219 research outputs found

    Het project 'Monitoring Diergezondheid', beschrijving en analyse van doorlopen processen

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    Het doel van het project is om tot een gemeenschappelijk ontwerp voor een informatieverzamelings- en analysesysteem te komen ten behoeve van de monitoring van diergezondheid én voedselveiligheid, dat kan rekenen op een breed draagvlak bij publieke en private partijen; draagvlak dat noodzakelijk is voor de realisering van zo’n dataverzame-lingssysteem (uit projectplan, 23 januari 2004). Dit ontwerp is echter nooit in de praktijk gerealiseerd. Een beschrijving en analyse van het proces van de laatste jaren in het project ‘Monitoring Diergezondheid’, is in dit document vastgelegd. Tevens zijn ervaringen die in dit project zijn opgedaan door het projectteam, inzichtelijk en bruikbaar gemaakt voor andere

    OH-selected AGB and post-AGB stellar objects II.Blue versus red evolution off the AGB

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    Using objects found in a systematic survey of the galactic Plane in the 1612-MHz OH line, we discuss in detail two ``sequences'' of post-AGB evolution, a red and a blue. We argue that the red and the blue groups separate by initial mass at 4Msun, based on evolutionary-sequence turn-off colours, spectral energy distributions, outflow velocities and scaleheight. The higher-mass (blue) objects may have earlier AGB termination. The lower-mass (red) objects undergo very sudden reddening for IRAS colour R21\sim1.2; these sources must all undergo a very similar process at AGB termination. The transition colour corresponds to average initial masses of 1.7Msun. A combined IRAS-MSX colour proves a very sensitive tool to distinguish lower-mass, early post-AGB objects from sources still on the AGB and also to distinguish more evolved post-AGB objects from star-forming regions. The high-mass blue objects are the likely precursors of bipolar planetary nebulae, whereas the low-mass red objects will evolve into elliptical planetary nebulae.Comment: 12 pages, LaTex, 7 figures (1 colour), AJ (accepted

    Leren van beleidsinstrumenten voor ondernemen met natuur

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    Deze brochure is gebaseerd op bevindingen uit het project Leren van Beleidsinstrumenten voor Ondernemen met Natuur deel uitmakend van het beleidsondersteunend onderzoek van het ministerie van EZ. Aanleiding vormde de zoektocht naar nieuwe rollen van de overheid bij de vermaatschappelijking van het natuurbeleid en de behoefte van het Team Natuurlijk! Ondernemen om daarbij te leren van praktijkervaringen met beleidsinstrumenten die het team al inzet. Voor de casestudy zijn relevante documenten geanalyseerd en betrokkenen bij de implementatie van het Revolverend Fonds van het Nationaal Groenfonds en de Green Deals Natuur en Recreatie geïnterviewd. Een uitvoeringsovereenkomst (1995) tussen rijk, provincies en Nationaal Groenfonds is de basis van het Revolverend Fon

    Astrometric Microlensing with the GAIA satellite

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    GAIA is the ``super-Hipparcos'' survey satellite selected as a Cornerstone 6 mission by the European Space Agency. GAIA can measure microlensing by the small excursions of the light centroid that occur during events. The all-sky source-averaged astrometric microlensing optical depth is about 10^{-5}. Some 25000 sources will have a significant variation of the centroid shift, together with a closest approach, during the lifetime of the mission. A covariance analysis is used to study the propagation of errors and the estimation of parameters from realistic sampling of the GAIA datastream of transits in the along-scan direction during microlensing events. Monte Carlo simulations are used to study the 2500 events for which the mass can be recovered with an error of less than 50 per cent. These high quality events are dominated by disk lenses within a few tens of parsecs and source stars within a few hundred parsecs. We show that the local mass function can be recovered from the high quality sample to good accuracy. GAIA is the first instrument with the capabilities of measuring the mass locally in very faint objects like black holes and very cool white and brown dwarfs. For only 5 per cent of all astrometric events will GAIA record even one photometric datapoint. There is a need for a dedicated telescope that densely samples the Galactic Centre and spiral arms, as this can improve the accuracy of parameter estimation by a factor of about 10.Comment: 18 pages, 18 figures, MNRAS, in pres

    Scanning tunneling microscopy and spectroscopy at low temperatures of the (110) surface of Te doped GaAs single crystals

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    We have performed voltage dependent imaging and spatially resolved spectroscopy on the (110) surface of Te doped GaAs single crystals with a low temperature scanning tunneling microscope (STM). A large fraction of the observed defects are identified as Te dopant atoms which can be observed down to the fifth subsurface layer. For negative sample voltages, the dopant atoms are surrounded by Friedel charge density oscillations. Spatially resolved spectroscopy above the dopant atoms and above defect free areas of the GaAs (110) surface reveals the presence of conductance peaks inside the semiconductor band gap. The appearance of the peaks can be linked to charges residing on states which are localized within the tunnel junction area. We show that these localized states can be present on the doped GaAs surface as well as at the STM tip apex.Comment: 8 pages, 8 figures, accepted for publication in PR

    2020 ESC Guidelines on acute coronary syndrome without ST-segment elevation Recommendations and critical appraisal from the Dutch ACS and Interventional Cardiology working groups

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    Recently, the European Society of Cardiology (ESC) has updated its guidelines for the management of patients with acute coronary syndrome (ACS) without ST-segment elevation. The current consensus document of the Dutch ACS working group and the Working Group of Interventional Cardiology of the Netherlands Society of Cardiology aims to put the 2020 ESC Guidelines into the Dutch perspective and to provide practical recommendations for Dutch cardiologists, focusing on antiplatelet therapy, risk assessment and criteria for invasive strategy.</p

    2020 ESC Guidelines on acute coronary syndrome without ST-segment elevation: recommendations and critical appraisal from the Dutch ACS and Interventional Cardiology working groups

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    Recently, the European Society of Cardiology (ESC) has updated its guidelines for the management of patients with acute coronary syndrome (ACS) without ST-segment elevation. The current consensus document of the Dutch ACS working group and the Working Group of Interventional Cardiology of the Netherlands Society of Cardiology aims to put the 2020 ESC Guidelines into the Dutch perspective and to provide practical recommendations for Dutch cardiologists, focusing on antiplatelet therapy, risk assessment and criteria for invasive strategy.Cardiolog
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