RESUMEN
A study carried out on 49 horses showed that it is possible to measure the attention time by operant conditioning. After teaching horses an instrumental task using a signal, we were then able to test their attention time by asking them to prolong it increasingly while setting success and failure criteria. Two tests were performed 3 weeks apart. The 2nd test was feasible without relearning, a proof of memory, and was repeatable, a proof of consistency in the attention time. A significant difference was observed between the 3 age groups. Young horses often performed very well during the 1st test but their attention dropped in the 2nd test while older horses were more stable with respect to attention and even increased it slightly. The study shows that there are individual differences but it was not possible to prove a significant influence of breed, gender and paternal influence. Consequently, learning appears to be one of the most interesting approaches for evaluating the attention of horses and for observing their behaviour.
Asunto(s)
Atención , Caballos/fisiología , Aprendizaje/fisiología , Memoria/fisiología , Factores de Edad , Animales , Atención/fisiología , Condicionamiento Operante , Estudios Cruzados , Femenino , Masculino , Factores de TiempoRESUMEN
In order to design high efficient pneumatic actuators for stomatology the experimental studies of microturbines operating in air turbine handpieces have been performed. Specially developed experimental set and torque meter-tachometer have been used for the purpose. As a result, the main parameters of commonly known stomatologic pneumatic instruments are specified, and the ways of their modifications are determined as well.
Asunto(s)
Equipo Dental de Alta Velocidad , Presión del Aire , Diseño de Equipo , Estudios de Evaluación como AsuntoRESUMEN
The hallmarks of diagnosis of medullary breast cancer (MedBC) used by the authors since 1977 have been that the tumor is well circumscribed, has syncytial architecture in greater than 75% of its surface, contains diffuse inflammatory infiltrate, has atypical nuclei, and forms no glandular pattern. In order to assess the clinical utility of these criteria, we studied a series of 95 previously untreated, surgically operable patients with breast carcinoma at the Institut Gustave-Roussy (IGR) between 1960 and 1979. A diagnosis of MedBC was initially made for these patients or suspected based on abundant inflammatory stroma observed in a histologic evaluation. Using these criteria, 26 cases were identified as typical medullary carcinoma (TMC), 23 cases as atypical medullary carcinoma (AMC), and 46 cases as nonmedullary carcinoma (NMC). The 26 cases of TMC represent a very small fraction of the total infiltrating operable breast carcinomas diagnosed at IGR during the same time period. The prognosis for these 26 patients was much more favorable than for the other groups. They had a 10-year disease-free survival of 92% compared with 53% for the AMC group and 51% for the NMC group. Neither distant metastasis nor secondary primaries of the same histology were seen. Therefore, it is possible with the use of strict histologic criteria to distinguish a group of patients with a much more favorable prognosis. This histologic diagnosis alone renders a most favorable prognosis for the patient even if other factors such as large tumor size and lymph node involvement are present and, by inference, the only therapy needed is the removal of all tumor. In contrast, atypical forms have a prognosis no different from other atypical types of breast carcinomas without inflammatory stroma, and adjuvant therapy appears to be justified if other factors warrant it.