G21 Z̃22 Z̃23 Z̃24 W̃21 G31 Z̃32 Z̃33 Z̃34 W̃31 G41 G42 Z̃43 Z̃44 W̃41 G51 G52 Z̃53 Z̃54 W̃51 Z11 Z12 Z13 Z14 W11 G21 Z̃22 Z̃23 Z̃24 W̃21 G31 Z̃32 Z̃33 Z̃34 W̃31 G41 G42 Z̃43 Z̃44 W̃41 G51 G52 Z̃53 Z̃54 W̃51 Two-Stage Least Squares algorithms with QR decomposition for Simultaneous Equations Models on heterogeneous multicore and multi-GPU systems Carla Ramiroa, José J. López-Espínb, Domingo Giménezc and Antonio M. Vidala

Article history: Received 24 February 2010 Available online 5 March 2012 JEL classification: C73 D82 L14 J30

Article history: Laffont and Tirole's [Laffon Received 31 July 2007 Received in revised form 28 December 2007 Accepted 8 April 2008 Available online 20 April 2008 JEL classification: D82 L14

This paper models employment relationship as a repeated principal-agent problem with private evaluation. The efficient contracts exhibit correlated movements between lagged wage and current effort that are consistent with the positive feedback between pay and morale in practice. Low morale therefore is an integral part of a well-functioning relationship. (JEL: C73, D82, J41, L14 )

La ‘pudrición escamosa’ es una de las enfermedades mayor importancia en el nopal, por tal motivo objetivo del presente trabajo fue aislar e identificar hongos asociados a la y evaluar capacidad bacterias género Bacillus sp. aisladas para evitar enfermedad nopal (Opuntia ficus-indica (L) Mill.). Diez fueron analizadas pruebas in vitro antagonismo frente al patógeno Neoscytalidium hyalinum que se...

We model the production of complex goods in a large supply network. Each firm sources several essential inputs through relationships with other firms. Individual are at risk idiosyncratic failure, which threatens to disrupt production. To protect against this, firms multisource and strategically invest make stronger, trading off cost investment benefits increased robustness. A network is called...