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Record-breaking summer forest fires have become a regular occurrence in California. Observations indicate a fivefold increase in summer burned area (BA) in forests in northern and central California during 1996 to 2021 relative to 1971 to 1995. While the higher temperature and increased dryness have been suggested to be the leading causes of increased BA, the extent to which BA changes are due to natural variability or anthropogenic climate change remains unresolved. Here, we develop a climate-driven model of summer BA evolution in California and combine it with natural-only and historical climate simulations to assess the importance of anthropogenic climate change on increased BA. Our results indicate that nearly all the observed increase in BA is due to anthropogenic climate change as historical model simulations accounting for anthropogenic forcing yield 172% (range 84 to 310%) more area burned than simulations with natural forcing only. We detect the signal of combined historical forcing on the observed BA emerging in 2001 with no detectable influence of the natural forcing alone. In addition, even when considering fuel limitations from fire-fuel feedbacks, a 3 to 52% increase in BA relative to the last decades is expected in the next decades (2031 to 2050), highlighting the need for proactive adaptations.
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Global outdoor biomass burning is a major contributor to air pollution, especially in low- and middle-income countries. Recent years have witnessed substantial changes in the extent of biomass burning, including large declines in Africa. However, direct evidence of the contribution of biomass burning to global health outcomes remains limited. Here, we use georeferenced data on more than 2 million births matched to satellite-derived burned area exposure to estimate the burden of biomass fires on infant mortality. We find that each additional square kilometer of burning is associated with nearly 2% higher infant mortality in nearby downwind locations. The share of infant deaths attributable to biomass fires has increased over time due to the rapid decline in other important causes of infant death. Applying our model estimates across harmonized district-level data covering 98% of global infant deaths, we find that exposure to outdoor biomass burning was associated with nearly 130,000 additional infant deaths per year globally over our 2004 to 2018 study period. Despite the observed decline in biomass burning in Africa, nearly 75% of global infant deaths due to burning still occur in Africa. While fully eliminating biomass burning is unlikely, we estimate that even achievable reductions-equivalent to the lowest observed annual burning in each location during our study period-could have avoided more than 70,000 infant deaths per year globally since 2004.
Assuntos
Poluentes Atmosféricos , Poluição do Ar , Incêndios , Lactente , Humanos , Biomassa , Mortalidade Infantil , Morte do Lactente , Mortalidade , Poluentes Atmosféricos/análiseRESUMO
SignificanceRecord-setting fires in the western United States over the last decade caused severe air pollution, loss of human life, and property damage. Enhanced drought and increased biomass in a warmer climate may fuel larger and more frequent wildfires in the coming decades. Applying an empirical statistical model to fires projected by Earth System Models including climate-ecosystem-socioeconomic interactions, we show that fine particulate pollution over the US Pacific Northwest could double to triple during late summer to fall by the late 21st century under intermediate- and low-mitigation scenarios. The historic fires and resulting pollution extremes of 2017-2020 could occur every 3 to 5 y under 21st-century climate change, posing challenges for air quality management and threatening public health.
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Poluição do Ar , Incêndios , Incêndios Florestais , Poluição do Ar/análise , Mudança Climática , Ecossistema , Humanos , Minerais , Saúde Pública , Estados UnidosRESUMO
STUDY QUESTION: Can illegal discharge of toxic waste into the environment induce a new condition of morpho-epigenetic pathozoospermia in normozoospermic young men? SUMMARY ANSWER: Toxic environmental contaminants promote the onset of a new pathozoospermic condition in young normozoospermic men, consisting of morpho-functional defects and a sperm increase of low-quality circular RNA (circRNA) cargo, tightly linked to contaminant bioaccumulation in seminal plasma. WHAT IS KNOWN ALREADY: Epidemiological findings have reported several reproductive anomalies depending on exposure to contaminants discharged into the environment, such as germ cell apoptosis, steroidogenesis defects, oxidative stress induction, blood-testis barrier dysfunctions, and poor sperm quality onset. In this scenario, a vast geographical area located in Campania, Italy, called the 'Land of Fires', has been associated with an excessive illegal discharge of toxic waste into the environment, negatively impacting human health, including male reproductive functions. STUDY DESIGN, SIZE, DURATION: Semen samples were obtained from healthy normozoospermic men divided into two experimental groups, consisting of men living in the 'Land of Fires' (LF; n = 80) or not (CTRL; n = 80), with age ranging from 25 to 40 years. The study was carried out following World Health Organization guidelines. PARTICIPANTS/MATERIALS, SETTING, METHODS: Quality parameters of semen from CTRL- and LF-normozoospermic men were evaluated by computer-assisted semen analysis; high-quality spermatozoa from CTRL and LF groups (n = 80 for each experimental group) were obtained using a 80-40% discontinuous centrifugation gradient. Seminal plasma was collected following centrifugation and used for the dosage of chemical elements, dioxins and steroid hormones by liquid chromatography with tandem mass spectrometry. Sperm morpho-functional investigations (cellular morphology, acrosome maturation, IZUMO1 fertility marker analysis, plasma membrane lipid state, oxidative stress) were assessed on the purified high-quality spermatozoa fraction by immunochemistry/immunofluorescence and western blot analyses. Sperm circRNA cargo was evaluated by quantitative RT-PCR, and the physical interaction among circRNAs and fused in sarcoma (FUS) protein was detected using an RNA-binding protein immunoprecipitation assay. Protein immunoprecipitation experiments were carried out to demonstrate FUS/p-300 protein interaction in sperm cells. Lastly, in vitro lead (Pb) treatment of high-quality spermatozoa collected from normozoospermic controls was used to investigate a correlation between Pb accumulation and onset of the morpho-epigenetic pathozoospermic phenotype. MAIN RESULTS AND THE ROLE OF CHANCE: Several morphological defects were identified in LF-spermatozoa, including: a significant increase (P < 0.05 versus CTRL) in the percentage of spermatozoa characterized by structural defects in sperm head and tail; and a high percentage (P < 0.01) of peanut agglutinin and IZUMO1 null signal cells. In agreement with these data, abnormal steroid hormone levels in LF seminal plasma suggest a premature acrosome reaction onset in LF-spermatozoa. The abnormal immunofluorescence signals of plasma membrane cholesterol complexes/lipid rafts organization (Filipin III and Flotillin-1) and of oxidative stress markers [3-nitrotyrosine and 3-nitrotyrosine and 4-hydroxy-2-nonenal] observed in LF-spermatozoa and associated with a sperm motility reduction (P < 0.01), demonstrated an affected membrane fluidity, potentially impacting sperm motility. Bioaccumulation of heavy metals and dioxins occurring in LF seminal plasma and a direct correlation between Pb and deregulated circRNAs related to high- and low-sperm quality was also revealed. In molecular terms, we demonstrated that Pb bioaccumulation promoted FUS hyperacetylation via physical interaction with p-300 and, in turn, its shuttling from sperm head to tail, significantly enhancing (P < 0.01 versus CTRL) the endogenous backsplicing of sperm low-quality circRNAs in LF-spermatozoa. LIMITATIONS, REASONS FOR CAUTION: Participants were interviewed to better understand their area of origin, their eating habits as well as their lifestyles, however any information incorrectly communicated or voluntarily omitted that could potentially compromise experimental group determination cannot be excluded. A possible association between seminal Pb content and other heavy metals in modulating sperm quality should be explored further. Future investigations will be performed in order to identify potential synergistic or anti-synergistic effects of heavy metals on male reproduction. WIDER IMPLICATIONS OF THE FINDINGS: Our study provides new findings regarding the effects of environmental contaminants on male reproduction, highlighting how a sperm phenotype classified as normozoospermic may potentially not match with a healthy morpho-functional and epigenetic one. Overall, our results improve the knowledge to allow a proper assessment of sperm quality through circRNAs as biomarkers to select spermatozoa with high morpho-epigenetic quality to use for ART. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by 'Convenzione Azienda Sanitaria Locale (ASL) Caserta, Regione Campania' (ASL CE Prot. N. 1217885/DIR. GE). The authors have no conflict of interest to declare. TRIAL REGISTRATION NUMBER: N/A.
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Metais Pesados , RNA Circular , Análise do Sêmen , Espermatozoides , Masculino , Humanos , Itália , Adulto , Espermatozoides/metabolismo , Espermatozoides/efeitos dos fármacos , RNA Circular/genética , RNA Circular/metabolismo , Metais Pesados/toxicidade , Metais Pesados/análise , Poluentes Ambientais/toxicidade , Exposição Ambiental/efeitos adversos , Motilidade dos Espermatozoides/efeitos dos fármacosRESUMO
Wildfires directly emit 2.1 Pg carbon (C) to the atmosphere annually. The net effect of wildfires on the C cycle, however, involves many interacting source and sink processes beyond these emissions from combustion. Among those, the role of post-fire enhanced soil organic carbon (SOC) erosion as a C sink mechanism remains essentially unquantified. Wildfires can greatly enhance soil erosion due to the loss of protective vegetation cover and changes to soil structure and wettability. Post-fire SOC erosion acts as a C sink when off-site burial and stabilization of C eroded after a fire, together with the on-site recovery of SOC content, exceed the C losses during its post-fire transport. Here we synthesize published data on post-fire SOC erosion and evaluate its overall potential to act as longer-term C sink. To explore its quantitative importance, we also model its magnitude at continental scale using the 2017 wildfire season in Europe. Our estimations show that the C sink ability of SOC water erosion during the first post-fire year could account for around 13% of the C emissions produced by wildland fires. This indicates that post-fire SOC erosion is a quantitatively important process in the overall C balance of fires and highlights the need for more field data to further validate this initial assessment.
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Ciclo do Carbono , Incêndios Florestais , Erosão do Solo , Carbono/análise , Europa (Continente) , Solo/química , Sequestro de Carbono , Incêndios , Modelos TeóricosRESUMO
The increasing frequency and severity of human-caused fires likely have deleterious effects on species distribution and persistence. In 2020, megafires in the Brazilian Pantanal burned 43% of the biome's unburned area and resulted in mass mortality of wildlife. We investigated changes in habitat use or occupancy for an assemblage of eight mammal species in Serra do Amolar, Brazil, following the 2020 fires using a pre- and post-fire camera trap dataset. Additionally, we estimated the density for two naturally marked species, jaguars Panthera onca and ocelots Leopardus pardalis. Of the eight species, six (ocelots, collared peccaries Dicotyles tajacu, giant armadillos Priodontes maximus, Azara's agouti Dasyprocta azarae, red brocket deer Mazama americana, and tapirs Tapirus terrestris) had declining occupancy following fires, and one had stable habitat use (pumas Puma concolor). Giant armadillo experienced the most precipitous decline in occupancy from 0.431 ± 0.171 to 0.077 ± 0.044 after the fires. Jaguars were the only species with increasing habitat use, from 0.393 ± 0.127 to 0.753 ± 0.085. Jaguar density remained stable across years (2.8 ± 1.3, 3.7 ± 1.3, 2.6 ± 0.85/100 km2), while ocelot density increased from 13.9 ± 3.2 to 16.1 ± 5.2/100 km2. However, the low number of both jaguars and ocelots recaptured after the fire period suggests that immigration may have sustained the population. Our results indicate that the megafires will have significant consequences for species occupancy and fitness in fire-affected areas. The scale of megafires may inhibit successful recolonization, thus wider studies are needed to investigate population trends.
A crescente frequência e gravidade dos incêndios causados pelo homem provavelmente terão efeitos deletérios na distribuição e persistência das espécies. Em 2020, mega incêndios no Pantanal brasileiro queimaram 43% do bioma e resultaram na mortalidade em massa da vida selvagem. Nós investigamos mudanças no uso ou ocupação do habitat para uma comunidade de oito espécies de mamíferos na Serra do Amolar, Brasil, após os incêndios de 2020, usando um conjunto de dados de armadilhas fotográficas instaladas no período pré e pósfogo. Além disso, estimamos a densidade de duas espécies naturalmente marcadas, a onçapintada Panthera onca e a jaguatirica Leopardus pardalis. Das oito espécies, seis (a jaguatirica, o cateto Dicotyles tajacu, o tatucanastra Priodontes maximus, a cutia Dasyprocta azarae, o veado mateiro Mazama americana e a anta Tapirus terrestris) tiveram ocupação reduzida após os incêndios, e uma teve uso de habitat estável (a onçaparda, Puma concolor). O tatucanastra apresentou o declínio mais acentuado na ocupação após os incêndios de 0,431 ± 0,171 para 0,077 ± 0,044. A onçapintada foi a única espécie com uso crescente de habitat, de 0,393 ± 0,127 para 0,753 ± 0,085. A densidade da onçapintada permaneceu estável ao longo dos anos (2,8 ± 1,3, 3,7 ± 1,3, 2,6 ± 0,85/100 km2), enquanto a densidade da jaguatirica aumentou de 13,9 ± 3,2 para 16,1 ± 5,2/100 km2. No entanto, o baixo número de onçaspintadas e jaguatiricas recapturadas após o período do fogo sugere que a imigração pode ter sustentado as populações. Nossos resultados indicam que os mega incêndios terão consequências significativas para a ocupação e resiliência das espécies nas áreas afetadas pelo fogo. A escala dos mega incêndios pode inibir uma recolonização bemsucedida, pelo que são necessários estudos mais amplos para investigar as tendências populacionais.
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Ecossistema , Animais , Brasil , Mamíferos/fisiologia , Dinâmica Populacional , Incêndios , Densidade Demográfica , Incêndios FlorestaisRESUMO
FIRES and NORSE are clinical presentations of disease processes that, to date, remain unexplained without an established etiology in many cases. Neuroinflammation is thought to have paramount importance in the genesis of these conditions. We hereby report the clinical, EEG, brain MRI, and genetic findings of a nuclear family with recurrent febrile-related encephalopathy with refractory de novo Status Epilepticus. Whole-exome sequencing (WES) revealed a homozygous p.C105W pathogenic variant of FADD gene (FAS-associated protein with death domain, FADD), known to cause ultrarare forms of autosomal recessive immunodeficiency that could be associated with variable degrees of lymphoproliferation, cerebral atrophy, and cardiac abnormalities. The FADD-related conditions disrupt FAS-mediated apoptosis and can cause a clinical picture with the characteristics of FIRES. This observation is important because, on one hand, it increases the number of reported patients with FADD deficiency, showing that this disorder may present variable expressivity, and on the other hand, it demonstrates a genetic cause of FIRES involving a cell-mediated inflammation regulatory pathway. This finding supports early treatment with immunomodulatory therapy and could represent a new avenue of research in the field of new onset refractory status epilepticus and related conditions.
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Proteína de Domínio de Morte Associada a Fas , Humanos , Proteína de Domínio de Morte Associada a Fas/genética , Feminino , Masculino , Convulsões Febris/genética , Estado Epiléptico/genética , Estado Epiléptico/etiologia , Linhagem , Sequenciamento do Exoma , Febre/genética , Febre/complicações , Síndromes Epilépticas/genética , EletroencefalografiaRESUMO
Several pieces of evidence suggest immune dysregulation could trigger the onset and modulate sequelae of new onset refractory status epilepticus (NORSE), including its subtype with prior fever known as febrile infection-related epilepsy syndrome (FIRES). Consensus-driven recommendations have been established to guide the initiation of first- and second-line immunotherapies in these patients. Here, we review the literature to date on second-line immunotherapy for NORSE/FIRES, presenting results from 28 case reports and series describing the use of anakinra, tocilizumab, or intrathecal dexamethasone in 75 patients with NORSE. Among them, 52 patients were managed with anakinra, 21 with tocilizumab, and eight with intrathecal dexamethasone. Most had elevated serum or cerebrospinal fluid cytokine levels at treatment initiation. Treatments were predominantly initiated during the acute phase of the disease (92%) and resulted, within the first 2 weeks, in seizure control for up to 73% of patients with anakinra, 70% with tocilizumab, and 50% with intrathecal dexamethasone. Cytokine levels decreased after treatment for most patients. Anakinra and intrathecal dexamethasone were mainly initiated in children with FIRES, whereas tocilizumab was more frequently prescribed for adults, with or without a prior febrile infection. There was no clear correlation between the response to treatment and the time to initiate the treatment. Most patients experienced long-term disability and drug-resistant post-NORSE epilepsy. Initiation of second-line immunotherapies during status epilepticus (SE) had no clear effect on the emergence of post-NORSE epilepsy or long-term functional outcomes. In a small number of cases, the initiation of anakinra or tocilizumab several years after SE onset resulted in a reduction of seizure frequency for 67% of patients. These data highlight the potential utility of anakinra, tocilizumab, and intrathecal dexamethasone in patients with NORSE. There continues to be interest in the utilization of early cytokine measurements to guide treatment selection and response. Prospective studies are necessary to understand the role of early immunomodulation and its associations with epilepsy and functional outcomes.
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Imunoterapia , Proteína Antagonista do Receptor de Interleucina 1 , Estado Epiléptico , Humanos , Estado Epiléptico/tratamento farmacológico , Estado Epiléptico/imunologia , Imunoterapia/métodos , Proteína Antagonista do Receptor de Interleucina 1/uso terapêutico , Dexametasona/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Epilepsia Resistente a Medicamentos/tratamento farmacológico , Epilepsia Resistente a Medicamentos/imunologia , Adulto , Feminino , Masculino , CriançaRESUMO
In 2014, a fire at an open cut coalmine in regional Victoria, Australia burned for 6 weeks. Residents of the nearby town of Morwell were exposed to smoke, which included high levels of fine particulate matter (PM2.5). We investigated whether the long-term effects of PM2.5 on respiratory health were moderated by diet quality. A cross-sectional analysis was conducted of data collected 8.5 years after the mine fire from 282 residents of Morwell and 166 residents from the nearby unexposed town of Sale. Primary outcomes were respiratory symptoms. Exposure was coalmine fire-related PM2.5 and diet quality was assessed as Australian Recommended Food Score (ARFS) derived using the Australian Eating Survey (AES). The moderating effect of diet quality on respiratory outcomes associated with PM2.5 was assessed using logistic regression models, adjusting for potential confounders. Diet quality was poor in this sample, with 60% in the lowest category of overall diet quality. Overall diet quality and fruit and vegetable quality significantly attenuated the association between PM2.5 and prevalence of chronic cough and phlegm. Sauce/condiment intake was associated with a greater effect of PM2.5 on COPD prevalence. No other moderating effects were significant. The moderating effects of overall diet quality and vegetable and fruit intake aligned with a priori hypotheses, suggesting potential protective benefits. While more evidence is needed to confirm these findings, improving diets, especially fruit and vegetable intake, may provide some protection against the effects of smoke exposure from fire events.
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Dieta , Material Particulado , Humanos , Material Particulado/análise , Masculino , Feminino , Pessoa de Meia-Idade , Estudos Transversais , Vitória/epidemiologia , Idoso , Adulto , Incêndios , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Exposição Ambiental/efeitos adversos , Minas de Carvão , Doenças Respiratórias/epidemiologia , Doenças Respiratórias/induzido quimicamenteRESUMO
BACKGROUND AND AIM: There are few long-term studies of respiratory health effects of landscape fires, despite increasing frequency and intensity due to climate change. We investigated the association between exposure to coal mine fire PM2.5 and fractional exhaled nitric oxide (FeNO) concentration 7.5 years later. METHODS: Adult residents of Morwell, who were exposed to the 2014 Hazelwood mine fire over 6 weeks, and unexposed residents of Sale, participated in the Hazelwood Health Study Respiratory Stream in 2021, including measurements of FeNO concentration, a marker of eosinophilic airway inflammation. Individual exposure to coal mine fire PM2.5 was modelled and mapped to time-location diaries. The effect of exposure to PM2.5 on log-transformed FeNO in exhaled breath was investigated using multivariate linear regression models in the entire sample and stratified by potentially vulnerable subgroups. RESULTS: A total of 326 adults (mean age: 57 years) had FeNO measured. The median FeNO level (interquartile range [IQR]) was 17.5 [15.0] ppb, and individual daily exposure to coal mine fire PM2.5 was 7.2 [13.8] µg/m3. We did not identify evidence of association between coal mine fire PM2.5 exposure and FeNO in the general adult sample, nor in various potentially vulnerable subgroups. The point estimates were consistently close to zero in the total sample and subgroups. CONCLUSION: Despite previous short-term impacts on FeNO and respiratory health outcomes in the medium term, we found no evidence that PM2.5 from the Hazelwood coal mine fire was associated with any long-term impact on eosinophilic airway inflammation measured by FeNO levels.
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Minas de Carvão , Óxido Nítrico , Material Particulado , Humanos , Masculino , Material Particulado/análise , Material Particulado/efeitos adversos , Feminino , Pessoa de Meia-Idade , Óxido Nítrico/análise , Óxido Nítrico/metabolismo , Idoso , Adulto , Incêndios , Exposição Ambiental/efeitos adversos , Testes Respiratórios , Modelos Lineares , Expiração , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/efeitos adversosRESUMO
With humanity facing an unprecedented climate crisis, the conservation of tropical forests has never been so important - their vast terrestrial carbon stocks can be turned into emissions by climatic and human disturbances. However, the duration of these effects is poorly understood, and it is unclear whether impacts are amplified in forests with a history of previous human disturbance. Here, we focus on the Amazonian epicenter of the 2015-16 El Niño, a region that encompasses 1.2% of the Brazilian Amazon. We quantify, at high temporal resolution, the impacts of an extreme El Niño (EN) drought and extensive forest fires on plant mortality and carbon loss in undisturbed and human-modified forests. Mortality remained higher than pre-El Niño levels for 36 mo in EN-drought-affected forests and for 30 mo in EN-fire-affected forests. In EN-fire-affected forests, human disturbance significantly increased plant mortality. Our investigation of the ecological and physiological predictors of tree mortality showed that trees with lower wood density, bark thickness and leaf nitrogen content, as well as those that experienced greater fire intensity, were more vulnerable. Across the region, the 2015-16 El Niño led to the death of an estimated 2.5 ± 0.3 billion stems, resulting in emissions of 495 ± 94 Tg CO2 Three years after the El Niño, plant growth and recruitment had offset only 37% of emissions. Our results show that limiting forest disturbance will not only help maintain carbon stocks, but will also maximize the resistance of Amazonian forests if fires do occur.
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Ciclo do Carbono , Secas , El Niño Oscilação Sul , Agricultura Florestal/estatística & dados numéricos , Fenômenos Fisiológicos Vegetais , Árvores/crescimento & desenvolvimento , Incêndios Florestais , Brasil , Florestas , HumanosRESUMO
Fires are a major contributor to atmospheric budgets of greenhouse gases and aerosols, affect soils and vegetation properties, and are a key driver of land use change. Since the 1990s, global burned area (BA) estimates based on satellite observations have provided critical insights into patterns and trends of fire occurrence. However, these global BA products are based on coarse spatial-resolution sensors, which are unsuitable for detecting small fires that burn only a fraction of a satellite pixel. We estimated the relevance of those small fires by comparing a BA product generated from Sentinel-2 MSI (Multispectral Instrument) images (20-m spatial resolution) with a widely used global BA product based on Moderate Resolution Imaging Spectroradiometer (MODIS) images (500 m) focusing on sub-Saharan Africa. For the year 2016, we detected 80% more BA with Sentinel-2 images than with the MODIS product. This difference was predominately related to small fires: we observed that 2.02 Mkm2 (out of a total of 4.89 Mkm2) was burned by fires smaller than 100 ha, whereas the MODIS product only detected 0.13 million km2 BA in that fire-size class. This increase in BA subsequently resulted in increased estimates of fire emissions; we computed 31 to 101% more fire carbon emissions than current estimates based on MODIS products. We conclude that small fires are a critical driver of BA in sub-Saharan Africa and that including those small fires in emission estimates raises the contribution of biomass burning to global burdens of (greenhouse) gases and aerosols.
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Poluentes Atmosféricos/análise , Carbono/análise , Monitoramento Ambiental , Imagens de Satélites , Incêndios Florestais , África , Monitoramento Ambiental/métodos , Incêndios , Estações do AnoRESUMO
Biomass burning (BB) is a very important emission source that significantly adversely impacts regional air quality. BB produces a large number of primary organic aerosol (POA) and black carbon (BC). Besides, BB also provides many precursors for secondary organic aerosol (SOA) generation. In this work, the ratio of levoglucosan (LG) to organic carbon (OC) and the fire hotspots map was used to identify the open biomass burning (OBB) events, which occurred in two representative episodes, October 13 to November 30, 2020, and April 1 to April 30, 2021. The ratio of organic aerosol (OA) to reconstructed PM2.5 concentration (PM2.5*) increased with the increase of LG/OC. When LG/OC ratio is higher than 0.03, the highest OA/PM2.5* ratio can reach 80%, which means the contribution of OBB to OA is crucial. According to the ratio of LG to K+, LG to mannosan (MN) and the regional characteristics of Longfengshan, it can be determined that the crop residuals are the main fuel. The occurrence of OBB coincides with farmers' preferred choices, i.e., burning biomass in "bright weather". The "bright weather" refers to the meteorological conditions with high temperature, low humidity, and without rain. Meteorological factors indirectly affect regional biomass combustion pollution by influencing farmers' active choices.
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Poluentes Atmosféricos , Material Particulado , Material Particulado/análise , Poluentes Atmosféricos/análise , Biomassa , Estações do Ano , Monitoramento Ambiental , China , Carbono/análise , Conceitos Meteorológicos , Aerossóis/análiseRESUMO
AbstractAcross plant communities worldwide, fire regimes reflect a combination of climatic factors and plant characteristics. To shed new light on the complex relationships between plant characteristics and fire regimes, we developed a new conceptual mechanistic model that includes plant competition, stochastic fires, and fire-vegetation feedback. Considering a single standing plant functional type, we observed that highly flammable and slowly colonizing plants can persist only when they have a strong fire response, while fast colonizing and less flammable plants can display a larger range of fire responses. At the community level, the fire response of the strongest competitor determines the existence of alternative ecological states (i.e., different plant communities) under the same environmental conditions. Specifically, when the strongest competitor had a very strong fire response, such as in Mediterranean forests, only one ecological state could be achieved. Conversely, when the strongest competitor was poorly fire adapted, alternative ecological states emerged-for example, between tropical humid savannas and forests or between different types of boreal forests. These findings underline the importance of including the plant fire response when modeling fire ecosystems, for example, to predict the vegetation response to invasive species or to climate change.
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Ecossistema , Incêndios , Florestas , Mudança Climática , Espécies IntroduzidasRESUMO
Fire seasons have become increasingly variable and extreme due to changing climatological, ecological, and social conditions. Earth observation data are critical for monitoring fires and their impacts. Herein, we present a whole-system framework for identifying and synthesizing fire monitoring objectives and data needs throughout the life cycle of a fire event. The four stages of fire monitoring using Earth observation data include the following: (1) pre-fire vegetation inventories, (2) active-fire monitoring, (3) post-fire assessment, and (4) multi-scale synthesis. We identify the challenges and opportunities associated with current approaches to fire monitoring, highlighting four case studies from North American boreal, montane, and grassland ecosystems. While the case studies are localized to these ecosystems and regional contexts, they provide insights for others experiencing similar monitoring challenges worldwide. The field of remote sensing is experiencing a rapid proliferation of new data sources, providing observations that can inform all aspects of our fire monitoring framework; however, significant challenges for meeting fire monitoring objectives remain. We identify future opportunities for data sharing and rapid co-development of information products using cloud computing that benefits from open-access Earth observation and other geospatial data layers.
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Incêndios , Incêndios Florestais , Ecossistema , FlorestasRESUMO
New onset refractory status epilepticus (NORSE) is a rare and devastating condition occurring in a previously healthy patient. It is called febrile infection-related epilepsy syndrome (FIRES) when preceded by a febrile infection. It often leads to intensive care treatment, including antiseizure drugs in combination with anesthetic agents, and sometimes ketogenic diet. The mortality rate is high, and severe epileptic and neuropsychiatric sequelae are usually observed. Based on the possible role of neuroinflammation, intravenous immunoglobulin, corticosteroids, and immunomodulatory treatment (anti-IL1, IL6) can be added. We describe here a child and a young adult with FIRES, both treated with tocilizumab. We observed a rapid positive response on the status epilepticus and good tolerance, but different neurological outcomes for our two patients. Further prospective studies may be necessary both to confirm the efficacy and the safety of this promising treatment and to optimize the immunomodulatory strategy in FIRES/NORSE.
Assuntos
Epilepsia Resistente a Medicamentos , Encefalite , Síndromes Epilépticas , Estado Epiléptico , Humanos , Criança , Adulto Jovem , Estudos Prospectivos , Convulsões , Estado Epiléptico/complicações , Estado Epiléptico/tratamento farmacológico , Epilepsia Resistente a Medicamentos/complicações , Epilepsia Resistente a Medicamentos/tratamento farmacológico , Doença Aguda , Síndromes Epilépticas/complicações , Síndromes Epilépticas/tratamento farmacológicoRESUMO
The etiology of new-onset refractory status epilepticus (NORSE), including its subtype with prior fever known as FIRES (febrile infection-related epilepsy syndrome), remains uncertain. Several arguments suggest that NORSE is a disorder of immunity, likely post-infectious. Consequently, seasonal occurrence might be anticipated. Herein we investigated if seasonality is a notable factor regarding NORSE presentation. We combined four different data sets with a total of 342 cases, all from the northern hemisphere, and 62% adults. The incidence of NORSE cases differed between seasons (p = .0068) and was highest in the summer (32.2%) (p = .0022) and lowest in the spring (19.0%, p = .010). Although both FIRES and non-FIRES cases occurred most commonly during the summer, there was a trend toward FIRES cases being more likely to occur in the winter than non-FIRES cases (OR 1.62, p = .071). The seasonality of NORSE cases differed according to the etiology (p = .024). NORSE cases eventually associated with autoimmune/paraneoplastic encephalitis occurred most frequently in the summer (p = .032) and least frequently in the winter (p = .047), whereas there was no seasonality for cryptogenic cases. This study suggests that NORSE overall and NORSE related to autoimmune/paraneoplastic encephalitis are more common in the summer, but that there is no definite seasonality in cryptogenic cases.
Assuntos
Epilepsia Resistente a Medicamentos , Encefalite , Estado Epiléptico , Adulto , Humanos , Estado Epiléptico/etiologia , Convulsões/complicações , Encefalite/complicações , Epilepsia Resistente a Medicamentos/epidemiologia , Epilepsia Resistente a Medicamentos/complicações , Autoanticorpos , Doença AgudaRESUMO
Wildfires and land use play a central role in the long-term carbon (C) dynamics of forested ecosystems of the United States. Understanding their linkages with changes in biomass, resource use, and consumption in the context of climate change mitigation is crucial. We reconstruct a long-term C balance of forests in the contiguous U.S. using historical reports, satellite data, and other sources at multiple scales (national scale 1926-2017, regional level 1941-2017) to disentangle the drivers of biomass C stock change. The balance includes removals of forest biomass by fire, by extraction of woody biomass, by forest grazing, and by biomass stock change, their sum representing the net ecosystem productivity (NEP). Nationally, the total forest NEP increased for most of the 20th century, while fire, harvest and grazing reduced total forest stocks on average by 14%, 51%, and 6%, respectively, resulting in a net increase in C stock density of nearly 40%. Recovery from past land-use, plus reductions in wildfires and forest grazing coincide with consistent forest regrowth in the eastern U.S. but associated C stock increases were offset by increased wood harvest. C stock changes across the western U.S. fluctuated, with fire, harvest, and other disturbances (e.g., insects, droughts) reducing stocks on average by 14%, 81%, and 7%, respectively, resulting in a net growth in C stock density of 14%. Although wildfire activities increased in recent decades, harvest was the key driver in the forest C balance in all regions for most of the observed timeframe.
RESUMO
This review systematically gathers and provides an analysis of pollutants levels emitted from wildfire (WF) and their impact on short-term health effects of affected populations. The available literature was searched according to Population, Exposure, Comparator, Outcome, and Study design (PECOS) database defined by the World Health Organization (WHO) and a meta-analysis was conducted whenever possible. Data obtained through PECOS characterized information from the USA, Europe, Australia, and some Asian countries; South American countries were seldom characterized, and no data were available for Africa and Russia. Extremely high levels of pollutants, mostly of fine fraction of particulate matter (PM) and ozone, were associated with intense WF emissions in North America, Oceania, and Asia and reported to exceed several-fold the WHO guidelines. Adverse health outcomes include emergency department visits and hospital admissions for cardiorespiratory diseases as well as mortality. Despite the heterogeneity among exposure and health assessment methods, all-cause mortality, and specific-cause mortality were significantly associated with WF emissions in most of the reports. Globally, a significant association was found for all-cause respiratory outcomes including asthma, but mixed results were noted for cardiovascular-related effects. For the latter, estimates were only significant several days after WF emissions, suggesting a more delayed impact on the heart. Different research gaps are presented, including the need for the application of standardized protocols for assessment of both exposure and adverse health risks. Mitigation actions also need to be strengthened, including dedicated efforts to communicate with the affected populations, to engage them for adoption of protective behaviors and measures.
Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Ambientais , Incêndios Florestais , Humanos , Poluentes Atmosféricos/toxicidade , Poluição do Ar/efeitos adversos , Material Particulado/toxicidade , Poluentes Ambientais/análiseRESUMO
Awareness of the long-term outcomes of status epilepticus is key to understanding the condition overall. Maintaining ties with patients' families is vital to both obtaining better long-term patient outcomes and obtaining that elusive data on long-term conditions. Common language and linked infrastructure support these ties. This position is posed within the context of NORSE (new-onset refractory status epilepticus) and FIRES (febrile infection-related epilepsy syndrome). This paper was presented at the 8th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures held in September 2022.