•UAV-lidar collects data sensitive to vegetation structure in tropical savanna.•First study to map total aboveground biomass density (AGBt) from UAV-lidar in Cerrado.•Besides tree biomass, AGBt ...includes surface and shrubs biomass.•AGBt uncertainty was lower in forest and savanna than in grassland formations.•The study is a step forward in using UAV-lidar for AGBt mapping in tropical savanna ecosystems.
Tropical savanna ecosystems play a major role in the seasonality of the global carbon cycle. However, their ability to store and sequester carbon is uncertain due to combined and intermingling effects of anthropogenic activities and climate change, which impact wildfire regimes and vegetation dynamics. Accurate measurements of tropical savanna vegetation aboveground biomass (AGB) over broad spatial scales are crucial to achieve effective carbon emission mitigation strategies. UAV-lidar is a new remote sensing technology that can enable rapid 3-D mapping of structure and related AGB in tropical savanna ecosystems. This study aimed to assess the capability of high-density UAV-lidar to estimate and map total (tree, shrubs, and surface layers) aboveground biomass density (AGBt) in the Brazilian Savanna (Cerrado). Five ordinary least square regression models estimating AGBt were adjusted using 50 field sample plots (30 m × 30 m). The best model was selected under Akaike Information Criterion, adjusted coefficient of determination (adj.R2), absolute and relative root mean square error (RMSE), and used to map AGBt from UAV-lidar data collected over 1,854 ha spanning the three major vegetation formations (forest, savanna, and grassland) in Cerrado. The model using vegetation height and cover was the most effective, with an overall model adj-R2 of 0.79 and a leave-one-out cross-validated RMSE of 19.11 Mg/ha (33.40%). The uncertainty and errors of our estimations were assessed for each vegetation formation separately, resulting in RMSEs of 27.08 Mg/ha (25.99%) for forests, 17.76 Mg/ha (43.96%) for savannas, and 7.72 Mg/ha (44.92%) for grasslands. These results prove the feasibility and potential of the UAV-lidar technology in Cerrado but also emphasize the need for further developing the estimation of biomass in grasslands, of high importance in the characterization of the global carbon balance and for supporting integrated fire management activities in tropical savanna ecosystems. Our results serve as a benchmark for future studies aiming to generate accurate biomass maps and provide baseline data for efficient management of fire and predicted climate change impacts on tropical savanna ecosystems.
Introducción: La diversidad representa un desafío en la atención en salud, pues supone que los enfermeros sean culturalmente competentes, capaces de brindar cuidados que se adapten a las creencias, ...valores y prácticas de los pacientes provenientes de diversas culturas. Objetivo: Determinar el nivel de competencia cultural en los estudiantes de enfermería de una Universidad Pública de Colombia. Materiales y métodos: Estudio cuantitativo descriptivo de corte transversal. Para la recolección de datos se utilizó la Escala de Competencia Cultural versión en español chilena, previamente validada en el contexto colombiano. La muestra estuvo conformada por 148 estudiantes de enfermería matriculados de tercer a octavo semestre, en el periodo de agosto a diciembre del 2021. Se realizó análisis univariado y bivariado mediante la prueba U de Mann Whitney y H de Kruskal Wallis. Resultados: El puntaje promedio (72.3), obtenido por los estudiantes de enfermería indica niveles moderados de competencia cultural. Se halló diferencias significativas del nivel de competencia respecto a la formación previa (p < 0.05) y a la experiencia en cuidado de pacientes con diversas culturas (p< 0.05). Discusión: Los participantes en este estudio mostraron niveles de competencia cultural similares a los encontrados en investigaciones realizadas con estudiantes de enfermería en otros países, como Corea del Sur, India, Sudáfrica, Irak, y Chile, entre otros. Conclusiones: El nivel de competencia cultural de los estudiantes de enfermería, les permite brindar acciones seguras humanas empáticas, efectivas y coherentes con la cultura de los pacientes.
Abnormal peripheral perfusion after septic shock resuscitation has been associated with organ dysfunction and mortality. The potential role of the clinical assessment of peripheral perfusion as a ...target during resuscitation in early septic shock has not been established.
To determine if a peripheral perfusion-targeted resuscitation during early septic shock in adults is more effective than a lactate level-targeted resuscitation for reducing mortality.
Multicenter, randomized trial conducted at 28 intensive care units in 5 countries. Four-hundred twenty-four patients with septic shock were included between March 2017 and March 2018. The last date of follow-up was June 12, 2018.
Patients were randomized to a step-by-step resuscitation protocol aimed at either normalizing capillary refill time (n = 212) or normalizing or decreasing lactate levels at rates greater than 20% per 2 hours (n = 212), during an 8-hour intervention period.
The primary outcome was all-cause mortality at 28 days. Secondary outcomes were organ dysfunction at 72 hours after randomization, as assessed by Sequential Organ Failure Assessment (SOFA) score (range, 0 best to 24 worst); death within 90 days; mechanical ventilation-, renal replacement therapy-, and vasopressor-free days within 28 days; intensive care unit and hospital length of stay.
Among 424 patients randomized (mean age, 63 years; 226 53% women), 416 (98%) completed the trial. By day 28, 74 patients (34.9%) in the peripheral perfusion group and 92 patients (43.4%) in the lactate group had died (hazard ratio, 0.75 95% CI, 0.55 to 1.02; P = .06; risk difference, -8.5% 95% CI, -18.2% to 1.2%). Peripheral perfusion-targeted resuscitation was associated with less organ dysfunction at 72 hours (mean SOFA score, 5.6 SD, 4.3 vs 6.6 SD, 4.7; mean difference, -1.00 95% CI, -1.97 to -0.02; P = .045). There were no significant differences in the other 6 secondary outcomes. No protocol-related serious adverse reactions were confirmed.
Among patients with septic shock, a resuscitation strategy targeting normalization of capillary refill time, compared with a strategy targeting serum lactate levels, did not reduce all-cause 28-day mortality.
ClinicalTrials.gov Identifier: NCT03078712.
•Understanding the dynamics of urban forests as carbon pools is crucial.•Tree height is relevant because it is used to predicting biomass and carbon storage.•It is relevant check the point density ...influence on deriving the tree height.•The UAV-Lidar provides a high density of returns, thus more tree’s details.•The UAV-Lidar’s high densities have derived heights similar to moderate densities.
Urban forest remnants contribute to climate change mitigation by reducing the amount of carbon dioxide in urban areas. Hence, understanding the dynamics and the potential of urban forests as carbon pools is crucial to propose effective policies addressing the ecosystem services' maintenance. Remote sensing technologies such as Light detection and ranging (Lidar) are alternatives to acquire information on urban forests accurately. In this paper, we evaluate a UAV-Lidar system's potential to derive individual tree heights of Araucaria angustifolia trees in an Urban Atlantic Forest. Additionally, the influence of point density when deriving tree heights was assessed (2500, 1000, 500, 250, 100, 50, 25, 10 and 5 returns.m−2). The UAV-Lidar data was collected with the GatorEye Unmanned Flying Laboratory ‘Generation 2’. The UAV-Lidar-derived and field-based tree heights were compared by statistical analysis. Higher densities of points allowed a better description of tree profiles. Lower densities presented gaps in the Crown Height Model (CHM). The highest agreement between UAV-Lidar-derived and field-based tree heights (r = 0.73) was noticed when using 100 returns.m−2. The lowest rRMSE was observed for 50 returns.m−2 (8.35 %). There are no explicit differences in derived tree heights using 25 to 2500 returns.m−2. UAV-Lidar data presented satisfactory performance when deriving individual tree heights of Araucaria angustifolia trees.
Quantifying fuel load over large areas is essential to support integrated fire management initiatives in fire-prone regions to preserve carbon stock, biodiversity and ecosystem functioning. It also ...allows a better understanding of global climate regulation as a potential carbon sink or source. Large area assessments usually require data from spaceborne remote sensors, but most of them cannot measure the vertical variability of vegetation structure, which is required for accurately measuring fuel loads and defining management interventions. The recently launched NASA's Global Ecosystem Dynamics Investigation (GEDI) full-waveform lidar sensor holds potential to meet this demand. However, its capability for estimating fuel load has yet not been evaluated. In this study, we developed a novel framework and tested machine learning models for predicting multi-layer fuel load in the Brazilian tropical savanna (i.e., Cerrado biome) using GEDI data. First, lidar data were collected using an unnamed aerial vehicle (UAV). The flights were conducted over selected sample plots in distinct Cerrado vegetation formations (i.e., grassland, savanna, forest) where field measurements were conducted to determine the load of surface, herbaceous, shrubs and small trees, woody fuels and the total fuel load. Subsequently, GEDI-like full-waveforms were simulated from the high-density UAV-lidar 3-D point clouds from which vegetation structure metrics were calculated and correlated to field-derived fuel load components using Random Forest models. From these models, we generate fuel load maps for the entire Cerrado using all on-orbit available GEDI data. Overall, the models had better performance for woody fuels and total fuel loads (R2 = 0.88 and 0.71, respectively). For components at the lower stratum, models had moderate to low performance (R2 between 0.15 and 0.46) but still showed reliable results. The presented framework can be extended to other fire-prone regions where accurate measurements of fuel components are needed. We hope this study will contribute to the expansion of spaceborne lidar applications for integrated fire management activities and supporting carbon monitoring initiatives in tropical savannas worldwide.
•GEDI allows large scale multi-layer characterization of fuels in tropical savannas.•A novel framework for fuel load modeling from simulated GEDI data is developed.•Random Forest models are derived for estimating multi-layer fuel loads.•Models performed better for woody and total than surface fuel loads.•A step change toward large scale fuel load mapping from space in tropical savanna.
Ruminant livestock are important sources of human food and global greenhouse gas emissions. Feed degradation and methane formation by ruminants rely on metabolic interactions between rumen microbes ...and affect ruminant productivity. Rumen and camelid foregut microbial community composition was determined in 742 samples from 32 animal species and 35 countries, to estimate if this was influenced by diet, host species, or geography. Similar bacteria and archaea dominated in nearly all samples, while protozoal communities were more variable. The dominant bacteria are poorly characterised, but the methanogenic archaea are better known and highly conserved across the world. This universality and limited diversity could make it possible to mitigate methane emissions by developing strategies that target the few dominant methanogens. Differences in microbial community compositions were predominantly attributable to diet, with the host being less influential. There were few strong co-occurrence patterns between microbes, suggesting that major metabolic interactions are non-selective rather than specific.
Compensated hypogonadism in men with sickle cell disease Ribeiro, Anna Paloma M. R.; Silva, Caroline S.; Zambrano, Jean Carlos C. ...
Clinical endocrinology (Oxford),
June 2021, 2021-Jun, 2021-06-00, 20210601, Letnik:
94, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Objective
To evaluate the prevalence of hypogonadism in a population of men with SCD and characterize its aetiology. Sickle cell disease (SCD) is associated with the development of hypogonadism, but ...there is still controversy regarding its aetiology and clinical implications.
Methods
We performed a cross‐sectional study of 34 men with SCD aged > 18 years. Sociodemographic and clinical data, including anthropometric measurements (weight, height and BMI), were obtained. Early morning, blood samples were collected and total testosterone (TT), free testosterone (FT), luteinizing hormone (LH), follicle stimulating hormone (FSH), a complete blood count and haemoglobin electrophoresis were measured. Eugonadism was defined as T ≥300 ng/dL and LH ≤9.4 mUI/mL; primary hypogonadism as T < 300 ng/dL and LH > 9.4 mUI/mL; secondary hypogonadism as T < 300 ng/dL and LH ≤ 9.4 mUI/mL; and compensated hypogonadism as T ≥ 300 ng/dL and LH > 9.4 mUI/mL.
Results
Median age was 33 (26‐41) years, and SS genotype was the most frequent (73.5%). The prevalence of eugonadism, compensated hypogonadism and secondary hypogonadism was 67.5%, 26.4% and 5.88%, respectively. No men with primary hypogonadism were identified in our sample. Those with compensated hypogonadism had also higher FSH levels (>7.8 mUI/mL, P < .0001).
Conclusion
In our study population of men with SCD, a high prevalence of compensated hypogonadism was identified, which is a controversial and distinct clinical entity that warrants monitoring and further research.
Unmanned aerial vehicles (UAV) allow efficient acquisition of forest data at very high resolution at relatively low cost, making it useful for multi-temporal assessment of detailed tree crowns and ...forest structure. Single-pass flight plans provide rapid surveys for key selected high-priority areas, but their accuracy is still unexplored. We compared aircraft-borne LiDAR with GatorEye UAV-borne LiDAR in the Apalachicola National Forest, USA. The single-pass approach produced digital terrain models (DTMs), with less than 1 m differences compared to the aircraft-derived DTM within a 145° field of view (FOV). Canopy height models (CHM) provided reliable information from the top layer of the forest, allowing reliable treetop detection up to wide angles; however, underestimations of tree heights were detected at 175 m from the flightline, with an error of 2.57 ± 1.57. Crown segmentation was reliable only within a 60° FOV, from which the shadowing effect made it unviable. Reasonable quality threshold values for LiDAR products were: 195 m (145° FOV) for DTMs, 95 m (110° FOV) for CHM, 160 to 180 m (~140° FOV) for ITD and tree heights, and 40 to 60 m (~60° FOV) for crown delineation. These findings also support the definition of mission parameters for standard grid-based flight plans under similar forest types and flight parameters.
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