Traveltime inversion for 2-D anomaly structures

This work presents a traveltime inversion method that uses parametric functions to represent 2-D anomaly structures. These functions are described by a small set of unknown parameters which in turn are obtained after solving a highly nonlinear optimization problem via simulated annealing (SA). The procedure favors neither smooth nor high contrasting anomalies and keeps the number of unknowns very small so as to make the problem tractable using SA. Yet the strategy allows one to accommodate a large class of velocity models. Results indicate that this new approach typically yields better images than a standard linearized inversion based on a cell parameterization scheme.Facultad de Ciencias Astronómicas y Geofísica

Traveltime inversion for 2-D anomaly structures

This work presents a traveltime inversion method that uses parametric functions to represent 2-D anomaly structures. These functions are described by a small set of unknown parameters which in turn are obtained after solving a highly nonlinear optimization problem via simulated annealing (SA). The procedure favors neither smooth nor high contrasting anomalies and keeps the number of unknowns very small so as to make the problem tractable using SA. Yet the strategy allows one to accommodate a large class of velocity models. Results indicate that this new approach typically yields better images than a standard linearized inversion based on a cell parameterization scheme.Facultad de Ciencias Astronómicas y Geofísica

El escritor polaco Jerzy Stefan Stawiński en su versión rusa: reflexiones sobre la importancia del estilo en la traducción

The present article analyzes the peculiarities of literary style and its preservation in translation taking as an example one of the novels of the outstanding Polish writer Jerzy Stefan Stawiński (1921-2010). In this writer, the issue is the study of the domineering stylistic units and of the suitable selection of linguistic equivalent in the translation to Russian from the original Polish bearing in mind some pragmatic aspects. The work also reflects on the possibilities of the Spanish language in transmitting the style of this author.El presente artículo analiza las particularidades del estilo literario y su preservación en la traducción tomando como ejemplo una de las novelas del destacado escritor polaco Jerzy Stefan Stawiński (1921-2010). Se trata del estudio de las dominantes estilísticas y de la adecuada selección de equivalentes lingüísticos en la traducción a la lengua rusa del original polaco teniendo en cuenta algunos aspectos pragmáticos. El trabajo también expone reflexiones sobre las posibilidades de la lengua española a la hora de transmitir el estilo de este autor

La reforma agraria de 1980 en El Salvador: lucha política, diseño y ejecución.

En este artículo presenta un avance de los resultado del proyecto de investigación que se realiza sobre la reforma agraria de 1980, esta fue organizado en tres partes. La primera cuenta brevemente el proceso de lucha política en el seno del Gobierno y a nivel Nacional, la segunda parte aborda el diseño de la Ley Básica de la Reforma Agraria que fue diseñada por un equipo de políticos técnicos que examinó los documentos del Primer Congreso Nacional de Reforma Agraria de 1970 y la última parte, examina la ejecución en un contexto de guerra civil

A Unique Case of Bilateral Valsalva Retinopathy

This is a Photo Essay and does not have an abstract

19th century London dust-yards: A case study in closed-loop resource efficiency

The material recovery methods used by dust-yards in early 19th century London, England and the conditions that led to their development, success and decline are reported. The overall system developed in response to the market value of constituents of municipal waste, and particularly the high coal ash content of household ‘dust’. The emergence of lucrative markets for ‘soil’ and ‘breeze’ products encouraged dust-contractors to recover effectively 100% of the residual wastes remaining after readily saleable items and materials had been removed by the thriving informal sector. Contracting dust collection to the private sector allowed parishes to keep the streets relatively clean, without the need to develop institutional capacity, and for a period this also generated useful income. The dust-yard system is, therefore, an early example of organised, municipal-wide solid waste management, and also of public–private sector participation. The dust-yard system had been working successfully for more than 50 years before the Public Health Acts of 1848 and 1875, and was thus important in facilitating a relatively smooth transition to an institutionalised, municipally-run solid waste management system in England. The dust-yards can be seen as early precursors of modern materials recycling facilities (MRFs) and mechanical–biological treatment (MBT) plants; however, it must be emphasised that dust-yards operated without any of the environmental and occupational health considerations that are indispensable today. In addition, there are analogies between dust-yards and informal sector recycling systems currently operating in many developing countries

THE AIDS EPIDEMIC IN SOUTH FLORIDA: BLACK NON-HISPANICS IN OUR COMMUNITIES REMAIN INCREASINGLY VULNERABLE

Objective. Demographic variables of individuals with AIDS were compared during two time periods (1993 - 1995 and 2011 - 2013). Incidence and mortality related data was also explored. Methods. This is an observational study. Tests of significance were performed to identify differences or associations between selected groups. A correlation analysis was conducted to identify relationships between AIDS diagnosis and socioeconomic indicators. Results. A reduction in new AIDS cases reported and AIDS-related mortality were observed. Nonetheless, AIDS is still disproportionately affecting the Black Non-Hispanic population. Black Non-Hispanic women remain particularly vulnerable to the disease. A positive correlation between AIDS diagnosis and poverty rate and the lack of health insurance and a negative correlation between AIDS diagnosis and education level was identified. Conclusion. Though the actual number of AIDS cases is declining, it continues to disproportionately discriminate against our poorer, less well educated communities. Despite the availability of improved medications, people in these communities remain particularly vulnerable

Seismic characterization of thin beds containing patchy carbon dioxide-brine distributions: A study based on numerical simulations

We studied the seismic attenuation and velocity dispersion effects produced by wave-induced fluid flow in weakly consolidated sandstones containing patchy carbon dioxide CO ð Þ2 -brine distributions. The analysis also focuses on the velocity pushdown because of the presence of this gas, as well as on the role of the wave-induced fluid flow (mesoscopic) effects on the amplitude variation with angle (AVA) seismic response of thin layers containing CO2, such as those found at the Utsira Sand, Sleipner field, offshore Norway. We found that this loss mechanism may play a key role on conventional surface seismic data, suggesting that further data analysis may provide useful information on the characteristics of the fluid distributions in these environments. Numerical experiments let us observe that although mesoscopic effects can be very significant in this kind of media, the seismic response of a given isolated thin layer computed considering such effects is very similar to that of a homogeneous elastic thin layer with a compressional velocity equal to that of the original porous rock averaged in the effective data bandwidth. This suggests that the thin-bed prestack spectral inversion method published by the authors could be used to estimate representative compressional velocities and layer thicknesses in these environments. In effect, results using realistic synthetic prestack seismic data show that isolated CO2- bearing thin beds can be characterized in terms of their thicknesses and representative compressional velocities. This information can be qualitatively related to CO2 saturations and volumes; thus, the prestack spectral inversion method could find application in the monitoring of the evolution of CO2 plumes at injection sites similar to that at the Sleipner field.Fil: Rubino, Jorge German. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Universite de Lausanne; SuizaFil: Velis, Danilo Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentin