Monday, November 25, 2024

Urgent need to enable more farmers and contractors to revive England’s network of hedgerows

Agri--environment schemes have improved the hedges' structural condition but not overall length

UK Centre for Ecology & Hydrology

Managed hedge — image:
A managed hedge.
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Credit: UKCEH

A new comprehensive survey has highlighted an urgent need to enable more farmers and contractors to revive England’s hedgerows to meet national restoration targets. While agri-environment schemes (AES) have improved the condition of these iconic landscape features, the overall length of hedgerows remains unchanged.

Hedgerows act as field boundaries, protect livestock, support biodiversity and help mitigate climate change. However, around half of these important habitats were lost in the post-war years due to agricultural intensification. In the 2007 Countryside Survey, fewer than 50% of remaining hedgerows were judged to be in good structural condition.

The UK Centre for Ecology & Hydrology repeated the hedgerow survey across England in a new project for Natural England. Defra has set a target to create or restore 45,000 miles of hedgerow by 2050.

UKCEH used the data to review the effectiveness of the agri-environment schemes (AES) for hedgerows and carried out a questionnaire of around 400 farmers and contractors to gain a better understanding about their hedge management practices.

Key findings

The England hedgerow survey shows that, overall, agri-environment schemes have had a positive impact on hedge condition, and that more recent schemes are supporting more restoration and planting of new hedges.

Findings of the UKCEH report, An evaluation of Agri-Environment Scheme impact on hedgerows in England, include:

There was no statistically significant change in the overall length of managed hedgerows in England between 2007 and 2023, which is estimated to have remained at around 400,000km.
The proportion of hedgerows in good structural condition increased from 43% to 55% between 2007 and 2023. For hedgerows under AES the figure rose to 63.5%, compared to 46.8% for those outside such schemes.
Hedgerow height generally increased between 2007 and 2023 with the majority of hedges now taller than two metres, rather than in the one to two metre category. Hedges under AES were slightly taller than those outside schemes.
Many hedges have deteriorated in recent years due a lack of ongoing maintenance, resulting in gappy hedges or lines of trees.
The diversity of plant species at the base of hedgerows has not improved.

Biodiversity and climate benefits

Defra aims to create or restore 30,000 miles of hedgerow by 2037 and 45,000 miles by 2050. However, the Climate Change Committee recommends that the national hedgerow network should be increased by 40% by 2050, while Natural England’s long-term aspiration is a 60% increase in hedgerow extent to support thriving plants and wildlife.

Dr Lisa Norton, the UKCEH agro-ecologist who led the hedgerows study, says: “There are signs that agri-environment schemes are having a positive effect on the condition of England’s hedgerows. However, efforts to meet national targets for lengths of managed hedges are falling short.

“To meet national targets, we urgently need to increase participation in these schemes among farmers and landowners through better incentives and advice so they can rejuvenate our network of hedgerows.”

Dr Norton emphasises that increased planting and better management, including laying and coppicing, would maximise hedges’ ability to capture and store carbon, helping us reach net zero. It would also provide more habitat for insects, nesting birds and small mammals, supporting ecosystem services such as pollination and natural pest control, as well as enhance our landscapes.

In addition to AES funding, many non-governmental organisations such as the Woodland Trust provide funding and support for hedgerow and tree planting.

Farmers’ feedback

UKCEH’s survey revealed that farmers are keen to maintain their hedges both to protect livestock and improve local wildlife. However, they highlighted the need for adequate funds for planting, establishment, and ongoing management of hedges.

Agricultural contractors reported that agri-environment schemes had been designed without their input and said there had been numerous issues with managing hedgerows in line with the schemes’ regulations, affecting their businesses. They also highlighted the potential advantages of investing in farmer and contractor training in hedgerow management.

The results of UKCEH’s survey and study will be used to shape future policies and strategies aimed at increasing the quantity and quality of hedges across England. The report and a summary are available on the Defra website.

- Ends -

Media enquiries

For interviews and further information, please contact Simon Williams, Media Relations Officer at UKCEH, via simwil@ceh.ac.uk or +44 (0)7920 295384.

Notes to Editors

Surveyors recorded the lengths, locations and attribute, such as height, width and management, of all hedgerows in the English Countryside Survey squares. Plots sampling species and additional hedgerow attributes in both the woody component and the area below and adjacent to hedgerows were recorded for both randomly sampled hedgerows and for hedgerows under agri-environment scheme options in squares.

UKCEH’s questionnaire complemented a separate survey of farmers, commissioned by CPRE, which showed strong support for government plans to increase our hedgerow networks but highlighted a lack of funding is by far the biggest obstacle to planting and maintaining hedgerows.

About the UK Centre for Ecology & Hydrology (UKCEH)

The UK Centre for Ecology & Hydrology (UKCEH) is a leading independent research institute dedicated to understanding and transforming how we interact with the natural world.

With over 600 researchers, we tackle the urgent environmental challenges of our time, such as climate change and biodiversity loss.

Our evidence-based insights empower governments, businesses, and communities to make informed decisions, shaping a future where both nature and people thrive.

www.ceh.ac.uk / @UK_CEH /  LinkedIn: UK Centre for Ecology & Hydrology

If there's a bustle in your hedgerow, don't be alarmed now, It's just a spring clean for the May queen

New study reveals half a century of change on Britain’s iconic limestone pavements

Fifty years of change on iconic limestone pavements has revealed mixed fortunes for one of the most distinctive landscapes in the UK

Lancaster University

image:
Limestone pavement in the Yorkshire Dales
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Credit: Professor Carly Stevens

Fifty years of change on iconic limestone pavements has revealed mixed fortunes for one of the most distinctive landscapes in the UK.

The landscapes - which will be familiar to visitors to the Yorkshire Dales and fans of Harry Potter and the Deathly Hallows film – have, in many places, seen reductions of specialist species and more common less desirable species become more abundant.

However, it is not all bad news as the picture is very mixed across the UK’s areas of limestone pavement with some areas increasing in plant biodiversity.

The findings, which reveal large changes since the 1970s, are from the first national assessment in half a century of plants and vegetation in Britain’s rare and iconic limestone pavements, which was conducted by Carly Stevens, Professor of Plant Ecology at Lancaster University.

An internationally important habitat, Britain’s limestone pavements are predominantly found in the northern English counties of Yorkshire, Lancashire and Cumbria, as well as in North Wales and Scotland.

Plants, such as ferns and herbaceous species more commonly found in woodland, heathlands and grasslands, grow within the deep gaps and cracks in limestone pavements known as grikes, often creating a hidden world that you cannot see until you stand directly above them.

In the early 1980s laws were introduced to protect limestone pavement from quarrying, and many areas are now covered by nature reserve status.

However, despite being a rare and treasured landscape feature, and habitat to many specialised plants and wildlife, Britain’s limestone pavements have undergone few scientific studies.

To help address this, Professor Stevens repeated a limestone pavement survey undertaken by two scientists (Stephen Ward and David Evans) in the early 1970s.

Professor Stevens used the same methods to replicate the 1970s study as best as possible, surveying areas of limestone pavement totalling 3157 hectares across five years between 2017 and 2022.

Her study, which is published in the academic journal Functional Ecology, recorded 313 plant species across UK limestone pavements – an additional 29 species on the number recorded in the 1970s.

And some pavements saw the number of plant species living there, or species richness, increase.

However, despite many areas falling under the protection of nature reserves, some less desirable species, such as thistles, nettles and bracken, have increased in abundance across different limestone pavements in the UK. And Professor Stevens also found that important specialist species, such as primrose, lily of the valley, elder flower trees and hairy violet, have declined in abundance across UK limestone pavements.

However, these declines were not uniform and some of these species did see increases in some areas – adding to a complex, but important picture that will be invaluable information for conservationists.

“Limestone pavements have undergone large changes in the number and types of plants that live in these rare and spectacular habitats,” said Professor Stevens. “Limestone pavements are a habitat of high conservation value and they are protected for their unusual geology and the plants and animals that live in them.

“But if we are to conserve them for future generations, it’s important to understand why these changes have occurred.”

A major factor appearing to affect some limestone pavements is tree cover. Professor Stevens undertook aerial photography comparisons with historical aerial images for all the limestone pavements in England to compare how the number and size of trees had changed.

She found that some pavements had seen their area shaded by trees increase by more than 50%. Despite this the number of pavements without trees also increased, showing there’s a very mixed picture across different areas – often depending on the number of trees in the surrounding area.

Pavements where the numbers of trees and shrubs increased have commonly seen reductions in plant biodiversity. Professor Stevens believes this is probably due to trees and shrubs blocking off the light for smaller plants in among the grikes. Those pavements most affected by tree cover are found in Lancashire and Cumbria.

Those pavements that have low or moderate tree cover are more likely to have seen increases in species richness – though not necessarily with desirable specialist species.

Professor Stevens found many open pavements were impacted by grazing of animals, though there have been changes in the 50 years between surveys.

“Grazing pressure has declined in a lot of areas since the 1970s as a result of agricultural policy but there are still some pavements that are overgrazed,” said Professor Stevens. “Grazing can be an important tool in the management of limestone habitats but it needs to be carefully considered as overgrazing can result in a loss of biodiversity. Similarly, under-grazing can result in scrub and tree encroachment, which we see can also affect diversity and species composition as light levels are reduced.”

The survey will help to inform the future management of limestone pavements, an area that is still developing and will benefit from the survey results and additional data.

“At this stage we don't actually know what optimal management looks like for limestone pavements,” said Professor Stevens. “This survey provides vital data to help further understanding on what the current picture is for limestone pavement vegetation. However, we still need more research to help improve our knowledge on what the threats are to habitat and the potential for restoring damaged limestone pavements.”

The study is outlined in the paper 'Large changes in vegetation composition seen over the last 50 years in British limestone pavements'.

ENDS

Journal

Functional Ecology

DOI

10.1111/1365-2435.14684

Method of Research

Survey

Subject of Research

Not applicable

Article Title

Large changes in vegetation composition seen over the last 50 years in British limestone pavements

Article Publication Date

14-Nov-2024

Revolutionizing biology education: Scientists film ‘giant’ mimivirus in action

For the first time, we can see footage of a ‘giant’ virus as it infects a cell

Tokyo University of Science

Mimivirus-infected Acanthamoeba cell, visualized under a light microscope — image:
A single *Acanthamoeba* cell (top) is shown in these screenshots from a video. The diagram below depicts the viral infection process—the large green circle indicates *Acanthamoeba* cell membranes and the small orange circles represent *Mimivirus* particles.
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Credit: Masaharu Takemura from the Tokyo University of Science, Japan

The COVID-19 pandemic led to heightened public interest in learning about viruses and how they can cause diseases. There has been a lot of focus on communicating virology concepts to the general public in order to increase awareness about the spread and prevention of viral diseases.

When it comes to teaching biology, however, how do we explain microscopic processes like viral infections to students in the classroom?

In modern science education, seeing is believing—educators are now attempting to capture the attention of students by using eye-catching visuals and videos, instead of just relying on diagrams in a textbook. In the case of viruses, however, one major issue arises. Viruses typically cannot be seen under the familiar ‘light microscope’ available in school and university classrooms, requiring highly specialized and expensive equipment for visualization.

Now, in a study published in the Journal of Microbiology & Biology Education on November 8, 2024, a team led by Professor Masaharu Takemura at the Tokyo University of Science has successfully captured the viral infection process under a light microscope, creating a stunning video showcasing their results. The key to this process was a unique ‘giant’ virus known as Mimivirus. This research was co-authored by Ms. Kanako Morioka and Ms. Ayumi Fujieda at Tokyo’s Yone Production Co., Tokyo, Japan.

Mimivirus has a much larger particle size than most viruses and can actually be seen under a light microscope, making it an ideal candidate for use as an educational tool. The researchers sought to visualize how the Mimivirus infects a microbe called Acanthamoeba. It is difficult to visualize amoebae under a microscope since they are constantly moving in a liquid medium; therefore, they used a modified growth medium containing a jelly-like substance called agar. This growth medium also contained viruses which infected the amoebae, and after infection, the Acanthamoeba cells moving under the agarose gel gradually slowed down.

The researchers were able to film individual cells as they were infected; indeed, we can observe all the steps of the viral infection process in their footage. While healthy Acanthamoeba cells are initially moving around, they gradually slow down and come to a stop following Mimivirus infection. As the amoeba cells stopped moving, the researchers observed the development of a ‘virion factory’ inside the amoeba cell, which produced more ‘virions’ or viral particles. The infected cell ultimately dies as its membrane ruptures.

Prof. Takemura highlights the study’s innovation, saying, “For the first time in the world, we have succeeded in continuously visualizing the events that are believed to occur in viral infection over a long period of time—such as the proliferation of the virus, its release from cells, and the death of cells during the process.”

The film showing how a single Acanthamoeba cell is infected by Mimivirus was then screened in a biology classroom at the Tokyo University of Science and garnered positive reactions. The researchers observed that the movie influenced the perception of some students regarding viruses and seems to have shifted their views towards more scientific and biological perspectives.

This study also ensures that there is no violation of biological safety guidelines since the Acanthamoeba cells and viruses are grown in an appropriately equipped laboratory. The students in the classroom do not actually handle any of the equipment; the focus is only on screening the filmed video in a classroom setting.

Prof. Takemura is confident that this film will be a valuable tool for teaching biology, explaining that, “It enhances students' understanding of virus proliferation mechanisms and highlights the biological significance of viruses, their impact on host cell fate, and their role in ecosystems.”

Until now, viruses have remained hidden in the shadows, visible only through advanced technology—but this groundbreaking footage changes everything. We are sure that this one-of-a-kind footage will be invaluable to virology and science education experts around the world!

***

Reference

Title of original paper: Visualization of giant Mimivirus in a movie for biology classrooms

Journal: Journal of Microbiology & Biology Education

DOI: 10.1128/jmbe.00138-24

About The Tokyo University of Science

Tokyo University of Science (TUS) is a well-known and respected university, and the largest science-specialized private research university in Japan, with four campuses in central Tokyo and its suburbs and in Hokkaido. Established in 1881, the university has continually contributed to Japan's development in science through inculcating the love for science in researchers, technicians, and educators.

With a mission of “Creating science and technology for the harmonious development of nature, human beings, and society," TUS has undertaken a wide range of research from basic to applied science. TUS has embraced a multidisciplinary approach to research and undertaken intensive study in some of today's most vital fields. TUS is a meritocracy where the best in science is recognized and nurtured. It is the only private university in Japan that has produced a Nobel Prize winner and the only private university in Asia to produce Nobel Prize winners within the natural sciences field.

Website: https://www.tus.ac.jp/en/mediarelations/

About Professor Masaharu Takemura from Tokyo University of Science

Dr. Masaharu Takemura is a Professor in the Department of Mathematics and Science Education, Graduate School of Science at the Tokyo University of Science. His research interests include giant virus biology, viral eukaryogenesis, and virus education. Over his career, he has published more than 120 papers, amassing over 2,400 citations for his work. His research goal is to elucidate the evolution of giant viruses and eukaryotes and develop teaching materials for virus education.

Funding information

This research was partially supported by the JSPS/KAKENHI grant number 20H03078 to M.T.

Journal

Journal of Microbiology and Biology Education

DOI

10.1128/jmbe.00138-24

Method of Research

Experimental study

Subject of Research

Cells

Article Title

Visualization of giant Mimivirus in a movie for biology classrooms

Article Publication Date

18-Nov-2024

Robotic shorts support people when walking

TUM researchers develop shorts with motor power

Technical University of Munich (TUM)

Same concept as the electric bike, but for walking
Target groups are the elderly as well as people with cardiovascular conditions
Testers used up to 18% less of their own energy to cover a defined distance

Researchers at the Technical University of Munich (TUM) have developed robotic trousers that enable people to walk more easily while expending measurably less energy. The aim is to keep frail individuals and in particular the elderly mobile and healthy for longer. “You can walk slowly with the shorts but you can also jog,” says TUM Professor Lorenzio Masia. “We have developed a system that makes people want to move around more. It's the same concept as the electric bike, but for walking.”

According to the researchers' analyses, when a young person walks 500 metres up a hill with the aid of the robotic trousers, the expended energy – known as the metabolic cost – is reduced by 18% as compared to unaided walking. For an older person walking 400 metres on level ground, it is reduced by more than 10%. This is comparable to the effects of a reduction in body weight of ten or six kilograms. The researchers have also come up with a suitable name for their robotic shorts: WalkON.

When doctoral student Enrica Tricomi transitions from standing to walking, two thin, artificial tendons extending from the thigh to a waist belt pull upwards at the same time and relieve the hip flexors of some of their load. A measuring device attached to the tendons determines the hip angle and velocity. The device sends a signal to the motors precisely at the transition to the swing phase of walking. Regardless of whether an older person or a sporty teenager is wearing the robotic shorts: “The system recognises how fast or slowly the person is moving, adapts to the respective weight of the legs and provides individual support accordingly,” explains the researcher. Her smart robotic shorts do not require any pre-settings and can be put on, ready to use, in just a few minutes: truly plug-and-play.

Health factor: especially beneficial for older people

A questionnaire completed by participants indicated a strong sense of control, with respondents awarding a mean rating of well over 6 on a seven-point scale from zero (no control possible) to seven (very good control possible). “It is particularly important for older people to feel safe,” says Masia, who believes his system is especially useful for people who are somewhat frail but do not yet need a rollator.

The professor, who has just moved from the University of Heidelberg to the Munich Institute of Robotics and Machine Intelligence (MIRMI) at TUM as Deputy Director, sees older people as well as those weakened by illness, for example with a weak heart or lung disease, as a target group for development. “Walking helps them to improve their metabolism, which in turn may have a positive effect on their illness,” says Masia. The fact that users can be out and about for longer makes them more mobile and independent overall. This in turn can have a positive impact on their quality of life.

Vision: developing exoskeletons for leisure time

In contrast to systems that are already available in outdoor shops as so-called exoskeletons, this is not a rigid frame, but a soft garment. “WalkOn looks more like clothing and is no bigger than a small rucksack overall,” says doctoral student Enrica Tricomi, who has gradually developed the system into its present form over the past four years. Prof Lorenzo Masia is convinced that in the future, a modular system will be created that users can put together themselves: “In a few years, you will buy a pair of shorts, attach a motor to them and plug in two cables. The system will then be ready to take you into the mountains.”

Publication

Enrica Tricomi, Francesco Missiroli, Michelle Xiloyannis, Nicola Lotti, Xiaohui Zhang, Marios Stefanakis, Maximilian Theisen, Jürgen Bauer, Clemens Becker, Lorenzo Masia; Soft robotic shorts improve outdoor walking efficiency in older adults; Nature Machine Intelligence, 2024; https://www.nature.com/articles/s42256-024-00894-8

Additional information:

The robotic trousers ‘WalkON’ are ready to wear within a minute. TUM scientist Enrica Tricomi demonstrates in a video how to put them on: https://youtu.be/6Ns3oFUqzu0

Additional material for media outlets:

Photos:
- https://mediatum.ub.tum.de/652209?show_id=1761659
- https://mediatum.ub.tum.de/652209?show_id=1761660

Subject matter expert

Prof. Lorenzo Masia

Deputy Director of Munich Institute of Robotics and Machine Intelligence (MIRMI)

Chair for Intelligent BioRobotics Systems

Technical University of Munich (TUM)

Lorenzo.masia@tum.de

TUM Corporate Communications Center contact:

Andreas Schmitz

0162-27 46 193

presse@tum.de

Journal

Nature

DOI

10.1038/s42256-024-00894-8

Method of Research

Experimental study

Subject of Research

People

Article Title

Soft robotic shorts improve outdoor walking efficiency in older adults

Walk this Way’: FSU researchers’ model explains how ants create trails to multiple food sources

Florida State University

It’s a common sight — ants marching in an orderly line over and around obstacles from their nest to a food source, guided by scent trails left by scouts marking the find. But what happens when those scouts find a comestible motherlode?

A team of Florida State University researchers led by Assistant Professor of Mathematics Bhargav Karamched has discovered that in a foraging ant’s search for food, it will leave pheromone trails connecting its colony to multiple food sources when they’re available, successfully creating the first model that explains the phenomenon of trail formation to multiple food sources.

Karamched, who also serves as faculty in FSU’s Institute of Molecular Biophysics, and music arts administration graduate student Sean Hartman, published “Walk This Way: Modeling Foraging Ant Dynamics in Multiple Food Source Environments” in the Journal of Mathematical Biology in September.

“The power of mathematics is that we can devise models that reproduce experimentally observed data and make concrete predictions about what will happen next,” Karamched said. “In this case, we uncovered something that hasn’t been described well by other models: if an ant has access to multiple food sources from its nest, it will initially make multiple trails to each of the sources.”

Karamched uses modeling, mathematical analysis and computer simulations to understand and solve problems in neuroscience and cell biology. Hartman, who earned dual bachelor’s degrees from FSU’s Department of Mathematics and College of Music in May 2023 and expects to complete his graduate studies this spring, approached Karamched about assisting with a Directed Individual Study (DIS). DIS allows students in FSU’s Honors Program to work one-on-one with faculty mentors in an open-ended, hands-on research experience and would allow Hartman to be more involved with mathematical modeling.

“I wanted to pursue research in mathematics, as I’ve had a lifelong interest in the subject, but never had the opportunity to take part in math-based research until now,” Hartman said. “I was intrigued by ant trail research that Dr. Karamched shared with me and became interested in pursuing further research on it and creating models based on this previous work.”

Foraging for resources is an essential process for the daily life of an ant colony, and ants will self-organize using chemical pheromones. Once an ant detects a food source, it secretes a chemical trail to lead other ants to the source. Using computational simulations of ants searching for food, stochastic modeling and a system of partial-differential equations, the researchers also observed that over time, ants will selectively travel to the food source that is the shortest distance from its nest in an environment with multiple sources.

“For this research, we divided the ants into two subpopulations: foragers and returners,” Karamched said. “These subpopulations behave differently, as foragers tend to wander around in search of food while returners always return directly to the nest after finding food, making their motion less stochastic or random. This allows us to predict with 100 percent certainty what they’re doing or where they would go.”

The team, including collaborator Shawn Ryan, associate professor in the Department of Mathematics and Statistics at Cleveland State University, considered the concentration of chemical pheromones that the ants secreted, signaling to other ants where food is. The probability of their models was based on the dynamics of these pheromones. The returning ants would secrete less pheromones depending on how close the food source was to the nest. More pheromones created a stronger scent for the ants to follow, a critical factor when the food source is located far from the nest.

“Once my code was fully tested and accurate, multiple trail formations became distinct and were easily understandable,” Hartman said. “It was so cool to see how equidistant food sources could maintain multiple food trails as an equilibrium. If one food source was just slightly closer to the ants’ nest, the ants would eventually form one singular trail to the closest source. It was at this moment that it felt all our hard work finally paid off.”

The model in this paper was designed to be simple and applicable to other organisms and biological systems that use pheromones as a form of communication, including bacteria, slime molds, other insects, fish, and even some reptiles and mammals.

“The framework for analyzing this collective behavior resides in the fundamental pheromone concentration gradient, then working from there,” Karamched said. “From a microbial level to complex organisms, using this chemical signaling to communicate allows certain organisms to coordinate activity on huge spatial scales, which is fascinating.”

To learn more about Karamched’s research and the FSU Department of Mathematics, visit math.fsu.edu

Sean Hartman, a dual bachelor's degree graduate from FSU's Department of Mathematics and College of Music, is set to complete his graduate studies this spring.

Credit

Courtesy of Sean Hartman

ematical modeling, Karamched and Hartman’s model shows that upon finding two food sources at an equal distance from their nest, ants will travel to both sources equally.

Credit

Courtesy of Bhargav Karamched, Sean Hartman

Journal

Journal of Mathematical Biology

DOI

10.1007/s00285-024-02136-2

Article Title

Walk this way: modeling foraging ant dynamics in multiple food source environments

New study shows how salmonella tricks gut defenses to cause infection

University of California - Davis Health

A new UC Davis Health study has uncovered how Salmonella bacteria, a major cause of food poisoning, can invade the gut even when protective bacteria are present. The research, published in the Proceedings of the National Academy of Sciences, explains how the pathogen tricks the gut environment to escape the body's natural defenses.

The digestive system is home to trillions of bacteria, many of which produce short-chain fatty acids (SCFAs) that help fight harmful pathogens. But Salmonella manages to grow and spread in the gut, even though these protective compounds are present. The study asks: How does Salmonella get around this defense?

“We knew that Salmonella invades the small intestine, although it is not its primary site of replication. The colon is,” said the lead author of the study Andreas Bäumler. Bäumler is a UC Davis distinguished professor and vice chair of research in the Department of Medical Microbiology and Immunology.

Bäumler and his team discovered that the answer lies in how the pathogen changes the gut’s nutrient balance. When Salmonella enters the small intestine, it causes inflammation in the gut lining and disrupts the normal absorption of amino acids from food. This creates an imbalance in nutrients in the gut.

The imbalance gives Salmonella the resources it needs to survive and multiply in the large intestine (colon), where beneficial bacteria usually curb its growth. The study showed that salmonella causes inflammation in the small intestine in order to derive nutrients that fuel its replication in the colon.

Salmonella alters gut nutrient environment to survive

Using a mouse model, the team looked closely at how Salmonella changed the chemical makeup of the gut. They traced amino acid absorption in the small and large intestines.

They found that in mice that were infected with Salmonella, there was less absorption of amino acids into the blood. In fact, two amino acids, lysine and ornithine, became more abundant in the gut after infection. These amino acids helped Salmonella survive by preventing the growth-inhibiting effects of SCFAs. They did this by restoring Salmonella’s acidity (pH) balance, allowing the pathogen to bypass the microbiota’s defenses.

“Our findings show that Salmonella has a clever way of changing the gut’s nutrient environment to its advantage. By making it harder for the body to absorb amino acids in the ileum, Salmonella creates a more favorable environment for itself in the large intestine,” Bäumler said.

In the study, the team showed that Salmonella uses its own virulence factors (disease causing molecules) to activate enzymes that break down key amino acids like lysine. This helps the pathogen avoid the SCFAs’ protective effects and grow more easily in the gut.

New insights could lead to better gut infection treatments

The new insights potentially explain how the gut environment changes during inflammatory bowel disorders , such as Crohn's disease and ulcerative colitis, and could lead to better treatments for gut infections. By understanding how Salmonella changes the gut environment, researchers hope to develop new ways to protect the gut microbiota and prevent these infections.

“This research uses a more holistic approach to studying gut health. It not only gives us a better understanding of how Salmonella works, but also highlights the importance of maintaining a healthy gut microbiota,” said Lauren Radlinski, the study’s first author and postdoctoral fellow in the Bäumler Lab. “Our findings could lead to new treatments that help support the microbiota during infection.”

The study’s results could inspire future treatments, including probiotics or dietary plans designed to strengthen the body’s natural defenses against harmful pathogens.

“By learning how a pathogen manipulates the host’s system, we can uncover ways to boost the host’s natural defenses,” Radlinski said.

Coauthors of the study are Andrew Rogers, Lalita Bechtold, Hugo Masson, Henry Nguyen, Anaïs B. Larabi, Connor Tiffany, Thaynara Parente de Carvalho and Renée Tsolis of UC Davis.

Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2417232121

Article Title

Salmonella virulence factors induce amino acid malabsorption in the ileum to promote ecosystem invasion of the large intestine

Article Publication Date

15-Nov-2024

Excessive screen time linked to early puberty and accelerated bone growth

Bioscientifica Ltd

Exposure to blue light, like that from smartphones or tablets, may accelerate bone growth and bone age, leading to early puberty in rats. This research, presented at the 62nd Annual European Society for Paediatric Endocrinology Meeting in Liverpool, sheds light on how the use of blue light-emitting devices could impact growth and development and raises important questions about the long-term health effects in children, who are increasingly exposed to screens from a young age.

As children grow and develop, long bones such as the femur progressively elongate at each end. These growing ends – areas of smooth, elastic cartilage known as ‘growth plates’ – eventually solidify which stops growth in height. Girls generally stop growing and reach their maximum height between ages 14 and 16, while boys finish their growth between 16 and 18 years of age. However, in recent years, several studies have reported a rise in early puberty in both girls and boys, in which they might grow quickly at first but often stop growing earlier than usual. One factor may be the increased use of blue light-emitting devices.

In this study, researchers from Gazi University in Turkey examined 18 male and 18 female rats aged 21-days-old, equally divided into three groups of six and exposed to either a normal light cycle, six hours or 12 hours of blue light until the first signs of puberty. They measured their length and femurs and found that the rats exposed to blue light had a faster growth, particularly in their bones, and started puberty earlier compared to those in standard light conditions.

Previous research from the same group has also shown that rats exposed to blue light have a higher risk of early puberty. However, this association has never been studied in bone growth and pubertal development before. “This is the first study to show how blue light could potentially influence physical growth and development, prompting further research into the effects of modern screen exposure on children’s growth,” said lead researcher Dr Aylin Kılınç Uğurlu.

Although Dr Kılınç Uğurlu warned: “As this a rat study, we cannot be sure that these findings would be replicated in children but our data suggest that prolonged exposure to blue light accelerates both the physical growth and maturation of the growth plate, leading to early puberty.”

“While the increased growth may sound beneficial, our study also found that blue light exposure led to earlier structural changes in the growth plates of the rats’ bones, suggesting an impact on long-term bone age,” said Dr Kılınç Uğurlu. “This means their bones matured too soon which could potentially cause them to be shorter than average as adults.”

The researchers are now planning to investigate how blue light exposure before puberty affects height and skeletal development in adult rats. “We want to explore the long-term effects of pre-pubertal blue light exposure and find out whether certain exposure durations or intensities have reversible or permanent effects on the skeleton later in life,” said Dr Kılınç Uğurlu. “Ultimately, this research could lead to preventative measures for safe screen use during childhood development.”

Method of Research

Randomized controlled/clinical trial

Subject of Research

Animals