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Archive for the ‘evolution’ category

Dec 25, 2019

Viewpoint: A Forbidden Transition Allowed for Stars

Posted by in categories: cosmology, evolution, nuclear energy, physics

The discovery of an exceptionally strong “forbidden” beta-decay involving fluorine and neon could change our understanding of the fate of intermediate-mass stars.

Every year roughly 100 billion stars are born and just as many die. To understand the life cycle of a star, nuclear physicists and astrophysicists collaborate to unravel the physical processes that take place in the star’s interior. Their aim is to determine how the star responds to these processes and from that response predict the star’s final fate. Intermediate-mass stars, whose masses lie somewhere between 7 and 11 times that of our Sun, are thought to die via one of two very different routes: thermonuclear explosion or gravitational collapse. Which one happens depends on the conditions within the star when oxygen nuclei begin to fuse, triggering the star’s demise. Researchers have now, for the first time, measured a rare nuclear decay of fluorine to neon that is key to understanding the fate of these “in between” stars [1, 2]. Their calculations indicate that thermonuclear explosion and not gravitational collapse is the more likely expiration route.

The evolution and fate of a star strongly depend on its mass at birth. Low-mass stars—such as the Sun—transition first into red giants and then into white dwarfs made of carbon and oxygen as they shed their outer layers. Massive stars—those whose mass is at least 11 times greater than the Sun’s—also transition to red giants, but in the cores of these giants, nuclear fusion continues until the core has turned completely to iron. Once that happens, the star stops generating energy and starts collapsing under the force of gravity. The star’s core then compresses into a neutron star, while its outer layers are ejected in a supernova explosion. The evolution of intermediate-mass stars is less clear. Predictions indicate that they can explode both via the gravitational collapse mechanism of massive stars and by a thermonuclear process [36]. The key to finding out which happens lies in the properties of an isotope of neon and its ability to capture electrons.

Dec 24, 2019

Evolutionary Changes in Brain Potentially Make us More Prone to Anxiety

Posted by in categories: biotech/medical, evolution, genetics, neuroscience

Neurochemicals such as serotonin and dopamine play crucial roles in cognitive and emotional functions of our brain. Vesicular monoamine transporter 1 (VMAT1) is one of the genes responsible for transporting neurotransmitters and regulating neuronal signaling. A research team led by Tohoku University has reconstructed ancestral VMAT1 proteins, revealing the functional changes in neurotransmitter uptake of VMAT1 throughout the course of human evolution.

Human bodies are made up of millions of cells. Each individual contains a specific set of instruction of codes that make up all of a living thing’s genetic material. These instructions are known as genomes. PhD candidate Daiki Sato and Professor Masakado Kawata of the Graduate School of Life Sciences at Tohoku University, and two of the authors involved in the current study, previously discovered VMAT1 to be one of the genes that had evolved throughout human lineage.

VMAT 1 contains two human-specific mutations, or where the genomes changed, with the change being represented as 130Glu to 130Gly and from 136Asn to 136Thr. Previous studies have shown that having the new 130Gly/136Thr variant decreases the uptake of neurotransmitters and is associated with higher depression and/or anxiety. In this study, Sato, Kawata and their colleagues revealed the evolutionary changes in neurotransmitter uptake of VMAT1 by reconstructing ancestral VMAT1 proteins. First they applied a fluorescent substrate to visualize and quantify the neurotransmitter uptake of each genotype. The ancestral (130Glu/136Asn) VMAT1 protein exhibited an increased uptake of neurotransmitters compared to a derived (130Gly/136Thr) genotype. Given that the derived (130Gly/136Thr) genotype is shown to be associated with depression and/or anxiety in modern human populations. “This results of our study reveal that our ancestors may have been able to withstand higher levels of anxiety or depression,” noted the authors.

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Dec 16, 2019

Physicist proposes a new approach in modeling the evolution of the universe

Posted by in categories: cosmology, evolution

A physicist from RUDN University has proposed a new theoretical model for the interaction of spinor and gravitational fields. He considered the evolution of the universe within one of the variants of the widespread Bianchi cosmological model. In this case, a change in the calculated field parameters led to changes in the evolution of the universe under consideration. Upon reaching certain values, it began to shrink down to the Big Bang. The article was published in the journal The European Physical Journal Plus.

The spinor field is characterized by its behavior in interaction with gravitational fields. Dr. Bijan Saha of RUDN University focused on the study of a nonlinear spinor field. With its help, he explained the accelerated expansion of the universe. The study of a spinor field with a non-minimal coupling made it possible to describe not only the expansion of the universe, but also its subsequent contraction and the resulting Big Bang within the framework of the standard Bianchi .

The basic calculations performed by Bijan Saha allow moving away from the isotropic of the Friedman-Robertson-Walker universe (FRW) that is most often used. According to this traditional model, the properties of the universe are independent of the direction in which they are considered. The physicist has put forward an alternative: an anisotropic model in which such dependence exists. On the one hand, the “classical” isotropic model describes the of the modern universe with great precision. On the other hand, there are theoretical arguments and that lead to the conclusion that an anisotropic phase existed in the distant past.

Dec 11, 2019

CRISPR-resistant viruses build ‘safe rooms’ to shield genomes from DNA-dicing enzymes

Posted by in categories: biotech/medical, evolution

Bacteria and the viruses that infect them are engaged in a molecular arms race as ancient as life itself. Evolution has equipped bacteria with an arsenal of immune enzymes, including CRISPR-Cas systems, that target and destroy viral DNA. But bacteria-killing viruses, also known as phages, have devised their own tools to help them outmaneuver even the most formidable of these bacterial defenses.

Now, scientists at UC San Francisco and UC San Diego have discovered a remarkable new strategy that some phages employ to avoid becoming the next casualty of these DNA-dicing enzymes: after they infect , these phages construct an impenetrable “safe room” inside of their host, which protects vulnerable phage DNA from antiviral enzymes. This compartment, which resembles a , is the most effective CRISPR shield ever discovered in viruses.

“In our experiments, these phages didn’t succumb to any of the DNA-targeting CRISPR systems they were challenged with. This is the first time that anyone has found phages that exhibit this level of pan-CRISPR resistance,” said Joseph Bondy-Denomy, Ph.D., assistant professor in the Department of Microbiology and Immunology at UCSF. Bondy-Denomy led the research team that made the discovery, which is detailed in a paper published Dec. 9, 2019 in the journal Nature.

Dec 11, 2019

Astrobiology And The Search For Extraterrestrial Like Life

Posted by in categories: alien life, chemistry, evolution, health

Ira Pastor, ideaXme exponential health ambassador, interviews Dr. Penelope “Penny” Boston, recent Director of NASA’s Astrobiology Institute.

Astrobiology is an interdisciplinary scientific field concerned with the origins, early evolution, distribution, and future of life in the universe, and considers the big question of whether extraterrestrial life exists, and if it does, how humans can detect it.

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Dec 10, 2019

AstroBiology and the Search for ExtraTerrestrial-Like Life!! — ideaXme — Dr. Penelope “Penny” Boston, PhD., Director of NASA’s Astrobiology Institute — Ira Pastor

Posted by in categories: alien life, astronomy, bioengineering, chemistry, DNA, Elon Musk, evolution, futurism, government, Mark Zuckerberg

Dec 3, 2019

We may finally know the answer to the biggest question, what happened before the Big Bang?

Posted by in categories: cosmology, evolution

The current Lambda CDM model may explain a great deal about the evolution and the chronology of the events that occurred in our Universe but it doesn’t paint the complete picture.

We know of the cosmic inflation that happened followed by the Big Bang itself however how these two are coherently connected has so far defied all our attempts to explain.

During the inflationary period, within less than a trillionth of a second, our universe grew from an infinitesimal point to an octillion (that’s 1 followed by 27 zeroes) times in size, which was followed by a more conventional and gradual period of expansion, nevertheless violent by our standards, which we know as the Big Bang.

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Nov 28, 2019

Studies Show that Breast Milk Grows Premature Infant Brains Faster than Formula

Posted by in categories: biotech/medical, evolution, food, neuroscience

It’s easy to get excited about breast milk. Just the basic fact that a woman can eat food and turn it into a complete food instantly tailored to grow that particular newborn is quite outstanding. But there is more to breast milk than what meets the eye and understanding the perfection of it could mean a better life for premature babies.

For starters, when a baby suckles her mama’s breast, a vacuum is created. That’s right. Saliva in, milk out. The infant’s saliva is sucked back into the mother’s nipple, where receptors in her mammary gland read its signals. Katie Hinde, a biologist and associate professor at the Center for Evolution and Medicine at the School of Human Evolution & Social Change at Arizona State University, calls this “baby spit backwash,” and it contains information about the baby’s immune status. As far as scientists can tell, baby spit backwash is one of the ways that breast milk adjusts its immunological composition. When mammary gland receptors detect the presence of pathogens, the mother’s body produces antibodies to fight it, and those antibodies travel through breast milk back into the baby’s body, where they target the infection.

“[Breast] Milk is so incredibly dynamic,” says Hinde. “There are hormones in breast milk, and they reflect the hormones in the mother’s circulation. The ones that help facilitate sleep or waking up are present in your milk. And day milk is going to have a completely different hormonal milieu than night milk.” That broken-down means that breastmilk made at night contains hormones that help your baby sleep.

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Nov 21, 2019

Fossils Of Prehistoric Legged Snake Explain The Evolution Slithering Reptiles

Posted by in category: evolution

Due to a lack of fossil records, the early evolution of snakes has been a mystery, until now. Paleontologists have discovered new fossils of the prehistoric legged snake, Najash that has helped solve the mystery of how this creepy-crawly evolved into the slithering reptile it is today.

Researchers have examined the fossils of Najash rionegrina, a rear-limbed snake from the Late Cretaceous period. it has been named after the Biblical legged snake, Nahash, who tempted Eve and Adam to eat the forbidden fruit in the Book of Genesis. Found in Patagonia, Argentina, the fossil has revealed that snakes not only had limbs 100 million years ago but also had cheekbones (jugal bone).

The study published in Science Advances reveals how snakes evolved from their lizard ancestors. Fernando Garberoglio from the Fundación Azara at Universidad Maimónides, Buenos Aires explained, “Our findings support the idea that the ancestors of modern snakes were big-bodied and big-mouthed—instead of small burrowing forms as previously thought.”

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Nov 18, 2019

The measurements of the expansion of the universe don’t add up

Posted by in categories: cosmology, evolution, physics

Physicists use two types of measurements to calculate the expansion rate of the universe, but their results do not coincide, which may make it necessary to update the cosmological model. “It’s like trying to thread a cosmic needle,” explains researcher Licia Verde of the University of Barcelona, co-author of an article on the implications of this problem.

More than a hundred scientists met this summer at the Kavli Institute for Theoretical Physics at the University of California (U.S.) to try to clarify what is happening with the discordant data on the expansion rate of the , an issue that affects the very origin, evolution and fate of our cosmos. Their conclusions have been published in Nature Astronomy journal.

“The problem lies in the Hubble constant (H0), a parameter which value—it is actually not a constant because it changes with time—indicates how fast the Universe is currently expanding,” points out cosmologist Licia Verde, an ICREA researcher at the Institute of Cosmos Sciences of the University of Barcelona (ICC-UB) and the main author of the article.

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