115 research outputs found
UAV-derived photogrammetric point clouds and multispectral indices for fuel estimation in Mediterranean forests
Sensors attached to unmanned aerial vehicles (UAVs) allow estimating a large number of forest attributes related to forest fuels. This study assesses photogrammetric point clouds and multispectral indices obtained from a fixed-wing UAV for the classification of Prometheus fuel types in 82 forest plots in Aragón (NE Spain). Images captured by an RGB camera and a multispectral sensor allowed generating high density photogrammetric point clouds (RGB: 3000 points/m2; multispectral: 85 points/m2), which were normalized using alternatively a Digital Elevation Model (DEM) of 0.5, 1, and 2 m resolution. A set of structural and textural variables were derived from the normalized point cloud heights, and for the latter, the gray-level co-occurrence matrix (GLCM) approach was used. Multispectral images were also used to create seven spectral vegetation indices. The most relevant structural, textural, and spectral variables to introduce into the fuel types classification models were selected using Dunn's test, which included: the vegetation height at the 50th percentile, the coefficient of variation of the heights, the percentage of returns above 4 m, the mean textural dissimilarity, and the mean of the Green Chlorophyll Index. Three different data samples were introduced in the models: i) the relevant structural and textural variables from the RGB camera (RGB data sample); ii) the relevant structural, textural, and spectral variables from the multispectral sensor (MS data sample); and iii) the relevant structural and textural variables from the RGB camera plus the relevant spectral variable from the multispectral sensor (integrated data sample). After comparing three machine learning classification techniques (Random Forest, and Linear and Radial Support Vector Machine), the best results were obtained with Random Forest with k-fold cross-validation (k-10) and the integrated data sample with normalized point clouds at 0.5 m DEM resolution (overall accuracy = 71%). The variables successfully identified the Prometheus main fire carriers (i.e., shrubs or trees) and confusions were mainly located within the fuel types of the same dominant stratum, especially in fuel types 3 and 6. These results demonstrate the ability of UAV imagery to classify forest fuels in Mediterranean environments when RGB and multispectral data are combined
Forest fire severity estimation based on the LiDAR-PNOA data and the values of the Composite Burn Index
Revista oficial de la Asociación Española de Teledetección[EN] Mediterranean pine forests in Spain experience wildland fire events with different frequencies, intensities, and severities. An estimation of the fire severity as accurate as possible is required by forest managers to decide which strategy is most appropriate to mitigate the effect of fire. The aim of this research is to estimate the post-fire severity, relating a pool of independent variables derived from the LiDAR (Light Detection And Ranging) points clouds delivered by the National Plan for Aerial Orthophotography (PNOA) to field data based on Composite Burn Index collected in four fires located in Aragón (Spain). Logistic regression models were developed and statistically tested and validated to map fire severity with up to 85.5% accuracy. The canopy relief ratio and the percentage of all returns above one meter height were the most significant variables. In addition, the obtained results are compared to different spectral indices derived from Landsat Thematic Mapper.[ES] Los pinares mediterráneos españoles se ven afectados por incendios forestales con diferente frecuencia, intensidad y severidad. Para su valoración, hay que recurrir a estimaciones lo más precisas posibles de la severidad, la cual podrá ayudar a los gestores del bosque a decidir qué estrategia es más adecuada para mitigar el efecto del fuego. El objetivo de esta investigación es la estimación de la severidad post-incendio, relacionando un conjunto de variables independientes derivadas de las nubes de puntos del vuelo LiDAR (Light Detection And Ranging) del Plan Nacional de Ortofotografía Aérea (PNOA), con datos de campo basados en el índice CBI (Composite Burn Index) y recogidos en cuatro incendios localizados en Aragón. Se ha ajustado un modelo de regresión logística, que tras la validación, ha reportado una precisión del 85,5%, siendo las variables “canopy relief ratio” y el porcentaje de puntos por encima de 1 m de altura sobre el terreno, las incluidas en dicho modelo. Por otro lado, se ha realizado una comparativa de los resultados con índices espectrales derivados de imágenes Landsat Thematic Mapper.Estos trabajos han sido financiados por la beca pre-doctoral (FPI BOA 30, 11/02/2011) del Gobierno de Aragón y el proyecto CGL2014-57013-C2-2-R, y han contado con la ayuda de Francisco Palú, Marco Lorenzo y Emilio Pérez-Aguilar del Servicio Provincial de Agricultura, Ganadería y Medio Ambiente del Gobierno de Aragón. Los au-tores agradecen al Centro Nacional de Información Geográfica y al Centro de Información Territorial de Aragón por proporcionar los datos LiDAR-PNOA y al CENAD “San Gregorio” por facilitar el acceso a las parcelas de campo.Montealegre, AL.; Lamelas, MT.; Tanase, MA.; De La Riva, J. (2017). Estimación de la severidad en incendios forestales a partir de datos LiDAR-PNOA y valores de Composite Burn Index. Revista de Teledetección. (49):1-16. https://doi.org/10.4995/raet.2017.7371SWORD1164
Cocaine promotes oxidative stress and microglial-macrophage activation in rat cerebellum
Different mechanisms have been suggested for cocaine neurotoxicity, including oxidative stress alterations. Nuclear factor kappa B (NF-κB), considered a sensor of oxidative stress and inflammation, is involved in drug toxicity and addiction. NF-κB is a key mediator for immune responses that induces microglial/macrophage activation under inflammatory processes and neuronal injury/degeneration. Although cerebellum is commonly associated to motor control, muscular tone, and balance. Its relation with addiction is getting relevance, being associated to compulsive and perseverative behaviors. Some reports indicate that cerebellar microglial activation induced by cannabis or ethanol, promote cerebellar alterations and these alterations could be associated to addictive-related behaviors. After considering the effects of some drugs on cerebellum, the aim of the present work analyzes pro-inflammatory changes after cocaine exposure. Rats received daily 15 mg/kg cocaine i.p., for 18 days. Reduced and oxidized forms of glutathione (GSH) and oxidized glutathione (GSSG), glutathione peroxidase (GPx) activity and glutamate were determined in cerebellar homogenates. NF-κB activity, CD68, and GFAP expression were determined. Cerebellar GPx activity and GSH/GSSG ratio are significantly decreased after cocaine exposure. A significant increase of glutamate concentration is also observed. Interestingly, increased NF-κB activity is also accompanied by an increased expression of the lysosomal mononuclear phagocytic marker ED1 without GFAP alterations. Current trends in addiction biology are focusing on the role of cerebellum on addictive behaviors. Cocaine-induced cerebellar changes described herein fit with previosus data showing cerebellar alterations on addict subjects and support the proposed role of cerebelum in addiction
Survival after Resection of Multiple Tumor Foci of Intrahepatic Cholangiocarcinoma
Background: Multiple tumor foci of intrahepatic cholangiocarcinoma (ICC) are often considered a contra-indication for resection. We sought to define long-term outcomes after resection of ICC in patients with multiple foci.
Methods: Patients who underwent resection for ICC between 1990 and 2017 were identified from 12 major HPB centers. Outcomes of patients with solitary lesions, multiple lesions (ML), and oligometastases (OM) were compared. OM were defined as extrahepatic metastases spread to a single organ.
Results: One thousand thirteen patients underwent resection of ICC. On final pathology, 185 patients (18.4%) had ML and 27 (2.7%) had OM. Median survival of patients with a solitary tumor was 43.2 months, while the median survival of patients with 2 tumors was 21.2 months; the median survival of patients with 3 or more tumors was 15.3 months (p < 0.001). Five-year survival was 43.3%, 28.0%, and 8.6%, respectively. The median survival of patients without OM was 37.8 months versus 14.9 months among patients with OM (p < 0.001); estimated 5-year survival was 39.3% and 10.6%, respectively. In multivariable analysis, the presence of two lesions was not an independent poor prognostic factor for OS (HR 1.19; 95%CI 0.90-1.57; p = 0.229). However, the presence of three or more tumors was an independent poor prognostic factor for OS (HR 1.97; 95%CI 1.48-2.64; p < 0.001).
Conclusion: Resection of multiple liver tumors for patients with ICC did not preclude 5-year survival: in particular, estimated 5-year OS for resection of two tumors was 28.0%.info:eu-repo/semantics/publishedVersio
Study of TLR3, TLR4 and TLR9 in breast carcinomas and their association with metastasis
<p>Abstract</p> <p>Background</p> <p>Toll-like receptors (TLRs) have garnered an extraordinary amount of interest in cancer research due to their role in tumor progression. By activating the production of several biological factors, TLRs induce type I interferons and other cytokines, which drive an inflammatory response and activate the adaptive immune system. The aim of this study was to investigate the expression and clinical relevance of TLR3, 4 and 9 in breast cancer.</p> <p>Methods</p> <p>The expression levels of TLR3, TLR4 and TLR9 were analyzed on tumors from 74 patients with breast cancer. The analysis was performed by immunohistochemistry.</p> <p>Results</p> <p>Samples of carcinomas with recurrence exhibited a significant increase in the mRNA levels of TLR3, TLR4 and TLR9. Tumors showed high expression of TLRs expression levels by cancer cells, especially TLR4 and 9. Nevertheless, a significant percentage of tumors also showed TLR4 expression by mononuclear inflammatory cells (21.6%) and TLR9 expression by fibroblast-like cells (57.5%). Tumors with high TLR3 expression by tumor cell or with high TLR4 expression by mononuclear inflammatory cells were significantly associated with higher probability of metastasis. However, tumours with high TLR9 expression by fibroblast-like cells were associated with low probability of metastasis.</p> <p>Conclusions</p> <p>The expression levels of TLR3, TLR4 and TLR9 have clinical interest as indicators of tumor aggressiveness in breast cancer. TLRs may represent therapeutic targets in breast cancer.</p
The Impact of Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio Among Patients with Intrahepatic Cholangiocarcinoma
BACKGROUND:
Neutrophil-to-lymphocyte ratio and platelets-to-lymphocyte ratio may be host factors associated with prognosis. We sought to determine whether neutrophil-to-lymphocyte and platelets-to-lymphocyte ratio were associated with overall survival among patients undergoing surgery for intrahepatic cholangiocarcinoma.
METHODS:
Patients who underwent resection for intrahepatic cholangiocarcinoma between 1990 and 2015 were identified from 12 major centers. Clinicopathologic factors and overall survival were compared among patients stratified by neutrophil-to-lymphocyte ratio and platelets-to-lymphocyte ratio. Risk factors identified on multivariable analysis were included in a prognostic model and the discrimination was assessed using Harrell's concordance index (C index).
RESULTS:
A total of 991 patients were identified. Median neutrophil-to-lymphocyte ratio and platelets-to-lymphocyte ratio were 2.7 (interquartile range [IQR]: 2.0-4.0) and 109.6 (IQR: 72.4-158.8), respectively. Preoperative neutrophil-to-lymphocyte ratio was elevated (≥5) in 100 patients (10.0%) and preoperative platelets-to-lymphocyte ratio (≥190) in 94 patients (15.2%). Patients with low and high neutrophil-to-lymphocyte ratio and platelets-to-lymphocyte ratio generally had similar baseline characteristics with regard to tumor characteristics. Overall survival was 37.7 months (95% confidence interval [CI]: 32.7-42.6); 1-, 3-, and 5-year overall survival was 78.8%, 51.6%, and 39.3%, respectively. Patients with an neutrophil-to-lymphocyte ratio .05). On multivariable analysis, an elevated neutrophil-to-lymphocyte ratio was independently associated with decreased overall survival (hazard ratio: 1.04, 95% CI: 1.01-1.07; P = .002). Patients could be stratified into low- versus high-risk groups based on standard tumor-specific factors such as lymph node status, tumor size, number, and vascular invasion (C index 0.62). When neutrophil-to-lymphocyte ratio was added to the prognostic model, the discriminatory ability of the model improved (C index 0.71).
CONCLUSION:
Elevated neutrophil-to-lymphocyte ratio was independently associated with worse overall survival and improved the prognostic estimation of long-term survival among patients with intrahepatic cholangiocarcinoma undergoing resection.info:eu-repo/semantics/publishedVersio
Global Chronic Total Occlusion Crossing Algorithm: JACC State-of-the-Art Review
The authors developed a global chronic total occlusion crossing algorithm following 10 steps: 1) dual angiography; 2) careful angiographic review focusing on proximal cap morphology, occlusion segment, distal vessel quality, and collateral circulation; 3) approaching proximal cap ambiguity using intravascular ultrasound, retrograde, and move-the-cap techniques; 4) approaching poor distal vessel quality using the retrograde approach and bifurcation at the distal cap by use of a dual-lumen catheter and intravascular ultrasound; 5) feasibility of retrograde crossing through grafts and septal and epicardial collateral vessels; 6) antegrade wiring strategies; 7) retrograde approach; 8) changing strategy when failing to achieve progress; 9) considering performing an investment procedure if crossing attempts fail; and 10) stopping when reaching high radiation or contrast dose or in case of long procedural time, occurrence of a serious complication, operator and patient fatigue, or lack of expertise or equipment. This algorithm can improve outcomes and expand discussion, research, and collaboration
Global Chronic Total Occlusion Crossing Algorithm
The authors developed a global chronic total occlusion crossing algorithm following 10 steps: 1) dual angiography; 2) careful angiographic review focusing on proximal cap morphology, occlusion segment, distal vessel quality, and collateral circulation; 3) approaching proximal cap ambiguity using intravascular ultrasound, retrograde, and move-the-cap techniques; 4) approaching poor distal vessel quality using the retrograde approach and bifurcation at the distal cap by use of a dual-lumen catheter and intravascular ultrasound; 5) feasibility of retrograde crossing through grafts and septal and epicardial collateral vessels; 6) antegrade wiring strategies; 7) retrograde approach; 8) changing strategy when failing to achieve progress; 9) considering performing an investment procedure if crossing attempts fail; and 10) stopping when reaching high radiation or contrast dose or in case of long procedural time, occurrence of a serious complication, operator and patient fatigue, or lack of expertise or equipment. This algorithm can improve outcomes and expand discussion, research, and collaboration.info:eu-repo/semantics/publishedVersio
Impact of chronic obstructive pulmonary disease on short-term outcome in patients with ST-elevation myocardial infarction during COVID-19 pandemic: insights from the international multicenter ISACS-STEMI registry
Background: Chronic obstructive pulmonary disease (COPD) is projected to become the third cause of mortality worldwide. COPD shares several pathophysiological mechanisms with cardiovascular disease, especially atherosclerosis. However, no definite answers are available on the prognostic role of COPD in the setting of ST elevation myocardial infarction (STEMI), especially during COVID-19 pandemic, among patients undergoing primary angioplasty, that is therefore the aim of the current study. Methods: In the ISACS-STEMI COVID-19 registry we included retrospectively patients with STEMI treated with primary percutaneous coronary intervention (PCI) between March and June of 2019 and 2020 from 109 high-volume primary PCI centers in 4 continents. Results: A total of 15,686 patients were included in this analysis. Of them, 810 (5.2%) subjects had a COPD diagnosis. They were more often elderly and with a more pronounced cardiovascular risk profile. No preminent procedural dissimilarities were noticed except for a lower proportion of dual antiplatelet therapy at discharge among COPD patients (98.9% vs. 98.1%, P = 0.038). With regards to short-term fatal outcomes, both in-hospital and 30-days mortality occurred more frequently among COPD patients, similarly in pre-COVID-19 and COVID-19 era. However, after adjustment for main baseline differences, COPD did not result as independent predictor for in-hospital death (adjusted OR [95% CI] = 0.913[0.658–1.266], P = 0.585) nor for 30-days mortality (adjusted OR [95% CI] = 0.850 [0.620–1.164], P = 0.310). No significant differences were detected in terms of SARS-CoV-2 positivity between the two groups. Conclusion: This is one of the largest studies investigating characteristics and outcome of COPD patients with STEMI undergoing primary angioplasty, especially during COVID pandemic. COPD was associated with significantly higher rates of in-hospital and 30-days mortality. However, this association disappeared after adjustment for baseline characteristics. Furthermore, COPD did not significantly affect SARS-CoV-2 positivity. Trial registration number: NCT 04412655 (2nd June 2020)
Gender Difference in the Effects of COVID-19 Pandemic on Mechanical Reperfusion and 30-Day Mortality for STEMI: Results of the ISACS-STEMI COVID-19 Registry
Background. Several reports have demonstrated the impact of the COVID-19 pandemic on the management and outcome of patients with ST-segment elevation myocardial infarction (STEMI). The aim of the current analysis is to investigate the potential gender difference in the effects of the COVID-19 pandemic on mechanical reperfusion and 30-day mortality for STEMI patients within the ISACS-STEMI COVID-19 Registry. Methods. This retrospective multicenter registry was performed in high-volume primary percutaneous coronary intervention (PPCI) centers on four continents and included STEMI patients undergoing PPCIs in March–June 2019 and 2020. Patients were divided according to gender. The main outcomes were the incidence and timing of the PPCI, (ischemia time ≥ 12 h and door-to-balloon ≥ 30 min) and in-hospital or 30-day mortality. Results. We included 16683 STEMI patients undergoing PPCIs in 109 centers. In 2020 during the pandemic, there was a significant reduction in PPCIs compared to 2019 (IRR 0.843 (95% CI: 0.825–0.861, p < 0.0001). We did not find a significant gender difference in the effects of the COVID-19 pandemic on the numbers of STEMI patients, which were similarly reduced from 2019 to 2020 in both groups, or in the mortality rates. Compared to prepandemia, 30-day mortality was significantly higher during the pandemic period among female (12.1% vs. 8.7%; adjusted HR [95% CI] = 1.66 [1.31–2.11], p < 0.001) but not male patients (5.8% vs. 6.7%; adjusted HR [95% CI] = 1.14 [0.96–1.34], p = 0.12). Conclusions. The COVID-19 pandemic had a significant impact on the treatment of patients with STEMI, with a 16% reduction in PPCI procedures similarly observed in both genders. Furthermore, we observed significantly increased in-hospital and 30-day mortality rates during the pandemic only among females. Trial registration number: NCT 04412655
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