Background: Salmonella enterica serovar Enteritidis (S. Enteritidis) is a human and animal pathogen that causes gastroenteritis characterized by inflammatory diarrhea and occasionally an invasive systemic infection. Salmonella pathogenicity islands (SPIs) are horizontally acquired genomic segments known to contribute to Salmonella pathogenesis. The objective of the current study was to determin...

The extracytoplasmic functioning sigma factor σ(E) is known to play an essential role for Salmonella enterica serovar Typhimurium to survive and proliferate in macrophages and mice. However, its regulatory network is not well-characterized, especially during infection. Here we used microarray to identify genes regulated by σ(E) in Salmonella grown in three conditions: a nutrient-rich condition ...

Although earlier studies revealed much about software process improvement (SPI) in Smallto Medium-sized Enterprises (software SMEs), no earlier research set out to determine the full extent of SPI being implemented in software SMEs. Therefore, this study was designed from the outset to elicit all instances of SPI, which we term SPI events – no matter how small or informal. We make the important...

The release of signaling molecules from neurons must be regulated, to accommodate their highly polarized structure. In the developing Drosophila visual system, photoreceptor neurons secrete the epidermal growth factor receptor ligand Spitz (Spi) from their cell bodies, as well as from their axonal termini. Here we show that subcellular localization of Rhomboid proteases, which process Spi, dete...

The quality of the software development process directly affects the quality of the software product. To be successful, software development organisations must respond to changes in technology and business circumstances, and therefore software process improvement (SPI) is required. SPI activity relates to any modification that is performed to the software process in order to improve an aspect o...

The principle behind software process improvement (SPI) is that product quality is strongly influenced by the quality of the associated software process for development and maintenance. A number of SPI frameworks have evolved from this principle. However, these frameworks are comprehensive and differ in a variety of aspects, making them difficult to compare objectively and to select between for...

Poxviruses encode multiple proteins that enable them to evade host responses. Among these are serine protease inhibitors (serpins). One of the earliest serpins described, cowpox virus crmA, acts to inhibit inflammation and apoptosis. crmA homologous serpins, known as SPI-2, are conserved in rabbitpox, vaccinia and variola viruses. Here, we describe the characterization of ectromelia virus (EV) ...

Expressions for error probabilities have been derived for commonly used signal constellations such as QAM and MPSK. However, closed form expressions cannot be found for more complex signal constellations such as hexagonally packed signals. Saddle point integration (SPI) has been shown to be an efficient method of evaluating the one dimensional cumulative distribution function (CDF) of a random ...

Spi Calculus is an untyped high level modeling language for security protocols, used for formal protocols specification and verification. In this paper, a type system for the Spi Calculus and a translation function are formally defined, in order to formalize the refinement of a Spi Calculus specification into a Java implementation. The Java implementation generated by the translation function u...