According to Freya Mowat, veterinary ophthalmologist and professor in the School of Veterinary Medicine’s department of surgical sciences, researchers wanted to determine factors, including age and vision, that influence a dog’s interest in interacting with video content. Ultimately, the goal of the study, which launched two years ago, was to support development of more sensitive ways to assess canine vision — something that has been sorely lacking in veterinary medicine.

“The method we currently use to assess vision in dogs is a very low bar. In humans, it would be equivalent to saying yes or no if a person was blind,” says Mowat. “We need more sensitive ways to assess vision in dogs, using a dog eye chart equivalent. We speculate that videos have the potential for sustaining a dog’s attention long enough to assess visual function, but we didn’t know what type of content is most engaging and appealing to dogs.”

Published recently in the journal Applied Animal Behaviour Science, the study found that dogs are most engaged when watching videos that feature other animals. Content featuring other dogs was the most popular. But if a National Geographic documentary about canine evolution seems too highbrow for your four-legged friend, Scooby Doo might be a perfectly acceptable option as well.

To better understand the type of content dogs might be most attracted to on screen, Mowat created a web-based questionnaire for dog owners around the globe to report the TV-watching habits of their canine companions.

Participants responded to questions about the types of screens in their homes, how their dogs interacted with screens, the kinds of content their dogs interacted with the most, as well as information about their dog’s age, sex, breed and where they live. They also provided descriptions of their dogs’ behavior when watching videos. Most commonly, dog owners described their pets’ behavior as active — including running, jumping, tracking action on screen and vocalizing — compared with passive behaviors like lying down or sitting. Dog owners also had the option to show their dog(s) four short videos featuring subjects of possible interest, including a panther, a dog, a bird and traffic moving along a road. They were then asked to rate their dog’s interest in each video and how closely the dog tracked the moving objects on the screen.

Mowat received 1,600 responses from dog owners across the world, including from the United States, Canada, the United Kingdom, the European Union and Australasia. Of those respondents, 1,246 ultimately completed the study. The following are some of the most interesting highlights:

• Age and vision were related to how much a dog interacted with a screen.
• Sporting and herding dog breeds appear to watch all content more than other breeds.
• Video content featuring animals was the most popular, with other dogs being by far the most engaging subjects to watch.
• Humans do not appear to be very appealing for dogs to watch, ranking ninth out of 17 predetermined categories.
• Cartoons were engaging for more than 10% of dogs.
• Movement on screens was a strong motivator for screen attention.

Mowat says she plans to build on the results of this study. Future research will focus on the development and optimization of video-based methods that can assess changes in visual attention as dogs age as well as answer questions that could help our four-legged friends age as gracefully as possible.

“We know that poor vision negatively impacts quality of life in older people, but the effect of aging and vision changes in dogs is largely unknown because we can’t accurately assess it,” she says. “Like people, dogs are living longer, and we want to make sure we support a healthier life for them as well.”

Another goal for Mowat is to compare how a dogs’ vision ages compared with the human or humans they share a home with.

“Dogs have a much shorter lifespan than their owner, of course, and if there are emerging environmental or lifestyle factors that influence visual aging, it might well show up in our dogs decades before it shows up in us,” she explains. “Our dogs could be our sentinels — the canine in the proverbial coal mine.”

Part of the immune system active for too long

A team of researchers led by Onur Boyman, professor of immunology at the University of Zurich (UZH) and Director of the Department of Immunology at the University Hospital Zurich (USZ), has shown in a study that the complement system plays an important role in Long Covid. It is part of the innate immune system and normally helps to fight infections and eliminate damaged and infected body cells. “In patients with Long Covid, the complement system no longer returns to its basal state, but remains activated and, thus, also damages healthy body cells,” says Boyman.

Continued activation of complement system damages tissue and blood cells

The researchers followed 113 COVID-19 patients for up to one year after their acute SARS-CoV-2 infection and compared them with 39 healthy controls. After six months, 40 patients had active Long Covid disease. More than 6,500 proteins in the blood of the study participants were analyzed both during the acute infection and six months later. “The analyses of which proteins were altered in Long Covid confirmed the excessive activity of the complement system. Patients with active Long Covid disease also had elevated blood levels indicating damage to various body cells, including red blood cells, platelets and blood vessels,” explains Carlo Cervia-Hasler, a postdoctoral researcher in Boyman’s team and first author of the study.

Bioinformatics recognizes protein patterns

The measurable changes in blood proteins in active Long Covid indicate an interaction between proteins of the complement system, which are involved in blood clotting and the repair of tissue damage and inflammation. In contrast, the blood levels of Long Covid patients who recovered from the disease returned to normal within six months. Active Long Covid is therefore characterized by the protein pattern in the blood. The blood markers were discovered using bioinformatics methods in collaboration with Karsten Borgwardt during his time as a professor at ETH Zurich.

Improved diagnostics and new therapeutic approaches

“Our work not only lays the foundation for better diagnosis, but also supports clinical research into substances that could be used to regulate the complement system. This opens up new avenues for the development of more targeted therapies for patients with Long Covid,” summarizes Onur Boyman.

Over the past decade, major technological advances have been made, making it possible to put a wide variety of systems into this state. Mechanical vibrations oscillating between two mirrors in a resonator can be cooled to very low temperatures as far as the quantum ground state. This has not yet been possible for optical fibers in which high-frequency sound waves can propagate. Now researchers from the Stiller Research Group have taken a step closer to this goal.

In their study, recently published in Physical Review Letters, they report that they were able to lower the temperature of a sound wave in an optical fiber initially at room temperature by 219 K using laser cooling, ten times further than had previously been reported. Ultimately, the initial phonon number was reduced by 75%, at a temperature of 74 K, -194 Celsius. Such a drastic reduction in temperature was made possible by the use of laser light. Cooling of the propagating sound waves was achieved via the nonlinear optical effect of stimulated Brillouin scattering, in which light waves are efficiently coupled to sound waves. Through this effect, the laser light cools the acoustic vibrations and creates an environment with less thermal noise which is, to an extent, “disturbing” noise for a quantum communication system, for example. “An interesting advantage of glass fibers, in addition to this strong interaction, is the fact that they can conduct light and sound excellently over long distances,” says Laura Blázquez Martínez, one of the lead authors of the article and a doctoral student in the Stiller research group.

Most physical platforms previously brought to the quantum ground state were microscopic. However, in this experiment, the length of the optical fiber was 50 cm and a sound wave extending over the full 50 cm of the core of the fiber was cooled to extremely low temperatures. “These results are a very exciting step towards the quantum ground state in waveguides and the manipulation of such long acoustic phonons opens up possibilities for broadband applications in quantum technology,” according to Dr. Birgit Stiller, head of the quantum optoacoustics group.

Sound, in the day-to-day classical world, can be understood as a density wave in a medium. However, from the perspective of quantum mechanics, sound can also be described as a particle: the phonon. This particle, the sound quantum, represents the smallest amount of energy which occurs as an acoustic wave at a certain frequency. In order to see and study single quanta of sound, the number of phonons must be minimized. The transition from the classical to quantum behavior of sound is often more easily observed in the quantum ground state, where the number of phonons is close to zero on average, such that the vibrations are almost frozen and quantum effects can be measured. Stiller: “This opens the door to a new landscape of experiments that allow us to gain deeper insights into the fundamental nature of matter.” The advantage of using a waveguide system is that light and sound are not bound between two mirrors, but propagating along the waveguide. The acoustic waves exist as a continuum — not only for certain frequencies — and can have a broad bandwidth, making them promising for applications such as high-speed communication systems.

“We are very enthusiastic about the new insights that pushing these fibers into the quantum ground state will bring,” emphasizes the research group leader. “Not only from the fundamental research point of view, allowing us to peek into the quantum nature of extended objects, but also because of the applications this could have in quantum communications schemes and future quantum technologies.”

Because it requires no battery that must be recharged or replaced, and because it requires no special wiring, such a sensor could be embedded in a hard-to-reach place, like inside the inner workings of a ship’s engine. There, it could automatically gather data on the machine’s power consumption and operations for long periods of time.

The researchers built a temperature-sensing device that harvests energy from the magnetic field generated in the open air around a wire. One could simply clip the sensor around a wire that carries electricity — perhaps the wire that powers a motor — and it will automatically harvest and store energy which it uses to monitor the motor’s temperature.

“This is ambient power — energy that I don’t have to make a specific, soldered connection to get. And that makes this sensor very easy to install,” says Steve Leeb, the Emanuel E. Landsman Professor of Electrical Engineering and Computer Science (EECS) and professor of mechanical engineering, a member of the Research Laboratory of Electronics, and senior author of a paper on the energy-harvesting sensor.

In the paper, which appeared as the featured article in the January issue of the IEEE Sensors Journal, the researchers offer a design guide for an energy-harvesting sensor that lets an engineer balance the available energy in the environment with their sensing needs.

The paper lays out a roadmap for the key components of a device that can sense and control the flow of energy continually during operation.

The versatile design framework is not limited to sensors that harvest magnetic field energy, and can be applied to those that use other power sources, like vibrations or sunlight. It could be used to build networks of sensors for factories, warehouses, and commercial spaces that cost less to install and maintain.

“We have provided an example of a battery-less sensor that does something useful, and shown that it is a practically realizable solution. Now others will hopefully use our framework to get the ball rolling to design their own sensors,” says lead author Daniel Monagle, an EECS graduate student.

Monagle and Leeb are joined on the paper by EECS graduate student Eric Ponce.

A how-to guide

The researchers had to meet three key challenges to develop an effective, battery-free, energy-harvesting sensor.

First, the system must be able to cold start, meaning it can fire up its electronics with no initial voltage. They accomplished this with a network of integrated circuits and transistors that allow the system to store energy until it reaches a certain threshold. The system will only turn on once it has stored enough power to fully operate.

Second, the system must store and convert the energy it harvests efficiently, and without a battery. While the researchers could have included a battery, that would add extra complexities to the system and could pose a fire risk.

“You might not even have the luxury of sending out a technician to replace a battery. Instead, our system is maintenance-free. It harvests energy and operates itself,” Monagle adds.

To avoid using a battery, they incorporate internal energy storage that can include a series of capacitors. Simpler than a battery, a capacitor stores energy in the electrical field between conductive plates. Capacitors can be made from a variety of materials, and their capabilities can be tuned to a range of operating conditions, safety requirements, and available space.

The team carefully designed the capacitors so they are big enough to store the energy the device needs to turn on and start harvesting power, but small enough that the charge-up phase doesn’t take too long.

In addition, since a sensor might go weeks or even months before turning on to take a measurement, they ensured the capacitors can hold enough energy even if some leaks out over time.

Finally, they developed a series of control algorithms that dynamically measure and budget the energy collected, stored, and used by the device. A microcontroller, the “brain” of the energy management interface, constantly checks how much energy is stored and infers whether to turn the sensor on or off, take a measurement, or kick the harvester into a higher gear so it can gather more energy for more complex sensing needs.

“Just like when you change gears on a bike, the energy management interface looks at how the harvester is doing, essentially seeing whether it is pedaling too hard or too soft, and then it varies the electronic load so it can maximize the amount of power it is harvesting and match the harvest to the needs of the sensor,” Monagle explains.

Self-powered sensor

Using this design framework, they built an energy management circuit for an off-the-shelf temperature sensor. The device harvests magnetic field energy and uses it to continually sample temperature data, which it sends to a smartphone interface using Bluetooth.

The researchers used super-low-power circuits to design the device, but quickly found that these circuits have tight restrictions on how much voltage they can withstand before breaking down. Harvesting too much power could cause the device to explode.

To avoid that, their energy harvester operating system in the microcontroller automatically adjusts or reduces the harvest if the amount of stored energy becomes excessive.

They also found that communication — transmitting data gathered by the temperature sensor — was by far the most power-hungry operation.

“Ensuring the sensor has enough stored energy to transmit data is a constant challenge that involves careful design,” Monagle says.

In the future, the researchers plan to explore less energy-intensive means of transmitting data, such as using optics or acoustics. They also want to more rigorously model and predict how much energy might be coming into a system, or how much energy a sensor might need to take measurements, so a device could effectively gather even more data.

“If you only make the measurements you think you need, you may miss something really valuable. With more information, you might be able to learn something you didn’t expect about a device’s operations. Our framework lets you balance those considerations,” Leeb says.

The work is supported, in part, by the Office of Naval Research and The Grainger Foundation.