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Northern high-latitudes are projected to get warmer and wetter, which will affect rates of permafrost thaw and mechanisms by which thaw occurs. To better understand the impact of rain, as well as other factors such as snow depth, canopy cover, and microtopography, we instrumented a degrading permafrost plateau in south-central Alaska with high-resolution soil temperature sensors. The site contains ecosystem-protected permafrost, which persists in unfavorable climates due to favorable ecologic conditions. Our study (2020–2022) captured three of the snowiest years and three of the four wettest years since the site was first studied in 2015. Average thaw rates along an across-site transect increased nine-fold from 6 ± 5 cm yr −1 (2015–2020) to 56 ± 12 cm yr −1 (2020–2022). This thaw was not uniform. Hummock locations, residing on topographic high points with relatively dense canopy, experienced only 8 ± 9 cm yr −1 of thaw, on average. Hollows, topographic low points with low canopy cover, and transition locations, which had canopy cover and elevation between hummocks and hollows, thawed 44 ± 6 cm yr −1 and 39 ± 13 cm yr −1 , respectively. Mechanisms of thaw differed between these locations. Hollows had high warm-season soil moisture, which increased thermal conductivity, and deep cold-season snow coverage, which insulated soil. Transition locations thawed primarily due to thermal energy transported through subsurface taliks during individual rain events. Most increases in depth to permafrost occurred below the ∼45 cm thickness seasonally frozen layer, and therefore, expanded existing site taliks. Results highlight the importance of canopy cover and microtopography in controlling soil thermal inputs, the ability of subsurface runoff from individual rain events to trigger warming and thaw, and the acceleration of thaw caused by consecutive wet and snowy years. As northern high-latitudes become warmer and wetter, and weather events become more extreme, the importance of these controls on soil warming and thaw is likely to increase.

Cold‐air pooling is an important topoclimatic process that creates temperature inversions with the coldest air at the lowest elevations. Incomplete understanding of sub‐canopy spatiotemporal cold‐air pooling dynamics and associated ecological impacts hinders predictions and conservation actions related to climate change and cold‐dependent species and functions. To determine if and how cold‐air pooling influences forest composition, we characterized the frequency, strength, and temporal dynamics of cold‐air pooling in the sub‐canopy at local to regional scales in New England, USA. We established a network of 48 plots along elevational transects and continuously measured sub‐canopy air temperatures for 6–10 months (depending on site). We then estimated overstory and understory community temperature preferences by surveying tree composition in each plot and combining these data with known species temperature preferences. We found that cold‐air pooling was frequent (19–43% seasonal occurrences) and that sites with the most frequent inversions displayed inverted forest composition patterns across slopes with more cold‐adapted species, namely conifers, at low instead of high elevations. We also observed both local and regional variability in cold‐air pooling dynamics, revealing that while cold‐air pooling is common, it is also spatially complex. Our study, which uniquely focused on broad spatial and temporal scales, has revealed some rarely reported cold‐air pooling dynamics. For instance, we discovered frequent and strong temperature inversions that occurred across seasons and in some locations were most frequent during the daytime, likely affecting forest composition. Together, our results show that cold‐air pooling is a fundamental ecological process that requires integration into modeling efforts predicting future forest vegetation patterns under climate change, as well as greater consideration for conservation strategies identifying potential climate refugia for cold‐adapted species. To determine if and how cold‐air pooling influences forest composition, we surveyed tree composition and characterized the frequency, strength, and temporal dynamics of cold‐air pooling in the sub‐canopy at local to regional scales in New England, USA. We found that cold‐air pooling was frequent (19–43% seasonal occurrences) and that sites with the most frequent inversions displayed inverted forest composition patterns across slopes with more cold‐adapted species, namely conifers, at low instead of high elevations. Cold‐air pooling occurred across seasons and times of day, and, in some locations, was surprisingly more frequent during the daytime than the nighttime.

Biodegradable plastic mulch films (BDMs) are essential in the production of vegetable and specialty crops due to their promotion of increased crop yield and quality. Unlike conventional polyethylene (PE) mulches, BDMs can be tilled into the soil after crop harvest to undergo biodegradation, thereby leading to minimal environmental impact. Agricultural weathering impacts both the performance of BDMs during crop production as a barrier to weeds and biodegradability of BDMs in the soil. To better understand the relative importance of climatic factors, the change of physicochemical properties of BDMs during single-season, 3–4 month, field trials for vegetable production at two diverse climates (Knoxville, TN and Mount Vernon, WA) across four successive years (2015–2018) was evaluated. Mulch treatments consisted of four commercially available BDMs composed primarily of polybutylene co-adipate- co-terephthalate (PBAT) that differed in color and polymeric feedstock, a black experimental BDM prepared from polylactic acid/polyhydroxybutyrate (PLA/PHA) blend, and conventional PE mulch. Solar radiation, an important factor to degradation of mulches, was higher in WA than TN in most sampling years. Yet, degradation occurred more greatly for BDMs in TN, which is attributable to higher temperatures in TN. Mulch deterioration did not very extensively between years. Loss of mechanical properties and color was greater than chemical property changes. Differences in the extent of molecular weight decrease between years correlated significantly with solar radiation exposure at the two locations. A black-colored PBAT-based BDM was less susceptible to degradation than equivalent clear and white-on-black films, due to carbon black acting as a photostabilizer. The impact of weathering also differed between three commercially available PBAT-based films. The PLA/PHA mulch was more susceptible to degradation than PBAT-based BDMs, particularly in the warmer location, TN, partially due to a leaching out of PHA and lower-molecular weight polymer molecules. The extent of change for physicochemical properties of BDMs due to agricultural weathering is greatly affected by polymeric composition, and is greater in warmer climates.

Northern high-latitudes are projected to get warmer and wetter, which will affect rates of permafrost thaw and mechanisms by which thaw occurs. To better understand the impact of rain, as well as other factors such as snow depth, canopy cover, and microtopography, we instrumented a degrading permafrost plateau in south-central Alaska with high-resolution soil temperature sensors. The site contains ecosystem-protected permafrost, which persists in unfavorable climates due to favorable ecologic conditions. Our study (2020–2022) captured three of the snowiest years and three of the four wettest years since the site was first studied in 2015. Average thaw rates along an across-site transect increased nine-fold from 6 ± 5 cm yr–1 (2015–2020) to 56 ± 12 cm yr–1 (2020–2022). This thaw was not uniform. Hummock locations, residing on topographic high points with relatively dense canopy, experienced only 8 ± 9 cm yr–1 of thaw, on average. Hollows, topographic low points with low canopy cover, and transition locations, which had canopy cover and elevation between hummocks and hollows, thawed 44 ± 6 cm yr–1 and 39 ± 13 cm yr–1, respectively. Mechanisms of thaw differed between these locations. Hollows had high warm-season soil moisture, which increased thermal conductivity, and deep cold-season snow coverage, which insulated soil. Transition locations thawed primarily due to thermal energy transported through subsurface taliks during individual rain events. Most increases in depth to permafrost occurred below the ~45 cm thickness seasonally frozen layer, and therefore, expanded existing site taliks. Results highlight the importance of canopy cover and microtopography in controlling soil thermal inputs, the ability of subsurface runoff from individual rain events to trigger warming and thaw, and the acceleration of thaw caused by consecutive wet and snowy years. As northern high-latitudes become warmer and wetter, and weather events become more extreme, the importance of these controls on soil warming and thaw is likely to increase.

On the State of Nature and On the Sovereignty of the People are Maistre's most comprehensive treatment of Rousseau's ideas and his most sustained critique of the ideological foundations of the revolution. On the State of Nature, a detailed critique of Rousseau's Discourse on the Origin and Foundations of Inequality, focuses on Rousseau's belief in the natural goodness of man; On the Sovereignty of the People, a critique of Social Contract, explores Rousseau's theory of popular sovereignty. In Maistre's eyes Rousseau encouraged the socially destructive individualism that lay at the heart of the French Revolution. However, the essays reveal some surprising ambiguities in the relationship between two seminal thinkers who are usually thought of as polar opposites, suggesting that Maistre's vision was more akin to Rousseau's than he would have admitted.

While co-design methods are becoming more popular in healthcare; there is a gap within the peer-reviewed literature on how to do co-design in practice. This paper addresses this gap by delineating the approach taken in the co-design of a collective leadership intervention to improve healthcare team performance and patient safety culture. Over the course of six workshops healthcare staff, patient representatives and advocates, and health systems researchers collaboratively co-designed the intervention. The inputs to the process, exercises and activities that took place during the workshops and the outputs of the workshops are described. The co-design method, while challenging at times, had many benefits including grounding the intervention in the real-world experiences of healthcare teams. Implications of the method for health systems research are discussed.

This study estimates the prevalence of, and associations between, family food insecurity and overweight/obesity among Native Hawaiian and Pacific Islander (NHPI) adolescents and explores socio-demographic factors which might have a moderation effect on the association. Cross-sectional study using 2014 NHPI-National Health Interview Survey data reported by a parent or guardian. Family-level food security was assessed by the US Department of Agriculture 10-item questionnaire. BMI for age and sex ≥ 85th and 95th percentiles defined overweight and obesity, respectively, according to US Centers for Disease Control and Prevention criteria. The USA, including all 50 states and the District of Columbia. 383 NHPI adolescents aged 12-17 in the USA. A third (33·5 %) of NHPI adolescents aged 12-17 were overweight (19·1 %) or obese (14·4 %); 8·1 % had low food security; and 8·5 % had very low food security. Mean family food security score was 1·06, which corresponds to marginal food security. We found no association between family food insecurity and adolescent overweight/obesity or between any other covariates and overweight/obesity, except for family Supplemental Nutrition Assistance Program (SNAP) participation. Odds of being overweight/obese were 77 % lower for adolescents in families participating in SNAP (OR: 0·23, 95 % CI: 0·08, 0·64, = 0·007). The association between SNAP participation and lower odds of overweight/obesity was particularly pronounced for adolescent girls in food-insecure families. The association between SNAP participation and lower odds of overweight/obesity suggests potential benefit of research to determine whether interventions to increase SNAP enrollment would improve NHPI adolescents' health outcomes.

The effect of a liberal transfusion strategy as compared with a restrictive strategy on outcomes in critically ill patients with traumatic brain injury is unclear. We randomly assigned adults with moderate or severe traumatic brain injury and anemia to receive transfusion of red cells according to a liberal strategy (transfusions initiated at a hemoglobin level of ≤10 g per deciliter) or a restrictive strategy (transfusions initiated at ≤7 g per deciliter). The primary outcome was an unfavorable outcome as assessed by the score on the Glasgow Outcome Scale-Extended at 6 months, which we categorized with the use of a sliding dichotomy that was based on the prognosis of each patient at baseline. Secondary outcomes included mortality, functional independence, quality of life, and depression at 6 months. A total of 742 patients underwent randomization, with 371 assigned to each group. The analysis of the primary outcome included 722 patients. The median hemoglobin level in the intensive care unit was 10.8 g per deciliter in the group assigned to the liberal strategy and 8.8 g per deciliter in the group assigned to the restrictive strategy. An unfavorable outcome occurred in 249 of 364 patients (68.4%) in the liberal-strategy group and in 263 of 358 (73.5%) in the restrictive-strategy group (adjusted absolute difference, restrictive strategy vs. liberal strategy, 5.4 percentage points; 95% confidence interval, -2.9 to 13.7). Among survivors, a liberal strategy was associated with higher scores on some but not all the scales assessing functional independence and quality of life. No association was observed between the transfusion strategy and mortality or depression. Venous thromboembolic events occurred in 8.4% of the patients in each group, and acute respiratory distress syndrome occurred in 3.3% and 0.8% of patients in the liberal-strategy and restrictive-strategy groups, respectively. In critically ill patients with traumatic brain injury and anemia, a liberal transfusion strategy did not reduce the risk of an unfavorable neurologic outcome at 6 months. (Funded by the Canadian Institutes of Health Research and others; HEMOTION ClinicalTrials.gov number, NCT03260478.).

PurposeCanadian donor management practices have not been reported. Our aim was to inform clinicians and other stakeholders about the range of current practices.MethodsThis prospective observational cohort study enrolled consecutive, newly consented organ donors from August 1 2015 to July 31 2018 at 27 academic and five community adult intensive care units in British Columbia, Alberta, Ontario, and Quebec. Research staff prospectively recorded donor management data. Provincial organ donation organizations verified the organs donated. We formally compared practices across provinces.ResultsOver a median collection period of eight months, 622 potential donors were classified at baseline as having neurologic determination of death (NDD donors; n = 403) or circulatory death (DCD donors; n = 219). Among NDD donors, 85.6% underwent apnea testing (rarely with carbon dioxide insufflation), 33.2% underwent ancillary testing, and subsequent therapeutic hypothermia (34–35°C) was rare. Neurologic determination of death donors were more hemodynamically unstable with most having received vasopressin and norepinephrine infusions, with a large majority having received high-dose corticosteroids and intravenous thyroxine. Among DCD donors, 61.6% received corticosteroids, and 8.9% received thyroxine. Most donors did not receive lung-protective ventilation strategies. Invasive procedures after donation consent included bronchoscopy (71.7%), cardiac catheterization (NDD donors only; 21.3%), and blood transfusions (19.3%). Physicians ordered intravenous antemortem heparin for 94.8% of DCD donors. The cohort donated 1,629 organs resulting in 1,532 transplants. Case selection, death determinations, and hormone, nutrition and heparin practices all varied across provinces.ConclusionThese study findings highlight areas for knowledge translation and further clinical research. Interprovincial discrepancies will likely pose unique challenges to national randomized trials.Trial registration: www.clinicaltrials.gov (NCT03114436); registered 10 April, 2017.

IntroductionMost solid organ transplants originate from donors meeting criteria for death by neurological criteria (DNC). Within the organ donor, physiological responses to brain death increase the risk of ischaemia reperfusion injury and delayed graft function. Donor preconditioning with calcineurin inhibition may reduce this risk.Methods and analysisWe designed a multicentre placebo-controlled pilot randomised trial involving nine organ donation hospitals and all 28 transplant programmes in the Canadian provinces of Ontario and Québec. We planned to enrol 90 DNC donors and their approximately 324 organ recipients, totalling 414 participants. Donors receive an intravenous infusion of either tacrolimus 0.02 mg/kg over 4 hours prior to organ retrieval, or a matching placebo, while monitored in an intensive care unit for any haemodynamic changes during the infusion. Among all study organ recipients, we record measures of graft function for the first 7 days in hospital and we will record graft survival after 1 year. We examine the feasibility of this trial with respect to the proportion of all eligible donors enrolled and the proportion of all eligible transplant recipients consenting to receive a CINERGY organ transplant and to allow the use of their health data for study purposes. We will report these feasibility outcomes as proportions with 95% CIs. We also record any barriers encountered in the launch and in the implementation of this trial with detailed source documentation.Ethics and disseminationWe will disseminate trial results through publications and presentations at participating sites and conferences. This study has been approved by Health Canada (HC6-24-c241083) and by the Research Ethics Boards of all participating sites and in Québec (MP-31-2020-3348) and Clinical Trials Ontario (Project #3309).Trial registration numberNCT05148715.