Organic electrochemical transistors (OECTs) are innovative devices that could be made into implantable biosensors, or used to analyze biological samples to help diagnose illnesses. KAUST researchers have studied how the semiconducting polymers inside OECTs interact with ions in the samples — a crucial step in designing materials that tune the performance of these devices for particular applications[1]
“The technology is rapidly advancing, and some OECT-based probes have already been used in clinical research settings, particularly in neuroscience for the brain–electronic device interfacing,” says Sahika Inal, who led the research. In biosensing applications, she explains, OECTs could operate directly in blood, sweat, or saliva; they might also be used to detect viruses or other pathogens in liquid samples.
OECTs contain a polymer film that can carry a current between two electrodes. These polymers are known as organic mixed ionic-electronic conductors. The film touches a water-based sample containing various ions, which are atoms or molecules bearing positive or negative charges. A third electrode delivers a voltage that drives one type of ion (for example, positive ions, known as cations) from the water into the polymer film, which increases the flow of current, producing a signal.
Researchers previously assumed the other ions in the electrolyte (negative ions, known as anions) were bystanders in this process and did not affect the device’s performance. But the KAUST team have now found that is not always true — these anions sometimes have a profound effect on how well OECTs perform.
The researchers made OECTs from two different semiconductive polymers. The first, P-100, is based on molecules with a water-repelling backbone, but with side chains that attract water molecules and the ions they carry. The second polymer, BBL, lacks these side chains.
The team tested the devices with water containing positive sodium ions and one of five different anions. With the BBL polymer, the type of anion made no difference to the OECT’s performance because all but the very largest anions infiltrate BBL films equally well. In contrast, the P-100 device showed considerable variation in performance. With anions based on a single atom – such as chloride or bromide – the P-100 device had a relatively good sensitivity. However, with larger anions, the performance declined by 90 percent over the course of an hour.
“By understanding these interactions more deeply, researchers can better tailor OECTs for specific applications, whether that means optimizing for stability, selectivity, signal amplification, or biocompatibility,” says team member David Ohayon, now at the National University of Singapore.
For instance, OECTs designed to measure ions involved in biological processes should be able to clearly differentiate between those ions. Other applications might require OECTs to operate independently of any ions present. “This is exactly why it is so crucial to understand how different ions affect device performance,” says Ohayon.
“The research may have wider implications for other devices,” adds Inal. “These findings could also inform the development of organic-based supercapacitors and batteries, where understanding how ions interact with the polymer matrix can help optimize charge storage and improve the stability of organic electrodes.”
If you have ever pushed yourself to the edge in a workout — legs on fire, lungs burning — you have probably crossed what physiologists call a lactate threshold. It is the point where muscles cannot clear a metabolic by-product called lactate fast enough, and performance starts to nosedive.
Athletes train for years to raise that threshold. But knowing exactly when it is crossed still requires lab gear, blood samples and a big interruption to your workout.
A research team at KAUST aims to change that. Atif Shamim and members of his group built a noninvasive sweat sensor that can detect lactate levels in real time using nothing more than microwaves and enzyme-coated glass beads[1]
No blood. No needles. No power source. Just stick on a cheap, disposable patch, sweat it out and let the physics do the rest.
Here’s how it works: the sensor uses a circuit design technology called a complementary split-ring resonator — essentially a microwave component that is finely tuned to detect subtle chemical shifts. With sweat, lactate molecules react with enzymes inside the sensor, producing hydrogen peroxide. That tiny chemical change shifts the way the sensor reflects microwave signals, creating a digital fingerprint of how hard the body is working during physical activity.
In tests, the device nailed its readings, tracking lactate in sweat across a range of exercise intensities and comparing favorably to more involved chemical analyses in the lab. Even better, it held up across different skin types, fitness levels and environments. Volunteers with higher endurance had lower sweat lactate spikes, while less fit individuals saw sharp climbs, as expected.
The device is still in an early prototype stage, tethered to a benchtop reader. But with further design optimization, the researchers expect it should be made fully compatible with passive, wireless technology. Ideally it will be wearable patches that beam lactate data to nearby radio frequency-powered readers, uploading measurements to the cloud and making them accessible via an online portal or smartphone app.
“This should allow both athletes and trainers to monitor real-time lactate levels throughout training sessions,” says lead author, Firas Fatani, a Ph.D. student in Shamim’s lab.
What’s more, because the platform uses enzymes to drive specific reactions, it could be retooled to detect other components of sweat associated with health and performance — biomarkers such as glucose, cortisol or hydration levels. Since it relies on microwaves instead of chemical dyes or electrical currents, it is robust, scalable and surprisingly simple, notes Sakandar Rauf, a research scientist on the team.
“We are expanding the sensor’s capabilities to monitor additional biomarkers,” Rauf says — starting with a dual-sensor system for simultaneous glucose and lactate monitoring.
Discussions are under way with Saudi hospitals, gyms and football clubs to pilot the technology. According to Shamim, these partnerships could aid the Kingdom in achieving its Vision 2030 goals for health innovation and wellness.
“This will help improve the quality of fitness plans by designing personalized exercises not only for professional athletes but also for anyone who is interested in pushing their physical limits,” he says, noting that “such sensors will have substantial acceptance as people are becoming more invested in physical health.”
Meaningful cuts to global warming could be quickly achieved by implementing readily achievable measures to reduce methane emissions, a KAUST computational modeling study has shown[1].
Interventions include fixing leaks of the potent greenhouse gas from natural gas extraction facilities and landfill sites that would not only slow warming but also enhance air quality, bringing cascading benefits to health and the environment.
Global methane emissions are modest compared to those of carbon dioxide, but each ton of methane in the atmosphere traps tens of times more heat than a ton of CO2. Today, methane causes about 30 percent of global warming, and its emissions have been rising rapidly.
There is some global traction on reducing methane emissions. Since 2021, more than 150 countries have signed up to the Global Methane Pledge (GMP), which targets anthropogenic methane emission reductions of at least 30 percent from 2020 levels by 2030. “The GMP offers a promising strategy to mitigate the accelerating global warming trend,” says study co-lead Evgeniya Predybaylo, a postdoc in the Climate and Livability Initiative at KAUST.
“The easily implemented and cost-effective methane abatement steps promoted by the GMP could buy time to tackle the harder problem of addressing CO2 emissions,” Predybaylo adds. “This motivated us to use numerical modeling to evaluate the climate benefits of the GMP.”
The team conducted its analysis in collaboration with the Max Planck Institute for Chemistry (MPIC), using a coupled chemistry-climate model that was ideally suited to the task. “Our model is among the few capable of simulating the intricate chemical mechanisms in the atmosphere, including methane’s effects on climate and air quality,” Predybaylo says.
The modeling showed that full GMP implementation could prevent 0.2°C of global warming by 2050 and up to 0.3°C by the end of the century. “Our findings indicate a two- to three-decade lag in the full temperature response to methane emission reductions, with the GMP’s greatest impact occurring from mid-century onward,” Predybaylo says. With global mean air temperatures already increased by 1.5°C, this effect could be ideally timed to avoid the worst impacts of climate change while CO2 emissions are underway.
“Our results show that delivering on the GMP provides a rare opportunity for fast, tangible climate benefit,” says Matthew McCabe, director of KAUST’s Climate and Livability Initiative. “Our findings can help reinforce the urgency of cutting methane emissions,” he adds. “Even with a lag in full climate response, every year of early action matters.”
The atmospheric modeling also showed that reducing anthropogenic methane emissions would enhance air quality by reducing the formation of near-surface ozone. “This reduction in ozone would yield important co-benefits, including improved human health through reducing respiratory issues and increased agricultural yields by minimizing crop damage,” Predybaylo says.
The team’s next steps will include leveraging new technologies to support global methane abatement efforts. “There have been recent and rapid advances in our capacity to monitor methane from space, with several countries launching satellite missions,” McCabe says. “Working with local and international collaborators, we are exploring how integrating satellite observations with modeling can help to better track progress and support methane mitigation efforts in real-time.”
Detailed ‘movies’ that show how electrical charge flows through a layered material known as a 2D perovskite provide insights into how the perovskite could be fine-tuned to develop electronic devices that operate faster, last longer, and perform more efficiently[1].
“Researchers can use these results to carefully select the right number of layers and tailor surface chemistry to design improved 2D perovskite materials for applications such as solar cells and photodetectors,” says Lijie Wang from KAUST, part of the team behind the work.
Perovskites can form thin crystalline films that convert light into electricity or vice versa. They are being commercialized in next-generation solar panels and show promise in applications such as light-emitting diodes (LEDs). Researchers make perovskites by combining inorganic materials like lead iodide with carbon-based organic molecules. However, exposure to heat, moisture, or intense light can degrade perovskites and their performance.
Researchers hope to solve these problems using closely related materials called 2D perovskites, in which the organic and inorganic components are arranged in alternating flat sheets, rather like a sandwich. The organic molecules serve as a barrier, preventing moisture and oxygen from reaching the inorganic slabs between them. “This structure significantly slows down the degradation processes and improves thermal stability,” says KAUST’s Omar Mohammed, who led the team.
In devices such as solar cells and LEDs, electrical charge is carried by negative electrons and the positive ‘holes’ they leave behind. The insulating organic components in 2D perovskites confine these charges to the inorganic slabs. While this can improve the efficiency of LEDs, it hinders the movement of charge in solar cells and photodetectors.
The KAUST team has now studied how the structure of 2D perovskites affects the behavior of electrons and holes using four-dimensional scanning ultrafast electron microscopy (4D-SUEM).
First, a laser pulse excites the perovskite, generating mobile electrons and holes that quickly spread out. An instant later, the microscope fires a pulse of electrons that bounce off the material and into a detector. Crucially, these pulse electrons are more readily reflected by parts of the sample with higher electron and hole densities.
By taking repeated snapshots of the perovskite in this way, the system creates a movie showing how the distribution of electrons and holes on the surface changes over mere quadrillionths of a second.
The team used this approach to study 2D perovskites with inorganic slabs, either one, two, or three layers thick. In samples with two or three layers, electrons and holes separated more easily, and the charges were more likely to move rapidly across the surface rather than through the bulk of the material. “Faster surface diffusion allows for more efficient charge collection in devices such as solar cells and photodetectors, leading to improved device performance,” explains Wang.
“The next stage of our research is to investigate how charge carriers behave under real-world conditions, such as high temperatures, intense illumination, or radiation — all conditions that devices might encounter in harsh environments,” adds Mohammed.
Gall crabs are tiny and yet these crustaceans have evolved fluorescence to help them be concealed within hideouts they have created in the coral itself[1].
“These crabs are everywhere,” says Susanne Bähr, who led the study. “People ask how they can see them, and I say, ‘Take a mask and a snorkel and go anywhere you find coral, and you’ll see them.’”
Gall crabs don’t just live among the corals; they have a strong symbiotic relationship with them. Some invertebrates hide within the branches and crannies of corals, but for gall crabs, the connection goes much deeper.
“They settle on a coral as larvae, and then, somehow, they make the coral grow around them in very specific shapes. We don’t know how they do that,” says Bähr. Female crabs then stay in this den for the rest of their life, feeding on nutritious mucus and producing larvae, while the males rove about looking for females to mate with.
Bähr noticed that gall crabs fluoresce when on a night dive. “I had been working with these crabs for some time, so this observation was particularly intriguing, and I started reading about fluorescence. It’s been well studied in reef fish, where it has a broad array of functions. However, less is known about fluorescence in crustaceans, and yet crabs and shrimps are enormously diverse. So I wondered if we could find similar patterns in crustaceans as we’ve observed in fish.”
Bähr and colleagues collected 286 gall crabs from 14 different genera, sampling from all the known host coral genera in the Red Sea and Indian Ocean. They developed an imaging technique to identify exactly which parts of the different crabs fluoresced, as well as how much of each body part was fluorescent. Using this, they carried out a morphological analysis of the different species. They also built an evolutionary tree based on the crabs’ genomic sequencing data.
The morphological analysis showed that the fluorescence patterns on the crabs grouped into four clusters. One cluster included non-fluorescent crabs, and another included crabs with diverse fluorescent patterns; the final two had strong fluorescence on specific body parts. The evolutionary tree identified the genus in which fluorescence first appeared – probably covering most of the body – and showed that for some specific lineages, fluorescence has been lost or reduced.
The researchers suggest that fluorescence evolved in different types of gall crabs to help camouflage them in their coral dens. Different gall crab species live in dwellings of different shapes on the coral — for example, open tunnels or enclosed galls — and the fluorescence patterns affect their visibility in their dens.
Bähr offers the examples of a species that lives in cylindrical pits in the coral. “Basically, the back of the crab is sticking out a little bit. It has this really striking fluorescence pattern that disrupts how the crab looks. It disguises the outline of the crab, so you really can’t see a crab shape.”
Francesca Benzoni, Bähr’s supervisor at KAUST, highlights the importance of better understanding coral reef ecosystems. “Gall crabs are one of the many types of invertebrates living in association with corals on tropical reefs,” she says. “Much remains to be discovered on cryptic and poorly studied reef invertebrates and their fundamental biology, ecological role, and the role they play in the resilience of coral reef ecosystems in the Red Sea and worldwide.”
Understanding these broader systems is also important to Bähr. “I want to use my research to highlight the importance of these coral-associated invertebrates and their significance for coral reef ecosystems,” she says. “They’re generally overlooked, and it’s very important for us to understand how many there are, why they’re there, and what they do for reef persistence and resilience.”
To tackle the growing ecological threat of microplastics, magnetic nanoparticles have been created that can remove plastic fragments from water. Researchers used machine learning to identify the ideal removal conditions for particular microplastics, a strategy that may help to optimize other clean-up methods[1].
Microplastics are scraps of waste plastic, typically 1 micrometer to 1 millimeter in size, which are now ubiquitous in the environment. The particles adsorb toxic metals and organic pollutants. They are easily ingested by aquatic life, and once microplastics and their toxic payloads are in the food chain, they can accumulate in other species, including humans.
Methods to remove microplastics from wastewater face various drawbacks. Using light to destroy microplastics is effective but expensive and energy-intensive. Certain microbes can break down microplastics, but this generates other molecules that may themselves be toxic.
Magnetic nanoparticles offer a simple, low-cost and environmentally friendly solution. But these nanoparticles are prone to oxidation and may clump together in water, reducing their effectiveness, explains Rifan Hardian of KAUST’s Physical Science and Engineering Division.
A collaboration between KAUST and University Malaysia Terengganu has now developed magnetic nanoparticles that overcome these problems and remove not only microplastics but also the organic pollutants they carry.
First, the researchers prepared iron oxide nanoparticles with a protective porous silica coating. Then, they added linker molecules to the silica, which allowed them to decorate the particles with more molecules called imines. This covered the nanoparticle with molecular strands that capture microplastics, while chemical groups in the imines bind organic pollutants.
The researchers tested these nanoparticles on different sizes of polystyrene microplastics carrying common pollutants. They used a magnet to pull the nanoparticles from the water, along with their microplastic cargo and then washed off the fragments so the nanoparticles could be reused.
But with so many different variables to consider — from the number and size of microplastics in the water, to the concentration of imines on the magnetic nanoparticles — the researchers needed an efficient way to identify which factors offered the best clean-up solution.
So they used a method called ‘design of experiments’ to determine which combinations of variables would produce the most useful data and then fed those data into a machine-learning system that quickly identified any trends. This highlighted ways to maximize microplastic removal while minimizing the amount of imine required.
For example, a relatively low concentration of imines could remove 90 percent of a sample of microplastics roughly 300 micrometers in size. With fewer, smaller microplastics, an extremely low concentration of imines could still achieve about 80 percent removal efficiency.
“With our machine-learning model, we can predict the efficiency of the microplastic removal at various numbers and sizes,” says Hardian. “This prediction can then be used to determine the required adsorbent concentration.”
“The next milestone will be applying our methodology in other microplastic removal technologies so we can compare the efficiency of available technologies,” says Gyorgy Szekely, who led the KAUST researchers. They also hope to develop an autonomous laboratory system that could continuously optimize the experimental conditions.
In August 2023, an intense marine heatwave along the Saudi Arabian coast of the central Red Sea coincided with the mass beaching of dead fish, prompting a team of KAUST researchers to investigate[1].
Temperatures in oceans and seas around the globe are rising due to anthropogenic climate change, increasing stress on marine ecosystems and wildlife. Marine heatwaves occur when localized water temperatures exceed historical average sea temperatures; extreme events occur when temperatures reach 2ºC or more above average for a prolonged period. This can have multifaceted and catastrophic effects on marine life.
“Coastguard officials began reporting high numbers of dead fish and invertebrates, such as cuttlefish, washing ashore,” says Matthew Tietbohl, postdoctoral fellow, who led the project under the supervision of KAUST’s Maggie Johnson. “By the time we got to the beaches, about a week later, the fishes had degraded enough that we couldn’t collect useful samples to determine the cause of death, such as possible bacterial infection.”
The team found almost 1,000 fish washed ashore along a 60-kilometer stretch of coastline north of Thuwal. The mortality event included at least 54 species of fish, highlighting a broad impact across the reef community. This is a highly conservative estimate, notes Tietbohl: It was impossible to survey the entire 60+ kilometers of impacted coastline, and only a quarter of dead fish typically wash ashore.
In collaboration with Ibrahim Hoteit’s team, the marine scientists turned to satellite data analyses to understand the environmental conditions in the weeks prior to the mass beaching.
Satellite data of sea surface temperatures confirmed that an intense marine heatwave was spread across the whole region. However, the area just north of where the fish were found had the highest water temperatures and the strongest daily temperature changes, which the researchers believe had placed physiological stress on the fish. The weakened and dying fish were likely pushed southwards by prevailing winds and currents.
“Just like humans, all creatures struggle when they get too hot: Once a certain thermal threshold is reached, it becomes very difficult for their bodies to function correctly,” explains Tietbohl. “Bodies also burn more energy when stressed and require more oxygen, but higher temperatures reduce the amount of oxygen that water can hold.”
Extreme heat can also lead to stratification, where water settles into layers with limited mixing. This reduces oxygen exchange and stops the water from cooling down. Suffocating algal blooms are common in this scenario, although the researchers did not find evidence of this phenomenon during the 2023 heatwave. Extensive coral bleaching also occurred in the region that summer, which is also an indication that temperatures were high.
“Satellite instruments tend to underestimate water temperatures in the Red Sea, so it is likely the region experienced temperatures well above 2ºC of warming,” adds Tietbohl.
“These results, together with data from similar fish kills in summer 2024, suggest that the Red Sea maximum temperatures may be getting too hot for coral reefs and many marine creatures,” says Johnson. “Their chances of recovery would be improved by implementing fishery regulations that limit fishing during this stressful time.”
“We’ve presented our findings to the Saudi National Center for Wildlife and are in discussions to incorporate mass fish mortality monitoring into their wider marine animal stranding network,” says Tietbohl. “Improved monitoring would feed back into temperature models to help predict marine heatwaves, thus boosting preparation windows and supporting possible mitigation strategies or damage control.”
The holy month of Ramadan is a sacred time when millions of Muslims around the world embark on a profound spiritual journey of fasting, prayer, and reflection. But it is also a time when many face serious health risks, as going without food or water from sunrise to sunset — often in scorching heat — can lead to dangerous levels of dehydration.
Now, scientists at KAUST have found a surprisingly simple way to track the body’s water levels during fasting: by measuring how skin interacts with a touchscreen[1].
It is not only useful when fasting. The research team, led by electrical engineer Tareq Al-Naffouri and colleagues at KAUST, showed that the same method applies to athletes, who often experience dehydration due to intense exertion and fluid loss through sweat.
“It is also reasonable to expect that the approach could one day benefit other vulnerable groups, including the very old, the very young, and those with kidney disease,” says Al-Naffouri.
To demonstrate the concept, Al-Naffouri’s team used a basic capacitive sensor — the same type found in smartphone screens — capable of detecting subtle shifts in skin moisture. When a fingertip touches the sensor, it registers changes in skin capacitance, a measure of how well the skin stores electric charge, which varies with hydration levels.
The researchers suggest that this data could eventually allow people to monitor their hydration in real time — no needles, wearables, or lab work required. A quick touch could alert someone to drink water or replenish fluids before symptoms like dizziness or fatigue begin to set in.
“We envision real-time, everyday, user-friendly hydration monitoring, where users simply place their finger on their smartphone screen to assess their hydration status,” says study author Soumia Siyoucef, a former visiting student in Al-Naffouri’s research group.
To validate their technology, the KAUST team collected more than 4,000 fingertip readings from people either observing Ramadan and fasting much of the day or athletes engaged in a game of ultimate Frisbee or working out at the gym. They trained machine-learning models to convert small changes in skin conductance into a measure of the body’s water content.
When put to the test, the system delivered impressive results — accurately distinguishing between hydrated and dehydrated states up to 92 percent of the time among athletes and 87 percent among fasting individuals.
Coral reefs form a vital part of the marine ecosystem, playing host to diverse species and supporting multiple industries, including fisheries, tourism, and recreation. However, these fragile ecosystems are under increasing threat from climate change, with warming oceans increasing stress on the coral animals and their symbiotic algal partners.
A new remote sensing tool developed by KAUST researchers has created an effective and efficient method of monitoring and predicting both the scope and severity of coral bleaching in the Red Sea[1]. The tool – developed by KAUST in partnership with SHAMS, General Organization for the Conservation of Coral Reefs and Turtles in the Red Sea – could aid conservation management and policymaking by enabling targeted, integrated management strategies to prioritize specific areas for intervention. It is applicable in the Red Sea as well as across the world.
The algae living within corals share nutrients and resources, giving corals their distinctive color. When corals are under stress and competing for limited resources, they ‘kick out’ their algal partners that help with nutrition. This results in bleaching, where corals lose their pigmentation and gradually turn white. This process weakens the coral animal and leaves it more vulnerable: prolonged bleaching events can kill corals and decimate reefs.
“Monitoring the health of coral reefs amid climate change is crucial, and satellite remote sensing provides a cost-effective strategy that is more efficient than traditional field sampling, which can be time-consuming and resource-intensive,” says Elamurugu Rajadurai Pandian at KAUST, who worked on the project during his Ph.D., under the supervision of KAUST’s, Ibrahim Hoteit.
The new tool utilizes the extensive datasets collected by satellite imaging every five days. While previous studies have used satellite imaging to monitor coral bleaching events, the team took this technique a step further by including an analysis of the severity of bleaching. This means that areas can be rapidly graded according to how intense the bleaching is likely to become.
“Healthy and bleached corals reflect light differently, and satellites can detect these variations,” says Rajadurai Pandian. The researchers took advantage of these differences in color and brightness in thousands of satellite images to accurately identify bleached corals.
Firstly, they analyzed how much light was reflected from the ocean floor by both healthy and bleached corals. Then, they used a mathematical technique called the least-squares approach. This helped identify patterns in the data and accurately segregated bleached corals from healthy ones, making the overall detection rate more precise and reliable.
“The detection accuracy depends on the atmospheric correction of satellite imagery, which is complicated by the Red Sea’s proximity to deserts and frequent dust storms,” says Rajadurai Pandian. “We used an advanced algorithm that removed erroneous reflectance values caused by aerosols and particulates. This significantly improved the accuracy of satellite ocean color data retrievals in our model, particularly over the complex, reef-filled shallow waters of the Red Sea.”
Their model also has improved spatial resolution compared to previous models, providing detailed analyses of coral health every ten meters. By monitoring bleaching severity, ranging from low to high, scientists can gain deeper insights into coral resilience and recovery potential.
“By serving as an early warning system for coral bleaching, our method will enable faster responses and better conservation strategies,” concludes Hoteit. “Such high-resolution monitoring will support sustainable fisheries and tourism management while also contributing to climate change research by tracking environmental changes in marine ecosystems.”
Combining data across mismatched maps is a key challenge in global health and environmental research. A powerful modeling approach has been developed to enable faster and more accurate integration of spatially misaligned datasets, including air pollution prediction and disease mapping[1].
Datasets describing important socio-environmental factors, such as disease prevalence and pollution, are collected on a variety of spatial scales. These range from point data values for specific locations up to areal or lattice data, where values are aggregated over regions as large as countries.
Merging these geographically inconsistent datasets is a surprisingly difficult technical challenge, embraced by biostatistician Paula Moraga and her Ph.D. student Hanan Alahmadi at KAUST.
“Our group develops innovative methods for analyzing the geographical and temporal patterns of diseases, quantifying risk factors, and enabling the early detection of disease outbreaks,” says Moraga. “We need to combine spatial data that are available at different resolutions, such as pollutant concentrations measured at monitoring stations and by satellites, and health data reported at different administrative boundary levels.”
Alahmadi and Moraga developed their new model through a Bayesian approach, which is often used to integrate large spatial datasets. Bayesian inference is usually performed using Markov chain Monte Carlo (MCMC) algorithms, which explore datasets through a ‘random walk’. The algorithms decide on each next step based on the previous one until they get as close as possible to a target (or ‘posterior’) distribution. However, MCMC can take up a lot of computational time, so the researchers used a different framework called the Integrated Nested Laplace Approximation (INLA).
“Unlike MCMC, which relies on sampling, INLA uses deterministic approximations to estimate posterior distributions efficiently,” explains Alahmadi. “This makes INLA significantly faster while still providing accurate results.”
The researchers demonstrated the power of their model by integrating point and areal data in three case studies: the prevalence of malaria in Madagascar, air pollution in the United Kingdom, and lung cancer risk in Alabama, USA. In all three, the model improved the speed and accuracy of predictions while providing insight into the importance of different spatial scales.
“In general, our model gives more weight to point data because they offer higher spatial precision and are often more reliable for detailed predictions,” says Alahmadi. “In all studies, point data played a dominant role. However, the influence of areal data was greater in the air pollution study. This is primarily because the air pollution areal data had a finer resolution, which made them more informative and complementary to the point data.”
Overall, the project addresses the increasing need for data analysis tools that support evidence-based decisions in health and environmental policy. For example, if public health officials can quickly assess disease prevalence, then they can work more effectively to allocate resources and intervene in high-risk areas.
The new model could be adapted to capture dynamic changes over space and time and to address biases that may arise due to preferential sampling in certain areas. The researchers plan several other applications of their model, such as using satellite pollution data to estimate disease risks.
“We hope to combine satellite and ground-based temperature data to detect thermal extremes in Mecca, particularly during the Hajj season, where heat stress is a serious public health concern,” says Moraga. “We also intend to monitor air pollutants and track emissions, supporting Saudi Arabia’s journey toward its net-zero goals.”
