i-science77: May 2011

Research Team Maps Lab Mouse Genome

10:23 AM |

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Sharing about 95 percent of their genes with humans, mice are recognized around the world as the leading experimental model for studying human biology and disease. But, says Jackson Laboratory Professor Gary Churchill, Ph.D., researchers can learn even more “now that we really know what a laboratory mouse is, genetically speaking.”

Thanks to an in-depth analysis by a team led by Fernando Pardo-Manuel de Villena, PhD, in the University of North Carolina, Chapel Hill Department of Genetics and Gary Churchill, PhD, at The Jackson Laboratory in Bar Harbor, Maine, researchers will be able to use an online resource dubbed the Mouse Phylogeny Viewer to select from among 162 strains of laboratory mice for which the entire genome has been characterized.

Phylogeny is the connections among all groups of organisms as understood by genetic relationships. The results of the analysis that make this tool possible were published online today in the journal Nature Genetics.

“The viewer provides scientists with a visual tool where they can actually go and look at the genome of the mouse strains they are using or considering, compare the differences and similarities between strains and select the ones most likely to provide the basis for experimental results that can be more effectively extrapolated to the diverse human population,” explains Pardo-Manuel de Villena.

“As scientists use this resource to find ways to prevent and treat the genetic changes that cause cancer, heart disease, and a host of other ailments, the diversity of our lab experiments should be much easier to translate to humans,” he noted.

In 2004 Churchill and Pardo-Manuel de Villena launched the Collaborative Cross, a project to interbreed eight different strains--five of the classic inbred strains and three wild-derived strains. In 2009 Churchill’s lab started the Diversity Outbred mouse population with breeding stock selected from the Collaborative Cross project.

The research team estimates that the standard laboratory mouse strains carry about 12 million single nucleotide polymorphisms (SNPs), single-letter variations in the A, C, G or T bases of DNA.

The Collaborative Cross mice deliver a whopping 45 million SNPs, as much as four times the genetic variation in the human population. “All these variants give us a lot more handles into understanding the genome,” Churchill says.

“This work creates a remarkable foundation for understanding the genetics of the laboratory mouse, a critical model for studying human health,” said James Anderson, Ph.D., who oversees bioinformatics grants at the National Institutes of Health.

“Knowledge of the ancestry of the many strains of this invaluable model vertebrate will not only inform future experimentation but will allow a retrospective analysis of the huge amounts of data already collected,” he concluded.

Their analysis exponentially increases the data available to geneticists who work with mice, allowing them to statistically impute the whole mouse genome sequence with very high accuracy for hundreds of laboratory mouse strains. This will lead to much greater precision in the interpretation of existing biomedical data and optimal selection of strains in future experiments.

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Reindeer see a weird and wonderful world of ultraviolet light

9:24 AM |

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Researchers have discovered that the ultraviolet (UV) light that causes the temporary but painful condition of snow blindness in humans is life-saving for reindeer in the arctic.

A BBSRC-funded team at UCL has published a May 12 paper in the Journal of Experimental Biology that shows that this remarkable visual ability is part of the reindeer's unique adaptation to the extreme arctic environment where they live. It allows them to take in live-saving information in conditions where normal mammalian vision would make them vulnerable to starvation, predators and territorial conflict. It also raises the question of how reindeer protect their eyes from being damaged by UV, which is thought to be harmful to human vision.

Lead researcher Professor Glen Jeffery said "We discovered that reindeer can not only see ultraviolet light but they can also make sense of the image to find food and stay safe. Humans and almost all other mammals could never do this as our lenses just don't let UV through into the eye.

"In conditions where there is a lot of UV – when surrounded by snow, for example – it can be damaging to our eyes. In the process of blocking UV light from reaching the retina, our cornea and lens absorb its damaging energy and can be temporarily burned. The front of the eye becomes cloudy and so we call this snow blindness. Although this is normally reversible and plays a vital role to protect our sensitive retinas from potential damage, it is very painful."

Human beings are able to see light with wavelengths ranging from around 700nm, which corresponds to the colour red, right through all the colours of the rainbow in sequence to 400nm, which corresponds to violet. Professor Jeffery and his team tested the reindeer's vision to see what wavelengths they could see and found that they can handle wavelengths down to around 350-320nm, which is termed ultraviolet, or UV, because it exceeds the extreme of the so-called visible spectrum of colours.

The winter conditions in the arctic are very severe; the ground is covered in snow and the sun is very low on the horizon. At times the sun barely rises in the middle of the day, making it dark for most of the time. Under these conditions light is scattered such that the majority of light that reaches objects is blue or UV. In addition to this, snow can reflect up to 90% of the UV light that falls on it.

Professor Jeffery continued "When we used cameras that could pick up UV, we noticed that there are some very important things that absorb UV light and therefore appear black, contrasting strongly with the snow. This includes urine - a sign of predators or competitors; lichens - a major food source in winter; and fur, making predators such as wolves very easy to see despite being camouflaged to other animals that can't see UV."

This research raises some interesting questions about the effect of UV on eye health. It had always been assumed that human eyes don't let UV in because of the potential that it will cause damage, just as it does to our skin. In our eyes, UV could damage our sensitive photoreceptors that cannot be replaced. This would lead to irreversible damage to our vision. Arctic reindeer are able to let UV into their eyes and use the information effectively in their environment without suffering any consequences.

Professor Jeffery added "The question remains as to why the reindeer's eyes don't seem to be damaged by UV. Perhaps it's not as bad for eyes as we first thought? Or maybe they have a unique way of protecting themselves, which we could learn from and perhaps develop new strategies to prevent or treat the damage the UV can cause to humans."

Professor Douglas Kell, Chief Executive, BBSRC said "We can learn a lot from studying the fundamental biology of animals and other organisms that live in extreme environments. Understanding their cell and molecular biology, neuroscience, and other aspects of how they work can uncover the biological mechanism that meant they can cope with severe conditions. This knowledge can have an impact on animal welfare and has the potential to be taken forward to new developments that underpin human health and wellbeing."

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Germany hunts source of deadly E. coli

8:37 AM |

"Until experts in Germany and Spain are able to positively identify the source of the pathogen, general warnings about vegetables remain valid," Consumer Affairs Minister Ilse Aigner told the Bild am Sonntag newspaper.

"The relevant authorities are doing all they can to clear this up, nationally and internationally."

The European Commission said on Friday that organic cucumbers from southern Spain have been confirmed as a source of the outbreak of enterohaemorrhagic E. coli (EHEC) poisoning.

Germany's national disease institute, the Robert Koch Institute (RKI), has said two deaths were from haemolytic uraemic syndrome (HUS), a disease caused by EHEC that can lead to bloody diarrhoea and serious liver damage.

But there are eight other suspected HUS deaths, and the RKI has said that close to 300 people have contracted the disease in recent weeks. Normally about 60 people in Germany a year contract HUS.

Spanish authorities said Saturday they had introduced restrictions on two distributors. Andalusia's regional council said suspect batches had been withdrawn pending tests, results of which were due on Monday.

But the European Commission said a batch of cucumbers originating either in The Netherlands or in Denmark, and traded in Germany, was also under investigation.

The deaths included four fatalities announced on Saturday in the northern state of Schleswig-Holstein and in Hamburg, including three women in their 80s and a fourth in her 30s. Nine of those who have died so far are women.

The epicentre of the outbreak has been in northern Germany, with more than 1,000 people suspected of being infected, reports said. Several are said to be fighting for their lives.

Hospitals in the city of Hamburg, where more than 400 people are believed to have been infected with EHEC, were said to be overwhelmed and sending patients to clinics elsewhere.

In nearby Luebeck, a spokesman for the university hospital, where some 20 suspected HUS cases were being treated and where one patient has died, told AFP that staff were "close to exhaustion."

Sweden has reported 25 E. coli cases, of whom 10 developed HUS, according to the European Commission. Denmark reported seven E. coli cases (including three HUS) while Britain counted three cases (two HUS).

More cases have been reported in France, the Netherlands, Switzerland and Austria, where authorities ordered organic cucumbers, tomatoes and aubergines delivered from Germany but grown in Spain withdrawn in 33 shops.

Denmark's veterinary and food products agency said Friday it had found contaminated cucumbers from Spain in the stocks of two wholesalers in the west of the country and ordered them withdrawn.

The Czech Republic has imported a batch of tainted organic cucumbers from Spain, the CTK news agency said Saturday, citing the country's agriculture and food inspection authority SZPI.

The Stockholm-based European Centre for Disease Prevention and Control (ECDC) said Friday that all of these cases involved people who had recently been in northern Germany.

The RKI said last week that a study conducted with the Federal Institute for Risk Assessment (BfR) had shown that those affected had eaten significantly above-average amounts of tomatoes, lettuce and cucumbers.

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NASA to explore potentially deadly space rock

8:01 AM |

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When it comes to visiting asteroids, NASA doesn't pick run-of-the-mill space rocks. The target of NASA's latest asteroid mission is not only thought to be rich in the building blocks of life, it also has a chance — although a remote one — of threatening Earth in the year 2182.

The asteroid 1999 RQ36 is the target of a new unmanned spacecraft, which NASA plans to launch in 2016 to collect a sample from the space rock and return it to Earth by 2023.

The mission's leaders spent a long time surveying possible destinations for the mission, and finally settled on 1999 RQ36. NASA calls the mission OSIRIS-Rex, which is short for Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer.

"We went through a whole series of selection criteria," OSIRIS-Rex's deputy principal investigator Dante Lauretta, a planetary scientist at the University of Arizona, told SPACE.com. "There are over 500,000 asteroids known. [1999 RQ36] looks really optimum."

A potentially dangerous asteroid

In addition to digging up clues about our solar system's history, the OSIRIS-Rex mission may be able to help Earth fend off potentially deadly space rocks. That's because asteroid 1999 RQ36 — which is about 1,900 feet (580 meters) wide — is public enemy No. 1 for space rock scientists.

"1999 RQ36 has the highest probability of impacting the Earth of any known Potentially Hazardous Asteroid," according to a mission proposal submitted to NASA by the OSIRIS-Rex in 2009.

A recent calculation found that the asteroid has a 1-in-1,800 chance of hitting Earth in the year 2170, and a 1-in-1,000 chanceof slamming into us in 2182.

While those are slim odds, they put 1999 RQ36 at the top of the danger list.

"I wouldn't go buy asteroid insurance," Lauretta said. "We're OK for 150 years or so. We're not saving the Earth from immediate danger."

Still, he said studying the asteroid and its orbit up close could help us better predict the risk, and outline a strategy to protect ourselves if necessary.

One reason the likelihood of Earth impact can't be better predicted is because scientists don't fully understand the Yarkovsky effect, which causes asteroids to accelerate slightly when they absorb sunlight and then re-emit it as heat.

"[1999 RQ36's] orbit is currently well known because of optical and radar data but the long-term motion is less well understood because of the poorly defined Yarkovsky effect," said Donald Yeomans, manager of NASA's Near-Earth Object Program Office, who is not directly involved with the OSIRIS-Rex mission. "This mission should allow a much better understanding of these effects once the asteroid's size, mass, rotation characteristics and thermal properties are studied."

Target: Asteroid 1999 RQ36

One of the most attractive features of asteroid 1999 RQ36 for scientists is its size: It is as large as five football fields, which means it won't be spinning too fast when OSIRIS-Rex approaches. The asteroid should also have a large supply of lose dirt, or regolith, on its surface for easy sampling.

1999 RQ36 is thought to be carbonaceous, or rich in carbon and organic material, and likely to contain some of the building blocks of life, such as the amino acids used to build the proteins vital to life on Earth.

"We cannot tell from telescopes exactly what kind of material, but we believe it's the sort of stuff that came in through the Earth's atmosphere after liquid oceans first formed, perhaps by 4.45 billion years ago, and provided those building blocks," said OSIRIS-Rex principal investigator Mike Drake of the University of Arizona, during a news conference yesterday (May 25).

In fact, the asteroid is a primitive B-class carbonaceous asteroid, a class that has never been studied up close by a spacecraft before, and should provide an unprecedented opportunity to learn about the history of the solar system and the origin of life on Earth.

The material inside 1999 RQ36 is thought to date to the very formation of our solar system around 4.56 billion years ago. While the space rock now orbits relatively near Earth — making it a convenient target for visiting — scientists think it is a fragment of an even larger asteroid that collided with another rock in the main asteroid belt between Mars and Jupiter, a few million years ago.

Building on asteroid successes

The OSIRIS-Rex mission is not NASA's first mission to an asteroid, but it will be the first U.S. probe to retrieve samples and return them to Earth. Only Japan's Hayabusa spacecraft, which returned samples of the asteroid Itokawa to Earth in June 2010 after a seven-year journey, has performed a similar feat.

NASA has sent probes to visit asteroids before. The agency's NEAR spacecraft rendezvoused with the asteroid Eros and ultimately touched down on that space rock at the end of its mission in February 2001.

NASA's Dawn probe, meanwhile, is nearing the asteroid Vesta — the second-largest space rock in the asteroid belt. Dawn will orbit Vesta for many months, then head off to visit Ceres, the largest asteroid in the solar system.

But the NEAR and Dawn missions are only visiting asteroids. OSIRIS-Rex will bring pieces back home. And that has scientists brimming with anticipation.

"Asteroid 1999 RQ36 is a perfect target for sample return and I can't wait to see the exciting results from both the in situ science activities and the sample return analysis," Yeomans said.

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Another Forest Defender Falls in the Amazon

2:50 PM |

John Collins Rudolf has posted a thorough overview of the latest murder on the eroding perimeter of the Amazon rain forest in Brazil. There’s been enormous progress in efforts to bring governance to forest frontiers in Brazil since the late 1980s, when I spent months in the western Amazon reporting on the life and assassination of Chico Mendes for “The Burning Season,” my first book. But pistols and shotguns still sometimes blaze.

Here’s a video of a recent TEDx appearance of the new victim, José Cláudio Ribeiro da Silva, a forest activist and tree nut harvester who was gunned down on Tuesday along with his wife as they rode a motorcycle in Brazil’s still turbulent Para State (for English subtitles, press play, then engage the “cc” closed-captioning button):

Read on for the nut of Rudolf’s report and a link to the rest:

News of the slayings, emerging on the same day that Brazil’s parliament was to vote on a controversial revision of the country’s forest protection laws, rocketed through Brazil’s political classes. Within hours, senior government officials were briefed on the crime and President Dilma Rousseff had ordered an investigation by the federal police.

Yet whether that investigation results in punishment for the killers — or those who likely hired them — is deeply uncertain. More than 1,000 rural activists, small farmers, religious workers and others fighting the region’s rampant deforestation have been slain in the past 20 years, but only a handful of killers have ever been successfully prosecuted, according to a statement by the Pastoral Land Commission, a Catholic organization that tracks rural violence. [Read the rest.]

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Drug Helps Overwrite Bad Memories

9:13 AM |

Recalling painful memories while under the influence of the drug metyrapone reduces the brain’s ability to re-record the negative emotions associated with them, according to a study published in The Endocrine Society’s Journal of Clinical Endocrinology & Metabolism. The study by a team of University of Montreal researchers at the Centre for Studies on Human Stress of Louis-H. Lafontaine Hospital challenges the theory that memories cannot be modified once they are stored in the brain.

“Metyrapone is a drug that significantly decreases the levels of cortisol, a stress hormone that is involved in memory recall,” explained lead author Marie-France Marin. Manipulating cortisol close to the time of forming new memories can decrease the negative emotions that may be associated with them. “The results show that when we decrease stress hormone levels at the time of recall of a negative event, we can impair the memory for this negative event with a long-lasting effect,” said Dr. Sonia Lupien, who directed the research.

Thirty-three men participated in the study, which involved learning a story composed of neutral and negative events. Three days later, they were divided into three groups – participants in the first group received a single dose of metyrapone, the second received double, while the third were given placebo. They were then asked to remember the story. Their memory performance was then evaluated again four days later, once the drug had cleared out.. “We found that the men in the group who received two doses of metyrapone were impaired when retrieving the negative events of the story, while they showed no impairment recalling the neutral parts of the story,” Marin explained. “We were surprised that the decreased memory of negative information was still present once cortisol levels had returned to normal.”

The research offers hope to people suffering from syndromes such as post-traumatic stress disorder. “Our findings may help people deal with traumatic events by offering them the opportunity to ‘write-over’ the emotional part of their memories during therapy,” Marin said. One major hurdle, however, is the fact that metyrapone is no longer commercially produced. Nevertheless, the findings are very promising in terms of future clinical treatments. “Other drugs also decrease cortisol levels, and further studies with these compounds will enable us to gain a better understanding of the brain mechanisms involved in the modulation of negative memories.”

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Fertilizer wastage costs China 52 million tons of grain

8:44 AM |

This is the result of a study conducted by Xiaobin Wang of the Chinese Academy of Agricultural Sciences (CAAS) and the Wageningen UR agrotechnologist Willem Hoogmoed, as reported in this month's Journal of the Science of Food and Agriculture.

In the wealthy eastern part of China, farmers spread more than 180 kilogrammes of nitrogen on each hectare of their land. Excessive amounts of nitrogen cannot be absorbed by the crops; instead, they pollute the groundwater and the air. In the poorer western part of China, nitrogen use is below 100 and even 50 kilogrammes per hectare per year. If the eastern provinces were to limit their fertilizer use to 180 kilogrammes per year, the remainder - 1.2 million tons of nitrogen - could go to the poorer agriculture areas. That would result in additional grain production of 52 million tons, Wang calculates.

That would make quite a difference in the global grain market. For comparison, China currently produces about 500 million tons of grain annually, and the European Union produces about 130 million tons. The inefficient use of nitrogen is one of the major limiting factors in food supply in China, writes Wang.

The Chinese Academy of Agricultural Sciences is adviser to the agriculture ministry in Beijing. Its conclusions have already been shared among policy makers, says Hoogmoed. But the re-distribution of fertilizers has not yet been put into practice. The distance between China's capital city and its countryside is big, and every province has its own policy and fertiliser factories.

Provided by Wageningen University

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Lost Pyramids: Peering Beneath Egypt's Surface With Satellite Images

8:11 AM |

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To find the ancient Egyptian city of Tanis, Indiana Jones had to confront snakes and outsmart Nazis. Archeologist Sarah Parcak had it easier.

With satellite imagery (and more than a decade of experience), Parcak uncovered not just Tanis, but as many as 17 lost pyramids and thousands of tombs and settlements buried under an Egyptian floodplain.

"This just hints at the possibilities and the potential of the archeology of Egypt," said Parcak, an Egyptologist and assistant professor of archeology at the University of Alabama at Birmingham. "There's just so much there."

Funded with a grant from the BBC, which will air a documentary on the project next week, Parcak and her team spent more than a year poring over NASA and commercial satellite imagery of Egypt's Nile Valley Delta -- an area that covers thousands of square miles.

By looking at images of the surface in different wavelengths of light, they discovered differences on the ground that reveal the presence of ancient temples, houses and pyramids.

"All of a sudden, these features jump out at you," she said. "It's almost like you've got Superman or Superwoman X-ray vision and you're able to look at the world a little differently."

When you walk on the ground over an Egyptian floodplain, Parcak said, you can't see much more than a brown, silty surface. But pictures from satellites about 435 miles above Earth show the chemical changes in the soil caused by the mud brick walls used to build the hidden structures.

Satellite Imagery Lets Archeologists Peer Beneath Earth's Surface

Though the imagery showed a treasure trove of ancient antiquities buried 8 to 20 inches below the surface, Parcak emphasized that excavation or ground surveys still need to confirm their existence. But initial excavations have already validated some of her findings, including one pyramid.

Parcak said the idea to harness satellite technology came from her grandfather, a forestry professor who pioneered the use of aerial photography in his field.

"I grew up thinking that was just the coolest thing in the world because of my grandfather," she said.

When she got to college and started looking into applications of the technology in archeology, she said she found that very little work had been done.

Especially in an era of budget cuts and reduced travel, Parcak said her project shows that satellite technology can help archeologists explore remotely, strategically and more efficiently.

"I don't know that we have to think about excavations all the time," she said. "We can use the technology to help us zoom in on certain parts of sites."

Ultimately, Parcak said, satellite technology's greatest contribution to archeology is the breadth of information it's able to uncover more quickly.

By giving scientists an overview of a geographic area, it lets them turn their attention to the people and society that lived there, she said.

"To me, the most important part of ancient Egypt is the people," she said. "This information will hopefully allow us to ask different questions."

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Bacterial Meningitis Rates Fall

8:20 AM |

Just a few decades ago, a pediatrician getting a frantic phone call from a parent whose child was running a high fever would immediately consider bacterial meningitis. Today, that diagnosis is unlikely: Vaccination against meningitis-causing bacteria has slashed incidence of the deadly brain inflammation, a nationwide survey shows.

Click here to find out more!

Researchers scanned data from more than 17 million people nationwide and found that bacterial meningitis cases in the United States had fallen by 31 percent from 1998 to 2007, researchers report in the May 25 New England Journal of Medicine.

“For people taking care of kids since the 1980s, the world of meningitis has completely changed in the United States—and it’s because of two vaccines,” says Matthew Davis, a pediatrician at the University of Michigan Medical School who wasn’t part of the new study. Parents know these as Hib, the vaccine for Haemophilus influenzae type B, and PCV, for Streptococcus pneumoniae. These two microbes were historically among the chief causes of bacterial meningitis.

The first hit came in the 1980s and 1990s with the introduction of Hib, which remains a routine immunization for children. Then in 2000 the Food and Drug Administration approved a PCV vaccine called Prevnar-7 for S. pneumoniae, a microbe that can cause meningitis, pneumonia, ear infections and other ailments.

That vaccine has reduced meningitis due to S. pneumoniae by 26 percent between 1998 and 2007, the new data show. A recently approved version of the vaccine will reduce cases further by broadening coverage to 13 strains of the bacterium, predicts study coauthor William Schaffner, a physician at Vanderbilt University School of Medicine in Nashville.

A third vaccine, aimed at another meningitis bacterium, Neisseria meningitidis, was also approved in recent years. Called the meningococcal vaccine, it is commonly given at the start of adolescence and as a booster for college freshmen.

The new study suggests that giving these vaccines to kids has also limited meningitis outbreaks among adults, who are now less likely to catch the microbes from youngsters, says study coauthor Cynthia Whitney of the Centers for Disease Control and Prevention in Atlanta. Screening pregnant women for another kind of strep has further reduced cases.

Bacterial meningitis is treated with antibiotics, but the inflammation that it causes in the membrane covering the brain and spinal cord can be lethal. Although the number of cases has dwindled, the fatality rate for bacterial meningitis in the nationwide sampling remained around 15 percent. Even wiping out the bacteria with antibiotics doesn’t rescue some patients if inflammation has already caused chemical imbalances, intracranial pressure and nervous system dysfunction, Schaffner says.

The authors estimate that 4,100 cases of bacterial meningitis occur annually in the United States.

Meningitis can also arise from viruses. While viral meningitis is more common than bacterial, it is less likely to be fatal unless a person has a weakened immune system. Viral meningitis can stem from infections with enteroviruses, which include polio and coxsackie viruses, or other common viruses.

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Planet of Viruses

7:54 AM |

Prolific science writer Carl Zimmer has a new book out, A Planet of Viruses, from University of Chicago Press. Part of a series sponsored by the Science Education Partnership Award (SEPA) to help support educational outreach to students, the book packs into 109 pages just about everything you’ve always wanted to know–and a lot you’ll probably wish you didn’t know–about the viruses that have caused humanity so much grief throughout history.

Here follows a brief review of the book’s contents, and a short Q&A with the author.

Zimmer, who better than anyone else, weaves the history of science into every topic he tackles, takes a three part approach to the subject. Part One (Old Companions), conducts the reader on a brief history of viruses, how they were first reported, and how scientists began to develop methods to fight them, with three key players familiar to everyone: the Rhinovirus (which causes the common cold), the Influenza Virus (which causes the flu) and the Human Papillomavirus (which causes multiple diseases, including cervical cancer in women).

But viruses also play a very constructive role in life, and Part Two (Everywhere in All Things) examines bacteriophages–viruses that destroy bacteria; marine phages, which scientists believe have the potential to help develop new vaccines; and our own inner parasites, endogenous retro viruses, which are part of our evolutionary heritage.

For a sobering conclusion to the book, in Part Three (The Viral Future), Zimmer discusses the viruses that will continue to threaten humanity the most: HIV, West Nile Virus, SARS (Severe Acute Respiratory Syndrome) and Ebola (which presents in a frightening way like Edgar Allan Poe’s Red Death).

The author was kind enough to take some time from a daunting schedule of presentations and research to do a little Q&A.

Progressive Download (PD): Could you tell me a little about how you came to write this book. Were each of the chapters written separately for the SEPA’s project?

Carl Zimmer (CZ): I was invited to work on a SEPA project on viruses, which would explore new ways to get people–including high school students–interested in the science of viruses. We did all sorts of things, from radio programs to comic books. My main involvement was picking out a dozen viruses to write about; I chose each one to illuminate some important concept about viruses, such as how they infect hosts, or how they evolve to jump from one host species to another.

PD: Which chapter, or which virus, surprised you the most in the research and the writing?

CZ: I was most surprised by the last chapter in which I write about a weird bunch of viruses that are 100 times bigger than viruses were supposed to be. It’s amazing that these so-called “giant viruses” were hiding in plain sight for decades or perhaps centuries–because people thought they were bacteria. Now they turn out to be abundant and profoundly different than other forms of life. They may even represent an entirely new branch on the tree of life.

PD: I was struck by a point in chapter 1 on the rhinovirus and the inefficacy of most medications. My wife, an M.D. and researcher, would never let me give our kids even cough syrup when they would get a cold or headache–and she made the same point. They don’t work–and they may even make it worse.

CZ: It’s remarkable that we have yet to have a proven treatment for a disease as seemingly simple as the cold. We want a treatment so badly that we’ll even use medicines that don’t actually work.

PD: On phages as potential treatments (Enemy of Our Enemy). Do you know if there are there companies now that are working on development–or is it too early to predict what could be used?

CZ: I’ve co-blogged with Tim Lu of MIT about phage therapy at the University of Chicago blog. Things are just starting to take hold in phage therapy–but a lot of people are looking for non-medical treatments for now, because the regulatory process is so murky. But all the research suggests that phages could complement, or perhaps even replace, many antibiotics.

PD: Identifying new threats. I’m assuming that with the speed of whole genome sequencing continuing to accelerate, this will also be a major tool in helping scientists identify new viruses as soon as they sicken or kill someone in a ‘new’ way (i.e., presenting new symptoms).

CZ: Virus hunters are adopting the newest DNA-sequencing technology as soon as it becomes practical. These devices are letting them fish out tiny wisps of DNA from host tissues and identify viruses that we’ve never seen before.

PD: It seems likely, as you suggest, that viruses played a key role in the origin of life. It seems ironic today that life from non-life seems to be such a major “gap” to fill in. [In the middle ages, for example, it was taken for granted that living things could spontaneously generate from nonliving matter.] And perhaps viruses are a key to understanding what ultimately is a very fine transition between the two. Is that your view?

CZ: We still don’t have a definition of life–or, better still, a theory of life. But we won’t find either if we get too stuck on false dichotomies. Viruses have been declared not alive, and yet some giant viruses straddle the boundary. They aren’t just packets of genes. Their shells stay intact once they invade a host, they suck in molecules, and they spit out DNA and proteins–using enzymes once believed only to be carried by “true” life forms. That’s pretty close to being alive, I think.

PD: The way viruses have survived and evolved across species down through the eons really underscores the stochastic processes at the heart of evolution. With creationists making a concerted effort to attack public science education, it seems this book in particular, more than even your earlier book on evolution, is a superb resource for teachers and interested science readers who want to be able to deflate the rhetoric of anti-evolutionists.

CZ: Thanks! Like all other aspects of life, viruses only make sense in the light of evolution. That doesn’t mean we know all there is to know about viruses. But the theory of evolution has been crucial for much of what we know already–and what we will learn in the future.

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Hypertension in young adults a "sleeping epidemic," scientists say

7:25 AM |

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(CBS) Nearly one in five. That's the proportion of young adults who have high blood pressure, a.k.a. hypertension, according to a shocking new study from scientists at the University of North Carolina.

The findings differed sharply from previous research showing hypertension to be a problem for only about 4 percent of adults 20 to 39 years of age. Researchers were unable to account for the discrepancy, according to a written statement issued in conjunction with the study.

But no matter what the exact proportion, scientists are sounding the alarm on hypertension.

"There is a sleeping epidemic among young adults," says study researcher Dr. Kathleen Mullan Harris, interim director of the university's Carolina Population Center in Chapel Hill, told WebMD. "We tend to think of them as a rather healthy group, but a prevalence of 19% with hypertension is alarming."

Hypertension can often be controlled with diet, exercise , and drug therapy, but uncontrolled hypertension can lead to heart failure, stroke, kidney failure, and other potentially deadly medical problems.

It's also an economic problem. In 2010, the federal government's Institute of Medicine declared hypertension a "neglected disease" that costs the U.S. health system $73 billion a year, Reuters reported.

For the study - published online in the journal Epidemiology - researchers took blood pressure readings of more than 14,000 men and women 24 to 32 years of age. They found that 19 percnt had blood pressure of 140/90 or higher - and that only about half of these individuals had been told by their doctors that they had the condition, according to Reuters.

The researchers didn't attempt to explain why hypertension might be so prevalent among young people. But in a statement reported by Reuters, Mullen Harris summed up the take-away message:

"Young adults and the medical professionals they visit shouldn't assume they're not old enough to have high blood pressure."

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Asteroid Sample Return Mission Selected

11:14 PM |

NASA announced the selection of the OSIRIS-REx near-Earth asteroid sample return for the next New Frontiers mission, beating out a Venus lander and a lunar sample return mission. Bruce Moomaw write about the OSIRIS-REx mission for this blog, and his description can be found here. There are also articles at Space News and at the Planetary Society's blog site. NASA press release site also includes a video (which I can't watch with my current slow internet while I'm traveling): http://www.nasa.gov/topics/solarsystem/features/osiris-rex.html

With the two Japanese Hayabusa sample return missions (one completed and another in development), this means we'll have samples from three near-Earth asteroids. ESA is also considering its own near-Earth asteroid sample return, Marco Polo.

The press release itself is copied below. And congratulations to the winning team which submitted versions of this mission at least twice and I think perhaps three times.

May 25, 2011

Dwayne C. Brown
Headquarters, Washington
202-358-1726
dwayne.c.brown@nasa.gov

RELEASE: 11-163

NASA TO LAUNCH NEW SCIENCE MISSION TO ASTEROID IN 2016

WASHINGTON -- NASA will launch a spacecraft to an asteroid in 2016 and
use a robotic arm to pluck samples that could better explain our
solar system's formation and how life began. The mission, called
Origins-Spectral Interpretation-Resource
Identification-Security-Regolith Explorer, or OSIRIS-REx, will be the
first U.S. mission to carry samples from an asteroid back to Earth.

"This is a critical step in meeting the objectives outlined by
President Obama to extend our reach beyond low-Earth orbit and
explore into deep space," said NASA Administrator Charlie Bolden.
"It's robotic missions like these that will pave the way for future
human space missions to an asteroid and other deep space
destinations."

NASA selected OSIRIS-REx after reviewing three concept study reports
for new scientific missions, which also included a sample return
mission from the far side of the moon and a mission to the surface of
Venus.

Asteroids are leftovers formed from the cloud of gas and dust -- the
solar nebula -- that collapsed to form our sun and the planets about
4.5 billion years ago. As such, they contain the original material
from the solar nebula, which can tell us about the conditions of our
solar system's birth.

After traveling four years, OSIRIS-REx will approach the primitive,
near Earth asteroid designated 1999 RQ36 in 2020. Once within three
miles of the asteroid, the spacecraft will begin six months of
comprehensive surface mapping. The science team then will pick a
location from where the spacecraft's arm will take a sample. The
spacecraft gradually will move closer to the site, and the arm will
extend to collect more than two ounces of material for return to
Earth in 2023. The mission, excluding the launch vehicle, is expected
to cost approximately $800 million.

The sample will be stored in a capsule that will land at Utah's Test
and Training Range in 2023. The capsule's design will be similar to
that used by NASA's Stardust spacecraft, which returned the world's
first comet particles from comet Wild 2 in 2006. The OSIRIS-REx
sample capsule will be taken to NASA's Johnson Space Center in
Houston. The material will be removed and delivered to a dedicated
research facility following stringent planetary protection protocol.
Precise analysis will be performed that cannot be duplicated by
spacecraft-based instruments.

RQ36 is approximately 1,900 feet in diameter or roughly the size of
five football fields. The asteroid, little altered over time, is
likely to represent a snapshot of our solar system's infancy. The
asteroid also is likely rich in carbon, a key element in the organic
molecules necessary for life. Organic molecules have been found in
meteorite and comet samples, indicating some of life's ingredients
can be created in space. Scientists want to see if they also are
present on RQ36.

"This asteroid is a time capsule from the birth of our solar system
and ushers in a new era of planetary exploration," said Jim Green,
director, NASA's Planetary Science Division in Washington. "The
knowledge from the mission also will help us to develop methods to
better track the orbits of asteroids."

The mission will accurately measure the "Yarkovsky effect" for the
first time. The effect is a small push caused by the sun on an
asteroid, as it absorbs sunlight and re-emits that energy as heat.
The small push adds up over time, but it is uneven due to an
asteroid's shape, wobble, surface composition and rotation. For
scientists to predict an Earth-approaching asteroid's path, they must
understand how the effect will change its orbit. OSIRIS-REx will help
refine RQ36's orbit to ascertain its trajectory and devise future
strategies to mitigate possible Earth impacts from celestial objects.

Michael Drake of the University of Arizona in Tucson is the mission's
principal investigator. NASA's Goddard Space Flight Center in
Greenbelt, Md., will provide overall mission management, systems
engineering, and safety and mission assurance. Lockheed Martin Space
Systems in Denver will build the spacecraft. The OSIRIS-REx payload
includes instruments from the University of Arizona, Goddard, Arizona
State University in Tempe and the Canadian Space Agency. NASA's Ames
Research Center at Moffett Field, Calif., the Langley Research Center
in Hampton Va., and the Jet Propulsion Laboratory in Pasadena,
Calif., also are involved. The science team is composed of numerous
researchers from universities, private and government agencies.

This is the third mission in NASA's New Frontiers Program. The first,
New Horizons, was launched in 2006. It will fly by the Pluto-Charon
system in July 2015, then target another Kuiper Belt object for
study. The second mission, Juno, will launch in August to become the
first spacecraft to orbit Jupiter from pole to pole and study the
giant planet's atmosphere and interior. NASA's Marshall Space Flight
Center in Huntsville, Ala., manages New Frontiers for the agency's
Science Mission Directorate in Washington.

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H1N1 study shows closing schools, other measures effective

7:26 AM |

Schools were closed, restaurants shuttered and large public gatherings cancelled.

The H1N1 virus was new, and most of the cases occurred among young people. Health professionals and scientists weren't sure at the onset what the world would encounter with the virus.

Social distancing measures were enacted in Mexico where the pandemic affected different geographical areas of the country during three distinct waves. During the spring of 2009 when the virus affected the Mexico City area, officials choose to take measures to limit the virus' spread including cancelling large gatherings like soccer games.

New evidence suggests that these measures were effective, according to a new study led by ASU assistant professor Gerardo Chowell-Puente, an investigator for the Fogarty International Center at the National Institutes of Health and an assistant professor in the Arizona State University School of Human Evolution and Social Change in the College of Liberal Arts and Sciences.

The study provides the first comprehensive epidemiological description of the age, geographical and severity pattern of the 2009 pandemic in Mexico. Results of the study will be published in PloS Medicine.

"The interesting finding is that school closures and other social distancing measures during the first wave were associated with a reduction in the transmission rate by approximately 29 to 37 percent," Chowell said. "That is a significant change for a rapidly disseminating pandemic virus." Approximately 1,500 deaths were directly attributed to H1N1 flu in Mexico during 2009, he added.

In addition, hospitalization rates declined from about 70 percent to 10 percent during the period when schools closed and other social distancing measures enacted. Results of the study were calculated by applying mathematical modeling to influenza surveillance data compiled by the Mexican Institute for Social Security, a private health system representing 40 percent of the population.

"We found a significant effect from the social distancing interventions that could help mitigate the impact of future pandemics by relieving the burden on hospitals," Chowell said. "The peak of the pandemic could be pushed farther away so that health officials can prepare with pharmaceuticals and anti-virals. A vaccine could potentially be developed during that time."

More young people were affected by the H1N1 virus since older people had some immunity after a similar strain circulated years ago.

"There were a significant number of young people with severe respiratory disease particularly during the early pandemic phase," Chowell said.

Researchers also examined how the virus spread spatially, identifying three H1N1 waves with the first cases primarily around the Mexico City metropolis in spring of 2009 and the second summer wave in southeastern Mexico. The third wave was more widespread throughout the country and coincided with the start of school during the fall.

Findings from the study have implications for improving preparedness plans in future pandemics, said Chowell, who noted that in a previous pandemic in the 19th century, the majority of deaths occurred two years after the initial wave.

"We must remain vigilant and continue to monitor the circulation and health burden of this flu virus in the coming years," he added.

Arizona State University

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X-ray Video Shows Dogs Drink Like Cats, Just Sloppier

6:49 AM |

New high-speed videos show us what we already knew: that dogs make a giant mess at the water bowl.
But the clips above and below, filmed in X-ray and visible light, challenge assertions that canines drink by scooping up fluid with a backwards-curled tongue. Instead, dogs pull up a column of liquid and chomp it — just like cats.

“It only looks like dogs scoop with back of their tongue. They drink the same way as cats, just sloppier,” said evolutionary biologist Alfred Crompton of Harvard University.
Crompton leads a study of dog drinking published May 25 in the Journal of the Royal Society Biology Letters. The new work follows research on cat-lapping mechanics published last fall by a group at MIT. In that study, researchers deconstructed how cats drink, and suggested dogs drink differently.
“We didn’t use X-ray video like Crompton. When we saw their clip, we were like, ‘Wow, it is the same!’” said physicist and mechanical engineer Pedro Reis of MIT, a co-author of last year’s cat research.

Cats and dogs last shared a common ancestor some 43 million years ago, but neither evolved thick cheeks now present in many other animals, including humans. Such cheeks form a tight seal that both retains liquid and allows suction-powered drinking. Without them, cats and dogs needed to develop a different way to drink.
Reis’ MIT group used high-speed videos to show a cat begins to drink by flattening its tongue and barely touching the surface of a liquid. As the tongue pulls back, liquid sticks to its underside, and a column is pulled into the air. Just before the column drops, the cat closes its mouth and squeezes the drink down.
But whereas Reis originally thought dogs drank in a different fashion, Crompton suspected the truth was simply losy amidst the mess. To test the proposition, he enlisted Matilda, his 10-year-old Portuguese water dog.
When Matilda lapped beef broth in front of high-speed X-ray and visible light cameras, she demonstrated the same column-lifting mechanics of cats. The clips do show Matilda scooping up fluid by curling the back of her tongue, but it doesn’t go anywhere useful.
“It sprays everywhere and drops out of the mouth. Without cheeks, there’s no mechanism to get it on top of the tongue,” Crompton said.
Once columns of liquid land on a dog’s tongue, they’re pushed against the roof of the dog’s mouth, where ridges called rugae stop liquid from rolling out. Crompton said it takes three or four laps to get a drink into the mouth, along the tongue, and down into the throat.
Crompton’s team hopes to investigate how other animals drink. Civil engineer Roman Stocker of MIT, who with Reis led the cat-lapping study, suggested bird drinking as ripe for more research.

“Nature’s plentiful solutions to a given problem suggest that many surprises still await us when it comes to animal drinking,” Stocker said.

Videos: AW Crompton, Catherine Musinsky/Journal of the Royal Society Biology Letters
Continue reading ...

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X-ray Video Shows Dogs Drink Like Cats, Just Sloppier