Proposal for a framework for environmental zoning of areas near gold mines based on the distribution of potentially toxic elements, pollution indices, and bioindicators: a case study in Antioquia, Colombia.

Gold mining, even under strict environmental regulations, inevitably causes environmental impacts and liabilities. To address this, the study proposes a framework for environmental zoning around gold mines based on the distribution of potentially toxic elements (PTEs), pollution indices, and bioindicators. Soil samples were collected from municipalities affected by gold mining projects, and concentrations of As, Cd, Pb, and Cr were measured. Then, the Pollution Load Index (PLI) was calculated. A plant model was used for the biomonitoring of PTEs, and the Plant Vigor Index (PVI) was determined. Finally, environmental zoning was proposed through geospatial analysis combining PTEs, PLI, and PVI values. The concentrations of PTEs were as follows: As ranged from 1.7 to 892, Cd from 0.1 to 65.2, Pb from 18.5 to 2345, and Cr from 5.4 to 118.4. Spearman's rank correlation showed significant relations (ρ > 0.76) between bioindicators and PTE concentrations and PLI. The PVI correlated significantly with PTE concentrations (ρ - 0.41 to - 0.67) and PLI (ρ - 0.65). The municipalities were categorized into three zones: highly contaminated, moderately contaminated, and minimally contaminated. Overall, the environmental zoning maps serve as a management tool for environmental monitoring.

Assessing pollution degree and human health risks from hazardous element distribution in soils near gold mines in a Colombian Andean region: Correlation with phytotoxicity biomarkers.

The assessment of human health risk due to the presence of hazardous elements in the environment is now necessary for environmental management and legislative initiatives. This study aims to determine the contamination by As, Cd, Pb, and Cr in soils near gold mines in three municipalities located in the Andean region of Colombia. One of the main objectives of the study is to explore possible correlations between the Lifetime Cancer Risk (LCR) and phytotoxicity biomarkers using a simple and rapid-response plant model, radish (Raphanus sativus L.). In the municipality of Yalí, Puerto Berrío, and Buriticá, the hazardous elements concentrations ranged from 8.1 to 35.5, 1.7 to 892, and 5.8 to 49.8 for As, 0.1 to 4.6, 0.1 to 65.2, and 0.5 to 18.2 for Cd, 18.5 to 201.3, 13.0 to 1908, and 189 to 2345 for Pb, and 5.4 to 118.4, 65.4 to 301, and 5.4 to 102.3 for Cr, respectively. The results showed that the biomarkers intracellular H2O2 concentration, antioxidant activity, and radicle elongation exhibited significant (P < 0.05) variations associated with the concentration of hazardous elements in the soils. Significant correlations (P < 0.05, r > 0.58) were found between the biomarkers and the LCR for Cd, Pb, and Cr, but not for As. The results using biomarkers reveal that soil pH and organic matter content are important variables that control the bioavailability of these elements in the soil. The use of indicators like LCR alone has limitations and should be accompanied by the use of biomarkers that allow for a better understanding of the biological system's response to exposure to potentially toxic elements. The results obtained show the urgent need to implement public policies to minimize exposure to hazardous substances in areas near gold mining projects.

Swirling Fluid Reduces the Bounce of Partially Filled Containers.

Certain spatial distributions of water inside partially filled containers can significantly reduce the bounce of the container. In experiments with containers filled to a volume fraction ϕ, we show that rotation offers control and high efficiency in setting such distributions and, consequently, in altering bounce markedly. High-speed imaging evidences the physics of the phenomenon and reveals a rich sequence of fluid-dynamics processes, which we translate into a model that captures our overall experimental findings.

Stability of bubble-like fluxons in disk-shaped Josephson junctions in the presence of a coaxial dipole current.

We investigate analytically and numerically the stability of bubble-like fluxons in disk-shaped heterogeneous Josephson junctions. Using ring solitons as a model of bubble fluxons in the two-dimensional sine-Gordon equation, we show that the insertion of coaxial dipole currents prevents their collapse. We characterize the onset of instability by introducing a single parameter that couples the radius of the bubble fluxon with the properties of the injected current. For different combinations of parameters, we report the formation of stable oscillating bubbles, the emergence of internal modes, and bubble breakup due to internal mode instability. We show that the critical germ depends on the ratio between its radius and the steepness of the wall separating the different phases in the system. If the steepness of the wall is increased (decreased), the critical radius decreases (increases). Our theoretical findings are in good agreement with numerical simulations.

Factores pronósticos para pérdida de extremidad con trauma arterial periférico en un hospital de Colombia / Prognostic factors for extreme loss in peripheral arterial trauma at a Colombian hospital

INTRODUCCIÓN: El trauma vascular es un evento de baja frecuencia, con alta morbimortalidad que afecta la población joven; requiere en general un manejo quirúrgico. Se asocia a complicaciones desde la reintervención quirúrgica hasta la amputación de la extremidad, influenciado por variables tanto asociadas al trauma como a la atención hospitalaria. OBJETIVO: Determinar los factores de riesgo relacionados con amputación, en pacientes con trauma arterial periférico (TAP), atendidos en un Hospital de III nivel Huila- Colombia entre 2014-2017. MATERIALES Y MÉTODOS: Estudio observacional, analítico de corte retrospectiva con pacientes mayores de 13 años con TAP. RESULTADOS: Se incluyeron 79 pacientes, con un 1,56% de las consultas en nuestro Servicio de Urgencia. 89% hombres, promedio de edad 28,5 años. La principal comorbilidad fue la farmacodependencia 8,8%. El MESS (mangled extremity severity) promedio fue de 5,27 puntos y un tiempo critico de isquemia de extremidad > a 6 horas en el 38%. El mayor compromiso fue de miembros superiores, secundario a heridas por arma cortopunzante. La lesión predominante fue la transección arterial. Las principales complicaciones posquirúrgicas fueron la trombosis del vaso (21,5%) y la amputación (13,9%). Factores de riesgo asociados a amputación fueron la edad > 20 años, estancia hospitalaria > 7 días, MESS > 7 puntos, que presentaran como complicación quirúrgica la trombosis arterial y que requirieran reintervención quirúrgica. CONCLUSIONES: El trauma arterial periférico es una patología con gran repercusión socioeconómica y secuelas funcionales. Es necesaria la atención oportuna con tratamiento de las variables relacionadas con mal pronóstico, con el fin de disminuir las tasas de morbimortalidad.

INTRODUCTION: Vascular trauma is a low frequency event, with high morbidity and mortality that affects the young population; In general, it requires surgical management. It is associated with complications from surgical reintervention to amputation of the limb, influenced by trauma associated variables such as hospital care. AIM: Determine risk factors related to amputation, in patients with peripheral arterial trauma (TAP), treated at a Hospital of III level Huila-Colombia between 2014-2017. MATERIALS AND METHOD: Observational, retrospective analytical study with patients older than 13 years with TAP. RESULTS: We included 79 patients with an incidence of 1.56%. 89% men, average age 28.5 years. The main comorbidity was 8.8% drug dependence. The MESS (Mangled extremity severity) average was of 5.27 points and a critical time of limb ischemia > to 6 hours in 38%. The greater commitment was of superior members, secondary to injuries by sharp weapon. The predominant lesion was arterial transection. The main postoperative complications were vessel thrombosis (21.5%) and amputation in 13.9%. Risk factors associated with amputation were determined by age > 20 years, hospital stay > 7 days, MESS > 7 points, and that they presented arterial thrombosis as a surgical complication and finally required surgical reoperation. CONCLUSIONS: Peripheral arterial trauma is a pathology with great socioeconomic impact and functional sequelae. It is necessary the timely attention with treatment of the variables related to poor prognosis, in order to decrease the morbidity and mortality rates.

Localized Faraday patterns under heterogeneous parametric excitation.

Faraday waves are a classic example of a system in which an extended pattern emerges under spatially uniform forcing. Motivated by systems in which uniform excitation is not plausible, we study both experimentally and theoretically the effect of heterogeneous forcing on Faraday waves. Our experiments show that vibrations restricted to finite regions lead to the formation of localized subharmonic wave patterns and change the onset of the instability. The prototype model used for the theoretical calculations is the parametrically driven and damped nonlinear Schrödinger equation, which is known to describe well Faraday-instability regimes. For an energy injection with a Gaussian spatial profile, we show that the evolution of the envelope of the wave pattern can be reduced to a Weber-equation eigenvalue problem. Our theoretical results provide very good predictions of our experimental observations provided that the decay length scale of the Gaussian profile is much larger than the pattern wavelength.

Bubblelike structures generated by activation of internal shape modes in two-dimensional sine-Gordon line solitons.

Nonlinear waves that collide with localized defects exhibit complex behavior. Apart from reflection, transmission, and annihilation of an incident wave, a local inhomogeneity can activate internal modes of solitons, producing many impressive phenomena. In this work we investigate a two-dimensional sine-Gordon model perturbed by a family of localized forces. We observed the formation of bubblelike and droplike structures due to local internal shape mode instabilities. We describe the formation of such structures on the basis of a one-dimensional theory of activation of internal modes of sine-Gordon solitons. An interpretation of the observed phenomena, in the context of phase transition theory, is given. Implications in Josephson junctions with a current dipole device are discussed.