A federal multibillion-dollar effort that subsidized internet service providers to bring broadband to underserved areas has provided much-needed high-speed internet to some of the country’s remote and rural areas. However, according to UC Santa Barbara researchers, once the federal subsidies ended, so did much of the service.

“We wanted to study how effective such an approach of directly subsidizing the ISPs to operate as regulated monopolies is in these rural areas, versus the ones that are served by regular monopolies, or compared to competitive markets,” said Arpit Gupta, an assistant professor in UCSB’s Computer Science Department and co-author of a paper presented in August at conference hosted by the Association for Computing Machinery’s (ACM) Special Interest Group on Data Communication (SIGCOMM).

“If you look at the data the regulators had on paper, the program looked like a great success, which amounts to something like six million addresses served and everybody compliant with what the FCC’s rate and service quality requirements were,” he continued. “But when we started digging in, we realized that was not the case, and people are actually not receiving service as is being certified by the ISPs.”

Bridging the digital divide

Everyone should have access to high-speed internet service. That’s the concept behind digital inclusion, an effort to bring internet connectivity to remote populations in an increasingly online world.

“Everybody needs internet access now, especially in the post-pandemic world,” said computer science professor and paper co-author Elizabeth Belding. “So much of what we do is online and all of the easiest places to reach have internet access.”

Urban areas are the likeliest places to have good internet access, thanks to their infrastructure and their population density, which can guarantee enough subscribers to generate a return on the internet service providers’ investment into covering these areas.

The areas often left out of coverage are predominantly rural, Belding added. “It costs more to bring access there; they’re harder to reach,” she said. “The terrain is difficult, and the population density is much smaller, so you get fewer people covered for the same cost of infrastructure, or perhaps a greater cost.”

To help bridge that gap, the Federal Communications Commission (FCC) in 2011 launched the Connect America Fund (CAF), a program to ensure high-speed internet in remote areas by allowing eligible carriers to recover some of their costs of deploying new infrastructure in these places. In exchange, the ISPs had to satisfy certain rate and service conditions: minimum 10Mbps download/1Mbps upload speeds at rates that were comparable to those charged in urban areas.

The program came in two parts: a smaller CAF I support period followed by a larger CAF II support period in 2014, which ended in 2021. The ISPs were required to certify the addresses served through the program.

To see whether the ISPs’ self-reported data were accurate, the researchers deployed their broadband plan querying tool (BQT), which allowed them to gather information about the broadband plans on offer, as well as their availability, performance and distribution for a given region, and at a scale of thousands to millions of addresses. Created for a previous project that allowed them to survey the value of broadband plan offerings across the country, BQT was now being used to sample the service areas supported by CAF funding and to see how they matched up with the certified reports.

The UCSB researchers, working with colleagues at UC Berkeley and broadband analytics company Ookla, Inc., narrowed their field of inquiry to the three ISPs that received the most significant amount of CAF funding: AT&T, CenturyLink (now Lumen) and Frontier, which collectively received 37.5% of the total $10 billion to serve just more than half of the total 6.13 million CAF addresses spanning 43 states. They also added a smaller ISP, Consolidated Communications, which received $193 million in CAF funding.

Additionally, they narrowed their address selection to where the selected providers were dominant, as well as where multiple ISPs in the same region provided service to equal numbers of addresses. They were also careful to sample from a wide variety of population sizes.

“We did expect that things should not be perfect, that there should be some gaps between what ISPs are telling to the regulators,” Gupta said. “That could be because of noise and how the reporting works. We were expecting discrepancies of maybe 5% here and 10% there.”

The need for independent evaluations

What they found was a 55% serviceability rate—that is, little more than half of the sampled addresses certified as served by the selected ISPs were now being served by them. They also found a 33% compliance rate, meaning that only about a third of the sampled locations that were certified met the requirements for upload/download speeds.

In some cases, CAF-served addresses did receive higher download speeds than their monopoly-served neighbors, but “overall, the CAF program has largely failed to achieve its intended goal, leaving many targeted rural communities with inadequate or no broadband connectivity,” according to the study.

In their comparison of the CAF-funded regulated monopoly against regular monopolies or competitive markets, the researchers also found that some competition is necessary to improve consumer value; improvements in broadband service were inconsistent where the CAF-funded ISP operated without competition.

The takeaway, according to the scientists, is that for large-scale interventions such as the CAF program, objective, data-centric post-hoc evaluations are needed to assess the true efficacy of the intervention and to provide transparency. These evaluations are also necessary to keep the targeted rural populations from falling through the cracks.

“To live in an unserved area that is said to be served means not only is there no internet, it’s also a challenge to get it because to the FCC, the area doesn’t look unserved,” Belding said. Without independent evaluations of service and price, she added, underserved customers—those who receive internet but at speeds too low or prices too high to be competitive—can also find themselves on the wrong side of the digital divide.

Such oversight will be crucial as momentum builds for the federal Broadband Equity Access and Deployment (BEAD) program, a $42.5 billion expansion of high-speed internet across the U.S. and its territories by paying for planning, infrastructure deployment and adoption programs.

“Now that we are in the process of starting with this $42.5 billion investment, we should be thinking about how to assess its efficacy,” Gupta said, adding that BEAD “could have a transformative effect in terms of fighting digital inequity.

“But if we don’t do it right, a lot of money could be wasted.”

Sea robins are ocean fish particularly suited to their bottom-dwelling lifestyle. Six leg-like appendages make them so adept at scurrying, digging, and finding prey that other fish tend to hang out with them and pilfer their spoils.

A chance encounter in 2019 with these strange, legged fish at Cape Cod’s Marine Biological Laboratory was enough to inspire Corey Allard to want to study them.

“We saw they had some sea robins in a tank, and they showed them to us, because they know we like weird animals,” said Allard, a postdoctoral fellow in the lab of Nicholas Bellono, professor in the Department of Molecular and Cellular Biology. The Bellono lab investigates the sensory biology and cellular physiology of many marine animals, including octopuses, jellyfish, and sea slugs.

“Sea robins are an example of a species with a very unusual, very novel trait,” Allard continued. “We wanted to use them as a model to ask, ‘How do you make a new organ?'”

Allard’s ensuing deep dive into sea robin biology led to a collaboration with Stanford researchers studying the fish’s developmental genetics and culminated in back-to-back papers in Current Biology, co-authored by Bellono and Amy Herbert and David Kingsley at Stanford University, and others.

The studies provide the most comprehensive understanding to date on how sea robins use their legs, what genes control the emergence of those legs, and how these animals could be used as a conceptual framework for evolutionary adaptations.

Sea robin “legs” are actually extensions of their pectoral fins, of which they have three on each side. Allard first sought to determine whether the legs are bona fide sensory organs, which scientists had suspected but never confirmed. He ran experiments observing captive sea robins hunting prey, in which they alternate between short bouts of swimming and “walking.”

They also occasionally scratch at the sand surface to find buried prey, like mussels and other shellfish, without visual cues. The researchers realized that the legs were sensitive to both mechanical and chemical stimuli. They even buried capsules containing only single chemicals, and the fish could easily find them.

Serendipity led to another chance discovery. They received a fresh shipment of fish mid-study that looked like the originals, but the new fish, Allard said, did not dig and find buried prey or capsules like the originals could. “I thought they were just some duds, or maybe the setup didn’t work,” Bellono recalled.

It turned out the researchers had acquired a different species of sea robin. In their studies, they ended up characterizing them both—Prionotus carolinus, which dig to find buried prey and are highly sensitive to touch and chemical signals, and P. evolans, which lack these sensory capabilities and use their legs for locomotion and probing, but not for digging.

Examining the leg differences between the two fish, they found that the digging variety’s were shovel-shaped and covered in protrusions called papillae, similar to our taste buds. The non-digging fish’s legs were rod-shaped and lacked papillae. Based on these differences, the researchers concluded that papillae are evolutionary sub-specializations.

Allard’s paper describing the evolution of sea robins’ novel sensory organs included analysis of sea robin specimens from the Museum of Comparative Zoology to examine leg morphologies across species and time. The digging species are restricted to only a few locations, he found, suggesting a relatively recent evolution of this trait.

Studying sea robin legs wasn’t just about hanging out with weird animals (although that was fun too). The walking fish are a potentially powerful model organism to compare specialized traits, and to teach us about how evolution allows for adaptation to very specific environments.

About 6 million years ago, humans evolved the ability to walk upright, separating from their primate ancestors. Bipedalism is a defining feature of our species, and we only know so much about how, when, and why that change occurred.

Sea robins and their adaptation to living on the ocean floor could offer clues. For example, there are genetic transcription factors that control the development of the sea robins’ legs that are also found in the limbs of other animals, including humans.

The second study that was focused on genetics included the Kingsley lab at Stanford; Italian physicist Agnese Seminara; and biologist Maude Baldwin from the Max Planck Institute in Germany; and comprehensively examined the genetic underpinnings of the walking fish’s unusual trait.

The researchers used techniques including transcriptomic and genomic editing to identify which gene transcription factors are used in leg formation and function in the sea robins. They also generated hybrids between two sea robin species with distinct leg shapes to explore the genetic basis for these differences.

“Amy and Corey did a lot to describe this animal, and I think it’s pretty rare to go from the description of the behavior, to the description of the molecules, to the description of an evolutionary hypothesis,” Bellono said. “I think this is a nice blueprint for how one poses a scientific question and rigorously follows it with a curious and open mind.”

Manually shaking or vibrating molten metal using ultrasonic waves helps reduce air bubbles, cracks and grain sizes in a finished metal part. Metal 3D printing researchers hypothesized that vibrations were the key to increasing quality, but until now, the mechanisms were not well understood.

Using high-energy X-ray imaging, a team of researchers led by Christopher Kube, associate professor of engineering science and of acoustics in the Penn State College of Engineering, captured footage of a cross-section of liquid metal as it cooled.

Their results confirmed longstanding hypotheses in the field that through local pressure changes, ultrasonic vibrations encourage air bubbles to increase in number, enlarge, migrate to the surface of a melt pool and pop.

Sonication, or vibration by ultrasound, also increases the speed that metal cools, which helps suppress additional bubbles from forming. The team published their findings in Communications Materials.

“Metal additive manufacturing has inherent constraints on part quality due to the process,” Kube said. “Our work aims to alleviate these constraints by utilizing external forces like ultrasound to afford better control of the process, leading to higher quality and better performing parts.”

To arrive at their findings, collaborators from the Advanced Photon Source at the Argonne National Laboratory used high-energy synchrotron X-ray imaging of an aluminum alloy sample as it was simultaneously melted by a laser and sonicated by an ultrasonic transducer.

Unlike the type of X-ray used at the doctor’s office, synchrotron X-ray can pass through metal and image hundreds of thousands of frames per second to see changes inside the materials very quickly, Kube explained.

The result was an X-ray video with direct visualization of the bubble behavior. Kube’s lab then corroborated the results through computational fluid dynamics simulations. Lovejoy Mutswatiwa, doctoral student in engineering science and mechanics at Penn State and first author on the paper, explained that the faster metal is solidified, the smaller the grain size will be.

“Grain size can affect a material’s performance, including corrosion resistance, strength, toughness, ductility and bending,” Mutswatiwa said. “Finer grain size allows a metal to be stronger and hold up under pressure.”

The experimental setup—a single laser melting a tiny point—allowed the researchers to infer what happens when the laser melts at points along a prescribed path, according to Mutswatiwa.

“If we understand the process at a small scale, it’s easy to apply to the whole additive manufacturing process,” Mutswatiwa said. “These results could also help us integrate more alloys into the additive manufacturing process.”

Currently, over 10,000 alloys are used in conventional manufacturing, but less than 10% of them can be used in additive manufacturing due to problems with porosity and cracking, Mutswatiwa explained.

“We are trying to increase the number of alloys we can print with while maintaining the quality of conventional manufacturing,” he said. “Though still a highly experimental technology, using ultrasound in metal manufacturing is showing promise to help avoid defects in metal.”

Kube’s team was recently awarded a three-year grant to extend the ultrasonic technique into a large-scale additive process known as gas metal wire arc additive manufacturing. The project aims to transition the technique from a fundamental investigation to real applications to help manufacturing efforts in the U.S. Navy’s nuclear fleet.

“We proved at a small scale that ultrasound can impact melt pools in additive manufacturing,” Kube said. “Our next step is to positively leverage the impact to help the Navy produce higher quality and better performing parts.”