A combined measure for quantifying and qualifying the topology preservation of growing self-organizing maps

The Self-OrganizingMap (SOM) is a neural network model that performs an ordered projection of a high dimensional input space in a low-dimensional topological structure. The process in which such mapping is formed is defined by the SOM algorithm, which is a competitive, unsupervised and nonparametric method, since it does not make any assumption about the input data distribution. The feature maps provided by this algorithm have been successfully applied for vector quantization, clustering and high dimensional data visualization processes. However, the initialization of the network topology and the selection of the SOM training parameters are two difficult tasks caused by the unknown distribution of the input signals. A misconfiguration of these parameters can generate a feature map of low-quality, so it is necessary to have some measure of the degree of adaptation of the SOM network to the input data model. The topologypreservation is the most common concept used to implement this measure. Several qualitative and quantitative methods have been proposed for measuring the degree of SOM topologypreservation, particularly using Kohonen's model. In this work, two methods for measuring the topologypreservation of the Growing Cell Structures (GCSs) model are proposed: the topographic function and the topology preserving ma

Growing Cell Structures Neural Networks for Designing Spectral Indexes

Remote sensing can be defined as the technique that facilitates the acquisition of land surface data without contact with the material object of observation. The development of tools for analyzing and processing multispectral images captured by sensors aboard satellites has provided the automation of tasks that could not be possible otherwise. The main problem related with this discipline is the large volume of data of multidimensional nature that must be handled. The concept of spectral index emerged as an idea to reduce the number of dimensions to one, and thus facilitate the study of different features associated to the types of land cover categories that exhibits a multispectral image. Formally, a spectral index is defined as a combination of spectral bands whose function is to enhance the contribution of one type of land cover mitigating the rest of covers. In this work a no-supervised methodology to analyze and discover spectral indexes based on growing self-organizing neural network (GCS-Growing Cell Structures) is presented

Growing Self-Organizing Maps for Data Analysis

Currently, there exist many research areas that produce large multivariable datasets that are difficult to visualize in order to extract useful information. Kohonen self organizing maps have been used successfully in the visualization and analysis of multidimensional data. In this work, a projection technique that compresses multidimensional datasets into two dimensional space using growing self-organizing maps is described. With this embedding scheme, traditional Kohonen visualization methods have been implemented using growing cell structures networks. New graphical map display have been compared with Kohonen graphs using two groups of simulated data and one group of real multidimensional data selected from a satellite scene

Uso de Redes Neuronales Autoorganizativas Dinámicas no Supervisadas para la Discriminación de tipos de aguas en Lagos.

Las técnicas de clasificación supervisadas aplicadas a imágenes de satélite requieren la selección de muestras representativas de los distintos tipos de clases de cubiertas presentes en la imagen a analizar. El proceso de selección de áreas y su categorización son trabajos que habitualmente se realizan de manera manual por un experto o bien mediante campañas de campo. Para el caso particular de clasificación de imágenes con cubiertas acuosas con diferentes características, hay tres aspectos muy importantes a considerar; en primer lugar, la baja separabilidad de las respuestas espectrales de cada una de las clases de aguas; en segundo lugar, el hecho de que para mejorar los resultados sea necesario trabajar con imágenes de alta resolución, lo que implica que para lagos de tamaños medios y grande el volumen de datos es muy elevado y consecuentemente se requieren una gran cantidad de muestras de entrenamiento; finalmente, cabe destacar el alto costo y complejidad de las tomas de datos en terreno

Enhancing the liquid phase exfoliation of graphite in both aqueous and organic mixtures

Two different solvent mixtures, aqueous and organic, were used in the graphite liquid phase exfoliation. These solvent mixtures were selected through a detailed study of Hansen Solubility Parameters. Different operational sonication parameters (sonication temperature, cycle, amplitude and time) were studied in order to analyze their influence over the exfoliation process. Exfoliated graphite obtained after different sonication conditions were further characterized by RAMAN spectroscopy and thermogravimetric techniques. Obtained results showed that, among all the studied sonication parameters, time is the most important one due to its influence over characteristics of the final exfoliated product. Thus, it was evidenced the defect formation at higher sonication times, being dominant the growth of bulk defects in the structure of exfoliated samples at sonication times superior to 5 hours. As consequence, a careful tuning of the sonication parameters is necessary in order to obtain exfoliated samples with low disorder.Se utilizaron dos mezclas de disolventes diferentes, acuosa y orgánica, en la exfoliación en fase líquida de grafito. Estas mezclas de disolventes se seleccionaron mediante un estudio detallado de los parámetros de solubilidad de Hansen. Se estudiaron diferentes parámetros operativos de sonicación (temperatura, ciclo, amplitud y tiempo de sonicación) para analizar su influencia sobre el proceso de exfoliación. El grafito exfoliado obtenido después de diferentes condiciones de sonicación se caracterizó aún más mediante espectroscopia RAMAN y técnicas termogravimétricas. Los resultados obtenidos mostraron que, entre todos los parámetros de sonicación estudiados, el tiempo es el más importante debido a su influencia sobre las características del producto final exfoliado. Así, se evidenció la formación de defectos a mayores tiempos de sonicación, siendo dominante el crecimiento de defectos de volumen en la estructura de muestras exfoliadas a tiempos de sonicación superiores a 5 horas. Como consecuencia, es necesario un ajuste cuidadoso de los parámetros de sonicación para obtener muestras exfoliadas con bajo desorde

Pregnancy control in patients with systemic lupus erythematosus/antiphospholipid syndrome. Part 2: Pregnancy follow-up

Objective: In order to agree on the fundamental aspects related to the management of pregnancy in patients with systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS), the Spanish Societies of Gynaecology and Obstetrics, Internal Medicine and Rheumatology set up a working group for the preparation of three consensus documents. Methods: Each of the Scientific Societies involved proposed five representatives based on their experience in the field of pregnancy control in patients with autoimmune diseases. The recommendations were developed following the Delphi methodology. Results: This second document contains the recommendations regarding the management of pregnancy in women with SLE and APS, including complications such as lupus activity, congenital heart block, thrombotic and obstetric manifestations of APS and placental vascular disease. Conclusions: These multidisciplinary recommendations are considered decision-making tools for clinicians involved in the care of patients with SLE/APS during pregnancy.Objetivo: Las sociedades españolas de ginecología y obstetricia, de medicina interna y de reumatología han constituido un grupo de trabajo paritario para la elaboración de 3 documentos de consenso sobre el control del embarazo en mujeres con lupus eritematoso sistémico (LES) y síndrome antifosfolípido (SAF).Métodos: Cada una de las sociedades científicas implicadas propuso 5 representantes en base a su experiencia en el área del control del embarazo en pacientes con enfermedades autoinmunes. Las recomendaciones se elaboraron siguiendo la metodología Delphi. Resultados: En este segundo documento se incluyen las recomendaciones que abordan el manejo del embarazo normal y sus complicaciones en mujeres con LES/SAF. Se presentan las recomendaciones relacionadas con el seguimiento del embarazo, la actividad lúpica, el bloqueo cardíaco congénito, las manifestaciones trombóticas y obstétricas del SAF y los defectos de placentación. Conclusiones: Estas recomendaciones multidisciplinares se consideran herramientas en la toma de decisiones para los clínicos involucrados en la asistencia a pacientes con LES/SAF durante el embarazo

Dynamic molecular mechanism of the nuclear pore complex permeability barrier

Nuclear pore complexes (NPCs) mediate nucleocytoplasmic transport of specific macromolecules while impeding the exchange of unsolicited material. However, key aspects of this gating mechanism remain controversial. To address this issue, we determined the nanoscopic behavior of the permeability barrier directly within yeast S. cerevisiae NPCs at transport-relevant timescales. We show that the large intrinsically disordered domains of phenylalanine-glycine repeat nucleoporins (FG Nups) exhibit highly dynamic fluctuations to create transient voids in the permeability barrier that continuously shape-shift and reseal, resembling a radial polymer brush. Together with cargo-carrying transport factors the FG domains form a feature called the central plug, which is also highly dynamic. Remarkably, NPC mutants with longer FG domains show interweaving meshwork-like behavior that attenuates nucleocytoplasmic transport in vivo. Importantly, the bona fide nanoscale NPC behaviors and morphologies are not recapitulated by in vitro FG domain hydrogels. NPCs also exclude self-assembling FG domain condensates in vivo, thereby indicating that the permeability barrier is not generated by a self-assembling phase condensate, but rather is largely a polymer brush, organized by the NPC scaffold, whose dynamic gating selectivity is strongly enhanced by the presence of transport factors.</p

Papel de las diatomeas como indicadores del grado de afección de embalses receptores de AMD: influencia del PH en el modo de ocurrencia

Este trabajo se basa en el estudio de 23 embalses ubicados en la Faja Pirítica Ibérica para llevar a cabo una clasificación ambiental basada en las comunidades de Diatomeas, con especial interés en aquellas acidófilas o ácido tolerantes, para definer la relación de estas comunidades con la físico-química de las aguas. Para ello, la distribución de diatomeas bentónicas se ha caracterizado, en particular en relación con el pH del medio, que ha permitido entender el papel de las diatomeas como indicadores de AMD en los embalses. Los resultados obtenidos confirmaron que las comunidades de diatomeas responden a variaciones en el pH y que el análisis cluster refleja los cambios en las comunidades de los embalses. Se verificó una relación de dependencia entre la abundancia y la distribución de las especies en relación con el pH del agua.Twenty three reservoirs located in the Iberian Pyrite Belt were studied in order to carry out an environmental assessment based on the communities of Diatoms, with special interest in those that present an acidophilic or acid-tolerant profile and to define the relation of these communities with the physical-chemical characteristics of the water. For this purpose, the distribution of benthic diatoms has been studied, in particular in relation to the pH of the medium, which has allowed. understanding the role of diatoms as indicators of AMD in the reservoirs. The obtained results confirmed that the diatom communities respond to variations in pH and that the cluster analysis reflects those changes in the communities of the reservoirs. A relationship of dependence between the abundance and distribution of the species under study with respect to the pH of the water was verified.info:eu-repo/semantics/publishedVersio

Pregnancy Control in Patients with Systemic Lupus Erythematosus and Antiphospholipid Syndrome. Part 1: Infertility, Ovarian Preservation and Preconception Assessment. Consensus Document of the Spanish Society of Gynaecology and Obstetrics (SEGO), the Spanish Society of Internal Medicine (SEMI) and the Spanish Society of Rheumatology (SER)

Objetivo: El embarazo y el puerperio se consideran una situación de riesgo en mujeres con lupus eritematoso sistémico (LES) y síndrome antifosfolípido (SAF). Es esencial que especialistas en enfermedades autoinmunes y en embarazo de alto riesgo intervengan en su seguimiento de forma coordinada. La Sociedad Española de Ginecología y Obstetricia, la Sociedad Española de Medicina Interna, y la Sociedad Española de Reumatología han constituido un grupo de trabajo paritario para la elaboración de 3 documentos de consenso. Métodos: Las fases del trabajo fueron: distribución del trabajo en grupos correspondientes a los 3 períodos relacionados con la gestación, identificación de áreas clave, revisión de la literatura y formulación de recomendaciones. Resultados: En este primer documento se incluyen las primeras 48 recomendaciones que tratan aspectos relacionados con la infertilidad, la necesidad y los tratamientos de preservación gonadal y la valoración preconcepcional. Conclusiones: Estas recomendaciones multidisciplinares se consideran herramientas en la toma de decisiones para los clínicos involucrados en la asistencia a pacientes con LES/SAF durante el embarazo

Rapid and sustained B-cell depletion with subcutaneous ofatumumab in relapsing multiple sclerosis : APLIOS, a randomized phase-2 study

Background: Ofatumumab, the first fully human anti-CD20 monoclonal antibody, is approved in several countries for relapsing multiple sclerosis (RMS). Objective: To demonstrate the bioequivalence of ofatumumab administered by an autoinjector versus a pre-filled syringe (PFS) and to explore the effect of ofatumumab on B-cell depletion. Methods: APLIOS (NCT03560739) is a 12-week, open-label, parallel-group, phase-2 study in patients with RMS receiving subcutaneous ofatumumab 20 mg every 4 weeks (q4w) (from Week 4, after initial doses on Days 1, 7, and 14). Patients were randomized 10:10:1:1 to autoinjector or PFS in the abdomen, or autoinjector or PFS in the thigh, respectively. Bioequivalence was determined by area under the curve (AUCτ) and maximum plasma concentration (Cmax) for Weeks 8-12. B-cell depletion and safety/tolerability were assessed. Results: A total of 256 patients contributed to the bioequivalence analyses (autoinjector-abdomen, n = 128; PFS-abdomen, n = 128). Abdominal ofatumumab pharmacokinetic exposure was bioequivalent for autoinjector and PFS (geometric mean AUCτ, 487.7 vs 474.1 h × µg/mL (ratio 1.03); Cmax, 1.409 vs 1.409 µg/mL (ratio 1.00)). B-cell counts (median cells/µL) depleted rapidly in all groups from 214.0 (baseline) to 2.0 (Day 14). Ofatumumab was well tolerated. Conclusion: Ofatumumab 20 mg q4w self-administered subcutaneously via autoinjector is bioequivalent to PFS administration and provides rapid B-cell depletion