Universidad de Ibagué
  • Ibagué, Tolima, Colombia
Recent publications
A new Rhodamine-based ́́Turn On‘‘ fluorescent probe (E)-3',6'-bis(diethylamino)-2-((2,5-dimethoxybenzylidene)amino)spiro[isoindoline-1,9'-xanthen]-3-one (WGB) was synthesized. Results show that WGB is selective for Cu2+ cations, forming a WGB-Cu2+ complex in a 2:1 stoichiometry, confirmed through density functional theory (DFT) electronic structure calculations and reactive molecular dynamics (MD) simulations. Theoretical calculations agreed with the experimental data. The detection limit of WGB-Cu+2 complex is 6.76 x 10-8 M. Preliminary studies employing epifluorescence microscopy demonstrate that Cu2+ can be imaged in neuroblastoma SH-SY5Y cells treated with WGB.
The present study examined how conspiracy beliefs about COVID-19 vaccines specifically relate to symptoms of fear of COVID-19 in a sample of four South American countries. A total of 1785 people from Bolivia, Colombia, Ecuador, and Peru participated, responding to a sociodemographic survey, the Fear of COVID-19 scale (FCV-19 S) and the Vaccine Conspiracy Beliefs Scale-COVID-19 (VCBS-COVID-19). Network analysis identified the most important symptoms of fear and conspiracy beliefs about COVID-19 vaccines (nodes) and the associations between them (edges). In addition, the robustness of the network of these indicators of centrality and the possible differences in the structure and connectivity of the networks between the four countries were evaluated. The results suggest that the nodes with the highest centrality were items 2 and 5 of the FCV-19 S and item 2 of the VCBS-COVID-19. Likewise, item 6 is the belief that most predicts conspiracy beliefs about vaccines against COVID-19; while item 6 was the symptom that most predicts fear of COVID-19. The findings strongly support cross-cultural similarities in the networks across the four countries rather than differences. Although it was expected that a higher presence of symptoms of fear of COVID-19 may lead people to compensate for their fear by believing in conspiratorial ideas about vaccines and, consequently, rejecting the COVID-19 vaccine, the results do not clearly show this relationship. This could lead other researchers to generate evidence to explain the differences between Latin American countries and countries in other contexts in terms of vaccination rates. This evidence could be useful to develop policies favoring vaccination against COVID-19 that are more contextualized to the Latin American region, characterized by social instability and economic recession during the pandemic.
The purpose of this paper is to show an application of variety engineering in the social realm (Beer in The heart of enterprise. Wiley, Chichester, 1979, in Brain of the firm. Wiley, Chichester 1981, in diagnosing the system for organizations. Wiley, Chichester, 1985). It focuses on reducing environmental complexity by catalysing self-organizing processes (Espejo and Reyes in Organizational systems: managing complexity with the VSM. Springer, London, 2011). This catalysis is based on the use of Sen and Nussbaum’s capabilities approach (Sen in Development as freedom. Oxford University Press, New York, 1999; Nusbaum in Women and human development: the capabilities approach. Cambridge University Press, New York, 2000). By doing this an organization may improve the quality of the relations with their clients by transforming environmental agents into new suppliers. This approach opens a new dimension of social responsibility for organizations. A particular case is presented in which a regional university in Colombia faces the challenge of attending low-income students coming from small municipalities. They designed a strategy to offer low-cost housing and a daily balanced meal without using the university's own resources. Instead, they managed to involve some agents of the community by developing their capabilities. This kind of variety engineering shows the possibility of new forms of social responsibility in universities by incorporating the capabilities approach into their managerial practices. This is something that is currently under study in other universities (Boni et al. in Science and engineering ethics. Springer, London, 2015).
The increasing interest in renewable energy sources has brought attention to large voltage-gain dc–dc converters; among the different available solutions to perform a large voltage-gain conversion, this article presents an overview of non-isolated dc–dc converter topologies that utilize switched-capacitor circuits, i.e., diode-capacitors voltage multipliers. The review includes combinations of a traditional power stage with a diode-capacitor-based voltage multiplier, such as the multilevel boost converter. This article starts by reviewing switched-capacitor (SC) circuits, different topologies, and different types of charge exchange; it provides a straightforward analysis to understand the discharging losses. It then covers the multilevel boost converter and other topologies recently introduced to the state-of-the-art. Special attention is put on SC circuits with resonant charge interchange that have recently been probed to achieve very good efficiency. An additional contribution of the article is new proof of the discharging losses in resonant switched-capacitor circuits focused on the initial and final stored energy in capacitors, and this proof explains the relatively large efficiency obtained with SC resonant converters.
In this study, isolation and purification of lichen substances from Usnea cornuta were performed using conventional solvents, green solvents and green technologies. In addition, several lichen compounds were tentatively identified by UHPLC/ESI/MS/MS and usnic acid, diffractaic and galbinic acids were quantified as well. Limonene, ethyl lactate and methanol, were compared regarding their extraction properties and antioxidant capacities, determined by DPPH, ORAC, and FRAP assays. In the ethyl lactate, methanol and limonene extracts, 28 compounds in all, were detected for the first time by high resolution UHPLC-MS/MS fingerprinting. Untargeted metabolomics tentatively identified 14 compounds from the methanolic extract, 4 from limonene extract, and 20 metabolites from ethyl lactate extract. The green extract of ethyl lactate showed a similar antioxidant capacity to toxic methanol extract, except at ORAC assay where it was higher. Therefore, ethyl lactate can replace methanol, to provide more sustainable green chemistry methods. ARTICLE HISTORY
Currently, there are no free databases of 3D point clouds and images for seedling pheno- typing. Therefore, this paper describes a platform for seedling scanning using 3D Lidar with which a database was acquired for use in plant phenotyping research. In total, 362 maize seedlings were recorded using an RGB camera and a SICK LMS4121R-13000 laser scanner with angular resolutions of 45 ° and 0.5 ° respectively. The scanned plants are diverse, with seedling captures ranging from less than 10 cm to 40 cm, and ranging from 7 to 24 days after planting in different light conditions in an indoor setting. The point clouds were processed to remove noise and imperfections with a mean absolute precision error of 0.03 cm, synchronized with the images, and time-stamped. The database includes the raw and processed data and manually assigned stem and leaf labels. As an example of a database application, a Random Forest classifier was employed to identify seedling parts based on morphological descriptors, with an accuracy of 89.41%.
The rapid emergence and spread of new variants of coronavirus type 2, as well as the emergence of zoonotic viruses, highlights the need for methodologies that contribute to the search for new pharmacological treatments. In the present work, we searched for new SARS-CoV-2 papain-like protease inhibitors in the PubChem database, which has more than 100 million compounds. Based on the ligand efficacy index obtained by molecular docking, 500 compounds with higher affinity than another experimentally tested inhibitor were selected. Finally, the seven compounds with ADME parameters within the acceptable range for such a drug were selected. Next, molecular dynamics simulation studies at 200 ns, ∆G calculations using molecular mechanics with generalized Born and surface solvation, and quantum mechanical calculations were performed with the selected compounds. Using this in silico protocol, seven papain-like protease inhibitors are proposed: three compounds with similar free energy (D28, D04, and D59) and three compounds with higher binding free energy (D60, D99, and D06) than the experimentally tested inhibitor, plus one compound (D24) that could bind to the ubiquitin-binding region and reduce the effect on the host immune system. The proposed compounds could be used in in vitro assays, and the described protocol could be used for smart drug design.
This research was aimed to identify the main reasons why entrepreneurs in the city of Ibagué, who structure business ideas and participate in contests and/or calls, do not continue the entrepreneurial process until the creation of their companies. After applying the validated instrument (survey) to more than 100 students from the Universidad de Ibagué and expert advisers from the department of Tolima, made up of universities, entrepreneurs, and public–private institutions, with interests in entrepreneurship; it was possible to recognize that the main reason, why entrepreneurs generate ideas, but not companies, is the cultural factor. The foregoing is based on the fact that Tolima has been a quintessential agricultural department and this situation has contributed greatly to the fact that the entrepreneurial spirit has not been developed in people. Within the research results it was detected that in contrast with other cities of Colombia, like Manizales and Medellín, Ibagué has not been able to consolidate a solid entrepreneurial ecosystem due to the lack of coordination among private, public, and academic sectors, and on the other side, a majority of people from Ibagué do not have family support for the development of their initiatives, being fundamental components for the creation of enterprises. Among the recommendations proposed in the study is the construction of an entrepreneurial ecosystem, because it will allow the participation of the Triple Helix by providing opportunities to all entrepreneurs in the region; in addition, it is considered important that educational institutions, both schools and universities, promote the development of entrepreneurial skills and competencies in individuals involving their families.
We design and evaluate the performance of a one-dimensional photonic crystal (PhC) optical filter that comprises the integration of alternating layers of a barium titanate ferroelectric (BaTiO3) and an yttrium oxide dielectric (Y2O3), with a critical high-temperature superconductor defect, yttrium–barium–copper oxide (YBa2Cu3O7−X), resulting in the (BTO/Y2O3)N/YBCO/(Y2O3/BTO)N multilayered nanostructure array. Here, we demonstrate that such a nanosystem allows for routing and switching optical signals at well-defined wavelengths, either in the visible or the near-infrared spectral regions—the latter as required in optical telecommunication channels. By tailoring the superconductor layer thickness, the multilayer period number N, the temperature and the direction of incident light, we provide a computational test-bed for the implementation of a PhC-optical filter that works for both wavelength-division multiplexing in the 300–800 nm region and for high-Q filtering in the 1300–1800 nm range. In particular, we show that the filter’s quality factor of resonances Q increases with the number of multilayers—it shows an exponential scaling with N (e.g., in the telecom C-band, Q≈470 for N=8). In the telecom region, the light transmission slightly shifts towards longer wavelengths with increasing temperature; this occurs at an average rate of 0.25 nm/K in the range from 20 to 80 K, for N=5 at normal incidence. This rate can be enhanced, and the filter can thus be used for temperature sensing in the NIR range. Moreover, the filter works at cryogenic temperature environments (e.g., in outer space conditions) and can be integrated into either photonic and optoelectronic circuits or in devices for the transmission of information.
This study assesses the relationship between COVID-19 anxiety and subjective well-being in terms of the mediating role of COVID-19 preventive behaviors. Additionally, the contribution of sociodemographic factors (sex and age) and risk perception on COVID-19 anxiety and its potential measurement invariance was tested in 5655 participants from 12 countries in Latin America and the Caribbean. A mixture of both latent and observable variables were analyzed using a system of structural equations. The Coronavirus Anxiety Scale (CAS), Preventive COVID-19 Infection Behaviors Scale (PCIBS) and single-item measures were used to assess the perceived probability of death, perceived severity and concern about transmitting COVID-19. The results indicated that there is a significant and relevant direct effect of COVID-19 anxiety on participants' well-being. Furthermore, COVID-19 anxiety significantly predicted both preventive behavior (β = .29, p < .01) and well-being (β = –.32, p < .01). The effects of COVID anxiety and preventive behavior explained 9.8% of the variance in well-being (R-square = .098); whereas, 8.4% of the variance in preventive behavior was associated with COVID anxiety (R-square = .084). Likewise, perceived likelihood of death from COVID, perceived severity of COVID, and concerns about COVID transmission were positively related to anxiety. Age was negatively related to anxiety, with men being less anxious than women. The results are invariant by country, i.e., the broad relationships found in the combined sample are also present in each individual country. The findings indicate that, although the exact relationships between variables may vary between countries, there are enough similarities to provide useful information about the impact of the COVID-19 pandemic in each of the countries included in the study.
Introduction In Ecuador, adoption is limited to heterosexual couples and information on attitudes toward same-sex couples who intend to become parents following this pathway is scarce. This study aimed to identify the beliefs of a sample of 319 cisgender people in Ecuador regarding the adoption of children by same-sex couples and explore the reasons why they consider it is appropriate or not for lesbian and gay (LG) couples to adopt children. Methods Between May and October 2019, participants responded quantitative and qualitative questions after reading a vignette about a couple interested in adopting a child. Participants were randomly presented with one out of three versions of the vignette based on the couples’ sexual orientation (L,G, heterosexual). Descriptive, correlational statistics and analysis of variance were used to conduct quantitative analyses. Qualitative responses were analyzed using thematic and content analysis. Results Results indicate favorability toward adoption by all couples in general. However, people showed the highest concerns about adoption by LG couples. Qualitative answers indicate the existence of nine types of arguments used by participants to explain their position in favor or against adoption by same-sex couples. Conclusion Some are problematic since they are rooted in prejudiced ideas about heterosexual people’s superiority regarding their capacities to create emotionally nurturing environments. Policy Implications Providing information regarding LG parenting might be a way of achieving legislative changes that might, in turn, promote social change by providing a legal platform for same-sex couples to achieve parenthood.
Se presenta el dimensionamiento de un sistema de riego aplicado a un cultivo de limón, haciendo uso de la energía solar. Dicho riego cumplió con valores de evapotranspiración potencial (ETP) de 4,31 mm/día y Uso Consuntivo (UC) de 1,85 mm/ha/día, cuya matriz experimental se encuentra compuesta por tres surcos de 57 árboles con requerimiento de 64,91 litros/árbol/día, utilizando goteros de una descarga de 4 litros/hora. El estudio demuestra en un nivel altamente significativo que la humedad se concentra en una profundidad de 15 cm, influenciado por las características físicas arenosas del suelo. Para el requerimiento del agua de riego, se dimensiona un sistema solar, obteniendo un arreglo de diez paneles en serie y dos en paralelo para un total de veinte en conjunto, un inversor de una capacidad de 5,0 kWp, para alimentar una bomba de 2 HP y una vivienda, con consumo promedio de 1,5 kWp, conectado a una red de baja tensión de 220V. La eficiencia global del sistema se registró en el rango de 10 y 14 % y la potencia máxima de salida del sistema fotovoltaico se alcanzó entre las 10 y las 14 horas con un 84 % de la capacidad total instalada (5,2 kWp).
Himantormia lugubris is a Chilean native small lichen shrub growing in the Antarctica region. In this study, the metabolite fingerprinting and the antioxidant and enzyme inhibitory potential from this species and its four major isolated compounds were investigated for the first time. Using ultra-high performance liquid chromatography coupled to quadrupole-Orbitrap mass spectrometry analysis (UHPLC-Q-Orbitrap-MS), several metabolites were identified including specific compounds as chemotaxonomical markers, while major metabolites were quantified in this species. A good inhibition activity against cholinesterase (acetylcholinesterase (AChE) IC50: 12.38 ± 0.09 µg/mL, butyrylcholinesterase (BChE) IC50: 31.54 ± 0.20 µg/mL) and tyrosinase (22.32 ± 0.21 µg/mL) enzymes of the alcoholic extract and the main compounds (IC50: 28.82 ± 0.10 µg/mL, 36.43 ± 0.08 µg/mL, and 7.25 ± 0.18 µg/mL, respectively, for the most active phenolic atranol) was found. The extract showed a total phenolic content of 47.4 + 0.0 mg of gallic acid equivalents/g. In addition, antioxidant activity was assessed using bleaching of DPPH and ORAC (IC50: 75.3 ± 0.02 µg/mL and 32.7 ± 0.7 μmol Trolox/g lichen, respectively) and FRAP (27.8 ± 0.0 μmol Trolox equivalent/g) experiments. The findings suggest that H. lugubris is a rich source of bioactive compounds with potentiality in the prevention of neurodegenerative or noncommunicable chronic diseases.
This work aimed to characterize the starch from arracacha at two phenological stages (S1: twelve months and S2: fourteen months) and assess its potential use blended with polylactic acid (PLA) for thermoplastic starch biodegradable film preparation using the extrusion technique. Arracacha starches showed high amylose content (25% and 24% for S1 and S2, respectively), which is related to its easy to cook properties, intermediate final viscosity, and the potential for its use as material for biodegradable films preparation. Production of Thermoplastic starch biodegradable films (SF1 and SF2) using arracacha starch blended with polylactic acid as raw materials were successful, the biofilms exhibited low solubility and water vapor permeability, which is due to the hydrophobic nature of polylactic acid, these results indicate its potential use for packaging of foods with intermediate or low water contents. Besides, biodegradable films showed good thermal properties, which are related to the stability of degradation. Arracacha for starch extraction and its use for biodegradable film preparation could be an alternative to add value to this crop. Likewise, the preparation of thermoplastic films using arracacha starch blended with polylactic acid is presented as an alternative to the use of plastic packaging.
This work proposes the implementation of a control system based servo-vision in a cable-driven parallel robot with four degrees of freedom. In the first instance, a servo-vision based position control system is designed for a correct positioning of the mobile platform (end-effector) within the working space of the fixed platform (frame). Also, this part integrates the application of techniques for object detection in images. The second part verifies the system by tracking trajectories and positioning of the end-effector in the workspace. Moreover, seedling monitoring will be performed in a seedbed located inside the robot, which consists of taking real-time video of the robot’s end-effector, for the location and monitoring of the seedlings.
AimsOver the past 2 years, the vaccine conspiracy beliefs construct has been used in a number of different studies. These publications have assessed the determinants and outcomes of vaccine conspiracy beliefs using, in some cases, pooled data from different countries, and compared the results across these contexts. However, studies often do not consider measurement invariance as a necessary requirement for comparative analyses. Therefore, the aim of this study was to develop and evaluate the cross-cultural MI of the COVID-19 Vaccine Conspiracy Beliefs Scale (COVID-VCBS) in 12 Latin American countries.Methods Confirmatory factor analysis, item response theory analysis and alignment method were applied to test measurement invariance in a large number of groups.ResultsThe COVID-VCBS showed robust psychometric properties and measurement invariance for both factor loadings and crosstabs. Also, a higher level of acceptance of conspiracy beliefs about vaccines is necessary to respond to higher response categories. Similarly, greater acceptance of conspiracy beliefs about COVID-19 vaccines was related to a lower intention to be vaccinated.Conclusion The results allow for improved understanding of conspiracy beliefs about COVID-19 vaccines in the countries assessed; furthermore, they provide researchers and practitioners with an invariant measure that they can use in cross-cultural studies in Latin America. However, further studies are needed to test invariance in other countries, with the goal of developing a truly international measure of conspiracy beliefs about COVID-19 vaccines.
Objetivos. Determinar la efectividad de acaricidas en poblaciones de campo de Rhipicephalus (Boophilus) microplus colectadas en fincas ganaderas de los municipios de Ibagué, Espinal y Cajamarca, departamento del Tolima. Metodología. En 12 fincas se colectaron 1200 teleoginas de R. microplus que fueron sometidas a una prueba de inmersión de adultas (PIA) modificada, a fin de evaluar cuatro acaricidas comúnmente usados en la región: cipermetrina al 15%, amitraz al 20,8%, etión al 84% e ivermectina al 1%. Se calcularon parámetros como la eficiencia reproductiva y el porcentaje de eclosión, con los cuales se determinó la eficacia de cada acaricida. Resultados. Se encontró que en el 91,66% de los predios evaluados las poblaciones de R. microplus fueron resistentes a la cipermetrina, el 91,66% al amitraz, 75% a etión y 66,66% a ivermectina, evidenciando pérdida de eficacia de estos químicos. Conclusión. Se demostró la alta dispersión de resistencia a los acaricidas de uso frecuente en campo para el control de poblaciones de R. microplus en tres municipios del Tolima, denotando la necesidad de establecer nuevas estrategias de control que permitan limitar las infestaciones de la garrapata común del ganado.
The aim of this study was to examine the prevalence and frequency of perpetration and victimization of different types of dating violence (DV), among adolescents from 13 to 19 years old in five capital cities of Colombia (Bogotá, Bucaramanga, Ibagué, Tunja, and Yopal), making comparisons by sex. The Spanish version of the Conflict in Adolescent Dating Relationships Inventory was used and various statistical analyses, including the one-way MANOVA, were performed. The results show a high prevalence of DV, particularly verbal/emotional and bi-directional (almost 90 % of the participants), pointing out that sex could have a statistically significant effect on the prevalence of the different types of DV, being higher the proportion of men who perpetrated sexual violence and higher the proportion of women who perpetrated verbal/emotional and physical violence. These results indicate the need to continue investigating the phenomenon in Colombia, to carry out different prevention campaigns that are sensitive to differences by sex in prevalence.
Conspiracy theories about COVID-19 began to emerge immediately after the first news about the disease and threaten to prolong the negative impact of the COVID-19 pandemic by limiting people’s willingness of receiving a life-saving vaccine. In this context, this study aimed to explore the variation of conspiracy beliefs regarding COVID-19 and the vaccine against it in 5779 people living in 13 Latin American countries (Argentina, Bolivia, Chile, Colombia, Cuba, Ecuador, El Salvador, Guatemala, Mexico, Paraguay, Peru, Uruguay and Venezuela) according to sociodemographic variables such as gender, age, educational level and source of information about COVID-19. The study was conducted during the COVID-19 pandemic between September 15 and October 25, 2021. The Spanish-language COVID-19 Vaccine Conspiracy Beliefs Scale (ECCV-COVID) and a sociodemographic survey were used. The results indicate that, in most countries, women, people with a lower educational level and those who receive information about the vaccine and COVID-19 from family/friends are more supportive of conspiracy ideas regarding the COVID-19 vaccine. In the case of age, the results vary by country. The analysis of the responses to each of the questions of the ECCV-COVID reveals that, in general, the countries evaluated are mostly in some degree of disagreement or indecision regarding conspiratorial beliefs about COVID-19 vaccines. The findings could help open further study which could support prevention and treatment efforts during the COVID-19 pandemic.
With the rapid emergence and spread of new variants of coronavirus type 2 causing acute respiratory syndrome, it is necessary to search for new pharmacological treatments for the disease, especially for patients infected by the new and more aggressive variants of the virus. In the present work, we selected from the PubChem database, ~ 18,000 compounds with similar structure to GRL0617, a papain-like protease inhibitor of SARS-CoV-2. Then, based on the ligand efficacy index obtained by molecular docking, the 500 compounds with higher affinity than GRL0617 for the protease were evaluated. Finally, the seven compounds with ADME parameters within the acceptable range for such a drug were selected. Then, 200 ns molecular dynamics simulation studies, ∆G calculations using Molecular mechanics with generalized Born and surface area solvation, and quantum mechanical calculations were performed with the selected compounds. Using this In Silico protocol, seven papain-like protease inhibitors are proposed: three compounds with binding free energy like GRL0617 (D28, D04 and D59), three compounds with binding free energy higher than GRL0617 (D60, D99 and D06) and one compound (D24) that could bind to the ubiquitin binding region and reduce the effect on the host immune system. The proposed compounds could be used in in vitro tests, and the described protocol could be used for intelligent drug design.
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854 members
Manuel G Forero
  • Engineering
Olimpo José García
  • Administración Ambiental
Lida marcela Franco perez
  • Facultad de ciencias Naturales y matematicas
Edison Humberto Osorio
  • Facultad de Ciencias Naturales y Matemática
Carrera 22 Calle 67, 730002, Ibagué, Tolima, Colombia
Head of institution
Alfonso Reyes Alvarado