TY - JOUR A1 - Kleines, H. A1 - Ziemons, Karl A1 - Zwoll, K. T1 - Experiences with ATM in a multivendor pilot system at Forschungszentrum Jülich JF - IEEE Transactions on Nuclear Science N2 - The ATM technology for high speed serial transmission provides a new quality of communication by introducing novel features in a LAN environment, especially support of real time communication, of both LAN and WAN communication and of multimedia streams. In order to evaluate ATM for future DAQ systems and remote control systems as well as for a high speed picture archiving and communications system for medical images, Forschungszentrum Julich has build up a pilot system for the evaluation of ATM and standard low cost multimedia systems. It is a heterogeneous multivendor system containing a variety of switches and desktop solutions, employing different protocol options of ATM. The tests conducted in the pilot system revealed major difficulties regarding stability, interoperability and performance. The paper presents motivations, layout and results of the pilot system. Discussion of results concentrates on performance issues relevant for realistic applications, e.g., connection to a RAID system via NFS over ATM Y1 - 1998 SN - 0018-9499 VL - 45 IS - 4 SP - 1867 EP - 1871 ER - TY - JOUR A1 - Weckesser, Martin A1 - Grießmeier, Martin A1 - Schmidt, Daniela A1 - Sonnenberg, Frank A1 - Ziemons, Karl A1 - Kemna, Lars A1 - Holschbach, Marcus A1 - Langen, Karl-J. A1 - Müller-Gärtner, Hans-W. T1 - Iodine-123 α-methyl tyrosine single-photon emission tomography of cerebral gliomas: standardised evaluation of tumour uptake and extent JF - European Journal of Nuclear Medicine N2 - Single-photon emission tomography (SPET) with the amino acid analogue l-3-[123I]iodo-α-methyl tyrosine (IMT) is helpful in the diagnosis and monitoring of cerebral gliomas. Radiolabelled amino acids seem to reflect tumour infiltration more specifically than conventional methods like magnetic resonance imaging and computed tomography. Automatic tumour delineation based on maximal tumour uptake may cause an overestimation of mean tumour uptake and an underestimation of tumour extension in tumours with circumscribed peaks. The aim of this study was to develop a program for tumour delineation and calculation of mean tumour uptake which takes into account the mean background activity and is thus optimised to the problem of tumour definition in IMT SPET. Using the frequency distribution of pixel intensities of the tomograms a program was developed which automatically detects a reference brain region and draws an isocontour region around the tumour taking into account mean brain radioactivity. Tumour area and tumour/brain ratios were calculated. A three-compartment phantom was simulated to test the program. The program was applied to IMT SPET studies of 20 patients with cerebral gliomas and was compared to the results of manual analysis by three different investigators. Activity ratios and chamber extension of the phantom were correctly calculated by the automatic analysis. A method based on image maxima alone failed to determine chamber extension correctly. Manual region of interest analysis in patient studies resulted in a mean inter-observer standard deviation of 8.7%±6.1% (range 2.7%–25.0%). The mean value of the results of the manual analysis showed a significant correlation to the results of the automatic analysis (r = 0.91, P<0.0001 for the uptake ratio; r = 0.87, P<0.0001 for the tumour area). We conclude that the algorithm proposed simplifies the calculation of uptake ratios and may be used for observer-independent evaluation of IMT SPET studies. Three-dimensional tumour recognition and transfer to co-registered morphological images based on this program may be useful for the planning of surgical and radiation treatment. Y1 - 1998 SN - 1619-7089 VL - 25 IS - 2 SP - 150 EP - 156 ER - TY - JOUR A1 - Meliß, Michael A1 - Neskakis, A. A1 - Plettner-Marliani, J. A1 - Lange, C. A1 - Hövelmann, A. A1 - Schumacher, J. T1 - Waste water recycling supplied by renewable energies : basic conditions and possible treatment technologies JF - Renewable energy. Vol. 14 (1998), iss. 1-4. 6th Arab International Solar Energy Conference: Bringing Solar Energy into the Daylight, Muscat, Sultanate of Oman, 29.03.-01.04.1998 Y1 - 1998 SN - 1879-0682 (E-Book); 0960-1481 (Print) SP - 325 EP - 331 ER - TY - JOUR A1 - Zientz, Evelyn A1 - Bongaerts, Johannes A1 - Unden, Gottfried T1 - Fumarate regulation of gene expression in Escherichia coli by the DcuSR (dcuSR genes) two-component regulatory system JF - Journal of bacteriology Y1 - 1998 SN - 1098-5530 (E-Journal); 0021-9193 (Print) VL - Vol. 180 IS - No. 20 SP - 5421 EP - 5425 ER - TY - JOUR A1 - Iding, Hans A1 - Siegert, Petra A1 - Mesch, K. A1 - Pohl, Martina T1 - Application of α-keto acid decarboxylases in biotransformations JF - Biochimica et biophysica acta (BBA) - Protein structure and molecular enzymology Y1 - 1998 SN - 1879-2588 (E-Journal); 0167-4838 (Print) VL - Vol. 1385 IS - Iss. 2 SP - 307 EP - 322 ER - TY - JOUR A1 - Pohl, Martina A1 - Siegert, Petra A1 - Mesch, K. A1 - Bruhn, H. A1 - Grötzinger, Joachim T1 - Active site mutants of pyruvate decarboxylase from Zymomonas mobilis : a site-directed mutagenesis study of L112, I472, I476, E473 and N482 JF - European journal of biochemistry Y1 - 1998 SN - 1432-1033 (E-Journal); 1742-4658 (E-Journal); 0014-2956 (Print); 1742-464X (Print) VL - Vol. 257 IS - Iss. 3 SP - 538 EP - 546 ER - TY - JOUR A1 - Seibler, Jost A1 - Schübeler, Dirk A1 - Fiering, Steven A1 - Groudine, Mark A1 - Bode, Jürgen T1 - DNA cassette exchange in ES cells mediated by Flp recombinase: an efficient strategy for repeated modification of tagged loci by marker-free constructs JF - Biochemistry Y1 - 1998 U6 - http://dx.doi.org/10.1021/bi980288t SN - 1520-4995 VL - 37 IS - 18 SP - 6229 EP - 6234 ER - TY - JOUR A1 - Bode, J. A1 - Bartsch, J. A1 - Boulikas, T. A1 - Iber, M. A1 - Mielke, C. A1 - Schübeler, D. A1 - Seibler, Jost A1 - Benham, C. T1 - Transcription-promoting genomic sites in mammalia: their elucidation and architectural principles JF - Gene therapy & molecular biology Y1 - 1998 SN - 1529-9120 VL - 1 IS - 1 SP - 1 EP - 29 ER - TY - JOUR A1 - Iber, Michaela A1 - Schübeler, Dirk A1 - Seibler, Jost A1 - Höxter, Maria A1 - Bode, Jürgen T1 - Efficient FACS selection procedure for cells undergoing Flp-mediated site-specific conversions JF - Technical Tips Online Y1 - 1998 U6 - http://dx.doi.org/10.1016/S1366-2120(08)70132-6 VL - 4 IS - 1 SP - 25 EP - 29 ER - TY - JOUR A1 - Benkner, Thorsten T1 - Wireless ATM - Broadband Mobile Radio Systems JF - Multiaccess, mobility and teletraffic for wireless communications. Workshop on Multiaccess, Mobility and Teletraffic for Wireless Communications <4, 1998, Washington, DC> Y1 - 1999 N1 - Proceedings of the IEEE MMT'98, 21.-23. Oktober 1998, Washington D.C., USA SP - 155 EP - 170 PB - Kluwer CY - Boston [u.a.] ER -