Teaching to make stone tools: new experimental evidence supporting a technological hypothesis for the origins of language.

The relationship between lithic technology, learning and language is a topic of growing interest in human evolution studies, and has therefore been the subject of numerous scientific papers in recent years. To evaluate the role of language in the social transmission of lithic technology, we designed and developed an experimental protocol through which we compared the acquisition of knapping skills in thirty non-experts in the early stages of learning, by means of three mechanisms of social transmission: imitation-emulation, gestural communication, and verbal communication. All the apprentice knappers carried out the experimental task with blanks that were equal in shape and size, and were requested to replicate what the expert knapper was doing: the alternating method, a sufficiently simple, but systematic technique for detaching flakes from a core. We analysed each participant's actions, including those of the master knapper, the final products (flakes and cores), and the knapping sequences, by analysing the refits. Our results show that the apprentices improved their knapping skills in teaching conditions -both gestural and verbal communication-, and specially through the latter. In conclusion, our study supports the hypothesis of co-evolution between lithic technology and social learning, which could have favoured the emergence of verbal language.

Colecistitis aguda como causa de muerte tras cirugía por estenosis del canal lumbar / Acute cholecystitis as cause of death after surgery for lumbar canal stenosis

La colecistitis aguda posquirúrgica se ha descrito fundamentalmente como una complicación de cirugía mayor abdominal o torácica, y en ocasiones asociada a cirugía del aparato locomotor. En cirugía del raquis se ha asociado a grandes procedimientos como la corrección de deformidades en el adulto. Los factores de riesgo más reconocidos son la restricción hídrica, fiebre, fenómenos hemolíticos, trasfusiones sanguíneas múltiples, trastornos nutricionales, fármacos (anestésicos, codeína, atropina, meperidina, morfina) y alteraciones hemodinámicas. Existe un riesgo especialmente elevado cuando confluyen varios de ellos en un paciente sometido a una situación de estrés físico como la cirugía. El diagnóstico de la colecistitis aguda posoperatoria suele ser difícil, al quedar frecuentemente enmascarado por el procedimiento quirúrgico inicial. Deberá existir un alto índice de sospecha ante todo paciente que tras un posoperatorio inmediato favorable desarrolle fiebre, leucocitosis y dolor abdominal. La confirmación ecográfica y la instauración rápida del tratamiento oportuno son el único modo de disminuir la elevada tasa de mortalidad de esta complicación

Post-surgical acute cholecystitis has been described mainly as a complication of major abdominal or thoracic surgery sometimes associated with musculoskeletal surgery. In spine surgery it has been related to large-scale procedures such as the correction of deformities in adults. The most frequently mentioned risk factors are hydric restriction, fever, hemolytic phenomena, multiple blood transfusions, nutritional disorders, certain drugs (anesthetics, codeine. atropine, meperidine, morphine) and hemodynamic alterations. The risk is especially high when several of the factors above co-occur in a single patient subjected to a physically stressful situation like surgery. Diagnosis of acute postoperative cholecystitis is often challenging since the condition is often marked by the initial surgical procedure. Symptoms like fever, leucocytosis and abdominal pain after a favorable immediate post-op should put us on guard. Sonographic confirmation and the quick implementation of appropriate treatment are the only way of reducing the high death toll of this complication (AU)