Evaluación del riesgo por metales pesados en suelos ácidos bajo diferentes sistemas agrícolas en el Piedemonte Llanero de Colombia

Agricultural soils may become polluted by heavy metals as a result of receiving a significant amount of pollutants from different sources of land applications, such as fertilizers, animal manure, sewage sludge, pesticides, and wastewater irrigation. Given that information on the distribution of heavy metals (HMs) in the Piedemonte Llanero of Colombia is still quite limited, the main objectives of this work were to characterize the content of these elements and their potential pollution level in acidic soils under different agricultural systems. The hypothesis is to verify if the type of land use poses an environmental threat. To achieve these goals, the concentrations of seven metals were determined in the soils of three agricultural production systems: oil palm, pastures, and semi-annual crops. Soil contamination was evaluated based on the Geo-Accumulation Index (I-geo), contamination factor (CF), Pollution Load Index (PLI), and Nemerov Integrated Pollution Index (NIPI). One outstanding result was that the average concentrations of HMs in the collected topsoil samples were as follows: Mn (110.5 mg kg-1), Zn (31.93 mg kg-1), Cr (8.85 mg kg-1), Ni (11.68 mg kg-1), Cu (11.28 mg kg-1), Pb (9.42 mg kg-1) and Cd (0.21 mg kg-1). The results obtained from this study provide an estimation of the pollution status of HMs. Agricultural activities, especially the overuse of phosphate fertilizer, were the main source of nutrients across the study area. This information can become a fundamental tool to establish monitoring and follow-up processes for sustainable soil management in the Piedemonte Llanero. In conclusion, the present study highlights and provides specific information in a hyperhumid environment.Los suelos agrícolas pueden contaminarse con metales pesados como consecuencia de recibir una cantidad significativa de contaminantes procedentes de diferentes fuentes de aplicaciones terrestres, tales como fertilizantes, estiércol animal, lodos de depuradora, pesticidas y/o riego con aguas residuales. Dado que la información sobre la distribución de metales pesados (MP) en el Piedemonte llanero de Colombia es aún bastante limitada, el objetivo principal de este trabajo fue caracterizar el contenido de estos elementos y su potencial nivel de contaminación en suelos ácidos bajo diferentes sistemas agrícolas. La hipótesis es verificar si el tipo de uso representa una amenaza ambiental. Para lograr estos objetivos, se determinaron las concentraciones de siete metales en los suelos de tres sistemas de producción agrícola: palma aceitera, pastos y cultivos semestrales. La contaminación del suelo se evaluó con base al índice de geo-acumulación (I-geo), el factor de contaminación (FC), el índice de carga contaminación (ICC) y el índice de contaminación integrada de Nemerov (ICIN). Un resultado sobresaliente fue que las concentraciones promedio de MP en las muestras de suelo recolectadas fueron en general: Mn (110.5 mg kg-1), Zn (31.93 mg kg-1), Cr (8.85 mg kg-1), Ni (11.68 mg kg-1), Cu (11.28 mg kg-1), Pb (9.42 mg kg-1) y Cd (0.21 mg kg-1). Las actividades agrícolas, especialmente el uso excesivo de fertilizantes fosfatados, fueron la principal fuente de nutrientes en toda el área de estudio. Esta información puede convertirse en una herramienta básica para establecer procesos de monitoreo y seguimiento que permitan establecer un manejo sustentable del suelo en el Piedemonte llanero. Además, los resultados obtenidos de este estudio constituyen una estimación del estado de contaminación de los MP en el contexto específico de un ambiente hiperhúmedo

Memoria del segundo simposium sobre historia, sociedad y cultura de México y América Latina

La presente obra reúne 20 ponencias de las 27 que se presentaron en el “Segundo simposium sobre historia, sociedad y cultura de México y América Latina”, realizado el 8 y 9 de noviembre de 2006, en el Centro de Investigación en Ciencias Sociales y Humanidades (CICSyH) de la Universidad Autónoma del Estado de México (UAEM), en Toluca, Estado de México

XVI International Congress of Control Electronics and Telecommunications: "Techno-scientific considerations for a post-pandemic world intensive in knowledge, innovation and sustainable local development"

Este título, sugestivo por los impactos durante la situación de la Covid 19 en el mundo, y que en Colombia lastimosamente han sido muy críticos, permiten asumir la obligada superación de tensiones sociales, políticas, y económicas; pero sobre todo científicas y tecnológicas. Inicialmente, esto supone la existencia de una capacidad de la sociedad colombiana por recuperar su estado inicial después de que haya cesado la perturbación a la que fue sometida por la catastrófica pandemia, y superar ese anterior estado de cosas ya que se encontraban -y aún se encuentran- muchos problemas locales mal resueltos, medianamente resueltos, y muchos sin resolver: es decir, habrá que rediseñar y fortalecer una probada resiliencia social existente - producto del prolongado conflicto social colombiano superado parcialmente por un proceso de paz exitoso - desde la tecnociencia local; como lo indicaba Markus Brunnermeier - economista alemán y catedrático de economía de la Universidad de Princeton- en su libro The Resilient Society…La cuestión no es preveerlo todo sino poder reaccionar…aprender a recuperarse rápido.This title, suggestive of the impacts during the Covid 19 situation in the world, and which have unfortunately been very critical in Colombia, allows us to assume the obligatory overcoming of social, political, and economic tensions; but above all scientific and technological. Initially, this supposes the existence of a capacity of Colombian society to recover its initial state after the disturbance to which it was subjected by the catastrophic pandemic has ceased, and to overcome that previous state of affairs since it was found -and still is find - many local problems poorly resolved, moderately resolved, and many unresolved: that is, an existing social resilience test will have to be redesigned and strengthened - product of the prolonged Colombian social conflict partially overcome by a successful peace process - from local technoscience; As Markus Brunnermeier - German economist and professor of economics at Princeton University - indicates in his book The Resilient Society...The question is not to foresee everything but to be able to react...learn to recover quickly.Bogot

Correlates and Longitudinal Renal and Cardiovascular Implications of FGF23 Levels in HIV-Positive Individuals.

Fibroblast growth factor23 (FGF23), an early marker of kidney dysfunction, is associated with cardiovascular death. Its role in HIV-positive individuals is unknown. We measured FGF23 in 100 HIV-negative and 191 HIV-positive nondiabetic adults with normal baseline estimated glomerular filtration rate (GFR). We measured GFR by iohexol annually, albumin-creatinine ratio (ACR) every 6 months, as well as pulse wave velocity, carotid plaque, and carotid intima media thickness (IMT) at baseline and 2 years. Progressive albuminuria was defined as follow-up ACR ≥2-fold than baseline and ≥30 mg/g. Regression models assessed associations of FGF23 with baseline factors and longitudinal changes in disease markers. FGF23 levels were similar in HIV serostatus. Among HIV-positive persons, factors independently associated with higher baseline FGF23 levels included female (adjusted ratio of geometric means [95% CI],1.46 [1.21,1.76]), serum phosphorus (1.20 [1.03,1.40]), HCV (1.31 [1.10,1.56]) and non-suppressed HIV RNA (1.27 [1.01,1.76]). At baseline, FGF23 was not associated with GFR, albuminuria, carotid plaque, or carotid IMT in cross-sectionally adjusted analysis of HIV-positive individuals. However, higher baseline FGF23 was associated with progressive albuminuria (odds ratio1.48 [95% CI]:1.05,2.08) and a more rapid increase in IMT (13 μm/year, 95% CI,3,24). These findings suggest a role for FGF23 in HIV-positive populations in identifying patients at greater risk for cardiovascular and kidney disease

Predictors of Acute Renal Injury Study (PARIS) among HIV-positive individuals: design and methods

Abstract Background Acute kidney injury (AKI), which is common among HIV-positive individuals, may contribute to the excess burden of chronic kidney disease (CKD) in this patient population; however, conventional clinical methods to detect AKI do not capture kidney injury sufficiently early to prevent irreversible damage. Further, large observational and interventional studies of AKI generally exclude HIV-positive persons in spite of their disproportionate risk. Methods The Predictors of Acute Renal Injury Study (PARIS) is a prospective observational cohort study among HIV-positive individuals established to determine the ability of candidate kidney injury biomarkers to predict future hospitalized clinical AKI, to characterize hospitalized subclinical AKI, and to discern the risk of progressive kidney disease following subclinical and clinical AKI. Among the candidate kidney injury markers, we will select the most promising to translate into a clinically viable, multiplex panel of urinary biomarkers which we will integrate with clinical factors to develop a model prognostic of risks for AKI and subsequent kidney function decline. This study has a targeted enrollment of 2000 participants. The overall follow-up of participants consists of two phases: 1) a 5-year active follow-up phase which involves serial evaluations at enrollment, annual clinic visits, and among participants who are hospitalized during this period, an evaluation at index hospitalization and 3 and 12 months post-hospitalization; and 2) a subsequent passive follow-up phase for the duration that the participant receives medical care at The Johns Hopkins Hospital. Discussions This study will serve as an important resource for future studies of AKI by establishing a repository with both ambulatory and inpatient biospecimens, a resource that is currently lacking in existing HIV clinical cohorts and studies of AKI. Upon completion of this study, the resulting prognostic model which will incorporate results from the multiplex HIV-AKI Risk Pane could serve as a pharmacodynamic endpoint for early phase therapeutic candidates for AKI

Time to progression to albuminuria by FGF23 level.

<p>Kaplan-Meier plot showing time to progressive albuminuria according to baseline FGF23 plasma concentration below or above the median (8.4 pg/mL) among HIV-positive individuals (P = 0.05, logrank test).</p

Baseline characteristics of the cohort overall, and stratified by HIV status.

<p>Baseline characteristics of the cohort overall, and stratified by HIV status.</p

Associations of baseline factors with fibroblast growth factor-23 plasma concentrations in HIV-negative and HIV-positive participants.

<p>Associations of baseline factors with fibroblast growth factor-23 plasma concentrations in HIV-negative and HIV-positive participants.</p

Data Collection Protocol for the Mr. Bean Study.

<p>Data Collection Protocol for the Mr. Bean Study.</p