Estimation of electric field impact in deep brain stimulation from axon diameter distribution in the human brain

Background: Finite element method (FEM) simulations of the electric field magnitude (EF) are commonly used to estimate the affected tissue surrounding the active contact of deep brain stimulation (DBS) leads. Previous studies have found that DBS starts to noticeably activate axons at approximately 0.2 V/mm, corresponding to activation of 3.4 $\mu$m axons in simulations of individual axon triggering. Most axons in the brain are considerably smaller however, and the effect of the electric field is thus expected to be stronger with increasing EF as more and more axons become activated. Objective: To estimate the fraction of activated axons as a function of electric field magnitude. Methods: The EF thresholds required for axon stimulation of myelinated axon diameters between 1 and 5 $\mu$m were obtained from a combined cable and Hodgkin-Huxley model in a FEM-simulated electric field from a Medtronic 3389 lead. These thresholds were compared with the average axon diameter distribution from literature from several structures in the human brain to obtain an estimate of the fraction of axons activated at EF levels between 0.1 and 1.8 V/mm. Results: The effect of DBS is estimated to be 41$\cdot$EF - 7.4 % starting at a threshold level EFt0 = 0.18 V/mm. Conclusion: The fraction of activated axons from DBS in a voxel is estimated to increase linearly with EF above the threshold level of 0.18 V/mm. This means linear regression between EF above 0.18 V/mm and clinical outcome is a suitable statistical method when doing improvement maps for DBS.Comment: 11 pages, 6 figure

Impacts of shared mobility on vehicle lifetimes and on\ua0the carbon footprint of electric vehicles

Shared cars will likely have larger annual vehicle driving distances than individually owned cars. This may accelerate passenger car retirement. Here we develop a semi-empirical lifetime-driving intensity model using statistics on Swedish vehicle retirement. This semi-empirical model is integrated with a carbon footprint model, which considers future decarbonization pathways. In this work, we show that the carbon footprint depends on the cumulative driving distance, which depends on both driving intensity and calendar aging. Higher driving intensities generally result in lower carbon footprints due to increased cumulative driving distance over the vehicle’s lifetime. Shared cars could decrease the carbon footprint by about 41% in 2050, if one shared vehicle replaces ten individually owned vehicles. However, potential empty travel by autonomous shared vehicles—the additional distance traveled to pick up passengers—may cause carbon footprints to increase. Hence, vehicle\ua0durability and empty travel should be considered when\ua0designing low-carbon car sharing\ua0systems

Critical Success Factors affecting Decision Support System Success, from an end-user perspective

In the history of DSS literature numerous of researchers have investigated the state of DSS and attempts have been made to develop an understanding for the role of certain critical success factors affecting the implementation success. However, the cumulative knowledge is in the literature suggested to be li-mited and regularly placing the end-user outside the centre of focus. This thesis have included these reporting and concen-trated on building a cumulative theoretical framework of IS re-search applicable to the field of DSS, starting from Wixom & Watson’s research model from 2001. Via a multi-method en-tailing the built up theoretical framework and two expert inter-views a research model was designed, which subsequently was tested and evaluated through a survey in order find the answer to which critical success factors that significantly affects end-users perceived net benefits of a DSS post-implementation. By analyzing the survey result, this study identified three factors that significantly affect end-users perceived net benefits, name-ly Data Quality, Problem Match and Support Quality. The the-sis finishes with a discussion and conclusion of how the find-ings can contribute to the field of research and practice, and how further studies can follow on where this thesis finishes

If Electric Cars Are Good for Reducing Emissions, They Could Be Even Better with Electric Roads

This research investigates carbon footprint impacts for full fleet electrification of Swedish passenger car travel in combination with different charging conditions, including electric road system (ERS) that enables dynamic on-road charging. The research applies a prospective life cycle analysis framework for estimating carbon footprints of vehicles, fuels, and infrastructure. The framework includes vehicle stock turnover modeling of fleet electrification and modeling of optimal battery capacity for different charging conditions based on Swedish real-world driving patterns. All new car sales are assumed to be electric after 2030 following phase-out policies for gasoline and diesel cars. Implementing ERS on selected high-traffic roads could yield significant avoided emissions in battery manufacturing compared to the additional emissions in ERS construction. ERS combined with stationary charging could enable additional reductions in the cumulative carbon footprint of about 12–24 million tons of CO2\ua0over 30 years (2030–2060) compared to an electrified fleet only relying on stationary charging. The range depends on uncertainty in emission abatement in global manufacturing, where the lower is based on Paris Agreement compliance and the higher on current climate policies. A large share of the reduction could be achieved even if only a small share of the cars adopts the optimized battery capacities

Assessing ocean ensemble drift predictions by comparison with observed oil slicks

Geophysical models are cornerstone pieces in marine forecasting of floating objects and pollution, such as marine surface oil slicks. Trajectory forecasts of oil spills inherit the uncertainties from the underlying geophysical forcing. In this work we compare the forecast capabilities of an ocean ensemble prediction system (EPS) to those from a higher resolution deterministic model on the representation of oil slick drift. As reference, we use produced water (PW) slicks detected and delineated from 41 C–band Sentinel-1A/B satellite synthetic aperture radar images between April and December, 2021. We found that the EPS provided at least equivalent member-wise results relative to simulations forced with the deterministic model. Ensemble verification through rank histograms and spread-error relationship showed that including the ocean fields is necessary to address model uncertainties. Whether considering the ocean field or not, the modeled slicks were counterclockwise rotated between 20° and 30° relative to the ones observed in the satellite images, and these were deflected about 45° to the right of the observed wind direction

Total BIM in Practice: A dynamic single source of information on the construction site

The rapid advancement of digital technologies presents the construction industry with opportunities to change how site work is performed. Traditionally site work has been dominated by taking information from static construction documents such as 2D paper drawings. However, recently in the Nordic region a dynamic approach known as Total BIM has gained interest. Total BIM is an approach where BIM replaces 2D drawings as the contractual and legally binding construction document, cloud-based production-oriented BIM and powerful mobile BIM-viewers are used on-site. By having a dynamic single source of information site workers face new demands as they extract construction information directly from BIM themselves. Instead of using static 2D drawings they interact dynamically with BIM on mobile devices, changing the process of how work was implemented on the construction site. This paper is based on four real-life case studies, site visits, workshops and semi-structured interviews. Key digital Total BIM features are investigated that site workers use to perform the new work methods, including measuring, filtering, visualizing, communicating, checklists, and requests for information. These lead to a more dynamic construction process where the mobile BIM-viewer software becomes a central communication and management platform. This paper highlights the opportunities of working with dynamic Total BIM over static 2D drawings that can be used for implementing Total BIM strategy on the construction site. Furthermore, this paper addresses issues commonly found in state-of-the-art BIM projects and contributes practical concrete examples of on-site Total BIM use

A Fully Abstract Symbolic Semantics for Psi-Calculi

We present a symbolic transition system and bisimulation equivalence for psi-calculi, and show that it is fully abstract with respect to bisimulation congruence in the non-symbolic semantics. A psi-calculus is an extension of the pi-calculus with nominal data types for data structures and for logical assertions representing facts about data. These can be transmitted between processes and their names can be statically scoped using the standard pi-calculus mechanism to allow for scope migrations. Psi-calculi can be more general than other proposed extensions of the pi-calculus such as the applied pi-calculus, the spi-calculus, the fusion calculus, or the concurrent constraint pi-calculus. Symbolic semantics are necessary for an efficient implementation of the calculus in automated tools exploring state spaces, and the full abstraction property means the semantics of a process does not change from the original

How justice shapes transition governance - a discourse analysis of Swedish policy debates

In both policy-making and academia, the realisation is growing that transitions striving for sustainability have to be just to be socially accepted. This insight has given rise to institutionalised approaches to a "just transition" - but also beyond these, justice is a key challenge in the governance of sustainability transitions. In this paper, we examine how justice arguments are being used in national-level discourses of transition governance in Sweden. Analysing 121 policy-related documents from 2019 to 2021, we found that justice was discursively treated in a way that essentially stifled change. Political actors attempted to trump each other's justice claims rather than to genuinely engage with them. Justice concerns that would not serve re-election, such as solidarity across social boundaries, were almost absent from the material. Based on these findings, we critically explore how justice arguments contribute to politicizing transition governance in particular ways, rendering some policy options impossible