Governance-technology co-evolution and misalignment in the electricity industry

This paper explores some reasons why the alignment between governance and technology in infrastructures may be unstable or not easy to achieve. Focusing on the electricity industry, we claim that the decentralization of governance – an essential step towards a decentralized technical coordination - may be hampered by if deregulation magnifies behavioural uncertainties and asset specificities; and that in a technically decentralized system, political demand for centralized coordination may arise if the players are able to collude and lobby, and if such practices lead to higher electricity rates and lower efficiency. Our claims are supported by insights coming from approaches as diverse as transaction cost economics, the competence-based view of the firm, and political economy.Governance; Technology; Coherence; Competence; Transaction costs; Regulation.

Spatial Complex Network Analysis and Accessibility Indicators: the Case of Municipal Commuting in Sardinia, Italy

In this paper a contribution is presented with respect to accessibility indicators modelling for commuters moving through the municipalities of Sardinia, in Italy. In this case, spatial complex network analysis is integrated into the construction of accessibility measures: one of the most relevant outcomes of the first tool –the detection of shortest road paths and distances- is adopted as an input for the second in modelling accessibility indicators. Instead of Euclidean distances often adopted in the literature, shortest road distances are chosen, as commuting implies movements that are usually repeated daily and very likely subjected, even unconsciously, to space and time minimization strategies. In particular, two commuter accessibility indicators are constructed according to approaches based on a travel cost and a spatial interaction model with impedance function calibrated in exponential and in power form. The accessibility indicators are confronted each other and with relevant socio-economic and infrastructure characteristics of Sardinia. In addition, they are described, with respect to their spatial distribution and their different implications, when adopted in decision-making and planning. The travel cost based accessibility indicator has a municipal spatial distribution strongly influenced by the main road infrastructure of the Island. By contrast, spatial interaction model based accessibility indicators are more reliable, with respect to their capacity to confirm a leading socio-economic role of the municipalities comprehended in the metropolitan area of the capital town Cagliari

Grouping complex systems: a weighted network comparative analysis

In this study, the authors compare two inter-municipal commuting networks (MCN) pertaining to the Italian islands of Sardinia and Sicily, by approaching their characterization through a weighted network analysis. They develop on the results obtained for the MCN of Sardinia (De Montis et al. 2007) and attempt to use network analysis as a mean of detection of similarities or dissimilarities between the systems at hand

Modeling commuting systems through a complex network analysis: a study of the Italian islands of Sardinia and Sicily

This study analyzes the inter-municipal commuting systems of the Italian islands of Sardinia and Sicily, employing weighted network analysis technique. Based on the results obtained for the Sardinian commuting network, the network analysis is used to identify similarities and dissimilarities between the two systems

Coupled swelling and nematic reordering in liquid crystal gels

We derive a multiphysics model that accounts for network elasticity with spontaneous strains, swelling and nematic interactions in liquid crystal gels (LCGs). We discuss the coupling among the various physical mechanisms, with particular reference to the effects of nematic interactions on chemical equilibrium and that of swelling on the nematic-isotropic transition. Building upon this discussion and using numerical simulations, we explore the transient phenomena involving concurrent swelling and phase transition in LCGs subject to a temperature change. Specifically, we demonstrate separation in time scales between solvent uptake and phase change, in agreement with experiments, which determines a kinetic decoupling between shape and volume changes. Finally, we discuss possible applications in the context of microswimmers, where such a kinetic decoupling is exploited to achieve non-reciprocal actuation and net motion in Stokes flow

Mechanisms of centrosome separation in C. elegans

Centrosomes are the major microtubule organizing centers of animal cells. The two centrosomes present at the onset of mitosis must separate in a timely fashion along the nuclear envelope to ensure proper bipolar spindle assembly and thus genome stability. Microtubuleassociated motors of the kinesin-5 family are required for centrosome separation in several systems, but are partially redundant or entirely dispensable in others, where the minus-end directed motor dynein plays an important role. The mechanisms by which dynein powers centrosome separation are incompletely understood. Furthermore, the nature of the symmetry-breaking mechanisms that imbalance the forces acting on centrosomes to favor theirmovement away from each other are not known. We addressed these questions using a combination of 3D time-lapse microscopy, image processing and computational modeling to dissect centrosome separation in the polarized one-cell C. elegans embryo that entirely relies on dynein for this process. First, we have characterized the quantitative features of centrosome separation in the wild-type. Next, we compared centrosome separation between wild-type and mutant/RNAi conditions. Our analysis revealed that centrosome separation is powered by the combined action of dynein at the nuclear envelope and at the cell cortex. Moreover, we demonstrated that cortical dynein requires actomyosin contractility to separate centrosomes. These observations suggest that cortical dynein acts by harnessing anterior-directed actomyosin cortical flows initiated earlier in the cell cycle by the centrosomes themselves. To confirmthismodel, we successfully tested experimentally two of its key predictions, namely that dynein complexes flow toward the anterior together with the cortex and that the velocity of centrosome separation correlates with that of the flow of the nearby cortex. Taken together, these results demonstrate that centrosome separation is driven by nuclear and cortical dynein, where the latter acts by transmitting forces produced by the cortical actomyosin flow. To test whether this model is sufficient to explain centrosome separation, we developed a 3D computationalmodel of cytoskeleton dynamics. Indeed, predicted centrosome separation agrees quantitatively with the experimental observations in wild-type and mutant/RNAi conditions. Moreover, the qualitative predictions of the model are robust for parameter changes. Furthermore, computational simulations demonstrate that forces are intrinsically organized to move centrosomes away from each other without the need of any extrinsic symmetry-breaking mechanism. Indeed, in the case of nuclear dynein-driven separation, the position of centrosomes between the nuclear envelope and the cortex results in an asymmetric microtubule aster that leads to centrosome outward movement. In the case of cortical dynein, cortical flows are triggered by centrosomes and always move away from them, such that their forces are always directed to separate centrosomes. Therefore, this separation mechanism functions irrespective of the initial position of centrosomes along the cortex. In conclusion, in this thesis we uncover a novel organizing principle in which dynein, coupled with cell geometry and flow pattern, serves to robustly separate centrosomes and thus ensure genome stability

Modulating the Perceived Softness of Real Objects Through Wearable Feel-Through Haptics

In vision, Augmented Reality (AR) allows the superposition of digital content on real-world visual information, relying on the well-established See-through paradigm. In the haptic domain, a putative Feel-through wearable device should allow to modify the tactile sensation without masking the actual cutaneous perception of the physical objects. To the best of our knowledge, a similar technology is still far to be effectively implemented. In this work, we present an approach that allows, for the first time, to modulate the perceived softness of real objects using a Feel-through wearable that uses a thin fabric as interaction surface. During the interaction with real objects, the device can modulate the growth of the contact area over the fingerpad without affecting the force experienced by the user, thus modulating the perceived softness. To this aim, the lifting mechanism of our system warps the fabric around the fingerpad in a way proportional to the force exerted on the specimen under exploration. At the same time, the stretching state of the fabric is controlled to keep a loose contact with the fingerpad. We demonstrated that different softness perceptions for the same specimens can be elicited, by suitably controlling the lifting mechanism of the system

Nutations in growing plant shoots: the role of elastic deformations due to gravity loading

Abstract The effect of elastic deformations induced by gravity loading on the active circumnutation movements of growing plant shoots is investigated. We consider first a discrete model (a gravitropic spring-pendulum system) and then a continuous rod model which is analyzed both analytically (under the assumption of small deformations) and numerically (in the large deformation regime). We find that, for a choice of material parameters consistent with values reported in the available literature on plant shoots, rods of sufficient length may exhibit lateral oscillations of increasing amplitude, which eventually converge to limit cycles. This behavior strongly suggests the occurrence of a Hopf bifurcation, just as for the gravitropic spring-pendulum system, for which this result is rigorously established. At least in this restricted set of material parameters, our analysis supports a view of Darwin's circumnutations as a biological analogue to structural systems exhibiting flutter instabilities, i.e., spontaneous oscillations away from equilibrium configurations driven by non-conservative loads. Here, in the context of nutation movements of growing plant shoots, the energy needed to sustain oscillations is continuously supplied to the system by the internal biochemical machinery presiding the capability of plants to maintain a vertical pose