Messung der semileptonischen Ξ°-Zerfälle mit dem NA48/1-Detektor

Im Jahre 2002 wurde mit dem NA48/1-Detektor eine Datennahme mit hoher Intensität von K_S-Mesonen und neutralen Hyperonen durchgeführt, bei der unter anderem etwa 10^9 Xi^0-Zerfallskandidaten aufgezeichnet wurden. Im Rahmen dieser Arbeit wurden aus diesem Datensatz 6657 Xi^0 -> Sigma^+ e^- Anti-nü und 581 Anti-Xi^0 -> Anti-Sigma^+ e^+ nü-Ereignisse ausgewählt und damit die Verzweigungsverhältnisse BR1(Gamma(Xi^0 -> Sigma^+ e^- Anti-nü)/Gamma(Xi^0 total))=( 2.533 +-0.032(stat) -0.076+0.089(syst) )10^-4 und BR2(Gamma(Anti-Xi^0 -> Anti-Sigma^+ e^+ nü)/Gamma(Anti-Xi^0 total))= ( 2.57 +-0.12(stat) -0.09+0.10(syst) )10^-4 bestimmt. Dieses Ergebnis für BR1 ist etwa 3.5-mal genauer als die bisher veröffentlichte Messung. Die Analyse der Anti-Xi^0-Beta-Zerfälle stellt die erste Messung von BR2 dar. Beide Ergebnisse stimmen mit der theoretischen Vorhersage von 2.6*10^-4 überein. Aus dem Xi^0-Beta-Verzweigungsverhältnis folgt unter Verwendung des experimentellen Wertes des Formfaktorverhältnisses g1/f1 für das CKM-Matrixelement |Vus| = 0.209 +- 0.004(exp) +- 0.026(syst), wobei die dominierende Unsicherheit von g1/f1 herrührt. Außerdem wurden in dieser Arbeit 99 Xi^0 -> Sigma^+ mu^- Anti-nü Zerfallskandidaten mit einem abgeschätzten Untergrund von 30 Ereignissen rekonstruiert und daraus ebenfalls das Verzweigungsverhältnis extrahiert: BR3(Gamma(Xi^0 -> Sigma^+ mu^- Anti-nü)/Gamma(Xi^0 total)) = ( 2.11 +- 0.31(stat) +- 0.15(syst) )10^-6.

La linea guida api - risk based inspection: Definizione delle frequenze di rilascio e ottimazione delle visite ispettive

La stima della frequenza di accadimento di eventi incidentali di tipo random da linee e apparecchiature è in generale effettuata sulla base delle informazioni presenti in banche dati specializzate. I dati presenti in tali banche contengono informazioni relative ad eventi incidentali avvenuti in varie tipologie di installazioni, che spaziano dagli impianti chimici a quelli petrolchimici. Alcune di queste banche dati risultano anche piuttosto datate, poiché fanno riferimento ad incidenti verificatisi ormai molto addietro negli anni. Ne segue che i valori relativi alle frequenze di perdita forniti dalle banche dati risultano molto conservativi. Per ovviare a tale limite e tenere in conto il progresso tecnico, la linea guida API Recommended Pratice 581, pubblicata nel 2000 e successivamente aggiornata nel 2008, ha introdotto un criterio per determinare frequenze di perdita specializzate alla realtà propria impiantistica, mediante l’ausilio di coefficienti correttivi che considerano il meccanismo di guasto del componente, il sistema di gestione della sicurezza e l’efficacia dell’attività ispettiva. Il presente lavoro di tesi ha lo scopo di mettere in evidenza l’evoluzione dell’approccio di valutazione delle frequenze di perdita da tubazione. Esso è articolato come descritto nel seguito. Il Capitolo 1 ha carattere introduttivo. Nel Capitolo 2 è affrontato lo studio delle frequenze di perdita reperibili nelle banche dati generaliste. Nel Capitolo 3 sono illustrati due approcci, uno qualitativo ed uno quantitativo, che permettono di determinare le linee che presentano priorità più alta per essere sottoposte all’attività ispettiva. Il Capitolo 4 è dedicato alla descrizione della guida API Recomended Practice 581. L’applicazione ad un caso di studio dei criteri di selezione delle linee illustrati nel Capitolo 3 e la definizione delle caratteristiche dell’attività ispettiva secondo la linea guida API Recomended Practice 581 sono illustrati nel Capitolo 5. Infine nel Capitolo 6 sono rese esplicite le considerazioni conclusive dello studio effettuato.

Comparison of two scoring systems for evaluation of treatment outcome in patients with complete bilateral cleft lip and palate

Objective : To compare two scoring systems: the Huddart/Bodenham system (HB system) and the Bauru-BCLP yardstick (BCLP yardstick), which classify treatment outcome in terms of dental arch relationships in patients with complete bilateral cleft lip and palate (CBCLP). The predictive value of these scoring systems for treatment outcome was also evaluated. Design : Retrospective longitudinal study. Patients : Dental arch relationships of 43 CBCLP patients were evaluated at 6, 9, and 12 years. Setting : Treatment outcome in BCLP patients using two scoring systems. Main Outcome Measures : For each age group, the HB scores were correlated with the BCLP yardstick scores using Spearman's correlation coefficient. The predictive value of the two scoring systems was evaluated by backward regression analysis. Results : Intraobserver Kappa values for the BCLP yardstick scoring for the two observers were .506 and .627, respectively, and the interobserver reliability ranged from .427 and .581. The intraobserver reliability for the HB system ranged from .92 to .97 and the interobserver reliability from .88 to .96. The BCLP yardstick scores of 6 and 9 years together were predictors for the outcome at 12 years (explained variance 41.3%). Adding the incisor and lateral HB scores in the regression model increased the explained variance to 67%. Conclusions : The BCLP yardstick and the HB system are reliable scoring systems for evaluation of dental arch relationships of CBCLP patients. The HB system categorizes treatment outcome into similar categories as the BCLP yardstick. In case a more sensitive measure of treatment outcome is needed, selectively both scoring systems should be used.

Statistical shape modeling of pathological scoliotic vertebrae: A comparative analysis

Statistical shape models (SSMs) have been used widely as a basis for segmenting and interpreting complex anatomical structures. The robustness of these models are sensitive to the registration procedures, i.e., establishment of a dense correspondence across a training data set. In this work, two SSMs based on the same training data set of scoliotic vertebrae, and registration procedures were compared. The first model was constructed based on the original binary masks without applying any image pre- and post-processing, and the second was obtained by means of a feature preserving smoothing method applied to the original training data set, followed by a standard rasterization algorithm. The accuracies of the correspondences were assessed quantitatively by means of the maximum of the mean minimum distance (MMMD) and Hausdorf distance (H(D)). Anatomical validity of the models were quantified by means of three different criteria, i.e., compactness, specificity, and model generalization ability. The objective of this study was to compare quasi-identical models based on standard metrics. Preliminary results suggest that the MMMD distance and eigenvalues are not sensitive metrics for evaluating the performance and robustness of SSMs.

Enantioselective determination of ondansetron and 8-hydroxyondansetron in human plasma from recovered surgery patients by liquid chromatography-tandem mass spectrometry

A liquid chromatographic-mass spectrometric assay with atmospheric pressure chemical ionization for quantification of ondansetron and its main metabolite 8-hydroxyondansetron in human plasma was presented. The enantiomeric separation was achieved on a Chiralcel OD-R column containing cellulose tris-(3,5-dimethylphenylcarbamate). The validation data were within the required limits. The assay was successfully applied to authentic plasma samples. Quantitative results from postoperative patients receiving ondansetron demonstrated a great interindividual variability in postoperative plasma drug concentrations, the metabolites were not detected in their unconjugated form. A wide variation in the S-(+)-/R-(-)-ondansetron concentration ratio between 0.14 and 7.18 is indicative for a stereoselective disposition or metabolism. In further studies CYP2D6 and CYP3A4 genotype dependent metabolism of ondansetron enantiomers as well as of co-administered drugs and clinical efficacy of the medication should be tested.

Definition of treatment goals for moderate to severe psoriasis: a European consensus

Patients with moderate to severe psoriasis are undertreated. To solve this persistent problem, the consensus programme was performed to define goals for treatment of plaque psoriasis with systemic therapy and to improve patient care. An expert consensus meeting and a collaborative Delphi procedure were carried out. Nineteen dermatologists from different European countries met for a face-to-face discussion and defined items through a four-round Delphi process. Severity of plaque psoriasis was graded into mild and moderate to severe disease. Mild disease was defined as body surface area (BSA) ≤10 and psoriasis area and severity index (PASI) ≤10 and dermatology life quality index (DLQI) ≤10 and moderate to severe psoriasis as (BSA > 10 or PASI > 10) and DLQI > 10. Special clinical situations may change mild psoriasis to moderate to severe including involvement of visible areas or severe nail involvement. For systemic therapy of plaque psoriasis two treatment phases were defined: (1) induction phase as the treatment period until week 16; however, depending on the type of drug and dose regimen used, this phase may be extended until week 24 and (2) maintenance phase for all drugs was defined as the treatment period after the induction phase. For the definition of treatment goals in plaque psoriasis, the change of PASI from baseline until the time of evaluation (ΔPASI) and the absolute DLQI were used. After induction and during maintenance therapy, treatment can be continued if reduction in PASI is ≥75%. The treatment regimen should be modified if improvement of PASI is <50%. In a situation where the therapeutic response improved ≥50% but <75%, as assessed by PASI, therapy should be modified if the DLQI is >5 but can be continued if the DLQI is ≤5. This programme defines the severity of plaque psoriasis for the first time using a formal consensus of 19 European experts. In addition, treatment goals for moderate to severe disease were established. Implementation of treatment goals in the daily management of psoriasis will improve patient care and mitigate the problem of undertreatment. It is planned to evaluate the implementation of these treatment goals in a subsequent programme involving patients and physicians.

Knuckling Under? School Superintendents and Accountability-Based Educational Reform

The goal of this article is to explore the various ways that superintendents have responded to accountability-based educational reform efforts such as No Child Left Behind, the factors that have influenced their responses, and the implications of these responses for current and future educational leaders. With respect to the first issue, empirical data from a number of nationai studies (T. E. Glass & Franceschini, 2007; Johnson, Arumi, & Ott, 2006; Johnstone, Dilkkers, & Luedeke, 2009; Stecher et al., 2008) make clear that while there have been a variety of responses from superintendents to accountability-based reform efforts, superintendents have mostly played a supportive role. Examining the situation more fully suggests that the driving factors behind superintendent support for accountability-based educational reform are complex and are often deeply embedded within the "DNA" of the role of superintendent. This article examines the structure of this DNA by looking at the factors that influence superintendents' views of accountability-based educational reform from historical, political, and institutional perspectives. This muitifaceted approach provides new insights into the complex relationship that exists between the structure of the role of superintendent and the agency of the individuals who inhabit that role.

Conventional and anti-erosion fluoride toothpastes: effect on enamel erosion and erosion-abrasion

New toothpastes with anti-erosion claims are marketed, but little is known about their effectiveness. This study investigates these products in comparison with various conventional NaF toothpastes and tin-containing products with respect to their erosion protection/abrasion prevention properties. In experiment 1, samples were demineralised (10 days, 6 × 2 min/day; citric acid, pH 2.4), exposed to toothpaste slurries (2 × 2 min/day) and intermittently stored in a mineral salt solution. In experiment 2, samples were additionally brushed for 15 s during the slurry immersion time. Study products were 8 conventional NaF toothpastes (1,400-1,490 ppm F), 4 formulations with anti-erosion claims (2 F toothpastes: NaF + KNO(3) and NaF + hydroxyapatite; and 2 F-free toothpastes: zinc-carbonate-hydroxyapatite, and chitosan) and 2 Sn-containing products (toothpaste: 3,436 ppm Sn, 1,450 ppm F as SnF(2)/NaF; gel: 970 ppm F, 3,030 ppm Sn as SnF(2)). A mouth rinse (500 ppm F as AmF/NaF, 800 ppm Sn as SnCl(2)) was the positive control. Tissue loss was quantified profilometrically. In experiment 1, most NaF toothpastes and 1 F-free formulation reduced tissue loss significantly (between 19 and 42%); the Sn-containing formulations were the most effective (toothpaste and gel 55 and 78% reduction, respectively). In experiment 2, only 4 NaF toothpastes revealed significant effects compared to the F-free control (reduction between 29 and 37%); the F-free special preparations and the Sn toothpaste had no significant effect. The Sn gel (reduction 75%) revealed the best result. Conventional NaF toothpastes reduced the erosive tissue loss, but had limited efficacy regarding the prevention of brushing abrasion. The special formulations were not superior, or were even less effective.

Fic domain-catalyzed adenylylation: insight provided by the structural analysis of the type IV secretion system effector BepA

Numerous bacterial pathogens subvert cellular functions of eukaryotic host cells by the injection of effector proteins via dedicated secretion systems. The type IV secretion system (T4SS) effector protein BepA from Bartonella henselae is composed of an N-terminal Fic domain and a C-terminal Bartonella intracellular delivery domain, the latter being responsible for T4SS-mediated translocation into host cells. A proteolysis resistant fragment (residues 10-302) that includes the Fic domain shows autoadenylylation activity and adenylyl transfer onto Hela cell extract proteins as demonstrated by autoradiography on incubation with α-[(32)P]-ATP. Its crystal structure, determined to 2.9-Å resolution by the SeMet-SAD method, exhibits the canonical Fic fold including the HPFxxGNGRxxR signature motif with several elaborations in loop regions and an additional β-rich domain at the C-terminus. On crystal soaking with ATP/Mg(2+), additional electron density indicated the presence of a PP(i) /Mg(2+) moiety, the side product of the adenylylation reaction, in the anion binding nest of the signature motif. On the basis of this information and that of the recent structure of IbpA(Fic2) in complex with the eukaryotic target protein Cdc42, we present a detailed model for the ternary complex of Fic with the two substrates, ATP/Mg(2+) and target tyrosine. The model is consistent with an in-line nucleophilic attack of the deprotonated side-chain hydroxyl group onto the α-phosphorus of the nucleotide to accomplish AMP transfer. Furthermore, a general, sequence-independent mechanism of target positioning through antiparallel β-strand interactions between enzyme and target is suggested.