What Is Alzheimer’s?
Dr. Samuel Gandy is a professor of neurology, psychiatry, and Alzheimer's disease research at Mount Sinai Hospital. He is also associate director of the Mount Sinai Alzheimer's Disease Research Center, and chairman emeritus of the National Medical and Scientific Advisory Council of the Alzheimer's Association.
Dr. Gandy is an international expert in the metabolism of the amyloid proteins that clog the brain in patients with Alzheimer's disease.
Meryl Comer: I'm going to give you a statistic that will be bothersome to most of us: January 1st, 2011, boomers will begin turning 65 every 8 seconds, 10,000 a day, 4 million a year, what does that say to you Dr. Guarente?
Dr. Guarente: Well that says we have a big problem on our hands and the problem is diseases of aging, diseases where aging is a major component of the onset of the disease and I would say Alzheimer’s is number one on the list of diseases of aging and we really have to worry about it.
Meryl Comer: Dr. Gandy, can you put that in perspective of prevalence and what is the risk when you turn 65 and take us forward?
Dr. Gandy: Well the current prevalence is about 6 million in the United States alone. At age 65 the risk becomes about 10%, but by age 85 half of the population at that age and older have Alzheimer’s disease.
Meryl Comer: And the pathology, does it start then? Has it been in our systems? What is the progression? What is the pathology?
Dr. Gandy: Well the pathology is really a couple of things that have been discovered over the past 30 or 40 years. The first pathology that was identified really was a biochemical pathology, a deficit in a transmitter, a chemical that nerve cells use to talk to each other and the currently available drugs all target that sort of molecular pathology. More recently we’ve studied the buildup of proteins, substances that are normally present in the brain and function happily for 50, 60 years... but for reasons that we often don’t understand these proteins change their shape, clump and accumulate and buildup and kill the nerve cells of the brain.
Meryl Comer: Dr. Arancio, you’re an expert in synaptic dysfunction. What is going on in that disconnect?
Dr. Arancio: It’s I think that synaptic disfunction is the key to everything. The concept is more than 100 years old, that memory occurs in normal conditions when we are normal where the synapses become stronger. And really about 100 years ago this nobel Prize winner from Spain. He just wrote down that dementia occurs when the strengthening of synapses no longer works well, so I think it’s the key to understand the mystery of this disease.
Meryl Comer: Dr. Troncoso, the area, your specialty is frontal temporal dementias, Parkinson’s, Huntington. In most of those diseases it goes hand in hand with dementia-related issues. Can you tell us what the connection is?
Dr. Troncoso: Sure. I think that first of all we should have like a definition. Dementia is a clinical term. It means that you lose certain cognitive abilities that you have attained previously and then there are many diseases that can lead to dementia as the ones that you mentioned now—frontal temporal dementia for instance can cause dementia. Some patients with Parkinson’s disease eventually can develop dementia and, more importantly, vascular diseases, strokes also can either cause or contribute to dementia. And I think that when we talk about Alzheimer’s disease in terms of the pathology we should be aware that not everybody has Alzheimer’s disease by itself. In fact, most patients with Alzheimer’s disease do have some what we call co-morbidity, a second disease and the most common of the co-morbidities is vascular diseases, so patients have both Alzheimer’s and strokes and together then they lead to dementia.
Meryl Comer: And from a family perspective the management issues are the same. It’s just complicated because there are two diseases versus one disease.
Dr. Troncoso: Exactly, from the standpoint of the caretaker it is probably the same, but I think from the perspective of a health provider it is not the same, because in the case of vascular disease there is an element of treatment. It is.... you can prevent at least some of the vascular disease. For instance, if you prevent hypertension, which is something that can be done fairly easily, you actually prevent at least in some cases the development of dementia.
Recorded October 29, 2010
For much of the past 100 years, little was known about Alzheimer’s disease and dementia. But recent research is revealing the neurotransmitter and genetic defects behind the disease.
It's just the current cycle that involves opiates, but methamphetamine, cocaine, and others have caused the trajectory of overdoses to head the same direction
- It appears that overdoses are increasing exponentially, no matter the drug itself
- If the study bears out, it means that even reducing opiates will not slow the trajectory.
- The causes of these trends remain obscure, but near the end of the write-up about the study, a hint might be apparent
Through computationally intensive computer simulations, researchers have discovered that "nuclear pasta," found in the crusts of neutron stars, is the strongest material in the universe.
- The strongest material in the universe may be the whimsically named "nuclear pasta."
- You can find this substance in the crust of neutron stars.
- This amazing material is super-dense, and is 10 billion times harder to break than steel.
Superman is known as the "Man of Steel" for his strength and indestructibility. But the discovery of a new material that's 10 billion times harder to break than steel begs the question—is it time for a new superhero known as "Nuclear Pasta"? That's the name of the substance that a team of researchers thinks is the strongest known material in the universe.
Unlike humans, when stars reach a certain age, they do not just wither and die, but they explode, collapsing into a mass of neurons. The resulting space entity, known as a neutron star, is incredibly dense. So much so that previous research showed that the surface of a such a star would feature amazingly strong material. The new research, which involved the largest-ever computer simulations of a neutron star's crust, proposes that "nuclear pasta," the material just under the surface, is actually stronger.
The competition between forces from protons and neutrons inside a neutron star create super-dense shapes that look like long cylinders or flat planes, referred to as "spaghetti" and "lasagna," respectively. That's also where we get the overall name of nuclear pasta.
Caplan & Horowitz/arXiv
Diagrams illustrating the different types of so-called nuclear pasta.
The researchers' computer simulations needed 2 million hours of processor time before completion, which would be, according to a press release from McGill University, "the equivalent of 250 years on a laptop with a single good GPU." Fortunately, the researchers had access to a supercomputer, although it still took a couple of years. The scientists' simulations consisted of stretching and deforming the nuclear pasta to see how it behaved and what it would take to break it.
While they were able to discover just how strong nuclear pasta seems to be, no one is holding their breath that we'll be sending out missions to mine this substance any time soon. Instead, the discovery has other significant applications.
One of the study's co-authors, Matthew Caplan, a postdoctoral research fellow at McGill University, said the neutron stars would be "a hundred trillion times denser than anything on earth." Understanding what's inside them would be valuable for astronomers because now only the outer layer of such starts can be observed.
"A lot of interesting physics is going on here under extreme conditions and so understanding the physical properties of a neutron star is a way for scientists to test their theories and models," Caplan added. "With this result, many problems need to be revisited. How large a mountain can you build on a neutron star before the crust breaks and it collapses? What will it look like? And most importantly, how can astronomers observe it?"
Another possibility worth studying is that, due to its instability, nuclear pasta might generate gravitational waves. It may be possible to observe them at some point here on Earth by utilizing very sensitive equipment.
The team of scientists also included A. S. Schneider from California Institute of Technology and C. J. Horowitz from Indiana University.
Check out the study "The elasticity of nuclear pasta," published in Physical Review Letters.
Scientists think constructing a miles-long wall along an ice shelf in Antarctica could help protect the world's largest glacier from melting.
- Rising ocean levels are a serious threat to coastal regions around the globe.
- Scientists have proposed large-scale geoengineering projects that would prevent ice shelves from melting.
- The most successful solution proposed would be a miles-long, incredibly tall underwater wall at the edge of the ice shelves.
The world's oceans will rise significantly over the next century if the massive ice shelves connected to Antarctica begin to fail as a result of global warming.
To prevent or hold off such a catastrophe, a team of scientists recently proposed a radical plan: build underwater walls that would either support the ice or protect it from warm waters.
In a paper published in The Cryosphere, Michael Wolovick and John Moore from Princeton and the Beijing Normal University, respectively, outlined several "targeted geoengineering" solutions that could help prevent the melting of western Antarctica's Florida-sized Thwaites Glacier, whose melting waters are projected to be the largest source of sea-level rise in the foreseeable future.
An "unthinkable" engineering project
"If [glacial geoengineering] works there then we would expect it to work on less challenging glaciers as well," the authors wrote in the study.
One approach involves using sand or gravel to build artificial mounds on the seafloor that would help support the glacier and hopefully allow it to regrow. In another strategy, an underwater wall would be built to prevent warm waters from eating away at the glacier's base.
The most effective design, according to the team's computer simulations, would be a miles-long and very tall wall, or "artificial sill," that serves as a "continuous barrier" across the length of the glacier, providing it both physical support and protection from warm waters. Although the study authors suggested this option is currently beyond any engineering feat humans have attempted, it was shown to be the most effective solution in preventing the glacier from collapsing.
Source: Wolovick et al.
An example of the proposed geoengineering project. By blocking off the warm water that would otherwise eat away at the glacier's base, further sea level rise might be preventable.
But other, more feasible options could also be effective. For example, building a smaller wall that blocks about 50% of warm water from reaching the glacier would have about a 70% chance of preventing a runaway collapse, while constructing a series of isolated, 1,000-foot-tall columns on the seafloor as supports had about a 30% chance of success.
Still, the authors note that the frigid waters of the Antarctica present unprecedently challenging conditions for such an ambitious geoengineering project. They were also sure to caution that their encouraging results shouldn't be seen as reasons to neglect other measures that would cut global emissions or otherwise combat climate change.
"There are dishonest elements of society that will try to use our research to argue against the necessity of emissions' reductions. Our research does not in any way support that interpretation," they wrote.
"The more carbon we emit, the less likely it becomes that the ice sheets will survive in the long term at anything close to their present volume."
A 2015 report from the National Academies of Sciences, Engineering, and Medicine illustrates the potentially devastating effects of ice-shelf melting in western Antarctica.
"As the oceans and atmosphere warm, melting of ice shelves in key areas around the edges of the Antarctic ice sheet could trigger a runaway collapse process known as Marine Ice Sheet Instability. If this were to occur, the collapse of the West Antarctic Ice Sheet (WAIS) could potentially contribute 2 to 4 meters (6.5 to 13 feet) of global sea level rise within just a few centuries."
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