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ObjectiveTo assess the effect of calcium, vitamin D, or combined supplementation on fractures and falls in adults.DesignSystematic review and meta-analysis.Data sourcesTrials included in systematic reviews from 2014, three databases (Medline, Embase, CENTRAL) to 19 February 2025, clinical trial registries, abstracts from scientific meetings, and references from included studies.Eligibility criteriaRandomised controlled trials comparing calcium, vitamin D, or combined supplementation with placebo or no treatment in adults (≥18 years) not receiving drug treatment for osteoporosis.Data extraction and synthesisThe primary outcome was the risk of any fracture. Secondary outcomes included the risk of hip fracture, non-vertebral fracture, vertebral fracture, and falling, as well as the total number of falls. Pairs of reviewers independently screened trials, extracted data, and assessed risk of bias using the second version of Cochrane’s risk of bias tool. Findings were synthesised using random effects meta-analyses and appraised using Grading of Recommendations Assessment, Development and Evaluation, with application of thresholds for absolute effects considered important.ResultsThis review included 69 trials involving 153 902 participants. Participants in most of the trials were community dwelling (87%) and not at high risk of fractures or falls (73%). For the primary outcome of any fracture, little to no effect was found from use of calcium supplements (11 trials, 9067 participants; risk ratio 0.91, 95% confidence interval 0.81 to 1.01; moderate certainty), vitamin D supplements (36 trials, 92 045 participants; 1.00, 0.95 to 1.06; high certainty), or combined supplementation (15 trials, 51 126 participants; 0.91, 0.84 to 0.99; high certainty). Calcium, vitamin D, or combined supplementation appeared to have little to no effect on other fracture and fall outcomes, based largely on moderate to high certainty of evidence. The findings remained robust after an extensive exploration of heterogeneity across multiple subgroup analyses. Evidence for high risk patients or those requiring residential care was limited for many outcomes for calcium monotherapy and for combined supplementation.ConclusionBased on absolute risk reductions and thresholds considered clinically meaningful, this review found little to no benefits from use of calcium, vitamin D, or combined supplementation on the prevention of fractures and falls.Systematic review registrationPROSPERO CRD42023483915.

ContextForest landscapes at the boreal–temperate ecotone have been extensively altered. Reducing the gap between current and presettlement forest conditions through ecosystem-based forest management (EBFM) is thought to enhance ecological integrity. However, climate change may interfere with this goal and make these targets unrealistic.ObjectivesWe evaluated the impacts of climate change on the ability of EBFM to reduce discrepancies between current and presettlement forest conditions in southeastern Canada.MethodsWe used early-land-survey data as well as projections from a forest landscape model (LANDIS-II) under four climate change scenarios and four management scenarios to evaluate future discrepancies between presettlement forest conditions and future forest landscapes.ResultsBy triggering swift declines in most late-succession boreal conifer species biomass, climate change would greatly reduce the ability of forest management to reduce the gap with presettlement forest composition, especially under severe anthropogenic climate forcing. Scenarios assuming extensive clearcutting also favor aggressive competitor species that have already increased with high historical harvest levels (e.g., poplars, maples).ConclusionsEBFM would still be the “less bad” forest harvesting strategy in order to mitigate composition discrepancies with the presettlement forests, though it is likely to fail under severe climate forcing. In this latter case, one might thus question the relevancy of using presettlement forest composition as a target for restoring degraded forest landscapes. As such, we advocate that managers should relax the centrality of the reference condition and focus on functional restoration rather than aiming at reducing the gaps with presettlement forest composition per se.

BackgroundPrevious systematic reviews on fracture and fall prevention have generally shown no efficacy with calcium or vitamin D alone and conflicting findings with that of vitamin D combined with calcium. Despite these findings, increases in vitamin D and calcium prescriptions have been reported in many countries, as many clinicians, guidelines and regulatory agencies still largely recommend universal supplementation to adults.Methods and analysisWe will conduct a systematic review of randomised controlled trials on the efficacy of vitamin D and/or calcium in fracture and fall prevention. A systematic search will be performed in Medline, Embase, CENTRAL, International Clinical Trials Registry Platform and Clinicaltrials.gov (1 January 2024). We will also hand search abstracts published in relevant congress and journals (2021–2023) and the reference lists of included trials. We will consider any trial involving the pharmacological administration of calcium alone, vitamin D alone or vitamin D combined with calcium against placebo or no treatment in adults. The primary outcome will be the number of participants with fractures at any site. The secondary outcomes will be the number of participants with hip fractures, non-vertebral fractures, vertebral fractures and falls, and the rate of falls. Two reviewers will independently screen and include the trials, extract the data and assess the risk of bias using the second version of the Cochrane risk-of-bias tool. We plan to pool outcomes to conduct random-effects meta-analyses and to appraise the certainty of evidence using Grading of Recommendations Assessment, Development and Evaluation (GRADE). Many prespecified subgroup and sensitivity analyses will be performed to explore the potential heterogeneity and to test the robustness of our findings.Ethics and disseminationThis systematic review does not require research ethics approval. The results will be disseminated in peer-reviewed journals and help inform clinicians, guidelines and regulatory agencies.PROSPERO registration numberCRD42023483915

Predicting future ecosystem dynamics depends critically on an improved understanding of how disturbances and climate change have driven long-term ecological changes in the past. Here we assembled a dataset of >100,000 tree species lists from the 19th century across a broad region (>130,000km 2 ) in temperate eastern Canada, as well as recent forest inventories, to test the effects of changes in anthropogenic disturbance, temperature and moisture on forest dynamics. We evaluate changes in forest composition using four indices quantifying the affinities of co-occurring tree species with temperature, drought, light and disturbance. Land-use driven shifts favouring more disturbance-adapted tree species are far stronger than any effects ascribable to climate change, although the responses of species to disturbance are correlated with their expected responses to climate change. As such, anthropogenic and natural disturbances are expected to have large direct effects on forests and also indirect effects via altered responses to future climate change. Separating anthropogenic and climatic impacts on forest compositions can be challenging due to a lack of data. Here the authors look at forest compositional changes in eastern Canada since the 19th century and find land use has most strongly shaped communities towards disturbance-adapted species.

BackgroundDelirium, agitation, and anxiety may hinder weaning from mechanical ventilation and lead to increased morbidity and healthcare costs. The most appropriate clinical approach to weaning in these contexts remains unclear and challenging to clinicians. The objective of this systematic review was to identify effective and safe interventions to wean patients that are difficult-to-wean from mechanical ventilation due to delirium, agitation, or anxiety.MethodsA systematic review was performed using MEDLINE, EMBASE, and PubMed. Studies evaluating mechanically ventilated patients deemed difficult-to-wean due to delirium, agitation, or anxiety, and comparing the effects of an intervention with a comparator arm were sought. Time-to-extubation was the primary outcome while the secondary outcome was intensive care unit (ICU) length of stay.ResultsFrom 10,860 studies identified, eight met the inclusion criteria: six studies assessed dexmedetomidine while the remaining two assessed loxapine and biofeedback. Pooled analysis of studies assessing dexmedetomidine showed reduced time-to-extubation (six studies, n = 303) by 10.9 hr compared with controls (95% confidence interval [CI], -15.7 to -6.1; I2 = 68%) and ICU length of stay (four studies, n = 191) by 2.6 days (95% CI, 1.9 to 3.3; I2 = 0%). Nevertheless, the evidence was deemed to be of low quality given the small sample sizes and high heterogeneity. Studies assessing other interventions did not identify improvements compared with controls. Safety assessment was globally poorly reported.ConclusionsThis systematic review and meta-analysis provides low quality evidence to suggest the use of dexmedetomidine in patients deemed difficult-to-wean due to agitation, delirium, or anxiety. Insufficient evidence was found regarding other interventions to provide any recommendation.Trial registrationPROSPERO (CRD42016042528); registered 15 July, 2016.

The dielectric properties of the solid solution Ba 1− x Sr x TiO 3−δ (0 ≤  x  ≤ 1) have been investigated. The nanopowders were prepared via a coprecipitation reaction followed by a calcination treatment. Spark plasma sintering allowed to obtain dense nanocrystalline ceramics. Broadband impedance spectroscopy revealed colossal permittivity (ε′ = 10 5 ) associated with low losses (tan δ = 0.03) in the most favorable case. The bulk conductivity data was analyzed using Jonscher’s universal dielectric response model. In the Ba-rich compound, conduction process followed variable range hopping conduction model while the Sr-rich BST compound showed the nearest neighbor hopping conduction mechanism associated with displacements of space charges. These two different conduction mechanisms might be able to explain superior temperature–frequency-independent dielectric properties in Sr-rich BST compound compared to Ba-rich BST compound.

Question How has European settlement of Eastern North America modified tree species assemblages? Location The northern temperate forests of the Lower St. Lawrence region (Quebec, Canada). Methods Changes in relative prevalence of tree taxa were reconstructed with early land survey records (1821–1900) and modern forest inventories (1980–2010). Forest composition reconstructions were then used to analyse changes in tree taxa assemblages at the landscape scale and test for potential landscape homogenization. Results Our results show important maple (Acer saccharum and A. rubrum) and poplar (Populus tremuloides and P. balsamifera) encroachment, shifting from the 6th to the 2nd position of relative prevalence and from the 7th to the 5th position, respectively, resulting in a significant shift in tree assemblage. Maple has spread throughout the whole landscape and tended to become the most abundant taxon in communities where they were already present in pre‐settlement times. Poplar also widely spread throughout the landscape but rarely became the most abundant taxon. Accordingly, deciduous encroachment clearly engendered a spatial homogenization of composition at the landscape scale. Conclusion Considering that both red maple and trembling aspen are opportunist early‐successional species, the increased relative prevalence of both species, as well as the consequent reorganization of tree taxon assemblages and landscape homogenization, probably resulted from the regional convergence toward an early‐successional state. Along with the restoration of long‐lived shade‐tolerant conifer populations, land and forest managers should aim to increase the heterogeneity of forest stand composition to improve forests resilience to future global changes. Changes in relative prevalence of tree taxa (1820–2010) were reconstructed for eastern Canada. The relative order of taxon prevalence has been reshuffled extensively following European settlement due to the regional expansion of maple and poplar taxa. Along with the restoration of long‐lived shade‐tolerant conifer populations, managers should aim to increase the heterogeneity of forest stand composition to improve forest resilience.

Objective Prolonged opioid use is common following traumatic injuries. Although preventive strategies have been recommended, the evidence supporting their use is low. The objectives of this study were to select interdisciplinary strategies to prevent long-term, detrimental opioid use in trauma patients for further evaluation and to identify implementation considerations. Design A consensus study using the nominal group technique. Setting Four trauma systems in Canada. Subjects Participants included expert clinicians and decision makers, and people with lived experience. Methods Participants had to discuss the relevance and implementation of 15 strategies and then rank them using a 7-point Likert scale. Implementation considerations were identified through a synthesis of discussions. Results A total of 41 expert stakeholders formed the nominal groups. Overall, eight strategies were favored: 1) using multimodal approach for pain management, 2) professional follow-up in physical health, 3) assessment of risk factors for opioid misuse, 4) physical stimulation, 5) downward adjustment of opioids based on patient recovery, 6) educational intervention for patients, 7) training offered to professionals on how to prescribe opioids, and 8) optimizing communication between professionals working in different settings. Discussions with expert stakeholders revealed the rationale for the selected strategies and identified issues to consider when implementing them. Conclusion This stakeholder consensus study identified, for further scientific study, a set of interdisciplinary strategies to promote appropriate opioid use following traumatic injuries. These strategies could ultimately decrease the burden associated with long-term opioid use.

To evaluate how Canadian clinicians involved in trauma patient care and prescribing opioids perceive the use and effectiveness of strategies to prevent long-term opioid therapy following trauma. Barriers and facilitators to the implementation of these strategies were also assessed. We conducted a web-based cross-sectional survey. Potential participants were identified by trauma program managers and directors of the targeted departments in three Canadian provinces. We designed our questionnaire using standard health survey research methods. The questionnaire was administered between April 2021 and November 2021. Our response rate was 47% (350/744), and 52% (181/350) of participants completed the entire survey. Most respondents (71%, 129/181) worked in teaching hospitals. Multimodal analgesia (93%, 240/257), nonsteroidal anti-inflammatory agents (77%, 198/257), and physical stimulation (75%, 193/257) were the strategies perceived to be the most frequently used. Several preventive strategies were perceived to be very effective by over 80% of respondents. Of these, some that were reported as not being frequently used were perceived to be among the most effective ones, including guidelines or protocols, assessing risk factors for opioid misuse, physical health follow-up by a professional, training for clinicians, patient education, and prescription monitoring systems. Staff shortages, time constraints, and organizational practices were identified as the main barriers to the implementation of the highest ranked preventive strategies. Several strategies to prevent long-term opioid therapy following trauma are perceived as being effective by those prescribing opioids in this population. Some of these strategies appear to be commonly used in everyday practice and others less so. Future research should focus on which preventive strategies should be given higher priority for implementation before assessing their effectiveness.

Purpose To evaluate how Canadian clinicians involved in trauma patient care and prescribing opioids perceive the use and effectiveness of strategies to prevent long-term opioid therapy following trauma. Barriers and facilitators to the implementation of these strategies were also assessed. Methods We conducted a web-based cross-sectional survey. Potential participants were identified by trauma program managers and directors of the targeted departments in three Canadian provinces. We designed our questionnaire using standard health survey research methods. The questionnaire was administered between April 2021 and November 2021. Results Our response rate was 47% (350/744), and 52% (181/350) of participants completed the entire survey. Most respondents (71%, 129/181) worked in teaching hospitals. Multimodal analgesia (93%, 240/257), nonsteroidal anti-inflammatory agents (77%, 198/257), and physical stimulation (75%, 193/257) were the strategies perceived to be the most frequently used. Several preventive strategies were perceived to be very effective by over 80% of respondents. Of these, some that were reported as not being frequently used were perceived to be among the most effective ones, including guidelines or protocols, assessing risk factors for opioid misuse, physical health follow-up by a professional, training for clinicians, patient education, and prescription monitoring systems. Staff shortages, time constraints, and organizational practices were identified as the main barriers to the implementation of the highest ranked preventive strategies. Conclusions Several strategies to prevent long-term opioid therapy following trauma are perceived as being effective by those prescribing opioids in this population. Some of these strategies appear to be commonly used in everyday practice and others less so. Future research should focus on which preventive strategies should be given higher priority for implementation before assessing their effectiveness.