RESUMEN
Forests are a substantial terrestrial carbon sink, but anthropogenic changes in land use and climate have considerably reduced the scale of this system1. Remote-sensing estimates to quantify carbon losses from global forests2-5 are characterized by considerable uncertainty and we lack a comprehensive ground-sourced evaluation to benchmark these estimates. Here we combine several ground-sourced6 and satellite-derived approaches2,7,8 to evaluate the scale of the global forest carbon potential outside agricultural and urban lands. Despite regional variation, the predictions demonstrated remarkable consistency at a global scale, with only a 12% difference between the ground-sourced and satellite-derived estimates. At present, global forest carbon storage is markedly under the natural potential, with a total deficit of 226 Gt (model range = 151-363 Gt) in areas with low human footprint. Most (61%, 139 Gt C) of this potential is in areas with existing forests, in which ecosystem protection can allow forests to recover to maturity. The remaining 39% (87 Gt C) of potential lies in regions in which forests have been removed or fragmented. Although forests cannot be a substitute for emissions reductions, our results support the idea2,3,9 that the conservation, restoration and sustainable management of diverse forests offer valuable contributions to meeting global climate and biodiversity targets.
Asunto(s)
Secuestro de Carbono , Carbono , Conservación de los Recursos Naturales , Bosques , Biodiversidad , Carbono/análisis , Carbono/metabolismo , Conservación de los Recursos Naturales/estadística & datos numéricos , Conservación de los Recursos Naturales/tendencias , Actividades Humanas , Restauración y Remediación Ambiental/tendencias , Desarrollo Sostenible/tendencias , Calentamiento Global/prevención & controlRESUMEN
PURPOSE: To compare the impact of burr hole drainage and craniotomy for acute liquid epidural hematoma (LEDH) in pediatric patients. METHODS: This retrospective study enrolled pediatric patients with LEDH who underwent surgery in the Affiliated Hospital of Nanyang Medical College, China, between October 2011 and December 2019. According to the surgical procedure, patients were divided into the craniotomy group and the burr hole drainage group. RESULTS: A total of 21 pediatric patients were enrolled (14 males, aged 7.19 ± 2.77 years), including 13 cases in the burr hole drainage group and 8 patients in the craniotomy group. The operation time and hospitalization period in the burr hole drainage group were 33.38 ± 6.99 min and 9.85 ± 1.07 days, respectively, which were significantly shorter than that in the craniotomy group (74.25 ± 9.68 min and 13.38 ± 1.71 days, respectively; all p < 0.05). The Glasgow Coma Scale (GCS) score after burr hole drainage was significantly improved than before (median: 15 vs 13, p < 0.05). No serious complications were observed in either group; one patient in the craniotomy group developed an infection at the incision point. All patients were conscious (GCS score was 15) at discharge. CONCLUSION: Compared with craniotomy, burr hole drainage was associated with better clinical outcomes and early recovery in patients with LEDH.
Asunto(s)
Hematoma Epidural Craneal , Hematoma Espinal Epidural , Hematoma Subdural Crónico , Masculino , Humanos , Niño , Estudios Retrospectivos , Hematoma Subdural Crónico/cirugía , Craneotomía/métodos , Drenaje/métodos , Hematoma Epidural Craneal/cirugía , Hematoma Espinal Epidural/cirugía , Resultado del TratamientoRESUMEN
Objective: To explore the knowledge, attitude, and practice (KAP) toward glioma of patients with neurological symptoms or diseases. Methods: This web-based cross-sectional study was conducted at two medical centers in Henan Province between January 2023 and April 2023 and enrolled patients with neurological symptoms or diseases. The demographic characteristics of the participants and their KAP toward glioma were collected using a self-administered questionnaire. A structural equation modeling (SEM) was used to examine the relationship among KAP dimensions. Results: The study included 442 valid questionnaires. The mean knowledge, attitude, and practice scores were 7.65 ± 1.62 (possible range: 0-9), 37.98 ± 3.17 (possible range: 9-45), and 40.16 ± 4.17 (possible range: 10-50), indicating good knowledge, favorable attitude, and active practice. The SEM analysis showed that knowledge directly affected attitudes (ß = 0.89, 95%CI: 0.73-1.06, P < 0.001) but not practice (ß = -0.08, 95%CI: -0.32-0.14, P = 0.487), while attitudes directly affected practice (ß = 0.35, 95%CI: 0.21-0.48, P < 0.001). Conclusion: Patients with neurological symptoms/diseases who had heard of gliomas had good knowledge, favorable attitudes, and active practice toward glioma. Specific knowledge items that would warrant improvements were identified in the specific population of patients with neurological symptoms/diseases who had heard of glioma. Future studies should also examine the general population.
RESUMEN
Purpose: This study aimed to examine the KAP of physicians regarding targeted drug therapy for lung cancer in China. Methods: This cross-sectional study enrolled physicians working in hospitals in Nanyang. A self-administered questionnaire was developed (Cronbach's α=0.912) to collect the demographic information and KAP. Results: This study included 191 valid questionnaires. Most participants were male (70.2%) and aged 36-50 (55.5%). The median knowledge score was 29 (24-31) (/36, 80.6%), the mean attitude score was 42 (39-44) (/50, 84.0%), and the mean practice score was 28 (26-29) (/30, 93.3%), indicating sufficient knowledge, positive attitudes, and proactive practice. The female gender (OR=5.291, 95% CI: 1.426-19.634, P=0.013), working in non-public tertiary hospitals (OR=0.053, 95% CI: 0.008-0.360, P=0.003), and working in medical oncology (OR=10.764, 95% CI: 2.638-43.922, P=0.001) were independently associated with adequate knowledge. Only the knowledge scores (OR=1.121, 95% CI: 1.036-1.212, P=0.004) were independently associated with a positive attitude. Only the attitude scores (OR=1.895, 95% CI: 1.333-2.694, P<0.001) were independently associated with proactive practice. Conclusion: Physicians working in thoracic surgery, respiratory medicine, or medical oncology displayed sufficient knowledge, positive attitude, and proactive practice toward targeted therapy for lung cancer.
RESUMEN
The emergence of alternative stable states in forest systems has significant implications for the functioning and structure of the terrestrial biosphere, yet empirical evidence remains scarce. Here, we combine global forest biodiversity observations and simulations to test for alternative stable states in the presence of evergreen and deciduous forest types. We reveal a bimodal distribution of forest leaf types across temperate regions of the Northern Hemisphere that cannot be explained by the environment alone, suggesting signatures of alternative forest states. Moreover, we empirically demonstrate the existence of positive feedbacks in tree growth, recruitment and mortality, with trees having 4-43% higher growth rates, 14-17% higher survival rates and 4-7 times higher recruitment rates when they are surrounded by trees of their own leaf type. Simulations show that the observed positive feedbacks are necessary and sufficient to generate alternative forest states, which also lead to dependency on history (hysteresis) during ecosystem transition from evergreen to deciduous forests and vice versa. We identify hotspots of bistable forest types in evergreen-deciduous ecotones, which are likely driven by soil-related positive feedbacks. These findings are integral to predicting the distribution of forest biomes, and aid to our understanding of biodiversity, carbon turnover, and terrestrial climate feedbacks.
Asunto(s)
Biodiversidad , Bosques , Hojas de la Planta , Árboles , Hojas de la Planta/crecimiento & desarrollo , Árboles/crecimiento & desarrollo , Ecosistema , Suelo/química , ClimaRESUMEN
The density of wood is a key indicator of the carbon investment strategies of trees, impacting productivity and carbon storage. Despite its importance, the global variation in wood density and its environmental controls remain poorly understood, preventing accurate predictions of global forest carbon stocks. Here we analyse information from 1.1 million forest inventory plots alongside wood density data from 10,703 tree species to create a spatially explicit understanding of the global wood density distribution and its drivers. Our findings reveal a pronounced latitudinal gradient, with wood in tropical forests being up to 30% denser than that in boreal forests. In both angiosperms and gymnosperms, hydrothermal conditions represented by annual mean temperature and soil moisture emerged as the primary factors influencing the variation in wood density globally. This indicates similar environmental filters and evolutionary adaptations among distinct plant groups, underscoring the essential role of abiotic factors in determining wood density in forest ecosystems. Additionally, our study highlights the prominent role of disturbance, such as human modification and fire risk, in influencing wood density at more local scales. Factoring in the spatial variation of wood density notably changes the estimates of forest carbon stocks, leading to differences of up to 21% within biomes. Therefore, our research contributes to a deeper understanding of terrestrial biomass distribution and how environmental changes and disturbances impact forest ecosystems.
RESUMEN
Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records. We found that global variation in leaf habit is primarily driven by isothermality and soil characteristics, while leaf form is predominantly driven by temperature. Given these relationships, we estimate that 38% of global tree individuals are needle-leaved evergreen, 29% are broadleaved evergreen, 27% are broadleaved deciduous and 5% are needle-leaved deciduous. The aboveground biomass distribution among these tree types is approximately 21% (126.4 Gt), 54% (335.7 Gt), 22% (136.2 Gt) and 3% (18.7 Gt), respectively. We further project that, depending on future emissions pathways, 17-34% of forested areas will experience climate conditions by the end of the century that currently support a different forest type, highlighting the intensification of climatic stress on existing forests. By quantifying the distribution of tree leaf types and their corresponding biomass, and identifying regions where climate change will exert greatest pressure on current leaf types, our results can help improve predictions of future terrestrial ecosystem functioning and carbon cycling.
Asunto(s)
Ecosistema , Árboles , Humanos , Árboles/metabolismo , Bosques , Hojas de la Planta/metabolismo , Hábitos , Carbono/metabolismoRESUMEN
Due to massive energetic investments in woody support structures, trees are subject to unique physiological, mechanical, and ecological pressures not experienced by herbaceous plants. Despite a wealth of studies exploring trait relationships across the entire plant kingdom, the dominant traits underpinning these unique aspects of tree form and function remain unclear. Here, by considering 18 functional traits, encompassing leaf, seed, bark, wood, crown, and root characteristics, we quantify the multidimensional relationships in tree trait expression. We find that nearly half of trait variation is captured by two axes: one reflecting leaf economics, the other reflecting tree size and competition for light. Yet these orthogonal axes reveal strong environmental convergence, exhibiting correlated responses to temperature, moisture, and elevation. By subsequently exploring multidimensional trait relationships, we show that the full dimensionality of trait space is captured by eight distinct clusters, each reflecting a unique aspect of tree form and function. Collectively, this work identifies a core set of traits needed to quantify global patterns in functional biodiversity, and it contributes to our fundamental understanding of the functioning of forests worldwide.
Asunto(s)
Árboles , Biodiversidad , Bosques , Corteza de la Planta/fisiología , Hojas de la Planta/fisiología , Raíces de Plantas/fisiología , Semillas/fisiología , Árboles/fisiología , Madera/fisiologíaRESUMEN
A poor understanding of the fraction of global plant biomass occurring belowground as roots limits our understanding of present and future ecosystem function and carbon pools. Here we create a database of root-mass fractions (RMFs), an index of plant below- versus aboveground biomass distributions, and generate quantitative, spatially explicit global maps of RMFs in trees, shrubs and grasses. Our analyses reveal large gradients in RMFs both across and within vegetation types that can be attributed to resource availability. High RMFs occur in cold and dry ecosystems, while low RMFs dominate in warm and wet regions. Across all vegetation types, the directional effect of temperature on RMFs depends on water availability, suggesting feedbacks between heat, water and nutrient supply. By integrating our RMF maps with existing aboveground plant biomass information, we estimate that in forests, shrublands and grasslands, respectively, 22%, 47% and 67% of plant biomass exists belowground, with a total global belowground fraction of 24% (20-28%), that is, 113 (90-135) Gt carbon. By documenting the environmental correlates of root biomass allocation, our results can inform model projections of global vegetation dynamics under current and future climate scenarios.
Asunto(s)
Ecosistema , Plantas , Biomasa , Carbono , BosquesRESUMEN
High-resolution hard X-ray grating-based imaging method with conventional X-ray sources provides attenuation, refraction and scattering information synchronously, and it is regarded as the next-generation X-ray imaging technology for medical and industrial applications. In this letter, a large phase-stepping approach with at least one order of magnitude lower resolution of the movement is presented to equivalently substitute the current high-positioning-resolution phase-stepping approach. Both the theoretical deduction and actual experiment prove that the new approach is available to relax the requirement of high positioning resolution and strict circumstances so as to benefit the future commercial applications of the grating-based multiple-information imaging technology.
Asunto(s)
Intensificación de Imagen Radiográfica/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Radiografía/métodos , Difracción de Rayos X/métodos , Almacenamiento y Recuperación de la Información/métodos , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
Combating climate change requires unified action across all sectors of society. However, this collective action is precluded by the 'consensus gap' between scientific knowledge and public opinion. Here, we test the extent to which the iconic cities around the world are likely to shift in response to climate change. By analyzing city pairs for 520 major cities of the world, we test if their climate in 2050 will resemble more closely to their own current climate conditions or to the current conditions of other cities in different bioclimatic regions. Even under an optimistic climate scenario (RCP 4.5), we found that 77% of future cities are very likely to experience a climate that is closer to that of another existing city than to its own current climate. In addition, 22% of cities will experience climate conditions that are not currently experienced by any existing major cities. As a general trend, we found that all the cities tend to shift towards the sub-tropics, with cities from the Northern hemisphere shifting to warmer conditions, on average ~1000 km south (velocity ~20 km.year-1), and cities from the tropics shifting to drier conditions. We notably predict that Madrid's climate in 2050 will resemble Marrakech's climate today, Stockholm will resemble Budapest, London to Barcelona, Moscow to Sofia, Seattle to San Francisco, Tokyo to Changsha. Our approach illustrates how complex climate data can be packaged to provide tangible information. The global assessment of city analogues can facilitate the understanding of climate change at a global level but also help land managers and city planners to visualize the climate futures of their respective cities, which can facilitate effective decision-making in response to on-going climate change.
Asunto(s)
Cambio Climático , Ciudades , Clima , Toma de Decisiones , Humanos , Modelos Teóricos , Análisis de Componente Principal , Factores de TiempoRESUMEN
[This corrects the article DOI: 10.1371/journal.pone.0217592.].