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Droughts and climate-change-driven warming are leading to more frequent and intense wildfires 1 – 3 , arguably contributing to the severe 2019–2020 Australian wildfires 4 . The environmental and ecological impacts of the fires include loss of habitats and the emission of substantial amounts of atmospheric aerosols 5 – 7 . Aerosol emissions from wildfires can lead to the atmospheric transport of macronutrients and bio-essential trace metals such as nitrogen and iron, respectively 8 – 10 . It has been suggested that the oceanic deposition of wildfire aerosols can relieve nutrient limitations and, consequently, enhance marine productivity 11 , 12 , but direct observations are lacking. Here we use satellite and autonomous biogeochemical Argo float data to evaluate the effect of 2019–2020 Australian wildfire aerosol deposition on phytoplankton productivity. We find anomalously widespread phytoplankton blooms from December 2019 to March 2020 in the Southern Ocean downwind of Australia. Aerosol samples originating from the Australian wildfires contained a high iron content and atmospheric trajectories show that these aerosols were likely to be transported to the bloom regions, suggesting that the blooms resulted from the fertilization of the iron-limited waters of the Southern Ocean. Climate models project more frequent and severe wildfires in many regions 1 – 3 . A greater appreciation of the links between wildfires, pyrogenic aerosols 13 , nutrient cycling and marine photosynthesis could improve our understanding of the contemporary and glacial–interglacial cycling of atmospheric CO 2 and the global climate system. Oceanic deposition of wildfire aerosols can enhance marine productivity, as supported here by satellite and in situ profiling floats data showing that emissions from the 2019–2020 Australian wildfires fuelled phytoplankton blooms in the Southern Ocean.

This work reports on the current status of the global modeling of iron (Fe) deposition fluxes and atmospheric concentrations and the analyses of the differences between models, as well as between models and observations. A total of four global 3-D chemistry transport (CTMs) and general circulation (GCMs) models participated in this intercomparison, in the framework of the United Nations Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP) Working Group 38, “The Atmospheric Input of Chemicals to the Ocean”. The global total Fe (TFe) emission strength in the models is equal to ∼72 Tg Fe yr−1 (38–134 Tg Fe yr−1) from mineral dust sources and around 2.1 Tg Fe yr−1 (1.8–2.7 Tg Fe yr−1) from combustion processes (the sum of anthropogenic combustion/biomass burning and wildfires). The mean global labile Fe (LFe) source strength in the models, considering both the primary emissions and the atmospheric processing, is calculated to be 0.7 (±0.3) Tg Fe yr−1, accounting for both mineral dust and combustion aerosols. The mean global deposition fluxes into the global ocean are estimated to be in the range of 10–30 and 0.2–0.4 Tg Fe yr−1 for TFe and LFe, respectively, which roughly corresponds to a respective 15 and 0.3 Tg Fe yr−1 for the multi-model ensemble model mean. The model intercomparison analysis indicates that the representation of the atmospheric Fe cycle varies among models, in terms of both the magnitude of natural and combustion Fe emissions as well as the complexity of atmospheric processing parameterizations of Fe-containing aerosols. The model comparison with aerosol Fe observations over oceanic regions indicates that most models overestimate surface level TFe mass concentrations near dust source regions and tend to underestimate the low concentrations observed in remote ocean regions. All models are able to simulate the tendency of higher Fe concentrations near and downwind from the dust source regions, with the mean normalized bias for the Northern Hemisphere (∼14), larger than that of the Southern Hemisphere (∼2.4) for the ensemble model mean. This model intercomparison and model–observation comparison study reveals two critical issues in LFe simulations that require further exploration: (1) the Fe-containing aerosol size distribution and (2) the relative contribution of dust and combustion sources of Fe to labile Fe in atmospheric aerosols over the remote oceanic regions.

[...]it becomes essential to accurately predict the external atmospheric trace nutrient load and properties using a combination of observations and global numerical models. While dust is the largest contributor to trace element atmospheric loading globally, anthropogenic and wildfire aerosols often contain a larger fraction of bioaccessible micronutrients, due to differences in particle size, mineralogy, and solubility-enhancing reactions with acidic and organic compounds in the atmosphere (and present in surface seawater). Reduce the Uncertainty in Soluble aerosol Trace Element Deposition (RUSTED) (Shelley et al., 2024). Since 2 November 2023, we have invited the international community to submit high-quality studies aimed at advancing our understanding of the sources, atmospheric processing, and deposition fluxes to the ocean and the impacts of aeolian trace elements on ocean marine biogeochemical cycles – in the past, present, or future.

A range of leaching protocols have been used to measure the soluble fraction of aerosol trace elements worldwide, and therefore these measurements may not be directly comparable. This work presents the first large-scale international laboratory intercomparison study for aerosol trace element leaching protocols. Eight widely-used protocols are compared using 33 samples that were subdivided and distributed to all participants. Protocols used ultrapure water, ammonium acetate, or acetic acid (the so-called “Berger leach”) as leaching solutions, although none of the protocols were identical to any other. The ultrapure water leach resulted in significantly lower soluble fractions, when compared to the ammonium acetate leach or the Berger leach. For Al, Cu, Fe and Mn, the ammonium acetate leach resulted in significantly lower soluble fractions than those obtained with the Berger leach, suggesting that categorizing these two methods together as “strong leach” in global databases is potentially misleading. Among the ultrapure water leaching methods, major differences seemed related to specific protocol features rather than the use of a batch or a flow-through technique. Differences in trace element solubilization among leach solutions were apparent for aerosols with different sources or transport histories, and further studies of this type are recommended on aerosols from other regions. We encourage the development of “best practices” guidance on analytical protocols, data treatment and data validation in order to reduce the variability in soluble aerosol trace element data reported. These developments will improve understanding of the impact of atmospheric deposition on ocean ecosystems and climate.

Background A number of patients have complex care needs that arise from interactions among multiple factors, such as multimorbidity, mental health issues, and social vulnerability. These factors influence decisions about healthcare and health services. Shared decision-making (SDM), a collaborative process between patients and professionals, is known to improve the quality of the decision-making process. However, follow-up challenges of patients with complex care needs (PCCNs) can lead to SDM specificities. Objective To identify specificities of SDM with PCCNs. Methods We conducted a scoping review using the Joanna Briggs Institute (JBI) methodology. We conducted a systematic search across MEDLINE, CINAHL, PsycINFO, and Academic Search Complete databases. Empirical studies about SDM with PCCNs published between 1997 and 2023 were eligible for inclusion. We conducted a mixed thematic analysis using deductive (Ottawa Decision Support Framework and Interprofessional Shared Decision-Making Model) and inductive approaches. Following Arksey & O’Malley’s and Levac et al.’s methodological recommendations, we consulted experts (researchers, healthcare professionals, and patient partners) to enhance the findings. Results Twelve studies were included in the review. Overall, our results demonstrated the importance of recognizing some specificities of SDM with PCCNs, such as the simultaneous presence of multiple decisions and the multidisciplinary and intersectoral nature of the healthcare and health services they receive. Conclusion This scoping review highlights some specificities that must be considered in SDM with PCCNs to maintain its already-known benefits and ensure positive health and decision-making outcomes.

Context The successful dispersal of an animal depends, partly, on landscape connectivity. Urbanization poses risks to dispersal activities by increasing hostile land cover types. Objectives We investigated how connectivity of urban ponds impacted Odonata communities (dragonflies and damselflies), an order of semi-aquatic insects that actively disperse. Methods We sampled 41 constructed stormwater ponds and 8 natural ponds in a metropolitan area. The effect of connectivity and the quantity of available adjacent habitats was tested at different scales for dragonflies (900 m) and damselflies (300 m), determined by a literature analysis, to account for differences in suborder dispersal capabilities. Results Lower levels of connectivity and fewer nearest neighbours negatively impacted abundance, species richness, and composition of dragonflies (p values < 0.01, R 2  = 0.18–0.70). Adult dragonfly abundance had a stronger positive relationship with connectivity than species richness. In particular, the abundance of adult dragonfly Leucorrhinia frigida, found almost exclusively at natural ponds, had a positive relationship with connectivity. Connectivity and the number of nearest neighbours had no significant impact on damselflies apart from a slight negative relationship between connectivity and species richness (p value = 0.02, R 2  = 0.11). Natural ponds had significantly higher levels of connectivity when compared to stormwater ponds. Conclusions Our results suggest that dragonflies are positively affected by increased connectivity in an urban landscape, with no benefit of connectivity to damselflies at the scale measured. We recommend intentional planning of urban stormwater pond networks, where individual ponds can act as stepping stones, incorporated with strategic inclusion of beneficial land cover types.

Background Musculoskeletal disorders are a leading cause of morbidity and the most prevalent source of disability among soldiers. Their high prevalence in armed forces and limited ressources have led to problems related to access to physical rehabilitation care. To increase access, supervised group-based exercise programs for the most prevalent musculoskeletal disorders (low back pain, patellofemoral pain, rotator cuff-related shoulder pain or lateral ankle sprain) have been developed at a Canadian Armed forces (CAF) base, but their effectiveness has not been evaluated. The primary objective of this randomized controlled trial is to evaluate the mid- and long-term effects of these group-based training programs on pain severity and functional limitations, in comparison with usual individual physiotherapy care. Secondary objectives include comparing both interventions in terms of health-related quality of life, pain-related fear, and patients’ satisfaction. Methods One hundred and twenty soldiers with a new medical referral for physiotherapy services for one of the four targeted musculoskeletal disorders will be consecutively recruited. They will be randomly assigned to either group-based training program or usual individual physiotherapy care, and will take part in the assigned 12-week intervention. There will be four evaluation sessions over 26 weeks (baseline, week 6, 12 and 26). At each follow-up, functional limitations, pain severity, health-related quality of life and pain-related fears will be assessed. Patients satisfaction with treatment will also be evaluated at the end of the intervention period. Either two-way repeated measures ANOVA will be used to analyse and compare the effects of the interventions. Discussion This RCT will determine the effectiveness of group-based training programs compared to usual individual physiotherapy care. This new intervention model could represent an efficient, and more pro-active approach to manage a higher number of soldiers with musculoskeletal disorders. It could improve access to physical rehabilitation care and improve the health of soldiers. Trial registration ClinicalTrials.gov ( NCT05235152 ), February 11th 2022.

Mineral dust is the major source of external micro-nutrients such as iron (Fe) to the open ocean. However, large uncertainties in model estimates of Fe emissions and aerosol-bearing Fe solubility (i.e., the ratio of labile Fe (LFe) to total Fe (TFe)) in the Southern Hemisphere (SH) hampered accurate estimates of atmospheric delivery of bioavailable Fe to the Southern Ocean. This study applied an inverse modeling technique to a global aerosol chemistry transport model (IMPACT) in order to optimize predictions of mineral aerosol Fe concentrations based on recent observational data over Australian coastal regions (110°E–160°E and 10°S–41°S). The optimized (a posteriori) model did not only better capture aerosol TFe concentrations downwind from Australian dust outbreak but also successfully reproduced enhanced Fe solubility (7.8 ± 8.4%) and resulted in much better agreement of LFe concentrations with the field measurements (1.4 ± 1.5 vs. 1.4 ± 2.3 ng Fe m–3). The a posteriori model estimates suggested that bushfires contributed a large fraction of LFe concentrations in aerosols, although substantial contribution from missing sources (e.g., coal mining activities, volcanic eruption, and secondary formation) was still inferred. These findings may have important implications for the projection of future micro-nutrient supply to the oceans as increasing frequency and intensity of open biomass burning are projected in the SH.

The purpose of this study was to examine sex differences in the maturation of white matter during adolescence (12 to 18 years of age). We measured lobular volumes of white matter and white-matter “density” throughout the brain using T1-weighted images, and estimated the myelination index using magnetisation-transfer ratio (MTR). In male adolescents, we observed age-related increases in white-matter lobular volumes accompanied by decreases in the lobular values of white-matter MTR. White-matter density in the putative cortico-spinal tract (pCST) decreased with age. In female adolescents, on the other hand, we found only small age-related increase in white-matter volumes and no age-related changes in white-matter MTR, with the exception of the frontal lobe where MTR increased. White-matter density in the pCST also increased with age. These results suggest that sex-specific mechanisms may underlie the growth of white matter during adolescence. We speculate that these mechanisms involve primarily age-related increases in axonal calibre in males and increased myelination in females.

In 2001, five French public organizations (CNRS, CEA, IRD, IRSN, and the Ministère de la Culture) signed an agreement to purchase a new accelerator mass spectrometer to provide radiocarbon dating services at the national level. The Laboratoire de Mesure du Carbone 14 (LMC14) was set up in Saclay (France) around ARTEMIS, an AMS system based on a 3MV Pelletron from NEC and installed in early 2003. In 2015, the LMC14 joined the Laboratoire des Sciences du Climat et de l’Environnement, making it possible to develop research projects in addition to the service activity and since 2021, the LMC14 has been a member of the IAEA Collaborating Centre “Atoms for Heritage” at the Université Paris-Saclay. Since 2003, 70,000 samples have been measured. Two-thirds of the samples have been prepared on site and one-third in two associated laboratories in Paris and Lyon. Over the past years, the LMC14 has participated in several international inter-comparisons and has continuously improved its capabilities by developing new protocols for preparation and measurement. In this paper, the radiocarbon dating services of the last 20 years for research institutions, museums and environmental monitoring are reviewed and recent results from environmental and archaeological research programs are highlighted.