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.     

Rekonstruktion von Barockspiegeln des Historischen Grünen Gewölbes im Dresdener Schloss

Reconstruction of Baroque Mirrors of the Historical Green Vault in the Dresden Royal Palace On the 1^st September 2006 the Federal Chancellor Dr. Angela Merkel inaugurated the reconstructed Historical Green Vault, the treasury museum of the Saxon electors and kings. Since its destruction on 13^th February 1945 two generations have been working scientific‐artistically in order to set the course for its reconstruction. The idea of a baroque mirror chamber has firstly been implemented on a sequence of 8 rooms in the Green Vault. The original mirrors, which were covered with tin amalgam, had a considerably lower reflexivity modern day silver mirrors. From originally 423 m² mirror surface, only 60 m² could be reused. For the restoration and reconstruction of the original mirrors extensive analytic investigations became necessary, which the state‐owned company Sächsisches Immobilien‐ und Baumanagement (SIB) commissioned the Fraunhofer Institute for Electron Beam and Plasma Technology (FEP). On basis of these results the responsible restoration commission decided to replace partly destroyed mirror surfaces using the historical tin amalgam mirror technology. The fully destroyed jewel room would be restored with mirrors including partial gold etching. Due to hygienical and temporal reasons those mirrors were coated through a mercury‐free vacuum thin film technology ‐ the magnetron sputtering. The results show that a layer system consisting of tin‐bronze‐titanium and protective lacquers represent an adequate replacement for the original tin amalgam mirrors. The procedure allows relatively uncomplicated partial silverings and a subsequent inserting of artistic gold etchings.     

Tracking, grading, and student motivation: Using group composition and status to predict self-concept and interest in ninth-grade mathematics.

Assigning students to different classes on the basis of their achievement levels (tracking, streaming, or ability grouping) is an extensively used strategy with widely debated consequences. The authors developed a model of the effects of tracking on self-concept and interest that integrates the opposing predictions of "assimilation" and "contrast" effects, which specifies teacher-assigned grades as a major mediating variable, and tested it in 2 settings in which track level is clearly associated with different status-systematic tracking as a function of school type (Study 1, N = 14,341 German 9th-grade students) and separate streams within a comprehensive school system (Study 2, N = 3,243 German 9th-grade students). The results support predictions that students' math self-concept and math interest differ as a function of the achievement of their reference group, their own achievement, and their teacher-assigned grades. No systematic association between track level and math self-concept was found once individual student achievement, school-/stream-average achievement, and teacher-assigned grades were controlled. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Heat pump assisted distillation. VII: A feasibility study on heat transformer assisted distillation systems

The problems in matching a heat driven heat transformer to a distillation process in heat pump assisted distillation are discussed. The performance of such a system is a function of the temperature difference across the distillation column. Plots are given of the calculated coefficients of performance against the temperatures of the top and bottom products. In addition plots are given of the calculated coefficients of performance against the generator temperature when the generator is independently heated. The percentage of energy saved is also plotted against coefficient of performance.     

Erfahrungen mit der Leybold ScrewLine in industriellen Anwendungen. ScrewLine Vacuum Pumps in Industrial Applications

Die Beispiele aus verschiedenen ?industriellen”? Applikationen zeigen, dass sich das Konzept der ScrewLine SP630 auch unter härtesten Bedingungen hervorragend bewährt. Die Pumpe ist eine echte ?Universalpumpe”? und kann durch ihr Zubehör auch an viele Prozesse im Randbereich der Chemischen Industrie oder in der Halbleiterindustrie angepaßt werden. In allen Fällen überzeugen vor allem die sehr niedrigen ?Cost of Ownership”? und die hohe Robustheit der Pumpe. Außerdem präsentiert sie sich als sehr modernes Produkt und setzt bei Vakuumleistung, Schallpegel und Wartungsfreundlichkeit neue Maßstäbe. Leybold Vacuum bietet mit der ScrewLine also wieder ein echtes ?Arbeitspferd”? und setzt so eine Tradition mit Produkten wie TRIVAC, SOGEVAC und RUVAC nahtlos fort.     

Amount of training affects associatively-activated event representation

The effects of variations in the amount of training on behavioral plasticity were examined in three experiments that used appetitive Pavlovian conditioning procedures with rats. In experiments 1 and 2, an auditory conditioned stimulus (CS) substituted for a food unconditioned stimulus (US) in the acquisition of new learning about the food US after small numbers of CS-US pairings, but not after larger numbers of pairings. After limited exposure to the relation between the auditory CS and food, pairings of the CS with the toxin LiCl, in the absence of food, were sufficient to establish an aversion to the food US that was previously paired with that CS. This CS-mediated learning did not occur after more extensive exposure to the CS-food relation. In contrast, in experiment 3. mediated performance of previously-established conditioned responding was unaffected by the number of CS-US pairings used to establish that performance. Conditioned responding to the auditory CS remained sensitive to post-training devaluation of the food US regardless of the amount of initial CS-US training. Implications of these results for the investigations of cortical and other brain mechanisms of behavioral plasticity are discussed.     

Levels of the native forms of GnRH in the pituitary of the gilthead seabream, Sparus aurata, at several characteristic stages of the gonadal cycle

Brains of the gilthead seabream, Sparus aurata, contain three different forms of gonadotropin-releasing hormone (GnRH): seabream (sb) GnRH, chicken (c) GnRH-II, and salmon (s) GnRH. In the present study, we developed three specific enzyme-linked-immunosorbent assays (ELISA) for sbGnRH, cGnRH-II, and sGnRH and used them to measure the levels of each GnRH form in the pituitary of male and female seabream at different stages of gametogenesis. The sensitivity was 6 pg/well for the sbGnRH assay, 7 pg/well for the cGnRH-II assay, and 2 pg/well for the sGnRH assay. Levels of each of the three GnRH forms were measured in pituitaries from fish sampled at the beginning of gonadal recrudescence and during the spawning season. Of the three forms, only sbGnRH and cGnRH-II were detected in the pituitary, irrespective of reproductive state or sex. Recrudescent fish had similar levels of sbGnRH and cGnRH-II in the pituitary. In sexually mature fish, the levels of sbGnRH were higher than those in recrudescent fish while pituitary cGnRH-II content remained unchanged. Consequently, sbGnRH levels were 3- to 17-fold higher than cGnRH-II levels in mature fish. Positive correlations also existed between pituitary sbGnRH content and pituitary and plasma gonadotropin (GtH) II levels. Surprisingly, mature 1-year-old males had significantly higher levels of sbGnRH in the pituitary than mature 3-year-old males, while pituitary and plasma GtH II levels were similar between these two groups. Although the reason for this difference in sbGnRH levels is unclear, a possible role of sbGnRH in the processes of puberty or sex-inversion is implied. Based on the present results, it can be suggested that in the gilthead seabream, sbGnRH is the most relevant form of GnRH in the control of reproduction.     

Parotid lipomatosis

A case of parotid lipomatosis is reported, and the literature is reviewed. This rare condition presents as a slow growing parotid mass, which may be diagnosed preoperatively using computed tomography or magnetic resonance imaging. Long-term clinical follow-up is important because apparently complete surgical excision may be complicated by recurrence.     

Teaching disability and rehabilitation to medical students. Steering Group on Medical Education and Disability

A survey of UK medical schools was undertaken to determine the teaching that was being offered on disability and rehabilitation. In general, teaching on this topic appeared fragmented and inadequate but a number of interesting innovations were identified. These included: a drama workshop run by a group whose members mainly have learning disabilities at St George's Medical School, student-directed learning at the University of Dundee and structured teaching programmes at the Universities of Leeds and Edinburgh. The General Medical Council Education Committee's 1991 discussion document on the undergraduate curriculum specifically mentions disability as an important topic. A number of schools mentioned that they were in the process of revising their curriculum as a consequence. Recommendations arising from the findings of the survey include integration of disability and rehabilitation into clinical teaching, focus of teaching on those types of disability which are common in the community, greater emphasis on functional assessment in teaching the physical examination, and the wider use of standard assessment instruments, for example for activities of daily living, cognitive impairment and locomotor disability. There is a need for improved communication between medical schools to facilitate the spread of educational activities on this topic.