Unlocking the secrets of nitrogen use in potatoes

A path to reduce fertilizer dependence

Center for Research in Agricultural Genomics (CRAG)

 

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Experiment with potato plants

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Credit: CRAG

Bellaterra (Barcelona), 4 November 2024 - In a world where food security is increasingly threatened by climate change and the population growth, researchers are turning to genetic solutions to enhance crop resilience. A recent study led by Salomé Prat, a CSIC researcher at CRAG has unveiled groundbreaking findings on the role of the StCDF1 gene in nitrogen use efficiency in potatoes (Solanum tuberosum), a staple food for millions of people.

The study published in New Phytologist in collaboration with the group of Christian Bachem from the University of Wageningen (WUR), expands the role of StCDF1 beyond its previously known function as a central regulator of day length tuberization. Tuber formation is an adaptive strategy of potato plants for winter survival and is triggered by shorter day lengths and cooler temperatures perceived by the plant as the approach of winter.

Maroof Ahmed Shaikh, first author of the study, notes, “Integration of these environmental signals encourages tuber formation.  These organs stay dormant in the soil over winter and wake up in spring to form a new plant. We often notice this awakening at home when older potatoes begin to sprout.”

In wild potatoes, tuber formation is strictly dependent on short days. However, modern cultivars carry mutations in a locus called earliness that allows them to escape this strict control. This adaptation took place after potatoes were introduced to Europe, resulting in early-maturing varieties that carry one or more copies of these alleles. These naturally occurring mutations enhance the stability of the StCDF1 factor, a key player in the day length pathway that modulates the expression of SP6A, a member of the FLOWERING LOCUS T family and a main tuberization signal.

Enhancing nitrogen utilization through genetic innovations

The findings reveal that StCDF1 not only acts as an upstream regulator of the tuberization pathway but also directly controls the expression of several genes involved in nitrogen assimilation and transport. Through a combination of DNA binding and gene expression studies, researchers observed that StCDF1 binds the promoter region of Nitrate Reductase (StNR), an enzyme that catalyses the rate-limiting step in nitrate reduction within the cell. Surprisingly, potatoes possess a single gene copy for StNR, unlike most plants that have several copies allowing them greater efficiency in nitrate utilization.

The research employed advanced techniques, including DAP-seq (DNA Affinity Purification and sequencing), to identify the direct targets of StCDF1. This method revealed DNA recognition peaks in several nitrogen responsive genes.

Knock-down lines of StCDF1, which reduced transcript levels, showed improved performance under nitrogen-limiting conditions due to the lifted repression of StNR. With StCDF1 silenced, the potato plants could express more StNR, leading to better nitrogen utilization. Additionally, the discovery of polymorphisms in the StNR regulatory region indicates that these genetic variations may have evolved in early potato cultivars as a compensatory mechanism, helping these plants adapt to the adverse effects of StCDF1 stabilization, thereby enhancing their nitrogen assimilation capabilities.

Salomé Prat emphasized the significance of these findings, stating, “The novelty of our research lies in uncovering StCDF1's dual role in regulating both tuberization and the nitrogen assimilation pathways. This insight reveals new genetic and molecular targets for enhancing nitrogen utilization in potatoes.”

Implications for sustainable agriculture

The implications of this research are profound, contributing to the broader goal of sustainable agriculture. The study provides molecular targets that can be used for breeding climate-smart potato varieties requiring less nitrate inputs for high tuber production. Breeders could leverage this knowledge to develop potato varieties less dependent on chemical fertilizers.

In conclusion, this study not only enriches our understanding of potato biology but also serves as a ray of hope for sustainable agriculture, demonstrating the power of plant science in addressing global challenges. By harnessing genetic advancements, the agricultural sector can move towards more resilient and environment friendly practices, ensuring food security for future generations.

 

Reference Article:

Maroof Ahmed Shaikh, Lorena Ramírez-Gonzales, José M. Franco-Zorrilla, Evyatar Steiner, Marian Oortwijn, Christian W.B. Bachem, Salomé Prat. StCDF1: A “jack of all trades” clock output with a central role in regulating potato nitrate reduction activity. New Phytologist, https://doi.org/10.1111/nph.20186

 

About the authors and funding of the study: This work was supported by the ERA CAPS 647 HotSol project funded by the Netherlands Organization for Scientific Research (NWO project 648 849.13.001), the FlowerPot project, and by the Division for Earth and Life Sciences ALW 649 financial aid from the NWO. Work within the Salomé Prat group was financed by the European H2020- 650 SFS-862858 ADAPT project. Maroof Ahmed Shaikh was supported by a pre-doctoral contract from the ADAPT 651 project. Lorena Ramírez-Gonzales received a fellowship from FONDECYT-CONCYTEC, Lima, Peru (grant no. 652 090-2016-FONDECYT). Work in José M. Franco-Zorrilla's group was funded by the Spanish Ministry for 653 Science and Innovation grant PID2020-119451GB-I00.

About the Centre for Research in Agricultural Genomics (CRAG): CRAG is a centre that forms part of the CERCA system of research centres of the Government of Catalonia (Spain), and which was established as a partnership of four institutions: the Spanish National Research Council (CSIC), the Institute for Agri-Food Research and Technology (IRTA), the Autonomous University of Barcelona (UAB) and the University of Barcelona (UB). CRAG’s research spans from basic research in plant and farm animal molecular biology, to applications of molecular approaches for breeding of species important for agriculture and food production in close collaboration with industry. In 2020, CRAG was recognized for the second time as a "Severo Ochoa Centre of Excellence” by the Spanish Ministry of Economy and Competitiveness.

About New Phytologist: New Phytologist is a leading international journal focusing on high quality, original research across the broad spectrum of plant sciences, from intracellular processes through to global environmental change. The journal is owned by the New Phytologist Foundation, a non-profit organisation dedicated to the promotion of plant science. https://www.newphytologist.org/

 

Schematic summary of the study

Credit

CRAG

Materials:

• 1_image potatoes.jpg: Experiment with potato plants (Credit: CRAG).
• 2_authors.jpg: On the left Salomé Prat, who led the study, and on the right Maroof Ahmed Shaikh, first author of the study (Credit: CRAG).
• 3_authors.jpg: On the left Salomé Prat, who led the study, and on the right Maroof Ahmed Shaikh, first author of the study (Credit: CRAG).
• 4_infographic_ENG.jpg: Schematic summary of the study (Credit: CRAG).

Materials can be downloaded here: https://t.ly/m2y9y

 

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Journal

New Phytologist

DOI

10.1111/nph.20186 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

StCDF1: A “jack of all trades” clock output with a central role in regulating potato nitrate reduction activity

Article Publication Date

6-Nov-2024

 

New study: Earthquake prediction techniques lend quick insight into strength, reliability of materials

University of Illinois at Urbana-Champaign, News Bureau

 

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Muscovite mica is used in many materials science applications and is known for its extremely flat and flaky layers, making it highly susceptible to hostile environmental conditions.

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Credit: Photo courtesy Karin Dahmin

CHAMPAIGN, Ill. — Materials scientists can now use insight from a very common mineral and well-established earthquake and avalanche statistics to quantify how hostile environmental interactions may impact the degradation and failure of materials used for advanced solar panels, geological carbon sequestration and infrastructure such as buildings, roads and bridges.

The new study, led by the University of Illinois Urbana-Champaign in collaboration with Sandia National Laboratories and Bucknell University, shows that the amount of deformation caused by stress applied locally to the surface of muscovite mica is controlled by the physical condition of the mineral’s surface and follows the same statistical dynamics observed in earthquakes and avalanches.

The study findings are published in the journal Nature Communications.        

When selecting materials for engineering applications, scientists want to know how the surface of that material will interact with the environment in which it will be used. Similarly, geologists want to understand how chemical reactions between minerals and groundwater along faults might slowly weaken rocks and result in quick bursts of mechanical failure due to a process called chemomechanical weakening.

“While previous attempts to quantify the effect of chemomechanical weakening in engineered materials have relied on complex molecular dynamics models requiring significant computational resources, our work instead emphasizes the bridge between laboratory experiments and real-world phenomena like earthquakes,” said graduate student Jordan Sickle, who led the study with Illinois physics professor Karin Dahmen.

“Muscovite was chosen for this study mainly because of this material’s extreme flatness,” Dahmen said. “Each of its flaky layers is flat down to the atomic level. Because of this flatness, the interaction between the surface of this material and its environment is especially important.”

To measure chemomechanical weakening on muscovite surfaces, Sandia National Laboratories exposed samples to different chemical conditions — dry, submersed in deionized water and in salt solutions with a pH of 9.8 and 12. During exposure, an instrument known as a nanoindenter poked the surface of the minerals and recorded the displacements, or failures, in the material at controlled mechanical loads.  

The researchers found that in dry conditions, muscovite can deform more before it fails than in wet conditions. At failure, the samples in each condition release their stored elastic energy. The study reports that when muscovite is exposed to a basic solution at pH 9.8 or 12, the top layer weakens, and less energy can be stored before failure occurs, which is reflected in the burst statistics.

“The results of this work allow researchers to test material failure more quickly than high-powered, detailed simulation models,” Sickle said. “By showing that we can observe the same results by using the statistical models already in place for earthquakes, researchers will be able to perform higher-throughput material analysis than previously possible.”

The U.S. Department of Energy and Sandia National Laboratories support this research.

 

 

Editor’s note:   

To reach Karin Dahmen, call 217-244-8873; email dahmen@illinois.edu.

The paper “Quantifying chemomechanical weakening in muscovite mica with a simple micromechanical mode” is available online. DOI: 10.1038/s41467-024-53213-5. Physics is part of The Grainger College of Engineering.

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Journal

Nature Communications

DOI

10.1038/s41467-024-53213-5 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Quantifying chemomechanical weakening in muscovite mica with a simple micromechanical mode

Article Publication Date

6-Nov-2024

 

The egg or the chicken? An ancient unicellular says egg!

A cell division resembling that of an animal embryo has been observed in a prehistoric unicellular organism, suggesting that embryonic development might have existed prior to the evolution of animals

Université de Genève

 

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Images of the multicellular development of the ichthyosporean Chromosphaera perkinsii, a close cousin of animals. In red, the membranes and in blue the nuclei with their DNA. The image was obtained using expansion microscopy.

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Credit: © O. Dudin - UNIGE

Chromosphaera perkinsii is a single-celled species discovered in 2017 in marine sediments around Hawaii. The first signs of its presence on Earth have been dated at over a billion years, well before the appearance of the first animals. A team from the University of Geneva (UNIGE) has observed that this species forms multicellular structures that bear striking similarities to animal embryos. These observations suggest that the genetic programmes responsible for embryonic development were already present before the emergence of animal life, or that C. perkinsii evolved independently to develop similar processes. Nature would therefore have possessed the genetic tools to “create eggs” long before it “invented chickens”. This study is published in the journal Nature.

The first life forms to appear on Earth were unicellular, i.e. composed of a single cell, such as yeast or bacteria. Later, animals - multicellular organisms - evolved, developing from a single cell, the egg cell, to form complex beings. This embryonic development follows precise stages that are remarkably similar between animal species and could date back to a period well before the appearance of animals. However, the transition from unicellular species to multicellular organisms is still very poorly understood.

Recently appointed as an assistant professor at the Department of Biochemistry in the UNIGE Faculty of Science, and formerly an SNSF Ambizione researcher at EPFL, Omaya Dudin and his team have focused on Chromosphaera perkinsii, or C. perkinsii, an ancestral species of protist. This unicellular organism separated from the animal evolutionary line more than a billion years ago, offering valuable insight into the mechanisms that may have led to the transition to multicellularity.

By observing C. perkinsii, the scientists discovered that these cells, once they have reached their maximum size, divide without growing any further, forming multicellular colonies resembling the early stages of animal embryonic development. Unprecedentedly, these colonies persist for around a third of their life cycle and comprise at least two distinct cell types, a surprising phenomenon for this type of organism.

‘‘Although C. perkinsii is a unicellular species, this behaviour shows that multicellular coordination and differentiation processes are already present in the species, well before the first animals appeared on Earth’’, explains Omaya Dudin, who led this research.

Even more surprisingly, the way these cells divide and the three-dimensional structure they adopt are strikingly reminiscent of the early stages of embryonic development in animals. In collaboration with Dr John Burns (Bigelow Laboratory for Ocean Sciences), analysis of the genetic activity within these colonies revealed intriguing similarities with that observed in animal embryos, suggesting that the genetic programmes governing complex multicellular development were already present over a billion years ago.

Marine Olivetta, laboratory technician at the Department of Biochemistry in the UNIGE Faculty of Science and first author of the study, explains: “It’s fascinating, a species discovered very recently allows us to go back in time more than a billion years”. In fact, the study shows that either the principle of embryonic development existed before animals, or multicellular development mechanisms evolved separately in C. perkinsii.

This discovery could also shed new light on a long-standing scientific debate concerning 600 million-year-old fossils that resemble embryos, and could challenge certain traditional conceptions of multicellularity.

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Journal

Nature

DOI

10.1038/s41586-024-08115-3 

Method of Research

News article

Subject of Research

Cells

Article Title

'A multicellular developmental program in a close animal relative'

Article Publication Date

6-Nov-2024

 

GIST scientists unveil strategies to make self-driven vehicles passenger-friendly

Researchers investigated a method of providing timely explanations to increase passengers’ sense of safety and confidence in automated vehicles

GIST (Gwangju Institute of Science and Technology)

 

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The novel TimelyTale dataset approach incorporates environmental, driving-related, and passenger-specific sensor data that can be used for providing timely and context-specific explanations.

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Credit: SeungJun Kim from Gwangju Institute of Science and Technology

The integration of automated vehicles promises several benefits for urban mobility, including increased safety, reduced traffic congestion, and enhanced accessibility. Automated vehicles also enable drivers to engage in non-driving related tasks (NDRTs) like relaxing, working, or watching multimedia en route. However, widespread adoption is hindered by passengers' limited trust. To address this, explanations for automated vehicle decisions can foster trust by providing control and reducing negative experiences. These explanations must be informative, understandable, and concise to be effective.

Existing explainable artificial intelligence (XAI) approaches majorly cater to developers, focusing on high-risk scenarios or comprehensive explanations, potentially unsuitable for passengers. To fill this gap, passenger-centric XAI models need to understand the type and timing of information needed in real-world driving scenarios.

Addressing this gap, a research team, led by Professor SeungJun Kim from the Gwangju Institute of Science and Technology (GIST), South Korea, investigated the explanation demands of automated vehicle passengers in real-road conditions. They then introduced a multimodal dataset, called TimelyTale, which includes passenger-specific sensor data for timely and context-relevant explanations. “Our research shifts the focus of XAI in autonomous driving from developers to passengers. We have developed an approach for gathering passenger's actual demand for in-vehicle explanations and methods to generate timely, situation-relevant explanations for passengers,” explains Prof. Kim.

Their findings are available in two studies published in the Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies on September 27, 2023, and September 09, 2024. The authors were awarded the ‘Distinguished Paper Award’ at UbiComp 2024 for their pioneering study titled ‘What and When to Explain?: On-road Evaluation of Explanations in Highly Automated Vehicles’.

The researchers first studied the impact of various visual explanation types, including perception, attention, and a combination of both, and their timing on passenger experience under real driving conditions by utilizing augmented reality. They found that the vehicle’s perception state alone improved trust, perceived safety, and situational awareness without overwhelming the passengers. They also discovered that traffic risk probability was most effective for deciding when to deliver explanations, especially when passengers felt overloaded with information.

Building upon these findings, the researchers developed the TimelyTale dataset. This approach includes exteroceptive (regarding the external environment, such as sights, sounds etc.), proprioceptive (about the body’ positions and movements), and interoceptive (about the body’s sensations such as pain etc.) data, gathered from passengers using a variety of sensors in naturalistic driving scenarios, as key features for predicting their explanation demands. Notably, this work also incorporates the concept of interruptibility, which refers to the shift in focus of the passengers from NDRTs to driving-related information. The method effectively identified both the timing and frequency of the passenger’s demands for explanations as well as specific explanations that passengers want during driving situations.

Using this approach, the researchers developed a machine-learning model that predicts the best time for providing an explanation. Additionally, as proof of concept, the researchers conducted city-wide modeling for generating textual explanations based on different driving locations.

"Our research lays the groundwork for increased acceptance and adoption of autonomous vehicles, potentially reshaping urban transportation and personal mobility in the coming years," remarks Prof. Kim.

 

***

 

Reference 1

DOI: 10.1145/3678544

 

Reference 2   

DOI: 10.1145/3610886

 

About the Gwangju Institute of Science and Technology (GIST)
The Gwangju Institute of Science and Technology (GIST) was founded in 1993 by the Korean government as a research-oriented graduate school to help ensure Korea's continued economic growth and prosperity by developing advanced science and technology with an emphasis on collaboration with the international community. Since that time, GIST has pioneered a highly regarded undergraduate science curriculum in 2010 that has become a model for other science universities in Korea. To learn more about GIST and its exciting opportunities for researchers and students alike, please visit: http://www.gist.ac.kr/.

 

About the author
Dr. SeungJun Kim is Professor and Director of the Human-Centered Intelligent Systems Lab at Gwangju Institute of Science and Technology (GIST). Before joining GIST, he was a research faculty at Carnegie Mellon University's Human-Computer Interaction Institute, leading interdisciplinary research projects exploring XR, robotics, and human-AI interaction. Prof. Kim holds a B.S. in Electrical Engineering from KAIST, and an M.S. and Ph.D. in Mechatronics from GIST, respectively. His research focuses on sensory intelligence and augmentation through multimodal XR in ubiquitous computing environments. He has been honored with several paper awards from UbiComp, ACM CHI, IEEE ISMAR, and ACM AutoUI.

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DOI

10.1145/3678544 

Method of Research

Experimental study

Subject of Research

People

Article Title

TimelyTale: A Multimodal Dataset Approach to Assessing Passengers’ Explanation Demands in Highly Automated Vehicles

 

Balancing quantity and quality: How X/Twitter's algorithm influences our consumption of news

University of Pennsylvania School of Engineering and Applied Science

 

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The paper’s authors, Shengchun Huang (left) and Stephanie Wang (right).

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Credit: Penn Engineering

Are we only seeing the kind of news we want to see on social media? What effects do personalized algorithms have on our perception of news quality? Do algorithms help us serendipitously encounter information that we didn’t expect? These are the questions researchers are now asking as AI and algorithms infiltrate the information environments we turn to for political news. 

Now more than ever, people are relying on social media to inform them of what is happening in the world. Today, half of U.S. adults get their news at least sometimes from social media, and 52% of X/Twitter users regularly turn to this particular platform for their news updates. While digital dissemination of news can make information more accessible, turning to algorithmically-mediated platforms presents its own set of challenges.

As we near the upcoming election season, voters will be looking to news and political information to make informed decisions. It is important to understand if and how these algorithms are exacerbating political polarization or inequality in political learning. Are they wreaking havoc on how we make decisions as individuals and function as a society? 

To understand if political polarization could be an issue exacerbated by social media algorithms, Penn Engineering researchers and collaborators at the Annenberg School of Communication (ASC) conducted a study of 243 X/Twitter users and over 800,000 tweets during a three-week period in late 2023. The research team, including Danaë Metaxa, Raj and Neera Singh Term Assistant Professor in Computer and Information Science (CIS), Penn doctoral candidates Stephanie Wang (CIS) and Shengchun Huang (ASC), and Alvin Zhou, Assistant Professor at The University of Minnesota Twin Cities, set out to investigate how news from users’ algorithmic feeds differ from news presented in a their chronological X/Twitter news feed composed only of accounts users follow. 

Their study, to be presented at The 27th ACM Conference on Computer-Supported Cooperative Work and Social Computing, performed a sociotechnical audit. This type of audit includes traditional methods of content and browsing history, deploying them directly with real users, alongside user experience surveys to simultaneously gain insight into users’ perceptions of information at multiple points in time.

At the highest level, the researchers confirmed that the X/Twitter algorithm significantly influences what users do and do not see relative to users’ independent choices in the accounts they follow. Why is this an issue?

“As we consume information, we form opinions and take actions based on those opinions,” says Huang. “When you only consume news aligned with what you believe, you miss a lot of what is happening in the world and are less able to see things from other perspectives. It is possible that algorithms of X/Twitter and other social platforms are filtering information and contributing to incomplete views of the world. One obvious issue with this is how those views will inform people’s voting behavior in our upcoming election.” 

But how exactly are these algorithms influencing the information we see? The researchers hypothesized that each user’s news feed would contain more extreme political content aligned with their beliefs that could push them to farther ends of the political spectrum. However, when they compared the personalized algorithm to the chronological timeline news content, they found the opposite.

“It turned out that, during the time we performed this audit, X/Twitter’s algorithmic feeds were presenting users with information that was milder and overall less polarizing than the chronological timeline,” says Wang. “We also found that the algorithmically-curated feeds presented users with less news content in general, specifically less content containing links to news articles and more content featuring other types of information.”

While personalized algorithms were not observed to push polarizing or noticeably controversial news, their significant influence on the type of content users were seeing has implications for the use of X/Twitter at any point in time. 

“During that particular moment, the information may not have been very extreme or disruptive, but this doesn’t mean we can rely on these algorithms to continue to operate in that way,” says Metaxa. “What concerns me is that users of these platforms have very little control over the algorithms. The lack of transparency, restricted APIs and the current controversies surrounding the direction and ownership of X/Twitter make it a challenging space for people to find and trust quality news.”

And even when users were able to find news content from legitimate sources, they tended to question its credibility.  

“Users reported that just the fact that they read the news on social media made it less credible,” says Zhou. “Additionally, if that news content expressed opposing views or opinions, the user reported it as being even less reliable. It’s a very interesting phenomenon that touches on our natural human instinct and behavior. We don’t like to see things we don’t agree with, so we tend to doubt their credibility. Without the surveys in this audit, we would not have captured this insight.”

This is the first time sociotechnical auditing has been used in a social media news consumption study, and Metaxa plans to continue using this tool to investigate other social media platforms.

“These types of audit studies are very important for any system that aims to instigate human action or behavior change,” says Metaxa. “Search engines, generative AI, targeted advertising and social media all fundamentally rely on human interaction, and they influence people and society. We need to incorporate users’ experiences into our audits to evaluate how well these systems work.”

The data gained from the sociotechnical audits in this study shows just how sensitive our perceptions are to the news we see on social media. But, rather than putting all of the responsibility on the user, the research team believes platforms such as X/Twitter should take measures to provide a safe, reliable and informative media environment. In today’s era of “fake news,” the team believes effective solutions will be made at the institutional level rather than the individual level.

This study was supported by research funds from the University of Pennsylvania and the University of Minnesota in addition to Amazon Web Service’s AI ASSET award which supported lead author Stephanie Wang’s doctorate degree.

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DOI

10.48550/arXiv.2406.17097 

Method of Research

Data/statistical analysis

 

Locally optimized urban form reduces carbon dioxide emissions

Hiroshima University

Research suggests that urban areas could reduce their carbon dioxide (CO2) emissions by optimizing their urban form. However, the relationship between urban form and emissions is highly context-dependent and generalizations cannot be made.

While atmospheric CO2 levels are higher than ever before, an estimated 2.5 billion additional people are expected to integrate into urban areas worldwide by 2050. Given the link between atmospheric CO2 levels and energy consumption and their contribution to climate change, interest in energy-conserving urban planning and design measures is growing.

Unfortunately, scientific research in energy-optimized urban forms is lacking, and most existing studies analyze only macro-scale urban form, lack standardization and only assess a limited number of urban form factors. To address this issue, a group of scientists from Hiroshima University, Shiraz University and Northern Arizona University designed a research study to investigate the effects of urban form on carbon emissions using more detailed assessment methods in three different U.S. cities.

The team published their study in the November 2024 issue of the Journal of Environmental Management.

“The relationship between urban form and CO2 emissions is well recognized. However, most studies so far have been limited to examining the urban form at the macro level and there is a lack of granular understanding of this dynamic relationship. [In contrast,] this study employs the Local Climate Zones (LCZ) framework to investigate the relationship between urban form and CO2 emissions at the micro level,” said Ayyoob Sharifi, professor at the IDEC Institute at Hiroshima University and an author of the research paper.

The LCZ framework is a way of universally classifying urban forms, ten of which are built (such as low-rise buildings, high-rise buildings and heavy industry) and seven that are natural. This framework has been successfully used to better assess urban heat island effects. For this study, the research team applied this framework to classify the urban form of Baltimore, Maryland; Indianapolis, Indiana; and Los Angeles, California using remote sensing methods, such as satellite imagery data.

The three cities chosen for the study were selected because of their differences in both climate and population density. Los Angeles is classified as a warm, dry climate with few temperature variations; Indianapolis is considered a cold, humid climate; and Baltimore is a mixed, humid climate. Baltimore has the highest population density of the three cities, while Los Angeles and Indianapolis have similar population densities. In comparison, Los Angeles is spread over a much larger area than Indianapolis.

The contrasting variables between the three cities were intentionally chosen to determine whether or not differences in LCZ could account for differences in CO2 emissions over the course of an entire year or individual seasons, depending on the per capita density and climate. CO2 emissions were calculated using Hestia Project data, which calculates the amount of fossil-fuel CO2 released in individual cities at street- and building-level scales each hour.

While the study provided new insights into the effect of LCZ on CO2 emissions, few generalities could be made between cities. “The results demonstrate that the relationship between urban form and CO2 emissions is complex and dynamic. Patterns could be different depending on the context and factors such as climatic conditions and size and function of the city. Patterns observed in a specific city cannot necessarily be generalized to other cities. This means that one-size-fits-all approaches cannot be applied to determine optimized urban forms,” said Sharifi.

Importantly, the study revealed that urban open and green spaces are paramount. “[W]ithout smart and adequate provision of open and green spaces, compact urban development will have limited capacity to mitigate urban CO2 emissions,” said Sharifi.

The research team plans to continue their investigation of the link between LCZ and urban CO2 emissions to mitigate the effects of urban fossil fuel usage. The authors suggest that further refinement of LCZ resolution in urban areas and studies of individual contributors to urban fossil fuel consumption, such as transportation, residential and commercial sectors, for example, may help scientists tease out patterns between LCZ and CO2 emissions.

“We aim to conduct more research involving data from a larger number of cities from different parts of the world to [better] understand… the association between LCZ type and CO2 emissions under different climatic and socioeconomic conditions,” said Sharifi.

###

Other contributors include Masoud Javadpoor from the School of Art & Architecture at Shiraz University in Shiraz, Iran and Kevin R. Gurney from the School of Informatics in Computing and Cyber Systems at Northern Arizona University in Flagstaff, Arizona.

This work was supported by JSPS KAKENHI Grant Number 19K20497 and National Institute of Standards and Technology Grant 70NANB16H264N.

About Hiroshima University

Since its foundation in 1949, Hiroshima University has striven to become one of the most prominent and comprehensive universities in Japan for the promotion and development of scholarship and education. Consisting of 12 schools for undergraduate level and 4 graduate schools, ranging from natural sciences to humanities and social sciences, the university has grown into one of the most distinguished comprehensive research universities in Japan. English website: https://www.hiroshima-u.ac.jp/en

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Journal

Journal of Environmental Management

Article Title

Mapping the relationship between urban form and CO2 emissions in three US cities using the Local Climate Zones (LCZ) framework

 

More US families purchased school meals after federal nutrition policies enacted

University of California - Davis

Families purchased more school lunches and breakfasts the year after the federal government toughened nutritional standards for school meals. A new University of California, Davis, study suggests that families turned to school lunches after the Obama administration initiative was in effect to save time and money and take advantage of more nutritious options.

Researchers looked at the purchasing habits of nearly 8,000 U.S. households over two years — one year before and after the change in standards. The results have important implications for policymakers and researchers, but also food manufacturers and retailers, researchers said.

The study, “Groceries or School Cafeterias: How Households Respond to Nutrition Mandates,” was published in September in the Journal of Marketing Research.

“We find that the Healthy, Hunger-Free Kids Act attracted even greater participation from households for whom the preexisting benefits of school meals (time and money savings) were already important and were now coupled with an additional benefit: healthier food for their kids,” said Mike Palazzolo, lead author of the study and assistant professor of marketing at the UC Davis Graduate School of Management. “It had a stronger pull among households with limited time and money, and whose pre-policy grocery food purchases were both smaller and less healthy.”

The U.S. Department of Agriculture program was a centerpiece of then-First Lady Michelle Obama’s “Let’s Move!” initiative to combat childhood obesity. It was signed into law in 2010, and schools nationwide were required to implement it by 2014. New standards called for milk to be fat-free or 1% fat, that more fruit and vegetables be served, and that unhealthy components such as sodium, sugar and saturated fat be capped. Portion sizes were also reduced.

The changes significantly improved the nutritional content of school-served breakfasts and lunches, according to the USDA Healthy Eating Index.

Opponents of the policies had predicted sales and participation in meal programs would decline. Even proponents predicted the participation would remain the same, not increase.

Retailers affected

Both retailers and manufacturers were affected by the nutrition mandates, researchers said, with a 4.4% reduction in spending among households with kids — translating to a 1.4% revenue loss for grocery retailers, researchers found. Researchers found the decrease was attributable to items likely to be purchased for children and categories traditionally associated with breakfast and lunch — the meals served at school. 

Grocery stores may need to revamp their lunch offerings to bring back lost sales, researchers said. “Relatedly, the school meal program is itself a large revenue source for manufacturers whose products fit (the standards),” with some brands reformulating their grocery store products to fits the needs of school lunch purchases at stores, the paper states. 

“Our findings add to a valuable knowledge base that marketers and nutrition policy advocates can utilize in efforts to encourage households to adopt healthier diets,” Palazzolo said. 

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Journal

Journal of Marketing Research

DOI

10.1177/00222437241291481 

Method of Research

Data/statistical analysis

Subject of Research

Not applicable

Article Title

Groceries or School Cafeterias: How Households Respond to School Nutrition Mandates