Quantum computing holds and processes information in a way that exploits the unique properties of fundamental particles: electrons, atoms, and small molecules can exist in multiple energy states at once, a phenomenon known as superposition, and the states of particles can become linked, or entangled, with one another. This means that information can be encoded and manipulated in novel ways, opening the door to a swath of classically impossible computing tasks.
As yet, quantum computers have not achieved anything useful that standard supercomputers cannot do. That is largely because they haven’t had enough qubits and because the systems are easily disrupted by tiny perturbations in their environment that physicists call noise.  Researchers have been exploring ways to make do with noisy systems, but many expect that quantum systems will have to scale up significantly to be truly useful, so that they can devote a large fraction of their qubits to correcting the errors induced by noise.

IBM is not the first to aim big. Google has said it is targeting a million qubits by the end of the decade, though error correction means only 10,000 will be available for computations. Maryland-based IonQ is aiming to have 1,024 “logical qubits,” each of which will be formed from an error-correcting circuit of 13 physical qubits, performing computations by 2028. Palo Alto–based PsiQuantum, like Google, is also aiming to build a million-qubit quantum computer, but it has not revealed its time scale or its error-correction requirements. Because of those requirements, citing the number of physical qubits is something of a red herring—the particulars of how they are built, which affect factors such as their resilience to noise and their ease of operation, are crucially important. The companies involved usually offer additional measures of performance, such as “quantum volume” and the number of “algorithmic qubits.” In the next decade advances in error correction, qubit performance, and software-led error “mitigation,” as well as the major distinctions between different types of qubits, will make this race especially tricky to follow.

Source: https://www.technologyreview.com/

Hearing loss affects about 48 million Americans and 430 million people worldwide, with those numbers expected to grow as populations age. More than 90 percent of individuals affected have sensorineural hearing loss, caused by damage to the inner ear and the destruction of the hair cells responsible for relaying sounds to the brain. Hair cells cannot be regenerated in mammals, including humans, because unlike other cells in the body, any remaining hair cells in the inner ear cannot divide and other inner ear cells cannot convert themselves into new hair cells. Species like fish, birds, and reptiles, however, possess this ability.

For this reason, effective hearing loss treatments for humans have eluded medicine, and the loss of hair cells, which can be caused by aging, noise exposure, and other factors, renders an individual’s hearing loss permanent.­ Now, Harvard Medical School (HMS) scientists at Mass Eye and Ear are hopeful they’ve developed a solution to address this longstanding limitation. A research team led by Zheng-Yi Chen, an HMS associate professor of otolaryngology and associate scientist in the Eaton-Peabody Laboratories at Mass Eye and Ear, reported creating a drug-like cocktail of different molecules that successfully regenerated hair cells in a mouse model by reprogramming a series of genetic pathways within the inner ear. The researchers hope their novel findings, published April 17 in PNAS, could one day pave the way for clinical trials for a gene therapy that can be administered to people with hearing loss.

“These findings are extremely exciting because throughout the history of the hearing loss field, the ability to regenerate hair cells in an inner ear has been the holy grail,” said Chen. “We now have a drug-like cocktail that shows the feasibility of an approach that we can explore for future clinical applications.”

Previously, Chen’s research team studied zebrafish and chickens to uncover which pathways were responsible for inducing the cell division required to regenerate new hair cells. They discovered that two molecular signaling pathways, ­­, were crucial to this process. In a study published in 2019, the team showed for the first time that when these pathways were activated in adult transgenic mice, remaining inner ear cells could divide and develop characteristics of hair cells. The new cells contained transduction channels that relay sound signals and the ability to form connections with auditory neurons — processes essential to hearing.

Source: https://hms.harvard.edu/

Some people are born with hearing loss, while others acquire it with age, infections or long-term noise exposures. In many instances, the tiny hairs in the inner ear’s cochlea that allow the brain to recognize electrical pulses as sound are damaged. As a step toward an advanced artificial cochlea, researchers in ACS Nano report a conductive membrane, which translated sound waves into matching electrical signals when implanted inside a model ear, without requiring external power.

An electrically conductive membrane implanted inside a model ear simulates cochlear hairs by converting sound waves into electrical pulses; wiring connects the prototype to a device that collects the output current signal.

When the hair cells inside the inner ear stop working, there’s no way to reverse the damage. Currently, treatment is limited to hearing aids or cochlear implants. But these devices require external power sources and can have difficulty amplifying speech correctly so that it’s understood by the user. One possible solution is to simulate healthy cochlear hairs, converting noise into the electrical signals processed by the brain as recognizable sounds. To accomplish this, previous researchers have tried self-powered piezoelectric materials, which become charged when they’re compressed by the pressure that accompanies sound waves, and triboelectric materials, which produce friction and static electricity when moved by these waves. However, the devices aren’t easy to make and don’t produce enough signal across the frequencies involved in human speech. So, Yunming Wang and colleagues from the University of Wuhan wanted a simple way to fabricate a material that used both compression and friction for an acoustic sensing device with high efficiency and sensitivity across a broad range of audio frequencies.

To create a piezo-triboelectric material, the researchers mixed barium titanate nanoparticles coated with silicon dioxide into a conductive polymer, which they dried into a thin, flexible film. Next, they removed the silicon dioxide shells with an alkaline solution. This step left behind a sponge-like membrane with spaces around the nanoparticles, allowing them to jostle around when hit by sound waves. In tests, the researchers showed that contact between the nanoparticles and polymer increased the membrane’s electrical output by 55% compared to the pristine polymer. When they sandwiched the membrane between two thin metal grids, the acoustic sensing device produced a maximum electrical signal at 170 hertz, a frequency within the range of most adult’s voices. Finally, the researchers implanted the device inside a model ear and played a music file. They recorded the electrical output and converted it into a new audio file, which displayed a strong similarity to the original version. The researchers say their self-powered device is sensitive to the wide acoustic range needed to hear most sounds and voices.

Source: https://www.acs.org/
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https://pubmed.ncbi.nlm.nih.gov/

People living in cities with warm climates face a problem during summer months: keeping windows open for ventilation means letting in traffic sounds. A noise-cancelling device could solve this dilemma. Bhan Lam at the Nanyang Technological University in Singapore and his colleagues have created a device that can halve the noisiness of urban traffic, reducing the sound coming through an open window by up to 10 decibels.

To cancel out road noise, the researchers used 24 small loudspeakers and fixed these to the security grilles of a typical window in Singapore in an 8×3 grid. These grilles are a common feature across South-East Asia, says Lam. He adds that the spacing of the speakers was dependent on the frequency of the noise that they wanted to cancel out.

The researchers spaced each speaker 12.5 centimetres apart facing outwards and programmed them to emit sounds at the same frequency of noise detected by a sensor placed outside the window. The device was most successful at cancelling noise between frequencies of 300 and 1000 Hz, with up to a 50 per cent reduction in loudness for sounds within this range. It isn’t optimised for the noise from human voices, which have higher frequencies.

“The effect is similar to the technology used in noise-cancelling headphones, which are often tuned specifically to cancel out the hum of aircraft engines”, says Lam. “The speakers the team used were only 4.5 centimetres in diameter – too small to cancel out noise at frequencies below 300 Hz. “A speaker needs to move a huge volume of air for low frequency sounds.”

The team placed the window in a replica room and played road traffic, train and aircraft noise from another loudspeaker 2 metres away. The frequency of most of the noise from traffic and passing aircraft ranges from 200 to 1000 hertz. Large trucks and motorcycles tend to generate sounds on the lower end of the range, while the majority of the sound from  is around 1000 Hz.

Source: https://www.newscientist.com/

Consumer passenger flight could be the next industry that’s transformed by electric powertrains, and Seattle’s Zunum Aero wants to be at the forefront of that change. The Seattle-based company, which is backed by Boeing’s HorizonX fund and Jet Blue’s Technology Ventures, has a plan to change the fundamental economics of regional flight, and shift the economics of air travel on a path towards eventual fully electric flight.

The first Zunum aircraft is designed for regional service, with seating for 12 passengers and a delivery window starting in 2022. The economics are potentially game-changing, with operating expenses of around $260 per hour for the aircraft. With a max cruise stepped of 340 miles per hour (547 km/h) in the air, a take-off distance of 2,200 feet (671 meters), a total hybrid-electric range of 700 miles (1127 km), which it hopes to scale to over 1,000 (1610 km) )in time and 80 percent lower noise and emissions vs. traditional regional planes, Zunum is position its airplane as the perfect way to light up under-utilized regional airports across the U.S., providing affordable and efficient commuter flights where economic realities have made running regular service impractical.

“In the past, very intentionally, we were quiet about operating costs, because it’s just shockingly low what you can get with an electric. So that you can get an aircraft of a size that could never compete with an airliner that can get you below commercial fares,” Zunum Aero CEO Ashish Kumar told in an interview. He put the cost per seat operating expenses at around 8 cents per mile. “That’s about one-tenth the operating cost of a business jet per hour,” he said.

Source: zunun.aero
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https://techcrunch.com/