1,588 research outputs found

    Development of railway contracting for the national passenger rail services in the Netherlands

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    This article mainly gives an overview of the policy developments in the Dutch railway sector over the past decade. The sector has come a long way and the outlook now looks positive. Customer satisfaction and performance have improved and the number of people that travel by train is rising. The development of a more long-term policy window for the sector seems to have brought rest and stability and room for continuous growth of passenger numbers. The combination of a policy making and negotiation regulatory style seems to have worked out very well on the performance of the sector. In a second section the paper also considers a theoretical framework on regulation schemes and develops a first tentative attempt to apply these schemes on an analysis of the Dutch railway sector by giving some statements for discussion.Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne

    Spiral Computed Tomography Based Maxillary Sinus Imaging in Relation to Tooth Loss, Implant Placement and Potential Grafting Procedure

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    Objectives: The purpose of the present study was to explore the maxillary sinus anatomy, its variations and volume in patients with a need for maxillary implant placement.Materials and Methods: Maxillary sinus data of 101 consecutive patients who underwent spiral computed tomography (CT) scans for preoperative implant planning in the maxilla at the Department of Periodontology, University Hospital, Catholic University of Leuven, Leuven, Belgium were retrospectively evaluated. The alveolar bone height was measured on serial cross-sectional images between alveolar crest and sinus floor, parallel to the tooth axis. In order to describe the size of the maxillary sinus anteroposterior (AP) and mediolateral (ML) diameters of the sinus were measured.Results: The results indicated that the alveolar bone height was significantly higher in the premolar regions in comparison to the molar region (n = 46, P < 0.01). The age showed negative relation to bone dimension (r = - 0.32, P = 0.04).Anterior and posterior border of the maxillary sinuses were mostly located in the first premolar (49%) and second molar (84%) regions, respectively. Maxillary sinus septa were indentified in 47% of the maxillary antra. Almost 2/3 (66%) of the patients showed major (> 4 mm) mucosal thickening mostly at the level of the sinus floor. The present sample did not allow revealing any significant difference (P > 0.05) in maxillary sinus dimensions for partially dentate and edentulous subjects.Conclusions: Cross-sectional imaging can be used in order to obtain more accurate information on the morphology, variation, and the amount of maxillary bone adjacent to the maxillary sinus

    Three-Dimensionally Preserved Integument Reveals Hydrodynamic Adaptations in the Extinct Marine Lizard Ectenosaurus (Reptilia, Mosasauridae)

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    The physical properties of water and the environment it presents to its inhabitants provide stringent constraints and selection pressures affecting aquatic adaptation and evolution. Mosasaurs (a group of secondarily aquatic reptiles that occupied a broad array of predatory niches in the Cretaceous marine ecosystems about 98–65 million years ago) have traditionally been considered as anguilliform locomotors capable only of generating short bursts of speed during brief ambush pursuits. Here we report on an exceptionally preserved, long-snouted mosasaur (Ectenosaurus clidastoides) from the Santonian (Upper Cretaceous) part of the Smoky Hill Chalk Member of the Niobrara Formation in western Kansas, USA, that contains phosphatized remains of the integument displaying both depth and structure. The small, ovoid neck and/or anterior trunk scales exhibit a longitudinal central keel, and are obliquely arrayed into an alternating pattern where neighboring scales overlap one another. Supportive sculpturing in the form of two parallel, longitudinal ridges on the inner scale surface and a complex system of multiple, superimposed layers of straight, cross-woven helical fiber bundles in the underlying dermis, may have served to minimize surface deformation and frictional drag during locomotion. Additional parallel fiber bundles oriented at acute angles to the long axis of the animal presumably provided stiffness in the lateral plane. These features suggest that the anterior torso of Ectenosaurus was held somewhat rigid during swimming, thereby limiting propulsive movements to the posterior body and tail

    Influence of applying different units of measurement on reporting antimicrobial consumption data for pig farms

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    Background: Antimicrobial use in livestock is one of the factors contributing to selection and spread of resistant microorganisms in the environment. National ve

    Epidemiology of chronic inflammatory demyelinating polyradiculoneuropathy in The Netherlands

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    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare but disabling disorder that often requires long‐term immunomodulatory treatment. Background incidence rates and prevalence and risk factors for developing CIDP are still poorly defined. In the current study, we used a longitudinal population‐based cohort study in The Netherlands to assess these rates and demographic factors and comorbidity associated with CIDP. We determined the incidence rate and prevalence of CIDP between 2008 and 2017 and the occurrence of potential risk factors in a retrospective Dutch cohort study using the Integrated Primary Care Information (IPCI) database. Cases were defined as CIDP if the diagnosis of CIDP was described in the electronic medical file. In a source population of 928 030 persons with a contributing follow‐up of 3 525 686 person‐years, we identified 65 patients diagnosed with CIDP. The overall incidence rate was 0.68 per 100 000 person‐years (95% CI 0.45‐0.99). The overall prevalence was 7.00 per 100 000 individuals (95% CI 5.41‐8.93). The overall incidence rate was higher in men compared to woman (IRR 3.00, 95% CI 1.27‐7.11), and higher in elderly of 50 years or older compared with people <50 years of age (IRR 17 95% CI 4‐73). Twenty percent of CIDP cases had DM and 9% a co‐existing other auto‐immune disease. These background rates are important to monitor changes in the frequency of CIDP following infectious disease outbreaks, identify potential risk factors, and to estimate the social and economic burden of CIDP

    Elliptically shaped quad-ridge horn antennas as feed for a reflector

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    Quad-ridge horn antennas of various geometries are considered as possible candidates for a wideband reflector antenna feed. It is demonstrated that shaping the sidewalls of the ridge horns significantly improves the radiation characteristics of the horns. The conical quad-ridge horn with an elliptically shaped sidewall shows the most promise as a wideband reflector antenna feed. The radiation patterns are rotationally symmetric, and the 10-dB beamwidth is reasonably constant over a wide frequency range.http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?reload=true&punumber=772

    Quad-ridge horn antenna with elliptically shaped sidewalls

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    We present a quad-ridge horn antenna as a feed for a reflector antenna for use in radio astronomy applications. The antenna uses elliptically shaped sidewalls to limit the variation of beamwidth over a wide frequency range and to obtain greater radiation pattern rotational symmetry. The antenna is dual-polarized and matched over more than a 4:1 bandwidth. A design procedure is presented and a prototype designed according to this procedure is shown. Measured and simulated results of the prototype agree with each other well. The antenna is analyzed with a prime focus reflector to determine the range of efficiencies that can be expected.National Research Foundationhttp://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=8hb2014ai201

    Systemic and Intra-Nodal Activation of NK Cells After Rituximab Monotherapy for Follicular Lymphoma

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    Monotherapy with the anti-CD20 monoclonal antibody rituximab can induce complete responses (CR) in patients with follicular lymphoma (FL). Resting FcRγIII+ (CD16+) natural killer (NK) cells respond strongly to rituximab-coated target cells in vitro. Yet, the contribution of NK cells in the therapeutic effect in vivo remains unknown. Here, we followed the NK cell repertoire dynamics in the lymph node and systemically during rituximab monotherapy in patients with FL. At baseline, NK cells in the tumor lymph node had a naïve phenotype albeit they were more differentiated than NK cells derived from control tonsils as determined by the frequency of CD56dim NK cells and the expression of killer cell immunoglobulin-like receptors (KIR), CD57 and CD16. Rituximab therapy induced a rapid drop in NK cell numbers coinciding with a relative increase in the frequency of Ki67+ NK cells both in the lymph node and peripheral blood. The Ki67+ NK cells had slightly increased expression of CD16, CD57 and higher levels of granzyme A and perforin. The in vivo activation of NK cells was paralleled by a temporary loss of in vitro functionality, primarily manifested as decreased IFNγ production in response to rituximab-coated targets. However, patients with pre-existing NKG2C+ adaptive NK cell subsets showed less Ki67 upregulation and were refractory to the loss of functionality. These data reveal variable imprints of rituximab monotherapy on the NK cell repertoire, which may depend on pre-existing repertoire diversity
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