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Genetically engineered mosquitoes pass lethal gene to offspring

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  • Scientists carry out ‘positive’ trial on Cayman Islands
  • New breed of insect could be used to tackle malaria and dengue fever
  • But critics say it could lead to public health problems

Breakthrough or danger? A UK-based research team has found a way of genetically modifying the Aedes aegypti mosquito so they pass on a deadly gene to their offspring

Breakthrough or danger? A UK-based research team has found a way of genetically modifying the Aedes aegypti mosquito so they pass on a deadly gene to their offspring

Serious concerns have been raised over the release of a new breed of disease-fighting mosquito which has been genetically engineered to kill their own offspring.

There are hopes the project could be used to control agricultural pests and tackle deadly insect-borne illnesses such as dengue fever and malaria.

But the research has raised concerns about the possible side-effects on public health and the environment because, once released, the mosquitos cannot be recalled.

A UK-based scientific team revealed there had been positive signs from the first release into the environment of the mosquitoes, which are engineered to pass a lethal gene onto their offspring, killing them before adulthood.

The study team – which includes experts from Imperial College London and the Liverpool School of Tropical Medicine – released batches of modified mosquitoes in an area of the Cayman Islands where the dengue virus-carrying Aedes aegypti mosquito is common.

The study, published in Nature Biotechnology journal, looked at how successfully the lab-reared, genetically modified insects could mate.

About 19,000 mosquitoes engineered in a lab were released over four weeks in 2009 in a 25-acre area on Grand Cayman island.

Based on data from traps, the genetically engineered males accounted for 16per cent of the overall male population in the test zone, and the lethal gene was found in almost 10 percent of larvae.

Those figures suggest the genetically engineered males were about half as successful in mating as wild ones, a rate sufficient to suppress the population.

Disease fighter? The new breed of mosquitoes could be used to tackle killer illnesses like dengue fever and malaria which affect the world's poorest populations

Disease fighter?  The new breed of mosquitoes could be used to tackle killer illnesses like dengue fever and malaria which affect the world’s poorest populations

Luke Alphey, chief scientific officer at Oxitec, the firm which devised the technique, told the BBC: ‘We were really surprised how well they did.

‘For this method, you just need to get a reasonable proportion of the females to mate with GM males – you’ll never get the males as competitive as the wild ones, but they don’t have to be, they just have to be reasonably good.’

HOW MOSQUITOES KILL THEIR OWN CHILDREN

  • The genetic approach used to create the mosquitoes is a system known as tetracycline-controlled transcriptional activation (tTA).
  • The technique is an extension of one successfully used for decades to control or eradicate pests which involves sterilising millions of insects with radiation.
  • But the process has not worked with mosquitoes, partly because the radiation also injures them, making it difficult for them to compete with healthy counterparts for mates.
  • So Oxitec has now created the Aedes aegypti mosquitoes with a gene that will kill them unless they are given the common antibiotic tetracycline.
  • With tetracycline provided in the lab, the mosquitoes can be bred for generations and multiplied.
  • Males are then released into the wild, where tetracycline is not available.
  • They live long enough to mate but their progeny will die before adulthood.

 

Authorities in the Florida Keys hope to carry out an open-air test on the modified insects as early as December after experiencing the region’s first cases of dengue fever in decades.

Dr Alphey said the technique was safe because only males were released as it was only the females that bite people and spread the disease.

But critics say the process is by no means foolproof.

Alfred Handler, a geneticist at the Agriculture Department in Gainesville, Florida, said the mosquitoes can evolve resistance to the lethal gene while being bred for generations in a lab.

Todd Shelly, an entomologist for the Agriculture Department in Hawaii, also said in a commentary published on Sunday by Nature Biotechnology that 3.5per cent of the insects in a lab test survived to adulthood despite presumably carrying the lethal gene.

Also, the sorting of male and female mosquitoes, which is done by hand, can result in up to 0.5per cent of the released insects being female, the commentary said.

If millions of mosquitoes were released, even that small percentage of females could lead to a temporary increase in disease spread, it was reported by the New York Times.

Oxitec and a molecular biologist, Anthony A. James of the University of California, Irvine, say they have developed a solution — a genetic modification that makes female mosquitoes, but not males, unable to fly.

The grounded females cannot mate or bite people, and separating males from females before release would be easier.

The World Health Organisation expects to release guidance on how GM insects should be deployed in developing countries by the end of the year.

 

Via DailyMail

Immune System Trained to Kill Cancer

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A year ago, when chemotherapy stopped working against his leukemia, William Ludwig signed up to be the first patient treated in a bold experiment at the University of Pennsylvania. Mr. Ludwig, then 65, a retired corrections officer from Bridgeton, N.J., felt his life draining away and thought he had nothing to lose.

Doctors removed a billion of his T-cells — a type of white blood cell that fights viruses andtumors — and gave them new genes that would program the cells to attack his cancer. Then the altered cells were dripped back into Mr. Ludwig’s veins.

At first, nothing happened. But after 10 days, hell broke loose in his hospital room. He began shaking with chills. His temperature shot up. Hisblood pressure shot down. He became so ill that doctors moved him into intensive care and warned that he might die. His family gathered at the hospital, fearing the worst.

A few weeks later, the fevers were gone. And so was the leukemia.

There was no trace of it anywhere — no leukemic cells in his blood or bone marrow, no more bulging lymph nodes on his CT scan. His doctors calculated that the treatment had killed off two pounds of cancer cells.

A year later, Mr. Ludwig is still in complete remission. Before, there were days when he could barely get out of bed; now, he plays golf and does yard work.

“I have my life back,” he said.

Mr. Ludwig’s doctors have not claimed that he is cured — it is too soon to tell — nor have they declared victory over leukemia on the basis of this experiment, which involved only three patients. The research, they say, has far to go; the treatment is still experimental, not available outside of studies.

But scientists say the treatment that helped Mr. Ludwig, described recently in The New England Journal of Medicine and Science Translational Medicine, may signify a turning point in the long struggle to develop effective gene therapies against cancer. And not just for leukemia patients: other cancers may also be vulnerable to this novel approach — which employs a disabled form of H.I.V.-1, the virus that causes AIDS, to carry cancer-fighting genes into the patients’ T-cells. In essence, the team is using gene therapy to accomplish something that researchers have hoped to do for decades: train a person’s own immune system to kill cancer cells.

Two other patients have undergone the experimental treatment. One had a partial remission: his disease lessened but did not go away completely. Another had a complete remission. All three had had advanced chronic lymphocytic leukemia and had run out of chemotherapy options. Usually, the only hope for a remission in such cases is a bone-marrow transplant, but these patients were not candidates for it.

Dr. Carl June, who led the research and directs translational medicine in the Abramson Cancer Center at the University of Pennsylvania, said that the results stunned even him and his colleagues, Dr. David L. Porter, Bruce Levine and Michael Kalos. They had hoped to see some benefit but had not dared dream of complete, prolonged remissions. Indeed, when Mr. Ludwig began running fevers, the doctors did not realize at first that it was a sign that his T-cells were engaged in a furious battle with his cancer.

Other experts in the field said the results were a major advance.

“It’s great work,” said Dr. Walter J. Urba of the Providence Cancer Center and Earle A. Chiles Research Institute in Portland, Ore. He called the patients’ recoveries remarkable, exciting and significant. “I feel very positive about this new technology. Conceptually, it’s very, very big.”

Dr. Urba said he thought the approach would ultimately be used against other types of cancer as well as leukemia and lymphoma. But he cautioned, “For patients today, we’re not there yet.” And he added the usual scientific caveat: To be considered valid, the results must be repeated in more patients, and by other research teams.

Dr. June called the techniques “a harvest of the information from the molecular biology revolution over the past two decades.”

Hitting a Genetic Jackpot

To make T-cells search out and destroy cancer, researchers must equip them to do several tasks: recognize the cancer, attack it, multiply, and live on inside the patient. A number of research groups have been trying to do this, but the T-cells they engineered could not accomplish all the tasks. As a result, the cells’ ability to fight tumors has generally been temporary.

The University of Pennsylvania team seems to have hit all the targets at once. Inside the patients, the T-cells modified by the researchers multiplied to 1,000 to 10,000 times the number infused, wiped out the cancer and then gradually diminished, leaving a population of “memory” cells that can quickly proliferate again if needed.

The researchers said they were not sure which parts of their strategy made it work — special cell-culturing techniques, the use of H.I.V.-1 to carry new genes into the T-cells, or the particular pieces of DNA that they selected to reprogram the T-cells.

The concept of doctoring T-cells genetically was first developed in the 1980s by Dr. Zelig Eshhar at the Weizmann Institute of Science in Rehovot, Israel. It involves adding gene sequences from different sources to enable the T-cells to produce what researchers call chimeric antigen receptors, or CARs — protein complexes that transform the cells into, in Dr. June’s words, “serial killers.”

 

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Japan’s citizen scientists map radiation, DIY-style

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With the Japanese government only providing spotty information about the radiation leaking from the damaged Fukushima nuclear plant in the early days after the devastating March 11 earthquake and tsunami, a group of tech-minded citizen scientists set out to fill in the “black holes” in the knowledge base.

They did so by crafting their own Geiger counters and handing them out to volunteers in the disaster area to measure the fallout. Months later, they have assembled thousands of radiation readings plotted on maps that they hope will one day be an invaluable resource for researchers studying the impact of the meltdown at the crippled nuclear complex.

Volunteer Toshikatsu Watanabe, left, and Safecast’s Kalin Kozhuharov take radiation measurements in Koriyama, Japan.

The volunteer network of scientists, tech enthusiasts and residents of Japan collectively known as Safecast (an amalgam of “safety” and “broadcast”) sprang to life in the weeks after the devastating 9.0-magnitude earthquake and tsunami struck Japan, cutting off power to the Fukushima Daiichi Nuclear Power Station and knocking out its backup generators. That shut down the plant’s cooling system, triggering meltdowns or partial meltdowns in three of the plant’s four reactors, followed by explosions that released radioactive substances into the air and allowed contaminated water to leak into the ocean.

“For the scientific community, this is a huge chance to further understand what this all means,” said Pieter Franken, co-founder of Safecast and a senior researcher at Keio University in Tokyo, which is collaborating on the project. “Chernobyl was 25 years ago and delivered lots of information. But we’re now in the Internet age, and we have a huge opportunity to do a much better job in measuring it and tracking it.”

Residents in the surrounding areas were understandably alarmed, but in the early days after the disaster, information from the government came in bits and pieces, and was difficult to find.

Franken and Sean Bonner, a Los Angeles-based technology buff involved in numerous online citizen-involved projects, saw an opportunity to use technology to augment the government’s reports and to make the information widely available.

The pair found Uncorked Studios, a Portland, Ore., website development firm, which wanted to map the radiation numbers from all sources “to try to get a better picture of things on a larger scale,” Bonner said.

‘Unknowns’
The initial effort resulted in a map that revealed the dearth of information available: “We realized that there were some massive holes and that the data that was being published was not that specific,” said Bonner. “There would be one reading for an entire city. But we wouldn’t know exactly where in the city that reading was taken.”

With so many “unknowns,” the group decided to buy as many Geiger counters as possible and distribute them to people in the map’s “black holes,” Bonner said. But that wasn’t feasible because the supply of the radiation-measuring devices was limited, he  said.

So Safecast turned to a source they knew well: Hackerspaces, a loose confederation of high-tech tinkerers around the globe.

The TokyoHackerSpace had already drafted a to-do list in the disaster’s aftermath that included radiation monitoring. But with Safecast’s encouragement, the group stepped up its efforts. Members soon figured out how to build basic Geiger counters with Geiger tubes (which measure radiation) purchased through an initial fundraising campaign and modified so they could be attached to vehicles and upload data to the Internet, Christopher Wang, a specialist in sensor networks also known by his hacker nickname of “Akiba,” wrote in an email to msnbc.com.

After meeting Safecast, the hackers decided the best use of the jury-rigged devices would be to drive around taking measurements, allowing one “Geiger counter to cover a huge amount of range,” Wang wrote.

“We put together a custom circuit board that would mount on the outside of a car and had GPS (for timestamp and location data), an input for the Geiger counter, an SD card slot (for data logging), and wireless communication (to send the data inside the car and let the driver know if they are in an area with high radiation),” he said.

Other hackerspaces around the world — such as CRASH space in Los Angeles — soon enlisted in the effort and before long Safecast had the resources to launch an ambitious measuring and mapping effort.

Components of the jury-rigged Geiger counters.

While signing up volunteers, Safecast also developed a training regimen so the recruits would be able to take reliable readings with the instruments and send the data to the group.

Having average citizens involved was crucial, Franken said.

“We want to bring the radiation levels to people’s doorstep, so people can see around their house what is happening,” he said.

Safecast took its first reading on April 16. Today, it has about 50 regular volunteers who collect data from their homes or while driving, build devices or assist in other ways. Those using vehicles equipped with Geiger counters cover an area that Franken estimates to be about 620 miles long by 185 miles wide. To date, they’ve collected 251,000 data points from their drives and fixed reporting stations, and have received about 60,000 more from other sources, including people with their own Geiger counters.

Safecast publishes the data on its website and publishes it to a number of other places so the information can be used by the greatest number of people, Bonner said. It also aggregates radiation data from a number of sources, including the Japanese government.

A Safecast map shows radiation readings from northeastern Japan.

The color-coded maps that Safecast has published don’t always agree with the government’s readings. But Franken said the effort isn’t intended to suggest that the government’s information is bad. The government currently has available a website with the readings of environmental radioactivity level by prefecture.

“We really don’t want to say that the government is wrong,” he said. “And, in fact, in many cases we find that the measurements are fairly much in sync where they are comparable — we have just much more data points and locations measured.”

For example, Safecast’s mapping has revealed some radiation hotspots far from the plant, while other areas closer to it show lower levels. This is due to local weather conditions and air flow, meaning distribution of radioactive materials is not just a matter of proximity, Franken said.

“It’s not so predictable and it really pays to go and map the whole area, and literally find areas that are higher or lower as we go,” he said, noting that in some cases radiation levels can vary by street and even within a home.

“It’s kind of a heavy task because it requires a certain amount of guts to go and do it,” he said of the volunteers, noting he had recently trained a woman and her 12-year-old son in Fukushima City how to measure radiation.

Anxiety
But knowing what the levels are has helped ease some of the anxiety over the radiation exposure, Franken said.

“The measurements may or may not affect people’s decisions but in many cases we see that it more or less gives a sense of confidence that this is what it is and, ‘yeah, I’m going to stay and this is probably going to be manageable,’ or ‘no, I really don’t want to take the risk for my family, I’m going to avoid this.’”

One of the volunteers helping in the effort is Brett Waterman, a 46-year-old Australian who runs an English-language after-school program for children nearly 30 miles from the Fukushima plant, in the city of Iwaki. He has been surveying the radiation levels using a Geiger counter mounted on his car.

“There are many people who have decided that the lack of information implied that there was too much risk so they just decided to leave,” he said.

But through his work, he has learned that the radiation levels were low in the area.

“We can’t see it, but if we map it out, like we are doing street by street, we can sort of start to see it in a sense. We can get a picture of what this radiation stuff is,” he said.

His 13-year-old son is a “significant motivator” for him to take the readings. He noted that though residents don’t yet know what the long-term effects of the radiation will be, the information will be key in the future.

“In 10 years or 20 years’ time, you can’t go back to three months after the event and then find out what the data was like. But if we record it now, and then we continue to record it over the months and years to come, then from a scientific and a community point of view there is a database that can be referenced.”

Some researchers and government agencies welcome Safecast’s endeavor. Andrew Maidment, associate professor of radiology at the Hospital of the University of Pennsylvania, said the efforts were “necessary and helpful,” though he added two “cautionary notes.”

“The first is that the data are only useful, if it is clear (1) how the measurements were performed and (2) exactly where the measurements are performed,” he wrote in an email to msnbc.com. “In general, it is very easy to get erroneous measurements; consistency in following a specific protocol and lots of practice are necessary to do this right. … However, I will say that the data looks consistent since there are repeated measurements and they are spatially correlated. The second problem is that interpretation of the data is hard. Thus, the use of a color code is questionable.”

Japan’s Ministry of Education, Culture, Sports, Science and Technology did not respond to emails and a call seeking comment on the project.

The U.S. Nuclear Regulatory Commission said it was not in a position to comment on the initiative, but public affairs officer Scott Burnell noted in an email: “Speaking very generally, significant training and specialized equipment is required to provide the most accurate surveying and analysis of radioactive materials in the environment.”

Franken said Safecast encouraged dialogue with critics and supporters: “We feel that it is good to have an independent measurement available to people … I think just having more is probably better,” he said.

And Bonner said the initiative has the potential to eventually extend far beyond Japan.

“What all of this did sort of brought to light the fact that this data doesn’t exist in the quantities that it should and is not as readily available as would be helpful,” he said. “So while Japan is the focus at the moment, you know, longer term we sort of are shifting to a global outlook. There is a lot more ground to cover once everything in Japan is wrapped up.”

 

Via MSNBC/Miranda Leitsinger

Microbe could make biofuels hot

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A 94°C geothermal pool, with a level-maintaining siphon, near Gerlach, Nevada. Sediment from the floor of this pool was enriched on pulverized miscanthus at 90°C and subsequently transferred to filter paper in order to isolate microbes able to subsist on cellulose alone.

A record-breaking microbe that thrives while munching plant material at near boiling temperatures has been discovered in a Nevada hot spring, researchers announced in a study published today.

Scientists are eyeing the microbe’s enzyme responsible for breaking down cellulose — called a cellulase — as a potential workhouse in the production of biofuels and other industrial processes.

Cellulose is a chain of linked sugar molecules that makes up the woody fiber of plants. To produce biofuels, enzymes are required to breakdown cellulose into its constituent sugars so that yeasts can then ferment them into the type of alcohol that makes cars (not people) go vroom.

At the industrial scale, this process is done most efficiently at high temperatures that kill other microbes that could otherwise contaminate the reaction, Douglas Clark, a chemical and biomolecular engineer at the University of California at Berkeley, told me today.

“So finding cellulases that can operate at those temperatures are of interest,” he said.

Hot spring
That’s what led Clark, microbiologist Frank Robb from the University of Maryland, and colleagues to collect sediment and water samples from the Great Boiling Springs near Gerlach, Nevada. The spring is 203 degrees F, just short of boiling.

“It’s on private land and has been surrounded by a low wall to keep cattle from going into it and that maintains the temperature,” Robb explained to me today, noting that most hot springs have varying temperatures depending on the weather and water levels in the spring.

In addition, a siphon has been added to Gerlach hot spring to keep it from overflowing. The combination gives whatever microbes that are in there no choice but to grow at high temperatures, Robb noted. Bits of grass and woody material blown into the spring serve as a food source.

The team grew microbes found in the samples on pulverized miscanthus, a type of grass that is a common biofuel feedstock, to isolate the microbes that grow with plant fiber as their only source of carbon.

They then sequenced the community of surviving microbes, which indicated three species of Archaea, a type of single celled microorganism, were able to utilize cellulose as food. Genetic techniques identified the specific cellulase involved in the breakdown of cellulose.

This cellulase, dubbed EBI-244, was found in the most abundant of the three Archaea.

“We didn’t really expect to find an organism that could grow at such a high temperature and degrade cellulose in this particular environment. But you never know,” Clark told me. “It really underscores the diversity of life. And, obviously, if you don’t look, you won’t find it.”

Too hot
The enzyme EBI-244 works optimally at 228 degrees F (109 degrees C), which is actually too hot for the efficient breakdown of cellulose into fermentable sugars due to side reactions that can occur, Clark noted.

“But it is interesting to know that such cellulases are out there,” Clark said. “And then this cellulase might also serve as a good starting point to be engineered to work at a lower temperature but maintain the high stability that it has naturally evolved to work at such high temperatures.”

Robb likened this engineering process to building a street car from parts used on cars found at the racetrack. “The enzyme itself could be the parts bin,” he said.

So, the enzyme itself probably won’t be hard at work anytime soon producing fuel to put in your gas tank, but it does lead researchers down the road to engineering the biofuels of the future. What’s more, EBI-244 is a record holder for heat tolerance in cellulase.

“It is always nice to have a record breaker,” Clark noted. “It adds to that wow factor a little bit.”

 

Via MSNBC

Mercury’s origins may differ from sister planets

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Mercury’s origins may be very different from its sister planets, including Earth, based on early findings that show surprisingly rich deposits of sulfur on the ground, scientists said on Thursday.

Early findings from the first spacecraft to orbit Mercury is forcing scientists to rethink how the planet closest to the sun formed and what has happened to it over the past 4 billion years.

NASA’s Mercury Surface, Space Environment, Geochemistry and Ranging spacecraft — nicknamed Messenger — is three months into a planned year-long mission. It has also uncovered evidence of a lopsided magnetic field and regular bursts of electrons jetting through the magnetosphere.

“It’s almost a new planet because we’ve never had this kind of observatory before,” said lead researcher Sean Solomon of the Carnegie Institution of Washington, D.C.

Volcanoes appear to have played a rather large role in shaping Mercury, providing fresh material to fill its cratered face, but also possibly providing an unexpected supply of sulfur to the surface, a finding that suggests Mercury may have had different building blocks than Venus, Earth and Mars.

Scientists expected that Mercury, which is believed to have formed in the hottest, densest part of the original solar nebula, wouldn’t have had the right temperatures to hang on to lighter-weight materials like sulfur.

“Elements like that are usually lost in space,” Solomon said. “The fact that we see sulfur from the surface points strongly that we had sulfur gases coming out.

“All of our simple ideas … a hot planet, easily depleted of volatiles … are not turning out to be the simple story we thought,” Solomon added.

New images from Messenger reveal a massive plain of ancient lava flow, the largest of which spans 400 million square kilometers, about half the size of the continental United States.

Another surprise was the planet’s lopsided magnetic field, which is stronger in the north than the south. Scientists can’t yet account for the asymmetry, but one theory is that the planet’s magnetic field is in the processing of flipping.

Mercury is the only terrestrial body besides Earth that has a magnetic field and one of the prime goals of the Messenger mission is to figure out how Mercury, which sports a massive iron core, was assembled. Scientists believe Mercury’s core, like Earth’s, is responsible for generating its magnetic field

Messenger also has been monitoring regular outbursts of electrons in Mercury’s magnetosphere. Hints of the phenomenon were first detected by NASA’s Mariner 10 probe, which flew past Mercury in 1974.

“We’re seeing these seeing these very dynamic phenomena in the magnetosphere. It’s very surprising and energetic,” Solomon said.

Still to come: measurements to reveal if Mercury hides ice insides its permanently shadowed craters.

 

Via DiscoveryOn

Forever young drug ? The pill that will keep you youthful by preventing the ills of old age

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Miracle cure? the pill could prevent many of the ills of old age A ‘forever young’ drug that allows people to grow old gracefully could be available in just ten years, a leading scientist said last night.

Professor Linda Partridge, an expert in the genetics of ageing, said that the science is moving so quickly that it will soon be possible to prevent many of the ills of old age.

By taking a pill a day from middle-age, we will grow old free from illnesses of the body and mind such as Alzheimer’s and heart disease.

People could work for longer – or simply make the most of their retirement. Some research even suggests skin and hair will retain its youthful lustre.

Professor Partridge, of University College London, said: ‘I would be surprised if there weren’t things within ten years. If told you could take a drug that has minimal side-effects and that’s going to keep you healthy for another five or ten years and then you’ll drop off your perch without disability, most people would want it.’

Extraordinary as the professor’s prediction may seem, it is based on a host of promising scientific studies from around the world.

They have discovered key genes linked to longevity and health – and found ways of tinkering with them, at least in animals.

In one of the remarkable examples, a Harvard University doctor made old mice young again, in experiments that mirrored the plot of The Curious Case Of Benjamin Button, where the lead character played by Brad Pitt ages in reverse.

At the start of the experiment, the animals’ skin, brains, guts and other organs resembled those of an 80-year-old person.

 

In development: One experiment saw a professor make old mice young again

In development: One experiment saw a professor make old mice young again.

Within just two months of being given a drug that switches on a key enzyme, the creatures had grown so many new cells that they had almost completely rejuvenated.

Remarkably, the male mice went from being infertile to fathering large litters.

Other research has shown that chains of reactions in the body involving insulin and related hormones are key to health and ageing. This means that years of research into diabetes could have yielded medicines that can be reinvented as anti-ageing drugs.

Professor Partridge told the Cheltenham Science Festival that some medicines abandoned by drug companies may soon be dusted off and put to use. She said:

‘There are drugs there already, some of them are just sitting in cupboards. I’d be surprised if people don’t start taking them out.

‘The principle is for drugs that if taken from middle-age will ward off quite a broad array of diseases rather than doing things piece-meal or acting when the diseases appear.’

However, she said any drugs would have to be shown to be extremely safe before they were given to healthy people to combat ageing.

 

 

Via DailyMail

Are we alien life forms ?

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A meteorite that exploded above Canada 11 years ago has provided strong evidence that life’s building blocks came from space.

Fragments of the rock that landed on Tagish Lake, British Columbia, yielded a mix of organic compounds.

They included amino acids and monocarboxylic acids, both essential to the evolution of the first simple life forms on Earth.

Analysis of the chemicals revealed information about their history on the asteroid from which the meteorite came, and lent weight to the theory that organic material originates in gas and dust clouds between the stars.

We are star dust: Lake Tagish in British Columbia yielded fragments of space rock that have led scientists to conclude that the building blocks of life originated in clouds of dust and gas between the stars

We are star dust: Lake Tagish in British Columbia yielded fragments of space rock that have led scientists to conclude that the building blocks of life originated in clouds of dust and gas between the stars.

If the theory is right, the building blocks of life would have been spread throughout our developing solar system.

They may, for example, also have provided a foothold for life on Mars.

Lead researcher Dr Chris Herd, of the University of Alberta, said: ‘The mix of pre-biotic molecules, so essential to jump-starting life, depended on what was happening out there in the asteroid belt.

‘The geology of an asteroid has an influence on what molecules actually make it to the surface of the Earth.’

The findings were published today in the journal Science.

Proof: Scientists now believe there is compelling evidence that human beings owe their existence to organic compounds found in deep space

Proof: Scientists now believe there is compelling evidence that human beings owe their existence to organic compounds found in deep space.

Experts are confident that the chemicals they analysed were not the result of contamination from the Earth.

Mark Sephton, a geochemist at Imperial College London, who was not involved in the study told The Scientist: ‘It’s real evidence of hydro-synthesis occurring in asteroids and creating compounds that might be biologically useful,’

Meteorite expert: Dr Chris Herd of the Department of Earth and Atmospheric Sciences at the University of Alberta
The four-metre-wide Tagish Lake meteorite exploded after heating up as it passed through the atmosphere 30 to 50 kilometres above the Earth.Pieces of the rock rained down on the frozen, snow-covered lake where they were preserved in sub-zero temperatures.

Water in the parent asteroid altered the organic compounds buried within it, leaving signatures that could be read in the meteorite fragments.

They indicated that the organic material had existed and undergone chemical processing since the birth of our solar system.

A man found nearly two pounds of the space rock in 2000 after the meteorite had exploded.

In order to preserve them and prevent any contamination he kept them frozen until 2008, when a consortium of Canadian research institutions bought them for $850,000.

 

 

Via DailyMail

Periodic table gains two elements

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Chemistry officials have confirmed the creation of two new elements – so now names will be given to elements 114 and 116.

The periodic table has two new heavyweights, elements 114 and 116, according to a committee of international chemists and physicists.

The elements are fleeting — they are created by bombarding lighter elements together and exist for less than a second before undergoing radioactive decay.

Such a short lifespan means that we can’t say much about them other than they really do exist.

“The lifetimes of these things have to be reasonably long so you can study the chemistry — meaning, pushing a minute,” Paul Karol  of Carnegie Mellon University in Pittsburgh, who chaired the committee that approved the new elements, told New Scientist.

The evidence for element’s existence has been mounting for more than a decade. In 1999, for example, Russian scientists with the Joint Institute for Nuclear Research bombarded plutonium-244 with calcium-48 to produce a single atom of 114, which has an atomic weight of 289.

Further collaboration between Russian and U.S. scientists at the Lawrence Livermore National Laboratory resulted in papers published in 2004 and 2006 on the creation of the elements 114, 116, and the yet-to-be-approved 118.

To create 116, the researchers smashed together curium atoms, which have 96 protons in their nucleui, with calcium nuclei, which have 20 protons. This lasted a few milliseconds before decaying into 114, which in turn decayed into copernicum, element 112.

These papers served as the basis for review by the International Union of Pure and Applied Chemistry, which made the formal announcement of the new elements on June 1 with the publication of a paper in Pure Applied Chemistry.

The elements currently go by the placeholder names ununquadium and unuhexium, which by IUPAC convention are derived from the digits 114 and 116.

The Russian discovery team at JINR has proposed flerovium for 114, after Soviet element finder Georgy Flyorov, and muscovium for 116, after Russia’s Moscow region, according to Wired.

The committee also reviewed claims associated with elements 113, 115, and 118, but found they are not yet conclusive and thus do not meet the criteria for discovery.

For more information on how the elements were discovered and the review process, check out the video above from the University of Nottingham’s Periodic Table of Videos series.

 

 

– John Roach

Via MSNBC

Does the Uranian gas giant contain the fuel required for an interstellar trek?

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Project Icarus: The Gas Mines of Uranus

Project Icarus is an ambitious five-year study into launching an unmanned spacecraft to an interstellar destination. Headed by the Tau Zero Foundation and British Interplanetary Society, a non-profit group of scientists dedicated to interstellar spaceflight, Icarus is working to develop a spacecraft that can travel to a nearby star.

Adam Crowl, Module Lead for Fuel and Fuel Acquisition for Project Icarus, investigates the pros and cons of various fusion fuels required to accelerate an interstellar vehicle to a nearby star.

How a Uranian mining operation may look -- balloons harvesting helium-3 for domestic energy needs and interstellar travel.

One might think that fusion propulsion requires some exotic fuel to propel a rocket a million-or-so-times more energetically than standard chemical fuels. However, one fusion fuel option isn’t so exotic.

In fact, by drinking the recommended 8 glasses of water per day you’ve ingested about half a pound of the stuff: hydrogen. One-ninth of all water on Earth is hydrogen. But there’s a snag in its widespread adoption as a fusion fuel.

Regular hydrogen fuses very, very slowly even in a place as unimaginably hot as the center of the sun. That’s fortunate for all life on Earth — because that’s what allows stars to shine for billions of years — but it does make it a very difficult fusion fuel to utilize.

But there’s an answer: Add a neutron to the single proton in the heart of every hydrogen atom and you have deuterium, also known as “heavy hydrogen.”

Deuterium is incredibly easy to fuse compared to hydrogen and most of the sun’s energy actually comes from fusing it. Inside the sun, deuterium is continuously made by banging two protons (hydrogen nuclei) together fast enough for one to become a neutron and stick to the other, and once made it fuses with another deuterium in less than a second.

Thus, no deuterium accumulates in the sun and in the rest of the natural world it’s relatively rare — 1 in every 6,500 atoms of the hydrogen we drink is deuterium. However, because deuterium, in so-called “Heavy-Water,” is used to moderate neutrons in some nuclear reactor designs, it is separated from regular water on a large scale.

Pure deuterium can already be fused by technological means and was used in the first hydrogen bomb detonated in 1952, but fusing it with tritium (hydrogen with two neutrons, so it’s heavier than deuterium) is even easier and this is the preferred reaction used by fusion research today.

Unfortunately, if this method was used to fuel a starship — such as the Icarus interstellar vehicle — the deuterium-tritium (D-T) reaction produces high-energy neutrons that transfer heat from the reaction directly to the engine’s structure. About 80 percent of the fusion energy released is in the form of those neutrons, so the reaction isn’t very healthy (or useful) for a starship.

Pure deuterium reactions also produce neutrons, though only about 1/3 of the fusion energy is released as such. That’s better than the D-T reaction, but when we’re talking about engine powers in the hundreds of gigawatts to terawatts, then such percentages mean gigawatts of heat that must be gotten rid of, adding to the mass of the engines and degrading the overall performance.

Seeking Helium-3

Fusion physics knows of other reactions. The reaction of boron-11 (an isotope of boron) and plain hydrogen produces all its energy in the form of charged particles which can be directed by a magnetic field, but the reaction is very difficult to sustain and many fusion physicists doubt it will ever prove practical. If it was successfully demonstrated as a viable fuel option, then the fuel mixture could be stored in solid form as decaborane, which remains solid below 100 degrees Celsius.

However, there is a very attractive reaction between deuterium and a light isotope of helium known as helium-3. Helium-3 has one less neutron than regular helium (helium-4) and is also produced in the sun and almost as quickly consumed in fusion reactions as deuterium.

Like deuterium, it is rare relative to helium-4, but, unlike hydrogen, helium doesn’t form chemical compounds as abundant as water. Almost all Earth’s helium has long since blown away and only small amounts are available on the planet — much of it can be found in the gas mines of North America. What helium is available is depleted in helium-3 relative to what we see in the sun, because most of Earth’s helium-4 is freshly made via natural radioactive decay of the elements uranium and thorium.

We know the sun contains lots of helium, and as the solar wind has been depositing helium into the rocky surface of the moon, perhaps we can extract it. Just how much is available can presently only be estimated at somewhere between 1 million and 2.5 million tons.

To extract it would require digging up much of the moon’s upper few feet of soil and baking the soil to release the solar wind-implanted gases. Project Icarus Consultant, Bob Parkinson, has examined this resource and, surprisingly, concluded it might take more energy to extract than would be produced by fusing the helium-3 liberated.

The Gas Mines of Uranus

However, there is a surprising amount of helium-3 in the gas giant planets of the outer solar system, and in the original 1978 “Project Daedalus” report Bob Parkinson suggested mining it via floating robotic factories in the atmosphere of Jupiter. Since then a different planet has moved to the forefront of gas-mining plans because it lacks Jupiter’s intense gravity, Saturn’s gigantic rings of orbital debris and is closer than distant Neptune.

You guessed it; the best helium-3 supply in the solar system is from the “Gas Mines” of Uranus.

That the planet which is the butt of so many poor jokes should be relatively rich in methane as well is purely coincidental, but as a mining site it has several advantages. The surface gravity, which is defined from the 1 bar pressure level in a gas giant’s atmosphere, is 90 percent that of Earth’s and the speed needed to reach low orbit is lowest of all the gas planets. Uranus’s rings are also high, thin and not showering the atmosphere below with a hail of meteors, unlike Saturn’s.

Accessing the gas riches of Uranus will require nuclear power, however. Designs exist for nuclear powered ramjets that could fly indefinitely in the atmospheres of the gas giants — this might prove a viable means of keeping an extraction factory aloft. Else we’ll be back to using balloons like “Project Daedalus,” serviced by nuclear ramjets.

An atmosphere composed of a cold gas mix that is lighter than helium and not much heavier than hydrogen, means that hot-air ballooning will need to be used. That the oldest technology of flight will find a role supporting the latest, fusion propulsion, has a certain poetic justice.

Getting the fuel home, where it can be used domestically as well as for tanking-up starships, could provide an early pay-off for developing a fusion propelled starship.

A Helium Market

The original “Daedalus” starprobe design had two stages. A Stage Two, by itself, would be well suited to being a deep space freighter, able to carry payloads of up to 500 tons at very high speed. Uranus is nearly three billion kilometers from the sun and Earth, thus traveling there, and back, requires a high-speed vehicle.

A Stage Two freighter could carry itself, with an empty mass of 500 tons, to Uranus in 70 days for just 114 tons of fuel, and then bring back a load of 614 tons using about 254 tons of fuel. Of the return load, 114 tons would be used to return the empty tanker to Uranus, while 500 tons would be used for starships and the terrestrial energy market.

A starprobe might launch by the year 2100 and if world energy demands continue to increase at their historic rate of 2.5 percent, then by 2100 about 14,000 tons of deuterium/helium-3 fuel-mix would supply the world’s energy demand per year, adding an incentive to develop the gas-mines of Uranus.

Alternatively, a means might be found to put the neutrons from pure deuterium fusion to good use. Some fusion ignition designs can confine the fusion neutrons in the dense plasma formed by the reaction, sharing their energy with the rest of the fusion plasma, thus reducing the damage to the reactor walls. If such a design can be successfully used for a starship engine, then a source of deuterium can be sought closer to home.

Unlike helium-3 we know the moon has large amounts of hydrogen, as ice, and a significant fraction of it will be deuterium. The moon’s low gravity also means that water composed of regular hydrogen and oxygen will escape quicker than heavy water, perhaps leading to a concentration of deuterium in the water of the moon. We won’t know until we return to the moon for a closer look.

Via Discovery

US approves new HIV drug

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The US Food and Drug Administration on Friday approved a new drug, Edurant, to fight HIV in combination with other antiretrovirals already on the market.

Made by the New Jersey based Tibotec Therapeutics, Edurant helps block the virus from replicating and is part of a class of drugs known as non-nucleoside reverse transcriptase inhibitor.

The pill is to be taken once daily with food, the FDA said.

“Patients may respond differently to various  or experience varied side effects,” said Edward Cox, director of the office of antimicrobial products in the FDA’s Center for Drug Evaluation and Research.

“FDA’s approval of Edurant provides an additional treatment option for patients who are starting .”

The approval followed phase II and II trials that showed that patients who had not received previous therapy saw an 83 percent lower viral load after they took Edurant along with other antiretroviral drugs.

Side effects included depression, insomnia, headache and rash.

(c) 2011 AFP

Via MedicalXpress