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Long-term outcome in double-chambered right ventricle: a retrospective single-center study.
No full textOBJECTIVE: Double-chambered right ventricle (DCRV) is a rare congenital heart defect (0.5%-2.0%), characterized by hypertrophied muscular tissue causing obstruction within the right ventricle (RV). DCRV is often associated with other congenital heart defects, such as ventricular septal defects. Although surgery is commonly performed, the long-term prognosis, after both surgical and conservative treatment, remains poorly studied. We investigated the long-term outcome of patients who were observed at a tertiary care center. METHODS: In this retrospective study, 90 patients were included (follow-up between 1980 and 2023). Demographic, clinical, echocardiographic, and electrical parameters were analyzed. Descriptive statistics were applied. RESULTS: Sixty-three patients (70%) underwent surgical intervention, mostly at a young age (median age 3 years, IQR: 0.8-12.3 years); 7.9% required reintervention at a later stage (median 12 years, IQR: 8.0-14.5 years). Conduction disorders were observed in 42% (mainly right bundle branch block), and 6.8% experienced arrhythmias. Most patients remained clinically stable (83% NYHA class I). Echocardiography showed persistent RV hypertrophy in 35.7% of patients; valve regurgitations were mostly mild. Four patients (4.4%) died in a maximum follow-up time of 7 decades. CONCLUSION: Patients with DCRV generally experience positive long-term outcomes and respond well to both surgical and conservative treatments. Although echocardiographic and electrical abnormalities may be present, most patients remain asymptomatic and clinically stable over time.status: Published onlin
Exploring material removal dynamics during femtosecond laser micromachining by in-situ acoustic emission monitoring with physics-based and data-driven analysis
No full textFemtosecond laser micromachining (FLµM) has emerged as a transformative technology for precision microfabrication, offering minimal thermal damage and exceptional resolution across diverse materials, including metals, semiconductors, polymers, and ceramics. Despite its advantages, FLµM faces challenges in maintaining consistent quality and efficiency, especially in industrial applications. This study investigates the integration of acoustic emission (AE) monitoring with FLµM for in-situ quality assessment and process optimization. AE signals, captured at high frequencies (up to 1.5 MHz), are analysed using physics-based methods such as RMS, MARSE, and STFT, as well as machine learning (ML)-based approaches. The results reveal strong correlations between AE signal characteristics and laser parameters such as pulse energy, scanning speed and focal position. They also show the possibility to detect critical material removal regimes, including ablation and melting. Feature importance analysis using ML techniques can identify process-specific frequency bands—350, 469, 547, and 664 kHz—which are particularly relevant for detecting process instabilities and ensuring quality control. By combining AE monitoring with advanced signal analysis, this approach demonstrates a scalable, non-invasive solution for improving the precision and reliability of FLµM, with potential applicability across a wide range of materials and microfabrication processes.sponsorship: This work was partially funded by the KU Leuven C3 IOF project fs-SPR (C3/20/084) , the Research Foundation-Flanders (FWO-Vlaande-ren) Medium-Scale Research Infrastructure project FemtoFac (I001120N) and SB fellowship (1S31024N) , as well as the Slovenian Research and Innovation Agency (P2-0270) . (KU Leuven C3 IOF project fs-SPR|C3/20/084, Research Foundation-Flanders (FWO-Vlaande-ren) Medium-Scale Research Infrastructure project FemtoFac|I001120N, Slovenian Research and Innovation Agency|P2-0270, SB fellowship|1S31024N)status: Published onlin
Het ontleden van de rol van afvalverwijdering bij veroudering: C. elegans coelomocyten als uitgangspunt
No full textOwing to significant advancements in public health, medicine, and living conditions, the past century marks a global increase in life expectancy. However, with age‑related diseases and a general decline in fitness being more pronounced at advanced age, unhealthy aging has emerged as a growing concern in current society. A deeper understanding of this phenomenon is required to effectively address the challenges posed by (unhealthy) aging. A well‑established model for research on the topic of aging is the nematode Caenorhabditis elegans, which combines a short lifespan with a substantial degree of evolutionary conservation.
By carefully reducing food intake while still ensuring adequate nutrition, dietary restriction is one of the most robust interventions known to decelerate aging across multiple species. However, its driving mechanisms remain incompletely understood. As one aspect of aging involves the accumulation of cellular damage and waste products, effective waste clearance is hypothesized to play a critical role in maintaining cellular homeostasis during aging. In fact, recent findings suggest a potential role for specialized cells responsible for molecular waste removal in mediating the beneficial effects of dietary restriction; yet, the precise mechanisms through which this occurs are still to be determined. In this study, I explored the mechanistic contribution of coelomocytes - endocytic scavenger cells residing in the body cavity of C. elegans - to the lifespan extension observed under dietary restriction.
I first pursued the development of an in vivo reporter system enabling to visually assess whether the endocytic capacity of coelomocytes is indeed altered under dietary restriction conditions and throughout aging. Two main approaches were explored to introduce visually discernable material into the body cavity: exogenous administration via microinjection and endogenous generation of pseudocoelomic content via conditional expression or release, the latter through either the Q system, the Tet/Q Hybrid system or the Beggiatoa sp. photoactivatable adenylyl cyclase system. Despite technical challenges preventing the successful implementation of such a tool, my efforts provide valuable insights and recommendations for future methodological improvements.
In parallel, a comparative transcriptomes analysis was conducted on coelomocytes isolated from worms subjected to ad libitum feeding or dietary restriction conditions. Two regimens for the practical implementation of dietary restriction were included: mutation of the eat‑2 gene and axenic dietary restriction. The goal was to identify transcriptional changes that could reveal candidate genes and pathways involved in the endocytic process and, by extension, in the lifespan extension observed under dietary restriction. While the data could suggest a shared mechanistic basis - accompanied by regimen‑specific nuances - across both dietary restriction interventions, the overall transcriptional response of coelomocytes to dietary restriction was limited, with no substantial evidence supporting a contribution of endocytosis. This might imply that post-transcriptional mechanisms could be at play for the coelomocytes to govern dietary restriction‑induced longevity, or alternatively, that aging animals become increasingly dependent on basal coelomocyte functioning, rather than experiencing intrinsic alterations to these cells.
In conclusion, this study aimed to advance our understanding of the role of waste clearance in dietary restriction‑induced longevity, focusing on C. elegans coelomocytes as key players in this process, with the ultimate goal of harnessing the fundamental anti‑aging properties of dietary restriction to explore future anti‑aging strategies with translation potential. Although the precise mechanistic underpinnings of the contribution of coelomocytes to aging, as well as the general physiological role of these cells remain enigmatic, the insights presented here offer a foundation for future research. More specifically, I provide a perspective and advice for refining future methodological approaches in developing a reporter system, along with a publicly accessible coelomocyte-specific transcriptomes dataset as resources for the scientific community.status: Publishe
De invloed van een stabiel gestratificeerde laag op golfbewegingen in de vloeibare kernen van planeten
No full textDeep beneath kilometers of silicate rocks, the four terrestrial planets in the Solar System hide a vast ocean of hot, molten metal alloys. The extreme pressures, high temperatures and inaccessible deep location of these liquid cores make any direct exploration impossible. Consequently, all knowledge about their properties, composition, location, and dynamics must be inferred indirectly from a variety of different sources, including seismology, gravimetry, high-pressure experiments and models, as well as detailed observations of their magnetic field, rotation, and tides.
Despite these obvious challenges in constraining the deep interior of the terrestrial planets, our understanding of the rotating, near-spherical regions dominated by iron has evolved into increasingly detailed models built up of many chemically and/or dynamically distinct regions. One type of internal region that has gained more attention over the past decade and may even be ubiquitous in the Solar System is the stably stratified one. A stably stratified layer is a region in the fluid where the density increases with depth in such a way that any small vertical displacement of a fluid parcel leads to a restoring buoyant force that returns it to its original position. The combination of buoyancy forces, rotating forces, and possible magnetic forces that occurs in such an environment can have a significant impact on, among others, the flow in the core, the magnetic field generated there, and the rotational dynamics of the planet. It is the nature of these influences that I have investigated in this thesis.
I studied gravito-inertial waves and other periodic oscillations restored by buoyancy and Coriolis forces in a stably stratified, rotating medium, making use of the numerical code Kore. I adapted this eigenvalue solver to calculate fluid motions in a sphere or spherical shell with a stably stratified outer layer and applied the modified code to model the fluid dynamics in the deep interior of two planets: Mercury, whose fluid outer core has a strong, stably stratified outer layer, and the Earth, which may have a thin and weakly stratified at the top of its core.
Regarding Mercury's core, I showed how the expected stable layer strongly influences the outermost core flow. Due to the stratified layer being mostly incompatible with radial motions, the radial flow induced by the librating motion of the mantle is converted to a strong horizontal motion just beneath the core-mantle boundary. This strong horizontal motion induces a non-axisymmetric magnetic field structure with an 88-day periodicity when it interacts with Mercury's weak magnetic field. Such a structure may be detectable in magnetic data from the forthcoming BepiColombo mission, providing constraints on the stable layer. Additionally, I performed the first explicit calculation of the torques exerted by the fluid core on Mercury's mantle. My results indicate that the effect of the librationally induced core flow on the planet's libration amplitude is negligible. This supports the validity of current libration studies, which typically assume that core flow does not influence this amplitude.
For the Earth, I investigated how the Earth's eigenmodes, specifically, torsional Alfvén and Magneto-Coriolis (MC) waves, are influenced by the presence of a thin, stable layer at the top of the core. Torsional waves at interannual periods remain largely unaffected by weak to moderate levels of stratification in the outer layer. Yet, even weak stable layers can support buoyancy-driven waves on decadal periods that primarily propagate within them. The electromagnetic torque exerted by these magneto-Archimedes-Coriolis (MAC)-like waves on the mantle exceeds that of their MC wave counterparts in a neutrally stratified core. This means that they are more likely to be responsible for the observed decadal changes in rotation that are attributed to motions in the core.status: Publishe
Public Support and VC Financing in Academic Startups
No full textWe investigate public support and venture capital (VC) investment in academic startups. Government support may enable follow-on investment by providing a quality signal to investors. This signal is especially important for academic startups, which face large funding gaps due to their complexity, cutting-edge nature, and uncertainty regarding the founders’ management capabilities and commitment. Using a panel of startups in Germany, our
analyses confirm that academic startups are more likely to obtain follow-on VC investment after receiving public support than non-academic startups. Further, this effect is limited in time, lasts longer for academic startups, is concentrated in high-tech manufacturing firms, and is stronger for investments from business angels. Our findings have implications for policymakers seeking
to foster academic entrepreneurship through policy programs and VC investment.status: Publishe
Psychiatrische kwetsbaarheid bij bewoners van woonzorghuizen
No full textHet aantal bewoners met een psychiatrische kwetsbaarheid in woonzorghuizen neemt toe. Huisartsen worden vaak pas voor advies geconsulteerd wanneer deze bewoners ernstige gedrags- en gemoedsveranderingen vertonen of wanneer de situatie dreigt te escaleren. Toch is de huisarts degene die de bewoner vaak goed kent, vroegtijdig achteruitgang van de mentale gezondheid kan detecteren en zicht heeft op wat de bewoner kan ondersteunen. In dit artikel wijzen we op de rol van de huisarts in het vroegtijdig detecteren van psychische destabilisatie, de mogelijkheden voor tijdig psychiatrisch advies en ondersteuning en het belang van het regionaal investeren in psychiatrische netwerken.status: Published onlin
Future projections of European maize yields using AquaCrop with an adaptive growing season
No full textsponsorship: The computer resources and services were provided by the High Performance Computing system of the Vlaams Supercomputer Center, funded by the Research Foundation Flanders FWO, Belgium and the Flemish Government (incl. Storage4Climate collaborative grant) . This work received support from project C14/21/057 of KU Leuven, and CROPWAVES of the Belgian Science Policy (Belspo) . Louise Busschaert is funded by FWO, Belgium grant 1158423N. Wim Thiery acknowledges Funding from the European Research Council (ERC) under the European Union's Horizon Framework research and innovation programme (grant agreement No 101124572; ERC Consolidator Grant 'LACRIMA') . (European Research Council (ERC) under the European Union|1158423N, (ERC Consolidator Grant 'LACRIMA')|101124572)status: Published onlin
Quantifying the Role of CME–CME Interactions in Geomagnetic Storm Severity: A Case Study Using EUHFORIA
No full textCoronal Mass Ejections (CMEs) are among the primary drivers of space weather
disturbances, with the potential to trigger severe geomagnetic storms and pose risks to
satellite operations, navigation systems, and astronaut safety. While initial
observational parameters such as CME speed and angular width, commonly derived
from coronagraphs like SOHO/LASCO, are essential for early detection, they are often
insufficient to reliably predict a CME’s geoeffectiveness. In this study, we investigate
two CMEs from June 21 and June 25, 2015, using both remote-sensing observations
and a data-driven simulation approach based on the EUHFORIA MHD model.
Our analysis reveals that, despite their comparable initial speeds, the two CMEs
produced markedly different geomagnetic responses. CME1 led to a major
geomagnetic storm (), while CME2 resulted in only moderate activity (). EUHFORIA simulations indicate that CME1's enhanced geoeffectiveness
was likely amplified by CME–CME interactions and favorable magnetic field orientation,
factors not discernible from coronagraph observations alone. In contrast, CME2
appears to have dissipated energy during propagation, possibly due to solar wind drag
or lack of interaction-driven compression.
By comparing model-derived indices with in situ data, we demonstrate the
importance of heliospheric modeling in capturing CME propagation dynamics and
magnetic field evolution. Our findings highlight that background solar wind conditions,
CME–CME interactions, and internal magnetic structure are critical to assessing a
CME’s space weather impact. This underscores the need for integrated modeling
frameworks like EUHFORIA to improve the accuracy of arrival time predictions and
geomagnetic storm forecasting. The research emphasizes that the interactions of
CMEs are crucial in shaping their effects on Earth, indicating that their initial speeds,
while comparable, have a lesser impact. In addition, the EUHFORIA numerical model
aligns with the values determined by the GFZ German research centre; this implies
that EUHFORIA can also compute and potentially forecast the impact of CMEs on the
Earth. While CMEs remain primary drivers of geomagnetic storms, this work
underscores that their space weather impacts are governed by complex interplay
between intrinsic properties and evolving heliospheric conditions.sponsorship: ERCEA|101141362, KU Leuven|C16/24/010, Fonds Wetenschappelijk Onderzoek|G0B5823N, Fonds Wetenschappelijk Onderzoek|G002523N, Fonds Wetenschappelijk Onderzoek|VSC, ESA Prodex|4000145223, Federaal Wetenschapsbeleid|B2/191/P1/SWiMstatus: Accepte
Vertex-Critical (P5,W4)-Free Graphs
No full textsponsorship: National Natural Science Foundation of China|12171256, National Natural Science Foundation of China|12161141006, National Natural Science Foundation of China|12311530678, Fonds Wetenschappelijk Onderzoek|VS01224N, Fonds Wetenschappelijk Onderzoek|G0AGX24N, Fonds Wetenschappelijk Onderzoek|1222524N, Natural Sciences and Engineering Research Council of Canada|RGPIN-2022-03697, Natural Sciences and Engineering Research Council of Canada|DGECR-2022-00446, Natural Sciences and Engineering Research Council of Canada|RGPIN-2025-06012, Natural Sciences and Engineering Research Council of Canada|DGECR-2025-00001status: Published onlin
Spectroscopie van zware sterren bij lage metalliciteit: Een gedetailleerde studie van de atmosfeer en de winden van B-sterren
No full textMassive stars have an initial mass above 8M . Even though massive stars are less numerous than low-mass stars, they shape the galaxies they inhabit both physically and chemically. They are partly responsible for enriching their galaxy with heavier elements which are created in their core and expelled through strong stellar winds. When the fuel in the core has been exhausted they end their lives in energetic supernova explosions which also contribute to chemical enrichment of the ambient environment. The strong outflows and high-pressure ionised regions that surround massive stars in the phases of their lives where they have high surface temperatures set in motion and sweep up interstellar material, potentially halting or initialising star formation elsewhere in their host galaxies. To understand all these feedback processes caused by massive stars, it is important to understand how these stars change over their lifetime.
Massive star evolution is heavily impacted by their strong mass-loss rate causing the star to loose multiple solar masses worth of material over its lifetime. In stellar evolution models mass-loss rates are included as prescriptions, simple formulas based on hydrodynamical predictions which compute the mass-loss rate from stellar parameters. There are multiple prescriptions which agree relatively well in the O- star regime (T eff > 30 kK), but disagree by orders of magnitude in the B-star regime 10 kK< Teff < 30 kK. This is partly because of a sudden increase in mass-loss rate for stars with T eff < 25 kK in some prescriptions called the bi-stability jump. It is possible to compare these prescriptions to observations by fitting the spectra of the star to model spectra based on 1D stellar atmosphere and wind models. Although some studies have compared these prescriptions to observations, they were not able to take into account the inhomogeneities of these winds, resulting in large uncertainties. This thesis has two goals: (1) empirically derive the mass-loss rate of B-stars while
accounting for the inhomogeneities to assess how the mass-loss rate is influenced by different stellar parameters, coincidently also assessing the viability of the bi-stability jump; (2) improve the methods for deriving the stellar and wind parameters both in terms of the fitting routine and including more physics in the 1D spectral modelling tools. Over the course of the thesis we will show the results of the spectral fits of 41 stars in the LMC and SMC, obtaining stellar parameters, mass-loss rates, clumping parameters describing the inhomogeneities in the wind and other wind parameters.
The derived mass-loss rates in both the SMC and LMC show only a weak dependence on T eff and no increase in mass-loss rate for cool B-stars disproving the bi-stability jump. As the standard mass-loss prescription in evolutionary models includes a bi-stability jump, evolutionary models overestimate the empirical mass-loss rate of stars cooler than 25 kK by up to a factor 1000 and on average a factor 30. By comparing
the empirical mass-loss rates of the LMC to the SMC, we found that the metallicity dependence of the mass-loss rate is much weaker than prescriptions suggest. As iron-group metals are historically believed to be the fundamental driver of the outflows of these stars, this is surprising and warrants a closer theoretical study.
The clumping description currently implemented in fastwind assumes a two-component medium, i.e. a medium having dense and rarefied regions. This description assumes that the dense regions contribute nearly all wind mass, in line with the theoretical 1D description of line de-shadowing instability. Instead, we find a wind structure where 40% of the wind mass is located in the rarefied regions, contradicting the assumption made in the models. This result is enforced by the study of multi-D radiation hydrodynamical models of stars, which find a wind-density distribution similar to our results, not distributed as a two-component medium, but rather turbulent and log-normal. This inappropriate formulation of clumping behaviour in the 1D model may explain the high uncertainties we find on the derived clumping parameters.
The average density and temperature atmosphere profile of multi-D radiation hydrodynamical models do not agree with the 1D models. This is alleviated by including a turbulent pressure term into the stellar structure calculations of the 1D models. Changing the stellar structure causes a shifts in most of the derived spectral lines, notably narrowing the Balmer-lines requiring a higher stellar mass to retrieve the same shape. This mass increase may help alleviate a persistent underestimation of stellar mass estimates based on spectroscopically derived gravities compared to mass estimates from other methods. To test this theory, we implement turbulent pressure in fastwind and fit the spectra of two gravitationally bound stars for which the masses are known and previous spectroscopically derived masses are underestimating the actual mass. This new method finds spectroscopic masses in agreement with those from other methods.
Using our current fitting method, each spectral fit of a star requires around 1.5 days. As the newest generation of spectroscopes will increase the amount of spectra to be analysed by orders of magnitude (e.g. 4MOST/VLT, WEAVE/WHT, MOSAIC/ELT), we also investigate new methods which could speed up our current process. The application of neural networks which are able to emulate fastwind are a possible solution. The neural network takes the same stellar and wind parameters as fastwind and outputs spectra mostly indistinguishable from fastwind spectra in a fraction of a second instead of 45 minutes.status: Publishe