1,722 research outputs found

    Development of supercritical pressure cryogenic storage and supply systems incorporating the radial bumper-discrete shield design Final report

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    Design of super critical pressure cryogenic storage and supply equipment with radial bumper shiel

    Schuivende panelen

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    Schuivende panelen was de titel van een partijprogramma uit de jaren tachtig. Deze rede is echter geen politiek manifest. Hoewel een wetenschapper in staat moet zijn om politiek te bedrijven en de Allergologie als discipline sinds haar oprichting speelbal geweest is van politieke krachten gaat deze lezing vooral over verschuivingen en ontwikkelingen in het vakgebied. rede In verkorte vorm uitgesproken ter gelegenheid van het aanvaarden van het ambt van bijzonder hoogleraar met als leeropdracht Allergologie aan het Erasmus MC, faculteit van de Erasmus Universiteit Rotterdam, op 20 april 200

    Positive and negative AIT trials: What makes the difference?

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    Background: Allergen immunotherapy has proven to be efficacious in allergic rhinitis and asthma. However, results from randomised clinical trials may vary substantially. Clinical trials may unexpectedly fail. The purpose of this review is to discuss the possible factors that may contribute to a successful or unsuccessful study. Methods: Descriptive review exploring the possible causes of negative outcomes in allergen immunotherapy trials. Results: A series of factors may lead to negative results. Among of these are underpowering of the study, low allergen content in tested extracts, insufficient allergen exposure during monitoring and recruitment of inappropriate patients. In addition, the choice of the primary endpoint may be critical. Discussion: A clinical trial aims to evaluate the efficacy of an agent. However, studies with potential effective compounds may fail because of methodical issues. Sometimes, they are the cause of discrepancies between successful phase II and unsuccessful phase III trials. To understand more about failure of studies, investigators and editors should be encouraged to publish negative trials

    Comparison of nasal responsiveness to histamine, methacholine and phentolamine in allergic rhinitis patients and controls

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    In a selected group of rhinitis patients with an IgE‐mediated allergy to house dust mites the nasal response to insufflation of histamine chloride, methacholine and phentolamine was demonstrated to be higher than in a control group. With the methods used histamine chloride was better at discriminating between healthy subjects and patients than methacholine or phentolamine. This discrimination was shown by assessing the severity of reflex‐mediated symptoms such as the number of sneezes and the amount of secretion, and not by differences in nasal airway resistance. Copyrigh

    Nasal allergy to avian antigens

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    This study describes the case of a patient who developed symptoms of rhinoconjunctivitis on exposure to budgerigars and parrots. An IgE‐mediated allergy to budgerigar, parrot and pigeon antigens was demonstrated using both in‐vivo challenge tests (skin and nasal provocation tests) and in‐vitro investigations (radio‐allergo‐sorbent test, histamine release test). The study shows that the development of nasal disease can be associated with allergy to avian antigens. Copyrigh

    Start to end simulations of the ERL prototype at Daresbury Laboratory

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    Daresbury Laboratory is currently building an Energy Recovery Linac Prototype (ERLP) that will serve as a research and development facility for the study of beam dynamics and accelerator technology important to the design and construction of the proposed 4th Generation Light Source (4GLS) project. Two major objectives of the ERLP are the demonstration of energy recovery and of energy recovery from a beam disrupted by an FEL interaction as supplied by an infrared oscillator system. In this paper we present start-to-end simulations of the ERLP including such an FEL interaction. The beam dynamics in the highbrightness injector, which consists of a DC photocathode Gun and a superconducting booster, have been modelled using the particle tracking code ASTRA. After the booster the particles have been tracked with the code elegant. The 3D code GENESIS 1.3 was used to model the FEL interaction with the electron beam at 35 MeV. A brief summary of impedance and wakefield calculations for the whole machine is also given

    Compact single-shot electro-optic detection system for THz pulses with femtosecond time resolution at MHz repetition rates

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    Electro-optical detection has proven to be a valuable technique to study temporal profiles of THz pulses with pulse durations down to femtoseconds. As the Coulomb field around a relativistic electron bunch resembles the current profile, electro-optical detection can be exploited for non-invasive bunch length measurements at accelerators. We have developed a very compact and robust electro-optical detection system based on spectral decoding for bunch length monitoring at the European XFEL with single-shot resolution better than 200~fs. Apart from the GaP crystal and the corresponding laser optics at the electron beamline, all components are housed in 19\" chassis for rack mount and remote operation inside the accelerator tunnel. An advanced laser synchronization scheme based on radio-frequency down-conversion has been developed for locking a custom-made Yb-fiber laser to the radio-frequency of the European XFEL accelerator. In order to cope with the high bunch repetition rate of the superconducting accelerator, a novel linear array detector (KALYPSO) has been employed for spectral measurements of the Yb-fiber laser pulses at frame rates of up to 2.26~MHz. In this paper, we describe all sub-systems of the electro-optical detection system as well as the measurement procedure in detail, and discuss first measurement results of longitudinal bunch profiles of around 400~fs (rms) with an arrival-time jitter of 35~fs (rms)

    Geometric representations for minimalist grammars

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    We reformulate minimalist grammars as partial functions on term algebras for strings and trees. Using filler/role bindings and tensor product representations, we construct homomorphisms for these data structures into geometric vector spaces. We prove that the structure-building functions as well as simple processors for minimalist languages can be realized by piecewise linear operators in representation space. We also propose harmony, i.e. the distance of an intermediate processing step from the final well-formed state in representation space, as a measure of processing complexity. Finally, we illustrate our findings by means of two particular arithmetic and fractal representations.Comment: 43 pages, 4 figure

    Intranasal cold dry air is superior to histamine challenge in determining the presence and degree of nasal hyperreactivity in nonallergic noninfectious perennial rhinitis

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    The objective of the study was to compare cold dry air (CDA) and histamine in differentiating patients with nonallergic noninfectious perennial rhinitis (NANIPER) from control subjects. Nasal reactivity (nasal patency, mucus production, and sneezing) in 16 symptomatic nonsmoking patients with NANIPER and seven nonsmoking control subjects was measured with standardized CDA and histamine provocation series in a randomized crossover study. Intranasal CDA resulted in increased mucus production and nasal blockage in a dose-dependent manner in patients with NANIPER but not in control subjects. Sneezing did not occur. The reproducibility of CDA for patency and mucus production was good. Sen

    SAT-based Explicit LTL Reasoning

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    We present here a new explicit reasoning framework for linear temporal logic (LTL), which is built on top of propositional satisfiability (SAT) solving. As a proof-of-concept of this framework, we describe a new LTL satisfiability tool, Aalta\_v2.0, which is built on top of the MiniSAT SAT solver. We test the effectiveness of this approach by demonnstrating that Aalta\_v2.0 significantly outperforms all existing LTL satisfiability solvers. Furthermore, we show that the framework can be extended from propositional LTL to assertional LTL (where we allow theory atoms), by replacing MiniSAT with the Z3 SMT solver, and demonstrating that this can yield an exponential improvement in performance
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