Models for predicting fire ignition probability in graminoids from boreo-temperate moorland ecosystems

An increase in both the frequency and severity of wildfires in boreo–temperate ecosystems is predicted. Therefore, to develop efficient fire rating systems, the relationship between the fuel moisture content (FMC) of vegetation and ignition thresholds needs to be determined. We developed fire ignition probability models for three graminoid species collected in central England, but common in boreo–temperate ecosystems (Eriophorum angustifolium, E. vaginatum and Molinia caerulea). Specifically, we assessed through laboratory experiments (1) seasonal differences between early spring and late summer in fuel traits such as height, fuel load, fuel bulk density and dead fuel load proportion, and (2) the role of these fuel traits, environmental conditions and dead FMC in determining the probability of ignition. There were seasonal differences in fuel traits among species, with an increase in dead fuel load proportion after winter. The dead FMC was the only variable determining initial sustained ignitions. However, the seasonal differences in dead fuel were not sufficient to affect the FMC threshold at which graminoids start to ignite. Graminoids begin to ignite at high levels of dead FMC, and there are differences between species (from 36.1% to 48.1%). This work assists in improving fire ignition predictions in graminoid-dominated ecosystems by providing warnings based on critical moisture thresholds.</jats:p

Prescribed moorland burning meets good practice guidelines: A monitoring case study using aerial photography in the Peak District, UK

AbstractUpland moors in the UK have been managed for centuries using rotational prescribed-burning, but in recent years there has been contentious debate over its continuing use due to varying effects on moorland ecosystem services. Prescribed-burning should only be carried out using good-practice codes, which include restrictions on the size, location and frequency of burns. Good burning practice is an indicator of management standards and habitat condition in moorland landscapes. However, there has been little attempt to assess management performance with respect to these restrictions. We investigated prescribed-burning on a case-study estate (Howden Moor) in the Peak District National Park from 1988 to 2009 using management maps and aerial photography. The annual area burned (0.9%) was far below recommendations (10%) and patches were in keeping with the target sizes specified (mean±se: 2370±70 m2). The risk of a large or escaped fire was very low, with less than 1% of fires greater than 15,000m2. However, only 28.9% of the total burnable area was burned, leaving the rest unmanaged and accumulating fuel. Future guidelines might recommend the application of prescribed-burning across the range of Calluna vulgaris growth phases, to reduce fuel load and promote biodiversity at the landscape scale. We show that vegetation mapping and aerial photography are an effective method for monitoring prescribed-burning practice on moorlands. The information derived from such monitoring studies should lead to greater confidence in the standard of prescribed-burning and adherence to good-practice guidelines and requirements imposed by statutory authorities

Modelling Carbon Emissions in Calluna vulgaris-Dominated Ecosystems when Prescribed Burning and Wildfires Interact

A present challenge in fire ecology is to optimize management techniques so that ecological services are maximized and C emissions minimized. Here, we modeled the effects of different prescribed-burning rotation intervals and wildfires on carbon emissions (present and future) in British moorlands. Biomass-accumulation curves from four Calluna-dominated ecosystems along a north-south gradient in Great Britain were calculated and used within a matrix-model based on Markov Chains to calculate above-ground biomass-loads and annual C emissions under different prescribed-burning rotation intervals. Additionally, we assessed the interaction of these parameters with a decreasing wildfire return intervals. We observed that litter accumulation patterns varied between sites. Northern sites (colder and wetter) accumulated lower amounts of litter with time than southern sites (hotter and drier). The accumulation patterns of the living vegetation dominated by Calluna were determined by site-specific conditions. The optimal prescribed-burning rotation interval for minimizing annual carbon emissions also differed between sites: the optimal rotation interval for northern sites was between 30 and 50 years, whereas for southern sites a hump-backed relationship was found with the optimal interval either between 8 to 10 years or between 30 to 50 years. Increasing wildfire frequency interacted with prescribed-burning rotation intervals by both increasing C emissions and modifying the optimum prescribed-burning interval for minimum C emission. This highlights the importance of studying site-specific biomass accumulation patterns with respect to environmental conditions for identifying suitable fire-rotation intervals to minimize C emissions.This project was supported financially by the BiodivERsA FIREMAN program (NERC/Defra: NE/G002096/1), the Ecological Continuity Trust and the Heather Trust. VMS was supported by ªBeatriu de PinoÂsº fellowship (2014BP-B 00056) from the Generalitat de Catalunya. JGA was supported by Juan de la Cierva-fellowship (IJCI- 2014-21393)

Increased aridity drives post‐fire recovery of Mediterranean forests towards open shrublands

Recent observations suggest that repeated fires could drive Mediterranean forests to shrublands, hosting flammable vegetation that regrows quickly after fire. This feedback supposedly favours shrubland persistence and may be strengthened in the future by predicted increased aridity. An assessment was made of how fires and aridity in combination modulated the dynamics of Mediterranean ecosystems and whether the feedback could be strong enough to maintain shrubland as an alternative stable state to forest. A model was developed for vegetation dynamics, including stochastic fires and different plant fire‐responses. Parameters were calibrated using observational data from a period up to 100 yr ago, from 77 sites with and without fires in Southeast Spain and Southern France. The forest state was resilient to the separate impact of fires and increased aridity. However, water stress could convert forests into open shrublands by hampering post‐fire recovery, with a possible tipping point at intermediate aridity. Projected increases in aridity may reduce the resilience of Mediterranean forests against fires and drive post‐fire ecosystem dynamics toward open shrubland. The main effect of increased aridity is the limitation of post‐fire recovery. Including plant fire‐responses is thus fundamental when modelling the fate of Mediterranean‐type vegetation under climate‐change scenarios

Health Equity in Pediatric Drug Development: Translating Aspiration into Operation

The concept of health equity—the attainment of the highest possible level of health for all members of society—requires equitable access to all aspects of healthcare, including pediatric drug development. However, many communities are under-represented in pediatric drug development programs. Barriers to participation include geographic, economic, racial/ethnic bias, legal, cultural, linguistic, and other factors. While there is no “one size fits all” approach to addressing these barriers, community engagement and collaboration is recognized by the Centers for Disease Control, the World Health Organization, and other global health organizations as a cornerstone for building a more equitable healthcare system. In this article, we will present case studies of stakeholder and community engagement in clinical research for rare diseases and other areas of healthcare, as examples of strategies and practices for actively involving under-represented communities and fostering their participation in pediatric drug development programs. These studies may serve as templates for facilitating equity in pediatric drug development from aspiration into operation

Global characteristics and outcomes of SARS-CoV-2 infection in children and adolescents with cancer (GRCCC): a cohort study

Background: Previous studies have shown that children and adolescents with COVID-19 generally have mild disease. Children and adolescents with cancer, however, can have severe disease when infected with respiratory viruses. In this study, we aimed to understand the clinical course and outcomes of SARS-CoV-2 infection in children and adolescents with cancer. Methods: We did a cohort study with data from 131 institutions in 45 countries. We created the Global Registry of COVID-19 in Childhood Cancer to capture de-identified data pertaining to laboratory-confirmed SARS-CoV-2 infections in children and adolescents (<19 years) with cancer or having received a haematopoietic stem-cell transplantation. There were no centre-specific exclusion criteria. The registry was disseminated through professional networks through email and conferences and health-care providers were invited to submit all qualifying cases. Data for demographics, oncological diagnosis, clinical course, and cancer therapy details were collected. Primary outcomes were disease severity and modification to cancer-directed therapy. The registry remains open to data collection. Findings: Of 1520 submitted episodes, 1500 patients were included in the study between April 15, 2020, and Feb 1, 2021. 1319 patients had complete 30-day follow-up. 259 (19·9%) of 1301 patients had a severe or critical infection, and 50 (3·8%) of 1319 died with the cause attributed to COVID-19 infection. Modifications to cancer-directed therapy occurred in 609 (55·8%) of 1092 patients receiving active oncological treatment. Multivariable analysis revealed several factors associated with severe or critical illness, including World Bank low-income or lower-middle-income (odds ratio [OR] 5·8 [95% CI 3·8–8·8]; p<0·0001) and upper-middle-income (1·6 [1·2–2·2]; p=0·0024) country status; age 15–18 years (1·6 [1·1–2·2]; p=0·013); absolute lymphocyte count of 300 or less cells per mm3 (2·5 [1·8–3·4]; p<0·0001), absolute neutrophil count of 500 or less cells per mm3 (1·8 [1·3–2·4]; p=0·0001), and intensive treatment (1·8 [1·3–2·3]; p=0·0005). Factors associated with treatment modification included upper-middle-income country status (OR 0·5 [95% CI 0·3–0·7]; p=0·0004), primary diagnosis of other haematological malignancies (0·5 [0·3–0·8]; p=0·0088), the presence of one of more COVID-19 symptoms at the time of presentation (1·8 [1·3–2·4]; p=0·0002), and the presence of one or more comorbidities (1·6 [1·1–2·3]; p=0·020). Interpretation: In this global cohort of children and adolescents with cancer and COVID-19, severe and critical illness occurred in one fifth of patients and deaths occurred in a higher proportion than is reported in the literature in the general paediatric population. Additionally, we found that variables associated with treatment modification were not the same as those associated with greater disease severity. These data could inform clinical practice guidelines and raise awareness globally that children and adolescents with cancer are at high-risk of developing severe COVID-19 illness. Funding: American Lebanese Syrian Associated Charities and the National Cancer Institute.Fil: Mukkada, Sheena. St Jude Children's Research Hospital; Estados UnidosFil: Bhakta, Nickhill. St Jude Children's Research Hospital; Estados UnidosFil: Chantada, Guillermo Luis. Hospital Sant Joan de Déu Barcelona; España. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chen, Yichen. St Jude Children's Research Hospital; Estados UnidosFil: Vedaraju, Yuvanesh. St Jude Children's Research Hospital; Estados UnidosFil: Faughnan, Lane. St Jude Children's Research Hospital; Estados UnidosFil: Homsi, Maysam R. St Jude Children's Research Hospital; Estados UnidosFil: Muniz Talavera, Hilmarie. St Jude Children's Research Hospital; Estados UnidosFil: Ranadive, Radhikesh. St Jude Children's Research Hospital; Estados UnidosFil: Metzger, Monika. St Jude Children's Research Hospital; Estados UnidosFil: Friedrich, Paola. St Jude Children's Research Hospital; Estados UnidosFil: Agulnik, Asya. St Jude Children's Research Hospital; Estados UnidosFil: Jeha, Sima. St Jude Children's Research Hospital; Estados UnidosFil: Lam, Catherine G.. St Jude Children's Research Hospital; Estados UnidosFil: Dalvi, Rashmi. Bombay Hospital And Medical Research Centre; IndiaFil: Hessissen, Laila. Universite Mohammed V. Rabat; Otros paises de ÁfricaFil: Moreira, Daniela. St Jude Children's Research Hospital; Estados UnidosFil: Santana, Victor M. St Jude Children's Research Hospital; Estados UnidosFil: Sullivan, Michael. University of Melbourne; AustraliaFil: Bouffet, Eric. University Of Toronto. Hospital For Sick Children; CanadáFil: Caniza, Miguela A.. St Jude Children's Research Hospital; Estados UnidosFil: Devidas, Meenakshi. St Jude Children's Research Hospital; Estados UnidosFil: Pritchard Jones, Kathy. UCL Great Ormond Street Institute of Child Health; Reino UnidoFil: Rodriguez Galindo, Carlos. St Jude Children's Research Hospital; Estados Unido

Global characteristics and outcomes of SARS-CoV-2 infection in children and adolescents with cancer (GRCCC): a cohort study

Background: Previous studies have shown that children and adolescents with COVID-19 generally have mild disease. Children and adolescents with cancer, however, can have severe disease when infected with respiratory viruses. In this study, we aimed to understand the clinical course and outcomes of SARS-CoV-2 infection in children and adolescents with cancer. Methods: We did a cohort study with data from 131 institutions in 45 countries. We created the Global Registry of COVID-19 in Childhood Cancer to capture de-identified data pertaining to laboratory-confirmed SARS-CoV-2 infections in children and adolescents (<19 years) with cancer or having received a haematopoietic stem-cell transplantation. There were no centre-specific exclusion criteria. The registry was disseminated through professional networks through email and conferences and health-care providers were invited to submit all qualifying cases. Data for demographics, oncological diagnosis, clinical course, and cancer therapy details were collected. Primary outcomes were disease severity and modification to cancer-directed therapy. The registry remains open to data collection. Findings: Of 1520 submitted episodes, 1500 patients were included in the study between April 15, 2020, and Feb 1, 2021. 1319 patients had complete 30-day follow-up. 259 (19·9%) of 1301 patients had a severe or critical infection, and 50 (3·8%) of 1319 died with the cause attributed to COVID-19 infection. Modifications to cancer-directed therapy occurred in 609 (55·8%) of 1092 patients receiving active oncological treatment. Multivariable analysis revealed several factors associated with severe or critical illness, including World Bank low-income or lower-middle-income (odds ratio [OR] 5·8 [95% CI 3·8–8·8]; p<0·0001) and upper-middle-income (1·6 [1·2–2·2]; p=0·0024) country status; age 15–18 years (1·6 [1·1–2·2]; p=0·013); absolute lymphocyte count of 300 or less cells per mm3 (2·5 [1·8–3·4]; p<0·0001), absolute neutrophil count of 500 or less cells per mm3 (1·8 [1·3–2·4]; p=0·0001), and intensive treatment (1·8 [1·3–2·3]; p=0·0005). Factors associated with treatment modification included upper-middle-income country status (OR 0·5 [95% CI 0·3–0·7]; p=0·0004), primary diagnosis of other haematological malignancies (0·5 [0·3–0·8]; p=0·0088), the presence of one of more COVID-19 symptoms at the time of presentation (1·8 [1·3–2·4]; p=0·0002), and the presence of one or more comorbidities (1·6 [1·1–2·3]; p=0·020). Interpretation: In this global cohort of children and adolescents with cancer and COVID-19, severe and critical illness occurred in one fifth of patients and deaths occurred in a higher proportion than is reported in the literature in the general paediatric population. Additionally, we found that variables associated with treatment modification were not the same as those associated with greater disease severity. These data could inform clinical practice guidelines and raise awareness globally that children and adolescents with cancer are at high-risk of developing severe COVID-19 illness. Funding: American Lebanese Syrian Associated Charities and the National Cancer Institute.Fil: Mukkada, Sheena. St Jude Children's Research Hospital; Estados UnidosFil: Bhakta, Nickhill. St Jude Children's Research Hospital; Estados UnidosFil: Chantada, Guillermo Luis. Hospital Sant Joan de Déu Barcelona; España. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chen, Yichen. St Jude Children's Research Hospital; Estados UnidosFil: Vedaraju, Yuvanesh. St Jude Children's Research Hospital; Estados UnidosFil: Faughnan, Lane. St Jude Children's Research Hospital; Estados UnidosFil: Homsi, Maysam R. St Jude Children's Research Hospital; Estados UnidosFil: Muniz Talavera, Hilmarie. St Jude Children's Research Hospital; Estados UnidosFil: Ranadive, Radhikesh. St Jude Children's Research Hospital; Estados UnidosFil: Metzger, Monika. St Jude Children's Research Hospital; Estados UnidosFil: Friedrich, Paola. St Jude Children's Research Hospital; Estados UnidosFil: Agulnik, Asya. St Jude Children's Research Hospital; Estados UnidosFil: Jeha, Sima. St Jude Children's Research Hospital; Estados UnidosFil: Lam, Catherine G.. St Jude Children's Research Hospital; Estados UnidosFil: Dalvi, Rashmi. Bombay Hospital And Medical Research Centre; IndiaFil: Hessissen, Laila. Universite Mohammed V. Rabat; Otros paises de ÁfricaFil: Moreira, Daniela. St Jude Children's Research Hospital; Estados UnidosFil: Santana, Victor M. St Jude Children's Research Hospital; Estados UnidosFil: Sullivan, Michael. University of Melbourne; AustraliaFil: Bouffet, Eric. University Of Toronto. Hospital For Sick Children; CanadáFil: Caniza, Miguela A.. St Jude Children's Research Hospital; Estados UnidosFil: Devidas, Meenakshi. St Jude Children's Research Hospital; Estados UnidosFil: Pritchard Jones, Kathy. UCL Great Ormond Street Institute of Child Health; Reino UnidoFil: Rodriguez Galindo, Carlos. St Jude Children's Research Hospital; Estados Unido