Characterizing the Delaunay decompositions of compact hyperbolic surfaces

Given a Delaunay decomposition of a compact hyperbolic surface, one may record the topological data of the decomposition, together with the intersection angles between the `empty disks' circumscribing the regions of the decomposition. The main result of this paper is a characterization of when a given topological decomposition and angle assignment can be realized as the data of an actual Delaunay decomposition of a hyperbolic surface.Comment: Published by Geometry and Topology at http://www.maths.warwick.ac.uk/gt/GTVol6/paper12.abs.htm

Finanzielle Berichterstattung von PPP unter IPSAS : Ein Projekt in Zusammenarbeit mit der Förderagentur für Innovation des Bundes KTI

In der wissenschaftlichen und politischen Debatte fällt die ambivalente Haltung gegenüber den PPP auf. Auf der einen Seite wird PPP wegen seiner Effizienz- und Effektivitätsvorteile gepriesen und auf der anderen Seite wird PPP als ein Mittel zur Umgehung der Schuldenbremsen betrachtet. Das Ziel unserer Studie ist mit Hilfe der wirtschaftlichen Betrachtungsweise aus der Rechnungslegungstheorie ("Substance over form") eine Brücke zwischen den beiden Lagern zu schlagen: Indem man klare Regeln für eine transparente Berichterstattung festlegt, kann man eine Instrumentalisierung von PPP für fiskalpolitische Spielereien verhindern und rückt so die Wirtschaftlichkeitsbetrachtung von PPP in den Vordergrund. Um dieses Ziel zu erreichen, steht die Beantwortungen der folgenden beiden Forschungsfragen im Zentrum dieser Arbeit: • Wie sind PPP gemäss einer wirtschaftlichen Betrachtungsweise in der Rechnungslegung nach IPSAS abzubilden und wie kann insbesondere der neue IPSAS zu den Dienstleistungskonzessionen in der Praxis angewendet werden? • Welche Auswirkungen hat die wirtschaftliche Betrachtungsweise auf die finanzielle Berichterstattung und die Schuldenbremse? Um diese Fragen zu beantworten, wird in einem ersten Schritt der Forschungsgegenstand PPP umschrieben. Insbesondere wird auf die zwei in der Praxis und Theorie am meisten diskutierten Gesichtspunkte rund um das Konzept PPP eingegangen: Die verdeckte Verschuldung sowie Effizienz- und Effektivitätsvorteile. Diese beiden Aspekte stehen in einem unmittelbaren Zusammenhang mit den Anforderungen der modernen Rechnungslegung und so wird der Bogen zur Darstellung von PPP in der Rechnungslegung auf Basis einer wirtschaftlichen Betrachtungsweise gespannt. Nach einem Überblick über die verschiedenen internationalen Ansätze wird der neue Lösungsansatz vom IPSAS-Board aufgezeigt. Die International Federation of Accountants, welche Projektpartner beim KTI-Projekt PPP unter IPSAS ist, hat unter Mitarbeit des Instituts für Verwaltungs-Management einen Lösungsvorschlag erarbeitet, der vom IPSAS-Board im September 2009 verabschiedet wird. Dieser neue Ansatz von IPSAS wird auf Praxisbeispiele angewendet und dadurch werden die Prinzipien dieses Ansatzes für die Anwendung in der Praxis aufbereitet. Mit den Praxisbeispielen und der strukturierten Übersicht im Anhang soll ein Leitfaden für die Anwendung dieses neuen Ansatzes in der Praxis gegeben werden. Im letzten Kapitel wird der IPSAS-Ansatz aus einer theoretischen Sicht gewürdigt und es werden die Auswirkungen auf die finanzielle Berichterstattung sowie die Schuldenbremse aufgezeigt

Late-Stage Molecular Editing Enabled by Ketone Chain-Walking Isomerization

Herein, a method for the isomerization of ketones in a manner akin to the chain-walking reaction of alkenes is described. Widely available and inexpensive pyrrolidine and elemental sulfur are deployed as catalysts to achieve this reversible transformation. Key to the utility of this approach was the elucidation of a stereochemical model to determine the thermodynamically favored product of the reaction and the kinetic selectivity observed. With the distinct selectivity profile of our ketone chain-walking process, the isomerization of various steroids was demonstrated to rapidly access novel steroids with "unnatural" oxidation patterns.ISSN:0002-7863ISSN:1520-512

Head Coverings in the Courtroom: A Question of Respect for the Judge or of Judicial Tolerance?

The Human Rights Centre at Ghent University (the HRC) first initiated the present research while preparing an amicus curiae brief in the Lachiri v. Belgium case before the European Court of Human Rights (ECtHR). The applicant in Lachiri, who was a civil party in legal proceedings concerning the murder of her brother, was denied access to a Brussels courtroom after refusing to remove her Islamic headscarf . Ms. Lachiri’s admission was refused in reliance on Article 759 of the Belgian Judicial Code (Gerechtelijk Wetboek/ Code Judiciaire), which provides that “[t]he audience will attend the sessions with their heads uncovered, respectfully and silently; whatever the judge commands for the maintenance of order will be punctually and immediately executed.” In its third-party intervention, the HRC sought to supply the ECtHR with additional information concerning three points: the debate on the wearing of Islamic headscarves in Belgium, the history, object and purpose of Article 759 of the Belgian Judicial Code, and the scope of the State margin of appreciation in prohibiting religious items of clothing

Bericht zum Leitbild der Stadt Winterthur für die musikalische Bildung im Schul- und Jugendalter

Das Zentrum für Kulturmanagement der Zürcher Hochschule für Angewandte Wissenschaften (ZKM / ZHAW) erhielt vom Departement Schule und Sport der Stadt Winterthur den Auftrag, ein Musikförderleitbild für den ausserschulischen Musikunterricht für Kinder und Jugendliche bis 20 Jahren zu erstellen. Das genannte Musikförderleitbild ist Teil eines Gesamtauftrages, der zusätzlich die Evaluation des bestehenden Angebots an Musikförderung auf Grund des Leitbildes und die Erarbeitung von Vorschlägen für die fachliche Qualitätsentwicklung bzw. -sicherung umfasst. Vorliegendes Dokument beinhaltet die musikpädagogischen Grundlagen, die rechtlichen und die institutionellen Rahmenbedingungen sowie die politischen und gesellschaftlichen Voraussetzungen für die Entwicklung eines Musikförderleitbildes. Ebenfalls enthält dieses Dokument Handlungsempfehlungen für die Weiterentwicklung der musikalischen Bildung sowie eine erste Version des Leitbildes, die in eine interne Vernehmlassung ins Departement Schule und Sport geht und anschliessend überarbeitet wird

Patient-reported outcome measures compared to professional dental assessments of monolithic ZrO(2) implant fixed dental prostheses in complete digital workflows: A double-blind crossover randomized controlled trial

PURPOSE This double-blind randomized controlled trial analyzed patient-reported outcome measures in terms of subjective patient satisfaction compared to objective dental evaluation of prosthetic treatment with 3-unit monolithic zirconium dioxide implant fixed dental prostheses (iFDPs) in 3 digital workflows. MATERIAL AND METHODS Twenty patients were restored with 3 iFDPs each on Straumann TL-implants with 2 completely digital workflows using different intraoral optical scanning systems with model-free fabrication of the restoration (Trios 3/3Shape [Test-1]; Virtuo Vivo/Straumann [Test-2]), and mixed analog-digital workflow with conventional impressions and digitized gypsum casts (Impregum/3M Espe [Control]). The order of impression-taking and the prosthetic try-in were randomly allocated. Sixty iFDPs were compared for patient satisfaction and dental evaluation using ANOVA. RESULTS For iFDP evaluation, patients generally provided more favorable ratings than dental experts, regardless of the workflow. ANOVA revealed no significant difference for overall satisfaction when comparing Test-1, Test-2, or Control, either for patients (f-ratio: 0.13; p = 0.876) or dentist (f-ratio: 1.55: p = 0.221). Secondary, patients clearly favored the digital impression workflows over the conventional approach (f-ratio: 14.57; p < 0.001). Overall, the 3Shape workflow (Test-1) received the highest scores for all analyses. CONCLUSIONS The different digital workflows demonstrated minor influence on the subjective and objective evaluation of the monolithic zirconium dioxide iFDPs in nonesthetic regions; however, the dentist may significantly increase patient satisfaction by choosing intraoral scanning instead of conventional impressions. The dentist has to consider individual patients' needs to fulfill their expectations for a personalized solution

Rigidity of polyhedral surfaces, II

We study the rigidity of polyhedral surfaces using variational principle. The action functionals are derived from the cosine laws. The main focus of this paper is on the cosine law for a non-triangular region bounded by three possibly disjoint geodesics. Several of these cosine laws were first discovered and used by Fenchel and Nielsen. By studying the derivative of the cosine laws, we discover a uniform approach on several variational principles on polyhedral surfaces with or without boundary. As a consequence, the work of Penner, Bobenko-Springborn and Thurston on rigidity of polyhedral surfaces and circle patterns are extended to a very general context.Comment: 37 pages, 23 figure

Survival and complication rates of tooth- and implant-supported restorations after an observation period up to 36 years.

BACKGROUND Tooth- and implant-supported fixed dental prostheses are well-documented and aesthetic treatment alternatives, and after a comprehensive periodontal treatment, a protocol with a good long-term prognosis if the maintenance program is strictly followed. AIM To reexamine a pre-existing patient cohort in order to obtain estimated long-term survival and complication outcomes of fixed dental prostheses. MATERIALS AND METHODS For this study, patients treated with fixed dental prostheses between 1978 and 2002 were reexamined between 2019 and 2020. The restorations were divided in single crowns and fixed dental prostheses supported by teeth (TSC, FPTDP) and implants (ISC, FPIDP). Survival and complication rates were obtained. Kaplan-Meier functions were used to model complication probabilities, and average hazard ratios of different strata were compared using weighted Cox regression. RESULTS The mean observation time of 40 patients and 223 reconstructions was 20.3 (±9.7, 1.2-36.2) years. The estimated survival rates were 84% (CI: 77%-92%) for TSC, 63% (CI: 51%-79%) for FPTDP, 87% (CI: 71%-100%) for ISC, and 64% (CI: 34%-100%) for FPIDP after 25 years. Biological complications included carious lesions (10.6%), periodontitis (7.9%), and peri-implantitis (6.8%). Technical complications included chipping (20.2%) and loss of retention (10.8%). CONCLUSION Biological complications lead to abutment loss in more than two-thirds of cases, regardless of the type of abutment (tooth or implant). Technical complications are less associated with abutment loss than biological complications

Monolithic implant‐supported lithium disilicate (LS2) crowns in a complete digital workflow: A prospective clinical trial with a 2‐year follow‐up

Background: The technical development of digital processing allows the production of anatomically full‐contoured implant‐supported restorations. Purpose: The aim of this prospective clinical trial was to analyze the treatment concept of monolithic lithium disilicate (LS2) single‐unit restorations in a complete digital workflow. Material and Methods: Forty‐four patients were restored with 50 screw‐retained monolithic implant LS2 crowns bonded to pre‐fabricated titanium abutments on soft tissue level implants (Institut Straumann AG, Basel, Switzerland) in premolar and molar sites. All implant restorations were digitally designed after intraoral optical scanning (IOS) and CAD/CAM‐processing without physical model situations. Study participants were clinically and radiographically examined based on an annually performed follow‐up. The “Functional Implant Prosthodontic Score” (FIPS) was applied for objective outcome assessment after 2 years of loading. Five variables were defined for FIPS evaluation, resulting in a maximum score of 10 per implant restoration. Descriptive statistics were calculated for mean scores standard deviations, medians, and Q₂₅–Q₇₅. Results: All patients could be successfully treated within two clinical appointments. No clinical modifications were necessary for the seating of the monolithic crowns, neither for interproximal nor occlusal sites. The implant LS2 restorations demonstrated survival rates of 100% without any technical or biological complications after 2 years. The mean total FIPS score was 7.7 ± 1.0, ranging from 6 to 10. Conclusions: CAD/CAM‐produced monolithic implant crowns out of LS2 in a complete digital workflow seem to be a feasible treatment concept for the rehabilitation of single‐tooth gaps in posterior sites under mid‐term observation