Wednesday, December 13, 2023

 

Smartwatches can pick up abnormal heart rhythms in kids, Stanford Medicine study finds


Apple watches have some advantages over traditional ways of diagnosing cardiac arrythmias in children but need more validation, finds a Stanford Medicine study.


Peer-Reviewed Publication

STANFORD MEDICINE




Smartwatches can help physicians detect and diagnose irregular heart rhythms in children, according to a new study from the Stanford School of Medicine. 

The finding comes from a survey of electronic medical records for pediatric cardiology patients receiving care at Stanford Medicine Children’s Health. The study will publish online Dec. 13 in Communications Medicine.

Over a four-year period, patients’ medical records mentioned “Apple Watch” 145 times. Among patients whose medical records mentioned the smartwatch, 41 had abnormal heart rhythms confirmed by traditional diagnostic methods; of these, 29 children had their arrythmias diagnosed for the first time.

“I was surprised by how often our standard monitoring didn’t pick up arrythmias and thewatch did,” said senior study author Scott Ceresnak, MD, professor of pediatrics. Ceresnak is a pediatric cardiologist who treats patients at Stanford Medicine. “It’s awesome to see that newer technology can really make a difference in how we’re able to care for patients.”

The study’s lead author is Aydin Zahedivash, MD, a clinical instructor in pediatrics.  

Most of the abnormal rhythms detected were not life-threatening, Ceresnak said. However, he added that the arrythmias detected can cause distressing symptoms such as a racing heartbeat, dizziness and fainting. 

Skipping a beat, sometimes

Doctors face two challenges in diagnosing children’s cardiac arrythmias, or heart rhythm abnormalities. 

The first is that cardiac diagnostic devices, though they have improved in recent years, still aren’t ideal for kids. Ten to 20 years ago, a child had to wear, for 24 to 48 hours, a Holter monitor consisting of a device about the size of a smartphone attached by wires to five electrodes that were adhered to the child’s chest. Patients can now wear event monitors — in the form of a single sticker placed on the chest — for a few weeks. Although the event monitors are more comfortable and can be worn longer than a Holter monitor, they sometimes fall off early or cause problems such as skin irritation from adhesives.

The second challenge is that even a few weeks of continuous monitoring may not capture the heart’s erratic behavior, as children experience arrythmias unpredictably. Kids may go months between episodes, making it tricky for their doctors to determine what’s going on. 

Connor Heinz and his family faced both challenges when he experienced periods of a racing heartbeat starting at age 12: An adhesive monitor was too irritating, and he was having irregular heart rhythms only once every few months. Ceresnak thought he knew what was causing the racing rhythms, but he wanted confirmation. He suggested that Connor and his mom, Amy Heinz, could try using Amy’s smartwatch to record the rhythm the next time Connor’s heart began racing.

Using smartwatches for measuring children’s heart rhythms is limited by the fact that existing smartwatch algorithms that detect heart problems have not been optimized for kids. Children have faster heartbeats than adults; they also tend to experience different types of abnormal rhythms than do adults who have cardiac arrythmias.

The paper showed that the smartwatches appear to help detect arrhythmias in kids, suggesting that it would be useful to design versions of the smartwatch algorithms based on real-world heart rhythm data from children. 

Evaluating medical records

The researchers searched patients’ electronic medical records from 2018 to 2022 for the phrase “Apple Watch,” then checked to see which patients with this phrase in their records had submitted smartwatch data and received a diagnosis of a cardiac arrythmia.

Data from watches included alerts about patients’ heart rates and patient-initiated electrocardiograms, or ECGs, from an app that uses the electrical sensors in the watch. When patients activate the app, the ECG function records the heart’s electrical signals; physicians can use this pattern of electrical pulses to diagnose different types of heart problems.

From 145 mentions of the smartwatch in patient records, 41 patients had arrythmias confirmed. Of these, 18 patients had collected an ECG with their watches, and 23 patients had received a notification from the watch about a high heart rate.

The information from the smartwatches prompted the children’s physicians to conduct medical workups, from which 29 children received new arrythmia diagnoses. In 10 patients, the smartwatch diagnosed arrythmias that traditional monitoring methods never picked up. 

One of those patients was Connor Heinz.

“At a basketball tryout, he had another episode,” Amy Heinz recalled. “I put the watch on him and emailed a bunch of captures [of his heartbeat] to Dr. Ceresnak.” The information from the watch confirmed Ceresnak’s suspicion that Connor had supraventricular tachycardia.

Most children with arrythmias had the same condition as Connor, a pattern of racing heartbeats originating in the heart’s upper chambers.

“These irregular heartbeats are not life-threatening, but they make kids feel terrible,” Ceresnak said. “They can be a problem and they’re scary, and if wearable devices can help us get to the bottom of what this arrythmia is, that’s super helpful.”

In many cases of supraventricular tachycardia, the abnormal heart rhythm is caused by a small short-circuit in the heart’s electrical circuitry. The problem can often be cured by a medical procedure called catheter ablation that destroys a small, precisely targeted region of heart cells causing the short circuit.

Now 15, Connor has been successfully treated with catheter ablation and is playing basketball for his high school team in Menlo Park, California.

The study also found smartwatch use noted in the medical records of 73 patients who did not ultimately receive diagnoses of arrythmias.

“A lot of kids have palpitations, a feeling of funny heartbeats, but the vast majority don’t have medically significant arrythmias,” Ceresnak said. “In the future, I think this technology may help us rule out anything serious.”

A new study

The Stanford Medicine research team plans to conduct a study to further assess the utility of the Apple Watch for detecting children’s heart problems. The study will measure whether, in kids, heart rate and heart rhythm measurements from the watches match measurements from standard diagnostic devices. 

The study is open only to children who are already cardiology patients at Stanford Medicine Children’s Health.

“The wearable market is exploding, and our kids are going to use them,” Ceresnak said. “We want to make sure the data we get from these devices is reliable and accurate for children. Down the road, we’d love to help develop pediatric-specific algorithms for monitoring heart rhythm.”  

The study was conducted without external funding. Apple was not involved in the work. Apple’s Investigator Support Program has agreed to donate watches for the next phase of the research.

Apple’s Irregular Rhythm Notification and ECG app are cleared by the Food and Drug Administration for use by people 22 years of age or older. The high heart rate notification is available only to users 13 years of age or older.

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About Stanford Medicine

Stanford Medicine is an integrated academic health system comprising the Stanford School of Medicine and adult and pediatric health care delivery systems. Together, they harness the full potential of biomedicine through collaborative research, education and clinical care for patients. For more information, please visit med.stanford.edu.

 

Pacific Northwest snowpack endangered by increasing spring heatwaves


Peer-Reviewed Publication

WASHINGTON STATE UNIVERSITY




VANCOUVER, Wash. –  Even in the precipitation-heavy Pacific Northwest, more frequent heatwaves are threatening a key source of water supply.

A Washington State University study that intended to look at snow melting under a single, extreme event, the 2021 “heat dome,” instead revealed an alarming, longer-term rising trend of successive heatwaves melting snowpack earlier in the year.  

The findings have implications for many areas worldwide that are dependent on snow-capped mountains to provide summer water since heatwaves have been on the rise globally.

“Short-term events like heatwaves have had an under-appreciated impact on accelerating snow melt, and cumulatively, they can amplify each other,” said Luke Reyes, a doctoral student in WSU’s School of the Environment, and lead author of the study published in npj Climate and Atmospheric Science.  

Heat domes, rare events that occur when the atmosphere traps hot ocean air, caused record temperatures nearing 122 degrees Fahrenheit across the Pacific Northwest in late June 2021. Yet, the researchers found that by the time the dome arrived, a lot of the region’s snowpack had already melted.

Their analysis of high-resolution snowpack and temperature data revealed that high-elevation snow had started melting during a series of heatwaves in April, May and early June -- when temperatures were 7.2 to 12.6 degrees Fahrenheit above normal.

Even more concerning, when the researchers looked back at temperature records spanning from 1940 to 2021, they saw that these springtime heatwaves have doubled in frequency, intensity or both since the mid-1990s.

“The data suggests that we don't necessarily need to be worried about a very rare event like the heat dome, but that heat waves are becoming far more prevalent and are more likely to be driving a lot of snowpack loss in the future,” said co-author Marc Kramer, a WSU associate professor of environmental chemistry.

The effect of short-term heatwaves on snowpack has been understudied because historically researchers looked at snowpack levels on April 1 and average monthly temperatures to estimate climate change impacts on snowpack loss. Those averages might show single-digit temperature increases but obscure the impact of heat spikes that may last just a couple days.

Also, for many years, mountainous snowpack was thought to be resilient to short-term high temperatures in spring because it remained sufficiently cold at high elevations. The WSU study revealed that this buffering capacity appears to have diminished in the face of more frequent and intense heatwaves.

In 2021, the combined result of heatwaves and the heat dome meant the snowpack melted about three weeks earlier than usual, with most snow cover gone by late June. Normally, snowmelt provides the Pacific Northwest with water well into August.

This extreme early melting occurred even though 2021 was a La Niña year, a global weather phenomenon that typically means a deeper snowpack. In fact, Pacific Northwest snowpack that spring was 135% of normal for the higher-elevation snow zone and its 18-year record examined by the study. By the end of June, though, that was gone.

This rapid melt does not bode well for the coming year, 2024, which is expected to have drier weather brought by El Niño.

“We have a coming El Niño year and next year, and there may be some amplification effects,” said Kramer. “If we have less snow to begin with, the snowpack is going to be all that much more vulnerable to these heat anomalies earlier in the season.”

The study is part of the Kramer lab’s broader research into heat wave impacts on ecosystems and agriculture. This research is supported by a grant from the U.S. Department of Agriculture’s National Institute of Food and Agriculture.

 UK

Homes in areas hit hardest by fuel poverty not benefiting from government’s flagship energy scheme, report warns


Energy Company Obligation (ECO) is not targeting the places in urgent need of support, say experts from Southampton and Bristol universities


Peer-Reviewed Publication

UNIVERSITY OF SOUTHAMPTON




Households in areas hit hardest by fuel poverty are not benefiting most from the government’s flagship energy support scheme, a damning report has found.

Experts examining the impact of the Energy Company Obligation (ECO) showed it is not targeting the places in urgent need of support.

The scheme, which was launched in 2012, pledged to cut bills for low-income households by improving insulation and focusing support on those in fuel poverty.

Academics from Southampton and Bristol universities published the report in the journal of Energy Research and Social Science.

They also warned that low-income homes would be “further entrenched in energy deprivation” if the government decides to revise its plans to fund the programme through fuel bills.

Report co-author Dr Paul Bridgen, from the University of Southampton, said the ECO is supposed to be the government’s flagship initiative to combat fuel poverty but the programme is flawed.

He added: “Homes in locations which are suffering the most from rising energy bills are not being helped the most and, worryingly, richer households are almost as likely to benefit.

“There is a sense that the fuel poverty crisis is finished but this is far from true.”

Since it was relaunched in its new format last year, the ECO programme has only upgraded around 65,000 households in the UK, according to the Department for Energy Security and Net Zero.

Its critics have claimed it is too slow and could take nearly 200 years to improve eligible homes, or 300 years for the government to meet its own targets to abolish fuel poverty.

The Southampton and Bristol social scientists based the study on government estimates for fuel poverty from 317 local authorities from 2012 to 2020.

They ranked all areas of the UK into five groups based on the severity of their energy poverty, from lowest to highest, and tracked their performances across the decade.

According to the experts, the ECO had mixed results in targeting people in the most energy deprived group, with an average of just 71 households per 1,000 receiving any home installations or upgrades.

Co-author Dr Caitlin Robinson from the University of Bristol said: “The scheme is not particularly effective at targeting areas of England that have been dealing with persistent fuel poverty.

“To properly address fuel poverty, the government needs to look at the extreme and long-standing issues of fuel poverty in certain places and then fund energy-efficiency home improvements using local councils.

“But first, ministers must indicate quickly that funding for the ECO does not return to household energy bills. If this happens, some of the most fuel-poor homes will be paying for a scheme from which they get no help.”

Read the full report in the journal of Energy Research and Social Science at doi.org/10.1016/j.erss.2023.103139

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Deep-reinforcement-learning-based robot motion strategies for grabbing objects from human hands


Peer-Reviewed Publication

BEIJING ZHONGKE JOURNAL PUBLISING CO. LTD.

Structure of RGRL. 

IMAGE: 

DEEPREINFORCEMENT LEARNING HAS DISADVANTAGES SUCH AS LOW SAMPLE UTILIZATION AND SLOW CONVERGENCE, AND THOUSANDSOF TRIAL-AND-ERROR ITERATIONS ARE REQUIRED TO PERFORM REINFORCEMENT LEARNING IN REALISTIC SCENARIOS, WHICH ISCOSTLY. TO ALLEVIATE THIS PROBLEM, RGRL FIRST SIMULATES A ROBOT GRASPING AN OBJECT FROM A USER IN A SIMULATEDSCENE IN WHICH TENS OF THOUSANDS OF LEARNING SESSIONS ARE PERFORMED. DOMAIN RANDOMIZATION IS USED TO NARROWTHE GAP BETWEEN THE SIMULATED AND REAL SCENES, AND A MULTI-OBJECTIVE REWARD FUNCTION IS USED TO EFFECTIVELYACCELERATE THE CONVERGENCE OF THE REINFORCEMENTLEARNING ALGORITHM.

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CREDIT: BEIJING ZHONGKE JOURNAL PUBLISING CO. LTD.




Owing to the rapid development of artificial intelligence, sensors, and robot control technology in recent years,“machine-centered” human–machine collaboration has become increasingly incompetent in the case ofcomplex scenarios, and “human-centered” human–machine collaboration is gradually revealing its advantages. Common industrial and service robots attempt to avoid contact with users for safety. With theincreasing demand for robot intelligence, contact human–robot collaboration is unavoidable in the future.Common industrial and service robots can easily grasp stationary objects; however, robots that can graspobjects from the hands of users are rare. In most scenarios in which this function is implemented, physical,spatial, or motion constraints are employed to prevent the manipulator from harming the human hand duringthe grasping process. Unlike robots independently grasping stationary objects placed in a scene, graspingobjects from a user's hands requires more considerations, and the recognition, positioning, and real-timebehavioral actions of the user must be carefully taken into account. Robots must determine the correct positionand direction from which to grasp an object from a user's hand. This paper presents a robot grasping algorithmbased on deep reinforcement learning (RGRL) to solve the problem of robots safely grasping an object from auser's hand. Deep reinforcement learning is used in the RGRL so that the robot can actively learn how to pick

up an object from the user's hand without touching the user.

The contributions of this study are three-fold:

(1) A new algorithm, RGRL, for grasping objects from users is proposed, by incorporating domain

Randomizationand a multi-objective reward function.

(2) The RGRL has low computational and hardware costs. Because we use domain randomization in thetraining phase, we eliminate the need for manual labeling of the data. Only a 3D model of the object needs tobe imported into the simulation software, and the algorithm can automatically learn the appropriate motionpath. The only required addition to the robot is the Leap Motion sensor, which is used to satisfy the conditionsfor the algorithm to run.

(3) The RGRL is evaluated in simulated and real scenarios.

 

Epigenetic changes can cause type 2 diabetes


Peer-Reviewed Publication

LUND UNIVERSITY





Do epigenetic changes cause type 2 diabetes, or do the changes occur only after a person has become ill? A new study by researchers at Lund University provides increased support for the idea that epigenetic changes can cause type 2 diabetes. The researchers behind the new findings published in Nature Communications now aim to develop methods for disease prevention.

We inherit our genes from our parents, and they seldom change. However, epigenetic changes that arise due to environmental and lifestyle factors can affect the function of genes.

“Our new extensive study confirms our previous findings from smaller studies, showing that epigenetic changes can contribute to the development of type 2 diabetes. In this study, we have also identified new genes that impact the development of the disease. Our hope is that with the help of these results, we can develop methods that can be used to prevent type 2 diabetes,” says Charlotte Ling, professor of diabetes and epigenetics at Lund University's Diabetes Centre (LUDC), who led the study.

The same epigenetic changes

The researchers studied epigenetics in insulin-producing cells from donors and found 5584 sites in the genome with changes that differed between 25 individuals with type 2 diabetes and 75 individuals without the disease. The same epigenetic changes found in people with type 2 diabetes were also found in individuals with elevated blood sugar levels, which increase the risk of developing the disease.

“Those of us who study epigenetics, have long tried to understand whether epigenetic changes cause type 2 diabetes or if the changes occur after the disease has already developed. Because we saw the same epigenetic changes in people with type 2 diabetes and individuals at risk for the disease, we conclude that these changes may contribute to the development of type 2 diabetes," says Tina Rönn, lead author and researcher at LUDC.

The study identified 203 genes with different expression in individuals with type 2 diabetes compared to the control group. The researchers found that the gene RHOT1 showed epigenetic changes in people with type 2 diabetes and that it also played a key role in insulin secretion in insulin-producing cells. When they knocked out the gene expression of RHOT1 in cells from donors without type 2 diabetes, insulin secretion decreased.

“When we examined the same type of cells in rats with diabetes, we found a lack of RHOT1, confirming the gene’s importance for insulin secretion,” says Tina Rönn.

Methods that can prevent the disease

One goal of the research is to develop a blood-based biomarker that can predict who is at risk of developing type 2 diabetes. Therefore, the researchers investigated whether their results from insulin-producing cells in the pancreas were reflected in the blood of living people. They found epigenetic changes in the blood of a group of 540 people without the disease and they linked this to the future development of type 2 diabetes in half of the individuals.

Factors such as unhealthy diet, sedentary lifestyle, and ageing increase the risk of type 2 diabetes, and they also affect our epigenetics. With the new study, researchers have identified new mechanisms that may make it possible to develop methods to help prevent type 2 diabetes.

“If we succeed in developing an epigenetic biomarker, we can identify individuals with epigenetic changes before they become ill. These individuals can, for example, receive personalised lifestyle advice that can reduce their risk of disease, or we can develop methods that aim to correct the activity of certain genes using epigenetic editing,” says Charlotte Ling.

 

Resource-efficient and climate-friendly with sodium-ion batteries


Peer-Reviewed Publication

CHALMERS UNIVERSITY OF TECHNOLOGY

Table salt, sodium chloride 

IMAGE: 

SODIUM-ION BATTERIES CONTAIN SODIUM – A VERY COMMON SUBSTANCE FOUND IN TABLE SALT – INSTEAD OF LITHIUM.
 

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CREDIT: CHALMERS




The transition to a society without fossil fuels means that the need for batteries is increasing at a rapid pace. At the same time, the increase will mean a shortage of the metals lithium and cobalt, which are key components in the most common battery types. One option is a sodium-ion battery, where table salt and biomass from the forest industry make up the main raw materials. Now, researchers from Chalmers University of Technology, Sweden, show that these sodium-ion batteries have an equivalent climate impact as their lithium-ion counterparts – without the risk of running out of raw materials. 
"The materials we use in the batteries of the future will be important in order to be able to switch to renewable energy and a fossil-free vehicle fleet," says Rickard Arvidsson, Associate Professor of Environmental Systems Analysis at Chalmers.

According to the European Commission's Critical Raw Materials Act, the demand for critical raw battery materials is expected to increase exponentially as EU countries transition to renewable energy systems and electric vehicles. The green transition will also require more local production of batteries and other new fossil-free technologies, and a steady supply of raw materials is needed to meet demand. At the same time, such production carries a high risk of supply disruptions, due to the limited number of sources for raw materials.
"Lithium-ion batteries are becoming a dominant technology in the world and they are better for the climate than fossil-based technology is, especially when it comes to transport. But lithium poses a bottleneck. You can't produce lithium-based batteries at the same rate as you want to produce electric cars, and the deposits risk being depleted in the long term," says Rickard Arvidsson. In addition to this, critical battery materials, such as lithium and cobalt, are largely mined in just a few places in the world, posing a risk to the supply. 

Sodium-ion batteries offer promising technology
The development of new battery technologies is moving fast in the quest for the next generation of sustainable energy storage – which should preferably have a long lifetime, have a high energy density and be easy to produce. The research team at Chalmers chose to look at sodium-ion batteries, which contain sodium – a very common substance found in common sodium chloride – instead of lithium. In a new study, they have carried out a so-called life cycle assessment of the batteries, where they have examined their total environmental and resource impact during raw material extraction and manufacturing.
"We came to the conclusion that sodium-ion batteries are much better than lithium-ion batteries in terms of impact on mineral resource scarcity, and equivalent in terms of climate impact. Depending on which scenario you look at, they end up at between 60 and just over 100 kilogrammes of carbon dioxide equivalents per kilowatt hour theoretical electricity storage capacity, which is lower than previously reported for this type of sodium-ion battery. It's clearly a promising technology," says Rickard Arvidsson.

The researchers also identified a number of measures with the potential to further reduce climate impact, such as developing an environmentally better electrolyte, as it accounted for a large part of the battery's total impact.

Green energy requires energy storage
Today's sodium-ion batteries are already expected to be used for stationary energy storage in the electricity grid, and with continued development, they will probably also be used in electric vehicles in the future.
"Energy storage is a prerequisite for the expansion of wind and solar power. Given that the storage is done predominantly with batteries, the question is what those batteries will be made from? Increased demand for lithium and cobalt could be an obstacle to this development," says Rickard Arvidsson.

The major advantage of the technology is that the materials in the sodium-ion batteries are abundant and can be found all over the world. One electrode in the batteries – the cathode – has sodium ions as a charge carrier, and the other electrode – the anode – consists of hard carbon, which in one of the examples the Chalmers researchers have investigated can be produced from biomass from the forest industry. In terms of production processes and geopolitics, sodium-ion batteries are also an alternative that can accelerate the transition to a fossil-free society.
"Batteries based on abundant raw materials could reduce geopolitical risks and dependencies on specific regions, both for battery manufacturers and countries," says Rickard Arvidsson. 

More about the study
The study is a prospective life cycle assessment of two different sodium-ion battery cells where the environmental and resource impact is calculated from cradle to gate, i.e. from raw material extraction to the manufacture of a battery cell. The functional unit of the study is 1 kWh theoretical electricity storage capacity at the cell level.  Both types of battery cells are mainly based on abundant raw materials. The anode is made up of hard carbon from either bio-based lignin or fossil raw materials, and the cathode is made up of so-called "Prussian white" (consisting of sodium, iron, carbon and nitrogen). The electrolyte contains a sodium salt. The production is modelled to correspond to a future, large-scale production. For example, the actual production of the battery cell is based on today's large-scale production of lithium-ion batteries in gigafactories.  
Two different electricity mixes were tested, as well as two different types of so-called allocation methods – that is, allocation of resources and emissions. One where the climate and resource impact is distributed between coproducts based on mass, and one method where all impact is allocated to the main product (the sodium-ion battery and its components and materials).


The article Prospective life cycle assessment of sodium-ion batteries made from abundant elements has been published in the Journal of Industrial Ecology. The authors of the study are Rickard Arvidsson, Sanna Wickerts, Anders Nordelöf, Magdalena Svanström and Patrik Johansson. The researchers are active at Chalmers University of Technology.

The study was funded by the Swedish Energy Agency through the Battery Fund Program.

 

For more information, please contact:

Rickard Arvidsson, Associate Professor, Department of Technology Economics and Management, Chalmers University of Technology, +46 31 772 21 61, rickard.arvidsson@chalmers.se

The researchers involved in this research, Rickard Arvidsson, Sanna Wickerts, Anders Nordelöf, Magdalena Svanström and Patrik Johansson speak English and Swedish fluently and are available for live and pre-recorded interviews. At Chalmers, we have podcast studios and broadcast filming equipment on site and would be able to assist a request for a television, radio or podcast interview.

 

A survey of real-time rendering on Web3D application


Peer-Reviewed Publication

BEIJING ZHONGKE JOURNAL PUBLISING CO. LTD.

Real-time rendering framework. 

IMAGE: 

ALL REAL-TIME RENDERING FRAMEWORKS ARE CLASSIFIED INTO THREE CATEGORIES, NAMELY WEB-BASED REAL-TIMERENDERING FRAMEWORKS, SERVER-BASED REAL-TIME RENDERING FRAMEWORKS, AND END-CLOUD COLLABORATIVE REAL-TIMERENDERING FRAMEWORKS.

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CREDIT: BEIJING ZHONGKE JOURNAL PUBLISING CO. LTD.




With the growth of web technologies, including HTML5 and WebAssembly, in the mobile Internet era, theconcept of “Web+” is gradually taking root in all industries and exerting a profound impact on people's lives.Be it travel, shopping, learning, or entertainment, several the activities in our daily lives can now be performedthrough a web browser. Meanwhile, human perceptions have gradually extended from the real world to thevirtual world of the internet. This has, in turn, created an even higher expectation for Web technologies, that is,Web technologies should not only realize the various application needs of users but also fulfill their demandfor perceptual experience at the same time. However, most current web applications still use text, sound,image, video, and 2D animation as their main communication media. These traditional forms have limitationswhich make them unable meet growing needs for a multi-sensory experience of high interactivity and immersionin the virtual world. With this background, 3D visualization technology has started to integrate intothe web and has become a new major trend.With the rapid development of Internet and 3D visualization technologies, sustained progress has been madein web-based 3D visualization technology. Today, web-based 3D visualization technology known as“Web3D” has enabled the display of 3D virtual scenes on mainstream web browsers, setting off new possibilitiesfor next-generation web services based on visualization. According to Zhao Qingping of the ChineseAcademy of Engineering, Web3D exerts a transformative and disruptive impact on existing browsers andemail systems and even becomes a new gateway to the Internet. In recent years, a number of Web3Dapplications have emerged in various industries, with typical examples including Web3D online tourism,Web3D online architecture, Web3D online educational environments, Web3D online medical care, andWeb3D online shopping.In all these applications, real-time rendering technology plays a key role: it not only affects the renderingeffect and quality but also determines the quality of user experience and future development of these applications.Therefore, it is necessary to examine the relationship between real-time rendering and Web3Dapplications and take a closer look at the real-time rendering technologies, tools, and frameworks used inWeb3D applications.

 

Highly resolved precipitation maps based on AI


KIT researchers use deep learning to enhance the spatial and temporal resolution of coarse precipitation maps


Peer-Reviewed Publication

KARLSRUHER INSTITUT FÜR TECHNOLOGIE (KIT)

KIT researchers use AI to produce highly resolved radar films from coarsely resolved maps in order to better forecast local precipitation events. (Photo: Luca Glawion, KIT) 

IMAGE: 

KIT RESEARCHERS USE AI TO PRODUCE HIGHLY RESOLVED RADAR FILMS FROM COARSELY RESOLVED MAPS IN ORDER TO BETTER FORECAST LOCAL PRECIPITATION EVENTS. (PHOTO: LUCA GLAWION, KIT)

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CREDIT: PHOTO: LUCA GLAWION, KIT




Strong precipitation may cause natural disasters, such as floodings or landslides. Global climate models are required to forecast the frequency of these extreme events, which is expected to change as a result of climate change. Researchers of Karlsruhe Institute of Technology (KIT) have now developed a first method based on artificial intelligence (AI), by means of which the precision of coarse precipitation fields generated by global climate models can be increased. The researchers succeeded in improving spatial resolution of precipitation fields from 32 to two kilometers and temporal resolution from one hour to ten minutes. This higher resolution is required to better forecast the more frequent occurrence of heavy local precipitation and the resulting natural disasters in future. (DOI 10.1029/2023EA002906)

 

Many natural disasters, such as floodings or landslides, are directly caused by extreme precipitation. Researchers expect that increasing average temperatures will cause extreme precipitation events to further increase. To adapt to a changing climate and prepare for disasters at an early stage, precise local and global data on the current and future water cycle are indispensable. “Precipitation is highly variable in space and time and, hence, difficult to forecast, in particular on the local level,” says Dr. Christian Chwala from the Atmospheric Environmental Research Division of KIT’s Institute of Meteorology and Climate Research (IMK-IFU), KIT’s Campus Alpine in Garmisch-Partenkirchen.” For this reason, we want to enhance the resolution of precipitation fields generated e.g. by global climate models and improve their classification as regards possible threats, such as floodings.”

 

Higher Resolution for More Precise Regional Climate Models 

Currently used global climate models are based on a grid that is not fine enough to precisely present the variability of precipitation. Highly resolved precipitation maps can only be produced with computationally expensive and, hence, spatially or temporally limited models. “For this reason, we have developed an AI-based generative neural network, called GAN, and trained it with high-resolution radar precipitation fields. In this way, the GAN learns how to generate realistic precipitation fields and derive their temporal sequence from coarsely resolved data,” says Luca Glawion from IMK-IFU. “The network is able to generate highly resolved radar precipitation films from very coarsely resolved maps.” These refined radar maps not only show how rain cells develop and move, but precisely reconstruct local rain statistics and the corresponding extreme value distribution.

 

“Our method serves as a basis to increase the resolution of coarsely grained precipitation fields, such that the high spatial and temporal variability of precipitation can be reproduced adequately and local effects can be studied,” says Julius Polz from IMK-IFU. “Our deep learning method is quicker by several orders of magnitude than the calculation of such highly resolved precipitation fields with numerical weather models usually applied to regionally refine data of global climate models.” The researchers point out that their method also generates an ensemble of different potential precipitation fields. This is important, as a multitude of physically plausible highly resolved solutions exists for each coarsely resolved precipitation field. Similar to a weather forecast, an ensemble allows for a more precise determination of the associated uncertainty.

 

Higher Resolution for Better Forecasts under Climate Change

The results show that the AI model and methodology developed by the researchers will enable future use of neural networks to improve the spatial and temporal resolution of precipitation calculated by climate models. This will allow for a more precise analysis of the impacts and developments of precipitation in a changing climate.

 

“In a next step, we will apply the method to global climate simulations that transfer specific large-scale weather situations to a future world with a changed climate, e.g. to the year of 2100. The higher resolution of precipitation events simulated with our method will allow for a better estimation of the impacts the weather conditions that caused the flooding of the river Ahr in 2021 would have had in a world warmer by 2 degrees,” Glawion explains. Such information is of decisive importance to develop climate adaptation methods. 

 

Original Publication

Luca Glawion, Julius Polz, Harald Kunstmann, Benjamin Fersch, Christian Chwala: spateGAN: Spatio-Temporal Downscaling of Rainfall Fields Using a cGAN Approach. Earth and Space Science, 2023. DOI 10.1029/2023EA002906.

https://doi.org/10.1029/2023EA002906

 

More about the KIT Climate and Environment Center

 

Being “The Research University in the Helmholtz Association”, KIT creates and imparts knowledge for the society and the environment. It is the objective to make significant contributions to the global challenges in the fields of energy, mobility, and information. For this, about 9,800 employees cooperate in a broad range of disciplines in natural sciences, engineering sciences, economics, and the humanities and social sciences. KIT prepares its 22,300 students for responsible tasks in society, industry, and science by offering research-based study programs. Innovation efforts at KIT build a bridge between important scientific findings and their application for the benefit of society, economic prosperity, and the preservation of our natural basis of life. KIT is one of the German universities of excellence.