77 research outputs found

    Biological effects of exposure to magnetic resonance imaging: an overview

    Get PDF
    The literature on biological effects of magnetic and electromagnetic fields commonly utilized in magnetic resonance imaging systems is surveyed here. After an introduction on the basic principles of magnetic resonance imaging and the electric and magnetic properties of biological tissues, the basic phenomena to understand the bio-effects are described in classical terms. Values of field strengths and frequencies commonly utilized in these diagnostic systems are reported in order to allow the integration of the specific literature on the bio-effects produced by magnetic resonance systems with the vast literature concerning the bio-effects produced by electromagnetic fields. This work gives an overview of the findings about the safety concerns of exposure to static magnetic fields, radio-frequency fields, and time varying magnetic field gradients, focusing primarily on the physics of the interactions between these electromagnetic fields and biological matter. The scientific literature is summarized, integrated, and critically analyzed with the help of authoritative reviews by recognized experts, international safety guidelines are also cited

    Re-branding Abu Dhabi: From oil giant to energy titan

    Get PDF
    This article presents a case study of Abu Dhabi\u27s \u27energy re-branding\u27 since 2005 when it declared its intention to transform itself from an oil exporter to a total energy giant that also embraces alternative (renewable and nuclear) energy. The first part of the article identifies the benefits of this policy for Abu Dhabi\u27s external diplomacy but argues that the real driver is the emirate\u27s domestic gas shortage and its effects on economic diversification and political legitimacy. The second part of the article discusses the motivations and interactions of local and foreign agents by focusing on the implementation of alternative energy platforms. It therefore provides a rare glimpse of the policy-making process in Abu Dhabi. The final part of the article examines the extent to which energy re-branding may be linked to a process by the government to reiterate, reinterpret and repudiate Emirati identity in order to enhance regime legitimacy in the twenty-first century. Β© 2012 Macmillan Publishers Ltd

    iSchools and archival studies

    Get PDF
    Whispers and rumors about the iSchool movement lead some to fear that this represents yet another shift away from the valued traditions of library schools, threatening something far different than what library science pioneers ever envisioned. Predating the iSchool movement, however, were other programmatic shifts such as those that led to the formalization of graduate archival education. This essay argues that such evolution is essential to our future, as iSchools tackle the increasingly complex issues confronting a digital society. We consider the mission and history of iSchools and of archival studies, the basic elements and concepts of archival studies that are critical to iSchools, and the relationship between iSchools and the changing nature of personal and institutional archives. Β© 2009 Springer Science+Business Media B.V

    Climate change, the Great Barrier Reef and the response of Australians

    Get PDF
    Β© 2016, Palgrave Macmillan Ltd. All rights reserved. Inspiration, aspirations, attitudes, and perception of threats play a pivotal role in the way that individuals associate themselves with natural environments. These sentiments affect how people connect to natural places, including their behaviours, perceived responsibility, and the management interventions they support. World Heritage Areas hold an important place in the lives of people who visit, aspire to visit, or derive a sense of security and well-being from their existence. Yet, the connection between people and special places is rarely quantified and policymakers find it difficult to incorporate these human dimensions into decision-making processes. Here we describe the personal concern and connection that Australians have with the Great Barrier Reef and discuss how the results may help with its management. We utilize a statistically representative sample of Australian residents (n = 2,002) and show empirically that climate change is perceived to be the biggest threat to the Great Barrier Reef, and that the Great Barrier Reef inspires Australians, promotes pride, and instills a sense of individual identity and collective responsibility to protect it. An increased understanding of the high levels of personal connection to iconic natural resources may help managers to enhance public support for protecting climate-sensitive systems within Australia and around the world

    The Relationship between Impulsive Choice and Impulsive Action: A Cross-Species Translational Study

    Get PDF
    Maladaptive impulsivity is a core symptom in various psychiatric disorders. However, there is only limited evidence available on whether different measures of impulsivity represent largely unrelated aspects or a unitary construct. In a cross-species translational study, thirty rats were trained in impulsive choice (delayed reward task) and impulsive action (five-choice serial reaction time task) paradigms. The correlation between those measures was assessed during baseline performance and after pharmacological manipulations with the psychostimulant amphetamine and the norepinephrine reuptake inhibitor atomoxetine. In parallel, to validate the animal data, 101 human subjects performed analogous measures of impulsive choice (delay discounting task, DDT) and impulsive action (immediate and delayed memory task, IMT/DMT). Moreover, all subjects completed the Stop Signal Task (SST, as an additional measure of impulsive action) and filled out the Barratt impulsiveness scale (BIS-11). Correlations between DDT and IMT/DMT were determined and a principal component analysis was performed on all human measures of impulsivity. In both rats and humans measures of impulsive choice and impulsive action did not correlate. In rats the within-subject pharmacological effects of amphetamine and atomoxetine did not correlate between tasks, suggesting distinct underlying neural correlates. Furthermore, in humans, principal component analysis identified three independent factors: (1) self-reported impulsivity (BIS-11); (2) impulsive action (IMT/DMT and SST); (3) impulsive choice (DDT). This is the first study directly comparing aspects of impulsivity using a cross-species translational approach. The present data reveal the non-unitary nature of impulsivity on a behavioral and pharmacological level. Collectively, this warrants a stronger focus on the relative contribution of distinct forms of impulsivity in psychopathology

    Neuronal Deletion of Caspase 8 Protects against Brain Injury in Mouse Models of Controlled Cortical Impact and Kainic Acid-Induced Excitotoxicity

    Get PDF
    system. mice demonstrated superior survival, reduced seizure severity, less apoptosis, and reduced caspase 3 processing. Uninjured aged knockout mice showed improved learning and memory, implicating a possible role for caspase 8 in cognitive decline with aging.Neuron-specific deletion of caspase 8 reduces brain damage and improves post-traumatic functional outcomes, suggesting an important role for this caspase in pathophysiology of acute brain trauma
    • …
    corecore