Universidad Nacional De Colombia Research Articles

Leaf spectrum analysis of three tropical timber species: Diomate (Astronium graveolens), Choibá (Dipteryx oleifera), and Algarrobo (Hymenaea courbaril)

This study analyzed the leaf spectral response of three native timber forest species in the tropical dry forest: Diomate (Astronium graveolens Jacq.), Choibá (Dipteryx oleifera Benth.), and Algarrobo (Hymenaea courbaril L.). The study was conducted at the León Morales Soto Arboretum and Palmetum, at the Universidad Nacional de Colombia in Medellín, Antioquia, Colombia. Spectral data from the leaves were collected in situ using the portable spectroradiometer ASD FieldSpec HandHeld-2, which operates with a spectral resolution of 1 nm (resampled to 10 nm) and covers a spectral range between 325 and 1,075 nm (limited to 400-900 nm). Based on the measurements, the behavior and spectral variability of the species were evaluated. One-factor Analysis of Variance and Mann Whitney-Wilcoxon U-test were implemented in reflectance spectra to select the optimal narrow bands for species discrimination. The classification capacity of the selected narrow bands was assessed using the K-nearest neighbors’ algorithm. It was found that A. graveolens and H. courbaril exhibited spectral signatures typical of healthy vegetation, while D. oleifera showed spectral changes during the early stages of senescence. Regarding spectral separability, 23 narrow bands in the visible region and near-infrared region were identified as optimal for distinguishing the plant species. The supervised classification algorithm applied to these 23 narrow bands achieved an overall accuracy of 95.8%. In conclusion, these findings provide valuable insights into the spectral response of important tropical species and contribute to their conservation efforts by enhancing understanding of their unique spectral characteristics in diverse and heterogeneous ecosystems like tropical forests.

Soil quality indicators related to the deterioration of Kikuyu grass Cenchrus clandestinus (Hochst. ex Chiov.) Morrone

Inadequate grassland management has resulted in the degradation of extensive areas, loss of productivity and sustainability of many of them, reflecting a common reality among livestock farmers in Colombia. Therefore, at the Paysandú Agricultural Station of the Universidad Nacional de Colombia, located in the Santa Elena township of the city of Medellín, a study was carried out to determine a soil quality index (SQI) by evaluating the physical and chemical indicators that were most related to the deterioration and dry matter production of kikuyu grass (Cenchrus clandestinus). A minimum data set (MDS) was established for the most sensitive indicators, selected by principal component analysis (PCA), and a nonlinear scoring function was used to obtain the SQI. Statistical differences were found between all the treatments in relation to dry matter production (P<0.05: 1.91x10-32). The most sensitive indicators were bulk density BD > total porosity TP > macropores MAC > micropores MIC > penetration resistance PR > effective cation exchange capacity ECEC > pH. As a result, the following formula was obtained: SQI = (0.225×BD) + (0.224×TP) + (0.220×MAC) + (0.218×MIC) + (0.113×PR) + (0.0879×ECEC) + (0.0877×pH). This index should be tested in kikuyu grass-dominated pastures located in the Colombian high tropics. The baseline is critical at values > 0.58 Mg m-3 for BD and > 2.25 MPa for PR. In addition, the optimum pH range for kikuyu grass development was between 5.4 and 6.4.

Twenty-Five Years Travelling the Publication Road: The Profile Journal Life Story

This article presents the life story of Profile. The story is based on an ethnographic case study that aimed to understand the viewpoints of Profile’s new writers and reviewers regarding the role of scientific journals in fostering communities in the knowledge society. To gather information, I relied on personal reflections from my experience as the creator and editor of the journal, along with documentary evidence (published issues, regularly collected statistics, editorial workflows, and communications with editorial teams and various bodies of Universidad Nacional de Colombia, which funds the publication). The story illustrates the inception, development, and primary challenges that need to be addressed to ensure its continuity.

Weeds and compacted soil in the establishment of an urban garden using the biointensive approach: Experiences and limitations

The interest of people in consuming their own agricultural products is on the rise, leading to an increase in the number of urban gardens established in Bogotá over the past years. These gardens operated using the biointensive method as a model for urban agriculture present an environmentally sustainable alternative. However, this system comes with challenges and limitations that may hinder the establishment of such a project. To test this, an urban garden focused on biosystems with high levels of agricultural biodiversity was established within a greenhouse of the Universidad Nacional de Colombia, Bogotá campus. This was carried out in an area with a covered and an uncovered section. A weed germination trial was conducted in planting containers, assessing the relative representation of weeds in two random samplings taken from different containers over a two-month measurement period and a previous soil analysis was realized to evaluate the physical and chemical conditions of the soil. Consequently, 13 weed species were identified in the soil bank of weeds, with Veronica spp. being the most relatively represented in both samplings. However, within the established orchard, the predominant plants were those belonging to the Poaceae family, such as Lolium temulentum and Cenchrus clandestinus. Finally, through the biointensive method and the addition of organic materials such as biochar and regular topsoil, soil properties like structure, porosity, and friability were improved. This, in turn, enabled better root development and the successful establishment of various cultivars in the garden.

ASYMPTOTIC BEHAVIOUR OF THE JACOBI SOBOLEV-TYPE ORTHOGONAL POLYNOMIALS. A NON DIAGONAL CASE

Asymptotic behaviour of the Jacobi Sobolev-type orthogonal polynomials. A non-diagonal case. Rev. Acad. Colomb. Cienc. 34 (133): 529-539, 2010. ISSN 0370-3908. MATEMÁTICAS 1 Universidad Nacional de Colombia, Bogotá, Colombia. Correo electrónico: haduenasr@unal.edu.co 2 Facultad de Ciencias, Universidad de Colima, Bernal Díaz del Castillo No. 340, Colima, Colima, México. Correo electrónico: garzaleg@gmail.com AMS Classification 2000: 33C47. Consider the following Sobolev type inner product (p, q) = ∫ p'(x)q(x)(1 - x)θ(1 + x)θdx + i[p'(1)q(1) - p(1)q'(1)], (1) where p and q are polynomials with real coefficients, 0 < θ > -1, ξ(x) = (p(x), q(x))', and A = [M0, M1; M1, M2] is a positive semidefinite matrix, with M0M1 ≥ 0, and A ∈ ℝ. The family of polynomials orthogonal with respect to (1), P_n^{(θ,θ)}, are called Jacobi Sobolev-type orthogonal polynomials. An expression that relates this family of polynomials with P_n^{(0,0)}, the usual Jacobi orthogonal polynomials, was obtained in [8]. Here, we obtain the outer relative asymptotic for P_n^{(0,0)}, as well as the corresponding Mehlér-Heine formula.

Genetic control of yield components in green beans (Phaseolus vulgaris L.)

Background. This work aimed at using Hayman’s methodology to study the inheritance of some quantitative traits, such as the number of pods per plant, pod length, mean pod weight, and yield per plant in 15 diallel hybrids of six green bean cultivars.Materials and methods. The research was carried out at the Experimental Center of Universidad Nacional de Colombia – Sede Palmira (CEUNP). A randomized complete block experimental design with four replications was used.Results. For most of the traits, except yield per plant, the additive-dominant model was adequate. Non-additive effects with overdominance controlled the number of pods per plant, pod length, and mean pod weight. Most of the characters presented an unequal proportion of positive and negative genes in the loci (H1 < H2). The asymmetric distribution of genes in the parents (H2/4H1) was below the maximum value (0.25), except for the character “number of pods per plant”. The KD/KR ratio confirmed for most of the traits that there was an excess of recessive alleles over dominant alleles. Dominance effects (h2) for most char-acters suggested that the substantial contribution of dominance was not due to heterogeneity of loci in these characters. The narrow-sense heritability was moderate to low. The correlation coefficient r (Yr; Wr + Vr) indicated that dominant genes were responsible for the increased number of pods per plant and recessive genes for increased pod length and mean pod weight.Conclusions. Conventional breeding methods like pedigree selection could be employed to improve the characters “pod length” and “mean pod weight”, and for the number of pods per plant, management of segregating populations should employ the single-seeded descent method.

THU314 Diagnosis Performance Of Insulin Surrogate Indices For Predicting Insulin Resistance In Young Men Defining As Reference The Matsuda Index - An Exploratory Case-Control Study Conducted In Latin America Population

Abstract Disclosure: V.M. Soriano: None. C. Espinel Pachon: None. Diagnosis performance of insulin surrogate indices for predicting insulin resistance in young men defining as reference the Matsuda index – An exploratory case-control study conducted in Latin America population Víctor Antonio Malagón – Soriano1, Álvaro Javier Burgos – Cárdenas1, Maria Fernanda Garcés2, Cristian Felipe Espinel – Pachon1, Roberto Franco – Vega3, Jorge Andres Rubio – Romero4, Sofia Alexandra Caminos – Cepeda5, Ezequiel Lacunza6, Ariel Iván Ruiz – Parra4, Jorge Eduardo Caminos2 1Department of Internal Medicine, 2Department of Physiology, 3Endocrinology Unit - Department of Internal Medicine, 4Department of Obstetrics & Gynecology, School of Medicine Universidad Nacional de Colombia, Bogotá 11001, Colombia. 5School of Medicine, Universidad Pompeu Fabra; Barcelona 08002, Spain.6Centro de Investigaciones Inmunológicas Básicas y Aplicadas (CINIBA), Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata 1900, Argentina. Correspondence: Jorge Eduardo Caminos, MSc. PhD., Department of Physiology, School of Medicine, Universidad Nacional de Colombia, Carrera 30 No. 45-03, Edificio 471 Oficina 406, Bogotá, Colombia, E-mail: jecaminosp@unal.edu.coRunning title: Diagnosis performance of Insulin Surrogate Indices using as reference the Matsuda index. Key words: Insulin surrogate indices, diagnosis performance, Matsuda index, healthy and insulin resistant young men Abstract Insulin plays an essential role in glucose and lipid homeostasis. Changes in insulin sensitivity in adipose tissue, liver and muscle occur in the course of different metabolic disorders, and have been proposed to be a potential contributor to obesity and type 2 diabetes. The euglycemic-hyperinsulinemic clamp technique is the gold standard approach for assessing insulin sensitivity in humans, with the disadvantages of being expensive, labor intensive, and time consuming. Therefore, this study aimed to investigate the diagnosis performance of insulin surrogate indices using as reference the Matsuda index, in healthy and insulin resistant young men in Latin America population. Thus, the current cross-sectional study was conducted in healthy (n=48) and insulin resistant (n=45) young adult men (18–31 year old) using the Matsuda index cut-off value as reference to determine insulin sensitivity/resistance. Receivers operating characteristic curves (ROC) were used to determine the cut-off, sensitivity, and specificity values for QUICKI, HOMA-IR, TG/HDL-C, TyG, TyG-WC, TyG-BMI, LAP and VAI. TyG-WC (AUC=1.0) and TyG-BMI (AUC=1.0) indices showed the highest diagnostic performance with high sensitivity and specificity to predict insulin resistance in young men. In addition, TyG-BMI index showed a statistically significant stronger correlation with waist circumference (WC), when compared with HOMA-IR, Matsuda and QUICKY indices. In conclusion, we were able to diagnose insulin resistance with high sensitivity and specificity in young individuals -supposedly metabolically healthy- who do not meet the criteria for metabolic syndrome diagnosis, using widely available, low-cost, and reliable surrogate indices. Additionally, the TyG-WC and TyG-BMI indices were the better predictors of insulin resistance. The cut-off values used to define insulin resistance in our Latin America population studied were similar to recent studies in the United States population, despite clinical and racial/ethnic differences. Presentation: Thursday, June 15, 2023

Notes on the marine algae of the International Biosphere Reserve Seaflower, Caribbean Colombia IX: new records of Lobophora declerckii, Taonia abbottiana and Verosphacela ebrachia for Colombia

Background and Aims: During the Seaflower Scientific Expedition in 2019, extensive seaweed collection was carried out around Old Providence and Santa Catalina islands. Despite the intensive phycological studies realized during the past decade, new reports of macroalgae are still recorded for the Seaflower Biosphere Reserve. The objective of this work is to present three new records of brown algae for Colombia.Methods: The algal sampling was carried out in September 2019 during the Seaflower Scientific Expedition. The samples were collected around the Providencia and Santa Catalina islands in coral patches ecosystems, by SCUBA diving at depths between 3 and 16 m. The algae collected were preserved in a 4% formalin/seawater solution. The identification was carried out using optical and stereoscopic microscopes. All specimens were deposited in the herbarium JIW of the Biology Department of the Universidad Nacional de Colombia, Bogotá, Colombia. Key results: Three species of brown algae are newly reported for Colombia: Lobophora declerckii, Taonia abbottiana and Verosphacela ebrachia. Verosphacela has been reported, to date, only from the type locality in Florida and from Isla Mujeres, in Mexico. Due to its cryptic and small habit, it may be much more common than actually reported. Lobophora declerckii is apparently the most common species of Lobophora in the Archipelago. Taonia abbottiana may be much more common than reported to date, but it is easily confused with Stypopodium zonale. Conclusions: Despite the intense phycological research carried out in the past decade in the Archipelago of San Andrés, Old Providence and Santa Catalina, there is still much to be discovered.

A Gender Gap Analysis on Academic Performance in Engineering Students on Admission and Exit Standardized Tests

This paper describes a gender-based research work on academic performance in engineering students. This study is based on the results of 9 469 students from Universidad Nacional de Colombia in the college`s Admission and exit standard tests (the latter known as Saber Pro Tests). Tools such as descriptive statistics, regression analysis, and data mining are used to estimate both gaps and leaps in scores per gender. These tools are not only used to estimate said gaps, but also to determine whether these gaps are broadened or closed throughout the university education process. The results show that there are still gender gaps in favor of men in the area of mathematics, even in STEM programs. On the contrary, a gap in favor of women is noted in the area of writing, although a decline is also observed in reading comprehension skills for both genders. On the other hand, in terms of the global scores, women improve more than men as a result of their undergraduate experience. Finally, purely disciplinary competencies exhibit a notorious gender gap in favor of men, which should lead to future reforms in this type of programs.

Development of a web application for the resource management in the course “Cycle 2: Execution of production project” at the Universidad Nacional de Colombia, Bogotá

The development of online tools has provided solutions to different activities, including academia. The Agronomy program at the Universidad Nacional de Colombia has updated its competency-based teaching approaches by encouraging the development and application of computational tools for analysis, modeling, and interpretation of data. A registration and follow-up system was chosen to automate tasks in the course “Cycle 2: Execution of production project” developed at the university farm (Marengo Agricultural Center), where technical, financial, and administrative variables inherent to the selected crop must be managed with monitoring and support by teachers and monitors. The aim of this research was to develop a web application for the academic-administrative management of certain components. This was mainly developed with Python and a PostgreSQL database. As an open resource, the app was hosted on GitHub and, for user access, it was hosted on PythonAnywhere. The Alpha version was validated by several students and academic staff involved in the course. The development of a web application consisting of three administrative modules was achieved and included an inventory management of supplies, machinery, and available tools; the allocation and management of the schedule of activities and list of requests, and the tracking of resource use through project costs. The web application is simple to execute, and its use will adjust the relevant processes of the productive projects of Cycle 2.

Curricular Experiences Leading to the ABET Accreditation in the Electrical and Electronics Engineering Programs

Accreditation processes not only recognize the high quality of curricular programs; they also guarantee their continuous self-improvement. This paper aims to socialize the curricular experiences in the Electrical and Electronics Engineering programs of Universidad Nacional de Colombia (Bogotá Campus) within the decade-long efforts to achieve international ABET accreditation in 2021. This work thoroughly describes the implementation of the CDIO curriculum design methodology and its subsequent transition towards a curricular assessment based on learning outcomes. The results of some qualitative studies regarding the perceptions of faculty and alumni are presented, as well as a detailed proposal of the skills to be developed in each year of the syllabus, establishing their level of implementation. Moreover, a detailed description is provided regarding the methodology adopted for measuring performance indices during four semesters and the main results of the assessment of each learning outcome. Finally, the main curricular challenges to be addressed over the following years within the Electrical and Electronics Engineering programs are described.

B-mode Ultrasound Characteristics of Thyroid Nodules With High-Benign Probability and Nodules With Risk of Malignancy.

Thyroid nodules are commonly found on clinical examination or diagnostic imaging of the neck. Malignant thyroid nodules are increasing worldwide, making thyroid cancer one of the most common endocrine malignancies worldwide. The aim of this study was to determine B-mode ultrasound characteristics of benign thyroid nodules and nodules with risk of malignancy. Material and methods: This retrospective study was conducted on subjects (n=99) who underwent thyroid ultrasound. Data were retrieved from the Thyroid Digital Image Database of Universidad Nacional de Colombia, a published open-access dataset, in which B-mode ultrasound images were interpreted by expert radiologists providing a complete diagnostic description of thyroid lesions using the Thyroid Imaging Reporting and Data System. Sponge-like appearance (Pearson Chi-Square 4.6, p=0.02), cystic (Pearson Chi-Square 27.3, p<0.001), isoechoic (Pearson Chi-Square 26, p<0.001), and well-defined (Pearson Chi-Square 13.7, p<0.001) thyroid nodules were more likely to be observed in benign nodules (risk of malignancy <5%). On the other hand, predominately solid (Pearson Chi-Square 5.9, p=0.01), microcalcifications (Pearson Chi-Square 50.7, p<0.001), hypoechoic (Pearson Chi-Square 27.7, p<0.001), irregular shape (Pearson Chi-Square 6.6, p=0.01), and ill-defined (Pearson Chi-Square 8.8, p=0.003) thyroid nodules were more likely to be observed in nodules with risk of malignancy (>5%). Ultrasound characteristics could be used to determine thyroid nodules with risk of malignancy and avoid over-diagnosing nodules with benign features. Further research evaluating the use of multiparametric ultrasound to distinguish between benign thyroid nodules and thyroid nodules with risk of malignancy is required.

University Educators’ Professional Learning in a PBL Pedagogical Development Programme

This study explored university teachers’ professional learning when participating in a pedagogical development (PD) programme. The PD programme, entitled the Aalborg Certificate on Basics of PBL and Curriculum Change, had a workload of 150 hours and ran for four months, involving 23 teachers from Universidad Nacional de Colombia (Bogotá, Colombia). The programme comprised four modules, delivered in a blended mode, and followed a problem- and project-based learning (PBL) approach, as well as being based on PBL principles. This investigation conceptualizes professional learning from the complex learning theory perspective, describing it as a complex dynamic system involving knowledge, motivations, values, attitudes, and beliefs dependent on social and individual contextual factors, and how these can lead to the implementation of alternative teaching practices in classroom (e.g., PBL). Building on that, this work addresses the following research questions: (1) What knowledge and beliefs have the PD programme participants developed about PBL? (2) In which ways do the developed knowledge and beliefs impact participants’ change towards PBL? This analysis takes a qualitative approach and uses multiple sources of data, namely participants’ portfolios and reflection essays, as well as a qualitative survey. The results show the participants developed a deep understanding of PBL principles and practices by experiencing them through the PD programme, and that reflective practice enables continuous professional learning and development. Additionally, their perceived challenges were related to time, as well as institutional support and infrastructures, in addition to student and teacher training.

Clinical Image: Histoplasmosis Mimicking Granulomatosis With Polyangiitis in HIV Patient.

From the *Department of Internal Medicine, Clinica SOMER, Rionegro; †Department of Rheumatology, Universidad de Antioquia, Medellín; and ‡Department of Internal Medicine, Universidad Nacional de Colombia, Bogotá, Colombia The authors declare no conflict of interest. Written consent for publication of the photographs was obtained from the patient. All authors had full access to the full data and accept responsibility for submit the publication. The authors confirm that no portion of the data has been or will be published elsewhere while the manuscript was under review by the Journal of Clinical Rheumatology. The Ethics Committee of Clinica SOMER approved the publication of the manuscript. Fabio Torres-Saavedra ORCID iD: https://orcid.org/0000-0003-0385-8160 Correspondence: Fabio Torres-Saavedra, MD, Department of Internal Medicine, Clinica SOMER, Rionegro 054040, Colombia, Calle 29 # 41-98, Medellín 050010, Colombia. E-mail: [email protected].

New records of parasitic fungi on Cassia fistula and Leucaena leucocephala (Fabaceae) in Colombia

In the arboretum of Universidad Nacional de Colombia sede Medellín, Cassia fistula (Golden Shower Tree) and Leucaena leucocephala (Leucaena) exhibited early defoliation. Erysiphe quercicola and Telimena canafistulae, associated with powdery mildew and tar spot, respectively, on C. fistula, were identified using morphological and molecular techniques, both representing new records of fungi for Colombia. Similarly, Phyllactinia leucaenae was proposed as a new combination for Ovulariopsis leucaenae and was associated with powdery mildew on L. leucocephala, which to the best of our knowledge is another new record for Colombia.

Women at the Faculty of Engineering of Universidad Nacional de Colombia, Bogotá Campus: History, Present, and Future

The Department of Engineering of Universidad Nacional de Colombia (UNAL) has a rich and complex history, which is inexorably linked to the convulsed history of Colombia. This article seeks to give visibility to the participation and historical contributions of women in the growth and development of the Department of Engineering throughout its 161 years of existence, as well as to recognize their contributions with the names of their protagonists, in order to honor their struggles and achievements in favor of women's rights in the country. This article also shows data and testimonials that reflect the significant gender gaps that still persist in the Department, it characterizes the women who are part of the academic community in their roles as students, professors, researchers, and directors, it lists the actions undertaken as institutional policies for closing gender gaps, and it proposes future measures to be implemented.

Evidencing Fluid Migration of the Crust during the Seismic Swarm by Using 1D Magnetotelluric Monitoring

We applied multi–temporal 1D magnetotelluric (MT) surveys to identify space–time anomalies of apparent resistivity (ρa) in the upper lithosphere in the Antarctic Peninsula (the border between the Antarctic and the Shetland plates). We used time series over several weeks of the natural Earth’s electric and magnetic fields registered at one MT station of the Universidad Nacional de Colombia (RSUNAL) located at Seymour–Marambio Island, Antarctica. We associated resistivity anomalies with contrasting earthquake activity. Anomalies of ρa were detected almost simultaneously with the beginning of a seismic crisis in the Bransfield Strait, south of King George Island (approximately 85.000 events were reported close to the Orca submarine volcano, with focal depths &lt; 20 km and MWW &lt; 6.9). We explained the origin of these anomalies in response to fluid migration near the place of the fractures linked with the seismic swarm, which could promote disturbances of the pore pressure field that reached some hundreds of km away.

Hospital Universitario Nacional de Colombia's expansion

The processes required to implement the phases of the of the Institutional and Academic Expansion Plan of the Hospital Universitario Nacional de Colombia (HUN) were presented as a priority in the work proposal of the Dean’s Office of the Faculty of Medicine of the Universidad Nacional de Colombia (UNAL) for the period 2020-2022. This plan was developed under the current administration of the faculty and the university, and its goal was to broaden the global concept of what was known as Phase II and is now known as the Expansion Phase.

Destabilising geographies in Colombia: Trajectories and perspectives

AbstractColombia has recently witnessed the emergence of new geographies, which opens new scenarios of analysis and political contexts leading to a better understanding of the multiplicity of humans–non‐humans and their territories, territorialities and their rights. These geographies enter dialogue with other disciplinary trajectories and Indigenous and Afro‐descendant perspectives. These new perspectives also interact with critical, feminist and decolonial geographies. These encounters have led to the arrival of new approaches, which I call destabilising geographies. The proposals positioned from these new perspectives look to decolonise the founding binary categories of geography. They are perspectives and proposals that destabilise institutionalised visions of geography because they emerge with and from social processes and movements that require political spaces and the recognition of territorial and environmental rights. These geographies propose an opening to other ontologies and epistemologies that contribute to the complexity of the categories of territory, body‐territory, human–non‐human territories, the political and the collective. They also reveal the racial territorial processes of extractive dynamics and armed conflict. In this text, I develop the following emergences: dissident feminist geographies, geographies of racialised extractivism, Black geographies and Indigenous relational spatialities. These reflections are based on my experience of over 16 years of teaching in the geography programme at Universidad Nacional de Colombia.

Wave Data Prepares for Hurricanes

As the latest hurricane season takes its toll on the Caribbean and US Atlantic coast, the paper reports on how field research in Colombia is improving hurricane preparedness. Adaptation and mitigation measures for hurricanes affecting Colombia have been historically hampered by the lack of any meteorological and oceanographic observational network. To overcome this shortcoming and help authorities better plan and prepare for future extreme weather events, researchers at the Universidad Nacional de Colombia have reached a technical agreement with the environmental institution Coralina (Corporation for the Sustainable Development of the Archipelago of San Andrés), to use data collected from acoustic wave and current profilers (AWACs).