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Apr 1, 2021

Simulating the Universe a Trillionth of a Second After the Big Bang

Posted by in categories: computing, cosmology

The Big Bang remains the best way to explain what happened at the beginning of the Universe. However, the incredible energies flowing during the early part of the bang are almost incomprehensive to our everyday experience. Luckily, computers aren’t so attached to normal human ways of thinking and have long been used to model the early universe right after the Bang. Now, a team from the University of Göttingen have created the most comprehensive model of what exactly happened in that very early stage of the universe – one trillionth of a second after the Big Bang.

Just because a computer can model it doesn’t really mean it is easy to explain, however. The model includes clumps of energy weighing grams, but which are one millionth the size of a single proton. These energy structures defined what would eventually become the structure of the universe today, with tiny variations in the original structure resulting in entire galaxies or complete voids, depending on the presence or absence of matter.

Throwing this much computing power at a physical space one millionth the size of a proton was no mean feat. “It is probably the largest simulation of the smallest area of the Universe that has been carried out thus far” says Professor Jens Niemeyer, who leads the group carrying out the research.

Apr 1, 2021

The Closest Star Cluster to Earth is Being Dismantled in Front of our Eyes

Posted by in categories: computing, cosmology, mapping

Star clusters are interesting inhabitants of the sky. They vary in sizes, distances, and number of stars, but almost all are spectacular to look at. And most of them are in the process of being torn apart. That is certainly the case for the Hyades star cluster – the closest one to Earth at only 153 light years away. The problem is, there is something causing a lot more destruction than would be expected given the mass and energy in the surrounding space. Now, a team of scientists from ESA have a theory as to what the cause of the destruction might be – a mysterious dark matter sub-halo.

This novel theory extends from findings gleaned from data collected by GAIA, ESA’s star mapping satellite. The GAIA team expected to see what are called “tidal tails” trailing and leading the star cluster as it moves throughout the galaxy. These tails are formed when some stars are forced to the outer edges of the cluster, and then pulled by the gravitational pull of the galaxy itself, pushing some stars forward in their journey through the galaxy, while other stars are pulled further behind.

The GAIA team did find tidal tails on either side of the Hyades cluster when they observed it. However, they were extraordinarily long – thousands of light years across the galaxy, each holding thousands of stars. Observing them in their entirety was only possible because of the GAIA data and a computer model that Dr. Tereza Jerabkova, an ESA research fellow, developed with her colleagues.

Apr 1, 2021

Social Determinants of Health Impact Fetal Brain Development

Posted by in categories: biotech/medical, education, employment, health, neuroscience

New data from Children’s National Hospital shows parental experience with a number of social determinants of health can ultimately impact brain development in utero, something researchers said should suggest future community health intervention among pregnant people. The data, published in JAMA Network Open, specifically found poorer brain development in fetuses among pregnant people with low socioeconomic status (SES), low educational attainment, and limited employment opportunity.


New data from Children’s National Hospital has found that social determinants of health like income, education, and occupation can impact fetal brain development, following that child into life.

Apr 1, 2021

Lab-made hexagonal diamonds stiffer than natural diamonds

Posted by in categories: materials, physics

Nature’s strongest material now has some stiff competition. For the first time, researchers have hard evidence that human-made hexagonal diamonds are stiffer than the common cubic diamonds found in nature and often used in jewelry.

Named for their six-sided , hexagonal diamonds have been found at some meteorite impact sites, and others have been made briefly in labs, but these were either too small or had too short of an existence to be measured.

Now scientists at Washington State University’s Institute for Shock Physics created hexagonal diamonds large enough to measure their stiffness using . Their findings are detailed in a recent paper in Physical Review B.

Apr 1, 2021

New theory suggests uranium ‘snowflakes’ in white dwarfs could set off star-destroying explosion

Posted by in categories: cosmology, materials

A pair of researchers with Indiana University and Illinois University, respectively, has developed a theory that suggests crystalizing uranium “snowflakes” deep inside white dwarfs could instigate an explosion large enough to destroy the star. In their paper published in the journal Physical Review Letters, C. J. Horowitz and M. E. Caplan describe their theory and what it could mean to astrophysical theories about white dwarfs and supernovas.

White dwarfs are small stars that have burned up most of their nuclear fuel—they are typically much cooler than they once were and are very dense. In this new effort, Horowitz and Caplan used data from the Gaia space observatory to theorize that sometimes small grains of uranium could begin to crystalize (due to enriched actinides), forming what they describe as snowflakes. They suggest this could happen because of the differing melting points of the material involved. They further suggest that if this were to occur, it could lead to splitting of atomic nuclei, resulting in a series of fission reactions as the solids become enriched in actinides. And if such reactions were to raise the temperature of the interior of the star by igniting carbon, the result would likely be merging of atomic nuclei and eventually a very large fusion reaction that would result in a large explosion—likely large enough to destroy the star.

Apr 1, 2021

Particles of a Meteor Explosion From 430,000 Years Ago Found Hidden in Antarctic Ice

Posted by in categories: asteroid/comet impacts, existential risks, particle physics

Approximately 430000 years ago, a meteorite exploded over Antarctica.

The only reason we know about it now is because scientists have just found tiny, once-molten particles of space rock that have been hidden away in the ice ever since.

Based on an analysis of those particles, the event was an unusual one — not quite powerful enough to produce an impact crater, but nor was it a lightweight. The jet of melted and vaporized material that blasted from the mid-air explosion would have been more hazardous than the Tunguska event that flattened a Siberian forest in 1908.

Apr 1, 2021

A Gamma-Ray Burst Just Revealed a ‘Goldilocks’ Black Hole in The Early Universe

Posted by in category: cosmology

Scientists have reported the discovery of a rare, medium-sized black hole that may help answer one of the more tantalizing questions in astronomy: how do their supermassive counterparts come into being?

There are two well-known sizes of black hole — at one end, so-called stellar-class ones which are typically three to ten times the mass of our Sun — and at the other, supermassive ones, found at the center of most galaxies, including the Milky Way, which are millions to billions times heavier.

The newly detected ‘goldilocks’ black hole — about 55000 solar masses — could be a missing link between these two extremes, scientists suggested Monday in the journal Nature Astronomy.

Apr 1, 2021

Hackers Using a Windows OS Feature to Evade Firewall and Gain Persistence

Posted by in category: futurism

Hackers are using Microsoft OS features to evade Firewalls and build persistent attacks on their targets.

Apr 1, 2021

Selective time-dependent changes in activity and cell-specific gene expression in human postmortem brain

Posted by in categories: biotech/medical, information science, neuroscience

As brain activity-dependent human genes are of great importance in human neuropsychiatric disorders we also examined the expression of these genes to postmortem RNAseq databases from patients suffering from various neurological and psychiatric disorders (Table 1). Datasets were chosen based on similarities in tissue processing and RNAseq methodology to our own protocol. We performed a PCA (Principal Component Analysis) of our fresh brain compared to postmortem brain from healthy, Parkinson’s, Schizophrenia, Huntington’s, and Autism brains for the top 500 brain activity-dependent genes that showed the greatest reduction in the healthy postmortem samples. The PCA revealed a significant separation between the 4 fresh samples and the postmortem samples, independent of whether or not the fresh tissue was from epileptic (high activity, H) or non-epileptic (low activity, L) brain regions (Fig. 2 J). This further demonstrates a selective reduction of activity-dependent genes in postmortem brain independent of whether the underlying tissue is electrically active or not.

The sudden removal of brain tissue from a living person in many ways mimics a catastrophic event that occurs with a hypoxic brain injury or a traumatic death with exsanguination. The human brain has high energy needs, estimated to be 10 times that of other tissues21. As a means to understand how the postmortem interval selectively affects some genes and not others in human neocortex, we performed RNAseq and histological analyses in cortical brain tissue as a function of time from 0–24 h at 24 °C in order to simulate a postmortem interval. Neuropathological examination of the tissue used for this study showed a normal-appearing cortical pattern with no histopathologic abnormalities. RNAseq analysis showed a loss of brain activity-dependent genes that were 3-times more prone to be degraded than expected by chance compared to more stable housekeeping genes (Table 2). The threshold to detect activity-dependent genes was related to the probability of being affected by the PMI. The higher the relative expression of the brain activity gene, the more it was enriched in the population of genes affected by the PMI. These findings confirm that genes involved in brain activity are more prone to degradation during the PMI.

One possible explanation for the selective loss of activity-dependent genes could relate to the stability of various cell populations during the simulated PMI. As a means to implicate specific cell populations that could be responsible for the reduction of genes during the simulated PMI we used a clustering algorithm as we have previously described9. We found that 1427 genes (71% known brain activity-dependent genes) could be clustered across the seven time points of the simulated PMI. For these clusters, we used AllegroMcode to identify two main clusters. One cluster of 317 rapidly declining genes was predicted to be neuronal and strongly overlapped with the activity-dependent genes. A second cluster of 474 genes was predicted to be glial, including astrocytes and microglia (Fig. 3A). Remarkably, as the neuronal cell cluster rapidly fell, there was a reciprocal and dramatic increase in the expression of the glial cell cluster (Fig. 3B).

Apr 1, 2021

Rich false memories of autobiographical events can be reversed

Posted by in category: law

Human memory is fallible and malleable. In forensic settings in particular, this poses a challenge because people may falsely remember events with legal implications that never actually happened. Despite an urgent need for remedies, however, research on whether and how rich false autobiographical memories can be reversed under realistic conditions (i.e., using reversal strategies that can be applied in real-world settings) is virtually nonexistent. The present study therefore not only replicates and extends previous demonstrations of false memories but, crucially, documents their reversibility after the fact: Employing two ecologically valid strategies, we show that rich but false autobiographical memories can mostly be undone. Importantly, reversal was specific to false memories (i.e., did not occur for true memories).

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