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)
Monday, June 09, 2025
Impact of ceiling of care on mortality across four COVID-19 epidemic waves in Catalonia
Researchers from the Biostatistics Unit at the Germans Trias i Pujol Research Institute (IGTP) have led a study, published in BMJ Open, which analyses how in-hospital mortality evolved during four waves of the COVID-19 pandemic in Catalonia, taking into account the patients' ceiling of care.
The study included 5,813 patients hospitalised with COVID-19 in five tertiary hospitals in Catalonia over the course of the first four pandemic waves. The ceiling of care-defined as the highest level of medical treatment a patient will receive-was assessed upon admission for all patients.
The results show that, among patients without a ceiling of care, those admitted during the first wave had a higher risk of in-hospital death compared to those admitted in subsequent waves. The adjusted models confirmed a significant decrease in mortality over time, likely due to improvements in clinical knowledge, treatment and patient management.
As expected, mortality was higher among patients with a ceiling of care. In this group, no significant differences in mortality were observed between the first three waves. However, in the fourth wave, adjusted analyses showed a reduction in mortality comparable to that of patients without a ceiling of care. This improvement may be associated with the higher vaccination coverage among this group.
"Understanding how mortality patterns evolve differently in patients with and without a ceiling of care could help inform clinical strategies in future public health emergencies," explains Natàlia Pallarès, first author of the study and researcher at IGTP at the unit led by Cristian Tebé.
Impact of ceiling of care on mortality across four COVID-19 epidemic waves in Catalonia: a multicentre prospective cohort study
Article Publication Date
30-May-2025
COI Statement
CT has received fees for speaker lectures and talks from Gedeon Richter, outside the submitted work. The rest of authors declare that they have no competing interests.
Wasps thought to be asexual could support chemical-free pest control enhancements
University of Stirling research has shed new light on the evolution of an important species of wasp
Scientists have shed new light on the evolution of an important species of wasp – and believe that the findings could help improve the effectiveness of natural pest control.
Dr Rebecca Boulton, from the University of Stirling, has shown, for the first time, that Lysiphlebus fabarum – a tiny species of wasp – can reproduce with or without a mate. This discovery challenges the previous assumption that asexual females could not mate and produce offspring sexually.
Significantly, the wasps lay their eggs inside small sap-sucking insects called aphids before consuming their host from the inside out — meaning that they are natural pest controllers.
Lysiphlebus fabarum is known to have both sexual and asexual populations but, until now, it was not known whether asexual females could reproduce sexually with males. The discovery opens up new possibilities for improving biological pest control.
Many species of parasitoid wasps are mass-reared and released as a natural alternative to pesticides because they lay their eggs on or in other species, many of which are pests, before the developing wasp larvae consumes their host, killing it in the process.
Asexual reproduction makes it easy to produce large numbers of wasps, but these need to be suitably adapted to local pests and environments to be effective. Currently, Lysiphlebus fabarum is not used commercially despite being found worldwide and naturally targeting aphids.
Developing an understanding of how the species reproduce could help boost genetic diversity in commercially reared lines, making future biocontrol agents more resilient and better adapted.
Dr Boulton, a lecturer in Biological and Environmental Sciences at the University’s Faculty of Natural Sciences, led the study. She said: “In an evolutionary sense, facultative sex seems like a perfect strategy – asexual reproduction is highly efficient, and takes away the costs of finding a mate as well as the risks of failing to find one.
“But sex is really important for evolution. When females reproduce asexually they don’t mix their genes up with any others which limits the potential for evolution to happen.
“If the environment changes, asexual species may be unable to adapt in the same way that sexuals can.
“Facultative sex brings the efficiency of asexual reproduction with the evolutionary benefits of sex and so has been touted as the best of both worlds.
“The results of my study show that there might be hidden costs to facultative sex though as it reduces female wasps’ reproductive success, and this might limit how frequently it occurs in nature.
“The wasps that I studied are an important natural enemy of aphids, they aren’t currently commercially reared, but they are found globally.
“My findings could be used to develop new biocontrol agents that can be used to control aphids throughout the world, harnessing their natural reproductive behaviour to ensure that they are adapted to the hosts and environments that are specific to different regions.”
Dr Boulton reared the wasps in a Controlled Environment Facility (CEF) at the University and had initially planned to put asexual and sexual wasps together, in direct competition, to see which parasitised the most aphids.
However, in the early stages of these experiments she realised the female asexual wasps were behaving unexpectedly and were mating with males from the sexual population.
This led to a change in strategy, as she started to record this behaviour in more detail, before carrying out wasp paternity testing to see whether the asexual females were just mating or actually fertilising eggs.
Once it confirmed that the asexual wasps were engaging in facultative sex, Dr Boulton carried out an experiment where asexual females either mated or didn’t, before examining how successful these females, and their daughters, were at parasitising aphids.
The study involved putting around 300 wasps, each around 1mm long, in their own petri dish with a colony of sap-sucking aphids and counting how many were parasitised.
Lysiphlebus fabarum wasps only live a few days but spend two weeks developing as larvae on their hosts.
The entire experiment, which was carried out across two generations of wasps, took six weeks to run.
On completion Dr Boulton extracted DNA from the wasps and sent it to be paternity tested. When the results were returned it was clear that the asexual wasps which mated were, in most cases, reproducing sexually as their offspring had bits of DNA that were only found in the fathers.
It was funded through a BBSRC Discovery fellowship.
Professor Anne Ferguson-Smith, Executive Chair of BBSRC, said: “This is an exciting example of how BBSRC’s Discovery Fellowships are helping talented early career researchers explore fundamental questions in bioscience with real-world relevance.
“Dr Boulton’s work, which measures the costs of sex in this predominantly asexual parasitoid wasp, opens up promising avenues for more sustainable pest control. Supporting curiosity-driven research like this not only strengthens the UK’s research base, but helps drive innovation that benefits the environment, food systems and society at large.”
University of Stirling
The University of Stirling is committed to providing education with a purpose and carrying out research which has a positive impact on communities across the globe. Driven by our mission to be the difference, we are addressing real issues, providing solutions, and helping to shape society.
The University has more than 17,500 students globally and employs 1,800 staff, with more than 140 nationalities represented within our community. Our campus environment is ranked first in the UK and top 10 in the world, and our sports facilities rank first in the UK and second in the world (International Student Barometer 2024, wave two), reflecting our long-standing designation as Scotland’s University for Sporting Excellence.
We were shortlisted for University of the Year 2024 at the Times Higher Education Awards and are proud holders of a Silver institutional award from the Athena Swan Charter, in recognition of our commitment to advancing gender equality. We have an overall five-star rating in the QS Stars University Ratings and are ranked top 30 in the UK for postgraduate teaching and learning (Postgraduate Taught Experience Survey 2024). In recognition of our excellence in business education, we are accredited by AACSB International.
Eighty-seven per cent of our research has an outstanding or very considerable impact on society, with more than 80% rated either world leading or internationally excellent (Research Excellence Framework 2021), and we are ranked among the top 100 institutions in the world for our contribution to meeting 10 of the 17 UN Sustainable Development Goals. We have twice been recognised with a Queen's Anniversary Prize; for our Institute for Social Marketing and Health (2014) and our Institute of Aquaculture (2019).
Alongside partners, the University spearheads the £214 million Stirling and Clackmannanshire City Region Deal – which will deliver three major University-led projects: the National Aquaculture Technology and Innovation Hub, Scotland’s International Environment Centre, and the Intergenerational Living Innovation Hub. We are also a central partner in the Forth Valley University College Health Partnership.
BBSRC is the UK’s major public funder of bioscience research and innovation. Our aim is to further scientific knowledge, promote economic growth, wealth and job creation to improve lives and livelihoods across the UK.
BBSRC invested £481.6 million in world-class bioscience in 2023/24. We support research and training in universities and strategically supported institutes. BBSRC research, and the people we fund, are helping society address major challenges including food security, green energy and healthier, longer lives.
Our investments underpin important UK economic sectors such as agriculture, food, industrial biotechnology and pharmaceuticals. ukri.org/councils/bbsrc. Follow BBSRC on LinkedIn or YouTube.
String theory's equations give rise to a near infinite variety of potential universes in a 'landscape.' This landscape is surrounded by a 'swampland' of solutions that are incompatible with any workable theory of quantum gravity.
String theory has long been touted as physicists’ best candidate for describing the fundamental nature of the universe, with elementary particles and forces described as vibrations of tiny threads of energy. But in the early 21st century, it was realized that most of the versions of reality described by string theory’s equations cannot match up with observations of our own universe. In particular, conventional string theory’s predictions are incompatible with the observation of dark energy, which appears to be causing our universe’s expansion to speed up, and with viable theories of quantum gravity, instead predicting a vast ‘swampland’ of impossible universes. Now, a new analysis by FQxI physicist Eduardo Guendelman, of Ben-Gurion University of the Negev, in Israel, shows that an exotic subset of string models–in which the tension of strings is generated dynamically–could provide an escape route out of the string theory swampland. The analysis was reported in The European Physical Journal C, in March.
In the early 2000s, string theorists realized that string theory's equations don’t give rise to just one description for the universe, but to a mind-boggling 10500 possible solutions, corresponding to a near infinite variety of potential universes. Each of these universes has its own particles and forces, creating what has become known as the ‘string theory landscape’ of multiple possible cosmoses. Shortly after, making things even worse, in 2005, it was realized that this landscape is itself surrounded by a so-called ‘swampland’ of solutions–superficially viable-looking quantum field theories that, in fact, turn out to be incompatible with any workable theory of quantum gravity, on closer inspection.
Swampland Constraints
To delineate the landscape from the swampland, it was proposed that plausible theories in the landscape must obey certain “swampland constraints.” The problem is that when conventional string theories satisfy these constraints, physicists find that they cannot easily reproduce inflation–the short burst of rapid expansion that our early universe is believed to have undergone–or dark energy, which is thought to be accelerating the growth of our universe today.
“The more conventional string theories are very unfriendly to inflation, in particular to ‘slow-roll scenarios,’ and even to the existence of de Sitter space as a vacuum of the theory–the vacuum of our actual universe–which is the basis not only of inflation, but also of dark energy,” says Guendelman, a member of FQxI, the Foundational Questions Institute. “The swampland constraints are making cosmology impossible or almost impossible for the practical cosmologist because the real universe appears to be firmly in the swampland of the conventional string theory.”
“The swampland constraints are making cosmology impossible or almost impossible for the practical cosmologist because the real universe appears to be firmly in the swampland of the conventional string theory,” says Eduardo Guendelman.
Now Guendelman has published a new paper, which shows a certain exotic subset of string theories may be more conducive to describing our real universe compared with its more conventional cousins.
Generating Tension
In all string theory models, the strings have some tension; but in most conventional models the value of this tension is a constant that is added in by hand, arbitrarily. Guendelman has been examining models in which this tension arises dynamically, generated by the behavior of the strings in the model.
Guendelman’s new paper describes the formulation of such a theory and shows that due to the dynamical nature of the tension, the swampland constraints are greatly weakened. This is because calculations deriving the constraints are related to the size of the so-called ‘Planck scale’–thought to correspond to the smallest possible size of anything in the universe, including a string. But because the Planck scale is itself related to the string tension, in these models, the Planck scale itself becomes dynamical, says Guendelman.
“In the regime where the dynamical tension, and therefore also the Planck scale, becomes very big, the constraints become irrelevant or very weak,” says Guendelman. “So dynamical tension string theory is friendly to inflation and dark energy.”
The Foundational Questions Institute, FQxI, catalyzes, supports, and disseminates research on questions at the foundations of science, particularly new frontiers in physics and innovative ideas integral to a deep understanding of reality but unlikely to be supported by conventional funding sources. Visit FQxI.org for more information.
Researchers: “Genetic editing in crop plants is a complex process. Our method overcomes major challenges and may be used to study and influence a variety of traits, such as resistance to diseases and drought, in different field crops.”
Researchers from the School of Plant Sciences and Food Security at the Faculty of Life Sciences at Tel Aviv University have developed a genetic editing method tailored to crop plants, which has influenced various traits in tomato plants, including the taste and shape of the fruit. The researchers believe this innovative technology can be applied to a wide variety of crop species and may eventually be used to cultivate new and improved plant varieties. “We demonstrated that with our technology, it is possible to select specific traits and influence them, a capability that is essential for advancing agriculture and achieving food security,” the researchers stated.
The study was led by Prof. Eilon Shani, Prof. Itay Mayrose and PhD student Amichai Berman (School of Plant Sciences and Food Security at Tel Aviv University) together with PhD student Ning Su and Dr. Yuqin Zhang (University of Chinese Academy of Sciences in Beijing), and Dr. Osnat Yanai from the Israeli Agri-Tech company NetaGenomiX. The article was published in the prestigious journal Nature Communications.
Prof. Shani explains: “Researchers around the world are engaged in advancing agriculture in order to address accelerated global changes and feed the global population in the coming decades. Among other things, genetic editing technologies are being advanced to develop new plant varieties with desirable traits such as resistance to drought, heat, and disease, improved flavor, optimized nutrient usage, and more. One such method is CRISPR-Cas9, which has revolutionized the field of genetic editing by enabling the precise modification of specific genes in the genome.
However, in the realm of agricultural development, this method has encountered several fundamental challenges: Firstly, while CRISPR technology allows for targeted gene editing, until now, this capability was limited in scale — the number of genes that could be edited and studied was very small. In the current study, we significantly improved the method’s efficiency, enabling us to examine the roles of thousands of genes. Secondly, many plants exhibit ‘genetic redundancy’: different genes from the same family, composed of similar amino acid sequences, compensate for one another and preserve the trait even if one gene is deactivated or edited”.
Amichai Berman: “To overcome genetic redundancy, we aimed to simultaneously alter entire families of similar genes. In a previous study, we developed a breakthrough solution to overcome the issue of genetic redundancy, a dedicated algorithm, and fed it a list of thousands of genes we wanted to edit. The algorithm identified a suitable CRISPR unit for each gene (or gene group) on the list that would induce the desired modification, thereby constructing CRISPR libraries. The first study achieved good results in the model plant Arabidopsis thaliana, and this time we sought to test the method in a crop plant for the first time. We chose the tomato.”
In the current study, the researchers built 10 libraries comprising approximately 15,000 unique CRISPR units targeting the tomato genome — each unit designed to affect a specific gene group from the same family. They then used the CRISPR units to induce edits in around 1,300 tomato plants, each plant with an alteration in a different gene group. The researchers then tracked the development of each plant to examine whether the selected changes appeared in fruit size, shape, taste, nutrient utilization, or pathogen resistance. Indeed, the researchers identified several lines with sweetness levels either lower or higher than the control plants.
Prof. Shani concludes: “In this study, using our innovative method, we successfully made targeted genetic changes to gene families in the tomato plant, and identified precisely which genetic edits produced the desired result.” The Israeli Agri-Tech company NetaGenomiX has received a license to commercialize the new technology, with the goal of advancing food security by developing non-GMO crops adapted to the changing climate, providing benefits for both farmers and consumers.
Amichai Berman adds: “We believe our research opens the door to breeding improved varieties for a wide range of crops, and also advances the field of plant science as a whole. In follow-up studies, we are working on developing additional selected traits in tomato and in rice.”
The tomato plant genome is divided into gene families. For each group of similar genes, a unique CRISPR unit is designed to alter their function (in total, over 15,000 CRISPR units were designed). These CRISPR units are delivered into tomato plants, which are then monitored for growth and development. In the final stage, plants exhibiting changes in selected traits are identified and genetically and physiologically characterized. This new approach enables the large-scale targeting of genetic redundancy within gene families, on the scale of hundreds of genes.
