Thursday, July 02, 2026

 

Zero-waste plastic and color recycling



The end of colored plastic downgrading could be near with new approach




Osaka Metropolitan University

Fully recyclable plastic shapes 

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Color-embedded silica and plastic were combined to form various shapes. Reusability was tested over multiple generations of molding, decomposition, and reuse.

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Credit: Osaka Metropolitan University





In the world of market competition, having the best and brightest package could send company sales into the millions. On the other hand, the amount of colored plastic waste increases, adding to the growing challenge of recycling it.

When these plastics are recycled, the various colors mix to create dark, low-value materials in a process known as downcycling. Conventional recycling methods cannot effectively separate colorants from plastics. Alternatively, chemical decomposition methods to remove colorants exist, but they require high temperatures of 300–500°C and lead to substantial energy consumption. These limitations thus present a growing need for upcycling technologies that enable efficient separation of colorants under milder conditions and allow plastics to be repeatedly reused as high-quality materials.

In search of a solution, a research team led by Associate Professor Kenji Okada and Professor Masahide Takahashi from Osaka Metropolitan University’s Graduate School of Engineering, in collaboration with Fuji Pigment Co., Ltd., developed a novel approach using silica microspheres to encapsulate colorants utilizing a spray-drying method. Silica, a primary component of sand and glass, is highly resistant to heat and chemicals, which allows these color capsules to withstand harsh manufacturing processes while maintaining vivid coloration in plastic products.

“A key advantage of this technology lies in its ease of recycling,” said Professor Okada. “When the plastic is dissolved in a solvent such as acetone, only the plastic dissolves, while the color capsules remain intact. Using centrifugation, both the colorless plastic solution and the capsules can be recovered separately with nearly 100% efficiency.”

Furthermore, by using capsules of different sizes for different colors, the researchers demonstrated that the colors can be selectively separated using simple mesh sieves. Even after repeated recycling over multiple generations, the materials retained their original color and quality without degradation.

“This approach enables used colored plastics previously destined for disposal or downcycling to be repeatedly reused as high-value resources,” stated Professor Takahashi.  “Moreover, because the process operates at room temperature and avoids energy-intensive decomposition, it significantly reduces energy requirements and environmental impact. In the future, we hope this technology is widely applied to used plastics, such as PET bottles and polyethylene bags, and potentially contribute to the realization of a sustainable circular recycling society."

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Nearly 100% recyclable pigment and plastic 

Colorant-embedded silica microspheres and plastic separate into their respective components.

Credit

Osaka Metropolitan University


About OMU  

Established in Osaka as one of the largest public universities in Japan, Osaka Metropolitan University is committed to shaping the future of society through the “Convergence of Knowledge” and the promotion of world-class research. For more research news, visit https://www.omu.ac.jp/en/ and follow us on social media: X, Instagram, LinkedIn

 

Hidden role of garnet reveals how Earth’s 660-km seismic boundary forms



Researchers show that garnet governs the mineral transitions shaping Earth's 660-km seismic boundary, supporting a pyrolite-like mantle





Okayama University

Garnet-driven mineral transitions explain the topography of Earth's 660-km seismic discontinuity 

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Schematic illustration of the 660-km seismic discontinuity showing how coupled post-spinel and post-garnet transitions shape the boundary in the average mantle, cold subducting slabs, and hot mantle plumes, explaining its complex seismic structure.

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Credit: Associate Professor Takayuki Ishii from Okayama University, Japan Source link: https://www.nature.com/articles/s41467-026-73717-





Nearly 660 kilometers beneath Earth's surface lies one of the planet's most important internal boundaries. Known as the 660-km seismic discontinuity, it separates the mantle transition zone from the lower mantle and plays a central role in controlling how heat and materials circulate through Earth's interior. This circulation helps drive mantle convection, plate tectonics, volcanic activity, and the long-term evolution of the planet. Although scientists have generally attributed this boundary to the breakdown of the mineral ringwoodite into bridgmanite and ferropericlase, that explanation has struggled to account for the complex structures detected by seismic observations beneath subduction zones and mantle plumes.

Addressing this challenge, a research team led by Associate Professor Takayuki Ishii at the Institute for Planetary Materials, Okayama University, along with Professor Hiroshi Kojitani and Professor Masaki Akaogi from the Department of Chemistry, Gakushuin University, Japan, investigated how majorite garnet, the second most abundant mineral in the mantle transition zone, influences this transformation. Using high-pressure, high-temperature experiments in a Kawai-type multi-anvil apparatus, they compared garnet-free and garnet-bearing mantle compositions under identical conditions. Their experiments revealed that the post-spinel transition does not occur independently in realistic mantle compositions but instead proceeds as a coupled reaction linked to the post-garnet transition. Their findings were published in Nature Communications on May 25, 2026.

The experiments showed that aluminum-bearing garnet changes both the pressure and temperature dependence of the post-spinel transition. Instead of behaving as an isolated mineral transformation, bridgmanite formation is governed by coupled mineral transitions involving ringwoodite breakdown and garnet. This coupled mechanism consistently explains why the average 660-km discontinuity forms at the observed depth, while also accounting for its roughness beneath cold subduction zones and hot mantle plumes. The findings indicate that garnet is not merely a passive component of the mantle but a key control on the mineral reactions responsible for this major seismic boundary.

“Our study shows that the 660-km boundary is created by a coupled post-spinel transition involving garnet rather than by the decomposition of ringwoodite alone,” says Dr. Ishii. “This mechanism provides a unified explanation for a wide range of seismic observations that previous models could not fully reconcile.”

The researchers further found that the linked mineral transformations support a mantle with a relatively homogeneous, pyrolite-like composition instead of a mechanical mixture of different rock types. This revised understanding provides a stronger framework for interpreting seismic images of Earth's deep interior and improves models of how material and heat move through the mantle.

A more accurate understanding of how the 660-km discontinuity forms also has broader implications for Earth science. By clarifying the mineral reactions that shape this boundary, the study provides a firmer basis for interpreting mantle convection, slab penetration into the lower mantle, and the ascent of hot mantle plumes. These processes govern the transport of heat and material within Earth and ultimately influence the tectonic and volcanic activity observed at the surface. The findings may also prompt a re-evaluation of prevailing models of mantle composition and Earth's long-term evolution.

Our work began with a question that remained unanswered from my first research project as a student—why the decomposition reaction of ringwoodite changes when garnet is present,” explains Dr. Ishii. “Resolving that question has now revealed a more realistic picture of Earth's deep interior and how the mantle behaves.”

Overall, the study identifies garnet as the key mineral governing the formation of Earth's 660-km seismic boundary, offering a comprehensive explanation for its complex seismic structure while reinforcing the view that the mantle is compositionally homogeneous with a pyrolite-like bulk composition.
 

Reference
Title of original paper: Role of garnet shaping the 660-km seismic discontinuity
Journal: Nature Communications
DOI: https://doi.org/10.1038/s41467-026-73717-6

About Okayama University, Japan
As one of the leading universities in Japan, Okayama University aims to create and establish a new paradigm for the sustainable development of the world. Okayama University offers a wide range of academic fields, which become the basis of the integrated graduate schools. This not only allows us to conduct the most advanced and up-to-date research, but also provides an enriching educational experience.
Website: https://www.okayama-u.ac.jp/index_e.html

About Associate Professor Takayuki Ishii from Okayama University, Japan
Dr. Takayuki Ishii is an Associate Professor at the Institute for Planetary Materials, Okayama University, Tottori, Japan. He earned his M.S. in Science in 2012 and Ph.D. in Science in 2015 from Gakushuin University. His research focuses on high-pressure phase transitions, Kawai-type multi-anvil high-pressure apparatus, high-pressure and high-temperature phase relations, crystal chemistry, Earth's mantle, and experimental mineral physics, with expertise in natural science and biogeosciences. In April 2026, he received the Commendation for Science and Technology: Young Scientists' Award from Japan's Ministry of Education, Culture, Sports, Science and Technology (MEXT). He has authored 95 peer-reviewed scientific publications.

 

Korea University study reveals sustainability trade-offs of reusable beverage systems



Prof. Yong Sik Ok and researchers show efficient washing technologies maximize environmental benefits of reusable beverage systems.




Cactus Communications

Prof. Yong Sik Ok advances sustainable reusable beverage systems through life-cycle assessment 

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Prof. Yong Sik Ok of Korea University demonstrates how washing technologies and reuse infrastructure influence the environmental performance of reusable beverage systems through comprehensive life-cycle assessment.

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Credit: Prof. Yong Sik Ok from Korea University, Seoul Image link: https://doi.org/10.1002/adsu.70534





The COVID-19 pandemic triggered an unprecedented surge in single-use plastic consumption worldwide. The widespread use of personal protective equipment (PPE), takeaway packaging, and disposable products intensified concerns about plastic pollution and waste management, reinforcing the need for a circular plastic economy.

Building on this global challenge, Professor Yong Sik Ok of Korea University investigates how the environmental benefits of reusable beverage systems depend on efficient washing technologies and reuse infrastructure. Using life-cycle assessment, the study identifies sustainability trade-offs among reusable and single-use beverage systems while providing practical evidence to support resource-efficient, circular consumption.

Prof. Ok has contributed to this global discussion through influential publications in Nature Reviews Earth & Environment, named "The COVID-19 Pandemic Necessitates a Shift to a Plastic Circular Economy," and Science, named "COVID-19’s Unsustainable Waste Management," highlighting the environmental consequences of plastic waste and the importance of reuse, resource efficiency, and sustainable waste management.

The study, “Environmental Trade-Offs and SDG Implications of Reusable Beverage Consumption Systems From a Life Cycle Perspective,” published in Volume 10, Issue 6 of the journal Advanced Sustainable Systems on June 12, 2026, was led by Professor Yong Sik Ok, with primary research conducted by PhD student Samhita Ankareddy and Assistant Professor Bin Cao, in collaboration with Professor Dan Tsang of the Hong Kong University of Science and Technology and Professor Xiangzhou Yuan of Southeast University.

To determine whether all reusable beverage systems deliver the same environmental benefits, the researchers evaluated a novel automatic tumbler washer that cleans and sterilizes a tumbler in just 15 seconds using only 350 mL of water, addressing the substantial water, energy, and detergent demands of conventional washing.

Using a comprehensive life-cycle assessment, the team compared refill-on-the-go (RFG) stainless-steel tumblers paired with the automatic washer, return-on-the-go (RTG) reusable polypropylene cups, and single-use paper, PET, and polypropylene cups.

The automatic tumbler washer system showed strong environmental performance. When paired with stainless-steel tumblers, it achieved the best results in more than half of the environmental impact categories assessed. RTG reusable cups recorded the lowest overall annual environmental impact because of their lightweight design and lower production footprint, while manually washed tumblers had the highest impacts among reusable options.

The researchers also examined contributions to the United Nations Sustainable Development Goals (SDGs). Overall, reusable systems outperformed single-use alternatives across human health, ecosystem, and resource-related SDG domains, with the automated tumbler washing system demonstrating the strongest overall sustainability performance.

The findings suggest that replacing disposable cups with reusable alternatives is only part of the solution. Maximizing environmental benefits requires efficient reuse infrastructure and operational practices. For universities, corporations, and municipalities, the study shows that the success of reusable systems depends not only on consumer participation but also on technologies that support reuse.

Reusable systems support a circular economy, but efficient washing technologies are essential to maximize their long-term environmental sustainability,” says Prof. Ok.

Reuse culture must be supported by both top-down institutional interventions and bottom-up behavioral changes to accelerate the transition toward reusable systems,” adds Ms. Ankareddy.

Together, the findings provide a practical roadmap for designing reusable beverage systems that maximize environmental benefits while advancing the transition to a circular economy.

 

Reference
Authors:Samhita Ankareddy, Bin Cao, Daniel C. W. Tsang, Xiangzhou Yuan, Yong Sik Ok
Title of original paper: Environmental Trade-Offs and SDG Implications of Reusable Beverage Consumption Systems From a Life Cycle Perspective
Journal: Advanced Sustainable Systems    
DOI: https://doi.org/10.1002/adsu.70534
Affiliations
1Division of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea
2International ESG Association (IESGA), Seoul, Republic of Korea
3Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China 
4Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, China 
5Key Laboratory of Functional Polymers for Sustainability of Jiangsu, School of Energy and Environment, Southeast University, Nanjing, China

 

About Korea University
Korea University, located in Seoul, is one of South Korea’s oldest and most prestigious institutions, founded in 1905. It is renowned for excellence in research, innovation, and global academic collaboration, playing a key role in advancing education, science, and technology. With a strong focus on interdisciplinary research, it contributes to addressing global challenges such as sustainability and climate change through cutting-edge programs and international partnerships.

For more information, visit Korea University's website.

 

About Professor Yong Sik Ok
Yong Sik Ok is a professor at the Division of Environmental Science and Ecological Engineering at Korea University. He is President of the International ESG Association and the International Society of Trace Element Biogeochemistry. In 2022, he became a Highly Cited Researcher recognized simultaneously in Environment and Ecology, Engineering, and Biology and Biochemistry. His research focuses on ESG principles, biochar, and climate technologies supporting the United Nations Sustainable Development Goals. His Google Scholar profile reflects substantial research impact, with an h-index of 196, more than 20,000 annual citations, and over 144,489 total citations. He serves as Editor-in-Chief of CleanMat.

 

 

Invisible threads: how our environment quietly shapes disease





CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences

Exposure–Exposure Network (EEN) 

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The EEN represents relationships among chemical exposures, where each node corresponds to a chemical compound and edges indicate shared biological activity. Nodes are coloured according to community structure, highlighting broad clusters of exposures with shared connectivity patterns.

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Credit: Christiane V.R. Hütter





From the air we breathe to the food we eat, we are constantly exposed to thousands of chemicals – yet how these exposures affect our health has remained surprisingly difficult to understand. A new study led by researchers at the CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences and the Ludwig Boltzmann Institute for Network Medicine at the University of Vienna, published in Nature Communications (DOI 10.1038/s41467-026-72402-y), offers a unifying view: diverse substances can disrupt the same biological systems and thereby contribute to disease risk in predictable ways.

Environmental pollution is estimated to contribute to around one in six deaths worldwide, but scientists have long struggled to connect specific exposures to specific diseases. One reason is the sheer complexity of the “exposome” – the totality of all environmental influences a person encounters over a lifetime. Traditionally, chemicals have been grouped by their structure or origin, but this says little about what they actually do inside the body. Two nearly identical molecules can have completely different effects, while entirely unrelated substances may trigger the same illness. This has made it difficult to move from observation to understanding.

A new study, led by Jörg Menche, CeMM Adjunct PI and Director of the Ludwig Boltzmann Institute for Network Medicine and first authored by former PhD Student at CeMM and LBI NetMed (now PostDoc at Harvard Medical School) Salvo Danilo Lombardo, takes a different route: instead of asking what chemicals look like, the researchers asked what they do. They compiled nearly 10,000 environmental exposures, ranging from pollutants and food components to medications, and mapped how each one affects human genes. The result is a large-scale network that links exposures based on shared biological effects.

When the researchers zoomed in on this network, a striking pattern emerged: Exposures grouped into clusters that reflect common biological functions, such as inflammation, metabolism, or blood clotting. Within these clusters, chemically diverse compounds like pharmaceuticals and environmental toxins were found to act on the same molecular pathways. The network showed that the body responds to these exposures not based on their chemical identity, but on the biological systems they perturb.

A map of hidden biological connections

To understand why some exposures are more harmful than others, the team looked at where their effects occur within the cell’s internal wiring, the so-called “protein interaction network”. Here, not all proteins are equal: some act as central hubs, coordinating many essential processes. The study shows that exposures targeting these hubs tend to be more damaging. Even a single hit to a highly connected protein can ripple through the system, amplifying its impact. This provides a simple but powerful principle: the more central the biological target, the greater the potential harm.

The researchers then took a step further, asking whether these molecular insights could help explain real-world disease patterns. By comparing their network predictions with large-scale health and environmental data from across Europe, they found that countries with higher levels of certain exposures also showed higher rates of diseases connected to those exposures at the molecular level. This suggests that the biological “distance” between an exposure and a disease, as measured within the network, can help predict which health outcomes are likely to occur.

From molecules to public health

“Taken together, the findings offer a new way of thinking about how the environment influences health,” says corresponding author Jörg Menche. “Rather than treating each chemical in isolation, the study shows that many exposures converge on shared biological pathways, forming a complex but structured system of interactions. By mapping these connections, researchers can begin to anticipate the health effects of exposures – even those that have not yet been studied in detail.”

This work provides a foundation for a more systematic understanding of the exposome, bridging the gap between molecular biology and public health. In the long term, such approaches could help identify hidden risks, improve environmental monitoring, and support strategies to reduce disease burden.

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The CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences is an international, independent and interdisciplinary research institution for molecular medicine under the scientific direction of Maria Rescignio. CeMM is oriented towards medical needs and integrates basic research and clinical expertise to develop innovative diagnostic and therapeutic approaches for precision medicine. Research focuses on cancer, inflammation, metabolic and immune disorders, rare diseases and aging. The Institute's research building is located on the campus of the Medical University and the Vienna General Hospital. www.cemm.at

The overarching ambition of the Ludwig Boltzmann Institute for Network Medicine at the University of Vienna is to leverage network theory, machine learning and artificial intelligence to formulate a holistic view of the intricate cross-scale nature of human biology and to translate the gained insights to concrete medical impact ranging from diagnosis to treatment. The LBI-NetMed pursues research lines along the hierarchical biological organization from molecules to tissues, organs, the whole-body system, and finally the population level. In parallel, a next generation data exploration platform will be developed aiming to open up entirely new ways of integrating and interpreting complex biomedical data. Work at the LBI-NetMed happens in close collaboration with clinical and industry partners to translate, validate and implement results on these fundamental questions into medical practice. netmed.lbg.ac.at

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UC3M study analyzes crime rates by nationality and debunks its link to immigration




Universidad Carlos III de Madrid





When analyzing crime, the foreign population typically shows higher rates than the native population. However, crime statistics change significantly when comparing groups of the same age and gender. A detailed data analysis conducted in a scientific study by the Universidad Carlos III de Madrid (UC3M) demonstrates that the apparent crime gap between the foreign and native populations is primarily due to the fact that the immigrant profile tends to concentrate more young men—the demographic sector with the highest crime rates in any society.

The research, recently published in the Revista Española de Investigaciones Sociológicas (REIS), concludes that structural and socioeconomic factors explain the crime gap and endorses regularization policies as effective security tools. "This work provides empirical evidence in a recurring social debate and concludes that immigrant status, on its own, does not explain crime levels once demographic factors and the socioeconomic context are taken into account," states the study's author, Jesús Javier Sánchez Barricarte, Professor in the Department of Social Sciences at UC3M.

Spain has undergone a highly significant demographic transformation in recent decades, going from barely 2% of the foreign population at the end of the 20th century to nearly 14% in 2025. In parallel, the notion that immigration brings greater insecurity has spread. Given the scarcity of robust empirical studies in the country on this potential link, the researcher set out to verify what the figures actually show. To achieve this, he analyzed more than 5.5 million offenses with final convictions recorded between 2007 and 2023, based on adult conviction statistics from the National Statistics Institute (INE). "What I have verified is that there is a stark contrast between what is perceived and what the data indicates," the author points out.

The key impact of demographic structure

One of the study's most significant contributions highlights the need to standardize crime rates to make methodologically valid comparisons. This is because crime is a variable that depends heavily on age and sex (being higher among males and young people), and the immigrant population is, on average, younger and has a higher proportion of males than the Spanish population. "If we want to compare populations with different demographic structures, performing a standardization exercise is imperative," Sánchez Barricarte explains. When applying this criterion, the statistical reality changes completely: "When rates are standardized, the gap between Spaniards and foreigners is cut in half. In other words, a large part of the gap has nothing to do with being an immigrant, but rather with age and gender structure."

The study shows that the remaining difference after standardization is also not explained by immigrant status itself. When various socioeconomic factors are taken into account, findings indicate that a higher presence of immigrants in a province is not associated with higher crime rates. Instead, factors that do consistently carry weight include the level of urbanization and the average age of the population.

"Across all population groups, crime rates are higher in cities than in rural areas, and it turns out that a larger percentage of immigrants live in urban areas," the UC3M researcher underscores. Other factors, such as average income levels and access to basic services like housing, also condition the levels of certain crimes. When controlling for these factors, no association is found between the percentage of the foreign population and crime rates.

Heterogeneity of origin and statistical distortions

The analysis highlights significant heterogeneity in crime levels depending on nationality, which invalidates any generalization. There are groups well above the native average (those from the Balkans have a rate nine times as high as the Spanish rate, Algeria five times as high as the Spanish rate, or Ecuador three times as high as the Spanish rate), while others present rates even lower than the Spanish average, such as those from India, China, the Philippines, or Pakistan. "If being an immigrant were the problem, we would not see such a wide dispersion," the professor argues, concluding that what explains the differences is not national origin, but rather the social and economic conditions of each group.

The researcher insists that distinguishing between "foreigner" and "immigrant" is fundamental to avoid distorting the figures. Conviction statistics record nationality but do not specify whether the person is a resident of Spain. Consequently, convictions of foreign tourists or members of international organized crime networks who do not reside in the country artificially inflate the crime rates of resident immigrants, explaining the elevated indicators for citizens from the Balkans and Georgia. Conversely, there is a notable underreporting of certain crimes committed by the native population, such as so-called white-collar crimes (financial fraud, corruption, or tax evasion), which show a higher incidence among the native population compared to the immigrant population and also account for part of the gap.

Furthermore, the data directly contradicts the perception of public alarm linked to irregular immigration. The study finds that between 2017 and 2023, the proportion of the irregular foreign population in Spain grew by 345%, while the standardized crime rate for foreigners dropped by 2%. "If it were true that irregular status caused crime rates to spike, that relationship would have to appear in the data. And it does not," he asserts.

Despite the general debunking of the link, the researcher clarifies that the study does not ignore the existence of real challenges. Specifically, it has found real and concerning differences in areas such as femicides or sexual offenses, which are associated with certain values and attitudes toward women and sexual minorities in the countries of origin—issues that demand the development of targeted public policies.

Organized crime, terrorism, and irregular status

The study contextualizes complex phenomena such as organized crime and jihadist terrorism. Sánchez Barricarte maintains that international organized crime follows its own dynamics and operates independently of settled immigration, often being composed of individuals who do not even reside in Spain: "It would be truly naive to think that restricting immigration will put an end to international organized crime."

Regarding jihadist terrorism, he points out that: "It is, above all, a security issue, not an exclusively migratory one: more than half of those arrested on these grounds between 2004 and 2023 were born in Spain." Furthermore, the analysis confirmed significant heterogeneity in crime rates among foreigners holding nationalities from Muslim-majority countries (with high rates for Algeria and Morocco, and rates lower than the Spanish average for Mali and Pakistan), finding no evidence linking the Islamic faith to higher levels of crime.

The underlying message of this scientific work is that immigrant status, on its own, does not explain crime. What truly influences it are structural factors such as age and sex composition, poverty, social exclusion, rural or urban residence, and access to housing and employment. For this reason, the professor concludes that integration and regularization policies, far from being a threat, help reduce crime, as regularization improves the living conditions of immigrants without harming the employment or wages of the native population: "Access to the formal labor market not only increases their income, but also increases the opportunity cost of committing a crime, by jeopardizing their economic and social stability." Migratory regularization policies are thus framed as effective tools for improving security and social cohesion, in an academic call to replace prejudice with data.

Video: https://youtu.be/zVSjIYsp0R0