Chromosomal DNA is exposed to continuous damage and repair. Cells contain a number of proteins and specific DNA repair systems that help maintain its correct structure. The SOS response was the first DNA repair system described in Escherichia coli induced upon treatment of bacteria with DNA damaging agents arrest DNA replication and cell division. Induction of the SOS response involves more tha...

Regulated activation of Ras by receptor tyrosine kinases (RTK) constitutes a key transduction step in signaling processes that control an array of fundamental cellular functions including proliferation, differentiation, and survival. The principle mechanism by which Ras is activated down stream of RTKs involves the stimulation of guanine nucleotide exchange by the ubiquitous guanine nucleotide ...

in today’s advanced world resulting from the improvement of technology, societies tend to encounter a large number of problems and accidents. as we know, university’s security personnel are classified as shift workers and are exposed to health disturbing factors. the aim of this study was investigation of shift work disorders among security personnel of the hospitals affiliated to shiraz univer...

Bacterial infections can be aggravated by antibiotic treatment that induces SOS response and vesiculation. This leads to a hypothesis concerning association of SOS with vesiculation. To test it, we conducted multiple analyses of outer membrane vesicles (OMVs) produced from the Pseudomonas aeruginosa wild type in which SOS is induced by ciprofloxacin and from the LexA noncleavable (lexAN) strain...

Understanding System of Systems (SoS) requires novel ways to apply systems engineering processes. Acknowledged SoS have recognized objectives, a designated manager and resources for the SoS. The goal of this research is to develop a proof of concept tool suite for Acknowledged SoS systems simulation. This suite is named flexible, intelligent and learning architectures for System of Systems (FIL...

System-of-systems (SoS) architectures based on common software platforms have been commercially successful. Common platforms are a goal of several DoD initiatives (US Army Common Operating Environment, US Navy Open Architecture, multi-service Future Avionics Capability Environment), but progress on creating and adopting such platforms has been slow. We conducted a study to understand the techni...

In contrast to a transition system specification in process algebra, a structural operational semantics (SOS) of a programming language usually involves auxiliary entities: stores, environments, etc. When specifying SOS rules, particular auxiliary entities often need to be propagated unchanged between premises and conclusions. The standard technique is to make such propagation explicit, using v...

Sucrose octasulfate (SOS) is believed to stimulate fibroblast growth factor (FGF) signaling by binding and stabilizing FGFs. In this report, we show that SOS induces FGF-dependent dimerization of FGF receptors (FGFRs). The crystal structure of the dimeric FGF2-FGFR1-SOS complex at 2.6-A resolution reveals a symmetric assemblage of two 1:1:1 FGF2-FGFR1-SOS ternary complexes. Within each ternary ...

One of the key issues facing architects of systems of systems (SOS) is the emergent nature of the context of the SOS. In the spirit of Herbert Simon, context here means all the stakeholders, objects, processes and other external effects that create the environment for goal attainment of a system. As SOS are systems, they too have contexts. Understanding the relationship between the contexts of ...