Hexbyte Glen Cove Building tough 3D nanomaterials with DNA thumbnail

Hexbyte Glen Cove Building tough 3D nanomaterials with DNA

Hexbyte Glen Cove

Mineralization of 3D lattice formed by DNA tetrahedra (about 30 nm) and gold nanoparticle into all-inorganic 3D silica-Au replicas with preserved architecture. Credit: Oleg Gang/Columbia Engineering

Columbia Engineering researchers, working with Brookhaven National Laboratory, report today that they have built designed nanoparticle-based 3D materials that can withstand a vacuum, high temperatures, high pressure, and high radiation. This new fabrication process results in robust and fully engineered nanoscale frameworks that not only can accommodate a variety of functional nanoparticle types but also can be quickly processed with conventional nanofabrication methods.

“These self-assembled nanoparticles-based materials are so resilient that they could fly in space,” says Oleg Gang, professor of chemical engineering and of applied physics and , who led the study published today by Science Advances. “We were able to transition 3D DNA-nanoparticle architectures from liquid state—and from being a pliable material—to , where silica re-enforces DNA struts. This new material fully maintains its original framework architecture of DNA-nanoparticle lattice, essentially creating a 3D inorganic replica. This allowed us to explore—for the first time—how these nanomaterials can battle harsh conditions, how they form, and what their properties are.”

Material properties are different at the nanoscale and researchers have long been exploring how to use these tiny materials—1,000 to 10,000 times smaller than the thickness of a human hair—in all kinds of applications, from making sensors for phones to building faster chips for laptops. Fabrication techniques, however, have been challenging in realizing 3D nano-architectures. DNA nanotechnology enables the creation of complexly organized materials from nanoparticles through , but given the soft and environment-dependent nature of DNA, such materials might be stable under only a narrow range of conditions. In contrast, the newly formed materials can now be used in a broad range of applications where these engineered structures are required. While conventional nanofabrication excels in creating planar structures, Gang’s new method allows for fabrication of 3D nanomaterials that are becoming essential to so many electronic, optical, and energy applications.

Movie visualizes a 3D reconstruction (using FIB-SEM) of silicated DNA-nanoparticle lattice. The reconstruction shows gold nanoparticles in lattice (silica structure is not visible). The lattice rotates about the axis to visualize the structure from multiple directions. Credit: Oleg Gang/Columbia Engineering

Gang, who holds a joint appointment as group leader of the Soft and Bio Nanomaterials Group at Brookhaven Lab’s Center for Functional Nanomaterials, is at the forefront of DNA nanotechnology, which relies on folding DNA chain into desired two and three-dimensional nanostructures. These nanostructures become building blocks that can be programmed via Watson-Crick interactions to self-assemble into 3D architectures. His group designs and forms these DNA nanostructures, integrates them with nanoparticles and directs the assembly of targeted nanoparticle-based materials. And, now, with this new technique, the team can transition these materials from being soft and fragile to solid and robust.

This new study demonstrates an efficient method for converting 3D DNA-nanoparticle lattices into silica replicas, while maintaining the topology of the interparticle connections by DNA struts and the integrity of the nanoparticle organization. Silica works well because it helps retain the nanostructure of the parent DNA lattice, forms a robust cast of the underlying DNA and does not affect nanoparticles arrangements.

“The DNA in such lattices takes on the properties of silica,” says Aaron Michelson, a Ph.D. student from Gang’s group. “It becomes stable in air and can be dried and allows for 3D nanoscale analysis of the material for the first time in real space. Moreover, silica provides strength and chemical stability, it’s low-cost and can be modified as needed—it’s a very convenient material.”

Different types of nanoscale lattices formed with polyhedra DNA nano-frames (tetrahedra, cubes, and octahedra) and gold nanoparticle are mineralized with controllable silica coating thicknesses (from about 5nm to a full space-filling). Credit: Oleg Gang/Columbia Engineering

To learn more about the properties of their nanostructures, the team exposed the converted to silica DNA-nanoparticles lattices to extreme conditions: high temperatures above 1,0000C and high mechanical stresses over 8GPa (about 80,000 times more than atmosphere pressure, or 80 times more than at the deepest ocean place, the Mariana trench), and studied these processes in-situ. To gauge the structures’ viability for applications and further processing steps, the researchers also exposed them to high doses of radiation and focused ion beams.

“Our analysis of the applicability of these structures to couple with traditional nanofabrication techniques demonstrates a truly robust platform for generating resilient nanomaterials via DNA-based approaches for discovering their novel properties,” Gang notes. “This is a big step forward, as these specific properties mean that we can use our 3D nanomaterial assembly and still access the full range of conventional materials processing steps. This integration of novel and conventional nanofabrication methods is needed to achieve advances in mechanics, electronics, plasmonics, photonics, superconductivity, and energy materials.”

Collaborations based on Gang’s work have already led to novel superconductivity and conversion of the silica to conductive and semiconductive media for further processing. These include an earlier study published by Nature Communications and one recently published by Nano Letters. The researchers are also planning to modify the structure to make a broad range of materials with highly desirable mechanical and optical properties.

“Computers have been made with silicon for over 40 years,” Gang adds. “It took four decades to push the fabrication down to about 10 nm for planar structures and devices. Now we can make and assemble nanoobjects in a test tube in a couple of hours without expensive tools. Eight billion connections on a single lattice can now be orchestrated to self-assemble through nanoscale processes that we can engineer. Each connection could be a transistor, a sensor, or an optical emitter—each can be a bit of data stored. While Moore’s law is slowing, the programmability of DNA assembly approaches is there to carry us forward for solving problems in novel materials and nanomanufacturing. While this has been extremely challenging for current methods, it is enormously important for emerging technologies.”



More information:
“Resilient three-dimensional ordered architectures assembled from nanoparticles by DNA” Science Advances (2021). advances.sciencemag.org/lookup … .1126/sciadv.abf0617

Citation:
Building tough 3D nanomaterials with DNA (2021, March 19)
retrieved 20 March 2021
from https://phys.org/news/2021-03-tough-3d-nanomaterials-dna.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

Read More Hexbyte Glen Cove Educational Blog Repost With Backlinks —

Hexbyte Glen Cove Found in space: Complex carbon-based molecules thumbnail

Hexbyte Glen Cove Found in space: Complex carbon-based molecules

Hexbyte Glen Cove

The Taurus Molecular Cloud, which contains the cold starless core TMC-1, is a dark streak on the sky near the Pleiades cluster as seen from Charlottesville, VA. Credit: Brett A. McGuire, Copyright 2018

Much of the carbon in space is believed to exist in the form of large molecules called polycyclic aromatic hydrocarbons (PAHs). Since the 1980s, circumstantial evidence has indicated that these molecules are abundant in space, but they have not been directly observed.

Now, a team of researchers led by MIT Assistant Professor Brett McGuire has identified two distinctive PAHs in a patch of space called the Taurus Molecular Cloud (TMC-1). PAHs were believed to form efficiently only at high temperatures—on Earth, they occur as byproducts of burning fossil fuels, and they’re also found in char marks on grilled food. But the interstellar cloud where the research team observed them has not yet started forming stars, and the temperature is about 10 degrees above absolute zero.

This discovery suggests that these molecules can form at much lower temperatures than expected, and it may lead scientists to rethink their assumptions about the role of PAH chemistry in the formation of stars and planets, the researchers say.

“What makes the detection so important is that not only have we confirmed a hypothesis that has been 30 years in the making, but now we can look at all of the other molecules in this one source and ask how they are reacting to form the PAHs we’re seeing, how the PAHs we’re seeing may react with other things to possibly form larger molecules, and what implications that may have for our understanding of the role of very large carbon molecules in forming planets and stars,” says McGuire, who is a senior author of the new study.

Michael McCarthy, associate director of the Harvard-Smithsonian Center for Astrophysics, is another senior author of the study, which appears today in Science. The research team also includes scientists from several other institutions, including the University of Virginia, the National Radio Astronomy Observatory, and NASA’s Goddard Space Flight Center.

Distinctive signals

Starting in the 1980s, astronomers have used telescopes to detect infrared signals that suggested the presence of aromatic molecules, which are molecules that typically include one or more carbon rings. About 10 to 25 percent of the carbon in space is believed to be found in PAHs, which contain at least two , but the infrared signals weren’t distinct enough to identify specific molecules.

“That means that we can’t dig into the detailed chemical mechanisms for how these are formed, how they react with one another or other molecules, how they’re destroyed, and the whole cycle of carbon throughout the process of forming stars and planets and eventually life,” McGuire says.

Although radio astronomy has been a workhorse of molecular discovery in space since the 1960s, radio telescopes powerful enough to detect these large molecules have only been around for a little over a decade. These telescopes can pick up molecules’ rotational spectra, which are distinctive patterns of light that molecules give off as they tumble through space. Researchers can then try to match patterns observed in space with patterns that they have seen from those same molecules in laboratories on Earth.

The 100-m Green Bank Telescope located in Green Bank, WV. Credit: Brett A. McGuire, Copyright 2018

“Once you have that pattern match, you know there is no other molecule in existence that could be giving off that exact spectrum. And, the intensity of the lines and the relative strength of the different pieces of the pattern tells you something about how much of the molecule there is, and how warm or cold the molecule is,” McGuire says.

McGuire and his colleagues have been studying TMC-1 for several years because previous observations have revealed it to be rich in complex carbon molecules. A few years ago, one member of the research team observed hints that the cloud contain benzonitrile—a six-carbon ring attached to a nitrile (carbon-nitrogen) group.

The researchers then used the Green Bank Telescope, the world’s largest steerable radio telescope, to confirm the presence of benzonitrile. In their data, they also found signatures of two other molecules—the PAHs reported in this study. Those molecules, called 1-cyanonaphthalene and 2-cyanonaphthalene, consist of two benzene rings fused together, with a nitrile group attached to one ring.

“Detecting these molecules is a major leap forward in astrochemistry. We are beginning to connect the dots between small molecules—like benzonitrile—that have been known to exist in space, to the monolithic PAHs that are so important in astrophysics,” says Kelvin Lee, an MIT postdoc who is one of the authors of the study.

Finding these molecules in the cold, starless TMC-1 suggests that PAHs are not just the byproducts of dying stars, but may be assembled from smaller molecules.

“In the place where we found them, there is no star, so either they’re being built up in place or they are the leftovers of a dead star,” McGuire says. “We think that it’s probably a combination of the two—the evidence suggests that it is neither one pathway nor the other exclusively. That’s new and interesting because there really hadn’t been any observational evidence for this bottom-up pathway before.”

In a series of nine papers, scientists from the GOTHAM–Green Bank Telescope Observations of TMC-1: Hunting Aromatic Molecules–project described the detection of more than a dozen polycyclic aromatic hydrocarbons in the Taurus Molecular Cloud, or TMC-1. These complex molecules, never before detected in the interstellar medium, are allowing scientists to better understand the formation of stars, planets, and other bodies in space. In this artist’s conception, some of the detected molecules include, from left to right: 1-cyanonaphthalene, 1-cyano-cyclopentadiene, HC11N, 2-cyanonaphthalene, vinylcyanoacetylene, 2-cyano-cyclopentadiene, benzonitrile, trans-(E)-cyanovinylacetylene, HC4NC, and propargylcyanide, among others. Credit: M. Weiss / Center for Astrophysics | Harvard & Smithsonian

Carbon chemistry

Carbon plays a critical role in the formation of planets, so the suggestion that PAHs might be present even in starless, cold regions of space, may prompt scientists to rethink their theories of what chemicals are available during planet formation, McGuire says. As PAHs react with other molecules, they may start to form interstellar dust grains, which are the seeds of asteroids and planets.

“We need to entirely rethink our models of how the chemistry is evolving, starting from these starless cores, to include the fact that they are forming these large aromatic molecules,” he says.

McGuire and his colleagues now plan to further investigate how these PAHs formed, and what kinds of reactions they may undergo in . They also plan to continue scanning TMC-1 with the powerful Green Bank Telescope. Once they have those observations from the , the researchers can try to match up the signatures they find with data that they generate on Earth by putting two molecules into a reactor and blasting them with kilovolts of electricity, breaking them into bits and letting them recombine. This could result in hundreds of different molecules, many of which have never been seen on Earth.

“We need to continue to see what are present in this interstellar source, because the more we know about the inventory, the more we can start trying to connect the pieces of this reaction web,” McGuire says.



More information:
B.A. McGuire el al., “Detection of two interstellar polycyclic aromatic hydrocarbons via spectral matched filtering,” Science (2021). science.sciencemag.org/cgi/doi … 1126/science.abb7535

Ci Xue et al. Detection of Interstellar HC4NC and an Investigation of Isocyanopolyyne Chemistry under TMC-1 Conditions, The Astrophysical Journal (2020). iopscience.iop.org/article/10. … 847/2041-8213/aba631

Brett A. McGuire et al. Early Science from GOTHAM: Project Overview, Methods, and the Detection of Interstellar Propargyl Cyanide (HCCCH2CN) in TMC-1, The Astrophysical Journal (2020). iopscience.iop.org/article/10. … 847/2041-8213/aba632

Andrew M. Burkhardt et al. Ubiquitous aromatic carbon chemistry at the earliest stages of star formation, Nature Astronomy (2021). DOI: 10.1038/s41550-020-01253-4

Michael C. McCarthy et al. Interstellar detection of the highly polar five-membered ring cyanocyclopentadiene, Nature Astronomy (2020). DOI: 10.1038/s41550-020-01213-y

Citation:
Found in space: Complex carbon-based molecules (2021, March 18)
retrieved 19 March 2021
from https://phys.org/news/2021-03-space-complex-carbon-based-molecules.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

Read More Hexbyte Glen Cove Educational Blog Repost With Backlinks —

Hexbyte Glen Cove Dogs infected with Leishmania parasites smell more attractive to female sand flies thumbnail

Hexbyte Glen Cove Dogs infected with Leishmania parasites smell more attractive to female sand flies

Hexbyte Glen Cove

A small (ca. 2g) sample of dorsal hair was taken from each canine recruit. The sample was removed near the dog skin using surgical scissors (cleaned in hexane to avoid contamination) and placed in a foil bag that was then heat sealed and stored at -20 C. Credit: Monica E. Staniek, 2019

Dogs infected with the Leishmania parasite smell more attractive to female sand flies than males, say researchers.

The study published in PLOS Pathogens is led by Professor Gordon Hamilton of Lancaster University.

In Brazil, the parasite Leishmania infantum is transmitted by the bite of infected female Lutzomyia longipalpis sand flies.

Globally over 350 million people are at risk of leishmaniasis, with up to 300,000 new cases annually. In Brazil alone there are approximately 4,500 deaths each year from the visceral form of the disease and children under 15 years old are more likely to be affected.

Leishmania parasites are transmitted from infected dogs to people by sand flies when they bite. Visceral leishmaniasis affects the internal organs and is fatal if not treated.

As only female sand flies transmit the parasite, researchers wanted to understand if infection made dogs more attractive to the insect.

Professor Gordon Hamilton of Lancaster University said: “In this study we showed that infected dog odour is much more attractive than uninfected dog odour to the female sand flies. Only the females can transmit the pathogen and male sand flies, which do not transmit the parasite, are not affected by the changed odour.

“This clear-cut difference in attraction of female and male sand flies suggests that the females are preferentially attracted by parasite infected hosts and this could lead to enhanced infection and transmission opportunities for the parasite.”

The researchers had previously found that dogs infected with Leishmania parasites smelled different compared to uninfected dogs.

Professor Hamilton said: “Domestic dogs are the reservoir of infection, therefore understanding how the infection affects the attractiveness of dogs to the insect vector is important in understanding the epidemiology of the disease and offers opportunities for new control and diagnostic methodologies.”



More information:
Staniek ME, Hamilton JGC (2021) Odour of domestic dogs infected with Leishmania infantum is attractive to female but not male sand flies: Evidence for parasite manipulation. PLoS Pathog 17(3): e1009354. doi.org/10.1371/journal.ppat.1009354

Citation:
Dogs infected with Leishmania parasites smell more attractive to female sand flies (2021, March 18)
retrieved 19 March 2021
from https://phys.org/news/2021-03-parasites-dogs-good-insect-vector.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

Read More Hexbyte Glen Cove Educational Blog Repost With Backlinks —

Hexbyte Glen Cove Scientists uncover the underlying genetics that make flies champion fliers thumbnail

Hexbyte Glen Cove Scientists uncover the underlying genetics that make flies champion fliers

Hexbyte Glen Cove

Fruit flies in the flight performance assay work to control their descent after an abrupt drop into a flight column. Credit: Spierer AN, et al., 2021, PLOS Genetics

Flies have developed excellent flying skills thanks to a set of complicated interactions between numerous genes influencing wing shape, muscle function, and nervous system development, as well as the regulation of gene expression during development. Adam Spierer and David Rand in collaboration with colleagues at Brown University identified these interactions, which they report March 18th in the journal PLOS Genetics.

Just like their name suggests, flies are exceptional fliers who rely on flight for vital tasks, like courtship, finding food and dispersing to new areas. But despite the importance of this ability, scientists know little about the genetics underlying flight performance. In the new study, Spierer, Rand and colleagues performed a , called a genome-wide association study, to identify genes associated with flight. Using 197 genetically different fruit fly lines, they tested the flies’ ability to pull out of a sudden drop. Then, using multiple computational approaches, they related the flies’ performance to different genes and genetics variants, as well as to networks of gene-gene and .

The researchers discovered that many genes and genetic variants involved in flight performance mapped to regions of the fly genome that determine wing shape, muscle and nervous system function, and regulate whether other genes are turned on or off. They also identified a gene called pickpocket 23 (ppk23) that serves as a central hub for regulating the interactions of these genes. Pickpocket family genes are involved in proprioception—a sense of how the body moves in space—and in detecting pheromones and other chemical signals.

This “snapshot” of the genetic variants that affect fruit fly may have implications for studying flight in other insects. Additionally, the researchers have demonstrated the benefit of using multiple approaches to unravel the complex genetic interactions underlying traits like flight, which involve a number of different genes.



More information:
Spierer AN, Mossman JA, Smith SP, Crawford L, Ramachandran S, Rand DM (2021) Natural variation in the regulation of neurodevelopmental genes modifies flight performance in Drosophila. PLoS Genet 17(3): e1008887. doi.org/10.1371/journal.pgen.1008887

Citation:
Scientists uncover the underlying genetics that make flies champion fliers (2021, March 18)
retrieved 19 March 2021
from https://phys.org/news/2021-03-scientists-uncover-underlying-genetics-flies.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

Read More Hexbyte Glen Cove Educational Blog Repost With Backlinks —

Hexbyte Glen Cove Ultrafast intra-atom motion tracked using synchrotron radiation thumbnail

Hexbyte Glen Cove Ultrafast intra-atom motion tracked using synchrotron radiation

Hexbyte Glen Cove

(a) Schematic diagram of synchrotron radiation generation by undulators. Time widths of radiation pulses are determined by the spatial broadening of electron bunches. (b) The radiation pulse contains many short waves (wave packets) emitted by individual electrons. In the present study, two undulators are arranged in series to generate pairs of wave packets. Each wave packet oscillates only 10 times in 2 femtoseconds. Time intervals of the wave packet pairs are adjusted by detouring the electron bunches with a magnet between the two undulators. Credit: NINS/IMS

Scientists in Japan have observed and interfered with the ultrafast motion of electron movement inside of a Xenon atom using the coherent pairs of short light waves in synchrotron radiation. Xenon, consisting of a nucleus surrounded by five nested shells containing a total of 54 electrons, is used in flash lamps, and it burns bright and fast. The luminescent electrons move there on a time scale of one billionth of a second. The fast electron movement is however six orders of magnitude slower than that the scientists observed. Using the synchrotron facility at Institute for Molecular Science, they tracked the electron movement in relaxation to shed energy by dropping from an outer shell to an inner shell. The process happens at a timescale of femtoseconds, or one millionth of a billionth of a second. A femtosecond is to a second as a second is to almost 32 million years. The ability to observe and control such ultrafast processes could open the door to next-generation experiments and applications, according to the researchers.

The results were published on March 17 in Physical Review Letters.

“Controlling and probing the electronic motion in atoms and molecules on their natural of attoseconds—which are one-thousandth of a femtosecond—is one of the frontiers in and attosecond physics,” said paper author Tatsuo Kaneyasu, researcher at the SAGA Light Source, Kyushu Synchrotron Light Research Center in Japan. “In this study, we demonstrated that ultrashort processes in atoms and molecules can be tracked using the ultrashort property of the radiation wave packet.”

Recent advances in laser technology enable us to produce ultraquick, or ultrashort, double light pulses that can interact with subatomic processes. This interference can be controlled by precisely tuning the time between each pulse. The pulse excites electrons, the motion of which is referred to as an electron wave packet. Kaneyasu and his team have achieved this technology using synchrotron radiation which has a great advantage in generating higher energy photons than those by lasers.

Top Panel shows fluorescence intensity from inner shell excited states of xenon atoms measured with changing time intervals of the wave packet pairs. Lower Panels show magnified views at positions a and b in top Panel. Fluctuations with a period of 63 attoseconds are observed due to the interference effect between the quantum states excited by the wave packet pairs. As the time interval between the two wave packets in a pair increases, the amplitude of the fluctuation decays due to electronic relaxation of the inner shell excited states. Credit: NINS/IMS

“This method, termed ‘wave packet interferometry,” is now a fundamental tool for studying and manipulating the quantum dynamics of matter,” Kaneyasu said. “In this study, the electron wave packet was produced by superimposing some electronic states in a xenon atom.”

Much like two overlapping beams producing a more intense light than either individually gives off, two overlapping electron wave packets produce quantum effects.

“The ultimate goal is controlling and probing the ultrafast electronic motion of a wide range of elements, not only in the gas-phase atoms and molecules but also in the condensed matters,” Kaneyasu said. “This new capability of not only helps scientists study ultrafast phenomena in atomic and molecular processes, but may also open up new applications in the development of functional materials and electronic devices in the future.”



Citation:
Ultrafast intra-atom motion tracked using synchrotron radiation (2021, March 17)
retrieved 18 March 2021
from https://phys.org/news/2021-03-ultrafast-intra-atom-motion-tracked-synchrotron.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

Read More Hexbyte Glen Cove Educational Blog Repost With Backlinks —

Hexbyte Glen Cove Ten years of safer skies with Europe's other satnav system thumbnail

Hexbyte Glen Cove Ten years of safer skies with Europe’s other satnav system

Hexbyte Glen Cove

The purpose of the European Geostationary Navigation Overlay Service, EGNOS, is to monitor the real-time performance of US GPS satellites, then generate a correction message, containing information on the reliability and accuracy of their positioning data, which are then broadcast via EGNOS’s geostationary satellites to all suitably equipped satnav receivers. EGNOS consists of three geostationary satellites and a Europe-wide ground segment composed of two master control stations, six uplink stations and a network of 40 monitoring stations, all connected and communicating in real time. Credit: ESA

With 26 satellites in orbit and more than two billion receivers in use, Europe’s Galileo satellite navigation system has made a massive impact. But our continent has another satnav system that has been providing safety-of-life services for ten years now—chances are that you’ve benefited from it without noticing.

Its name is EGNOS, the European Geostationary Navigation Overlay Service. Transmitting signals from a duo of satellite transponders in geostationary orbit, EGNOS gives additional precision to US GPS signals—delivering an average precision of 1.5 metres over European territory, a tenfold improvement over un-augmented signals in the worst-case—and also confirmation of their ‘integrity’ – or reliability—through additional messaging identifying any residual errors.

While its Open Service has been in general operation since 2009, EGNOS began its EU-guaranteed safety-of-life in March 2011.

ESA designed EGNOS as the European equivalent of the US WAAS, Wide Area Augmentation System, working closely with the European air traffic management agency Eurocontrol, passing it to the European GNSS Agency, GSA, to run operationally.

Guiding airliners down

First and foremost its primary customer is aircraft. Imagine an airliner coming into land at Charles de Gaulle, or another major European airport, in bad weather. The pilots cannot see their runway through clouds and rain, but without needing any guidance from the ground they can still confidently descend all the way down to just 60 metres’ altitude before needing to make visual contact with the tarmac—thanks to EGNOS.

France’s Pau Pyrénées Airport was the first airport to utilize EGNOS, on 17 March 2011. Today, more than 385 airports and helipads and 60 airlines across Europe are today utilising such EGNOS-based LPV-200 approaches, short for ‘Localizer Performance with Vertical guidance—200 ft (60 m)’. The freely-available EGNOS service requires no ground equipment whatsoever, replacing the radio guidance beamed upward by traditional CAT I Instrument Landing System (ILS) infrastructure with no decrease in performance.

Cockpit of a new EGNOS-equipped Airbus 350 XWB, on show during the inaugural EGNOS Day at Toulouse-Blagnac Airport on 7 May 2015. Credit: GSA

EGNOS serving drones

Having guided hundreds of thousands of passengers down safely during the past decade—and employed widely in additional sectors such as maritime navigation—EGNOS is now being eyed as the enabler of smaller aerial vehicles making safe use of airspace, in the shape of autonomous drones.

The GSA has supported numerous trials of ‘remotely piloted aircraft systems’ equipped with EGNOS as well as Galileo through its EGNSS4RPAS project. The projection is that crewed aircraft will be vastly outnumbered in our skies by all kinds of automated aerial vehicles, employed for everything from weather and environmental monitoring to personalised delivery services.

The traditional person-based traditional air traffic control model will need to evolve to accommodate such a shift, based on automated monitoring, traffic management and collision avoidance. This highly automated version of air traffic control is termed ‘U-space’.

More than 385 airports and helipads and 60 airlines across Europe are as of March 2021 utilising EGNOS-based LPV-200 approaches, short for ‘Localizer Performance with Vertical guidance – 200 ft (60 m)’. The freely-available EGNOS service requires no ground equipment whatsoever, replacing the radio guidance beamed upward by traditional CAT I Instrument Landing System (ILS) infrastructure with no decrease in performance. Credit: GSA

EGNOS’s safety-of-life service is seen as essential to making this happen, moving from today’s situation where drones are limited to specific air corridors and line-of-sight operations to let them roam freely but safely in busy airspace and built-up areas.

“The whole idea behind EGNOS’s safety-of-life has been to render satellite navigation sufficiently reliable for any kind of use,” explains Didier Flament, leading ESA’s EGNOS team. “After ten years of faultless operations, new applications are becoming plain: drone flight is one example, and EGNOS is also being evaluated for train positioning as well as assisted and autonomous automobile driving.”

New generation of service

ESA retains responsibility for the system’s future evolution, and the middle of this decade should see the debut of its new generation, known as ‘EGNOS v3’.

Didier adds: “While the current system only works with single-frequency GPS signals, EGNOS v3 will operate on a multi-frequency, multi-constellation basis, able to augment all available satellite signals in both L1 and L5 bands, including Galileo. The result will be far enhanced performance and reliability.

“In addition, we are working with developers of other satellite-based augmentation systems around the globe to ensure they stay fully interoperable so for instance EGNOS-equipped aircraft can fly between continents on a seamless basis. Such Interoperability combined with the arrival of the other SBAS systems under development in other regions will lead to a quasi-global worldwide safety of life service coverage in the year 2030.”



Citation:
Ten years of safer skies with Europe’s other satnav system (2021, March 17)
retrieved 18 March 2021
from https://phys.org/news/2021-03-ten-years-safer-europe-satnav.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

Read More Hexbyte Glen Cove Educational Blog Repost With Backlinks —

Hexbyte Glen Cove Tweens and TV: UCLA's 50-year survey reveals the values kids learn from popular shows thumbnail

Hexbyte Glen Cove Tweens and TV: UCLA’s 50-year survey reveals the values kids learn from popular shows

Hexbyte Glen Cove

UCLA’s chart tracking the ranking of TV values over each decade, from 1967 to 2017. Credit: UCLA Center for Scholars and Storytellers

How important is fame? What about self-acceptance? Benevolence? The messages children between the ages of 8 and 12 glean from TV play a significant role in their development, influencing attitudes and behaviors as they grow into their teenage years and beyond, UCLA psychologists say.

Now, a new report by UCLA’s Center for Scholars and Storytellers assesses the values emphasized by popular with tweens over each decade from 1967 to 2017, charting how 16 values have waxed and waned in importance during that 50-year span.

Among the key findings is that , after nearly 40 years of ranking near the bottom (it was 15th in 1967, 1987 and 1997), rose to become the No. 1 value in 2007, then dropped to sixth in importance in 2017.

Achievement—being very successful—was ranked first in 2017, with self-acceptance, image, popularity and being part of a community rounding out the top five.

The report, “The Rise and Fall of Fame: Tracking the Landscape of Values Portrayed on Television from 1967 to 2017” (PDF), evaluated two programs per decade (and four in 2017), from “The Andy Griffith Show” in 1967 and “Happy Days” in 1977 to “American Idol” and “Hannah Montana” in 2007 and “America’s Got Talent” and “Girl Meets World” in 2017.

Like fame, values such as community feeling and benevolence have also seen dramatic rises and falls over the past half-century, with their rankings typically echoing changes in the larger culture, the researchers found.

Being part of community, for instance, which ranked No. 1 in 1967, 1977 and 1997 (and No. 2 in 1987), plummeted to the 11th spot in 2007—10 spots below fame—before rising again to fifth in 2017. Likewise, being kind and helping others, the No. 2 value in 1967 and 1997, fell to the 12th spot in 2007. It is now ranked eighth.

“I believe that television reflects the culture, and this half-century of data shows that American culture has changed drastically,” said report author Yalda Uhls, founder and executive director of the Center for Scholars and Storytellers and an adjunct assistant professor of psychology. “Media plays an important role as young people are developing a concept of the social world outside of their immediate environment.”

The concepts children develop can also vary widely based on what types of programs they’re watching, according to the authors, who found a stark divergence between the values conveyed in —first evaluated in 2007—and those of scripted fictional shows.

Values in reality TV vs. fictional programs

The most popular tween reality shows in 2017, based on Nielsen ratings, were “America’s Got Talent” and “American Ninja Warrior,” while the top two scripted shows were “Thundermans” and “Girl Meets World.” In the scripted shows, the top values conveyed were self-acceptance, benevolence and being part of a community. In contrast, the top values conveyed in reality shows were fame, image and self-centeredness.

Reality shows, created for a broad audience and watched frequently by tweens, often highlight competition and the importance of being No. 1 and include bullying, cheating and a winning-at-all-costs value system, the authors note.

“If tweens watch, admire and identify with people who mostly care about fame and winning, these values may become even more important in our culture,” said the report’s lead author, Agnes Varghese, a fellow of the center and a UC Riverside graduate student. “Reality television shows continued to reflect the same trend we saw in 2007, with self-focused values such as fame ranking highest.”

The authors recommend that parents help children understand that reality shows do not depict the experience of the average person and that fictional shows do not adequately depict the hard work and struggles associated with achieving fame.

TV values and the rise of social media

Uhls believes the explosive growth and popularity of social media platforms such as Facebook, launched in 2004, and YouTube, launched in 2005, may have influenced television content creators in the first decade of the 2000s to make fame-focused tween shows. Other research has shown that social media growth was accompanied by a rise in narcissism and a decrease in empathy among college students in the U.S., she notes.

“I don’t think this is a coincidence,” said Uhls, who was formerly a movie studio executive. “The growth of social media gives children access to an audience beyond the school grounds.”

By 2017, the social media landscape had expanded to include platforms like Snapchat and Instagram, and the access they provided to an ever-widening audience made popularity seem more easily attainable. For that reason, Uhls believes, achieving fame may have become less desirable and unique. In addition, the severe recession of 2007-09 may have shifted the culture away from self-focused values such as fame and getting rich.

Research conducted by UCLA distinguished professor of psychology Patricia Greenfield and colleagues has shown that society tends to become more community-focused in times of collective distress, Uhls noted.

Because children, particularly in their tween years, are forming a belief system that integrates the many messages about desirable future aspirations they receive from parents, school, peers and media, it is crucial to understand the role television plays in promoting values—both positive and negative, the researchers say.



Citation:

Read More Hexbyte Glen Cove Educational Blog Repost With Backlinks —

Hexbyte Glen Cove Why cash payments aren't always the best tool to help poor people thumbnail

Hexbyte Glen Cove Why cash payments aren’t always the best tool to help poor people

Hexbyte Glen Cove

Credit: CC0 Public Domain

The concept is simple and seductive: Give people cash, lift them out of poverty. It’s a strategy increasingly being used in both lower- and higher-income countries to help poor people.

International organizations such as the World Bank, USAID and the United Nations are funding more projects that focus on giving people , while charities like GiveDirectly have been set up to do only that. Mexico, Brazil and Kenya are leading examples of countries that have already implemented ambitious guaranteed income programs of their own.

The U.S. is also experimenting more with . The US$1.9 trillion relief package, for example, will give recurring payments to most families with children. Stockton, California—the first U.S. city to give low-income people cash with no strings attached—just completed a two-year pilot program. And a number of U.S. mayors are attempting to do the same as the list of high-profile supporters continues to grow.

In short, there seem to be a growing consensus that cash is the best tool in the fight against . But is it?

As an economist studying poverty and development, I have devoted my career to researching questions like this one. While cash can be an effective tool, I don’t believe it’s always the best one.

The limitations of cash

There is ample evidence that cash transfers have positive impacts on people living in poverty, at least on average. For example, a recent review of 165 studies found that cash assistance tends to increase spending on food and other goods, while also improving education and health outcomes. The authors further found little to no evidence of unintended consequences, such as people working less because they had higher nonlabor incomes.

Similarly, a recently released study of Stockton’s basic income experiment, which gave randomly selected residents $500 a month for two years, found that the cash payments stabilized recipient incomes, helped them get more full-time jobs and reduced depression and anxiety.

But this doesn’t mean that cash is the best strategy for fighting poverty, as some people, such as New York City mayoral candidate Andrew Yang, have argued. I believe there are, in fact, several reasons policymakers should view this evidence with caution.

For one thing, it is often difficult to identify people who are actually poor and need the money so that cash assistance can be given to the right people. A recent study examined data from nine sub-Saharan African countries to evaluate the performance of a common method anti-poverty programs use to target . It found that about half of the households selected by the method were not poor, while half of the households that were actually poor were not selected.

This targeting problem is not unique to developing countries. For example, the Stockton experiment limited eligibility to people living in neighborhoods with a median income below the citywide median, meaning that more affluent people in these neighborhoods were eligible. Furthermore, eligible households were notified via physical mail to register online, implying that the program excluded the homeless and less tech-savvy people.

Another problem relates directly to the definition of poverty, which is more precisely defined as a lack of well-being instead of a lack of income. In short, giving cash does not directly improve somebody’s well-being; rather, it’s a tool that can be used to purchase things—such as food and shelter—that do directly contribute to well-being.

Even if the poor can be successfully identified, some people may not receive the typical or average benefit because of problems converting cash into improvements in their well-being.

For example, people may be experiencing mental or physical health issues, or they may be affected by the subtle ways that poverty itself compromises economic decision-making. Similarly, in some cases, cash may not do much good because some of the things that contribute to improved well-being—such as health care or schooling – may be inaccessible or of low quality.

Put simply, cash can’t buy everything.

A final problem is that direct cash assistance does not combat the structural issues—such as discrimination, weak democratic governance and unfair international trade practices – that cause poverty in the first place. Reforms in these areas typically require collective action to create change at the national or global level.

Problematically, recent research suggests that cash programs can actually be counterproductive because conflicts can arise over who receives assistance. This can erode social capital within communities.

The failure of cash to remedy structural issues may be one reason its long-term effects are often limited. For example, a recent study in Uganda looked at the impacts of cash transfers nine years after people were given money. While the researchers found positive effects on employment and earnings after four years, these impacts virtually disappeared after nine. Other long-term studies also have found “a fair share of results that are not statistically different from zero.”

Empowering people

Cash can certainly help some people, and this is undoubtedly an important consideration, especially in emergency situations when immediate assistance is critical—such as during a pandemic.

But there is simply no one-size-fits-all approach to poverty alleviation. Different countries, communities and individuals have unique needs and face different obstacles to escaping poverty. Sometimes that means investing in structural reforms, sometimes it means providing food aid and sometimes, yes, it means direct payments.



This article is republished from The Conversation under a Creative Commons license. Read the original article.

Citation:
Why cash payments aren’t always the best tool to help poor people (2021, March 17)
retrieved 17 March 2021
from https://phys.org/news/2021-03-cash-payments-tool-poor-people.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

Read More Hexbyte Glen Cove Educational Blog Repost With Backlinks —

Hexbyte Glen Cove Magnetism meets topology on a superconductor's surface thumbnail

Hexbyte Glen Cove Magnetism meets topology on a superconductor’s surface

Hexbyte Glen Cove

An illustration depicting a topological surface state with an energy band gap (an energy range where electrons are forbidden) between the apices of the top and corresponding bottom cones (allowed energy bands, or the range of energies electrons are allowed to have). A topological surface state is a unique electronic state, only existing at the surface of a material, that reflects strong interactions between an electron’s spin (red arrow) and its orbital motion around an atom’s nucleus. When the electron spins align parallel to each another, as they do here, the material has a type of magnetism called ferromagnetism. Credit: Dan Nevola, Brookhaven National Laboratory

Electrons in a solid occupy distinct energy bands separated by gaps. Energy band gaps are an electronic “no man’s land,” an energy range where no electrons are allowed. Now, scientists studying a compound containing iron, tellurium, and selenium have found that an energy band gap opens at a point where two allowed energy bands intersect on the material’s surface. They observed this unexpected electronic behavior when they cooled the material and probed its electronic structure with laser light. Their findings, reported in the Proceedings of the National Academy of Sciences, could have implications for future quantum information science and electronics.

The particular compound belongs to the family of iron-based , which were initially discovered in 2008. These materials not only conduct electricity without resistance at relatively higher temperatures (but still very cold ones) than other classes of superconductors but also show magnetic properties.

“For a while, people thought that superconductivity and magnetism would work against each other,” said first author Nader Zaki, a scientific associate in the Electron Spectroscopy Group of the Condensed Matter Physics and Materials Science (CMPMS) Division at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory. “We have explored a material where both develop at the same time.”

Aside from superconductivity and magnetism, some iron-based superconductors have the right conditions to host “topological” surface states. The existence of these unique electronic states, localized at the surface (they do not exist in the bulk of the material), reflects between an electron’s spin and its orbital motion around the nucleus of an atom.

“When you have a superconductor with topological surface properties, you’re excited by the possibility of topological superconductivity,” said corresponding author Peter Johnson, leader of the Electron Spectroscopy Group. “Topological superconductivity is potentially capable of supporting Majorana fermions, which could serve as qubits, the information-storing building blocks of quantum computers.”

Quantum computers promise tremendous speedups for calculations that would take an impractical amount of time or be impossible on traditional computers. One of the challenges to realizing practical quantum computing is that qubits are highly sensitive to their environment. Small interactions cause them to lose their quantum state and thus stored information becomes lost. Theory predicts that Majorana fermions (sought-after quasiparticles) existing in superconducting are immune to environmental disturbances, making them an ideal platform for robust qubits.

Seeing the iron-based superconductors as a platform for a range of exotic and potentially important phenomena, Zaki, Johnson, and their colleagues set out to understand the roles of topology, superconductivity and magnetism.

CMPMS Division senior physicist Genda Gu first grew high-quality single crystals of the iron-based compound. Then, Zaki mapped the electronic band structure of the material via laser-based photoemission spectroscopy. When light from a laser is focused onto a small spot on the material, electrons from the surface are “kicked out” (i.e., photoemitted). The energy and momentum of these electrons can then be measured.

When they lowered the temperature, something surprising happened.

“The material went superconducting, as we expected, and we saw a superconducting gap associated with that,” said Zaki. “But what we didn’t expect was the topological surface state opening up a second gap at the Dirac point. You can picture the energy band structure of this surface state as an hourglass or two cones attached at their apex. Where these cones intersect is called the Dirac point.”

As Johnson and Zaki explained, when a gap opens up at the Dirac point, it’s evidence that has been broken. Time-reversal symmetry means that the laws of physics are the same whether you look at a system going forward or backward in time—akin to rewinding a video and seeing the same sequence of events playing in reverse. But under time reversal, electron spins change their direction and break this symmetry. Thus, one of the ways to break time-reversal symmetry is by developing magnetism—specifically, ferromagnetism, a type of magnetism where all electron spins align in a parallel fashion.

“The system is going into the superconducting state and seemingly magnetism is developing,” said Johnson. “We have to assume the magnetism is in the surface region because in this form it cannot coexist in the bulk. This discovery is exciting because the material has a lot of different physics in it: superconductivity, topology, and now magnetism. I like to say it’s one-stop shopping. Understanding how these phenomena arise in the material could provide a basis for many new and exciting technological directions.”

As previously noted, the material’s superconductivity and strong spin-orbit effects could be harnessed for quantum information technologies. Alternatively, the material’s magnetism and strong spin-orbit interactions could enable dissipationless (no energy loss) transport of electrical current in electronics. This capability could be leveraged to develop electronic devices that consume low amounts of power.

Coauthors Alexei Tsvelik, senior scientist and group leader of the CMPMS Division Condensed Matter Theory Group, and Congjun Wu, a professor of physics at the University of California, San Diego, provided theoretical insights on how time reversal symmetry is broken and magnetism originates in the surface region.

“This discovery not only reveals deep connections between topological superconducting states and spontaneous magnetization but also provides important insights into the nature of superconducting gap functions in iron-based superconductors—an outstanding problem in the investigation of strongly correlated unconventional superconductors,” said Wu.

In a separate study with other collaborators in the CMPMS Division, the experimental team is examining how different concentrations of the three elements in the sample contribute to the observed phenomena. Seemingly, tellurium is needed for the topological effects, too much iron kills superconductivity, and selenium enhances superconductivity.

In follow-on experiments, the team hopes to verify the time-reversal symmetry breaking with other methods and explore how substituting elements in the compound modifies its electronic behavior.

“As materials scientists, we like to alter the ingredients in the mixture to see what happens,” said Johnson. “The goal is to figure out how superconductivity, topology, and magnetism interact in these complex materials.”



More information:
Nader Zaki et al. Time-reversal symmetry breaking in the Fe-chalcogenide superconductors, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2007241118

Citation:
Magnetism meets topology on a superconductor’s surface (2021, March 17)
retrieved 17 March 2021
from https://phys.org/news/2021-03-magnetism-topology-superconductor-surface.html

Read More Hexbyte Glen Cove Educational Blog Repost With Backlinks —

Hexbyte Glen Cove Pioneering study gives new insight into formation of copper deposits thumbnail

Hexbyte Glen Cove Pioneering study gives new insight into formation of copper deposits

Hexbyte Glen Cove

Credit: Pixabay/CC0 Public Domain

A groundbreaking study has given new insights into how copper deposit-forming fluids are transported naturally from their source deep underground towards the Earth’s surface.

A team of geologists, led by Lawrence Carter from the University of Exeter’s Camborne School of Mines, has published a new theory for how porphyry deposits form.

Porphyry deposits provide around 75 percent of the world’s copper which is in increasing demand for , power infrastructure and green technologies such as wind turbines. They originally develop several kilometers below the Earth’s surface above large magma chambers. Not only are rare but most large near-surface examples have already been found. Any new model for how and where they form will be of great interest to mining companies.

In the new study, the researchers have shown that vast quantities of mineralising fluids could be extracted and transported from their source magmas and focussed into the ore-forming environment through “crystal mush dykes.”

Lawrence Carter, a final year Ph.D. student at Camborne School of Mines, based at the University of Exeter’s Penryn Campus said: “Our study addresses the missing link in models for the formation of porphyry-type copper deposits—how vast quantities of mineralising fluids are extracted and transported from their source magmas and focussed into the ore-forming environment.

“In doing so we provide the first field, petrographic and microscale evidence for transport through what we term ‘crystal mush dykes.” Their recognition is paramount to the development of more reliable porphyry exploration models and has significance for other ore-forming systems and volcanic processes.”

Collaborating with scientists from the British Geological Survey (BGS) and University of Surrey, this research involved field studies and micro-textural and geochemical analyzes of samples from the archetypal Yerington porphyry district in Nevada, where an exceptional ~8 km palaeo-vertical cross-section through a number of porphyry copper deposit systems is exposed.

The team were able to identify a wormy interconnected network of quartz within dykes found in rocks that were once beneath the copper deposits. This represents palaeo-porosity in a once permeable magmatic crystal mush of feldspar and quartz. The mush acted as conduits for vast quantities of porphyry-deposit-forming fluids from deep portions of underlying magmas.

It is believed that this breakthrough may provide insights for the discovery of new porphyry copper deposits, and the proposed mechanism key to the formation of other ore deposit types as well as degassing processes in volcanic systems.

The paper, titled “Crystal mush dykes as conduits for mineralising fluids in the Yerington porphyry copper district, Nevada,” was published in the leading journal Nature Communications Earth & Environment on March 17, 2021.



More information:
Lawrence C. Carter et al. Crystal mush dykes as conduits for mineralising fluids in the Yerington porphyry copper district, Nevada, Communications Earth & Environment (2021). DOI: 10.1038/s43247-021-00128-4

Citation:
Pioneering study gives new insight into formation of copper deposits (2021, March 17)
retrieved 17 March 2021
from https://phys.org/news/2021-03-insight-formation-copper-deposits.html

Read More Hexbyte Glen Cove Educational Blog Repost With Backlinks —