589 research outputs found

    Rotational precision MEMS-based clamping mechanism for stable fixation of elastic mechanisms

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    Conventional TEM sample manipulators often lack the crucial stability of 0.1 nm/min. A MEMS manipulator attached directly to the TEM pole would greatly increase both thermal and dynamic stability. However a stable E-beam requires no interference of electric or magnetic fields. Therefore the manipulator should be stably fixed without power. To this end a mechanical clamp is presented which clamps one of the actuators of the TEM sample manipulator (Figure 2). The clamp incorporates a relatively large clamp force of 0.5 mN with respect to the device area and is able to maintain the clamp force without external power. In previous work [1] a theoretical basis has been presented of an earlier clamp version. In this paper a rotational clamp which has been made and tested is presented. This clamp design is part of a research project for a 6 Degree of Freedom MEMS TEM sample manipulator. \u

    Health care consumption and costs due to foot and ankle injuries in the Netherlands, 1986-2010

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    Background: Foot and ankle injuries account for a large proportion of Emergency Department attendance. The aim of this study was to assess population-based trends in attendances due to foot and ankle injuries in the Netherlands since 1986, and to provide a detailed analysis of health care costs in these patients. Methods. Age- and gender-standardized emergency attendance rates and incidence rates for hospital admission were calculated for each year of the study. Injury cases and hospital length of stay were extracted from the National Injury Surveillance System (non-hospitalized patients) and the National Medical Registration (hospitalized patients). Data were grouped into osseous and ligamentous injuries for foot and ankle separately. An incidence-based cost model was applied to calculate associated direct health care costs. Results: Since 1986 the overall emergency attendance rate decreased from 858 to 640 per 100,000 person years. In non-admitted patients (90% of cases), ligamentous injuries approximately halved, whereas osseous injuries increased by 28% (foot) and 25% (ankle). The incidence rate for hospital admission increased by 35%, mainly due to an almost doubling of osseous injuries. Attendance rates showed a peak in adolescents and adults until ∼45 years of age in males and (less pronounced) in females. The total number of hospital days decreased to 58,708 days in 2010. Hospital length of stay (HLOS) increased with age and was highest for osseous injuries. HLOS was unaffected by gender, apart for longer stay in elderly females with an osseous ankle injury. Health care costs per case were highest for osseous injuries of the ankle ( 3,461). Costs were higher for females and increased with age to 6,023 in elderly males and 10,949 in elderly females. Main cost determinants were in-hospital care (56% of total costs), rehabilitation/nursing care (15%), and physical therapy (12%). Conclusions: Since 1986, the emergency attendance rate of foot and ankle injuries in the Netherlands decreased by 25%. Throughout the years, the attendance rate of (relatively simple) ligamentous injuries strongly reduced, whereas osseous injuries nearly doubled. Attendance rates and health care costs were gender- and age-related. Main cost determinants were in-hospital care, rehabilitation/ nursing care, and physical therapy

    Comparative genome analysis of a large Dutch Legionella pneumophila strain collection identifies five markers highly correlated with clinical strains

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    <p>Abstract</p> <p>Background</p> <p>Discrimination between clinical and environmental strains within many bacterial species is currently underexplored. Genomic analyses have clearly shown the enormous variability in genome composition between different strains of a bacterial species. In this study we have used <it>Legionella pneumophila</it>, the causative agent of Legionnaire's disease, to search for genomic markers related to pathogenicity. During a large surveillance study in The Netherlands well-characterized patient-derived strains and environmental strains were collected. We have used a mixed-genome microarray to perform comparative-genome analysis of 257 strains from this collection.</p> <p>Results</p> <p>Microarray analysis indicated that 480 DNA markers (out of in total 3360 markers) showed clear variation in presence between individual strains and these were therefore selected for further analysis. Unsupervised statistical analysis of these markers showed the enormous genomic variation within the species but did not show any correlation with a pathogenic phenotype. We therefore used supervised statistical analysis to identify discriminating markers. Genetic programming was used both to identify predictive markers and to define their interrelationships. A model consisting of five markers was developed that together correctly predicted 100% of the clinical strains and 69% of the environmental strains.</p> <p>Conclusions</p> <p>A novel approach for identifying predictive markers enabling discrimination between clinical and environmental isolates of <it>L. pneumophila </it>is presented. Out of over 3000 possible markers, five were selected that together enabled correct prediction of all the clinical strains included in this study. This novel approach for identifying predictive markers can be applied to all bacterial species, allowing for better discrimination between strains well equipped to cause human disease and relatively harmless strains.</p

    Exact Half-BPS Flux Solutions in M-theory III: Existence and rigidity of global solutions asymptotic to AdS4 x S7

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    The BPS equations in M-theory for solutions with 16 residual supersymmetries, SO(2,2)×SO(4)×SO(4)SO(2,2)\times SO(4)\times SO(4) symmetry, and AdS4×S7AdS_4 \times S^7 asymptotics, were reduced in [arXiv:0806.0605] to a linear first order partial differential equation on a Riemann surface with boundary, subject to a non-trivial quadratic constraint. In the present paper, suitable regularity and boundary conditions are imposed for the existence of global solutions. We seek regular solutions with multiple distinct asymptotic AdS4×S7AdS_4 \times S^7 regions, but find that, remarkably, such solutions invariably reduce to multiple covers of the M-Janus solution found by the authors in [arXiv:0904.3313], suggesting rigidity of the half-BPS M-Janus solution. In particular, we prove analytically that no other smooth deformations away from the M-Janus solution exist, as such deformations invariably violate the quadratic constraint. These rigidity results are contrasted to the existence of half-BPS solutions with non-trivial 4-form fluxes and charges asymptotic to AdS7×S4AdS_7 \times S^4. The results are related to the possibility of M2-branes to end on M5-branes, but the impossibility of M5-branes to end on M2-branes, and to the non-existence of half-BPS solutions with simultaneous AdS4×S7AdS_4 \times S^7 and AdS7×S4AdS_7 \times S^4 asymptotic regions.Comment: 52 pages, 2 figures, pdf-latex. Minor change
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