University of Los Andes

About: University of Los Andes is a education organization based out in Bogotá, Colombia. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 17616 authors who have published 25555 publications receiving 413463 citations.

Modeling traffic through a sequence of traffic lights.

Abstract: We introduce a microscopic traffic model, based on kinematic behavior, which consists of a single vehicle traveling through a sequence of traffic lights that turn on and off with a specific frequency. The reconstructed function that maps the state of the vehicle from light to light displays complex behavior for certain conditions. This chaotic behavior, which arises by the discontinuous nature of the map, displays an essential ingredient in traffic patterns and could be of relevance in studying traffic situations.

Surfactant-oil-water systems near the affinity inversion part i: relationship between equilibrium phase behavior and emulsion type and stability

Abstract: A systematic relationship was found between the equilibrium phase behavior of a surfactant-alcohol-oil-water system and the type and stability of the corresponding emulsion. Formulations are scanned through the three phase transition by changing (one at the time) brine salinity, oil EACN, surfactant nature and alcohol concentration. Whatever the scanning variable, it is found that the electrical conductivity exhibits a large change near the optimum formulation, indicating the inversion of the continuous phase of the dispersed system. On the other hand, the emulsion stability is found to undergo a deep minimum for formulations corresponding to the three phase behavior at equilibrium. The large but relatively smooth variation of the conductivity gives some hints on the possible continuity structure of the MOW triphasic emulsions.

Isolation of Trypanosoma cruzi DNA in 4,000-year-old mummified human tissue from northern Chile.

Abstract: A segment of DNA unique to the kinetoplast of Trypanosoma cruzi was isolated from spontaneously mummified human remains from the coastal area of northern Chile at sites dated from 2000 BC to about AD 1400. Following rehydration of the desiccated human tissue samples of heart, esophagus, or colon, the samples were extracted and primers employed to bind to a 330 bp kinetoplast minicircle DNA sequence present in T. cruzi. This segment was then amplified using the polymerase chain reaction (PCR), and the target segment was visualized by gel electrophoresis. This method enables the identification of Chagas' disease in an ancient body in the absence of recognizable anatomic pathological changes.