Towards Validation of SMOS Land Products Using the Synergy Between Models, Airborne and Ground-based Data Over the Valencia Anchor Station. Definition of Matching-up Points to SMOS Observations

Ponencia presentada en el International Geoscience and Remote Sensing Symposium celebrado en Honolulu (Hawaii) del 25 al 30 de julio de 2010López-Baeza et al.The main goal of ESA’s (European Space Agency) SMOS (Soil Moisture and Ocean Salinity) mission is to deliver global fields of surface soil moisture (SM) and sea surface salinity, with enough resolution to be used in numerical weather prediction and global climate models, usin g L-band (1.4 GHz) radiometry. Within the context of the preparation for this mission over land, the Valencia Anchor Station (VAS) experimental site, in Spain, was chosen as a preferential test sites in Europe for SMOS Cal/Val activities. Ground and meteorological measurements over the area are used as input to a Soil-Vegetation-Atmosphere-Transfer (SVAT) model, SURFEX (SURFace EXternalisé) - module ISBA (Interactions between Soil-Biosphere-Atmosphere) to simulate surface SM. Calibration as well as validation of the ISBA model was made by using in situ SM measurements.Peer Reviewe

Association between tonsillectomy, adenoidectomy, and appendicitis Asociación entre amigdalectomía, adenoidectomía y apendicitis

Introduction: tonsillectomy, with or without adenoidectomy, is one of the most frequent surgical procedures generally performed, especially in young patients. Several studies suggest that there is a relationship between tonsillectomy and altered MALT immune system. Objective: to examine the possible association between tonsillectomy or adenoidectomy and the risk of subsequent appendicitis. Material and method: a cross-sectional study was performed in 650 patients admitted to the emergency department of a general hospital in Valencia, Spain. Previous history of tonsillectomy and/or adenoidectomy was related to a history of appendectomy. A descriptive study and an analysis of the relationship between previous operations and appendicitis was performed. A multivariable analysis controlled for age and sex was also performed, including the possible interaction of the gender variable. The independent effect of each of the procedures (tonsillectomy, adenoidectomy) was tested. Results: the 25.5% of patients had undergone tonsillectomy and 11.5% adenoidectomy; 17.5% had had an appendectomy. On average, women were operated on more frequently than men. In the bivariate analysis, both tonsillectomy and adenoidectomy were significantly associated with subsequent appendectomy. In the multivariate analysis, this association was only maintained for tonsillectomy (OR: 3.23; 95% CI: 2.11-4.94). A stratified analysis controlling for sex showed a modification of this effect, with a higher association in women (OR: 5.20; 95% CI: 2.91-9.28) than in men (OR: 1.74; 95% CI: 0.90-3.39). Conclusions: a clear association has been found, especially in women, between previous tonsillectomy and subsequent acute appendicitis. Due to a lack of data on acute appendicitis there should be further studies to explain the findings of this study, as this could be the first described risk factor of acute appendicitis.<br>Introducción: la amigdalectomía, sola o acompañada de adenoidectomía, es una de las intervenciones quirúrgicas más frecuentes, especialmente en las personas más jóvenes. Diversos estudios sugieren la existencia de algún tipo de relación entre el hecho de sufrir una amigdalectomía y la inmunidad a nivel del sistema MALT digestivo. Objetivo: examinar la posible asociación entre el hecho de haber sido sometido a la extirpación de las amígdalas o las adenoides y padecer posteriormente una apendicitis aguda. Material y método: encuesta transversal en 650 pacientes que acuden al Servicio de Urgencias de un Hospital de Valencia, España. Se relacionaron los antecedentes de apendicectomía con amigdalectomía y/o adenoidectomía previa. Se llevó a cabo la descripción de las variables así como el análisis de la relación entre las intervenciones previas y la apendicitis. Se efectuó un análisis multivariante controlando por las variables edad y sexo así como la posible interacción con la variable sexo. Se comprobó el efecto independiente de cada una de las dos intervenciones (amigdalectomía, adenoidectomía). Resultados: el 25,5% de pacientes habían sido intervenidos de amigdalectomía, el 11,5% de adenoidectomía y el 17,5% de apendicectomía. En promedio, las mujeres han sido sometidas a intervenciones con mayor frecuencia que los hombres. En el análisis simple, los antecedentes, tanto de amigdalectomía, como de adenoidectomía, se asociaron significativamente con haber sido sometidos posteriormente a apendicectomía. En el análisis multivariante, dicha asociación sólo se mantuvo para la amigdalectomía (OR: 3,23; IC 95%: 2,11-4,94). Por otro lado, se encontró una modificación de dicho efecto según la variable sexo, siendo la asociación más alta en mujeres (OR: 5,20; IC 95% 2,91-9,28) que en hombres (OR: 1,74; IC 95%: 0,90-3,39). Conclusiones: se ha encontrado una asociación clara, especialmente en mujeres, entre el hecho de ser amigdalectomizado y sufrir apendicitis con posterioridad. Dada la escasez de conocimientos de apendicitis aguda se debería investigar con mayor profundidad los factores que explicaran los hallazgos de este estudio, ya que podría ser el primer factor de riesgo descrito de apendicitis aguda

CNES and ESA CAROLS Airborne Campaigns at the Valencia Anchor Station in the framework of SMOS Validation

Wigneron et al.Ponencia presentada en la 38th COSPAR Scientific Assembly celebrada en Brema (Alemania) del 18 al 25 de julio de 2010This communication will present the main results of a series of airborne campaigns conducted at the Valencia Anchor Station (VAS) site for the implementation of the SMOS emission model L-MEB (L-band Microwave Emission model of the Biosphere, Wigneron et al., 2007), in the framework of the validation of SMOS land data and products. CNES CAROLS campaigns: In 2009, the L-band CAROLS (Combined Airborne Radio-instruments for Ocean and Land Studies) radiometer was flown on three occasions over an area of 1500 km2 covering vineyards, shrub land and Mediterranean pine forest. Main results of CAROLS 2009 will be presented in this communication, and the emphasis will be on comparing local to regional scale results given that CAROLS flights were performed at 4000 m above the surface. ESA-CNES CAROLS campaigns: In 2010, the L-band CAROLS radiometer was flown on four occasions over an area of about 20 km x 20 km containing a large number of homogeneous units (`environmental units'), with flight lines performed at approximately 2200 m above sea level and in alternate E-W and W-E directions in order to have multi-angular signatures over the same area, and avoid potential RFI in Western Spain. The preliminary results of this campaign will be presented in this communication, and the emphasis will be the validation of the L-MEB model.Peer Reviewe

CNS and ESA CAROLS Airborne Campaigns at the Valencia Anchor Station and Los Monegros site in the framework of SMOS validation

2 ficheros .pdf, copias de la Presentación original (41 Pags.) y del Resumen ampliado (1 Pag.) en Libro de Actas del Congreso.This communication will present the main results of a series of airborne campaigns conducted at the Valencia Anchor Station (VAS) and Los Monegros site using the CAROLS (Combined Airborne Radio-instruments for Ocean and Land Studies) radiometer on board the ATR 42 aircraft from M¶et¶eo-France. The main objective was to contribute to the implementation of the SMOS emission model L-MEB (L-band Microwave Emission model of the Biosphere) in the framework of the validation of SMOS land data and products. Speci¯cally, the objectives of the CAROLS campaigns were the following:Soil Moisture Validation Studies: Previous °ights at the VAS area took place in 2008 in the context of the ESA SMOS Validation Rehearsal Campaign 2008 (EMIRAD radiometer, L-band) over a control area of 10km£10km where intensive soil moisture data was acquired concurrently to airborne L-band measurements. One of the objectives of that campaign was to establish homogeneous units to characterize the average soil moisture of that area, and to investigate the possibility of extending the methodology to the whole SMOS validation pixel at the VAS site. The `homogeneous units' characterisation was studied and extended further in the context of CAROLS 2009, and validated during the CAROLS 2010 campaign.Radiometric Characterisation & SMOS Data Validation: The 10km £ 10km mentioned above is part of a larger area of » 50km £ 50km within the VAS SMOS validation pixel. For CAROLS 2009, °ights were performed over a 30km £ 50km area in order to examine the ra- diometric signature of other surfaces that are present in the VAS SMOS pixel but not in the 10km £ 10km control area examined in 2008 (mostly dense forests, matorral, and non-°at sur- faces). Main results of CAROLS 2009 will be presented in this communication, and the emphasis will be on comparing local to regional scale results given that CAROLS °ights were performed at 4000m above the surface. For 2010, lower altitude °ights (» 2200m a.s.l.) over an area of 20km£20km containing a large number of homogeneous units (`environmental units'), were used for validation of SMOS microwave model L-MEB. The preliminary results of this campaign will be presented in this communication, and the emphasis will be on the validation of the L-MEB model.In addition to the activities at the VAS site, °ights over Los Monegros' salt pans near Zaragoza were performed in the 2010 CAROLS Campaign to study their emissivity at L-band. Three playa-lakes (Guallar, La Playa, and Salineta) were sampled to measure gravimetric soil moisture and electrical conductivity.Peer reviewe

Predictors of complications and mortality following left colectomy with primary stapled anastomosis for cancer: results of a multicentric study with 1111 patients

Aim: Reports detailing the morbidity–mortality after left colectomy are sparse and do not allow definitive conclusions to be drawn. We aimed to identify risk factors for anastomotic leakage, perioperative mortality and complications following left colectomy for colonic malignancies. Method: We undertook a STROBE-compliant analysis of left colectomies included in a national prospective online database. Forty-two variables were analysed as potential independent risk factors for anastomotic leakage, postoperative morbidity and mortality. Variables were selected using the ‘least absolute shrinkage and selection operator’ (LASSO) method. Results: We analysed 1111 patients. Eight per cent of patients had a leakage and in 80% of them reoperation or surgical drainage was needed. A quarter of patients (24.9%) experienced at least one minor complication. Perioperative mortality was 2%, leakage being responsible for 47.6% of deaths. Obesity (OR 2.8, 95% CI 1.00–7.05, P = 0.04) and total parenteral nutrition (TPN) (OR 3.7, 95% CI 1.58–8.51, P = 0.002) were associated with increased risk of leakage, whereas female patients had a lower risk (OR 0.36, 95% CI 0.18–0.67, P = 0.002). Corticosteroids (P = 0.03) and oral anticoagulants (P = 0.01) doubled the risk of complications, which was lower with hyperlipidaemia (OR 0.3, P = 0.02). Patients on TPN had more complications (OR 4.02, 95% CI 2.03–8.07, P = 0.04) and higher mortality (OR 8.7, 95% CI 1.8–40.9, P = 0.006). Liver disease and advanced age impaired survival, corticosteroids being the strongest predictor of mortality (OR 21.5, P = 0.001). Conclusion: Requirement for TPN was associated with more leaks, complications and mortality. Leakage was presumably responsible for almost half of deaths. Hyperlipidaemia and female gender were associated with lower rates of complications. These findings warrant a better understanding of metabolic status on perioperative outcome after left colectomy

Safety of hospital discharge before return of bowel function after elective colorectal surgery

Background: Ileus is common after colorectal surgery and is associated with an increased risk of postoperative complications. Identifying features of normal bowel recovery and the appropriateness for hospital discharge is challenging. This study explored the safety of hospital discharge before the return of bowel function.Methods: A prospective, multicentre cohort study was undertaken across an international collaborative network. Adult patients undergoing elective colorectal resection between January and April 2018 were included. The main outcome of interest was readmission to hospital within 30 days of surgery. The impact of discharge timing according to the return of bowel function was explored using multivariable regression analysis. Other outcomes were postoperative complications within 30 days of surgery, measured using the Clavien-Dindo classification system.Results: A total of 3288 patients were included in the analysis, of whom 301 (9.2 per cent) were discharged before the return of bowel function. The median duration of hospital stay for patients discharged before and after return of bowel function was 5 (i.q.r. 4-7) and 7 (6-8) days respectively (P &lt; 0.001). There were no significant differences in rates of readmission between these groups (6.6 versus 8.0 per cent; P = 0.499), and this remained the case after multivariable adjustment for baseline differences (odds ratio 0.90, 95 per cent c.i. 0.55 to 1.46; P = 0.659). Rates of postoperative complications were also similar in those discharged before versus after return of bowel function (minor: 34.7 versus 39.5 per cent; major 3.3 versus 3.4 per cent; P = 0.110).Conclusion: Discharge before return of bowel function after elective colorectal surgery appears to be safe in appropriately selected patients

Timing of nasogastric tube insertion and the risk of postoperative pneumonia: an international, prospective cohort study

Aim: Aspiration is a common cause of pneumonia in patients with postoperative ileus. Insertion of a nasogastric tube (NGT) is often performed, but this can be distressing. The aim of this study was to determine whether the timing of NGT insertion after surgery (before versus after vomiting) was associated with reduced rates of pneumonia in patients undergoing elective colorectal surgery. Method: This was a preplanned secondary analysis of a multicentre, prospective cohort study. Patients undergoing elective colorectal surgery between January 2018 and April 2018 were eligible. Those receiving a NGT were divided into three groups, based on the timing of the insertion: routine NGT (inserted at the time of surgery), prophylactic NGT (inserted after surgery but before vomiting) and reactive NGT (inserted after surgery and after vomiting). The primary outcome was the development of pneumonia within 30 days of surgery, which was compared between the prophylactic and reactive NGT groups using multivariable regression analysis. Results: A total of 4715 patients were included in the analysis and 1536 (32.6%) received a NGT. These were classified as routine in 926 (60.3%), reactive in 461 (30.0%) and prophylactic in 149 (9.7%). Two hundred patients (4.2%) developed pneumonia (no NGT 2.7%; routine NGT 5.2%; reactive NGT 10.6%; prophylactic NGT 11.4%). After adjustment for confounding factors, no significant difference in pneumonia rates was detected between the prophylactic and reactive NGT groups (odds ratio 1.03, 95% CI 0.56–1.87, P = 0.932). Conclusion: In patients who required the insertion of a NGT after surgery, prophylactic insertion was not associated with fewer cases of pneumonia within 30 days of surgery compared with reactive insertion

Safety of hospital discharge before return of bowel function after elective colorectal surgery

© 2020 BJS Society Ltd Published by John Wiley & Sons LtdBackground: Ileus is common after colorectal surgery and is associated with an increased risk of postoperative complications. Identifying features of normal bowel recovery and the appropriateness for hospital discharge is challenging. This study explored the safety of hospital discharge before the return of bowel function. Methods: A prospective, multicentre cohort study was undertaken across an international collaborative network. Adult patients undergoing elective colorectal resection between January and April 2018 were included. The main outcome of interest was readmission to hospital within 30 days of surgery. The impact of discharge timing according to the return of bowel function was explored using multivariable regression analysis. Other outcomes were postoperative complications within 30 days of surgery, measured using the Clavien–Dindo classification system. Results: A total of 3288 patients were included in the analysis, of whom 301 (9·2 per cent) were discharged before the return of bowel function. The median duration of hospital stay for patients discharged before and after return of bowel function was 5 (i.q.r. 4–7) and 7 (6–8) days respectively (P < 0·001). There were no significant differences in rates of readmission between these groups (6·6 versus 8·0 per cent; P = 0·499), and this remained the case after multivariable adjustment for baseline differences (odds ratio 0·90, 95 per cent c.i. 0·55 to 1·46; P = 0·659). Rates of postoperative complications were also similar in those discharged before versus after return of bowel function (minor: 34·7 versus 39·5 per cent; major 3·3 versus 3·4 per cent; P = 0·110). Conclusion: Discharge before return of bowel function after elective colorectal surgery appears to be safe in appropriately selected patients