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Climate change is increasing the frequency and severity of short-term (~1 y) drought events-the most common duration of drought-globally. Yet the impact of this intensification of drought on ecosystem functioning remains poorly resolved. This is due in part to the widely disparate approaches ecologists have employed to study drought, variation in the severity and duration of drought studied, and differences among ecosystems in vegetation, edaphic and climatic attributes that can mediate drought impacts. To overcome these problems and better identify the factors that modulate drought responses, we used a coordinated distributed experiment to quantify the impact of short-term drought on grassland and shrubland ecosystems. With a standardized approach, we imposed ~a single year of drought at 100 sites on six continents. Here we show that loss of a foundational ecosystem function-aboveground net primary production (ANPP)-was 60% greater at sites that experienced statistically extreme drought (1-in-100-y event) vs. those sites where drought was nominal (historically more common) in magnitude (35% vs. 21%, respectively). This reduction in a key carbon cycle process with a single year of extreme drought greatly exceeds previously reported losses for grasslands and shrublands. Our global experiment also revealed high variability in drought response but that relative reductions in ANPP were greater in drier ecosystems and those with fewer plant species. Overall, our results demonstrate with unprecedented rigor that the global impacts of projected increases in drought severity have been significantly underestimated and that drier and less diverse sites are likely to be most vulnerable to extreme drought.
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Secas , Ecossistema , Pradaria , Ciclo do Carbono , Mudança Climática , Receptores Proteína Tirosina QuinasesRESUMO
Climate variability and periodic droughts have complex effects on carbon (C) fluxes, with uncertain implications for ecosystem C balance under a changing climate. Responses to climate change can be modulated by persistent effects of climate history on plant communities, soil microbial activity, and nutrient cycling (i.e., legacies). To assess how legacies of past precipitation regimes influence tallgrass prairie C cycling under new precipitation regimes, we modified a long-term irrigation experiment that simulated a wetter climate for >25 years. We reversed irrigated and control (ambient precipitation) treatments in some plots and imposed an experimental drought in plots with a history of irrigation or ambient precipitation to assess how climate legacies affect aboveground net primary productivity (ANPP), soil respiration, and selected soil C pools. Legacy effects of elevated precipitation (irrigation) included higher C fluxes and altered labile soil C pools, and in some cases altered sensitivity to new climate treatments. Indeed, decades of irrigation reduced the sensitivity of both ANPP and soil respiration to drought compared with controls. Positive legacy effects of irrigation on ANPP persisted for at least 3 years following treatment reversal, were apparent in both wet and dry years, and were associated with altered plant functional composition. In contrast, legacy effects on soil respiration were comparatively short-lived and did not manifest under natural or experimentally-imposed "wet years," suggesting that legacy effects on CO2 efflux are contingent on current conditions. Although total soil C remained similar across treatments, long-term irrigation increased labile soil C and the sensitivity of microbial biomass C to drought. Importantly, the magnitude of legacy effects for all response variables varied with topography, suggesting that landscape can modulate the strength and direction of climate legacies. Our results demonstrate the role of climate history as an important determinant of terrestrial C cycling responses to future climate changes.
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Ecossistema , Pradaria , Mudança Climática , Secas , Plantas , Chuva , SoloRESUMO
Climate change is predicted to increase the frequency and intensity of extreme events including droughts and large precipitation events or "deluges." While many studies have focused on the ecological impacts of individual events (e.g., a heat wave), there is growing recognition that when extreme events co-occur as compound extremes, (e.g., a heatwave during a drought), the additive effects on ecosystems are often greater than either extreme alone. In this study, we assessed a unique type of extreme-a contrasting compound extreme-where the extremes may have offsetting, rather than additive ecological effects, by examining how a deluge during a drought impacts productivity and carbon cycling in a semi-arid grassland. The experiment consisted of four treatments: a control (average precipitation), an extreme drought (<5th percentile), an extreme drought interrupted by a single deluge (>95th percentile), or an extreme drought interrupted by the equivalent amount of precipitation added in several smaller events. We highlight three key results. First, extreme drought resulted in early senescence, reduced carbon uptake, and a decline in net primary productivity relative to the control treatment. Second, the deluge imposed during extreme drought stimulated carbon fluxes and plant growth well above the levels of both the control and the drought treatment with several additional smaller rainfall events, emphasizing the importance of precipitation amount, event size, and timing. Third, while the deluge's positive effects on carbon fluxes and plant growth persisted for 1 month, the deluge did not completely offset the negative effects of extreme drought on end-of-season productivity. Thus, in the case of these contrasting hydroclimatic extremes, a deluge during a drought can stimulate temporally dynamic ecosystem processes (e.g., net ecosystem exchange) while only partially compensating for reductions in ecosystem functions over longer time scales (e.g., aboveground net primary productivity).
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Secas , Ecossistema , Carbono , Ciclo do Carbono , Mudança Climática , Pradaria , ChuvaRESUMO
Objectives: This study aims to explore patients' and clinicians' experiences in managing and living with refractory disease (RD) and persistent physical and emotional symptoms (PPES) in patients with RA or polyarticular JIA from their perspectives through interviews and/or focus groups. Methods: A qualitative exploration with 25 patients and 32 multidisciplinary rheumatology healthcare professionals (HCPs) was conducted to obtain participants respective understanding and experiences of managing RD/PPES and its impact on the patient-professional relationship. A pragmatic epistemology approach with framework analysis was employed. Results: Four key themes were identified from both patients and professionals in the management of RD/PPES: risk/perpetuating factors/triggers; need for a patient-centred holistic approach to care, diagnosis and treatment; discordance and impact on the patient-practitioner relationship and current problems in managing RD/PPES. These themes covered 22 subthemes, with none being patient specific and seven being HCP specific. Suggestions for potential management strategies were highlighted throughout, such as involving other specialties or a multidisciplinary team, assessing/treating patient-reported outcome measures and psychosocial factors, patient (re)education, need for adjustments/aids or adaptations, checking the diagnosis and further investigations/imaging and optimizing medications. Conclusion: Management strategies need to be developed that enable appropriate treatment plans for those with RD/PPES that account for wider biopsychosocial factors beyond inflammation and reduce discordance in the patient-practitioner relationship.
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The increasing prevalence of drought events in grasslands and shrublands worldwide potentially has impacts on soil organic carbon (SOC). We leveraged the International Drought Experiment to study how SOC, including particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) concentrations, responds to extreme drought treatments (1-in-100-year) for 1 to 5 years at 19 sites worldwide. In more mesic areas (aridity index > 0.65), SOC and POC concentrations decreased by 7.9% (±3.9) and 15.9% (±6.2) with drought, respectively, but there were no impacts on MAOC concentrations. However, drought had no impact on SOC, POC, or MAOC concentrations in drylands (aridity index < 0.65). The response of SOC to drought varied along an aridity gradient, concomitant with interannual precipitation variability and standing SOC concentration gradients. These findings highlight the differing response magnitudes of POC and MAOC concentrations to drought and the key regulating role of aridity.
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Carbono , Secas , Pradaria , Solo , Solo/química , Carbono/metabolismo , Ecossistema , Clima DesérticoRESUMO
BACKGROUND: Patients with inflammatory rheumatic diseases (IRDs) face challenges including pain, fatigue and disease flares. Evidence suggests their levels of anxiety and depression are higher compared to the general population. Rheumatology teams report psychologically distressed patients have additional support needs and require more clinical time. Little is currently known about models of support and their integration into care pathways. AIM: To understand rheumatology health professionals' perspectives on patients' psychological distress and ways to meet support needs. METHODS: The study used a qualitative design, with data collected in telephone semi-structured interviews. Inductive thematic analysis was used to analyse the data. RESULTS: Fifteen interviews were conducted. Two main themes with sub-themes represent the data: Theme 1: 'No one shoe fits all'-the many manifestations of distress in patients (sub-themes: recognising distress, dealing with distress, dealing with life events alongside an IRD) and Theme 2: 'If rheumatology could be interwoven with psychological principles'-the need to attend to the psychological impact of IRDs, alongside the physical impact (sub-themes: priority given to physical health, working together to help patients in distress, how should patient distress be measured?, the need for extra time and resources). CONCLUSION: Distress can be obvious or hidden, cause issues for patients and health professionals and lead to poor engagement with care provision. Health professionals described the powerful link between physical and mental distress. This study suggests psychological support provision should be embedded within the rheumatology team and that patients' emotional wellbeing should be given equal priority to their physical wellbeing.
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Angústia Psicológica , Reumatologia , Humanos , Pesquisa Qualitativa , Ansiedade , DorRESUMO
OBJECTIVE: Various definitions have been proposed for Refractory Disease in people with Rheumatoid Arthritis; however, none were generated for Polyarticular Juvenile Idiopathic Arthritis or involving adult and paediatric multidisciplinary healthcare professionals and patients. The study aim is to redefine Refractory Disease, using Delphi methodology. METHODS: Three rounds of surveys (one nominal group and two online (2019-2020)) to achieve consensus using a predetermined cut-off were conducted voting on: a) name, b) treatment and inflammation, c) symptoms and impact domains, and d) rating of individual components within domains. Theoretical application of the definition was conducted through a scoping exercise. RESULTS: Votes were collected across three rounds from Patients, Researchers and nine multi-disciplinary healthcare professional groups (n = 106). Refractory Inflammatory Arthritis was the most popular name. Regarding treatment and inflammation, these were voted to be kept broad rather than specifying numbers/cut-offs. From 10 domains identified to capture symptoms and disease impact, six domains reached consensus for inclusion: 1) Disease Activity, 2) Joint Involvement, 3) Pain, 4) Fatigue, 5) Functioning and Quality of Life, and 6) Disease-Modifying Anti-Rheumatic Drug Experiences. Within these domains, 18 components, from an initial pool (n = 73), were identified as related and important to capture multi-faceted presentation of Refractory Inflammatory Arthritis, specifically in Rheumatoid Arthritis and Polyarticular Juvenile Idiopathic Arthritis. Feasibility of the revised definition was established (2022-2023) with good utility as was applied to 82% of datasets (n = 61) incorporating 20 outcome measures, with two further measures added to increase its utility and coverage of Pain and Fatigue. CONCLUSION: Refractory Inflammatory Arthritis has been found to be broader than not achieving low disease activity, with wider biopsychosocial components and factors incorporating Persistent Inflammation or Symptoms identified as important. This definition needs further refinement to assess utility as a classification tool to identify patients with unmet needs.
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Artrite Juvenil , Artrite Reumatoide , Humanos , Criança , Artrite Juvenil/tratamento farmacológico , Qualidade de Vida , Artrite Reumatoide/diagnóstico , Artrite Reumatoide/tratamento farmacológico , Dor , Inflamação , Técnica DelphiRESUMO
BACKGROUND: Involving patients and members of the public in healthcare planning is beneficial for many reasons including that the outcomes focus on topics relevant to service users. The National Early Inflammatory Arthritis Audit (NEIAA) aims to improve care quality for patients with inflammatory arthritis. CASE STUDY: This paper presents a case study detailing how the NEIAA Patient Panel worked with NEIAA governance groups, the National Rheumatoid Arthritis Society and the National Axial Spondyloarthritis Society to co-create an outpatient clinic visit framework for rheumatology professionals. A framework was co-created, divided into nine sections: pre-appointment preparation, waiting area (face-to-face appointments), face-to-face consultations, physical examination, establishing a forward plan, post consultation, annual holistic reviews, virtual appointments and key considerations. Providing insight into how the multi-disciplinary team can meet the diverse needs of patients with inflammatory arthritis, this framework now informs the teaching content about people who live with physical and mental disability for Year 3 and 4 undergraduate medical students at King's College London. CONCLUSION: Patients play an important role in helping to address gaps in health service provision in England/Wales. The co-production of a clinic visit framework, informed by their own lived experience and their own expectations can lead to improved and relevant outcomes for the benefit of patients and raises awareness to medical students what matters to patients with physical disabilities when attending outpatient care.
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A diverse and inclusive scientific community is more productive, innovative and impactful, yet ecology and evolutionary biology continues to be dominated by white male faculty. We quantify faculty engagement in activities related to diversity and inclusion and identify factors that either facilitate or hinder participation. Through a nationwide survey, we show that faculty with underrepresented identities disproportionally engage in diversity and inclusion activities, yet such engagement was not considered important for tenure. Faculty perceived time and funding as major limitations, which suggests that institutions should reallocate resources and reconsider how faculty are evaluated to promote shared responsibility in advancing diversity and inclusion.