Climate change and the long-term viability of the World’s busiest heavy haul ice road

Climate models project that the northern high latitudes will warm at a rate in excess of the global mean. This will pose severe problems for Arctic and sub-Arctic infrastructure dependent on maintaining low temperatures for structural integrity. This is the case for the economically important Tibbitt to Contwoyto Winter Road (TCWR)—the world’s busiest heavy haul ice road, spanning 400 km across mostly frozen lakes within the Northwest Territories of Canada. In this study, future climate scenarios are developed for the region using statistical downscaling methods. In addition, changes in lake ice thickness are projected based on historical relationships between measured ice thickness and air temperatures. These projections are used to infer the theoretical operational dates of the TCWR based on weight limits for trucks on the ice. Results across three climate models driven by four RCPs reveal a considerable warming trend over the coming decades. Projected changes in ice thickness reveal a trend towards thinner lake ice and a reduced time window when lake ice is at sufficient thickness to support trucks on the ice road, driven by increasing future temperatures. Given the uncertainties inherent in climate modelling and the resultant projections, caution should be exercised in interpreting the magnitude of these scenarios. More certain is the direction of change, with a clear trend towards winter warming that will reduce the operation time window of the TCWR. This illustrates the need for planners and policymakers to consider future changes in climate when planning annual haulage along the TCWR.

Optimal day-ahead scheduling of integrated urban energy systems

An optimal day-ahead scheduling method (ODSM) for the integrated urban energy system (IUES) is introduced, which considers the reconfigurable capability of an electric distribution network. The hourly topology of a distribution network, a natural gas network, the energy centers including the combined heat and power (CHP) units, different energy conversion devices and demand responsive loads (DRLs), are optimized to minimize the day-ahead operation cost of the IUES. The hourly reconfigurable capability of the electric distribution network utilizing remotely controlled switches (RCSs) is explored and discussed. The operational constraints from the unbalanced three-phase electric distribution network, the natural gas network, and the energy centers are considered. The interactions between the electric distribution network and the natural gas network take place through conversion of energy among different energy vectors in the energy centers. An energy conversion analysis model for the energy center was developed based on the energy hub model. A hybrid optimization method based on genetic algorithm (GA) and a nonlinear interior point method (IPM) is utilized to solve the ODSM model. Numerical studies demonstrate that the proposed ODSM is able to provide the IUES with an effective and economical day-ahead scheduling scheme and reduce the operational cost of the IUES.

Possibility and agency in Figured Worlds: Becoming a ‘good doctor’

Context: Figured Worlds is a socio-cultural theory drawing on Vygotskian and Bakhtinian traditions, which has been applied in research into the development of identities of both learners and teachers in the wider education literature. It is now being adopted in medical education.

Objective: The objective of this paper is to show what Figured Worlds can offer in medical education. Having explained some of its central tenets, we apply it to an important tension in our field.

Application: The assumption that there is a uniform ‘good doctor’ identity, which must be inculcated into medical students, underlies much of what medical educators do, and what our regulators enforce. While diversity is encouraged when students are selected for medical school, pressure to professionalise students creates a drive towards a standardised professional identity by graduation. Using excerpts from reflective pieces written by two junior medical students, we review the basic concepts of Figured Worlds and demonstrate how it can shed light on the implications of this tension. Taking a Bakhtinian approach to discourse, we show how Adam and Sarah develop their professional identities as they negotiate the multiple overlapping and competing ways of being a doctor which they encounter in the world of medical practice. Each demonstrates agency by ‘authoring’ a unique identity in the cultural world of medicine, as they appropriate and re-voice the words of others.

Discussion: Finally, we consider some important areas in medical education where Figured Worlds might prove to be a useful lens: the negotiation of discourses of gender, sexuality and social class, career choice as identification within specialty-specific cultural worlds, and the influence of hidden and informal curricula on doctor identity.