4,856 research outputs found

    Quantifying the Indirect Effect of Wolves on Aspen in Northern Yellowstone National Park: Evidence for a Trophic Cascade?

    Get PDF
    Yellowstone National Park is renowned for its incredible wildlife, and perhaps the most famous of these species is the gray wolf, which was reintroduced to the Park in the mid-1990s. After reintroduction, it was highly publicized by scientists, journalists, and environmentalists that the wolf both decreased elk density and changed elk behavior in a way that reduced elk effects on plants, a process known as a “trophic cascade.” Aspen, which is eaten by elk in winter, is one species at the forefront of Yellowstone trophic cascade research because it has been in decline across the Park for over a century. However, due to the challenges of measuring trophic cascades, there is continued uncertainty regarding the effects of wolves on aspen in northern Yellowstone. Thus, the purpose of my dissertation was to provide a comprehensive test of a trophic cascade in this system. Specifically, I used 20 years of data on aspen, elk, and wolves in Yellowstone to: 1) clarify annual trends in browsing and height of young aspen (a proxy for regeneration) after wolf reintroduction, 2) assess the influence of wolves scaring elk on aspen (“trait-mediated indirect effects”), and 3) evaluate the effect of wolves killing elk on aspen (“density-mediated indirect effects”). My research suggests that wolves indirectly contributed to increased aspen over story recruitment following their reintroduction by helping to reduce the elk population size, but elk response to the risk of wolf predation did not reduce elk foraging in a way that measurably increased aspen recruitment. Additionally, hunter harvest of elk north of the park was twice as important as wolf predation in causing increased aspen recruitment. However, despite wolves and hunters limiting elk abundance, it is still uncommon for young aspen to grow past peak browsing height (120-cm), indicating that many stands remain vulnerable to elk herbivory nearly 30 years after wolf reintroduction. These results highlight that the strength and mechanism of predator effects on plant communities are context-specific. Thus, using predator reintroduction as a tool for ecosystem restoration without considering the many factors that shape trophic cascades may result in different management and conservation outcomes than intended

    Educating Sub-Saharan Africa:Assessing Mobile Application Use in a Higher Learning Engineering Programme

    Get PDF
    In the institution where I teach, insufficient laboratory equipment for engineering education pushed students to learn via mobile phones or devices. Using mobile technologies to learn and practice is not the issue, but the more important question lies in finding out where and how they use mobile tools for learning. Through the lens of Kearney et al.’s (2012) pedagogical model, using authenticity, personalisation, and collaboration as constructs, this case study adopts a mixed-method approach to investigate the mobile learning activities of students and find out their experiences of what works and what does not work. Four questions are borne out of the over-arching research question, ‘How do students studying at a University in Nigeria perceive mobile learning in electrical and electronic engineering education?’ The first three questions are answered from qualitative, interview data analysed using thematic analysis. The fourth question investigates their collaborations on two mobile social networks using social network and message analysis. The study found how students’ mobile learning relates to the real-world practice of engineering and explained ways of adapting and overcoming the mobile tools’ limitations, and the nature of the collaborations that the students adopted, naturally, when they learn in mobile social networks. It found that mobile engineering learning can be possibly located in an offline mobile zone. It also demonstrates that investigating the effectiveness of mobile learning in the mobile social environment is possible by examining users’ interactions. The study shows how mobile learning personalisation that leads to impactful engineering learning can be achieved. The study shows how to manage most interface and technical challenges associated with mobile engineering learning and provides a new guide for educators on where and how mobile learning can be harnessed. And it revealed how engineering education can be successfully implemented through mobile tools

    Investigating and mitigating the role of neutralisation techniques on information security policies violation in healthcare organisations

    Get PDF
    Healthcare organisations today rely heavily on Electronic Medical Records systems (EMRs), which have become highly crucial IT assets that require significant security efforts to safeguard patients’ information. Individuals who have legitimate access to an organisation’s assets to perform their day-to-day duties but intentionally or unintentionally violate information security policies can jeopardise their organisation’s information security efforts and cause significant legal and financial losses. In the information security (InfoSec) literature, several studies emphasised the necessity to understand why employees behave in ways that contradict information security requirements but have offered widely different solutions. In an effort to respond to this situation, this thesis addressed the gap in the information security academic research by providing a deep understanding of the problem of medical practitioners’ behavioural justifications to violate information security policies and then determining proper solutions to reduce this undesirable behaviour. Neutralisation theory was used as the theoretical basis for the research. This thesis adopted a mixed-method research approach that comprises four consecutive phases, and each phase represents a research study that was conducted in light of the results from the preceding phase. The first phase of the thesis started by investigating the relationship between medical practitioners’ neutralisation techniques and their intention to violate information security policies that protect a patient’s privacy. A quantitative study was conducted to extend the work of Siponen and Vance [1] through a study of the Saudi Arabia healthcare industry. The data was collected via an online questionnaire from 66 Medical Interns (MIs) working in four academic hospitals. The study found that six neutralisation techniques—(1) appeal to higher loyalties, (2) defence of necessity, (3) the metaphor of ledger, (4) denial of responsibility, (5) denial of injury, and (6) condemnation of condemners—significantly contribute to the justifications of the MIs in hypothetically violating information security policies. The second phase of this research used a series of semi-structured interviews with IT security professionals in one of the largest academic hospitals in Saudi Arabia to explore the environmental factors that motivated the medical practitioners to evoke various neutralisation techniques. The results revealed that social, organisational, and emotional factors all stimulated the behavioural justifications to breach information security policies. During these interviews, it became clear that the IT department needed to ensure that security policies fit the daily tasks of the medical practitioners by providing alternative solutions to ensure the effectiveness of those policies. Based on these interviews, the objective of the following two phases was to improve the effectiveness of InfoSec policies against the use of behavioural justification by engaging the end users in the modification of existing policies via a collaborative writing process. Those two phases were conducted in the UK and Saudi Arabia to determine whether the collaborative writing process could produce a more effective security policy that balanced the security requirements with daily business needs, thus leading to a reduction in the use of neutralisation techniques to violate security policies. The overall result confirmed that the involvement of the end users via a collaborative writing process positively improved the effectiveness of the security policy to mitigate the individual behavioural justifications, showing that the process is a promising one to enhance security compliance

    Stratigraphy, chronology, and correlation of the Plio-Pleistocene (c. 2.2-0.8 Ma) Kauroa Ash sequence, western central North Island, New Zealand

    Get PDF
    The Kauroa Ash beds (K-beds) comprise a 12-20 m-thick sequence of extremely weathered, clay-rich (40-95% <4 μm clay) beds of tephra and loess, and associated paleosols. Found in isolated remnants throughout the western central North Island, the sequence comprises 15 defined members, with as many as 44 constituent macroscopic beds. The type site, ‘Woodstock’, near Raglan, is the most comprehensive sequence known, but other sites (e.g. Papakura Creek and Tiritirimatangi Peninsula) contain units not found or poorly defined at Woodstock. Field properties as well as magnetic susceptibility measurements and particle-size analysis characterise the facies in the sequence. Field properties (in particular colour, consistence, macrofabric) describe the lithostratigraphy. The sequence contains five interpretive (i.e. genetic) ‘facies’: paleosols, primary tephra, very weathered tephra (possibly composite beds), loess and ‘tephric loess’ beds. At least seven loess beds are (newly) identified in the sequence: K4a, K5, K6ai, K8ai, K8bi, K10a and K14ai. Mass-specific susceptibility and frequency-dependent susceptibility results partly conform to established models (developed mostly on Chinese loess-paleosol deposits) of susceptibility enhancement in paleosols and depletion in loess. Many parts of the sequence do not appear to conform to this model and the results more closely resemble the inverse relationship found on Alaskan loess-paleosol beds. Frequency-dependent susceptibility is reliable in delineating paleosols by their ‘ultrafine’ ferrimagnetic mineral content, and citrate-bicarbonate-dithionite treatments successfully remove all iron oxides so that remeasurement of susceptibility isolates a strictly ‘pedogenic’, rather than lithogenic, fraction. Laser diffraction particle-size analysis shows that the Kauroa Ash beds are texturally reasonably homogenous. They have bimodal particle-size distributions with the most dominant mode at around 11.25 ɸ inferred to be the product of intense and prolonged weathering. Other modes are variously centred on 7-8.5 ɸ and, despite weathering and pedogenesis, have some relationship to the original depositional particle-size distributions because trends between facies (i.e. genetic units) are delineated. Principal components analysis objectively characterises these modes as (Wentworth size classes) ‘very fine clay’ and ‘coarse silt’, although there is no proportional relationship between them, supporting a post-depositional origin for the former mode. The chronology of the sequence, previously poorly defined, is greatly improved by a combination of tephrochronologic correlations, fission-track dating, and paleomagnetism. Five zircon fission-track dates provide independent age ‘spikes’ and range from 2.24 ± 0.29 Ma in the basal member, K1, to 1.28 ± 0.11 Ma for the distal ignimbrite unit K12a. Paleomagnetism is invaluable in providing additional age information. The top of the sequence, member K15, is dated as >0.78 Ma (Brunhes-Matuyama boundary) because of its reversed polarity; two episodes of normal polarity are found in beds K14b and K2b and are inferred to represent the Jaramillo (1.07-0.99 Ma) and Olduvai (1.95-1.79 Ma) subchrons, respectively. Beds underlying the Kauroa Ash sequence are also of normal polarity, indicating that they were deposited in the Gauss Chron (>2.6 Ma). Identification and correlation of tephras by conventional means (fingerprinting by their lithological or geochemical properties) is impossible in the Kauroa Ash sequence because the beds have no remaining volcanic glass, which has instead been altered to an assemblage of authigenic phases (clays) by weathering and pedogenesis. However, a new technique analysing fresh glass found as melt inclusions in quartz grains is successful in circumventing this problem. Inclusions represent samples of non-degassed magma that became entrapped during phenocryst growth prior to eruption. The glass has remained unaltered because it is hermetically sealed in a chemically resistant phenocryst, which has protected it from weathering processes. Electron microprobe analysis of the glass inclusions yield results which are wholly reasonable for glass (totals ranging from 93-97%; low standard deviations of <1 %), and a number of provisional correlations are established by comparing the major element composition of Kauroa Ash tephra beds with those of proximal deposits. The Kauroa Ash sequence may contain deposits correlated with at least seven major TVZ eruptions, in many cases expanding the known extent of the (distal) deposit and, for the first time answering the question as to the origin of the Kauroa Ash beds. These correlations, together with an improved chronology, enable the Kauroa Ash sequence to be placed in a regional stratigraphic framework alongside other New Zealand Plio-Pleistocene sequences such as those in the Wanganui Basin, Wairarapa, Cape Kidnappers and Port Waikato. Using paleosols as chrono- and climatostratigraphic entities (correlated to warm periods in global climate), the sequence can also be placed alongside a global reference, the marine oxygen isotope stratigraphy. A further correlation to the Chinese loess-paleosol record suggests that large parts of the Kauroa Ash sequence were deposited in an incremental manner akin to deposition of loess, so that the sequence is not only a record of TVZ volcanism, but also of Plio-Pleistocene paleoclimate

    Love Between Worlds: Edward Burne-Jones and the Theology of Art

    Get PDF
    This dissertation explores the theological formation of Edward Burne-Jones (1833-1898) and argues that his artistic vision was shaped by and became a practice of theology. Burne-Jones was drawn to the controversial Oxford ‘Tractarian’ Movement and pursued education at the University of Oxford to become an Anglican priest. He was inspired by John Henry Newman, who lived and preached in Birmingham during Burne-Jones’s adolescence. Contrary to most scholarship, I argue for the continuing prevalence of the Tractarian theological perspective in his art, even after he decided not to preach or practise conventional religion. His art is deeply informed by the complex theological principles he studied. This becomes what I identify as a theology of art that considers and presents theological ideas not in words but in art. I have conducted archival research into Burne-Jones’s personal history and education, and the theological figures, debates, and controversies that shaped him. This included letters and diaries of mentors and friends of Burne-Jones which have been scarcely accessed. Furthermore, Burne-Jones’s own university notebooks and letters have shown direct evidence of Burne-Jones’s theological knowledge. I have also pursued extensive research into theology and church history, particularly of Anglicanism before and in the nineteenth century. To understand how this translates into his artistic practice, I have researched and interpreted various works and projects of Burne-Jones, emphasising his methods of design. This has led to a wide-ranging assessment of his drawings in print rooms across Britain. Ultimately, I argue for the recurrence of the theological and artistic theme I call love between worlds, a concept connecting Burne-Jones’s study of the Tractarian notions of incarnation, sacramentality, and God’s love expressed through the economy of salvation in Christ, and the subject of the pursuit of romantic love that pervades Burne-Jones’s artistic projects

    Modelling Group Dynamics with SYMLOG and Snowdrift for Intelligent Classroom Environment

    Get PDF
    The aim of this thesis is to provide assistance to human teachers focusing on supporting group work within a classroom environment. This is achieved by incorporating theories from Psychology and Game Theory in order to provide a better method of modelling and predicting group interactions. This research proposes a framework that extends the pre-existing Intelligent Tutorial System (ITS) beyond the individual and into one that encompasses one or more groups of learners within a learning space. This framework transforms a traditional school classroom into a group interface as part of the communication module of an ITS and enhances the role of a human teacher. This is achieved by automating class management tasks and providing an immersive learning experience. Moreover, the proposed framework monitors emotional well-being and feeds back, to the teacher, emotional profiles of individuals and groups. This new ITS system is named Intelligent Classroom Tutoring System (ICTS). 6 experiments were conducted to support the ICTS. 2 experiments were set up to compare experimental frameworks for SYMLOG allowing the researchers to test a new mod-SYMLOG which was found to be an effective tool for modelling groups interactions. 1 experiment was centred around a longitudinal study of group work, and the final 3 composing of both AI and human studies, examining applying a new mod-Snowdift game to produce a predictive mechanism for group interaction

    The effects of ocean acidification on microbial nutrient cycling and productivity in coastal marine sediments

    Get PDF
    Ocean Acidification (OA), commonly referred to as the “other CO₂ problem,” illustrates the current rise in atmospheric carbon dioxide (CO₂) levels, precipitated in large by human-related activity (e.g., fossil fuel combustion and mass deforestation). The dissolution of atmospheric CO₂ into the surface of the ocean over time has reduced oceanic pH levels by 0.1 units since the start of the pre-industrial era and has resulted in wholesale shifts in seawater carbonate chemistry on a planetary scale. The chemical processes of ocean acidification are increasingly well documented, demonstrating clear rates of increase for global CO₂ emissions predicted by the IPCC (Intergovernmental Panel on Climate Change) under the business-as-usual CO₂ emissions scenario. The ecological impact of ocean acidification alters seawater chemical speciation and disrupts vital biogeochemical cycling processes for various chemicals and compounds. Whereby the unidentified potential fallout of this is the cascading effects on the microbial communities within the benthic sediments. These microorganisms drive the marine ecosystem through a network of vast biogeochemical cycling processes aiding in the moderation of ecosystem-wide primary productivity and fundamentally regulating the global climate. The benthic sediments are determinably one of the largest and most diverse ecosystems on the planet. Marine sediments are also conceivably one of the most productive in terms of microbial activity and nutrient flux between the water-sediment interface (i.e., boundary layer). The absorption and sequestering of CO₂ from the atmosphere have demonstrated significant impacts on various marine taxa and their associated ecological processes. This is commonly observed in the reduction in calcium carbonate saturation states in most shell-forming organisms (i.e., plankton, benthic mollusks, echinoderms, and Scleractinia corals). However, the response of benthic sediment microbial communities to a reduction in global ocean pH remains considerably less well characterized. As these microorganisms operate as the lifeblood of the marine ecosystem, understanding their response and physiological plasticity to increased levels of CO₂ is of critical importance when it comes to investigating regional and global implications for the effects of ocean acidification

    Assessing primate skull shape variation in relation to habitat: a 3D geometric morphometric approach

    Get PDF
    The advancement of digital imaging and open-source geometric morphometric (GM) software is positively impacting the way we understand morphological adaptation as an evolutionary response. Shape-space data and multivariate statistics quantify shape variation patterning and, therefore, consolidate hominoid systematic procedures. This thesis identifies ecomorphological patterns of variation within extant primates. Through a comparative, multivariate and geometric morphometric approach, this research provides a better understanding of the effects of the environment on craniomandibular form in early hominins. In this study, 107 cranial and 108 mandible specimens of 9 modern primate species were 3D imaged, and geometric morphometrics statistics were used to quantify and assess the patterns of variation between intra- and interspecific datasets concerning habitat type. Results were visualised through Principal Component scatter plots and Thin-plate Spline deformation warps, which identified critical morphological high-to-low-energy bending areas. This application addressed the questions: • to what extent does ecology influence craniomandibular morphology? • what are the main environmental pressures that encourage morphological variance in hominins? The main methodological aims sought to a) create accurate 3D digital renderings of primate skull specimens and b) define a reproducible geometric morphometric technique, which could be used as a valid and precise statistical procedure for future studies regarding hominin ecomorphology. This was achieved by pilot testing laser scanning hardware, digitising cranial and mandibular specimen, testing 3D scanning accuracy, and the best practice for capturing accurate 3D imagery, e.g. environment, lighting and meshing multiple scans. The pilot phase of this thesis also tested statistical programming toolkits capable of carrying out the finalised geometric morphometric methodology. This was achieved through trials of landmarking and statistical procedures on various data processing software, e.g. Checkpoint, TINA, and MeshLabs. Ultimately, the R Project software and accompanying IDE, R Studio, was used to collect, process and analyse the specimen shape data. This thesis contributes to the study of hominin ecomorphological patterning through a comparative approach investigating primate skull adaptation. The main findings showed habitat type as having statistical significance on the cranium's morphology but quantifiably more so in the mandible, which reported 63.71% of the overall variance observed in the first two Principal Components. This was an increase of 10.44% compared to the interspecific cranial dataset and was supported by Two-block Partial Least Squares and Procrustes ANOVA analysis. The geometric morphometric results showed significant environmental influence on the morphology of the primate cranium, most notably concerned with locomotive functions and visualises a distinction between primates who are more arboreally inclined versus those whose primary form of locomotion is terrestrial. The study also found that dietary specialisations are particularly distinguished by patterns of variation between highly folivorous versus more frugivorous species in both inter-and intraspecific groups

    The British Bombing Offensive: Media Representation and Public Perception, 1939-1945

    Get PDF
    The British strategic bombing campaign against Germany between May 1940 and April 1945 has featured prominently in the British psyche since the end of World War II. There is rarely a month that passes when a new book is not published or a documentary features on television, which eulogises or criticises Royal Air Force (RAF) Bomber Command operations. However, what has yet to be fully explored is how the British people felt about the bombing of Germany during the war itself. The aim of this thesis is to identify the views of the British public between 1940 and 1945 towards the bombing of Germany and to attempt to understand why such views were held. The thesis takes a chronological approach, with each chapter focusing on a different period. Within each chapter, a number of themes are considered. Firstly, the role of the Publicity Department at the Air Ministry and developments in policies and practices regarding the dissemination of information to the media. Secondly, the operational activities of Bomber Command. Thirdly, an investigation into how media outlets in Britain portrayed the campaigns, most notably the national press and the British Broadcasting Corporation (BBC). Finally, and most significantly, the public’s response. This fourth theme calls upon a vast array of social investigation material, most notably Mass-Observation diary submissions and surveys, in order to analyse the views of the public. It can be determined that throughout the conflict, despite continual media coverage, the bombing of Germany never featured as one of the most popular topics of interest amongst the public. Thus, despite a number of small spikes in interest, caused by major raids or events, it can be concluded that the public were, for the most part, unenthusiastic about the actions of Bomber Command between 1939 and 1945
    • …
    corecore