Abstract: A system for exposing a cell culture to a fluid shear force imparted by a fluid flow is provided. Specifically, various embodiments of the present invention provide flow chambers defining channels for retaining a cell culture in the fluid flow wherein the flow chambers may be removably disposed within a bioreactor system such that the flow chambers may be removed and/or replaced without disturbing the cell cultures retained therein or disposed elsewhere within the bioreactor system. The flow chambers are composed of a transparent material such that a user of the system may observe the development of the cell culture retained within the chamber as the cell culture is imposed to a fluid shear stress imparted by the fluid flow.

Abstract: A transaction system (10) in which a customer computer (12) can use a broker or host computer (14) in a communications network to obtain quotations for goods and services from merchant computers (12). The broker computer (14) carries out most of the transaction tasks on behalf of the customer. These can be conventional shopping for goods, factory procurement, wagering or even the reporting and retrieval of goods lost and/or found.