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Concussion may exacerbate existing mental health issues. Little evidence exists on whether concussion is associated with the onset of new psychopathologies or long-term mental health problems.To investigate associations between concussion and risk of subsequent mental health issues, psychiatric hospitalizations, self-harm, or suicides.This population-based retrospective cohort study including children and youths aged 5 to 18 years with a concussion or orthopedic injury incurred between April 1, 2010, and March 31, 2020, in Ontario, Canada. Participants had no previous mental health visit in the year before the index event for cohort entry and no prior concussion or traumatic brain injury 5 years before the index visit. Data were collected from provincewide health administrative databases. Participants with concussion were included in the exposed cohort, and those with an orthopedic injury were included in the comparison cohort; these groups were matched 1:2, respectively, on age and sex.Concussion or orthopedic injury.The primary outcome was mental health problems, such as psychopathologies and psychiatric disorders, identified from health care visits in emergency departments, hospitalizations, or primary care settings. Secondary outcomes were psychiatric hospitalizations, self-harm health care visits, and death by suicide (identified in health care or vital statistics databases).A total of 152 321 children and youths with concussion (median [IQR] age, 13 [10-16] years; 86 423 [56.7%] male) and 296 482 children and youths with orthopedic injury (median [IQR] age, 13 [10-16] years; 171 563 [57.9%] male) were matched by age and sex. The incidence rates of any mental health problem were 11 141 per 100 000 person-years (exposed group) and 7960 per 100 000 person-years (unexposed group); with a difference of 3181 (95% CI, 3073-3291) per 100 000 person-years. The exposed group had an increased risk of developing a mental health issue (adjusted hazard ratio [aHR], 1.39; 95% CI, 1.37-1.40), self-harm (aHR, 1.49; 95% CI, 1.42-1.56), and psychiatric hospitalization (aHR, 1.47; 95% CI, 1.41-1.53) after a concussion. There was no statistically significant difference in death by suicide between exposed and unexposed groups (HR, 1.54; 95% CI, 0.90-2.61).Among children and youths aged 5 to 18 years, concussion was associated with an increased risk of mental health issues, psychiatric hospitalization, and self-harm compared with children and youths with an orthopedic injury.

Objectives: The pressures related to the COVID-19 pandemic have resulted in the need to develop innovative ways to deliver mental health (MH) care to patients with emergent needs. This study evaluates the Emergency Department Virtual Care (EDVC) program providing virtual in-home assessments completed by emergency department (ED) physicians for patients with emergent MH needs compared to those seen in person. Methods: We used a mixed-methods design to evaluate the EDVC program with input from patients, caregivers, and ED physicians. Data were collected on those who used or provided in-person or virtual ED services from May 4 through December 31, 2020. Data sources included online surveys, focus groups, and retrospective chart audits. Results: A total of 1499 youth aged 3 to 17 visited the Children’s Hospital of Eastern Ontario (CHEO) ED in person for an MH concern, and 61 booked a virtual appointment. The groups differed in presenting problem (47% depression/suicidal/deliberate self-harm vs 31% anxiety), age (13.75 vs 12.26;p < 0.001), and suicide score on the Home, Education, Activities/peers, Drugs/alcohol, Suicidality, Emotions/behavior, Discharge resources (HEADS-ED;0.843 vs 0.529;p = 0.096). Families who visited the ED in person (n = 67) or who used the EDVC (n = 13) platform responded to the experience survey. Most families (83%) who used EDVC reported a willingness to recommend the platform to others and felt it was as good as an in-person ED visit (66.67%). Two-thirds of the ED physicians who completed the survey (n = 25) reported that patients benefited from EDVC (64%);however, responses were mixed regarding the impact on job satisfaction, with 44% reporting feeling neutral and only 24% reporting a positive impact. Conclusions: ED physicians providing in-home virtual assessments for patients with emergent MH needs have been well received by families who indicated they would use the service again. The EDVC program potentially prevents unnecessary ED visits for patients with MH needs, which is crucial during a pandemic. RCR, TVM, OTH

Agriculture is under pressure to achieve sustainable development goals for biodiversity and ecosystem services. Services in agro-ecosystems are typically driven by key species, and changes in the community composition and species abundance can have multifaceted effects. Assessment of individual services overlooks co-variance between different, but related, services coupled by a common group of species. This partial view ignores how effects propagate through an ecosystem. We conduct an analysis of 374 agricultural multilayer networks of two related services of weed seed regulation and gastropod mollusc predation delivered by carabid beetles. We found that weed seed regulation increased with the herbivore predation interaction frequency, computed from the network of trophic links between carabids and weed seeds in the herbivore layer. Weed seed regulation and herbivore interaction frequencies declined as the interaction frequencies between carabids and molluscs in the carnivore layer increased. This suggests that carabids can switch to gastropod predation with community change, and that link turnover rewires the herbivore and carnivore network layers affecting seed regulation. Our study reveals that ecosystem services are governed by ecological plasticity in structurally complex, multi-layer networks. Sustainable management therefore needs to go beyond the autecological approaches to ecosystem services that predominate, particularly in agriculture., Clare Gray et al. construct multilayer networks of weed seed regulation and pest gastropod predation by carabid beetles in 374 agricultural fields and show that these ecosystem services are mediated by trophic interaction frequencies. This study reveals that ecosystem services are governed by ecological plasticity in structurally complex, multi-layer trophic networks and these could assist in the assessment of the contribution of biodiversity to ecosystem services.

Objectives: Suicidal ideation (SI) is common in adolescents and increases the risk of completed suicide. Due to the COVID-19 pandemic, healthcare providers rapidly shifted to providing telehealth and virtual options for clients. Building Resilience and Attachment in Vulnerable Adolescents (BRAVA) is a group intervention designed for adolescents and their caregivers to reduce adolescent SI. The objective of this study was to adapt BRAVA for virtual delivery and evaluate the feasibility of this adaptation. Methods: We conducted an 8-week open trial between October and December 2020. Twelve participants (6 adolescents and 6 primary caregivers) were recruited from a pediatric hospital in Eastern Ontario. Through Zoom, adolescents and caregivers completed an intake assessment together, 6 weekly BRAVA group sessions separately, and an exit assessment together 1-week post-BRAVA. The primary adolescent outcome variable was the Suicidal Ideation Questionnaire Junior (SIQ-JR). Data were analyzed in IBM SPSS v.27. Pre-post comparisons on the SIQ-JR were done with a 2-tailed t test for matched pairs. Results: The study uptake rate was 42.9% of the eligible participants. There were no study dropouts. Adolescent (Mean [M] age = 15.3 years;SD age = 1.0;66.7% female) and caregiver attendance rates for BRAVA group sessions were high (median = 6). Overall group satisfaction scores were high for adolescents (M = 4.2;SD = 0.8) and their caregivers (M = 4.2;SD = 0.7). Most youth (83.4%) and caregivers (66.7%) reported that the virtual process worked well. Whereas all caregivers (100%) agreed they would participate in a virtual group session again, youth responses were more variable (50% agree, 33.3% neutral, 16.7% disagree). Adolescent SI decreased after completing the intervention (M pretreatment [tx] = 50.7, SD pretreatment [tx] = 16.7;M post-tx = 29.7, SD post-tx = 20.4;t = 5.7;95% CI, 11.52-30.5;p = 0.002). Conclusions: Study results indicate that the virtual delivery of BRAVA is feasible. Study uptake was good, retention was complete, and satisfaction was high for adolescents and their caregivers. Importantly, initial results suggest that this adaptation of BRAVA may help reduce SI in adolescents. Feedback from participants will inform further changes to improve the adaptation of BRAVA for use in a planned RCT. S, ADOL, FT

ObjectivesThe goal of this study was to examine the mental health needs of children and youth who present to the emergency department (ED) for mental health care and to describe the type of, and satisfaction with, follow-up mental health services accessed.MethodsA 6-month to 1.5-year prospective cohort study was conducted in three Canadian pediatric EDs and one general ED, with a 1-month follow-up post-ED discharge. Measures included 1) clinician rating of mental health needs, 2) patient and caregiver self-reports of follow-up services, and 3) interviews regarding follow-up satisfaction. Data analysis included descriptive statistics and the Fisher’s exact test to compare sites.ResultsThe cohort consisted of 373 children and youth (61.1% female; mean age 15.1 years, 1.5 standard deviation). The main reason for ED presentations was a mental health crisis. The three most frequent areas of need requiring action were mood (43.8%), suicide risk (37.4%), and parent-child relational problems (34.6%). During the ED visit, 21.6% of patients received medical clearance, 40.9% received a psychiatric consult, and 19.4% were admitted to inpatient psychiatric care. At the 1-month post-ED visit, 84.3% of patients/caregivers received mental health follow-up. Ratings of service recommendations were generally positive, as 60.9% of patients obtained the recommended follow-up care and 13.9% were wait-listed.ConclusionsChildren and youth and their families presenting to the ED with mental health needs had substantial clinical morbidity, were connected with services, were satisfied with their ED visit, and accessed follow-up care within 1-month with some variability.

Extensive habitat destruction and pollution have caused dramatic declines in aquatic biodiversity at local to global scales. In rivers, the reintroduction of large woody debris is a common method aimed at restoring degraded ecosystems through "rewilding." However, causal evidence for its effectiveness is lacking due to a dearth of replicated before-after control-impact field experiments. We conducted the first replicated experiment of large woody debris rewilding across multiple rivers and organisational levels, from individual target species populations to entire food webs. For the first time, we demonstrate causal links between habitat restoration, biodiversity restoration and food web responses. Populations of invertebrates and an apex predator, brown trout (Salmo trutta), increased, and food web analysis suggested increased biomass flux from basal resources to invertebrates and subsequently fishes within restored reaches. Synthesis and applications. This study contributes significant new evidence demonstrating that large woody debris rewilding can help to restore human-impacted river ecosystems, primarily through altering the abundance and biomass of consumers and resources in the food web. We also outline a means to gauge the magnitude of ecological responses to restoration, relative to environmental stressors, which could help to prioritise the most effective conservation efforts.

OBJECTIVES: Repeat visits represent up to 45% of mental health (MH) presentations to emergency departments (EDs) and are associated with higher health care costs. We aimed to synthesize available literature on predictors of pediatric MH repeat ED visits and differences between repeat visitors and nonrepeat visitors. METHODS: A systematic review was performed using PsycINFO, PubMed, and CINAHL databases. Reporting followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement checklist. Methodologic quality was assessed using the following 8 criteria: design, generalizability, breadth of predictors, reporting of effect sizes, additional outcomes, interaction terms, confounding variables, and clear definition of repeat visits. RESULTS: A total of 178 articles were retrieved; 11 articles met inclusion criteria. Quality assessment revealed that all studies used chart review or administrative data. Predictors were grouped into 3 categories: demographic, clinical, and MH care access and utilization factors. Common predictors associated with repeat ED MH visits included socioeconomic status, involvement with child protective services, and previous and current MH service use. For studies using a 6-month repeat window, the most common factors were previous psychiatric hospitalization and currently receiving MH services. Heterogeneity in statistical analyses and determinants explored precluded the use of meta-analysis. CONCLUSIONS: Findings revealed that repeat visits to the ED for MH concerns is a complex phenomenon that can be attributed to various demographic, clinical, and MH care access and utilization factors. To further elucidate the strongest predictors, future prospective research should consider prospective designs and include family factors. Investigating recency and frequency outcomes can also inform clinical practice.

Objective:To document the rates of intentional self-harm and mental disorders among youths aged 13 to 17 years visiting Ontario emergency departments (EDs) from 2003-2017.Methods:This was a repeated cross-sectional observational design. Outcomes were rates of adolescents with (1) at least 1 self-harm ED visit and (2) a visit with a mental disorder code.Results:Rates of youths with self-harm visits fell 32% from 2.6/1000 in 2003 to 1.8 in 2009 but rose 135% to 4.2 by 2017. The slope of the trend in self-harm visits changed from –0.18 youths/1000/year (confidence interval [CI], –0.24 to –0.13) during 2003 to 2009 to 0.31 youths/1000/year (CI, 0.27 to 0.35) during 2009 to 2017 ( P < 0.001). Rates of youths with mental health visits rose from 11.7/1000 in 2003 to 13.5 in 2009 (15%) and to 24.1 (78%) by 2017. The slope of mental health visits changed from 0.22 youths/1000/year (CI, 0.02 to 0.42) during 2003 to 2009 to 1.84 youths/1000/year (CI, 1.38 to 2.30) in 2009 to 2017 ( P < 0.001). Females were more likely to have self-harm ( P < 0.001) and mental health visits ( P < 0.001). Rates of increase after 2009 were greater for females for both self-harm ( P < 0.001) and mental health ( P < 0.001).Conclusions:Rates of adolescents with self-harm and mental health ED visits have increased since 2009, with greater increases among females. Research is required on the determinants of adolescents’ self-harm and mental health ED visits and how they can be addressed in that setting. Sufficient treatment resources must be supplied to address increased demands for services.

Attention-deficit hyperactivity disorder (ADHD) is a chronic neurodevelopmental disorder. Three position statements have been developed by the Canadian Paediatric Society, following systematic literature reviews. Statement objectives are to: 1) Summarize the current clinical evidence regarding ADHD,2) Establish a standard for ADHD care, and3) Assist Canadian clinicians in making well-informed, evidence-based decisions to enhance care of children and youth with this condition. Specific topics reviewed in Part 1, which focuses on diagnosis, include: prevalence, genetics, pathophysiology, differential diagnosis and comorbid psychiatric disorders and developmental disorders. In addition to database searches, the most recent guidelines of the American Academy of Pediatrics, the American Academy of Child and Adolescent Psychiatry, the National Institute for Health and Clinical Excellence, the Scottish Intercollegiate Guidelines Network, and the Eunethydis European ADHD Guidelines Group, were reviewed. Because ADHD is a heterogeneous disorder, comprehensive medical assessment for ADHD should always include a complete history, a physical examination, and a thorough consideration of differential diagnosis and related comorbidities. Specific recommendations for information gathering, testing, and referral are offered.

International audience; Predator-prey interactions in natural ecosystems generate complex food webs that have a simple universal body-size architecture where predators are systematically larger than their prey. Food-web theory shows that the highest predator-prey body-mass ratios found in natural food webs may be especially important as they create weak interactions with slow dynamics that stabilize communities against perturbations and maintain ecosystem functioning. Identifying these vital interactions in real communities typically requires arduous identification of interactions in complex food webs. Here, we overcome this obstacle by developing predator-trait models to predict average body-mass ratios based on a database comprising 290 food webs from freshwater, marine and terrestrial ecosystems across all continents. We analyzed how species traits constrain body-size architecture by changing the slope of the predator-prey body-mass scaling. Across ecosystems, we found high body-mass ratios for predator groups with specific trait combinations including (1) small vertebrates and (2) large swimming or flying predators. Including the metabolic and movement types of predators increased the accuracy of predicting which species are engaged in high body-mass ratio interactions. We demonstrate that species traits explain striking patterns in the body-size architecture of natural food webs that underpin the stability and functioning of ecosystems, paving the way for community-level management of the most complex natural ecosystems.

Sustainable management of ecosystems and growth in agricultural productivity is at the heart of the United Nations' Sustainable Development Goals for 2030. New management regimes could revolutionize agricultural production, but require an evaluation of the risks and opportunities. Replacing existing conventional weed management with genetically modified, herbicide-tolerant (GMHT) crops, for example, might reduce herbicide applications and increase crop yields, but remains controversial owing to concerns about potential impacts on biodiversity. Until now, such new regimes have been assessed at the species or assemblage level, whereas higher-level ecological network effects remain largely unconsidered. Here, we conduct a large-scale network analysis of invertebrate communities across 502 UK farm sites to GMHT management in different crop types. We find that network-level properties were overwhelmingly shaped by crop type, whereas network structure and robustness were apparently unaltered by GMHT management. This suggests that taxon-specific effects reported previously did not escalate into higher-level systemic structural change in the wider agricultural ecosystem. Our study highlights current limitations of autecological assessments of effect in agriculture in which species interactions and potential compensatory effects are overlooked. We advocate adopting the more holistic system-level evaluations that we explore here, which complement existing assessments for meeting our future agricultural needs.

1) Résumer les données probantes cliniques à jour sur le TDAH. 2) Établir une norme pour les soins du TDAH. 3) Aider les cliniciens canadiens à prendre des décisions éclairées et fondées sur des données probantes pour rehausser la qualité des soins aux enfants et aux adolescents qui présentent cette affection. Les thèmes abordés dans la partie 1, qui est axée sur le diagnostic, incluent la prévalence, la génétique, la physiopathologie, le diagnostic différentiel, ainsi que les troubles psychiatriques et les troubles du développement comorbides. En plus des recherches dans les bases de données, les auteurs ont analysé les directives les plus récentes de l’American Academy of Pediatrics, de l’American Academy of Child and Adolescent Psychiatry, du National Institute for Health and Clinical Excellence, du Scottish Intercollegiate Guidelines Network et de l’Eunethydis European ADHD Guidelines Group. Puisque le TDAH est un trouble hétérogène, son évaluation médicale complète devrait toujours inclure une anamnèse fouillée, un examen physique et une évaluation approfondie du diagnostic différentiel et des comorbidités connexes. Les auteurs proposent des recommandations précises sur la récolte d’information, les tests à effectuer et les orientations vers divers services.

Approximately 45% of youth presenting to the emergency department (ED) for mental health (MH) concerns will have a repeat ED visit. Since youth greatly depend on their caregivers to access MH services, the objective of this study was to determine if family characteristics were associated with repeat ED visits.A retrospective cohort study of youth aged 6-18 years (62% female) treated at a tertiary pediatric ED for a discharge diagnosis related to MH was conducted. Data were gathered from medical records, telephone interviews, and questionnaires. Family factor contribution was analyzed using a multivariable logistic regression model controlling for demographic, clinical and service utilization factors. Variables associated with earlier and more frequent visits were determined using cox regression and negative binomial regression.Of 266 participants, 70 (26%) had a repeat visit. While caregiver history of MH treatment decreased the odds of having a repeat ED visit, family functioning and perceived family burden were not associated with repeat visits. Post-visit MH services, prior psychiatric hospitalization, higher severity of symptoms, and living closer to the hospital increased the odds of repeat visits.This study examined the contribution of multiple family factors in predicting repeat MH visits to the ED. Results suggest caregiver characteristics may impact the decision to return. Healthcare providers should therefore consider caregiver and youth service utilization factors to inform patient management and discharge planning.Environ 45 % des adolescents qui se présentent au service d’urgence (SU) pour des raisons de santé mentale (SM) auront une visite répétée au SU. Puisque les adolescents dépendent beaucoup de leurs aidants pour avoir accès aux services de SM, l’objectif de cette étude était de déterminer si les caractéristiques familiales étaient associées aux visites répétées au SU.Une étude de cohorte rétrospective a été menée sur des adolescents de 6 à 18 ans (62 % de sexe féminin) traités dans un SU pédiatrique tertiaire pour un diagnostic lié à la SM posé au moment du congé. Les données ont été recueillies d’après les dossiers médicaux, les entrevues téléphoniques et les questionnaires. La contribution des facteurs familiaux a été analysée à l’aide d’un modèle de régression logistique multivariable après contrôle des facteurs démographiques, cliniques et d’utilisation des services. Les variables associées à des visites précédentes et plus fréquentes ont été déterminées à l’aide de la régression de Cox et la régression binomiale négative.Sur les 266 participants, 70 (26 %) avaient une visite répétée. Les antécédents de traitement de SM des aidants diminuaient les probabilités d’avoir une visite répétée au SU, et le fonctionnement familial et le fardeau familial perçu n’étaient pas associés à des visites répétées. Les services de SM ultérieurs à la visite, une hospitalisation psychiatrique précédente, une gravité plus élevée des symptômes et le fait d’habiter à proximité de l’hôpital augmentaient les probabilités de visites répétées.Cette étude a examiné la contribution de multiples facteurs familiaux à la prédiction de visites répétées au SU pour raisons de SM. Les résultats suggèrent que les caractéristiques des aidants puissent influer sur la décision de retourner au SU. Les prestataires de soins de santé devraient donc prendre en compte les facteurs d’utilisation des services des aidants et des adolescents afin d’éclairer la prise en charge des patients et la planification du congé.

International audience; Global environmental change is a pressing issue as evidenced by the rise of extreme weather conditions in many parts of the world, threatening the survival of vulnerable species and habitats. Effective monitoring of climatic and anthropogenic impacts is therefore critical to safeguarding ecosystems, and it would allow us to better understand their response to stressors and predict long-term impacts. Ecological networks provide a biomonitoring framework for examining the system-level response and functioning of an ecosystem, but have been, until recently, constrained by limited empirical data due to the laborious nature of their construction. Hence, most experimental designs have been confined to a single network or a small number of replicate networks, resulting in statistical uncertainty, low resolution, limited spatiotemporal scale and oversimplified assumptions. Advances in data sampling and curation methodologies, such as next-generation sequencing (NGS) and the Internet 'Cloud', have facilitated the emergence of the 'Big Data' phenomenon in Ecology, enabling the construction of ecological networks to be carried out effectively and efficiently. This provides to ecologists an excellent opportunity to expand the way they study ecological networks. In particular, highly replicated networks are now within our grasp if new NGS technologies are combined with machine learning to develop network building methods. A replicated network approach will allow temporal and spatial variations embedded in the data to be taken into consideration, overcoming the limitations in the current 'single network' approach. We are still at the embryonic stage in exploring replicated networks, and with these new opportunities we also face new challenges. In this chapter, we discuss some of these challenges and highlight potential approaches that will help us build and analyse replicated networks to better understand how complex ecosystems operate, and the services and functioning they provide, paving the way for deciphering ecological big data reliably in the future.

BACKGROUND: Over the last few decades, there has been a surge in the use of laboratory testing during patient encounters. Many suggest that laboratory investigations for psychiatric inpatient units are unnecessary, thus warranting further research and support. Furthermore, though the results of completed investigations may fall out of normal range, they are most often deemed not clinically significant and do not affect patient management. OBJECTIVES: Determine the clinical relevance of routine bloodwork completed upon patient admission to a pediatric psychiatric inpatient unitIdentify which blood tests fell most often outside the range of normal and whether they resulted in follow-up. Recommend a more streamlined and cost-efficient approach towards ordering admission bloodwork. DESIGN/METHODS: Through a retrospective chart review, 485 patient admissions to the pediatric inpatient unit at a tertiary care teaching hospital between January 1st and December 31st, 2016 were reviewed and analyzed. Demographics (age, sex) were collected along with results and clinical significance of 17 routinely ordered laboratory tests (CBC and differential, serum glucose, sodium, potassium, chloride, urea, creatinine, bilirubin, ALP, AST, ALT, LDH, GGT, TSH, ferritin, folate and B12 levels). RESULTS: Routine bloodwork was completed for 79.8% (n=387) of patient admissions. However, no more than 1.7% of the completed bloodwork led to changes in patient management. Tests which were most frequently clinically significant included Ferritin (6.1%), TSH (4.7%), and B12 (3.2%). The remaining 14 routine laboratory tests were each clinically significant less than 2.5% of the time. CONCLUSION: The results of this study suggest that not all routine laboratory investigations are useful on admission given few led to changes in patient management. Our study proposes that physicians admitting pediatric patients to the inpatient psychiatry ward order a subset of routine blood work including Ferritin, TSH, B12, and others only when deemed necessary by the attending physician and based on patient presentation.

ObjectivesDespite documented increases in emergency department (ED) mental health (MH) presentations, there are inconsistent findings on the characteristics of patients with repeat presentations to pediatric EDs (PEDs) for MH concerns. Our study sought to explore the characteristics of MH patients with repeat PED visits and determine predictors of return visits, of earlier repeat visits, and of more frequent repeat visits.MethodsWe examined data collected prospectively in a clinical database looking at MH presentations to a crisis intervention program housed within a PED from October 2006 to December 2011. Predictive models based on demographic and clinical variables were constructed using logistic, Cox, and negative binomial regression.ResultsA total of 4,080 presentations to the PED were made by the 2,900 children and youth. Repeat visits accounted for almost half (45.8%) of all presentations. Multivariable analysis identified five variables that independently predicted greater odds of having repeat presentations, greater risk of earlier repeat presentations, and greater risk of frequent repeat presentations. The five variables were: female, living in the metropolitan community close to the PED, being in the care of child protective services, taking psychotropic medications, and presenting with an actionable need in the area of mood disturbances.ConclusionsRepeat visits account for a large portion of all MH presentations to the PED. Furthermore, several patient characteristics are significant predictors of repeat PED use and of repeating use sooner and more frequently. Further research is needed to examine interventions targeting this patient group to ensure appropriate MH patient management.

Droughts are intensifying under climate change. Research into the resilience of stream food webs to drought now shows that ‘rewiring’ of food web structure in the face of species losses helps to buffer changes to the overall network structure. Droughts are intensifying across the globe1,2, with potentially devastating implications for freshwater ecosystems3,4. We used new network science approaches to investigate drought impacts on stream food webs and explored potential consequences for web robustness to future perturbations. The substructure of the webs was characterized by a core of richly connected species5 surrounded by poorly connected peripheral species. Although drought caused the partial collapse of the food webs6, the loss of the most extinction-prone peripheral species triggered a substantial rewiring of interactions within the networks’ cores. These shifts in species interactions in the core conserved the underlying core/periphery substructure and stability of the drought-impacted webs. When we subsequently perturbed the webs by simulating species loss in silico, the rewired drought webs were as robust as the larger, undisturbed webs. Our research unearths previously unknown compensatory dynamics arising from within the core that could underpin food web stability in the face of environmental perturbations.

Most research on the effects of environmental change in freshwaters has focused on incremental changes in average conditions, rather than fluctuations or extreme events such as heatwaves, cold snaps, droughts, floods or wildfires, which may have even more profound consequences. Such events are commonly predicted to increase in frequency, intensity and duration with global climate change, with many systems being exposed to conditions with no recent historical precedent. We propose a mechanistic framework for predicting potential impacts of environmental fluctuations on running-water ecosystems by scaling up effects of fluctuations from individuals to entire ecosystems. This framework requires integration of four key components: effects of the environment on individual metabolism, metabolic and biomechanical constraints on fluctuating species interactions, assembly dynamics of local food webs, and mapping the dynamics of the meta-community onto ecosystem function. We illustrate the framework by developing a mathematical model of environmental fluctuations on dynamically assembling food webs. We highlight (currently limited) empirical evidence for emerging insights and theoretical predictions. For example, widely supported predictions about the effects of environmental fluctuations are: high vulnerability of species with high per capita metabolic demands such as large-bodied ones at the top of food webs; simplification of food web network structure and impaired energetic transfer efficiency; and reduced resilience and top-down relative to bottom-up regulation of food web and ecosystem processes. We conclude by identifying key questions and challenges that need to be addressed to develop more accurate and predictive bio-assessments of the effects of fluctuations, and implications of fluctuations for management practices in an increasingly uncertain world.

An innovative crisis intervention programme was created at the Children's Hospital of Eastern Ontario in Canada in order to provide emergency assessments for youth presenting with mental health crises. The current investigation presents an overview of the programme and examines the emergency staff's perception and satisfaction with it. Eighty-seven emergency department medical staff completed a survey. Overall, emergency department staff place high value on having access to emergency mental health services, are pleased with the quality of service and appreciate that the crisis intervention worker's presence allows them to spend more time with other patients.

Il est demontre que le traitement pharmacologique par des stimulants reduit les symptomes associes au trouble de deficit de l’attention avec hyperactivite (TDAH), et ce traitement fait partie des recommandations therapeutiques de l’American Academy of Pediatrics pour les enfants presentant ce trouble (1,2). Cependant, de recentes decisions en matiere de reglementation sur l’homologation et l’etiquetage des medicaments contre le TDAH (3,4), ainsi qu’un recent document de principes de l’American Heart Association (5), une correction et une reponse (clarification) de l’American Academy of Pediatrics (6,7), ont souleve des questions sur l’evaluation et la therapie du TDAH que preconisent les praticiens canadiens. La pratique canadienne actuelle dans le domaine de la pharmacotherapie du TDAH et du depistage cardiovasculaire est mixte, et il y a peu de consensus quant a l’evaluation pertinente des enfants avant d’instaurer la pharmacotherapie du TDAH (8). Les avis sont encore plus partages au sujet de l’innocuite du traitement des enfants ayant subi une refection ou une palliation de leur cardiopathie congenitale (CPC) et qui prennent des medicaments contre le TDAH (8). Afin d’orienter les medecins canadiens qui soignent les enfants ayant un TDAH et de clarifier la situation, la Societe canadienne de pediatrie, la Societe canadienne de cardiologie et l’Academie canadienne de psychiatrie de l’enfant et de l’adolescent ont prepare conjointement le present document de principes. Il contient des recommandations consensuelles sur l’evaluation du risque cardiaque chez les enfants ayant un TDAH a qui on envisage d’administrer des stimulants. Il ne s’attarde pas au diagnostic de TDAH, ni aux bienfaits therapeutiques des stimulants. De meme, il n’aborde pas le bien-fonde ou les risques relatifs d’un medicament par rapport a un autre au sein de cette population de patients. Enfin, les medicaments non stimulants utilises dans le traitement du TDAH, y compris l’atomoxetine, les antidepresseurs et les agonistes alpha-adrenergiques, ne font pas l’objet d’une analyse particuliere.

Many previous attempts to understand how ecological networks respond to and recover from environmental stressors have been hindered by poorly resolved and unreplicated food web data. Few studies have assessed how the topological structure of large, replicated collections of food webs recovers from perturbations. We analysed food web data taken from 23 UK freshwaters, sampled repeatedly over 24 years, yielding a collection of 442 stream and lake food webs. Our main goal was to determine the effect of acidity on food web structure and to analyse the way food web structure recovered from the effects of acidity over time. Long-term monotonic reversals of acidification were evident at many of the sites, but the ecological responses were generally far less evident than chemical changes, or absent. Across the acidity gradient, food web linkage density and network efficiency declined with increasing acidity, while node redundancy (i.e. trophic similarity among species within a web) increased. Within individual sites, connectance, linkage density, trophic height, resource vulnerability and network efficiency tended to increase over time as sites recovered from acidification, while consumer generality and node redundancy tended to decrease. There was evidence for a lag in biological recovery, as those sites showing a recovery in both their biology and their chemistry were a nested subset of those which only showed a chemistry trend. These findings support the notion that food web structure is fundamentally altered by acidity, and that inertia within the food web may be hindering biological recovery. This suggestion of lagged recovery highlights the importance of long-term monitoring when assessing the impacts of anthropogenic stressors on the natural world. This temporal dimension, and recognition that species interactions can shape community dynamics, is missing from most national biomonitoring schemes, which often rely on space-for-time proxies.

1. Pesticides can have strong deleterious impacts in fresh waters, but understanding how these effects cascade through natural ecosystems, from microbes to apex predators, is limited because research that spans multiple levels of biological organisation is rare. 2. We report how an accidental insecticide spill altered the structure and functioning of a river across levels ranging from genes to ecosystems. We quantified the impacts on assemblages of microbes, diatoms, macroinvertebrates and fish and measured leaf-litter decomposition rates and microbial functional potential at upstream control and downstream impacted sites 2 months after the spill. 3. Both direct and indirect impacts were evident across multiple levels of organisation and taxa, from the base of the food web to higher trophic levels. At the molecular level, differences in functional gene abundance within the impacted sites reflected a combination of direct and indirect effects of the pesticide, via elevated abundances of microbial populations capable of using chlorpyrifos as a resource (i.e. direct effect) and oxidising ammonia released by decaying macroinvertebrate carcasses (i.e. indirect effect). 4. At the base of the food chains, diatom taxa found only in the impacted sites were an order-of- magnitude larger in cell size than the largest comparable taxa in control communities, following the near extirpation of their consumers. Population biomass of the key detritivore Gammarus pulex was markedly lower, as was the rate of litter decomposition in the impacted sites. This was partially compensated for, however, by elevated microbial breakdown, suggesting another indirect food-web effect of the toxic spill. 5. Although many species exhibited population crashes or local extirpation, total macroinvertebrate biomass and abundance were largely unaffected due to a compensatory elevation in small tolerant taxa such as oligochaetes, and/or taxa which were in their adult aerial life stage at the time of the spill (e.g. chironomids) and thus avoided contact with the polluted waters and were able to repopu- late the river quickly. Mass–abundance scaling of trophic links between consumers and resources revealed extensive restructuring within the food web. 6. This case study shows that pesticides can affect food-web structure and ecosystem functioning, both directly and indirectly across levels of biological organisation. It also demonstrates how an integrated assessment approach, as adopted here, can elucidate links between microbiota, macroinvertebrates and fish, for instance, thus improving our understanding of the range of biological consequences of chemical contamination in natural ecosystems.

The demand for freshwater is projected to increase worldwide over the coming decades, resulting in severe water stress and threats to riverine biodiversity, ecosystem functioning, and services. A major societal challenge is to determine where environmental changes will have the greatest impacts on riverine ecosystem services and where resilience can be incorporated into adaptive resource planning. Both water managers and scientists need new integrative tools to guide them toward the best solutions that meet the demands of a growing human population but also ensure riverine biodiversity and ecosystem integrity. Resource planners and scientists could better address a growing set of riverine management and risk mitigation issues by (1) using a `virtual watersheds¿ approach based on improved digital river networks and better connections to terrestrial systems, (2) integrating virtual watersheds with ecosystem services technology (ARtificial Intelligence for Ecosystem Services: ARIES), and (3) incorporating the role of riverine biotic interactions in shaping ecological responses. This integrative platform can support both interdisciplinary scientific analyses of pressing societal issues and effective dissemination of findings across river research and management communities. It should also provide new integrative tools to identify the best solutions and trade-offs to ensure the conservation of riverine biodiversity and ecosystem services., This study was partly funded by the Spanish Ministry of Economy and Competitiveness as part of the project RIVERLANDS (BIA2012-33572). José Barquín is supported by a Ramon y Cajal grant (Ref: RYC-2011-08313) of the Ministry of Economy and Competitiveness. David Vieites is supported by the ERANET Biodiversa EC21C: European Conservation for the 21st Century.

Monitoring anthropogenic impacts is essential for managing and conserving ecosystems, yet current biomonitoring approaches lack the tools required to deal with the effects of stressors on species and their interactions in complex natural systems. Ecological networks (trophic or mutualistic) can offer new insights into ecosystem degradation, adding value to current taxonomically constrained schemes. We highlight some examples to show how new network approaches can be used to interpret ecological responses. Synthesis and applications. Augmenting routine biomonitoring data with interaction data derived from the literature, complemented with ground-truthed data from direct observations where feasible, allows us to begin to characterise large numbers of ecological networks across environmental gradients. This process can be accelerated by adopting emerging technologies and novel analytical approaches, enabling biomonitoring to move beyond simple pass/fail schemes and to address the many ecological responses that can only be understood from a network-based perspective.

Food webs are important tools for understanding how complex natural communities are structured and how they respond to environmental change. However their full potential has yet to be realised because of the huge amount of resources required to construct them de novo. Consequently, the current catalogue of networks that are suitable for rigorous and comparative analyses and theoretical development still suffers from a lack of standardisation and replication. Here, we present a novel R function, WebBuilder , which automates the construction of food webs from taxonomic lists, and a dataset of trophic interactions. This function works by matching species against those within a dataset of trophic interactions, and ‘filling in’ missing trophic interactions based on these matches. We also present a dataset of over 20,000 freshwater trophic interactions, and use this and four well-characterised freshwater food webs to test the method. The WebBuilder function facilitates the generation of food webs of comparable quality to the most detailed published food webs, but at a fraction of the research effort or cost. Furthermore, it matched and often outperformed a selection of predictive models, which are currently among the best, in terms of capturing key properties of empirical food webs. The method is simple to use, systematic and, perhaps most importantly, reproducible, which will facilitate (re-) analysis and data sharing. Although developed and tested on a sample of freshwater food webs, this method could easily be extended to cover other types of ecological interactions (such as mutualistic interactions).

While the emergency department (ED) is often a first point of entry for children and youth with mental health (MH) concerns, there is a limited capacity to respond to MH needs in this setting. Child MH systems are typically fragmented among multiple ministries, organizations, and providers. Communication among these groups is often poor, resulting in gaps, particularly in transitions of care, for this vulnerable population. The evidence-based Emergency Department Mental Health Clinical Pathway (EDMHCP) was created with two main goals: (1) to guide risk assessment and disposition decision-making for children and youth presenting to the ED with MH concerns and (2) to provide a streamlined transition to follow-up services with community MH agencies (CMHAs) and other providers. The purpose of this paper is to describe our study protocol to implement and evaluate the EDMHCP. This mixed methods health services research project will involve implementation and evaluation of the EDMHCP in four exemplar ED-CMHA dyads. The Theoretical Domains Framework will be used to develop a tailored intervention strategy to implement the EDMHCP. A multiple baseline study design and interrupted time-series analysis will be used to determine if the EDMHCP has improved health care utilization, medical management of the MH problems, and health sector coordination. The primary process outcome will be the proportion of patients with MH-specific recommendations documented in the health record. The primary service outcome will be the proportion of patients receiving the EDMHCP-recommended follow-up at 24-h or at 7 days. Data sources will include qualitative interviews, health record audits, administrative databases, and patient surveys. A concurrent process evaluation will be conducted to assess the degree of variability and fidelity in implementation across the sites. This paper presents a novel model for measuring the effects of the EDMHCP. Our development process will identify how the EDMHCP is best implemented among partner organizations to deliver evidence-based risk management of children and youth presenting with MH concerns. More broadly, it will contribute to the body of evidence supporting clinical pathway implementation within novel partnerships. ClinicalTrials.gov ( NCT02590302 )

Regulatory decisions and scientific statements regarding the management of attention-deficit hyperactivity disorder (ADHD) raise questions about the safety of medications and the appropriate pretreatment evaluation to determine suitability for treatment with medication. This is particularly true in the setting of known structural or functional heart disease. The present paper reviews the available data, including peer-reviewed literature, data from the United States Food and Drug Administration Web site on reported adverse reactions in children using stimulant medication, and Health Canada data on the same problem. A consensus-based guideline on appropriate assessment is provided, based on input from members of the Canadian Paediatric Society, the Canadian Cardiovascular Society and the Canadian Academy of Child and Adolescent Psychiatry, with specific expertise and knowledge in the areas of both ADHD and pediatric cardiology. The present statement advocates a thorough history and physical examination before starting stimulant medications, with an emphasis on the identification of risk factors for sudden death, but does not routinely recommend electrocardiographic screening or cardiac subspecialist consultation unless indicated by history or physical examination findings. A checklist for identifying children who are potentially at risk of sudden death (independent of ADHD or medications used to treat it) is provided. Although recommendations are based on the best evidence currently available, the committee further agrees that more research on this subject is necessary to optimize the approach to this common clinical scenario.

Regulatory decisions and scientific statements regarding the management of attention-deficit hyperactivity disorder (ADHD) raise questions about the safety of medications and the appropriate pretreatment evaluation to determine suitability for treatment with medication. This is particularly true in the setting of known structural or functional heart disease. The present paper reviews the available data, including peer-reviewed literature, data from the United States Food and Drug Administration Web site on reported adverse reactions in children using stimulant medication, and Health Canada data on the same problem. A consensus-based guideline on appropriate assessment is provided, based on input from members of the Canadian Paediatric Society, the Canadian Cardiovascular Society and the Canadian Academy of Child and Adolescent Psychiatry, with specific expertise and knowledge in the areas of both ADHD and paediatric cardiology. The present statement advocates a thorough history and physical examination before starting stimulant medications, with an emphasis on the identification of risk factors for sudden death, but does not routinely recommend electrocardiographic screening or cardiac sub-specialist consultation unless indicated by history or physical examination findings. A checklist for identifying children who are potentially at risk of sudden death (independent of ADHD or medications used to treat it) is provided. Although recommendations are based on the best evidence currently available, the committee further agrees that more research on this subject is necessary to optimize the approach to this common clinical scenario.