Roland W. Scholz

Modeled environmental concentrations of engineered nanomaterials (TiO2, ZnO, Ag, CNT, fullerenes) for different regions.

Engineered nanomaterials (ENM) are already used in many products and consequently released into environmental compartments. In this study, we calculated predicted environmental concentrations (PEC) based on a probabilistic material flow analysis from a life-cycle perspective of ENM-containing products. We modeled nano-TiO(2), nano-ZnO, nano-Ag, carbon nanotubes (CNT), and fullerenes for the U.S., Europe and Switzerland. The environmental concentrations were calculated as probabilistic density functions and were compared to data from ecotoxicological studies. The simulated modes (most frequent values) range from 0.003 ng L(-1) (fullerenes) to 21 ng L(-1) (nano-TiO(2)) for surface waters and from 4 ng L(-1) (fullerenes) to 4 microg L(-1) (nano-TiO(2)) for sewage treatment effluents. For Europe and the U.S., the annual increase of ENMs on sludge-treated soil ranges from 1 ng kg(-1) for fullerenes to 89 microg kg(-1) for nano-TiO(2). The results of this study indicate that risks to aquatic organisms may currently emanate from nano-Ag, nano-TiO(2), and nano-ZnO in sewage treatment effluents for all considered regions and for nano-Ag in surface waters. For the other environmental compartments for which ecotoxicological data were available, no risks to organisms are presently expected.

Embedded Case Study Methods. Integrating Quantitative and Qualitative Knowledge

1. Introduction Methods of Knowledge Integration Embedded Case Studies for Complex, Contextualized Problems Historical Landmarks PART I: CASE STUDY DESIGN AND SYNTHESIS 2. Types of Case Studies Design Motivation Epistemological Status Purpose Format Data Collection and Methods of Knowledge Integration 3. The Use of Case Studies in Different Disciplines Neuropsychology Educational Sciences Law Business Environmental Sciences 4. The Architecture of Knowledge Integration in Embedded Case Studies The Architecture of Embedded Case Studies Strategies of Synthesis The Brunswikian Lens Model Types of Knowledge Integration 5. The ETH-UNS Case Study Zurich North The Zurich North Case Case Prospects and History Understanding the Case Faceting the Case for Embedded Case Design Constraints of the Study Organizing the Study PART II: METHODS OF KNOWLEDGE INTEGRATION 6. Overview 7. The Methods in Brief 8. How to Choose the Right Method PART III: THE METHODS IN DETAIL 9. Formative Scenario Analysis The Rationale The Method in Detail 10. System Dynamics The Rationale The Method in Detail 11. Multi-Attribute Utility Theory The Rationale The Method in Detail 12. Integrated Risk Management The Rationale Incorporating Different Perspectives The Method in Detail 13. Mediation: Area Development Negotiations The Rationale The Method in Detail 14. Future Workshops The Rationale The Method in Detail 15. Experiential Case Encounter The Rationale The Method in Detail 16. Synthesis Moderation and Group Techniques The Rationale The Method in Detail 17. Material Flux Analysis The Rationale The Method in Detail 18. Life Cycle Assessment The Rationale The Method in Detail 19. Bio-Ecological Potential Analysis The Rationale The Method in Detail PART IV: VALIDATION PERSPECTIVES 20. The Validation of Embedded Case Studies The Rationale Validation of Embedded Case Studies: A Practical View References Index About the Authors

Didactics of Mathematics as a Scientific Discipline

Preface.- Preparing Mathematics for Students.- Teacher Education and Research on Teaching.- Interaction in the Classroom.- Technology and Mathematics Teaching.- Psychology of Mathematical Thinking.- Differential Didactics.- History and Epistemology of Mathematics and Mathematics Education.- Cultural Framing of Teaching and Learning Mathematics.

Transdisciplinary case studies as a means of sustainability learning: Historical framework and theory

Purpose – This paper aims at presenting the theoretical concepts of the transdisciplinary case study approach (TCS), which is a research and teaching approach developed and elaborated at the Swiss Federal Institute of Technology (ETH), as a means of transition support.Design/methodology/approach – The paper reveals the historical roots of case studies, transdisciplinarity and sustainable development as teaching and research paradigms. The TCS approach is presented, which has been developed at ETH for supporting transition management of regional, urban, and organizational systems. This approach is entrenched by an ontology that reveals the basic characteristics of ill‐defined transition problems, an epistemology that refers to Probabilistic Functionalism and distinguishes between multi‐layered systemic and normative epistemics, a methodology that includes a set of methods for case representation (including modelling and projection), assessment, and strategy building, and a project management model that ref...

Higher education as a change agent for sustainability in different cultures and contexts

Purpose – The goal of this paper is to enhance consideration for the potential for institutions of higher education throughout the world, in different cultures and contexts, to be change agents for sustainability. As society faces unprecedented and increasingly urgent challenges associated with accelerating environmental change, resource scarcity, increasing inequality and injustice, as well as rapid technological change, new opportunities for higher education are emerging. Design/methodology/approach – The paper builds on the emerging literature on transition management and identifies five critical issues to be considered in assessing the potential for higher education as a change agent in any particular region or place. To demonstrate the value of these critical issues, exemplary challenges and opportunities in different contexts are provided. Findings – The five critical issues include regional-specific dominant sustainability challenges, financing structure and independence, institutional organization, the extent of democratic processes, and communication and interaction with society. Originality/value – Given that the challenges and opportunities for higher education as a change agent are context-specific, identifying, synthesizing, and integrating common themes is a valuable and unique contribution.

Phosphorylation of LKB1 at Serine 428 by Protein Kinase C-ζ Is Required for Metformin-Enhanced Activation of the AMP-Activated Protein Kinase in Endothelial Cells

Background— Metformin, one of most commonly used antidiabetes drugs, is reported to exert its therapeutic effects by activating AMP-activated protein kinase (AMPK); however, the mechanism by which metformin activates AMPK is poorly defined. The objective of the present study was to determine how metformin activates AMPK in endothelial cells. Methods and Results— Exposure of human umbilical vein endothelial cells or bovine aortic endothelial cells to metformin significantly increased AMPK activity and the phosphorylation of both AMPK at Thr172 and LKB1 at Ser428, an AMPK kinase, which was paralleled by increased activation of protein kinase C (PKC)-&zgr;, as evidenced by increased activity, phosphorylation (Thr410/403), and nuclear translocation of PKC-&zgr;. Consistently, either pharmacological or genetic inhibition of PKC-&zgr; ablated metformin-enhanced phosphorylation of both AMPK-Thr172 and LKB1-Ser428, suggesting that PKC-&zgr; might act as an upstream kinase for LKB1. Furthermore, adenoviral overexpression of LKB1 kinase-dead mutants abolished but LKB1 wild-type overexpression enhanced the effects of metformin on AMPK in bovine aortic endothelial cells. In addition, metformin increased the phosphorylation and nuclear export of LKB1 into the cytosols as well as the association of AMPK with LKB1 in bovine aortic endothelial cells. Similarly, overexpression of LKB1 wild-type but not LKB1 S428A mutants (serine replaced by alanine) restored the effects of metformin on AMPK in LKB1-deficient HeLa-S3 cells, suggesting that Ser428 phosphorylation of LKB1 is required for metformin-enhanced AMPK activation. Moreover, LKB1 S428A, like kinase-dead LKB1 D194A, abolished metformin-enhanced LKB1 translocation as well as the association of LKB1 with AMPK in HeLa-S3 cells. Finally, inhibition of PKC-&zgr; abolished metformin-enhanced coimmunoprecipitation of LKB1 with both AMPK&agr;1 and AMPK&agr;2. Conclusions— We conclude that PKC-&zgr; phosphorylates LKB1 at Ser428, resulting in LKB1 nuclear export and hence AMPK activation.

PKA phosphorylates and inactivates AMPKα to promote efficient lipolysis

The mobilization of metabolic energy from adipocytes depends on a tightly regulated balance between hydrolysis and resynthesis of triacylglycerides (TAGs). Hydrolysis is stimulated by β‐adrenergic signalling to PKA that mediates phosphorylation of lipolytic enzymes, including hormone‐sensitive lipase (HSL). TAG resynthesis is associated with high‐energy consumption, which when inordinate, leads to increased AMPK activity that acts to restrain hydrolysis of TAGs by inhibiting PKA‐mediated activation of HSL. Here, we report that in primary mouse adipocytes, PKA associates with and phosphorylates AMPKα1 at Ser‐173 to impede threonine (Thr‐172) phosphorylation and thus activation of AMPKα1 by LKB1 in response to lipolytic signals. Activation of AMPKα1 by LKB1 is also blocked by PKA‐mediated phosphorylation of AMPKα1 in vitro. Functional analysis of an AMPKα1 species carrying a non‐phosphorylatable mutation at Ser‐173 revealed a critical function of this phosphorylation for efficient release of free fatty acids and glycerol in response to PKA‐activating signals. These results suggest a new mechanism of negative regulation of AMPK activity by PKA that is important for converting a lipolytic signal into an effective lipolytic response.

Possibilities and limitations of modeling environmental exposure to engineered nanomaterials by probabilistic material flow analysis

Information on environmental concentrations is needed to assess the risks that engineered nanomaterials (ENM) may pose to the environment. In this study, predicted environmental concentrations (PEC) were modeled for nano-TiO2, carbon nanotubes (CNT) and nano-Ag for Switzerland. Based on a life-cycle perspective, the model considered as input parameters the production volumes of the ENMs, the manufacturing and consumption quantities of products containing those materials, and the fate and pathways of ENMs in natural and technical environments. Faced with a distinct scarcity of data, we used a probabilistic material flow analysis model, treating all parameters as probability distributions. The modeling included Monte Carlo and Markov Chain Monte Carlo simulations as well as a sensitivity and uncertainty analysis. The PEC values of the ENMs in the different environmental compartments vary widely due to different ENM production volumes and different life cycles of the nanoproducts. The use of ENM in products with high water relevance leads to higher water and sediment concentrations for nano-TiO2 and nano-Ag, compared to CNTs, where smaller amounts of ENM reach the aquatic compartments. This study also presents a sensitivity analysis and a comprehensive discussion of the uncertainties of the simulation results and the limitations of the used approach. To estimate potential risks, the PEC values were compared to the predicted-no-effect concentrations (PNEC) derived from published data. The risk quotients (PEC/PNEC) for nano-TiO2 and nano-Ag were larger than one for treated wastewater and much smaller for all other environmental compartments (e.g., water, sediments, soils). We conclude that probabilistic modeling is very useful for predicting environmental concentrations of ENMs given the current lack of substantiated data.

Food purchases: Impacts from the consumers’ point of view investigated with a modular LCA

The goal of this research work was to assist consumers in considering environmental aspects of food consumption. A simplified, modular LCA approach has been used to evaluate the impacts from the consumers’ point of view. Comparative LCA’s have been calculated for five single aspects of decisions: type of agricultural practice, origin, packaging material, type of preservation, and consumption. The inventory for one module includes the environmental impacts related to one particular product characteristic. The modular LCA allows one to investigate the trade-offs among different decision parameters. It could be shown that most of the decision parameters might have an influence on the overall impact of a vegetable product. Greenhouse production and vegetables transported by air cause the highest surplus environmental impact. For meat products, the agricultural production determines the overall environmental impact. The total impact for vegetable or meat purchases may vary by a factor of eight or two-and-a-half. Different suggestions for consumers have been ranked according to the variation of average impacts, due to a marginal change of behaviour. Avoiding air-transported food products leads to the highest decrease of environmental impacts.

Establishing sustainability science in higher education institutions: towards an integration of academic development, institutionalization, and stakeholder collaborations

The field of sustainability science aims to understand the complex and dynamic interactions between natural and human systems in order to transform and develop these in a sustainable manner. As sustainability problems cut across diverse academic disciplines, ranging from the natural sciences to the social sciences and humanities, interdisciplinarity has become a central idea to the realm of sustainability science. Yet, for addressing complicated, real-world sustainability problems, interdisciplinarity per se does not suffice. Active collaboration with various stakeholders throughout society—transdisciplinarity—must form another critical component of sustainability science. In addition to implementing interdisciplinarity and transdisciplinarity in practice, higher education institutions also need to deal with the challenges of institutionalization. In this article, drawing on the experiences of selected higher education academic programs on sustainability, we discuss academic, institutional, and societal challenges in sustainability science and explore the potential of uniting education, research and societal contributions to form a systematic and integrated response to the sustainability crisis.