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Gene circuits reshape DNA folding and affect how genes are expressed, study finds

When a gene is turned on in a cell, it creates a ripple effect along the DNA strand, changing the physical structure of the strand. A new study by MIT researchers, appearing in Science, shows that these ripples can stimulate or suppress neighboring genes. These effects, which result from the winding or unwinding of neighboring DNA, are determined by the order of genes along a strand of DNA. Genes upstream of the active gene are usually turned up, while those downstream are inhibited.

The new findings offer guidance that could make it easier to control the output of synthetic gene circuits. By altering the relative ordering and arrangement of genes (gene syntax), researchers could create circuits that synergize to maximize their output, or that alternate the output of two different genes.

“This is really exciting because we can coordinate gene expression in ways that just weren’t possible before,” says Katie Galloway, an assistant professor of chemical engineering at MIT. “Syntax will be really useful for dynamic circuits. Now we have the ability to select not only the biochemistry of circuits, but also the physical design to support dynamics.”

Laser-plasma accelerators can preserve polarization of Helium-3 ions

Particle accelerators such as those at the European Organization for Nuclear Research (CERN) in Geneva are typically highly complex large-scale devices. In these ring-shaped facilities, which are often several kilometers in length, magnets and radio-frequency cavities are used to accelerate elementary particles. An alternative approach is now emerging: compact laser–plasma accelerators that can be built and operated at a fraction of the cost. These accelerators can achieve acceleration gradients up to around 1,000 times higher than those of conventional accelerators. Researchers at HHU contributed significantly to this development.

A research team led by Prof. Dr. Markus Büscher, a professor of physics at HHU and group leader at the Peter Grünberg Institute in Jülich, presented the current state of research in a review article in Reports on Progress in Physics. In a separate study published in High Power Laser Science and Engineering, they report on one specific aspect of laser–plasma acceleration, namely whether the polarization—that is to say, the collective spin alignment—of accelerated particles is preserved in laser–plasma accelerators.

Why is this relevant? “Spin alignment is crucial to a range of fundamental scientific questions as it influences the interaction between particles,” explains Professor Büscher. “In controlled nuclear fusion, the reaction probability—and thus ultimately the energy produced in the reactor—increases significantly when the spins of the fusing nuclei, the ‘fusion fuel’ so to speak, are aligned in parallel.”

Quantum computing’s next dark horse emerges from a frozen surface, where almost nothing behaves as expected

Quantum bits (qubits) are the fundamental building blocks of quantum information processing. A novel qubit platform invented at the U.S. Department of Energy’s (DOE) Argonne National Laboratory exhibits noise levels thousands of times lower than those of most traditional qubits. “Noise” refers to disturbances in the environment that diminish a qubit’s performance. The platform was built by trapping single electrons on the surface of frozen neon gas. The recent finding positions Argonne’s platform as a strong contender in the field of high-performance quantum technologies.

The new study, jointly led by Argonne and the University of Notre Dame, was published in Nature Electronics. Collaborating institutions included the University of Chicago, Harvard University, Northeastern University and Florida State University (FSU).

“In previous work, we demonstrated the outstanding performance of our electron-on-neon qubit,” said Xu Han, an Argonne scientist and co-corresponding author. “By thoroughly characterizing the qubit’s noise properties, this latest study shows why its performance is so good. Our results prove that our technology is promising for quantum information processing at larger scales.”

A longstanding quantum roadblock just fell, opening existing fiber networks to ultra-secure light signals

Researchers at the Niels Bohr Institute have broken a longstanding barrier by managing to send single photons—that can’t be copied or split and thus are secure—in the network of optical fibers we already have. This opens up a broad range of applications relying on secure quantum information. The research is published in the journal Nature Nanotechnology.

Quantum dots are unsurpassed in their ability to generate coherent single photons—single particles of light which cannot be split or copied and therefore are secure for quantum communication. So far, the problem was that the best quantum dots only worked around 930 nm wavelengths, which is far short of the telecommunication-compatible wavelengths starting at 1,260 nm. Only these longer wavelengths can be used to distribute the information-carrying photons and it has so far been restricted to sub-optimal platforms.

Now, scientists have managed to create a new type of quantum dot, which exploits the best of both worlds.

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