Science & TechnologyS


Galaxy

Milky Way could be blasting stars into far reaches of the galaxy

Steph Panecasio
CNET
Sun, 19 Apr 2020 17:19 UTC
Milky Way Galaxy
© ESA/Hubble & NASA
In an era of social distancing, it turns out even our twisted home galaxy, the Milky Way, is following suit, catapulting its stars farther away from the center.

A study, published Monday in the Monthly Notices of the Royal Astronomical Society, demonstrated how hyper-realistic cosmological simulations were used as a base for scientists from the University of California, Irvine, to show how clusters of supernova -- explosions from dying stars -- can create a scattering of hot suns in the outer reaches of the Milky Way.

Enabled by the Feedback in Realistic Environments 2 (FIRE-2) project, these simulations not only illustrate plumes of stars as they've been flung from the center of the Milky Way, but also demonstrate how the galaxy may be evolving and expanding.
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Brain

If damaged, the adult brain repairs itself by going back to the beginning


Neuroscience News
Wed, 15 Apr 2020 00:00 UTC
HTT light level
© UC San Diego Health SciencesA cross-section of a rat brain depicts cells (in blue) expressing normal levels of the Huntingtin gene while cells (in red) have had the gene knocked out. The latter cells, without the Huntingtin gene, displayed less regeneration.
Summary: Mouse models of corticospinal injuries reveal adult neurons begin a natural regeneration process by reverting back to an embryonic state. The regeneration is sustained with the help of a gene more commonly associated with Huntington's disease.

When adult brain cells are injured, they revert to an embryonic state, according to new findings published in the April 15, 2020 issue of Nature by researchers at University of California San Diego School of Medicine, with colleagues elsewhere. The scientists report that in their newly adopted immature state, the cells become capable of re-growing new connections that, under the right conditions, can help to restore lost function.

Repairing damage to the brain and spinal cord may be medical science's most daunting challenge. Until relatively recently, it seemed an impossible task. The new study lays out a "transcriptional roadmap of regeneration in the adult brain."
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Info

Microbiome collaborate to cheat death


Carnegie Institution for Science
Thu, 05 Mar 2020 00:13 UTC
Antibiotics and Microbiome
© Illustration courtesy of Navid Marvi and Andres Aranda-Diaz.
Baltimore, MD — Antibiotics can make easy work of infections. But how do they affect the complex ecosystems of friendly bacteria that make up our microbiome?

"When a doctor prescribes antibiotics, it sets up a multi-faceted experiment in your gastrointestinal system," explains Carnegie's Will Ludington "What can it teach us about the molecular principles of species interactions in nature?"

New work led by Ludington and Stanford University's K.C. Huang set out to answer this challenging question and discovered a new form of antibiotic tolerance. Their findings, which have important health implications, are published by eLife.

This is one of several research fronts on which Ludington uses the fruit fly microbiome to understand interactions between species in a bacterial community. It poses an ideal environment for probing both natural bacterial populations and the human microbiome.

The human microbiome is an ecosystem of hundreds to thousands of microbial species living within our guts. It affects our health and even our longevity. But it's difficult to elucidate the myriad ways that the different species that comprise our microbiome interact with and influence each other, even under normal conditions. Once antibiotics are introduced, little is understood about how these vital communities are impacted on a biochemical level.

This is why the fruit fly makes such an excellent model. Unlike the human microbiome, it consists of only a handful of bacterial species.
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Butterfly

When the map doesn't work: Evolutionary trees can't reveal speciation and extinction rates

Mark Pagel
Nature
Sat, 18 Apr 2020 17:22 UTC
speciation equus horses donkeys zebras
Living species of the genus Equus
Scientists often want to make inferences about what the biological past was like, and how that past gave rise to the present, because doing so allows them to understand the processes that drive evolution. But, writing in Nature, Louca and Pennell1 challenge a major aspect of that enterprise.

Specifically, their work regards the issue of estimating past rates of speciation and extinction, which are, respectively, the rates at which new species arise and existing species go extinct. These rates determine the number of contemporary species of various forms. There are, for instance, around 6,600 species of songbird (passerines), which constitute more than half of all existing bird species, and we might therefore be tempted to say that songbirds have a high rate of speciation in comparison with that of other birds. But it's also possible to speculate that they have a low extinction rate. Louca and Pennell show that the uncertainty is even worse than this: not only can we not estimate these two rates, but also there is an infinite number of different sets of these two parameters that are equally good at describing any particular outcome, such as the number of species of contemporary songbird.

Comment:

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Seismograph

Timing of Earth's biggest earthquakes follows a 'devil's staircase' pattern

Brooks Hays
UPI.com
Tue, 14 Apr 2020 17:30 UTC
Scientists have found global earthquake sequences tend to occur in clusters
© Angelo_Giordano/PixabayScientists have found global earthquake sequences tend to occur in clusters -- outbursts of seismic events separated by long but irregular intervals of silence.
The timing of large, shallow earthquakes across the globe follows a mathematical pattern known as the devil's staircase, according to a new study of seismic sequences.

Previously, scientists and their models have theorized that earthquake sequences happen periodically or quasi-periodically, following cycles of growing tension and release. Researchers call it the elastic rebound model. In reality, periodic earthquake sequences are surprisingly rare.

Instead, scientists found global earthquake sequences tend to occur in clusters -- outbursts of seismic events separated by long but irregular intervals of silence.

The findings, published this week in the journal Bulletin of the Seismological Society of America, suggest large earthquakes increase the probability of subsequent seismic events.

Previous models failed to account for the interconnected nature of global fault systems. Seismic event don't occur in isolation. Each major quake alters the dynamics of other fault systems.

While the research suggests large quake sequences are "burstier" than previously thought, they remain as unpredictable as ever. The gaps between bursts are irregular, making it exceedingly difficult to anticipate the next cluster.

"Mathematically described as the devil's staircase, such temporal patterns are a fractal property of nonlinear complex systems, in which a change of any part -- e.g., rupture of a fault or fault segment -- could affect the behavior of the whole system," scientists wrote in their paper.
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Fish

'Longest animal ever' discovered in deep-sea canyon off Australia's Ningaloo coast

Rachael Rettner
Live Science
Mon, 13 Apr 2020 21:15 UTC
siphonophore australia
© Schmidt Ocean InstituteAn image shows the coils of the long siphonophore.
Does it really count as one animal though?

Underwater explorers found a 150-foot-long (45 meters) siphonophore — a translucent, stringy creature that, like coral, is made up of smaller critters — living in a submarine canyon off the coast of Australia. It's "seemingly the largest animal ever discovered," they said.

Every individual siphonophore is made up of many little "zooids," which each live lives that are more similar to animals we're used to talking about, albeit always connected to the larger colony. Zooids are born axsexually, and each one performs a function for the siphonophore's larger body, according to a research article published in the journal Developmental Dynamics in 2005. Linked together in long chains, the colonies were already known to reach lengths of up to 130 feet (40 m) according to the Monterey Bay Aquarium — though each siphonophore is only about as thick as a broomstick.
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Comet 2

New Comet P/2020 G1 (Pimentel)

Ernesto Guido & Adriano Valvasori
Remanzacco Blogspot
Fri, 17 Apr 2020 18:11 UTC
CBET 4754 & MPEC 2020-H06, issued on 2020, April 17, announce the discovery of a comet (magnitude ~15) by Eduardo Pimentel on CCD images taken by Jacques, Pimentel, and J. Barros with a 0.28-m f/2.2 astrograph of the "Southern Observatory for Near Earth Research" (SONEAR) at Oliveira, Brazil. The new comet has been designated P/2020 G1 (Pimentel).

We performed follow-up measurements of this object while it was still on the PCCP webpage.

Stacking of 7 unfiltered exposures, 24 seconds each, obtained remotely on 2020, April 15.4 from Q62 (iTelescope network) through a 0.50-m f/6.8 astrograph + CCD + focal reducer, shows that this object is a comet with a compact coma about 15" in diameter and a tail 20" long in PA 90.

Our confirmation image (click on it for a bigger version)
Comet P/2020 G1 Pimentel
© Remanzacco Blogspot
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Microscope 1

Transposons: Formerly designated "useless junk", now speculated to drive speciation?


Uncommon Descent
Fri, 17 Apr 2020 16:15 UTC
transposons
© Adam DiehlChromatin loops are important for gene regulation because they define a gene's regulatory neighbor-hood, which contains the promoter and enhancer sequences responsible for determining its expression level. Remarkably, transposable elements (TEs) are responsible for creating around 1/3 of all loop boundaries in the human and mouse genomes, and contribute up to 75% of loops unique to either species.
PaV asks us to draw attention to this new paper on transposons:
Until recently, little was known about how transposable elements contribute to gene regulation. These are little pieces of DNA that can replicate themselves and spread out in the genome. Although they make up nearly half of the human genome, these were often ignored and commonly thought of as "useless junk," with a minimal role, if any at all, in the activity of a cell. A new study by Adam Diehl, Ningxin Ouyang, and Alan Boyle, University of Michigan Medical School and members of the U-M Center for RNA Biomedicine, shows that transposable elements play an important role in regulating genetic expression with implications to advance the understanding of genetic evolution.

Transposable elements move around the cell, and, unlike previously thought, the authors of this paper found that when they go to different sites, transposable elements sometimes change the way DNA strands interact in 3-D space, and therefore the structure of the 3-D genome. It appears a third of the 3-D contacts in the genome actually originate from transposable elements leading to an outsized contribution by these regions to looping variation and demonstrating their very significant role in genetic expression and evolution.

University of Michigan, " Transposable elements play an important role in genetic expression and evolution" at Phys.org

Comment: Transposon activity was not always viewed so favorably: Attitudes are shifting, albeit slowly and reluctantly. The author's question is valid. Why is it so hard to believe that just because science doesn't understand the reason something exists, it assumes there is no purpose to it. Nature makes no waste:

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Biohazard

Ancient doctors knew of copper's virus-killing powers


Smithsonian Magazine
Tue, 14 Apr 2020 02:44 UTC
copper wire
© Getty ImagesCopper wire
The SARS-CoV-2 virus endures for days on plastic or metal but disintegrates soon after landing on copper surfaces. Here's why

When researchers reported last month that the novel coronavirus causing the COVID-19 pandemic survives for days on glass and stainless steel but dies within hours after landing on copper, the only thing that surprised Bill Keevil was that the pathogen lasted so long on copper.

Keevil, a microbiology researcher at the University of Southampton (U.K.), has studied the antimicrobial effects of copper for more than two decades. He has watched in his laboratory as the simple metal slew one bad bug after another. He began with the bacteria that causes Legionnaire's Disease and then turned to drug-resistant killer infections like Methicillin-resistant Staphylococcus aureus (MRSA). He tested viruses that caused worldwide health scares such as Middle East Respiratory Syndrome (MERS) and the Swine Flu (H1N1) pandemic of 2009. In each case, copper contact killed the pathogen within minutes. "It just blew it apart," he says.

In 2015, Keevil turned his attention to Coronavirus 229E, a relative of the COVID-19 virus that causes the common cold and pneumonia. Once again, copper zapped the virus within minutes while it remained infectious for five days on surfaces such as stainless steel or glass.

Comment:

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Eye 1

Facebook constructs bot-based universe to test out scenarios for manipulating humans, but don't worry, it's safe


rappler.com
Thu, 16 Apr 2020 01:50 UTC
facebook and westworld
© Global Look Press via ZUMA Press / Jaap Arriens Youtube
Facebook is using bots to simulate the behavior of users when updates occur on the social meda platform.

The MIT Technology Review on Wednesday, April 15, cited a paper by Facebook engineers, titled "WES: Agent-based User Interaction Simulation on Real Infrastructure." The paper describes how Facebook created a scaled-down version of the platform, called WW, to simulate user behavior with the help of bots.

In WW, hard-coded and machine-learning-based bots act as users with different goals or agendas which play out differently depending on the scenario set up by the engineers.

Comment: RT writer Helen Buyinski explains why this is such a concerning technological development:
While the writers have cloaked their and their bots' activities in several layers of academic language, the report reveals their creations are interacting through the real-life Facebook platform, not a simulation. The bots are set up to model different "negative" behaviors - scamming, phishing, posting 'wrongthink' - that Facebook wants to curtail, and the simulation allows Facebook to tweak its control mechanisms for suppressing these behaviors.

Even though the bots are technically operating on real-life Facebook, with only the thinnest veil of programming separating them from interacting with real-world users, the researchers seem convinced enough of their ability to keep fantasy and reality separate that they feel comfortable hinting in the paper of new and different ways of invading Facebook users' privacy.


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