Université Libre de Bruxelles
Recent publications
Conspiracy theories – which posit that secret groups cooperate to pursue malevolent goals – are a prominent feature in social and political discourse. Psychological research on conspiracy theories has boomed in the past 20 years, generating insights to the correlates and consequences of conspiracy beliefs. However, the literature suffers some limitations; the current editorial identifies five that constrain this relatively young field of research and recommends that future research (1) consider different forms of conspiracy beliefs and their distinct correlates and effects, (2) rely more on experiments to allow for conclusions about causality, (3) conduct more research that is high in external validity, (4) dedicate more attention to the cognitive processes underlying conspiracy beliefs, and (5) study methods for potential interventions. The current Virtual Special Issue highlights cutting-edge research that addresses some of these limitations. In particular, they highlight the importance of experimental methods in advancing this growing research field.
We show the existence of a majorization ladder in bosonic Gaussian channels, that is, we prove that the channel output resulting from the [Formula: see text] energy eigenstate (Fock state) majorizes the channel output resulting from the [Formula: see text] energy eigenstate (Fock state). This reflects a remarkable link between the energy at the input of the channel and a disorder relation at its output as captured by majorization theory. This result was previously known in the special cases of a pure-loss channel and quantum-limited amplifier, and we achieve here its non-trivial generalization to any single-mode phase-covariant (or -contravariant) bosonic Gaussian channel. The key to our proof is the explicit construction of a column-stochastic matrix that relates the outputs of the channel for any two subsequent Fock states at its input. This is made possible by exploiting a recently found recurrence relation on multiphoton transition probabilities for Gaussian unitaries [Jabbour and Cerf, Phys. Rev. Res. 3, 043065 (2021)]. Possible generalizations and implications of these results are then discussed.
From 10 months of age, human infants start to understand the function of the eyes in the looking behavior of others to the point where they preferentially orient toward an object if the social partner has open eyes rather than closed eyes. Thus far, gaze following has been investigated in controlled laboratory paradigms. The current study investigated this early ability using a remote live testing procedure, testing infants in their everyday environment while manipulating whether the experimenter could or could not see some target objects. A total of 32 11- and 12-month-old infants’ looking behavior was assessed, varying the experimenter’s eye status condition (open eyes vs closed eyes) in a between-participant design. Results showed that infants followed the gaze of a virtual social partner and that they preferentially followed open eyes rather than closed eyes. These data generalize past laboratory findings to a noisier home environment and demonstrate gaze processing capacities of infants to a virtual partner interacting with the participants in a live setup.
On 4-symmetric symplectic spaces, invariant almost complex structures -up to sign- arise in pairs. We exhibit some 4-symmetric symplectic spaces, with a pair of “natural” compatible (usually not positive) invariant almost complex structures, one of them being integrable and the other one being maximally non-integrable (i.e. the image of its Nijenhuis tensor at any point is the whole tangent space at that point). The integrable one defines a pseudo-Kähler Einstein metric on the manifold, and the non-integrable one is Ricci Hermitian (in the sense that the almost complex structure preserves the Ricci tensor of the associated Levi Civita connection) and special in the sense that the associated Chern Ricci form is proportional to the symplectic form.
Aims: Upregulated p38MAPK signaling is implicated in the accelerated proliferation of pulmonary artery smooth muscle cells (PA-SMCs) and the pathogenesis of pulmonary artery remodeling observed in pulmonary arterial hypertension (PAH). Previously, we reported that after endothelin-1 (ET-1) pretreatment, bone morphogenetic protein 2 (BMP2) activates p38MAPK signaling and accelerates PA-SMC proliferation. The activity of p38MAPK signaling is tightly regulated by the inactivation of dual-specificity phosphatase 1 (DUSP1). Activated p38MAPK induces DUSP1 expression, forming a negative feedback loop. Prostacyclin IP receptor agonists (prostacyclin and selexipag) are used to treat PAH. In this study, we aimed to verify whether IP receptor agonists affect DUSP1 expression and accelerate the proliferation of PA-SMCs. Main methods: PA-SMCs were treated with BMP2, ET-1, prostacyclin, and MRE-269, an active metabolite of selexipag, either alone or in combination. We quantified mRNA expressions using real-time quantitative polymerase chain reaction. Pulmonary artery specimens and PA-SMCs were obtained during lung transplantation in patients with PAH. Key findings: Both prostacyclin and MRE-269 increased DUSP1 expression. Combined treatment with BMP2 and ET-1 induced cyclin D1 and DUSP1 expression and increased PA-SMC proliferation. MRE-269 attenuated BMP2/ET-1-induced cell proliferation. ET-1 increased DUSP1 expression in PA-SMCs from control patients but not in PA-SMCs from patients with PAH. Significance: This study showed that the p38MAPK/DUSP1 negative feedback loop is impaired in PAH, contributing to unregulated p38MAPK activation and PA-SMC hyperplasia. IP receptor agonist MRE-269 increases DUSP1 expression and inhibit p38MAPK-mediated PA-SMC proliferation. Future elucidation of the detailed mechanism underlying reduced DUSP1 expression would be informative for PAH treatment.
Owing to its high porosity and tunable surface chemistry activated carbon (AC) is considered a promising material for CO2 adsorption. Functionalising porous materials by plasma is challenging but if successful, it could enhance the CO2 uptake capacity of AC via chemisorption. This work presents an in-depth analysis of the interactions between ammonia plasmas and the porous surface of AC monolithic samples. The treatment involved an ammonia based atmospheric-pressure dielectric barrier discharge and a low-pressure radio frequency plasma. Unique plasma reactor designs for treating 3-dimensional, electrically conducting and non-conducting monolithic structures at atmospheric pressure with versatile applications are presented. The plasma-surface interactions were analysed using emission spectroscopy and X-ray photoelectron spectroscopy. High surface N containing AC samples were then used to assess the treatment effect on the subsurface. A much lower although a still significant amount of N was found at depths of ∼30 µm. A simple fit of the results showed that the ratio of plasma species reaching the surface with higher to lower sticking probability was 4:1. A slight decrease in the microporosity of the plasma treated samples was found and attributed to pore blocking by the grafted N species. Plasma treated AC with high N showed an improved CO2 adsorption capacity of up to 14 % and selectivity against CH4 and N2 adsorption showed that the treatment was selective primarily towards CO2.
Background Immune checkpoint-inhibitors (ICIs) are changing outcomes in different cancer settings, notably for patients with non-small-cell lung cancer (NSCLC). There are, however, still important gaps of evidence for clinical practice when using these novel treatments. In this study, we assessed physicians’ opinion and experience on challenges for clinical practice with ICIs monotherapy in NSCLC. Methods A survey was conducted on experienced physicians treating patients with NSCLC with ICIs. Two rounds of pilot tests were carried out for validation among a group of experts. Topics under analysis were in relation to treatment of elderly populations, performance status, brain metastases, use of steroids or antibiotics, the effects of gut microbiome, autoimmune diseases, human immunodeficiency virus infection, solid organ transplants, use of anti-programmed cell death protein 1 versus anti-programmed death-ligand 1 drugs, atypical tumour responses, predictors of response, duration of treatment and a final open question on additional relevant challenges. Results Two hundred and twenty-one answers were collected, including 106 (48%) valid answers from experts for final analysis (physicians who have treated at least 20 patients with NSCLC with ICIs). The vast majority agreed that the selected topics in this study are important challenges ahead and more evidence is needed. Moreover, predictors of response, treating brain metastasis, shorter duration of treatment, the effects of gut microbiome and concomitant use of steroids were voted the most important topics to be further addressed in prospective clinical research. Conclusions This survey contributed to understanding which are the main challenges for clinical practice with ICIs monotherapy in NSCLC. It can also contribute to guide further clinical research, considering the opinions and experience of those who regularly treat NSCLC patients with ICIs.
Politicians regularly bargain with colleagues and other actors. Bargaining dynamics are central to theories of legislative politics and representative democracy, bearing directly on the substance and success of legislation, policy, and on politicians’ careers. Yet, controlled evidence on how legislators bargain is scarce. Do they apply different strategies when engaging different actors? If so, what are they, and why? To study these questions, we field an ultimatum game bargaining experiment to 1,100 sitting politicians in Belgium, Canada, Germany, Switzerland, and the United States. We find that politicians exhibit a strong partisan bias when bargaining, a pattern that we document across all of our cases. The size of the partisan bias in bargaining is about double the size when politicians engage citizens than when they face colleagues. We discuss implications for existing models of bargaining and outline future research directions.
Molecular packing controls optoelectronic properties in organic molecular nanomaterials. Here we report a donor–acceptor organic molecule (2,6-bis(4-cyanophenyl)-4-(9-phenyl-9H-carbazol-3-yl)pyridine-3,5-dicarbonitrile) that exhibits two aggregate states in aqueous dispersions: amorphous nanospheres and ordered nanofibres with π–π molecular stacking. The nanofibres promote sacrificial photocatalytic H2 production (31.85 mmol g−1 h−1) while the nanospheres produce hydrogen peroxide (H2O2) (3.20 mmol g−1 h−1 in the presence of O2). This is the first example of an organic photocatalyst that can be directed to produce these two different solar fuels simply by changing the molecular packing. These different packings affect energy band levels, the extent of excited state delocalization, the excited state dynamics, charge transfer to O2 and the light absorption profile. We use a combination of structural and photophysical measurements to understand how this influences photocatalytic selectivity. This illustrates the potential to achieve multiple photocatalytic functionalities with a single organic molecule by engineering nanomorphology and solid-state packing. A donor–acceptor molecule assembles with different molecular packing to form photocatalysts which selectively produce either H2 or H2O2, depending on the aggregate structure, a proof-of-concept of photoactivity polymorphism.
The lifetime of the 11/21+ state in the Sb131 nucleus was measured at the LOHENGRIN spectrometer of the Institut Laue-Langevin via neutron-induced fission of U235 using γ-ray fast-timing techniques. The obtained value of T1/2=3(2) ps, at the edge of the sensitivity of the experimental method, is the first result for the 11/21+ state half-life in neutron-rich Sb isotopes. The corresponding quadrupole reduced transition probability to the ground state is B(E2)=1.4−0.6+1.5W.u., indicating a noncollective nature of this state. Realistic shell-model calculations performed in a large valence space reproduce well the experimental value and point to a dominant 2+(Sn130)⊗πg7/2 configuration for the 11/21+ state, as expected in a weak-coupling scenario. At the same time, the sum of the quadrupole strength of the multiplet states is predicted to exceed the one of the Sn130 core as a consequence of the equal contribution of the proton and the proton-neutron quadrupole matrix elements, pointing to possible development of collectivity already in the close neighborhood of Sn132.
Purpose: This study reports the short- and mid-term benefits of an eight-session emotion and self-regulation group intervention ecologically boosted through daily app-based prompts. The intervention was designed for breast cancer patients in the early survivorship period meeting criteria for clinical levels of psychological symptoms. Methods: Patients were randomly assigned to the immediate intervention arm (n=61; intervention received immediately) or to the delayed intervention arm (n=59; intervention received five months later). Psychological symptoms, including anxiety, depressive symptoms, emotional distress, fear of cancer recurrence (FCR), worry, and intrusive thoughts were assessed through questionnaires. Emotion regulation was assessed in a dynamic emotion regulation task and in everyday life. Assessments were completed at baseline (T1), five months (T2) and ten months (T3) later. Results: Treated patients reported lower levels of worry and intrusive thoughts. They improved their ability to down-regulate the intensity of their negative emotions when exposed to cancer-related triggers in the dynamic emotion regulation task. They reported fewer and less intense negative emotions and more positive emotions in their everyday life. Benefits were maintained five months later, except for positive emotions in everyday life. Conclusions: The results showed that focusing on emotion regulation is a relevant approach in the treatment of psychological symptoms for breast cancer patients in the early survivorship period meeting criteria for clinical levels of psychological symptoms. The intervention led to changes in patients' dynamic and everyday life emotion regulation. Consolidation sessions may be needed to sustain benefits in positive emotions and to increase the effect sizes. This article is protected by copyright. All rights reserved.
We developed a reaction-transport model capable of tracing iron isotopes in marine sediments to quantify the influence of bioturbation on the isotopic signature of the benthic dissolved (DFe) flux. By fitting the model to published data from marine sediments, we calibrated effective overall fractionation factors for iron reduction (–1.3‰), oxidation (+0.4‰), iron-sulfide precipitation (+0.5‰) and dissolution (−0.5‰) and pyrite precipitation (−0.7‰) that agree with literature values. Results show that for bottom-water oxygen concentrations greater than 50 µM, higher bioturbation increased the benthic DFe flux and its δ ⁵⁶ Fe signature. By contrast, for oxygen concentrations less than 50 µM, higher bioturbation decreased the benthic DFe flux and its δ ⁵⁶ Fe signature. The expressed overall fractionation of the benthic DFe flux relative to the δ ⁵⁶ Fe of the iron oxides entering the sediment ranges from −1.67‰ to 0.0‰. On a global scale, the presence of bioturbation increases sedimentary DFe release from approximately 70 G mol DFe yr ⁻¹ to approximately 160 G mol DFe yr ⁻¹ and decreases the δ ⁵⁶ Fe signature of the DFe flux.
Blood phenotypes are defined by the presence or absence of specific blood group antigens at the red blood cell (RBC) surface, due to genetic polymorphisms among individuals. The recent development of genomic and proteomic approaches enabled the characterization of several enigmatic antigens. The choline transporter-like protein CTL2 encoded by the SLC44A2 gene plays an important role in platelet aggregation and neutrophil activation. By investigating alloantibodies to a high-prevalence antigen of unknown specificity, found in patients with a rare blood type, we showed that SLC44A2 is also expressed in RBCs and carries a new blood group system. Furthermore, we identified three siblings homozygous for a large deletion in SLC44A2, resulting in complete SLC44A2 deficiency. Interestingly, the first-ever reported SLC44A2-deficient individuals suffer from progressive hearing impairment, recurrent arterial aneurysms, and epilepsy. Furthermore, SLC44A2null individuals showed no significant platelet aggregation changes and do not suffer from any apparent hematological disorders. Overall, our findings confirm the function of SLC44A2 in hearing preservation and provide new insights into the possible role of this protein in maintaining cerebrovascular homeostasis.
Over recent decades, increasing attention has been paid to how low-molecular-weight molecules impact thermal tolerance in animals. While the disaccharide sugar trehalose is known to serve as a thermal protectant in unicellular organisms, nothing is known about its potential role in insects. In this study, we investigated the effect of trehalose on heat tolerance in the Namib desert ant, Ocymyrmex robustior, one of the most thermotolerant animals found in terrestrial ecosystems. First, we tested whether a trehalose-supplemented diet increased worker survival following exposure to heat stress. Second, we assessed the degree of protein damage by comparing protein aggregation levels for trehalose-supplemented workers and control workers. Third, we compared the expression levels of three genes involved in trehalose metabolism. We found that trehalose supplementation significantly enhanced worker heat tolerance, increased metabolic levels of trehalose, and reduced protein aggregation under conditions of heat stress. Expression levels of the three genes varied in a manner that was consistent with the maintenance of trehalose in the hemolymph and tissues under conditions of heat stress. Altogether, these results suggest that increased trehalose concentration may help protect individuals against heat stress in the Namib desert ant. More generally, they highlight the role played by sugar metabolites in boosting tolerance in extremophiles.
In this technical note we study the computation of the Maximal Output Admissible Set for linear systems subject to polynomial constraints. The computation of an inner approximation of the Maximal Output Admissible Sets requires the determination of constraint redundancy. We use a procedure to determine polynomial constraint redundancy based on a consequence of Putinar's Positivstellensatz. Further, we present a modification of the algorithm to compute the Maximal Output Admissible Set with improved performance. Lastly, demonstrate the potential for practical applications in two case studies of spacecraft rendezvous and control of an electromagnetic actuator.
Main recommendations Obesity is a chronic, relapsing, degenerative, multifactorial disease that is associated with many co-morbidities. The global increasing burden of obesity has led to calls for an urgent need for additional treatment options. Given the rapid expansion of bariatric endoscopy and bariatric surgery across Europe, the European Society of Gastrointestinal Endoscopy (ESGE) has recognized the need to formalize and enhance training in bariatric endoscopy and the endoscopic treatment of bariatric surgical adverse events. This manuscript represents the outcome of a formal Delphi process resulting in an official Position Statement of the ESGE and provides a framework to develop and maintain skills in bariatric endoscopy and the endoscopic treatment of bariatric surgical adverse events. This curriculum is set out in terms of the prerequisites prior to training, minimum number of procedures, the steps for training and quality of training, and how competence should be defined and evidenced before independent practice. 1 ESGE recommends that every endoscopist should have achieved competence in upper gastrointestinal endoscopy before commencing training in bariatric endoscopy and the endoscopic treatment of bariatric surgical adverse events. 2 Trainees in bariatric endoscopy and the endoscopic treatment of the complications of bariatric surgery should have basic knowledge of the definition, classification, and social impact of obesity, its pathophysiology, and its related co-morbidities. The recognition and management of gastrointestinal diseases that are more common in patients with obesity, along with participation in multidisciplinary teams where obese patients are evaluated, are mandatory. 3 ESGE recommends that competency in bariatric endoscopy and the endoscopic treatment of the complications of bariatric surgery can be learned by attending validated training courses on simulators initially, structured training courses, and then hands-on training in tertiary referral centers.
Initially proposed by Martin Gardner in the 1950s, the famous two-children problem is often presented as a paradox in probability theory. A relatively recent variant of this paradox states that, while in a two-children family for which at least one child is a girl, the probability that the other child is a boy is 2/3, this probability becomes 1/2 if the first name of the girl is disclosed (provided that two sisters may not be given the same first name). We revisit this variant of the problem and show that, if one adopts a natural model for the way first names are given to girls, then the probability that the other child is a boy may take any value in (0,2/3). By exploiting the concept of Schur-concavity, we study how this probability depends on model parameters.
The abyssal plains are vast areas without large scale relief that occupy much of the ocean floor. Although long considered relatively featureless, they are now known to display substantial biological heterogeneity across different spatial scales. Ecological research in these regions benefits increasingly from non-destructive visual sampling of epifaunal organisms with imaging technology. We analysed images from ultra-high-definition towed camera transects at depths of around 3500 m across three stations (100–130 km apart) in the Bering Sea, to ask whether the density and distribution of visible epifauna indicated any substantial heterogeneity. We identified 71 different megafaunal taxa, of which 24 occurred at only one station. Measurements of the two most abundant faunal elements, the holothurian Elpidia minutissima and two xenophyophores morphotypes (the more common identifiable as Syringammina limosa), indicated significant differences in local densities and patchy aggregations that were strikingly dissimilar among stations. One station was dominated by xenophyophores, one was relatively depauperate in both target taxa as well as other identified megafauna, and the third station was dominated by Elpidia. This is an unexpected level of variation within comparable transects in a well-mixed oceanic basin, reinforcing the emerging view that abyssal habitats encompass biological heterogeneity at similar spatial scales to terrestrial continental realms.
Background Congenital heart defects (CHDs) are a major global health problem, yet their crucial environmental risk factors are still unclear. We aimed to explore the associations between maternal periconceptional environmental exposures and all CHDs, isolated and multiple CHDs and CHDs subtypes. Method A case–control study including 675 infants with CHDs and 1545 healthy controls was conducted. Participating mothers who delivered in Guangzhou from October 2019 to November 2021 were recruited. To examine the independent associations between maternal periconceptional environmental exposure and offspring with CHDs, we calculated odds ratios (ORs) and 95% confidence intervals (CIs) using multivariable logistic regression model. Results Maternal exposure to living near main roads [adjusted OR (aOR) = 1.94, 95% CI = 1.06–3.56] and housing renovation (aOR = 1.94, 95% CI = 1.03–3.67) during the periconceptional period were positively related to a greater risk of all CHDs, similar results were also found in isolated CHDs rather than multiple CHDs. Additionally, living near main roads was positively associated with secundum atrial septal defect/patent foramen ovale (aOR = 2.65, 95% CI = 1.03–6.81) and housing renovation was strongly positively associated with ventricular septal defect (aOR = 5.08, 95% CI = 2.05–12.60). However, no association was observed between incense burning and family relationships and all CHDs, isolated and multiple CHDs and CHDs subtypes. Conclusion Living near main roads and housing renovation during the periconceptional period are significantly associated with the increased risks for all CHDs and isolated CHDs. Further study is needed to extend sample size to explore the effects of time and frequency of burning incense and family relationships on CHDs in offspring.
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Matteo Gagliolo
  • Research Group on Ethnic Relations, Migration and Equality (GERME)
Marco Dorigo
  • Artificial Intelligence Research Laboratory of the Université Libre de Bruxelles (IRIDIA)
Martin Van Damme
  • Service de Chimie quantique et Photophysique
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Head of institution
Annemie Schaus
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