It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Sunday, September 06, 2026
COVID's toll on kids was milder than predicted, six-country study finds
Setbacks were concentrated among children already facing other risks; most children recovered
Six years after COVID-19 disrupted childhood around the world, new research following the same children from before the pandemic through today finds that the damage was far less widespread than early warnings predicted. A Special Section in the journal Child Development, synthesizing 17 long-term studies across six countries, finds that most children's health, learning, social development, and wellbeing recovered substantially. Setbacks that persisted were concentrated among children who already faced other risks before the pandemic began.
Early studies of COVID-19, based on short-term data collected during the pandemic itself, warned of widespread and lasting harm to child development. This new research, tracking children over a longer period, tells a different story: pandemic impacts were real and wide-ranging, but not as severe as initially feared, and many effects weakened over time. The children who fared worst and recovered more slowly were disproportionately those shaped by pre-existing risks — not the pandemic alone.
These findings are featured in the Society for Research in Child Development's flagship journal, Child Development, in a Special Section on COVID-19 titled "Children's Developmental Trajectories in the Long Shadow of COVID-19." The Special Section is led by co-editors Anna D. Johnson (Georgetown University), Gabriela Livas (University of Texas, Austin), and Seth Pollak (University of Wisconsin-Madison).
"Overall, the evidence in this special section challenges dominant narratives of universal 'learning loss,' suggesting instead that COVID-19 interacted with existing inequalities," said co-editor Anna Johnson from Georgetown University. "The research highlights the resilience in children and shows the importance of context in shaping their physical, cognitive, and emotional skills over time."
The Society for Research in Child Development advances the developmental sciences and promotes the use of developmental research to improve human lives.
For additional information, or interviews with authors of specific studies, please contact SRCD's Public Relations lead, Jessica Efstathiou: jefstathiou@srcd.org.
Journal
Child Development
Subject of Research
People
Article Title
Children’s Developmental Trajectories in the Long Shadow of COVID-19
To promote climate action, emotion matters more than information
A UNIGE study shows that campaigns designed to appeal to people’s emotions are more likely to inspire climate action
What types of communication are most effective in motivating people to take action on climate change? To find out, a team from the University of Geneva (UNIGE) reviewed a vast body of research from Switzerland and abroad examining the impact of different climate communication campaigns. The findings suggest that messages designed to evoke emotions – such as a sense of wonder at the beauty of a landscape – are more effective than simply presenting scientific facts. By contrast, messages emphasising individual and collective responsibility appear to have little or no effect. Published in the Journal of Environmental Psychology, these findings offer practical guidance to public authorities and organisations seeking to communicate more effectively about climate change.
Every year, public authorities and non-governmental organisations spend millions on communication campaigns designed to encourage people to take action on climate change. But which strategies work best? Should campaigns rely on fear or positive messages, prioritise facts or appeal to emotions, and focus on words or visuals?
A team from UNIGE’s Consumer Decision and Sustainable Behavior Lab, part of the Faculty of Psychology and Educational Sciences and the Swiss Center for Affective Sciences, has conducted the first large-scale study of its kind. The researchers analysed and synthesised the findings of 71 studies examining the impact of specific climate communication strategies, drawing on data from a total of 216,000 participants.
Almost all strategies have a positive effect
The strategies reviewed encompassed 15 different approaches, ranging from providing factual information to fill knowledge gaps to appealing to emotions – for example, by evoking a sense of wonder or awe at the beauty of nature. They also included approaches based on the principle of bounded rationality, which are designed to facilitate decision-making by highlighting specific aspects of climate change, such as its health or financial consequences.
"Our research shows that almost all of these strategies are likely to have a positive effect on people’s intentions and behaviours, as well as on their support for climate policies," explains Tobias Brosch, director of the laboratory, who led the study with Mario Herberz, a postdoctoral researcher. “Only strategies based on individual and collective responsibility – with messages such as ‘success depends largely on you’ – appear to have little or no effect. They may even foster reactance.”
Stories rather than facts
But not all effective strategies are equally effective. “Campaigns that evoke a strong emotional response – particularly through storytelling or by inspiring a sense of wonder at the beauty of nature – are significantly more effective than simply presenting facts and scientific evidence. Messages that draw on moral, ethical or even religious considerations, highlighting our connection to something greater than ourselves that we have a responsibility to preserve, also achieve better results.”
The researchers also found that messages are more effective when they include images.
“Despite these differences, the fact that almost all of these strategies can have a positive effect is encouraging,” says Tobias Brosch. “This is particularly encouraging given that the studies reviewed mainly measured the effects of messages to which people were exposed only once. Yet we know that repeated exposure can strengthen their impact. At a time when the scientific evidence is well established and the challenge is to turn knowledge into action, there is considerable scope to improve climate communication.”
Peter Puschnig (centre) with PhD student Siegfried Kaidisch (left) and postdoctoral researcher Christian Kern from his research group at the University of Graz
Physicists at the University of Graz (Austria), in collaboration with colleagues from Marburg University and Forschungszentrum Jülich (Germany), have achieved a scientific breakthrough. For the first time, the generation of electrical energy from light has been filmed and described theoretically. This work is of far-reaching significance, not least for optimising sustainable energy production from photovoltaics. This is because it provides fundamental building blocks for understanding the physical processes that take place, for example, in organic solar cells. The paper was published in the journal Physical Review X, one of the world’s most prestigious physics journals.
Whether in solar cells or during photosynthesis – when light strikes a surface, its particles, the photons, are absorbed by the material and thereby energise electrons. In the process, their spatial distribution – the so-called wave function – changes, and a bond is formed between an electron and the resulting electron hole. These ‘excited pairs’ are known as excitons. They play a key role in modern optoelectronic materials. However, although they have been known for decades, their internal quantum-mechanical structure has remained largely hidden until now. “We have now succeeded for the first time in experimentally reconstructing the spatial distribution and temporal evolution of an exciton’s wave function in the very first moments of its existence,” reports Peter Puschnig, Professor of Electronic Structure of Nanomaterials at the Department of Physics, University of Graz. “The measurements show that, after its formation, the electron-hole pair extends across approximately three molecules and then shrinks by around 25 per cent within the first 400 femtoseconds – a quadrillionth of a second,” explains the researcher.
To film this process, the scientists first excited the exciton with an ultrashort light pulse and then ejected the electrons from the pair bond using a second high-energy laser pulse. The latter process is as known photoemission. “If we then measure the energy and direction of the electrons, theoretical models allow us to infer their quantum-mechanical state. By varying the time delay between the excitation and the subsequent laser pulse, one obtains different snapshots of the exciton, which can be pieced together to form a video of the quantum world,” explains Puschnig.
Leading international research
The work was carried out in close collaboration between three leading international research groups. Stefan Tautz and his team at Forschungszentrum Jülich produced the organic semiconductor samples, characterised them and transported them to Marburg under ultra-high vacuum conditions, ensuring that their exceptional quality was maintained right up to the measurement. “The samples consist of wafer-thin, ordered films of the rod-shaped 6T molecule that have been deposited onto a specially prepared copper surface. The precise alignment of the molecules and their targeted decoupling from the substrate are important for maintaining the exciton long enough to make its formation visible,” explains Monja Stettner, who prepared the samples as part of her dissertation and assisted with the experiments in Marburg. The group led by Ulrich Höfer at Marburg University carried out the high-precision photoemission experiments and analysed the measurement data.
At the University of Graz, Peter Puschnig’s team developed the theoretical concepts for describing photoemission from excitons, carried out the quantum mechanical simulations and developed an analytical model that enabled the interpretation of the experimental data. “Using our model, it is possible to deduce the spatial shape and the internal quantum-mechanical phase of the exciton wave function directly from measured photoelectron images,” explains Siegfried Kaidisch, who made a key contribution to this work as part of his PhD thesis.
The experimental method underlying the research – Photoemission Orbital Tomography (POT) – was also developed in Peter Puschnig’s group and has, in recent years, been expanded in collaboration with Stefan Tautz’s team at Forschungszentrum Jülich into an internationally established tool for investigating electronic states in organic materials.
EU research project
The current publication marks one of the most significant milestones to date in the EU project ‘Orbital Cinema’. Funded by an ERC Synergy Grant, the research project aims to visualise the dynamics of electrons in materials with unprecedented spatial and temporal resolution. “In the next step, we want to observe the separation of electrons and holes in so-called donor-acceptor systems. This process determines how efficiently light can be converted into electrical current and is therefore central to future developments in organic photovoltaics,” says Puschnig.
https://orbital-cinema.eu/
Publication
Observing the spatial and temporal evolution of exciton wave functions in organic semiconductors
Marcel Theilen, Siegfried Kaidisch, Monja Stettner, Sarah Zajusch, Eric Fackelman, Alexa Adamkiewicz, Robert Wallauer, Andreas Windischbacher, Christian S. Kern, Michael G. Ramsey, François C. Bocquet, Serguei Soubatch, F. Stefan Tautz, Ulrich Höfer, and Peter Puschnig
In time-resolved Photoemission Orbital Tomography, a pump laser pulse (blue) generates a bound electron-hole pair (exciton) in the organic semiconductor material alpha-sexithiophene. The subsequent high-energy UV laser pulse ejects an electron from the exciton, and the energy and direction of this electron are measured.
The measured energy and angular distributions of the emitted electrons allow the exciton wave functions to be reconstructed. It is observed that the size of the exciton shrinks by 25 per cent over the first 400 femtoseconds, from an initial value of approximately 1.5 nanometres.
The evolution of an exciton: The animation is based on data calculated using the model developed by Peter Puschnig’s research group at the University of Graz. It shows an amplified version of what was measured in the experiment, in order to make the processes more clearly visible. In principle, however, the wave function (right) can be inferred from experimental photoemission data (left).
Credit
Siegfried Kaidisch, University of Graz
Post-combustion reaction model for aluminum in thermobaric effects field
(1) Through systematic experimentation and theoretical investigation, this work elucidates the underlying mechanism of the afterburning effect and proposes effective enhancement strategies.
(2) The dynamic evolution characteristics of the explosion fireball morphology as a function of time are revealed for TNT and thermobaric explosives.
(3) Integrating theoretical analysis, numerical modeling, and experimental results to elucidate the afterburning reaction mechanisms and quantify the combustion extent of aluminum powder under thermobaric conditions.
Credit: Wen-xiang Bian, Hai-jun Zhao, Jian Li, Bo-liang Wang and Ya-ning Li
Introduction
Thermobaric explosives generate their characteristic effects through the coupling of detonation, metallic-fuel combustion and subsequent interactions with oxygen in the surrounding environment. Yet the role of aluminum post-combustion in sustaining the high-temperature blast field has remained difficult to quantify.
In a study published in Energetic Materials Frontiers, Wen-xiang Bian and co-workers compared two CL-20-based thermobaric formulations containing different potassium perchlorate contents with volume-equivalent TNT charges. Their experiments tracked fireball temperature, morphology and hotspot migration, while pressure sensors captured the corresponding blast-wave response. A theoretical model was established to connect fireball temperature and aluminum particle size with combustion completeness.
“Our analysis indicated that the thermobaric effect is not determined solely by the initial detonation,” shares Bian. “Instead, the subsequent combustion of aluminum provides an important source of energy that modifies both the thermal field and the development of the blast wave.”
The results suggested that controlling the balance between oxidizer-driven early combustion and later oxygen-assisted afterburning is central to understanding the performance of thermobaric formulations.
A concentrated fireball reveals the distinctive nature of thermobaric combustion
Infrared imaging shows that thermobaric explosives develop a concentrated and relatively localized hotspot, maintaining a volumetric explosion character throughout the evolving fireball. "This behavior contrasted with the more fragmented combustion observed for TNT,” says Bian. “The difference is also reflected in temperature evolution: immediately after detonation, thermobaric fireballs can exceed same-volume TNT fireballs by more than 1500 °C, while remaining hotter as the fireball expands.”
Oxidizer content determines the balance between early combustion and afterburning
The comparison between TBX30% and TBX5% revealed a clear temporal crossover. During the first 30 ms, the higher-oxidizer TBX30% maintained the higher fireball temperature because more oxidizing products promote rapid ooxygen-deficient combustion of aluminum. After approximately 30 ms, however, TBX5% became hotter as its larger amount of unreacted aluminum participated in secondary combustion with entrained ambient oxygen. After about 60 ms, the temperature histories of the two systems converged. TBX5% also showed more pronounced secondary afterburning and greater hotspot migration, highlighting the different roles of oxidizer-rich and oxidizer-lean formulations.
A temperature-based model identifies a route toward stronger thermobaric output
The team's theoretical analysis provided a quantitative link between fireball temperature and aluminum consumption. The Average Fireball Temperature model predicted mean temperatures of 2863 K for TBX5% and 3001 K for TBX30%, corresponding to aluminum burn-off times of 88 and 43 ms, respectively. “The model predicted that more than 95% of the aluminum can undergo complete combustion in both systems,” says Bian. “The hotter TBX30% fireball enabled a faster and more intense reaction, showing how increasing the early thermal environment can broaden the range of aluminum particles capable of reacting during secondary combustion.”
These findings provide a practical framework for understanding how post-combustion contributes to sustained blast-wave energy, particularly in the far field.
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Contact author details:
School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China. E-mail address: lyn_00446@163.com (Y.-n. Li)
The publisher KeAi was established by Elsevier and China Science Publishing & Media Ltd to unfold quality research globally. In 2013, our focus shifted to open access publishing. We now proudly publish more than 200 world-class, open access, English language journals, spanning all scientific disciplines. Many of these are titles we publish in partnership with prestigious societies and academic institutions, such as the National Natural Science Foundation of China (NSFC).
A post-combustion reaction model for aluminum in thermobaric effects field
COI Statement
The authors declare the following financial interests which may be considered as potential competing interests: the author Hai-junZhao is currently employed by Ansteel Industrial Micro Fine Aluminum Powder Co., Ltd. The other authors declare that they have no competing interests.
