Universidad del Valle (Colombia)
  • Cali, Valle del Cauca, Colombia
Recent publications
This study shows that capital structure choices of US corporations are interdependent across time. We follow a two-step estimation approach. First, using a large cross-section of firms we estimate year-by-year average capital structure choices, i.e., the average firm’s percentage of new funding that is secured through debt, its term composition, and the percentage of new equity represented by retained earnings. Second, these time series are included in a Factor Augmented Vector Autoregressive model in which three factors representing real economic activity, expected future funding conditions, and prices, are included. We test for the interdependence between optimal capital structure decisions and for the influence exerted by macroeconomic conditions on these decisions. Results show there is a hierarchical order in which firms make capital structure decisions. They first decide on the share of debt out of total new funding they will hire. Conditional on this they decide on the term of their debt and on their earnings retention policy. Of outmost importance, macroeconomic factors are key for making capital structure decisions.
In view of the population growth trends and urbanization processes, one of the current challenges is the surveillance and control of invasive alien species within urban settings, particularly of those species that can serve as vectors or reservoirs of diseases with the potential to affect human health. In this regard, the present study evaluated the public management for the surveillance and control of African snails (Lissachatina fulica) in the city of Santiago de Cali in Colombia between 2016 and 2019 and proposed minimum guidelines for their surveillance and effective control in the urban settings of developing countries. The Giant African snails can be intermediate hosts of various microorganisms that have a great impact on urban public health. The latter may include parasitic, viral, bacterial, and fungal diseases, which are transported by the snail to homes or nearby areas exposing humans and animals to contagion. In the Colombian case the most important are Angiostrongylus parasites, which can cause eosinophilic meningoencephalitis, gastrointestinal disorders in humans and pulmonary hemorrhage in dogs. However, it is also possible that the same snails carry other nematodes such as Aleurostrogylus which can affect cats and dogs in urban areas. Comprehensive actions are required to address the problems related to urban invasive species such the African snail in Santiago de Cali as well as to develop environmental public policies and implement through municipal and state public management. We concluded that government action should be supported by reliable data to identify cases in situ, and to determine pest, environmental, and ecoepidemiological variables. Qualitative and quantitative data analyses will contribute to effective decision-making and the development of control protocols designed for each specific urban scenario.
The COVID-19 pandemic has caused a dramatic increase in plastic wastes associated with the use of single-use masks, gloves, gowns, and other personal protective equipment (PPE). The accumulation of PPE, especially single-use masks, end up polluting environment, causing harm mainly to aquatic and terrestrial ecosystems. Due to the enormous concern about plastic pollution, many efforts are being made to develop efficient technologies to tackle it, among which solid-state photocatalysis is highlighted. Even though the outstanding results that have been obtained with the solid-state application of photocatalysis, there are fewer publications and reports on the use of it in comparison with aqueous and/or gaseous phase photocatalysis. Then, this review presents the most relevant works published on this topic and provide an in-depth analysis of solid-state photocatalysis for plastic abatement, including the incorporation of the usually hydrophilic photocatalyst into the hydrophobic plastic matrix, the common experimental procedures for evaluating its effectiveness (gravimetric, optical, spectroscopic, and mechanical methods) and the description of the intricate reaction mechanism suggested so far. The aim is increasing the awareness on this innovative topic among the academic/industrial community and advancing the research thereon.
Background: Although psoriasis burden and treatment have been well characterized in developed countries, there are scarce in-depth epidemiological studies in Latin American countries. Objectives: To describe the sociodemographic and clinical features and the economic burden of psoriasis among children and adult patients from Colombia. Methods: This cross-sectional study included patients from dermatology private practice offices, health provider institutions and hospitals in seven Colombian cities. We collected data on disease distribution, weight, height, body mass index, waist-hip ratio, disease severity, therapy, personal history of comorbidities, and direct costs. Multiple logistic regression analyses were conducted to assess the associations between severity scales and sociodemographic and clinical variables. Results: Two-hundred-three patients (43.8% women, 56.2% men) with an age range between 7 to 89 years old were included. The main subtype was psoriasis vulgaris and mean age of diagnosis was 37.1 years. The most common comorbidities were obesity, hypertension, psoriatic arthritis, dyslipidemia and diabetes. Women had a significant increased odds of presenting with psoriatic arthritis. Body-mass-index and hypertension were significantly associated with a higher psoriasis severity, whereas being female and non-obese was associated with a lower risk. A third of the patients had a family history of psoriasis and sleeping disorders. Forty-one percent of participants either had no income or had an income below 224 US dollars per month and >20% of their income was spent on their disease. Conclusions: This study is supported by robust scientific data and contributes to understanding the burden of psoriasis in Latin America. This study adds well-supported data through an in-depth clinical and economical characterization of Colombian children and adult patients with psoriasis and shows the high impact and burden of the disease on patients and their families.
Resumo O presente artigo tem como objetivo analisar a reação da organização indígena na região do norte do Cauca, na Côlombia, em face do confronto armado em seu território no período 2000–2005, tentando explicar como esta organização consegue realizar um tipo de resistência ativa ao conflito. O estudo é essencialmente do tipo etnográfico e trabalha com uma perspectiva que privilegia o estudo dos elementos culturais e identitários para a compreensão das ações coletivas, aos moldes de Sonia Alvarez, Evelina Dagnino e Arturo Escobar (2001) em seu livro “Política Cultural e Cultura Política nos Movimentos Sociais Latino-Americanos”. O artigo apresenta as interpretações e definições de conflito armado e paz encontradas nos discursos dos membros do movimento indígena nortecaucano. Argumenta-se que, no caso indígena, a cultura e seu processo identitário no âmbito da organização são fontes importantes de elementos simbólicos que sustentam os processos de resistência e ao mesmo tempo criam um espaço alternativo importante sobre o tema do conflito armado e da paz no país a partir da sociedade civil, em contraponto às visões tanto do Estado quanto dos atores armados e suas propostas sobre este tema.
Objective To identify associated factors with the appearance of pseudophakic retinal detachment in patients with history of cataract surgery. Methods Retrospective case-control study of 802 eyes of 783 patients with history of cataract surgery. Cases were patients with pseudophakic retinal detachment (n = 258 eyes), while controls were patients with cataract surgery who did not developed retinal detachment during a 10-year follow-up period (n = 544 eyes). Results Age at cataract surgery among cases was lower than in the control group (57 ± 13 vs. 67 ± 14 years old, respectively; p < 0.0001). Age at retinal detachment was 59 ± 13 years old (range 6-88) and the time between the cataract surgery and the retinal detachment had a median of 2 years (interquartile range 1–4) with a range of 1 month to 14 years. Associated factors for pseudophakic retinal detachment were younger age (<50 years: adjusted odds ratio [aOR] = 18.03, 95% confidence interval [95%CI] = 5.92–54.87; 50–59 years: aOR = 10.09, 95%CI = 3.37–30.23; and 60–69 years: aOR = 5.48, 95%CI = 1.88–15.93), male sex (aOR = 3.71, 95%CI = 2.54–5.44), anterior vitrectomy (aOR = 3.26, 95%CI = 1.16–9.16), history of retinal detachment in the fellow eye (aOR = 6.95, 95%CI = 3.15–15.31), and intraoperative complications during cataract extraction (aOR = 7.45, 95%CI = 3.54–15.69). Conclusions This is the first report of associated factors with pseudophakic retinal detachment in a Colombian population. Surgical complications, sex, and age were found to be associated with retinal detachment. Patients should be aware of these potential risks to make informed decisions about their eye health.
The effect of multiyear La Niña (LN) events on precipitation in South America (SA) was assessed considering ten persistent LN events over two successive years, referred to as Y1 and Y2 for the 1901‐2012 period. Y1 spans from the austral winter of the first year to autumn of the second year, and Y2 spans from the austral winter of the second year to autumn of the third year. Comparisons were done season by season of the Y1 and Y2. Composites revealed that the teleconnections related to a multiyear LN event during its Y1 and Y2 years, responsible for distinct seasonal precipitation anomaly patterns in SA, were associated with different tropical ocean conditions. In spring, the negative Sea Surface Temperature (SST) dipole in the Indian Ocean during the Y2 was not observed during Y1. Different LN‐related SST anomaly patterns in the tropical Atlantic between Y1 and Y2 occurred in the other seasons. Over northern/northeastern SA, the positive precipitation anomalies became weaker (stronger) during austral summer and autumn (winter and spring) of the Y2 than Y1 and were associated with changes in the Walker cells. During austral spring and summer, southeastern presented drier conditions during the Y2 than Y1. In the spring of Y2, two Rossby wave trains, one associated with the LN‐related anomalous cooling in the equatorial Pacific and another triggered by the upper‐level anticyclone in the tropical Indian Ocean, characterized the circulation pattern over SA which explains the difference in precipitation anomalies between the Y2 and Y1. These drier (wetter) conditions during austral spring and summer (winter and spring), particularly over southern and southeastern Brazil (Colombia) in the Y2, might have more severe effects on the regional hydrological cycle than those in the Y1. The results here indicate that accurate prediction of LN duration is crucial in a climate‐monitoring context. This article is protected by copyright. All rights reserved.
Amylose-free and wild-type cassava starches were fermented for up to 30 days and oven- or sun-dried. The specific volume (ν) after baking was measured in native and fermented starches. The average ν (across treatments) for waxy starch was 3.5 times higher than that in wild-type starches (17.6 vs. 4.8 cm3 g-1). The best wild-type starch (obtained after fermentation and sun-drying) had considerably poorer breadmaking potential than native waxy cassava (8.4 vs. 16.4 cm3 g-1, respectively). The best results were generally obtained through the synergistic combination of fermentation (for about 10-14 days) and sun-drying. Fermentation reduced viscosities and the weight average molar mass led to denser macromolecules and increased branching degree, which are linked to a high loaf volume. The absence of amylose, however, was shown to be a main determinant as well. Native waxy starch (neutral in taste, gluten-free, and considerably less expensive than the current alternatives to cassava) could become a new ingredient for the formulation of clean label-baked or fried expanded products.
The objective of this study was to evaluate different quality parameters and the oxidative stability of a vegetable margarine made with different concentrations: 100, 200, and 300 ppm of sweet red pepper peel and pulp (Capsicum annuum) oleoresin and tree tomato (Solanum betaceum Cav.) juice at 5, 10, and 15%. The oleoresin was added as an enriching agent in the fat phase, and tree tomato juice was added as an enriching agent in the aqueous phase. The results showed that sweet red pepper oleoresin obtained by ultrasound presented a higher concentration of bioactive compounds compared to that obtained by conventional methods with a content of total carotenoids (1473 ± 10.24 mg/100 g), total phenolic compounds (1158 ± 8.65 mg GAE/100 g), flavonoids (814 ± 7.63 mg CE/100 g), and ASTA color (765 ± 3.51); additionally tree tomato juice is a source of vitamin C: 22.34 ± 1.51 mg AA/100 g. The addition of these two natural extracts increased the content of bioactive compounds and notably improved the antioxidant activity, peroxides index, and p-anisidine during storage of the developed margarine formulations. The results of the physicochemical and microbiological tests showed that the vegetable margarine developed met the quality standards established for a commercial margarine. The qualification of the sensory analysis indicated that the evaluated attributes were acceptable in all the formulations. The margarine elaborated with the addition of 200 ppm of sweet red pepper oleoresin, and 10% of tree tomato juice was the one that presented the best sensory qualification.
The goal of the present study was to propose a set of preliminary regional diagnostic reference levels (DRLs) for paediatric interventional cardiology procedures in Latin America and the Caribbean countries, classified by age and weight groups. The study is conducted in the framework of the OPRIPALC programme coordinated by the World Health Organization and the Pan American Health Organization in cooperation with the International Atomic Energy Agency. The first step of the programme was focused on paediatric interventional cardiology. Dose data from diagnostic and therapeutic procedures were collected between December 2020 and December 2021. Regional DRLs have been set as the 3rd quartile of patient dose data (kerma area-product) collected in 18 hospitals from 10 countries in an initial sample of 968 procedures. DRLs have been set for four age bands and five weight ranges. The values obtained for the four age bands (<1 year, 1 to <5 years, 5 to <10 years and 10 to <16 years) have been 2.9; 6.1; 8.8 and 14.4 Gy.cm2 for diagnostic procedures, and 4.0, 5.0, 10.0 and 38.1 Gy.cm2 for therapeutic procedures, respectively. The values obtained for the five weight bands (<5 kg, 5 to <15 kg, 15 to <30 kg, 30 to <50 kg and 50 to <80 kg) have been 3.0, 4.5, 8.1, 9.2 and 26.8 Gy.cm2 for diagnostic procedures and 3.7, 4,3, 7.3, 16.1 and 53.4 Gy.cm2 for therapeutic procedures, respectively. While initial data were collected manually as patient dose management systems were not available in most of the hospitals involved in the programme, a centralized automatic dose management system for the collection and management of patient dose indicators has now been introduced and is envisaged to increase the sample size. The possibility of alerting on high dose values and introducing corrective actions will help in optimization.
The supply chains of perishable food (PFSC) fresh, present imbalances between supply and demand, in times of supply deficit is necessary to guarantee the food security through the availability, the access and other pillars. In the PFSC losses are highest, whereby the delivery times must be low to guarantee the availability. For the access, must be include the largest number of retailed storekeepers, thus monopolies from large hypermarkets are avoided. In this context, the modeling In PFSC presents big challenges such as the inclusion of delivery times, losses and fresh food biophysical specific conditions which depend of the transport time and storage, the configuration and the number of echelons on the PFSC. In this article, a multiobjective, multiproduct and multi-echelon for perishable food logistics networks design mixed linear programming model is presented. The model allows determining the best configuration so that the different actors of the PFSC, so that could move closer to more efficient borders. The model considers the losses in perishable food derived from the impacts caused by changes in temperature (T°) and relative humidity (RH), on a mountainous environment of developing countries. It is solved in AMPL through e-constrains method. The model is applied in a case study around the perishable fruit supply chains (PFrSC). The information to the model parameterization was obtained through surveys done to the actors of the different echelons of PFrSC during a 4-year period that were complemented with secondary information from public and private enterprises.
The inclusion of ethnicity in equations for estimating the glomerular filtration rate (eGFR) from serum creatinine levels has been challenged since ethnicity is socially defined and therefore a poor proxy for biological differences. We hypothesized that genetic ancestry (GA) would be more strongly associated with creatinine levels among healthy individuals than self-identified ethnicity. We studied a diverse cohort of 35,590 participants characterized as part of the UK Biobank, grouped by self-reported ethnicity: Black, East Asian, Mixed, Other, South Asian, and White. We used multivariable modeling to test for associations between ethnicity, GA, socioeconomic deprivation, and serum creatinine levels, including covariates for age, sex, height, and body mass index. Model fit comparisons and relative importance analysis were used to compare the effects of ethnicity and GA on creatinine levels. Black ethnicity shows a positive effect on participant serum creatinine levels (β = 9.36 ± 0.38), whereas East Asian (β = -1.80 ± 0.66) and South Asian (β = -0.28 ± 0.36) ethnicity show negative effects on creatinine. Male sex (β = 17.69 ± 0.34) and height (β = 0.13 ± 0.02) also show high positive associations with creatinine levels, while socioeconomic deprivation (β = -0.04 ± 0.04) shows no significant association. African ancestry has the highest association (β = 13.81 ± 0.52) with creatinine levels. Overall, GA (9.06%) explains significantly more of the variation in creatinine levels than ethnicity (4.96%), with African ancestry (6.36%) alone explaining more of the variation than ethnicity. We found that GA explains more of the variation in serum creatinine levels than socioeconomic deprivation, suggesting the possibility that ethnic differences in creatinine are shaped by genetic rather than social factors.
The objective of the article is to describe Afro-rurality as a historical category corresponding to a rural world that has been invisible until now in the flatlands of Northern Cauca, Colombia. Methodologically, this historical analysis uses secondary sources and is enriched by the author’s direct experience of Afro-rural territoriality in that region. This work falls in the theoretical category of black ethnogenesis, as approached in the works of Oscar Almario García, Giselle Invernon Duconge, Menara Lube Guizardi and others. Four topics are addressed: slavery and haciendas-cimarrones and palenques; ethnogenesis and Afro-rurality in the northern Cauca during the nineteenth century; dispossession of Afro rural lands in the twentieth century and the traditional farm as the symbol of northern Cauca Afro-rurality and its current context. One important outcome of this work was to give visibility to historical and territorial Afro-rurality as the product of ethnogenesis based on ethnic-cultural identity, the struggle for freedom and the traditional farm as the current reference point.
In Colombia, 317 species of snakes have been recognized, of which 51 (17%) have medical importance due to the toxicity of their venom. A total of 95% of envenomations are caused by snakes of the family Viperidae and 5% of the family Elapidae. The latter form of envenomation is mainly caused by snakes of the genus Micrurus. The only sea snake described is the yellow-bellied snake (Hydrophis platurus), present in the Pacific Ocean. Although Colombia has approximately 1300 km on the Pacific coast and a significant presence of H platurus, envenomation is rare. As a result of the care of a patient with this type of envenomation and of the donation of a H platurus specimen to our laboratory, we decided to conduct this review on the most relevant biological, epidemiological and clinical aspects of this enigmatic and interesting species.
Resumen Objetivo Identificar factores asociados a la aparición de desprendimiento de retina pseudofáquico en pacientes con antecedente de cirugía de catarata. Métodos Estudio retrospectivo de casos y controles de 802 ojos de 783 pacientes con antecedente de cirugía de catarata. Los casos fueron pacientes con desprendimiento de retina pseudofáquico (n = 258 ojos), mientras que los controles fueron pacientes con cirugía de cataratas que no desarrollaron desprendimiento de retina durante un período de seguimiento de 10 años (n = 544 ojos). Resultados La edad de la cirugía de cataratas entre los casos fue menor que en el grupo control (57 ± 13 vs. 67 ± 14 años, respectivamente; p < 0,0001). La edad al desprendimiento de retina fue de 59 ± 13 años (rango 6-88) y el tiempo entre la cirugía de catarata y el desprendimiento de retina tuvo una mediana de 2 años (rango intercuartílico 1-4), con un rango de un mes a 14 años. Los factores asociados para el desprendimiento de retina pseudofáquico fueron la edad más joven (< 50 años: razón de probabilidad ajustada [ORa] = 18,03; intervalo de confianza del 95% [IC 95%] = 5,92-54,87; 50-59 años: ORa = 10,09, IC 95% = 3,37-30,23 y 60-69 años: ORa = 5,48, IC 95% = 1,88-15,93), sexo masculino (ORa = 3,71, IC 95% = 2,54-5,44), vitrectomía anterior (ORa = 3,26, IC 95% = 1,16-9,16), antecedentes de desprendimiento de retina en el ojo contralateral (ORa = 6,95, IC 95% = 3,15-15,31) y complicaciones intraoperatorias durante la extracción de cataratas (ORa = 7,45, IC 95% = 3,54-15,69). Conclusiones Este es el primer artículo de factores asociados al desprendimiento de retina pseudofáquico en población colombiana. Se encontró que las complicaciones quirúrgicas, el sexo y la edad estaban asociados con el desprendimiento de retina. Los pacientes deben ser conscientes de estos riesgos potenciales para tomar decisiones informadas sobre su salud ocular.
Contexto: Identificar la relación entre el desempeño académico de los estudiantes y las métricas de los grafos obtenidos correspondientes a las interacciones de los usuarios en la plataforma Piazza. Método: Se estudian los resultados obtenidos correspondientes a las interacciones entre estudiantes y docentes en la plataforma Piazza, realizando un caso práctico de análisis de redes sociales a través de herramientas computacionales y definición de métricas. Resultados: La información resultante es un valioso apoyo para la implementación de estrategias en los contenidos de un curso asistido con plataformas virtuales, puesto que se identifican las estructuras sociales que resultan de las diferentes formas de relación, lo que permite mapear o analizar relaciones entre personas y cooperación entre actores, grupos o comunidades, entre otras. Conclusiones: Las métricas establecidas para evaluar las redes sociales obtenidas de la plataforma permiten a los docentes determinar la participación y la interacción entre los estudiantes, identificando diferentes patrones de interacción que determinan una relación en la construcción de los vínculos sociales con el desempeño académico de los estudiantes.
The global burden of cervical cancer remains a concern and higher early mortality rates are associated with poverty and limited health education. However, screening programs continue to face implementation challenges, especially in developing country contexts. In this study, we use a mixed-methods approach to understand the reasons for no-show behaviour for cervical cancer screening appointments among hard-to-reach low-income women in Bogotá, Colombia. In the quantitative phase, individual attendance probabilities are predicted using administrative records from an outreach program (N = 23384) using both LASSO regression and Random Forest methods. In the qualitative phase, semi-structured interviews are analysed to understand patient perspectives (N = 60). Both inductive and deductive coding are used to identify first-order categories and content analysis is facilitated using the Framework method. Quantitative analysis shows that younger patients and those living in zones of poverty are more likely to miss their appointments. Likewise, appointments scheduled on Saturdays, during the school vacation periods or with lead times longer than 10 days have higher no-show risk. Qualitative data shows that patients find it hard to navigate the service delivery process, face barriers accessing the health system and hold negative beliefs about cervical cytology.
This paper proposes a novel political pedagogic approach to conducting engaged research. Drawing critically on elements of Participatory Action Research and popular education, this approach - Engaged Pedagogic Research (EPR) - generates processes of collective co-learning and empowerment for local communities and activist researchers. Central to conducting EPR are five processes: generating situated learning practices, recognizing alternative knowledges, engaging in inter-cultural and inter-ethnic dialogue, deconstructing power relations, and promoting empowerment and social action. The experiences of engaging in EPR through developing and running a Diploma in Territorial Planning to support peacebuilding in Colombia are discussed. Different social groups living in conflict areas gained new knowledge and built social relationships that strengthen collaborative action, while activist academics achieved a deeper understanding of how members of these cultural groups manage their territories, relate to each other, and develop visions for collaborative futures in the context of peacebuilding. By developing participatory, decolonized and transformative bridges to connect and engage universities with communities, EPR facilitates learning that is collectively created and has the potential to contribute to more just and egalitarian societies.
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9,043 members
Joao Ealo
  • School of Mechanical Engineering (EIME)
Carlos Valencia
  • School of Dentistry
Osorio Lyda
  • School of Public Health
Olga Vasilieva
  • Department of Mathematics
Andrés Fandiño-Losada
  • School of Public Health
Calle 13 100 00, 760032, Cali, Valle del Cauca, Colombia
Head of institution
Phd. Édgar Varela Barrios
+57 2 33 212100