The role of social interaction in farmers' climate adaptation choice

Adaptation to climate change might not always occur, with potentially\ud catastrophic results. Success depends on coordinated actions at both\ud governmental and individual levels (public and private adaptation). Even for a “wet” country like the Netherlands, climate change projections show that the frequency and severity of droughts are likely to increase. Freshwater is an important factor for agricultural production. A deficit causes damage to crop production and consequently to a loss of income. Adaptation is the key to decrease farmers’ vulnerability at the micro level and the sector’s vulnerability at the macro level. Individual adaptation decision-making is determined by the behavior of economic agents and social interaction among them. This can be best studied with agentbased modelling. Given the uncertainty about future weather conditions and the costs and effectiveness of adaptation strategies, a farmer in the model uses a cognitive process (or heuristic) to make adaptation decisions. In this process, he can rely on his experiences and on information from interactions within his social network. Interaction leads to the spread of information and knowledge that causes learning. Learning changes the conditions for individual adaptation decisionmaking. All these interactions cause emergent phenomena: the diffusion of adaptation strategies and a change of drought vulnerability of the agricultural sector. In this paper, we present a conceptual model and the first implementation of an agent-based model. The aim is to study the role of interaction in a farmer’s social network on adaptation decisions and on the diffusion of adaptation strategies\ud and vulnerability of the agricultural sector. Micro-level survey data will be used to parameterize agents’ behavioral and interaction rules at a later stage. This knowledge is necessary for the successful design of public adaptation strategies, since governmental adaptation actions need to be fine-tuned to private adaptation behavior

OH-selected AGB and post-AGB stellar objects II.Blue versus red evolution off the AGB

Using objects found in a systematic survey of the galactic Plane in the 1612-MHz OH line, we discuss in detail two ``sequences'' of post-AGB evolution, a red and a blue. We argue that the red and the blue groups separate by initial mass at 4Msun, based on evolutionary-sequence turn-off colours, spectral energy distributions, outflow velocities and scaleheight. The higher-mass (blue) objects may have earlier AGB termination. The lower-mass (red) objects undergo very sudden reddening for IRAS colour R21\sim1.2; these sources must all undergo a very similar process at AGB termination. The transition colour corresponds to average initial masses of 1.7Msun. A combined IRAS-MSX colour proves a very sensitive tool to distinguish lower-mass, early post-AGB objects from sources still on the AGB and also to distinguish more evolved post-AGB objects from star-forming regions. The high-mass blue objects are the likely precursors of bipolar planetary nebulae, whereas the low-mass red objects will evolve into elliptical planetary nebulae.Comment: 12 pages, LaTex, 7 figures (1 colour), AJ (accepted

In vivo magnetomyograms of skeletal muscle

Magnetomyography (MMG) is a new noninvasive technique inspired by the magnetoneurographic method of J.P. Wikswo (IEEE Trans. Biomed. Eng., Vol.BME-30, p.215-21, 1983). MMG is used to detect action currents in a muscle, which is immersed in a highly conducting fluid. The detection coil is of a toroidal shape, with the muscle passing through the center of the coil. For a long muscle which fits tightly in the toroid, it is to be expected that magnetic fields correspond almost completely to the intracellular longitudinal (axial) currents in active muscle fibers. An experimental setup with specific coils for rat and mouse skeletal muscles was developed. It is sensitive enough to detect currents from single motor units. The technique can be used to record stimulated twitch activity in live muscle as a function of force level, coil position along the muscle, temperature, etc. By simulating the response with a finite-element forward model, it is possible to calculate action currents under various experimental condition

Valuation of functions of the Wadden Area

The rationale of this position paper is to explore ways to employ valuation methods to assess the impacts of alternative policy decisions on the functions of the Wadden Area. Based on this rationale, this paper aims to bring an ecological-economic perspective on the benefits of the Wadden Area. It highlights key issues involved in the notion and application of monetary valuation methods for valuing the (ecological) functions of the area. It also pays attention to the development of policy handles on the basis of the outcome of the valuation of ecological functions. Particularly, the paper discuss Payment for Environmental Services (PES), which aims at preservation and protection by purchasing conservation. The use of a valuation instrument within a Payment for Environmental Services Scheme is new. Valuation is of course an established technique within a Cost-Benefit framework. However, Payment for Environmental Services is an innovative way of designing policy instruments in the collaboration between ecologists and economist

A homoclinic tangle on the edge of shear turbulence

Experiments and simulations lend mounting evidence for the edge state hypothesis on subcritical transition to turbulence, which asserts that simple states of fluid motion mediate between laminar and turbulent shear flow as their stable manifolds separate the two in state space. In this Letter we describe a flow homoclinic to a time-periodic edge state. Its existence explains turbulent bursting through the classical Smale-Birkhoff theorem. During a burst, vortical structures and the associated energy dissipation are highly localized near the wall, in contrast to the familiar regeneration cycle

Bubble drag reduction requires large bubbles

In the maritime industry, the injection of air bubbles into the turbulent boundary layer under the ship hull is seen as one of the most promising techniques to reduce the overall fuel consumption. However, the exact mechanism behind bubble drag reduction is unknown. Here we show that bubble drag reduction in turbulent flow dramatically depends on the bubble size. By adding minute concentrations (6 ppm) of the surfactant Triton X-100 into otherwise completely unchanged strongly turbulent Taylor-Couette flow containing bubbles, we dramatically reduce the drag reduction from more than 40% to about 4%, corresponding to the trivial effect of the bubbles on the density and viscosity of the liquid. The reason for this striking behavior is that the addition of surfactants prevents bubble coalescence, leading to much smaller bubbles. Our result demonstrates that bubble deformability is crucial for bubble drag reduction in turbulent flow and opens the door for an optimization of the process.Comment: 4 pages, 2 figure

Fifty Years of Public (Dis)Satisfaction with European Governance: Preferences, Europeanization and Support for the EU

Since its beginnings in the 1950s, the policymaking scope and authority of the European Union have dramatically expanded across a wide range of issue areas. Yet much remains unknown about the interaction between public preferences for EU-level governance, changes in such governance and overall support for European integration. This article analyses surveys ranging from 1962 to 2010 to show that while support for integration in different policy areas has fluctuated over time, it has been surprisingly stable overall; moreover, the relative preference ordering across issue areas has been even more consistent. In addition, this consistency is not affected by changes in Europeanization, nor do such changes appear to be driven by the relative strength of preferences. Finally, issue-specific support for EU-level governance has an impact on overall EU support that becomes stronger as Europeanization in that issue area increases, an effect that increases further with greater political knowledge. These findings call into question understandings of rising Euroscepticism as a reaction to Europeanization taking place primarily in areas where publics oppose it. In addition, they indicate that public awareness of European integration is far greater than political knowledge tests appear to indicate

Use of tracers to determine the dynamic nature of organic matter, The

Includes bibliographical references (pages 31-43).Early experiments with 13C, 14C and 15N established the high rate of internal cycling of soil organic matter and reintroduced the concept of an active and passive phase in soil humus turnover. Later studies confirmed non-tracer investigations indicating that the percent decomposition of added materials is relatively independent of the rates of addition but dependent on its form and composition. The initial decomposition rate, plus the stabilization of microbial products in soil, must be taken into account when interpreting degradation of 14C enriched straw, roots, microbial tissue and specific components or in carbon dating naturally occurring 14C. Where initial decomposition data could be described by first order kinetics we calculated decay rate constants with and without the consideration of biosynthesis. Decay rates for laboratory systems were twice those for tropical field soils and eight times those calculated for temperate climates. The data were used in a model incorporating the concepts of microbial biosynthesis and recalcitrant and decomposable soil organic fractions which can both be physically protected. This realistically described the behaviour of soil-C in a Canadian grassland before and after cultivation