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Dual role of electrical stimulation and a biomimetic matrix in neural differentiation within a microfluidic platform
Get PDFNeurodegenerative diseases mostly stem from oxidative stress and/or misfolded proteins in the central and peripheral nervous systems, posing clinical and economic burdens globally. Despite the advances in this field, biomimetic models recapitulating the neural microphysiological environment of both patients and healthy individuals are needed to accelerate drug development. Herein, a biomimetic microfluidic platform was developed to promote neural differentiation of stem cells by recapitulating physicochemical and physicomechanical factors in the neural microenvironment. In order to address this, the supportive role of electrical stimulation (ES) was assessed under various conditions by using immunofluorescence staining of mesenchymal stromal cell markers (CD45, CD90), the neuroepithelial stem cell protein marker (Nestin) and the microtubule-associated protein 2 marker (MAP2). Moreover, the combinational effect of ES and a cell-derived matrix (CDM), or a three-dimensional tissue-derived matrix (TDM), was explored. The matrices were obtained and characterized by scanning electron microscopy, contact angle analysis, DNA analysis, agarose gel electrophoresis, and in terms of extracellular matrix proteins. Neural differentiation was further validated by analysis of changes in gene expressions. ES applied in a rectangular manner with a 10 ms frequency at an intensity of 200 mV cm−1 for 1 h per day for 7 days, followed by an additional 7 day recovery phase, revealed optimum neural differentiation for the combinational approach with brain TDM in both 2D and 3D. In conclusion, this work highlights the critical role of both physicochemical and physicomechanical factors in neural differentiation, offering valuable insights for advancing biomimetic models and stem cell research.</p
Modelling tidal sandbank dynamics and impacts of sand extraction in sediment-scarce environments:Literature report
Get PDFRONOM:Reduced-Order Neural Operator Modeling
Get PDFTime-dependent partial differential equations are ubiquitous in physics-based modeling, but they remain computationally intensive in many-query scenarios, such as real-time forecasting, optimal control, and uncertainty quantification. Reduced-order modeling (ROM) addresses these challenges by constructing a low-dimensional surrogate model but relies on a fixed discretization, which limits flexibility across varying meshes during evaluation. Operator learning approaches, such as neural operators, offer an alternative by parameterizing mappings between infinite-dimensional function spaces, enabling adaptation to data across different resolutions. Whereas ROM provides rigorous numerical error estimates, neural operator learning largely focuses on discretization convergence and invariance without quantifying the error between the infinite-dimensional and the discretized operators. This work introduces the reduced-order neural operator modeling (RONOM) framework, which bridges concepts from ROM and operator learning. We establish a discretization error bound analogous to those in ROM, and get insights into RONOM's discretization convergence and discretization robustness. Moreover, two numerical examples are presented that compare RONOM to existing neural operators for solving partial differential equations. The results demonstrate that RONOM using standard vector-to-vector neural networks achieves comparable performance in input generalization and superior performance in both spatial super-resolution and discretization robustness, while also offering novel insights into temporal super-resolution scenarios
Towards a framework for land conflicts management in Oyo State, Nigeria
Get PDFAll over the world, land is synonymous with people’s identity, power, livelihoods and an agent of development. Besides, it is a generational asset with spiritual, economic, historical and cultural significance. Given the significance of land to humanity, competition to get access to land results in land conflicts. Land conflicts in various forms are driven by many factors. The impacts are evident in individuals, communities and the economy. To promote a peaceful and inclusive society in line with Sustainable Development Goal 16, there is a need for an inclusive land conflict framework that would reduce the incessant land conflicts and their impacts, also enhancing a good land administration system. The problem identified in this research revolves around the less-than-effective nature of the current land conflict management frameworks, which have been unable to reduce the incessant land conflict in Oyo State, Nigeria. Previous studies such as Lar, (2017) and Zwan (2011) have identified the need for an inclusive framework for land conflict management. The studies show a minimal, if any, involvement of land conflict stakeholders in managing land conflict. This study aims to design an inclusive framework for land conflict management by examining the nature and management of land ownership conflicts in Oyo State, Nigeria. The study started by reviewing literature on conflict, land conflict, land conflict management, stakeholders, tenure and land administration system. It was discovered that land conflict is localised, suggesting the need to manage every land conflict locally. In addition, it was reiterated that there are links between land conflict, land tenure and the land administration system. Four sub-objectives were set to achieve the aim of the study. The first sub-objective focused on understanding the nature of land conflict and the stakeholders' roles in land conflict and land conflict management in Oyo State, Nigeria. The study established that the beliefs, interests, and roles stakeholders play determine the forms, stages and intensity of land conflict and how the conflict would be managed. The findings revealed the importance of land as an identity and generational heritage. It also emphasised the stakeholders' beliefs, interests and roles in land conflict and its management. These underscore the incessant land conflict in Oyo State, and the stakeholders' beliefs, interests, and important roles play in land conflict management. The second sub-objective focused on the impacts of land conflict. Beyond the loss of lives and properties, other impacts are sometimes even more grievous. It was revealed that land conflict creates sour relationships among the conflicting parties and increases age-long hostilities among individuals and communities. If land conflict is not managed well, it increases distrust among conflicting parties, families, and communities and stalls development. In addition, it increases tenure insecurity and leads to a loss of identity among others. The impacts resonate throughout the affected individuals and communities' social, economic, and institutional impacts. This underscores the need for inclusive and proactive interventions that align with people's cultural beliefs, which could manage land conflict beyond the loss of lives and properties as impacts. Since land conflict is localised, a local intervention could reduce land conflict. So, to identify the drivers of land conflict and the management mechanisms in Oyo state, the third sub-objective explored the drivers of land conflict and the management mechanisms employed to manage land conflict. The study revealed that understanding the drivers relates to the underlying cultural beliefs and customs that make land conflict thrive. It also helps in choosing the appropriate management mechanisms for land conflict management, as it is affected by cultural beliefs. Besides, factors such as the possibility of getting justice, the time frame, the cost implications of the mechanisms, inclusivity and effectiveness, among others, influence the choice of the mechanisms. The study further revealed that mediation is the most effective mechanism. Stakeholders believe that it is an inclusive mechanism that manages the relationship of the conflicting parties well. The mechanism aligns with the cultural beliefs of the people. Thereby, it promotes dialogue, mutual understanding and peaceful co-existence. However, applying mediation to manage land conflict has some flaws that make land conflict recur and thrive.In finding the most feasible and sustainable solution to land conflict, the study integrated the findings of the previous sub-objectives as well as the principles of good land governance as a base for designing an inclusive land conflict framework. The findings established that the previous frameworks lack inclusivity and do not consider the cultural beliefs, traditions and customs of people. It further revealed that the previous frameworks lack adherence to the principles of good land governance. The study designed an inclusive framework incorporating the deficiencies of the previous frameworks that made them less effective. The inclusive framework accommodates the stakeholders' input and assessment and considers the people's culture, traditions, and customs. The framework has the potential to reduce and manage land conflict effectively. The potential for effective land conflict management depends on stakeholders' implementation, transparency, and fair application of all the good land governance principles in the framework.This framework is similar to what is in operation in other African countries such as Burkina Faso, Mali, Uganda, and Tanzania, among others. These countries have embedded in their laws a committee to manage land conflict at the village level and the use of mediation to manage land disputes or conflicts. Litigation is the last approach to be employed to manage land conflict. Those countries ' laws spelt out the village committee composition, procedure, timelines and enforceability of mediation. While acknowledging the insights provided by the study, the study also has limitations. The study is a case study in part of one state and could not be conducted in the whole of Nigeria due to time limitations. There are other stakeholders also that could have been included to improve the quantitative and qualitative information obtained from the stakeholders, such as real estate developers. Investigating land conflict from the perspectives of land use and land cover change over the years could provide a deeper understanding and more insights into the drivers of land conflict. The identified limitations can serve as a valuable pointer for researchers to conduct further studies. Generally, the study offers insightful information that can help reduce and manage land conflict effectively, thereby enhancing the land administration system of Oyo State, Nigeria.<br/
Which emotion regulation strategies are mediating the outcome of acceptance and commitment therapy compared to cognitive-behaviour therapy in the treatment of anxiety symptoms?
Get PDFObjective: To examine multiple emotion regulation strategies as mediators in ACT compared to CBT for anxiety. It was hypothesized that augmenting acceptance and reducing suppression, distraction, and perseverative thinking would mediate the effect of ACT compared to CBT. Cognitive reappraisal was included as a competitive mediator. Method: Data were collected as part of a randomized controlled trial comparing ACT and CBT in a sample of 314 older adults with anxiety symptomatology. Participants filled in self-report questionnaires assessing anxiety symptom severity (Generalized Anxiety Disorder-2) and the putative mediators a total of five times over the course of treatment. Latent growth curve models, parallel process models, random intercept-cross lagged panel models, and autoregressive latent trajectory models were used to model the hypothesized prospective and mediational relationship. Results: ACT differentially affected acceptance, suppression, and distraction, and changes in all mediators (except acceptance) showed significant cross-sectional associations with outcome. Only cognitive reappraisal predicted subsequent anxiety levels and vice versa, irrespective of treatment. However, none of the emotion regulation variables mediated the effect of ACT. Conclusions: The discrepancy with previous positive findings on emotion regulation as a mediator may be attributed to earlier studies not using a longitudinal design and analysis on the within-person level.</p
Supporting the mental health of parents of neurodivergent children with a mobile app: the cocreation of “Adappt” .
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Solute mixing in porous media with dispersion and buoyancy
Get PDFWe analyse the process of convective mixing in two-dimensional, homogeneous and isotropic porous media with dispersion. We considered a Rayleigh-Taylor instability in which the presence of a solute produces density differences driving the flow. The effect of dispersion is modelled using an anisotropic Fickian dispersion tensor (Bear, J. Geophys. Res., vol. 66, 1961, pp. 1185-1197). In addition to molecular diffusion , the solute is redistributed by an additional spreading, in longitudinal and transverse flow directions, which is quantified by the coefficients and, respectively, and it is produced by the presence of the pores. The flow is controlled by three dimensionless parameters: the Rayleigh-Darcy number, defining the relative strength of convection and diffusion, and the dispersion parameters and. With the aid of numerical Darcy simulations, we investigate the mixing dynamics without and with dispersion. We find that in the absence of dispersion the dynamics is self-similar and independent of, and the flow evolves following several regimes, which we analyse. Then we analyse the effect of dispersion on the flow evolution for a fixed value of the Rayleigh-Darcy number . A detailed analysis of the molecular and dispersive components of the mean scalar dissipation reveals a complex interplay between flow structures and solute mixing. We find that the dispersion parameters and affect the formation of fingers and their dynamics: the lower the value of (or the larger the value of), the wider, more convoluted and diffused the fingers. We also find that for strong anisotropy, the role of is crucial: except for the intermediate phases of the flow dynamics, dispersive flows show more efficient (or at least comparable) mixing than in non-dispersive systems. Finally, we look at the effect of the anisotropy ratio, and we find that it produces only second-order effects, with relevant changes limited to the intermediate phase of the flow evolution, where it appears that the mixing is more efficient for small values of anisotropy. The proposed theoretical framework, in combination with pore-scale simulations and bead packs experiments, can be used to validate and improve current dispersion models to obtain more reliable estimates of solute transport and spreading in buoyancy-driven subsurface flows.</p
