Abstract Previously, linalool was found to be the most abundant component among the cocktail of volatiles released from flowers of Freesia hybrida. Linalool formation is catalysed by monoterpene synthase TPS1. However, the regulatory network developmentally modulating the expression of the TPS1 gene in Freesia hybrida remains unexplored. In this study, three regulatory genes, FhMYB21L1, FhMYB21L2, and FhMYC2, were screened from 52 candidates. Two MYB transcription factor genes were synchronously expressed with FhTPS1 and could activate its expression significantly when overexpressed, and the binding of FhMYB21L2 to the MYBCORE sites in the FhTPS1 promoter was further confirmed, indicating a direct role in activation. FhMYC2 showed an inverse expression pattern compared with FhTPS1; its expression led to a decreased binding of FhMYB21 to the FhTPS1 promoter to reduce its activation capacity when co-expressed, suggesting a role for an MYB–bHLH complex in the regulation of the FhTPS1 gene. In Arabidopsis, both MYB21 and MYC2 regulators were shown to activate the expression of sesquiterpene synthase genes, and the regulatory roles of AtMYB21 and AtMYC2 in the expression of the linalool synthase gene were also confirmed, implying conserved functions of the MYB–bHLH complex in these two evolutionarily divergent plants. Moreover, the expression ratio between MYB21 and MYC2 orthologues might be a determinant factor in floral linalool emission.

This paper develops and evaluates new share-based scheduling algorithms for differentiated service quality in network services, such as network storage servers. This form of resource control makes it possible to share a server among multiple request flows with probabilistic assurance that each flow receives a specified minimum share of a server's capacity to serve requests. This assurance is important for safe outsourcing of services to shared utilities such as Storage Service Providers.Our approach interposes share-based request dispatching on the network path between the server and its clients. Two new scheduling algorithms are designed to run within an intermediary (e.g., a network switch), where they enforce fair sharing by throttling request flows and reordering requests; these algorithms are adaptations of Start-time Fair Queuing (SFQ) for servers with a configurable degree of internal concurrency. A third algorithm, Request Windows (RW), bounds the outstanding requests for each flow independently; it is amenable to a decentralized implementation, but may restrict concurrency under light load. The analysis and experimental results show that these new algorithms can enforce shares effectively when the shares are not saturated, and that they provide acceptable performance isolation under saturation. Although the evaluation uses a storage service as an example, interposed request scheduling is non-intrusive and views the server as a black box, so it is useful for complex services with no internal support for differentiated service quality.

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This paper develops and evaluates new share-based scheduling algorithms for differentiated service quality in network services, such as network storage servers. This form of resource control makes it possible to share a server among multiple request flows with probabilistic assurance that each flow receives a specified minimum share of a server's capacity to serve requests. This assurance is important for safe outsourcing of services to shared utilities such as Storage Service Providers.Our approach interposes share-based request dispatching on the network path between the server and its clients. Two new scheduling algorithms are designed to run within an intermediary (e.g., a network switch), where they enforce fair sharing by throttling request flows and reordering requests; these algorithms are adaptations of Start-time Fair Queuing (SFQ) for servers with a configurable degree of internal concurrency. A third algorithm, Request Windows (RW), bounds the outstanding requests for each flow independently; it is amenable to a decentralized implementation, but may restrict concurrency under light load. The analysis and experimental results show that these new algorithms can enforce shares effectively when the shares are not saturated, and that they provide acceptable performance isolation under saturation. Although the evaluation uses a storage service as an example, interposed request scheduling is non-intrusive and views the server as a black box, so it is useful for complex services with no internal support for differentiated service quality.