Vrije Universiteit Brussel

Islands are fundamental model systems in ecology, biogeography, and evolutionary biology. However, terrestrial islands, unlike their aquatic counterparts, have received comparatively less attention. Among these land islands, inselbergs (i.e. isolated rock outcrops with diverse lithologies and a modest topographical prominence) stand out as iconic examples distributed worldwide across global biomes. Due to their durable lithology, inselbergs change slowly, persisting for tens of millions of years. In this review, we propose a biological definition for inselbergs that captures three fundamental characteristics of inselbergs from the perspective of biota. These are old age, isolation and the presence of unique microhabitats that are rare or absent in the surrounding matrix, fostering distinct communities often with unique and endemic biota. We synthesise the state of the art and formulate a set of testable hypotheses to deepen our understanding of the origins and maintenance of diversity on inselbergs, which are increasingly exposed to anthropogenic threats. By offering different habitats compared to the surrounding habitat matrix (e.g. moist microhabitats in dryland landscapes and xeric environments in humid tropical landscapes), insel-bergs may allow specific lineages to thrive beyond their typical geographical limits. Particularly in drylands and degraded landscapes, inselbergs may not just provide different habitats but also act as ecological refuges or evolutionary refugia by providing a wider range of potential microhabitats than the surrounding matrix, enhancing resilience and promoting regional biodiversity. The central role of the matrix ensures that the ecological and evolutionary dynamics of inselbergs differ from those of true islands such as oceanic islands. Given that inselberg biota coexist within a terrestrial matrix, interactions between inselberg and matrix populations impact each other significantly. Over evolutionary timescales, matrix species may contract to inselberg refugia, preserving lineages while cycles of isolation and reconnection may drive speciation via a species pump. Although inselberg biodiversity has been studied predominantly from an island biogeography perspective, we argue that depending on the spatial scale, habitat specificity and mobility of the organisms considered, a range of different theories and paradigms can help explain the biogeography and local distribution patterns of different taxonomic and functional groups of inselberg species.

Conjugation of low‐cost and high‐performance semiconductors is essential in solar‐driven photoelectrochemical (PEC) energy conversion. Sb2S3 is a wide‐bandgap (≈1.7 eV) semiconductor with the potential to deliver a maximum photocurrent density of 24.5 mA cm⁻², making it highly attractive for PEC water splitting applications. However, bulk Sb2S3 exhibits intrinsic recombination issues and low electron–hole separation, posing a limit to photocurrent generation. This study clarifies the carrier dynamics by ultrafast spectroscopy measurements and proposes the design of a heterojunction between Sb2S3 and SnO2, with suitable band‐edge energy offset. The SnO2/Sb2S3 heterojunction enhances the charge separation efficiency, resulting in improvement of the photocurrent. The SnO2/Sb2S3 photoanode, fabricated entirely by vapor deposition processes, demonstrates photoelectrochemical water oxidation with a photocurrent density up to ≈3 mA cm⁻² at 1.38 V versus RHE.

Peptide-based hydrogels are promising materials for biomedical applications including drug delivery and wound healing. However, the morphological complexity of these self-assembling materials leads to an incomplete understanding of the systems,...

This paper addresses the identification of Nonlinear (NL) systems using a linearization approach, introducing a combined estimator to tackle this challenge. We assume that the unknown NL system operates around a stable, slowly varying (nominal) operating point. The system trajectory is then perturbed slightly via small input perturbations. While the system's operating point evolves slowly over time, the small (broadband) input signal excites the system dynamics. We demonstrate that the NL system's response to these small perturbations can be approximated by a Linear Parameter‐Varying (LPV) system model. Furthermore, we show that this LPV model represents the linearized version of the unknown NL system around the operating point. A new parametrization for the LPV model coefficients, referred to as “gradient‐parameterized” LPV coefficients, is introduced, establishing a structural relationship between the coefficients. This structural relationship reduces the number of parameters to be estimated and ensures that the LPV model always corresponds to the linearized form of the NL system. Additionally, we demonstrate that this LPV model structure allows for the unique reconstruction of the NL system model through symbolic integration, resulting in a closed‐form nonlinear Ordinary Differential Equation (ODE). This integration introduces a second structural relationship, linking the LPV model to the NL model. By leveraging these two structural relationships, we reformulate the problem of NL system identification via linearization as a combined estimation problem, leading to a unified LPV‐NL estimation framework. This approach utilizes all available data, including perturbation data (linear response) and the varying operating point (NL response). The proposed approach employs a combined estimator to locally identify the joint LPV‐NL model within the neighborhood of the system's operating point. Although the estimated NL model is localized around this nominal trajectory, an experimental approach is proposed to reduce the linear approximation error, thereby enlarging the validity region of the final model. Finally, we present a numerical example to illustrate the performance of the proposed method.

Many species produce rhythmic sound sequences. Some purportedly speed up their vocalizations throughout a display, reminiscent of—but not necessarily equivalent to—accelerando in human music. This phenomenon has been frequently reported but rarely quantified, which limits our ability to understand its mechanism, function, and evolution. Here, we use a suite of rhythm analyses to quantify temporal and acoustic features in the ecstatic display songs of male African penguins (Spheniscus demersus). We show that songs get faster (i.e., accelerando) and louder (i.e., crescendo) as they progress. The accelerando occurs because the intersyllable silences, not the syllables themselves, predictably shorten over time. This rhythmicity is maintained even when individuals take audible breaths. Individuals also show plasticity: when they start with a slow tempo, they speed up more strongly than when they start with a fast tempo. We hypothesize that this well‐timed accelerando may stem from arousal‐based mechanisms, biomechanical constraints, or more complex rhythmic control. Future work should test the mechanisms behind this intra‐individual rhythmic variation since nonpasserine birds are thought to have limited vocal plasticity. By integrating a rich empirical dataset with cutting‐edge rhythm analyses, we establish the necessary foundation to determine how such features evolved and their role(s) across communication systems.

Membrane technology offers substantial economic and environmental benefits for energy‐intensive chemical separations. Chabazite‐type zeolite, possessing a 3‐D channel system with molecular‐sieving windows, can be an ideal membrane material, but conditions to synthesize zeolite‐only membranes limit optimization strategies. Guided by advanced quantum chemistry calculations on inner‐pore molecular interactions, zeolite properties are tailored for different separations and optimized particles incorporated in polyimide at very high loadings. A membrane platform is thus created that largely outperforms state‐of‐the‐art membranes for a broad variety of industry‐relevant applications, that is, carbon capture, natural gas/biogas purification, hydrocarbon, helium and hydrogen recovery. Accurate size‐sieving of gas molecules is realized together with rational determination of optimal gas‐zeolite interactions. Crucial for industrial applications, these well‐tuned membranes displayed excellent non‐aging properties, high flexibility and higher mixed‐gas selectivities than ideal‐gas selectivities. Moreover, they performed even better at low CO2‐partial pressure in CO2‐removal and can be made humidity‐insensitive.

This article investigates Dutch coastal risk management in light of recent scientific evidence on long-term sea level rise. While the so-called Delta Programme, meant as a national boost for flood safety, remains central to the Netherlands’ coastal defence strategy, our analysis reveals that it does not offer sufficient protection beyond the year 2050. It is therefore evidence of a climate adaptation gap. Drawing on the concept of lock-ins, this study examines how certain mechanisms may be at play. The study uses a framework on “adaptation lock-ins” developed by Groen et al. (2022) in an attempt to study and explain this adaptation gap. A qualitative analysis of policy documents, secondary literature and semi-structured interviews with experts points to the existence of several lock-in mechanisms which are implied in the stagnation of Dutch coastal risk management. The insights gathered are relevant for practitioners and academics alike as it might be used to inform the upcoming revision of the Delta Programme in 2027. At the conceptual level, the study adds insights on previously undiscovered types of lock-ins, thus adding to the explanatory power of the lock-in concept. The article concludes that further research can focus on how lock-ins vary across time, regions or contexts, and how they can be addressed and overcome.

Background Tuberous Sclerosis Complex (TSC) is a rare multi-system genetic disorder characterised by benign growths in multiple body systems. TSC-Associated Neuropsychiatric Disorders (TAND) are very common in individuals with TSC, but families often struggle to access appropriate clinical care. To address this gap, the new TAND-SQ Checklist allows individuals with TSC or their caregivers to self-report and quantify characteristics of TAND. The 33 items make up seven natural TAND clusters and an eighth cluster reflecting psychosocial difficulties in individuals with TSC and their caregivers. Respondents rate items as having ever been present to generate cluster scores (CS), and rate item severity (over the last month) on a 10-point scale to generate cluster severity scores (CSS mean ) and a total TAND severity score (TTSS mean ). The purpose of this study was to determine the reliability and validity of the CS, CSS mean and TTSS mean of the TAND-SQ. Methods A descriptive group design was used. Two convenience samples with existing clinical data were recruited from the TSC Alliance Natural History Database (NHD) in the USA (n = 69), and from the Developmental Synaptopathies Consortium Rare Diseases Clinical Research Network (RDCRN) study based at Boston and Cincinnati Children's Hospitals (n = 23), totalling 92 participants. Results Analyses showed good internal consistency for CS (Cronbach’s alphas: 0.67–0.89) and CSS mean (0.76–0.95) with the exception of the eat/sleep cluster. Within the TAND-SQ, most CS and all CSS mean were significantly correlated to corresponding self-reported clinical diagnoses, and the TTSS mean was significantly correlated to a global self-rating of TAND burden (ρ = 0.75; p < .001). Significant correlations were observed between the CS and CSS mean and a range of relevant standardised behavioural measures in the RDCRN cohort. The TTSS mean was significantly correlated with global measures of adaptive behaviour (ρ = − 0.75; p < .001) and emotional/behavioural difficulties (ρ = 0.71; p = .001). All CS were significantly correlated with corresponding diagnoses of autism, ADHD, anxiety disorder, depressive disorder, scholastic difficulties, and neuropsychological difficulties where reported in the RDCRN and NHD cohorts. Conclusions Findings provide support for the reliability and validity of the CS, CSS mean and TTSS mean of the TAND-SQ and support their use in clinical decision-making for TAND management and in further research.

This technical review, one of five developed by the European Society for Pediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) Special Interest Group (SIG) on Gut Microbiota and Modifications (GMM), supports the creation of a Paper on the use of biotic‐supplemented formulas, including those containing postbiotics. Postbiotics are defined as inanimate [i.e., dead, nonviable] microorganisms and/or their components that confer health benefits to the host. This review focuses on the clinical outcomes of infant formulas supplemented with postbiotics. The SIG‐GMM conducted technical review to evaluate the clinical outcomes of postbiotic‐supplemented infant formulas in healthy infants (0–12 months) published before 2024. Based on the findings of a technical review, all members of the SIG voted anonymously on statements related to clinical outcomes with a score between 0 and 9. A score higher than 6 indicated agreements. A statement was rejected if <75% of the members agreed. Twelve randomized controlled trials (RCTs) met the inclusion criteria. The postbiotics studied so far showed no difference compared to the control formula in outcomes such as anthropometric data, gastrointestinal symptoms, stool characteristics, allergy, infections, tolerability and safety. The RCTs evaluating postbiotics added to infant formula are heterogeneous due to differences in study design, variations in postbiotics and durations of interventions. The studies were powered to demonstrate and did show that there was good tolerance and adequate, safe growth comparable to nonsupplemented formula in presumed healthy infants. This technical review provides the foundation for recommendations on the use of postbiotic‐supplemented infant formulas in healthy infants.

Background Religiousness has been positively associated with better mental health and stronger self-control, including in patients with substance use disorders (SUDs) or attention deficit/hyperactivity disorder (ADHD). However, data on religiousness in patients with SUD and comorbid ADHD are lacking. Objectives This study aims to test in patients with SUD and comorbid ADHD whether (1) religiousness is negatively associated with SUD and ADHD symptom severity, and (2) self-control mediates the assumed negative association of religiousness with SUD and ADHD symptom severity. Method In an international cohort study, baseline religiousness, self-control, SUD and ADHD symptom severity, and craving were assessed with self-report questionnaires and structured clinical interviews in 578 treatment-seeking SUD patients with comorbid adult ADHD (SUD + ADHD). Data were analyzed using structural equation modeling (SEM). Results Stronger self-control wad associated with lower severity of both ADHD and SUD, but higher religiousness was only associated with lower severity of ADHD. This association was not mediated by self-control. Conclusion Religiousness may have a salutary relationship with ADHD severity, but not with SUD severity. While self-control was associated with lower symptom severity for both co-occurring conditions, it may not be involved in the potentially salutary effects of religiousness in patients with SUD + ADHD.

Purpose Cold- and hot-water immersion (CWI and HWI, respectively) are popular post-exercise recovery methods in competitive soccer. The aims of this study were to (1) compare the effect of post-exercise CWI, HWI and placebo on the recovery of physical performance in national level soccer players, and (2) investigate whether repeated use of these recovery modalities has an impact on training adaptations over a 15 week period. Methods For Part I, 40 male soccer players (15–19 years) were randomized to either CWI (10 °C, 10 min), HWI (42 °C, 20 min), or placebo (6 min, sham laser), applied after a 90 min simulated soccer match (SSM). Physical performance was assessed using submaximal aerobic, 20 m sprint, countermovement jump (CMJ), and knee extension strength tests [i.e., maximum voluntary isometric contraction (MVIC) and time to exhaustion (TTE) at 60% of MVIC] performed at Pre-SSM and 0, 21 and 45 h Post-SSM. For Part II, 19 participants applied their respective recovery modality (~ twice a week) in their usual training. After 15 weeks, physical performance and body composition were assessed and compared to pre-intervention. Results All three modalities similarly affected the recovery of physical performance during the 21–45 h Post-SSM period (p < 0.05). Moreover, no significant effects of the recovery modalities on body composition and on development of physical performance were found over the 15 week recovery intervention (p > 0.05). Conclusion Compared to a placebo, CWI and HWI do not improve post-match recovery of physical performance and do not impact long-term training adaptations in highly trained soccer players.

The correct specification of covariance structures in linear mixed models (LMMs) is critical for accurate longitudinal data analysis. These data, characterised by repeated measurements on subjects over time, demand careful handling of inherent correlations to avoid biased estimates and invalid inferences. Incorrect covariance structure specification can lead to inflated type I error rates, reduced statistical power, and inefficient estimation, ultimately compromising the reliability of statistical inferences. Traditional methods for selecting appropriate covariance structures, such as AIC and BIC, often fall short, particularly as model complexity increases or sample sizes decrease. Studies have shown that these criteria can misidentify the correct structure, resulting in suboptimal parameter estimates and poor assessment of standard errors for fixed effects. Additionally, relying on trial-and-error comparisons in LMMs can lead to overfitting and arbitrary decisions, further undermining the robustness of model selection and inference. To address this challenge, we introduce LiMMCov, an interactive app that uniquely integrates time-series concepts into the process of covariance structure selection. Unlike existing tools, LiMMCov allows researchers to explore and model complex structures using autoregressive models, a novel feature that enhances the accuracy of model specification. The app provides interactive visualisations of residuals, offering insights into underlying patterns that traditional methods may overlook. LiMMCov facilitates a systematic approach to covariance structure selection with a user-friendly interface and integrated theoretical guidance. This paper details the development and features of LiMMCov, demonstrates its application with an example dataset, and discusses its potential impact on research. The app is freely accessible at https://zq9mvv-vub0square.shinyapps.io/LiMMCov-research-tool/.

This article uncovers the potential of Augmented Reality (AR) to enhance the well‐being of the rapidly growing aging population. This substantial consumer group faces numerous challenges in sustaining well‐being and digital inclusion. Analyzing 21 records via the Theory–Context–Characteristics–Methodology (TCCM) framework provides a structured overview of how previous research investigated the use of AR to improve different types of well‐being among older consumers (i.e., physical, cognitive, psychological, and social well‐being). Prior research has been limited due to its overemphasis on AR in healthcare contexts and a lack of theoretical frameworks and methodological diversity. Furthermore, the TCCM analysis indicates that using AR to promote older adults' psychological and social well‐being is understudied. Next to presenting future research directions for consumer behavior and service researchers, this paper emphasizes five emerging themes: (1) theorizing about augmented humanity, (2) enhancing older consumers' psychological and social well‐being, (3) examining AR's versatility, (4) co‐research with older consumers, and (5) the heterogeneity in the aging population. To promote older adults' well‐being via AR, researchers, industry leaders, and policymakers should provide user‐centered service environments adjusted to older adults' heterogeneity. Finally, this review highlights what, how, and when scholars and practitioners should explore using AR to facilitate and empower older consumers' well‐being within services and consumer research.

Purpose Computer-aided navigation and patient-specific 3D printed guides have demonstrated superior outcomes in total shoulder arthroplasty (TSA). Nevertheless, few TSAs are inserted using these technologies. Head-worn augmented reality (AR) devices can provide intuitive 3D computer navigation to the surgeon. This study investigates AR navigation in conjunction with adaptive spatial drift correction toward TSA. Methods A phantom study was performed to assess the performance of AR navigated pin placement in TSA. Two medical experts performed a total of 12 pin placements into phantom scapula; six were placed using an end-to-end AR-navigated technique, and six using a common freehand technique. Inside-out infrared (IR) tracking was designed and integrated into the AR headset to correct for device drift and provide tool tracking. Additionally, the impact of IR tool tracking, registration, and superposed/juxtaposed visualization techniques was investigated. Results The AR-navigated pin placement resulted in a mean entry point error of 1.06 mm ± 0.64 mm and directional error of ${1.66^\circ \pm 0.65^\circ }$ 1 . 66 ∘ ± 0 . 65 ∘ . Compared with the freehand technique, AR navigation resulted in improved directional outcomes ( p=0.03 p = 0.03 ), while entry point accuracy was not significantly different ( p=0.44 p = 0.44 ). IR tool tracking error was 1.47 mm ± 0.69 mm and ${0.92^\circ \pm 0.50^\circ }$ 0 . 92 ∘ ± 0 . 50 ∘ , and registration error was 4.32 mm ± 1.75 mm and ${2.56^\circ \pm 0.82^\circ }$ 2 . 56 ∘ ± 0 . 82 ∘ . No statistical difference between AR visualization techniques was found in entry point ( p=0.22 p = 0.22 ) or directional ( p=0.31 p = 0.31 ) errors. Conclusion AR navigation allowed for comparable pin placement outcomes with those reported in the literature for patient-specific 3D printed guides; moreover, it complements the patient-specific planning without the need for the guides themselves.