869 research outputs found

    The variance-covariance method: Microdosimetry in time-varying low dose-rate radiation fields

    Get PDF
    The variance-covariance method is employed at low doses and in radiation fields of low dose rates from an241Am (4 nGy/s) and a90Sr (300 nGy/s) source. The preliminary applications and results illustrate some of the potential of the method, and show that the dose average of lineal energy or energy imparted can be determined over a wide range of doses and dose rates. The dose averages obtained with the variance-covariance method in time-varying fields, for which the conventional variance method is not suitable, agree well with results obtained under the condition of constant dose rate. The results are compared to data obtained in terms of the conventional single-event measurements. The method has evident advantages, such as facility and speed of measurement

    Embedding behavioral and social sciences across the medical curriculum: (Auto) ethnographic insights from medical schools in the United Kingdom

    Get PDF
    Key concepts and theories that are taught in order to develop cultural competency skills are often introduced to medical students throughout behavioral and social science (BSS) learning content. BSS represents a core component of medical education in the United Kingdom. In this paper, we examine, through (auto)ethnographic data and reflections, the experiences of BSS in medical education. The empirical data and insights have been collected in two ways: (1) through long-term ethnographic fieldwork among medical students and (2) via autoethnographic reflexive practice undertaken by the co-authors who studied, worked, examined, and collaborated with colleagues at different UK medical schools. Our findings indicate that despite BSS constituting a mandatory, essential component of the medical curriculum, medical students did not always perceive BSS as useful for their future practice as doctors, nor did they find it to be clinically relevant, in comparison to the biomedical learning content. We suggest that it is paramount for all stakeholders to commit to cultivating and developing cultural competency skills in medical education, through robustly embedding BSS learning content across the undergraduate medical curriculum. We conclude with recommendations for a wide range of educational practices that would ensure a full integration of BSS in the medical curriculum

    Transparent Personal Data Processing: The Road Ahead

    Get PDF
    The European General Data Protection Regulation defines a set of obligations for personal data controllers and processors. Primary obligations include: obtaining explicit consent from the data subject for the processing of personal data, providing full transparency with respect to the processing, and enabling data rectification and erasure (albeit only in certain circumstances). At the core of any transparency architecture is the logging of events in relation to the processing and sharing of personal data. The logs should enable verification that data processors abide by the access and usage control policies that have been associated with the data based on the data subject's consent and the applicable regulations. In this position paper, we: (i) identify the requirements that need to be satisfied by such a transparency architecture, (ii) examine the suitability of existing logging mechanisms in light of said requirements, and (iii) present a number of open challenges and opportunities

    Die de Rham-Kohomologie auf zweidimensionalen schwach normalen komplexen Räumen

    Full text link
    In der vorliegenden Dissertation wird die Monodromie eines isolierten kritischen Punktes einer holomorphen Abbildung f auf einem zweidimensionalen schwach normalen komplexen Raum zunächst topologisch und anschließend analytisch mittels relativer de Rham-Kohomologie untersucht. Ausgangspunkt der topologischen Beschreibung ist ein lokal triviales Faserbündel, welches sich nach einer geeigneten Einschränkung ähnlich wie bei Milnor ergibt. Wir erhalten den topologischen Gauss-Manin-Zusammenhang. Für die analytische Beschreibung werden zweidimensionale schwach normale Räume explizit mit Hilfe von Koordinatenkreuzen beschrieben. Damit kann das relative Poincaré-Lemma in den nicht kritischen Punkten von f nachgewiesen werden. Anschließend kann der Gauss-Manin-Zusammenhang analytisch definiert und unter Ausnutzung der expliziten Beschreibung meromorph über den kritischen Wert fortgesetzt werden

    The effect of deletion of the orphan G – protein coupled receptor (GPCR) gene MrgE on pain-like behaviours in mice

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The orphan GPCR <it>MrgE </it>is one of an extended family of GPCRs that are expressed in dorsal root ganglia (DRG). Based on these expression patterns it has been suggested that GPCRs like <it>MrgE </it>may play a role in nociception however, to date, no direct supporting evidence has emerged. We generated mutant mice lacking <it>MrgE </it>and examined the effects of deletion of this gene in three pain behavioural models. The effect of <it>MrgE </it>gene deletion on expression of <it>Mrgs </it>and genes involved in sensory neurone function was also investigated.</p> <p>Results</p> <p>The absence of <it>MrgE </it>had no effect on the development of pain responses to a noxious chemical stimulus or an acute thermal stimulus. However, in contrast, the development but not the maintenance of neuropathic pain was affected by deletion of <it>MrgE</it>. The expression of <it>Mrg </it>genes was not significantly affected in the <it>MrgE </it>knockout (KO) mice with the sole exception of <it>MrgF</it>. In addition, the expression of 77 of 84 genes involved in sensory neuron development and function was also unaffected by deletion of <it>MrgE</it>. Of the 7 genes affected by <it>MrgE </it>deletion, 4 have previously been implicated in nociception.</p> <p>Conclusion</p> <p>The data suggests that <it>MrgE </it>may play a role in selective pain behavioural responses in mice.</p

    Friction Laws for Elastic Nano-Scale Contacts

    Full text link
    The effect of surface curvature on the law relating frictional forces F with normal load L is investigated by molecular dynamics simulations as a function of surface symmetry, adhesion, and contamination. Curved, non-adhering, dry, commensurate surfaces show a linear dependency, F proportional to L, similar to dry flat commensurate or amorphous surfaces and macroscopic surfaces. In contrast, curved, non-adhering, dry, amorphous surfaces show F proportional to L^(2/3) similar to friction force microscopes. In our model, adhesive effects are most adequately described by the Hertz plus offset model, as the simulations are confined to small contact radii. Curved lubricated or contaminated surfaces show again different behavior; details depend on how much of the contaminant gets squeezed out of the contact. Also, it is seen that the friction force in the lubricated case is mainly due to atoms at the entrance of the tip.Comment: 7 pages, 5 figures, submitted to Europhys. Let

    Integrating Fiber Optic Strain Sensors into Metal Using Ultrasonic Additive Manufacturing

    Get PDF
    Ultrasonic additive manufacturing, a rather new three-dimensional (3D) printing technology, uses ultrasonic energy to produce metallurgical bonds between layers of metal foils near room temperature. This low temperature attribute of the process enables integration of temperature sensitive components, such as fiber optic strain sensors, directly into metal structures. This may be an enabling technology for Digital Twin applications, i.e., virtual model interaction and feedback with live load data. This study evaluates the consolidation quality, interface robustness, and load sensing limits of commercially available fiber optic strain sensors embedded into aluminum alloy 6061. Lastly, an outlook on the technology and its applications is described

    Development of Reacted Channel During Flow of CO2 Rich Water Along a Cement Fracture

    Get PDF
    AbstractLab scale experiments were performed to characterize how coupling between reaction and flow affect time-dependent flux of CO2-rich water along leaky wells. The core flow system applies confining stress to a cement core with a single tensile fracture while CO2-rich water is injected at constant rate and elevated pore pressure. Results show no significant variation in pressure differential, despite the development of a texturally distinct calcium depleted channel along the fracture surfaces which is bounded by thin rims of precipitation. Silicon rich material remains in the channel and prevents wormhole development and large increases in aperture. Implications for time-dependent CO2 leakage are that even with high fluid flux, the leak does not get appreciably worse

    Data Privacy Vocabularies and Controls: Semantic Web for Transparency and Privacy

    Get PDF
    Managing Privacy and understanding the handling of personal data has turned into a fundamental right-at least for Europeans-since May 25th with the coming into force of the General Data Protection Regulation. Yet, whereas many different tools by different vendors promise companies to guarantee their compliance to GDPR in terms of consent management and keeping track of the personal data they handle in their processes, interoperability between such tools as well uniform user facing interfaces will be needed to enable true transparency, user-configurable and -manageable privacy policies and data portability (as also implicitly promised by GDPR). We argue that such interoperability can be enabled by agreed upon vocabularies and Linked Data

    Urodynamic Evaluation in Multiple System Atrophy: A Retrospective Cohort Study.

    Get PDF
    Background: Urological dysfunction in patients with multiple system atrophy (MSA) is one of the main manifestations of autonomic failure. Urodynamic examination is clinically relevant since underlying pathophysiology of lower urinary tract (LUT) dysfunction can be variable. Objective: Evaluation of the pathophysiology of urological symptoms and exploration of differences in urodynamic patterns of LUT dysfunction between MSA-P and MSA-C. Methods: Retrospective study of patients with possible and probable MSA who were referred for urodynamic studies between 2004 and 2019. Demographic data, medical history, physical examination and urodynamic studies assessing storage and voiding dysfunction were obtained. Results: Seventy-four patients were included in this study (MSA-P 64.9% n = 48; median age 62.5 (IQR 56.8-70) years). Detrusor overactivity during filling phase was noted in 58.1% (n = 43) of the patients. In the voiding phase, detrusor sphincter dyssynergia and detrusor underactivity were observed in 24.6% (n = 17) and in 62.1% (n = 41) of the patients, respectively. A postmicturition residual volume of over 100 ml was present in 71.4% (n = 50) of the patients. Comparison of MSA subtypes showed weaker detrusor contractility in MSA-P compared to MSA-C [pdetQmax 26.2 vs. 34.4 cmH20, P = 0.04]. In 56.2% (n = 41) of patients pathophysiology of LUT dysfunction was deemed to be neurogenic and consistent with the diagnosis of MSA. In 35.6% (n = 26) urodynamic pattern suggested other urological co-morbidities. Conclusion: Urodynamic evaluation is an important tool to analyze the pattern of LUT dysfunction in MSA. Impaired detrusor contractility was seen more in MSA-P which needs to be investigated in further studies
    • …
    corecore