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Climate variability is one of the main challenges faced by mankind, and understanding its relationship with water quality will generate knowledge that will enable the development of early adaptation strategies and the integral management of water resources. This study assessed the impact of the different intensities of the "El Niño-Southern Oscillation" (ENSO) climate phenomenon on Dissolved Oxygen (DO) from 1985 to 2015, at two monitoring stations on Cauca River. Spatial-temporal variation analysis of DO was performed using descriptive and inferential statistical techniques under different ENSO phases. The correlation between DO and the intensities of the ENSO phases was assessed using the Spearman correlation coefficient. No statistical differences were found in DO concentration at the two studied stations (p = 0.1164). Statical differences of DO were found depending on the ENSO phases at the Mediacanoa station (p = 0.002556); it was also found that the highest median concentrations of DO took place when La Niña was present. No correlation was found at the studied stations between the intensities of the ENSO phases and DO. The water quality of the Cauca River, at the Yotoco and Mediacanoa stations, showed very poor conditions, which has produced negative social, economic and environmental effects. [ABSTRACT FROM AUTHOR]

The analysis of the spatial and temporal variability of precipitation is a transcendental component for decision making in watersheds because it influences the activities of the people who inhabit them; however, in Colombia this type of research is carried out mainly at national and departmental levels, leaving aside studies at watershed scale. For this reason, in this study, an analysis of the influence of the El Niño Southern Oscillation phenomenon on the spatial and temporal distribution of precipitation in the Cali River Basin was carried out. The methodology consisted of the estimation of missing data, precipitation anomalies, comparison of various indices such as ONI, SOI and EMI and the spatial and temporal analysis of precipitation. During the study years 1972 to 2016, a 10% decrease in rainfall was observed in the upper area of the Cali River basin, with a negative trend, in addition, it was found that the months of May and August are more susceptible to events of extreme precipitation in periods of the ENSO phenomenon. Among the probable causes of the decrease in rainfall in the study area, it has been found that the change in the average state of rainfall in the tropical Pacific (Andean region) tends to show a pattern similar to El Niño. [ABSTRACT FROM AUTHOR]

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Introduction: In spite nearly 40% of the variability in blood pressure can be explained by genetic factors, the identification of genes associated to essential high blood pressure is difficult in populations where individuals have different genetic precedents; in these circumstances it is necessary to determinate whether the population is sub-structured because this can bias studies associated with this disease. Objectives: To determine the genetic structure of the population in Bucaramanga from genetic polymorphisms associated with the regulation of blood pressure: 448G>T, 679C>T y 1711C>T from the gene kinase 4 of the dopaminergic receptor linked to the protein G and Glu298Asp, -786T>C and the VNTR of the intron 4 of the gene of endothelial nitric oxide. Methodology: A sample of 552 unrelated individuals was studied through analysis of Restriction fragment length polymorphism. The allelic, haplotypic and genotypic frequencies were calculated, the Hardy-Weinberg equilibrium was determined and a molecular analysis of variance was performed to determine the genetic structure. Results: 38 Haplotypes were identified, with GCCTG4b as the most frequent (21.2%). The most diverse polymorphism was 448G>T with a frequency of 49.9% for heterozygous. The six polymorphisms were found in genetic equilibrium and genetic structure of populations was not evidenced (FST = 0,0038). Conclusion: The population studied does not present a genetic sub-structure and the polymorphisms analyzed were found in genetic equilibrium, this indicates that the population mixes randomly and there are no sub-groups capable of affecting the results of the association studies. [ABSTRACT FROM AUTHOR]

This article reports on a time - series analysis of monthly precipitation (mm), river discharge (m³/s) and sediment export (kton/day) in Urabá Gulf. We analyzed the dynamics of sediment exports relative to river discharge, and the dynamics of this latter variable relative to precipitation. We inferred the role of seasonal and multi - annual atmospheric drivers, and anthropogenic factors. We found significant intra - annual variability (ANOVA: p<0.001) consistent with the movement of the Inter - Tropical Convergence Zone. The Pearson correlation between variables showed direct and significant relationships (p<0.001). The ENSO did not influence precipitation. Using aerial - photographs, we analyzed anthropogenic factors in the municipalities of Apartadó (1961 - 2005) and Chigorodó (1961 - 2007), finding up to a 90% forest - cover loss. Using double - mass graphs, it was observed an increase in slope steepness (during mid 90's), consistent with an increase in sediment export rate relative to discharge, thus suggesting that there was a significant effect of human factors, such as deforestation. [ABSTRACT FROM AUTHOR]

The knowledge of the phenomenon El Niño Southern Oscillation (ENSO) still is partial, the variations in the Colombian climate and the ENSO events make difficult its understanding and the prediction of its impacts. This research used the Climate Explorer, to establish linear relations between the precipitation and the average temperature of the air (annual and quarterly) with associated variables to ENSO, between 1975 and 2000. It is concluded that in the center, north and west of the country, El Niño (warm phase) brings rain diminution and increases the temperature, the opposite happens during La Niña. Greater significant correlations obtained with quarterly periods (mainly in DJF) and lags around zero; which decay in trimester MAM of the climatological variables; between the precipitation and index IMENSO greater coefficients in DJF were obtained (r=-0.44). Greater incidence of ENSO exists on the temperature of the country. [ABSTRACT FROM AUTHOR]