Lifeboat Foundation

Materials that exhibit topological phases can be classified by their dimensionality, symmetries and topological invariants to form conductive-edge states with peculiar transport and spin properties. For example, the quantum Hall effect can arise in two-dimensional (2-D) electron systems subjected to a perpendicular magnetic field. When distinct characteristics of quantum Hall systems are compared with time-reversal symmetric (entropy conserved) topological insulators (TIs), they appear to rely on Coulomb interactions between electrons to induce a wealth of strongly correlated, topologically or symmetry-projected phases in a variety of experimental systems.

In a new report now on Science, Louis Veyrat and a research team in materials science, quantum optics and optoelectronics in France, China and Japan tuned the ground state of the graphene zeroth Landau level i.e. orbitals occupied by charged particles with discrete energy values. Using suitable screening of the Coulomb interaction with the high dielectric constant of a strontium titanate (SrTiO₃) substrate, they observed robust helical edge transport at magnetic fields as low as 1 Tesla, withstanding temperatures of up to 110 kelvin across micron-long distances. These versatile graphene platforms will have applications in spintronics and topological quantum computation.

Topological insulators (TIs), i.e., a material that behaves as an insulator in its interior but retains a conducting surface state, with zero Chern number have emerged as quantum Hall topological insulators (QHTIs) arising from many-body interacting Landau levels. They can be pictured as two independent copies of quantum Hall systems with opposite chirality, but the experimental system is at odds with the described scenario, where a strong insulating state is observed on increasing the perpendicular magnetic field in charge-neutral, high-mobility graphene devices.

Synthetic biology researchers at Northwestern University have developed a system that can rapidly create cell-free ribosomes in a test tube, then select the ribosome that can perform a certain function.

The system, called ribosome synthesis and evolution (RISE), is an important step toward using ribosomes beyond their natural capabilities. The key feature of RISE is the ability to evolve ribosomes without cell viability constraints. The result could be new ways to synthesize materials, like nylon, or therapies, like new antibiotics that could address rising antibiotic resistance.

“Ribosomes have an extraordinary capability as the protein synthesis machinery of the cell,” said Michael Jewett, Walter P. Murphy Professor of Chemical and Biological Engineering and director of the Center for Synthetic Biology at Northwestern’s McCormick School of Engineering, who led the research. “But to synthesize proteins beyond those found in nature, we have to design and modify the ribosome to work with non-natural substrates. Developing ribosomes in vitro is an important part of that system, and we are very excited to have this new capability.”

Boards and management teams can easily find themselves either stepping on each other’s toes – or, conversely, functioning in parallel universes. So how do you find the perfect balance? Top tips on achieving a Venn-like state from Patrick Dunne – a serial social entrepreneur, chair of the EY foundation and the author of a new book on governance.

Authorities in China step up surveillance and roll out new artificial intelligence tools to fight deadly epidemic.

Curr Top Microbiol Immunol. 2005;287:1–30.

In addition to the SARS coronavirus (treated separately elsewhere in this volume), the complete genome sequences of six species in the coronavirus genus of the coronavirus family [avian infectious bronchitis virus-Beaudette strain (IBV-Beaudette), bovine coronavirus-ENT strain (BCoV-ENT), human coronavirus-229E strain (HCoV-229E), murine hepatitis virus-A59 strain (MHV-A59), porcine transmissible gastroenteritis-Purdue 115 strain (TGEV-Purdue 115), and porcine epidemic diarrhea virus-CV777 strain (PEDV-CV777)] have now been reported. Their lengths range from 27,317 nt for HCoV-229E to 31,357 nt for the murine hepatitis virus-A59, establishing the coronavirus genome as the largest known among RNA viruses.

Cells can both survive and multiply under more stress than previously thought, shows research from the Faculty of Health and Medical Sciences.

This was found by inhibiting the essential gene DNA polymerase alpha, or POLA1, which initiates DNA replication during cell division.

The discovery gives researchers new insights into DNA replication and may potentially be used for a new type of cancer treatment. Research Leader and Associate Professor Luis Toledo of the Center for Chromosome Stability at the Department of Cellular and Molecular Medicine states as follows:

New paper sheds light on the age-old question about the frequency of planets around binary versus single stars.

I think so.

A handful of clinical trials are underway to find out whether drugs that target senescent cells can slow the ravages of old age.

A quiet revolution is reshaping the agricultural world, with farmers like Danie Slabbert saying that if we want to save the planet, it’s not so much about what we eat, but how we farm. CNN’s David McKenzie reports.