The interpretations and uses of fitness landscapes in the social sciences

__Abstract__ This working paper precedes our full article entitled “The evolution of Wright’s (1932) adaptive field to contemporary interpretations and uses of fitness landscapes in the social sciences” as published in the journal Biology & Philosophy (http://link.springer.com/article/10.1007/s10539-014-9450-2). The working paper features an extended literature overview of the ways in which fitness landscapes have been interpreted and used in the social sciences, for which there was not enough space in the full article. The article features an in-depth philosophical discussion about the added value of the various ways in which fitness landscapes are used in the social sciences. This discussion is absent in the current working paper. Th

Logistics in the Circular Economy: Challenges and Opportunities

Circular economy (CE) is a concept that has gained considerable attentionin recent years, particularly in the domain of Industrial Ecology. CE requiresproducts to be easily repaired, refurbished, remanufactured, and eventually recycled.The transition to a CE creates distinct material flows that have to be managed in an efficient and sustainable manner. Existing studies on CE tend to focus on product design, material use, and the market potential of CE products with little attention paid to the logistics challenges associated with such developments. From a logistics perspective, CE can be seen as the integrated management of forward and reverse flows of products in a supply chain. In the operations and supply chain management literature, a large body of knowledge on how to operationalize closed-loop supply chains (CLSCs) already exists and is a starting point for understanding logistics in the CE context. As with traditional forward supply chain network design, CLSC and CE supply chains also require decisions on the role of facilities, their location, their capacity allocation, and their demand and supply allocation. The CE concept does however introduce new challenges especially as circular business innovations converge to increased servitization and to more collaborative and open business models.The transition towards circular business models requires businesses to positionthemselves according to three key strategic decision-making problems, namely,(1) the extent to which the logistics network is centralized, (2) the extent to which the product is servitized, and (3) the extent to which logistics services are coordinated. This chapter presents a theoretical overview of the three trade-offs and what their potential implications are

The miRNA-212/132 family regulates both cardiac hypertrophy and cardiomyocyte autophagy

Pathological growth of cardiomyocytes (hypertrophy) is a major determinant for the development of heart failure, one of the leading medical causes of mortality worldwide. Here we show that the microRNA (miRNA)-212/132 family regulates cardiac hypertrophy and autophagy in cardiomyocytes. Hypertrophic stimuli upregulate cardiomyocyte expression of miR-212 and miR-132, which are both necessary and sufficient to drive the hypertrophic growth of cardiomyocytes. MiR-212/132 null mice are protected from pressure-overload-induced heart failure, whereas cardiomyocyte-specific overexpression of the miR-212/132 family leads to pathological cardiac hypertrophy, heart failure and death in mice. Both miR-212 and miR-132 directly target the anti-hypertrophic and pro-autophagic FoxO3 transcription factor and overexpression of these miRNAs leads to hyperactivation of pro-hypertrophic calcineurin/NFAT signalling and an impaired autophagic response upon starvation. Pharmacological inhibition of miR-132 by antagomir injection rescues cardiac hypertrophy and heart failure in mice, offering a possible therapeutic approach for cardiac failure

Studying the Evolution of the ‘Circular Economy’ Concept using Topic Modelling

Circular Economy has gained immense popularity for its perceived capacity to operationalise sustainable development. However, a comprehensive long-term understanding of the concept, characterising its evolution in academic literature, has not yet been provided. As a first step, we apply unsupervised topic models on academic articles to identify patterns in concept evolution. We generate topics using LDA, and investigate topic prevalence over time. We determine the optimal number of topics for the model (k) through coherence scorings and evaluate the topic model results by expert judgement. Specifying k as 20, we find topics in the literature focussing on resources, business models, process modelling, conceptual research and policies. We identify a shift in the research focus of contemporary literature, moving away from the Chinese predominance to a European perspective, along with a shift towards micro level interventions, e.g., circular design, business models, around 2014-2015.</p