A novel neural network based system for assessing risks associated with information technology security breaches

Security remains a top priority for organizations as their information systems continue to be plagued by security breaches. This dissertation developed a unique approach to assess the security risks associated with information systems based on dynamic neural network architecture. The risks that are considered encompass the production computing environment and the client machine environment. The risks are established as metrics that define how susceptible each of the computing environments is to security breaches. ^ The merit of the approach developed in this dissertation is based on the design and implementation of Artificial Neural Networks to assess the risks in the computing and client machine environments. The datasets that were utilized in the implementation and validation of the model were obtained from business organizations using a web survey tool hosted by Microsoft. This site was designed as a host site for anonymous surveys that were devised specifically as part of this dissertation. Microsoft customers can login to the website and submit their responses to the questionnaire. ^ This work asserted that security in information systems is not dependent exclusively on technology but rather on the triumvirate people, process and technology. The questionnaire and consequently the developed neural network architecture accounted for all three key factors that impact information systems security. ^ As part of the study, a methodology on how to develop, train and validate such a predictive model was devised and successfully deployed. This methodology prescribed how to determine the optimal topology, activation function, and associated parameters for this security based scenario. The assessment of the effects of security breaches to the information systems has traditionally been post-mortem whereas this dissertation provided a predictive solution where organizations can determine how susceptible their environments are to security breaches in a proactive way. ^

Studying Key Amino Acids in the Function of Ras Interference 1 (Rinl) SH2 and Vps9 Domains

Receptor mediated endocytosis effectively removes the "ears" with which a cell would "hear" a signal conveyed by extracellular signaling molecules, but does not necessarily block the signaling pathway in which the endocytosed receptor participates. In the process of signal attenuation, this newly formed vesicle is fused with a phagosome and the receptor molecules are degraded. Receptor mediated endocytosis as a way to attenuate epidermal growth factor (EGF) and insulin signaling will be the focus here. Ras Interference 1 (Rin 1) is a multifunctional protein involved in intracellular membrane trafficking and receptor mediated endocytosis through its Rab5 Guanine Exchange Factor and SH2 domains. The goal of this investigation is to determine the role of key amino acids involved in the interaction of Rinl with Epidermal Growth Factor Receptor and Rab5. To elucidate this role, a number of point mutations have been created and the effects of each mutation on Rin 1 function will be investigated. Key amino acids in the SH2 and Vps9 Domain were identified and effects of mutations on rate of endocytosis were observed.

Novel insights into the mechanisms of regulation of tyrosine kinase receptors by Ras Interference 1

Receptor-tyrosine kinases (RTKs) are membrane bound receptors characterized by their intrinsic kinase activity. RTK activities play an essential role in several human diseases, including cancer, diabetes and neurodegenerative diseases. RTK activities have been regulated by the expression or silencing of several genes as well as by the utilization of small molecules. Ras Interference 1 (Rin1) is a multifunctional protein that becomes associated with activated RTKs upon ligand stimulation. Rin1 plays a key role in receptor internalization and in signal transduction via activation of Rab5 and association with active form of Ras. This study has two main objectives: (1) It determines the role of Rin1 in the regulation of several RTKs focusing on insulin receptor. This was accomplished by studying the Rin1-insulin receptor interaction using a variety of biochemical and morphological assays. This study shows a novel interaction between the insulin receptor and Rin1 through the Vps9 domain. Two more RTKs (epidermal growth factor receptor and nerve growth factor receptor) also interacted with the SH2 domain of Rin1. The effect of the Rin1-RTK interaction on the activation of both Rab5 and Ras was also studied during receptor internalization and intracellular signaling. Finally, the role of Rin1 was examined in two differentiation processes (adipogenesis and neurogenesis). Rin1 showed a strong inhibitory effect on 3T3-L1 preadipocyte differentiation but it seems to show a modest effect in PC12 neurite outgrowth. These data indicate a selective function and specific interaction of Rin1 toward RTKs. (2) It examines the role of the small molecule Dehydroleucodine (DhL) on several key signaling molecules during adipogenesis. This was accomplished by studying the differentiation of 3T3-L1 preadipocytes exposed to different concentrations of DhL in different days of the adipocyte formation process. The results indicate that DhL selectively blocked adipocyte formation, as well as the expression of PPARγ, and C/EBP&agr;. However, DhL treatment did not affect Rin1 or Rab5 expression and their activities. Taken together, the data indicate a potential molecular mechanism by which proteins or small molecules regulate selective and specific RTK intracellular membrane trafficking and signaling during cell growth and differentiation in normal and pathological conditions.