Abstract: Viable biological material is cryogenically preserved (cryopreservation) by preparing the material for freezing, immersing the material in a tank of cooling fluid, and circulating the cooling fluid past the material at a substantially constant predetermined velocity and temperature to freeze the material. A method according to the present invention freezes the biologic material quickly enough to avoid the formation of ice crystals within cell structures (vitrification). The temperature of the cooling fluid is preferably between −20° C. and −30° C., which is warm enough to minimize the formation of stress fractures in cell membranes due to thermal changes. Cells frozen using a method according to the present invention have been shown to have approximately an 80 percent survival rate, which is significantly higher than other cryopreservation methods.

Abstract: A scheduling system and methodology for use in a network switch element having multiserver, multiple-arbiter architecture. Ingress ports and egress ports coupled to the cross-connect fabric of the network element are provided with multiple ingress and egress arbiters, respectively, for effectuating an iterative arbitration strategy such as RGA or RG. Arbiter architectures include singe-arbiter-per-port; single-arbiter-per-server; multiple-arbiters-per-port; and multiple-arbiters-per-server arrangements, wherein the arbiters can be implemented using RRA, BTA, Flexible Ring, or any other arbiter technology. Depending on the iteration strategy, ingress arbiter architecture and egress arbiter architecture, a variety of iterative, multiserver-capable scheduling algorithms can be obtained, which scheduling algorithms can also be implemented in QoS-aware network nodes.

Abstract: Viable biological material is cryogenically preserved (cryopreservation) by immersing the material in a tank of cooling fluid, and circulating the cooling fluid past the material at a substantially constant predetermined velocity and temperature to freeze the material. The material may either be directly plunged into the cooling fluid without preparation, or chemically prepared prior to freezing. A method according to the present invention freezes the biologic material quickly enough to avoid the formation of ice crystals within cell structures (vitrification) and allows the samples to maintain anatomical structure and remain biochemically active after thaw. The temperature of the cooling fluid is preferably between −20 degrees centigrade and−30 degrees centigrade, which is warm enough to minimize the formation of stress fractures and other artefacts in cell membranes due to thermal changes.