Ciudades y poder político en al-Andalus. Una hipótesis sobre el origen de las revueltas urbanas en Murcia en el siglo XIII
Throughout the 13th century a succession of urban revolts took place in al-Andalus, which caused the withdrawal of the Almohad Empire and the establishment of the third taifas, initially led by Muhammad b. Yūsuf b. Hūd al-Mutawakkil. The inability of this emir to hold together this newly-built state, and the continuous insurrections inside and utside of Murcia have led historians to investigate the nature of political power during this period. This article examines each one of these proposals and, on the basis of an analysis of some socio-economic aspects relating to Murcia (being a representative city of al-Andalus and capital of the hūdi movement during the first half of the thirteenth century), proposes a hypothesis on the nature of its power.
Guerra y avituallamiento del ejército y carestías en la Corona de Aragón: la provisión de cereal para la expedición granadina de Alfonso el Benigno (1329-1333).
A pesar de tratarse de una expedicion frustrada o, por lo menos, no materializada en la forma inicialmente prevista por el rey, la guerra contra el sultanato granadino recorre como un autentico leit-motiv casi todo el breve reinado de Alfonso el Benigno (1327-1336) Gracias a la considerable masa documental conservada sobre esta campana, es posible obtener algunos datos de interes acerca de como se preveia avituallar de cereal al importante ejercito que el monarca sonaba con desplazar hasta la ciudad de Almeria. Por otra parte, el hecho de que la expedicion coincida cronologicamente con el desarrollo de la grave crisis de subsistencias de los primeros anos 30 en los territorios de la Corona de Aragon aconseja examinar, aunque sea de forma superficial, las repercusiones mutuas de ambos acontecimientos. Antes de entrar en materia, quizas sea conveniente precisar un par de cuestiones. En primer lugar, parece innecesario advertir que, tratandose de una campana que apenas paso el umbral de los preparativos, no sera posible abundar en los problemas puntuales que hubiese podido plantear el avituallamiento del ejercito en campana. Quiero decir con ello que los aspectos mas directamente relacionados con el regimen alimenticio de los combatientes no pueden ser abordados aqui. De hecho, voy a utilizar documentos tan relativamente alejados de la realidad concreta como el pliego de previsiones generales para la expedicion redactado en 1329 o los albaranes extendidos por el Maestro Racional a los agentes encargados de las compras de cereal para el ejercito. En segundo lugar, las cantidades de grano que los comisarios reales decian haber adquirido y los precios que confesaban haber pagado por ellas a los mercaderes aragoneses, tal y como se reflejan con sequedad en los mencionados albaranes, dejan naturalmente en la penumbra la intrincada red de intereses particulares que debio tejerse bajo
Fatigue effects on the coordinative pattern during cycling: kinetics and kinematics evaluation.
The aim of the present study was to analyze the net joint moment distribution, joint forces and kinematics during cycling to exhaustion. Right pedal forces and lower limb kinematics of ten cyclists were measured throughout a fatigue cycling test at 100% of PO(MAX). The absolute net joint moments, resultant force and kinematics were calculated for the hip, knee and ankle joint through inverse dynamics. The contribution of each joint to the total net joint moments was computed. Decreased pedaling cadence was observed followed by a decreased ankle moment contribution to the total joint moments in the end of the test. The total absolute joint moment, and the hip and knee moments has also increased with fatigue. Resultant force was increased, while kinematics has changed in the end of the test for hip, knee and ankle joints. Reduced ankle contribution to the total absolute joint moment combined with higher ankle force and changes in kinematics has indicated a different mechanical function for this joint. Kinetics and kinematics changes observed at hip and knee joint was expected due to their function as power sources. Kinematics changes would be explained as an attempt to overcome decreased contractile properties of muscles during fatigue.