The Theory of Zero-Suppressed BDDs and the Number of Knight's Tours

Zero-suppressed binary decision diagrams (ZBDDs) have been introduced by Minato [14–17] who presents applications for cube set representations, fault simulation, timing analysis and the n-queens problem. Here the structural properties of ZBDDs are worked out and a generic synthesis algorithm is presented and analyzed. It is proved that ZBDDs can be at most by a factor n + 1 smaller or larger than ordered BDDs (OBDDs) for the same function on n variables. Using ZBDDs the best known upper bound on the number of knight's tours on an 8 × 8 chessboard is improved significantly.     

Reputation — A hard-currency medium of interchange

Within the theoretical framework of reputation as a social medium of interchange in the system of higher education this study analyses the institutional stratification of university departments in the field of economics and business administration. In contrast to the still prevailing normative idea of basic equality between academic institutions in the Federal Republic of Germany the empirical results indicate a stable hierarchy of reputation, very similar to the stratification pattern typical of the US American university system. Structural equation models show that the institutional hierarchy can be predicted with considerable accuracy with indicators of scientific activity and impact and structural characteristics of departments and universities. The analyses show both the performance-based validity of institutional reputation and the bias in access to the competitive academic markets due to structural differences of the universities and departments.     

包装行业教育的未来

作为战略因素的包装工业 近年来,整个包装工业的地位突然有了巨大的提高,尤其是在亚洲,如中国.     

The method of angular lines to solve cylindrical electromagnetic boundary-value problems

A method for solving cylindrical electromagnetic boundary-value problems is presented. The method is semidiscrete. The wave equation is written in cylindrical coordinates and a differential-discretizing process is used in angular direction, and in the radial direction the analytic solutions are used. The new method is called the method of angular lines (MAL). To confirm the validity of MAL Dirichlet- and Neumann-type boundary-value problems of a two-dimensional scalar wave equation are investigated. The results show good agreement with previously published results. Advantages and disadvantages of the method are discussed. © 1995 John Wiley & Sons, Inc.     

Abdominal lymphomas, convulsive seizure and coma: a case of successfully treated, advanced Whipple's disease with cerebral involvement

Whipple's disease is a rare, generalized inflammatory disorder due to the recently described bacterium Tropheryma whippelii. We report an unusual, successfully treated case of a 32-year-old woman, who presented with a 25 month history of large abdominal lymphomas, polyserositis and cachexia. The diagnosis of Whipple's disease was confirmed by duodenoscopy, lymph node and duodenal histology and polymerase chain reaction analysis of biopsy material and cerebrospinal fluid. A prolonged convulsive seizure with a subsequent 5 day period of coma were interpreted as signs of cerebral involvement. Under antibiotic treatment with trimethoprim-sulfamethoxazole (co-trimoxazole) the patient recovered completely, CT scans showed a complete regression of abdominal lymphomas. The therapy was continued over 18 months without the occurrence of a relapse.     

Hexokinase 2 from Saccharomyces cerevisiae: regulation of oligomeric structure by in vivo phosphorylation at serine-14

Homodimeric hexokinase 2 from Saccharomyces cerevisiae is known to have two sites of phosphorylation: for serine-14 the modification in vivo increases with glucose exhaustion [Kriegel et al. (1994) Biochemistry 33, 148-152], while for serine-157 it occurs in vitro with ATP in the presence of nonphosphorylateable five-carbon analogues of glucose [Heidrich et al. (1997) Biochemistry 36, 1960-1964]. We show now by site-directed mutagenesis and sedimentation analysis that serine-14 phosphorylation affects the oligomeric state of hexokinase, its substitution by glutamate causing complete dissociation; glutamate exchange for serine-157 does not. Phosphorylation of wild-type hexokinase at serine-14 likewise causes dissociation in vitro. In view of the higher glucose affinity of monomeric hexokinase and the high hexokinase concentration in yeast [Womack, F., and Colowick, S. P. (1978) Arch. Biochem. Biophys. 191, 742-747; Mayes, E. L., Hoggett, J. G., and Kellett, G. L. (1983) Eur. J. Biochem. 133, 127-134], we speculate that the in vivo phosphorylation at serine-14 as transiently occurring in glucose derepression might provide a mechanism to improve glucose utilization from low level and/or that nuclear localization of the monomer might be involved in the signal transduction whereby glucose causes catabolite repression.     

Cyanogenesis—a general phenomenon in the lepidoptera?

There are two different pathways known to be used for the detoxification of hydrocyanic acid in insects, viz., rhodanese and -cyano-l-ala-nine synthase. We consider the latter to be indicative for cyanogenesis, while rhodanese might, in general, play a more important role in sulfur transfer for protein synthesis. This paper reports on the distribution of -cyano-l-alanine (BCA) in the Lepidoptera. First reports of cyanogenesis are presented for the following families: Papilionidae, Pieridae, Lycaenidae, Hesperiidae, Lymantriidae, Arctiidae, Notodontidae, Megalopygidae, Limacodidae, Cymatophoridae, Noctuidae, Geometridae, and Yponomeutidae. New and old records for three other families, the Nymphalidae, Zygaenidae, and Heterogynidae, are included to complete the present state of knowledge. Special emphasis has been laid on the Nymphalidae, where BCA has been detected in eight subfamilies. Taxonomic, geographic, and seasonal variation has been found in a number of cases. In all cases observed so far, the source of cyanogenesis in the Lepidoptera is most probably the cyanoglucosides linamarin and lotaustralin, although cyanogenesis based on mustard oil glucosides and cyclopentenoid glucosides might occur as well. BCA has been found in both cryptic and aposematic species, including taxa such as the Pieridae, Danainae, Ithomiinae, and Arctiidae, where the defensive biology is believed to be linked with other compounds, like mustard oil glucosides, cardenolides, or pyrrolizidine alkaloids. The ecological interaction and significance of such secondary compounds is not yet understood.