An Adaptive Semi-Parametric and Context-Based Approach to Unsupervised Change Detection in Multitemporal Remote-Sensing Images

In this paper, a novel automatic approach to the unsupervised identification of changes in multitemporal remote-sensing images is proposed. This approach, unlike classical ones, is based on the formulation of the unsupervised change-detection problem in terms of the Bayesian decision theory. In this context, an adaptive semi-parametric technique for the unsupervised estimation of the statistical terms associated with the gray levels of changed and unchanged pixels in a difference image is presented. Such a technique exploits the effectivenesses of two theoretically well-founded estimation procedures: the reduced Parzen estimate (RPE) procedure and the expectation-maximization (EM) algorithm. Then, thanks to the resulting estimates and to a Markov Random Field (MRF) approach used to model the spatial-contextual information contained in the multitemporal images considered, a change detection map is generated. The adaptive semi-parametric nature of the proposed technique allows its application to different kinds of remote-sensing images. Experimental results, obtained on two sets of multitemporal remote-sensing images acquired by two different sensors, confirm the validity of the proposed approach

A partially unsupervised cascade classifier for the analysis of multitemporal remote-sensing images

A partially unsupervised approach to the classification of multitemporal remote-sensing images is presented. Such an approach allows the automatic classification of a remote-sensing image for which training data are not available, drawing on the information derived from an image acquired in the same area at a previous time. In particular, the proposed technique is based on a cascade classifier approach and on a specific formulation of the expectation-maximization (EM) algorithm used for the unsupervised estimation of the statistical parameters of the image to be classified. The results of experiments carried out on a multitemporal data set confirm the validity of the proposed approach

La formación de profesores de Ciencias en y para la diversidad

Este escrito da a conocer el producto de un equipo de docentes de diferentes áreas que forman parte del Grupo de Investigación en Educación en Ciencias Experimentales (GREECE), y desarrollan el proyecto AIDETC y ACACIA, éste último soporta el mismo pero no se profundizará en esta comunicación. Dentro de la Alianza de Instituciones para el Desarrollo de la Educación y la Tecnología en Colombia (AIDETC), el grupo tiene como objetivo desarrollar material didáctico para el uso, aprovechamiento y desarrollo adecuados de Tecnologías de la Información y Comunicación. En este sentido se desarrolló un curso con docentes en formación y en ejercicio para la elaboración Ambientes Virtuales de Aprendizaje (AVA), organizados y soportados bajo la estructura de una unidad didáctica (UD) de Sanmartí (2002). Se tiene presente que una de las características del AVA es que debía funcionar para poblaciones con diversidad, oyentes, hipo acúsicos o sordas

Quantum Singular Value Decomposer

We present a variational quantum circuit that produces the Singular Value Decomposition of a bipartite pure state. The proposed circuit, that we name Quantum Singular Value Decomposer or QSVD, is made of two unitaries respectively acting on each part of the system. The key idea of the algorithm is to train this circuit so that the final state displays exact output coincidence from both subsystems for every measurement in the computational basis. Such circuit preserves entanglement between the parties and acts as a diagonalizer that delivers the eigenvalues of the Schmidt decomposition. Our algorithm only requires measurements in one single setting, in striking contrast to the $3^n$ settings required by state tomography. Furthermore, the adjoints of the unitaries making the circuit are used to create the eigenvectors of the decomposition up to a global phase. Some further applications of QSVD are readily obtained. The proposed QSVD circuit allows to construct a SWAP between the two parties of the system without the need of any quantum gate communicating them. We also show that a circuit made with QSVD and CNOTs acts as an encoder of information of the original state onto one of its parties. This idea can be reversed and used to create random states with a precise entanglement structure.Comment: 6 + 1 pages, 5 figure

Arsenic immobilization and transformation by biofilms developed over riverbed sediments

Biofilms are complex communities of autotrophic and heterotrophic organisms immersed in a matrix mainly composed by polysaccharides. They are ubiquitous over wet surfaces and provide protection for microorganisms. In river environments there is evidence that biofilms play an important role in the biogeochemical cycles of nutrients and contaminants. The objective of this work is to evaluate the effect of the fluvial epipsammic biofilm on the retention and transformation of As and to understand its interaction with this metalloid in the Anllóns River (Galicia, NW Spain), where As pollution has been observed. The results revealed that biofilms play a key role in As biogeochemistry in freshwater environments, favouring As immobilization, especially in environments where As and P occur simultaneously, and promoting As detoxification by inhibiting the reduction of AsV to AsIII and methylating inorganic As

Seed Policy in Colombia

Este ensayo pretende dar una visión general de la nueva política de semillas en Colombia teniendo como base el hecho de la tradición campesina que recoge sus mejores frutos para próximas cosechas y contrastando con los nuevos esquemas donde esta práctica es condenada por la ley debido a la creciente inserción de Colombia a la economía global y el establecimiento de un monopolio semillero con base en la protección de la propiedad intelectual. Así mismo examina las implicaciones del uso de semillas genéticamente modificadas y sus efectos a nivel de biodiversidad, legislación, en lo cultural y lo económico.This paper aims to give an overview of the new seed policy in Colombia based on the peasant's tradition that collect the best products for future harvests contrasting with the new schemes where this practice is condemned by the law due to the increasing integration of Colombia to the global economy and the establishment of a seed monopoly based on the protection of intellectual property. This text also examines the implications of the use of genetically modified seeds and their effects on biodiversity, legislation, culture and economy

AIUTA : software de apoyo a las terapias de logogenia en niños sordos de 8 a 12 años

Ingeniero (a) de SistemasPregrad

GLEAM v3 : satellite-based land evaporation and root-zone soil moisture

The Global Land Evaporation Amsterdam Model (GLEAM) is a set of algorithms dedicated to the estimation of terrestrial evaporation and root-zone soil moisture from satellite data. Ever since its development in 2011, the model has been regularly revised, aiming at the optimal incorporation of new satellite-observed geophysical variables, and improving the representation of physical processes. In this study, the next version of this model (v3) is presented. Key changes relative to the previous version include (1) a revised formulation of the evaporative stress, (2) an optimized drainage algorithm, and (3) a new soil moisture data assimilation system. GLEAM v3 is used to produce three new data sets of terrestrial evaporation and root-zone soil moisture, including a 36-year data set spanning 1980-2015, referred to as v3a (based on satellite-observed soil moisture, vegetation optical depth and snow-water equivalent, reanalysis air temperature and radiation, and a multi-source precipitation product), and two satellite-based data sets. The latter share most of their forcing, except for the vegetation optical depth and soil moisture, which are based on observations from different passive and active C-and L-band microwave sensors (European Space Agency Climate Change Initiative, ESA CCI) for the v3b data set (spanning 2003-2015) and observations from the Soil Moisture and Ocean Salinity (SMOS) satellite in the v3c data set (spanning 2011-2015). Here, these three data sets are described in detail, compared against analogous data sets generated using the previous version of GLEAM (v2), and validated against measurements from 91 eddy-covariance towers and 2325 soil moisture sensors across a broad range of ecosystems. Results indicate that the quality of the v3 soil moisture is consistently better than the one from v2: average correlations against in situ surface soil moisture measurements increase from 0.61 to 0.64 in the case of the v3a data set and the representation of soil moisture in the second layer improves as well, with correlations increasing from 0.47 to 0.53. Similar improvements are observed for the v3b and c data sets. Despite regional differences, the quality of the evaporation fluxes remains overall similar to the one obtained using the previous version of GLEAM, with average correlations against eddy-covariance measurements ranging between 0.78 and 0.81 for the different data sets. These global data sets of terrestrial evaporation and root-zone soil moisture are now openly available at www.GLEAM.eu and may be used for large-scale hydrological applications, climate studies, or research on land-atmosphere feedbacks

Genetic relatedness of Burkholderia contaminans clinical isolates from cystic fibrosis and non-cystic fibrosis patients in Argentina

Introduction: The Burkholderia cepacia complex (BCC) bacteria are opportunistic pathogens that cause nosocomial infections and are especially dangerous for cystic fibrosis (CF) patients. Burkholderia contaminans is an emerging BCC species isolated from CF patients that also occurs as a contaminant in pharmaceutical and personal care products, sometimes linking it with outbreaks. Methodology: A total of 55 B. contaminans isolates from CF and non-CF patients in Argentina were identified by recA sequencing and MALDI TOF MS. A standardized Pulsed Field Gel Electrophoresis (PFGE) protocol was set up in order to assess genetic diversity, outbreak investigations, and possible clone persistence. Results: All isolates were identified as B. contaminans by both MALDI-TOF MS and recA sequence analysis. PFGE has enabled us to compare and determine the genetic relationship between B. contaminans isolates. Isolates were distributed in different PFGE clusters with evidence of the presence and persistence of a clone, over a period of 3 years, in the same hospital. This large hospital outbreak involved CF and non-CF patients. Moreover, PFGE results showed a good correlation between sporadic or outbreak-related isolates and the available epidemiological information. Conclusions: These findings highlight the importance of B. contaminans in Argentina and provide evidence for encouraging the surveillance of highly transmissible clones. The study also contributes to global knowledge about B. contaminans infections.Fil: Cipolla, Lucia. Dirección Nacional de Instituto de Investigación.Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos G. Malbrán"; ArgentinaFil: Prieto, Monica. Bacteriología Especial, Inei-anlis Dr. Malbran; ArgentinaFil: Faccone, Diego Francisco. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas. Área de Antimicrobianos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Tracking Sensory Characteristics of Virgin Olive Oils During Storage: Interpretation of Their Changes from a Multiparametric Perspective

Virgin olive oil is inevitably subject to an oxidation process during storage that can affect its stability and quality due to off-flavors that develop before the oil surpasses its ‘best before’ date. Many parameters are involved in the oxidation process at moderate conditions. Therefore, a multiparametric study is necessary to establish a link between physico-chemical changes and sensory quality degradation in a real storage experiment. In this context, a storage experiment of 27 months was performed for four monovarietal virgin olive oils, bottled in transparent 500-mL PET bottles and subjected to conditions close to a supermarket scenario. Volatile composition, quality parameters and phenolic compounds were determined monthly. Simultaneously, an accredited sensory panel assessed their sensory characteristics. The stability of the fresh samples was also studied with the oxidative stability index (OSI) and mesh cell-FTIR. (E)-2-hexenal, (Z)-3-hexen-1-ol and (E)-2-hexen-1-ol were identified as markers of the fruity attribute. Hexanal and nonanal were also identified as compounds that were associated with the rise of median of defect during storage. Some disagreements were observed between the sensory assessment and the OSI analyzed by Rancimat. However, the increase of concentration of rancid markers agreed with the increase of aldehyde band measured with mesh cell-FTIR.Spanish Research State Agency (research projects AGL2015-69320-R and RTI2018-101546-B-C21