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Biomedical subjects

D Rios

Publications and source records attributed to D Rios.

5 recordsLinked to original sources
PubMed1996

Using artificial bat sonar neural networks for complex pattern recognition: recognizing faces and the speed of a moving target.

Two sets of studies examined the viability of using bat-like sonar input for artificial neural networks in complex pattern recognition tasks. In the first set of studies, a sonar neural network was required to perform two face recognition tasks. In the first task, the network was trained to recognize different faces regardless of facial expressions. Following training, the network was tested on its ability to generalize and correctly recognize faces using echoes of novel facial expressions that were not included in the training set. The neural network was able to recognize novel echoes of faces almost perfectly (above 96% accuracy) when it was required to recognize up to five faces. In the second face recognition task, a sonar neural network was trained to recognize the sex of 16 faces (eight males and eight females). After training, the network was able to correctly recognize novel echoes of those faces as 'male' or as 'female' faces with accuracy levels of 88%. However, the network was not able to recognize novel faces as 'male' or 'female' faces. In the second set of studies, a sonar neural network was required to learn to recognize the speed of a target that was moving towards the viewer. During training, the target was presented in a variety of orientations, and the network's performance was evaluated when the target was presented in novel orientations that were not included in the training set. The different orientations dramatically affected the amplitude and the frequency composition of the echoes. The neural network was able to learn and recognize the speed of a moving target, and to generalize to new orientations of the target. However, the network was not able to generalize to new speeds that were not included in the training set. The potential and limitations of using bat-like sonar as input for artifical neural networks are discussed.

Adult↗
PubMed1978

[Immunite reaction of hamsters infected or immunized with Entamoeba histolytica].

The immune response in hamsters either infected or immunized with Entamoeba histolytica was studied. The response was tested by determination of antibodies by the counterimmunoelectrophoresis technique and by lymphocyte transformation induced by the amebic antigen. The results obtained showed differences among both groups when the ability of amebic antigen to induce 3H-thymidine incorporation of lymphocyte cultures is compared. However, the response of lymphocyte cultures to Concanavalin A was similar in both studied groups. On the other hand, a group of hamsters hyperimmunized with E. histolytica antigen incorporated in complete Frend's adjuvant showed a greater immune response than the group receiving a single dose.

Amebiasis↗