Iwan Holleman

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A fully automated method for the detection and quantification of bird migration was developed for operational C-band weather radar, measuring bird density, speed and direction as a function of altitude. These weather radar bird observations have been validated with data from a high-accuracy dedicated bird radar, which was stationed in the measurement volume(More)
Amethod for operationalmonitoring of a weather radar receiving chain, including the antenna gain and the receiver, is presented. The ‘‘online’’ method is entirely based on the analysis of sun signals in the polar volume data produced during operational scanning of weather radars. The method is an extension of that for determining the weather radar antenna(More)
a Institute for Biodiversity and Ecosystem Dynamics, Computational Geo-Ecology, University of Amsterdam, Amsterdam, The Netherlands Royal Netherlands Meteorological Institute, De Bilt, The Netherlands Department of Biology, Centre for Animal Movement Research, Lund, Sweden Military Aviation Authority, The Hague, The Netherlands Royal Netherlands Air Force,(More)
Psammoma bodies associated with cancer cells of ovarian and endometrial origins have been previously described in cervicovaginal smears, as have psammoma bodies from totally benign processes. We describe the presence of numerous psammoma bodies in the cervical smear, endometrial curettage, and peritoneal wash specimens from a patient with subsequently(More)
Cardiac rhabdomyoma is the most common tumour of the heart in infancy and childhood. The clinical presentation, diagnosis and histopathological characteristics have been extensively studied; however, reports on the ultrastructure and histogenesis of this lesion are scanty and inconclusive. The case to be discussed is that of a 10-year-old male who presented(More)
The ophthalmic literature of the past half century contains relatively few reports of true exfoliation of the lens capsule, reflecting a reduction in the occupation-related occurrence of "glassblower's cataract." The authors report 11 eyes (7 patients) with a diaphanous membrane arising from the anterior lens capsule, which they have identified by slit-lamp(More)
At temperate latitudes the synoptic patterns of bird migration are strongly structured by the presence of cyclones and anticyclones, both in the horizontal and altitudinal dimensions. In certain synoptic conditions, birds may efficiently cross regions with opposing surface wind by choosing a higher flight altitude with more favourable wind. We observed(More)
Vascular embolic and thrombotic problems postulated to be the cause of inner ear sudden deafness have been reported with decompression sickness also. Decompression sickness has been found to lead to cochlear potential loss in the guinea pig, and these losses are minimized by the prophylactic administration of heparin. Preliminary results show that inner ear(More)