In Cordoba, the grass pollen season has grown longer over the last 23 years

A study analyzes the relationship between pollen and meteorological data spanning 23 years, verifying how the wind impacts each phase of the pollen season differently, thereby helping to manage and prevent allergy seasons

University of Córdoba

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A multidisciplinary study conducted by the Aerobiology and Physical Systems Modeling and Simulation research groups at the University of Cordoba has verified how the pollen season of grasses, a family of plants made up of thousands of species, and whose pollen is the most frequent cause of respiratory allergies, has been getting longer. Specifically, almost 4 more days each year, as flowering begins earlier and ends later.

The team confirmed this after analyzing daily pollen concentrations spanning 23 years and correlating them with meteorological variables such as temperature, rainfall and, mainly, wind patterns.

Although the temperature and previous rains lengthen the pollen season, the team found that wind is a key factor in understanding day-to-day differences in the amount of this type of pollen in the air, and its origin. As researcher Herminia García Mozo states: “wind analysis is important to explaining the behaviour of pollen season characteristics.”

This study analyzes wind behavior through the combined use of meteorological models and observations. By calculating air mass back-trajectories — a meteorological tool that estimates the prior path of an air mass through the atmosphere before reaching a given area — and using wind speed data, the team has characterized wind dynamics more comprehensively and confirmed how wind influences the two main phases of the pollen season differently: one prior to and one following the moment of peak pollen concentration in the atmosphere.

During the prior phase, winds tend to be mild, on average, and air masses travel short distances, which favors pollen accumulation near its source. In the later phase, however, the wind moves at higher average speeds, and the air masses travel further, which, combined with the concentration data, suggests contributions from more distant areas. That is, the wind helps to concentrate the pollen at the beginning and favors its transport/dispersion at the end of the pollen period.

Understanding that pollen dynamics change according to the phase of the season allows us to lay the foundations to prevent and manage allergy seasons more precisely. As researcher Miguel Ángel Hernández Ceballos explained: “in this study we are assessing the past to try to anticipate the future scenarios that we may encounter. The more years we study, the better we can track pollen concentrations and the relationship  established between all the factors involved. This will allow us to establish scenarios and anticipate actions.”

By determining these patterns and their variability it is possible to foresee whether a season will be more intense or last longer than usual. In this way, the alert systems for allergy sufferers can be improved, and preventive measures can be taken earlier.

Reference

M.A. Hernández-Ceballos, R. López-Orozco, M.J. Tenor-Ortiz, C. Galán, H. García-Mozo, “Wind dynamics drive the changes of the 2001–2023 grass pollen seasons in Córdoba (southern Spain)”, Agricultural and Forest Meteorology, Volume 378, 2026, 110955, ISSN 0168-1923, https://doi.org/10.1016/j.agrformet.2025.110955.

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Journal

Agricultural and Forest Meteorology

DOI

10.1016/j.agrformet.2025.110955. 

Article Title

Wind dynamics drives the changes of the 2001–2023 grass pollen seasons in Córdoba (southern Spain)

 

Traumatic brain injury can lead to higher probability of work disability

Uppsala University

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Elham Rostami, Adjunct Senior Lecturer at the Department of Medical Sciences and Specialist in Neurosurgery, Uppsala University Hospital.

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Credit: Mikael Wallerstedt

People affected by traumatic brain injury (TBI) have an increased risk of work disability that can recur even years after the injury, regardless of its severity. This has been shown in a new national registry study from Uppsala University in collaboration with Karolinska Institutet (KI) and is based on close to 100,000 people with a traumatic brain injury.

TBI is caused by trauma to the head and can happen when a person falls or is in a traffic accident, for example. In the current study, the researchers investigated the relationship between TBI and work disability (sickness absence and disability pension or activity compensation).

“The results indicate that people who suffer from a traumatic brain injury often have lasting difficulties. Even minor injuries can affect their ability to be gainfully employed in the long term. People who have difficulty returning to work after a traumatic brain injury may need long-term, multidisciplinary care, where medical, psychiatric, social and work-related factors are assessed in combination,” says Elham Rostami, specialist in neurosurgery and the responsible researcher.

Based on data from close to 100,000 people living in Sweden

The study included nearly 100,000 people who had suffered a TBI and nearly one million people who had not suffered a TBI. The follow-up period was for up to five years.

The researchers categorised the severity of the TBIs into three groups based on the type of hospitalisation required:

• The person presented to the emergency ward and/or was admitted for observation for 1-2 days.
• The injury required more than two days in hospital.
• The injury required neurosurgery.

Greater probability of work disability

All three groups had a higher probability of work disability compared to people without a TBI. During the five-year period, 45–72 per cent of the people with a TBI had had at least one period of work disability.

In the group without a TBI, the corresponding figure was 26 per cent.

In the case of more severe TBI, the probability of work disability was high immediately after the injury, while in the milder cases this risk increased more gradually during the follow-up period.

“We could see that even people with milder injuries had an increased risk of work disability and that it did not necessarily happen directly after the injury; it could also happen later. This may be due to the person returning to work, but when challenges arise later on, the person realises that they are unable to function as they did before the injury,” says Andrea Klang, doctoral student, specialist in rehabilitation medicine and the study’s lead author.

Higher age a factor in work disability

In all groups, being older carried an increased risk of work disability. In all groups, except those with the most severe TBI, it was found that people with psychiatric disorders or who had had periods of work disability before their TBI were more likely to transition to work disability following the TBI.

“Our study shows that the healthcare system needs to be more aware of the patients who do not recover fully and examine what support they need. They may also need support for a longer period of time – not just directly after the injury,” says Andrea Klang.

Facts

The study is based on data from the National Patient Register (NPR), Total Population Register, Longitudinal Integrated Database for Health Insurance and Labor Market Studies, the Cause of Death register, and the Micro-Data for Analysis of the Social Insurance System (MiDAS), which is a database that contains detailed information about sickness absence, activity compensation and disability pension for people in Sweden.

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Journal

Neurology

DOI

10.1212/WNL.0000000000214674 

Method of Research

Observational study

Subject of Research

People

Article Title

Five-Year Follow-Up of Work Disability After Traumatic Brain Injury

Article Publication Date

11-Feb-2026

 

A Pitt-Johnstown professor found syntax in the warbling duets of wild parrots

How wild birds use language has long flown under the radar — but now Christine Dahlin’s research is moving scientists closer to understanding

University of Pittsburgh

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Professor Christine Dahlin and colleagues combined fieldwork, manual sorting and machine learning to begin to decode the warble duets of mated Yellow-naped Amazon parrots, a critically endangered species with a habitat that stretches from southern Mexico to southern Costa Rica.

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Credit: JD Gilardi, World Parrot Trust

With a few minutes of searching, anyone can find videos online of chatty birds: macaws talk to their keepers, cockatoos sing to the camera, corvids mimic the jarring sounds of construction sites.  

Research has shown that some birds can understand and use words in context — so, when Polly speaks up from inside her cage, she may really want a cracker — but scientists know far less about how birds use their vocal abilities in the wild. Christine Dahlin, professor of biology at the University of Pittsburgh at Johnstown, is working to change that. 

“Ultimately I really want to understand how these birds are communicating in the wild,” she said. “I want to know what they are saying, and how they are saying it.”

In one of the first steps to figuring this out, Dahlin and colleagues combined fieldwork, manual sorting and machine learning to begin to decode the warble duets of mated Yellow-naped Amazon parrots, a critically endangered species with a habitat that stretches from southern Mexico to southern Costa Rica. The researchers found these duets have language-like properties, including syntax, collocates and an impressive lexicon.   

The work was published in the Journal of Avian Biology. 

Contact Professor Christine Dahlin at cdahlin@pitt.edu

Why warble?

Dahlin previously studied a less complex type of duet, a “standard duet” made up of far fewer notes, and found it had syntax and other rules. It was unclear whether warble duets, which draw from a much larger repertoire of notes, had similar rules.

“One hypothesis is that maybe warble duets have different notes simply to show their prowess,” Dahlin said. Yellow-naped parrots use these more complex vocalizations when they are fighting for territory. “So maybe the point is just to have a lot of variety — or maybe it’s something else entirely.” 

Some research suggests songbirds will match or not match another bird’s notes during a counter-duet to either escalate or de-escalate a situation. Dahlin was curious about the possibility, but soon realized she couldn’t study the warble duet matching patterns until she knew how many call types the birds were actually using. 

“That started this whole process.” 

In the field

Dahlin and field assistants made several trips to Costa Rica over three years to gather the data they needed. “We’d sit with an old-school video camera and directional microphone and wait for the birds to arrive at their territories,” Dahlin said of sitting in cattle pastures and observing large trees where the birds bred.

“The warble duets would get really fast and really loud when there was a territory dispute,” Dahlin said. “They just sounded very irate and like they were getting in each other’s faces. You could tell the context was changing.” The few physical altercations Dahlin caught in the wild were all preceded by warble duets.

It was, she said, studying animal behavior in its purest form. “Just recording the animals and then seeing what kind of behaviors they have.”

It took more than 10 years for Dahlin and undergraduate students to parse such a massive amount of data, especially with other projects to pursue. Ultimately, they found that of the hundreds of duets recorded, about 50 were warble duets from 13 pairs of parrots. Altogether, the warble duets contained more than 450 calls.

Flexible complexity

Standard duets consist of four call types. In the warbling duets, researchers identified 36 types of calls. 

“There are actually more than 36,” Dahlin said. “Some were rare, some only appeared once, so we didn’t even put them into a category.” 

The researchers needed a way to identify syntactic rules structuring this new, larger set of calls.  Owen Small (UPJ ’19) brought an idea to the team. He’d been using a program called Voyant Tools in a humanities class that he suggested might be useful. “We have this program we’re using to analyze literature,” he said. “Do you think we could use it for the birds?”

They gave it a try. “Voyant was able to run the same analysis as if it were a body of writing,” Dahlin said. “And the results show the parallels between these complex signals the birds are giving and our own language.”

Significantly, Dahlin said, they found what are known in human language as collocates, words that are often paired together — for example, “eat” and “food” or “grass” and “green.” 

The group uncovered more than 20 syntactic rules that the duets followed. Even so, there was very little repetition within a duet, which lasted for 5-10 seconds. “This shows that the parrots are being very precise,” Dahlin said. “They are not simply throwing random notes around.” 

This flexibility bound by rules indicates birds of a pair are taking part in an elaborate calculus.  

“They’re making multiple decisions,” Dahlin said. “Are they going to duet at all? If so, what kind? And what notes are they giving? All of this is happening very rapidly, and they have to do it in coordination with their partner.”

Next, Dahlin plans to return to the disregarded data, of both the warble and standard duets, to learn more about counter-duetting between pairs of Yellow-naped parrots. She also studies the birds’ dialects and other kinds of vocalizations and has plenty of questions about those aspects of their communication. Luckily, she said, “I’ve got years of sound recordings to dive into.”

Warbling duet [AUDIO] 
 

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Journal

Journal of Avian Biology

DOI

10.1002/jav.70016 

Method of Research

Observational study

Subject of Research

Animals

Article Title

Decoding parrot duets: complex communication in yellow-naped amazons

Article Publication Date

12-Feb-2026

 

Artificial wetlands to protect water quality

Research conducted by the UPV shows that artificial wetlands improve water quality and enable agricultural waste to be transformed into usable resources

Universitat Politècnica de València

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On the occasion of World Wetlands Day, the Institute of Water and Environmental Engineering (IIAMA) at the Universitat Politècnica de València highlights the importance of these ecosystems as key tools for improving water quality, protecting soil and mitigating diffuse pollution, as well as the role of scientific research in developing sustainable, nature-based solutions.

In this context, they have recently developed a scientific study, within the framework of the TED2021 Rainwetpipa project funded by PRTR funds, which analyses the hydraulic behaviour and purifying capacity of the 'Tancat de la Pipa' free-surface artificial wetland in the Albufera de València Natural Park when it receives urban and agricultural runoff.

'The results of the study confirm that artificial wetlands function as buffer systems, capable of mitigating pollution peaks and significantly improving water quality, even when they receive variable pollutant loads and have not been specifically designed for that purpose,' says Adrián Martínez, a researcher at IIAMA who participated in the study.

The research was carried out by Adrián Martínez-Biosca, Carmen Hernández-Crespo, Enrique Asensi, Ignacio Andrés-Doménech, Vicent Benedito-Durá and Miguel Martín, researchers at IIAMA-UPV, together with Mª Eugènia Rodrigo-Santamalia, a researcher at the Research Institute for Mediterranean Agroforestry of the UPV.

Conclusions of the study

Among the main conclusions, they highlight the high retention capacity of suspended solids, reaching values close to 80% of the incoming material, due to natural sedimentation.

Likewise, the wetland showed a significant reduction in ammoniacal nitrogen, driven by dilution, retention, and biogeochemical transformations, such as nitrification, which are essential for protecting aquatic ecosystems from eutrophication.

The study also emphasises the importance of hydraulic design in artificial wetlands, demonstrating that configurations with multiple cells in parallel improve water residence time and treatment efficiency.

'These results provide relevant technical criteria for the design and optimisation of new green infrastructure aimed at treating contaminated water,' says Carmen Hernández, an IIAMA researcher participating in the study.

Potential for the application of constructed wetlands

This scientific knowledge is directly applied in initiatives such as the VALPURIN project (Development of nature-based solutions for the sustainable treatment of slurry and subsequent recovery of its fractions), funded by the Valencian Innovation Agency (2023), in which IIAMA-UPV, Global Omnium and Servyeco are participating.

The aim of the project is to minimise the environmental impact of agricultural waste on soil and water resources by developing and validating innovative treatment processes.

'VALPURIN is committed to the use of artificial wetlands as Nature-Based Solutions, allowing slurry to be transformed into new usable resources and moving towards circular economy models, contributing to the sustainable development of the agricultural and livestock sector and the mitigation of the effects of climate change,' says Miguel Martín, who conducts research at IIAMA.

Overall, IIAMA reaffirms its commitment to applied research, knowledge transfer and the development of sustainable solutions that contribute to the protection of aquatic ecosystems and more efficient water resource management.

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Journal

Ecological Modelling

DOI

10.1016/j.ecolmodel.2025.111468 

Subject of Research

Not applicable

Article Title

Hydrodynamic and water quality modelling of a free water surface constructed wetland for urban runoff mitigation

Article Publication Date

1-Apr-2026