Evaluation of resampling applied to UAV imagery for weed detection using OBIA

Los vehículos aéreos no tripulados (UAVs) son una tecnología emergente en el estudio de parámetros agrícolas por sus características y por portar sensores en diferente rango espectral. En este trabajo se ha detectado y cartografiado rodales de malas hierbas en fase temprana mediante análisis OBIA para elaborar mapas que optimicen el tratamiento herbicida localizado. Se ha aplicado resampling (resampleo) sobre imágenes tomadas en campo desde un UAV (UAV-I) para crear una nueva imagen con distinta resolución espacial. A las imágenes resampleadas (RS-I) se les evaluó la calidad espacial y espectral y la eficacia de nuestro análisis en la detección de malas hierbas. Los resultados de las imágenes RS-I muestran una precisión similar a las imágenes UAV-I siendo factible su utilización en tecnologías de manejo localizado de malas hierbas. Se discuten las ventajas del uso de la técnica de resampling en imágenes UAV.Unmanned aerial vehicles (UAV) are an emerging technology for the study of agriculture parameters due to its characteristics and the availability of embedding sensors with different spectral range. In our study, the detection and mapping of weeds in early phenological stage allowed to design a strategy for the optimizing of herbicide treatment. In this work, resampling is used to create a new version of an image with a different spatial resolution, using real UAV imagery. A spatial and spectral quality evaluation was carried out to resampled images (RS-I), and then, our workflow for weed detection applied. The results showed that RS-I and UAV-I showed similar accuracy on weed detection and thus could be used for site-specific weed management achieving a percentage of savings in the herbicide. Opportunities of using RS-I are discussed

El programa informático “Clustering Assessment IDL.IAS.1” para el agrupamiento e integración de píxeles contiguos en imágenes remotas

Contiene 7 documentos (1. Objetivos, alcance y publicaciones. 2. Registro y código) y 5 con el softwareA research group of the Institute for Sustainable Agriculture (CSIC, Cordoba, Spain) has developed a procedure to spatially assess key agronomic and environmental characteristics of tree orchards from remote sensing images through the software named Clustering Assessment® (CLUAS).In the attached paper the CLUAS software development and the information generated by for selected olive orchards and its validation with ground-truth data is shown. CLUAS works as an add-on of ENVI®, and operates integrating the digital values (DV) of the neighboring pixels within a defined range of DV. In the orchards plots trees, other vegetation cover and bare soil were the land uses considered and the range of digital values (BDV) which best define each of them determined. CLUAS provides parameters of each tree, such as the geometric centre, the number of pixels or area, and the integrated digital values or relative potential yield. CLUAS also characterizes key parameters of tree groves, such as the total area and the number, area and the relative potential productivity of the whole trees; and similarly for the other land uses such as vegetation cover and bare soil. Remote images with spatial resolution from 0.25 to 1.5m were suitable for olive grove characterization.CLUAS can contribute to the site-specific management of tree groves, providing quantitative information on each tree, small areas of an orchard, or whole orchards.Peer reviewe

Optimizing algorithms for thresholding segmentation applied to weed detection on UAV remote images.

En este trabajo se ha buscado la implementación de una alternativa al método de Otsu (1979) desarrollada por Hui-Fuang Ng (2006), el cual maximiza la diferencia entre varianzas espectrales y realiza una búsqueda multiumbral. En el estudio se emplearon imágenes procedentes de vehículos aéreos no tripulados (UAVs) tomadas en cultivos de maíz y girasol. Con una única ejecución del algoritmo en un entorno de análisis orientado a objetos, se discriminan aquellos objetos correspondientes a la fracción vegetal del suelo desnudo y se estima un umbral diferenciador entre cultivo y malas hierbas que contribuya a un subsiguiente proceso de clasificación. La técnica de Hui-Fuang detectó un mayor porcentaje de vegetación en todos los casos estudiados, oscilando el incremento entre un 3% y un 20%.This works aimed to implement an alternative to Otsu’s method (1979) developed by Hui- Fuang Ng (2006), which maximizes the difference between spectral variances and performs a multithreshold seeking. Unmanned aerial images taken in maize and sunflower crops were used in the research. In a single algorithm execution applied to an Object Based Image Analysis environment, the objects corresponding to both the vegetation fraction and bare soil are discriminated and a threshold to separate crop from weeds was also estimated, making easier a subsequent classification process. Fui-Huang’s technique provides a higher percentage of vegetation detection in all the cases, with an improvement which ranges from 3% to 20%

Sectioning remote imagery for characterization of Avena sterilis infestations. Part A: Weed abundance

Software was developed to spatially assess key crop characteristics from remotely sensed imagery. Sectioning and Assessment of Remote Images (SARI ®), written in IDL ® works as an add-on to ENVI ®, has been developed to implement precision agriculture strategies. SARI ® splits field plot images into grids of rectangular >micro-images> or >micro-plots>. The micro-plot length and width were defined as multiples of the image spatial resolution. SARI ® calculates different indicators for each micro-plot, including the integrated pixel digital values. Studies on weed patches were done with SARI ® using ground-truth data and remote images of two wheat plots infested with Avena sterilis at LaFloridaII and Navajas (Southern Spain). Patches of A. sterilis represented 47.5 and 19.2% of the field areas at the two locations, respectively; the infested areas were a combination of a few large and several small patches. At LaFloridaII, 2.1% of all patches were >500 m 2 and 55.0% of all patches were smaller than 10 m 2. Based on ground-truth weed abundance data, SARI ® output includes geo-referenced and visual herbicide prescription maps, which could be used with variable-rate application equipment. © 2011 Springer Science+Business Media, LLC.This research was partially financed by the Spanish Commission of Science and Technology through the projects AGL2007-60926 and AGL2010-15506.This research was partially financed by the Spanish Commission of Science and Technology through the projects AGL2007-60926 and AGL2010-15506.Peer Reviewe

Mapeo y cuantificación de las infestaciones de Orobanche crenata en guisantes mediante teledetección

Póster presentado en el XIII Congreso Nacional de Malherbología celebrado en La Laguna (Tenerife) en noviembre de 2011.Los jopos (Orobanche crenata Forsk.) son especies parásitas de cultivos leguminosos, muy extendidas en el área mediterránea (García-Torres et al., 1994). La agricultura de precisión trata de determinar y manejar la distribución espacial de factores bióticos, tales como malas hierbas y patógenos, y de factores abióticos y así fundamentar la aplicación de inputs a dosis variables, ajustados a las necesidades de pequeñas aéreas o sub-parcelas. El objetivo de este trabajo es describir brevemente la discriminación de rodales de jopos en el cultivo de guisante (Pisum sativum L.) mediante imágenes remotas multiespectrales y su manejo de precisión mediante el software SARI® (Sectioning and Assessment of Remote Images) un módulo complementario de ENVI® que divide y cuantifica la imagen de una parcela en sub-parcelas.Esta investigación se ha financiado en parte a través de los proyectos AGL2007-60926 (FEDER) y AGL2010-15506 (FEDER).Peer reviewe

Doping of graphene nanoribbons via functional group edge modification

We report the on-surface synthesis of 7-armchair graphene nanoribbons (7-AGNRs) substituted with nitrile (CN) functional groups. The CN groups are attached to the GNR backbone by modifying the 7-AGNR precursor. Whereas many of these groups survive the on-surface synthesis, the reaction process causes the cleavage of some CN from the ribbon backbone and the on-surface cycloisomerization of few nitriles onto pyridine rings. Scanning tunneling spectroscopy and density functional theory reveal that CN groups behave as very efficient n-dopants, significantly downshifting the bands of the ribbon and introducing deep impurity levels associated with the nitrogen electron lone pairs.This work was supported by FP7 FET-ICT “Planar Atomic and Molecular Scale devices” (PAMS) project (funded by the European Commission under Contract No. 610446), by the Agencia Estatal de Investigacion (Cooperative Grant No. MAT2016-78293 and Grant FIS2015-62538-ERC), the Basque Government (Dep. de Educacion and UPV/EHU, Grant No. IT-756-13, and Dep. Industry, Grant PI_2015_1_42), the Xunta de Galicia (Centro singular de investigacion de Galicia accreditation 2016−2019, ED431G/09), and the European Regional Development Fund (ERDF).Peer Reviewe

Electronic consequences of chemical doping of 7-Armchair Graphene Nanoribbons

Resumen del trabajo presentado a la International Conference on Nanoscience + Technology (ICN+T), celebrada en Brno (Czech Republic) del 22 al 27 de julio de 2018.The tunable electronic structure of Graphene Nanoribbons (GNRs) with different edge types has provoked great interest due to potential applications in electronic devices as molecular diodes or transistors. Thanks to the on-surface synthesis of chemically customized molecular precursors, nanoribbons with atomically defined structure can be grown. This high precision in their bottom-up growth allows to tune their electronic structure via width control or chemical doping. Here we use two different strategies to chemically modify 7-armchair GNRs (7-AGNRs) to clarify how the chemical modifications on the nanoribbons’ structure affect their electronic properties. By means of Scanning Tunneling Spectroscopy we tackle with atomic precision this issue on 7-AGNRs with substitutional nitrile functional groups at the ribbons’ edges and on 7-AGNRs with substitutional boron atoms within the ribbons’ backbone. We find that in the first case the CN groups lead to an efficient n-like doping of the ribbon, while in the second case B atoms induce the formation of a new acceptor band and bandgap renormalization.Peer Reviewe

Hierarchy in the halogen activation during surface-promoted ullmann coupling

Within the collection of surface-supported reactions currently accessible for the production of extended molecular nanostructures under ultra-high vacuum, Ullmann coupling has been the most successful in the controlled formation of covalent single C−C bonds. Particularly advanced control of this synthetic tool has been obtained by means of hierarchical reactivity, commonly achieved by the use of different halogen atoms that consequently display distinct activation temperatures. Here we report on the site-selective reactivity of certain carbon-halogen bonds. We use precursor molecules halogenated with bromine atoms at two non-equivalent carbon atoms and found that the Ullmann coupling occurs on Au(111) with a remarkable predilection for one of the positions. Experimental evidence is provided by means of scanning tunneling microscopy and core level photoemission spectroscopy, and a rationalized understanding of the observed preference is obtained from density functional theory calculations.The project leading to this publication has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No 635919), from the Spanish Ministry of Economy, Industry and Competitiveness (MINECO, Grant Nos. MAT2016‐78293‐C6‐R) and María de Maeztu Units of Excellence Program MDM‐2026‐0618. We also acknowledge financial support from the Xunta de Galicia (Centro singular de investigación de Galicia, accreditation 2016–2019, ED431G/09) and Fondo Europeo de Desarrollo Regional (FEDER). This work used the “Imbabura” computer cluster of Yachay Tech University, which was purchased under contract No. 2017‐024 (SIE‐UITEY‐007‐2017).Peer reviewe

Current clinical spectrum of common variable immunodeficiency in Spain: The multicentric nationwide GTEM-SEMI-CVID registry

Common variable immunodeficiency (CVID) constitutes a heterogenic group of primary immunodeficiency disorders with a wide-ranging clinical spectrum. CVID-associated non-infectious morbidity constitutes a major challenge requiring a full understanding of its pathophysiology and its clinical importance and global variability, especially considering the broad clinical, genetic, and regional heterogeneity of CVID disorders. This work aimed to develop a nationwide, multicenter, retrospective study over a 3-year period describing epidemiological, clinical, laboratory, therapeutic, and prognostic features of 250 CVID patients in Spain. The mean diagnostic delay was around 10 years and most patients initially presented with infectious complications followed by non-infectious immune disorders. However, infectious diseases were not the main cause of morbimortality. Non-infectious lung disease was extraordinarily frequent in our registry affecting approximately 60% of the patients. More than one-third of the patients in our cohort showed lymphadenopathies and splenomegaly in their follow-up, and more than 33% presented immune cytopenias, especially Evans' syndrome. Gastrointestinal disease was observed in more than 40% of the patients. Among biopsied organs in our cohort, benign lymphoproliferation was the principal histopathological alteration. Reaching 15.26%, the global prevalence of cancer in our registry was one of the highest reported to date, with non-Hodgkin B lymphoma being the most frequent. These data emphasize the importance of basic and translational research delving into the pathophysiological pathways involved in immune dysregulation and diffuse lymphocytic infiltration. This would reveal new tailored strategies to reduce immune complications, and the associated healthcare burden, and ensure a better quality of life for CVID patients

Dietary Iron, Anemia Markers, Cognition, and Quality of Life in Older Community-Dwelling Subjects at High Cardiovascular Risk

Anemia causes hypo-oxygenation in the brain, which could lead to cognitive disorders. We examined dietary iron intake as well as anemia markers (i.e., hemoglobin, hematocrit, mean corpuscular volume) and diabetes coexistence in relation to neuropsychological function and quality of life. In this study, 6117 community-dwelling adults aged 55-75 years (men) and 60-75 years (women) with overweight/obesity and metabolic syndrome were involved. We performed the Mini-Mental State Examination (MMSE), the Trail Making Test parts A and B (TMT-A/B), Semantic Verbal Fluency of animals (VFT-a), Phonological Verbal Fluency of letter P (VFT-p), Digit Span Test (DST), the Clock Drawing Test (CDT), and the Short Form-36 Health Survey (SF36-HRQL test). Dietary iron intake did not influence neuropsychological function or quality of life. However, anemia and lower levels of anemia markers were associated with worse scores in all neurophysiological and SF36-HRQL tests overall, but were especially clear in the MMSE, TMT-B (cognitive flexibility), and the physical component of the SF36-HRQL test. The relationships between anemia and diminished performance in the TMT-A/B and VFT tasks were notably pronounced and statistically significant solely among participants with diabetes. In brief, anemia and reduced levels of anemia markers were linked to inferior cognitive function, worse scores in different domains of executive function, as well as a poorer physical, but not mental, component of quality of life. It was also suggested that the coexistence of diabetes in anemic patients may exacerbate this negative impact on cognition. Nevertheless, dietary iron intake showed no correlation with any of the outcomes. To make conclusive recommendations for clinical practice, our findings need to be thoroughly tested through methodologically rigorous studies that minimize the risk of reverse causality