Researchers warn that official figures underestimate the pandemic’s real death toll, which could more than triple if the virus is allowed to spread unchecked.
What was once a health crisis that Americans feared has evolved into one virtually everyone has experienced up close. That will affect behavior, but in many different ways.
In their paper published in Frontiers of Physics, Franco Vazza (astrophysicist at the University of Bologna) and Alberto Feletti (neurosurgeon at the University of Verona) investigated the similarities between two of the most challenging and complex systems in nature: the cosmic network of galaxies and the network of neuronal cells in the human brain.
Despite the substantial difference in scale between the two networks (more than 27 orders of magnitude), their quantitative analysis, which sits at the crossroads of cosmology and neurosurgery, suggests that diverse physical processes can build structures characterized by similar levels of complexity and self-organization.
The human brain functions thanks to its wide neuronal network that is deemed to contain approximately 69 billion neurons. On the other hand, the observable universe can count upon a cosmic web of at least 100 billion galaxies. Within both systems, only 30% of their masses are composed of galaxies and neurons. Within both systems, galaxies and neurons arrange themselves in long filaments or nodes between the filaments. Finally, within both systems, 70% of the distribution of mass or energy is composed of components playing an apparently passive role: water in the brain and dark energy in the observable Universe.
Like walking and breathing and could one day allow people to control prosthetics simply by thinking…
The US Army is funding a project that could lead to brain-machine interfaces. It includes an algorithm capable of isolating brain signals and linking them to specific behaviors such as walking and breathing.
Continue reading “Army-funded algorithm decodes brain signals responsible for behaviors” »
Even genes essential for life can be caught in an evolutionary arms race that forces them to change or be replaced.
Circa 2013
The Book of Genesis puts Adam and Eve together in the Garden of Eden, but geneticists’ version of the duo — the ancestors to whom the Y chromosomes and mitochondrial DNA of today’s humans can be traced — were thought to have lived tens of thousands of years apart. Now, two major studies of modern humans’ Y chromosomes suggest that ‘Y-chromosome Adam’ and ‘mitochondrial Eve’ may have lived around the same time after all1, 2.
When the overall population size does not change (as is likely to have happened for long periods of human history), men have, on average, just one son. In this case, evolutionary theory predicts that for any given man there is a high probability that his paternal line will eventually come to an end. All of his male descendants will then have inherited Y chromosomes from other men. In fact, it is highly probable that at some point in the past, all men except one possessed Y chromosomes that by now are extinct. All men living now, then, would have a Y chromosome descended from that one man — identified as Y-chromosome Adam. (The biblical reference is a bit of a misnomer because this Adam was by no means the only man alive at his time.)
Continue reading “Genetic Adam and Eve did not live too far apart in time” »
Circa 2013
A group of scientists from Kyoto has managed to successfully analyze and “record” the basic elements of what people see when they dream. The idea of recording dreams has been a mainstay in science fiction, but also a frequent goal for researchers. As Smithsonian Magazine writes, this group designed its study based on the premise that brains react to “seeing” objects with repeatable patterns that can be measured with MRI. If a machine can recognize the patterns well enough, it can reverse-engineer them, giving us a window into what’s going on inside people’s heads while they dream.
Three participants were selected for a study and asked to sleep for several three-hour blocks in an MRI scanner. Once they fell asleep, scientists woke them up and asked them to describe what they’d seen in the dream, grouping them into loose categories and sub-categories like “car,” “male,” “female,” or “dwelling.” The group then picked representations of those categories from an online image search and showed them to the participants, once again measuring their brain activity to figure out what patterns might be unique to that concept. Finally, the participants were asked to sleep again, but this time, a machine wouldn’t simply record how their brain responded to dreaming — it would attempt to match it to one of the categories with a series of images, as seen in the video below.
Continue reading “Scientists turn dreams into eerie short films with an MRI scan” »
First introduced into wide use in the middle of the 20th century, nuclear magnetic resonance (NMR) has since become an indispensable technique for examining materials down to their atoms, revealing molecular structure and other details without interfering with the material itself.
“It’s a broadly used technique in chemical analysis, materials characterization, MRI—situations in which you do a non-invasive analysis, but with atomic and molecular details,” said UC Santa Barbara chemistry professor Songi Han. By placing a sample in a strong magnetic field and then probing it with radio waves scientists can determine from the response from the oscillating nuclei in the material’s atoms the molecular structure of the material.
“However, the problem with NMR has been that because it’s such a low-energy technique, it’s not very sensitive,” Han said. “It’s very detailed, but you don’t get much signal.” As a result, large amounts of sample material may be needed relative to other techniques, and the signals’ general weakness makes NMR less than ideal for studying complex chemical processes.
