38 research outputs found

    Spin Motion in Electron Transmission through Ultrathin Ferromagnetic Films Accessed by Photoelectron Spectroscopy

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    Ab initio and model calculations demonstrate that the spin motion of electrons transmitted through ferromagnetic films can be analyzed in detail by means of angle- and spin-resolved core-level photoelectron spectroscopy. The spin motion appears as precession of the photoelectron spin polarization around and as relaxation towards the magnetization direction. In a systematic study for ultrathin Fe films on Pd(001) we elucidate its dependence on the Fe film thickness and on the Fe electronic structure. In addition to elastic and inelastic scattering, the effect of band gaps on the spin motion is addressed in particular.Comment: 4 pages, 5 figure

    Dynamical electron transport through a nanoelectromechanical wire in a magnetic field

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    We investigate dynamical transport properties of interacting electrons moving in a vibrating nanoelectromechanical wire in a magnetic field. We have built an exactly solvable model in which electric current and mechanical oscillation are treated fully quantum mechanically on an equal footing. Quantum mechanically fluctuating Aharonov-Bohm phases obtained by the electrons cause nontrivial contribution to mechanical vibration and electrical conduction of the wire. We demonstrate our theory by calculating the admittance of the wire which are influenced by the multiple interplay between the mechanical and the electrical energy scales, magnetic field strength, and the electron-electron interaction

    Graph-Based Vertebra Segmentation Using a Cubic Template

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    Purpose -The current development of the population's structure leads to a growing part of older patients with a more frequent insistence for surgical treatment like lumbar spinal stenosis (LS), which is the most common cause of spinal surgery in individuals older than 65 years of age Methods -The presented approach is an extension from our recent articles [3, 4] to a third dimension and it starts by setting up a directed 3D graph from a user-defined seed point that is located inside the vertebra. To set up the graph, the method samples points along rays, which are distributed on a cube's surface. The sampled points are the nodes n V of the graph G(V,E) and e E is a corresponding set of edges. Besides, there are (inter-) edges between the nodes and there are edges that connect the nodes to a source s and a sink t. An additional delta value determines the construction of the xy-edges and therefore the smoothness of the segmentation results, like shown in the image on the right side. After the graph has been generated, the minimal cost closed set on the graph is calculated via a polynomial time s-t-cu

    Preventive home care of frail older people: a review of recent case management studies.

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    Preventive actions targeting community-dwelling frail older people will be increasingly important with the growing number of very old and thereby also frail older people. This study aimed to explore and summarize the empirical literature on recent studies of case/care management interventions for community-dwelling frail older people and especially with regard to the content of the interventions and the nurse's role and outcome of it. Very few of the interventions took either a preventive or a rehabilitative approach using psycho-educative interventions focusing, for instance, on self-care activities, risk prevention, health complaints management or how to preserve or strengthen social activities, community involvement and functional ability. Moreover, it was striking that very few included a family-oriented approach also including support and education for informal caregivers. Thus it seems that the content of case/care management needs to be expanded and more influenced by a salutogenic health care perspective. Targeting frail older people seemed to benefit from a standardized two-stage strategy for inclusion and for planning the interventions. A comprehensive geriatric assessment seemed useful as a base. Nurses, preferably trained in gerontological practice, have a key role in case/care management for frail older people. This approach calls for developing the content of case/care management so that it involves a more salutogenic, rehabilitative and family-oriented approach. To this end it may be useful for nurses to strengthen their psychosocial skills or develop close collaboration with social workers. The outcome measures examined in this study represented one of three perspectives: the consumer's perspective, the perspective of health care consumption or the recipient's health and functional ability. Perhaps effects would be expected in all three areas and thus these should be included in evaluative studies in addition to measures for family and/or informal caregiver's strain and satisfaction
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