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Our ability to deal with external changes is determined by our collective willingness to transform and adopt new technologies. These factors are driven by people’s opinion on the change itself and the proposed policies. Humans constantly update their opinion by integrating new information they hear with their values, which helps them make a judgement about that new information. Here, we create an agent-based model that explicitly incorporates the concept of values to explore possible drivers of opinion dynamics. In the model, we explore several factors and perform local and global sensitivity analysis to test their individual and interaction effects. We find that consensus formation in the model is mainly determined by factors related to (1) the amount of stochasticity in the opinion updating procedure and (2) the relative ease with which old links are removed and new links are created. Our results demonstrate how opinions and values may co-evolve. Furthermore, they may help in understanding human responses to new policies such as covid-related restrictions or calls to shift to a more plant-based diet.

Models of socio-environmental or social-ecological systems (SES) commonly address problems requiring interdisciplinary scientific expertise and input from a heterogeneous group of stakeholders. In SES modelling multiple interactions occur on different scales among various phenomena. These scale phenomena include the technical, such as system variables, process detail, inputs and outputs, which most often require spatial, temporal, thematic and organisational choices. From a good practice and project efficiency perspective, the problem scoping and conceptual model formulation phase of modelling is the one to address well from the outset. During this phase, intense and substantive discussions should arise regarding appropriate scales at which to represent the different phenomena. Although the details of these discussions influence the path of model development, they are seldom documented and as a result often forgotten. We draw upon personal experience with existing protocols and communications in recent literature to propose preliminary guidelines for documenting these early discussions about the scale(s) of the studied phenomena. Our guidelines aim to aid modelling group members in building and capturing the richness of their rationale for scoping and scale decisions. The resulting transcripts are intended to promote transparency of modelling decisions and provide essential support for the justification of the final model for its intended use. They also facilitate adaptive modifications of the pathway of model development via retracing decisions and iterative reflection upon alternative scale options.

Many societal, environmental and technological challenges can be characterized as wicked problems by virtue of being difficult to understand, define and solve. examples include sustainable management and consumption of resources, resilient technical infrastructure or curbing plastic pollution of the oceans. One method of tackling such wicked problems is the use of computer-aided modelling and simulation. Model-based decision support is a growing discipline involving the use of computer models of complex systems to explore, understand and manage them. A core concept in model-based decision support is scenario discovery. In scenario discovery, a model’s inputs and outputs are related to understand under which conditions policy-relevant outputs may occur. In a first step, a diverse set of inputs is used to generate a variety of outputs. In a second step, the subset of decision-relevant outputs is identified among the outputs through some external criterion, such as a threshold value. Finally, the inputs which generated those outputs of interest are identified, and a generative rule set is induced which usefully predicts under which conditions an input will generate an output meeting the external criterion. This rule set bounds an input subspace of interest, from which (most of) the outputs of interest originate. While scenario discovery performs adequately for quasi-linear and simple models, it is not well suited to behaviorally complex, nonlinear models. This is both because external criteria are hard to define for complex model behaviors, and also because there are often significant interactions and dependencies between model inputs, which current rule induction algorithms have trouble identifying......., Engineering and Policy Analysis

Between 2013 and 2015, over one million migrants entered Europe. Many European countries were unprepared for and overwhelmed by the rapidly unfolding, chaotic situation. To better handle future migration waves, and allow quicker exploration of government policy effects and interactions, a geospatial-based system dynamics model of migration flows across Europe was developed together with the national police of a major EU country. The model, built around subscripted data and vector operations, distributes migration inflows across the continent based on dynamic mechanisms such as societal stress, social group pull and country attractiveness. It is lightweight yet versatile, and is useful for exploratory, early-stage policy modelling, especially when investigating the system-wide effects and interactions of national migration policies., Policy Analysis

Skeletal muscle atrophy and fatty infiltration develop after tendon tearing. The extent of atrophy serves as one prognostic factor for the outcome of surgical repair of rotator cuff tendon tears. We asked whether mRNA of genes involved in regulation of degradative processes leading to muscle atrophy, ie, FOXOs, MSTN, calpains, cathepsins, and transcripts of the ubiquitin-proteasome pathway, are overexpressed in the supraspinatus muscle in patients with and without rotator cuff tears. We evaluated biopsy specimens collected during surgery of 53 consecutive patients with different sizes of rotator cuff tendon tears and six without tears. The levels of corresponding gene transcripts in total RNA extracts were assessed by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Supraspinatus muscle atrophy was assessed by MRI. The area of muscle tissue (or atrophy), decreased (increased) with increasing tendon tear size. The transcripts of CAPN1, UBE2B, and UBE3A were upregulated more than twofold in massive rotator cuff tears as opposed to smaller tears or patients without tears. These atrophy gene products may be involved in cellular processes that impair functional recovery of affected muscles after surgical rotator cuff repair. However, the damaging effects of gene products in their respective proteolytic processes on muscle structures and proteins remains to be investigated