The effects of climatic fluctuations and extreme events on running water ecosystems

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; 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

Drought rewires the cores of food webs

Droughts are intensifying across the globe, with potentially devastating implications for freshwater ecosystems. 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 species surrounded by poorly connected peripheral species. Although drought caused the partial collapse of the food webs, 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

The effects of climatic fluctuations and extreme events on running water ecosystems

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

Prehistory of Transit Searches

Nowadays the more powerful method to detect extrasolar planets is the transit method. We review the planet transits which were anticipated, searched, and the first ones which were observed all through history. Indeed transits of planets in front of their star were first investigated and studied in the solar system. The first observations of sunspots were sometimes mistaken for transits of unknown planets. The first scientific observation and study of a transit in the solar system was the observation of Mercury transit by Pierre Gassendi in 1631. Because observations of Venus transits could give a way to determine the distance Sun-Earth, transits of Venus were overwhelmingly observed. Some objects which actually do not exist were searched by their hypothetical transits on the Sun, as some examples a Venus satellite and an infra-mercurial planet. We evoke the possibly first use of the hypothesis of an exoplanet transit to explain some periodic variations of the luminosity of a star, namely the star Algol, during the eighteen century. Then we review the predictions of detection of exoplanets by their transits, those predictions being sometimes ancient, and made by astronomers as well as popular science writers. However, these very interesting predictions were never published in peer-reviewed journals specialized in astronomical discoveries and results. A possible transit of the planet beta Pic b was observed in 1981. Shall we see another transit expected for the same planet during 2018? Today, some studies of transits which are connected to hypothetical extraterrestrial civilisations are published in astronomical refereed journals. Some studies which would be classified not long ago as science fiction are now considered as scientific ones.Comment: Submiited to Handbook of Exoplanets (Springer

Rapid Evaluation of the Special Measures for Quality and Challenged Provider Regimes: A Mixed-Methods Study

Background: Healthcare organisations in England rated as inadequate for leadership and one other domain enter Special Measures for Quality (SMQ) to receive support and oversight. A ‘watch list’ of challenged providers (CPs) at risk of entering SMQ also receive support. Knowledge is limited about whether the support interventions drive improvements in quality, their costs, and whether they strike the right balance between support and scrutiny. Objective: Analyse trust responses to the implementation of a) interventions for SMQ trusts and b) interventions for CP trusts to determine their impact on these organisations' capacity to achieve and sustain quality improvements. Design: Rapid research comprising five inter-related workstreams: 1. Literature review using systematic methods. 2. Analysis of policy documents and interviews at national level. 3. Eight multi-site, mixed method trust case studies. 4. Analysis of national performance and workforce indicators. 5. Economic analysis. Results: SMQ/CP were intended to be “support” programmes. SMQ/CP had an emotional impact on staff. Perceptions of NHSI interventions were mixed overall. Senior leadership teams were a key driver of change, with strong clinical input vital. Local systems have a role in improvement. Trusts focus efforts to improve across multiple domains. Internal and external factors contribute to positive performance trajectories. Nationally, only 15.8% of SMQ trusts exited within 24 months. Relative to national trends, entry into SMQ/CP corresponded to positive changes in 4-hour waits in Emergency Departments, mortality and delayed transfers of care. Trends in staff sickness and absence improved after trusts left SMQ/CP. There was some evidence that staff survey results improve. No association was found between SMQ/CP and referral to treatment times or cancer waiting times. The largest components of NHSI spending in case studies were interventions directed at 'training on cultural change' (33.6%), 'workforce quality and safety' (21.7%) and 'governance and assurance' (18.4%). Impact of SMQ on financial stability was equivocal; most trusts exiting SMQ experienced the same financial stability before and after exiting. Limitations: The rapid research design and one-year timeframe precludes longitudinal observations of trusts and local systems. The small number of indicators limited the quantitative analysis of impact. Measuring workforce effects was limited by data availability. Conclusions: Empirical evidence of positive impacts from SMQ/CP were identified, however, perceptions were mixed. Key lessons: • Time is needed to implement and embed changes. • Ways to mitigate emotional costs and stigma are needed. • Support strategies should be more trust specific. • Poor organisational performance needs to be addressed within local systems. • Senior leadership teams with stability, strong clinical input and previous SMQ experience helped enact change. • Organisation-wide quality improvement strategies and capabilities are needed. • Staff engagement and an open listening culture promote continuous learning and a quality improvement ‘mindset’, critical for sustainable improvement. • Need to consider level of sustainable funds required to improve patients’ outcomes. Future work: Evaluating recent changes to the regimes; role of local systems; longitudinal approaches. Study registration: Review protocol registered with PROSPERO (CRD: 42019131024). Funding: The National Institute for Health Research Health Services and Delivery Research programme (16/138/17 – Rapid Service Evaluation Research Team)

Validation of the Emergency Department-Paediatric Early Warning Score (ED-PEWS) for use in low- and middle-income countries:A multicentre observational study

Early recognition of children at risk of serious illness is essential in preventing morbidity and mortality, particularly in low- and middle-income countries (LMICs). This study aimed to validate the Emergency Department-Paediatric Early Warning Score (ED-PEWS) for use in acute care settings in LMICs. This observational study is based on previously collected clinical data from consecutive children attending four diverse settings in LMICs. Inclusion criteria and study periods (2010–2021) varied. We simulated the ED-PEWS, consisting of patient age, consciousness, work of breathing, respiratory rate, oxygen saturation, heart rate, and capillary refill time, based on the first available parameters. Discrimination was assessed by the area under the curve (AUC), sensitivity and specificity (previously defined cut-offs &lt; 6 and ≥ 15). The outcome measure was for each setting a composite marker of high urgency. 41,917 visits from Gambia rural, 501 visits from Gambia urban, 2,608 visits from Suriname, and 1,682 visits from Tanzania were included. The proportion of high urgency was variable (range 4.6% to 24.9%). Performance ranged from AUC 0.80 (95%CI 0.70–0.89) in Gambia urban to 0.62 (95%CI 0.55–0.67) in Tanzania. The low-urgency cut-off showed a high sensitivity in all settings ranging from 0.83 (95%CI 0.81–0.84) to 1.00 (95%CI 0.97–1.00). The high-urgency cut-off showed a specificity ranging from 0.71 (95%CI 0.66–0.75) to 0.97 (95%CI 0.97–0.97). The ED-PEWS has a moderate to good performance for the recognition of high urgency children in these LMIC settings. The performance appears to have potential in improving the identification of high urgency children in LMICs.</p

Extreme low flow effects on riverine fauna: a perspective on methodological assessments

River flow regimes face increasing pressure from human activities including water resource management operations and climate change. Consequently, extreme hydrological events are becoming more severe and commonplace, and there is a pressing need to understand and manage their ecological effects. Extreme low-flows (ELFs) – those displaying significantly greater magnitudes and durations than typical low-flow conditions – are being increasingly experienced globally. Fish and macroinvertebrate responses to ELFs have been more widely researched relative to other organism groups in riverine environments, although such studies have employed variable methodological techniques. In this perspective piece, we identify field-based assessments and controlled experiments as two key research paradigms used to examine riverine faunal responses to ELFs. Field-based assessments are often explorative and can benefit from utilising large-scale and long-term datasets. Alternatively, controlled experiments typically employ more hypothesis-driven approaches and can establish strong cause and effect linkages through high replication and control over potentially confounding parameters. Each paradigm clearly possesses their respective strengths, which we highlight and discuss how these could be better harnessed to optimise scientific advancements. To date, studies examining faunal responses to ELFs in these two research paradigms have largely been undertaken in parallel. Here, we argue that future research should seek to develop closer synergies to optimise the quality and quantity of evidence to better understand riverine faunal responses to ELFs. Such scientific advances are of paramount importance given the vulnerability of riverine fauna, and the ecosystems they comprise, as they face a new era of ELFs in many global regions