI) machine scanned their brains. The researchers also tracked the subjects' eye movements as they studied the images. "This is the very first published study that assesses how individuals with autism look at faces while simultaneously monitoring which of their brain areas are active," Dalton says. When the image included a direct gaze from a nonthreatening face, brain activity in the amygdala--a brain region associated with negative feelings--was much higher for autistic children than it was in members of the control group. "Imagine walking through the world and interpreting every face that looks at you as a threat, even the face of your own mother," remarks study co-author Richard Davidson, also at UW-Madison.

The results also indicate that a brain area associated with face perception, known as the fusiform region, is fundamentally normal in autistic children; it does exhibit decreased activity, however. Davidson notes that this could result because the over-aroused amygdala makes an autistic child want to look away from faces. In addition, he comments that it was surprising that "when subjects with autism averted their gaze away from the eye region of a face, they showed reduced activity in the amygdala, suggesting that the gaze aversion is serving a functional purpose." The findings are published today in the journal Nature Neuroscience. --Sarah Graham

BBC NEWS | Science/Nature | Local food 'greener than organic'

BBC NEWS | Science/Nature | Local food 'greener than organic'
Local food 'greener than organic'

Local food is usually more "green" than organic food, according to a report published in Food Policy journal.

The authors say people can help protect the environment by buying food produced within a 20km radius.

They claim British consumers are not fully aware of the severe damage done to the environment by driving food long distances around the UK.

Proportionately, "road miles" account for more environmental damage than "air miles", the authors claim.

Therefore the message to consumers is this: It is not good enough to buy food from within the UK - it must come from within your area.

However, the authors admit that consumers are prevented from "doing the right thing" because of inadequate labelling.

"The most political act we do on a daily basis is to eat, as our actions affect farms, landscapes and food businesses," said co-author Professor Jules Pretty from the University of Essex, UK.

"Food miles are more significant than we previously thought, and much now needs to be done to encourage local production and consumption of food."

Clean-up costs

Professor Pretty and his colleague Tim Lang, from City University, UK, painstakingly estimated the environmental "price tag" on each stage of the food production process.

That price might reflect, for example, the clean-up costs following pollution, or the loss of profits caused by erosion damage.

"The price of food is disguising externalised costs - damage to the environment, damage to climate, damage to infrastructure and the cost of transporting food on roads," Professor Lang told the BBC News website.

The authors calculated that if all foods were sourced from within 20km of where it is was consumed, environmental and congestion costs would fall from more than £2.3bn to under £230m - an "environmental saving" of £2.1bn annually.

They pointed out that organic methods can also make an important contribution. If all farms in the UK were to turn organic, then the country would save £1.1bn of environmental costs each year.

Consumers can save a further £100m in environmental costs, the authors claim, if they cycle, walk or catch the bus to the shops rather than drive.

Each week the average person clocks up 93p worth of environmental costs, the report concludes.

These costs should be addressed by the government, companies and consumers, the authors believe.

Sophisticated policy

"It is going to need some sophisticated policy solutions," Professor Pretty said. "You could say we should internalise those costs in prices, so that it effects people's behaviour. That might be economically efficient but it lacks on the social justice side because it will affect rich people much less."

Instead, the authors are advocating a softer approach. Consumers should make ethical choices about the food that they buy, and supermarkets should be open with customers about where their food is coming from.

At the moment, as every UK consumer will know, it is impossible to tell whether your carrot has come from Devon or Scotland.

"In the short term our paper adds to consumer frustration," Professor Lang concedes. "The problem is we don't get the information. Food labels don't tell you the sort of information you really need to know if you want to do the right thing by the environment."

Since supermarkets do know exactly where their food is coming from, Professor Lang believes they have a duty to inform their customers.

Eventually, the authors hope, the food production infrastructure within Britain will be transformed.

"We think farming methods will change - farming will undergo a re-birth, if you like," said Professor Lang.

"A big city like London could be provided with a lot more seasonal vegetables from local farms. Because at the moment, the shape of the supply chain is all wrong from the point of view of food, environment and public health."

Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/1/hi/sci/tech/4312591.stm

Published: 2005/03/02 20:04:44 GMT

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