Archive for April, 2014

Apr 29 2014

Neuromorphic Computing

Published by under Neuroscience

Kwabena Boahen and other engineers at Stanford University announce that they have developed a computer chip modeled after the human brain. They call the technology “neuromorphic” and their current device the neurogrid. They say it can simulate 1 million neurons in real time, a feat that would otherwise require a super computer.

The idea is that the human brain is much more powerful and energy efficient than our current computers. A mouse brain can process information 9,000 times faster than a computer simulation of its functions, while using much less energy.

The article does not explicitly state it, but I suspect these numbers are for virtual simulations – in other words, we are not building mouse brain circuits in silicon, we are using standard digital computer to simulate the mouse circuits in software. Virtual simulations are much less efficient (about an order of magnitude) than dedicated circuits.

Even still, the neurogrid looks like a huge advance even over building dedicated brain circuits using standard digital chip technology.

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Apr 28 2014

Dueling Narratives on Organic Farming

Published by under General Science

There are many public debates raging that are essentially dueling narratives, both sides claiming to have science, evidence, and logic on their side. It always fascinates me when two groups can look at the same evidence and come to opposite conclusions. Is man-made climate change a real danger or all hype? Are alternative medicine treatments a revolution or a scam? Is GMO our best hope for sustainable agriculture or a looming health menace? Is organic farming useful or just marketing the naturalistic fallacy?

These binary choices are a bit of a false dichotomy, but not entirely, as people do tend to fall into one or the other camp. The narratives then tend to polarize the two sides with self-reinforcing echochambers of opinion and information.

I am also not suggesting that in each of the topics above the two sides are symmetrical or equally valid. Alternative medicine, for example, is a scam – it is the explicit creation of a double standard in order to market treatments that fail the test of scientific validity.

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Apr 25 2014

Prebiotic Earth

Published by under Evolution

One of the great scientific mysteries is the specific processes and pathways that led to the first living organisms on earth. This is not mysterious in that we don’t know how it could have happened, it’s just that it is extremely difficult to reconstruct how is actually did happen. Chemical reactions don’t fossilize, and so understanding a complex process that likely took millions of years to unfold billions of year ago is a bit challenging.

Researchers have mostly had to rely on plausibility studies – experiments that show how prebiotic evolution could have happened and extrapolating from data on early earth conditions. More progress has been made with this type of research. The title of the paper says it all – Non-enzymatic glycolysis and pentose phosphate pathway-like reactions in a plausible Archean ocean. (Markus A. Keller, Alexandra V. Turchyn, Markus Ralser)

The researchers showed that, in conditions based upon published literature about the early prebiotic ocean, certain metabolic pathways central to life could happen spontaneously and without the presence of enzymes. That last bit is critical – enzymes are proteins that act as catalysts, which are substances that make a chemical reaction happen faster. Enzymes are critical to life, as the biochemical reactions of life would occur at too slow a rate without them.

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Apr 24 2014

Ernst on Homeopathy

Edzard Ernst is one of my intellectual heroes. If you are a skeptic, you need to know who he is. He began his career amenable to the claims of alternative medicine. He became the world’s first professor of complementary and alternative medicine, and set about to do the one thing that no other CAM proponent (to my knowledge) has truly ever done – he wanted to use rigorous scientific research to find out if any specific CAM modality worked. Most proponents use research to prove that CAM does work, or simply to describe how it is used or how it can best be implemented.

Throughout the publication of his more than a thousand scientific articles, Edzard became increasingly convinced that most CAM methods simply do not work. Further, he learned what happens to people who point to the scientific truth about CAM, they are vilified by true believers.

I have to admire anyone who changes their world-view significantly in the face of scientific evidence. His intellectual honesty is refreshing.

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Apr 22 2014

Motivated Memory

Published by under Neuroscience

I have had the following experience many times, and so I suspect that it is a near-universal experience. You are in a heated conversation with one or more other people who have differing opinions on the topic of discussion. Perhaps it’s just a fight over personal matters. After the heat has died down and calmer emotions prevail, you try to come to some sort of resolution about the prior conversation. Such efforts, however, are complicated by the fact that everyone has a very different memory of the conversation you just shared.

A related experience that is also common occurs when discussing a topic about which there is disagreement (such as politics), and then revisiting the topic weeks or months later. Again, everyone has a different memory of the prior discussion, including which facts were established. It’s almost as if the previous conversation had not taken place.

It’s as if everyone edits their memories to fit their existing narrative. In this way, memory can be a very dangerous thing – it gives us a false confidence in our current beliefs and attitudes. We believe the facts support our position. However, we often choose our facts based on our narrative, rather than craft a narrative based upon facts.

We tend to easily see this process in others, but of course often fail to see it in ourselves.

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Apr 21 2014

Not Looking Good for Biofuels

Published by under General Science

I have yet to be convinced that biofuels will be a significant benefit in our attempts to achieve sustainable energy production. Ideally we would run our civilization on energy that does not burn a limited resource or contribute CO2 or other compounds into the atmosphere. Any limited resource will eventually run out, by definition. Further, no matter what you think about the current effects of climate change, it’s hard to deny that if we continue to pump CO2 into the atmosphere this is likely to be a problem.

Biofuels sound like a good idea at first. Plants get their energy from the sun and fix CO2 from the atmosphere. Because we can grow plants, this is a renewable resource. When we burn fuel made from plants we are releasing the previously captured CO2 back into the atmosphere, and so the process is carbon neutral. Sound pretty good.

However, experts argue that we have to consider in this equation every aspect of the production of biofuels. The equation will change depending on the source of the fuel, and it is possible that if we use the right plant source and have a sufficiently efficient process, then we might have a biofuel with a net benefit. I think we will get there, but even still how much of a benefit is an important question.

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Apr 18 2014

OMG – The Chemicalz

The Foodbabe is at it again – well, she never stopped being at it. She is apparently trying to make a career out of a combination of the naturalistic fallacy and chemical illiteracy.

I wrote previously about her campaign to scaremonger about completely safe ingredients in food. She called azodicarbonamide, an ingredient to make bread fluffier, the yoga mat chemical because it also has a variety of industrial uses, including making yoga mats. Soy also has a variety of uses, including making yoga mats.

She successfully marshaled her scientific illiteracy to pressure Subway into removing the ingredient from their bread.

Her modus operandi is simple – look at ingredient lists for names that sound like chemicals or are difficult to pronounce, bypass any scientific analysis or evidence and go straight to hyperbolic fearmongering. Then just hope that companies cave in order to avoid negative press before anyone can ask too many questions.

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Apr 17 2014

Predicting Recovery from Coma

Published by under Neuroscience

I have been following the literature on using newer technologies (PET, fMRI, and quantitative EEG) to evaluate the brain activity of patients who appear unresponsive, loosely referred to as coma, or more generally disorders of consciousness. A new study, which I will get to below, adds an interesting element to the research.

For background, disorders of consciousness result from brain injury or disease that affects either the brainstem (needed for arousal) and/or both brain hemispheres. Level of consciousness is a continuum from drowsy to brain dead, but for the purposes of this discussion I am going to focus on three categories of chronic impairment of consciousness.

The first is called a minimally conscious state. In this condition patients are barely able to interact with their environment. They are mostly unresponsive, non-verbal, cannot care for themselves, but may respond to stimulation or show some interaction with their environment.

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Apr 15 2014

Why We Need a Skeptical Movement

Published by under Skepticism

Skeptics tend (as they should) to question everything, even the need for a movement of self-identified skeptics. It is an interesting question – what is the net cultural effect of organized scientific skepticism?

Of course, we can’t really ever know the answer to this question. There are too many moving parts. We could point to cultural trends, but this is probably the worst line of evidence. There is no way to control for skepticism as an isolated variable. We have no way of knowing what the world would be like without organized skepticism.

We can point to individuals whose lives have been changed, they believe for the better. I am heartened by every e-mail I receive from a reader or listener who says their life has been changed for the better because of skeptical outreach. Perhaps they were steered away from a career in pseudoscience, learned how to think more critically about everything, or just found a community to which they could connect.

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Apr 14 2014

Navy Process to Make Fuel from Seawater

Researchers at the US Naval Research Laboratory (NRL) announced that they have successfully tested a process to convert seawater into jet fuel. They can extract CO2 both dissolved and bound from the water as a source of carbon, and can extract H2 through electrolysis. They then convert the CO2 and hydrogen into long chain hydrocarbons:

NRL has made significant advances in the development of a gas-to-liquids (GTL) synthesis process to convert CO2 and H2 from seawater to a fuel-like fraction of C9-C16 molecules. In the first patented step, an iron-based catalyst has been developed that can achieve CO2 conversion levels up to 60 percent and decrease unwanted methane production in favor of longer-chain unsaturated hydrocarbons (olefins). These value-added hydrocarbons from this process serve as building blocks for the production of industrial chemicals and designer fuels.

They claim that with this process they can mass produce jet fuel for $3-6 per gallon. They tested the fuel on a model airplane, and it appeared to work fine.

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