Lifeboat Foundation

Viruses that infect bacteria may drive the evolution of drug-resistant superbugs by inserting their genes into the bacterial DNA, a new study suggests.

The bacteria-attacking viruses, called phages, act as parasites in that they depend on their hosts for survival. The viral parasites often kill off their microbial hosts after infiltrating their DNA, said senior study author Vaughn Cooper, director of the Center for Evolutionary Biology and Medicine at the University of Pittsburgh School of Medicine. But sometimes, the phages slip into the bacterial genome and then lay low, making sneaky changes to the bacterium’s behavior, Cooper said.

For the first time ever, researchers from the University of Pittsburgh School of Medicine discovered that phages — tiny viruses that attack bacteria — are key to initiating rapid bacterial evolution leading to the emergence of treatment-resistant “superbugs.” The findings were published today in Science Advances.

The researchers showed that, contrary to a dominant theory in the field of evolutionary microbiology, the process of adaptation and diversification in bacterial colonies doesn’t start from a homogenous clonal population. They were shocked to discover that the cause of much of the early adaptation wasn’t random point mutations. Instead, they found that phages, which we normally think of as bacterial parasites, are what gave the winning strains the evolutionary advantage early on.

“Essentially, a parasite became a weapon,” said senior author Vaughn Cooper, Ph.D., professor of microbiology and molecular genetics at Pitt. “Phages endowed the victors with the means of winning. What killed off more sensitive bugs gave the advantage to others.”

A tachyon field might be responsible for cosmological inflation at an early time and contribute to cosmological dark matter at a later time. We investigate tachyonic inflation by analyzing a tachyon field with different potentials in the framework of loop quantum cosmology. No matter which tachyon field energy dominates at the bounce, the evolution of the background can be divided into three phases: super-inflation, damping, and slow-roll inflation. The duration of each phase depends on the initial condition. During the slow-roll inflation, when the initial condition is $$V(T_\mathrm{B})/\rho _\mathrm{c}\ge 10^{-6}$$ V(TB)/ρc≥10–6, the number of e-folds is very high ($$N\gg 60$$ N≫60) for $$V\propto T^{-n}$$ V∝T-n with $$n=1$$ n=1 and 1 / 2. For an exponential potential, to get enough e-folds, $$V(T_\mathrm{B})/\rho _\mathrm{c}$$ V(TB)/ρc should be greater than $$7.802\times 10^{-4}$$7.

This animated map shows the last billion years of Earth’s tectonic plate movement in just 40 seconds, showing how continents formed.

Data collected can be used to provide new insights into the evolution of the Kuiper Belt, and the larger solar system.

Trans-Neptunian Objects (TNOs), small objects that orbit the sun beyond Neptune, are fossils from the early days of the solar system which can tell us a lot about its formation and evolution.

A new study led by Mohamad Ali-Dib, a research scientist at the NYU Abu Dhabi Center for Astro, Particle, and Planetary Physics, reports the significant discovery that two groups of TNOs with different surface colors also have very different orbital patterns. This new information can be compared to models of the solar system to provide fresh insights into its early chemistry. Additionally, this discovery paves the way for further understanding of the formation of the Kuiper Belt itself, an area beyond Neptune comprised of icy objects, that is also the source of some comets.

Finding the hypothetical particle axion could mean finding out for the first time what happened in the Universe a second after the Big Bang, suggests a new study published in Physical Review D.

How far back into the Universe’s past can we look today? In the electromagnetic spectrum, observations of the Cosmic Microwave Background — commonly referred to as the CMB — allow us to see back almost 14 billion years to when the Universe cooled sufficiently for protons and electrons to combine and form neutral hydrogen. The CMB has taught us an inordinate amount about the evolution of the cosmos, but photons in the CMB were released 400000 years after the Big Bang making it extremely challenging to learn about the history of the universe prior to this epoch.

To open a new window, a trio of theoretical researchers, including Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) Principal Investigator, University of California, Berkeley, MacAdams Professor of Physics and Lawrence Berkeley National Laboratory senior faculty scientist Hitoshi Murayama, Lawrence Berkeley National Laboratory physics researcher and University of California, Berkeley, postdoctoral fellow Jeff Dror (now at University of California, Santa Cruz), and UC Berkeley Miller Research Fellow Nicholas Rodd, looked beyond photons, and into the realm of hypothetical particles known as axions, which may have been emitted in the first second of the Universe’s history.

The star is only a little bit larger than Earth’s Moon, but more massive than the Sun and might be a Frankenstein zombie star.

Astronomers discovered the smallest and most massive white dwarf star, about the same size as Earth’s Moon with a mass greater than the Sun.

Continue reading “Moon-sized ‘zombie’ star challenges what we know about celestial evolution” »

An international group of astronomers has created images with never-before-seen detail of a galaxy cluster with a black hole at its center, traveling at high speed along an intergalactic “road of matter.” The findings also support existing theories of the origins and evolution of the universe.

The concept that roads of thin gas connect clusters of galaxies across the universe has been difficult to prove until recently, because the matter in these ‘roads’ is so sparse it eluded the gaze of even the most sensitive instruments. Following the 2020 discovery of an intergalactic thread of gas at least 50 million light-years long, scientists have now developed images with an unprecedented level of detail of the Northern Clump—a cluster of galaxies found on this thread.

By combining imagery from various sources including CSIRO’s ASKAP radio telescope, SRG/eROSITA, XMM-Newton and Chandra satellites, and DECam optical data, the scientists could make out a large galaxy at the center of the clump, with a black hole at its center.

Submillimeter galaxies (SMGs) are a class of the most luminous, distant, and rapidly star-forming galaxies known and can shine brighter than a trillion Suns (about one hundred times more luminous in total than the Milky Way). They are generally hard to detect in the visible, however, because most of their ultraviloet and optical light is absorbed by dust which in turn is heated and radiates at submillimeter wavelengths—the reason they are called submillimeter galaxies. The power source for these galaxies is thought to be high rates of star formation, as much as one thousand stars per year (in the Milky Way, the rate is more like one star per year). SMGs typically date from the early universe; they are so distant that their light has been traveling for over ten billion years, more than 70% of the lifetime of the universe, from the epoch about three billion years after the big bang. Because it takes time for them to have evolved, astronomers think that even a billion years earlier they probably were actively making stars and influencing their environments, but very little is known about this phase of their evolution.

SMGs have recently been identified in galaxy protoclusters, groups of dozens of galaxies in the universe when it was less than a few billion years old. Observing massive SMGs in these distant protoclusters provides crucial details for understanding both their early evolution and that of the larger structures to which they belong. CfA astronomers Emily Pass and Matt Ashby were members of a team that used infrared and optical data from the Spitzer IRAC and Gemini-South instruments, respectively, to study a previosly identified protocluster, SPT2349-56, in the era only 1.4 billion years after the big bang. The protocluster was spotted by the South Pole Telescope millimeter wavelengths and then observed in more detail with Spitzer, Gemini, and the ALMA submillimeter array.

The protocluster contains a remarkable concentration of fourteen SMGs, nine of which were detected by these optical and infrared observations. The astronomers were then able to estimate the stellar masses, ages, and gas content in these SMGs, as well as their star formation histories, a remarkable acheievment for such distant objects. Among other properties of the protocluster, the scientists deduce that its total mass is about one trillion solar-masses, and its galaxies are making stars in a manner similar to star formation processes in the current universe. They also conclude that the whole ensemble is probably in the midst of a colossal merger.