However, measuring and tracking the quality of an urban environment, its evolution and its spatial disparities is difficult due to the amount of on-the-ground data needed to capture these patterns. To address the issue, Yong Suk Lee, assistant professor of technology, economy and global affairs in the Keough School of Global Affairs at the University of Notre Dame, and Andrea Vallebueno from Stanford University used machine learning to develop a scalable method to measure urban decay at a spatially granular level over time.

Their findings were recently published in Scientific Reports.

“As the world urbanizes, urban planners and policymakers need to make sure urban design and policies adequately address critical issues such as infrastructure and transportation improvements, poverty and the health and safety of urbanites, as well as the increasing inequality within and across cities,” Lee said. “Using machine learning to recognize patterns of neighborhood development and urban inequality, we can help urban planners and policymakers better understand the deterioration of urban space and its importance in future planning.”

Traditionally, the measurement of urban quality and quality of life in urban spaces has used sociodemographic and economic characteristics such as crime rates and income levels, survey data of urbanites’ perception and valued attributes of the urban environment, or image datasets describing the urban space and its socioeconomic qualities. The growing availability of street view images presents new prospects in identifying urban features, Lee said, but the reliability and consistency of these methods across different locations and time remains largely unexplored.

In their study, Lee and Vallebueno used the YOLOv5 model (a form of artificial intelligence that can detect objects) to detect eight object classes that indicate urban decay or contribute to an unsightly urban space — things like potholes, graffiti, garbage, tents, barred or broken windows, discolored or dilapidated façades, weeds and utility markings. They focused on three cities: San Francisco, Mexico City and South Bend, Indiana. They chose neighborhoods in these cities based on factors including urban diversity, stages of urban decay and the authors’ familiarity with the cities.

Using comparative data, they evaluated their method in three contexts: homelessness in the Tenderloin District of San Francisco between 2009 and 2021, a set of small-scale housing projects carried out in 2017 through 2019 in a subset of Mexico City neighborhoods, and the western neighborhoods of South Bend in the 2011 through 2019 period — a part of the city that had been declining for decades but also saw urban revival initiatives.

Researchers found that the trained model could adequately detect the objects it sought across different cities and neighborhoods, and did especially well where there are denser populations, such as San Francisco.

For instance, the maps allowed researchers to assess the temporal and geographic variation in homelessness in the San Francisco area, an issue that has grown over the years.

The model struggled in the more suburban area of South Bend, according to Lee, demonstrating a need to tweak the model and the types of objects identified in less dense populations. In addition, the researchers found there is still a risk for bias that should be addressed.

“Our findings indicate that trained models such as ours are capable of detecting the incidence of decay across different neighborhoods and cities, highlighting the potential of this approach to be scaled in order to track urban quality and change for urban centers across the U.S. and cities in other countries where street view imagery is available,” he said.

Lee said the model has potential to provide valuable information using data that can be collected in a more efficient way compared to using coarser, traditional economic data sources, and that it could be a valuable and timely tool for the government, nongovernmental organizations and the public.

“We found that our approach can employ machine learning to effectively track urban quality and change across multiple cities and urban areas,” Lee said. “This type of data could then be used to inform urban policy and planning and the social issues that are impacted by urbanization, including homelessness.”

Researchers developed prototype technology to filter out interference from other radio signals while sweeping underutilized spectrum frequency bands for high-traffic periods. The technology could help regulators distribute wireless access at an affordable cost during low-traffic periods.

“Through meticulous analysis of spectrum usage, we can identify underutilized segments and hidden opportunities, which, when leveraged, would lead to a cost-effective connectivity solution for users around the globe,” said Bharadia. “Crescendo stands at the forefront of this initiative, offering a low-complexity yet highly effective solution with advanced algorithms that provides robust spectrum insights for all.”

Accessing a “Quiet” Resource

When unoccupied, broadband frequencies owned by users like the U.S. Navy or military can offer wireless connection to the public or corporations at low cost. The challenge is determining when the primary owners use the frequencies, and when they would be available for public use.

Working with Associate Professor Aaron Schulman of the Jacobs School of Engineering Computer Science and Engineering Department, researchers from Bharadia’s Wireless Communications, Sensing and Networking Group created a novel device called “Crescendo.”

Crescendo features adaptive software that allows it to sweep for activity across a range of frequencies within an agency-owned wideband spectrum. The device can adapt to signal interference in real-time by dynamically adjusting which signals it receives to tune out interference from nearby towers, base stations and other sources of high power signals. The technology’s high signal fidelity also ensures that users can count on a secure connection, with any cyberattacks identified in real-time.

“Knowing what’s going on in the spectrum helps us improve communications, regulation, privacy and security,” said UC San Diego Ph.D. student and lead author Raghav Subbaraman.

Crescendo improves on an earlier design called “SweepSense,” a prototype developed by Subbaraman and colleagues in Bharadia’s lab and the Jacobs School of Engineering’s Department of Computer Science and Engineering.

In practice, Crescendo can be built using commercial off-the-shelf parts and attached to existing radio units with programmable software. Researchers can monitor a particular spectrum’s activity through color-coded graphs showing hot spots of activity in red.

“When I look at this plot, I get very excited because I can see the [wireless] spectrum as colors or visible light,” said Subbaraman. “I think as more people learn about this, it should hopefully become more accessible to them. We take it for granted that we turn on WiFi, our phone just connects, and we get the Internet. But what actually happens is what we see here.”

As a prototype, Crescendo still has areas Subbaraman would like to fine-tune, including reducing its number of components to decrease the cost of production. Subbaraman would also like to conduct field tests with multiple “spectrum sensors” — devices that measure wireless network activity — to determine whether they might work in concert.

Participants who ate only during an eight-hour window between noon and 8 p.m. each day actually lost more weight over six months than participants who were instructed to reduce their calorie intake by 25%. Both groups had similar reductions in long-term blood sugar levels, as measured by a test of hemoglobin A1C, which shows blood sugar levels over the past three months.

The study was conducted at UIC and enrolled 75 participants into three groups: those who followed the time-restricted eating rules, those who reduced calories and a control group. Participants’ weight, waist circumference, blood sugar levels and other health indicators were measured over the course of six months.

Senior author Krista Varady said that participants in the time-restricted eating group had an easier time following the regime than those in the calorie-reducing group. The researchers believe this is partly because patients with diabetes are generally told to cut back on calories by their doctors as a first line of defense, so many of these participants likely had already tried — and struggled with — that form of dieting. And while the participants in the time-restricted eating group were not instructed to reduce their calorie intake, they ended up doing so by eating within a fixed window.

“Our study shows that time-restricted eating might be an effective alternative to traditional dieting for people who can’t do the traditional diet or are burned out on it,” said Varady, a professor of kinesiology and nutrition. “For many people trying to lose weight, counting time is easier than counting calories.”

There were no serious adverse events reported during the six-month study. Occurrences of hypoglycemia (low blood sugar) and hyperglycemia (high blood sugar) did not differ between the diet groups and control groups.

Today, 1 in 10 U.S. residents has diabetes, and that number is expected to rise to 1 in 3 by 2050 if current trends continue, the researchers explain. Finding more options for controlling weight and blood sugar levels for these patients, therefore, is crucial.

Just over half the participants in the study were Black and another 40% were Hispanic. This is notable as diabetes is particularly prevalent among those groups, so having studies that document the success of time-restricted eating for them is particularly useful, the researchers said.

The study was small and should be followed up by larger ones, said Varady, who is also a member of the University of Illinois Cancer Center. While it acts as a proof of concept to show that time-restricted eating is safe for those with Type 2 diabetes, Varady said people with diabetes should consult their doctors before starting this sort of diet.

The other current and former UIC authors on the paper are Vasiliki Pavlou, Sofia Cienfuegos, Shuhao Lin, Mark Ezpeleta, Kathleen Ready, Sarah Corapi, Jackie Wu, Jason Lopez, Kelsey Gabel, Lisa Tussing-Humphreys, Vanessa Oddo, Julienne Sanchez and Dr. Terry Unterman. Other authors are from Northwestern University, the University of Minnesota, Minneapolis, and the University of Southern California.

Male sperm cells are constantly produced in large quantities in the testicles during so-called spermatogenesis. In this process, the typical elongated sperm cells are formed from round germ cells. This enormous change in shape requires the fine tuned reorganization of specialized structural proteins. One of these structural proteins is ACTL7B. “Since it is exclusively made in humans and mice during the maturation of male sperm, it has been postulated that the protein is important for this phase of development,” notes corresponding author Prof. Hubert Schorle from the Institute of Pathology at UKB, who is also a member of the Transdisciplinary Research Area (TRA) “Life & Health” at the University of Bonn.

To investigate the role of the structural protein in spermiogenesis, Prof. Schorle’s team generated a mouse model with a mutation in the Actl7b gene using gene-editing technology. This results in a complete loss of function of ACTL7B. “Without ACTL7B, development is blocked, the cells often remain in a roundish shape, usually do not form the elongated, typical sperm shape and die to a large extent ,” says first author Gina Esther Merges, a doctoral student in Professor Schorle’s laboratory.

Disruption in the network of proteins

In this context, the Bonn researchers found that ACTL7B is required for the reorganization of the cytoskeleton of spermatids. Using mass spectrometric analyses, they identified two interaction partners of ACTL7B, DYNLL1 and DYNLL2. “We were able to show that without the structural protein, DYNLL1 and 2 are not correctly localized in the round spermatids. Since it is probably a larger protein complex with further interaction partners, we attribute the above described effect to a loss of temporally and spatially precisely regulated and targeted redistribution of these proteins,” Prof. Schorle notes.

This explains why the sperm of male mice with a mutated Actl7b gene is not able to develop the characteristic shape. Due to this, the animals are infertile. In addition, according to other research, there is evidence that levels of the protein ACTL7B are reduced in some fertility patients. “Our study shows that mutations in the Actl7b gene could be the cause of male infertility,” says Prof. Schorle.

The innovative method, presented in a paper published Wednesday in the journal Nature, suppresses the growth of lithium dendrites — damaging branch-like structures that develop inside so-called all-solid-state lithium batteries, preventing firms from broadly commercializing the promising technology. But this new design for a battery “interlayer,” led by Department of Chemical and Biomolecular Engineering Professor Chunsheng Wang, stops dendrite formation, and could open the door for production of viable all-solid-state batteries for EVs.

At least 750,000 registered EVs in the U.S. run on lithium-ion batteries — popular because of their high energy storage but containing a flammable liquid electrolyte component that burns when overheated. While no government agency tracks vehicle fires by type of car, and electric car battery fires appear to be relatively rare, they pose particular risks; the National Transportation Safety Board reports that first responders are vulnerable to safety risks, including electric shock and the exposure to toxic gasses emanating from damaged or burning batteries.

All-solid-state batteries could lead to cars that are safer than current electric or internal combustion models, but creating a strategy to bypass the drawbacks was laborious, Wang said. When these batteries are operated at the high capacities and charging-discharging rates that electric vehicles demand, lithium dendrites grow toward the cathode side, causing short circuits and a decay in capacity.

He and Postdoctoral Associate Hongli Wan began to develop a theory for the formation of lithium dendrite growth in 2021; it remains a matter of scientific debate, the researchers said.

“After we figured out that part, we proposed the idea to redesign the interlayers that would effectively suppress the lithium dendrite growth,” he said.

Their solution is unique because of the stabilizing of the battery’s interfaces between the solid electrolyte and the anode (where electrons from a circuit enter the battery) and the electrolyte and the cathode (where energy flows out of the battery). The new battery structure adds a fluorine-rich interlayer that stabilizes the cathode side, as well as a modification of the anode’s interlayer with magnesium and bismuth — suppressing the lithium dendrite.

“Solid-state batteries are next-generation because they can achieve high energy and safety. In current batteries, if you achieve high energy, you’ll sacrifice safety,” said Wang.

Researchers have other challenges to solve before the product enters the market. To commercialize all-solid-state batteries, experts will have to scale down the solid electrolyte layer to achieve a similar thickness to the lithium-ion batteries’ electrolyte, which will improve energy density — or how much power the battery can store. High costs of basic materials are another challenge, the team said.

Aiming to release the new batteries to the market by 2026, advanced battery manufacturer Solid Power plans to begin trials of the new technology to assess its potential for commercialization. Continuing research aims to further boost energy density, the researchers said.

The model’s simulations suggest this effect is large enough to make a meaningful contribution to global sea-level rise under high greenhouse gas emissions scenarios.

The extra ice loss caused by this meltwater flowing out to sea from beneath Antarctic glaciers is not currently accounted for in the models generating major sea-level rise projections, such as those of the Intergovernmental Panel on Climate Change (IPCC). If this process turns out to be an important driver of ice loss across the entire Antarctic ice sheet, it could mean current projections underestimate the pace of global sea-level rise in decades to come.

“Knowing when and how much global sea-level will rise is critical to the welfare of coastal communities,” said Tyler Pelle, the study’s lead author and a postdoctoral researcher at Scripps. “Millions of people live in low-lying coastal zones and we can’t adequately prepare our communities without accurate sea-level rise projections.”

The study, published October 27 in Science Advances and funded by the National Science Foundation (NSF), NASA, and the Cecil H. and the Ida M. Green Foundation for Earth Sciences at the Institute of Geophysics and Planetary Physics at Scripps, modeled the retreat of two glaciers in East Antarctica through the year 2300 under different emissions scenarios and projected their contributions to sea-level rise. Unlike previous Antarctic ice sheet models, this one included the influence of this flow of meltwater from beneath glaciers out to sea, which is known as subglacial discharge.

The two glaciers the study focused on, named Denman and Scott, together hold enough ice to cause nearly 1.5 meters (5 feet) of sea-level rise. In a high emissions scenario (IPCC’s SSP5-8.5 scenario, which assumes no new climate policy and features 20% higher CO₂ emissions by 2100), the model found that subglacial discharge increased the sea-level rise contribution of these glaciers by 15.7%, from 19 millimeters (0.74 inches) to 22 millimeters (0.86 inches) by the year 2300.

These glaciers, which are right next to each other, sit atop a continental trench that is more than two miles deep; once their retreat reaches the trench’s steep slope, their contribution to sea-level rise is expected to accelerate dramatically. With the added influence of subglacial discharge, the model found that the glaciers retreated past this threshold about 25 years earlier than they did without it.

“I think this paper is a wake up call for the modeling community. It shows you can’t accurately model these systems without taking this process into account,” said Jamin Greenbaum, co-author of the study and a researcher at Scripps’ Institute of Geophysics and Planetary Physics.

A key takeaway, beyond the understudied role of subglacial discharge in accelerating sea-level rise, is the importance of what humanity does in the coming decades to rein in greenhouse gas emissions, said Greenbaum. The low emissions scenario runs of the model did not show the glaciers retreating all the way into the trench and avoided the resulting runaway contributions to sea-level rise.

“If there is a doomsday story here it isn’t subglacial discharge,” said Greenbaum. “The real doomsday story is still emissions and humanity is still the one with its finger on the button.”

In Antarctica, subglacial meltwater is generated from melting that occurs where the ice sits on continental bedrock. The main sources of the heat melting the ice in contact with the ground are friction from the ice grinding across the bedrock and geothermal heat from Earth’s interior permeating up through the crust.

Prior research suggested that subglacial meltwater is a common feature of glaciers around the world and that it is present under several other massive Antarctic glaciers, including the infamous Thwaites Glacier in West Antarctica.

When subglacial discharge flows out to sea it is thought to accelerate melting of the glacier’s ice shelf — a long floating tongue of ice that extends out to sea beyond the last part of the glacier that is still in contact with solid ground (known as the grounding line). Subglacial discharge is thought to speed up ice shelf melting and glacial retreat by causing ocean mixing that stirs in additional ocean heat within the cavity beneath a glacier’s floating ice shelf. This enhanced ice shelf melting then causes the upstream glacier to accelerate, which can drive sea level rise.

The notion that subglacial discharge causes additional ice shelf melting is widely accepted in the scientific community, said Greenbaum. But it hasn’t been included in sea-level rise projections because many researchers weren’t sure if the process’ effect was sufficiently large to increase sea-level rise, mainly because its effects are localized around the glacier’s ice shelf.

Pelle said subglacial discharge came onto his radar in 2021 when he and his colleagues observed that East Antarctica’s Denman Glacier’s ice shelf was melting faster than expected given local ocean temperatures. Puzzlingly, Denman’s neighbor Scott Glacier’s ice shelf was melting much more slowly despite virtually identical ocean conditions.

To test whether subglacial discharge could reconcile the melt rates seen at the Denman and Scott ice shelves, as well as whether subglacial meltwater might accelerate sea-level rise, the team combined models for three different environments: the ice sheet, the space between the ice sheet and bedrock, and the ocean.

Once the researchers married the three models into one they ran a series of projections up to 2300 using a NASA supercomputer.

The projections featured three main scenarios: a control that featured no additional ocean warming, a low emissions pathway (SSP1-2.6), and a high emissions pathway (SSP5-8.5). For each scenario, the researchers created projections with and without the effect of present-day levels of subglacial discharge.

The model’s simulations revealed that adding in subglacial discharge reconciled the melt rates seen at Denman and Scott Glaciers. As for why Scott Glacier was melting so much slower than Denman, Pelle said the model showed that “a strong subglacial discharge channel drained across the Denman Glacier grounding line, while a weaker discharge channel drained across the Scott Glacier grounding line.” The strength of the discharge channel at Denman, Pelle explained, was behind its speedy melt.

For the control and low-emissions model runs the contributions to sea-level rise were close to zero or even slightly negative with or without subglacial discharge at 2300. But in a high emissions scenario, the model found that subglacial discharge increased the sea-level rise contribution of these glaciers from 19 millimeters (0.74 inches) to 22 millimeters (0.86 inches) in 2300.

In the high emissions scenario that included subglacial discharge, Denman and Scott Glaciers retreated into the two-mile-deep trench beneath them by 2240, about 25 years earlier than they did in the model runs without subglacial discharge. Once the grounding lines of the Denman and Scott Glaciers retreat past the lip of this trench their yearly sea-level rise contribution explodes, reaching a peak of 0.33 millimeters (0.01 inches) per year — roughly half of the present-day annual sea-level rise contribution of the entire Antarctic ice sheet.

Pelle said the trench’s steep slope is behind this explosive increase in sea-level rise contribution. As the glacier retreats down slope, its ice shelf begins losing thicker and thicker slabs of ice from its leading edge. This process of ice loss quickly outpaces ice accumulation at the ice sheet’s interior, causing further glacial retreat. Researchers refer to this process as “Marine Ice Sheet Instability,” and it can promote explosive ice loss from glaciers like Denman and Scott.

Researchers refer to topography such as the trench beneath Denman and Scott Glaciers as a retrograde slope and worry that it creates a positive feedback loop by which glacial retreat begets more retreat. Large areas of the West Antarctic Ice Sheet, such as Thwaites Glacier, also have retrograde slopes that, while not as dramatic as the Denman-Scott trench, contribute to fears of broader ice sheet instability.

“Subglacial meltwater has been inferred beneath most if not all Antarctic glaciers, including Thwaites, Pine Island, and Totten glaciers,” said Pelle. “All these glaciers are retreating and contributing to sea-level rise and we are showing that subglacial discharge could be accelerating their retreat. It’s urgent that we model these other glaciers so we can get a handle on the magnitude of the effect subglacial discharge is having.”

The researchers behind this study are doing just that. Pelle said they are in the process of submitting a research proposal to extend their new model to the entire Antarctic ice sheet.

Future iterations of the model may also attempt to couple the subglacial environment with the ice sheet and ocean models so that the amount of subglacial meltwater dynamically responds to these other factors. Greenbaum said that the current version of their model kept the amount of subglacial meltwater constant throughout the model runs, and that making it respond dynamically to the surrounding environment would likely make the model more true to life.

“This also means that our results are probably a conservative estimate of the effect of subglacial discharge,” said Greenbaum. “That said, we can’t yet say how much sea-level rise will be accelerated by this process — hopefully it’s not too much.”

Part of Greenbaum’s upcoming fieldwork in Antarctica, supported by NSF and NASA, aims to directly investigate the impacts of subglacial meltwater in both the East and West Antarctic ice sheets. In collaboration with the Australian Antarctic Division and the Korea Polar Research Institute, Greenbaum and his collaborators will be visiting the ice shelves of Denman and Thwaites Glaciers in East and West Antarctica, respectively, looking for direct evidence that subglacial freshwater is discharging into the ocean beneath the glaciers’ ice shelves and contributing to warming.

In addition to Pelle and Greenbaum, the study was co-authored by Christine Dow of the University of Waterloo, Adrian Jenkins of Northumbria University, and Mathieu Morlighem of Dartmouth College.