Reduced caterpillar damage can benefit plant bugs in Bt cotton

Bt cotton was genetically modified to produce insecticidal proteins targeting Lepidopteran pests and is therefore only minimally affected by caterpillar damage. This could lead to reduced levels of inherent, systemically inducible defensive compounds in Bt cotton which might benefit other important cotton herbivores such as plant bugs. We studied the effects of plant defense induction on the performance of the plant bug Lygus hesperus by caging nymphs on different food sources (bolls/squares) of Bt and non-Bt cotton which were either undamaged, damaged by Bt tolerant caterpillars, or treated with jasmonic acid (JA). Terpenoid induction patterns of JA-treated and L. hesperus-damaged plants were characterized for different plant structures and artificial diet assays using purified terpenoids (gossypol/heliocide H1/4) were conducted. Nymphs were negatively affected if kept on plants damaged by caterpillars or sprayed with JA. Performance of nymphs was increased if they fed on squares and by the Bt-trait which had a positive effect on boll quality as food. In general, JA-sprayed plants (but not L. hesperus infested plants) showed increased levels of terpenoids in the plant structures analyzed, which was especially pronounced in Bt cotton. Nymphs were not negatively affected by terpenoids in artificial diet assays indicating that other inducible cotton responses are responsible for the found negative effects on L. hesperus. Overall, genetically engineered plant defenses can benefit plant bugs by releasing them from plant-mediated indirect competition with lepidopterans which might contribute to increasing numbers of hemipterans in Bt cotton

Domain-Specific Interface Generation from Dataflow Specifications

In this paper, the problem of automatically mapping large-grain dataflow programs onto heterogeneous hardware /software architectures is treated. Starting with a given hardware/software partition, interfaces are automatically inserted into the specification to account for communication, in particular across hardware/software boundaries. Depending on the target architecture, the interfaces are refined according to given communication constraints (bus protocols, memory mapping, interrupts, DMA, etc.). An objectoriented approach is presented that enables an easy migration (retargeting) of typical communication primitives to other target architectures. 1 Introduction This paper deals with the problem of automatic generation of hardware/software interfaces for certain classes of dataflow graph based specifications. The variety of different abstract communication styles (e.g., buffered versus non-buffered, blocking versus nonblocking, synchronous versus asynchronous communication, etc.) en..

Conflicting Criteria in Embedded System Design

The design of complex embedded systems involves the simultaneous optimization of several often competing objectives. Instead of a single optimal design, there is rather a set of alternative trade-offs. The paper describes the involved issues and proposes a methodology to cope with the different sources of heterogeneity in embedded system design. This combination of a design framework, new hybrid evolutionary optimization algorithms and synthesis procedures is explained using examples from architecture, interface and software design

CoFrame: A Modular Co-Design Framework for Heterogeneous Distributed Systems

This paper presents CoFrame, a novel modular co-design framework for heterogeneous distributed systems. The center of the approach is a pool of dynamic data structures which is analyzed, modified and refined by algorithms and tools to map a system specification to a feasible implementation consisting of arbitrary linked processors, DSPs and FPGAs. Due to its modular structure, CoFrame can be easily adapted to various control and data flow oriented problems by exchanging the domainspecific components. As an example we present a CoFrame tool configuration providing i) design space exploration for architecture synthesis using a state-of-the-art evolutionary algorithm for multiobjective optimization and ii) communication synthesis using an object-oriented approach. Finally, a case study of a molecular dynamic solver is described. 1 Introduction As the design and implementation of heterogeneous embedded systems is growing in its complexity, there is a strong need for flexible and modular ..

Rapid Prototyping of Dataflow Programs on Hardware/Software Architectures

In this paper, the problem of automatically mapping large-grain dataflow programs onto heterogeneous hardware/software architectures is treated. Starting with a given hardware/software partition, interfaces are inserted into the specification to account for communication, in particular across hardware/software boundaries. Depending on the target architecture, the interfaces are refined according to given communication constraints (bus protocols, memory mapping, interrupts, DMA, etc.). A framework is described that uses an object-oriented approach to transform a given dataflow graph and to generate code for the actors as well as for the interfaces. The object-orientation enables an easy migration (retargeting) of typical communication primitives to other target architectures