259 research outputs found

    Histology in 3D:development of an online interactive student resource on epithelium

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    Epithelium is an important and highly specialised tissue type that makes up the lining of inner and outer surfaces of the human body. It is proposed that a self-study tool adds to efficient learning and lecturing on this complicated topic in medical curricula. This paper describes the development and evaluation of an online interactive 3D resource on epithelium for undergraduate medical students. A first evaluation was carried out by means of an online survey (n = 37). The resource was evaluated positively on the website in general, its visual contents and its value and potential for the medical curriculum

    Exterior and interior metrics with quadrupole moment

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    We present the Ernst potential and the line element of an exact solution of Einstein's vacuum field equations that contains as arbitrary parameters the total mass, the angular momentum, and the quadrupole moment of a rotating mass distribution. We show that in the limiting case of slowly rotating and slightly deformed configuration, there exists a coordinate transformation that relates the exact solution with the approximate Hartle solution. It is shown that this approximate solution can be smoothly matched with an interior perfect fluid solution with physically reasonable properties. This opens the possibility of considering the quadrupole moment as an additional physical degree of freedom that could be used to search for a realistic exact solution, representing both the interior and exterior gravitational field generated by a self-gravitating axisymmetric distribution of mass of perfect fluid in stationary rotation.Comment: Latex, 15 pages, 3 figures, final versio

    Evolution of virulence: triggering host inflammation allows invading pathogens to exclude competitors.

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    Virulence is generally considered to benefit parasites by enhancing resource-transfer from host to pathogen. Here, we offer an alternative framework where virulent immune-provoking behaviours and enhanced immune resistance are joint tactics of invading pathogens to eliminate resident competitors (transferring resources from resident to invading pathogen). The pathogen wins by creating a novel immunological challenge to which it is already adapted. We analyse a general ecological model of 'proactive invasion' where invaders not adapted to a local environment can succeed by changing it to one where they are better adapted than residents. However, the two-trait nature of the 'proactive' strategy (provocation of, and adaptation to environmental change) presents an evolutionary conundrum, as neither trait alone is favoured in a homogenous host population. We show that this conundrum can be resolved by allowing for host heterogeneity. We relate our model to emerging empirical findings on immunological mediation of parasite competition

    Effects of acceleration on the collision of particles in the rotating black hole spacetime

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    We study the collision of two geodesic particles in the accelerating and rotating black hole spacetime and probe the effects of the acceleration of black hole on the center-of-mass energy of the colliding particles and on the high-velocity collision belts. We find that the dependence of the center-of-mass energy on the acceleration in the near event-horizon collision is different from that in the near acceleration-horizon case. Moreover, the presence of the acceleration changes the shape and position of the high-velocity collision belts. Our results show that the acceleration of black holes brings richer physics for the collision of particles.Comment: 7 pages, 2 figures, The corrected version accepted for publication in EPJ

    A rotating three component perfect fluid source and its junction with empty space-time

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    The Kerr solution for empty space-time is presented in an ellipsoidally symmetric coordinate system and it is used to produce generalised ellipsoidal metrics appropriate for the generation of rotating interior solutions of Einstein's equations. It is shown that these solutions are the familiar static perfect fluid cases commonly derived in curvature coordinates but now endowed with rotation. The resulting solutions are also discussed in the context of T-solutions of Einstein's equations and the vacuum T-solution outside a rotating source is presented. The interior source for these solutions is shown not to be a perfect fluid but rather an anisotropic three component perfect fluid for which the energy momentum tensor is derived. The Schwarzschild interior solution is given as an example of the approach.Comment: 14 page

    Effect of liraglutide on cardiovascular outcomes in elderly patients: A post hoc analysis of a randomized controlled trial

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    Background: Comorbidities and complications associ-ated with type 2 diabetes mellitus (T2DM) increase with age, making treatment of elderly persons with this condition chal-lenging. Clinical data on the effect of antihyperglycemic treat-ment on cardiovascular (CV) events in elderly persons are limited (1). The U.S. Food and Drug Administration and Euro-pean Medicines Agency recommend collecting comprehen-sive data on elderly patients with diabetes, particularly those aged 75 years or older, to inform appropriate treatment of this growing populatio

    One-dimensional quantum channel and Hawking radiation of the Kerr and Kerr-Newman black holes

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    In this paper, we review the one-dimensional quantum channel and investigate Hawking radiation of bosons and fermions in Kerr and Kerr-Newman black holes. The result shows the Hawking radiation can be described by the quantum channel. The thermal conductances are derived and related to the black holes' temperatures.Comment: V2, 12 pages. Typo correcte
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