University of Caldas
  • Manizales, Caldas, Colombia
Recent publications
The syntheses of six salts, N-halomethylated (1a, 1b, 1c) and non-N-halomethylated (2a, 2b, 2c), are achieved by a four-step sequence involving: (i) Grignard reaction starting from p-(F)C6H4MgBr and Br(CH2)n+1COOEt; (ii) acid-catalyzed dehydration of the resulting tertiary alcohols Br(CH2)n+1C(OH) (C6H4-p-F)2; (iii) bromide substitution by aqueous dimethylamine in the resulting olefins Br(CH2)nCH=C(C6H4-pF)2; and (iv) displacement of an iodide anion by reaction of the resulting amines of (CH3)2N(CH2)nCH=C(C6H4-pF)2 with CH2I2. These compounds were crystallized in a binary mixture of water-isopropanol in slow evaporation. Crystallographic studies show that the crystal growth of these compounds is controlled by C-H‧‧‧X (X=F, I or I⁻) and I‧‧‧I⁻ interactions with a complete absence of classic hydrogen bonds. The detected H‧‧‧X and I‧‧‧I⁻ distances are very short compared with the values normally observed in literature. The results suggest that, in the lack of other hydrogen bonds, halogen atoms form strong interactions and, in the case of these salts, control completely the supramolecular structure. Moreover, it was found that the length of (CH2)n chains influences the intermolecular interactions, being longer for lengthy chains. Hirshfeld surface (HS) analysis support this observation showing that these halogenated intermolecular interactions conform in high proportion the contacts in the crystal. Additionally, HS allowed the detection of σ-holes were I‧‧‧I⁻ act as Lewis´s acid-base pair, respectively.
Objective This study aimed to assess the longitudinal predictions between glycated hemoglobin A1c (HbA1c) and physical performance scores in different epidemiological contexts of aging. Material and Methods: Longitudinal data of 1,337 older people from three countries (Canada, Brazil and Colombia) of the International Mobility in Aging Study (IMIAS) were used to assess the relationship between HbA1c and Short Physical Performance Battery (SPPB) scores between 2012 and 2016. Linear Mixed Models grouped by sex and adjusted by Age, Study site, Chronic Conditions, Anthropometric Measures, and Inflammatory Level were used to estimate the influence of HbA1c and covariates on SPPB scores. Results At the IMIAS baseline, Latin American (LA) cities had higher HbA1c averages compared to Canadian cities, with Natal (Brazil) being the city with the highest HbA1c averages in men and women (6.32 ± 1.49; 6,56 ± 1.70 respectively). SPPB scores were significantly lower in LA cities, and older people in Natal had lower SPPB averages in men (9.67 ± 2.38; p-value < 0.05) and women (8.52 ± 2.33; p-value <0.05). In the multivariate mixed linear models of longitudinal analyses, HbA1c was significantly associated with lower SPPB scores in men (β = -0.25, 95% CI: -0.39 to -0.12, p-value = 0.02) but not in women. Conclusion High HbA1c levels at baseline were longitudinally associated in older adults from different countries, and this association was observed only in men and not in women. This study highlights a possible influence of gender on this relationship.
Background Habitat fragmentation and degradation processes affect biodiversity by reducing habitat quantity and quality, with differential effects on the resident species. However, their consequences are not always noticeable as some ecological processes affected involve idiosyncratic responses among different animal groups. The Valdivian temperate rainforests of southern Chile are experiencing a rapid fragmentation and degradation process despite being a biodiversity hotspot. Deforestation is one of the main threats to these forests. There inhabits the arboreal marsupial Dromiciops gliroides , an iconic species from the Valdivian rainforest, it is the only extant representative of the ancient Microbiotheria order, and it is currently threatened by habitat loss. Here we tested the effects of habitat configuration on D. gliroides occurrence and abundance along 12 landscapes of southern Chile with different disturbance levels. Methods We estimated D. gliroides occurrence and abundance using camera traps and related those metrics with landscape configuration indices obtained from FRAGSTATS (i.e., forest %, connectivity, patch number, contiguity, and distance to the nearest patch) using Bayesian linear mixed models. Results We found that D. gliroides occurrence was not influenced by landscape configuration, while its abundance was positively influenced by forest contiguity. Conclusions Although this arboreal marsupial is present in disturbed forests, its restricted movement capabilities and high dependency on the forest three-dimensional structure may affect its long-term persistence. We urge to rethink native forest conservation and management policies to improve habitat connectivity with possible positive consequences for native fauna.
To determine urban–rural differences influencing mortality in patients with hip fracture in Colombian Andes Mountains over a 1-year period. Purpose To identify the urban–rural differences of sociodemographic variables, fracture-related characteristics, and preoperative and postoperative clinical factors associated with 1-year mortality in patients over 60 years old who underwent hip fracture surgery in the Andes Mountains. Methods A total of 126 patients with a fragility hip fracture during 2019–2020 were admitted to a tertiary care hospital. They were evaluated preoperatively and followed up until discharge. Those who survived were contacted by telephone at 1, 3, and 12 months. Univariate, bivariate, and Kaplan–Meier analyses with survival curves were performed. Relative risk was calculated with a 95% confidence interval. Results A total of 32.5% of the patients died within 1 year after surgery, with a significant difference between those who resided in rural areas (43.1%) and those who resided in urban areas (23.5%) (RR 1.70; 95% CI, 1.03 to 2.80, p = 0.036). In the multivariate analysis, anemia (hemoglobin level ≤ 9.0 g/dL during hospitalization) (RR 6.61; 95% CI, 1.49–29.37, p = 0.003), a blood transfusion requirement (RR 1.47; 95% CI, 1.07 to 2.01, p = 0.015), the type of fracture (subtrochanteric fracture (RR = 4.9, 95% CI = 1.418–16.943, p = 0.005)), and postoperative acute decompensation of chronic disease (RR 1.60; 95% CI, 1.01 to 2.53, p = 0.043) were found to be independent predictive factors of 1-year mortality after surgery. Conclusions There was a difference in 1-year mortality between patients from rural and urban areas. More studies must be conducted to determine whether rurality behaves as an independent risk factor or is related to other variables, such as the burden of comorbidities and in-hospital complications.
Este artículo presenta los resultados de un proyecto transmedial de investigación creación que recogió una diversidad de voces para reconstruir algunas de las experiencias individuales y colectivas del conflicto armado en la región conocida como Eje cafetero en Colombia. Además de la realización de una serie de obras, integradas por una narrativa transmedia, el proyecto muestra la utilidad de los proyectos transmediales en la doble tarea de contribuir a la reconstrucción de la memoria histórica del conflicto y de llegar a distintos públicos en diferentes formatos. El proyecto también evidencia la existencia de una conciencia dispersa pero persistente acerca de los horrores del conflicto armado en el Eje cafetero, una región que en las versiones oficiales y el imaginario social aparece como una zona de paz y prosperidad asociadas al cultivo del café. Para lograr esto, el proyecto convocó públicamente la participación de distintas personas, para que contaran sus relatos, en unos casos, y para que mostraran los resultados de su trabajo de investigación y de creación, en otros. De esta manera, el proyecto articuló voces y subjetividades que tradicionalmente se expresan por canales separados.
The objective of this study was to document and analyze the effect of climate on the phenological development of ‘Hass’ avocado in two contrasting zones of the Andean tropics of Caldas, located at altitudes of 1,950m and 2,400m a.s.l., respectively. A completely randomized experimental design was carried out using a five to seven year-old ‘Hass’ tree as experimental unit and 15 replicates on each area. Observations were conducted on lateral sylleptic shoots and their corresponding apical buds located on the eastern and western sides of each tree. The destination of the apical bud of lateral shoots was quantified, floral phenology was documented, heat units were calculated from reproductive bud stage 1 to anthesis and to harvest and root growth was followed for each study area. Air temperature, soil temperature, precipitation and photosynthetically active radiation (PAR) values were recorded over time. Differences were found in the number of apical buds of lateral shoots with reproductive and vegetative destination, flowering phenology, heat units, root growth, PAR and precipitation. Differences were found among variables evaluated at the two contrasting altitudes. There is a clear need for further ecophysiological studies on this fruit tree in tropical areas in particular.
The Late Cretaceous in northwest South America was a period marked by synchronous regional geological processes (e.g., accretion of oceanic terranes, arc magmatism, sea-level fluctuations, oceanographic dynamics), related to the interaction of the Caribbean Large Igneous Province (CLIP) with the NW margin of South America. This synchroneity makes it difficult to reconstruct the complex geological evolution of this region. In Colombia, Upper Cretaceous marine sedimentary and low-grade metamorphic rocks are commonly exposed in both the Western Cordillera and the Sinú-San Jacinto Basin in the Pacific and Caribbean regions respectively. Significant deformation and structural complexity are the main limiting factors for sedimentological and paleontological studies of these deposits. Detailed sedimentological and ichnological analyses were carried out in eight sections, two in the Caribbean region and six in the Pacific region. The Caribbean sections are composed of limestones, mudrocks, siliceous and calcareous mudrocks, and cherts, associated with pelagic and hemipelagic deposits (E2.2 and G2.1 facies). The Pacific sections are characterized by two facies associations, one composed of mudrocks, limestones, as well as chert associated with pelagic and hemipelagic deposits (E2.2 and G2.1 facies) and the other of interlayered siliceous mudrocks and sandstones associated with turbiditic systems (C2 facies). Upper Cretaceous deposits in both regions are characterized by relatively low to moderate abundant and diverse trace fossils assemblages, consisting of Chondrites, Planolites, and Zoophycos in the Caribbean region and Chondrites, ?Nereites, Phycodes, Phycosiphon, Planolites, Thalassinoides, and Zoophycos in the Pacific region, assigned to the Zoophycos ichnofacies. Sedimentological and ichnological features suggest deposition in deep-marine environments characterized by pelagic, hemipelagic, and turbiditic sedimentation. Integrated with the biostratigraphical framework, this allows us to establish a regional correlation between both regions. High nutrient supply, poor oxygenation, and low hydrodynamic energy and sedimentation rates interrupted by episodic increases associated with turbiditic deposits are main paleoenvironmental factors controlling the sedimentation over the CLIP during Late Cretaceous.
Background This study sought to analyse the trend in smoking-attributable mortality (SAM) in Spain among the population aged ≥35 years across the period 1990–2018. Methods SAM was estimated by applying a prevalence-independent method, which uses lung cancer (LC) mortality as a proxy of tobacco consumption. We sourced observed mortality from the National Institute of Statistics (Spain), LC mortality rates in smokers and never smokers from the Cancer Prevention Study I–II, and relative risks from 5 US cohorts. Estimates of annual SAM by cause of death, sex and age are shown, along with crude and annual standardised SAM rates. The trend in standardised all-cause and LC rates was analysed using a joinpoint regression model. Results Tobacco caused 1 717 150 deaths in Spain in the period 1990–2018. Among men, cancers replaced cardiovascular diseases–diabetes mellitus (CVD–DM) as the leading group of tobacco-related cause of death in 1994. Among women, CVD–DM remained the leading cause of death throughout the period. Trend analysis of standardised SAM rates due to all causes and LC showed a decrease in men and an increase in women. Conclusions The tobacco epidemic in Spain across the period 1990–2018 has had an important impact on mortality and has evolved differently in both genders. SAM is expected to increase dramatically in women in the coming years. SAM data highlight the importance of including a gender perspective in SAM analyses, in designing more effective and comprehensive public health interventions and in developing gender-specific tobacco control policies to curb tobacco consumption.
Resumen Las obras de infraestructura inconclusas que generan altos costos económicos y sociales a las ciudades son un problema para el urbanismo. El objetivo de este artículo es estudiar un macroproyecto inconcluso adelantado en Manizales (Colombia) desde 2009, en el marco de una política del Gobierno Nacional creada para promover renovación urbana con fines de vivienda. Se trata de una operación de urbanismo que presenta bajos índices de ejecución, incumplimientos, incremento de costos, afectó derechos individuales y colectivos, y produjo caos urbano en el centro de la ciudad. Analizamos una contradicción normativa que permitió que los intereses de actores representantes del Gobierno Nacional, del sector de la construcción y del capital financiero transformaran un sector céntrico de la ciudad, con escasa participación ciudadana, representando un juego de actores y de intereses inconvenientes para el desarrollo local. Encontramos igualmente que esta iniciativa carece de articulación con un proyecto de ciudad, que garantizara su continuidad y coherencia. Los resultados se derivan de una investigación cualitativa, centrada en métodos de análisis documental, entrevistas y revisión sistemática de prensa local.
Occasionally the scapular notch can be replaced by a bony foramen product of the ossification of the superior transverse scapular ligament. This bone formation is considered a precipitating factor for compression of the suprascapular nerve. One hundred and ninety-five adult scapulae from Colombian (114 scapulae) and Chilean (81 scapulae) university osteotheques were studied macroscopically to determine the presence of a bony scapular foramen. Both scapulae of the same Colombian individual (1.75% of the total) presented the scapular foramen and one left scapula (1.23%) presented this formation in a Chilean individual. The prevalence of ossification of the superior transverse scapular ligament is highly variable in the different studies and tends to be less than 10%; however, it can become a risk factor due to entrapment or compression of the suprascapular nerve, a fact known as suprascapular neuropathy.
Integrative taxonomic reviews of highly charismatic carnivores such as the neotropical olingos (Bassaricyon) is limited by the scarcity of specimens for morphological and associated material, such as fresh tissues for molecular analyses. Although Colombia harbors three olingo species (Bassaricyon alleni, B. medius, and B. neblina), only sequences of a single individual are available. Here, we present records that fill gaps in areas with sampling bias and extend the information on the current and potential distribution of olingos from Colombia. Furthermore, we generated new cytochrome-b and Cholinergic Receptor Nicotinic Alpha Polypeptide 1 precursor sequences from three additional specimens from Colombia. B. medius shows the widest distribution from northern Panama, crossing the Pacific Forest, the Magdalena basin, the Caribbean, and the Andean slopes in Colombia to Tumbes in Peru. For B. neblina, the potential distribution extends over the northern Andes, including the Occidental and the Central cordilleras of Colombia, and the Occidental and Oriental Andes of Ecuador. Despite B. alleni has the largest potential distribution in Colombia, we only found seven records from the montane forests of the Cordillera Oriental. The area of occupancy (AOO) and the extent of occurrence (EOO) in Colombia is 84 km 2 and 141,970 km 2 for B. medius, 116 km 2 and 126,530 km 2 for B. neblina. Although B. alleni has a larger potential distribution, there is a scarcity of records for this species in Colombia, and its AOO is only 28 km 2. This information could be useful to assess research priorities and threats for olingos in Colombia.
Based on most neuroanatomical descriptions, the anterior spinal artery (ASA) originates from two small vessels of the vertebral arteries, which are anastomosed just before forming the basilar artery. This study aimed to determine and quantify the possible variants of the origin of the ASA and its trajectory in samples of human brain stems. Male brain stems with the superior portion of the spinal cord until myelomera C3 of 23 adult human, and no evident morphological alterations were selected. The brain stems were collected for three years and fixed in a 10% formalin solution at the Anatomy Laboratory of the Universidad de Caldas (Colombia). Five samples (21.7%) had variations in the origin and trajectory of the anterior spinal artery. The variations in the origin of the ASA could generate morphofunctional advantages instead of leading to complications. That is the case when there are two anterior spinal arteries since it would increase tissue perfusion, thus protecting part of the spinal cord from ischemic pathologies. It is essential to consider the variations that may exist in the supply of the anterior region of the spinal cord for clinical and surgical assessments due to variations in its supplied territory.
The welfare of working equids in developing countries is sometimes threatened due to the limited resources and/or knowledge of their owners. The objective of this study is to evaluate the welfare of creole horses and mules using a validated protocol that assesses animal-based indicators. A total of 160 horses and 40 mules from three municipalities in the Colombian coffee-growing region were evaluated by means of direct observation of health and behavioral parameters. A descriptive analysis of the variables expressed in proportions was performed. Interactions between the different measurements were examined using the Chi-squared test. Spearman correlations were used to relate the measurements. Horses and mules demonstrated friendly behavior in front of the evaluators (78.13 and 61.54%, respectively); apathetic or severely depressed behavior was low (10.7 and 17.5%, P > 0.05). Significant differences in body condition score (BCS) were observed between mules and horses (P < 0.05); eighty percent of the mules and 54.4% of the horses exhibited a healthy body condition score (3 or more on a scale of 1 to 5). Less than 15% of the animals had eye problems, limb deformities, and gait abnormalities. Injuries to the head, withers, spine, ribs/flank, hindquarters, and hind legs were observed in a frequency between 12.5 and 30.43% of the animals, with a higher frequency in horses (P < 0.05). Weak correlations (R2 coefficient < 0.5), although statistically significant, were observed between low body conditions and the presence of skin and deeper tissue lesions, systemic health abnormalities, and limb problems (P < 0.05). The results indicate that owners care for their animals. However, the presence of skin and deep tissue lesions, especially in horses, suggests that they are subjected to high workloads. Therefore, it is essential to train owners in aspects related to the importance of providing their equids with adequate rest periods to recover from work and develop actions to strengthen human-equine interaction.
Entomological collections represent a key source of information about the biological heritage of a country. However, the taxonomy and knowledge of many arthropods from megadiverse countries are underrepresented in these natural history collections as is the case with several planthoppers of the suborder Auchenorrhyncha. Issidae are fulgoromorphs distributed worldwide, except the poles and Greenland. Despite this ubiquity, Colombian planthoppers remain very poorly known and studied. Our objective was to provide the first consolidated records and distributional data for Colombian Issidae. We used reports of the representative genus Thionia deposited in biological collections in Colombia. In addition, we linked voucher specimen information and Olson’s life zones showing an inter-Andean valley and Eastern Andean Cordillera distribution within Colombia. Our survey of Colombian biological collections revealed 55 individuals of the genus Thionia Stål, 1859 (53 adults, 2 immatures [nymphs]), which were collected by different methods; however, many of those records may be opportunistic. This genus (and its species) needs further study, with systematic and ecological revision, as is the case with other terrestrial Colombian hemipterans. Our consolidated records represent an advance to the knowledge of Issidae (and Thionia specifically) for the Neotropics and Colombia in particular, and a baseline for further study of distributional and biogeographic patterns of the suborder Auchenorrhyncha.
The Colombian Speckled Tree Rat, Pattonomys semivillosus, is a little-known rodent endemic to the Lower Magdalena River basin at the Caribbean Coast of Colombia. To date it is the only species of Pattonomys documented in the country. We provide information on the rarity, and conservation status of P. semivillosus based on the current and potential distribution, population density and size using information from the literature, new records, and museum vouchers. We confirmed 66 occurrences that belong to 25 localities in six departments (Atlántico, Bolívar, Cesar, La Guajira, Magdalena, Santander, and Sucre) in northern Colombia, including 18 new localities not previously reported in the literature, mostly in the highly threatened Tropical Dry Forest ecosystem. The population density in three sites of Department of Cesar was 5.4 ind/km2, 5.9 ind/km2, and 32.4 ind/km2. The species matches with the Category D of rarity, and we suggest an update to the threatened assessment (from Least Concern to Near Threatened). This information will contribute to update the current IUCN assessment of the species.
Multiple studies have investigated the impact of teaching coding on some cognitive processes, with promising results. Based on this background, the current study evaluated the effect of a computational thinking intervention on the executive functioning of school-age children. The research had a between-subjects experimental design, with pre and post measurements and a control group. The measurement instrument was the BANFE-2 battery. The experimental group participated in an 8-week intervention in which they were taught to coding using the micro:bit device and the MakeCode programming environment. The findings revealed significant transfer effects on the executive functions of the students.
In this paper, we obtain the approximate value of 42.9815 arcsec/century for Mercury’s perihelion precession by solving both numerically and analytically the nonlinear ordinary differential equation derived from the geodesic equation in Einstein’s Theory of Relativity. We also compare our result with known results, and we illustrate graphically the way Mercury’s perihelion moves. The results we obtained are applicable to any body that moves around the Sun. We give predictions about the value of the Cosmological Constant. Simple algebraic formulas allow to estimate perihelion shifts with high accuracy.
The plantain agro-industry generates different residues in the harvest and post-harvest stages. Therefore, the design of processes for valorization is required. The aim of this work was to design and techno-economically evaluate the processes for the production of single-cell protein, natural fibers, and biomethane from plantain residues by process simulation in the framework of the design of a future biorefinery for valorization of these residues. The processes were simulated using SuperPro Designer. The scale size was calculated at 1,267,071 tons for the processing of plantain lignocellulosic waste (pseudostems) and 3179 tons for the processing of starchy waste (rejected unripe plantain fruits). The results obtained suggest that the best alternative for the valorization of plantain residues corresponded to the production of natural fibers, with a net present value of $29,299,000. This work shows that waste from the plantain agro-industry exhibits high potential as a feedstock for the production of value-added products. In addition, the process flowsheets simulated in this work can be integrated into the basic design of a biorefinery processing plantain waste.
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Calle 65 No 26-10, NA, Manizales, Caldas, Colombia
Head of institution
Alejandro Ceballos Marquez
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