Feed additives can reduce campylobacter in free-range broilers

Trials demonstrate that adding biochar to chicken feed can reduce campylobacter in chickens by up to 80%. This could potentially lead to fewer foodborne illnesses among humans.

Technical University of Denmark

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DTU National Food Institute researchers have conducted trials in a commercial free-range chicken farm in Denmark. They achieved an 80% reduction in campylobacter in the chickens by supplementing their feed with biochar.

“Campylobacter causes numerous cases of illness in humans every year. Reducing bacterial levels in chickens can make a significant difference in public health. Our findings highlight biochar’s potential—particularly for free-range and organic chickens, where controlling bacteria is more challenging than in conventionally raised poultry,” says senior researcher Brian Lassen from DTU National Food Institute, who leads the SafeChicken project.

Many studies of this kind are conducted in laboratories and show positive outcomes, but they often struggle to replicate these findings under actual farm management conditions.

“We demonstrate that it’s possible to significantly reduce campylobacter in free-range chickens slaughtered at two months of age without finding adverse effects on their health. This is significant for production systems where chickens have access to outdoor areas, which typically increases their exposure to campylobacter from the environment,” says PhD student Cristina Calvo-Fernandez, who has worked on the project as part of her doctoral studies.

Potential for organic farming

The researchers tested feed and water additives on the free-range chickens that had previously shown evidence of potentially reducing campylobacter under experimental conditions. The trials were conducted three times on the same farm.

“The best results came from using biochar, which is made from organic waste material, such as wood, transformed into biochar through pyrolysis. In addition to reducing campylobacter, biochar can help lower CO2 emissions and has the potential for becoming part of a circular economy,” says Brian Lassen. 

Biochar could potentially be used in organic chicken production and implemented quickly, as it is a substance that can be used in this production type, which is otherwise more restricted in what can be added to feed than other production types.

Researchers also tested organic acids added to the chickens’ drinking water. Previous studies have shown that these acids can reduce campylobacter levels.

“In our trials, we observed a 76% reduction in campylobacter when the chickens were 36 days old - half of this breed’s slaughter age - but the effect diminished by the slaughter age of the free-range chickens three weeks later. This suggests that timing the administration of organic acids may need to be optimized from the experimental setup,” says Cristina Calvo-Fernandez.

Food safety for the future

Chickens are natural hosts for campylobacter and thus can be found in chicken meat if the flock is infected. In humans, it can cause gastrointestinal illness if meat is undercooked or improperly handled. National initiatives in Denmark have already reduced levels of bacteria such as salmonella and campylobacter through Action Plans, but new methods are still needed to reduce their presence. Campylobacter can be found in free-range and organic chicken flocks, especially in summer. Maintaining good kitchen hygiene and thoroughly cooking chicken meat can prevent illness, as high heat kills the bacteria.

“The result provides an important tool in making chicken meat as safe as possible. With 5,000 registered cases of campylobacter-related illness annually in Denmark—and many more unreported—campylobacter is a significant cause of gastrointestinal problems,” says Brian Lassen.

The SafeChicken project will continue until autumn 2025 and investigate additional methods to combat campylobacter, including slaughterhouse interventions.

The researchers also analyze why biochar reduces campylobacter levels in chickens.

“We are currently studying how biochar affects the families of bacteria in the chicken gut microbiome. Campylobacter is a naturally present bacterium in the chicken’s gut microbiome, and understanding just how biochar affects the chicken’s microbiome and reduces campylobacter is essential,” says Cristina Calvo-Fernandez.

If the researchers can uncover this mechanism, it offers hope that the method could also be applied to conventional poultry farming and other livestock.

Read more

The findings are published in the scientific journal Poultry Science.

Authors: Brian Lassen, Nao Takeuchi-Storm, Cristina Calvo-Fernandez, Annette Nygaard Jensen, Giulia Ravenni, Marianne Sandberg, Ulrik Birk Henriksen—all from DTU.

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Journal

Poultry Science

DOI

10.1016/j.psj.2024.104706 

Article Title

Effect of feeding biochar, oat hulls, yeast fermentate, and organic acids on reduction of Campylobacter in free-range broilers from hatching to slaughter

 

A breakthrough in hydrogen catalysis: Electronic fine-tuning unlocks superior performance

Advanced Institute for Materials Research (AIMR), Tohoku University

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(a) Schematic illustration of synthesis procedure for Ru@Zn-SAs/N-C catalysts, where the electrostatic potential diagram of the iso-surface value is 0.03 e Å-3; (b-d) SEM images with different magnification; (e) TEM image; (f-g) HRTEM images, (f) the inset is the corresponding particle-size distribution of Ru clusters and (g) the inset shows the Moiré images extracted from the FFT; (h) AC HADDF-STEM image and integrated pixel intensities; (i) AFM image and corresponding height profiles of Ru@Zn-SAs/N-C.
 

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Credit: Hao Li et al.

As the world moves toward sustainable energy, hydrogen will likely play an invaluable role as a clean and versatile fuel. Yet, adoption of hydrogen technologies hinges on overcoming key challenges in electrocatalysis, where costly and scarce platinum-group metals have long been the industry standard. Taking one step to rectify this, a research team has now developed a new strategy that fine-tunes electronic interactions at the atomic level.

The study introduces an innovative electronic fine-tuning (EFT) approach to enhance the interactions between zinc (Zn) and ruthenium (Ru) species, resulting in a highly active and stable catalyst for both the oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER). By anchoring Ru clusters onto hierarchically layered Zn-N-C nanosheets (denoted as Ru@Zn-SAs/N-C), the team has designed a material that outperforms commercial platinum-based catalysts.

"Our work demonstrates how precise control over electronic structures can fundamentally reshape catalytic performance," says Hao Li, associate professor at Tohoku University's Advanced Institute for Materials Research (WPI-AIMR) and corresponding author of the paper. "By leveraging the synergy between Zn and Ru, we have developed a cost-effective alternative to conventional platinum catalysts, offering new possibilities for sustainable hydrogen production."

Key to this breakthrough is the strong electronic metal-support interaction (EMSI) between Zn and Ru, which optimizes the adsorption energy of critical reaction intermediates. X-ray absorption spectroscopy and computational modeling confirm that this synergy shifts *OOH and *OH adsorption energies to an optimal balance, enhancing ORR efficiency. Simultaneously, Ru sites achieve near-ideal hydrogen binding free energy, placing the catalyst at the peak of theoretical HER activity.

"This research is not just about replacing platinum," Li explains. "It's about understanding how electronic properties at the atomic level dictate catalytic efficiency. That knowledge allows us to design better, more accessible materials for real-world applications."

These findings have significant implications for the affordability and scalability of hydrogen energy. By reducing dependence on expensive platinum while improving performance, this research contributes to the development of cost-effective hydrogen fuel cells, water electrolysis systems, and sustainable industrial processes.

Looking ahead, the team plans to further refine the EFT strategy, improve catalyst stability under real-world conditions, and develop scalable production methods. Applications in zinc-air batteries, fuel cells, and carbon and nitrogen reduction reactions are also under investigation.

The research has been made available through the Digital Catalysis Platform (DigCat), the largest experimental catalysis database to date, developed by the Hao Li Lab.

Details of its findings were published in the journal Advanced Functional Materials. The article processing charge (APC) was supported by the Tohoku University Support Program.

About the World Premier International Research Center Initiative (WPI)

The WPI program was launched in 2007 by Japan's Ministry of Education, Culture, Sports, Science and Technology (MEXT) to foster globally visible research centers boasting the highest standards and outstanding research environments. Numbering more than a dozen and operating at institutions throughout the country, these centers are given a high degree of autonomy, allowing them to engage in innovative modes of management and research. The program is administered by the Japan Society for the Promotion of Science (JSPS).

See the latest research news from the centers at the WPI News Portal: https://www.eurekalert.org/newsportal/WPI
Main WPI program site:  www.jsps.go.jp/english/e-toplevel

Advanced Institute for Materials Research (AIMR)
Tohoku University
Establishing a World-Leading Research Center for Materials Science
AIMR aims to contribute to society through its actions as a world-leading research center for materials science and push the boundaries of research frontiers. To this end, the institute gathers excellent researchers in the fields of physics, chemistry, materials science, engineering, and mathematics and provides a world-class research environment.
 

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Journal

Advanced Functional Materials

DOI

10.1002/adfm.202422594 

Did Twitter favour tweets from right-wing politicians? International study ends prematurely in 2023

 ‘Is there anything Left;   A Global Analysis on Changes in Engagement with Political Content on Twitter in the Musk Era

A research group at Saarland University has analysed the Twitter accounts of some 8,600 politicians from twelve countries

Saarland University

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Ingmar Weber, Humboldt Professor of Artificial Intelligence

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Credit: UdS/Thorsten Mohr

Social media platforms provide a rich source of data for academic study. A research group at Saarland University has now analysed the Twitter accounts of some 8,600 politicians from twelve countries. The team, led by Ingmar Weber, who holds an Alexander von Humboldt Professorship in AI at Saarland University, wanted to know whether between 2021 and 2023 Twitter prioritized tweets from politicians from the right of the political spectrum. The short answer for the period in question is no. In June 2023, however, Elon Musk blocked free access to Twitter data for academic research purposes.

Sometimes research work ends just when things are starting to get exciting. Someone who knows what that feels like is graduate computer scientist Brahmani Nutakki, who is working on her PhD under Professor Ingmar Weber at the Institute for Societal Computing at Saarland University. Over a period of two years, Brahmani Nutakki and the two Saarbrücken-based political scientists Rosa M. Navarrete and Giuseppe Carteny analysed the tweets from 6,550 Twitter accounts, which were associated with some 8,600 politicians from twelve countries. ‘Sadly, our analyses came to an abrupt end in June 2023 when Elon Musk, who acquired Twitter in October 2022, removed free academic access to Twitter’s data,’ explained Brahmani Nutakki. Nevertheless, Nutakki was able to draw some important conclusions from the data that the team had been able to collect up to that point. The analysis has now been published in the respected free-to-access scholarly journal Journal of Quantitative Description: Digital Media.

The researchers selected twelve countries with the highest user activity on the Twitter (now X) platform, namely Argentina, Brazil, Canada, Colombia, France, Germany, India, Japan, Mexico, Spain, the United Kingdom, and the United States. For each of these countries, the researchers divided the parliamentary representatives into two groups depending on whether they could be assigned more to the political left or more to the political right. ‘We opted for this binary distinction for the sake of simplicity and because the use of the labels “left” and “right” to denote particular political positions is broadly accepted around the world. To determine how politicians and parties should be assigned within this binary classification scheme, we consulted numerous sources such as expert surveys and party manifestos,’ explained political scientist Rosa M. Navarrete.

Having analysed several thousand tweets for each politician, the researchers found no significant difference between the dissemination of content from left-leaning or right-leaning politicians across all countries studied. ‘In the period we studied from 2021 to 2023, we did, however, observe a considerable increase in the number of likes, a slight increase in the likes-per-retweet ratio and a significant reduction in the number of retweets post Musk acquisition. We believe that this is because early followers of a Twitter account are more politically engaged and tend to support content more actively. But as the political message gets spread to a broader audience, it becomes more likely that the number of likes will go up, while the retweet rate declines,’ said Brahmani Nutakki. The researchers used the metric ‘likes’ rather than ‘views’, as the latter were only introduced after Elon Musk acquired the platform and were not available for previous tweets. They were, nevertheless, able to establish a correlation between the two metrics.

Nutakki also faced a number of problems when analysing the huge amounts of data involved. Many of these difficulties were related to the dynamic changes occurring on the Twitter platform between November 2022 and June 2023. One such change was the transformation of Twitter Blue from a premium subscription service for high-profile accounts with high levels of user engagement into a low-cost subscription service that only required a verified phone number. This new feature was then temporarily removed shortly after it was introduced. A similar fate befell the rules prohibiting hateful conduct, which were intended to prevent attacks on individuals and were also removed after Musk’s takeover. ‘Changes to Twitter’s functionality also resulted in changes in the user population, which made it difficult for us to attribute the changes we observed to a single specific cause,’ said Brahmani Nutakki.

‘We believe that our study is the first to provide a global analysis of how trends in political engagement have shifted over time by examining how user activity on Twitter has evolved during the recent changes that the platform has undergone. Our findings indicate that political content on the platform reached a wider audience following these changes. In the period before June 2023, we found no evidence of a significant difference in engagement patterns between users on the left and those on the right of the political spectrum,’ explained Professor Ingmar Weber. Professor Weber also highlighted an article in the Washington Post last October that reported that those Republican politicians most active on X (formerly Twitter) were posting more frequently, getting more views and had more followers than top-tweeting Democrats, though no evidence of platform censorship was found. Other observers have pointed out that since Musk’s takeover, the Twitter/X platform has become problematic by failing to remove reported hate tweets and by reactivating many previously suspended accounts.

‘These worrying changes to social media platforms such as Twitter/X are jeopardizing the democratic structures in many countries and require continuous scrutiny by academic researchers. We are calling for the implementation of legislation such as Article 40 of the Digital Services Act so that academic researchers can regain access to social network data. It is simply not acceptable that access to these vast amounts of data is either unaffordable or provided so selectively that no meaningful analyses can be conducted,’ said Ingmar Weber.

Background: Interdisciplinary Institute for Societal Computing (I2SC)

I2SC advances interdisciplinary research at Saarland University and provides a platform for interaction and knowledge sharing between the social sciences, the humanities and computer sciences. The institute is headed by Ingmar Weber, Alexander von Humboldt Professor for Artificial Intelligence, and Daniela Braun, Professor for Political Science. The research conducted at I2SC covers two core areas: Computing of Society and Computing for Society. The first of these areas concerns the use of computational methods to understand societal phenomena. The second relates to the use of these methods to facilitate digitally assisted interventions that improve society.

Learn more at: www.i2sc.net

Original publication:

‘Is there anything Left? A Global Analysis on Changes in Engagement with Political Content on Twitter in the Musk Era’, Brahmani Nutakki, Rosa M. Navarrete, Giuseppe Carteny and Ingmar Weber, Interdisciplinary Institute for Societal Computing (I2SC), Saarland University

Journal of Quantitative Description: https://journalqd.org/article/view/8875/7391

DOI: https://doi.org/10.51685/jqd.2025.004

Press photographs that can be used free of charge with this press release can be found at the bottom of the following web page.

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Journal

Journal of Quantitative Description Digital Media

DOI

10.51685/jqd.2025.004 

Method of Research

Data/statistical analysis

Subject of Research

People

Article Title

‘Is there anything LeftA Global Analysis on Changes in Engagement with Political Content on Twitter in the Musk Era

 

‘Glacial fracking’: A hidden source of Arctic greenhouse gas emissions

Gabrielle Kleber and Leonard Magerl, postdoctoral researchers at iC3, have discovered that Arctic glaciers are leaking significant amounts of methane, a potent greenhouse gas.

UiT The Arctic University of Norway

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Gabrielle and Leonard lived in this remote cabin on Svalbard for three summers, staying close to Vallåkrabreen while conducting their study.

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Credit: Leonard Magerl / iC3 / UiT

Gabrielle Kleber and Leonard Magerl, postdoctoral researchers at iC3, have discovered that Arctic glaciers are leaking significant amounts of methane, a potent greenhouse gas. 

They found that glacial melt rivers and groundwater springs are transporting large volumes of methane from beneath the ice to the atmosphere. This previously unrecognised process could contribute to Arctic climate feedbacks, accelerating global warming.

iC3 – Centre for ice, Cryosphere, Carbon and Climate is a Centre of Excellence at UiT The Arctic university of Norway.

A surprising source of methane 

Methane emissions from Arctic wetlands, permafrost, and geological seeps are well known. However, until now, the role of glacial meltwater in mobilising methane had been largely overlooked.

Gabrielle and Leonard focused on Vallåkrabreen, a small valley glacier in central Svalbard, where they measured methane levels in groundwater springs and the melt river draining from the glacier. 

Their results were striking. Methane concentrations in the melt river were found to be up to 800 times higher than the atmospheric equilibrium level, with peak levels of 3,170 nanomolar recorded early in the melt season. 

This methane was not produced by microbial activity beneath the ice, as previously suspected in other glacial settings, but instead came from thermogenic sources—methane that has been trapped in the region’s ancient geological formations for millions of years. 

Gabrielle explains:

“We expected to see some methane in the meltwater, but the concentrations we measured were surprisingly high. Our isotopic analysis showed that this methane is geologic in origin and is released as the glacier retreats and glacial meltwater flushes through fractures in the rock.”. 

Glacial fracking

By tracking methane concentrations throughout the melt season, the researchers estimated that Vallåkrabreen’s melt river alone released around 616 kg of methane into the atmosphere between June and October.

This accounted for 63% of the total methane emissions from the glacier catchment, with groundwater springs and bubbling gas vents contributing the rest.

Leonard highlights the importance of meltwater in driving these emissions:

“Glaciers act like giant lids, trapping methane underground. But as they melt, water percolates flushes through cracks in the bedrock, carrying transporting the gas to the surface. You can think of as a natural ‘fracking’ process process, or as we have called it: ‘glacial fracking’.”

The study suggests that similar emissions could be happening at hundreds of other glaciers across Svalbard. There are over 1,400 land-terminating glaciers on the archipelago, many of which overlie methane-rich bedrock. 

If similar processes are occurring elsewhere, glacial methane emissions could be a substantial and previously unaccounted-for source of Arctic greenhouse gas emissions.

A new climate feedback loop?

The implications of this research go far beyond Svalbard. 

The Arctic is warming at four times the global average, and glaciers across the region are shrinking rapidly. As they melt, more methane could be released, creating a positive feedback loop—where warming melts glaciers, releasing methane, which in turn traps more heat in the atmosphere and accelerates further melting.

Gabrielle warns that this process could have global climate consequences:

“Methane is a much more powerful greenhouse gas than carbon dioxide over short timescales. Even though these emissions are seasonal, they could add up as more glaciers retreat.”

Future research agenda 

The discovery raises questions about how the Arctic carbon cycle is changing in response to climate change.

Scientists now need to reassess methane budgets in the region, incorporating glacial emissions alongside permafrost thaw and wetland methane fluxes.

This study is the first to document methane emissions from a glacial melt river in Svalbard, but more research is needed to understand the full scale of the problem. The iC3 researchers plan to expand their work to other glacier systems and develop methods to quantify methane emissions on a larger scale.

Find out more 

The study, Proglacial methane emissions driven by meltwater and groundwater flushing in a high-Arctic glacial catchment has been published open access in Biogeosciences. 

Gabrielle Kleber is a postdoctoral researcher at iC3 and with the Arctic Geology department at the University Centre in Svalbard (UNIS). Her research focuses on Arctic methane emissions and glacial hydrology. Publications here. 

Leonard Magerl is a doctoral researcher at iC3, specialising in biogeochemical processes in polar environments. His work investigates the interactions between glaciers, nutrients, and carbon cycling in the Arctic. Publications here.

For more updates on polar research and postdoctoral opportunities at iC3, subscribe to email updates and check out our news page.

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Journal

Biogeosciences

DOI

10.5194/bg-22-659-2025 

Subject of Research

Not applicable

Article Title

Proglacial methane emissions driven by meltwater and groundwater flushing in a high-Arctic glacial catchment

Article Publication Date

16-Feb-2025

Gabrielle Kleber assesses meltwater streams.

The melt river flows from the terminus of Vallåkrabreen into the valley, where it meets many methane-rich groundwater springs.

Credit

Leonard Magerl / iC3 / UiT