Quotulatiousness

December 15, 2015

Asthma and the “Hygiene Hypothesis”

Filed under: Cancon, Health, Science — Tags: , , , — Nicholas @ 02:00

An older report at the BBC News website discusses recent research into childhood asthma:

Being exposed to “good bacteria” early in life could prevent asthma developing, say Canadian scientists.

The team, reporting in Science Translational Medicine, were analysing the billions of bugs that naturally call the human body home.

Their analysis of 319 children showed they were at higher risk of asthma if four types of bacteria were missing.

Experts said the “right bugs at the right time” could be the best way of preventing allergies and asthma.

In the body, bacteria, fungi and viruses outnumber human cells 10 to one, and this “microbiome” is thought to have a huge impact on health.

The team, at the University of British Columbia and the Children’s Hospital in Vancouver, compared the microbiome at three months and at one year with asthma risk at the age of three.

Children lacking four types of bacteria – Faecalibacterium, Lachnospira, Veillonella, and Rothia (Flvr) – at three months were at high risk of developing asthma at the age of three, based on wheeze and skin allergy tests.

The same effect was not noticed in the microbiome of one-year-olds, suggesting that the first few months of life are crucial.

Further experiments showed that giving the bacterial cocktail to previously germ-free mice reduced inflammation in the airways of their pups.

One of the researchers, Dr Stuart Turvey, said: “Our longer-term vision would be that children in early life could be supplemented with Flvr to look to prevent the ultimate development of asthma

“I want to emphasise that we are not ready for that yet, we know very little about these bacteria, [but] our ultimate vision of the future would be to prevent this disease.”

December 8, 2015

Still more to learn about the human immune system

Filed under: Health, Science — Tags: , , — Nicholas @ 03:00

A brief post at Real Clear Science on a recent discovery in human immunology:

Think again if you thought that doctors had long since identified and described exactly how the body defends itself against microorganisms.

Scientists have recently discovered a whole new side to the immune system: a rapid immune response that kicks in well before any of the other known mechanisms.

“I hate to use the term ‘text books will write about this’, but this [discovery] really is brand new and we will need to write a new chapter,” says co-author Søren R. Paludan, professor of virology and immunology form the Department of Biomedicine, Aarhus University, Denmark.

In collaboration with groups from the US and Germany, the scientists showed that when the body’s outer defence, the mucosa lining that surrounds certain organs, is disturbed by a virus, the underlying layer of cells are the first to react and sound the alarm. They summon the body’s cell soldiers, which attack the invading virus.

Both this alarm system and the ‘soldier’ cells operate completely separately from what were believed to be the first responders to immune system attacks.

December 3, 2015

Medical charities and their prime mission

Filed under: Bureaucracy, Health — Tags: , , — Nicholas @ 05:00

David Warren is rather a skeptic on the long-term usefulness of big medical charities (and not just because, like any big bureaucracy, sooner or later the primary goal becomes for the organization itself to survive and grow rather than pursuing whatever they were originally created to do):

Medical “research” does similar direct damage. Huge foundations are created to “fight” every imaginable human ailment, and find new ones on which to build fresh fundraising efforts, should any of the old ones go stale. Grand sums are expended on “public awareness” campaigns, to encourage hypochondria and psychosomatic disorders. (I suspect, for instance, that the chief cause of lung cancer today is grisly health warnings on packets of cigarettes.) Money is raised in billions to “find a cure” for whatever. (Snake oil sales were on a much smaller scale.)

At the most elementary level, people should try to understand cause and effect. Vast numbers come to rely upon the metastasis of these soi-disant “charitable” bureaucracies. And if a cure is ever found, they will all be out of their overpaid jobs. Moreover, it is almost invariably some isolated, eccentric, unqualified and unfunded tyro, who makes the fatal discovery. That is why one of the principal tasks of any large medical foundation is to locate these brilliant “inventor” types, and sue them into surrender.

Does gentle reader know that almost all the increase in human longevity, over the last century or so, can be attributed to people washing their hands and taking showers? And most of the rest to better sewage disposal? Or that it took until almost the middle of the last century for life expectancy in the West to rise to levels last seen in the parish records of the Middle Ages? Which was when “modern” hygienic practices were last observed. (Large, centralized hospitals are the most efficient spreaders of infection today.)

Painkillers are nice, and I’m inclined to keep them, only if we realize that the blessing is mixed. They turn our minds away from futurity; they displace faith in God, to faith in doctors. They create the mindset that embraces “euthanasia.”

Of course, the main focus of contemporary liberal “philanthropy” is not on saving lives at all; rather on killing off babies — in Africa, by first choice. It is what the proggies used to call “population control,” until they invented better euphemisms. That is what truly gladdens the peons in the foundations of all the Bills and Melindas; and lights the corridors of the United Nations. That and the (still historically recent) “climate change” agenda.

November 21, 2015

QotD: Investigating the reactionary view of racism

Filed under: Media, Quotations, Science — Tags: , , — Nicholas @ 01:00

Almost all of our hard data on race comes from sociology programs in universities – ie the most liberal departments in the most liberal institutions in the country. Most of these sociology departments have an explicit mission statement of existing to fight racism. Many sociologists studying race will tell you quite openly that they went into the field – which is not especially high-paying or prestigious – in order to help crusade against the evil of racism.

Imagine a Pfizer laboratory whose mission statement was to prove Pfizer drugs had no side effects, and whose staff all went into pharmacology specifically to help crusade against the evil of believing Pfizer’s drugs have side effects. Imagine that this laboratory hands you their study showing that the latest Pfizer drug has zero side effects, c’mon, trust us! Is there any way you’re taking that drug?

We know that a lot of medical research, especially medical research by drug companies, turns up the wrong answer simply through the file-drawer effect. That is, studies that turn up an exciting result everyone wants to hear get published, and studies that turn up a disappointing result don’t – either because the scientist never submits it to the journals, or because the journal doesn’t want to publish it. If this happens all the time in medical research despite growing safeguards to prevent it, how often do you think it happens in sociological research?

Do you think the average sociologist selects the study design most likely to turn up evidence of racist beliefs being correct, or the study design most likely to turn up the opposite? If despite her best efforts a study does turn up evidence of racist beliefs being correct, do you think she’s going to submit it to a major journal with her name on it for everyone to see? And if by some bizarre chance she does submit it, do you think the International Journal Of We Hate Racism So We Publish Studies Proving How Dumb Racists Are is going to cheerfully include it in their next edition?

And so when people triumphantly say “Modern science has completely disproven racism, there’s not a shred of evidence in support of it”, we should consider that exactly the same level of proof as the guy from 1900 who said “Modern science has completely proven racism, there’s not a shred of evidence against it”. The field is still just made of people pushing their own dogmatic opinions and calling them science; only the dogma has changed.

And although Reactionaries love to talk about race, in the end race is nothing more than a particularly strong and obvious taboo. There are taboos in history, too, and in economics, and in political science, and although they’re less obvious and interesting they still mean you need this same skepticism when parsing results from these fields. “But every legitimate scientist disagrees with this particular Reactionary belief!” should be said with the same intonation as “But every legitimate archbishop disagrees with this particular heresy.”

This is not intended as a proof that racism is correct, or even as the slightest shred of evidence for that hypothesis (although a lot of Reactionaries are, in fact, racist as heck). No doubt the Spanish Inquisition found a couple of real Satanists, and probably some genuine murderers and rapists got sent to Siberia. Sometimes, once in a blue moon, a government will even censor an idea that happens to be false. But it’s still useful to know when something is being censored, so you don’t actually think the absence of evidence for one side of the story is evidence of anything other than people on that side being smart enough to keep their mouths shut.

Scott Alexander, “Reactionary Philosophy In An Enormous, Planet-Sized Nutshell”, Slate Star Codex, 2013-03-03.

November 19, 2015

Is a possible cure for old age now in sight?

Filed under: Health, Science — Tags: , , , — Nicholas @ 05:00

Matt Ridley on recent developments in the search for ways to ameliorate the effects of aging:

Squeezed between falling birth rates and better healthcare, the world population is getting rapidly older. Learning how to deal with that is one of the great challenges of this century. The World Health Organisation has just produced a report on the implications of an ageing population, which — inadvertently — reveals a dismal fatalism we share about the illnesses of old age: that they will always be inevitable.

This could soon be wrong. A new book, The Telomerase Revolution, published in America this week by the doctor and medical researcher Michael Fossel, argues that we now understand enough about the fundamental cause of ageing to be confident that we will eventually be able to reverse it. This would mean curing diseases such as Alzheimer’s, heart disease and osteoporosis, rather than coping with them or treating their symptoms.

Let me show you what I mean about fatalism. The WHO report on ageing and health, for all its talk of the need for “profound changes” to health care for the elderly, actually urges us to stop trying to cure the afflictions of old age and learn to live with them: “The societal response to population ageing will require a transformation of health systems that moves away from disease-based curative models and towards the provision of older-person-centred and integrated care.”

Yet it also subscribes to the somewhat magical hope that illnesses of old age can be “prevented or delayed by engaging in healthy behaviours” and that “physical activity and good nutrition can have powerful benefits for health and wellbeing.” This is largely wishful thinking. There is no evidence that, say, Alzheimer’s can be prevented by a certain diet or activity. A lack of activity and poor nutrition can worsen health at any age, but the underlying chronic diseases of old age are caused by age itself.

When I asked Dr Fossel what he thought of the WHO report, he replied: “In 1950 we could have talked (and did) about ‘active polio’ in the sense of keeping polio victims active rather than giving up, but the very phrase itself implies that one has already given up. I would prefer that we cure the fundamental problem. Why talk about ‘active ageing’, ‘successful ageing’, and ‘healthy ageing’ when we could talk about not ageing?”

September 5, 2015

The subtle lure of “research” that confirms our biases

Filed under: Health, Science — Tags: , , , , — Nicholas @ 02:00

Megan McArdle on why we fall for bogus research:

Almost three years ago, Nobel Prize-winning psychologist Daniel Kahneman penned an open letter to researchers working on “social priming,” the study of how thoughts and environmental cues can change later, mostly unrelated behaviors. After highlighting a series of embarrassing revelations, ranging from outright fraud to unreproducible results, he warned:

    For all these reasons, right or wrong, your field is now the poster child for doubts about the integrity of psychological research. Your problem is not with the few people who have actively challenged the validity of some priming results. It is with the much larger population of colleagues who in the past accepted your surprising results as facts when they were published. These people have now attached a question mark to the field, and it is your responsibility to remove it.

At the time it was a bombshell. Now it seems almost delicate. Replication of psychology studies has become a hot topic, and on Thursday, Science published the results of a project that aimed to replicate 100 famous studies — and found that only about one-third of them held up. The others showed weaker effects, or failed to find the effect at all.

This is, to put it mildly, a problem. But it is not necessarily the problem that many people seem to assume, which is that psychology research standards are terrible, or that the teams that put out the papers are stupid. Sure, some researchers doubtless are stupid, and some psychological research standards could be tighter, because we live in a wide and varied universe where almost anything you can say is certain to be true about some part of it. But for me, the problem is not individual research papers, or even the field of psychology. It’s the way that academic culture filters papers, and the way that the larger society gets their results.

August 13, 2015

A potential breakthrough in Alzheimer’s and Parkinson’s research

Filed under: Health, Science — Tags: — Nicholas @ 03:00

At New Scientist, a report on some very hopeful research findings:

A virus found in sewage has spawned a unique drug that targets plaques implicated in a host of brain-crippling diseases, including Alzheimer’s disease, Parkinson’s disease and Creutzfeldt-Jakob disease (CJD).

Results from tests of the drug, announced this week, show that it breaks up plaques in mice affected with Alzheimer’s disease or Parkinson’s disease, and improves the memories and cognitive abilities of the animals.

Other promising results in rats and monkeys mean that the drug developers, NeuroPhage Pharmaceuticals, are poised to apply for permission to start testing it in people, with trials starting perhaps as early as next year.

The drug is the first that seems to target and destroy the multiple types of plaque implicated in human brain disease. Plaques are clumps of misfolded proteins that gradually accumulate into sticky, brain-clogging gunk that kills neurons and robs people of their memories and other mental faculties. Different kinds of misfolded proteins are implicated in different brain diseases, and some can be seen within the same condition.

Proteins gone rogue

July 28, 2015

Viking genes

Filed under: Europe, History, Science — Tags: , , , , — Nicholas @ 03:00

In Nautilis, Adam Piore talks about the project to thoroughly map Icelanders’ DNA:

In the ninth century there was a Norwegian Viking named Kveldulf, so big and strong that no man could defeat him. He sailed the seas in a long-ship and raided and plundered towns and homesteads of distant lands for many years. He settled down to farm, a very wealthy man.

Kveldulf had two sons who grew up to become mighty warriors. One joined the service of King Harald Tangle Hair. But in time the King grew fearful of the son’s growing power and had him murdered. Kveldulf vowed revenge. With his surviving son and allies, Kveldulf caught up with the killers, and wielding a double-bladed ax, slew 50 men. He sent the paltriest survivors back to the king to recount his deed and fled toward the newly settled realm of Iceland. Kveldulf died on the journey. But his remaining son Skallagrim landed on Iceland’s west coast, prospered, and had children.

Skallagrim’s children had children. Those children had children. And the blood and genes of Kveldulf the Viking and Skallagrim his son were passed down the ages. Then, in 1949, in the capital of Reykjavik, a descendent named Kari Stefansson was born.

Like Kveldulf, Stefansson would grow to be a giant, 6’5”, with piercing eyes and a beard. As a young man, he set out for the distant lands of the universities of Chicago and Harvard in search of intellectual bounty. But at the dawn of modern genetics in the 1990s, Stefansson, a neurologist, was lured back to his homeland by an unlikely enticement — the very genes that he and his 300,000-plus countrymen had inherited from Kveldulf and the tiny band of settlers who gave birth to Iceland.

Stefansson had a bold vision. He would create a library of DNA from every single living descendent of his nation’s early inhabitants. This library, coupled with Iceland’s rich trove of genealogical data and meticulous medical records, would constitute an unparalleled resource that could reveal the causes — and point to cures — for human diseases.

In 1996, Stefansson founded a company called Decode, and thrust his tiny island nation into the center of the burgeoning field of gene hunting. “Our genetic heritage is a natural resource,” Stefansson declared after returning to Iceland. “Like fish and hot pools.”

June 25, 2015

Refuting Piketty on the inevitable “rich get richer” meme

Filed under: Economics — Tags: , , — Nicholas @ 05:00

At Reason, Ronald Bailey links to a study that appears to undermine most of Thomas Picketty’s claims:

From the study:

    We believe Piketty’s core message is provably flawed on several levels, as a result of fundamental and avoidable errors in his basic assumptions. He begins with the sensible presumption that the return on invested capital, r, exceeds macroeconomic growth, g, as must be true in any healthy economy. But from this near-tautology, he moves on to presume that wealthy families will grow ever richer over future generations, leading to a society dominated by unearned, hereditary wealth. Alas, this logic holds true only if the wealthy never dissipate their wealth through spending, charitable giving, taxation, and splitting bequests among multiple heirs.

    As individuals, and as families, the rich generally do not get richer; after a fortune is first built, the rich get relentlessly and inevitably poorer.

    The “evidence” Piketty uses in support of his thesis is largely anecdotal, drawn from the novels of Austen and Balzac, and from the current fortunes of Bill Gates and Liliane Bettencourt. If Piketty is right, where are the current hyper-wealthy descendants of past entrepreneurial dynasties — the Astors, Vanderbilts, Carnegies, Rockefellers, Mellons, and Gettys? Almost to a man (or woman) they are absent from the realms of the super-affluent. Our evidence — used to refute Piketty’s argument — is empirical, drawn from the rapid rotation of the hyper-wealthy through the ranks of the Forbes 400, and suggests that, at any given time, roughly half of the collective worth of the hyper-wealthy is first-generation earned wealth, not inherited wealth.

    The originators of great wealth are one-in-a-million geniuses; their innovation, invention, and single-minded entrepreneurial focus create myriad jobs and productivity enhancements for society at large. They create wealth for society, from which they draw wealth for themselves. In contrast, the descendants of the hyper-wealthy rarely have that same one-in-a-million genius. Bettencourt, cited by Piketty, is a clear exception. Typically, we find that descendants halve their inherited wealth — relative to the growth of per capita GDP — every 20 years or less, without any additional assistance from Piketty’s redistribution prescription.

    Dynastic wealth accumulation is simply a myth. The reality is that each generation spawns its own entrepreneurs who create vast pools of entirely new wealth, and enjoy their share of it, displacing many of the preceding generations’ entrepreneurial wealth creators. Today, the massive fortunes of the 19th century are largely depleted and almost all of the fortunes generated just a half-century ago are also gone. Do we really want to stifle entrepreneurialism, invention, and innovation in an effort to accelerate the already-rapid process of wealth redistribution?

June 19, 2015

Camouflage – the changing of the spots

Filed under: Military, USA — Tags: , , , — Nicholas @ 02:00

At Strategy Page, a quick look at the US Army’s latest change in camouflage clothing and equipment:

The U.S. Army has begun issuing its new combat uniforms featuring a new and improved camouflage pattern. This is yet another effort to deal with troop complaints about the shortcomings of earlier camouflage patterns. Back in 2012 the army has decided to scrap its current digital pattern camouflage combat uniforms and replace them with the more effective (according to the troops), but more expensive, MultiCam. Actually, MultiCam itself was not used but a pattern selected for the new uniforms, but one based on MultiCam. This variant is called Scorpion W2 and the army gave it another, official, name; Operational Camouflage Pattern (OCP). So if you hear someone talking about the new uniform being Scorpion W2 or MultiCam they are not entirely wrong. But the final, official term is OCP.

Since 2001 both the army and marines adopted new, digital camouflage pattern field uniforms. But in Afghanistan U.S. soldiers noted that the marine digital uniforms (called MARPAT, for Marine Pattern) were superior to the army UCP (Universal Camouflage Pattern). Both UCP and MARPAT were introduced at the same time (2002). From the beginning there was growing dissatisfaction with UCP, and it became a major issue because all the infantry have access to the Internet, where the constant clamor for something better than UCP eventually forced the army to do something.

This is ironic because UCP itself was another variant of MARPAT but a poor one, at least according to soldiers in UCP who encountered marines wearing MARPAT. Even more ironic is that MARPAT is based on research originally done by the army. Thus some of the resistance to copying MARPAT is admitting the marines took the same research on digital camouflage and produced a superior pattern for combat uniforms.

May 28, 2015

The ways that scientific journalism fails

Filed under: Media, Science — Tags: , — Nicholas @ 03:00

At Vox.com, Julia Belluz and Steven Hoffman show how perverse incentives and human frailty contribute to the wasted efforts — and sometimes outright fraudulent methods — that get “scientific” results published. It’s getting so bad that “the editor of The Lancet … recently lamented, ‘Much of the scientific literature, perhaps half, may simply be untrue.'”:

From study design to dissemination of research, there are dozens of ways science can go off the rails. Many of the scientific studies that are published each year are poorly designed, redundant, or simply useless. Researchers looking into the problem have found that more than half of studies fail to take steps to reduce biases, such as blinding whether people receive treatment or placebo.

In an analysis of 300 clinical research papers about epilepsy — published in 1981, 1991, and 2001 — 71 percent were categorized as having no enduring value. Of those, 55.6 percent were classified as inherently unimportant and 38.8 percent as not new. All told, according to one estimate, about $200 billion — or the equivalent of 85 percent of global spending on research — is routinely wasted on flawed and redundant studies.

After publication, there’s the well-documented irreproducibility problem — the fact that researchers often can’t validate findings when they go back and run experiments again. Just last month, a team of researchers published the findings of a project to replicate 100 of psychology’s biggest experiments. They were only able to replicate 39 of the experiments, and one observer — Daniele Fanelli, who studies bias and scientific misconduct at Stanford University in California — told Nature that the reproducibility problem in cancer biology and drug discovery may actually be even more acute.

Indeed, another review found that researchers at Amgen were unable to reproduce 89 percent of landmark cancer research findings for potential drug targets. (The problem even inspired a satirical publication called the Journal of Irreproducible Results.)

So why aren’t these problems caught prior to publication of a study? Consider peer review, in which scientists send their papers to other experts for vetting prior to publication. The idea is that those peers will detect flaws and help improve papers before they are published as journal articles. Peer review won’t guarantee that an article is perfect or even accurate, but it’s supposed to act as an initial quality-control step.

Yet there are flaws in this traditional “pre-publication” review model: it relies on the goodwill of scientists who are increasingly pressed and may not spend the time required to properly critique a work, it’s subject to the biases of a select few, and it’s slow – so it’s no surprise that peer review sometimes fails. These factors raise the odds that even in the highest-quality journals, mistakes, flaws, and even fraudulent work will make it through. (“Fake peer review” reports are also now a thing.)

April 28, 2015

QotD: Pursuit of truth

Filed under: History, Humour, Quotations, Science — Tags: , — Nicholas @ 01:00

Truth, indeed, is something that is believed in completely only by persons who have never tried personally to pursue it to its fastnesses and grab it by the tail. It is the adoration of second-rate men — men who always receive it at second-hand. Pedagogues believe in immutable truths and spend their lives trying to determine them and propagate them; the intellectual progress of man consists largely of a concerted effort to block and destroy their enterprise. Nine times out of ten, in the arts as in life, there is actually no truth to be discovered; there is only error to be exposed. In whole departments of human inquiry it seems to me quite unlikely that the truth ever will be discovered. Nevertheless, the rubber-stamp thinking of the world always makes the assumption that the exposure of an error is identical with the discovery of the truth — that error and truth are simple opposites. They are nothing of the sort. What the world turns to, when it has been cured of one error, is usually simply another error, and maybe one worse than the first one. This is the whole history of the intellect in brief. The average man of to-day does not believe in precisely the same imbecilities that the Greek of the fourth century before Christ believed in, but the things that he does believe in are often quite as idiotic. Perhaps this statement is a bit too sweeping. There is, year by year, a gradual accumulation of what may be called, provisionally, truths — there is a slow accretion of ideas that somehow manage to meet all practicable human tests, and so survive. But even so, it is risky to call them absolute truths. All that one may safely say of them is that no one, as yet, has demonstrated that they are errors. Soon or late, if experience teaches us anything, they are likely to succumb too. The profoundest truths of the Middle Ages are now laughed at by schoolboys. The profoundest truths of democracy will be laughed at, a few centuries hence, even by school-teachers.

H.L. Mencken, “Footnote on Criticism”, Prejudices, Third Series, 1922.

April 18, 2015

Correlation, causation, and lobby money

Filed under: Books, Business, Health — Tags: , — Nicholas @ 02:00

Tim Harford‘s latest column on tobacco, research, and lobby money:

It is said that there is a correlation between the number of storks’ nests found on Danish houses and the number of children born in those houses. Could the old story about babies being delivered by storks really be true? No. Correlation is not causation. Storks do not deliver children but larger houses have more room both for children and for storks.

This much-loved statistical anecdote seems less amusing when you consider how it was used in a US Senate committee hearing in 1965. The expert witness giving testimony was arguing that while smoking may be correlated with lung cancer, a causal relationship was unproven and implausible. Pressed on the statistical parallels between storks and cigarettes, he replied that they “seem to me the same”.

The witness’s name was Darrell Huff, a freelance journalist beloved by generations of geeks for his wonderful and hugely successful 1954 book How to Lie with Statistics. His reputation today might be rather different had the proposed sequel made it to print. How to Lie with Smoking Statistics used a variety of stork-style arguments to throw doubt on the connection between smoking and cancer, and it was supported by a grant from the Tobacco Institute. It was never published, for reasons that remain unclear. (The story of Huff’s career as a tobacco consultant was brought to the attention of statisticians in articles by Andrew Gelman in Chance in 2012 and by Alex Reinhart in Significance in 2014.)

Indisputably, smoking causes lung cancer and various other deadly conditions. But the problematic relationship between correlation and causation in general remains an active area of debate and confusion. The “spurious correlations” compiled by Harvard law student Tyler Vigen and displayed on his website (tylervigen.com) should be a warning. Did you realise that consumption of margarine is strongly correlated with the divorce rate in Maine?

April 3, 2015

Updating the old saying “where there’s muck, there’s money”

Filed under: Economics, Science, Technology — Tags: , , , — Nicholas @ 04:00

According to this story in the Guardian, a typical city of one million people poops out $13 million in (potentially recoverable) precious metals every year:

Sewage sludge contains traces of gold, silver and platinum at levels that would be seen as commercially viable by traditional prospectors. “The gold we found was at the level of a minimal mineral deposit,” said Kathleen Smith, of the US Geological Survey.

Smith and her colleagues argue that extracting metals from waste could also help limit the release of harmful metals, such as lead, into the environment in fertilisers and reduce the amount of toxic sewage that has to be buried or burnt.

“If you can get rid of some of the nuisance metals that currently limit how much of these biosolids we can use on fields and forests, and at the same time recover valuable metals and other elements, that’s a win-win,” she said.

A previous study, by Arizona State University, estimated that a city of 1 million inhabitants flushed about $13m (£8.7m) worth of precious metals down toilets and sewer drains each year.

The task of sifting sewage for microscopic quantities of gold may sound grim, but it could have a variety of unexpected benefits over traditional gold mining. The use of powerful chemicals, called leachates, used by the industry to pull metals out of rock is controversial, because these chemicals can be devastating to ecosystems when they leak into the environment. In the controlled setting of a sewage plant, the chemicals could be used liberally without the ecological risks.

March 20, 2015

Epigenetic researchers – “We can double the size of these bugs!” Everyone else – “No, thanks. We’re good.”

Filed under: Science — Tags: , , , , — Nicholas @ 03:00

Science can be a great source of fascinating experiments. Doubling the size of insects is perhaps not the best way to advertise your particular speciality, however:

Florida carpenter ants

Researchers have changed the size of a handful of Florida ants by chemically modifying their DNA, rather than by changing its encoded information. The work is the latest advance from a field known as epigenetics and may help explain how the insects — despite their high degree of genetic similarity — grow into the different varieties of workers needed in a colony.

This discovery “takes the field leaps and bounds forward,” says entomologist Andrew Suarez of the University of Illinois, Urbana-Champaign, who wasn’t connected to the study. “It’s providing a better understanding of how genes interact with the environment to generate diversity.”

Ant nests have division of labor down pat. The queen spends her time pumping out eggs, and the workers, which are genetically similar sisters, perform all the other jobs necessary to keep the colony thriving, such as tending the young, gathering food, and excavating tunnels. Workers in many ant species specialize even further, forming so-called subcastes that look different and have different roles. In Florida carpenter ants (Camponotus floridanus), for example, workers tend to fall into two groups. Minor workers, which can be less than 6 mm long, rear the young and forage for food. Major workers, which can be almost twice as long, use their large jaws to protect the colony from predators.

A team from McGill University in Montreal, Canada, suspected that the mechanism involves DNA methylation: the addition of a chemical to DNA. Genome sequencing and other methods suggest that these physical differences don’t usually stem from genetic differences between individual ants. Instead, environmental factors help push workers to become majors or minors — specifically, the amount of food and coddling that young ants receive. But just how do these factors change the size of ants?

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