Amazon Web Services is offering access to quantum computers so developers can tinker around.
Category: computing – Page 627
Artificial neurons which could be implanted in the brain to repair the damage caused by Alzheimer’s disease or other neurodegenerative conditions, have been invented by scientists.
The electronic cells, developed by teams at the University of Bath and a team of international collaborators, sit on a silicon chip and mimic the responses of biological neurons when triggered by the nervous system.
Neurons are specialised cells which transmit nerve impulses, allowing parts of the body to communicate, and are the core components of the brain, spinal cord and nervous system. They are also present around the heart.
Artificial neurons on silicon chips that behave just like the real thing have been invented by scientists—a first-of-its-kind achievement with enormous scope for medical devices to cure chronic diseases, such as heart failure, Alzheimer’s, and other diseases of neuronal degeneration.
Critically the artificial neurons not only behave just like biological neurons but only need one billionth the power of a microprocessor, making them ideally suited for use in medical implants and other bio-electronic devices.
The research team, led by the University of Bath and including researchers from the Universities of Bristol, Zurich and Auckland, describe the artificial neurons in a study published in Nature Communications.
Just one hour of brain–computer interface use led to clear changes in neuronal patterns, raising hopes of a potential new therapy for stroke victims.
Researchers have long known that some genes can cause cancer when overactive, but exactly what happens inside the cell nucleus when the cancer grows has so far remained enigmatic. Now, researchers at Karolinska Institutet in Sweden have found a new mechanism that renders one canonical driver of cancer overactive. The findings, published in Nature Genetics, create conditions for brand new strategies to fight cancer.
One gene that is called MYC is central for normal cell growth. However, if the gene mutates and/or becomes overactive, it could lead to abnormal cell growth and cancer. It is previously known that so-called super-enhancers, large regions in the DNA that develop near cancer genes, could somehow make the MYC gene overactive.
The current study increases our understanding of how this process takes place by highlighting how environmental cues can conspire with the architecture of the cell nucleus to cause overexpression. With the help of new laboratory techniques and computer models, the researchers show how the activation of the pathway of the signal-molecule WNT charges the super-enhancer with proteins that lures the MYC gene to the cell nucleus pores. The pores are situated on the membrane of the cell nucleus and control the flow of information between the cell nucleus and the cytoplasm.
New research from the University of Rochester will enhance the accuracy of computer models used in simulations of laser-driven implosions. The research, published in the journal Nature Physics, addresses one of the challenges in scientists’ longstanding quest to achieve fusion.
In laser-driven inertial confinement fusion (ICF) experiments, such as the experiments conducted at the University of Rochester’s Laboratory for Laser Energetics (LLE), short beams consisting of intense pulses of light—pulses lasting mere billionths of a second—deliver energy to heat and compress a target of hydrogen fuel cells. Ideally, this process would release more energy than was used to heat the system.
Laser-driven ICF experiments require that many laser beams propagate through a plasma—a hot soup of free moving electrons and ions—to deposit their radiation energy precisely at their intended target. But, as the beams do so, they interact with the plasma in ways that can complicate the intended result.
A team of neuroscientists and electrical engineers from Germany and Switzerland developed a highly sensitive implant that enables to probe brain physiology with unparalleled spatial and temporal resolution. They introduce an ultra-fine needle with an integrated chip that is capable of detecting and transmitting nuclear magnetic resonance (NMR) data from nanoliter volumes of brain oxygen metabolism. The breakthrough design will allow entirely new applications in the life sciences.
Determining the quantum mechanical behavior of many interacting particles is essential to solving important problems in a variety of scientific fields, including physics, chemistry and mathematics. For instance, in order to describe the electronic structure of materials and molecules, researchers first need to find the ground, excited and thermal states of the Born-Oppenheimer Hamiltonian approximation. In quantum chemistry, the Born-Oppenheimer approximation is the assumption that electronic and nuclear motions in molecules can be separated.
A variety of other scientific problems also require the accurate computation of Hamiltonian ground, excited and thermal states on a quantum computer. An important example are combinatorial optimization problems, which can be reduced to finding the ground state of suitable spin systems.
So far, techniques for computing Hamiltonian eigenstates on quantum computers have been primarily based on phase estimation or variational algorithms, which are designed to approximate the lowest energy eigenstate (i.e., ground state) and a number of excited states. Unfortunately, these techniques can have significant disadvantages, which make them impracticable for solving many scientific problems.
A team at Samsung Advanced Institute of Technology has announced that they have improved quantum dot (QD) technology for use in large displays by developing QDs that are both more efficient and have no heavy metals. In their paper published in the journal Nature, the group describes their work and their plans for the future. Alexander Efros, with the Naval Research Laboratory, in Washington D.C. has published a companion piece in the same journal issue outlining the work by the team at Samsung.
Quantum dots are nanoscale semiconducting crystals that have unique optical and electronic properties due to quirks of quantum mechanics. Since their development in the 1980s, scientists have been finding many uses for them in optical devices. Unfortunately, as Efros notes, they suffer from two problems that have prevented them from being fully utilized. The first is that they are based on cadmium, a toxic heavy metal. The second is the QD phosphors that are used in display devices—they are not self- emissive, which means they need to be replaced by QD light-emitting diodes in order for them to be competitively efficient. Notably current Samsung QLED TV screens do not use the QLEDs as a source of light—instead, LCDs produce backlight which is then absorbed by a film of quantum dots. In this new effort, the group at Samsung has made progress towards addressing both problems.