Computer "Insecurity" and Viral Attacks : Liability Issues Regarding Unsafe Computer Systems Under Quebec Law

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Études des mécanismes d’induction de l’immunosuppression par le virus Herpès Humain 6

HHV-6 is a ubiquitous human herpesvirus. Most individuals become infected at the age of 2 years. Primary infection by the virus causes a self-limiting febrile illness called exanthem subitum or roseola. In adults, primary infection may cause mononucleosis-like illnesses. The infection usually remains latent in healthy individuals, but often reactivates in immunocompromised individuals, for example, transplant patients and AIDS patients. The virus has also been associated with cancers and lymphoproliferative disorders. The virus encodes two proteins that interact with p53. However, little is known concerning the impact of the virus on cell cycle progression in human cells. The investigations reported in the thesis were focused on this issue. We show here that that HHV-6 infection delays the cell cycle progression in human T cell line HSB-2, as well as in primary human T cells and causes their accumulation in S and G2/M phase. By degrading the viral DNA in the virus-infected cells, we show that the infected cells accumulate in the G2/M and not in the S phase. We observed an increase in the kinase activity of cdc2 in virus-infected cells despite lower levels of its catalytic partners, cyclin A and cyclin B. We show here that the viral early antigen p41 associates with, and increases the kinase activity of, CDK1. Our studies have shown that there is a drastic reduction of p21 protein, despite the virus-induced stabilization and activation of p53 suggesting that p53 may be transcriptionally inactivated in the virus-infected cells. This decrease of p21 in infected cells was partially restored by proteasome inhibitors. These results suggest that HHV-6 causes perturbations in the normal progression of cell cycle in human T cells. Autophagy is a physiological cell process during which old cellular constituents and long-lived proteins in cells are degraded. This process is regulated in a cell cycle-dependent manner. We show here that infection with HHV-6 induces autophagy in HSB-2 cells. This was shown by the induction of LC-3 II as well as by the appearance of autophagic vacuoles in the virus-infected cells. However, we found that the virus inhibits fusion between autophagic vacuoles and lysosomes formed in infected cells, thus evading the autophagic response of infected host cells. Finally we tried to investigate replication of the virus in human cells in the absence of P53; a tumor suppressor gene which is also known as "the guardian of the genome ". During these investigations, we found that that inhibition of p53 gene expression mediated by siRNA as well as its inhibition by pharmacological inhibitors leads to massive cell death in human T cell line HSB-2 that carries a wild-type p53. We show that this death also occurs in another cell line CEM, which carries a transcriptionally mutated p53. Interestingly, the cell death could be prevented by pharmacological inhibitors of autophagy and necroptosis. Taken together, our results provide important novel insights concerning the impact of HHV-6 on cell cycle regulation and autophagy as well as of basal level p53 in cell survival.

"Computer ""Insecurity"" and Viral Attacks:Liability Issues Regarding Unsafe Computer Systems Under Quebec Law"

Dans un contexte où les virus informatiques présentent un risque sérieux pour les réseaux à travers le globe, il est impératif de retenir la responsabilité des compagnies qui n’y maintiennent pas une sécurité adéquate. À ce jour, les tribunaux québécois n’ont pas encore été saisis d’affaires en responsabilité pour des virus informatiques. Cet article brosse un portrait général de la responsabilité entourant les virus informatiques en fonction des principes généraux de responsabilité civile en vigueur au Québec. L’auteur propose des solutions pour interpréter les trois critères traditionnels ­ la faute, le dommage et le lien causal ­ en mettant l’accent sur l’obligation de précaution qui repose sur les épaules de l’administrateur de réseau. Ce joueur clé pourrait bénéficier de l’adoption de dispositions générales afin de limiter sa responsabilité. De plus, les manufacturiers et les distributeurs peuvent également partager une partie de la responsabilité en proportion de la gravité de leur faute. Les entreprises ont un devoir légal de s’assurer que leurs systèmes sont sécuritaires afin de protéger les intérêts de leurs clients et des tiers.

La responsabilité civile des prestateurs de moteurs de recherches et des fournisseurs d’hyperliens en droit québécois

L’auteur se penche sur la question de la responsabilité civile des prestateurs de moteurs de recherches et des fournisseurs d’hyperliens eu égard aux contenus illicites situés sur les sites qu’ils répertorient. Pour ce faire, il analyse la disposition législative régissant la responsabilité de ces intermédiaires, à savoir l’article 22 de la Loi concernant le cadre juridique des technologies de l’information, et se questionne sur l’efficacité véritable de cette disposition eu égard à l’intention présumée du législateur et à la position adoptée à l’étranger. L’auteur constate effectivement que la rédaction de cet article de loi laisse place à plusieurs problématiques qui risquent d’avoir des répercussions indésirables pour ces intermédiaires. Dans la seconde partie de son exposé, l’auteur aborde certaines situations pratiques pouvant entraîner la responsabilité de ces intermédiaires, notamment les questions liées aux virus informatiques, à la diffamation et à la propriété intellectuelle.

Content-Based Image Retrieval of Axial Brain Slices Using a Novel LBP with a Ternary Encoding

Retrieval of similar anatomical structures of brain MR images across patients would help the expert in diagnosis of diseases. In this paper, modified local binary pattern with ternary encoding called modified local ternary pattern (MOD-LTP) is introduced, which is more discriminant and less sensitive to noise in near-uniform regions, to locate slices belonging to the same level from the brain MR image database. The ternary encoding depends on a threshold, which is a user-specified one or calculated locally, based on the variance of the pixel intensities in each window. The variancebased local threshold makes the MOD-LTP more robust to noise and global illumination changes. The retrieval performance is shown to improve by taking region-based moment features of MODLTP and iteratively reweighting the moment features of MOD-LTP based on the user’s feedback. The average rank obtained using iterated and weighted moment features of MOD-LTP with a local variance-based threshold, is one to two times better than rotational invariant LBP (Unay, D., Ekin, A. and Jasinschi, R.S. (2010) Local structure-based region-of-interest retrieval in brain MR images. IEEE Trans. Inf. Technol. Biomed., 14, 897–903.) in retrieving the first 10 relevant images

Example Based Image Analysis and Synthesis

Image analysis and graphics synthesis can be achieved with learning techniques using directly image examples without physically-based, 3D models. In our technique: -- the mapping from novel images to a vector of "pose" and "expression" parameters can be learned from a small set of example images using a function approximation technique that we call an analysis network; -- the inverse mapping from input "pose" and "expression" parameters to output images can be synthesized from a small set of example images and used to produce new images using a similar synthesis network. The techniques described here have several applications in computer graphics, special effects, interactive multimedia and very low bandwidth teleconferencing.

Interaction and Intelligent Behavior

We introduce basic behaviors as primitives for control and learning in situated, embodied agents interacting in complex domains. We propose methods for selecting, formally specifying, algorithmically implementing, empirically evaluating, and combining behaviors from a basic set. We also introduce a general methodology for automatically constructing higher--level behaviors by learning to select from this set. Based on a formulation of reinforcement learning using conditions, behaviors, and shaped reinforcement, out approach makes behavior selection learnable in noisy, uncertain environments with stochastic dynamics. All described ideas are validated with groups of up to 20 mobile robots performing safe--wandering, following, aggregation, dispersion, homing, flocking, foraging, and learning to forage.

Hybrid coordination of reinforcement learning-based behaviors for AUV control

This paper proposes a hybrid coordination method for behavior-based control architectures. The hybrid method takes advantages of the robustness and modularity in competitive approaches as well as optimized trajectories in cooperative ones. This paper shows the feasibility of applying this hybrid method with a 3D-navigation to an autonomous underwater vehicle (AUV). The behaviors are learnt online by means of reinforcement learning. A continuous Q-learning implemented with a feed-forward neural network is employed. Realistic simulations were carried out. The results obtained show the good performance of the hybrid method on behavior coordination as well as the convergence of the behaviors

Model-based objects recognition in industrial environments for autonomous vehicles control

Behavior-based navigation of autonomous vehicles requires the recognition of the navigable areas and the potential obstacles. In this paper we describe a model-based objects recognition system which is part of an image interpretation system intended to assist the navigation of autonomous vehicles that operate in industrial environments. The recognition system integrates color, shape and texture information together with the location of the vanishing point. The recognition process starts from some prior scene knowledge, that is, a generic model of the expected scene and the potential objects. The recognition system constitutes an approach where different low-level vision techniques extract a multitude of image descriptors which are then analyzed using a rule-based reasoning system to interpret the image content. This system has been implemented using a rule-based cooperative expert system

Model-based objects recognition in man-made environments

We describe a model-based objects recognition system which is part of an image interpretation system intended to assist autonomous vehicles navigation. The system is intended to operate in man-made environments. Behavior-based navigation of autonomous vehicles involves the recognition of navigable areas and the potential obstacles. The recognition system integrates color, shape and texture information together with the location of the vanishing point. The recognition process starts from some prior scene knowledge, that is, a generic model of the expected scene and the potential objects. The recognition system constitutes an approach where different low-level vision techniques extract a multitude of image descriptors which are then analyzed using a rule-based reasoning system to interpret the image content. This system has been implemented using CEES, the C++ embedded expert system shell developed in the Systems Engineering and Automatic Control Laboratory (University of Girona) as a specific rule-based problem solving tool. It has been especially conceived for supporting cooperative expert systems, and uses the object oriented programming paradigm

Behaviours implemented using a vision system based on coded light projection

In a search for new sensor systems and new methods for underwater vehicle positioning based on visual observation, this paper presents a computer vision system based on coded light projection. 3D information is taken from an underwater scene. This information is used to test obstacle avoidance behaviour. In addition, the main ideas for achieving stabilisation of the vehicle in front of an object are presented

Incidencia de las agresiones a la seguridad cibernética en el desarrollo informático de las Fuerzas Armadas de Estados Unidos (2003-2013)

La presente investigación tiene como objetivo analizar la incidencia de las agresiones cibernéticas en el desarrollo informático de las Fuerzas Armadas de Estados Unidos. Los diferentes estudios que se han realizado sobre el ciberespacio se han enfocado en el papel del individuo como actor principal y se ha dejado de lado las repercusiones que éste ha tenido para el Estado, como un nuevo eje de amenazas. Teniendo en cuenta lo anterior, esta investigación demostrará a partir del concepto de securitización, que se busca priorizar la “ciberseguridad” dentro de la agenda del gobierno estadounidense. Al ser este un estudio que aborda experiencias concretas durante un periodo de tiempo de más de 10 años, el diseño metodológico de la investigación será longitudinal, ya que abarcará estudios, artículos, textos y resoluciones que se han realizado desde 2003 hasta la actualidad.

Normative modeling for personalized clinical pathway using organizational semiotics methods

Clinical pathways are widely adopted by many large hospitals around the world in order to provide high-quality patient treatment and reduce the length and cost of hospital stay. However, nowadays most of them are static and nonpersonalized. Our objective is to capture and represent clinical pathway using organizational semiotics method including Semantic Analysis which determines semantic units in clinical pathway, their relationship and their patterns of behavior, and Norm Analysis which extracts and specifies the norms that establish how and when these medical behaviors will occur. Finally, we propose a method to develop clinical pathway ontology based on the results of Semantic Analysis and Norm analysis. This approach will give a contribution to design personalized clinical pathway by defining a set of possible patterns of behavior and theClinical pathways are widely adopted by many large hospitals around the world in order to provide high-quality patient treatment and reduce the length and cost of hospital stay. However, nowadays most of them are static and nonpersonalized. Our objective is to capture and represent clinical pathway using organizational semiotics method including Semantic Analysis which determines semantic units in clinical pathway, their relationship and their patterns of behavior, and Norm Analysis which extracts and specifies the norms that establish how and when these medical behaviors will occur. Finally, we propose a method to develop clinical pathway ontology based on the results of Semantic Analysis and Norm analysis. This approach will give a contribution to design personalized clinical pathway by defining a set of possible patterns of behavior and the norms that govern the behavior based on patient’s condition.

Hybrid proton and electron transport in peptide fibrils

Protons and electrons are being exploited in different natural charge transfer processes. Both types of charge carriers could be, therefore, responsible for charge transport in biomimetic self-assembled peptide nanostructures. The relative contribution of each type of charge carrier is studied in the present work for fi brils self-assembled from amyloid- β derived peptide molecules, in which two non-natural thiophene-based amino acids are included. It is shown that under low humidity conditions both electrons and protons contribute to the conduction, with current ratio of 1:2 respectively, while at higher relative humidity proton transport dominates the conductance. This hybrid conduction behavior leads to a bimodal exponential dependence of the conductance on the relative humidity. Furthermore, in both cases the conductance is shown to be affected by the peptide folding state under the entire relative humidity range. This unique hybrid conductivity behavior makes self-assembled peptide nanostructures powerful building blocks for the construction of electric devices that could use either or both types of charge carriers for their function.

Effect of acceptable use policy on employee computer use : case of Sri Lankan software development organizations

It is a known fact that some employees misuse the organizational computers to do their personal work such as sending emails, surfing the Internet, chatting, playing games. These activities not only waste productive time of employees but also bring a risk factor to the organization. This affects organizations in the software industry very much as almost all of their employees are connected to the Internet throughout them day./ By introducing an Acceptable Use Policy (AUP) for an organization, it is believed that the computer misuse by its employees could be reduced. In many countries Acceptable Use Policies are used and they have been studied with various perspectives. In Sri Lankan context research on these areas are scarce. This research explored the situation in Sri Lanka with respect to AUPs and their effectiveness./ A descriptive study was carried out to identify the large and medium scale software development organizations that had implemented computer usage guidelines for employees. A questionnaire was used to gather information regarding employee’s usual computer usage behavior. Stratified random sampling was employed to draw a representative sample from the population./ Majority of the organizations have not employed a written guideline on acceptable use of work computers. The study results did not provide evidence to conclude that the presence or non presence of an AUP has a significant difference in computer use behaviors of employees. A significant negative correlation was observed between level of awareness about AUP and misuse. Access to the Internet and organizational settings were identified as significant factors that influence employee computer misuse behavior.