Universidad Central "Marta Abreu" de las Villas
Recent publications
Abstract Ascorbate peroxidase enzymes play a very important role by balancing reactive oxygen species in cells, mainly H 2O2. The present study aims to perform comparative research on APX4 protein in 30 plant species to identify conserved motifs and construct phylogenetic trees using bioinformatics tools. A total of 30 APX4 protein sequences were subjected to homology search, multiple sequence alignment, phylogenetic tree construction, and motif analysis. The constructed phylogenetic tree showed different groups based on APX4 heme binding in relation to different plant species such as Arabidopsis thaliana L., Manihot esculenta Crantz, Cannabis sativa L., Citrus clementina Tanaka, Jatropha curcas L., Mangifera indica L., Coffea arabica L., Cucurbita pepo subsp. pepo, Malus domestica Borkh, Eucalyptus grandis W.Hill ex Maiden, Rosa chinensis Jacq., Beta vulgaris subsp. vulgaris, Solanum tuberosum L., Zea mays L., Dendrobium catenatum L., Phoenix dactylifera L., Vitis vinifera L., Pistacia vera L., Prunus dulcis (Mill), Quercus lobata Née, Musa acuminata Colla subsp. malaccensis, Nymphaea colorata Peter and Papaver somniferum L. Multiple alignment of these APX4 protein sequences from different plants revealed conserved regions. Motif analysis revealed a domain found consistently in APX4 regardless of the different plant species, suggesting its possible role in structural and enzymatic functions. The results of the study provide fundamental information for further functional characterization of APX4 in the investigated plant species.
The present work aimed to evaluate the agro-productive response of bell pepper 'Robur F1' and 'Clair F1' hybrids. The experiment was conducted in a tropical sheltered production system at the "Valle del Yabú" Agricultural Enterprise. The experimental design was a randomized complete block with four replicates. The height and diameter of the main stem, length of internodes, and number of days to flowering were evaluated. Additionally, the number of fruits per plant, average fruit weight and yield, and fruit quality attributes (thickness of the pericarp, length, top width, color, shape, and number of lobes) were recorded. Results showed that 'Robur F1' reached a higher height (33.9 cm), the diameter of the main stem (12.9 mm) and the length of the internodes (9.84 cm). 'Clair F1' showed the highest number of fruits per plant (12), average fruit weight (273.60 g), and yield (3.87 kg/m2). A higher pericarp thickness and fruit width were observed in 'Clair F1', while the fruit was longer in 'Robur F1 (13 cm). Both hybrids had green bell peppers and fruits. With the knowledge of agro-productive characteristics of both pepper hybrids, Cuba may select the most remarkable genotype under a tropical sheltered production system. Keywords: agricultural yield, Capsicum annuum, fruit quality, morphological traits.
Teacher self-efficacy is a construct whose study has increased in recent years. Since the emergence of the category, various instruments have been designed for its evaluation. The objective of the study was oriented to determine the dimensions of teaching self-efficacy of university professors, which have been evaluated in research in the last five years. For this, a systematic review of the literature was carried out with six articles indexed in the Scielo, Redalyc, Dialnet and Redib databases, in the period 2018 to 2022. Analysis questions were raised such as: which scales have been validated for the evaluation of teaching self-efficacy in university teaching staff? what are the dimensions that they evaluate? what criteria are the basis for the selection of said dimensions? The predominant use of the self-efficacy scale of the university teaching staff of the year 2005 and its dimensions for the evaluation of the construct were identified. The findings led to determine the presence of 10 dimensions evaluated globally in the teaching self-efficacy of the university professor. In addition, the need to propose dimensions of self-efficacy of the university teacher consistent with the dynamics of Higher Education was identified, according to the changes in education in the 21st century.
Industrial automation is dominated by solutions that are implemented with distributed controllers, such as programmable logic controllers. Currently, companies such as Industrial Shields, Norvi, Controllino, or Arduino offer industrial controller solutions that are based on open hardware. These, although they do not have the capacity to work in applications that require high safety integrity levels, represent a low-cost alternative to traditional solutions. This study is the result of the collaboration between Universidad Central Marta Abreu de Las Villas and company CEDAI UEB Villa Clara. The objective of this article is to make a proposal for a programmable controller based on open hardware that is an economical and flexible alternative for industrial automation. The MCI-VC v1.0 is intended to be a compact, low-cost, STM32 microcontroller-based controller that complies with parts of the IEC 61131 standard. The controller will have digital and analog inputs, digital outputs, and RS485, Ethernet, USB, and SPI communication for expansion modules. The proposal is conceptually cheaper than its counterparts, which should allow obtaining a competitive product. The design meets the defined technical requirements and has higher performance than several commercialized controllers.
A new chiral amplification mechanism based on a stochastic approach is proposed. The mechanism includes five different chemical species, an achiral substrate (A), two chiral forms (L, D), and two intermediary species (LA, DA). The process occurs within a small, semipermeable compartment that can be diffusively coupled with the outside environment. The study considers two alternative primary sources for chiral species within the compartment, one chemical and the other diffusive. As a remarkable fact, the chiral amplification process occurs due to stochastic fluctuations of an intermediary catalytic species (LA, DA) produced in situ, given the interaction of the chiral species with the achiral substrate. The net process includes two different steps: the synthesis of the catalyst (LA and DA) and the catalytic production of new chiral species from the substrate. Stochastic simulations show that proper parameterization can induce a robust chiral state within the compartment regardless of whether the system is open or closed. We also show how an increase in the non-catalytic production of chiral species tends to negatively impact the homochirality degree of the system. By its conception, the proposed mechanism suggests a deeper connection with how most biochemical processes occur in living beings, a fact that could open new avenues for studying this fascinating phenomenon.
This contribution shows the possibilities of applying a low-cost, multipurpose data logger built around an Arduino Mega 2560 single-board computer. Most projects use this kind of hardware to develop single-purpose data loggers. In this work, a data logger with a more general hardware and software architecture was built to perform measurement campaigns in very different domains. The wide applicability of this data logger was demonstrated with short-term monitoring campaigns in relation to outdoor air quality, human activity in an office, motion of a journey on a bike, and exhaust gas monitoring of a diesel generator. In addition, an assessment process and corresponding evaluation framework are proposed to assess the credibility of low-cost scientific devices built in-house. The experiences acquired during the development of the system and the short measurement campaigns were used as inputs in the assessment process. The assessment showed that the system scores positively on most product-related targets. However, unexpected events affect the assessment over the longer term. This makes the development of low-cost scientific devices harder than expected. To assure stability and long-term performance of this type of design, continuous evaluation and regular engineering corrections are needed throughout longer testing periods.
One of the problems identified in the sugar industry is the deficient management of science and innovation. The objective of the research is to determine the potential savings of bagasse, fuel oil, steam and water in the raw sugar production process, through energy management, to increase energy efficiency indicators. A procedure is applied that includes the analysis methodologies of energy use analysis based on the energy review according to ISO 500001. The determination of 12 energy performance indicators, currently not reported for this industry, contribute to the definition of a line energy base and the systematic measurement of efficiency in industry. The general thermal efficiency, with a value of 77%, is affected by heat losses in the process, associated with heat recovery from hot streams, leaks and insulation, which can be reduced with energy integration to identify heat recovery potential. The modifications made to the energy system are of immediate economic recovery, given the significant potential savings of bagasse at the sugar mill and fuel at the distillery.
The production of phosphoric acid as a source of numerous phosphate products represents one pf the issues of greatest economic interest for Cuba today. The industry of this product derives a series of phosphates that can be used in the production of fertilizers, which, in our country, is very scarce and has a high demand. In addition, there are natural reserves of phosphorite rock that can be used to produce phosphoric acid, develop the fertilizer industry and in turn boost agriculture and the national economy. The objective of this work is to propose the preliminary design of a chemical plant to obtain phosphoric acid from Cuban phosphorite. For this, a bibliographic search was carried out that provided very useful data for the process and from it the production scheme was established with fundamental stages of chemical reaction, filtration and evaporation. The corresponding material balances were made and the necessary equipment was determined, which includes reactors, press filters and an evaporator. Finally, the economic evaluation was carried out through the determination of profitability indicators, which revealed a net present value of $10 205 137,34, an internal rate of return of 65% and an investment recovery period of approximately 1,8 years, which demonstrates that the process of obtaining phosphoric acid from phosphorite is economically viable.
This research consisted of a study of the behavior of the counterattack actions in handball, and to diagnose the behavior of counterattack actions of the junior male handball team of Villa Clara during the competitions. A comparative analysis with the international state of the art in this category was conducted, which evidenced low efficacy in the execution of counterattacks by the team during the games. Different methods, like bibliographic review, were conducted to unveil the existing background about counterattacks in handball. Scientific observation was performed in 15 training sessions and games to identify the treatment and efficacy of counterattack. Coaches and players were interviewed to check their preparedness for a counterattack. A documentary review of the handball training manuals was conducted as well. Consequently, several counterattack issues were found in the guidelines of the Comprehensive Program for Athlete Training, the training plan, and the methodological procedures of the course. Besides, low absolute and relative efficacy values were found in the different games observed. The study found the need for a change in the conception of the relative methodological procedures linked to counterattack teaching, in the junior male handball team of Villa Clara, Cuba.
Identifying the functional networks underpinning indirectly observed processes poses an inverse problem for neurosciences or other fields. A solution of such inverse problems estimates as a first step the activity emerging within functional networks from EEG or MEG data. These EEG or MEG estimates are a direct reflection of functional brain network activity with a temporal resolution that no other in vivo neuroimage may provide. A second step estimating functional connectivity from such activity pseudodata unveil the oscillatory brain networks that strongly correlate with all cognition and behavior. Simulations of such MEG or EEG inverse problem also reveal estimation errors of the functional connectivity determined by any of the state-of-the-art inverse solutions. We disclose a significant cause of estimation errors originating from misspecification of the functional network model incorporated into either inverse solution steps. We introduce the Bayesian identification of a Hidden Gaussian Graphical Spectral (HIGGS) model specifying such oscillatory brain networks model. In human EEG alpha rhythm simulations, the estimation errors measured as ROC performance do not surpass 2% in our HIGGS inverse solution and reach 20% in state-of-the-art methods. Macaque simultaneous EEG/ECoG recordings provide experimental confirmation for our results with 1/3 times larger congruence according to Riemannian distances than state-of-the-art methods.
Introducción. La quinua (Chenopodium quinoa Willd.) es un cultivo estratégico e importante en la seguridad y soberanía alimentaria. Es el único alimento vegetal que proporciona todos los aminoácidos esenciales. Su amplia diversidad varietal constituye un acervo genético valioso, se adapta a diferentes condiciones agroecológicas y es tolerante a heladas, sequías y salinidad. Objetivo. Caracterización morfoagronómica de la quinua nativa tipo Chimborazo en Ecuador. Materiales y métodos. La investigación se realizó en la provincia de Chimborazo, cantón Colta, parroquia Sicalpa, comunidad de Ocpote Tablarumi en Ecuador entre enero y julio de 2021. Se emplearon semillas pertenecientes a una familia andina que las ha seleccionado y conservado ciclo tras ciclo de cultivo durante generaciones familiares. El cultivo se estableció con siembra a chorro continuo a razón de 12 kg/ha en un área total de la parcela de 640 m2 (estimado de 10 240 plantas). Después de la emergencia se seleccionaron al azar y se marcaron 100 plantas que se tomaron como unidades básicas para la caracterización de la población. Se utilizaron descriptores fenotípicos del cultivo establecidos a nivel internacional y se evaluaron caracteres cualitativos (16) y cuantitativos (12). Resultados. Los resultados evidenciaron variabilidad fenotípica. El color del tallo, el color de las estrías, el diámetro de la panoja, longitud de la panoja y días a la cosecha fueron las características que más contribuyeron a la variabilidad observada. Conclusiones. La población de plantas de quinua nativa tipo Chimborazo evaluada a través de 100 individuos, mostró variabilidad fenotípica tanto en características cuantitativas como cualitativas, y con mayor frecuencia en el diámetro de la panoja, la longitud de la panoja, la longitud del peciolo, la altura de la planta, el ancho de la hoja, el rendimiento, el color del tallo y el color de las estrías.
Organizations that aspire to obtain long-term results must correctly manage compliance with laws, regulations, codes, international standards and best practices related to ethics and society's expectations. This research aims to development a procedure to manage compliance risks with a focus on organizational values. The paper includes the main stages of traditional risk analysis: analysis of the organizational context, identification of obligations, evaluation and assessment of compliance risks and their treatment through action plans. As the main novelty, the authors include a tool that allows the integration of the elements of the context, with the identified obligations, their associated risks and the ethical values shared by the organization, called CORVAL map. The results of the implementation of the procedure in the process of Production of Computer Services in an cuban entity allow to identify as main risks: illicit contractual relations, lack of knowledge of the code of conduct by the workers, affectations to the prestige of the organization and high rates of electric energy consumption, identifying the shared value Responsibility and its associated behavior, as the most influential principle in the mitigation of the risks of compliance of the process.
Limnospira maxima is a remarkable organism showing great potential as a versatile and sustainable food source, offering a powerful solution to address the pressing issues of malnutrition and undernourishment worldwide. L. maxima contains high amounts of proteins, vitamins, minerals, and essential fatty acids. It can be grown in both bioreactors and open systems; however, before considering industrial production, optimization studies of the cultivation must be conducted to obtain knowledge about the ideal environmental conditions. Additionally, for the molecular typing of L. maxima strains and their industrial scaling, high-quality and large quantity DNA extraction is required. Notwithstanding, DNA extraction from L. maxima can be challenging due to the low amount of DNA in cells and the presence of difficult-to-remove substances such as polysaccharides and polyphenols. In this study, the quality and quantity of DNA extracted from two types of L. maxima samples (Limnospira maxima strain SISCA accession GenBank: OR195505.1) were evaluated using three commercially available DNA extraction kits and two types of input biological material. The results showed that Pbact-P kit had the highest quantity and quality of DNA, while CTAB-P allowed for a higher quantity and quality of RNA, making them optimal protocols for nucleic acid extraction to improve PCR, rt-PCR, and genome sequencing of L. maxima compared with other extraction methods.
La obtención de patrones de distribución temporal de la lluvia mediante curvas de masa sintéticas o hietogramas es un recurso aplicado a nivel internacional para elaborar la tormenta de diseño. En el presente artículo se realizó un análisis de 243 eventos lluviosos convectivos de más de 25 mm ocurridos en la estación meteorológica Yabú de la provincia Villa Clara, Cuba, en el periodo comprendido desde 1989 hasta 2019, con el objetivo de elaborar los hietogramas sintéticos característicos de la estación mediante el método de Huff. Se categorizaron las lluvias y se identificaron tres tipos SC-T1, SC-T2, SC-T3 de acuerdo con la relación entre el tiempo de duración del aguacero y el tiempo donde ocurren las mayores intensidades. Las curvas de masa obtenidas para cada probabilidad de ocurrencia se expresaron en hietogramas adimensionales, los cuales fueron ajustados a los modelos paramétricos de Sherman, Wenzel y uno propio elaborado por los autores, que describen la distribución de las intensidades con respecto al tiempo. Este resultado permitió obtener las curvas de intensidad-frecuencia-duración para cada tipo de aguacero, y cada probabilidad de ocurrencia. Se lograron elevados coeficientes de correlación de Pearson y el modelo elaborado por los autores mostró el mejor desempeño. Los resultados indican que los hietogramas adimensionales obtenidos reflejan satisfactoriamente el fenómeno de lluvias convectivas en la localidad de estudio
Understanding how tropical cyclones affect phytoplankton communities is important for studies on ecological variability. Most studies assessing the post-storm phytoplankton response rely on satellite observations of chlorophyll a concentration, which inform on the ocean surface conditions and the whole phytoplankton community. In this work, we assess the potential of the Massachusetts Institute of Technology marine ecosystem model to account for the response of individual phytoplankton functional types (PFTs, coccolithophores, diatoms, diazotrophs, mixotrophic dinoflagellates, picoeukaryotes, Prochlorococcus and Synechococcus) in the euphotic zone to the passage of Hurricane Fabian (2003) across the tropical and subtropical Sargasso Sea. Fabian induced a significant mean concentration increase (t-test, p < 0.05) of all PFTs in the tropical waters (except for Prochlorococcus), which was driven by the mean nutrient concentration increase and by a limited zooplankton grazing pressure. More specifically, the post-storm nutrient enrichment increased the contribution of fast-growing PFTs (e.g. diatoms and coccolithophores) to the total phytoplankton concentration and decreased the contribution of slow-growing dominant groups (e.g. picoeukaryotes, Prochlorococcus and Synechococcus), which lead to a significant increase (t-test, p < 0.05) of the Shannon diversity index values. Overall, the model captured the causal relationship between nutrient and PFT concentration increases in the tropical waters, although it only reproduced the most pronounced PFT responses such as those in the deep euphotic zone. In contrast, the model did not capture the oceanic perturbations induced by Fabian as observed in satellite imagery in the subtropical waters, probably due to its limited performance in this complex oceanographic area.
Este artículo analiza la investigación colombiana sobre Comunicación registrada en la base de datos Scopus, la evaluación de las principales tendencias de su actividad científica y rasgos presentes en su estructura intelectual, social y temática. Se utilizó la información publicada por autores colombianos en las revistas de la categoría Comunicación (versión 2021) del Scimago Journal Rank (SJR), con agregado de revistas indexadas en Scopus. Se emplearon indicadores bibliométricos de producción, impacto y colaboración y técnicas como la cocitación, el acoplamiento y la coocurrencia mediante el software VOSViewer. Los principales resultados muestran un crecimiento sostenido de la cantidad de documentos y citas, el liderazgo de dos de las más importantes revistas nacionales, como Palabra Clave y Signo y Pensamiento, además del significativo aporte de un grupo de autores nacionales y universidades de amplio reconocimiento en el campo, tanto en docencia como en investigación, como las universidades de La Sabana, Javeriana y del Norte. Las técnicas de análisis permitieron conocer la estructura de la investigación disciplinar presente en la muestra, las relaciones de colaboración, en su mayoría con énfasis en lo nacional, y los frentes de investigación, información útil para investigadores, editores y gestores de políticas científicas, mostrando la amplia diversidad de temas y ausencia de investigación teórica.
Este artículo analiza la investigación colombiana sobre Comunicación registrada en la base de datos Scopus, la evaluación de las principales tendencias de su actividad científica y rasgos presentes en su estructura intelectual, social y temática. Se utilizó la información publicada por autores colombianos en las revistas de la categoría Comunicación (versión 2021) del Scimago Journal Rank (SJR), con agregado de revistas indexadas en Scopus. Se emplearon indicadores bibliométricos de producción, impacto y colaboración y técnicas como la cocitación, el acoplamiento y la coocurrencia mediante el software VOSViewer. Los principales resultados muestran un crecimiento sostenido de la cantidad de documentos y citas, el liderazgo de dos de las más importantes revistas nacionales, como Palabra Clave y Signo y Pensamiento, además del significativo aporte de un grupo de autores nacionales y universidades de amplio reconocimiento en el campo, tanto en docencia como en investigación, como las universidades de La Sabana, Javeriana y del Norte. Las técnicas de análisis permitieron conocer la estructura de la investigación disciplinar presente en la muestra, las relaciones de colaboración, en su mayoría con énfasis en lo nacional, y los frentes de investigación, información útil para investigadores, editores y gestores de políticas científicas, mostrando la amplia diversidad de temas y ausencia de investigación teórica.
This contribution examines the interpretation of the Graph Derivative Indices (GDIs) from the Quantum Mechanics (QM) perspective and its relation with the Hückel molecular orbital (HMO) method. The different elements used for calculating Graph Discrete Derivatives over atom-pairs are related to the QM integrals appearing in the Hückel Determinant. The relation between the Coulomb and Resonance Integrals was estimated by the topological way and quantitative values for resonance energies were calculated. Some GDI calculations were performed to the topological interpretation of the aromaticity, expressing the frequencies as probabilities. Starting from topological interpretation for aromaticity, GDI calculations were performed. There is the possibility of expressing the frequencies as probabilities. It allows explaining the atypical formation of cyclobutadiene from the entropic point of view. Considering this hypothesis, experimental resonance energies for 14 molecules were correlated with GDI-topological resonance energies by the same structures. Taking into consideration the regularity and coherence stablished in experiments performed with the GDIs, it is possible to assure that GDIs have interpretations in QM terms.
The production of cow manure far exceeds the quantity that can be utilized in primary applications such as fertilizer or for the generation of biogas. As a result, alternative value-added applications are being investigated. The purpose of this study is to evaluate the production of lactic acid, using cow manure as the raw material. The methodology involved the implementation of thermochemical pretreatment for the cow manure, followed by simultaneous saccharification and fermentation for lactic acid production. Response surface methodology based on a central composite design was employed to analyze the simultaneous saccharification and fermentation process. The factorial design of the experiments was carried out with three factors, cow manure concentration, temperature, and enzyme concentration, with 80 g·L−1, 50 °C, and 212.5 IU/gCMDry Matter as central point values, respectively. Following the addition of Bacillus coagulans DSM2314 inoculum to enzymatically hydrolyzed cow manure at pH 5.0, after a 24 h period the concentration of lactic acid was recorded at 13.65 g·L−1, with a conversion efficiency of 33.1%. Studies were conducted until 48 h to analyze time impact. Characterization studies for native cow manure and that pretreated using acid reagent were conducted. Sugar content and by-product formation were analyzed, resulting in 23.24 g·L−1 of sugar remaining as the maximum after fermentation, while low values of furfural (1.04 g·L−1), 5-hydroxymethylfurfural (1.35 g·L−1), and acetic acid (1.45 g·L−1) were found. Optimal conditions were calculated at 24 and 48 h with R software, obtaining the lactic acid, with yields of 13.4 g·L−1, 36.28% (for 24 h) and 15.27 g·L−1, 32.76% (for 48 h), respectively. Experimental and statistical studies of enzymatic hydrolysis and fermentation stated that cow manure was a feasible substrate for the production of lactic acid.
Curriculum design is a dimension of the curriculum that reveals the methodology, theactions and the result of the diagnosis, modeling, structuring, and organization ofcurriculum projects. The research presented was carried out in the Bachelor's Degree inEducation career, Pedagogy - Psychology of the Faculty of Early Childhood Education, atthe "Marta Abreu" Central University in Las Villas. It is aimed at proposing a model ofcurricular design for the training of the professional and pedagogical educationalorientation skill in the Physical Education Discipline. Theoretical, empirical and statisticalmethods were used to systematize the theoretical bases that support educationalorientation as a constitutive process of the Bachelor ́s degree in Education training. Thesample consisted of 12 teachers and 81 students from Pedagogy - Psychology distributedin the four years of the career. The evaluation of the model was based on the user'scriteria, who stated that the proposal is very pertinent and the structure and contentswere in correspondence with the modes of professional performance proposed as a core.For evaluating the proposal different categories were established in order to know thelevel reached by the students. The validity of the proposal was confirmed by theimprovement of the direction of this process.Keywords: curricular model; professional pedagogical skills; Physical Education; educational orientation.
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2,030 members
Lizet Rodríguez-Machín
  • Centre for Energy Studies and Environmental Technologies (CEETA)
Alberto Taboada-Crispi
  • Informatics Research Center
Ernesto Villar Cociña
  • Faculty of Mathematics, Physics and Computing
Sandra H. Mejias Herrera
  • Department of Industrial Engineering, Facult of Mecanic and Industrial Engineering
Carretera a Camajuaní km 5 1/2, 54830, Santa Clara, Villa Clara, Cuba
Head of institution
Dra. Osana Molerio Pérez