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June 24, 2015
Risks Vs Rewards: Why People With HIV Volunteer For ‘Cure’ Research
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Participating in a HIV cure trial offers few benefits for the individual but many for the community. Morgan DDL/Shutterstock
A recent survey of people living with HIV in the United Kingdom found that more than half would participate in a clinical study to develop a cure for HIV, despite this posing a risk to their health.
Solar Fuels: How Planes And Cars Could Be Powered By The Sun
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Packing heat: concentrating sunlight into a reactor to split H2O and CO2 – a step toward making liquid fuels. Courtesy of Professor David Hahn, University of Florida, Author provided
Solar energy is the world’s most plentiful and ubiquitous energy source, and researchers around the world are pursuing ways to convert sunlight into a useful form.
Most people are aware of solar photovoltaics that generate electricity and solar panels that produce hot water. But there is another thrust of solar research: turning sunlight into liquid fuels.
Paleo Diet? Science Has Moved On Since The Stone Age
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Paleo-no diet for me but burger diet not too good either. Lord Jim, CC BY
“Our ancestors didn’t eat like this, so we shouldn’t.” This is the main ethos of many modern diets which advise us to exclude a number of recent additions to our plates because they were not part of our distant predecessors diet. There are many different variations on the theme – from all-encompassing “palaeolithic-style” diets to grain-free or gluten-free regimes – which are all generating a massive boom in specialised shops, products and even restaurants.
June 23, 2015
Should Italy’s Prized Olive Groves Be Burned to the Ground? [Video]
SALENTO, Italy—There is only one certainty in what has fast become a Dantesque drama to save world-renowned olive groves in Puglia from the deadly Xylella fastidiosa bacterium: olive trees, the very symbol of this southern Italian region, are dying en masse. Hundreds of acres of once-vibrant, postcard-perfect groves that have prospered for centuries are now cemeteries where twisted, dead tree trunks protrude like arboreal zombies from fertile soil in which grass and flowers easily grow.
Almost every other aspect of the drama, especially the science of how the bacterium spreads and how to stop it, is far less clear. No one even knows how many trees have perished so far, although reports by Italy’s farm cooperative Coldiretti estimate that more than one million of Puglia’s 60 million olive trees are infected by the bacterium, either dying on their own or cut down and burned by authorities, under pressure to do something from national and European leaders who fear the bacteria could wipe out olive groves across the continent and infect almond and cherry trees, too. As I stand among the sawed-off stumps and charred remains of a small grove here, officials have just painted more of the ancient tree trunks with red X marks to signify eventual destruction. Angry owners protest defiantly, calling the men with chainsaws assassins. Activists shout insults at agronomists inspecting the groves.
But no one can tell me exactly how this bacterium sickens the trees, how it moves from tree to tree or whether burning can ever work unless it destroys the entire industry. Puglia produces more than 40 percent of Italy’s olive oil, and the oil is considered among the world’s finest. The outbreak could cost the region more than $225 million in olive oil production losses this year alone, and could threaten olive trees across Italy and all of Europe, substantially raising the price of oil worldwide. The stunning, centuries-old trees are more than agricultural champions, too; they are cultural monuments that are as vital to the “heel” region of Italy’s “boot” as its conical-roofed stone trullo houses and its many castles.
Nor can anyone say with certainty whether all of those dead trees actually succumbed to X. fastidiosa. Although current wisdom, based on random samples, holds that they did die from the bacterium, hardly a tiny fraction of the dead trees has been tested. Yet like conducting autopsies in a war zone, officials seem to have little impetus to confirm what is assumed as fact.
A red X marks trees destined to be destroyed. Credit: Pier Paolo Cito
Less certain still is just how the deadly bacterium was introduced to the area. The most likely explanation, supported by the scientific community, is that it was inadvertently brought in with a shipment of ornamental plants from Costa Rica, where the same strain of bacterium has been well documented. But local people here have their own theories, which range from the intentional killing of the trees by everyone from British land developers who want to clear the land to build fancy resorts and golf courses to the so-called ecomafia that apparently intends to repurpose the land as a toxic chemical dump.
Residents tell tales of dark-colored Mercedes and Jaguar cars apparently dumping chemicals on tree roots. Others whisper that the U.S. biotech firm Monsanto released a genetically modified strain of the bacterium they bought from a Brazilian company called Allelyx so it could sweep in with a cure. Still others claim that officials who support a proposal to build the Trans Adriatic Pipeline from Turkey to Europe via Puglia need to clear the land now occupied by olive groves to secure the lucrative deal.
Putting aside for the moment just how the bacterium came to Puglia, a far more pressing issue is how to keep it from spreading up the Italian boot and into Europe. Xylella is carried by infectious, meadow spittle bugs that feed on the trees’ xylem—tissue that supports the plant and conducts water. The bugs harbor the bacterium in their throats, moving among the trees, injecting the bacterium when they puncture trees to feed. As I look at several of the dead bugs floating in ammonia in petri dishes at the National Research Council of Italy (CNR) laboratory in Bari, it seems unfathomable that such small creatures could wreak such havoc. But even the bugs’ life is unclear; some scientists tell me the bugs can only travel 100 meters but others say the insects can travel for kilometers. That complicates the leading theory that in order to prevent the bugs from spreading the deadly bacterium, the infected trees must be destroyed before they die on their own, no matter how old or culturally important they are to the region.
Alarmed, the European Union has mandated the creation of a buffer zone just north of the Pugliese town of Lecce, essentially writing off everything south of a line that extends between the Ionian and Adriatic seas as a dead zone. Testing is more vigorous in and above the buffer zone. Infected trees are marked with a red X and destroyed. Eventually, every tree within 100 meters of any infected tree will also be cut down. Farmers are understandably defiant. “There is no such thing as Xylella,” says Pasquale Spina, a farmer whose trees are in the buffer zone. As he talks to me he stands next to the sawed off remains of an ancient tree that tested positive for the bacterium, stroking the new growth sprouting from the top of the supposedly infected, dead stump (see the video below). “Does this tree look sick to you?” he asks? “Xylella only exists in the head!”
One of the heads he is referring to is that of Donato Boscia, a virologist who is the research director of the CNR’s Institute for Sustainable Plant Protection. He found the first confirmed case of X. fastiodosa in his father-in-law’s olive grove in 2013 when he was there with his wife’s family. “I knew right away we had something big here,” he told Scientific American in his greenhouse laboratory in Bari. Boscia, whose cell phone shows an olive tree from his father-in-law’s grove as its screen saver, is leading an epic battle against a mountain of bureaucracy and funding cuts to institute an open-air research center to study the disease and eventually find a way to stop it. Although he advocates tree cutting and burning, he also knows it is the equivalent of taking an aspirin to fight cancer. “Eradication is not a utopia,” he says. “We need to work on containment. We have to adopt good practices to live with Xylella because stopping it is not going to be easy.”
>> Click here for a transcript of the video above
Boscia is also at the center of a criminal investigation being conducted by the regional court in Lecce into the potential culpability of scientists for either introducing the virus or succumbing to pressure or financial persuasion not to stop it. Boscia is unfazed—at least on the surface— shrugging off the allegations and vowing to continue to find enough proof to implement what is necessary to stop the bacteria. “We can’t get distracted,” he says. “To beat this we need to stay focused.”
But science does not always play well in a land where adherence to tradition is rivaled only by suspicion of authority. Boscia’s job in convincing the public that the E.U. plan is the best they’ve got is complicated by the lack of proper funding and the blatant lack of an infrastructure that makes transparency nearly impossible. If an olive grower notices a suspect patch of drying leaves on a tree limb, he is more likely to cut the tree down and burn it himself than to wait for authorities to potentially come in and destroy the entire grove. There is not a single publicized help line or outreach program in the area to guide olive growers through the crisis, which means they have to take care of it on their own.
The delay in establishing an aggressive research and treatment strategy only makes matters worse because hard statistics are scarce and often contradictory. “The problem is that at the moment it is all speculation,” Boscia says. “We are fighting a number of fronts without any artillery—from the vectors that carry the bacterium to the accurate testing of the trees. [The bacterium] lives in the xylem, so an infected tree could have a healthy limb, and if we test the wrong one, we may allow the tree to live and continue to be a host. That’s not comforting to the growers.”
Few experts are as versed in the X. fastidiosa bacterium as Alexander Purcell, a professor emeritus at the University of California, Berkeley, who has written some of the most extensive research on the effects of Xylella on agricultural crops. “The ancient iconic symbolism and cultural impact of the olive tree in Europe and the Mediterranean gives this disease an impact I haven’t experienced with grapes, citrus and other crops that were hit suddenly with Xylella,” he told Scientific American on Skype. “But until the majority of people are willing to cooperate and take action in the local community, nothing is going to slow down.”
If there can be any good news for Puglia’s legendary olive growers it is the fact that the bacterium has no impact on the fruit and oil the healthy trees produce, says Boscia, precisely because infected trees do not produce olives. The only danger to people who consume the unique Pugliese oil is that there won’t be enough to go around. The bad news, of course, is that as the trees are dying, so is a culture that has prevailed for millennia.
Climate Change Threatens Global Health
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abutyrin/Shutterstock
“Climate change is a medical emergency. It thus demands an emergency response, using the technologies available right now.”
Physicists say Interstellar Should be Shown in School Classrooms
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Screenshot of the rendered black hole from Interstellar.
The film that explores our universe in more epic proportions than ever before – "Interstellar" – should be shown in science lessons at school.
Before you make a quick judgement on this statement, it is not the mere opinion of someone completely unqualified to make such a surprising assertion. Rather, this is the conclusion from a paper that explores the hard physics used to make the film as accurate as possible.
Programmed Bacteria Can Detect Tumors
Probiotics are hot. Bacteria that we consume in foods like yogurt, miso and pickles can help our gut microbiomes stay happy and healthy. Now there might be another role for those probiotic bacteria: cancer detection. Two papers in the journal Science Translational Medicine explain how researchers hope to get bacteria to be diagnostic tools. [Tal Danino et al, Programmable probiotics for detection of cancer in urine], [Alexis Courbet et al, Detection of pathological biomarkers in human clinical samples via amplifying genetic switches and logic gates]
Sangeeta Bhatia of MIT is a liver expert and senior author of one of the papers. Her lab had been trying to figure out how to get nanoparticles to the liver that would send a signal detectable in urine if they encountered a tumor. Cancers that start in the colon or pancreas can metastasize to the liver, which can be deadly.
SB: “And one of the students on the team had the idea that if you can imagine that there's a material, a diagnostic material, that would grow itself then you wouldn’t need very much of it to arrive at the tumor and sort of self-amplify. And we realized that bacteria are in many ways just such a device. That they can naturally home in on tumors…so we thought maybe we can hijack that ability of bacteria to home in on tumors and self-amplify to create a urinary diagnostic.”
Bhatia’s lab teamed up with a lab at the University of California, San Diego with expertise in synthetic biology—basically altering microbes to have specific functions.
SB: “So instead of just going out and finding natural strains that would colonize tumors and do what wanted, we could pick strains that have good homing and then endow them with the capabilities that we were interested in.”
The two labs took a strain of E. coli called Nissle that is already used as a probiotic to help people with digestive issues. They programmed the bacteria to express a specific enzyme after it occupied liver tumors. If the bacteria colonized a tumor in mice, the mice would produce urine that, thanks to the enzyme, would turn red.
The system worked—the bacteria found tumors in mice known to have them, and the urine changed color, indicating the presence of cancer. Cancer-free mice that also ate the engineered probiotics showed no negative health effects a year later.
The technique is at this stage just a proof of concept, says Bhatia. But it’s got a lot of promise.
SB: “Well what we're really excited about the idea that you can take synthetic biology some day into both diagnostics and also therapeutics. So in this particular case the circuit that we put the bacteria gave off a diagnostic signal that could be detected remotely. But you can also imagine and were working on circuits that give off chemotherapy that would kill the tumor directly. And making smart circuits do that in response of ways. And you can even imagine having mixtures of bacteria that do both diagnosis and therapy. So I think there's really a whole world of possibilities once you start thinking about using bacteria as a platform upon which to engineer functions.”
—Cynthia Graber
(The above text is a transcript of this podcast)
Crows Rival Most Mammals with Their Cognitive Ability
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Arun Roisri/Shutterstock
When you think of an intelligent animal, most people probably picture the same critters: chimps, dolphins, or dogs. But many scientists believe that corvids – the group containing crows, ravens, rooks and jays – also deserve a position at the top table. They’ve shown through many experiments that crows display high cognitive abilities, often on par with those classically ‘intelligent’ animals.
Genetically Modified Lamb with Jellyfish Protein Accidentally Sold as Meat in Paris
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Aaltair/Shutterstock
A lamb that was genetically modified to contain a fluorescent jellyfish protein somehow ended up on someone’s dinner plate. The French authorities have launched an investigation to find out how the ‘jellyfish-lamb’ was sold as meat. I wonder if it tasted baaaaaad?
Samsung Unveils ‘See-Through’ Safety Trucks
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Four screens on the back of a Safety Truck show drivers when it is safe to overtake the vehicle. Samsung
Have you ever been stuck behind a truck and unsure whether to overtake it because your view of the road ahead is obscured? To overcome this potentially dangerous situation, Samsung has revealed its "Safety Truck," which allows you to ‘see-through’ the truck to the traffic ahead.
The Safety Truck is equipped with a camera on the front that displays its footage on four panels at the rear of the truck. Drivers are thus able to see the road ahead, allowing them to overtake the truck safely.
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