Adsorption studies of DNA origami on silicon dioxide

Self-assembled DNA nanostructures promise low-cost ways to create nanoscale shapes. DNA nanostructures can also be used to position particles with nanometer precision. Yet, reliable and low-cost ways of integrating the structures with MEMS technology still have to be developed and innovations are of great interest to the field. We have examined in detail the adherence of DNA origami tiles on silicon oxide surfaces of wafers in dependence on pH-value and magnesium ion concentration. The results of this work will help to pursue new strategies of positioning DNA nanostruc-tures on SiO2. Precise control over the strength of structure-surface adhesion is a prerequisite of relia-ble processes

Strategic planning as the intentional production of a “Trading Zone”

For a long period of time there has been a kind of mirroring between the development of decision making models in Political science and the concepts and paradigms used in Planning theory. The dialogue has been interrupted when the "Garbage Can" model was proposed by Choen, March and Olsen in 1972: a model that emphasized the irreducible complexity of the policy processes. The article reconstructs this relationship and its evolution showing the influence of decision-making models on planning theory, and showing the difficulties of managing complexity for planners. The paper holds that interpreting planning processes through the lens of the "Trading zone" concept proposed by Peter Galison in the field of history of science could be an interesting way of dealing with the extreme complexity of contemporary planning problems. The conclusion is that the use of the Trading Zone concept is very promising to solve some dilemmas of planning theory and that it is particularly useful if we employ it in the growing area of strategic spatial planning

Implementation and effects of user participation in playground management: a comparative study of two Swedish municipalities

This paper describes and analyses how customer orientation strategies, with the focus on user participation, are implemented in playground management and their effects on managers’ attitudes and work with physical playgrounds. A comparative case study was conducted in two Swedish municipalities that involve users in different ways: through a manager-driven participation process and through informal user-initiated dialogue. The empirical material consisted of qualitative interviews with professionals in the management organisations and studies of local playgrounds. Implementation of strategies for user participation and tactical management activities appeared to be of importance. The manager-driven participation strategy was associated with a particularly positive attitude among managers, but also difficulties such as maintaining continuous dialogue with users. The small differences found in playground provision between the two municipalities give reason to question the physical effects of participation processes, and show the need for further research

Interrogating informality: Conceptualisations, practices and policies in the light of the New Urban Agenda

Informality is growing in a context of increasing inequity, and in many places becoming the norm. However, despite decades of studies and interventions, ‘recognising informality’ is still a key issue. This paper provides a review of the literature on informality showing the shifts in its conceptualisations. The paper firstly discusses conceptual approaches related to the term ‘informality’ in the context of urban development; it then examines practices within, and related to, informality; and it concludes with an appraisal of policy approaches and their impact as reported in the literature. The paper finds a wide range of conceptualisations, including the questioning of the usefulness and appropriateness of the term. It finds reported evidence of ‘informality’ (as understood to date) spreading to the middle classes, and increasingly emerging in the Global North. Policies seem to be lagging behind in how they engage with so-called informality, with little acknowledgement of theory and limited understanding of their impacts on ‘informal’ practices. Finally, the paper identifies the need for better understanding of governance frameworks that include the range of actors that would normally be associated with so-called ‘informality’