Universidad EAFIT Research Articles

Identification of non-model mammal species using the MinION DNA sequencer from Oxford Nanopore.

The Neotropics harbors the largest species richness of the planet; however, even in well-studied groups, there are potentially hundreds of species that lack a formal description, and likewise, many already described taxa are difficult to identify using morphology. Specifically in small mammals, complex morphological diagnoses have been facilitated by the use of molecular data, particularly from mitochondrial sequences, to obtain accurate species identifications. Obtaining mitochondrial markers implies the use of PCR and specific primers, which are largely absent for non-model organisms. Oxford Nanopore Technologies (ONT) is a new alternative for sequencing the entire mitochondrial genome without the need for specific primers. Only a limited number of studies have employed exclusively ONT long-reads to assemble mitochondrial genomes, and few studies have yet evaluated the usefulness of such reads in multiple non-model organisms. We implemented fieldwork to collect small mammals, including rodents, bats, and marsupials, in five localities in the northern extreme of the Cordillera Central of Colombia. DNA samples were sequenced using the MinION device and Flongle flow cells. Shotgun-sequenced data was used to reconstruct the mitochondrial genome of all the samples. In parallel, using a customized computational pipeline, species-level identifications were obtained based on sequencing raw reads (Whole Genome Sequencing). ONT-based identifications were corroborated using traditional morphological characters and phylogenetic analyses. A total of 24 individuals from 18 species were collected, morphologically identified, and deposited in the biological collection of Universidad EAFIT. Our different computational pipelines were able to reconstruct mitochondrial genomes from exclusively ONT reads. We obtained three new mitochondrial genomes and eight new molecular mitochondrial sequences for six species. Our species identification pipeline was able to obtain accurate species identifications for up to 75% of the individuals in as little as 5 s. Finally, our phylogenetic analyses corroborated the identifications from our automated species identification pipeline and revealed important contributions to the knowledge of the diversity of Neotropical small mammals. This study was able to evaluate different pipelines to reconstruct mitochondrial genomes from non-model organisms, using exclusively ONT reads, benchmarking these protocols on a multi-species dataset. The proposed methodology can be applied by non-expert taxonomists and has the potential to be implemented in real-time, without the need to euthanize the organisms and under field conditions. Therefore, it stands as a relevant tool to help increase the available data for non-model organisms, and the rate at which researchers can characterize life specially in highly biodiverse places as the Neotropics.

VI International Conference Days of Applied Mathematics

A Sandoval-Amador1,2, E Gelves Almeida3, J P Salazar Torres3, L M Dueñas Ramirez1,4 and E D V-Niño1 1 Foundation of Researchers in Science and Technology of Materials, Colombia 2 Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Argentina 3 Universidad Simón Bolívar, San José de Cúcuta, Colombia 4 Universidad EAFIT, Medellin, ColombiaE-mail: foristom@gmail.com, anderson84f@gmail.comOrganizing Committee, International Scienctific Committee, National Scienctific Committee and all this titles are available in this pdf.

Modeling, simulation and test of the heat flow in a liquid nitrogen cryostat for Mössbauer spectroscopy

In this work, we present a heat flow analysis for a conceptual design of an open cycle liquid nitrogen cryostat with application in Mössbauer spectroscopy. Initially, we made a study of the different configurations of Dewar type cryostats reported in the literature. These configurations are based on existing designs and the Mössbauer spectrometer requirements of the Instrumentation and Spectroscopy Laboratory at Universidad EAFIT in Medellín. From this study, we establish our own conceptual design. A first heat flow analysis in stationary state was calculated to obtain the dimensions of the reservoir vessel. The heat flow model obtained predicted an adequate evaporation time of the liquid nitrogen for the acquisition of Mössbauer spectra. For this model we employed the Fourier’s law, the heat flow by radiation in grey bodies and the properties of 304 stainless steel, 6061 aluminium alloy and OFHC copper. In consequence, the mechanical design of the cryostat was defined and the new heat loads associated with it were added to the initial model. Finally, the prototype was built, the model was tested and some final corrections were made.

Design and thermal modeling of a cold finger open cycle cryostat for Mössbauer spectroscopy

In this work we present the design and thermal modeling of a cold finger open cycle cryostat that operates with liquid nitrogen, intended to be implemented into the Mossbauer spectrometer available at the Universidad EAFIT of Medellin, Colombia, with the purpose of obtaining a low cost and good performance system for the acquisition of low temperature Mossbauer spectra. Initially, we propose a design that meets the requirements of the spectrometer, afterward, based on the initial design, we develop the calculations of heat flow into the system. The results of the thermal model allowed us to define the dimensions of the vessels, as well as calculate the evaporation time of a given column of liquid nitrogen in the cryogenic vessel. Finally, some progresses in the construction of the physical prototype are presented.

Implementation of a platform for the remote access to a transmission Mössbauer spectrometer

In this work, we present the development of a platform for the remote access to the Mossbauer spectrometer of the Instrumentation and Spectroscopy Laboratory of Universidad EAFIT of Medellin, Colombia. This platform was developed looking for a proper use of the radioactive source of 57Co(Rh) during recess periods of the staff of the laboratory, reduction of exposure of the users to the ionizing radiation coming from radioactive source, as well as spread Mossbauer spectroscopy between new researchers during their academic formation in materials characterization. The application is executed from the server “Neutron” of the “Laboratorio para la Innovacion y el Aprendizaje” of Universidad EAFIT of Medellin. Through a web application based on the e-learning platform Moodle, the user can access, after registration, to a web site with a series of introductory contents related to Mossbauer spectroscopy, a field with remote connection to the Mossbauer spectrometer and other fields with support materials, among them: suggested papers, video of the experiment through an IP camera, chat with the administrator of the spectrometer and access to the file with the experimental spectra. Details of the design of the platform are presented through the sections of this paper.

Full scale fatigue test performed to the bolster beam of a railway vehicle

Many structural elements are exposed to conditions of load that are difficult to consider during the design stage, such as environment uncertainties, random impacts, overloads and inherent material idealization amongst others, hence, miss-estimating its life-time cycle. One way to test those designs is to construct a representative full-scale specimen and test it under the most critical load conditions in a controlled laboratory. Herein, we present a case of study of the fatigue test performed over a bolster beam redesigned in Universidad EAFIT belonging to a railway vehicle. The test was composed by three stages, each one testing a different load hypothesis. The bolster beam was instrumented at the most critical locations, following the results of a FEM analysis previously computed. As results, the most critical welds were identified and the total damage computed for an equivalent operation of eighteen-years, and also the behaviour of the specimen in presence of extreme longitudinal loads.

Aligning English Language Testing With Curriculum

<p>Frustrations with traditional testing led a group of teachers at the English for adults program at Universidad EAFIT (Colombia) to design tests aligned with the institutional teaching philosophy and classroom practices. This article reports on a study of an item-by-item evaluation of a series of English exams for validity and reliability in an effort to guarantee the quality of the process of test design. The study included descriptive statistics, item analysis, correlational analyses, reliability estimates, and validity analyses. The results show that the new tests are an excellent addition to the program and an improvement over traditional tests. Implications are discussed and recommendations given for the development of any institutional testing program.</p>

Disaster risk management in business education entrepreneurial formation for corporate sustainability

The purpose of this paper is to show the importance of business education in Disaster Risk Management (DRM). This paper aims to evaluate the awareness level of the Master in Business Administration’s (MBA) students regarding the importance disaster risk management (DRM) plays. This paper develops a literature review concerning the concept of disasters, Disaster Risk Management, Disaster Risk Reduction, and the role of MBA programs. Furthermore, a survey at Universidad EAFIT (Medellin, Colombia) was designed and implemented as primary source information with the purpose of showing the DRM awareness level of MBA’s students. Finally, a case study connecting DRM with entrepreneurship formation is described.This paper identified a limited formal education in DRM Latin American MBA programs, and specifically at Universidad EAFIT. Additionally, a lack of awareness in MBA’s students about the importance of DRM was identified. In this sense, the paper proposes a DRM education model that uses a Corporate Social Responsibility (CSR) and entrepreneurial formation in business education. This study aims to show the importance of the inclusion of disaster risk reduction and management knowledge as part of the courses in: Corporate Social Responsibility (CSR), Sustainability, and Entrepreneurship content in Masters in Business Administration (MBA) programs.

ECAES, SaberPro, and the History of Economic Thought at EAFIT

This article studies implications of the recent redesign of the Economic Analysis module of the standardized test formerly known as ECAES, lately redsignated SaberPro. Its main concern is with the implications to the curriculum at the Universidad EAFIT – more specifically, with the adequacy of the history of economic thought (h.e.t.) part of the curriculum as preparation for the test and for other purposes. The sources of information for the article include conversations and correspondence with the academic and administrative leadership of the EAFIT Escuela de Economia y Finanzas and Departmento de Economia. They also include h.e.t. course syllabi from the Universidad EAFIT and, by way of comparison, from the Universidad de los Andes, the Universidad de Antioquia, and elsewhere; documents regarding the objectives and format of the ECAES economics exam obtained from the ICFES and AFADECO websites; and data for exam results over the period 2006 to 2009 obtained from ICFES.

Descripción analítica de la “Sonata sobre temas colombianos” del compositor Luis Antonio Escobar

The purpose of this work is the rescue of the sonata on Colombian themes of the composer Luis Antonio Escobar. The score, composed in 1948 intended to be presented to the music of Colombia Fabricato contest that year, can be found in the Heritage Hall of the cultural center library Luis Echavarria Villegas of the Universidad EAFIT in Medellin - Colombia.The work aims to determine the musical elements of the work and enhance its artistic content. Through description and analysis of the score, whose transcription is taken here as a primary source, the musical language, artistic, stylistic trends and its creative development are identified. Encrypted in its notes, are both primordial national composer influences, and new, acquired at that time by its newly started upper study of music in the United States. The work puts in relief some musical elements inherent in the composer.

<i>La novela sicaresca. Testimonio, sensacionalismo y ficción</i> (review)

Reviewed by: La novela sicaresca. Testimonio, sensacionalismo y ficción Aldona Bialowas Pobutsky Margarita Jácome. La novela sicaresca. Testimonio, sensacionalismo y ficción. Medellín: Fondo Editorial Universidad EAFIT, 2009. 255 pp. Jácome's book is a timely project because, although the subject of narcocultura has moved to the fore of academic debates on Colombia, no systematic book-length study dedicated to the literature inspired by Colombian drug trafficking has emerged until now. Jácome's analysis begins by identifying the origin of the term "novela sicaresca" and by describing the sociopolitical circumstances that led to the emergence of the sicario. While the genre of narcocultura comprises all the actors of drug trafficking as well as a number of social phenomena resulting from drug-inspired violence, Jácome's analysis centers squarely on sicarios, meaning adolescent hitmen from the shantytowns of Medellín who found criminal employment with powerful cartels during the 1980s. Since their emergence in the crime subculture resulted from specific historical circumstances related to Pablo Escobar's reign of terror, Jácome is careful to provide a well-thoughtout and informed panorama of violence in Colombia that led to the appearance of the sicario. Her examination returns to the blood-drenched period of the mid-twentieth century known as La Violencia, a historical moment that saw the emergence of the thug for hire and antecedent of the sicario, the so-called pájaro. It then includes a discussion on the expansion of marijuana use and sale in Medellín in the 1960s, the embrace of the hippy movement and its hedonistic celebration of life and individual freedom as a reaction to conservative politics and clericalism, and the discontent of the underprivileged sectors who were virtually abandoned by the state, itself in economic crisis. The chapter substantiates how this discord led to the rise in popularity of drug traffickers, who gained public support by injecting money into the faltering economy. Their hold over the poor sectors became particularly strong, in that they offered high-paying jobs to the unemployed who, as a result, grew to rely more on criminal organizations than on the state-sponsored infrastructures. These circumstances led to a curious inversion of social values, where drug trafficking lost its criminal stigma for a period of time, all the while ingraining itself into every aspect of Colombian life. It also coincided with the emergence of the counterculture of criminal youth—the sicarios—unique [End Page 235] in their bizarre religious practices, their idiosyncratic slang (parlache) and, above all, in their acceptance of an early and violent death, both for themselves and for their victims. Jácome divides her project into five sections. After the first part described above, she examines Fernando Vallejo's bestselling novel La virgen de los sicarios as an example of orality. Here she underscores the role played by its semifictitious narrator, Fernando, putting emphasis on how his speech mediates his position in relation to the nation and to the young hitmen whom he befriends. Jácome argues that the intellectual discourse of the narrator—which serves initially to mark the distance between him and the volatile new Colombia infested by narco violence—morphs gradually into a more informal speech littered with the slang of the criminal youth. This in turn attests to the mutation of social relations in Colombia and to the subject's impotence vis-à-vis the country's gradual disintegration precipitated by corruption and impunity for its criminals. Jácome argues that since Vallejo's novel transfers responsibility for the crimes committed by sicarios onto society in general, it ends up idealizing the figure of the sicario, rather than giving him a voice in a testimonial fashion. The third section of the book examines three different archetypes of the sicario, as evidenced in Alape's Sangre ajena (2000), Collazos's Morir con papa (1997), and Franco's Rosario Tijeras (1999). Perhaps due to the relative obscurity of the first two novels, which have received scant attention in Colombia and none abroad, Jácome thoughtfully offers close readings, paying attention to the features that render them unique. Thus Alape's narrative about two preteen brothers is one of very few...

Innovation and Wage Differentials: A Bayesian Approach

This paper intervenes into the debate of the role of radical innovations in shaping the wage distribution, in terms of the differences between skilled and unskilled workers, and in affecting productivity. The context is that of the debate over Skilled Biased Technological Change and the productivity paradox, but the road we follow is, in our opinion, radically new: we build models of conjectural equilibria with Bayesian agents, where equilibrium outcomes strongly depend on the participants’ opinions about unknown parameters of their environment. We claim that this can be a road to understand the weight that subjective factors like expectations over future success of the technology play into this type of processes. In general, we will be able to find a multiplicity of equilibria for the models we are going to study. Sometimes, equilibria differ as regards individual effort and productivity, sometimes as regards to aggregate values. The problems of coordination and the difficulties of implementation that are usually invoked to explain productivity lags when major innovation are introduced are directly addressed. The relation between the timing of increase in wage differentials and productivity boom seems indeed to be at odd with the determinism of a great part of the literature. JEL Classification: B41, D92, J31, O33 Heterogeneity, Learning, Wage Differentials, Innovation ∗Departamento de Economia, Universidad EAFIT Carrera 49 7 Sur 50 Apartado 3300 Medellin, Colombia francesco.bogliacino@gmail.com 2 Quality Uncertainty, Risk Aversion, and New Product Diffusion