Narrow Results

Empirical studies show that coverage-based fault localizations are very effective in testing and debugging software applications. It is also a commonly held belief that no software testing techniques would perform best for all programs with various data structures and complexity. An important research question posed in this paper is whether the type and complexity of faults in a given program has any influence on the performance of these fault localization techniques.

This paper investigates the performance of coverage-based fault localizations for different types of faults. We explore and compare the accuracy of these techniques for two large groups of faults often observed in object-oriented programs. First, we explore different types of traditional method-level faults grouped into six categories including those related to arithmetic, relational, conditional, logical, assignment, and shift. We then focus on class-level faults related to object-oriented features and group them into four categories including inheritance, overriding, Java-specific features, and common programming mistakes. The results show that coverage-based fault localizations are less effective for class-level faults associated with object-oriented features of programs. We therefore advocate the needs for designing more effective fault localizations for debugging object-oriented and class-level defects.

Identifying functions for the predicted 25 000 to 40 000 plant genes is the new focus of genomic research following the sequencing of genomes from model plants like Arabidopsis and rice. It is important that researchers and plant breeders especially from Asian countries access the techniques and resources of plant functional genomics, not only to remain competitive globally in rice research and development activities, but also to increase yields by alleviating some of the rice production constraints. These newly identified genes and gene control sequences can be used in transformation breeding and as molecular markers in classical plant breeding.

At CSIRO Plant Industry we are using an insertional mutagenesis approach in rice to relate genes to their functions. With national and international collaboration we hope to create a substantial "Rice Gene Machine" comprised of many thousands of rice insertion lines with their associated phenotypes and the gene sequences flanking insertion sites identified. This Rice Gene Machine will allow the identification of gene functions, which will benefit rice research and the rice industry for years to come.

Human butyrylcholinesterase (BChE) is a bioscavenger that protects the enzyme which is critical for the central nerve system, acetylcholinesterase, from poisoning by organophosphorus agents. Elucidating the details of the hydrolysis reaction mechanism is important to understand how the phosphorylated BChE can be reactivated. Application of the QM(DFTB)/MM(AMBER) method to construct the minimum energy pathways for the hydrolysis reaction of the diethylphosphorylated BChE allowed us to suggest a mechanism of reactivation of the wild-type and the G117H mutated enzyme. Unlike previous approaches assuming that either His438 or His117 serves as a general base in the catalysis, in our proposal the Glu197 residue is responsible for activation of the nucleophilic water molecule (Wat) leading to the chemical transformations that restore the catalytic Ser198 residue in BChE. In agreement with the experimental data, it is shown that the G117H mutation facilitates the reactivation of the inhibited enzyme.