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Experience sampling method studies in physical activity research : the relevance of causal reasoning
No full textBackgroundThe experience sampling method (ESM), also known as ecological momentary assessment, is gaining popularity in physical activity research. This method involves assessing participants' behaviors and experiences repeatedly over time. One key advantage of ESM is its ability to temporally separate the dependent and independent variable of interest, reducing the risk of reverse causality. However, temporal separation alone is insufficient for establishing causality. This methodology paper illustrates the importance of the identification phase in drawing causal conclusions from ESM data. In the identification phase the causal effect of interest (or estimand) is specified and the assumptions under which a statistical association can be considered as causal are visualized using causal directed acyclic graphs (DAGs).MethodsWe demonstrate how to define a causal estimand and construct a DAG for a specific ESM research question. The example focuses on the causal effect of physical activity performed in real-life on subsequent executive functioning among older adults. The DAG development process combines literature review and expert consultations to identify time-varying and time-invariant confounders.ResultsThe developed DAG shows multiple open backdoor paths causing confounding bias, even with temporal separation of the exposure (physical activity) and outcome (executive functioning). Two approaches to address this confounding bias are illustrated: (1) physical control using the within-person encouragement design, where participants receive randomized prompts to perform physical activity in their natural environment, and (2) analytic control, involving assessing all confounding variables and adjusting for these variables in the analysis phase.ConclusionsImplementing the identification phase enables ESM researchers to make more informed decisions, thereby enhancing the validity of causal inferences in studies aimed at answering causal questions.BackgroundThe experience sampling method (ESM), also known as ecological momentary assessment, is gaining popularity in physical activity research. This method involves assessing participants' behaviors and experiences repeatedly over time. One key advantage of ESM is its ability to temporally separate the dependent and independent variable of interest, reducing the risk of reverse causality. However, temporal separation alone is insufficient for establishing causality. This methodology paper illustrates the importance of the identification phase in drawing causal conclusions from ESM data. In the identification phase the causal effect of interest (or estimand) is specified and the assumptions under which a statistical association can be considered as causal are visualized using causal directed acyclic graphs (DAGs).MethodsWe demonstrate how to define a causal estimand and construct a DAG for a specific ESM research question. The example focuses on the causal effect of physical activity performed in real-life on subsequent executive functioning among older adults. The DAG development process combines literature review and expert consultations to identify time-varying and time-invariant confounders.ResultsThe developed DAG shows multiple open backdoor paths causing confounding bias, even with temporal separation of the exposure (physical activity) and outcome (executive functioning). Two approaches to address this confounding bias are illustrated: (1) physical control using the within-person encouragement design, where participants receive randomized prompts to perform physical activity in their natural environment, and (2) analytic control, involving assessing all confounding variables and adjusting for these variables in the analysis phase.ConclusionsImplementing the identification phase enables ESM researchers to make more informed decisions, thereby enhancing the validity of causal inferences in studies aimed at answering causal questions.A
How to set up a formal design thinking course that works? A practical guide for higher education settings
No full textDesign Thinking has been gaining ground in different disciplines at higher education institutions worldwide as it is seen as a way to develop 21st century student skills; especially creativity, problem solving and teamwork. It provides a student-centred approach linked to constructivist learning theory. However, the available literature fails to shed light on how to successfully facilitate Design Thinking for non-designers, not only to learn the methodology but also to improve such 21st century skills. This paper shares a thorough guide to assist any educator or educational manager interested in implementing an evidence-based intervention that has proven to teach Design Thinking while also improving key skills such as problem solving, creativity and teamwork. We provide full disclosure of a semester-wide intervention of a university level course for first-year undergraduate students enrolled in different programs. We present results about the course effectiveness from the point of view of students, facilitators and sponsors. Key features of this course design include: a stepwise approach to learn the Design Thinking methodology, class sessions that follow a hands-on approach with space for instant feedback, exposition to real-life problems and teamwork, and a classroom environment pertinent for teaching Design Thinking. This work not only provides theoretical and practical implications but also serves as a guiding framework for effective design facilitation, from non-designer facilitators to non-designer students, with potential to be applied, adjusted, or even rebuilt for diverse subject disciplines and specific contexts.Design Thinking has been gaining ground in different disciplines at higher education institutions worldwide as it is seen as a way to develop 21st century student skills; especially creativity, problem solving and teamwork. It provides a student-centred approach linked to constructivist learning theory. However, the available literature fails to shed light on how to successfully facilitate Design Thinking for non-designers, not only to learn the methodology but also to improve such 21st century skills. This paper shares a thorough guide to assist any educator or educational manager interested in implementing an evidence-based intervention that has proven to teach Design Thinking while also improving key skills such as problem solving, creativity and teamwork. We provide full disclosure of a semester-wide intervention of a university level course for first-year undergraduate students enrolled in different programs. We present results about the course effectiveness from the point of view of students, facilitators and sponsors. Key features of this course design include: a stepwise approach to learn the Design Thinking methodology, class sessions that follow a hands-on approach with space for instant feedback, exposition to real-life problems and teamwork, and a classroom environment pertinent for teaching Design Thinking. This work not only provides theoretical and practical implications but also serves as a guiding framework for effective design facilitation, from non-designer facilitators to non-designer students, with potential to be applied, adjusted, or even rebuilt for diverse subject disciplines and specific contexts.A
Multi-physics simulation of adhesives for structural joints in hygrothermal environments considering mechanical degradation
No full textAdhesive joints are increasingly utilized to address structural challenges by overcoming non-uniform stress transfer and stress concentration common in mechanical joint systems. For hybrid Fiber Reinforced Polymer (FRP)/concrete systems, interfacial bond strength is governed by adhesive joints, which are highly sensitive to environmental factors like moisture and temperature. Moisture ingress, from the surrounding environment and from concrete, can induce hydrolytic degradation, significantly altering the mechanical properties of the adhesive. To address these issues, a nonlinear Finite Element Method (FEM)-based model has been developed, coupling moisture diffusion with a mechanical degradation model for thermoset polymers. This multi-physics framework is able to capture moisture exchange between adhesive, concrete, and the environment, predicting the performance of bulk adhesive under hygrothermal conditions. Calibration and validation were performed using experimental data from bulk adhesive samples. A parametric study on the diffusion model was performed to discuss the influence of the model parameters on the mechanical behavior of bulk adhesive. Furthermore, predictive proof-of concept simulations were conducted, including its application to two representative single-lap shear tests: steel-steel system and FRP-concrete system. This case study aids in evaluating and understanding the fundamental mechanisms of moisture diffusion and mechanical degradation in structural joints.Adhesive joints are increasingly utilized to address structural challenges by overcoming non-uniform stress transfer and stress concentration common in mechanical joint systems. For hybrid Fiber Reinforced Polymer (FRP)/concrete systems, interfacial bond strength is governed by adhesive joints, which are highly sensitive to environmental factors like moisture and temperature. Moisture ingress, from the surrounding environment and from concrete, can induce hydrolytic degradation, significantly altering the mechanical properties of the adhesive. To address these issues, a nonlinear Finite Element Method (FEM)-based model has been developed, coupling moisture diffusion with a mechanical degradation model for thermoset polymers. This multi-physics framework is able to capture moisture exchange between adhesive, concrete, and the environment, predicting the performance of bulk adhesive under hygrothermal conditions. Calibration and validation were performed using experimental data from bulk adhesive samples. A parametric study on the diffusion model was performed to discuss the influence of the model parameters on the mechanical behavior of bulk adhesive. Furthermore, predictive proof-of concept simulations were conducted, including its application to two representative single-lap shear tests: steel-steel system and FRP-concrete system. This case study aids in evaluating and understanding the fundamental mechanisms of moisture diffusion and mechanical degradation in structural joints.A
Security governance, harms and resistance : recalibrating security and redefining incivility through legitimacy concerns
No full textExamining the harmful effects of some existing governance approaches to urban space and various types of resistance to them, we outline a new framework to develop and evaluate security approaches in the city – in particular, towards ‘incivilities’. This framework relies on the redefinition of security, which we extended far beyond the realm of crime to include social security and concerns around vulnerability, sustainability, inclusion and so on, and takes into account the critique of existing governance measures. Simultaneously, it relies on the rethinking of ‘incivilities’, which involves shifting the focus away from behaviour deemed ‘anti-social’ to the actions or inactions of those who decide what ‘anti-social’ is in the first place, and their harmful consequences. The framework we propose – that takes into account harms, people’s broader sensitivities around public space and pro-social alternatives to current security approaches – should hopefully contribute to a more just and legitimate urban security governance.Examining the harmful effects of some existing governance approaches to urban space and various types of resistance to them, we outline a new framework to develop and evaluate security approaches in the city – in particular, towards ‘incivilities’. This framework relies on the redefinition of security, which we extended far beyond the realm of crime to include social security and concerns around vulnerability, sustainability, inclusion and so on, and takes into account the critique of existing governance measures. Simultaneously, it relies on the rethinking of ‘incivilities’, which involves shifting the focus away from behaviour deemed ‘anti-social’ to the actions or inactions of those who decide what ‘anti-social’ is in the first place, and their harmful consequences. The framework we propose – that takes into account harms, people’s broader sensitivities around public space and pro-social alternatives to current security approaches – should hopefully contribute to a more just and legitimate urban security governance.A
Detailed characterisation of the fluids responsible for orogenic gold mineralisation at Imonga-Saramabila (Maniema) in the Karagwe-Ankole Belt, DR Congo
No full textThe Western Domain (WD) of the Karagwe-Ankole Belt (KAB) in the Great Lakes Region in Central Africa is part of a metallogenic province rich in elements such as Nb-Ta-Sn-W-Li-Be-Au, which are essential for high-tech and green industries. In contrast to the Sn, W and Nb-Ta mineralisation, the characteristics and source of the Au mineralising fluids are largely unknown. Therefore, the Imonga gold prospect in the WD of the KAB in the Democratic Republic of the Congo (DR Congo) was studied to investigate the gold mineralising fluids. The host rocks at Imonga are deformed and intensely altered, dominantly by dolomitisation and chloritisation. Metamorphism is characterised by foliation development (e.g. mica-schist) and post-foliation andalusite porphyroblasts. In total, four vein generations were distinguished. Most important for the mineralisation is the post- foliation second vein generation (V2), composed of mainly quartz and ferroan-dolomite, with the gold in close association with sulfides. The subsequent post-foliation third vein generation (V3) is composed of mainly ferroan-calcite and quartz, and is inferred to post-date V2 by cross-cutting relationships. This vein generation is also associated with sulfides, but no gold mineralisation was observed. The characterisation of the mineralising fluid in both vein generations was performed through extensive fluid inclusion petrography, microthermometry, Raman spectroscopy, LA-ICP-MS and modelling to deduce the fluid characteristics, source and formation conditions of the mineralisation. Both vein generations (V2 and V3) are characterised by a low saline (3.1-7.0 eq. wt. % NaCl) H2O-NaCl-KCl-CO2 fluid with a wide range in CO2-N2-CH4 composition, indicating varying degrees of fluid rock interactions during metamorphism. This fluid composition corresponds to a typical metamorphic origin of the orogenic gold mineralising fluid. Individual fluid inclusion LA-ICP-MS data for Mg, K, Ca, Mn, Fe, Rb, Sr and Ba were compared with the typical composition of sedimentary, metamorphic and magmatic fluids in the literature. The elemental compositions correspond with those of a metamorphic fluid and resemble those found in other studies on orogenic gold deposits. The low concentrations of Rb and Cs (as well as Sr and Ba) indicate that there has been no influence of a magmatic fluid. The fluids have a density between 0.74 and 0.94 g/ cm3. For a formation temperature window of 350-400 degrees C (based on the occurrence of andalusite porphyroblasts, the type of quartz deformation and the total homogenisation temperatures of fluid inclusions), a pressure window of 75-250 MPa is derived corresponding to a formation depth of 7.6-9.6 km. The gold was likely transported as gold-sulfur complexes, as indicated by the presence of H2S in the fluid inclusions. Precipitation of the gold could have occurred due to the destabilisation of the gold-sulfur complex by interaction with the iron-bearing host-rock resulting in the precipitation of Fe-sulfide minerals, and by changes in fluid pressure related to fault-valve activity.The Western Domain (WD) of the Karagwe-Ankole Belt (KAB) in the Great Lakes Region in Central Africa is part of a metallogenic province rich in elements such as Nb-Ta-Sn-W-Li-Be-Au, which are essential for high-tech and green industries. In contrast to the Sn, W and Nb-Ta mineralisation, the characteristics and source of the Au mineralising fluids are largely unknown. Therefore, the Imonga gold prospect in the WD of the KAB in the Democratic Republic of the Congo (DR Congo) was studied to investigate the gold mineralising fluids. The host rocks at Imonga are deformed and intensely altered, dominantly by dolomitisation and chloritisation. Metamorphism is characterised by foliation development (e.g. mica-schist) and post-foliation andalusite porphyroblasts. In total, four vein generations were distinguished. Most important for the mineralisation is the post- foliation second vein generation (V2), composed of mainly quartz and ferroan-dolomite, with the gold in close association with sulfides. The subsequent post-foliation third vein generation (V3) is composed of mainly ferroan-calcite and quartz, and is inferred to post-date V2 by cross-cutting relationships. This vein generation is also associated with sulfides, but no gold mineralisation was observed. The characterisation of the mineralising fluid in both vein generations was performed through extensive fluid inclusion petrography, microthermometry, Raman spectroscopy, LA-ICP-MS and modelling to deduce the fluid characteristics, source and formation conditions of the mineralisation. Both vein generations (V2 and V3) are characterised by a low saline (3.1-7.0 eq. wt. % NaCl) H2O-NaCl-KCl-CO2 fluid with a wide range in CO2-N2-CH4 composition, indicating varying degrees of fluid rock interactions during metamorphism. This fluid composition corresponds to a typical metamorphic origin of the orogenic gold mineralising fluid. Individual fluid inclusion LA-ICP-MS data for Mg, K, Ca, Mn, Fe, Rb, Sr and Ba were compared with the typical composition of sedimentary, metamorphic and magmatic fluids in the literature. The elemental compositions correspond with those of a metamorphic fluid and resemble those found in other studies on orogenic gold deposits. The low concentrations of Rb and Cs (as well as Sr and Ba) indicate that there has been no influence of a magmatic fluid. The fluids have a density between 0.74 and 0.94 g/ cm3. For a formation temperature window of 350-400 degrees C (based on the occurrence of andalusite porphyroblasts, the type of quartz deformation and the total homogenisation temperatures of fluid inclusions), a pressure window of 75-250 MPa is derived corresponding to a formation depth of 7.6-9.6 km. The gold was likely transported as gold-sulfur complexes, as indicated by the presence of H2S in the fluid inclusions. Precipitation of the gold could have occurred due to the destabilisation of the gold-sulfur complex by interaction with the iron-bearing host-rock resulting in the precipitation of Fe-sulfide minerals, and by changes in fluid pressure related to fault-valve activity.A
Radicalisation : a concept in judicial reasoning?
No full textThe radicalisation process is often portrayed in the literature as a pathway. Whilst the author previously developed a meta-framework that embodies the current state of research on phase models of radicalisation (De Coensel, 2018), no research has been conducted on the use and operationalisation of these phases in the courtroom. This chapter therefore examines to what extent and how the concept of radicalisation is used to motivate the conviction of terrorist offenders by conducting a systematic, qualitative content analysis of 33 Belgian court rulings pronounced between 2012 and 2017 on terrorism-related acts. The analysis reveals that, while phase models of radicalisation are not explicitly referenced in judicial reasoning, courts implicitly rely on elements from these models, such as social ties, cognitive factors, and attitudes towards violence, to assess ideological convictions and infer terrorist intentions from these convictions. Although the analysis also sheds light on the trajectories of convicted terrorist offenders, court rulings often lack detail on the early stages of radicalisation, limiting their suitability for empirically testing theoretical models like the meta-framework.The radicalisation process is often portrayed in the literature as a pathway. Whilst the author previously developed a meta-framework that embodies the current state of research on phase models of radicalisation (De Coensel, 2018), no research has been conducted on the use and operationalisation of these phases in the courtroom. This chapter therefore examines to what extent and how the concept of radicalisation is used to motivate the conviction of terrorist offenders by conducting a systematic, qualitative content analysis of 33 Belgian court rulings pronounced between 2012 and 2017 on terrorism-related acts. The analysis reveals that, while phase models of radicalisation are not explicitly referenced in judicial reasoning, courts implicitly rely on elements from these models, such as social ties, cognitive factors, and attitudes towards violence, to assess ideological convictions and infer terrorist intentions from these convictions. Although the analysis also sheds light on the trajectories of convicted terrorist offenders, court rulings often lack detail on the early stages of radicalisation, limiting their suitability for empirically testing theoretical models like the meta-framework.B
Thiosulfate-involved S-N biotransformation enables the long-term stability of a novel sulfur-cycle driven mainstream anammox process
No full textThe recently developed Sulfate reduction, mixed sulfide- and thiosulfate-driven Autotrophic denitrification, NItrification, and Anammox (SANIA) integrated process is beneficial for sustainable wastewater treatment due to its potential of achieving resource recovery maximization and energy consumption minimization in mainstream. However, little is known about the long-term stability of the integrated SANIA process. In this study, an integrated SANIA system, including three bioreactors for sulfate reduction, mixed sulfide- and thiosulfate-driven denitrification anammox, and nitrification, was operated for 270 days under various conditions (e.g., influent sulfate concentrations, the key substance of the sulfur cycle in SANIA). During operation, organics, NH4+-N, and TN were stably removed in SANIA system with the effluent concentrations of below 13.9 COD mg/L, 2.0 mgN/L, and 12.8 mgN/L respectively, lower than the discharging limit under the varying concentrations of sulfate (36.0–72.7 mgS/L) in influent. Yet the different sulfate concentrations affected the thiosulfate and sulfide production in sulfate reduction and anammox contribution ratio in MSPDA. The effect of sulfate concentrations on the thiosulfate-involved S-N biotransformation was further confirmed by batch tests. Notably, the presence of thiosulfate during both biological sulfate reduction and sulfide oxidation guaranteed the anammox contribution ratio at above 83 % in mixed sulfide- and thiosulfate-driven denitrification anammox (MSPDA), facilitating stable nitrogen removal through durable provision of electron and nitrite. Additionally, the complete thiosulfate-involved S-N biotransformation metabolism was interpreted by metagenomics analysis for the first time. Thiosulfate was formed mainly through sulfide oxidation in both sulfate reduction and MSPDA, regulated by the expression of sqr and sox genes. Overall, the findings shed light on the mechanisms underlying thiosulfate-involved S-N biotransformation and provide valuable guidance for application of SANIA process.The recently developed Sulfate reduction, mixed sulfide- and thiosulfate-driven Autotrophic denitrification, NItrification, and Anammox (SANIA) integrated process is beneficial for sustainable wastewater treatment due to its potential of achieving resource recovery maximization and energy consumption minimization in mainstream. However, little is known about the long-term stability of the integrated SANIA process. In this study, an integrated SANIA system, including three bioreactors for sulfate reduction, mixed sulfide- and thiosulfate-driven denitrification anammox, and nitrification, was operated for 270 days under various conditions (e.g., influent sulfate concentrations, the key substance of the sulfur cycle in SANIA). During operation, organics, NH4+-N, and TN were stably removed in SANIA system with the effluent concentrations of below 13.9 COD mg/L, 2.0 mgN/L, and 12.8 mgN/L respectively, lower than the discharging limit under the varying concentrations of sulfate (36.0–72.7 mgS/L) in influent. Yet the different sulfate concentrations affected the thiosulfate and sulfide production in sulfate reduction and anammox contribution ratio in MSPDA. The effect of sulfate concentrations on the thiosulfate-involved S-N biotransformation was further confirmed by batch tests. Notably, the presence of thiosulfate during both biological sulfate reduction and sulfide oxidation guaranteed the anammox contribution ratio at above 83 % in mixed sulfide- and thiosulfate-driven denitrification anammox (MSPDA), facilitating stable nitrogen removal through durable provision of electron and nitrite. Additionally, the complete thiosulfate-involved S-N biotransformation metabolism was interpreted by metagenomics analysis for the first time. Thiosulfate was formed mainly through sulfide oxidation in both sulfate reduction and MSPDA, regulated by the expression of sqr and sox genes. Overall, the findings shed light on the mechanisms underlying thiosulfate-involved S-N biotransformation and provide valuable guidance for application of SANIA process.A