Search strategies and the automated control of plant diseases

We propose the use of the "infotaxis" search strategy as the navigation system of a robotic platform, able to search and localize infectious foci by detecting the changes in the profile of volatile organic compounds emitted by and infected plant. We builded a simple and cost effective robot platform that substitutes odour sensors in favour of light sensors and study their robustness and performance under non ideal conditions such as the exitence of obstacles due to land topology or weeds

Control asíncrono de sistemas BCI basados en ERP mediante la detección de potenciales evocados visuales de estado estable provocados por los estímulos periféricos del paradigma oddball

[ES] Los sistemas Brain-Computer Interface (BCI) permiten la comunicación en tiempo real entre el cerebro y el entorno midiendo la actividad neuronal, sin la necesidad de que intervengan músculos o nervios periféricos. En la práctica, normalmente se emplea el electroencefalograma (EEG) para registrar la actividad cerebral, debido a que se realiza con un equipo portable, no invasivo y de bajo coste en comparación con otras técnicas disponibles. Una vez adquirida la señal EEG, esta es analizada en tiempo real por un software que determina las intenciones del usuario y las traduce en comandos de la aplicación, proporcionando una realimentación visual o auditiva. En concreto, los sistemas BCI basados en potenciales relacionados con eventos (event related potentials, ERP) utilizan el llamado paradigma oddball. Este paradigma presenta una matriz de comandos, cuyas filas y columnas se iluminan de manera secuencial. Para seleccionar un comando, el usuario debe mirar a fijamente a la celda correspondiente de la matriz. Los estímulos visuales, percibidos con la región central de su campo visual, provocan un ERP en la señal de EEG. Posteriormente, el sistema determina el comando que quiere seleccionar el usuario mediante la detección de estos ERP. Actualmente, una de las mayores limitaciones de los sistemas BCI basados en ERP es que son inherentemente síncronos. La aplicación selecciona un comando después de un número predefinido de iluminaciones, aunque el usuario no esté atendiendo a los estímulos. Esta limitación restringe el uso de estos sistemas en la vida real, donde los usuarios deberían poder dejar de prestar atención a la aplicación para realizar otras tareas sin que se seleccionen comandos indeseados. Esta característica es especialmente importante en aplicaciones BCI enfocadas al aumento de la calidad de vida de personas con grave discapacidad, como navegadores web o sistemas de control de sillas de ruedas. Para resolver esta limitación, es necesario añadir al sistema un método que detecte en tiempo real si el usuario realmente quiere seleccionar un comando. En este estudio presentamos un novedoso método de asincronía para detectar en tiempo real el estado de control del usuario en los sistemas BCI basados en EPR. Con este objetivo, el sistema detecta los potenciales evocados visuales de estado estable (steady-state visual evoked potentials, SSVEP) provocados por los estímulos periféricos del paradigma oddball. Estas ondas son la respuesta oscilatoria que aparece en la señal de EEG cuando se recibe una estimulación repetitiva a una frecuencia constante. Las iluminaciones periféricas del paradigma oddball provocan un SSVEP a la frecuencia de estimulación, que aparece únicamente cuando el usuario está mirando a la matriz. Por tanto, la detección de esta componente permite determinar si el usuario quiere seleccionar un comando o no. El método propuesto ha sido validado de manera offline con 5 sujetos sanos, alcanzando una precisión media en la detección del estado de control del usuario del 99.7% con 15 secuencias de estimulación. Estos resultados sugieren que esta metodología permite un control asíncrono fiable del sistema BCI, lo que es de gran utilidad en aplicaciones para la mejora de la calidad de las personas con grave discapacidad.[EN] Synchronicity is an inherent feature of brain–computer interface (BCI) spellers based on event related potentials (ERPs). These systems always make a selection, even when users are engaged in another task. This represents a great limitation in real-life applications, such as wheelchair control or web browsers, in which an asynchronous control should be a key feature. The aim of this study is to design, develop and test a novel algorithm to discriminate whether the user wants to select a command or is not attending the stimuli. In order to achieve such asynchronous control, our method detects the steady-state visual evoked potentials provoked by nontarget stimuli of ERP-based spellers. The proposed method was validated with offline data from 5 healthy subjects, achieving an average accuracy of 99.7%. Our approach is independent of the ERP classification stage, which reduces inter-session variability. Furthermore, to the best of our knowledge, it is the first algorithm for asynchronous control that does not need to extend the duration of the calibration sessions.Este estudio ha sido financiado por el proyecto DPI2017-84280-R del Ministerio de Ciencia, Innovación y Universidades y FEDER y el proyecto “Análisis y correlación entre el genoma completo y la actividad cerebral para la ayuda en el diagnóstico de la enfermedad de Alzheimer” (Programa Operativo de Cooperación Transfronteriza España-Portugal, POCTEP, 2014-2020) de la Comisión Europea y FEDER. Eduardo Santamaría Vázquez es beneficiario de una ayuda de Personal Investigador en Formación (PIF) financiada por la Consejería de Educación de la Junta de Castilla y León y el Fondo Social Europeo. Víctor Martínez-Cagigal es beneficiario de una ayuda PIF-UVa de la Universidad de Valladolid.Santamaría-Vázquez, E.; Martínez-Cagigal, V.; Gomez-Pilar, J.; Hornero, R. (2019). Control asíncrono de sistemas BCI basados en ERP mediante la detección de potenciales evocados visuales de estado estable provocados por los estímulos periféricos del paradigma oddball. En 11º Simposio CEA de Bioingeniería. Editorial Universitat Politècnica de València. 86-96. https://doi.org/10.4995/CEABioIng.2019.10022OCS869

Altered predictive capability of the brain network EEG model in schizophrenia during cognition

[EN]The study of the mechanisms involved in cognition is of paramount importance for the understanding of the neurobiological substrates in psychiatric disorders. Hence, this research is aimed at exploring the brain network dynamics during a cognitive task. Specifically, we analyze the predictive capability of the pre-stimulus theta activity to ascertain the functional brain dynamics during cognition in both healthy and schizophrenia subjects. Firstly, EEG recordings were acquired during a three-tone oddball task from fifty-one healthy subjects and thirty-five schizophrenia patients. Secondly, phase-based coupling measures were used to generate the time-varying functional network for each subject. Finally, pre-stimulus network connections were iteratively modified according to different models of network reorganization. This adjustment was applied by minimizing the prediction error through recurrent iterations, following the predictive coding approach. Both controls and schizophrenia patients follow a reinforcement of the secondary neural pathways (i.e., pathways between cortical brain regions weakly connected during pre-stimulus) for most of the subjects, though the ratio of controls that exhibited this behavior was statistically significant higher than for patients. These findings suggest that schizophrenia is associated with an impaired ability to modify brain network configuration during cognition

Complexity Analysis of Spontaneous Brain Activity in Attention-Deficit/Hyperactivity Disorder: Diagnostic Implications

Background: Attention-deficit/hyperactivity disorder (ADHD) is defined as the most common neurobehavioral disorder of childhood, but an objective diagnostic test is not available yet to date. Neurophychological, neuroimaging, and neurophysiological research offer ample evidence of brain and behavioral dysfunctions in ADHD, but these findings have not been useful as a diagnostic test. Methods: Whole-head magnetoencephalographic recordings were obtained from 14 diagnosed ADHD patients and 14 healthy children during resting conditions. Lempel-Ziv complexity (LZC) values were obtained for each channel and child and averaged in five sensor groups: anterior, central, left lateral, right lateral, and posterior. Results: Lempel-Ziv complexity scores were significantly higher in control subjects, with the maximum value in anterior region. Combining age and anterior complexity values allowed the correct classification of ADHD patients and control subjects with a 93% sensitivity and 79% specificity. Control subjects showed an age-related monotonic increase of LZC scores in all sensor groups, while children with ADHD exhibited a nonsignificant tendency toward decreased LZC scores. The age-related divergence resulted in a 100% specificity in children older than 9 years. Conclusions: Results support the role of a frontal hypoactivity in the diagnosis of ADHD. Moreover, the age-related divergence of complexity scores between ADHD patients and control subjects might reflect distinctive developmental trajectories. This interpretation of our results is in agreement with recent investigations reporting a delay of cortical maturation in the prefrontal corte

Calibrating a photogrammetric digital frame sensor using a test field

In this paper a twofold calibration approach for a digital frame sensor has been developed which tries to cope with panchromatic and multispectral calibration separately. Although there have been several improvements and developments in calibration of the digital frame sensor, only limited progresses has been made in the context of multispectral image calibration. To this end, a specific photogrammetric flight was executed to try to calibrate the geometric parameters of a large format aerial digital camera. This photogrammetric flight was performed in the “Principado de Asturias” and it has been designed with a Ground Sample Distance of 6 cm, formed by two strips perpendicular between each other, with five images each one and a longitudinal overlap of 60%. Numerous points have been presignalled over the ground, both check points and control points

NFATc3 controls tumour growth by regulating proliferation and migration of human astroglioma cells

Calcium/Calcineurin/Nuclear Factor of Activated T cells (Ca/CN/NFAT) signalling pathway is the main calcium (Ca2+) dependent signalling pathway involved in the homeostasis of brain tissue. Here, we study the presence of NFATc members in human glioma by using U251 cells and a collection of primary human glioblastoma (hGB) cell lines. We show that NFATc3 member is the predominant member. Furthermore, by using constitutive active NFATc3 mutant and shRNA lentiviral vectors to achieve specific silencing of this NFATc member, we describe cytokines and molecules regulated by this pathway which are required for the normal biology of cancer cells. Implanting U251 in an orthotopic intracranial assay, we show that specific NFATc3 silencing has a role in tumour growth. In addition NFATc3 knock-down affects both the proliferation and migration capacities of glioma cells in vitro. Our data open the possibility of NFATc3 as a target for the treatment of glioma.This work was supported by grants from the Fondo de Investigaciones Sanitarias (FIS) Spain (PI09/0218) and Red Temática Investigación Cooperativa en Cáncer (RTICC. (RD12/0036/0027) Grants from the Spanish Ministry (MINECO) (SAF2016-76451) to E.C.S

Structural connectivity in schizophrenia and bipolar disorder: Effects of chronicity and antipsychotic treatment

Previous studies based on graph theory parameters applied to diffusion tensor imaging support an alteration of the global properties of structural connectivity network in schizophrenia. However, the specificity of this alteration and its possible relation with chronicity and treatment have received small attention. We have assessed small-world (SW) and connectivity strength indexes of the structural network built using fractional anisotropy values of the white matter tracts connecting 84 cortical and subcortical regions in 25 chronic and 18 first episode (FE) schizophrenia and 24 bipolar patients and 28 healthy controls. Chronic schizophrenia and bipolar patients showed significantly smaller SW and connectivity strength indexes in comparison with controls and FE patients. SW reduction was driven by increased averaged path-length (PL) values. Illness duration but not treatment doses were negatively associated with connectivity strength, SW and PL in patients. Bipolar patients exposed to antipsychotics did not differ in SW or connectivity strength from bipolar patients without such an exposure. Executive functions and social cognition were related to SW index in the schizophrenia group. Our results support a role for chronicity but not treatment in structural network alterations in major psychoses, which may not differ between schizophrenia and bipolar disorder, and may hamper cognition

Switching to Glycerol Phenylbutyrate in 48 Patients with Urea Cycle Disorders: Clinical Experience in Spain

Clinical practice; Glycerol phenylbutyrate; Urea cycle disordersPráctica clinica; Fenilbutirato de glicerol; Trastornos del ciclo de la ureaPràctica clínica; Fenilbutirat de glicerol; Trastorns del cicle de la ureaBackground and objectives: Glycerol phenylbutyrate (GPB) has demonstrated safety and efficacy in patients with urea cycle disorders (UCDs) by means of its clinical trial program, but there are limited data in clinical practice. In order to analyze the efficacy and safety of GPB in clinical practice, here we present a national Spanish experience after direct switching from another nitrogen scavenger to GPB. Methods: This observational, retrospective, multicenter study was performed in 48 UCD patients (age 11.7 ± 8.2 years) switching to GPB in 13 centers from nine Spanish regions. Clinical, biochemical, and nutritional data were collected at three different times: prior to GPB introduction, at first follow-up assessment, and after one year of GPB treatment. Number of related adverse effects and hyperammonemic crisis 12 months before and after GPB introduction were recorded. Results: GPB was administered at a 247.8 ± 102.1 mg/kg/day dose, compared to 262.6 ± 126.1 mg/kg/day of previous scavenger (46/48 Na-phenylbutyrate). At first follow-up (79 ± 59 days), a statistically significant reduction in ammonia (from 40.2 ± 17.3 to 32.6 ± 13.9 μmol/L, p < 0.001) and glutamine levels (from 791.4 ± 289.8 to 648.6 ± 247.41 μmol/L, p < 0.001) was observed. After one year of GPB treatment (411 ± 92 days), we observed an improved metabolic control (maintenance of ammonia and glutamine reduction, with improved branched chain amino acids profile), and a reduction in hyperammonemic crisis rate (from 0.3 ± 0.7 to less than 0.1 ± 0.3 crisis/patients/year, p = 0.02) and related adverse effects (RAE, from 0.5 to less than 0.1 RAEs/patients/year p < 0.001). Conclusions: This study demonstrates the safety of direct switching from other nitrogen scavengers to GPB in clinical practice, which improves efficacy, metabolic control, and RAE compared to previous treatments.This study was funded by AECOM (Spanish Association for the Study of Inborn Errors of Metabolism). Immedica Pharma Spain funded medical writing support and article processing charges

Hepatocellular carcinoma risk-stratification based on ASGR1 in circulating epithelial cells for cancer interception

Purpose: Lack of diagnostic and prognostic biomarkers in hepatocellular carcinoma impedes stratifying patients based on their risk of developing cancer. The aim of this study was to evaluate phenotypic and genetic heterogeneity of circulating epithelial cells (CECs) based on asialoglycoprotein receptor 1 (ASGR1) and miR-122-5p expression as potential diagnostic and prognostic tools in patients with hepatocellular carcinoma (HCC) and liver cirrhosis (LC). Methods: Peripheral blood samples were extracted from LC and HCC patients at different disease stages. CECs were isolated using positive immunomagnetic selection. Genetic and phenotypic characterization was validated by double immunocytochemistry for cytokeratin (CK) and ASGR1 or by in situ hybridization with miR-122-5p and CECs were visualized by confocal microscopy. Results: The presence of CECs increased HCC risk by 2.58-fold, however, this was only significant for patients with previous LC (p = 0.028) and not for those without prior LC (p = 0.23). Furthermore, the number of CECs lacking ASGR1 expression correlated significantly with HCC incidence and absence of miR-122-5p expression (p = 0.014; r = 0.23). Finally, overall survival was significantly greater for patients at earlier cancer stages (p = 0.018), but this difference was only maintained in the group with the presence of CECs (p = 0.021) whereas progression-free survival was influenced by the absence of ASGR1 expression. Conclusion: Identification and characterization of CECs by ASGR1 and/or miR- 122-5p expression may be used as a risk-stratification tool in LC patients, as it was shown to be an independent prognostic and risk-stratification marker in LC and early disease stage HCC patients

Role of the human concentrative nucleoside transporter (hCNT1) in the cytotoxic action of 5[Prime]-deoxy-5-fluorouridine, an active intermediate metabolite of capecitabine, a novel oral anticancer drug.

We attempt to identify the plasma membrane transporter involved in the uptake of 5'-deoxy-5-fluorouridine (5'-DFUR), an intermediate metabolite of capecitabine. This novel oral fluoropyrimidine is used in cancer treatments and is a direct precursor of the cytostatic agent 5'-fluorouracil. We also examine the role of the transporter in 5'-DFUR cytotoxicity. The human concentrative nucleoside transporter (hCNT1) was cloned from human fetal liver and expressed in Xenopus laevis oocytes. The two-electrode voltage-clamp technique was used to demonstrate that 5'-DFUR, but not capecitabine or 5'-FU, is an hCNT1 substrate. Then, hCNT1 was heterologously expressed in the mammalian cell line Chinese hamster ovary-K1. Functional expression was demonstrated by monitoring transport of radiolabeled substrates and by using a monospecific polyclonal antibody generated against the transporter. hCNT1-expressing cells were more sensitive to 5'-DFUR than vector-transfected or wild-type cells. The sensitivity of the three cell types to other agents such as cisplatin or 5'-FU was identical. In conclusion, this study shows that 1) the pharmacological profile of a nucleoside transporter can be determined by an electrophysiological approach; 2) the hCNT1 transporter is involved in 5'-DFUR uptake; and 3) hCNT1 expression may increase cell sensitivity to 5'-DFUR treatment. This study also reports for the first time the generation of an antibody against hCNT1, which may be useful in the elucidation of the relationship between hCNT1 expression and tumor response to capecitabine treatmen