Optimización de la solución numérica por elementos finitos de sondeos geoeléctricos

En el artículo se presenta una nueva metodología de solución para resolver problemas de flujo y potencial modelados con elementos finitos. El sistema de ecuaciones resultantes de dicha solución conocido como CGEIS (Gradientes Conjugados con Precondicionamiento y Escalonamiento, utilizando la Descomposición Incompleta de Cholesky). Este método puede ser utilizado sólo para el caso de matrices simétricas y positivamente definidas, las cuales son encontradas en problemas de potencial tales como sondeos geoeléctricos, flujo de aguas subterráneas, hidraúlica, contaminación, petróleos, etc.. El método fue implementado con el fin de simular sondeos geoeléctricos y flujo de aguas subterráneas. Su montaje se realizó en un computador VAX-2, y se utilizó el FORTRAN 77, como lenguaje de programación. Adicionalmente el método optimiza los recursos computacionales tales como tiempo de ejecución y memoria principal.A new solution method is presented to solve potencial and flow problems, when a finite element representation is used. The resulting equations can be arranged in a matrix form and apply a new solution method called CGEIS (Conjugated Gradients Escaled and Preconditioned, using the Incomplet Cholesky Descomposition). This method can be used for symetric and positively defined matrices, which are found in many potentials problems such as in reservoir engineering, geoelectrics, hidraulics, oil, etc.. The method was implemented to solve complex matrices obtained in standar and continuous geolectrics soundings, and in groundwater flow. A FORTRAN 77 code was developed in a VAX-2 computer. Also, the method optimizes the computer resources (Time and memory).Peer Reviewe

Optimización de la solución numérica por elementos finitos de sondeos geoeléctricos

En el artículo se presenta una nueva metodología de solución para resolver problemas de flujo y potencial modelados con elementos finitos. El sistema de ecuaciones resultantes de dicha solución conocido como CGEIS (Gradientes Conjugados con Precondicionamiento y Escalonamiento, utilizando la Descomposición Incompleta de Cholesky). Este método puede ser utilizado sólo para el caso de matrices simétricas y positivamente definidas, las cuales son encontradas en problemas de potencial tales como sondeos geoeléctricos, flujo de aguas subterráneas, hidraúlica, contaminación, petróleos, etc.. El método fue implementado con el fin de simular sondeos geoeléctricos y flujo de aguas subterráneas. Su montaje se realizó en un computador VAX-2, y se utilizó el FORTRAN 77, como lenguaje de programación. Adicionalmente el método optimiza los recursos computacionales tales como tiempo de ejecución y memoria principal.A new solution method is presented to solve potencial and flow problems, when a finite element representation is used. The resulting equations can be arranged in a matrix form and apply a new solution method called CGEIS (Conjugated Gradients Escaled and Preconditioned, using the Incomplet Cholesky Descomposition). This method can be used for symetric and positively defined matrices, which are found in many potentials problems such as in reservoir engineering, geoelectrics, hidraulics, oil, etc.. The method was implemented to solve complex matrices obtained in standar and continuous geolectrics soundings, and in groundwater flow. A FORTRAN 77 code was developed in a VAX-2 computer. Also, the method optimizes the computer resources (Time and memory).Peer Reviewe

FSI simulations for explosions very near reinforced concrete structures

The analysis of explosives in contact or very near to reinforced concrete (RC) structures is an important aspect in the design of protective structures and vulnerability assessments. Although this remains a topic of high importance for defence, a more widespread interest has developed as civilian structures become the targets of terrorism. This type of assessment requires a robust simulation method for coupled fluid-structural interactions (FSI) which can handle the explosive detonation, air blast propagation, structural deformation, and damage evolution. This paper describes the application of a loose-coupling method which combines the FEFLO CFD code and SAIC’s CSD code for 3D numerical simulations of unconfined and semi-confined explosions near RC structures. This approach takes advantage of the unstructured tetrahedral mesh for the CFD and an embedded method for CSD structures inside the fluid domain. Comparisons of simulations with experiment provide validation, but also reveal some weaknesses of the method. A good agreement between simulation and experiment is found with moderate explosive loading. However, a severe explosive loading with confinement results in extensive damage to the structure which is difficult to reproduce in simulations

On the simulation of dropletization

Compressible and near-incompressible solvers, together with particle update techniques and chemistry packages are combined in order to compute complex multiphase flows that include dropletization, vaporization and subsquent combustion

Achievement of generic and profesional competencies through virtual environments

This study is aimed to prove how Virtual Environments (VE) and Information and Communication Technologies (ICT) can be used as a tool to verify professional competencies. The incursion of virtual environments in education has shown that there is much potential in distance learning development. To find out how it influences the achievement of competencies, there was made an experimental study with a post-test design and control group. Students were divided into two groups; each of them was submitted to a different test. The results demonstrate that with the implementation of VE using ICT, the students who used the VE had a better performance than students who used the traditional evaluations. Confirmed with the 83% of the sample who achieved the highest levels (50% got strategical professional competencies, and 33% got autonomous professional competencies). Considering the study, the authors could notice that students do develop professional competencies along virtual environments, reflected not only in the level of competence achieved by the ones tested on the virtual environment but also in the average time they spend to do the test. Therefore, virtual environments have positives effects in the education field

Endocrine-disrupting effects of cattle feedlot effluent on an aquatic sentinel species, the fathead minnow.

Over the last decade, research has examined the endocrine-disrupting action of various environmental pollutants, including hormones, pharmaceuticals, and surfactants, in sewage treatment plant effluent. Responding to the growth of concentrated animal feeding operations (CAFOs) and the pollutants present in their wastewater (e.g., nutrients, pharmaceuticals, and hormones), the U.S. Environmental Protection Agency developed a new rule that tightens the regulation of CAFOs. In this study, we collected wild fathead minnows (Pimephales promelas) exposed to feedlot effluent (FLE) and observed significant alterations in their reproductive biology. Male fish were demasculinized (having lower testicular testosterone synthesis, altered head morphometrics, and smaller testis size). Defeminization of females, as evidenced by a decreased estrogen:androgen ratio of in vitro steroid hormone synthesis, was also documented. We did not observe characteristics in either male or female fish indicative of exposure to environmental estrogens. Using cells transfected with the human androgen receptor, we detected potent androgenic responses from the FLE. Taken together, our morphologic, endocrinologic, and in vitro gene activation assay data suggest two hypotheses: a) there are potent androgenic substance(s) in the FLE, and/or b) there is a complex mixture of androgenic and estrogenic substances that alter the hypothalamic-pituitary-gonadal axis, inhibiting the release of gonadotropin-releasing hormone or gonadotropins. This is the first study demonstrating that the endocrine and reproductive systems of wild fish can be adversely affected by FLE. Future studies are needed to further investigate the effects of agricultural runoff and to identify the biologically active agents, whether natural or pharmaceutical in origin

Optimizing Dietary Net Energy for Maximum Profitability in Growing- Finishing Pigs

Feed accounts for a significant portion of swine production cost, with dietary energy alone representing more than half of the total cost. Considering the financial implications of determining the energy content of the diet, the objective of this research project was to develop a tool to accurately estimate the dietary NE content that yields maximum profitability for growing-finishing pigs. A Microsoft Excel®-based model was developed to contrast dietary NE defined by the user with recommended concentrations that are intended to maximize profitability in user defined production and economic scenarios. To calculate pig performance, the model uses prediction equations for ADG and feed efficiency. In addition, the model also uses the NDF content of the diet because of its effect on dressing percentage. For profitability calculations, a non-linear mathematical programming model was designed to select the optimum dietary NE content that yields the greatest income over total cost per pig on a live or carcass basis. The model can be used to predict dietary NE content that yields the highest economic benefit considering dynamic productive and economic scenarios. The model can be downloaded at www.ksuswine.org

Transforming healthcare through regenerative medicine

Regenerative medicine therapies, underpinned by the core principles of rejuvenation, regeneration and replacement, are shifting the paradigm in healthcare from symptomatic treatment in the 20th century to curative treatment in the 21st century. By addressing the reasons behind the rapid expansion of regenerative medicine research and presenting an overview of current clinical trials, we explore the potential of regenerative medicine to reshape modern healthcare

Epidemiología molecular y análisis filogenético de la infección por el virus del papiloma humano en mujeres con lesiones cervicales y cáncer en la región litoral del Ecuador

The aim of the present study was to gather information regarding the molecular epidemiology of Human papillomavirus (HPV) and related risk factors in a group of women with low- and high-grade cervical lesions and cancer from the coastal region of Ecuador. In addition, we studied the evolution of HPV variants from the most prevalent types and provided a temporal framework for their emergence, which may help to trace the source of dissemination within the region. We analyzed 166 samples, including 57 CIN1, 95 CIN2/3 and 14 cancer cases. HPV detection and typing was done by PCR-sequencing (MY09/MY11). HPV variants and estimation of the time to most recent common ancestor (tMRCA) was assessed through phylogeny and coalescence analysis. HPV DNA was found in 54.4% of CIN1, 74.7% of CIN2/3 and 78.6% of cancer samples. HPV16 (38.9%) and HPV58 (19.5%) were the most prevalent types. Risk factors for the development of cervical lesions/cancer were the following: three or more pregnancies (OR = 4.3), HPV infection (OR = 3.7 for high-risk types; OR = 3.5 for HPV16), among others. With regard to HPV evolution, HPV16 isolates belonged to lineages A (69%) and D (31%) whereas HPV58 isolates belonged only to lineage A. The period of emergence of HPV16 was in association with human populations (tMRCA = 91. 052 years for HPV16A and 27. 000 years for HPV16D), whereas HPV58A preceded Homo sapiens evolution (322. 257 years). This study provides novel data on HPV epidemiology and evolution in Ecuador, which will be fundamental in the vaccine era.Fil: Bedoya Pilozo, Cesar H.. Escuela Superior Politécnica del Litoral; Ecuador. Instituto Nacional de Investigaciones en Salud Pública; EcuadorFil: Medina Magües, Lex G.. Escuela Superior Politécnica del Litoral; EcuadorFil: Espinosa García, Maylen. Instituto Nacional de Investigaciones en Salud Pública; EcuadorFil: Sánchez, Martha. Instituto Nacional de Investigaciones en Salud Pública; EcuadorFil: Parrales Valdiviezo, Johanna V.. Instituto Nacional de Investigaciones en Salud Pública; EcuadorFil: Molina, Denisse. Instituto Nacional de Investigaciones en Salud Pública; EcuadorFil: Ibarra, María A.. Instituto Nacional de Investigaciones en Salud Pública; EcuadorFil: Quimis Ponce, María. Instituto Nacional de Investigaciones en Salud Pública; EcuadorFil: España, Karool. Instituto Nacional de Investigaciones en Salud Pública; EcuadorFil: Párraga Macias, Karla E.. Instituto Nacional de Investigaciones en Salud Pública; EcuadorFil: Cajas Flores, Nancy V.. Instituto Nacional de Investigaciones en Salud Pública; EcuadorFil: Solon, Orlando A.. Instituto Nacional de Investigaciones en Salud Pública; Ecuador. Universidad Agraria del Ecuador; EcuadorFil: Robalino Penaherrera, Jorge A.. Instituto Nacional de Investigaciones en Salud Pública; EcuadorFil: Chedraui, Peter. Hospital Gineco-Obstétrico Enrique C. Sotomayor; EcuadorFil: Escobar, Saul. Universidad Católica de Guayaquil; EcuadorFil: Loja Chango, Rita D.. Universidad Católica de Guayaquil; EcuadorFil: Ramirez Morán, Cecibel. Universidad Católica de Guayaquil; EcuadorFil: Espinoza Caicedo, Jasson. Universidad Católica de Guayaquil; EcuadorFil: Sánchez Giler, Sunny. Universidad Especialidades Espíritu Santo. Facultad de Ciencias Médicas; EcuadorFil: Limia, Celia M.. Instituto de Medicina Tropical Pedro Kouri; CubaFil: Alemán, Yoan. Instituto de Medicina Tropical Pedro Kouri; CubaFil: Soto, Yudira. Instituto de Medicina Tropical Pedro Kouri; CubaFil: Kouri, Vivian. Instituto de Medicina Tropical Pedro Kouri; CubaFil: Culasso, Andrés Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Virología; ArgentinaFil: Badano, Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Secretaría de Educación Superior, Ciencia, Tecnología e Innovación; Ecuador. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales. Laboratorio de Biología Molecular Aplicada; Argentin