Towards Nootropia : a non-linear approach to adaptive document filtering

In recent years, it has become increasingly difficult for users to find relevant information within the accessible glut. Research in Information Filtering (IF) tackles this problem through a tailored representation of the user interests, a user profile. Traditionally, IF inherits techniques from the related and more well established domains of Information Retrieval and Text Categorisation. These include, linear profile representations that exclude term dependencies and may only effectively represent a single topic of interest, and linear learning algorithms that achieve a steady profile adaptation pace. We argue that these practices are not attuned to the dynamic nature of user interests. A user may be interested in more than one topic in parallel, and both frequent variations and occasional radical changes of interests are inevitable over time. With our experimental system "Nootropia", we achieve adaptive document filtering with a single, multi-topic user profile. A hierarchical term network that takes into account topical and lexical correlations between terms and identifies topic-subtopic relations between them, is used to represent a user's multiple topics of interest and distinguish between them. A series of non-linear document evaluation functions is then established on the hierarchical network. Experiments using a variation of TREC's routing subtask to test the ability of a single profile to represent two and three topics of interest, reveal the approach's superiority over a linear profile representation. Adaptation of this single, multi-topic profile to a variety of changes in the user interests, is achieved through a process of self-organisation that constantly readjusts the profile stucturally, in response to user feedback. We used virtual users and another variation of TREC's routing subtask to test the profile on two learning and two forgetting tasks. The results clearly indicate the profile's ability to adapt to both frequent variations and radical changes in user interests

Loss of microbial diversity and pathogen domination of the gut microbiota in critically ill patients

Among long-stay critically ill patients in the adult intensive care unit (ICU), there are often marked changes in the complexity of the gut microbiota. However, it remains unclear whether such patients might benefit from enhanced surveillance or from interventions targeting the gut microbiota or the pathogens therein. We therefore undertook a prospective observational study of 24 ICU patients, in which serial faecal samples were subjected to shotgun metagenomic sequencing, phylogenetic profiling and microbial genome analyses. Two-thirds of the patients experienced a marked drop in gut microbial diversity (to an inverse Simpson's index of <4) at some stage during their stay in the ICU, often accompanied by the absence or loss of potentially beneficial bacteria. Intravenous administration of the broad-spectrum antimicrobial agent meropenem was significantly associated with loss of gut microbial diversity, but the administration of other antibiotics, including piperacillin/tazobactam, failed to trigger statistically detectable changes in microbial diversity. In three-quarters of ICU patients, we documented episodes of gut domination by pathogenic strains, with evidence of cryptic nosocomial transmission of Enterococcus faecium. In some patients, we also saw an increase in the relative abundance of apparent commensal organisms in the gut microbiome, including the archaeal species Methanobrevibacter smithii. In conclusion, we have documented a dramatic absence of microbial diversity and pathogen domination of the gut microbiota in a high proportion of critically ill patients using shotgun metagenomics

National Security Surveillance in an Age of Terror: Statutory Powers & Charter Limits

The communications surveillance powers granted to Canada\u27s national security agencies have rarely resulted in prosecution and, as a result, have been subject to very little judicial, academic, or public scrutiny. However, as the state increasingly seeks to prosecute alleged terrorists, courts will have to interpret the scope of these powers and decide whether they violate section 8 of the Canadian Charter of Rights and Freedoms (the Charter). A review of the powers granted to police, the Canadian Security Intelligence Service (CSIS), and the Communications Security Establishment Canada (CSEC) reveals two constitutional infirmities: allowing police to conduct communications surveillance in terrorism investigations without establishing investigative necessity, and allowing CSEC to intercept domestic communications without prior judicial authorization. Put simply, these powers should be found to violate section 8 of the Charter because they substantially infringe on the privacy of innocent Canadians, especially of Muslim or Arab background, while doing little to advance national security

THE EAR OF DIONYSUS: RETHINKING FOREIGN INTELLIGENCE SURVEILLANCE

As the 110th Congress begins to flex its atrophied oversight muscle, it bears remembering that, in the ongoing debate over who should have the authority to authorize and oversee foreign intelligence surveillance programs, someone must, and the existing mechanisms, in particular, the Foreign Intelligence Surveillance Act of 1978 ( FISA\u27) and its related procedures, are no longer adequate and must be updated. The FISA simply did not anticipate the nature of the current threat to national security from transnational terrorism, nor did it anticipate the development of global communication networks or advanced technical methods for intelligence gathering

National Security Surveillance in an Age of Terror: Statutory Powers & Charter Limits

The communications surveillance powers granted to Canada\u27s national security agencies have rarely resulted in prosecution and, as a result, have been subject to very little judicial, academic, or public scrutiny. However, as the state increasingly seeks to prosecute alleged terrorists, courts will have to interpret the scope of these powers and decide whether they violate section 8 of the Canadian Charter of Rights and Freedoms (the Charter). A review of the powers granted to police, the Canadian Security Intelligence Service (CSIS), and the Communications Security Establishment Canada (CSEC) reveals two constitutional infirmities: allowing police to conduct communications surveillance in terrorism investigations without establishing investigative necessity, and allowing CSEC to intercept domestic communications without prior judicial authorization. Put simply, these powers should be found to violate section 8 of the Charter because they substantially infringe on the privacy of innocent Canadians, especially of Muslim or Arab background, while doing little to advance national security

Automatic text categorisation of racist webpages

Automatic Text Categorisation (TC) involves the assignment of one or more predefined categories to text documents in order that they can be effectively managed. In this thesis we examine the possibility of applying automatic text categorisation to the problem of categorising texts (web pages) based on whether or not they are racist. TC has proven successful for topic-based problems such as news story categorisation. However, the problem of detecting racism is dissimilar to topic-based problems in that lexical items present in racist documents can also appear in anti-racist documents or indeed potentially any document. The mere presence of a potentially racist term does not necessarily mean the document is racist. The difficulty is finding what discerns racist documents from non-racist. We use a machine learning method called Support Vector Machines (SVM) to automatically learn features of racism in order to be capable of making a decision about the target class of unseen documents. We examine various representations within an SVM so as to identify the most effective method for handling this problem. Our work shows that it is possible to develop automatic categorisation of web pages, based on these approache

In and Out of Place: Islamic Domestic Extremism and the Case of the "Toronto 18"

In the aftermath of the tragic events of 11 September 2001 a veritable cornucopia of formal, practical, and popular materials have emerged that offer analyses of various dimensions of the phenomenon of Islamitic extremism. Unfortunately, despite the voluminous amount of analytical capital and resources expended, significant advances in our collective understanding of this phenomenon continue to be elusive. This situation is certainly evident when one surveys the current literature available that focuses on the processes of Islamitic extremization. To date, the predominant focus of this important research has been on the micro social relations and structures that make the development of particular subjectivities probable. Although this mode of inquiry is valuable, there is a danger in overly subjectivizing the process of extremization. As demonstrated through an analysis of the so-called Toronto 18—a group of Islamitic social actors apprehended in June, 2006, for activities that contravened the Canadian Anti-Terrorism Act (ATA)—macro social relations and structures served a significant function in creating the conditions through which the process of extremization becomes probable. In the context of this analysis, the macro social relations and structures that made the ideological conditioning and political transformation of these Islamitic social actors probable include, what is referred to as, the following spheres of influence: Transnational, State, and Group. In effect, these spheres of influence formed a network of scales that converged and condensed in the place-specific context of the Greater Toronto Area (GTA) and facilitated the transgression of some of the actors involved from a Dominant to a Subversive discursive formation and concomitant field of action and practice. However, to develop a greater appreciation for the context within which these processes took place required not only a re-evaluation of the conceptual and terminological tools used to apprehend this phenomenon, but an analysis of the historical processes and forces that made the emergence of particular discursive formations possible. If a comprehensive understanding of the processes of extremization are to be reached and effective counter- terrorism policies developed, the macro social relations and structures that make the emergence of particular extremist subjectivities probable need to be given greater consideration. Ignoring these relations and structures will potentially result in the continuation of counter-productive anti-terrorism policies and counter-terrorism practices which contribute to the oxygen of violence rather than facilitating the de-escalation of extremist activities

The Reasonableness of Probable Cause

Probable cause is generally cast in judicial opinions and the scholarly literature as a fixed probability of criminal activity. In the weeks before the September 11 attacks, FBI headquarters, applying such an unbending standard, rejected a warrant application to search Zacarias Moussaoui’s laptop computer. This article, which begins with an analysis of the Moussaoui episode, argues that the probable cause standard should be calibrated to the gravity of the investigated offense and the intrusiveness of a proposed search. Tracing the evolution of probable cause from the common law through its American development, the article argues that the Supreme Court’s current insistence on a “single standard” lacks historical support. Probable cause should be recast within a reasonableness framework, embracing the common sense view that not all searches equally trench on privacy concerns and not all crimes equally threaten the social order

Rover-II: A Context-Aware Middleware for Pervasive Computing Environment

It is well recognized that context plays a significant role in all human endeavors. All decisions are based on information which has to be interpreted in context. By making information systems context-aware we can have systems that significantly enhance human capabilities to make critical decisions. A major challenge of context-aware systems is to balance usability with generality and extensibility. The relevant context changes depending on the particular application. The model used to represent the context and its relationship to entities must be general enough to allow additions of context categories without redesign while remaining usable across many applications. Also, while efforts are put in by application designers and developers to make applications context-aware, these efforts are customized to specific needs of the target application, and only certain common contexts like location and time are taken into account. Therefore, a general framework is called for that can (i) efficiently maintain, represent and integrate contextual information, (ii) act as an integration platform where different applications can share contexts and (iii) provide relevant services to make efficient use of the contextual information. This dissertation presents: * a generic and effective context model - Rover Context Model (RoCoM) that is structured around four primitives: entities, events, relationships, and activities; and practically usable through the concept of templates, * a flexible, extensible and generic ontology - Rover Context Model Ontology (RoCoMO) supporting the model, that addresses the shortcomings of existing ontologies, * an effective mechanism of modeling the context of a situation, through the concept of relevant context, with the help of situation graph, efficiently handling and making best use of context information, * a context middleware - Rover-II, which serves as a framework for contextual information integration, that could be used not just to store and compile the contextual information, but also integrate relevant services to enhance the context information; and more importantly, enable sharing of context among the applications subscribed to it, * the initial design and implementation of a distributed architecture for Rover-II, following a P2P arrangement inspired from Tapestry, The above concepts are illustrated through M-Urgency, a context-aware public safety system that has been deployed at the University of Maryland Police Department