An expert assessment on playspace designs and thermal environments in a Canadian context

Playgrounds are a hub for child play and concerns that may impact children\u27s play there may hinder their health and well-being. Extreme temperatures can increase risks in children of sunstroke, burns from playground surfaces, and exposure to ultraviolet radiation. Despite health risks from extreme heat to children, existing playground design standards around the world, including in Canada, make little-to-no mention of how to design playgrounds for thermal comfort, particularly in summer. To help fill this gap in the Canadian context, several organizations collaborated to develop guidance for thermally comfortable playgrounds in Canada. As part of this project, an online survey was administered to 55 experts with diverse professional backgrounds, largely from Canada and the United States, to determine how thermal comfort is viewed in playground design and safety. Survey results showed agreement among experts that thermal comfort receives low or no priority in playground design but should be prioritized or considered alongside other safety factors in relevant playground safety guidelines and standards. The results of this survey not only helped inform the 2020 publication of a Thermal Comfort annex to the CSA Group\u27s Children\u27s playgrounds and equipment standard (CAN/CSA Z614) but could also help inform future research and practice globally

The Impact of Frozen Ground Degradation on Surface-Atmosphere Interactions

Climate change is having a significant impact on the Arctic and will continue to do so in the future. Much of the previous literature has focused on heat and moisture exchange associated with diminished sea ice and increased amounts of open Arctic waters, but overlooked the impact of land areas. Permafrost regions of Eurasia have experienced an increase in active layer thickness over the past century due to this warming climate, according to previous studies. As a result, these soils have been able to absorb and retain more heat during the warm season, leading to a delayed freeze-up and a seasonally redistributed surface energy budget. This has also led to changes in surface hydrology in the region. These factors can play a role in energy transfer into the boundary layer and, on extended time scales, synoptic circulation patterns. However, most previous research on permafrost’s impact on climate change has been centered on biogeochemical cycles and carbon feedbacks. A geophysical narrative is important to fully describe the role of frozen ground on the climate, but it can be difficult to separate the influence on atmospheric variables only due to permafrost degradation. In this dissertation, an idealized modeling study was completed to quantify the differences across scales given different permafrost conditions as well as synoptic setups. Moister active layers in continuous permafrost led to decreased surface air temperatures but increased atmospheric instability on short time scales. With confirmation that permafrost degradation does impact land-atmosphere interactions, analysis of a large ensemble of the Community Earth System Model and use of the dynamical adjustment methodology indicated that permafrost influences on the evolution of surface air temperatures were restricted to the autumn as dynamics and internal variability dominated in the spring. Autumn surface-based influence was due to a shift in the partitioning of turbulent surface fluxes in the summer and autumn over the 21st century and subsequent hydrothermal responses at the surface and sub-surface in continuous and discontinuous permafrost, including increased spring snow, soil moisture, and convective precipitation. This novel dissertation shows that permafrost degradation has geophysical implications in climate change which must be considered

Workplace heat exposure, health protection, and economic impacts: A case study in Canada

Background: Occupational heat exposure is a serious concern for worker health, productivity, and the economy. Few studies in North America assess how on‐site wet bulb globe temperature (WBGT) levels and guidelines are applied in practice

Heat stress vulnerability and critical environmental limits for older adults

Abstract The present study examined heat stress vulnerability of apparently healthy older vs. young adults and characterized critical environmental limits for older adults in an indoor setting at rest (Rest) and during minimal activity associated with activities of daily living. Critical environmental limits are combinations of ambient temperature and humidity above which heat balance cannot be maintained (i.e., becomes uncompensable) for a given metabolic heat production. Here we exposed fifty-one young (23 ± 4 yrs) and 49 older (71 ± 6 yrs) adults to progressive heat stress across a wide range of environments in an environmental chamber during Minimal Activity (young and older subjects) and Rest (older adults only). Heat compensability curves were shifted leftward for older adults indicating age-dependent heat vulnerablity (p < 0.01). During Minimal Activity, critical environmental limits were lower in older compared to young adults (p < 0.0001) and lower than those at Rest (p < 0.0001). These data document heat vulnerability of apparently healthy older adults and define critical environmental limits for indoor settings in older adults at rest and during activities of daily living, and can be used to develop evidence-based recommendations to minimize the deleterious impacts of extreme heat events in this population

Spino-dendritic cross-talk in rodent Purkinje neurons mediated by endogenous Ca2+-binding proteins

The range of actions of the second messenger Ca2+ is a key determinant of neuronal excitability and plasticity. For dendritic spines, there is on-going debate regarding how diffusional efflux of Ca2+ affects spine signalling. However, the consequences of spino-dendritic coupling for dendritic Ca2+ homeostasis and downstream signalling cascades have not been explored to date. We addressed this question by four-dimensional computer simulations, which were based on Ca2+-imaging data from mice that either express or lack distinct endogenous Ca2+-binding proteins. Our simulations revealed that single active spines do not affect dendritic Ca2+ signalling. Neighbouring, coactive spines, however, induce sizeable increases in dendritic [Ca2+]i when they process slow synaptic Ca2+ signals, such as those implicated in the induction of long-term plasticity. This spino-dendritic coupling is mediated by buffered diffusion, specifically by diffusing calbindin-bound Ca2+. This represents a central mechanism for activating calmodulin in dendritic shafts and therefore a novel form of signal integration in spiny dendrites

The Permafrost Young Researchers Network (PYRN) is getting older: The past, present, and future of our evolving community

International audienceA lasting legacy of the International Polar Year (IPY) 2007–2008 was the promotion of the Permafrost Young Researchers Network (PYRN), initially an IPY outreach and education activity by the International Permafrost Association (IPA). With the momentum of IPY, PYRN developed into a thriving network that still connects young permafrost scientists, engineers, and researchers from other disciplines. This research note summarises (1) PYRN’s development since 2005 and the IPY’s role, (2) the first 2015 PYRN census and survey results, and (3) PYRN’s future plans to improve international and interdisciplinary exchange between young researchers. The review concludes that PYRN is an established network within the polar research community that has continually developed since 2005. PYRN’s successful activities were largely fostered by IPY. With >200 of the 1200 registered members active and engaged, PYRN is capitalising on the availability of social media tools and rising to meet environmental challenges while maintaining its role as a successful network honouring the legacy of IPY