Central University of Ecuador

About: Central University of Ecuador is a education organization based out in Quito, Ecuador. It is known for research contribution in the topics: Population & Medicine. The organization has 2220 authors who have published 1910 publications receiving 15052 citations.

Uptake and Toxicity of Respirable Carbon-Rich Uranium-Bearing Particles: Insights into the Role of Particulates in Uranium Toxicity.

Abstract: Particulate matter (PM) presents an environmental health risk for communities residing close to uranium (U) mine sites. However, the role of the particulate form of U on its cellular toxicity is still poorly understood. Here, we investigated the cellular uptake and toxicity of C-rich U-bearing particles as a model organic particulate containing uranyl citrate over a range of environmentally relevant concentrations of U (0-445 μM). The cytotoxicity of C-rich U-bearing particles in human epithelial cells (A549) was U-dose-dependent. No cytotoxic effects were detected with soluble U doses. Carbon-rich U-bearing particles with a wide size distribution (<10 μm) presented 2.7 times higher U uptake into cells than the particles with a narrow size distribution (<1 μm) at 100 μM U concentration. TEM-EDS analysis identified the intracellular translocation of clusters of C-rich U-bearing particles. The accumulation of C-rich U-bearing particles induced DNA damage and cytotoxicity as indicated by the increased phosphorylation of the histone H2AX and cell death, respectively. These findings reveal the toxicity of the particulate form of U under environmentally relevant heterogeneous size distributions. Our study opens new avenues for future investigations on the health impacts resulting from environmental exposures to the particulate form of U near mine sites.

Mine-site derived particulate matter exposure exacerbates neurological and pulmonary inflammatory outcomes in an autoimmune mouse model

Abstract: The Southwestern United States has a legacy of industrial mining due to the presence of rich mineral ore deposits. The relationship between environmental inhaled particulate matter (PM) exposures a...

Machine Learning Methods Based Preprocessing to Improve Categorical Data Classification

Abstract: The following study is aimed at dealing with large volumes of data whose main characteristic is to contain a high number of variables, most of which are categorical in nature. In the knowledge extraction process, Knowledge Discovery in Databases (KDD), it is very common to deal with a stage of data pre-processing and dimensionality reduction. A key part of extracting information is having high quality data. This paper proposes the use of the Pairwise and Listwise methods as part of the dimensionality reduction process, when there is a high level of missing values present in one or more variables. As part of the pre-processing, we generate n-clusters using Kohonen Self-Organizing Maps (SOM) algorithm with H2O on R. A comparison of the performance and accuracy of classification algorithms is made with the complete subdata set and the algorithms are applied to each cluster. As a case study, we analyzed the characteristics that influence the level of schooling of women of childbearing age.

Production of lipids from psychrophilic microalgae present in antarctic glaciers for the synthesis of biofuel

Abstract: Microalgae had a negative impact on the overall sensory quality. Psychrophilic microalgae live in extremely cold environments, their growth increases because they have enzymes in their structure that only adapt to temperatures below 0 ° C. For this reason, the Sustainable Chemistry Laboratory of the Central University of Ecuador, together with the Ecuadorian Antarctic Institute (INAE), made an expedition in the Greenwich, Roberts, Dee, Barrientos and Antarctic Towers where several microalgae consortia were collected, where 15 samples from Greenwich Island and Roberts were analyzed at 21 days at different temperatures, from which the genera Chlorella sp, Chlorococcum sp and Stichococcus sp. Subsequently, isolation was made in Petri dishes to obtain monoalgal cultures. Each of the isolated genera was massified in a volume of 5 mL until reaching a volume of 250 mL in modified M1 medium at a temperature of 4 ° C and 24 ° C, 5000 lux and a photoperiod of 12:12 hours. The Bligh & Dyer method was used for the extraction of lipids. The values of the lipid concentration showed that the genus Chlorella sp is the highest concentration with a value of 0.2802 mg / mL at 4 ° C and a value of 2.6704 mg / mL at 24 ° C on the 22nd day of its exponential phase in comparison with the genera Chlorococcum and Stichococcus sp.