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136 results on '"Kooistra, E."'

1. Apertif, Phased Array Feeds for the Westerbork Synthesis Radio Telescope

Author

van Cappellen, W. A., Oosterloo, T. A., Verheijen, M. A. W., Adams, E. A. K., Adebahr, B., Braun, R., Hess, K. M., Holties, H., van der Hulst, J. M., Hut, B., Kooistra, E., van Leeuwen, J., Loose, G. M., Morganti, R., Moss, V. A., Orrú, E., Ruiter, M., Schoenmakers, A. P., Vermaas, N. J., Wijnholds, S. J., van Amesfoort, A. S., Arts, M. J., Attema, J. J., Bakker, L., Bassa, C. G., Bast, J. E., Benthem, P., Beukema, R., Blaauw, R., de Blok, W. J. G., Bouwhuis, M., Brink, R. H. van den, Connor, L., Coolen, A. H. W. M., Damstra, S., van Diepen, G. N. J., de Goei, R., Dénes, H., Drost, M., Ebbendorf, N., Frank, B. S., Gardenier, D. W., Gerbers, M., Grange, Y. G., Grit, T., Gunst, A. W., Gupta, N., Ivashina, M. V., Józsa, G. I. G., Janssen, G. H., Koster, A., Kruithof, G. H., Kuindersma, S. J., Kutkin, A., Lucero, D. M., Maan, Y., Maccagni, F. M., van der Marel, J., Mika, A., Morawietz, J., Mulder, H., Mulder, E., Norden, M. J., Offringa, A. R., Oostrum, L. C., Overeem, R. E., Paragi, Z., Pepping, H. J., Petroff, E., Pisano, D. J., Polatidis, A. G., Prasad, P., de Reijer, J. P. R., Romein, J. W., Schaap, J., Schoonderbeek, G. W., Schulz, R., van der Schuur, D., Sclocco, A., Sluman, J. J., Smits, R., Stappers, B. W., Straal, S. M., Stuurwold, K. J. C., Verstappen, J., Vohl, D., Wierenga, K. J., Woestenburg, E. E. M., Zanting, A. W., and Ziemke, J.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

We describe the APERture Tile In Focus (Apertif) system, a phased array feed (PAF) upgrade of the Westerbork Synthesis Radio Telescope which has transformed this telescope into a high-sensitivity, wide field-of-view L-band imaging and transient survey instrument. Using novel PAF technology, up to 40 partially overlapping beams can be formed on the sky simultaneously, significantly increasing the survey speed of the telescope. With this upgraded instrument, an imaging survey covering an area of 2300 deg2 is being performed which will deliver both continuum and spectral line data sets, of which the first data has been publicly released. In addition, a time domain transient and pulsar survey covering 15,000 deg2 is in progress. An overview of the Apertif science drivers, hardware and software of the upgraded telescope is presented, along with its key performance characteristics., Comment: 29 pages, 42 figures, accepted for publication by A&A

Published
2021
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2. A bright, high rotation-measure FRB that skewers the M33 halo

Author

Connor, Liam, van Leeuwen, Joeri, Oostrum, L. C., Petroff, E., Maan, Yogesh, Adams, E. A. K., Attema, J. J., Bast, J. E., Boersma, O. M., Dénes, H., Gardenier, D. W., Hargreaves, J. E., Kooistra, E., Pastor-Marazuela, I., Schulz, R., Sclocco, A., Smits, R., Straal, S. M., van der Schuur, D., Vohl, Dany, Adebahr, B., de Blok, W. J. G., van Cappellen, W. A., Coolen, A. H. W. M., Damstra, S., van Diepen, G. N. J., Frank, B. S., Hess, K. M., Hut, B., Loose, G. Marcel, Lucero, D. M., Mika, Á., Moss, V. A., Mulder, H., Oosterloo, T. A., Ruiter, M., Vedantham, H., Vermaas, N. J., Wijnholds, S. J., and Ziemke, J.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We report the detection of a bright fast radio burst, FRB\,191108, with Apertif on the Westerbork Synthesis Radio Telescope (WSRT). The interferometer allows us to localise the FRB to a narrow $5\arcsec\times7\arcmin$ ellipse by employing both multibeam information within the Apertif phased-array feed (PAF) beam pattern, and across different tied-array beams. The resulting sight line passes close to Local Group galaxy M33, with an impact parameter of only 18\,kpc with respect to the core. It also traverses the much larger circumgalactic medium of M31, the Andromeda Galaxy. We find that the shared plasma of the Local Group galaxies could contribute $\sim$10\% of its dispersion measure of 588\,pc\,cm$^{-3}$. FRB\,191108 has a Faraday rotation measure of +474\,$\pm\,3$\,rad\,m$^{-2}$, which is too large to be explained by either the Milky Way or the intergalactic medium. Based on the more moderate RMs of other extragalactic sources that traverse the halo of M33, we conclude that the dense magnetised plasma resides in the host galaxy. The FRB exhibits frequency structure on two scales, one that is consistent with quenched Galactic scintillation and broader spectral structure with $\Delta\nu\approx40$\,MHz. If the latter is due to scattering in the shared M33/M31 CGM, our results constrain the Local Group plasma environment. We found no accompanying persistent radio sources in the Apertif imaging survey data.

Published
2020
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3. Repeating fast radio bursts with WSRT/Apertif

Author

Oostrum, L. C., Maan, Y., van Leeuwen, J., Connor, L., Petroff, E., Attema, J. J., Bast, J. E., Gardenier, D. W., Hargreaves, J. E., Kooistra, E., van der Schuur, D., Sclocco, A., Smits, R., Straal, S. M., ter Veen, S., Vohl, D., Adams, E. A. K., Adebahr, B., de Blok, W. J. G., Brink, R. H. van den, van Cappellen, W. A., Coolen, A. H. W. M., Damstra, S., van Diepen, G. N. J., Frank, B. S., Hess, K. M., van der Hulst, J. M., Hut, B., Ivashina, M. V., Loose, G. M., Lucero, D. M., Mika, Á., Morganti, R. H., Moss, V. A., Mulder, H., Norden, M. J., Oosterloo, T. A., Orrú, E., de Reijer, J. P. R., Ruiter, M., Vermaas, N. J., Wijnholds, S. J., and Ziemke, J.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Repeating fast radio bursts (FRBs) present excellent opportunities to identify FRB progenitors and host environments, as well as decipher the underlying emission mechanism. Detailed studies of repeating FRBs might also hold clues to the origin of FRBs as a population. We aim to detect the first two repeating FRBs: FRB 121102 (R1) and FRB 180814.J0422+73 (R2), and characterise their repeat statistics. We also want to significantly improve the sky localisation of R2. We use the Westerbork Synthesis Radio Telescope to conduct extensive follow-up of these two repeating FRBs. The new phased-array feed system, Apertif, allows covering the entire sky position uncertainty of R2 with fine spatial resolution in one pointing. We characterise the energy distribution and the clustering of detected R1 bursts. We detected 30 bursts from R1. Our measurements indicate a dispersion measure of 563.5(2) pc cm$^{-3}$, suggesting a significant increase in DM over the past few years. We place an upper limit of 8% on the linear polarisation fraction of the brightest burst. We did not detect any bursts from R2. A single power-law might not fit the R1 burst energy distribution across the full energy range or widely separated detections. Our observations provide improved constraints on the clustering of R1 bursts. Our stringent upper limits on the linear polarisation fraction imply a significant depolarisation, either intrinsic to the emission mechanism or caused by the intervening medium, at 1400 MHz that is not observed at higher frequencies. The non-detection of any bursts from R2 implies either a highly clustered nature of the bursts, a steep spectral index, or a combination of both. Alternatively, R2 has turned off completely, either permanently or for an extended period of time., Comment: 11 pages, 7 figures, submitted to A&A

Published
2019
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4. LOFAR: The LOw-Frequency ARray

Author

van Haarlem, M. P., Wise, M. W., Gunst, A. W., Heald, G., McKean, J. P., Hessels, J. W. T., de Bruyn, A. G., Nijboer, R., Swinbank, J., Fallows, R., Brentjens, M., Nelles, A., Beck, R., Falcke, H., Fender, R., Hörandel, J., Koopmans, L. V. E., Mann, G., Miley, G., Röttgering, H., Stappers, B. W., Wijers, R. A. M. J., Zaroubi, S., Akker, M. van den, Alexov, A., Anderson, J., Anderson, K., van Ardenne, A., Arts, M., Asgekar, A., Avruch, I. M., Batejat, F., Bähren, L., Bell, M. E., Bell, M. R., van Bemmel, I., Bennema, P., Bentum, M. J., Bernardi, G., Best, P., Bîrzan, L., Bonafede, A., Boonstra, A. -J., Braun, R., Bregman, J., Breitling, F., van de Brink, R. H., Broderick, J., Broekema, P. C., Brouw, W. N., Brüggen, M., Butcher, H. R., van Cappellen, W., Ciardi, B., Coenen, T., Conway, J., Coolen, A., Corstanje, A., Damstra, S., Davies, O., Deller, A. T., Dettmar, R. -J., van Diepen, G., Dijkstra, K., Donker, P., Doorduin, A., Dromer, J., Drost, M., van Duin, A., Eislöffel, J., van Enst, J., Ferrari, C., Frieswijk, W., Gankema, H., Garrett, M. A., de Gasperin, F., Gerbers, M., de Geus, E., Grießmeier, J. -M., Grit, T., Gruppen, P., Hamaker, J. P., Hassall, T., Hoeft, M., Holties, H., Horneffer, A., van der Horst, A., van Houwelingen, A., Huijgen, A., Iacobelli, M., Intema, H., Jackson, N., Jelic, V., de Jong, A., Juette, E., Kant, D., Karastergiou, A., Koers, A., Kollen, H., Kondratiev, V. I., Kooistra, E., Koopman, Y., Koster, A., Kuniyoshi, M., Kramer, M., Kuper, G., Lambropoulos, P., Law, C., van Leeuwen, J., Lemaitre, J., Loose, M., Maat, P., Macario, G., Markoff, S., Masters, J., McKay-Bukowski, D., Meijering, H., Meulman, H., Mevius, M., Middelberg, E., Millenaar, R., Miller-Jones, J. C. A., Mohan, R. N., Mol, J. D., Morawietz, J., Morganti, R., Mulcahy, D. D., Mulder, E., Munk, H., Nieuwenhuis, L., van Nieuwpoort, R., Noordam, J. E., Norden, M., Noutsos, A., Offringa, A. R., Olofsson, H., Omar, A., Orrú, E., Overeem, R., Paas, H., Pandey-Pommier, M., Pandey, V. N., Pizzo, R., Polatidis, A., Rafferty, D., Rawlings, S., Reich, W., de Reijer, J. -P., Reitsma, J., Renting, A., Riemers, P., Rol, E., Romein, J. W., Roosjen, J., Ruiter, M., Scaife, A., van der Schaaf, K., Scheers, B., Schellart, P., Schoenmakers, A., Schoonderbeek, G., Serylak, M., Shulevski, A., Sluman, J., Smirnov, O., Sobey, C., Spreeuw, H., Steinmetz, M., Sterks, C. G. M., Stiepel, H. -J., Stuurwold, K., Tagger, M., Tang, Y., Tasse, C., Thomas, I., Thoudam, S., Toribio, M. C., van der Tol, B., Usov, O., van Veelen, M., van der Veen, A. -J., ter Veen, S., Verbiest, J. P. W., Vermeulen, R., Vermaas, N., Vocks, C., Vogt, C., de Vos, M., van der Wal, E., van Weeren, R., Weggemans, H., Weltevrede, P., White, S., Wijnholds, S. J., Wilhelmsson, T., Wucknitz, O., Yatawatta, S., Zarka, P., Zensus, A., and van Zwieten, J.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

LOFAR, the LOw-Frequency ARray, is a new-generation radio interferometer constructed in the north of the Netherlands and across europe. Utilizing a novel phased-array design, LOFAR covers the largely unexplored low-frequency range from 10-240 MHz and provides a number of unique observing capabilities. Spreading out from a core located near the village of Exloo in the northeast of the Netherlands, a total of 40 LOFAR stations are nearing completion. A further five stations have been deployed throughout Germany, and one station has been built in each of France, Sweden, and the UK. Digital beam-forming techniques make the LOFAR system agile and allow for rapid repointing of the telescope as well as the potential for multiple simultaneous observations. With its dense core array and long interferometric baselines, LOFAR achieves unparalleled sensitivity and angular resolution in the low-frequency radio regime. The LOFAR facilities are jointly operated by the International LOFAR Telescope (ILT) foundation, as an observatory open to the global astronomical community. LOFAR is one of the first radio observatories to feature automated processing pipelines to deliver fully calibrated science products to its user community. LOFAR's new capabilities, techniques and modus operandi make it an important pathfinder for the Square Kilometre Array (SKA). We give an overview of the LOFAR instrument, its major hardware and software components, and the core science objectives that have driven its design. In addition, we present a selection of new results from the commissioning phase of this new radio observatory., Comment: 56 pages, 34 figures, accepted for publication by A&A

Published
2013
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5. Optimized Trigger for Ultra-High-Energy Cosmic-Ray and Neutrino Observations with the Low Frequency Radio Array

Author

Singh, K., Mevius, M., Scholten, O., Anderson, J. M., van Ardenne, A., Arts, M., Avruch, M., Asgekar, A., Bell, M., Bennema, P., Bentum, M., Bernadi, G., Best, P., Boonstra, A. -J., Bregman, J., van de Brink, R., Broekema, C., Brouw, W., Brueggen, M., Buitink, S., Butcher, H., van Cappellen, W., Ciardi, B., Coolen, A., Damstra, S., Dettmar, R., van Diepen, G., Dijkstra, K., Donker, P., Doorduin, A., Drost, M., van Duin, A., Eisloeffel, J., Falcke, H., Garrett, M., Gerbers, M., Griessmeier, J., Grit, T., Gruppen, P., Gunst, A., van Haarlem, M., Hoeft, M., Holties, H., Horandel, J., Horneffer, L. A., Huijgen, A., James, C., de Jong, A., Kant, D., Kooistra, E., Koopman, Y., Koopmans, L., Kuper, G., Lambropoulos, P., van Leeuwen, J., Loose, M., Maat, P., Mallary, C., McFadden, R., Meulman, H., Mol, J. -D., Morawietz, J., Mulder, E., Munk, H., Nieuwenhuis, L., Nijboer, R., Norden, M., Noordam, J., Overeem, R., Paas, H., Pandey, V. N., Pandey-Pommier, M., Pizzo, R., Polatidis, A., Reich, W., de Reijer, J., Renting, A., Riemers, P., Roettgering, H., Romein, J., Roosjen, J., Ruiter, M., Schoenmakers, A., Schoonderbeek, G., Sluman, J., Smirnov, O., Stappers, B., Steinmetz, M., Stiepel, H., Stuurwold, K., Tagger, M., Tang, Y., ter Veen, S., Vermeulen, R., de Vos, M., Vogt, C., van der Wal, E., Weggemans, H., Wijnholds, S., Wise, M., Wucknitz, O., Yattawatta, S., and van Zwieten, J.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

When an ultra-high energy neutrino or cosmic ray strikes the Lunar surface a radio-frequency pulse is emitted. We plan to use the LOFAR radio telescope to detect these pulses. In this work we propose an efficient trigger implementation for LOFAR optimized for the observation of short radio pulses., Comment: Submitted to Nuclear Instruments and Methods in Physics Research Section A

Published
2011
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6. Apertif: Phased array feeds for the Westerbork Synthesis Radio Telescope

Author

van Cappellen, W. A., primary, Oosterloo, T. A., additional, Verheijen, M. A. W., additional, Adams, E. A. K., additional, Adebahr, B., additional, Braun, R., additional, Hess, K. M., additional, Holties, H., additional, van der Hulst, J. M., additional, Hut, B., additional, Kooistra, E., additional, van Leeuwen, J., additional, Loose, G. M., additional, Morganti, R., additional, Moss, V. A., additional, Orrú, E., additional, Ruiter, M., additional, Schoenmakers, A. P., additional, Vermaas, N. J., additional, Wijnholds, S. J., additional, van Amesfoort, A. S., additional, Arts, M. J., additional, Attema, J. J., additional, Bakker, L., additional, Bassa, C. G., additional, Bast, J. E., additional, Benthem, P., additional, Beukema, R., additional, Blaauw, R., additional, de Blok, W. J. G., additional, Bouwhuis, M., additional, van den Brink, R. H., additional, Connor, L., additional, Coolen, A. H. W. M., additional, Damstra, S., additional, van Diepen, G. N. J., additional, de Goei, R., additional, Dénes, H., additional, Drost, M., additional, Ebbendorf, N., additional, Frank, B. S., additional, Gardenier, D. W., additional, Gerbers, M., additional, Grange, Y. G., additional, Grit, T., additional, Gunst, A. W., additional, Gupta, N., additional, Ivashina, M. V., additional, Józsa, G. I. G., additional, Janssen, G. H., additional, Koster, A., additional, Kruithof, G. H., additional, Kuindersma, S. J., additional, Kutkin, A., additional, Lucero, D. M., additional, Maan, Y., additional, Maccagni, F. M., additional, van der Marel, J., additional, Mika, A., additional, Morawietz, J., additional, Mulder, H., additional, Mulder, E., additional, Norden, M. J., additional, Offringa, A. R., additional, Oostrum, L. C., additional, Overeem, R. E., additional, Paragi, Z., additional, Pepping, H. J., additional, Petroff, E., additional, Pisano, D. J., additional, Polatidis, A. G., additional, Prasad, P., additional, de Reijer, J. P. R., additional, Romein, J. W., additional, Schaap, J., additional, Schoonderbeek, G. W., additional, Schulz, R., additional, van der Schuur, D., additional, Sclocco, A., additional, Sluman, J. J., additional, Smits, R., additional, Stappers, B. W., additional, Straal, S. M., additional, Stuurwold, K. J. C., additional, Verstappen, J., additional, Vohl, D., additional, Wierenga, K. J., additional, Woestenburg, E. E. M., additional, Zanting, A. W., additional, and Ziemke, J., additional

Published
2022
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7. Complement Activation in the Disease Course of Coronavirus Disease 2019 and Its Effects on Clinical Outcomes

Author

De Nooijer, A.H. Grondman, I. Janssen, N.A.F. Netea, M.G. Willems, L. Van De Veerdonk, F.L. Giamarellos-Bourboulis, E.J. Toonen, E.J.M. Joosten, L.A.B. Jaeger, M. Dijkstra, H. Lemmers, H. Van Emst, L. Schraa, K. Jacobs, C. Hijmans, A. Jansen, T. Weren, F. Fransman, L. Gerretsen, J. Van De Maat, J. Nijman, G. Moorlag, S. Taks, E. Debisarun, P. Kouijzer, I. Wertheim, H. Hopman, J. Rahamat-Langendoen, J. Bleeker-Rovers, C. Ten Oever, J. Van Crevel, R. Hoogerwerf, J. De Mast, Q. Van Der Hoeven, H. Pickkers, P. Kox, M. Frenzel, T. Schouten, J. Hemelaar, P. Beunders, R. Van Der Velde, S. Kooistra, E. Waalders, N. Claassen, W. Heesakkers, H. Van Schaik, T. Van Der Eng, H. Rovers, N. Klop-Riehl, M.

Abstract

Background: Excessive activation of immune responses in coronavirus disease 2019 (COVID-19) is considered to be related to disease severity, complications, and mortality rate. The complement system is an important component of innate immunity and can stimulate inflammation, but its role in COVID-19 is unknown. Methods: A prospective, longitudinal, single center study was performed in hospitalized patients with COVID-19. Plasma concentrations of complement factors C3a, C3c, and terminal complement complex (TCC) were assessed at baseline and during hospital admission. In parallel, routine laboratory and clinical parameters were collected from medical files and analyzed. Results: Complement factors C3a, C3c, and TCC were significantly increased in plasma of patients with COVID-19 compared with healthy controls (P

Published
2021

8. Effect of anakinra on mortality in patients with COVID-19: a systematic review and patient-level meta-analysis

Author

Kyriazopoulou, E. Huet, T. Cavalli, G. Gori, A. Kyprianou, M. Pickkers, P. Eugen-Olsen, J. Clerici, M. Veas, F. Chatellier, G. Kaplanski, G. Netea, M.G. Pontali, E. Gattorno, M. Cauchois, R. Kooistra, E. Kox, M. Bandera, A. Beaussier, H. Mangioni, D. Dagna, L. van der Meer, J.W.M. Giamarellos-Bourboulis, E.J. Hayem, G. Netea, M.G. van der Meer, J.W.M. Giamarellos-Bourboulis, E.J. Volpi, S. Sormani, M.P. Signori, A. Bozzi, G. Minoia, F. Aliberti, S. Grasselli, G. Alagna, L. Lombardi, A. Ungaro, R. Agostoni, C. Blasi, F. Costantino, G. Fracanzani, A.L. Montano, N. Peyvandi, F. Sottocorno, M. Muscatello, A. Filocamo, G. Papadopoulos, A. Mouktaroudi, M. Karakike, E. Saridaki, M. Gkavogianni, T. Katrini, K. Vechlidis, N. Avgoustou, C. Chalvatzis, S. Marantos, T. Damoulari, C. Damoraki, G. Ktena, S. Tsilika, M. Koufargyris, P. Karageorgos, A. Droggiti, D.-I. Koliakou, A. Poulakou, G. Tsiakos, K. Myrodia, D.-M. Gravvani, A. Trontzas, I.P. Syrigos, K. Kalomenidis, I. Kranidioti, E. Panagopoulos, P. Petrakis, V. Metallidis, S. Loli, G. Tsachouridou, O. Dalekos, G.N. Gatselis, N. Stefos, A. Georgiadou, S. Lygoura, V. Milionis, H. Kosmidou, M. Papanikolaou, I.C. Akinosoglou, K. Giannitsioti, E. Chrysos, G. Mavroudis, P. Sidiropoulou, C. Adamis, G. Fragkou, A. Rapti, A. Alexiou, Z. Symbardi, S. Masgala, A. Kostaki, K. Kostis, E. Samarkos, M. Bakakos, P. Tzavara, V. Dimakou, K. Tzatzagou, G. Chini, M. Kotsis, V. Tsoukalas, G. Bliziotis, I. Doumas, M. Argyraki, A. Kainis, I. Fantoni, M. Cingolani, A. Angheben, A. Cardellino, C.S. Castelli, F. Serino, F.S. Nicastri, E. Ippolito, G. Bassetti, M. Selmi, C. International Collaborative Group for Anakinra in COVID-19

Abstract

Background: Anakinra might improve the prognosis of patients with moderate to severe COVID-19 (ie, patients requiring oxygen supplementation but not yet receiving organ support). We aimed to assess the effect of anakinra treatment on mortality in patients admitted to hospital with COVID-19. Methods: For this systematic review and individual patient-level meta-analysis, a systematic literature search was done on Dec 28, 2020, in Medline (PubMed), Cochrane, medRxiv, bioRxiv, and the ClinicalTrials.gov databases for randomised trials, comparative studies, and observational studies of patients admitted to hospital with COVID-19, comparing administration of anakinra with standard of care, or placebo, or both. The search was repeated on Jan 22, 2021. Individual patient-level data were requested from investigators and corresponding authors of eligible studies; if individual patient-level data were not available, published data were extracted from the original reports. The primary endpoint was mortality after 28 days and the secondary endpoint was safety (eg, the risk of secondary infections). This study is registered on PROSPERO (CRD42020221491). Findings: 209 articles were identified, of which 178 full-text articles fulfilled screening criteria and were assessed. Aggregate data on 1185 patients from nine studies were analysed, and individual patient-level data on 895 patients were provided from six of these studies. Eight studies were observational and one was a randomised controlled trial. Most studies used historical controls. In the individual patient-level meta-analysis, after adjusting for age, comorbidities, baseline ratio of the arterial partial oxygen pressure divided by the fraction of inspired oxygen (PaO2/FiO2), C-reactive protein (CRP) concentrations, and lymphopenia, mortality was significantly lower in patients treated with anakinra (38 [11%] of 342) than in those receiving standard of care with or without placebo (137 [25%] of 553; adjusted odds ratio [OR] 0·32 [95% CI 0·20–0·51]). The mortality benefit was similar across subgroups regardless of comorbidities (ie, diabetes), ferritin concentrations, or the baseline PaO2/FiO2. In a subgroup analysis, anakinra was more effective in lowering mortality in patients with CRP concentrations higher than 100 mg/L (OR 0·28 [95% CI 0·17–0·47]). Anakinra showed a significant survival benefit when given without dexamethasone (OR 0·23 [95% CI 0·12–0·43]), but not with dexamethasone co-administration (0·72 [95% CI 0·37–1·41]). Anakinra was not associated with a significantly increased risk of secondary infections when compared with standard of care (OR 1·35 [95% CI 0·59–3·10]). Interpretation: Anakinra could be a safe, anti-inflammatory treatment option to reduce the mortality risk in patients admitted to hospital with moderate to severe COVID-19 pneumonia, especially in the presence of signs of hyperinflammation such as CRP concentrations higher than 100 mg/L. Funding: Sobi. © 2021 Elsevier Ltd

Published
2021

9. Effect of anakinra on mortality in patients with COVID-19: a systematic review and patient-level meta-analysis

Author

Kyriazopoulou, E., Huet, T., Cavalli, G., Gori, A., Kyprianou, M., Pickkers, P., Eugen-Olsen, J., Clerici, M., Veas, F., Chatellier, G., Kaplanski, G., Netea, M.G., Pontali, E., Gattorno, M., Cauchois, R., Kooistra, E., Kox, M., Bandera, A., Beaussier, H., Mangioni, D., Dagna, L., Meer, J.W.M. van der, Giamarellos-Bourboulis, E.J., Hayem, G., Kyriazopoulou, E., Huet, T., Cavalli, G., Gori, A., Kyprianou, M., Pickkers, P., Eugen-Olsen, J., Clerici, M., Veas, F., Chatellier, G., Kaplanski, G., Netea, M.G., Pontali, E., Gattorno, M., Cauchois, R., Kooistra, E., Kox, M., Bandera, A., Beaussier, H., Mangioni, D., Dagna, L., Meer, J.W.M. van der, Giamarellos-Bourboulis, E.J., and Hayem, G.

Abstract

Item does not contain fulltext, BACKGROUND: Anakinra might improve the prognosis of patients with moderate to severe COVID-19 (ie, patients requiring oxygen supplementation but not yet receiving organ support). We aimed to assess the effect of anakinra treatment on mortality in patients admitted to hospital with COVID-19. METHODS: For this systematic review and individual patient-level meta-analysis, a systematic literature search was done on Dec 28, 2020, in Medline (PubMed), Cochrane, medRxiv, bioRxiv, and the ClinicalTrials.gov databases for randomised trials, comparative studies, and observational studies of patients admitted to hospital with COVID-19, comparing administration of anakinra with standard of care, or placebo, or both. The search was repeated on Jan 22, 2021. Individual patient-level data were requested from investigators and corresponding authors of eligible studies; if individual patient-level data were not available, published data were extracted from the original reports. The primary endpoint was mortality after 28 days and the secondary endpoint was safety (eg, the risk of secondary infections). This study is registered on PROSPERO (CRD42020221491). FINDINGS: 209 articles were identified, of which 178 full-text articles fulfilled screening criteria and were assessed. Aggregate data on 1185 patients from nine studies were analysed, and individual patient-level data on 895 patients were provided from six of these studies. Eight studies were observational and one was a randomised controlled trial. Most studies used historical controls. In the individual patient-level meta-analysis, after adjusting for age, comorbidities, baseline ratio of the arterial partial oxygen pressure divided by the fraction of inspired oxygen (PaO(2)/FiO(2)), C-reactive protein (CRP) concentrations, and lymphopenia, mortality was significantly lower in patients treated with anakinra (38 [11%] of 342) than in those receiving standard of care with or without placebo (137 [25%] of 553; adjusted odds ratio [

Published
2021

10. A bright, high rotation-measure FRB that skewers the M33 halo

Author

Connor, L, primary, van Leeuwen, J, additional, Oostrum, L C, additional, Petroff, E, additional, Maan, Y, additional, Adams, E A K, additional, Attema, J J, additional, Bast, J E, additional, Boersma, O M, additional, Dénes, H, additional, Gardenier, D W, additional, Hargreaves, J E, additional, Kooistra, E, additional, Pastor-Marazuela, I, additional, Schulz, R, additional, Sclocco, A, additional, Smits, R, additional, Straal, S M, additional, van der Schuur, D, additional, Vohl, D, additional, Adebahr, B, additional, de Blok, W J G, additional, van Cappellen, W A, additional, Coolen, A H W M, additional, Damstra, S, additional, van Diepen, G N J, additional, Frank, B S, additional, Hess, K M, additional, Hut, B, additional, Kutkin, A, additional, Loose, G Marcel, additional, Lucero, D M, additional, Mika, Á, additional, Moss, V A, additional, Mulder, H, additional, Oosterloo, T A, additional, Ruiter, M, additional, Vedantham, H, additional, Vermaas, N J, additional, Wijnholds, S J, additional, and Ziemke, J, additional

Published
2020
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12. Repeating fast radio bursts with WSRT/Apertif

Author

Oostrum, L. C., primary, Maan, Y., additional, van Leeuwen, J., additional, Connor, L., additional, Petroff, E., additional, Attema, J. J., additional, Bast, J. E., additional, Gardenier, D. W., additional, Hargreaves, J. E., additional, Kooistra, E., additional, van der Schuur, D., additional, Sclocco, A., additional, Smits, R., additional, Straal, S. M., additional, ter Veen, S., additional, Vohl, D., additional, Adams, E. A. K., additional, Adebahr, B., additional, de Blok, W. J. G., additional, van den Brink, R. H., additional, van Cappellen, W. A., additional, Coolen, A. H. W. M., additional, Damstra, S., additional, van Diepen, G. N. J., additional, Frank, B. S., additional, Hess, K. M., additional, van der Hulst, J. M., additional, Hut, B., additional, Ivashina, M. V., additional, Loose, G. M., additional, Lucero, D. M., additional, Mika, Á., additional, Morganti, R. H., additional, Moss, V. A., additional, Mulder, H., additional, Norden, M. J., additional, Oosterloo, T. A., additional, Orrú, E., additional, de Reijer, J. P. R., additional, Ruiter, M., additional, Vermaas, N. J., additional, Wijnholds, S. J., additional, and Ziemke, J., additional

Published
2020
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13. The Impact of the Out of Body Illusion on Body Dissatisfaction in Anorexia Nervosa

Author

Kooistra, E., Hagenaars, M. (Thesis Advisor), Kooistra, E., and Hagenaars, M. (Thesis Advisor)

Abstract

Objective. Body image distortions are a core element of anorexia nervosa (AN) and often lead to body dissatisfaction. Body dissatisfaction increases the chances of relapse and the treatment of it is difficult. Treatment often entails cognitive and affective techniques. The aim of the current study is to investigate the following hypotheses: 1) whether the out of body illusion (OBI) task, a virtual reality task rooted in experimental psychology, decreases the amount of body dissatisfaction in patients with AN and 2) whether the effect of the illusion is related to the change in body dissatisfaction. It is also examined whether 3) the levels of embodiment, the degree to which participants identify with the virtual body, play a role in the amount of change in body dissatisfaction when the OBI was induced. Method. Fifteen AN patients completed the Body Satisfaction Scale (BSS), the OBI task, and a self-constructed questionnaire called the Embodiment Questionnaire (EQ). Results. A certain trend towards significance was found for the first hypothesis, suggesting a decrease in body dissatisfaction after the OBI task was conducted. No significant effects were found for the second and third hypotheses. Discussion. The trend towards significance suggesting a decrease in body dissatisfaction calls for further research. Future research should mainly aim to recruit larger samples and to validate the used measures. Furthermore, it would be interesting to explore whether multiple sessions prove to be more effective. Current study offers a good starting point and new directions to a better understanding of body image distortions and of how tasks rooted in experimental psychology might aid in reducing those distortions.

Published
2019

27. Implementation of trigger for detection of ultra high energy cosmic rays with LOFAR

Author

Singh, K., Bähren, L., Falcke, H., Horneffer, A., Kooistra, E., Olaf Scholten, Research unit Nuclear & Hadron Physics, and Research unit Astroparticle Physics

Subjects
Astrophysics::Instrumentation and Methods for Astrophysics
Abstract

Using all stations of LOFAR we are planning to explore the possibility of using Moon as a detector of ultra high energy (>10 21 eV) cosmic rays. The idea is to cover the whole visible lunar surface and to look for short pulses of Cherenkov radiation emitted by showers induced just below the surface of the Moon when the cosmic rays strike it. In the LOFAR station, a large number of digital data streams coming from the receivers are filtered and combined into a single, beamformed digital signal stream per station. This processing takes place in the cascade of a filterbank and a beam-former at station level, however triggering for radio pulses will be performed on a tied array beam formed at central processing level. Therefore, in order to implement this trigger we need to invert the station level digital processing at central processing level to achieve the required accuracy for triggering of real time signal. Additionally, pulse will be influenced by the ionosphere of the earth; therefore coherent dedispersion follow up is required to retrieve the original signal.

Published
2008

30. Optimized trigger for ultra-high-energy cosmic-ray and neutrino observations with the low frequency radio array

Author

Singh, K., Mevius, M., Scholten, O., Anderson, J., van Ardenne, A., Arts, M., Avruch, M., Asgekar, A., Bell, M., Bennema, P., Bentum, M., Bernadi, G., Best, P., Boonstra, A., Bregman, J., van de Brink, R., Broekema, C., Brouw, W., Brueggen, M., Buitink, S., Butcher, H., van Cappellen, W., Ciardi, B., Coolen, A., Damstra, S., Dettmar, R., van Diepen, G., Dijkstra, K., Donker, P., Doorduin, A., Drost, M., van Duin, A., Eisloeffel, J., Falcke, H., Garrett, M., Gerbers, M., Griessmeier, J., Grit, T., Gruppen, P., Gunst, A., van Haarlem, M., Hoeft, M., Holties, H., Horandel, J., Horneffer, L., Huijgen, A., James, Clancy, de Jong, A., Kant, D., Kooistra, E., Koopman, Y., Koopmans, L., Kuper, G., Lambropoulos, P., van Leeuwen, J., Loose, M., Maat, P., Mallary, C., McFadden, R., Meulman, H., Mol, J., Morawietz, J., Mulder, E., Munk, H., Nieuwenhuis, L., Nijboer, R., Norden, M., Noordam, J., Overeem, R., Paas, H., Pandey, V., Pandey-Pommier, M., Pizzo, R., Polatidis, A., Reich, W., de Reijer, J., Renting, A., Riemers, P., Roettgering, H., Romein, J., Roosjen, J., Ruiter, M., Schoenmakers, A., Schoonderbeek, G., Sluman, J., Smirnov, O., Stappers, B., Steinmetz, M., Stiepel, H., Stuurwold, K., Tagger, M., Tang, Y., ter Veen, S., Vermeulen, R., de Vos, M., Vogt, C., van der Wal, E., Weggemans, H., Wijnholds, S., Wise, M., Wucknitz, O., Yattawatta, S., van Zwieten, J., Singh, K., Mevius, M., Scholten, O., Anderson, J., van Ardenne, A., Arts, M., Avruch, M., Asgekar, A., Bell, M., Bennema, P., Bentum, M., Bernadi, G., Best, P., Boonstra, A., Bregman, J., van de Brink, R., Broekema, C., Brouw, W., Brueggen, M., Buitink, S., Butcher, H., van Cappellen, W., Ciardi, B., Coolen, A., Damstra, S., Dettmar, R., van Diepen, G., Dijkstra, K., Donker, P., Doorduin, A., Drost, M., van Duin, A., Eisloeffel, J., Falcke, H., Garrett, M., Gerbers, M., Griessmeier, J., Grit, T., Gruppen, P., Gunst, A., van Haarlem, M., Hoeft, M., Holties, H., Horandel, J., Horneffer, L., Huijgen, A., James, Clancy, de Jong, A., Kant, D., Kooistra, E., Koopman, Y., Koopmans, L., Kuper, G., Lambropoulos, P., van Leeuwen, J., Loose, M., Maat, P., Mallary, C., McFadden, R., Meulman, H., Mol, J., Morawietz, J., Mulder, E., Munk, H., Nieuwenhuis, L., Nijboer, R., Norden, M., Noordam, J., Overeem, R., Paas, H., Pandey, V., Pandey-Pommier, M., Pizzo, R., Polatidis, A., Reich, W., de Reijer, J., Renting, A., Riemers, P., Roettgering, H., Romein, J., Roosjen, J., Ruiter, M., Schoenmakers, A., Schoonderbeek, G., Sluman, J., Smirnov, O., Stappers, B., Steinmetz, M., Stiepel, H., Stuurwold, K., Tagger, M., Tang, Y., ter Veen, S., Vermeulen, R., de Vos, M., Vogt, C., van der Wal, E., Weggemans, H., Wijnholds, S., Wise, M., Wucknitz, O., Yattawatta, S., and van Zwieten, J.

Published
2012

31. LOFAR: The LOw-Frequency ARray

Author

van Haarlem, M. P., primary, Wise, M. W., additional, Gunst, A. W., additional, Heald, G., additional, McKean, J. P., additional, Hessels, J. W. T., additional, de Bruyn, A. G., additional, Nijboer, R., additional, Swinbank, J., additional, Fallows, R., additional, Brentjens, M., additional, Nelles, A., additional, Beck, R., additional, Falcke, H., additional, Fender, R., additional, Hörandel, J., additional, Koopmans, L. V. E., additional, Mann, G., additional, Miley, G., additional, Röttgering, H., additional, Stappers, B. W., additional, Wijers, R. A. M. J., additional, Zaroubi, S., additional, van den Akker, M., additional, Alexov, A., additional, Anderson, J., additional, Anderson, K., additional, van Ardenne, A., additional, Arts, M., additional, Asgekar, A., additional, Avruch, I. M., additional, Batejat, F., additional, Bähren, L., additional, Bell, M. E., additional, Bell, M. R., additional, van Bemmel, I., additional, Bennema, P., additional, Bentum, M. J., additional, Bernardi, G., additional, Best, P., additional, Bîrzan, L., additional, Bonafede, A., additional, Boonstra, A.-J., additional, Braun, R., additional, Bregman, J., additional, Breitling, F., additional, van de Brink, R. H., additional, Broderick, J., additional, Broekema, P. C., additional, Brouw, W. N., additional, Brüggen, M., additional, Butcher, H. R., additional, van Cappellen, W., additional, Ciardi, B., additional, Coenen, T., additional, Conway, J., additional, Coolen, A., additional, Corstanje, A., additional, Damstra, S., additional, Davies, O., additional, Deller, A. T., additional, Dettmar, R.-J., additional, van Diepen, G., additional, Dijkstra, K., additional, Donker, P., additional, Doorduin, A., additional, Dromer, J., additional, Drost, M., additional, van Duin, A., additional, Eislöffel, J., additional, van Enst, J., additional, Ferrari, C., additional, Frieswijk, W., additional, Gankema, H., additional, Garrett, M. A., additional, de Gasperin, F., additional, Gerbers, M., additional, de Geus, E., additional, Grießmeier, J.-M., additional, Grit, T., additional, Gruppen, P., additional, Hamaker, J. P., additional, Hassall, T., additional, Hoeft, M., additional, Holties, H. A., additional, Horneffer, A., additional, van der Horst, A., additional, van Houwelingen, A., additional, Huijgen, A., additional, Iacobelli, M., additional, Intema, H., additional, Jackson, N., additional, Jelic, V., additional, de Jong, A., additional, Juette, E., additional, Kant, D., additional, Karastergiou, A., additional, Koers, A., additional, Kollen, H., additional, Kondratiev, V. I., additional, Kooistra, E., additional, Koopman, Y., additional, Koster, A., additional, Kuniyoshi, M., additional, Kramer, M., additional, Kuper, G., additional, Lambropoulos, P., additional, Law, C., additional, van Leeuwen, J., additional, Lemaitre, J., additional, Loose, M., additional, Maat, P., additional, Macario, G., additional, Markoff, S., additional, Masters, J., additional, McFadden, R. A., additional, McKay-Bukowski, D., additional, Meijering, H., additional, Meulman, H., additional, Mevius, M., additional, Middelberg, E., additional, Millenaar, R., additional, Miller-Jones, J. C. A., additional, Mohan, R. N., additional, Mol, J. D., additional, Morawietz, J., additional, Morganti, R., additional, Mulcahy, D. D., additional, Mulder, E., additional, Munk, H., additional, Nieuwenhuis, L., additional, van Nieuwpoort, R., additional, Noordam, J. E., additional, Norden, M., additional, Noutsos, A., additional, Offringa, A. R., additional, Olofsson, H., additional, Omar, A., additional, Orrú, E., additional, Overeem, R., additional, Paas, H., additional, Pandey-Pommier, M., additional, Pandey, V. N., additional, Pizzo, R., additional, Polatidis, A., additional, Rafferty, D., additional, Rawlings, S., additional, Reich, W., additional, de Reijer, J.-P., additional, Reitsma, J., additional, Renting, G. A., additional, Riemers, P., additional, Rol, E., additional, Romein, J. W., additional, Roosjen, J., additional, Ruiter, M., additional, Scaife, A., additional, van der Schaaf, K., additional, Scheers, B., additional, Schellart, P., additional, Schoenmakers, A., additional, Schoonderbeek, G., additional, Serylak, M., additional, Shulevski, A., additional, Sluman, J., additional, Smirnov, O., additional, Sobey, C., additional, Spreeuw, H., additional, Steinmetz, M., additional, Sterks, C. G. M., additional, Stiepel, H.-J., additional, Stuurwold, K., additional, Tagger, M., additional, Tang, Y., additional, Tasse, C., additional, Thomas, I., additional, Thoudam, S., additional, Toribio, M. C., additional, van der Tol, B., additional, Usov, O., additional, van Veelen, M., additional, van der Veen, A.-J., additional, ter Veen, S., additional, Verbiest, J. P. W., additional, Vermeulen, R., additional, Vermaas, N., additional, Vocks, C., additional, Vogt, C., additional, de Vos, M., additional, van der Wal, E., additional, van Weeren, R., additional, Weggemans, H., additional, Weltevrede, P., additional, White, S., additional, Wijnholds, S. J., additional, Wilhelmsson, T., additional, Wucknitz, O., additional, Yatawatta, S., additional, Zarka, P., additional, Zensus, A., additional, and van Zwieten, J., additional

Published
2013
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32. Optimized trigger for ultra-high-energy cosmic-ray and neutrino observations with the low frequency radio array

Author

Singh, K., primary, Mevius, M., additional, Scholten, O., additional, Anderson, J.M., additional, van Ardenne, A., additional, Arts, M., additional, Avruch, M., additional, Asgekar, A., additional, Bell, M., additional, Bennema, P., additional, Bentum, M., additional, Bernadi, G., additional, Best, P., additional, Boonstra, A.-J., additional, Bregman, J., additional, van de Brink, R., additional, Broekema, C., additional, Brouw, W., additional, Brueggen, M., additional, Buitink, S., additional, Butcher, H., additional, van Cappellen, W., additional, Ciardi, B., additional, Coolen, A., additional, Damstra, S., additional, Dettmar, R., additional, van Diepen, G., additional, Dijkstra, K., additional, Donker, P., additional, Doorduin, A., additional, Drost, M., additional, van Duin, A., additional, Eisloeffel, J., additional, Falcke, H., additional, Garrett, M., additional, Gerbers, M., additional, Grießmeier, J.-M., additional, Grit, T., additional, Gruppen, P., additional, Gunst, A., additional, van Haarlem, M., additional, Hoeft, M., additional, Holties, H., additional, Hörandel, J., additional, Horneffer, L.A., additional, Huijgen, A., additional, James, C., additional, de Jong, A., additional, Kant, D., additional, Kooistra, E., additional, Koopman, Y., additional, Koopmans, L., additional, Kuper, G., additional, Lambropoulos, P., additional, van Leeuwen, J., additional, Loose, M., additional, Maat, P., additional, Mallary, C., additional, McFadden, R., additional, Meulman, H., additional, Mol, J.-D., additional, Morawietz, J., additional, Mulder, E., additional, Munk, H., additional, Nieuwenhuis, L., additional, Nijboer, R., additional, Norden, M.J., additional, Noordam, J., additional, Overeem, R., additional, Paas, H., additional, Pandey, V.N., additional, Pandey-Pommier, M., additional, Pizzo, R., additional, Polatidis, A., additional, Reich, W., additional, de Reijer, J., additional, Renting, A., additional, Riemers, P., additional, Roettgering, H., additional, Romein, J., additional, Roosjen, J., additional, Ruiter, M., additional, Schoenmakers, A., additional, Schoonderbeek, G., additional, Sluman, J., additional, Smirnov, O., additional, Stappers, B., additional, Steinmetz, M., additional, Stiepel, H., additional, Stuurwold, K., additional, Tagger, M., additional, Tang, Y., additional, ter Veen, S., additional, Vermeulen, R., additional, de Vos, M., additional, Vogt, C., additional, van der Wal, E., additional, Weggemans, H., additional, Wijnholds, S., additional, Wise, M., additional, Wucknitz, O., additional, Yattawatta, S., additional, and van Zwieten, J., additional

Published
2012
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34. A software implemented spread spectrum modem based on two TMS320C50 DSPs

Author

Kooistra, E., Smulders, Peter, and Meerendonk, van den, Harald

Abstract

A BPSKIDS-CDMA modem is described. Many functions of this spread spectrum modem are implemented in software on a DSP board. Constraints for proper IF receiver operation are given, plus BER measurement results for a prototype and a frequency-synthesizer resolution enhancement algorithm.

Published
1995

35. A Bluetooth radio in 0.18-/spl mu/m CMOS

Author

van Zeijl, P., primary, Eikenbroek, J.-W.T., additional, Vervoort, P.-P., additional, Setty, S., additional, Tangenherg, J., additional, Shipton, G., additional, Kooistra, E., additional, Keekstra, I.C., additional, Belot, D., additional, Visser, K., additional, Bosma, E., additional, and Blaakmeer, S.C., additional

Published
2002
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41. 75 Years research at Naaldwijk : twelve papers on current research

Author

Kooistra, E., van den Ende, J., and Koornneef, P.

Subjects
vegetables, Proefstation voor de Groenten- en Fruitteelt onder Glas, research, groenten, zuid-holland, netherlands, tuinieren, wetenschappelijk onderzoek, vegetable growing, onderzoek, nederland, sierplanten, wetenschap, gardening, scientific research, ornamental plants, groenteteelt, science
Published
1975

44. Verslag van een reis naar Engeland van 12 - 17 mei 1969

Author

Dorsman, C., Hogenboom, N.G., and Kooistra, E.

Subjects
vegetables, Instituut voor de Veredeling van Tuinbouwgewassen, Institute for Horticultural Plant Breeding, travel reports, groenten, plant breeding, reisverslagen, plantenveredeling, groenteteelt, vegetable growing, groot-brittannië, great britain
Published
1969

45. De groenteteelt onder plastic op Sicilie : verslag van een studiereis in april 1971

Author

Kooistra, E., Rijneveld, R., and Vijverberg, A.J.

Subjects
vegetables, teelt onder bescherming, Proefstation voor de Groenten- en Fruitteelt onder Glas, industry, synthetic materials, kunststoffen, groenten, protected cultivation, industrie, eiwitten, vegetable growing, cellulose, proteins, macromolecular materials, macromoleculaire stoffen, synthetische materialen, italië, italy, plastics, groenteteelt
Published
1971

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