76 research outputs found

    Intrusion Detection and Security Assessment in a University Network

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    This thesis first explores how intrusion detection (ID) techniques can be used to provide an extra security layer for today‟s typically security-unaware Internet user. A review of the ever-growing network security threat is presented along with an analysis of the suitability of existing ID systems (IDS) for protecting users of varying security expertise. In light of the impracticality of many IDS for today‟s users, a web-enabled, agent-based, hybrid IDS is proposed. The motivations for the system are presented along with details of its design and implementation. As a test case, the system is deployed on the DCU network and results analysed. One of the aims of an IDS is to uncover security-related issues in its host network. The issues revealed by our IDS demonstrate that a full DCU network security assessment is warranted. This thesis describes how such an assessment should be carried out and presents corresponding results. A set of security-enhancing recommendations for the DCU network are presented

    PEDAGOGIA CRÍTICA E NEOLIBERALISMO

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    In this article, we reflect on the possibilities and responsibilities of critical pedagogy in relation to neoliberalism and physical education. In exploring these ideas, we also discuss problems of definition, such as the collapse and confusion of terms like critical pedagogy, critical research, and critical health and PE, as well the problematic positioning of ‘neoliberalism’ in critical scholarship. Although there is a growing body of research that illuminates the nuances and pervasiveness of neoliberal HPE policies and practices – both globally and in specific social contexts – we argue that there is still more work to be done to identify how critical pedagogical work may address (or at least attend to) the effects of neoliberalism. After all, there remains a ‘danger’ that critical pedagogy in neoliberal times may forward, rather than contest, the worst effects of neoliberal schooling and neoliberal HPE.En este artículo, reflexionamos sobre las posibilidades y las responsabilidades de la pedagogía crítica en relación al neoliberalismo y la Educación Física. Además de explorar estas ideas, debatimos los problemas de la definición, así como el colapso y la confusión de los términos como pedagogía crítica, investigación crítica, salud crítica y Educación Física, así como la problemática del neoliberalismo en los estudios críticos. Si bien hay un creciente cuerpo de investigaciones que iluminan los matices y la omnipresencia de las políticas y practicas neoliberales en HPE – tanto en los contextos globales como sociales específicos – nosotros argumentamos que ha todavia más trabajo por hacer para identificar  como el trabajo pedagógico puede dirigirse (o por lo menos intentar) a los efectos del neoliberalismo. Al ultimo, sigue existiendo el peligro de que la pedagogía crítica en tiempos neoliberales pueda transmitir, en lugar de cuestionar, los peores efectos de la escolarización neoliberal y del neoliberalismo en salud y Educación Física. Neste artigo, nós refletimos sobre as possibilidade e responsabilidades da pedagogia crítica em relação ao neoliberalismo e a Educação Física. Ao explorar essas ideias, nós também discutimos os problemas da definição, bem como o colapso e confusão de termos como pedagogia crítica, pesquisa crítica e saúde crítica e Educação Física, bem como a problemática posição do neoliberalismo nos estudos críticos. Embora exista um crescente corpo de pesquisas que iluminam as nuanças e onipresença das políticas e práticas neoliberais em HPE – tanto em contextos globais e em contextos sociais específicos – nós argumentamos que ainda existe mais trabalho a ser feito para identificar como o trabalho pedagógico crítico pode dirigir-se (ou ao menos tentar) aos efeitos do neoliberalismo. Ao fim, continua a existir o perigo de que a pedagogia crítica em tempos neoliberais possa transmitir, em vez de contestar, os piores efeitos da escolarização neoliberal e do neoliberalismo em saúde e Educação Física.  

    Using mobile technology to create flexible learning contexts

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    This paper discusses the importance of learning context with a particular focus upon the educational application of mobile technologies. We suggest that one way to understand a learning context is to perceive it as a Learner Centric Ecology of Resources. These resources can be deployed variously but with a concern to promote and support different kinds of mediations, including those of the teacher and learner. Our approach is informed by sociocultural theory and is used to construct a framework for the evaluation of learning experiences that encompass various combinations of technologies, people, spaces and knowledge. The usefulness of the framework is tested through two case studies that evaluate a range of learning contexts in which mobile technologies are used to support learning. We identify the benefits and challenges that arise when introducing technology across multiple locations. An analytical technique mapped from the Ecology of Resources framework is presented and used to identify the ways in which different technologies can require learners to adopt particular roles and means of communication. We illustrate how we involve participants in the analysis of their context and highlight the extent to which apparently similar contexts vary in ways that are significant for learners. The use of the Ecology of Resources framework to evaluate a range of learning contexts has demonstrated that technology can be used to provide continuity across locations: the appropriate contextualization of activities across school and home contexts, for example. It has also provided evidence to support the use of technology to identify ways in which resources can be adapted to meet the needs of a learner

    First-year Sloan Digital Sky Survey-II (SDSS-II) Supernova Results: Hubble Diagram and Cosmological Parameters

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    We present measurements of the Hubble diagram for 103 Type Ia supernovae (SNe) with redshifts 0.04 < z < 0.42, discovered during the first season (Fall 2005) of the Sloan Digital Sky Survey-II (SDSS-II) Supernova Survey. These data fill in the redshift "desert" between low- and high-redshift SN Ia surveys. We combine the SDSS-II measurements with new distance estimates for published SN data from the ESSENCE survey, the Supernova Legacy Survey, the Hubble Space Telescope, and a compilation of nearby SN Ia measurements. Combining the SN Hubble diagram with measurements of Baryon Acoustic Oscillations from the SDSS Luminous Red Galaxy sample and with CMB temperature anisotropy measurements from WMAP, we estimate the cosmological parameters w and Omega_M, assuming a spatially flat cosmological model (FwCDM) with constant dark energy equation of state parameter, w. For the FwCDM model and the combined sample of 288 SNe Ia, we find w = -0.76 +- 0.07(stat) +- 0.11(syst), Omega_M = 0.306 +- 0.019(stat) +- 0.023(syst) using MLCS2k2 and w = -0.96 +- 0.06(stat) +- 0.12(syst), Omega_M = 0.265 +- 0.016(stat) +- 0.025(syst) using the SALT-II fitter. We trace the discrepancy between these results to a difference in the rest-frame UV model combined with a different luminosity correction from color variations; these differences mostly affect the distance estimates for the SNLS and HST supernovae. We present detailed discussions of systematic errors for both light-curve methods and find that they both show data-model discrepancies in rest-frame UU-band. For the SALT-II approach, we also see strong evidence for redshift-dependence of the color-luminosity parameter (beta). Restricting the analysis to the 136 SNe Ia in the Nearby+SDSS-II samples, we find much better agreement between the two analysis methods but with larger uncertainties.Comment: Accepted for publication by ApJ

    A revised northern European Turonian (Upper Cretaceous) dinoflagellate cyst biostratigraphy: Integrating palynology and carbon isotope events

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    Organic walled dinoflagellate cyst (dinocyst) assemblage data are presented for a new Turonian regional reference core (Bch-1) drilled at Běchary in the Bohemian Cretaceous Basin, east-central Czech Republic. The detailed stratigraphic framework for the section is summarised based on calcareous nannofossil and macrofossil biostratigraphy, regional e-log correlation, sequence stratigraphy and carbon isotope chemostratigraphy. Dinocyst results obtained for 196 samples from the 405 m long core offer the highest resolution (~ 22 kyr) stratigraphically well-constrained data set available to date for the Turonian Stage, 93.9–89.8 Ma. A dinocyst biostratigraphic framework is presented based on the evolutionary first and last occurrence, first common occurrence, and acmes of key species. Published dinocyst data from English Turonian Chalk successions in East Sussex, Berkshire, Kent and Norfolk are reviewed within a stratigraphic framework provided by macrofossil records and carbon isotope event (CIE) chemostratigraphy. Critical analysis of existing published Turonian dinocyst zonation schemes shows them to be untenable. Correlation of the English Chalk data to Bch-1 provides a basis for defining a regional dinocyst event stratigraphy with 22 datum levels, and a revised dinocyst zonation scheme constrained within a chemostratigraphic framework of 10 major CIEs. The new zones consist of a Cenomanian Litosphaeridium siphoniphorum Zone, followed by the Cauveridinium membraniphorum Zone spanning the uppermost Cenomanian to Lower Coniacian. This is subdivided into: Senoniasphaera turonica (Lower–mid-Middle Turonian); and Raetiaedinium truncigerum (mid-Middle Turonian–mid-Lower Coniacian) subzones. The Oligosphaeridium pulcherrimum Zone (Senonisphaera rotundata Subzone) characterises the Lower Coniacian. The new stratigraphy offers a basis for improved correlation and dating of Upper Cretaceous successions

    Previous Lung Diseases and Lung Cancer Risk: A Systematic Review and Meta-Analysis

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    In order to review the epidemiologic evidence concerning previous lung diseases as risk factors for lung cancer, a meta-analysis and systematic review was conducted.Relevant studies were identified through MEDLINE searches. Using random effects models, summary effects of specific previous conditions were evaluated separately and combined. Stratified analyses were conducted based on smoking status, gender, control sources and continent.A previous history of COPD, chronic bronchitis or emphysema conferred relative risks (RR) of 2.22 (95% confidence interval (CI): 1.66, 2.97) (from 16 studies), 1.52 (95% CI: 1.25, 1.84) (from 23 studies) and 2.04 (95% CI: 1.72, 2.41) (from 20 studies), respectively, and for all these diseases combined 1.80 (95% CI: 1.60, 2.11) (from 39 studies). The RR of lung cancer for subjects with a previous history of pneumonia was 1.43 (95% CI: 1.22-1.68) (from 22 studies) and for subjects with a previous history of tuberculosis was 1.76 (95% CI=1.49, 2.08), (from 30 studies). Effects were attenuated when restricting analysis to never smokers only for COPD/emphysema/chronic bronchitis (RR=1.22, 0.97-1.53), however remained significant for pneumonia 1.36 (95% CI: 1.10, 1.69) (from 8 studies) and tuberculosis 1.90 (95% CI: 1.45, 2.50) (from 11 studies).Previous lung diseases are associated with an increased risk of lung cancer with the evidence among never smokers supporting a direct relationship between previous lung diseases and lung cancer

    Early ultrasound surveillance of newly-created haemodialysis arteriovenous fistula

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    IntroductionWe assess if ultrasound surveillance of newly-created arteriovenous fistulas (AVFs) can predict nonmaturation sufficiently reliably to justify randomized controlled trial (RCT) evaluation of ultrasound-directed salvage intervention.MethodsConsenting adults underwent blinded fortnightly ultrasound scanning of their AVF after creation, with scan characteristics that predicted AVF nonmaturation identified by logistic regression modeling.ResultsOf 333 AVFs created, 65.8% matured by 10 weeks. Serial scanning revealed that maturation occurred rapidly, whereas consistently lower fistula flow rates and venous diameters were observed in those that did not mature. Wrist and elbow AVF nonmaturation could be optimally modeled from week 4 ultrasound parameters alone, but with only moderate positive predictive values (PPVs) (wrist, 60.6% [95% confidence interval, CI: 43.9–77.3]; elbow, 66.7% [48.9–84.4]). Moreover, 40 (70.2%) of the 57 AVFs that thrombosed by week 10 had already failed by the week 4 scan, thus limiting the potential of salvage procedures initiated by that scan’s findings to alter overall maturation rates. Modeling of the early ultrasound characteristics could also predict primary patency failure at 6 months; however, that model performed poorly at predicting assisted primary failure (those AVFs that failed despite a salvage attempt), partly because patency of at-risk AVFs was maintained by successful salvage performed without recourse to the early scan data.ConclusionEarly ultrasound surveillance may predict fistula maturation, but is likely, at best, to result in only very modest improvements in fistula patency. Power calculations suggest that an impractically large number of participants (>1700) would be required for formal RCT evaluation
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