Universidad del Cauca
  • Popayán, Cauca, Colombia
Recent publications
In this article, we propose a quasi-Newton algorithm to solve a matrix polynomial equation, which can be seen as a generalization of the algorithm of the same type to solve the matrix quadratic equation proposed in Macías et al. (2016). The proposed algorithm reduces the computational cost of the Newton–Schur method traditionally used to solve this type of equations. We show that this algorithm is local and even quadratically convergent. Finally, we present numerical experiments that ratify the theoretical results developed.
Agronomic and nutritional parameters of a set of 28 accessions of Megathyrsus maximus established in Colombia during the rainy season were evaluated to identify accessions with differences in nutritional quality and characterize germplasm of M. maximus. ANOVA and multivariate analysis showed differences among accessions. Agronomic variables such as plant height, dry matter yield and green fresh weight were not correlated with nutritional variables. Flowering affected nutritional quality (neutral detergent fiber, acid detergent fiber and relative feed value). Flowering, fiber content, digestibility and crude protein content had the most influence on forage quality of M. maximus. The integral evaluation of biomass and nutritional parameters showed that the set of 28 M. maximus accessions contained 2 accessions with high nutritional quality and competitive biomass production. Heterogeneity of the collection in nutritional and agronomic assessments supports plant-breeding and offers alternatives for cattle producers in the tropics.
Introduction The food industries play a fundamental role in feeding for the functions of animal metabolism. Fish feed extrusion cooking includes process-independent factors such as temperature (°C), screw speed (RPM), throughput, feed, and moisture content that influence the final product's nutritional value and physical properties. The evidence suggests that the application of hydrolyzed protein flour (HPH) is a crucial step for the techno-functional properties of the product. Therefore, this work aimed to study the effect of hydrolyzed protein meal from silage of trout ( Oncorhynchus mykiss ) on the parameters of the extrusion system and their physical transformations. Methods In this study, the influence of hydrolyzed protein meals ranges between 10 and 30% as a substitute for fish meals. The physical properties of the extrudate were monitored, evaluating the hardness, durability, buoyancy, expansion index, and apparent density. Results Consistent with this, parameters such as feed composition, screw speed, moisture content, and extrusion process affected the composition and properties of the final product. Discussion The physical properties indicated that the hydrolyzed protein flour presented cohesiveness and decreased the mean retention time in the extruder barrel and the specific mechanical energy (SME). Hydrolyzed protein flour during the extrusion process produces pellets with high durability and low hardness due to the high porosity presented, which allows for obtaining nutritional characteristics in the extruded product.
Introduction Hypoglycemia is one of the most frequent metabolic conditions in neonates. Clinical practice guidelines (CPGs) influence clinical practice as high-quality CPGs facilitate the use of evidence in practice. This proposed study aims to systematically identify and appraise CPGs and CPG recommendations (CPGRs) for treating neonatal hypoglycemia (NH). Methods and analysis We will conduct searches in MEDLINE, EMBASE, CINAHL, Cochrane Library, LILACS (Latin American & Caribbean Health Sciences Literature), and Epistemonikos. Authors will search CPGs-specific databases and grey literature. Two reviewers will independently perform the titles and abstract screening, full-text review, and data extraction. Two appraisers will assess the quality of the CPGs and their recommendations using AGREE II (Appraisal of Guidelines Research and Evaluation) and AGREE-REX (Appraisal of Guidelines Research and Evaluation–Recommendations Excellence) instruments. Scores of ≥ 60% in the rigour of development domain will be considered for defining high-quality with AGREE II tool. CPGRs with scores >60% in the three domains will be used to determine high quality with the AGREE REX tool. We will perform a synthesis of the CPGRs to identify the consistency among the CPGRs and the methodological quality of primary studies that support them. Ethics and dissemination The results will help us to identify the methodological and quality gaps in the existing CPGs for the treatment of NH. Our findings will be submitted to peer-review journals and presented at academic conferences. Based on the study design, approval from the institutional ethics board is not required for this project. Trial registrations Systematic Review Registration Number (PROSPERO): CRD 42021239921 .
Vaccination against the Covid-19 pandemic, decreed by the WHO in 2020, has shown in the initial trials an admissible efficacy for the scientific community, but with many doubts and concerns for the communities, developing the phenomenon known as vaccine hesitancy. Objective: to understand the factors associated with the intention or rejection of vaccination against COVID-19 in the city of Popayán in the year 2022. Methodology: Cross-sectional descriptive-analytical study, carried out between August 2021 and March 2022; with a non-probabilistic sampling, for convenience, with a sample size of 993 people; A questionnaire-type survey was applied in person and virtually to know the intention of vaccination, knowledge and perceptions. Results: The surveyed population was characterized as 56.19% female, 49.24% between 18 and 28 years old; 23.16% state that they do not intend to be vaccinated against COVID-19, the main reasons being: not being well informed 56.29%, ineffective vaccine 54.8% and that the vaccine weakens the immune system 27,5%; as well as the low confidence with the Vaccination Plan and with the pharmaceutical companies that produce the vaccine. Conclusion: The intention to vaccinate against COVID-19 is determined not only by the technical-administrative dynamics of the immunization program and the health system, variables of the context and the perception of risk, add up to explain the vaccination processes.
Ubiquitous learning is an evolution of educational learning processes that implements the concept of ubiquity. That is to say, it is found at all times and in all places. This article summarizes our previous works and proposes an alternative to answer our main research question: how can we develop a U-Learning model that integrates connective learning and xAPI user experiences? This paper presents the U-Learning Model Supported by Learning Experiences and Connective Learning for virtual higher education (U-CLX Model) to measure U-Learning in virtual institutions. The U-CLX Model measures ubiquitous learning in four dimensions: time, place, medium, and context. To develop the model, we proposed a theoretical and technological framework, a definition of the U-Learning concept, a unit of measurement for ubiquitous learning (UbiquoL), and a description of the measurement process. We validated the proposal by thematic specialists and applied the instrument in two universities. The model aims to assess the level of ubiquitous learning in virtual higher education institutions and to suggest how these institutions can improve within their current operations.
Microbial diversity is fundamental for the sustainable development of the production system, in the particular case of fish and agricultural production systems, as well as the use of native microorganisms for the development of probiotics positively impacts animal development and diminishes the environmental damage caused by the traditional management of the production system. An example of agricultural systems such as fish farming and grape production, in which animals within the aquatic system and plants in vineyards are exposed to aetiologies of viral, parasitic, fungal and bacterial origin that can cause economic losses to the producer associated with decreased yield and shelf life or mortality, causing the excessive use of antibiotics and other chemicals. For this reason, it is opportune to develop products with probiotic properties, which allow the control of pathogenic microorganisms and generate advantages to the host such as: strengthening of the immune system, better assimilation of food, gain in weight and height, besides preserving the physicochemical and microbiological quality of the environment. Regarding post-harvest and post-production management, microbial biodiversity is of special importance, mainly when it comes to conservation processes. Therefore, in many sectors there is great interest in those biomolecules with bioactive capacity to protect fresh foods that contribute to the development of products and their freshness for commercialization.
This chapter briefly explains the anaerobic digestion system to optimize biogas production and integrate digestion stabilization in rural semi-lot digesters, using agro-industrial waste mixtures to establish C/N ratios; with and without the inclusion of methanogenic inoculants. A second topic refers to obtaining second generation bioethanol from lignocellulosic wastes. General concepts of biogas and bioethanol production, related parameters and typical production schemes are described. On the other hand, it will focus on the application of fermentative processes as an activity of three different bacterial communities in biogas production and on induction systems using microorganisms to obtain bioethanol. The symbiosis between microorganisms will be presented, in the sense that in fermentation processes, metabolic actions of several microorganisms act together. In the final part, some practical applications related to the installation and start up of rural biodigesters are presented. In the case of lignocellulosic materials, pre-treatments, and processes for obtaining second generation bioethanol will be presented, as well as the current market trend. Similarly, it seeks to show the benefits for users, society and the environment, in the sectors of energy production, transformation of organic waste into high quality fertilizers, improvement of hygienic conditions, reduction or elimination of wood consumption and environmental advantages.
Lotic and lenitic ecosystems tend to the stability of physicochemical parameters in time, and sometimes they can present extreme conditions or in conditions of natural environmental stress for different organisms that are habiting them. Some of the impacts that affect the microorganisms are the permanent contribution of nutrients by the particulate matter and energy favouring the growth of producing organisms, which conform dense communities, with diverse populations of algae, distributed both in the water column (ticoplankton) and in peripheral growths, formed these communities an important refuge and source of food other organisms, including various species of fish, aquatic macroinvertebrates in its adult and larval phases, and zooplankton, which is why it is of interest to present some species are used as bioindicators of environmental quality given its ecological importance, with a view to preserving the environment, making decisions for mitigation or restoration.
Information overload is a common phenomenon in the advertising dynamics of the twenty-first century, this not only causes inefficiencies in terms of advertising spending, but also, its management affects firms’ potential market power. This article builds a model in which firms compete by sending informative ads to passive consumers with reduced attention. Ads are sent through different transmission technologies, distinguished by their levels of information on consumer preferences. In equilibrium, sender strategies from firms with better-informed transmission technologies dominate sender strategies from firms with worse-informed transmission technologies, generating latent market power as a result of higher efficiency in ad location. This contribution is contrary to pro-competitive effects stated by current literature on strictly informative advertising. For context and simplicity, an iterative simulation of the model in equilibrium is carried out for the case of two transmission technologies, with the best-informed transmission technology belonging to an intermediary monopolist: the segmentation agent. The simulation yields consistent evidence of market power and industrial concentration in favor of firms that resort to intermediation by the segmentation agent. Our findings can be applied to suggest state intervention policies towards segmentation monopolists/oligopolists in information markets, to promote competition and diminish information overload.
A novel peptide, Cm39, was identified in the venom of the scorpion Centruroides margaritatus. Its primary structure was determined. It consists of 37 amino acid residues with a MW of 3980.2 Da. The full chemical synthesis and proper folding of Cm39 was obtained. Based on amino acid sequence alignment with different K+ channel inhibitor scorpion toxin (KTx) families and phylogenetic analysis, Cm39 belongs to the α-KTx 4 family and was registered with the systematic number of α-KTx 4.8. Synthetic Cm39 inhibits the voltage-gated K+ channel hKV1.2 with high affinity (Kd = 65 nM). The conductance–voltage relationship of KV1.2 was not altered in the presence of Cm39, and the analysis of the toxin binding kinetics was consistent with a bimolecular interaction between the peptide and the channel; therefore, the pore blocking mechanism is proposed for the toxin–channel interaction. Cm39 also inhibits the Ca2+-activated KCa2.2 and KCa3.1 channels, with Kd = 502 nM, and Kd = 58 nM, respectively. However, the peptide does not inhibit hKV1.1, hKV1.3, hKV1.4, hKV1.5, hKV1.6, hKV11.1, mKCa1.1 K+ channels or the hNaV1.5 and hNaV1.4 Na+ channels at 1 μM concentrations. Understanding the unusual selectivity profile of Cm39 motivates further experiments to reveal novel interactions with the vestibule of toxin-sensitive channels.
Crop yield is an important factor for evaluating production processes and determining the profitability of growing coffee. Frequently, the total number of coffee beans per area unit is estimated manually by physically counting the coffee cherries, the branches, or the flowers. However, estimating yield requires an investment in time and work, so it is not usual for small producers. This paper studies a non-intrusive and attainable alternative to predicting coffee crop yield through multispectral aerial images. The proposal is designed for small low-tech producers monitored by capturing aerial photos with a MapIR camera on an unmanned aerial vehicle. This research shows how to predict yields in the early stages of the coffee tree productive cycle, such as at flowering by using aerial imagery. Physical and spectral descriptors were evaluated as predictors for yield prediction models. The results showed correlations between the selected predictors and 370 yield samples of a Colombian Arabica coffee crop. The coffee tree volume, the Normalized Difference Vegetation Index (NDVI), and the Coffee Ripeness Index (CRI) showed the highest values with 71%, 55%, and 63%, respectively. Further, these predictors were used as the inputs for regression models to analyze their precision in predicting coffee crop yield. The validation stage concluded that Linear Regression and Stochastic Descending Gradient Regression were better models with determination coefficient values of 56% and 55%, respectively, which are promising for predicting yield.
In recent years it has been shown that the secure exchange of medical information significantly benefits people’s life quality, improving their care and treatment. The interoperability of the entire healthcare ecosystem is a constant challenge, and even more, with all the risks posed to the security of healthcare information. Blockchain technology is emerging as one of the main alternatives when it comes to finding a balance in the healthcare ecosystem. However, the constant development of new Blockchain technologies and the evolution of healthcare systems make it difficult to find established proposals. From an architectural point of view, the design of blockchain-based solutions requires trade-offs e.g. security and interoperability. This paper focuses on two main objectives, in the first one, it was carried out a Systematic Literature Review for exploring architectural mechanisms used to support the interoperability and security of Blockchain-based Health Management Systems. Taking into account of results, a series of scenarios were generated where these mechanisms can be used along with their context, issues, and various architectural concerns (interoperability and security). In the second objective, a high-level architecture and its validation were proposed through an experiment for the whole process of developing a Domain Specific Language, using the Model Driven Engineering methodology for specific Smart Contracts.
Resumen: en este trabajo se presenta una comparación entre la enseñanza presencial y remota de un curso de nivel universitario sobre sistemas de control automático. Se propone un conjunto de actividades de aprendizaje para enseñar y evaluar el curso. Estas actividades tienen como obje-tivo fortalecer la resolución de problemas, el trabajo en equipo, la comunicación y las habilidades de autoaprendizaje. Las actividades se desarrollaron utilizando las aplicaciones de aprendizaje in-teractivas: Matlab Grader, Matlab Live Scripts, Google Classroom, Google Meet y Google Docs. Una encuesta aplicada a los estudiantes que realizaron el curso presencial en 2019 y a distancia durante 2020 mostraron las ventajas del acercamiento remoto para la mayoría de los aspectos de cada una de las habilidades mencionadas. Sin embargo, los estudiantes percibieron que su contribución al trabajo en equipo era mayor cuando se encontraban en un aula física. Las calificaciones del curso mejoraron en promedio un 10 % para la modalidad remota.
El Parque Nacional Natural Munchique conserva ecosistemas estratégicos de Selva Inferior, Subandina y Andina, que han sido alterados por factores antrópicos; por ello, implementa una estrategia de restauración ecológica pasiva como alternativa para recuperar cobertura vegetal y proteger la biodiversidad. El monitoreo se realizó en un bosque subandino con 20 transectos tipo Gentry en dos procesos denominados restauración avanzada y restauración temprana, solo para los años 2013, 2015 y 2017, debido al orden público. Se censaron los individuos con DAP ≥ 1 cm. La riqueza en restauración avanzada fue de 35/2013, 39/2015 y 45/2017 especies mientras que en restauración temprana se registró una riqueza de 31/2013, 44/2015 y 45/2017. En los tres periodos de muestreo y para ambos procesos, las familias Rubiaceae y Melastomataceae fueron las más frecuentes. Restauración avanzada presentó una marcada dominancia de Miconia theizans con el 98 %/2013, 83 %/2015 y 65 %/2017 para el valor de importancia (IVI) y en restauración temprana la especie más importante fue Meriana speciosa con el 38 %/2013, 50 %/2015 y 55 %/2017. El monitoreo a largo plazo en ambos escenarios de restauración permitió evidenciar una recuperación lenta, pero efectiva para el aumento en diversidad y mejoramiento de la estructura vegetal.
La fragmentación del bosque subandino es preocupante, tanto por su valor intrínseco, como por los servicios ecosistémicos que provee. La restauración pasiva se presenta como una opción para contrarrestar esa situación. Esta investigación presenta información sobre la variación en la riqueza de la comunidad de aves frugívoras con relación al tiempo de regeneración natural del bosque para los periodos bianuales I (2012-2013), II (2014-2015) y III (2016-2017). Los registros de las aves se realizaron en seis puntos de observación para cada uno de los escenarios definidos (restauración temprana, avanzada y potrero), del PNN Munchique, departamento del Cauca. En total se registraron 50 especies de aves frugívoras de 15 familias, donde la familia Thraupidae representó el 44% de la riqueza de la comunidad de aves. Del total de especies, 43 eran frugívoros pequeños y siete de frugívoros medianos y grandes. El periodo con mayor riqueza fue el III con 36 especies y el menor fue el I con 15. Tras varios años de sucesión natural, se evidencia el aumento temporal en la riqueza de especies de aves frugívoras de pequeño tamaño, con la incorporación minoritaria de algunas especies de frugívoras medianas y grandes hacia el final del periodo de observación.
The consumption of foods with high protein content from pseudocereals is of great industrial interest. Pasta has a high gluten content; consequently, obtaining these gluten-free products is a technological challenge. The products obtained from quinoa show excellent results in protein and fiber with low glycemic index. This work focused on studying the effect of quinoa fat on the production of long pasta by extrusion in different mixtures of hyperprotein quinoa (HHP). It was observed that formulations with high percentages of starch showed a higher expansion rate, due to a higher fat content. Likewise, extruded pastes showed higher values of brightness than those containing lower percentages of starch and crude fat. The fracturability results were associated with the resistance of the paste to the pressure exerted for its deformation, which does not exceed 3.73 mm. The formulations with lower fat content presented high values in fracture stress due to the low diffusion of water and lipids. It was shown that fat has an indirect influence with a strong correlation with the expansion index and fracture stress and a moderate correlation ( p > 0.05) with Young's modulus, indicating that increasing the added fat content increases the percentage of mass loss by baking. The melting and cohesiveness of all components improved during extrusion due to the pregelatinization of cassava starch, the addition of defatted HHP and the availability of quinoa starch granules.
The presence of Afro-descendant students in Colombian universities took place long before constitutional multiculturalism, as we know them today. The emergence of affirmative actions in higher education in Colombia is result of the mobilization and claim processes that took place in different cities from the fifties of the last century. This article aims to make this political event visible as a milestone in the history of claims in the educational field of our country, as well as to highlight the agency of Afro-Colombian student organizations during this century in the implementation and expansion of the universe of affirmative actions. at various public universities. Keywords Afro-Colombians; Organizations; Affirmative actions; Higher education
In this work, the results of the design and construction of a bipedal robot with 12 degrees of freedom are presented, for the experimentation of gait joint trajectories. The physical-mathematical models of the robot (geometric model and simplified dynamics) are presented. The prototype allows the robot's center of gravity to be monitored by means of pressure sensors installed in the feet, in addition to the zero moment point, used to evaluate the stability of the gait. The validation of the experiments carried out was done by simulating the model and comparing it with the real robot.
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4,021 members
Mario F. Delgado-Noguera
  • Departamento de Pediatría
Jose Andres Calvache
  • Departamento de Anestesiología
Juan Carlos Aguirre García
  • Departamento de Filosofía
José Fernando Solanilla Duque
  • Departamento de Agroindustria
Hector Samuel
  • Departamento de Agroindustria
Calle 5 # 4-70, 19003, Popayán, Cauca, Colombia