Design and analysis of a variable bit rate caching algorithm for continuous media data

10.1007/s11042-007-0151-6Multimedia Tools and Applications38191-117MTAP

Secure Mediation: Requirements and Design

In this paper we discuss the security requirements for mediation, and present our approach towards satisfying them, with an emphasis on confidentiality and authenticity. Furthermore we outline the design of the basic security mechanisms for mediators. Our basic approach suitably combines the concepts of credentials, for authentic authorization with some kind of anonymity, and of asymmetric encryption, for confidentiality, and it can be extended to include additional mechanisms like digital signatures and fingerprints. Additionally it adopts the model of role based security policies because of its application orientation and of its potentials to integrate and unify various policies

Effect of Temperature, Modified Atmosphere and Ethylene During Olive Storage on Quality and Bitterness Level of the Oil

6 pages, 4 tables.-- Printed version published Mar 2009.Mill olives (Olea europaea L. cv. ‘Lechín’), harvested at the green mature stage of ripening, were stored for 72 h under six different storage conditions: in air, in a closed container, and in a closed container with 30 ppm ethylene either at 20 or at 40 °C. The use of 40 °C as the fruit storage temperature reduced oil bitterness, regardless of the atmosphere applied; however, it also induced a significant reduction in stability and pigment content of the oil extracted. At 20 °C, mill olives stored under air supplemented with 30 ppm ethylene engendered oils with middle bitterness intensity, whereas the oils obtained from fruit stored similarly, but without ethylene, or in an open container exhibited a strong intensity of this sensory attribute. Fruit respiration in the closed containers caused a CO2 accumulation and an O2 decrease in the storage atmosphere. This CO2 concentration was increased by the previous ethylene addition, but O2 presence did not suffer an additional reduction. The use of modified atmospheres in fruit storage induced off-flavor development in the oils extracted, producing a significant reduction in the overall grading of their sensory quality.The authors are grateful to the Project Citrisaude SP5.P120/03 of the Program Interreg IIIA of the European Community for their financial support. The authors also gratefully acknowledge M.C. Martínez for technical assistance and Sociedad Agraria de Transformacion N-1941 Santa Teresa de Osuna for supplying the olive fruit.Peer reviewe