Operations Research is governed internationally by the International Federation of Operations Research Societies (IFORS). It is therefore fitting that this newsletter, which is published under the auspices of IFORS, introduces our readers to the President of IFORS, Tom Magnanti, and the Vice President, Theo Stewart, who is responsible for developing countries. Apart from providing more informat...

Two-dimensional conformal field theory (CFT) has several sources: the search for simple examples of quantum field theory, the description of surface critical phenomena, the study of (super)string vacua. In the present overview of the subject we emphasize the role of CFT in bridging the gap between mathematics and quantum field theory and discuss some new physical concepts that emerged in the st...

"I want to paint men and women with that something of the eternal which the halo used to symbolize and which we seek to convey by the actual radiance and vibration of our coloring," wrote Vincent van Gogh in one of his celebrated letters. Hundreds of these were written mostly to his brother Theo, an art dealer in Paris who provided him with financial and emotional support throughout his brief b...

If there is any primary rule of science, it is . . . acceptance of the obligation to acknowledge and describe all of re a l i ty, all that exists, e ve rything that is the case. . . . it must accept within its jurisdiction e ven that which it cannot understand or explain, that for which no theo ry exists, that which cannot be measured, predicted, controlled, or o rd e red. . . . It includes all...

Editor: Prof. Frans JM Hilgers, MD PhD 
 
 The Netherlands Cancer Institute / Antoni van Leeuwenhoek, Amsterdam, The Netherlands
 5th updated edition, 2016
 (with QR codes to watch videos on smart phone) 
 Update from: 4th edition CD-Rom 2003; ISBN 90-75575-05-X, edited by: Frans JM Hilgers, MD, PhD, Otolaryngologist/Head & Neck surgeon With contributions of: Alfons JM Balm, MD, PhD, FACS, R Th...

Eric P van der Veer, Ruben G de Bruin Adriaan O Kraaijeveld, Margreet R de Vries, Ilze Bot, Tonio Pera, Filip M Segers, Stella Trompet, Janine M van Gils, Marko K Roeten, Cora M Beckers, Peter J van Santbrink, Anique Janssen, Coen van Solingen, Jim Swildens, Hetty C de Boer, Erna A Peters, Roel Bijkerk, Mat Rousch, Merijn Doop, Martin Jan Schalij , Allard C van der Wal, Stéphane Richard, Theo J...

832 Assessment of Simplified Blood Dose Protocols for the Estimation of the Maximum Tolerable Activity in Thyroid Cancer Patients Undergoing Radioiodine Therapy Using I Walter Jentzen, Andreas Bockisch, and Marcus Ruhlmann 839 Semiquantitative I-Metaiodobenzylguanidine Scintigraphy to Distinguish Pheochromocytoma and Paraganglioma from Physiologic Adrenal Uptake and Its Correlation with Genotyp...

T he nature and effects of heat have intrigued philosophers and scientists since ancient times. Different theo['ies were deve loped to exp lain the phenomena, and of these, the wave theory and the ca loric theory were the ones that reillained in force until the second half of the nineteenth century when overwhelming evidence led to the conclusion that heat was not a material substance, that the...

We present three di erent methods based on the conditional mean im putation when binary explanatory variables are incomplete Apart from the single imputation and multiple imputation especially the so called pi imputation is presented as a new procedure Seven procedures are com pared in a simulation experiment when missing data are con ned to one independent binary variable complete case analysi...

We give two short proofs that for fixed d, a d-regular Cayley graph on an Abelian group of order n has second eigenvalue bounded below by d −O(dn−4/d ), where the implied constant is absolute. We estimate the constant in the O(dn−4/d ) notation. We show that for any fixed d, then for a large odd prime, n, theO(dn−4/d ) cannot be improved; more precisely, most d-regular graphs on prime n vertice...