Geoengineering

In 1991, the Philippines' Mount Pinatubo volcano threw so much sulfur dioxide into the air that the sunlight was reduced by about 10%. As a result, global temperatures dropped by 0.5 degrees over the next 18 months.

A temperature reduction is what the Earth needs now, so a similar event may help us fight global warming, perhaps the most dangerous problem for humanity.

Geoengineering, the deliberate modification of the environment, has been considered the top of arrogance by many people and most environmentalists. We are very far from understanding how the climate system works. Who could say that we won't make things worse? We'd better be alert. Geoengineering should proceed with caution.

However, even if we try, it will take us decades to make the transition from a carbon-based economy to one powered by new energy technologies. In the meantime, it is possible that global warming may get to a point of no return. This is where geoengineering comes in: it's not a long-term solution but a way to keep the earth from overheating while we wait for efficient, green-energy technologies to come on line.

Can geoengineering really do the job? In fact, modern global warming is evidence of negative geoengineering, the result of all that carbon dioxide and other greenhouse gases we've been throwing into the atmosphere for a century or so. But it was the Pinatubo eruption that provided an example of geoengineering's potential. Scientists studying the eruption wondered if they could do the same thing deliberately.

They are, as many critics have pointed out, merely Band-Aids. But Band-Aids have their uses, except that the only real solution to global warming is to end our dependency on fossil fuels.

Adapted from an article by Bjorn Lomborg in Time Magazine. Picture by Getty Images.

NDM1 in Japan

A gene, NDM1, that makes microorganisms drug-resistant has been detected in Japan for the first time, in a man who had medical treatment in India. It is a serious case because scientists say the gene -which is frequent in India- alters bacteria, making them resistant to all antibiotics.

Drug-resistant bacteria are not new. Many bacteria are resistant to the world's first antibiotic, penicillin, as well as successive generations of drugs. Excessive use and improper use of antibiotics have made the problem worse.

NDM-1 could be a global health problem in a short time and international coordination is needed. Apart from India, the new gene has been detected in small numbers in Australia, Canada, the United States, the Netherlands, Sweden and the U.K. Investigators say that many Americans and Europeans travel to India and Pakistan for cosmetic surgery, and it is there where the generalizing process may begin.

Antimicrobial resistance -the ability of microorganisms to escape drugs' efficacy- is an increasing global health problem that could affect diseases such as respiratory infections and dysentery, according to the WHO (World Health Organization).

The WHO says NDM-1 requires monitoring and study. With effective measures, countries have successfully battled multi-drug resistant microorganisms in the past. It recommends that governments improve their efforts in four areas: surveillance, rational antibiotic use, legislation to stop sales of antibiotics without prescription, and infection prevention measures such as hand-washing in hospitals.

Red parrot feathers resist bacterial degradation

Many white bird species, such as gulls and geese, have black wing feathers. This is because black colour is the result of melanins that are incorporated into the feather while it is growing. Melanins make feathers stronger, especially in birds that fly long distances.

But among birds, parrots are unique: they sinthesize their bright reds, oranges and yellows, with pigments that are not found anywhere else. Unlike other birds, their colours are not derived from their diet. 

These unique feather pigments may serve more functions than just visual communication in parrots, according to Edward Burtt, a professor at an American university. He noticed that some microbes, -Bacillus licheniformis, Bacillus pumilus and other Bacillus species- were eating feathers, and he also found that green feathers were resistant to bacterial degradation. 
 
Dr Burtt's team first classified colourful feathers from thirteen parrot species into six general colour categories: blue, green, red, yellow, black and white. The team placed differently-coloured feathers into a bacterial medium containing Bacillus licheniformis, a bacteria that degrades feathers. They measured how much the bacteria broke down the feathers and compared this between feathers of different colours. The investigation resulted in clear conclusions: feather colour affected the bacterial degradation: white feathers degraded more rapidly than black, blue, green and red feathers. 
 
Biochemical analysis of yellow molecules found that they are formed by small carbon chains with few double-bonds, while red ones have longer carbon chains with more double-bonds. In short, red molecules are bigger than yellow ones and have stronger bonds, so they should be more difficult for bacteria to break down.
    
Adapted from an article in guardian.co.uk, based on Burtt, E., Schroeder, M., Smith, L., Sroka, L. and McGraw, K. (2010) Colourful parrot feathers resist bacterial degradation. Biology Letters DOI 10.1098/rsbl.2010.0716 

The Uncommon Life of Your Common Cold

Misinformation about the common cold is perhaps much more frequent than the cold itself.

Do you catch cold from the cold? Cold doesn't cause colds, viruses do. Colds are more common in the fall and winter because the cooler, wetter weather drives people inside, and viruses can more easily jump from one person to the next.

Are some people genetically more inclined to colds? Scientists are really interested in this idea that if you infect people with the virus, everybody will get infected, but only 75% of people will actually come down with the cold.

What is the biggest mistake about colds? Probably that susceptibility to colds requires a weak immune system. If you want to diminish your cold symptoms, boosting elements of your immune system may be the last thing you want to do.

Will there ever be a cure for the common cold? Some promising drugs are being investigated. But it's a really tough nut to crack.

What about the power of empathy? Empathy can actually cut short a cold by a full day. That's better than any drug on the market, and there aren't any side effects!
Adapted from an article by Alexandra Silver. Picture by Corbis.

Animal and plant genes create new species

The genes of plants and animals act as engines for speciation, that is, they are “programmed” to cause the development of new species, according to investigations on two very different groups of organisms.

When two diverging populations of organisms do not interbreed — a phenomenon of hybrid sterility or incompatibility — the number of genes that prevent them from producing new organisms starts to grow very fast. This process promotes the evolution of new species.

In the first of the studies, Daniel Matute and his colleagues at the University of Chicago counted the number of genes in species incompatibility between fruitflies that belong to three species: Drosophila melanogaster, Drosophila simulans and Drosophila santomea. These three species can interbreed, but the new organisms are sterile.

The team created two hybrid populations — one by crossing D. melanogaster with D. simulans and the other by crossing D. melanogaster with D. santomea — and counted the number of incompatibilities in the hybrid chromosomes.

They found 65 incompatibilities in the hybrids between D. melanogaster and D. santomea, while there were just ten in the hybrids between D. melanogaster and D. simulans. Taking into account the relative number of genetic changes between species, this suggests that the number of incompatibilities does not increase in a linear way, but is accelerating.

Similar results were found out when studying the plant genus “solanum”, which includes potatoes and tomatoes. A lot of genes contributing to sterility were growing faster than the linear rate, while genes that had nothing to do with sterility were not.
Adapted from an article by Joseph Milton in Nature. Picture by Stockphoto.

Precursor to H.I.V. Was in Monkeys for Millenniums

In a discovery that throws new light on the history of AIDS, scientists have found evidence that the ancestor to the virus that causes the disease has been in monkeys for at least 32,000 years.

That means humans have presumably been exposed many times to SIV, the simian immunodeficiency virus, because people have been hunting monkeys for millenniums.

So what happened in Africa in the early 20th century that turned an unimportant monkey disease into one of history’s great killers, 25 million human lives so far?

Confirming that the virus is very old also helps explain why it infects almost all African monkeys but does not sicken them. A disease kills off vulnerable victims, but the host adapts to it.

The new study, published on Thursday in Science magazine, was relatively simple. Scientists tested 79 monkeys from Bioko, a volcanic island 19 miles off the West African coast. Bioko used to be the end of a peninsula what is now Cameroon, but it was cut off when sea levels went up 10,000 years ago.

Since then, six monkey species have developed in isolation on the island, and scientists found that four of them were infected with SIV. The disease must have existed before Bioko was cut off.

AIDS is obviously very new to us. If it had been in humans before the 20th century, it would have arrived in America in some of the 12 million Africans carried as slaves.
Adapted from an article by Donald G. McNeil in The New York Times. Picture by Tim Laman.

Skin cells converted to heart muscle cells

By simply switching on three critical genes, scientists turned mouse skin cells into heart muscle cells. So far, this has been only possible with embryonic cells.

If the technique works in humans, it could provide new heart muscle for the millions of people who suffer from heart failure each year. It is also a new example of a process called 'transdifferentiation', in which adult cells take on an entirely different identity.

Once it is damaged, heart muscle cannot repair itself. Further damage makes the heart weaker, eventually causing it to fail. In the United States, 5 million patients have heart failure, but only 2,000 heart transplants are performed each year.

A team of scientists searched for genes that are expressed at high levels in heart muscle cells, and then narrowed the list down to three that were sufficient to convert another type of heart cell, structural cells called cardiac fibroblasts, into heart muscle cells. Activating those three genes was sufficient to convert the cardiac fibroblasts or similar cells in skin to heart muscle cells. When implanted into mouse hearts, the cells made from cardiac fibroblasts contracted normally.

The results raise the possibility that a similar approach could be used to convert cardiac fibroblasts already in the heart to muscle cells, without the need for cell transplants. The team is now investigating whether the same three genes are enough to switch cell identity in humans. 

Adapted from an article by Heidi Ledford in Nature. IStockphoto

Early puberty in girls related to absent fathers

Children getting older while they are still young is not just a cultural phenomenon. Girls are literally reaching puberty at a younger age, and alarming doctors because it is associated with a higher incidence of breast cancer.

Now a new study has suggested that fathers may be important in how their daughters mature. Scientists from University of California have discovered that if a girl lives in a home without a biological father she will mature before those girls who live with their biological father. People had always assumed this was because girls in such homes had poorer diets and then higher body mass index, and weight boosts early puberty.

But here's the mystery: early puberty is more frequent among white non-Hispanic girls who live in relatively rich homes. And the absent father effect was there even taking into account the weight factor.

Some explanations are suggested for the absent father effect. Perhaps there are other men in the home, stepfathers or boyfriends, whose pheromones start the girls' biological clocks. But that is not so clear, because the presence of other men in the home didn't alter the results. Maturing early is a reaction to the instability. Artificial light from computer screens and TVs increases the speed of puberty, and these are more prevalent in higher income single parent homes. And there's also a correlation between early puberty and some haircare treatments that contain placental products.

Perhaps the most controversial hypothesis is related to mothers, not fathers. A study published this week showed that the cause is very little emotional communication: mothers who have jobs don't spend much time at home.
Adapted from an article by Belinda Luscombe in Time Magazine. Photo by Bill Davila / Filmmagic

Asian unicorn seen for the first time in a decade

One of the world's rarest animals, the saola, knwon as the "Asian unicorn", has been seen for the forst time in more than a decade. However, the animal died after been captured by villagers in a remote region of Laos.

The critically endangered mammal, which is found in the mountains of Vietnam and Laos, was first discovered in 1992. It looks similar to the antelopes of North Africa, but is more closely related to wild bulls and cows. It is so difficult to see that it has been compared to the unicorn, although it has two horns. It has never been seen by conservation experts in the wild and the last confirmed sighting was from camera traps in 1999.

The animal is listed as critically endangered, with just a few hundred thought to exist in the wild. Conservationists said that with none in zoos and almost nothing known about how to keep them in captivity, if the species disappear in the wild they will be extinct.

The Laos government said villagers in the country's central province of Bolikhamxay captured the saola in late August and brought it back to their village. A team was sent to examine and release the animal. Unfortunately the adult male saola was weakened by several days in captivity and died shortly after the team reached the remote village. It was photographed while still alive.

It is not clear why the villagers, who found the animal in the village's sacred forest, took the saola into captivity, but the authorities are asking farmers in the area not to capture them.

Adapted from an article in The Telegraph. Picture: PA.

2010 on the way to be record-hot year

After eight months, 2010 is running with 1998 for the record as the hottest year at this point.

The planet's temperature for January-August was 14.7 Celsius, the same as the record heat set for that period in 1998. While 1998 was the hottest year through the first eight months, 2005 is the hottest full year on record.

It was the third-hottest August on record with an average temperature for the month of 16.2 C. The hottest August was 1998, followed by 2009. The meteorological summer — June-August — was 16.2 C, making it the second-hottest summer on record worldwide behind 1998.

Meanwhile, a separate report said Arctic sea ice cover appears to have reached its minimum extent for the year and is the third-lowest extent recorded since satellites began measuring minimum sea ice extent in 1979.

Arctic sea ice covered 6.0 million square kilometers during August. This is 22 percent under the 1979-2000 extent and the 14th consecutive August with below-average Arctic sea ice extent.

Melting sea ice is part of a pattern of changes atmospheric scientists attribute to global warming, which has been documented in rising temperatures over the last several decades. Other changes include melting ice in Greenland and Antarctica, which can make sea levels rise, a decline in glaciers and changes in weather patterns around the world.
Adapted from an article by Cass Bird for Time Magazine. Picture by Jim Elliott.

Good news for cancer treatment

Scientists are really happy with a new drug that uses genetic data to fight the formation of specific tumours. Hopefully, drug manufacturers will be able to create drugs to individual cancers that will stop them and even reverse the growth of existing tumours. It is one of the most significant advances in our knowledge of DNA to deal with the root causes of disease.

For years scientists have been assembling vast amounts of genetic information through the human genome sequencing project. As part of the latest investigation, scientists in California developed a drug to block the effects of a specific gene mutation, B-RAF, linked to malignant melanoma – one of the most dangerous cancers. In a recent test, tumours diminished by at least 30 per cent in 24 out of 32 patients with B-RAF mutations, and disappeared entirely in two other patients.

A study of the chemical process behind the drug demonstrates the potential for quick development of similar treatments dealing with the particular genetic mutations that affect different types of tumour. The pharmaceutical company Plexxikon is now working on a test that can diagnose which patients suffering from malignant melanoma have the B-RAF mutation and would benefit from the drug.

Sir Mark Walport, director of the Wellcome Trust, agreed with suggestions that the discovery was a ‘penicillin moment’ for cancer researchers. However, he added that the fight against the illness is not finished yet. In fact, cancer is complicated.

 Adapted from an article by Alastair Jamieson in The Telegraph. Picture of human melanoma cells by Getty Images.

The price of happiness

What makes us happy? According to the testimonies of the people who describe themselves as contented, you need to be highly educated, female, rich, married, self-employed and not middle-aged. The booming discipline of 'happiness studies' continues to cause controversy. Questions abound over cause and effect — for example, are people happier when they marry, or do happy people marry?

One of the most controversial topics for those measuring happiness is its relationship to income. Most people would agree that poverty is miserable, but the relationship is not clear above that unfortunate state. Because being female or married are all-or-nothing factors, but income is quantitative: if being rich makes you happy, does being richer make you more happy?

In an article in the Proceedings of the National Academy of Sciences USA Nobel laureate economist Daniel Kahneman and his colleague Angus Deaton at Princeton University use the US data from the Gallup survey to argue that income continues to impact on our evaluation of 'life satisfaction' as we enter the state of the rich. Although reported well-being generally goes up with income, this relationship stops going up at an income of around $75,000 (about €60,000) a year.

Although some could extract the conclusion that, as The New York Times said, "maybe money buys happiness after all", perhaps better education, secure health provision, lowering of stress, and the nurturing of social and familial relationships offer a greater dividend of smiles.
 Adapted from an article by Philip Ball.

Climate wars

Does climate change make conflict in Africa more likely?

In his popular 2008 book Climate Wars, the US journalist Gwynne Dyer depicted a terrible scenario. Climate change would put pressure on fresh water and food over the next hundred years, he wrote, causing social disorder, mass migration and violent conflict.

But is there real evidence of a link between climate change and civil war — particularly in parts of Africa?

Yes, a study published last year said they had found a causal connection between climate warming and civil violence in Africa. Marshall Burke, an economist at the University of California, Berkeley, and colleagues, reported a strong historical relationship between temperature and the incidence of civil war. They found that the possibility of armed conflict across the continent went up by around 50% in unusually warm years during 1981-2002.

No, says Halvard Buhaug, a political scientist with the Peace Research Institute Oslo in Norway. In research just published in Proceedings of the National Academy of Sciences, he finds virtually no correlation between climate-change indicators such as temperature and rainfall variability and the frequency of civil wars over the past 50 years in sub-Saharan Africa, possibly the part of the world that is socially and environmentally most vulnerable to climate change.

The two rival groups are now disputing the validity of each other's findings. Perhaps more research is needed to know who is right in such a highly controversial issue...
 Adapted from an article by Quirn Schiermeier in Nature (picture:  Ismail Taxta / Reuters / Corbis)

Feathers appeared long before we thought

A predatory dinosaur with bumps on its arms and a strange hump on its back gives evidence that feathers began to appear earlier than scientists thought, according to an article in Nature.

The new species, named Concavenator corcovatus, was about 4 m long from nose to tail and lived during the Early Cretaceous period, about 130 million years ago. Paleontologist Francisco Ortega, of the National University of Distance Learning in Madrid (UNED), found the fossil in a place called Las Hoyas, Cuenca, which was a subtropical wetland during the Early Cretaceous.

But it is the bumps on the dinosaur's arms that have shocked the scientific community: they may have been part of structures with feathers on the creature's bones.

One branch of the dinosaur family tree, called the Coelurosauria, is already known to have developed feathers structures. That lineage, which includes the dinosaur celebrities Tyrannosaurus Rex and Velociraptor, also contains the ancestors of modern-day birds. When Ortega and his team tried to place their find in the evolutionary tree, however, they found that the shape and texture of other bones placed it in the neighbouring branch of predators, the Allosauroidea, but nobody knew they had feathers.

Yet the bumps on Concavenator's arms "look exactly like insertions on rather massive flight feathers on bird wings", says Michael Benton, a palaeobiologist at the University of Bristol, UK.

All this implies that dinosaurs are more and more being considered birds!

Adapted from an article by Lucas Laursen (picture by Raúl Martín)

Artificial plants escape!

A genetically modified (GM) plant has been found living in the wild for the first time in the United States.

GM canola is usually grown to produce edible oil that is good for human consumption. Farmers have increased their use of genetically modified crops since the plants were introduced in the early 1990s. Last year, nearly half the world's GM plants were grown in the USA.

A scientific team found two varieties of transgenic canola in the wild — one modified to be resistant to a herbicide (glyphosate), and one resistant to a different one (gluphosinate). But what is really interesting is that they also found some plants that were resistant to both herbicides, showing that  a new plant had appeared with qualities that did not exist before!

Populations of herbicide-resistant canola were found growing along roads, near petrol stations and grocery stores, often at large distances from areas of agricultural production. The number of canola plants was counted, and one plant was collected and tested for the presence of proteins that could give it resistance to either of the herbicides.

New studies are needed to establish whether these escaped GM canola plants have any ecological consequences. But those that have evolved resistance to both herbicides could become a problem for farmers because they could substitute whole populations of conventional canola plants.

What's next? What happens when an alien population of plants or animals makes the previous ones disappear?

Adapted from an article in Nature by Natasha Gilbert and different pages and pictures from Wikipedia.