Los Andes University (Colombia)
Recent publications
Introduction Despite its toxic and carcinogenic nature, formaldehyde is a widely used reactant for specimen preservation. With the need of specimens for both anatomical and surgical training, alternative preservation solutions (PS) have been proposed, however, their use is limited due to high costs and complexity. Hence, a new formaldehyde-free solution (FFS) is evaluated as a potential alternative for anatomical and surgical training. Methods Qualitative and Quantitative data were acquired. Specimens preserved using three different methods were selected. Flexibility was measured by joints goniometry and pneumoperitoneum pressures were evaluated followed by an exploratory laparoscopy. Undergraduate student's perceptions on cadavers preserved with different PS were obtained using surveys and focus groups. Results The main reason why cadaveric specimens were considered as useful tools was the perceived interaction with real tissues and the ‘practical’ concept of getting in touch with what students would be facing in the future as physicians, what we call “hands on” activities. FFS treated specimens showed better joint-movement ranges in comparison to other methods and pneumoperitoneum was acquired after 5 mmHg CO2 pressure. Students appreciated working with corpses regardless the technique used, however FFS specimens were defined as less uncomfortable, while presenting no sensory discomfort. Conclusions Even though alternative PS are effective, high costs and complexity restrict their usage. Cadavers preserved with FFS had similar range of movements compared with Thiel. Students preferred to work with FFS rather than FF due to flexibility, color, and no sensorial hassles. Thus, we propose FFS as viable alternative to traditional PS.
The Palagua swamp in the Middle Magdalena region of Colombia is a territory governed by nearly a century of petro-development and armed conflict. This toxic reality, along with the disappointment of temporary legal victories and demands for environmental compensation, have left deep marks on individuals’ psyche, eroding the self-confidence and spirit of communities. Drawing on archival research, secondary regional sources, and 13 semi-structured interviews with former oil workers, fishers, farmers, and women activists, we delve into the meaning, implications, and transformation of petro-development and internal colonialism. We suggest that the decolonization of being in a petrolized environment implies challenging imposed imaginaries of development and perceiving forces of internal colonialism. This should be recognized as a long-term process, a painful incubation of possibilities, marked by persistent and transformative day-to-day actions.
Este artículo analiza las decisiones educativas de las clases medias altas montevideanas y su significado como prácticas de reproducción y distinción de clase. Con base en una serie temporal de encuestas de hogares y el análisis cualitativo de entrevistas en profundidad a profesionales universitarios, se indaga por la forma en que las clases medias altas eligen la educación de sus hijos. Para ello, se identifican y describen varios perfiles diferentes: leales, fugados y militantes. Las ansiedades, las ambivalencias y los sentimientos de nostalgia, culpa y orgullo que experimentan estos sectores a la hora de elegir la escuela de sus hijos revelan la importancia de esta decisión en la generación y reproducción de desigualdades. Estas decisiones, sobre todo las de salida de clases medias altas hacia el sector privado, así como las de segregación dentro del sistema público, tienen consecuencias profundas en la generación de desigualdades y la integración social.
Abstract The challenges that Latin America faces in health are deeply related to others, such as access to clean water, the right to education, and housing. Health professionals that work in an environment where the population faces constant barriers to accessing care in the public health system or has limited resources to pay for it in a private sector will face an ethical dilemma, the question of how to honor the call to care for patients when there is not enough support system or infrastructure to do so. Within the schools of medicine and health sciences, the question is how to train students to face or resolve these conflicts. The social responsibility approach is a proposal that allows the alignment of education for health professionals and health systems to contribute to the creation of an effective, equitable, and sustainable system. The present article aims to discuss this problem from the importance of training health professionals, ethical and committed to their communities, that have the skills and attitudes to implement a patient-centered vision. The involvement of universities and training institutions of the next generation of health professionals cannot be postponed.
Purpose: The artificial urinary sphincter (AUS) is one of the most effective surgical treatments for male urinary incontinence regardless of its severity. Current knowledge comes from high-volume centers, but little is known about the performance of this surgery from community practices. This study aims to report contemporary AUS performance in a nationwide observational study in Colombia. Methods: Male patients who underwent AUS surgery with AMS 800™ between 2000 and 2020 in more than 17 centers and four cities were identified. Pre, intra, and postoperative characteristics were evaluated, mainly addressing patient reported outcomes measurements in the postoperative period. Retrospective and prospective data collection and descriptive analysis were completed. Kaplan-Meier analysis was used to determine AUS survival rate. Results: Out of an initial 667 cases, a total of 215 patients met inclusion and exclusion criteria and were included. Mean age was 67 ± 9.4 years, and mean follow-up was 6.0 ± 4.4 years with maximum range of 14 years. The etiology of urinary incontinence was prostate cancer surgery in 141 (81%) of the cases. The rest of the cases were related to benign prostatic disease or spinal cord injury. It is noteworthy that out of 115 patients, only 59 (51.3%) reported previous formal pelvic floor rehabilitation. Subjective severity of urinary incontinence determined by a visual analog scale showed a decrease in 4.5 points after sphincter implantation. Sphincter removal was required in 50 (23.2%) cases. The main reasons for implant removal were urethral erosion and infection. The sphincter survival rate at 2, 5, 8, 10, and 14 years was 76%, 70%, 60%, 57%, and 17%, respectively. Of the subjects at the last follow-up with the device still in place, 80.7% defined their urinary condition as "does not cause or causes minor discomfort," and 99% would recommend the device to a friend or relative in the same condition. Conclusions: This series from a community-based practice shows the lack of adherence to clinical practice guidelines and the lack of standardized data collection. In contrast, this study provides real-world data on explantation and revision rates, allows physicians to inform patients and to have clear metrics for a shared decision-making process before the procedure.
International challenges have become the de facto standard for comparative assessment of image analysis algorithms. Although segmentation is the most widely investigated medical image processing task, the various challenges have been organized to focus only on specific clinical tasks. We organized the Medical Segmentation Decathlon (MSD)—a biomedical image analysis challenge, in which algorithms compete in a multitude of both tasks and modalities to investigate the hypothesis that a method capable of performing well on multiple tasks will generalize well to a previously unseen task and potentially outperform a custom-designed solution. MSD results confirmed this hypothesis, moreover, MSD winner continued generalizing well to a wide range of other clinical problems for the next two years. Three main conclusions can be drawn from this study: (1) state-of-the-art image segmentation algorithms generalize well when retrained on unseen tasks; (2) consistent algorithmic performance across multiple tasks is a strong surrogate of algorithmic generalizability; (3) the training of accurate AI segmentation models is now commoditized to scientists that are not versed in AI model training. International challenges have become the de facto standard for comparative assessment of image analysis algorithms. Here, the authors present the results of a biomedical image segmentation challenge, showing that a method capable of performing well on multiple tasks will generalize well to a previously unseen task.
Este artículo estima la curva de Laffer mediante un análisis de estática comparativa y un ejercicio econométrico. A partir de una especificación microeconómica, primero analiza la distorsión que causaría establecer un impuesto indirecto y las implicaciones de bienestar si se maximizara el recaudo tributario. Luego, con datos del ingreso tributario real per cápita y de la tasa impositiva, estima un modelo econométrico para calcular la tasa tributaria óptima en Colombia. Los resultados muestran que los postulados de Laffer se cumplen con una tasa óptima de un 32%, y sugieren que el Gobierno tiene un margen de casi 12 puntos porcentuales.
The associated production of a W and a Z boson is studied in final states with multiple leptons produced in proton-proton (pp) collisions at a centre-of-mass energy of 13 TeV using 137 fb−1 of data collected with the CMS detector at the LHC. A measurement of the total inclusive production cross section yields σtot(pp → WZ) = 50.6 ± 0.8 (stat) ± 1.5 (syst) ± 1.1 (lumi) ± 0.5 (theo) pb. Measurements of the fiducial and differential cross sections for several key observables are also performed in all the final-state lepton flavour and charge compositions with a total of three charged leptons, which can be electrons or muons. All results are compared with theoretical predictions computed up to next-to-next-to-leading order in quantum chromodynamics plus next-to-leading or- der in electroweak theory and for various sets of parton distribution functions. The results include direct measurements of the charge asymmetry and the W and Z vector boson polarization. The first observation of longitudinally polarized W bosons in WZ production is reported. Anomalous gauge couplings are searched for, leading to new constraints on beyond-the-standard-model contributions to the WZ triple gauge coupling.
Objective/Context: The year 2021 marked the 50th anniversary of the Regional Indigenous Council of Cauca (CRIC), the first organization established in Colombia to fight for territorial and identity rights of Indigenous Peoples. From a historical perspective and proposing an approach related to the concept of resistance, this paper focuses on how this latter has been expressed through this indigenous movement since its inception. Methodology: The information and reflections presented here are based on a corpus of bibliographical and documentary sources, as well as on a follow-up of the political mobilizations of indigenous peoples in situ, in the media, digital social networks, official minutes, and other statements. Conclusions: The analysis reveals the persistence of indigenous resistance and an expansion of the project that accompanies it, from a struggle for land and territory to efforts carried out along with other actors and social organizations to create a “better world.” Originality: The originality of the article consists of an analysis of the political dimensions of the resistance of Indigenous Peoples, which are still little known. In addition, it offers a novel approach to stress the intersection of (sub) national and global dynamics in which the demands of Indigenous Peoples and issues related to Colombia’s society and the whole world converge.
In judicial processes involving indigenous peoples, it has become increasingly recurrent to integrate special mechanisms to allow for dialogue, and the interpretation and translation of the cultural differences of the indigenous worlds before state justice operators. Expert appraisal is one of these devices that summon the anthropological discipline to the courts. The purpose of this article is to show how expert opinion is a device of professional practice for the intervention of anthropology in processes of demand for justice intended to guarantee the understanding of cultural and social diversity. The arguments and elements detailed in the article are based on a research experience involving the Arhuaco indigenous people of the Sierra Nevada de Santa Marta in Colombia between 2018 and 2020, the documentary/bibliographic analysis, and the study of the judicial file related to the facts concerning the retention, torture, and death of three Arhuaco indigenous authorities that occurred in 1990. The article concludes that anthropological expertise is a device of disciplinary practice that can support the demands of indigenous peoples for access to justice and, therefore, to the understanding of cultural diversity in the courts. Its production and the associated epistemological, political, and intersubjective relationships merit further disciplinary analysis. Finally, revealing the methodological process of the elaboration of an anthropological expert opinion, its adaptation to the demands of justice, and the gaps of a particular judicialization process, as well as further exploring the questions posed by anthropology, are discussed in the article as a relevant and pertinent exercise for reflection on the practice of the discipline in judicial scenarios.
A bstract A search for physics beyond the standard model (SM) in final states with an electron or muon and missing transverse momentum is presented. The analysis uses data from proton-proton collisions at a centre-of-mass energy of 13 TeV, collected with the CMS detector at the LHC in 2016–2018 and corresponding to an integrated luminosity of 138 fb − 1 . No significant deviation from the SM prediction is observed. Model-independent limits are set on the production cross section of W’ bosons decaying into lepton-plus-neutrino final states. Within the framework of the sequential standard model, with the combined results from the electron and muon decay channels a W’ boson with mass less than 5.7 TeV is excluded at 95% confidence level. Results on a SM precision test, the determination of the oblique electroweak W parameter, are presented using LHC data for the first time. These results together with those from the direct W’ resonance search are used to extend existing constraints on composite Higgs scenarios. This is the first experimental exclusion on compositeness parameters using results from LHC data other than Higgs boson measurements.
This article shows the process of carrying out an innovation proposal at the Cali Experimental Theatre (TEC) in the context of isolation measures due to the Covid-19 pandemic. Through a process of “infrastructural inversion” inspired on the canonical work work of Star and Bowker, and following Simonsen and Hertzum, we revealed the deep historical connections that not only the TEC but the entire Colombian theatre movement of the 1960s had with the activists of social change such as workers’ organizations, trade unions and revolutionary movements. We present the iterative process of how this proposal was co-created with leadership of the TEC exposing infrastructural points of resistance and opportunity in the realisation of digital innovation. Our resulting proposal to the TEC reconnects the theatre group with the equivalent current actants of social change, such as independent journalism, citizen movements and non-governmental organizations, through a digital transformation, positioning it not only as a product of artistic quality but also as a social and historical research group. All this without altering the identity and dramaturgical tradition that the group has maintained intact for 65 years of existence. We conclude the paper by discussing the disciplinary paradoxes and sociotechnical limitations faced by this type of innovation requiring a digital transformation of their performing and delivery infrastructures.
To increase public transport use, especially for individuals with lower incomes, many cities worldwide have introduced subsidies for public transport systems. However, quantitative evidence of their effects on actual ridership remains scarce, especially in Global South countries. Using a quasi-experimental regression discontinuity design (RDD) in combination with administrative data for all personalized travel cards of public transport users during the years 2017–2019 in Bogotá, Colombia, the present paper assesses the causal effect of a transport subsidy focused on low-income individuals on the number of trips that individuals undertake. Our results show that the subsidy, equaling 32% of the regular fare, significantly and substantially increases the total number of monthly public transport trips. However, the results suggest that the size of the subsidy's effect on ridership has decreased over time, while also evidencing a more pronounced effect among economically active individuals compared to inactive ones. Overall, our results suggest that public transport subsidies for low-income individuals can be an effective way for increasing public transport use among this population segment, which may translate into improved wellbeing because of improved access to local labor markets and recreational activities.
El eje central de este artículo apunta a abordar la relación que existió entre las autoridades políticas y militares españolas en Venezuela y las Colonias extranjeras en el Caribe en la etapa culminante de la lucha independentista. Bajo el ambiente de tensión e incertidumbre a causa de la guerra, fue clave el despliegue diplomático del gobierno español asentado en Venezuela, no solo en su acercamiento con los gobiernos de aquellas islas sino con las potencias de las cuales dependían. Aún con todas las dificultades, fue valioso el auxilio de estas colonias extranjeras al agónico gobierno de Venezuela, aunque no fue suficiente para evitar que sucumbiera frente a la ofensiva de los republicanos, quienes de manera creciente recurrieron también el apoyo político, económico y militar de las posesiones insulares en el Caribe.
We designed an activity to improve students’ knowledge and understanding of the Carbon cycle, which is typically a difficult concept. We wanted users to understand what are the main Carbon repositories and how the element circulates, as well as how human activity is impacting it. Originally designed for an advanced biogeochemistry course on paper, it was later redesigned using augmented reality to reach a wider audience and increase accessibility to both specialized and nonspecialized audiences. The Carbon cycle was divided into 7 stations that will be placed throughout the university campus, and which can be accessed by anybody using an android smartphone. They can choose to complete the whole cycle and answer the activity’s questionnaire, or just browse freely. We expect that the activity will improve understanding of the Carbon cycle in a didactic, playful and non-threatening way, and motivate users to learn independently.
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12,194 members
Augusto Valderrama
  • Department of Biological Sciences
Juan Gabriel Ramirez
  • Department of Physics
Luis A. Guzman
  • Department of Civil & Environmental Engineering
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Alejandro Gaviria
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