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Item Multiparticle Solutions to Einstein’s Equations(2021-10-29) Gomez, Humberto; Lipinski Jusinskas, RenannIn this Letter, we present the first multiparticle solutions to Einstein’s field equations in the presence of matter. These solutions are iteratively obtained via the perturbiner method, which can circumvent gravity’s infinite number of vertices with the definition of a multiparticle expansion for the inverse spacetime metric as well. Our construction provides a simple layout for the computation of tree level field theory amplitudes in spacetime dimensions involving any number of gravitons and matter fields, with or without supersymmetry. © 2021 Published by the American Physical SocietyItem Using subsurface flow wetlands with phragmites australis as a bioremediation alternative for surface sources affected by acid drainage from coal mines(2021-11-01) Silva Leal, Jorge Antonio; Leal Magón, Ángela María; Arismendi Henao, Juan Pablo; Pérez Vidal, AndreaMining generates environmental impacts such as Acid Mine Drainage (AMD). The Cali River is one of the main water resources in the city of Santiago de Cali, Colombia and it is affected by drainage from abandoned mines, which reach the Cali River through the Las Minas brook. As bioremediation alternatives, the use of subsurface flow wetlands coupled with a limestone-based pretreatment was assessed in this study. The research methodology was structured in two stages: i) physicochemical monitoring of Las Minas brook waters, and ii) treatment system operations. For these purposes, four systems were evaluated: 1) Wetlands with plants (WL1), 2) Limestone + WL1 (LS + WL1), 3) Wetlands without plants (WL2) and 4) Limestone + WL2 (LS + WL2). The results revealed that the water from the Las Minas brook presents characteristics similar to AMD (pH: 2.4-4.0; acidity: 1,303.2 mg/L ± 139.2; iron: 715.3 mg/50 ± 70.6; sulfate: 1,134.5 mg/L ± 314.6) and affects the Cali River mainly owing to the increase in iron, aluminum, and the presence of ferric hydroxide precipitates. In addition, limestone-based treatment systems achieved greater efficiencies, and the LS + WL1 configuration is recommended. All systems were able to reduce the affluent acidity from 31% to 52%. Furthermore, the average iron removal efficiencies achieved were between 54% and 67%, sulfates between 16% and 35%, nickel between 25% and 50%, and aluminum between 0% and 73%. However, manganese could not be removed.Item Falkner–skan flow with stream-wise pressure gradient and transfer of mass over a dynamic wall(2021-11) Khan, Muhammad Fawad; Sulaiman, Muhammad; Tavera Romero, Carlos Andrés; Alkhathlan, AliIn this work, an important model in fluid dynamics is analyzed by a new hybrid neurocom-puting algorithm. We have considered the Falkner–Skan (FS) with the stream-wise pressure gradient transfer of mass over a dynamic wall. To analyze the boundary flow of the FS model, we have utilized the global search characteristic of a recently developed heuristic, the Sine Cosine Algorithm (SCA), and the local search characteristic of Sequential Quadratic Programming (SQP). Artificial neural network (ANN) architecture is utilized to construct a series solution of the mathematical model. We have called our technique the ANN-SCA-SQP algorithm. The dynamic of the FS system is observed by varying stream-wise pressure gradient mass transfer and dynamic wall. To validate the effectiveness of ANN-SCA-SQP algorithm, our solutions are compared with state-of-the-art reference solutions. We have repeated a hundred experiments to establish the robustness of our approach. Our experimental outcome validates the superiority of the ANN-SCA-SQP algorithm.Item Computational investigation of thermal decomposition mechanism of 5-nitro-5-R-1,3-dioxane compounds(2022-08) Ruiz, Pablo; Quijano, Silvia; Quijano, JairoThis paper features the results of the computational study of thermal decomposition reaction of 5-nitro-5-R-1,3-dioxane compounds, with R = H, Br, and CH3. Computational calculations were performed with M06-2X, MPWB1K, PBE0 and ωB97X-D functionals, and 6–311 + G(d,p) basis set in gas phase and also in solution with DMSO, at different temperatures. The kinetic and thermodynamic data obtained indicate a favoring of the reaction when the molecule presents substituent groups in position 5 and when carried out in DMSO, the stability of the molecules in their energetic components was discussed, too. For R = H two different reaction mechanisms were proposed and studied. Wiberg bond indices were obtained for the reactions studied and the results were examined in terms of bond formation and bond breaking progress as well.Item Effective field theories and cosmological scattering equations(2022-08) Armstrong C.; Gomez H.; Jusinskas, R. Lipinski; Lipstein A.; Mei J.We propose worldsheet formulae for wavefunction coefficients of the massive non-linear sigma model (NLSM), scalar Dirac-Born-Infeld (DBI), and special Galileon (sGal) theories in de Sitter momentum space in terms of the recently proposed cosmological scattering equations constructed from conformal generators in the future boundary. The four-point integrands are assembled from simple building blocks and we identify a double copy prescription mapping the NLSM wavefunction coefficient to the DBI and sGal wavefunction coefficients, including mass deformations and curvature corrections. Finally, we compute the soft limits of these wavefunction coefficients and find that they can be written in terms of boundary conformal generators acting on contact diagrams.Item A hybrid metaheuristic based on neurocomputing for analysis of unipolar electrohydrodynamic pump flow(2021-11) Khan, Muhammad Fawad; Sulaiman, Muhammad; Tavera Romero, Carlos Andrés; Alkhathlan, AliA unipolar electrohydrodynamic (UP-EHD) pump flow is studied with known electric potential at the emitter and zero electric potential at the collector. The model is designed for electric potential, charge density, and electric field. The dimensionless parameters, namely the electrical source number (Es ), the electrical Reynolds number (ReE ), and electrical slip number (Esl ), are considered with wide ranges of variation to analyze the UP-EHD pump flow. To interpret the pump flow of the UP-EHD model, a hybrid metaheuristic solver is designed, consisting of the recently developed technique sine–cosine algorithm (SCA) and sequential quadratic programming (SQP) under the influence of an artificial neural network. The method is abbreviated as ANN-SCA-SQP. The superiority of the technique is shown by comparing the solution with reference solutions. For a large data set, the technique is executed for one hundred independent experiments. The performance is evaluated through performance operators and convergence plots.Item QoS/QoE in Flying Ad Hoc Networks Applied in Natural Disasters(2022-08) Ortiz Monedero, Jesús Hamilton; Arciniegas Herrera, José Luis; Cuellar Quiñones, Juan Carlos; Tavera Romero, Carlos Andrés; Ahmed, Bazil TahaIn this work, a group of mechanisms are exposed to provide quality of experience in flying ad hoc networks using a swarm of drones in a natural disaster service. End-to-end video traffic was analyzed. The metrics used to experimentally measure QoE/QoS are: delay, jitter and packet loss. The experience quality was evaluated before the disaster (C00), at the moment (B00) and after the disaster (I00). The methodology used to perform the design was experimental, and the NS simulator was used to evaluate the behavior of the swarm of drones connected through a flying ad hoc network. To perform data analysis, treatment and repetitions related to video traffic, the response surface methodology (MSR) was used, which is a set of mathematical techniques in order to optimize the obtained responses. The composite core design (DCC) was also used as it was the best fit to our experiment due to its flexibility. Since the quality of the experience was evaluated at three moments, the quality of services was also analyzed with three metrics. The main contributions of the research are a mathematical model of the quality of the experience based on the quality of the service; an experiment design using the end-to-end NS simulator; a methodology for the mathematical and statistical analysis of the data obtained; an algorithm that allows, from service quality metrics, to obtain the quality of the experience for end-to-end video traffic; and a proposal for future work for data analysis in a physical environment and applied to the environmental sector.Item Educational Strategies to Promote Adherence to Treatment in Patients with Cardiovascular Disease(2022-08) Martínez-Riera, José Ramon; Aviles Gonzalez, Cesar Ivan; Zambrano Bermeo, Rosa Nury; Curcio, Felice; González Correa, Julián Alberto; Estrada González, Catalina; Melo, Pedro; Galletta, MauraIntroduction: Educational material is a key strategy for primary health care promotion. Purpose: To design and validate educational material adapted to the population and aimed to increase knowledge about adherence to the treatment of arterial hypertension and diabetes mellitus. Methodology: Methodological study for the design of educational material for people with diabetes mellitus and high blood pressure. For the design, content validity tests were carried out, with the participation of six experts in health education and six patients with chronic diseases. Validation was performed pursuant to the attraction, understanding, engagement, and acceptance criteria. Results: The validation confirmed that all items and criteria were above the minimal expected range. Conclusion: The design and validation of educational material provide elements that improve the education of patients about their pathologies and their adherence to treatmentItem Comparative In Vitro Activity of Ceftolozane/Tazobactam against Clinical Isolates of Pseudomonas aeruginosa and Enterobacterales from Five Latin American Countries(2022-08) García Betancur, Juan Carlos; De La Cadena, Elsa; Mojica, María F.; Hernández-Gómez, Cristhian; Correa, Adriana; Radice, Marcela A.; Castañeda Méndez, Paulo; Jaime Villalon, Diego A.; Gales, Ana C.; Munita, José M.; Villegas, María VirginiaBackground: Ceftolozane/tazobactam (C/T) is a combination of an antipseudomonal oxyiminoaminothiazolyl cephalosporin with potent in vitro activity against Pseudomonas aeruginosa and tazobactam, a known β-lactamase inhibitor. The aim of this study was to evaluate the activity of C/T against clinical isolates of P. aeruginosa and Enterobacterales collected from five Latin American countries between 2016 and 2017, before its clinical use in Latin America, and to compare it with the activity of other available broad-spectrum antimicrobial agents. Methods: a total of 2760 clinical isolates (508 P. aeruginosa and 2252 Enterobacterales) were consecutively collected from 20 hospitals and susceptibility to C/T and comparator agents was tested and interpreted following the current guidelines. Results: according to the CLSI breakpoints, 68.1% (346/508) of P. aeruginosa and 83.9% (1889/2252) of Enterobacterales isolates were susceptible to C/T. Overall, C/T demonstrated higher in vitro activity than currently available cephalosporins, piperacillin/tazobactam and carbapenems when tested against P. aeruginosa, and its performance in vitro was comparable to fosfomycin. When tested against Enterobacterales, it showed higher activity than cephalosporins and piperacillin/tazobactam, and similar activity to ertapenem. Conclusions: these results show that C/T is an active β-lactam agent against clinical isolates of P. aeruginosa and Enterobacterales.Item Electrochemical modified electrode with bismuth film for ultrasensitive determination of aluminum (iii)(2022-09-15) Camila Ayala, Maria; Lorena López, Lizbeth; Jaramillo Botero, Andres; Valencia, DrochssThe quantification of heavy metals is crucial to many different applications, and particularly relevant to agriculture. Here we describe an electrochemical sensor to detect and quantify ultra-low concentrations of aluminum in solutions. High aluminum levels are associated with inadequate crop development, growth, and production. To this end, we demonstrate and validate a cheaper glassy carbon electrode modified by the electrochemical reduction of bismuth in an acetate buffer, for square wave voltammetry (SWV) of Al3+ in a cupferron solution 0.22 mmol L−1 + ammonium sulfate buffer 0.4 mmol L−1 pH 5.50, using double-potential pulse chronoamperometry. The proposed method ensures reproducible and stable surface modification of the electrode, and a sensor with linear response in the concentration range of 1.85×10−10 to 3.70×10−6 mol L−1 with a detection limit of 0.025 ppb and resistance to interfering metals such as lead (Pb) cadmium (Cd) and zinc (Zn). This type of technology is amenable to industrial scaling and production and could be used for soil characterization and remediation in agriculture, as well as other applications related to food production and safety where accurate and rapid, yet cost-effective, on-site monitoring is required.Item Phylogenetic biome conservatism as a key concept for an integrative understanding of evolutionary history: Galliformes and Falconiformes as study cases(2023-05-01) Pelegrin, Jonathan S.; Cantalapiedra, Juan L.; Gamboa, Sara; Menéndez, Iris; Fernández, Manuel HernándezBiomes are climatically and biotically distinctive macroecological units that formed over geological time scales. Their features consolidate them as ‘evolutionary scenarios’, with their own diversification dynamics. Under the concept of phylogenetic niche conservatism, we assessed, for the first time, the evolution of biome occupation in birds. We aimed to analyse patterns of adaptation to different climatic regimes and the determinant factors for colonization of emerging biomes by clades from different ancestral biomes. In this work, we reconstructed the biome occupation history of two clades of birds (Galliformes and Falconiformes) under an integrative perspective through a comprehensive review of ecological, phylogenetic, palaeontological and biogeographical evidence. Our findings for both groups are consistent with a scenario of phylogenetic biome conservatism and highlight the importance of changes in climate during the Miocene in the adaptation and evolution of climatic niches. In particular, our results indicate high biome conservatism associated with biomes situated in some of the extremes of the global climate gradient (evergreen tropical rainforest, steppe and tundra) for both bird taxa. Finally, the historical dynamics of tropical seasonal biomes, such as tropical deciduous woodlands and savannas, appear to have played a preponderant role during the diversification processes of these bird lineages.Item Social Determinants of Fruit and Vegetable Consumption in Florida, Valle del Cauca – Colombia(2023-05-09) Loaiza Buitrago, Diana Fernanda; Tombé Reyes, Shirley; Estrada Trujillo, Victoria EugeniaIntroducción: el consumo de frutas y verduras como proceso protector de la salud se ha analizado principalmente desde la perspectiva de los estilos de vida individuales; sin embargo, procesos de tipo estructural como los modelos de producción de alimentos y las políticas de alimentación determinan su producción, disponibilidad y acceso. Se planteó como objetivo analizar los procesos de determinación social del consumo de frutas y verduras en el municipio de Florida (Valle del Cauca, Colombia). Materiales y métodos: estudio cualitativo, tipo estudio de caso, con enfoque de determinación social. Incluyó revisión documental de políticas alimentarias y grupos de discusión con actores clave; el análisis de contenido permitió explicitar mensajes y discursos. Resultados: en la dimensión general, resaltan como procesos críticos de determinación, que limitan la producción y el acceso de frutas y verduras, el uso y tenencia inequitativa de la tierra y la explotación de las fuentes hídricas, y unas políticas que desde la lógica de libre mercado reducen cada vez más las estrategias locales de autosostenimiento y autoconsumo. En la dimensión particular, el conflicto armado (como proceso crítico adverso) y los ejercicios de soberanía alimentaria (como proceso crítico favorable al consumo de frutas y verduras). Conclusiones: la política alimentaria nacional y local reconoce, de manera discursiva, las determinaciones sociales de la seguridad alimentaria, pero en la práctica privilegia estrategias focalizadas y contingentes que no apuntan a la solución de condiciones estructurales que limitan la producción, disponibilidad, acceso y, por ende, el consumo de frutas y verduras.Item Physical-mechanical behavior and water-barrier properties of biopolymers-clay nanocomposites(2021-11-01) Calambas, Heidy Lorena; Fonseca, Abril; Adames, Dayana; Aguirren Loredo, Yaneli; Caicedo, CarolinaThe preparation and characterization of biodegradable films based on starch-PVA-nanoclay by solvent casting are reported in this study. The films were prepared with a relation of 3:2 of starch:PVA and nanoclay (0.5, 1.0, and 1.5% w/v), and glycerol as plasticizer. The nanoclays before being incorporated in the filmogenic solution of starch-PVA were dispersed in two ways: by magnetic stirring and by sonication. The SEM results suggest that the sonication of nanoclay is necessary to reach a good dispersion along the polymeric matrix. FTIR results of films with 1.0 and 1.5% w/v of sonicated nanoclay suggest a strong interaction of hydrogen bond with the polymeric matrix of starch-PVA. However, the properties of WVP, tensile strength, percentage of elongation at break, and Young’s modulus improved to the film with sonicated nanoclay at 0.5% w/v, while in films with 1.0 and 1.5% w/w these properties were even worse than in film without nanoclay. Nanoclay concentrations higher than 1.0 w/v saturate the polymer matrix, affecting the physicochemical properties. Accordingly, the successful incorporation of nanoclays at 0.5% w/v into the matrix starch-PVA suggests that this film is a good candidate for use as biodegradable packaging.Item Towards an upper limb rehabilitation tool after stroke based on surface electromyography biofeedback and virtual reality(2022-09) Cardoso, Vivianne F.; Valencia, Nicolás; Loterio, Flávia A.; Floriano, Alan; Valadão, Carlos; Frizera Neto, Anselmo; Freire Bastos Filho, TeodianoPurpose The impaired motor function of upper limbs caused by stroke reduces the performance of daily activities. There fore, recent development in post-stroke rehabilitation works with exercises using virtual reality environment and surface electromyography biofeedback. This work aims to evaluate the usability of an upper limb rehabilitation tool, based on surface electromyography biofeedback and virtual reality, designed for post-stroke patients. Methods The tool was developed based on the requirements raised in the conception and design phase. Virtual reality is used to motivate the patient to perform elbow extension movements. Twenty-eight participants without motor or neurologi cal impairment and five rehabilitation professionals performed experiments and usability tests for evaluation purposes. The usability tests used were the questionnaires Goal Attainment Scale and the System Usability Scale that were filled by the volunteers after the evaluation. Results In the trials, the volunteers evaluated the developed tool, elbow extension and flexion movements were performed, and both the user and the rehabilitation professional received outcomes feedback and electromyography biofeedback. The feedback results showed that there is no significant difference (p = 0.9216) between playing with the dominant and non dominant arms. However, significant differences (p = 0.0003 and p = 0.0018) were observed when comparing the unilateral movement with the coordinated bilateral movement. Furthermore, the result of the System Usability Scale for participants showed a result of 82.59 ± 14.31, which is above the average of the scale (68 points), while for the professionals it was 71.25 ± 6.15. On the other hand, the results of the Goal Attainment Scale—where the score is analyzed from the T value (T value > 50 means that the result was better than expected)—presented a T value of 72.25 ± 2.77 and 73.56 ± 6.13, for participants and professionals, respectively. The maximum scores for each scale were 96.9 for SUS and 78.38 for GAS. Conclusion A new rehabilitation tool is presented here, which is based on the raised requirements for post-stroke patients. The tool proved to be easily configurable, and results of usability and attainment scales showed high levels of usability for end-usersItem Patients, caregivers, and healthcare professionals' needs when designing the content of a mobile application for the clinical monitoring of patients with chronic obstructive pulmonary disease and home oxygen therapy: A user-centered design(2022-09) Naranjo Rojas, Anisbed; Perula de Torres, Luis Ángel; Molina Recio, GuillermoBackground: Patients with chronic respiratory diseases require oxygen supply in a considerable amount to reduce their symptoms and increase their survival. The development of abilities for the self-management of chronic diseases has been shown to be essential to decrease exacerbation of symptoms. Therefore, the design and development of health mobile applications (apps) that aid in educating and training for disease self-management are cost-effective strategies. Objective: The purpose of this research was to describe the main characteristics that, according to final users, should be included in a mobile application for monitoring patients prescribed home oxygen therapy. Methods: A participative-qualitative design was used, involving direct participation of patients, caregivers, and healthcare professionals. Focus groups were conducted to identify the needs and perspectives related to the app. A card sorting method was used to determine the contents and basic architecture of the app. Results: By means of the focus groups, we could identify nine basic functions of the app for the clinical monitoring of patients under home oxygen therapy. For both profiles, the app structure was determined by identifying the most frequent contents among participants. Conclusions: The implementation of a user-centered design allowed for the detection of the functions, contents, and basic architecture of the app by identifying healthcare professionals and patients' needs and preferences regarding the self-management and monitoring of home oxygen prescriptionsItem Design and validation of a predictive model for determining the risk of developing fibromyalgia(2023-06) Sandoval, N. Benachi; Solà, J. Fernández; Mateo, A. Guaita; Durán, M.P. Navarrete; Urrea, L.A. Meneses; Belmonte, S. Torres; López, E. Mañes; Poyato, M. LópezOBJECTIVES: Fibromyalgia is a prevalent disease of unknown aetiology and is difficult to diagnose. Despite the availability of the American College of Rheumatology criteria for diagnosis, it continues to be a challenge in the field of primary health care in terms of identifying individuals with susceptibility to developing the disease. The aim of this study is to design and validate a predictive model of fibromyalgia in subjects with a history of chronic pain. METHODS: This multicentre observational retrospective cohort study was performed on patients aged >18 years, who visited four primary health centres between 2017 and 2020, with a diagnosis of fibromyalgia or arthritis. The Bootstrapping resampling method was used for the validation of the model. RESULTS: A total of 198 subjects with fibromyalgia (93 with osteoarthritis, 20 with other types of arthritis, 4 with rheumatoid arthritis) and 120 without fibromyalgia (116 with osteoarthritis, 23 with other types of arthritis, 7 with rheumatoid arthritis) participated in the study. The predictive factors of the final model were self-reported age at onset of symptoms, first-line family history of neurological diseases, exposure to levels of stress, history of post-traumatic acute emotional stress, and personal history of chronic widespread pain prior to diagnosis, comorbidity, and pharmacological prescription during the year of diagnostic confirmation. The predictive capacity adjusted by Bootstrapping was 0.972 (95% CI: 0.955–0.986). CONCLUSIONS: The proposed model showed an excellent predictive capacity. The risk calculator designed from the predictive model allows health professionals to have a useful tool to identify subjects at risk of developing fibromyalgia.Item Latin America: Situation and preparedness facing the multi-country human monkeypox outbreak(2022-09) Rodriguez-Morales, Alfonso J.; Lopardo, Gustavo; Verbanaz, Sergio; Orduna, Tomas; Lloveras, Susana; Azeñas-Burgoa, Jose María; Escalera-Antezana, Juan Pablo; Alvarado-Arnez, Lucia Elena; Barbosa, Alexandre Naime; Diaz-Quijano, Fredi; Cimerman, Sergio; Chaves, Tânia do Socorro Souza; Rodriguez-Morales, Andrea G.; Perret, Cecilia; Méndez, Claudio A.; Riera, Jorge A.; Bonilla-Aldana, D. Katterine; Camacho-Moreno, German; Mendoza, Henry; Rodriguez-Sabogal, Ivan Arturo; Oñate, Jose; Escobedo, Angel A.; Thormann, Monica; Roque, Yori; Zambrano, Patricia Gabriela; Carrero, Yenddy; Sandoval, Nancy; Zambrano, Lysien; Franco-Paredes, Carlos; Chacon-Cruz, Enrique; Lopez-Delgado, Iván; Cuadra-Sánchez, Cesar; Pachar-Flores, Monica; Correa, Ricardo; Rodriguez-Enciso, Hernan D.; Rotela-Fisch, Veronica; Maquera-Afaray, Julio; Herrera-Añazco, Percy; Benites-Zapata, Vicente; Savio-Larriera, Eduardo; Ramírez, Juan David; Paniz-Mondolfi, Alberto; Risquez, Alejandro; Forero-Peña, David A.; Torres, Jaime R.; Suarez, Jose AntonioStill without ceasing the Coronavirus Disease 2019 (COVID-19) pandemic, a new viral threat has now emerged outside its endemic niche in Africa affecting multiple countries and continents. After its appearance in May 2022, a multi-country outbreak of monkeypox disease (MPX) has triggered significant concerns due to its rapid spread and potential for sexual transmission (as suggested by the detection of viral DNA in sexual fluids); this, in addition to the previously known transmission routes described throughout endemic countries of Africa over the last decades or the imported or travel-related cases reported since 2003.1 By June 28, 2022, at least 48 cases in seven Latin American countries (Argentina, Brazil, Chile, Colombia, Mexico, Peru, and Venezuela) have been PCR-confirmed, with at least 16 additional suspected cases (Figure 1).2 Most countries in the region have settled their epidemiological surveillance to detect probable and suspected cases according to national and international case definitions (by the World Health Organization). In addition, the Pan-American Health Organization has issued an epidemiological alert (https://bit.ly/3MUwYNI), with a series of considerations addressing the identification of cases, isolation, follow-up, contact tracing, clinical management, prevention and control. Nevertheless, multiple concerns have been raised, mainly from the healthcare sector, regarding currently available treatments and vaccination. Despite the absence of specific therapeutic alternatives for MPX, drugs with proven experimental efficacy and potential clinical impact such as cidofovir (especially its lipid conjugate brincidofovir) and tecovirimat, are not widely available in the region. Also, although MPX vaccination has been implemented for contacts of positive cases, at this stage, neither non-replicating/replicating-deficient live vaccinia virus-based vaccines with low reactogenicity, such as JYNNEOS®, nor classical anti-smallpox vaccines are available in most Latin American countries.Item Numerical analysis of electrohydrodynamic flow in a circular cylindrical conduit by using neuro evolutionary technique(2021-11-02) Khan, Naveed Ahmad; Sulaiman, Muhammad; Romero, Carlos Andrés Tavera; Alarfaj, Fawaz KhaledThis paper analyzes the mathematical model of electrohydrodynamic (EHD) fluid flow in a circular cylindrical conduit with an ion drag configuration. The phenomenon was modelled as a nonlinear differential equation. Furthermore, an application of artificial neural networks (ANNs) with a generalized normal distribution optimization algorithm (GNDO) and sequential quadratic programming (SQP) were utilized to suggest approximate solutions for the velocity, displacements, and acceleration profiles of the fluid by varying the Hartmann electric number (Ha2) and the strength of nonlinearity (α). ANNs were used to model the fitness function for the governing equation in terms of mean square error (MSE), which was further optimized initially by GNDO to exploit the global search. Then SQP was implemented to complement its local convergence. Numerical solutions obtained by the design scheme were compared with RK‐4, the least square method (LSM), and the orthonormal Bernstein collocation method (OBCM). Stability, convergence, and robustness of the proposed algorithm were endorsed by the statistics and analysis on results of absolute errors, mean absolute deviation (MAD), Theil’s inequality coefficient (TIC), and error in Nash Sutcliffe efficiency (ENSE).Item Usability of a mobile application for the clinical follow-up of patients with chronic obstructive pulmonary disease and home oxygen therapy(2023-07) Naranjo Rojas, Anisbed; Perula de Torres, Luis Ángel; Cruz Mosquera, Freiser Eceomo; Molina Recio, GuillermoBackground Technological health tools (e-Health) may potentially facilitate the treatment of patients with chronic diseases through development of self-management and -care skills in patients and caregivers. However, these tools are usually marketed without prior analysis and without providing any context to final users, which frequently results in low adherence to their use. Purpose To determine the usability of and satisfaction toward a mobile app for the clinical monitoring of patients with chronic obstructive pulmonary disease (COPD) receiving oxygen therapy at home. Methods This was a participative-qualitative study focused on final users—with direct intervention by patients and professionals—consisting of three phases as follows: (i) medium-fidelity mockups design, (ii) development of a usability test for each user profile, and (iii) assessment of the satisfaction level regarding the usability of the mobile app. A sample was established and selected through non-probability convenience sampling and was divided into two groups as follows: healthcare professionals (n = 13) and patients (n = 7). Each participant received a smartphone with mockup designs. The “think-aloud” method was applied in the usability test. Participants were audio recorded and the anonymous transcriptions were analyzed, highlighting fragments about mockups characteristics and the usability test. The difficulty level of the tasks was assessed with a scale from 1 (very easy) to 5 (too difficult), and task non-completion was considered a critical mistake. The satisfaction level related to test usability was assessed with a 4-score Likert scale ranging from 4 (totally agree) to 1 (totally disagree). Results Regarding the difficulty level, >60% of professionals described most tasks as “very easy” and 70% of patients as “easy.” No participant made critical mistakes and both groups reported a high satisfaction level regarding the usability variables. The patient and professionals group required 18 and 11 min to complete all tasks, respectively. Conclusions Participants described the app as intuitive and easy to use. The usability satisfaction results show a high level of satisfaction for both groups. This positive assessment and performance in user tests showed that the mobile application was able to be apprehended and used by participants in the circumstances of use in the usability tests. Usability evaluation through satisfaction surveys and qualitative data analysis allows for greater insight into the use of mobile applications in healthcare.Item Methodology for the prediction of paroxysmal atrial fibrillation based on heart rate variability feature analysis(2021) Castro, Henry; Garcia Racines, Juan D.; Bernal Norena, AlvaroAtrial fibrillation (AF) is the most clinically diagnosed arrhythmia, as its prevalence increases with age, and its initial stage is paroxysmal atrial fibrillation (PAF). This pathology usually triggers hemodynamic disorders that can generate cerebrovascular accidents (CVA), causing morbidity and even death. The aim of this study is to predict the occurrence of PAF episodes in order to take precautions to prevent PAF episodes. The PhysioNet AFPDB prediction database was used to extract 77 heart rate variability (HRV) features using time domain, geometrical analysis, Poincaré plot, nonlinear analysis, detrended fluctuation analysis, autoregressive modeling, fast Fourier transform (FFT), Lomb-Scargle periodogram, wavelet packet transform (WPT) and bispectrum measurements. The number of features was reduced using the near-zero value, correlation, and recursive feature elimination (RFE) methods for time windows of 1, 2, 5, 10, and 30 min. Feature selection was performed using backwards selection, genetic algorithm, analysis of variance (ANOVA), and non-dominated sorting genetic algorithm (NSGA-III) methods, and then random forest, conditional random forest, k-nearest neighbor (KNN), and support vector machine (SVM) classification algorithms were applied and evaluated using 10-fold cross-validation. The proposed method achieved a precision of 93.24% with a 5-minute window and 89.21% with a 2-minute window, improving performance in predicting PAF when compared with similar studies in the literature.