161 research outputs found

    The Jacobian as a measure of planar dose congruence

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    We propose a new starting point for comparing dose distributions in therapeutic radiation physics using a Jacobian-based measure. The measure is normalization independent, free of tunable parameters, bounded and converges to a unique value when comparing unrelated dose distributions. We present a preliminary demonstration of the sensitivity and general characteristics of this measure.Comment: 9 pages, 2 figure

    Return of the Great Spaghetti Monster : Learnings from a Twelve-Year Adventure in Web Software Development

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    The widespread adoption of the World Wide Web has fundamentally changed the landscape of software development. Only ten years ago, very few developers would write software for the Web, let alone consider using JavaScript or other web technologies for writing any serious software applications. In this paper, we reflect upon a twelve-year adventure in web development that began with the development of the Lively Kernel system at Sun Microsystems Labs in 2006. Back then, we also published some papers that identified important challenges in web-based software development based on established software engineering principles. We will revisit our earlier findings and compare the state of the art in web development today to our earlier learnings, followed by some reflections and suggestions for the road forward.Peer reviewe

    Differences in the Population Structure of Invasive Streptococcus suis Strains Isolated from Pigs and from Humans in the Netherlands

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    Streptococcus suis serotype 2 is the main cause of zoonotic S. suis infection despite the fact that other serotypes are frequently isolated from diseased pigs. Studies comparing concurrent invasive human and pig isolates from a single geographical location are lacking. We compared the population structures of invasive S. suis strains isolated between 1986 and 2008 from human patients (N = 24) and from pigs with invasive disease (N = 124) in the Netherlands by serotyping and multi locus sequence typing (MLST). Fifty-six percent of pig isolates were of serotype 9 belonging to 15 clonal complexes (CCs) or singleton sequence types (ST). In contrast, all human isolates were of serotype 2 and belonged to two non-overlapping clonal complexes CC1 (58%) and CC20 (42%). The proportion of serotype 2 isolates among S. suis strains isolated from humans was significantly higher than among strains isolated from pigs (24/24 vs. 29/124; P<0.0001). This difference remained significant when only strains within CC1 and CC20 were considered (24/24 vs. 27/37,P = 0.004). The Simpson diversity index of the S. suis population isolated from humans (0.598) was smaller than of the population isolated from pigs (0.765, P = 0.05) indicating that the S. suis population isolated from infected pigs was more diverse than the S. suis population isolated from human patients. S. suis serotype 2 strains of CC20 were all negative in a PCR for detection of genes encoding extracellular protein factor (EF) variants. These data indicate that the polysaccharide capsule is an important correlate of human S. suis infection, irrespective of the ST and EF encoding gene type of S. suis strains

    Brain data:Scanning, scraping and sculpting the plastic learning brain through neurotechnology

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    Neurotechnology is an advancing field of research and development with significant implications for education. As 'postdigital' hybrids of biological and informational codes, novel neurotechnologies combine neuroscience insights into the human brain with advanced technical development in brain imaging, brain-computer interfaces, neurofeedback platforms, brain stimulation and other neuroenhancement applications. Merging neurobiological knowledge about human life with computational technologies, neurotechnology exemplifies how postdigital science will play a significant role in societies and education in decades to come. As neurotechnology developments are being extended to education, they present potential for businesses and governments to enact new techniques of 'neurogovernance' by 'scanning' the brain, 'scraping' it for data and then 'sculpting' the brain toward particular capacities. The aim of this article is to critically review neurotechnology developments and implications for education. It examines the purposes to which neurotechnology development is being put in education, interrogating the commercial and governmental objectives associated with it and the neuroscientific concepts and expertise that underpin it. Finally, the article raises significant ethical and governance issues related to neurotechnology development and postdigital science that require concerted attention from education researchers

    Antimicrobial activity of ProRoot MTA in contact with blood

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    Dental materials based on Portland cement, which is used in the construction industry have gained popularity for clinical use due to their hydraulic properties, the interaction with tooth tissue and their antimicrobial properties. The antimicrobial properties are optimal in vitro. However in clinical use contact with blood may affect the antimicrobial properties. This study aims to assess whether antimicrobial properties of the Portland cement-based dental cements such as mineral trioxide aggregate (MTA) are also affected by contact with blood present in clinical situations. ProRoot MTA, a Portland cement-based dental cement was characterized following contact with water, or heparinized blood after 1 day and 7 days aging. The antimicrobial activity under the mentioned conditions was assessed using 3 antimicrobial tests: agar diffusion test, direct contact test and intratubular infection test. MTA in contact with blood was severely discoloured, exhibited an additional phosphorus peak in elemental analysis, no calcium hydroxide peaks and no areas of bacterial inhibition growth in the agar diffusion test were demonstrated. ProRoot MTA showed limited antimicrobial activity, in both the direct contact test and intratubular infection test. When aged in water ProRoot MTA showed higher antimicrobial activity than when aged in blood. Antimicrobial activity reduced significantly after 7 days. Further assessment is required to investigate behaviour in clinical situations.ERDF (Malta) for the financing of the testing equipment through the project: “Developing an Interdisciplinary Material Testing and Rapid Prototyping R&D Facility” (Ref. no. 012)

    Meditation-induced near-death experiences: a 3-year longitudinal study

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    Near-death experiences (NDEs) are life transformational events that are increasingly being subjected to empirical research. However, to date, no study has investigated the phenomenon of a meditation-induced near-death experience (MI-NDE) that is referred to in ancient Buddhist texts. Given that some advanced Buddhist meditators can induce NDEs at a pre-planned point in time, the MI-NDE may make NDEs more empirically accessible and thus advance understanding into the psychology of death-related processes. The present study recruited 12 advanced Buddhist meditators and compared the MI-NDE against two other meditation practices (i.e. that acted as control conditions) in the same participant group. Changes in the content and profundity of the MI-NDE were assessed longitudinally over a 3-year period. Findings demonstrated that compared to the control conditions, the MI-NDE prompted significantly greater pre-post increases in NDE profundity, mystical experiences and non-attachment. Furthermore, participants demonstrated significant increases in NDE profundity across the 3-year study period. Findings from an embedded qualitative analysis (using grounded theory) demonstrated that participants (i) were consciously aware of experiencing NDEs, (ii) retained volitional control over the content and duration of NDEs and (iii) elicited a rich array of non-worldly encounters and spiritual experiences. In addition to providing corroborating evidence in terms of the content of a “regular” (i.e. non-meditation-induced) NDE, novel NDE features identified in the present study indicate that there exist unexplored and/or poorly understood dimensions to NDEs. Furthermore, the study indicates that it would be feasible - including ethically feasible - for future research to recruit advanced meditators in order to assess real-time changes in neurological activity during NDEs

    The induction of antibody production by IL-6 is indirectly mediated by IL-21 produced by CD4+ T cells

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    Interleukin (IL) 6 is a proinflammtory cytokine produced by antigen-presenting cells and nonhematopoietic cells in response to external stimuli. It was initially identified as a B cell growth factor and inducer of plasma cell differentiation in vitro and plays an important role in antibody production and class switching in vivo. However, it is not clear whether IL-6 directly affects B cells or acts through other mechanisms. We show that IL-6 is sufficient and necessary to induce IL-21 production by naive and memory CD4+ T cells upon T cell receptor stimulation. IL-21 production by CD4+ T cells is required for IL-6 to promote B cell antibody production in vitro. Moreover, administration of IL-6 with inactive influenza virus enhances virus-specific antibody production, and importantly, this effect is dependent on IL-21. Thus, IL-6 promotes antibody production by promoting the B cell helper capabilities of CD4+ T cells through increased IL-21 production. IL-6 could therefore be a potential coadjuvant to enhance humoral immunity

    No Weight for “Due Weight”? A Children’s Autonomy Principle in Best Interest Proceedings

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    Article 12 of the un Convention on the Rights of the Child (crc) stipulates that children should have their views accorded due weight in accordance with age and maturity, including in proceedings affecting them. Yet there is no accepted understanding as to how to weigh children’s views, and it is associated strongly with the indeterminate notion of “competence”. In this article, case law and empirical research is drawn upon to argue that the concept of weighing their views has been an obstacle to children’s rights, preventing influence on outcomes for children in proceedings in which their best interests are determined. Younger children and those whose wishes incline against the prevailing orthodoxy (they may resist contact with a parent, for example) particularly lose out. Children’s views appear only to be given “significant weight” if the judge agrees with them anyway. As it is the notion of autonomy which is prioritised in areas such as medical and disability law and parents’ rights, it is proposed in this article that a children’s autonomy principle is adopted in proceedings – in legal decisions in which the best interest of the child is the primary consideration, children should get to choose, if they wish, how they are involved and the outcome, unless it is likely that significant harm will arise from their wishes. They should also have “autonomy support” to assist them in proceedings. This would likely ensure greater influence for children and require more transparent decision-making by adults.</jats:p
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