A Case of a C-Stem Fracture at the Head-Neck Junction and a Review of the Literature

We report the first case of a fracture of the standard C-stem in combination with a large metal-on-metal articulation. This occurred at the head-neck junction. Analysis of the fractured stem showed evidence of fatigue failure with possible corrosion. The use of large femoral heads with neck adaptors and narrow tapers should be used with caution, especially in heavy, active patients

La televisión digital terrestre: experiencias nacionales y diversidad en Europa, América y Asia

“Diversidad cultural y audiovisual: buenas prácticas e indicadores” (ref. CSO2011-26241), pertenece al Plan Nacional I+D+i del Ministerio de Economía y Competitividad de España. “Convergencia digital: el futuro de las tecnologías y los contenidos de la información y la comunicación”, está financiado por la Comisión de Apoyo al Personal de Educación Superior (CAPES), de Brasil, y cuenta con la participación de investigadores de las universidades Carlos III de Madrid, do Vale do Rio dos Sinos y Federal de Sergip

A Case of a C-Stem Fracture at the Head-Neck Junction and a Review of the Literature

We report the first case of a fracture of the standard C-stem in combination with a large metal-on-metal articulation. This occurred at the head-neck junction. Analysis of the fractured stem showed evidence of fatigue failure with possible corrosion. The use of large femoral heads with neck adaptors and narrow tapers should be used with caution, especially in heavy, active patients

Evolutionary causes and consequences of consistent individual variation in cooperative behaviour

Behaviour is typically regarded as among the most flexible of animal phenotypic traits. In particular, expression of cooperative behaviour is often assumed to be conditional upon the behaviours of others. This flexibility is a key component of many hypothesized mechanisms favouring the evolution of cooperative behaviour. However, evidence shows that cooperative behaviours are often less flexible than expected and that, in many species, individuals show consistent differences in the amount and type of cooperative and non-cooperative behaviours displayed. This phenomenon is known as ‘animal personality’ or a ‘behavioural syndrome’. Animal personality is evolutionarily relevant, as it typically shows heritable variation and can entail fitness consequences, and hence, is subject to evolutionary change. Here, we review the empirical evidence for individual variation in cooperative behaviour across taxa, we examine the evolutionary processes that have been invoked to explain the existence of individual variation in cooperative behaviour and we discuss the consequences of consistent individual differences on the evolutionary stability of cooperation. We highlight that consistent individual variation in cooperativeness can both stabilize or disrupt cooperation in populations. We conclude that recognizing the existence of consistent individual differences in cooperativeness is essential for an understanding of the evolution and prevalence of cooperation