Discovery of Small Molecule Interleukin 17A Inhibitors with Novel Binding Mode and Stoichiometry: Optimization of DNA-Encoded Chemical Library Hits to In Vivo Active Compounds.

Dysregulation of IL17A drives numerous inflammatory and autoimmune disorders with inhibition of IL17A using antibodies proven as an effective treatment. Oral anti-IL17 therapies are an attractive alternative option, and several preclinical small molecule IL17 inhibitors have previously been described. Herein, we report the discovery of a novel class of small molecule IL17A inhibitors, identified via a DNA-encoded chemical library screen, and their subsequent optimization to provide in vivo efficacious inhibitors. These new protein-protein interaction (PPI) inhibitors bind in a previously undescribed mode in the IL17A protein with two copies binding symmetrically to the central cavities of the IL17A homodimer.

Dispositional mindfulness moderates the links between potentially morally injurious event exposure and symptoms of anxiety and depression but not suicidal ideation.

Exposure to potentially morally injurious events (PMIEs) is a pervasive threat for military service members and may be associated with symptoms of anxiety, depression, and suicidal ideation. However, coping mechanisms, such as mindfulness, may ameliorate symptoms and improve recovery. Two studies were conducted to test dispositional mindfulness as a moderator of the links between PMIEs, as assessed using the Moral Injury Events Scale (i.e., total score and Self-Transgression, Other-Transgression, and Betrayal subscale scores), and symptoms of anxiety, depression, and suicidal ideation among different samples of active-duty soldiers in garrison. In Sample 1 (N = 310), mindfulness buffered the links between PMIE exposure and symptoms of both anxiety, ∆R2 = .02, and depression, ∆R2 = .03. In Sample 2 (N = 669), mindfulness moderated the link between the MIES Betrayal subscale and anxiety symptoms, ∆R2 = .01. The results suggest that dispositional mindfulness may be a protective factor against some of the negative impacts of PMIE exposure. Further implications are discussed.

Cerebral autoregulation-based mean arterial pressure targets and delirium in critically ill adults without brain injury: a retrospective cohort study.

PURPOSE: Cerebral autoregulation (CA) is a mechanism that acts to maintain consistent cerebral perfusion across a range of blood pressures, and impaired CA is associated with delirium. Individualized CA-derived blood pressure targets are poorly characterized in critically ill patients and the association with intensive care unit (ICU) delirium is unknown. Our objectives were to characterize optimal mean arterial pressure (MAPopt) ranges in critically ill adults without brain injury and determine whether deviations from these targets contribute to ICU delirium. METHODS: We performed a retrospective cohort analysis of patients with shock of any etiology and/or respiratory failure requiring invasive mechanical ventilation, without a neurologic admitting diagnosis. Patients were screened daily for delirium. Cerebral oximetry and mean arterial pressure data were captured for the first 24 hr from enrolment. RESULTS: Forty-two patients with invasive blood pressure monitoring data were analyzed. Optimal mean arterial pressure targets ranged from 55 to 100 mm Hg. Optimal mean arterial pressure values were not significantly different based on history of hypertension or delirium status, and delirium was not associated with deviations from MAPopt. Nevertheless, the majority (69%) of blood pressure targets exceeded the current 65 mm Hg Surviving Sepsis guidelines. CONCLUSION: We observed that MAPopt targets across patients were highly variable, but did not observe an association with the incidence of delirium. Studies designed to evaluate the impact on neurologic outcomes are needed to understand the association with individualized mean arterial pressure targets in the ICU. STUDY REGISTRATION: ClinicalTrials.gov (NCT02344043); first submitted 22 January 2015.

RéSUMé: OBJECTIF: L'autorégulation cérébrale (AC) est un mécanisme qui agit pour maintenir une perfusion cérébrale constante pour une gamme de tensions artérielles, et une altération de l'AC est associée au delirium. Les cibles de tension artérielle individualisées dérivées de l'AC sont mal caractérisées chez les patient·es gravement malades et l'association avec le delirium à l'unité de soins intensifs (USI) est inconnue. Nos objectifs étaient de caractériser la tension artérielle moyenne optimale (TAMopt) chez les adultes gravement malades sans lésion cérébrale et de déterminer si les écarts par rapport à ces cibles contribuaient au delirium à l'USI. MéTHODE: Nous avons réalisé une analyse de cohorte rétrospective de patient·es présentant un choc de toute étiologie et/ou une insuffisance respiratoire nécessitant une ventilation mécanique invasive, et n'ayant pas reçu de diagnostic d'atteinte neurologique à l'admission. Les patients ont été dépistés quotidiennement pour le delirium. Les données d'oxymétrie cérébrale et de tension artérielle moyenne ont été saisies pendant les 24 premières heures suivant le recrutement. RéSULTATS: Quarante-deux patient·es pour qui des données de monitorage invasif de la tension artérielle étaient disponibles ont été analysé·es. Les cibles optimales de tension artérielle moyenne variaient de 55 à 100 mm Hg. Les valeurs optimales de tension artérielle moyenne n'étaient pas significativement différentes en fonction des antécédents d'hypertension ou de delirium, et le delirium n'était pas associé à des écarts par rapport à la TAMopt. Néanmoins, la majorité (69 %) des cibles de tension artérielle dépassaient celle de 65 mm Hg préconisée par les lignes directrices Surviving Sepsis. CONCLUSION: Nous avons observé que les cibles de TAMopt étaient très variables chez les patient·es, mais nous n'avons pas observé d'association avec l'incidence de delirium. Des études conçues pour évaluer l'impact sur les issues neurologiques sont nécessaires pour comprendre l'association avec les cibles de tension artérielle moyenne individualisées à l'USI. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT02344043); soumis pour la première fois le 22 janvier 2015.

Pilot Lipidomics Study of Copepods: Investigation of Potential Lipid-Based Biomarkers for the Early Detection and Quantification of the Biological Effects of Climate Change on the Oceanic Food Chain.

Maintenance of the health of our oceans is critical for the survival of the oceanic food chain upon which humanity is dependent. Zooplanktonic copepods are among the most numerous multicellular organisms on earth. As the base of the primary consumer food web, they constitute a major biomass in oceans, being an important food source for fish and functioning in the carbon cycle. The potential impact of climate change on copepod populations is an area of intense study. Omics technologies offer the potential to detect early metabolic alterations induced by the stresses of climate change. One such omics approach is lipidomics, which can accurately quantify changes in lipid pools serving structural, signal transduction, and energy roles. We utilized high-resolution mass spectrometry (≤2 ppm mass error) to characterize the lipidome of three different species of copepods in an effort to identify lipid-based biomarkers of copepod health and viability which are more sensitive than observational tools. With the establishment of such a lipid database, we will have an analytical platform useful for prospectively monitoring the lipidome of copepods in a planned long-term five-year ecological study of climate change on this oceanic sentinel species. The copepods examined in this pilot study included a North Atlantic species (Calanus finmarchicus) and two species from the Gulf of Mexico, one a filter feeder (Acartia tonsa) and one a hunter (Labidocerca aestiva). Our findings clearly indicate that the lipidomes of copepod species can vary greatly, supporting the need to obtain a broad snapshot of each unique lipidome in a long-term multigeneration prospective study of climate change. This is critical, since there may well be species-specific responses to the stressors of climate change and co-stressors such as pollution. While lipid nomenclature and biochemistry are extremely complex, it is not essential for all readers interested in climate change to understand all of the various lipid classes presented in this study. The clear message from this research is that we can monitor key copepod lipid families with high accuracy, and therefore potentially monitor lipid families that respond to environmental perturbations evoked by climate change.

An Individualized Postoperative Pain Risk Communication Tool for Use in Pediatric Surgery: Co-Design and Usability Evaluation.

BACKGROUND: Risk identification and communication tools have the potential to improve health care by supporting clinician-patient or family discussion of treatment risks and benefits and helping patients make more informed decisions; however, they have yet to be tailored to pediatric surgery. User-centered design principles can help to ensure the successful development and uptake of health care tools. OBJECTIVE: We aimed to develop and evaluate the usability of an easy-to-use tool to communicate a child's risk of postoperative pain to improve informed and collaborative preoperative decision-making between clinicians and families. METHODS: With research ethics board approval, we conducted web-based co-design sessions with clinicians and family participants (people with lived surgical experience and parents of children who had recently undergone a surgical or medical procedure) at a tertiary pediatric hospital. Qualitative data from these sessions were analyzed thematically using NVivo (Lumivero) to identify design requirements to inform the iterative redesign of an existing prototype. We then evaluated the usability of our final prototype in one-to-one sessions with a new group of participants, in which we measured mental workload with the National Aeronautics and Space Administration (NASA) Task Load Index (TLX) and user satisfaction with the Post-Study System Usability Questionnaire (PSSUQ). RESULTS: A total of 12 participants (8 clinicians and 4 family participants) attended 5 co-design sessions. The 5 requirements were identified: (A) present risk severity descriptively and visually; (B) ensure appearance and navigation are user-friendly; (C) frame risk identification and mitigation strategies in positive terms; (D) categorize and describe risks clearly; and (E) emphasize collaboration and effective communication. A total of 12 new participants (7 clinicians and 5 family participants) completed a usability evaluation. Tasks were completed quickly (range 5-17 s) and accurately (range 11/12, 92% to 12/12, 100%), needing only 2 requests for assistance. The median (IQR) NASA TLX performance score of 78 (66-89) indicated that participants felt able to perform the required tasks, and an overall PSSUQ score of 2.1 (IQR 1.5-2.7) suggested acceptable user satisfaction with the tool. CONCLUSIONS: The key design requirements were identified, and that guided the prototype redesign, which was positively evaluated during usability testing. Implementing a personalized risk communication tool into pediatric surgery can enhance the care process and improve informed and collaborative presurgical preparation and decision-making between clinicians and families of pediatric patients.

Enhanced recovery support for people with eating disorders during the COVID-19 pandemic: quality improvement using a web-based, stepped-care programme in Canada.

BACKGROUND: Throughout the COVID-19 pandemic, the number of individuals struggling with eating disorders (EDs) increased substantially. Body Brave (a not-for-profit) created and implemented a web-based stepped-care Recovery Support Programme (RSP) to improve access to community-based ED services. This quality improvement study describes the RSP and assesses its ability to deliver timely access to treatment and platform engagement. METHODS: We conducted a retrospective cohort study comparing access to, and use of Body Brave services 6 months before and 12 months after implementation of the RSP platform (using 6-month increments for two postimplementation periods). Primary programme quality measures included registration requests, number of participants onboarded and time to access services; secondary measures included use of RSP action plans, attendance for recovery sessions and workshops, number of participants accessing treatment and text-based patient experience data. RESULTS: A substantial increase in registration requests was observed during the first postimplementation period compared with the preimplementation period (176.5 vs 85.5; p=0.028). When compared with the preimplementation period, the second postimplementation observed a significantly larger percentage of successfully onboarded participants (76.6 vs 37.9; p<0.01) and a reduction in the number of days to access services (2 days vs 31 days; p<0.01). Although participant feedback rates were low, many users found the RSP helpful, easy to access, user-friendly and were satisfied overall. Users provided suggestions for improvement (eg, a platform instructional video, offer multiple times of day for live sessions and drop-in hours). CONCLUSIONS: Although clinical benefit needs to be assessed, our findings demonstrate that the RSP enabled participants to quickly onboard and access initial services and have informed subsequent improvements. Understanding initial programme effects and usage will help assess the feasibility of adapting and expanding the RSP across Canada to address the urgent need for low-barrier, patient-centred ED care.

Limitations of benefit finding as a coping mechanism for combat-related PTSD symptoms.

Benefit finding has been identified as a buffer of the combat exposure-PTSD symptom link in soldiers. However, benefit finding may have a limited buffering capacity on the combat-PTSD symptom link over the course of a soldier's post-deployment recovery period. In the present study, soldiers returning from Operation Iraqi Freedom (OIF) were surveyed at two different time periods post-deployment: Time 1 was 4 months post-deployment (n = 1,510), and Time 2 was at 9 months post-deployment (n = 783). The surveys assessed benefit finding, PTSD symptoms, and combat exposure. Benefit finding was a successful buffer of the cross-sectional relationship between combat exposure and PTSD reexperiencing symptoms at Time 1, but not at Time 2. In addition, the benefit finding by combat interaction at time 1 revealed that greater benefit finding was associated with higher symptoms under high combat exposure at Time 2 after controlling for PTSD arousal symptoms at Time 1. The results of the present study indicate that benefit finding may have a buffering capacity in the immediate months following a combat deployment, but also indicates that more time than is allotted during the post-deployment adjustment period is needed to enable recovery from PTSD. Theoretical implications are discussed.

Determination of bioavailable arsenic threshold and validation of modeled permissible total arsenic in paddy soil using machine learning.

Minimizing arsenic intake from food consumption is a key aspect of the public health response in arsenic (As)-contaminated regions. In many of these regions, rice is the predominant staple food. Here, we present a validated maximum allowable concentration of total As in paddy soil and provide the first derivation of a maximum allowable soil concentration for bioavailable As. We have previously used meta-analysis to predict the maximum allowable total As in soil based on decision tree (DT) and logistic regression (LR) models. The models were defined using the maximum tolerable concentration (MTC) of As in rice grains as per the codex recommendation. In the present study, we validated these models using three test data sets derived from purposely collected field data. The DT model performed better than the LR in terms of accuracy and Matthews correlation coefficient (MCC). Therefore, the DT estimated maximum allowable total As in paddy soil of 14 mg kg-1 could confidently be used as an appropriate guideline value. We further used the purposely collected field data to predict the concentration of bioavailable As in the paddy soil with the help of random forest (RF), gradient boosting machine (GBM), and LR models. The category of grain As (MTC) was considered as the dependent variable; bioavailable As (BAs), total As (TAs), pH, organic carbon (OC), available phosphorus (AvP), and available iron (AvFe) were the predictor variables. LR performed better than RF and GBM in terms of accuracy, sensitivity, specificity, kappa, precision, log loss, F1score, and MCC. From the better-performing LR model, bioavailable As (BAs), TAs, AvFe, and OC were significant variables for grain As. From the partial dependence plots (PDP) and individual conditional expectation (ICE) of the LR model, 5.70 mg kg-1 was estimated to be the limit for BAs in soil.

Identifying Risk Factors, Patient-Reported Experience and Outcome Measures, and Data Capture Tools for an Individualized Pain Prediction Tool in Pediatrics: Focus Group Study.

BACKGROUND: The perioperative period is a data-rich environment with potential for innovation through digital health tools and predictive analytics to optimize patients' health with targeted prehabilitation. Although some risk factors for postoperative pain following pediatric surgery are already known, the systematic use of preoperative information to guide personalized interventions is not yet widespread in clinical practice. OBJECTIVE: Our long-term goal is to reduce the incidence of persistent postsurgical pain (PPSP) and long-term opioid use in children by developing personalized pain risk prediction models that can guide clinicians and families to identify targeted prehabilitation strategies. To develop such a system, our first objective was to identify risk factors, outcomes, and relevant experience measures, as well as data collection tools, for a future data collection and risk modeling study. METHODS: This study used a patient-oriented research methodology, leveraging parental/caregiver and clinician expertise. We conducted virtual focus groups with participants recruited at a tertiary pediatric hospital; each session lasted approximately 1 hour and was composed of clinicians or family members (people with lived surgical experience and parents of children who had recently undergone a procedure requiring general anesthesia) or both. Data were analyzed thematically to identify potential risk factors for pain, as well as relevant patient-reported experience and outcome measures (PREMs and PROMs, respectively) that can be used to evaluate the progress of postoperative recovery at home. This guidance was combined with a targeted literature review to select tools to collect risk factor and outcome information for implementation in a future study. RESULTS: In total, 22 participants (n=12, 55%, clinicians and n=10, 45%, family members) attended 10 focus group sessions; participants included 12 (55%) of 22 persons identifying as female, and 12 (55%) were under 50 years of age. Thematic analysis identified 5 key domains: (1) demographic risk factors, including both child and family characteristics; (2) psychosocial risk factors, including anxiety, depression, and medical phobias; (3) clinical risk factors, including length of hospital stay, procedure type, medications, and pre-existing conditions; (4) PREMs, including patient and family satisfaction with care; and (5) PROMs, including nausea and vomiting, functional recovery, and return to normal activities of daily living. Participants further suggested desirable functional requirements, including use of standardized and validated tools, and longitudinal data collection, as well as delivery modes, including electronic, parent proxy, and self-reporting, that can be used to capture these metrics, both in the hospital and following discharge. Established PREM/PROM questionnaires, pain-catastrophizing scales (PCSs), and substance use questionnaires for adolescents were subsequently selected for our proposed data collection platform. CONCLUSIONS: This study established 5 key data domains for identifying pain risk factors and evaluating postoperative recovery at home, as well as the functional requirements and delivery modes of selected tools with which to capture these metrics both in the hospital and after discharge. These tools have been implemented to generate data for the development of personalized pain risk prediction models.

Targeting σ2R/TMEM97 with novel aminotetralins.

Initially associated with cancer diagnosis and therapy, the sigma 2 receptor (σ2R) has recently been implicated in several disorders of the central nervous system (CNS). It remained a poorly characterized target until we identified it as the transmembrane protein 97 (TMEM97). As part of a program to identify novel compounds that bind with high affinity and selectivity to σ2R/TMEM97 relative to the sigma 1 receptor (σ1R) and other CNS proteins, we employed a scaffold simplification strategy to design novel sets of piperazine-substituted aminotetralins based on analogous norbenzomorphans that we previously developed. JVW-1601 was identified as a reference aminotetralin analog that had high affinity (Ki = 5.5 nM) and selectivity (36-fold) for σ2R/TMEM97 versus σ1R. An expanded investigation of structure-activity relationships (SAR) in several structural regions of this compound was conducted, and among the ligands thus prepared, many had Ki values < 20 nM for σ2R/TMEM97 and selectivities of >20-fold versus σ1R. Structural features that enhance σ2R/TMEM97 affinity and selectivity were identified, leading to an optimized compound having a high σ2R/TMEM97 affinity (Ki of 4.5 nM) and 366-fold selectivity relative to σ1R. Significantly, during the course of this work we discovered JVW-1625, which enabled the isolation and identification of σ2R as TMEM97 and resolved a question that had eluded researchers for decades. Computational docking studies for selected aminotetralins suggest they adopt similar poses upon binding to σ2R/TMEM97, engaging in highly conserved salt bridges with Asp29 and cation-π interactions with Tyr150. Collectively, these studies show that aminotetralins are useful tool compounds for studying the mechanism and function of σ2R/TMEM97.

Adverse outcome pathways (AOPs) for radiation-induced reproductive effects in environmental species: state of science and identification of a consensus AOP network.

BACKGROUND: Reproductive effects of ionizing radiation in organisms have been observed under laboratory and field conditions. Such assessments often rely on associations between exposure and effects, and thus lacking a detailed mechanistic understanding of causality between effects occurring at different levels of biological organization. The Adverse Outcome Pathway (AOP), a conceptual knowledge framework to capture, organize, evaluate and visualize the scientific knowledge of relevant toxicological effects, has the potential to evaluate the causal relationships between molecular, cellular, individual, and population effects. This paper presents the first development of a set of consensus AOPs for reproductive effects of ionizing radiation in wildlife. This work was performed by a group of experts formed during a workshop organized jointly by the Multidisciplinary European Low Dose Initiative (MELODI) and the European Radioecology Alliance (ALLIANCE) associations to present the AOP approach and tools. The work presents a series of taxon-specific case studies that were used to identify relevant empirical evidence, identify common AOP components and propose a set of consensus AOPs that could be organized into an AOP network with broader taxonomic applicability. CONCLUSION: Expert consultation led to the identification of key biological events and description of causal linkages between ionizing radiation, reproductive impairment and reduction in population fitness. The study characterized the knowledge domain of taxon-specific AOPs, identified knowledge gaps pertinent to reproductive-relevant AOP development and reflected on how AOPs could assist applications in radiation (radioecological) research, environmental health assessment, and radiological protection. Future advancement and consolidation of the AOPs is planned to include structured weight of evidence considerations, formalized review and critical assessment of the empirical evidence prior to formal submission and review by the OECD sponsored AOP development program.

Identification of Requirements for a Postoperative Pediatric Pain Risk Communication Tool: Focus Group Study With Clinicians and Family Members.

BACKGROUND: Pediatric surgery is associated with a risk of postoperative pain that can impact the family's quality of life. Although some risk factors for postoperative pain are known, these are often not consistently communicated to families. In addition, although tools for risk communication exist in other domains, none are tailored to pediatric surgery. OBJECTIVE: As part of a larger project to develop pain risk prediction tools, we aimed to design an easy-to-use tool to effectively communicate a child's risk of postoperative pain to both clinicians and family members. METHODS: With research ethics board approval, we conducted virtual focus groups (~1 hour each) comprising clinicians and family members (people with lived surgical experience and parents of children who had recently undergone surgery/medical procedures) at a tertiary pediatric hospital to understand and evaluate potential design approaches and strategies for effectively communicating and visualizing postoperative pain risk. Data were analyzed thematically to generate design requirements and to inform iterative prototype development. RESULTS: In total, 19 participants (clinicians: n=10, 53%; family members: n=9, 47%) attended 6 focus group sessions. Participants indicated that risk was typically communicated verbally by clinicians to patients and their families, with severity indicated using a descriptive or a numerical representation or both, which would only occasionally be contextualized. Participants indicated that risk communication tools were seldom used but that families would benefit from risk information, time to reflect on the information, and follow-up with questions. In addition, 9 key design requirements and feature considerations for effective risk communication were identified: (1) present risk information clearly and with contextualization, (2) quantify the risk and contextualize it, (3) include checklists for preoperative family preparation, (4) provide risk information digitally to facilitate recall and sharing, (5) query the family's understanding to ensure comprehension of risk, (6) present the risk score using multimodal formats, (7) use color coding that is nonthreatening and avoids limitations with color blindness, (8) present the most significant factors contributing to the risk prediction, and (9) provide risk mitigation strategies to potentially decrease the patient's level of risk. CONCLUSIONS: Key design requirements for a pediatric postoperative pain risk visualization tool were established and guided the development of an initial prototype. Implementing a risk communication tool into clinical practice has the potential to bridge existing gaps in the accessibility, utilization, and comprehension of personalized risk information between health care professionals and family members. Future iterative codesign and clinical evaluation of this risk communication tool are needed to confirm its utility in practice.

Some observations on meaningful and objective inference in radioecological field studies.

Anthropogenic releases of radiation are of ongoing importance for environmental protection, but the radiation doses at which natural systems begin to show effects are controversial. More certainty is required in this area to achieve optimal regulation for radioactive substances. We recently carried out a large survey (268 sampled animals and 20 sites) of the association between environmental radiation exposures and small mammal gut-associated microbiomes (fungal and bacterial) in the Chornobyl Exclusion zone (CEZ). Using individual measurements of total absorbed dose rates and a study design and analyses that accounted for spatial non-independence, we found no, or only limited, association. Watts et al. have criticised our study: for not filtering candidate non-resident components prior to our fungal microbiome analyses, for our qualified speculations on the relative merits of faecal and gut samples, and for the design of our study which they felt lacked sufficient replication. The advantage of filtering non-resident-fungal taxa is not clear and it would not have changed the null (spatially adjusted) association we found between radioactive dose and mycobiome composition because the most discriminatory fungal taxa with regard to dose were non-resident taxa. We maintain that it was legitimate for us to make qualified discussion comments on the differences in results between our faecal and gut microbiome analyses and on the relative merits of these sample types. Most importantly, the criticism of our study design by Watts et al. and the designs and analysis of their recent studies in the CEZ show a misunderstanding of the true nature of independent replication in field studies. Recognising the importance of spatial non-independence is essential in the design and analysis of radioecological field surveys.

Varietal differences influence arsenic and lead contamination of rice grown in mining impacted agricultural fields of Zamfara State, Nigeria.

In Zamfara state, Nigeria, rice is cultivated in fields contaminated with Pb (lead) from artisanal and illicit mining activities. Rice grown in such contaminated agricultural areas risks not only Pb contamination but also contamination from other toxic elements, like arsenic (As); co-contamination of Pb and As in rice cultivated in mining impacted areas has been previously reported and rice is a hyperaccumulator of As. A field study was conducted with ten different commonly-cultivated Nigerian rice varieties in the mining-impacted farmlands of Dareta village, Zamfara State. The aim was to determine the optimal rice variety for cultivation on these contaminated farmlands; an optimal variety would have the lowest contaminant concentrations and highest essential elements concentrations in the rice grains. A total of 300 paired soil and rice plants were collected. The mean As and Pb concentrations in paddy soils were 0.91 ± 0.82 mg kg-1 and 288.5 ± 464.2 mg kg-1, respectively. Mean As (30.4 ± 15.1 µg kg-1) content in rice grains was an order of magnitude lower than the Codex recommendation of 200 µg kg-1 (for milled rice) while the Pb content in all the rice varieties (overall mean of 743 ± 327 µg kg-1) was approximately four times higher than the Codex recommendation of 200 µg kg-1. Contrary to previous studies, a negative correlation was observed between As and Pb in rice grains across all the varieties. Rice variety Bisalayi was the variety with the lowest Pb transfer factor (TF = 0.08), but the average Pb concentration in rice grain was still above the Codex recommendation. Bisalayi also had the highest TF for iron. Variety ART_15, which had the lowest As uptake (TF = 0.10), had the highest TF for essential elements (magnesium, potassium, manganese, zinc, and copper). In areas of Pb contamination, Bisalayi rice may therefore be a suitable variety to choose for cultivation.

Strategic roadmap to assess forest vulnerability under air pollution and climate change.

Although it is an integral part of global change, most of the research addressing the effects of climate change on forests have overlooked the role of environmental pollution. Similarly, most studies investigating the effects of air pollutants on forests have generally neglected the impacts of climate change. We review the current knowledge on combined air pollution and climate change effects on global forest ecosystems and identify several key research priorities as a roadmap for the future. Specifically, we recommend (1) the establishment of much denser array of monitoring sites, particularly in the South Hemisphere; (2) further integration of ground and satellite monitoring; (3) generation of flux-based standards and critical levels taking into account the sensitivity of dominant forest tree species; (4) long-term monitoring of N, S, P cycles and base cations deposition together at global scale; (5) intensification of experimental studies, addressing the combined effects of different abiotic factors on forests by assuring a better representation of taxonomic and functional diversity across the ~73,000 tree species on Earth; (6) more experimental focus on phenomics and genomics; (7) improved knowledge on key processes regulating the dynamics of radionuclides in forest systems; and (8) development of models integrating air pollution and climate change data from long-term monitoring programs.

Current ionising radiation doses in the Chernobyl Exclusion Zone do not directly impact on soil biological activity.

Although soil organisms are essential for ecosystem function, the impacts of radiation on soil biological activity at highly contaminated sites has been relatively poorly studied. In April-May 2016, we conducted the first largescale deployment of bait lamina to estimate soil organism (largely soil invertebrate) feeding activity in situ at study plots in the Chernobyl Exclusion Zone (CEZ). Across our 53 study plots, estimated weighted absorbed dose rates to soil organisms ranged from 0.7 µGy h-1 to 1753 µGy h-1. There was no significant relationship between soil organism feeding activity and estimated weighted absorbed dose rate. Soil biological activity did show significant relationships with soil moisture content, bulk density (used as a proxy for soil organic matter) and pH. At plots in the Red Forest (an area of coniferous plantation where trees died because of high radiation exposure in 1986) soil biological activity was low compared to plots elsewhere in the CEZ. It is possible that the lower biological activity observed in the Red Forest is a residual consequence of what was in effect an acute high exposure to radiation in 1986.

Best practices for predictions of radionuclide activity concentrations and total absorbed dose rates to freshwater organisms exposed to uranium mining/milling.

Predictions of radionuclide dose rates to freshwater organisms can be used to evaluate the radiological environmental impacts of releases from uranium mining and milling projects. These predictions help inform decisions on the implementation of mitigation measures. The objective of this study was to identify how dose rate modelling could be improved to reduce uncertainty in predictions to non-human biota. For this purpose, we modelled the activity concentrations of 210Pb, 210Po, 226Ra, 230Th, and 238U downstream of uranium mines and mills in northern Saskatchewan, Canada, together with associated weighted absorbed dose rates for a freshwater food chain using measured activity concentrations in water and sediments. Differences in predictions of radionuclide activity concentrations occurred mainly from the different default partition coefficient and concentration ratio values from one model to another and including all or only some 238U decay daughters in the dose rate assessments. Consequently, we recommend a standardized best-practice approach to calculate weighted absorbed dose rates to freshwater biota whether a facility is at the planning, operating or decommissioned stage. At the initial planning stage, the best-practice approach recommend using conservative site-specific baseline activity concentrations in water, sediments and organisms and predict conservative incremental activity concentrations in these media by selecting concentration ratios based on species similarity and similar water quality conditions to reduce the uncertainty in dose rate calculations. At the operating and decommissioned stages, the best-practice approach recommends relying on measured activity concentrations in water, sediment, fish tissue and whole-body of small organisms to further reduce uncertainty in dose rate estimates. This approach would allow for more realistic but still conservative dose assessments when evaluating impacts from uranium mining projects and making decision on adequate controls of releases.

From tangled banks to toxic bunnies; a reflection on the issues involved in developing an ecosystem approach for environmental radiation protection.

The objective of this paper is to present the results of discussions at a workshop held as part of the International Congress of Radiation Research (Environmental Health stream) in Manchester UK, 2019. The main objective of the workshop was to provide a platform for radioecologists to engage with radiobiologists to address major questions around developing an Ecosystem approach in radioecology and radiation protection of the environment. The aim was to establish a critical framework to guide research that would permit integration of a pan-ecosystem approach into radiation protection guidelines and regulation for the environment. The conclusions were that the interaction between radioecologists and radiobiologists is useful in particular in addressing field versus laboratory issues where there are issues and challenges in designing good field experiments and a need to cross validate field data against laboratory data and vice versa. Other main conclusions were that there is a need to appreciate wider issues in ecology to design good approaches for an ecosystems approach in radioecology and that with the capture of 'Big Data', novel tools such as machine learning can now be applied to help with the complex issues involved in developing an ecosystem approach.