Registros recientes de Avicennia bicolor (Acanthaceae) en la costa del Pacífico mexicano con notas sobre su distribución y estado de conservación

Background. The mangrove Avicennia bicolor was first recorded in Mexico in 1946, however until now there is no basic information about its distribution supported by herbarium specimens. Goals. Three recent records of A. bicolor are provided at a new location in Mexico on the coastal wetlands of the Gulf of Tehuantepec, Chiapas; and the information about its known records on the American Pacific is summarized. Methods. Plant specimens were collected, which then, were dried, corroborated and deposited in four national herbaria. In the field, some structural attributes of the mangroves were determined such as density, basal area and height. A database and publications of species records were reviewed to preliminarily analyze their known distribution in the Pacific. Results. In Mexico, A. bicolor has been recorded only on the coastal wetlands of Mar Muerto and Los Patos-Solo Dios. The preliminary ecological diagnosis showed its presence in relatively dense stands (234 ± 86 trees ha-1) and with high structural development (basal area: 16.1 m2 ha-1, height: 13.9 m). Although its presence is apparently conspicuous in several localities of Panama and Costa Rica, data on the species in the coastal strip between the Gulf of Fonseca and the Gulf of Tehuantepec is lacking. Conclusions. The importance of these records is evident, considering the scarce information available on A. bicolor and its restricted distribution in Mexico. We consider it appropriate to increase the ecological studies in its distribution area and give it protection through its inclusion in the Official Mexican Standard (NOM-059).Antecedentes. El mangle Avicennia bicolor fue registrado por primera vez en México en 1946, sin embargo, hasta ahora se carece de información básica sobre su distribución respaldada en ejemplares de herbario. Objetivos. Aportar tres registros recientes de A. bicolor en una nueva localidad para México en humedales costeros del Golfo de Tehuantepec, Chiapas y resumir la información sobre sus registros conocidos en el Pacífico americano. Métodos. Se recolectaron ejemplares botánicos, los cuales fueron herborizados, corroborados y depositados en cuatro herbarios nacionales. En campo se determinaron algunos atributos estructurales de los manglares (densidad, área basal, altura). Se revisó una base de datos y publicaciones de registros de la especie para analizar preliminarmente su distribución conocida en el Pacífico. Resultados. En México, A. bicolor se ha registrado únicamente en los humedales costeros de Mar Muerto y Los Patos-Solo Dios. El diagnóstico ecológico preliminar demostró su presencia en rodales relativamente densos (234±86 árboles ha-1) y con elevado desarrollo estructural (área basal: 16.1 m2 ha-1; altura: 13.9 m). Aunque su presencia es apa rentemente conspicua en varias localidades de Panamá y Costa Rica, se carece de datos sobre la especie en la franja costera comprendida entre el Golfo de Fonseca y el Golfo de Tehuantepec. Conclusiones. Se evidencia la importancia de estos registros, considerando la escasa información disponible y su restringida distribución en México. Consideramos congruente incrementar los estudios ecológicos en su área de distribución y darle protección mediante su inclusión en la Norma Oficial Mexicana (NOM-059)

Experiencias de capacitación en la enseñanza de la Matemática en primaria: estrategias didácticas desde un proyecto de acción social

Costa Rican education has been in constant change for some years and this means that adaptation processes respond in a timely manner to such changes. From a social action project registered at the University of Costa Rica, efforts are made to contribute to the continuous improvement of mathematics education at the primary level through the generation and execution of teaching strategies and training processes that support teaching work and the promotion of mathematical abilities and skills in both the teaching staff and the students with the purpose of laying the mathematical foundations that allow them to function better at other levels of the Costa Rican educational system. The objective of this study is to present the results generated with the application of these training processes.: La educación costarricense desde hace unos años viene en cambio constante y esto conlleva a que los procesos de adaptación respondan de manera oportuna a tales cambios. Desde un proyecto de acción social inscrito en la Universidad de Costa Rica se realizan esfuerzos para coadyuvar con la mejora continua de la educación matemática a nivel de primaria mediante la generación y ejecución de estrategias didácticas y procesos de capacitación que apoyen la labor docente y el fomento de habilidades y destrezas matemáticas tanto en el personal docente como en los estudiantes con la finalidad de cimentar las bases matemáticas que le permitan desenvolverse de mejor manera en otros niveles del sistema educativo costarricense. El objetivo del presente estudio es presentar los resultados generados con la aplicación de estos procesos de capacitación

An evaluation on the clinical outcome prediction of rotor detection in non-invasive phase maps

[EN] Phase maps obtained from Electrocardiographic imaging (ECGI) have been used in the past for rotor identification and ablation guidance in atrial fibrillation (AF). In this study, we propose a new rotor detection algorithm and evaluate its potential use for prediction of pulmonary vein isolation (PVI) success. The mean precision and recall of the algorithm were evaluated by using manually annotated ECGI phase maps and resulted in 0.82 and 0.75, respectively. Phase singularities and rotors were then quantified on ECGI signals from 29 patients prior to PVI. A significantly higher concentration of phase singularities (PSs) in the pulmonary veins in patients with a successful PVI was found. Our results suggest that rotorrelated metrics obtained from ECGI derived phase maps contain relevant information to predict clinical outcome in PVI patients.This work was supported by PersonalizeAF project. This project has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Skodowska-Curie grant agreement No 860974.Fambuena-Santos, C.; Hernández-Romero, I.; Molero-Alabau, R.; Climent, AM.; Guillem Sánchez, MS. (2021). An evaluation on the clinical outcome prediction of rotor detection in non-invasive phase maps. 1-4. https://doi.org/10.22489/CinC.2021.2511

An Evaluation on the Clinical Outcome Prediction of Rotor Detection in Non-Invasive Phase Maps. Abstract

[EN] Phase maps obtained from Electrocardiographic imaging (ECGI) have been used in the past for rotor identification and ablation guidance in atrial fibrillation (AF). In this study, we propose a new rotor detection algorithm and evaluate its potential use for prediction of pulmonary vein isolation (PVI) success. The mean precision and recall of the algorithm were evaluated by using manually annotated ECGI phase maps and resulted in 0.82 and 0.75, respectively. Phase singularities and rotors were then quantified on ECGI signals from 29 patients prior to PVI. A significantly higher concentration of phase singularities (PSs) in the pulmonary veins in patients with a successful PVI was found. Our results suggest that rotorrelated metrics obtained from ECGI derived phase maps contain relevant information to predict clinical outcome in PVI patients.This work was supported by PersonalizeAF project. This project has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Skodowska-Curie grant agreement No 860974.Fambuena-Santos, C.; Hernández-Romero, I.; Molero-Alabau, R.; Climent, AM.; Guillem Sánchez, MS. (2021). An evaluation on the clinical outcome prediction of rotor detection in non-invasive phase maps. 1-4. https://doi.org/10.22489/CinC.2021.2511

Optical imaging of voltage and calcium in isolated hearts: Linking spatiotemporal heterogeneities and ventricular fibrillation initiation

[EN] Background Alternans have been associated with the development of ventricular fibrillation and its control has been proposed as antiarrhythmic strategy. However, cardiac arrhythmias are a spatiotemporal phenomenon in which multiple factors are involved (e.g. calcium and voltage spatial alternans or heterogeneous conduction velocity) and how an antiarrhythmic drug modifies these factors is poorly understood. Objective The objective of the present study is to evaluate the relation between spatial electrophysiological properties (i.e. spatial discordant alternans and conduction velocity) and the induction of ventricular fibrillation (VF) when a calcium blocker is applied. Methods The mechanisms of initiation of VF were studied by simultaneous epicardial voltage and calcium optical mapping in isolated rabbit hearts using an incremental fast pacing protocol. The additional value of analyzing spatial phenomena in the generation of unidirectional blocks and reentries as precursors of VF was depicted. Specifically, the role of action potential duration (APD), calcium transients (CaT), spatial alternans and conduction velocity in the initiation of VF was evaluated during basal conditions and after the administration of verapamil. Results Our results enhance the relation between (1) calcium spatial alternans and (2) slow conduction velocities with the dynamic creation of unidirectional blocks that allowed the induction of VF. In fact, the administration of verapamil demonstrated that calcium and not voltage spatial alternans were the main responsible for VF induction. Conclusions VF induction at high activation rates was linked with the concurrence of a low conduction velocity and high magnitude of calcium alternans, but not necessarily related with increases of APD. Verapamil can postpone the development of cardiac alternans and the apparition of ventricular arrhythmias.This work was funded in part by the CIBERCV (Centro de Investigacion Biomedica en Red Enfermedades Cardiovasculares), Instituto de Salud Carlos III (PI14/00857, PI16/01123, DTS16/0160, PI17/01059, PI17/01106 and IJCI-2014-22178); Spanish Ministry of Ecomomy (TEC2013-46067-R); Generalitat Valenciana Grants (APOSTD/2017 and APOSTD/2018) and projects (GVA/2018/103), EIT-Health 19600 AFFINE and cofound by FEDER.Hernández-Romero, I.; Guillem Sánchez, MS.; Figuera, C.; Atienza, F.; Fernández-Avilés, F.; Martínez Climent, BA. (2019). Optical imaging of voltage and calcium in isolated hearts: Linking spatiotemporal heterogeneities and ventricular fibrillation initiation. PLoS ONE. 14(5):1-15. https://doi.org/10.1371/journal.pone.0215951S115145Hayashi, M., Shimizu, W., & Albert, C. M. (2015). The Spectrum of Epidemiology Underlying Sudden Cardiac Death. 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F., Tasiam, A., … Cinca, J. (2017). Cardiac activation–repolarization patterns and ion channel expression mapping in intact isolated normal human hearts. Heart Rhythm, 14(2), 265-272. doi:10.1016/j.hrthm.2016.10.010Wilson, F. N., Macleod, A. G., Barker, P. S., & Johnston, F. D. (1934). The determination and the significance of the areas of the ventricular deflections of the electrocardiogram. American Heart Journal, 10(1), 46-61. doi:10.1016/s0002-8703(34)90303-3Ashman, R., & Byer, E. (1943). The normal human ventricular gradient. American Heart Journal, 25(1), 16-35. doi:10.1016/s0002-8703(43)90379-5Pastore, J. M., Girouard, S. D., Laurita, K. R., Akar, F. G., & Rosenbaum, D. S. (1999). Mechanism Linking T-Wave Alternans to the Genesis of Cardiac Fibrillation. Circulation, 99(10), 1385-1394. doi:10.1161/01.cir.99.10.1385Qu, Z., Garfinkel, A., Chen, P.-S., & Weiss, J. N. (2000). Mechanisms of Discordant Alternans and Induction of Reentry in Simulated Cardiac Tissue. 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American Journal of Physiology-Heart and Circulatory Physiology, 308(9), H1112-H1125. doi:10.1152/ajpheart.00556.2014Laughner, J. I., Ng, F. S., Sulkin, M. S., Arthur, R. M., & Efimov, I. R. (2012). Processing and analysis of cardiac optical mapping data obtained with potentiometric dyes. American Journal of Physiology-Heart and Circulatory Physiology, 303(7), H753-H765. doi:10.1152/ajpheart.00404.2012Gizzi, A., Cherry, E. M., Gilmour, R. F., Luther, S., Filippi, S., & Fenton, F. H. (2013). Effects of Pacing Site and Stimulation History on Alternans Dynamics and the Development of Complex Spatiotemporal Patterns in Cardiac Tissue. Frontiers in Physiology, 4. doi:10.3389/fphys.2013.00071VISWESWARAN, R., McINTYRE, S. D., RAMKRISHNAN, K., ZHAO, X., & TOLKACHEVA, E. G. (2013). Spatiotemporal Evolution and Prediction of [Ca2+ ]i and APD Alternans in Isolated Rabbit Hearts. Journal of Cardiovascular Electrophysiology, 24(11), 1287-1295. doi:10.1111/jce.12200Bayly, P. V., KenKnight, B. 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Characterization of QT Interval Adaptation to RR Interval Changes and Its Use as a Risk-Stratifier of Arrhythmic Mortality in Amiodarone-Treated Survivors of Acute Myocardial Infarction. IEEE Transactions on Biomedical Engineering, 51(9), 1511-1520. doi:10.1109/tbme.2004.828050Noujaim, S. F., Auerbach, D. S., & Jalife, J. (2007). Ventricular Fibrillation. Circulation Journal, 71(SupplementA), A1-A11. doi:10.1253/circj.71.a1Choi, B., & Salama, G. (2000). Simultaneous maps of optical action potentials and calcium transients in guinea‐pig hearts: mechanisms underlying concordant alternans. The Journal of Physiology, 529(1), 171-188. doi:10.1111/j.1469-7793.2000.00171.xCao, J.-M., Qu, Z., Kim, Y.-H., Wu, T.-J., Garfinkel, A., Weiss, J. N., … Chen, P.-S. (1999). Spatiotemporal Heterogeneity in the Induction of Ventricular Fibrillation by Rapid Pacing. Circulation Research, 84(11), 1318-1331. doi:10.1161/01.res.84.11.1318De Diego, C., Pai, R. K., Dave, A. S., Lynch, A., Thu, M., Chen, F., … Valderrábano, M. (2008). Spatially discordant alternans in cardiomyocyte monolayers. American Journal of Physiology-Heart and Circulatory Physiology, 294(3), H1417-H1425. doi:10.1152/ajpheart.01233.2007Aistrup, G. L., Kelly, J. E., Kapur, S., Kowalczyk, M., Sysman-Wolpin, I., Kadish, A. H., & Wasserstrom, J. A. (2006). Pacing-induced Heterogeneities in Intracellular Ca2+Signaling, Cardiac Alternans, and Ventricular Arrhythmias in Intact Rat Heart. Circulation Research, 99(7). doi:10.1161/01.res.0000244087.36230.bfChudin, E., Goldhaber, J., Garfinkel, A., Weiss, J., & Kogan, B. (1999). Intracellular Ca2+ Dynamics and the Stability of Ventricular Tachycardia. Biophysical Journal, 77(6), 2930-2941. doi:10.1016/s0006-3495(99)77126-2Sato, D., Bers, D. M., & Shiferaw, Y. (2013). Formation of Spatially Discordant Alternans Due to Fluctuations and Diffusion of Calcium. 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A New Optimization Strategy for Solving the Fall-Off Boundary Value Problem in Pixel-Value Di®erencing Steganography

In Digital Image Steganography, Pixel-Value Di®erencing (PVD) methods use the di®erence between neighboring pixel values to determine the amount of data bits to be inserted. The main advantage of these methods is the size of input data that an image can hold. However, the fall- o® boundary problem and the fall in error problem are persistent in many PVD steganographic methods. This results in an incorrect output image. To ¯x these issues, usually the pixel values are either somehow adjusted or simply not considered to carry part of the input data. In this paper, we enhance the Tri-way Pixel-Value Di®erencing method by ¯nding an optimal pixel value for each pixel pair such that it carries the maximum input data possible without ignoring any pair and without yielding incorrect pixel values

Detection of Atrial Fibrillation Driver Locations Using CNN and Body Surface Potentials

[EN] Atrial fibrillation (AF) is characterized by complex and irregular propagation patterns, and AF onset locations and drivers responsible for its perpetuation are main targets for ablation procedures. Several Deep Learningbased methods have proposed to detect AF, but the estimation of the atrial area where the drivers are found is a topic where further research is needed. In this work, we propose to estimate the zone where AF drivers are found from body surface potentials (BSPs) and Convolutional Neural Networks (CNN), modeling a supervised classification problem. Accuracy in the test set was 0.89 when using noisy BSPs (SNR=20dB), while the Cohen¿s Kappa was 0.85. Therefore, the proposed method could help to identify target regions for ablation using a non-invasive procedure, and avoiding the use of ECG Imaging (ECGI).This work has been partially supported by: Ministerio de Ciencia e Innovacion (PID2019-105032GB-I00), Instituto de Salud Carlos III, and Ministerio de Ciencia, Innovacion y Universidades (supported by FEDER Fondo Europeo de Desarrollo Regional PI17/01106 and RYC2018-024346B-750), Consejeria de Ciencia, Universidades e Innovacion of the Comunidad de Madrid through the program RIS3 (S-2020/L2-622), EIT Health (Activity code 19600, EIT Health is supported by EIT, a body of the European Union) and the European Union's Horizon 2020 research and innovation program under the Marie Skodowska-Curie grant agreement No. 860974.Cámara-Vázquez, MÁ.; Hernández-Romero, I.; Morgado-Reyes, E.; Guillem Sánchez, MS.; Climent, AM.; Barquero-Pérez, Ó. (2021). Detection of Atrial Fibrillation Driver Locations Using CNN and Body Surface Potentials. 1-4. https://doi.org/10.22489/CinC.2021.2561

Personalized Modeling of Atrial Activation and P-waves: a Comparison Between Invasive and Non-Invasive Cardiac Mapping

Biatrial personalized models incorporating functional and anatomical features are becoming a promising tool for planning therapy for patients with atrial fibrillation (AF). Conduction velocity (CV) is one of the main features to be matched during the process of functional personalization, as it can identify electrical abnormalities in the cardiac tissue. The spatial distribution of CV can be estimated from local activation times (LAT) maps from non-invasive electrocardiographic imaging (ECGI) or invasive electroanatomical mapping systems (EAMS). We investigated the effect of using either invasive LAT maps from EAMS or non-invasive LAT maps from ECGI to personalize two biatrial models by comparing the virtual P-waves obtained from these LAT maps with the measured P-waves from the surface electrocardiogram (ECG). For both modalities – ECGI and EAMS – we found a qualitative match between simulated and measured P-waves but observed quantitative differences. The root-mean-square error (RMSE) between measured and simulated signals for patient A was 0.26±0.11 mV and 0.38±0.31 mV, while for patient B it was 0.21±0.09 mV and 0.14±0.05 mV for EAMS and ECGI, respectively. The correlation between measured and simulated signals from ECGI and EAMS was 0.69±0.34 and 0.71±0.26 for patient A and 0.71±0.18 and 0.72±0.18 for patient B. Our results suggest that LAT maps from ECGI and EAMS show differences, which are also reflected in the computed P-wave on the body surface

Effects of Geometry in Atrial Fibrillation Markers Obtained With Electrocardiographic Imaging

[EN] Electrocardiographic imaging (ECGI) can characterise cardiac pathologies such as atrial fibrillation (AF) through specific markers based on frequency or phase analysis. In this study, the effect of the geometry of patients torso and atria in the ECGI resolution is studied. A realistic 3D atrial geometry was located on 30 patient torsos and ECGI signals were calculated for 30 different AF simulations in each torso. Dominant frequency (DF) and reentrant activity analysis were calculated for each scenario. Anatomical and geometrical measurements of each torso (30-80% of variability between patients) and atria were calculated and compared with the errors in the ECGI estimation versus the departing EGM maps. Results show evidences that big chest dimensions worsen the non-invasive calculation of AF markers (p<0.05). Also, higher number of visible electrodes from each atrial region improves ECGI characterization measured as lower DF deviations (0.64±0.26 Hz vs 0.72±0.27 Hz, p<0.05) and higher reentrant activity coincidence (10.1±12.2% vs 3.4±3.4%, p<0.05). Torso and atrial geometry affect the quality of the non-invasive reconstruction of AF markers such as DF or reentrant activity. Knowing the geometrical parameters that worsen non-invasive AF maps may help to measure each detected AF driver reliability.Supported in part by: Instituto de Salud Carlos III FEDER (Fondo Europeo de Desarrollo Regional; IJCI2014-22178, DTS16/00160; PI14/00857, PI16/01123; PI17/01059; PI17/01106), Generalitat Valenciana Grants (APOSTD/2017 and APOSTD/2018) and projects (GVA/2018/103) and EIT-Health 19600 AFFINE.Molero-Alabau, R.; Climent, AM.; Hernández-Romero, I.; Liberos, A.; Fernández-Avilés, F.; Atienza, F.; Guillem Sánchez, MS.... (2019). Effects of Geometry in Atrial Fibrillation Markers Obtained With Electrocardiographic Imaging. IEEE. 1-4. https://doi.org/10.22489/CinC.2019.3081

Non-invasive Estimation of Atrial Fibrillation Driver Position With Convolutional Neural Networks and Body Surface Potentials

[EN] Atrial fibrillation (AF) is characterized by complex and irregular propagation patterns, and AF onset locations and drivers responsible for its perpetuation are the main targets for ablation procedures. ECG imaging (ECGI) has been demonstrated as a promising tool to identify AF drivers and guide ablation procedures, being able to reconstruct the electrophysiological activity on the heart surface by using a non-invasive recording of body surface potentials (BSP). However, the inverse problem of ECGI is ill-posed, and it requires accurate mathematical modeling of both atria and torso, mainly from CT or MR images. Several deep learning-based methods have been proposed to detect AF, but most of the AF-based studies do not include the estimation of ablation targets. In this study, we propose to model the location of AF drivers from BSP as a supervised classification problem using convolutional neural networks (CNN). Accuracy in the test set ranged between 0.75 (SNR = 5 dB) and 0.93 (SNR = 20 dB upward) when assuming time independence, but it worsened to 0.52 or lower when dividing AF models into blocks. Therefore, CNN could be a robust method that could help to non-invasively identify target regions for ablation in AF by using body surface potential mapping, avoiding the use of ECGI.This work has been partially supported by: Ministerio de Ciencia e Innovacion (PID2019-105032GB-I00), Instituto de Salud Carlos III, and Ministerio de Ciencia, Innovacion y Universidades (supported by FEDER Fondo Europeo de Desarrollo Regional PI17/01106 and RYC2018-024346B-750), Consejeria de Ciencia, Universidades e Innovacion of the Comunidad de Madrid through the program RIS3 (S-2020/L2-622), EIT Health (Activity code 19600, EIT Health is supported by EIT, a body of the European Union) and the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 860974.Cámara-Vázquez, MÁ.; Hernández-Romero, I.; Morgado-Reyes, E.; Guillem Sánchez, MS.; Climent, AM.; Barquero-Pérez, O. (2021). Non-invasive Estimation of Atrial Fibrillation Driver Position With Convolutional Neural Networks and Body Surface Potentials. Frontiers in Physiology. 12:1-11. https://doi.org/10.3389/fphys.2021.733449S1111