This is a very cool study, with the massive caveat that it is extremely preliminary – but scientists have concluded an in vitro study of nanodevices that can reduce one of the pathological changes thought to be a significant cause of Alzheimer’s disease. This has to be put into context, but let me first describe what they did.

Alzheimer’s disease (AD) is a neurodegenerative disorder that affects the brain diffusely. Little by little brain cells die, the brain atrophies, and cognitive ability slowly declines causing dementia. The disease affects about 10% of people over 65, producing a huge burden on individuals, families, and society. As our population ages, it is becoming even more prevalent. There is extensive research on how Alzheimer’s disease progresses, looking for clues that might lead to an effective treatment. However, it has proven a tough nut to crack. We have many clues, but nothing that has lead to a treatment that can prevent, stall, or reverse the neurodegeneration. It is, in short, a complex disease.

One piece of this complex puzzle is the β-amyloid peptide (Aβ), which is a breakdown product of an amyloid protein precursor. The simple version is that this peptide is normally cleared from brain cells as a waste product, but in some individuals it is not sufficiently cleared and there is enough hanging around to form conglomerations or clumps of the protein. These clumps form plaques, which are a major pathological sign of AD. However, the picture is more complex than that. The amount of plaques in the brain don’t necessarily correlate with the severity of the dementia in AD, so it is clearly not the whole picture. More recent studies have found:

Substantial evidence now indicates that the solubility of Aβ, and the quantity of Aβ in different pools, may be more closely related to disease state. The composition of these pools of Aβ reflects different populations of amyloid deposits, and has definite correlates with the clinical status of the patient.

There are also pathological processes in AD that are not related to amyloid plaques, so again we are only dealing with part of the picture here. Still, researchers have been looking for ways to prevent plaque formation as a possible way to slow, stop, or even reverse AD. So far nothing has led to an approved treatment. (Current treatments for AD are only symptomatic.)

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Dr. Matt Hill is filling the role of the Lorax for insects. They are a critical part of our ecosystem, and they are experiencing a long term decline. I know there is a lot to worry about in our complex world, and insects may not immediately jump to near the top of the list, but they are important, and also an index of ecological change.

We are used to thinking of insects as pests, just as we are used to thinking of bacteria as germs that cause infections. But most species of bacteria or completely neutral when it comes to humans, and some are actually beneficial (even critical). The same is true for insects. Only a relatively small percentage are pests (which itself is a relative term), while most go about their lives indifferent to humanity. Some species are directly beneficial, like pollinators. Regardless of their relationship to humanity, insects are a critical part of the ecosystem. Insects have the largest biomass of all animals (although animals as a group are dwarfed by plants and to a lesser extent bacteria).

A 2019 study concluded that 40% of insect species were at risk of extinction over the next few decades. Other studies show a significant decrease in insect biomass over the last 50 years. This is a loss of a critical source of food for the entire ecosystem.  Hill and his colleagues (Pedro Cardoso is first author) now have published a review of this research, warning the world of this critical decline, summarizing possible causes, and recommendations some steps individuals can take as partial solutions. They summarize the causes:

We are causing insect extinctions by driving habitat loss, degradation, and fragmentation, use of polluting and harmful substances, the spread of invasive species, global climate change, direct overexploitation, and co-extinction of species dependent on other species.

Like most stresses on the ecosystem, the biggest factor is land use. Recent estimates are that humans actively use almost half of all land on Earth, mostly for agriculture and ranges for domestic animals. Some of what is left is also “semi-natural”, meaning that it is not directly occupied or used, but is not “pristine” wilderness either. And of course the entire planet is now affected by things like pollution, climate change, and the introduction by human activity of invasive species. We are putting tremendous stress on ecosystems.

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Binaural beats are an auditory illusion created by listening to two tones of slightly different frequency. This produces a type of feedback effect in the brain that produces a third illusory sound that has a pulsating quality, hence binaural beats. All perceptual illusions are fascinating, at least to neuroscientists, because they are clues to how the brain processes sensory information. What we ultimately perceive is the result of a complex constructive process (not passive recording) and understanding the process offers insight into the strengths and weaknesses of human perception.

But there is another angle to binaural beats about which I have always been, appropriately, skeptical. There is popular belief that listening to the binaural beat illusion is a method for “hacking” into the brain and affecting mood and cognition, improving memory and alertness. Most “brain hack” claims turn out to be false, or at least massively overstated, so initial skepticism is warranted. Such claims are often based on, “Look, something is happening in the brain, therefore…” types of evidence.  But the brain is a machine, albeit a biological one, and it is not impossible that outside stimulation can make the machine work more or less efficiently. So I filed this away as – a small effect is not impossible, but I would need to see convincing evidence before I believe this “one simple trick” claim.

There is a recent study of the effects of binaural beats which prompted this review, but this is just the latest in a couple of decades of research. Let’s first look at the most recent study – Binaural beats through the auditory pathway: from brainstem to connectivity patterns. The study looked at two things, the effect of binaural beats on the overall pattern of brain activity, and the effect on mood. What they found is discouraging for those who think binaural beats have some special effect on the brain. They found: Continue Reading »

More than a thousand scientists working for over a decade in 37 countries have just published the results of their comprehensive analysis of cancer genetics – Pan-cancer analysis of whole genomes. This was a massive effort, facilitated by modern computing allowing for international collaboration. It is a good example of the collaborative nature of science. There are some interesting take-aways from the results, but first let’s review the basics of cancer.

In healthy tissue there are multiple mechanisms to keep cells from reproducing and growing without limit. Cell proliferation is a carefully regulated process, and when that process goes awry one potential result is cancer. It has already been established for many cancers that they are caused by a combination of genetic mutations, which disable one or more of these regulatory mechanisms. The result are cells that will grow without limit, either in the blood or forming a solid tumor. Cancers can vary in terms of how aggressive they are – how fast do they grow, how much do they invade neighboring tissue, and how likely are they to metastasize (spread to remote areas).

Treating cancer involves removing tumors, and using drugs and radiation to kill rapidly dividing cells. Cancer cells are rapidly dividing, but so are some healthy tissues and this leads to significant side effects. Newer treatments block the formation of new blood cells to feed tumors, and also harness the immune system to attack cancer cells. Despite the fact that cancer is a horrifically complex set of diseases (not one disease), progress in our understanding and treatment of cancer has lead to a steady increase in survival.

The death rate from cancer in the US declined by 29% from 1991 to 2017, including a 2.2% drop from 2016 to 2017, the largest single-year drop ever recorded, according to annual statistics reporting from the American Cancer Society.

It is unlikely that there will ever be a “cure for cancer” but progress will lead to a steady slow improvement in survival, so that fewer and fewer people will actually die from their cancer, as opposed to living long enough to die from something else.

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Remember the “Solar Freakin’ Roadways?” The idea was to pave roads with solar cells that would produce electricity for the grid. The power could also be used for LEDs that could serve as traffic lights and warning signals, and the power could melt snow and ice to boot. I wrote about this in 2014 and at the time I was not impressed with the arguments that were being made.

As many people pointed out – there are huge practical problems with this concept. The main problem is that you would have to engineer the solar cells to withstand traffic and all the abuse that roads take. This would likely degrade their efficiency over time, and also make upkeep very expensive. For the money you would be far better off simply installing solar panels on rooftops, or even suspending them over roads or wherever that might make sense.

I wasn’t entirely negative. I liked the idea in theory, just thought there were serious practical hurdles and we need some real-world testing. I also said this:

“It’s also possible that such panels might find a niche use, but not be cost effective for our entire highway infrastructure. For example, they may find a market for private driveways. I would like not to have to plow or shovel my driveway, and it may reduce my energy bills a bit. Also, a driveway takes a lot less abuse than a highway.

Or perhaps parking lots, bike paths, or playgrounds may find a use. Perhaps they will be better for small back roads than highways, or the other way around, or they will be perfect for cities or sidewalks. Maybe airport runways might justify the cost.”

Well now it’s 5 years later, and we have some real-world testing. The largest test was in France, which two years ago installed a 1 kilometer stretch of solar roadway. Le Monde reports that the experiment was a complete failure. The roadway is deteriorating rapidly. A large section had to be completely demolished. Panels come loose and then are broken or dislodged by traffic. Leaves and other debris cover the surface. Also:

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A new paper published in Nature, and signed by over 800 researchers, adds to the growing backlash against overreliance on P-values and statistical significance. This one makes a compelling argument for getting rid of the concept of “statistical significance” altogether. I completely agree.

Statistical significance is now the primary way in which scientific results are recorded and reported. The primary problem is that it is a false dichotomy, and further it reduces a more thorough analysis of the results to a single number and encourages interpreting the results as all or nothing – either demonstrating an effect is real or not real.

The primary method for determining significance is the P-value – a measure of the probability that the results obtained would deviate as much as they do or more from a null result if the null hypothesis were true. This is not the same as the probability that the hypothesis is false, but it is often treated that way. Also, studies often assign a cutoff for “significance” (usually a p-value of 0.05) and if the p-value is equal to or less than the cutoff the results are significant, if not then the study is negative.

When you think about it, this makes no sense. Further, the p-value was never intended to be used this way. It is only the human penchant for simplicity that has elevated this one number to the ultimate arbiter of how to interpret the results of a study.

The consequences of this simplistic analysis is that the interpretation of study results are often misleading. The authors, for example, looked at 791 articles in 5 journals and found that half of them made wrong conclusions about the results based on overinterpreting the implication of “significance”.

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A recent opinion piece in the New York Times by Krista Burton is perhaps one sign of recent social trends – increasing belief in things like astrology, especially among millennials. Burton provides some insight into this phenomenon, but then also makes some horrible justifications for it.

Belief in astrology, the notion that the relative positions of planets and start affect our personality and perhaps our destiny, has been measured at about 25% in the UK, Canada and US in recent decades. However, as researchers, Nicholas Campion, points out, the number depends greatly on what exactly you ask:

In one of my groups – of mostly male students aged 18 to 21 – I found that 70% read a horoscope column once a month and 51% valued its advice. Other questions produced a huge variation: 98% knew their sun sign, 45% thought it described their personalities, 25% said it can make accurate forecasts, and 20% think the stars influence life on Earth. The higher figures are close to previous research which showed that 73% of British adults believe in astrology, while the lowest figures are similar to those found by Gallup’s polls.

It’s difficult to know how to parse all of that, but it seems like about half of people take astrology seriously to some extent, and 20-25% very seriously. That is a significant percentage of the population to believe in something which is 100% superstitious nonsense. Let’s get this out of the way now – there is no plausible mechanism by which astrology could work, there is no evidence that any form of astrology does work, and it is structured and functions like a classic pseudoscience. A moderate amount of scientific literacy, and a trace of critical thinking skills, should be enough to purge any belief in astrology.

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A new review of the past few decades of satellite data published in the most recent edition of Nature tells the story of what is happening to ice on Antarctica. The result is probably exactly what you think – the ice is melting, at an accelerating rate. But the details are interesting.

First, we should note that Antarctica is a continent. There is land under all that ice, unlike the Arctic which is floating ice without any land. This makes a huge difference. While Arctic ice melts, the water fits exactly into the space previously displaced by the ice, so does not result in any sea-level rise. There are other effects to be concerned about, such as the effect on ecosystems and the effects of all that fresh water melting into the North Atlantic.

When ice sitting on top of land melts, however, that is new water finding its way to the sea, resulting in direct sea-level rise. As water gets warmer, it also expands, which further causes sea level rise. Also, the weight of all that ice pushes down the land, and when the mass of that ice decreases the land actually lifts up a bit.

The Antarctic ice system is also more complex than the Arctic. There are different glacier systems, which terminate at the ocean, and then there is the surrounding sea ice. There are several ways to estimate the extent of ice also, not just land coverage. Scientists need to also measure the thickness of the ice, the relationship between land and sea ice, the weight of the ice (the gravity it produces), and look at the under side of the glaciers that can erode away from warm sea water.

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A recent article in the Independent is, in my opinion, a good example of how ideology can overwhelm evidence and logic. The article is basically an advertisement for a book, Dead Zone by ornithologist Philip Lymbery , which is out in paperback this week.

Lymbery’s thesis is that bird and other animal populations are steadily declining due to modern farming. If we want to stabilize the environment, and stop or reverse this trend, we need to make major changes to how we grow our food. He then advocates for organic farming and a return to older farming practices. He blames the situation on the attempt to maximize food production.

I think that Lymbery has correctly identified a real problem – an alarming decline in wild species over the last century. However, his proposed solution would actually make the problem worse. It is a classic example of narrative or ideology getting in the way of evidence-based solutions.

I don’t pretend to have any magic solution to the current issues Lymbery discusses. It is important to recognize that they are very complex, and we need to think carefully about what the real source of the problems are and what the best solutions might be.

Lymbery, as an ornithologist, has expertise when it comes to understanding bird populations and reasons contributing to their decline. However, he does not have farming expertise, and his statements about farming sound like knee-jerk appeal to nature fallacies, rather than informed opinion.

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Perhaps one of the most underrated science stories of 2017 was the separation of a massive iceberg the size of Delaware from the Larsen C Ice Shelf in Antarctica. That is because this is not an isolated event, but just a dramatic part of a larger story – the melting of Antarctica.

Antarctica contains most of the ice on Earth (90%). Much of that ice sits on top of land, unlike Arctic ice which is floating. When floating ice melts it just fills the space that it had displaced. There is a little bit a sea rise due to rising temperatures – water expands as it warms. But this amount of sea rise is small overall. When ice that was sitting on land flows into the ocean, it raises the sea level more significantly.

Antarctica is comprised of glaciers sitting on top of the continent, which itself is mostly below sea level. These glaciers are as thick as three miles. They are divided into a western glacier system and an eastern glacier system. West Antarctica, which is melting faster, contains enough ice to raise the sea level by 14 feet. East Antarctica is more stable but still showing some early signs of melting. All the ice here could raise the sea level by 175 feet.

As the glaciers melt during the warmer months they follow channels out to the ocean. These channels, however, are blocked by ice shelves, which act like a cork, keeping back the ice and helping to maintain the stability of the glaciers.

The ice shelves themselves have a certain structure – they rest on the sea floor but as they extend out from the continent eventually the ice lifts off the sea floor (called the grounding point) and as the ice extends out further it is floating on top of the water. The breakup of these ice shelves is a concern, because that would essentially remove the stopper and greatly accelerate the rate at which glacier melt finds its way to the ocean.

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