Category: Science

No increase in teen pot smoking in states with medical marijuana

The availability of medical marijuana does not cause a surge in pot smoking among teens, according to a national, school-based survey.

When the survey results were aggregated across grade (grade 8 through 12) they found that the risk of marijuana use did not significantly change after the state passed a medical marijuana law…

“Hasin and colleagues postulated, as many would, that the passage of medical marijuana laws would increase adolescent marijuana use by contributing to the declining perception of the potential harms of marijuana,” Kevin P. Hill…of Harvard’s McLean Hospital…wrote in an editorial in The Lancet Psychiatry. “Their well designed, methodologically sound study showed that this was not the case.”

“This study draws attention to the importance of undertaking rigorous scientific research to test hypotheses and using the results to develop sensible health policies,” Hill added. “Policies might sometimes be shaped by preconceived notions that do not end up being true, and Hasin and colleagues’ study is an example of such an occurrence.”

“The growing body of research that includes this study suggests that medical marijuana laws do not increase adolescent use, and future decisions that states make about whether or not to enact medical marijuana laws should be at least partly guided by this evidence,” Hill wrote.

Another socially-derived bit of preconception bites the dust.

If you’re so inclined, RTFA for methodology and sources. I wasn’t surprised by the result.

Eating human brains protected a tribe from brain disease

The Fore people, a once-isolated tribe in eastern Papua New Guinea, had a long-standing tradition of mortuary feasts — eating the dead from their own community at funerals. Men consumed the flesh of their deceased relatives, while women and children ate the brain. It was an expression of respect for the lost loved ones, but the practice wreaked havoc on the communities they left behind. That’s because a deadly molecule that lives in brains was spreading to the women who ate them, causing a horrible degenerative illness called “kuru” that at one point killed 2 percent of the population each year.

The practice was outlawed in the 1950s, and the kuru epidemic began to recede. But in its wake it left a curious and irreversible mark on the Fore, one that has implications far beyond Papua New Guinea: After years of eating brains, some Fore have developed a genetic resistance to the molecule that causes several fatal brain diseases, including kuru, mad cow disease and some cases of dementia.

The single, protective gene is identified in a study published…in the journal Nature. Researchers say the finding is a huge step toward understanding these diseases and other degenerative brain problems, including Alzheimer’s and Parkinson’s.

The gene works by protecting people against prions, a strange and sometimes deadly kind of protein. Though prions are naturally manufactured in all mammals, they can be deformed in a way that makes them turn on the body that made them, acting like a virus and attacking tissue. The deformed prion is even capable of infecting the prions that surround it, reshaping them to mimic its structure and its malicious ways…

The study by Collinge and his colleagues offers a critical insight into ways that humans might be protected from the still-little-understood prions. They found it by examining the genetic code of those families at the center of the Fore’s kuru epidemic, people who they knew had been exposed to the disease at multiple feasts, who seemed to have escaped unscathed.

When the researchers looked at the part of the genome that encodes prion-manufacturing proteins, they found something completely unprecedented. Where humans and every other vertebrate animal in the world have an amino acid called glycine, the resistant Fore had a different amino acid, valine…

When the scientists re-created the genetic types observed in humans — giving the mice both the normal protein and the variant in roughly equal amounts — the mice were completely resistant to kuru and to CJD. But when they looked at a second group of mice that had been genetically modified to produce only the variant protein, giving them even stronger protection, the mice were resistant to every prion strain they tested — 18 in all.

“This is a striking example of Darwinian evolution in humans, the epidemic of prion disease selecting a single genetic change that provided complete protection against an invariably fatal dementia,” Collinge told Reuters…

Unintended consequences – one of the best reasons in science for basic research.

Fortunately, for our economy, beaucoup CEOs recognize the importance of that process. Unfortunately, for our economy, damned few of the hacks holding elected office recognize the importance of that process.

Deep Learning Machine surpasses humans in IQ test


University of Science and Technology China, Hefei

Just over 100 years ago, the German psychologist William Stern introduced the intelligence quotient test as a way of evaluating human intelligence. Since then, IQ tests have become a standard feature of modern life and are used to determine children’s suitability for schools and adults’ ability to perform jobs.

These tests usually contain three categories of questions: logic questions such as patterns in sequences of images, mathematical questions such as finding patterns in sequences of numbers and verbal reasoning questions, which are based around analogies, classifications, as well as synonyms and antonyms.

It is this last category that has interested Huazheng Wang and pals at the University of Science and Technology of China and Bin Gao and buddies at Microsoft Research in Beijing. Computers have never been good at these. Pose a verbal reasoning question to a natural language processing machine and its performance will be poor, much worse than the average human ability.

Today, that changes thanks to Huazheng and pals who have built a deep learning machine that outperforms the average human ability to answer verbal reasoning questions for the first time…

Huazheng and buddies devised an algorithm for solving natural language verbal questions using standard vector methods but also the multi-sense upgrade they’ve developed.

They compare this deep learning technique with other algorithmic approaches to verbal reasoning tests and also with the ability of humans to do it. For this, they posed the questions to 200 humans gathered via Amazon’s Mechanical Turk crowdsourcing facility along with basic information about their ages and educational background.

And the results are impressive. “To our surprise, the average performance of human beings is a little lower than that of our proposed method,” they say.

Human performance on these tests tends to correlate with educational background. So people with a high school education tend to do least well, while those with a bachelor’s degree do better and those with a doctorate perform best. “Our model can reach the intelligence level between the people with the bachelor degrees and those with the master degrees,” say Huazheng and co…

Deep learning techniques are currently sweeping through computer science like wildfire and the revolution they are creating is still in its early stages. There’s no telling where this revolution will take us but one thing is for sure: William Stern would be amazed.

Every chucklehead writing articles that conclude artificial intelligence, computational analysis and reasoning will never pass a Turing test is shuttered from reality. Much less useful. The best minds already predict the opposite even if it takes the usual road to scientific success – recognition one death at a time. As the old farts or those who think like old farts die off, reality moves progress beyond the ennui of culture.

RTFA for the reasoning employed by Huazheng in development of their deep learning machine.

DARPA contest sends robots into mock-up nuclear reactor

On Friday and Saturday, the Darpa Robotics Challenge – the “Robolympics”, unofficially…completes its final competition, with 25 teams of engineers and scientists giving orders to huge machines trundling across a landscape designed to simulate the impassible environment that greeted aid workers after the Fukushima Daiichi reactor in Japan melted down multiple times in 2011.

Engineers tried to help, but no robots could navigate the hazardous terrain and disaster ensued, rendering a huge area around the plant uninhabitable after toxic steam exploded into the skies. The radioactive leftovers are still emitting a million watts of heat.

If a Darpa contestant is able to navigate the terrain successfully, and in a short amount of time (each team has an hour to run the course) it will become the richest robot in town: first prize is $2m, second prize is $1m, and third gets $500,000.

The public event is a cross between the Consumer Electronics Show and an episode of Mythbusters. Inside the Fairplex, the stands were filled on Friday with people cheering for their favorite androids. Outside was a big expo with kids running around playing with (or staring terrified at) all kinds of robots: some dancing, some playing music, some swimming in a giant tank where they can be piloted with a video game controller. One company, Ekso, makes robotic trousers that make it easier to carry a backpack.

The purpose of the main event, however, is deadly serious.

“The idea, inspired by Fukushima, is to come up with a simulation of a disaster that is like [that],” said Dr Gill Pratt, the avuncular, eloquent director of the Tactical Technology Office (TTO) program at Darpa that oversees the project.

Darpa is the Defense Advanced Research Projects Agency, the arm of the US Defense Department that is responsible in large part for the creation of the computer network, Arpanet, that became the internet.

“The teams will not have any human help for the robots themselves, and the key element, again, between the human controllers and the robot is a very degraded communication link,” Pratt explained.,,

“Particularly when you need to improvise, the environment you’re going into is a human environment, and a humanoid robot is designed to take on a human environment and we can adapt to it like humans,” Darwin Caldwell said.

“If you’ve got a quadruped robot, or a robot with wheels, it’s not really designed for that environment, so it might be able to adapt. But we know humans can go in there. We know humans can do that. That’s one thing we’re certain of.”

Some DARPA competitions don’t come close to succeeding in the first year of trials. Or more. But, unlike many extremely narrow experimental targets proposed for military trials, DARPA projects often have a broad framework and move sooner rather than later into civilian-focused experimentation, potentially global adoption.

Like autonomous automobiles or the Internet.

Pollination can be honeybee free


Bryan Danforth at the Cornell OrchardsJason Koski/University Photography

As the state’s land-grant institution, Cornell University was born to explore science for the public good – a mission that can sometimes require a leap of faith.

Just such a leap is paying off now at Cornell Orchards in Ithaca, as researchers and managers from the Horticulture Section of the School of Integrative Plant Science and the Department of Entomology celebrate a solid spring pollination season for the site’s apple trees. While crisp apples and fresh cider are no strangers to fans of the 37-acre research and outreach site, this year’s crop provides an extra bonus for New York apple growers: proof that pollination can be done commercial honeybee free…

Populations of imported European honeybees, relied upon for centuries in American agriculture, continue to decline under pressure from an array of pathogens, parasites and other problems. Danforth said honeybee hive managers are seeing losses at 30 to 40 percent each year, with damages during the worst “colony collapse” years topping 70 percent. With that key agricultural resource insecure, apple growers in New York – the nation’s No. 2 apple-producing state – face a future of higher hive rental costs or limits on honeybee availability.

As one of the nation’s leading advocates for native bees as an agricultural asset, Danforth is among 11 faculty members who rely upon Cornell Orchards for research support. Since 2008, he and members of his lab have been surveying bee activity at 20 upstate orchards, including Cornell’s Ithaca and Lansing sites. His team has found more than 100 wild bee species at these orchards, far more than previously thought, with often surprising levels of diversity and abundance. Danforth’s group has detected a total of 26 wild bee species at Cornell’s Ithaca orchard alone…

That idea took flight during a walk through the Ithaca orchards in May 2014. Danforth and farm manager Eric Shatt were checking bee activity when, in addition to the honeybees from six rented hives, they noticed countless wild bees elbowing in for a meal – from mud-building mason bees and honeybee lookalike Colletes inaequalis to solitary carpenter bees and social halictids. They also spotted many species of Andrena, a mild-mannered ground nesting bee that “scrabbles” deep into flowers, a technique former Danforth Lab researcher Mia Park…demonstrated is four times more effective at pollinating than “side working” honeybees.

The two agreed to take a leap few large commercial orchards can afford: fly through the next apple blossom season on the wings of wild bees alone. A confident Shatt took the idea to the committee that oversees the orchards and, as Justine Vanden Heuvel, associate professor in plant sciences and committee chair recalled, the panel agreed jumping in to prove the concept was worth the risk…

It’s turned out to be a gamble that’s paid off for the orchards, Danforth and growers statewide. In the closing days of May, Shatt reported wild bees provided enough fruitlets to support a full crop this year…

While he’s quick to concede wild bees will never replace honeybees in massive agricultural settings, Danforth said research and fieldwork is proving wild bees can play a critical role in saving growers money, easing pressure on vulnerable honeybee hives, increasing sustainability and, most importantly, enhancing food security. His current work, such as the new study he co-authored with Park on the impact of pesticides on wild bee populations, will focus on exploring what keeps wild bee populations high. That will let Cornell promote best practices and develop assessment tools so growers know when they, too, can afford to take the leap.

Bravo!

I can’t wait to discuss this with our family beekeeper.

Soft batteries created from wood


Fanciful – but, you get the idea

Wood pulp-derived nanocellulose is turning out to be pretty useful stuff. Previously, we’d heard how it could be used in things like high-strength lightweight composites, oil-absorbing sponges and biodegradable computer chips. Now, researchers from Sweden and the US have used the material to build soft-bodied batteries that are more shock- and stress-resistant than their traditional hard counterparts.

Nanocellulose is also known as nanofibrillated cellulose or Cellulose NanoFibrils (CNF). In a nutshell, it’s typically made using wood waste from sources such as lumber or paper mills, which has been added to water and then mechanically ripped apart to the point that the wood fibers are rendered into much smaller cellulose nanofibers. The resulting gel is subsequently freeze-dried, thus removing the water and leaving behind the long and interconnected nanofibers.

In the case of the latest research, scientists from Sweden’s Royal Institute of Technology (KTH) and California’s Stanford University used CNF to create a lightweight porous aerogel-like material. “The material resembles foam in a mattress, though it is a little harder, lighter and more porous,” says KTH researcher Max Hamedi…

It is now hoped that once developed further, the batteries could be used in applications such as flexible electronics, smart fabrics and safer electric cars.

Any commercial use up to and including space vehicles can use extra shock-resistance.

Using a recyclable material like cellulose is a win-win. The fact that source material is something we can grow rather than acquire through extractive processes like mining is another plus AFAIC.

Immunotherapy successes are “new era” for cancer treatment

A “whole new era” for cancer treatment is upon us, according to experts. Two new studies published in the New England Journal of Medicine provide further evidence that immunotherapy – the use of drugs to stimulate immune response – is highly effective against the disease.

Recently presented at the 2015 American Society for Clinical Oncology annual meeting, one study revealed that a drug combination of ipilimumab and nivolumab (an immune therapy drug) reduced tumor size in almost 60% of individuals with advanced melanoma – the deadliest form of skin cancer – compared with ipilimumab alone, while another study found nivolumab reduced the risk of lung cancer death by more than 40%.

Nivolumab is a drug already approved by the Food and Drug Administration (FDA) for the treatment of metastatic melanoma in patients who have not responded to ipilimumab or other medications. It is also approved for the treatment of non-small cell lung cancer (NSCLC) that has metastasized during or after chemotherapy.

According to cancer experts, however, the results of these latest studies indicate that nivolumab and other immune therapy drugs could one day become standard treatment for cancer, replacing chemotherapy

…Study co-leader Dr. James Larkin, of the Royal Marsden Hospital in the UK, told BBC News: “By giving these drugs together you are effectively taking two brakes off the immune system rather than one, so the immune system is able to recognize tumors it wasn’t previously recognizing and react to that and destroy them.

For immunotherapies, we’ve never seen tumor shrinkage rates over 50% so that’s very significant to see. This is a treatment modality that I think is going to have a big future for the treatment of cancer.”

RTFA for details, expansive coverage of parallels in methodology.

For a start, costs will be prohibitive, perhaps $200K per patient. Which doesn’t faze the medical-industrial complex. If we’re lucky and this system replaces chemotherapy, there is a possibility that further research might make this a qualitative change in cost as well as success rate.

We don’t know enough about quake, tsunami hazards, along Southern California

While their attention may be inland on the San Andreas Fault, residents of coastal Southern California could be surprised by very large earthquakes – and even tsunamis – from several major faults that lie offshore…

The latest research into the little known, fault-riddled, undersea landscape off of Southern California and northern Baja California has revealed more worrisome details about a tectonic train wreck in the Earth’s crust with the potential for magnitude 7.9 to 8.0 earthquakes. The new study supports the likelihood that these vertical fault zones have displaced the seafloor in the past, which means they could send out tsunami-generating pulses towards the nearby coastal mega-city of Los Angeles and neighboring San Diego.

“We’re dealing with continental collision,” said geologist Mark Legg of Legg Geophysical in Huntington Beach, California, regarding the cause of the offshore danger. “That’s fundamental. That’s why we have this mess of a complicated logjam…”

The logjam Legg referred to is composed of blocks of the Earth’s crust caught in the ongoing tectonic battle between the North American tectonic plate and the Pacific plate…The mostly underwater part of this region is called the California Continental Borderland, and includes the Channel Islands.

…What they were searching for are signs, like those seen along the San Andreas, that indicate how much the faults have slipped over time and whether some of that slippage caused some of the seafloor to thrust upwards.

What they found along the Santa Cruz-Catalina Ridge Fault are ridges, valleys and other clear signs that the fragmented, blocky crust has been lifted upward, while also slipping sideways like the plates along the San Andreas Fault do. Further out to sea, the Ferrelo Fault zone showed thrust faulting – which is an upwards movement of one side of the fault. The vertical movement means that blocks of crust are being compressed as well as sliding horizontally relative to each other-what Legg describes as “transpression…”

As Southern California’s pile-up continues, the plate movements that build up seismic stress on the San Andreas are also putting stress on the long Santa Cruz-Catalina Ridge and Ferrelo Faults. And there is no reason to believe that those faults and others in the Borderlands can’t rupture in the same manner as the San Andreas, said Legg…

NOAA was working on complete high-resolution bathymetry of the U.S. Exclusive Economic Zone – the waters within 200 miles of shore – until the budget was cut, said Legg. That left out Southern California and left researchers like himself using whatever bits and pieces of smaller surveys to assemble a picture of what’s going on in the Borderland, he explained.

“We’ve got high resolution maps of the surface of Mars,” Legg said, “yet we still don’t have decent bathymetry for our own backyard.”

Just in case our readers in the Southland didn’t have enough to worry about. :)

RTFA for the scary details.

Population benefits of sexual selection confirm that males are useful

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Biologists have long puzzled about how evolutionary selection, known for its ruthless requirement for efficiency, allows the existence of males — when in so many species their only contribution to reproduction are spermatozoa.

But research published…in Nature shows that sexual selection — when males compete and females choose over reproduction — improves population health and protects against extinction, even in the face of genetic stress from high levels of inbreeding.

The findings help explain why sex persists as a dominant mechanism for reproducing offspring.

Lead researcher Prof Matt Gage, from UEA’s School of Biological Sciences, said: “Sexual selection was Darwin’s second great idea, explaining the evolution of a fascinating array of sights, sounds and smells that help in the struggle to reproduce — sometimes at the expense of survival.

“Sexual selection operates when males compete for reproduction and females choose, and the existence of two different sexes encourages these processes. It ultimately dictates who gets to reproduce their genes into the next generation — so it’s a widespread and very powerful evolutionary force.

“Almost all multicellular species on earth reproduce using sex, but its existence isn’t easy to explain because sex carries big burdens, the most obvious of which is that only half of your offspring — daughters — will actually produce offspring. Why should any species waste all that effort on sons?

“We wanted to understand how Darwinian selection can allow this widespread and seemingly wasteful reproductive system to persist, when a system where all individuals produce offspring without sex — as in all-female asexual populations — would be a far more effective route to reproduce greater numbers of offspring.

“Our research shows that competition among males for reproduction provides a really important benefit, because it improves the genetic health of populations. Sexual selection achieves this by acting as a filter to remove harmful genetic mutations, helping populations to flourish and avoid extinction in the long-term.”

Phew! Had me worried for a while. :)

RTFA for details of the analysis.

Motherhood permanently alters your brain

motherhood

New research by Dr. Liisa Galea…suggests the form of estrogens used in hormone therapy and previous motherhood could be critical to explain why HT has variable effects. Research in women, and Dr. Galea’s research in animals, shows that one form of estrogens, called estradiol, which is the predominant form of estrogens in young women, had beneficial effects, while estrone, which is the predominant form of estrogens in older women, did not. Furthermore, the effects of estrone also depended on whether the rats had experienced motherhood: estrone-based HT impaired learning in middle-aged rats that were mothers, while it improved learning in rats that were not….

“Our most recent research shows that previous motherhood alters cognition and neuroplasticity in response to hormone therapy, demonstrating that motherhood permanently alters the brain” says Dr. Liisa Galea.

Dr. Liisa Galea is interested in how hormones affect brain and behaviour. Hormone therapy (HT) has been shown to have variable effects on brain function and Dr. Galea noted that one factor that had not received much attention was the form of estrogens used in HT. There are three forms of estrogens: estradiol, estrone and estriol. Estradiol is the most potent of estrogens, and it is the predominant form in young women, while estrone is a weaker estrogen and is the predominant form in post-menopausal women. A systematic review of the published scientific literature indicates that estradiol-based HT may have more beneficial effects, while estrone-based HTs may have more detrimental effect on cognition and dementia risk in women…

…Dr. Galea’s previous research had shown that motherhood causes changes in the architecture of connections in the hippocampus, so her team investigated whether the different forms of estrogens could have different effects on rats that had experienced motherhood once (primiparous rats) and on those who had not (nulliparous rats). They found that estrone-based HT improved learning in middle-aged nulliparous rats, but impaired learning in primiparous rats of the same age. These primiparous rats also showed a reduction in neurogenesis and zif268, a protein involved in neuroplasticity in the hippocampus.

As estrone is a component of the most common form of HT prescribed for women in the US, these findings could have implications for the treatment of age-related neurodegenerative disorders in women.

“Hormones have a profound impact on our mind. Pregnancy and motherhood are life-changing events resulting in marked alterations in the psychology and physiology of a woman. Our results argue that these factors should be taken into account when treating brain disorders in women” concludes Dr. Liisa Galea.

Questions relating to procreation are more scientific than social – just as the opposite is true of questions about religious belief, even though the hypothetical average individual has been taught otherwise.

I find it all interesting because I not only never had any interest in becoming a father, I had a vasectomy quite young. Of course, living, then, in a good Catholic state that simple out-patient procedure was illegal along with contraception. My urologist asked me to swear I would tell anyone who asked that I went to Rhode Island to have it done. :)