Normal view
- The Debrief
- Decades of NASA Satellite Data Reveals the Elusive, Enigmatic βUrban Pulseβ of Six Major Cities
Decades of NASA Satellite Data Reveals the Elusive, Enigmatic βUrban Pulseβ of Six Major Cities
A multi-institutional team of researchers led by University of Connecticut Professor Zhe Zhu has developed a method for measuring the dynamic, real-time activity of urban environments from space, which they are calling an βUrban Pulse.β
The research team behind the novel urban activity metric said that monitoring a cityβs Urban Pulse could help mitigate uncontrolled urban sprawl or decay and enable environmentalists and urban planners to intervene before disasters become unavoidable.
Measuring an Urban Pulse Could Reveal Neighborhoods βNot Doing Wellβ
Although environmentalists and urban planners have a wide range of tools to measure the activities within a city, Zhu notes that scientists have spent decades merely capturing the βoutcome of urbanization,β such as a finished road or a newly completed home. However, the researcher and lead author of a study detailing the Urban Pulse methodology added that, even with all the current tools, βyou donβt really see the dynamics within an urban area.β
According to a statement detailing the new approach, a cityβs pulse is determined by all construction activity within it. Along with new construction, the metric includes repairs, infrastructure improvements, or expansion into previously undeveloped green spaces. When used correctly, the researchers said that it can help determine βif and where their city is not doing well.β
βThis would allow (authorities) to be proactive rather than conducting a metaphorical autopsy after the decay of an area is evident,β the team explained.
Bridging the Gap Between Abstract Urban Theories and Measurable, Real-World Data
To test their approach, the team evaluated the Urban Pulse of six cities: Seattle, Shenzhen, Lagos, Mumbai, Dubai, and Mexico City. This involved a deep examination of what the team termed βdecades of dense time-series dataβ collected by NASAβs Harmonized Landsat and Sentinel-2 (HLS) Β satellites for physical transformations in an urban environment, such as new construction, measurable infrastructure improvements, and demolition.
Instead of analyzing each cityβs changes manually, the team evaluated the above changes on what they called βthe neighborhood levelβ using a deep-learning and time-series-analysis approach called CAPES, developed by former UConn postdoctoral researcher Ji Won Suh. The team said that, by observing these βhigh-frequency rhythms of developmentβ from a broad βouter spaceβ perspective, their approach βbridges the gap between abstract urban theories and measurable, real-world data.β

After examining CAPESβ results, the team found several key markers within the Urban Pulse. For example, the view from space revealed that growth within cities is not smooth and steady. Instead, Zhu and colleagues said that development happens in βabrupt, intense, and episodic bursts of construction.β
CAPES also revealed that the rhythms of an urban environment are cyclical. For example, while a city may show relatively steady growth on a broader level, individual neighborhoods go through βdramatic boom-and-rest cyclesβ of expansion and dormancy that donβt appear to follow predictable annual seasons.
The third pattern revealed by measuring the six citiesβ Urban Pulse from space was that cities are βasynchronous,β meaning a single city does not βbeatβ in unison. The team noted that neighborhoods βpulse at completely different times.β When it functions properly, this βuncoordinated rhythmβ helps prevent the cityβs infrastructure and labor markets from βoverheating.β
Unlike previous methods for tracking a cityβs evolution, the team noted that their Urban Pulse approach can help researchers βvisualize a cityβs reaction to global shocks.β For example, the team said that their analysis captured βthe exact moment the COVID-19 pandemic triggered a widespread, synchronized βcardiac arrestβ in urban development worldwide.β
However, their new tool also revealed what the researchers termed βprofound inequalitiesβ in how individual cities recovered from the dramatic halt to urban growth. For example, the team said that the Urban Pulse of Shenzhen revealed synchronized βdipsβ in activity, followed almost immediately by βrapid, policy-driven rebounds.β However, the same Orban Pulse analysis showed that the reactions in Mumbai and Mexico City were much more βmuted.β
βItβs like in human beings,β Zhu explained. βWhen you get a disease, itβs not going to show up exactly the same in different people.β
A βVery Impactful Toolβ for Navigating Cities
Although the Urban Pulse metric offers a tantalizing tool for academics, the team noted real-world benefits for global policymakers, urban planners, and environmentalists, adding that βit serves as an early warning system.β
βBy monitoring the rhythm, rate, and amplitude of neighborhood pulses, governments can identify early signs of urban decay or unsustainable sprawl and intervene before crises become entrenched,β they explained.
The team also suggested that making Urban Pulse data publicly available could βrevolutionize how everyday people interact with their cities.β For example, an urban family considering a move to a new city or a new part of their current city could track a target neighborhoodβs pulse to spot early warning signs of decay or early indicators of positive-trending growth. The same data could help business owners plan new locations or expanded service routes, depending on the business profile and the local Urban Pulse trends.
βThis is going to be a very impactful tool influencing not only top-down policy decisions from governments but also bottom-up decisions from everyday people navigating their cities,β Zhu explained.
In a recent study, βThe Urban Pulse: Diagnosing the urbanization process as spiky, cyclical, and asynchronousβ was published in theΒ Proceedings of the National Academy of Sciences.
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.
- The Daily Sceptic
- Ten Expensive and Woke Studies Funded by the Governmentβs UKRI Future Leaders Fellowships
Ten Expensive and Woke Studies Funded by the Governmentβs UKRI Future Leaders Fellowships
The first thing a future anti-woke UK government should cut is the billions spent on useless Left-wing research, says Charlotte Gill. For starters, here are 10 studies funded by UKRI's Future Leaders Fellowships.
The post Ten Expensive and Woke Studies Funded by the Governmentβs UKRI Future Leaders Fellowships appeared first on The Daily Sceptic.
Humpback Whale Stuns Scientists With 15,000 Kilometer Journey Across Oceans
Cancerβs βUndruggableβ Protein Has a Dangerous New Superpower
- The Debrief
- βSpiderCam, SpiderCam, Does Whatever a Spider Can?β 3D Camera Inspired by Jumping Spider is First to Operate Below One Watt
βSpiderCam, SpiderCam, Does Whatever a Spider Can?β 3D Camera Inspired by Jumping Spider is First to Operate Below One Watt
Northwestern University engineers have unveiled an extremely energy-efficient 3D camera, called SpiderCam, inspired by how jumping spiders judge depth before making a calculated leap.
The research team behind the novel device said their technology could help engineers build wearable technologies, assistive devices, robots, drones, and other futuristic technologies that benefit from quickly and efficiently gauging their surroundings.
How Jumping Spiders Inspired Energy-Efficient SpiderCam
According to a statement announcing SpiderCam, 3D cameras typically estimate image depth in two ways. The first approach involves captured images from multiple viewpoints and comparing them, and the second involves projecting a light source, often an infrared (IR) laser, and then measuring the reflection.
Although both methods can produce realistic three-dimensional images, they can require significant computing power, additional operational energy, and often expensive hardware such as lasers.
Fortunately, millions of years of evolution have resulted in a creature that possesses a hyper-efficient way of estimating depth: the jumping spider.
βJumping spiders jump to catch prey, to avoid predators and to get around, and that requires excellent vision,β said NorthwesternβsΒ Emma Alexander, the studyβs corresponding author and an expert in bio-inspired computer vision. However, the researcher notes that their brains are extremely small, requiring the ability to calculate distances in an energy- and computationally efficient way.
According to Alexander, jumping spider eyes have multiple layers of retinas in each eye, rather than just one as in human eyes. When measuring distance, each retina focuses on an image at a slightly different distance, resulting in some images being blurrier than others.
βThey see multiple levels of focus at all times,β Alexander explained. βSo, they are always collecting pairs of images.β
After collecting these images in real time, the flyβs poppyseed-sized brain compares their sharpness, yielding a surprisingly accurate depth estimate, as evidenced by the creatureβs ability to jump with precision.
Prototype Captures Images at Two Distances and Compares Their Blurriness
Inspired by natureβs hyper-efficient, extremely accurate depth estimation method, Alexanderβs team decided to build a 3D camera using the same basic approach.
βWe wanted to understand whether we could borrow some of the same principles to create an extremely energy-efficient depth sensor that could be used in resource-constrained situations where users donβt have unlimited access to power,β Alexander explained.

Instead of capturing images at multiple distances, as the jumping spiderβs eye does, the Northwestern teamβs initial design captures two images of the same scene at different focal lengths. Next, the system uses a custom algorithm to analyze the sharpness of the edges and textures captured in each image. The team said this analysis acts as a βtranslator between blur and distanceβ in the flyβs brain, resulting in βdepth measurements in real time.β
To best approximate the naturally evolved energy efficiency of a jumping spiderβs eye, Alexanderβs team built the algorithm directly into a customizable computer chip specifically optimized for energy efficiency called a field-programmable gate array (FPGA).
The final prototype integrating the teamβs dual-lens system generates depth maps at 32.5 frames per second. Critically, it generates this level of accurate 3D maps while consuming 624 milliwatts of power. For comparison, the team notes that 624 milliwatts is βless energy than used by a standard nightlight.β
Future Versions Could be Even More Energy Efficient
Although the team said that the current version of the SpiderCam is the βfirst passive FPGA-based 3D camera system to operate below one watt,β they hope to improve its optics and expand its field of view. Once they have a commercial-grade version, the team hopes to integrate SpiderCam into wearable devices and small robots.
Beyond proposed applications, the Northwestern team said that they βenvisionβ a future, ultra-energy-efficient versionΒ of the chip capable of βbringing 3D vision to applications where conventional depth sensors are impractical.β
βIβm very interested in settings where youβre very resource constrained and canβt just plug a camera into a wall,β Alexander explained. βFor example, it could be deployed in field settings with limited power.β
βSeparately, I also think itβs particularly exciting for applications like augmented reality where youβre interfacing with the physical world and need to know the locations of objects around you,β the researcher added.
The studyβs co-first authors, Marcos Ferreira and Tianao Li, presented this work at the Computer Vision Foundationβs Conference on Computer Vision and Pattern RecognitionΒ (CVPR) in Denver.Β Complimentary registration is available for members of the media.
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.
- The Debrief
- Ancient Europeans Ate Some Pretty Gross Things, but The Ickiest One Was Probably by Accident
Ancient Europeans Ate Some Pretty Gross Things, but The Ickiest One Was Probably by Accident
An analysis of dental tartar containing traces of human diets dating back over 33,000 years has revealed that ancient Europeans and many early Asian populations likely only ate insects by accident, perhaps as larvae in the carcasses of dead animals.
Conversely, the new study found that intentional insect consumption, called entomophagy, was more common in tropical regions and among Neanderthal populations.
Although the difference has some cultural and religious roots, the team found evidence that the abundance of insects in the tropics and the decreasing ability of humans migrating away from the tropics to digest insects likely led to the modern-day separation over thousands of years.
TheΒ Institute of Evolutionary Biology (IBE),Β a joint center of theΒ Spanish NationalΒ Research CouncilΒ (CSIC)Β andΒ Pompeu Fabra University (UPF), research team behind the new findings suggests their research could help explain why some modern populations still consume insects as food while other parts of the world consider it gross or taboo, especially given the increasing food demands of a rising world population.
Insect Consumption in Ancient Northern Europeans Likely Accidental
According to a statement announcing the new research, hundreds of millions of people currently include insects in their diet. However, they also note that most of the Western world continues to βshow an aversionβ to including any of the more than 1,611 insect species designated as edible by the Food and Agriculture Organization of the United Nations (FAO) in theirs. Although some theories suggest the difference is almost purely cultural, the team concedes that βits origin remains unknown.β
To explore the origins of human entomophagy, the IBE analyzed 745 samples of ancient human dental tartar dating back to 33,000 before present. According to the teamβs results published in the journal Science Advances, dental tartar (sometimes called dental βcalculusβ) is a critical archaeological tool because it preserves the DNA of the species these human ancestors consumed during their lifetimes.
Although the analysis found evidence for entomophagy amongst virtually all ancient populations sampled in the study, the levels varied dramatically. Notably, the evidence suggested that ancient humans in northern Eurasia did not routinely eat insects in measurable quantities. Instead, any consumption was likely incidental, including consumption of insect larvae in rotting food.
Curious whether the lack of entomophagy in ancient European and Central and Northern Asian populations was purely cultural or whether genetic and geographic factors were involved, the team studied human genes involved in chitin digestion. Chitin, which can be found in some marine animal shells, is also part of an insectβs hard exoskeleton.
According to the study authors, the analysis revealed that the βchitinaseβ genes in North Eurasian human populations βcarry mutations that confer a reduced capacity to digest insect exoskeletons.β Their analysis revealed that this reduced capacity to digest insect exoskeletons has persisted in the genomes of modern Eurasian populations βfor the last 9,000 years,β which would coincide with the widely accepted date for the origin of agriculture.
Pablo Librado, study leader and a principal investigator at the IBE, said the βscarce presence of insects in the diet of northern Eurasiansβ suggests that the cause may not lie solely in more recent cultural factors but also in ecological and evolutionary components dating back several millennia.Β
Neanderthals and Denisovans Probably Ate Insect Larvae in Rotting Meat
When the team compared data from ancient human tartar with that of ancient Neanderthals, they found that Neanderthals engaged in much higher levels of entomophagy than humans living in the same regions. According to the study authors, Neanderthal insect consumption levels were similar to those found in western chimpanzee populations, which the researchers note βrely on entomophagy to supplement their diet on the savanna, especially during periods of drought.β
Further analysis of the extracted insect DNA showed that the group most commonly consumed by the Neanderthal specimens included flies and mosquitoes. Although the team only analyzed the DNA, they noted that a recent hypothesis suggests Neanderthals ate carcasses laden with mosquito larvae.
βThe abundance of mosquito remains reinforces the possibility that the carcasses of their prey were kept in ponds and marshy areas, where mosquitoes lay their eggs,β the teamβs statement explained.
An analysis of the Neanderthal DNA and the DNA from the lone Denisovan study subject revealed that both ancient hominid populations could digest chitin. This result reinforced the genetic basis for increased or reduced entomophagy beyond cultural factors.Β
Humans Ate Fewer Bugs When They Moved Away from Tropical Regions
One geographic component identified by the chitinase DNA analysis showed higher levels of digestive enzyme expression among humans living in or near the tropics. However, the expression of these enzymes gradually decreased as populations moved away from tropical regions. The team said this variation, which has been maintained for at least the last 9,000 years, βreflects the abandonment of entomophagy in European populations.β
Manuel PiΓ±ero, a predoctoral researcher at the IBE and first author of the study, noted that large numbers of insects must be consumed to offset the βhigh caloric costβ of collecting them, which might explain the higher levels of entomophagy in this region.
βIn the tropics, there is a greater availability of social insects, such as termites and locusts,β Β PiΓ±ero Β explained, adding that the biomass and diversity of tropical edible insects enable βsustainable exploitation throughout the year.β The researcher also noted that insect consumption βadds to pest control.β
When discussing the implications of their findings, Librado highlighted the DNA and geographic factors the IBE team uncovered.
βBeyond cultural or religious factors, our results suggest that the reduced availability of insects in non-tropical areas may have been a key factor in the abandonment of entomophagy, leading to a reduced capacity to digest insect exoskeletons,β the researcher explained.
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.
Tiny Genetic Change Turns Female Mice Into Males, Scientists Discover
This Simple Drink Could Help Calm the Inflammation Behind Many Diseases
- SciTechDaily
- According to Scientists, This Simple Dietary Change Is Linked to Lower Depression Scores
According to Scientists, This Simple Dietary Change Is Linked to Lower Depression Scores
Researchers Discover a Hidden Vitamin D Problem That Persists Year-Round
Record-Breaking Black Hole Wind Blasts Through Space at 30% the Speed of Light
A Newly Found Cellular Shift May Explain Why Aging Leads to Disease
Constantly Tired? Scientists Say These Vitamin Deficiencies May Be Why
Chemists Capture a Bizarre Molecular Structure Never Seen Before
Mass Spectrometry Breakthrough Detects Billions of Molecules at Once
In a First, Scientists Precisely Edit Human Embryo Genes
Researchers Solve the Mystery Behind a Billion-Dollar Dental Implant Disease
- SciTechDaily
- Mystery Solved: The Decades-Old Secret Lurking Beneath North Carolinaβs Blueberry Farms