44197 research outputs found
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Leerlingen en diversiteit: Hoe scholen intercultureel onderwijs bevorderen
No full textAls gevolg van de steeds diverser wordende samenleving staat het onderwijs voor een grote uitdaging: een hervorming van het onderwijssysteem waarbij alle leerlingen zich gezien, gewaardeerd en gestimuleerd voelen. Deze O3-proef kan een bijdrage leveren aan de ontwikkeling van het diversiteitsbewustzijn en interculturele competenties bij jongeren, met als doel leerlingen bewust te maken van diversiteit en interculturaliteit.
De onderzoeksvraag werd in samenwerking met de middelbare school het TISM als volgt geformuleerd: ‘Hoe kan het secundair onderwijs bijdragen aan de diversiteitsontwikkeling en interculturele competenties van leerlingen om multicultureel samen te werken, zowel binnen de schoolcontext als in de maatschappij?
Assessing the impact of phosphogypsum composition on radon exhalation from alkali-activated materials
No full textThis study assessed the influence of phosphogypsum (PG) composition on the immobilisation potential of 222Rn in alkali-activated materials (AAMs) made with ground granulated blast furnace slag (GGBFS). The elemental composition of PG varies according to the origin of the ore and the process used. To improve recycling of PG, the effect of varying elemental composition on binder properties and radon exhalation needs to be assessed. The matrix properties were altered by incorporating different types and concentrations of PG as dry precursor as well as by varying the molarity of the sodium hydroxide alkali-activator. The resulting alkali-activated binders were characterised using gamma-ray spectrometry, X-ray diffraction (XRD), radon exhalation, mercury porosity, and compressive strength measurements. The massic activities of 226Ra, 228Th, 228Ra, and 40K were used to determine the Activity Concentration Index (ACI) of the dry precursor mixtures. Qualitative analysis of XRD diffractograms revealed the presence of mainly ettringite, bassanite, vaterite, aragonite, gypsum, and calcite with varying peak intensities in the different binders compositions. Radon exhalation rates ranged from 8 mBq/(kg.h) to 182 mBq/ (kg.h), and these values were used to calculate the radon emanation coefficient. An increase in the PG/GGBFS ratio was associated with a reduction in total mesoporous and microporous surface area. Additionally, higher PG content in the dry precursor mix resulted in a more consistent stabilisation of compressive strength with values ranging from 15 MPa to 20 MPa. These findings highlight a novel route to reduce radon exhalation while valorising an industrial by-product. By showing that PG incorporation both densifies the AAM matrix and sustains strength, this work provides a practical framework for developing safer, radiation-aware building materials.Funding
This project has received funding from the Euratom research and training programme 2019–2020 under grant agreement No 900009 (RadoNorm) and runs under the Collaborative Doctoral Partnership between JRC and UHasselt, agreement number 35,342. Support for this work was provided by the King Baudouin foundation [project 2020- E2141050-E001].
Acknowledgement
This project has received funding from the Euratom research and training programme 2019–2020 under grant agreement No 900009 (RadoNorm) and runs under the Collaborative Doctoral Partnership between JRC and UHasselt, agreement number 35342. Support for this work was provided by the King Baudouin foundation [project 2020- E2141050-E001]
Using Read Promotion and Mixed Isolation Levels for Performant Yet Serializable Execution of Transaction Programs
No full textWe propose a theory that can determine the lowest isolation level that can be allocated to each transaction program in an application in a mixed-isolation-level setting, to guarantee that all executions will be serializable and thus preserve all integrity constraints, even those that are not explicitly declared. This extends prior work applied to completely known transactions, to deal with the realistic situation where transactions are generated by running programs with parameters that are not known in advance. Using our theory, we propose an optimization method that allows for high throughput while ensuring that all executions are serializable. Our method is based on searching for application code modifications that are semantics-preserving while improving the isolation level allocation. We illustrate our approach to the SmallBank benchmark.This work was partly funded by FWO-grant G019921. Stijn Vansummeren was partially supported by the Bijzonder Onderzoeksfonds (BOF) of Hasselt University (Belgium) under Grant No. BOF20ZAP02. The resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Research Foundation - Flanders (FWO) and the Flemish Government
Mobile LiDAR applications to monitor the urban forest in the city of Hasselt, Belgium
No full textUrban forests provide essential ecosystem services and are key components of urban policy-making. Both accounting for these ecosystem services and effective urban forest management planning, however, requires an upto-date and detailed 3D tree inventory. Conducting and maintaining up-to-date tree inventories often involves field visits and manual recordings. In this study, we demonstrate the applicability of close-range remote sensing in measuring and monitoring tree characteristics over time. A mobile LiDAR system was deployed to collect dense point clouds (1789.92 points/m2) in the city of Hasselt, Belgium. The proposed individual tree detection algorithm obtained a recall score of 0.84, a precision of 0.82 and an F-score of 0.83. The average estimated characteristics were: tree height (H) of 9.84 f 2.68 m, diameter at breast height (DBH) of 0.48 f 0.74 m, crown projection (PA) of 14.87 f 11.60 m2 and crown volume (AV) of 73.59 f 98.42 m3 . For a subset of 47 manually measured trees (r)RMSE values were 0.58 m (259 %) and 0.96 m (10 %) for DBH and H, respectively. Excluding incorrectly segmented trees mainly improved (r)RMSE values of DBH (0.05 m, 21 %) and only had a minor effect on H (0.95 m, 11 %). Two case studies based on multi-temporal MLS-datasets allowed to estimate the volume of pruning biomass and to detect a nest of Asian hornet (Vespa velutina). The obtained results can support both policy-making and operational planning by integrating 3D tree inventories and assessing the effect of management activities.We acknowledge the support of the city administration of Hassel
Statistical methods for analysis of overdispersed and correlated next-generation sequencing data
No full textAdvances in next-generation sequencing (NGS) have fundamentally transformed the
study of genome biology, providing researchers with an unprecedented ability to investigate
gene expression and epigenetic modifications at high resolution. This technological
breakthrough has driven advances in multiple “-omics” fields, including
transcriptomics, epigenomics, metagenomics, and more. Unlike traditional sequencing
methods, NGS allows for parallel sequencing of hundreds to thousands of genes,
or even entire genomes, within a short timeframe. With vast amounts of data, NGS
offers insights into fundamental biological processes and their role in disease. However,
the complexity of NGS data presents significant statistical challenges, requiring
specialized methods to account for overdispersed and correlated data, and ambiguities
in read assignment.
The main goal of this dissertation was the development of statistical methodologies
tailored for the analysis of epigenomic and transcriptomic datasets, which are often
characterized by complex structures, including overdispersion, correlation, and dependence
between observations. These challenges arise due to the nature of bisulfite
sequencing (BS-seq) and RNA sequencing (RNA-seq) technologies, both of which generate
high-dimensional and structured count-based data requiring advanced statistical
approaches for accurate inference
Prediction of Left Ventricular Filling Pressures Using Natural Shear Waves
No full textBackground
Increased myocardial stiffness can lead to diastolic dysfunction, resulting eventually in increased left ventricular filling pressures (LVFPs). The clinical assessment of left ventricular (LV) diastolic function is challenging. Shear wave elastography is a novel method based on tracking shear waves, such as those induced by mitral valve closure (MVC), using high frame rate (HFR) echocardiography. The propagation velocity of shear waves is directly related to myocardial stiffness.
Objectives
This study investigated whether shear wave velocity at MVC is related to invasively measured LVFP.
Methods
Eighty-five patients were prospectively enrolled. Left ventricular mid-diastolic pressure (LVMDP) and left ventricular end-diastolic pressure (LVEDP) were invasively measured. HFR (average frame rate: 1,050 ± 220 Hz) and conventional echocardiography were performed immediately after catheterization. Shear wave velocity at MVC was measured in the anteroseptal wall. The findings were compared with conventional echocardiographic parameters and the multiparametric 2021 guideline-recommended algorithm for the estimation of LVFP. The direct response of shear wave velocity at MVC on changing LV filling pressures was tested in a group of 16 patients with acutely decompensated heart failure (DHF) on admission and after diuretic therapy.
Results
Single conventional echocardiographic parameters correlated moderately with LVFP (Pearson r between 0.39 and 0.58) and had a moderate ability to detect elevated LVFP (AUC between 0.66 and 0.79). This was similar for the multiparametric guideline algorithm (LVMDP AUC: 0.78; LVEDP AUC: 0.60). In comparison, shear wave velocities at MVC as a single measure correlated strongly with LVEDP (r = 0.71; P < 0.001) and had an similar ability to predict elevated LVMDP (AUC: 0.79; sensitivity: 87%; specificity: 65%) and an excellent ability to predict elevated LVEDP (AUC: 0.95; sensitivity: 92%; specificity: 94%) when a cutoff value of 4.8 m/s was used. In DHF patients, we observed a significant decrease in shear wave velocity after diuretic therapy (7.1 ± 1.7 m/s vs 5.3 ± 1.3 m/s; P < 0.002).
Conclusions
In comparison with the multivariable guideline approach, end-diastolic shear wave velocity as a single measure had similar accuracy in detecting elevated LVMDP and a higher accuracy for LVEDP. Shear wave elastography might therefore be a promising new tool for the noninvasive assessment of diastolic function
De kracht van ervaringsdeskundigheid binnen de kinderrevalidatie: een kwalitatieve verkenning van de percepties van zorgprofessionals
No full textAchtergrond: Ervaringsdeskundigheid krijgt meer erkenning in de zorg, maar ontbreekt vaak
in de kinderrevalidatie. Ervaringskennis, gevormd door eigen beleving en gedeeld met
anderen, kan tot deskundigheid leiden. Het integreren van deze kennis naast
wetenschappelijke en professionele inzichten verrijkt het revalidatieproces en erkent de
waarde van persoonlijke ervaringen in de zorg. Er is nauwelijks literatuur over het gebruik van
ervaringskennis en -deskundigheid en er zijn tot nu toe geen studies gedaan in de Belgische
context. Deze studie onderzoekt hoe zorgprofessionals de inzet van ex-patiënten als ervaringsdeskundigen binnen kinderrevalidatieteams duiden.
Methode: Beschrijvend kwalitatief onderzoek via semigestructureerde interviews met acht zorgprofessionals in de kinderrevalidatie.
Resultaten: Twee hoofdthema’s kwamen naar voren: voorwaarden voor succesvolle inzet (zoals een passende match en ondersteuning) en uitdagingen (zoals impact op betrokkenen en onbekendheid met het concept).
Conclusie: De ervaringsdeskundige vormt een brug tussen patiënt en zorgverlener met unieke inzichten die de zorg verrijken. Ondanks beperkte ervaring zien zorgprofessionals een duidelijke meerwaarde, mits goede begeleiding en ondersteuning worden voorzien
Renal transcriptome-wide analyses in association with kidney black carbon load
No full textRationale and objectiveInhaled black carbon (BC) has been previously shown to reach and accumulate in the kidneys. As kidneys filter toxicants, they may be susceptible to adverse effects caused by BC accumulation. We studied gene expressions and pathways related to BC particle load in kidney biopsy tissue.Study designGene expression was measured in 29 kidney biopsies performed at one or two years post-transplantation using Affymetrix microarray. We performed a transcriptome-wide association analysis using linear regression analyses, adjusting for individual characteristics to investigate alterations in gene expression in association with kidney BC. Finally, we performed overrepresentation analyses (ConsensusPathDB) to identify enriched pathways and gene ontology sets.ResultsThe geometric mean (5th, 95th percentile) of BC particle levels was 5.4 x 103 (1.5 x 103, 4.1 x 104) number of BC particles per mm(3) kidney tissue. The BC particle load associated with gene expression in overrepresenting pathways related to ciliopathies, macrophage-derived proteins involved in anti-inflammatory response, DNA damage response, TP53 regulation, and necrosis. We identified BC associated genes involved in GO terms ciliogenesis and ciliary structure, including genes involved in the ciliary plasm and axoneme. Furthermore, we found significantly BC-associated genes involved in RNA-related processes, including e.g., genes in the integrator complex.ConclusionsHere, we identified genes and pathways associated with real-life kidney BC particle load, indicating alterations in gene expression involved in assembly and maintenance of primary cilia, the anti-inflammatory properties of the innate immune system, and DNA damage-related pathways. These findings highlight the need for public health measures to reduce exposure and protect kidney health in at-risk populations.Funding
LR acknowledges funding from the Special Research Fund (Special Research Fund, BOF) for a doctoral fellowship: BOF20DOC15. The BC work is supported by a Methusalem grant from TSN. The Research Foundation Flanders (FWO) funds JC (1196119 N) and MN (1844019 N). Additionally, MN is supported by an ERAcoSysMed H2020 grant (JTC2_29), and a C3 internal grant from the KU Leuven (C32/17/049). None of the funding agencies had a role in the design and conduct of the study, in the collection, analysis and interpretation of the data, or in the preparation, review, or approval of the manuscript.
Acknowledgements
The authors want to express their greatest gratitude to the kidney transplant patients, as well as the staff of the department of Nephrology at the University Hospitals Leuven
