Spatial distributed modelling of erosion and sediment transport in mountain catchments in the Pyrenees: challenges for calibration and validation

28 p., 10 Figs., 5 Tabls.Publicado inicialmente por la Universidad de La Rioja (España) en: Cuadernos de Investigación Geográfica 39(2) (2013)[EN] Most erosion models applied at basin scale are based on spatially aggregated representation, for example, in a space subdivision of the surfaces to which behavior is assumed homogeneous (sub-basins, hydrological units, etc.). This approach leads to a desirable simplification of the calculations, but presents difficulties in addressing problems related to sediment transport and identification of sediment source areas, which should be treated by a continuous spatial representation. Spatially distributed models, however, allow a more accurate approach to this problem, at the cost of an increased computational complexity. The objective of this work is the calibration and validation of the model WATEM/SEDEM, an empirical-conceptual spatially distributed model, to predict erosion and sediment yield in two watersheds in the Central Spanish Pyrenees: i) the watershed of the Barasona Reservoir (1504 km2), which is drained by the Esera and Isabena Rivers, the model calibration and validation was based on the depositional history of the Barasona Reservoir and suspended sediment records over 3 years (May 2005–May 2008) at the outlet of the Isabena River; ii) the experimental Arnas catchment (2.84 km2), the model calibration was performed based on a dataset of soil redistribution rates derived from point 137Cs inventories, allowing capture differences per land use in the main model parameters. The validation process was carried with the registration of six years of suspended sediment at the outlet of the Arnas catchment. The calibration process for watershed of the Barasona Reservoir showed the problem you have when trying to calibrate the parameters of transport capacity with a single variable (the export of sediment to the basin outlet), making impossible to find a single set of parameters that optimize the error function, making it necessary to adopt a compromise solution. For the experimental Arnas catchment the model calibration processes using spatially distributed sediment yield derived from 137Cs inventories allowed calibrating the empirical parameters of transport capacity in a satisfactory way, finding a single combination of values that optimizes the error function. These results show that the calibration parameters of transport capacity are a fundamental aspect of the model WATEM/SEDEM and other similar models. To obtain a reliable estimate of the spatial distribution of erosion and sediment transport requires a calibration and validation by means of spatially distributed data of soil loss, which in turn allows a calibration of spatially distributed parameters concerning transport capacity.[ES] Una gran parte de los modelos de erosion aplicados a escala de cuenca se basan en una representacion espacialmente agregada, es decir en la subdivision del espacio en superficies a las que se supone un comportamiento homogeneo (subcuencas, unidades hidrologicas, etc.). Esta aproximacion conlleva una deseable simplificacion de los calculos, pero presenta dificultades para abordar problemas relacionados con el transporte de sedimentos y la identificacion de areas fuente de sedimento, que deben tratarse mediante una representacion espacial continua. Los modelos espacialmente distribuidos, en cambio, permiten una aproximacion mas precisa a este problema, a costa de una mayor complejidad de calculo. El objetivo de este trabajo es la calibracion y validacion del modelo WATEM/SEDEM, un modelo empirico-conceptual espacialmente distribuido, para predecir erosion y la produccion de sedimentos en dos cuencas del Pirineo aragones: i) la cuenca del embalse de Barasona (1504 km2), drenada por los rios Esera e Isabena, donde la base de datos para el proceso de calibracion fue el registro de 3 anos de sedimentos en suspension (mayo 2005-mayo 2008) a la salida de la subcuenca del Rio Isabena y para la validacion se utilizo el registro historico de sedimentacion del embalse de Barasona; y, ii) la cuenca experimental de Arnas (2.84 km2), donde se conto para la calibracion con datos espacialmente distribuidos de tasas de erosion y sedimentacion derivadas de inventarios de Cs137, mas el registro de seis anos de sedimento en suspension a la salida de la cuenca de Arnas para el proceso de validacion. El proceso de calibracion para el embalse de Barasona mostro el problema que se tiene al intentar calibrar los parametros de capacidad de transporte con una sola variable (la exportacion de sedimento a la salida de la cuenca), haciendo imposible encontrar un solo conjunto de parametros que optimicen la funcion de error y obligando a adoptar una solucion de compromiso. En la cuenca de Arnas el uso de datos espacialmente distribuidos de produccion de sedimentos derivados de inventarios de Cs137 permitio calibrar los parametros empiricos de capacidad de transporte de una forma satisfactoria, encontrando una sola combinacion de valores que optimiza la funcion de error. Con los resultados obtenidos se demuestra que la calibracion de los parametros de capacidad de transporte es un aspecto fundamental de WATEM/SEDEM y de otros modelos similares. Para obtener una estimacion fiable de la distribucion espacial de los procesos de erosion y transporte de sedimento se requiere de una calibracion y validacion con datos espacialmente distribuidos de perdida o ganancia de suelo que permita a su vez realizar una calibracion espacialmente distribuida de los parametros relativos a la capacidad de transporte.Este trabajo se ha llevado a cabo con el apoyo del proyecto INDICA (CGL2011- 27753-C02-01 y -02), financiado por el Ministerio de Economia y Competitividad, el proyecto ACQWA (FP7-ENV-2007-1-212250), financiado por la Comision Europea y un acuerdo entre el CSIC y el Ministerio de Medio Ambiente (RESEL). N. Lana-Renault ha disfrutado de un contrato de investigacion en el Programa Juan de la Cierva (Ministerio de Economia y Competitividad). En este articulo han participado numerosos colegas del Departamento de Procesos Geoambientales y Cambio Global del Instituto Pirenaico de Ecologia (IPE), asi como del Departamento de Suelo y Agua de la Est. Exp. Aula Dei (EEAD-CSIC).Peer reviewe

A youth empowerment intervention to prevent childhood obesity: design and methods for a cluster randomized trial of the H2GO! program

BACKGROUND: Reducing sugar-sweetened beverage (SSB) consumption is a promising dietary target for childhood obesity prevention. This paper describes the design and methods of a cluster randomized trial of H2GO!, a youth empowerment intervention to prevent childhood obesity through reducing SSB consumption among a low-income, ethnically diverse sample of youth. METHODS: This cluster randomized controlled trial is an academic-community partnership with the Massachusetts Alliance of Boys and Girls Clubs (BGC). Ten BGC sites will be randomly assigned to the H2GO! intervention or a wait-list, usual care control. Eligible study participants will be N = 450 parent-child pairs (youth ages 9-12 years and their parents/caregivers) recruited from participating BGCs. The 6-week in-person H2GO! intervention consists of 12 group-based sessions delivered by BGC staff and youth-led activities. An innovative feature of the intervention is the development of youth-produced narratives as a strategy to facilitate youth empowerment and parental engagement. Child outcomes include measured body mass index z scores (zBMI), beverage intake, and youth empowerment. Parent outcomes include beverage intake and availability of SSBs at home. Outcomes will be measured at baseline and at 2, 6, and 12 months. With a 75% retention rate, the study is powered to detect a minimum group difference of 0.1 zBMI units over 12 months. DISCUSSION: Empowering youth may be a promising intervention approach to prevent childhood obesity through reducing SSB consumption. This intervention was designed to be delivered through BGCs and is hypothesized to be efficacious, relevant, and acceptable for the target population of low-income and ethnically diverse youth. TRIAL REGISTRATION: ClinicalTrials.gov NCT04265794 . Registered 11 February 2020

Temporal changes of NDVI for qualitative environmental assessment of mangroves: Shrimp farming impact on the health decline of the arid mangroves in the Gulf of California (1990-2010)

We assessed the temporal evolution of vegetation activity of mangroves in the Southeastern coastal of the Gulf of California (Mexico) through a multi-temporal analysis of Landsat TM images from 1990 to 2010 where time series of the Normalized Difference Vegetation Index (NDVI) were obtained. A multivariate regression analysis showed the presence of statistically significant negative trends of NDVI (low vegetation activity) in the coverage of mangrove forest, mangrove forest with pickleweed, and pickleweed; however, we did not found any meteorological variable (built time series of average minimum and maximum temperatures, and of accumulated rainfall) that controlled the observed trends. A pixel-by-pixel spatially distributed analysis of the temporal trends of NDVI, complemented by digitalization through photo interpretation of the shrimp farms present in the study area, showed a spatial relationship between the zones of greatest loss of vegetation activity (1990–2010) and the areas with greater proliferation of shrimp farms in the study area. Our study demonstrated the applicability of NDVI for the environmental assessment of mangroves. The relationship between changes in remote sensing indices and environmental variables allows for an efficient evaluation of the main environmental impacts, which can be used for coastal planning and management.The research was supported by the Mexican Secretary of Natural Resources and Environment (SEMARNAT-CONACYT; grant number SEMARNAT-2002-C01-0147). SM-B and RJM are students of Academic Program of Geoinformatics (UACJ).Peer Reviewe

Biocompatible polymeric microparticles produced by a simple biomimetic approach

The use of superhydrophobic surfaces to produce polymeric particles proves to be biologically friendly since it entails the pipetting and subsequent cross-linking of polymeric solutions under mild experimental conditions. Moreover, it renders encapsulation efficiencies of ∼100%. However, the obtained particles are 1 to 2 mm in size, hindering to a large extent their application in clinical trials. Improving on this technique, we propose the fabrication of polymeric microparticles by spraying a hydrogel precursor over superhydrophobic surfaces followed by photo-cross-linking. The particles were produced from methacrylamide chitosan (MA-CH) and characterized in terms of their size and morphology. As demonstrated by optical and fluorescence microscopy, spraying followed by photo-cross-linking led, for the first time, to the production of spherical particles with diameters on the order of micrometers, nominal sizes not attainable by pipetting. Particles such as these are suitable for medical applications such as drug delivery and tissue engineering.We thank Ivo Aroso and Ana Isabel Neto for their valuable support with FTIR and compression experiments, respectively. A.M.S.C. thanks FCT for financial support through grant BIM/PTDC/CTM-BPC/112774/2009_02. M.A.-M. thanks CONACyT (Mexico) for financial support through post-doc grant no. 203732. N.M.O. thanks FCT for financial support through Ph.D. scholarship no. SFRH/BD/73172/2010. This work was funded by the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. REGPOT-CT2012-316331-POLARIS, by FEDER through the Competitive Factors Operation Program-COMPETE, and by national funds through FCT - Fundacao para a Ciencia e a Tecnologia in the scope of project PTDC/CTM-BIO/1814/2012

Characterization of a membrane-bound C-glucosyltransferase responsible for carminic acid biosynthesis in Dactylopius coccus Costa

Carminic acid is a widely applied red colorant that is still harvested from insects because its biosynthesis is not fully understood. Here, the authors identify and characterize a membrane-bound C-glucosyltransferase catalyzing the final step during carminic acid biosynthesis

Unravelling Chemical Composition of Agave Spines: News from Agave fourcroydes Lem.

Spines are key plant modifications developed to deal against herbivores; however, its physical structure and chemical composition have been little explored in plant species. Here, we took advantage of high-throughput chromatography to characterize chemical composition of Agave fourcroydes Lem. spines, a species traditionally used for fiber extraction. Analyses of structural carbohydrate showed that spines have lower cellulose content than leaf fibers (52 and 72%, respectively) but contain more than 2-fold the hemicellulose and 1.5-fold pectin. Xylose and galacturonic acid were enriched in spines compared to fibers. The total lignin content in spines was 1.5-fold higher than those found in fibers, with elevated levels of syringyl (S) and guaiacyl (G) subunits but similar S/G ratios within tissues. Metabolomic profiling based on accurate mass spectrometry revealed the presence of phenolic compounds including quercetin, kaempferol, (+)-catechin, and (-)-epicatechin in A. fourcroydes spines, which were also detected in situ in spines tissues and could be implicated in the color of these plants' structures. Abundance of (+)-catechins could also explain proanthocyanidins found in spines. Agave spines may become a plant model to obtain more insights about cellulose and lignin interactions and condensed tannin deposition, which is valuable knowledge for the bioenergy industry and development of naturally dyed fibers, respectively

Pseudoprogression and hyperprogression secondary to immunotherapy in lung cancer

BACKGROUND: The treatment of non-small cell lung cancer (NSCLC) has undergone changes that have improved the prognosis of patients. With the advent of immunotherapy, it has been possible to prolong significantly the overall and progression-free survival as well as quality of life. Nevertheless, its use represents clinical challenges which may turn into adverse events, such as progression and pseudo-progression, which are uncontrolled and often deleterious immune responses that simulate tumoral progression, generate worsening of symptoms and performance status of patients and even may lead to non-cancer related death of patients. MATERIALS AND METHODS: We assessed 128 records (clinical trials, reports, meta-analyses) in order to provide an updated review of the treatment of NSCLC, current definitions proposed for pseudo and hyperprogression (which are not homogeneous so far), incidence, theories about their physiopathogenesis, importance of making a judicious diagnostic workup, imaging criteria as well as biochemical markers in order to predict their appearance, concluding with a brief discussion about the topic addressed. CONCLUSIONS: Since there is no definition or standardized diagnostic and imaging criteria, these entities are a topic of major interest in the area of oncologic immunotherapy, for which the following review has been generated