Can humans really tell apart a trillion smells?

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It’s been reported that our noses were a 100 million times more sensitive than had been previously believed and that humans could apparently discriminate 1 trillion different smells.

Finally we could hold our collective noses up high and know that we could walk into any duty-free perfumery and tell the difference between a cheap eau-de-cologne and the expensive scent of Clive Christian’s Imperial Majesty [selling at a mere $215,000 for 16 ounces].

But wait, not so fast. A study published on arxiv by Markus Meister, a professor of Molecular and Cellular Biology at Harvard University, disputes the logic of the original paper and argues that the original Science paper’s claims are wrong by “astronomical factors.”

The authors were misled by failures in a mathematical method they designed. As a result, their claims have no basis. The paper’s extravagant claims are based on errors of mathematical logic.

Ten as opposed to one trillion—that is some logical error. Now it is important to note here that Meister isn’t saying we can only discriminate between 10 different smells, merely that the logic of the original paper could just as easily support that we could only tell the difference between 10 smells.

So our sense of smell isn’t as superior as we thought?

Meister doesn’t address this in his paper, but in his dismissal of the original paper he does point the way to answering this question in the future. So it is worth a look at the original experiment to see exactly how the researchers came up with their 1 trillion different smells, and how Meister believes their logic was flawed:

The researchers gathered up 128 odorant molecules including citrus, tobacco, mint and garlic and combined them in varying quantities into mixtures of 10, 20 and 30 smells and put them in glass vials. The scientists gave the test subjects three vials at a time: two with the same concoction, and a third that was different. Based on how often the test subjects were able to correctly identify which of the vials smelled different, the scientists extrapolated that humans could differentiate among at least 1 trillion different smells.

Meister gave three arguments against the logic used in the paper and the second of these Adam J. Coulhon, blogger at neuroecology covers in his blog:

The second criticism concerns the dimensionality of the sensory data. How many ways does it vary? In vision, we know that people are trichromats (for the most part). Red, blue, green: these are the three fundamental dimensions color vision varies across. How many are dimensions are there in olfaction? There are at least 400 odorant receptor genes in humans, which suggest that there are at least 400 different odorant molecules that we could detect – though the exact number depends on the wiring of the olfactory system. This suggests that smells exist in 400 orthogonal directions in humans.

Markus Meister shows that if odors are represented along one dimension then the same analysis used in the initial paper yields ten discriminable odors. On the other hand, if you have more (non-orthogonal) dimensions, you could potential discriminate an infinite number odors. Therefore, he claims, this analysis is just plain wrong. We’ll call this the “choose your own dimension” criticism and probably has an empirical answer (which happens to be ~400

This argument hints at how Meister thinks scientists might progress in investigating how many smells humans can actually discriminate. If scientists can identify the primary color equivalent in smells, what he calls the “dimensionality of odor precepts” they can stand a chance of finding how many smells we can discriminate, rather than just specifying the number of smells out there that we could possibly discriminate between. He states it, in more rigorous terms, in his paper:

Regardless of approach, determining the dimensionality of the space of odor percepts is a precondition to estimating the number of distinct percepts. The recognition that color space is three-dimensional has had enormous impact in science, art, and technology, as anyone reading this on a color monitor will confirm. By comparison, knowing that there are >1 million distinct color percepts is a minor advance. Similarly, finding a low-dimensional basis set for odors would be truly profound.

Jane Palmer is a freelance science writer and radio journalist based near Boulder, Colorado. Follow Jane Palmer on @JanePalmerComms

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Breakthrough research: Bioengineered human muscle that contracts like real tissue

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In what’s being hailed as a medical first, researchers at Duke University announced this week that they had bioengineered human skeletal muscle tissue capable of contracting like the real thing.

The scientists said the lab-grown tissue could become a powerful new tool for studying diseases like muscular dystrophy. In addition, it could facilitate the development of specialized drugs to treat these diseases–and eliminate the need to test the drugs on humans, which can be risky.

“One of our goals is to use this method to provide personalized medicine to patients,” Dr. Nenad Bursac, a professor of biomedical engineering at the university and one of the researchers, said in a written statement. “We can take a biopsy from each patient,grow many new muscles to use as test samples and experiment to see which drugs would work best for each person.”

The moment of truth came when researchers watched as they stimulated the lab grown muscle fibers with electrical impulses and a range of drugs, including cholesterol-lowering statins and the performance-enhancing drug clenbuterol. Sure enough, the researchers said, the muscle reacted to these stimuli just like native human tissue.

Read full, original article: Scientists Grow Human Muscle That Contracts Like The Real Thing

Why new guidelines for sharing clinical trial data are important

We’re in the middle of a major flu epidemic, and the CDC has recommended treatment with an antiviral (e.g., Tamiflu or Relenza) for high-risk people. Yet there is considerable controversy over whether Tamiflu even works and, despite promises, Roche staunchly refused to release all their data for others to verify for years. The Cochrane Collaborative was finally able to review data and, in 2014, reported that Tamiflu did not reduce the number of hospitalizations, and they could not tell whether it reduced deaths.

The example of Roche’s stonewalling is why I greeted today’s report from the Institute of Medicine (IOM), Sharing Clinical Trial Data: Maximizing Benefits, Minimizing Risk, with such hope.

There are now 182,168 trials registered on ClinicalTrials.gov. While there has been a gradual increase in reporting of results, only 15,845 registered trials posted results in 2014. Estimates are that the results from half of all clinical trial results have never been published; positive trials are twice as likely to be published as others, whether these are industry sponsored or not.

Keep in mind that these trials are funded by the public through our taxes, as are many trials for drugs that are then licensed to public universities and pharmaceutical companies (like some of the new Ebola vaccines in development). Shouldn’t knowledge from publicly funded trials be in the public domain?

Read full, original article: Why Transparency And Data Sharing In Clinical Trials Matters

 

 

Mutation in gene causing heart failure identified

Researchers have uncovered a major genetic risk for heart failure — a mutation affecting a key muscle protein that makes the heart less elastic.The mutation increases a person’s risk of dilated cardiomyopathy. This is a form of heart failure in which the walls of the heart muscle are stretched out and become thinner, enlarging the heart and impairing its ability to pump blood efficiently, a new international study has revealed.

The mutation causes the body to produce shortened forms of titin, the largest human protein and an essential component of muscle, the researchers said in background information.

In this study, researchers studied more than 5,200 people, including both healthy people and people suffering from dilated cardiomyopathy. The researchers performed genetic sequencing on all these people, examining the specific gene that the body uses to create titin.

They uncovered a specific type of titin mutation that occurs in families and appears to greatly increase the risk of dilated cardiomyopathy (DCM).

Up to now, genetic testing for heart failure has been difficult because it’s been hard to interpret which mutations might lead to heart disease, [study author] Roberts said. These findings could better help doctors figure out which people are at greater risk for heart failure — especially those who have a family history of the disease.

Read full, original article: Scientists Spot Mutation Behind Genetic Form of Heart Failure

Low vaccination rates linked to rapidly spreading California Disneyland measles outbreak

Most people have heard by now that two dozen individuals who visited Disneyland between Dec. 15 and Dec. 20, 2014, have fallen ill with measles, which means they were almost certainly exposed to someone at the theme park with the disease.

But it’s not just those who visited Disneyland that week who should be concerned. Advocates against vaccines scoff at the oft-repeated warning that “polio [or any other vaccine-preventable disease] is just a plane ride away,” but it’s harder to scoff when such a textbook example presents itself. The news broke about the Disneyland outbreak on January 7 with seven cases, and the number has more than tripled in less than a week. More importantly, however, it’s been exported to three other states: Utah, Colorado and Washington.

Among the 16 California cases where vaccination status is known, 12 individuals (75 percent) were unvaccinated, despite the fact that measles vaccination involves extremely low risk, far below the risk posed by measles itself.

“This happened exactly where you would expect to see this happen – in a place where people from different parts of the country congregate in one spot,” said Paul Offit, director of the Vaccine Education Center and an attending physician with the Division of Infectious Diseases at The Children’s Hospital of Philadelphia. “It’s not surprising that it happened in a southern California theme park because southern California over the past few years has had pretty woeful rates of vaccination.”

Read full, original story: Disneyland Measles Outbreak: It Is Indeed a Small World After All

Can changes in gut microbiome help predict colorectal cancer risk?

Changes in the gut microbiome could help distinguish individuals with healthy colons from those with either colorectal adenomas (polyps with a risk of becoming cancer) or colorectal cancer, according to results of two recent studies.

In the first study, Patrick Schloss, Ph.D., and his colleagues at the University of Michigan analyzed and compared the microbial DNA found in stool samples from three groups of participants: healthy individuals, individuals with colorectal adenomas, and patients with colorectal cancer.

The researchers identified distinct gut microbiome signatures for each group. When combined with other known clinical risk factors for colorectal cancer (e.g. older age, African American and American Indian/Alaskan Native race, high body mass index), the microbiome signatures were better able than risk factors alone to distinguish individuals with healthy colons from those bearing adenomas and carcinomas.

If corroborated in a larger study population, the authors wrote, the results suggest that non-invasive analysis of the microorganisms in the digestive tract could complement existing screening methods for colorectal cancer.

In the second study, Peer Bork, Ph.D., of the European Molecular Biology Laboratory, and his colleagues utilized newer sequencing methods developed by the Human Microbiome Project to characterize microbial diversity in stool samples from patient groups from four different countries. As was the case in the first study, the researchers could distinguish people with colorectal cancer from healthy subjects based on differences in their microbiome.

Read full, original story: Analyzing the Gut Microbiome to Help Detect Colorectal Cancer

Chinese publish genome of Tibetan barley

Scientists from a genomics organisation in south China’s Shenzhen City on January 13, 2015 published the first genetic map of Tibetan highland barley. Highland barley, known in Tibetan as Ne, is being grown on the Qinghai-Tibet Plateau for nearly 4,000 years.

The draft genome was published in the Proceedings of the National Academy of Sciences (PNAS).

Highland Barley consists of up to 70 percent of all cereal crops in southwest China’s Tibet Autonomous Region. It is the home to the world’s leading barley production base and centre for barley diversity research.

Genetic map of Tibetan barley will help to cultivate better strains of the Himalayan region’s staple food and increase yield. Also, it could help explain adaptation to extreme environmental conditions and increase yields.

Read full, original article: Chinese scientists published first genetic map of Tibetan Highland Barley

Local food to eclipse organic, as consumers begin to doubt definition

New consumers continue to enter the organic category for the first time, but the health halo cast by the US Department of Agriculture’s certification is dimming as it becomes more mainstream and as shoppers’ interpretation of the standard evolves.

At the same time, consumer desire for “local” products is increasing and the claim could wquickly replace organic as the most desirable qualification by many consumers, according to research analysts.

Shoppers continue to buy organic products “for what they lack: pestices, herbicdes, growth horones, antibiotics, artificial flavors, artificial colors, preservatives and GMOs,” according to a blog post by thThe Hartman Group promoting its report.

Despite this interest, some consumers wonder how highly process “junk food” can bear the organic label and if large manufacturers are “diluting the spirit of organics,” according to the Hartman Group.

Read full, original article: Local claims are rising star as sun sets on organic claims

Farmers Union not on board with GM-Free Wales

The Welsh Government has been urged to firmly set out is position on genetically-modified crops following an European Parliament vote which could lead to a new era of GM cultivation in England and, opponents fear, the threat of “cross-contamination.”

Individual member states will have the freedom to ban GM crops – but the move is expected to pave the way for pro-GM governments to give the green light to greater use of the controversial technology.

Speaking in the European Parliament, Plaid MEP Jill Evans said:

“In theory, this could be appealing for a country like Wales, where agriculture is devolved. Wales was a founding member of the GM Free Regions Network. We don’t have the same policy as the UK Government on GM crops.

However, Conservative MEP Kay Swinburne welcomed the new stance on GM crops.

She said: “I hope that the Welsh Government will also look to the many advances in science that have taken place in the area of GMOs and take a fully informed view on the future of GMOs in Wales.”

A spokeswoman for National Farmers Union Cymru said: “We recognise that a number of people have concerns about this technology, and the Welsh Government may hold different views to the UK Government on this issue, but we do believe that this technology does at least need to be considered.”

Read full, original article: Is a new era of GM crops about to begin – and should Wales be part of it?

Could genetically engineered chickens reverse the avian flu epidemic?

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Avian bird flu, found recently in backyard poultry in the Pacific Northwest, could devastate poultry producers now that China has added its name to the list of countries banning U.S. poultry products, including eggs and live breeding stock.

The strains, H5N2 and H5N8, are similar to infections found late last year in Germany, the United Kingdom and the Netherlands, as well as on commercial farms in British Columbia, Canada. Canadian poultry exports are also banned by seven countries.

The outbreak began in Asia last January and caused producers to cull nearly 600,000 poultry in South Korea and 120,000 in Japan, according to the World Animal Health Organization.

Large-scale commercial facilities respond to the threat of infection by creating physical barriers and cleaning living areas. Producers also swiftly culled flocks as necessary.

For traditionally raised poultry by small households or farms in poor countries, the same measures are not practical. Vaccinations are often the preferred prevention method, but if not monitored, vaccinated birds could still catch mild forms of the flu and unsuspectingly pass it onto other birds. Additionally, viruses are good at mutating and slipping past vaccines.

One fairly novel solution exists, at least in concept—genetically engineered chicken—but before a product could even be marketed, it first needs to win over regulators and producers.

According to the study in Science journal published in January 2011, researchers in the UK genetically inserted a gene into chickens that diverted an enzyme necessary in the transmission of the bird flu H5N1. The transgenic chickens died within days, but they stopped the virus from infecting other poultry—even nontransgenic chickens.

The team comprised of researchers led by Helen Sang from the Roslin Institute at the University of Edinburgh said that genetic modification is more effective than vaccines that are currently used because the transgenic technique works even if the virus mutates.

“Our goal was a proof-of-principle demonstration that genetic modification can be used to prevent avian influenza infection in chickens…

Our approach is technically applicable to other domestic species that are hosts of influenza A, such as pigs, ducks, quail, and turkeys.”

Transgenes can be added to multiple varieties of poultry without affecting genetic diversity or valuable production traits, the researchers added.

Scientists at the time of the study were responding to the H5N1 epidemic of 2005-2006, which spread from Asia into Europe and Africa killing nearly 400 people and hundreds of millions of poultry.

But fast forward four years and two related viruses, H5N2 and H5N8, have now been found around the world.

In the U.S., the avian flu could be economically devastating to poultry producers. China is the thirty-first country in addition to the European Union to cut off U.S. poultry exports (ranging from the specific areas affected by the flu to the entire country), according to a U.S. Department of Agriculture Food Safety and Inspection Service list.

The financial impact could be deep. U.S. exports of poultry products sent to China reached nearly $272 million during the first 11 months of 2014, said Toby Moore, spokesman for the U.S. Poultry & Egg Export Council.

The avian flu has also been studied with some concern due to its potential to recombine with human influenza. Humans who are in regular contact with birds have become infected in rare cases, but so far, transmission from person-to-person has not been reported. This particular strain has not yet affected humans.

However, Ron Fouchier, a Dutch virologist at the Erasmus Medical Center, and Yoshihiro Kawaoka of the School of Veterinary Medicine at the University of Wisconsin, demonstrated that “it takes only five mutations to transform the bird flu virus into a form that is transmissible from mammal to mammal by coughs and sneezes. Two of the five mutations have already been found in wild birds—which means that some avian virsuses are just three mutations away from becoming transmissible between mammals.”

However, organic activists say that the large-scale farms are part of the reason the avian flu can be so devastating.

Organic farmer Tim Elsdale said:

“Organic methods of husbandry doesn’t encourage disease if the animals are well spaced enough. They live in a natural environment and they eat normal food then a lot of diseases that are prevalent on conventional farming would not be apparent to us.”

Peter Melchett, policy director for the UK organic farming advocacy group Soil Association and a well known anti-GMO activist, echoed that sentiment:

“Keeping animals cramped together in inhumane factories encourages the spread of diseases such as bird flu and swine flu,” he said. “This GM fantasy simply tries to cover up for flawed farming practice.”

Yet that doesn’t ring true with the experience thus far in the U.S., where the avian flu has yet to hit commercial poultry farms. It’s the backyard poultry flocks and wild birds that have been infected.

While the world faces yet another outbreak of the avian flu, it is obvious there is need for a solution. The UK research team proved the concept in 2011. In time, perhaps, genetic engineering may help prevent avian flu from devastating livelihood or even human life.

Rebecca Randall is a journalist focusing on international relations and global food issues. Follow her @beccawrites.

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Germany appears headed for complete GMO ban

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After the European Parliament on Tuesday, 13 January passed a new Directive on Genetically Modified Organisms (GMO) in Europe, the German Environment Ministry is insisting on a complete ban on green genetic engineering in Germany. It is very important that a political agreement be reached to generally apply the exclusion clause to Germany, emphasised State Secretary on Environment Jochen Flasbarth on Tuesday (13 January) in Berlin.

Under the new directive, EU member states will now be able to choose to opt-out, restricting or completely banning GMO cultivation within their borders. One of the leading proponents of such a legal ban in Germany is its Ministry of Agriculture, which is led by the Bavarian conservative Christian Social Union (CSU). The Ministry also supports a national ban on cultivation. In a position paper from the Federal Ministry of the Environment, Minister Barbara Hendricks outlines that she does not want to leave any backdoors open for genetic engineering.

The GMO law must be changed, so that controversial green genetic engineering cannot be used under any pretext in Germany, she states in the document, according to a report in the Süddeutsche newspaper.

“Green genetic engineering has turned out to be the wrong track,” Hendricks said. It is risky for nature and the environment and is not desired by consumers. “For this reason I would like us to use the EU rules in the future, that can guarantee freedom from genetic engineering in Germany,” she explained.

Read full, original article: German Environment Ministry seeks unconditional GMO ban

South’s original peanut provides genetic diversity

In one field just outside Charleston grows the South’s original peanut, long thought to be extinct but now primed for revival. Once ubiquitous throughout the South, they were prized for both their flavor and the quality of the oil they produced. The Carolina fell out of favor because its small size made it more difficult to harvest (and less appealing to the eye) and new strains proved more disease-resistant. By the 1950s, it was thought to have disappeared entirely.

But just a couple of years ago, Dr. David Shields, a food historian at University of South Carolina, tracked down a peanut sample, realizing that, in fact, these were the last of the Carolina runners. He contacted Dr. Brian Ward, a horticulturist at Clemson University’s vegetable research center and asked him if he’d be willing to cultivate some peanuts for him. Ward agreed. “I didn’t know at the time I’d been given half the seeds in existence,” he says.

Ward has been their only grower for the last two years.

“The fact that this cultivar is on the verge of being generally released after being on the verge of extinction is largely due to his talent as an organic cultivator,” says Shields.

From the original handful, Ward has managed to produce enough seeds to start 1,200 plants last year. This year, he will be able to provide seeds to commercial growers. These peanuts don’t have the resistance to disease that has been bred into modern ones, but they do provide vital genetic diversity.

Read full, original article: The Original Southern Peanut Was Thought To Be Extinct, But One Farmer Is Bringing It Back

On GMO labeling: Are consumers getting label fatigue?

Shoppers are shelling out a lot of money for products they believe are good because of clever marketing, labeling, and claims they don’t understand. Some of them are happy to pay more for products they believe to be better than others. It helps them feel good about the choices they are making for their families. And it helps keep food companies fat. But this isn’t going to last.

Recently, we asked 300 consumers around the country about their knowledge and understanding of the foods they buy. To my surprise, 76 percent of respondents said they were more concerned today than they were three years ago about the food they eat. But only 30 percent of them could define the meaning of an “organic” product. A majority said they were concerned about GMOs — and those who buy non-GMO products pay a premium for them — but only 24 percent knew the meaning of “GMO,” or genetically modified organisms. (By the way, all certified organic products are non-GMO. But a product labeled “non- GMO” isn’t necessarily organic.)

Is ignorance bliss when it comes to food buying? Not necessarily. There are signs of growing skepticism and label fatigue in the market. We found that 72 percent of shoppers believe some food labels and terms are meaningless. Twelve percent are outright disbelieving of company claims. Marketers beware: How much longer will consumers continue to pay a premium for products with an unclear or, worse, a misleading promise?

Read full, original article: Let’s Take The B.S. Out Of Food Marketing

Eleven genomic medicine centers to lead UK’s 100,000 genomes project

Eleven NHS Genomic Medicine Centres (GMCs) have been announced by Genomics England. They will spearhead the 100,000 Genomes Project, which aims to decode the genomes of patients affected by cancers or rare diseases, and subsequently use this knowledge to develop better diagnostic tests and treatments for these conditions.

Professor Mark Caulfield, chief scientist for Genomics England, said the centres would bring researchers and clinicians together ‘to work as part of Genomic England’s Clinical Interpretation Partnership on whole genome data that has never been collected on this scale before. We have a clear goal of accelerating the findings from the programme back into mainstream healthcare at the fastest possible pace, meaning more rapid results for patients.’

The 100,000 Genomes Project will focus on the five most common cancers – breast, bowel, ovarian, lung and the commonest form of leukaemia – as well as 110 rare diseases. DNA samples collected at the GMCs will be decoded and analysed by the biotech company Illumina. The results will be returned to NHS England, where they will be validated and shared with patients. The project will cost £300million and is scheduled to run for three years.

Read full, original story: Genomics England announces 11 centres spearheading 100,000 Genomes Project

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