Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: computing – Page 614

Researchers discover hidden SARS-CoV-2 ‘gate’ that opens to allow COVID infection

Since the early days of the COVID pandemic, scientists have aggressively pursued the secrets of the mechanisms that allow severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to enter and infect healthy human cells.

Early in the pandemic, University of California San Diego’s Rommie Amaro, a computational biophysical chemist, helped develop a detailed visualization of the SARS-CoV-2 spike protein that efficiently latches onto our cell receptors.

Now, Amaro and her research colleagues from UC San Diego, University of Pittsburgh, University of Texas at Austin, Columbia University and University of Wisconsin-Milwaukee have discovered how glycans–molecules that make up a sugary residue around the edges of the spike protein–act as infection gateways.

Published August 19 in the journal Nature Chemistry, a research study led by Amaro, co-senior author Lillian Chong at the University of Pittsburgh, first author and UC San Diego graduate student Terra Sztain and co-first author and UC San Diego postdoctoral scholar Surl-Hee Ahn, describes the discovery of glycan “gates” that open to allow SARS-CoV-2 entry.

Exotic property of ‘ambidextrous’ crystals points to new magnetic phenomena

Researchers from Skoltech, KTH Royal Institute of Technology, and Uppsala University have predicted the existence of antichiral ferromagnetism, a nontrivial property of some magnetic crystals that opens the door to a variety of new magnetic phenomena. The paper was published in the journal Physical Review B.

Chirality, or handedness, is an extremely important fundamental property of objects in many fields of physics, mathematics, chemistry and biology; a chiral object cannot be superimposed on its in any way. The simplest chiral objects are human hands, hence the term itself. The opposite of chiral is achiral: a circle or a square are simple achiral objects.

Chirality can be applied to much more complex entities; for instance, competing internal interactions in a can lead to the appearance of periodic magnetic textures in the structure that differ from their mirror images—this is called chiral ferromagnetic ordering. Chiral crystals are widely considered promising candidates for and processing device realization as information can be encoded via their nontrivial magnetic textures.

Many-body thermodynamics on quantum computers via partition function zeros

Partition functions are ubiquitous in physics: They are important in determining the thermodynamic properties of many-body systems and in understanding their phase transitions. As shown by Lee and Yang, analytically continuing the partition function to the complex plane allows us to obtain its zeros and thus the entire function. Moreover, the scaling and nature of these zeros can elucidate phase transitions. Here, we show how to find partition function zeros on noisy intermediate-scale trapped-ion quantum computers in a scalable manner, using the XXZ spin chain model as a prototype, and observe their transition from XY-like behavior to Ising-like behavior as a function of the anisotropy. While quantum computers cannot yet scale to the thermodynamic limit, our work provides a pathway to do so as hardware improves, allowing the future calculation of critical phenomena for systems beyond classical computing limits.

Interacting quantum systems exhibit complex phenomena including phase transitions to various ordered phases. The universal nature of critical phenomena reduces their description to determining only the transition temperature and the critical exponents. However, numerically calculating these quantities for systems in new universality classes is complicated because of critical slowing down, requiring increasing resources near the critical point. An alternative approach is to analytically continue the calculation of the partition function to the complex plane and determine its zeros.

The partition function is a positive function of multiple real parameters representing physical quantities such as temperature and applied fields. When the partition function is analytically continued in one of the respective parameters, its zeros show notable structure for a variety of models of interest. Lee and Yang (1, 2) studied the partition function zeros of Ising-like systems in the complex plane of the magnetic field h and found that, at the critical temperature (and in the thermodynamic limit), the loci of zeros pinch to the real axis. Alternatively, Fisher (3) studied the partition function zeros by making the inverse temperature β complex.

A ground-breaking modeling toolkit to predict current of new type of memory

Resistive-switching memory (RSM) is an emerging candidate for next-generation memory and computing devices, such as storage-class memory devices, multilevel memories and as a synapse in neuromorphic computing. A significant challenge in the global research efforts towards better energy technologies is efficient and accurate device modeling. Now, researchers have created a new modeling toolkit which can predict the current of a new type of memory with excellent accuracy.

Intel previews its Alder Lake chip, promises hybrid CPUs for desktops and laptops

Intel’s new approach to chips, details.

The new Alder Lake chips, however, are aspiring to be far more ambitious. Intel teased a full range of chips from 9W to 125W that would utilize the new hybrid approach, combining multiple high-end performance cores with efficient cores for a wider range of power when users need it and efficiency when running less strenuous tasks.

Given that Intel’s announcements today largely focused on the architectures, there are no hard product announcements, but the company did tease several planned Alder Lake SoCs that would utilize the new cores. Those include a desktop SoC with eight performance cores, eight efficiency cores, and integrated memory, graphics, and I/O; a laptop SoC with six performance cores, eight efficiency cores, imaging, Thunderbolt 4 support, memory, I/O, and more powerful Xe graphics all integrated in; and an ultramobile-focused SoC with two performance cores and eight efficiency cores.

To make all that work together, Intel also showed off its new scheduling technology, Intel Thread Director, which is designed to better handle how activity is assigned to performance or efficiency cores depending on need. For example, Thread Director can automatically assign high-priority tasks to performance cores, while offsetting background threads to efficiency cores. Intel also says that it’s collaborating with Microsoft specifically to ensure that Thread Director is optimized for “the best performance on Windows 11.”

Levitation: Classic Magic Trick May Enable Quantum Computing

A new project will use the electric field in an accelerator cavity to try to levitate a tiny metallic particle, allowing it to store quantum information.

Quantum computing could solve problems that are difficult for traditional computer systems. It may seem like magic. One step toward achieving quantum computing even resembles a magician’s trick: levitation. A new project at the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility will attempt this trick by levitating a microscopic particle in a superconducting radiofrequency (SRF) cavity to observe quantum phenomena.

Typically at Jefferson Lab and other particle accelerator facilities, SRF cavities enable studies of the atom.

Facebook launches VR remote work app, calling it a step to the ‘metaverse’

In its first full VR news briefing, the company showed how Workrooms users can design avatar versions of themselves to meet in virtual reality conference rooms and collaborate on shared whiteboards or documents, still interacting with their own physical desk and computer keyboard.

Aug 19 (Reuters) — Facebook Inc (FB.O) on Thursday launched a test of a new virtual-reality remote work app where users of the company’s Oculus Quest 2 headsets can hold meetings as avatar versions of themselves.

The beta test of Facebook’s Horizon Workrooms app comes as many companies continue to work from home after the COVID-19 pandemic shut down physical workspaces and as a new variant is sweeping across the globe.

Facebook sees its latest launch as an early step toward building the futuristic “metaverse” that CEO Mark Zuckerberg has touted in recent weeks.

Martian Crust Could Sustain Life through Radiation

Deep below the ground, radioactive elements disintegrate water molecules, producing ingredients that can fuel subterranean life. This process, known as radiolysis, has sustained bacteria in isolated, water-filled cracks and rock pores on Earth for millions to billions of years. Now a study published in Astrobiology contends that radiolysis could have powered microbial life in the Martian subsurface.

Dust storms, cosmic rays and solar winds ravage the Red Planet’s surface. But belowground, some life might find refuge. “The environment with the best chance of habitability on Mars is the subsurface,” says Jesse Tarnas, a planetary scientist at NASA’s Jet Propulsion Laboratory and the new study’s lead author. Examining the Martian underground could help scientists learn whether life could have survived there—and the best subsurface samples available today are Martian meteorites that have crash-landed on Earth.

Tarnas and his colleagues evaluated the grain sizes, mineral makeup and radioactive element abundance in Martian meteorites and estimated the Martian crust’s porosity using satellite and rover data. They plugged these attributes into a computer model that simulated radiolysis to see how efficiently the process would have generated hydrogen gas and sulfates: chemical ingredients that can power the metabolism of underground bacteria. The researchers report that if water was present, radiolysis in the Martian subsurface could have sustained microbial communities for billions of years—and perhaps still could today.

Virtual reality boosts brain rhythms crucial for neuroplasticity, learning and memory

This is interesting. 😃

A new discovery in rats shows that the brain responds differently in immersive virtual reality environments versus the real world. The finding could help scientists understand how the brain brings together sensory information from different sources to create a cohesive picture of the world around us. It could also pave the way for “virtual reality therapy” for learning and memory-related disorders ranging including ADHD, Autism, Alzheimer’s disease, epilepsy and depression.

Mayank Mehta, PhD, is the head of W. M. Keck Center for Neurophysics and a professor in the departments of physics, neurology, and electrical and computer engineering at UCLA. His laboratory studies a brain region called the hippocampus, which is a primary driver of learning and memory, including spatial navigation. To understand its role in learning and memory, the hippocampus has been extensively studied in rats as they perform spatial navigation tasks.

When rats walk around, neurons in this part of the brain synchronize their electrical activity at a rate of 8 pulses per second, or 8 Hz. This is a type of brain wave known as the “theta rhythm,” and it was discovered more than six decades ago.

/* */