Measurement and Interpretation of Moments of the Combined Hadronic Mass and Energy Spectrum in Inclusive Semileptonic B-meson Decays

This thesis presents first measurements of moments of the hadronic n_X^2 distribution measured in inclusive semileptonic decays of B mesons to final states containing a charm quark, B->Xc l nu. The variable n_X^2 is a combination of the invariant mass of the charmed meson m_X, its energy in the B-meson rest-frame E_X, and a constant \tilde{\Lambda} = 0.65 GeV, n_X^2 = m_X^2 c^4 - 2 \tilde{\Lambda} E_X + \tilde{\Lambda}^2. The moments <n_X^k> with k=2,4,6 are measured as proposed by theory to constrain assumptions made in the theoretical description of inclusive observables in semileptonic B-meson decays. This description uses Heavy Quark Expansion (HQE), an effective QCD combined with an Operator Product Expansion. The measurement is based on a sample of 231.6 million e+e- -> Y(4S) -> B\bar{B} events recorded with the BABAR experiment at the PEP-II e+e--storage rings at SLAC. We reconstruct the semileptonic decay by identifying a charged lepton in events tagged by a fully reconstructed hadronic decay of the second B meson. Correction procedures are derived from Monte Carlo simulations to ensure an unbiased measurement of the moments of the n_X^2 distribution. All moments are measured requiring minimum lepton momenta between 0.8 GeV/c and 1.9 GeV/c in the rest frame of the B meson. Performing a simultaneous fit to the measured moments <n_X^k> up to order k=6 combined with other measurements of moments of the lepton-energy spectrum in decays B->Xc l nu and moments of the photon-energy spectrum in decays B->Xs gamma, we determine the quark-mixing parameter |V_{cb}|, the bottom and charm quark masses, the semileptonic branching fraction BR(B->X l nu), and four non-perturbative heavy quark parameters. Using HQE calculations in the kinetic scheme up to order 1/m_b^3 we find |V_{cb}| = (41.65 +- 0.43 +- 0.40 +- 0.58) x 10^{-3} and m_b = (4.570 \pm 0.033 \pm 0.043)GeV/c^2, where the first uncertainty refers to experimental contributions, the second to uncertainties in the HQE, and the third to theoretical uncertainties in the calculations of the semileptonic decay rate. All obtained results are consistent with previous determinations. The inclusion of the moments <n_X^6> decreases the uncertainty on the HQE parameters mu_{pi} and rho_{D}. Furthermore, the theoretical treatment of higher order corrections in the HQE used for the moments <m_X^k> has been verified with these new measurements

A new approach to analyzing the development of domain-specific knowledge among undergraduate medical students using learning scores

Medicine is one of the domains in higher education with the highest demands [1] . The importance of acquiring domain-specific knowledge to understand the scientific rationales of practical work in medicine is considered vital [2] , about the specific responsibilities associated with medical professions. Teachers in medicine are faced with specific instructional challenges, for instance, being required to teach and examine several hundred students with heterogeneous educational backgrounds and study preconditions [3] . Consequently, in medical education practice, Multiple-Choice (MC) tests are often used in examinations because of their high level of efficiency and practicability, and despite their well-known disadvantages such as construct-irrelevant bias and low levels of explanatory power [4, 5] . In particular, the extent to which teaching contributes to the development of domain-specific knowledge cannot be measured by simple post-testing with MC tests and analyzing test sum scores only [6, 7] . Thus, practical implications for teaching and learning in medicine can only be derived to a very limited extent. In this paper, we present a new approach to analyzing the development of medical knowledge and suggest that a design with pre- and post-measurements and the consideration of decomposed pre- and posttest scores, which we define as learning scores, can provide substantial additional information on medical students’ learning over the course of their studies. This practicable approach can help to inform educational practitioners about students’ difficulties in learning and understanding certain medical contents, as well as to uncover possible student misconceptions about medical concepts and models

Task involvement as a facet of teacher job satisfaction in inclusive schools

Die Arbeitszufriedenheit von Lehrkräften stellt eine zentrale Komponente dar, um guten Unterricht zu gewährleisten und schulische Entwicklungsprozesse - worunter auch die Umsetzung von schulischer Inklusion gefasst wird - erfolgreich durchzuführen. In inklusiven Schulen müssen die Aufgaben und Zuständigkeiten von sonderpädagogischen Lehrkräften und Regelschullehrkräften verhandelt werden. Im vorliegenden Beitrag wird einerseits die Arbeitszufriedenheit von sonderpädagogischen Lehrkräften und Regelschullehrkräften in inklusiven Gesamt- und Sekundarschulen in NRW untersucht. Andererseits wird die Zufriedenheit mit der Beteiligung an verschiedenen schulischen Aufgaben als Einflussgröße auf die allgemeine Arbeitszufriedenheit überprüft. Dazu werden Daten aus dem Projekt BiFoKi analysiert. Die Ergebnisse der Analysen zeigen, dass von einer relativen Zufriedenheit beider Lehrkräftegruppen gesprochen werden kann, wobei die Regelschullehrkräfte signifikant zufriedener mit ihrer Arbeit sind als die sonderpädagogischen Lehrkräfte. Die Zufriedenheit mit der Beteiligung an den unterschiedlichen Aufgaben zeigt für beide Gruppen einen signifikanten Zusammenhang zur allgemeinen Arbeitszufriedenheit. (DIPF/Orig.)The job satisfaction of teachers is a central component in ensuring good teaching and successful school development processes, including the implementation of school inclusion. In inclusive schools, the tasks and responsibilities of special education teachers and general education teachers need to be negotiated. In this paper, on the one hand, the job satisfaction of special education teachers and general education teachers in inclusive comprehensive and secondary schools in NRW is investigated. On the other hand, satisfaction with participation in various school tasks is examined as a variable influencing general job satisfaction. For this purpose, data from the project BiFoKi are analyzed. The results of the analyses show that it is possible to speak of a relative satisfaction of both groups of teachers, whereby the general education teachers are significantly more satisfied with their work than the special education teachers. The satisfaction with the participation in the different tasks shows a significant correlation to the general job satisfaction for both groups. (DIPF/Orig.

The USP7/Dnmt1 complex stimulates the DNA methylation activity of Dnmt1 and regulates the stability of UHRF1

Aberrant DNA methylation is often associated with cancer and the formation of tumors; however, the underlying mechanisms, in particular the recruitment and regulation of DNA methyltransferases remain largely unknown. In this study, we identified USP7 as an interaction partner of Dnmt1 and UHRF1 in vivo. Dnmt1 and USP7 formed a soluble dimer complex that associated with UHRF1 as a trimeric complex on chromatin. Complex interactions were mediated by the C-terminal domain of USP7 with the TS-domain of Dnmt1, whereas the TRAF-domain of USP7 bound to the SRA-domain of UHRF1. USP7 was capable of targeting UHRF1 for deubiquitination and affects UHRF1 protein stability in vivo. Furthermore, Dnmt1, UHRF1 and USP7 co-localized on silenced, methylated genes in vivo. Strikingly, when analyzing the impact of UHRF1 and USP7 on Dnmt1-dependent DNA methylation, we found that USP7 stimulated both the maintenance and de novo DNA methylation activity of Dnmt1 in vitro. Therefore, we propose a dual role of USP7, regulating the protein turnover of UHRF1 and stimulating the enzymatic activity of Dnmt1 in vitro and in vivo

PLoS One

Age-related macular degeneration (AMD) is a common, progressive multifactorial vision-threatening disease and many genetic and environmental risk factors have been identified. The risk of AMD is influenced by lifestyle and diet, which may be reflected by an altered metabolic profile. Therefore, measurements of metabolites could identify biomarkers for AMD, and could aid in identifying high-risk individuals. Hypothesis-free technologies such as metabolomics have a great potential to uncover biomarkers or pathways that contribute to disease pathophysiology. To date, only a limited number of metabolomic studies have been performed in AMD. Here, we aim to contribute to the discovery of novel biomarkers and metabolic pathways for AMD using a targeted metabolomics approach of 188 metabolites. This study focuses on non-advanced AMD, since there is a need for biomarkers for the early stages of disease before severe visual loss has occurred. Targeted metabolomics was performed in 72 patients with early or intermediate AMD and 72 control individuals, and metabolites predictive for AMD were identified by a sparse partial least squares discriminant analysis. In our cohort, we identified four metabolite variables that were most predictive for early and intermediate stages of AMD. Increased glutamine and phosphatidylcholine diacyl C28:1 levels were detected in non-advanced AMD cases compared to controls, while the rate of glutaminolysis and the glutamine to glutamate ratio were reduced in non-advanced AMD. The association of glutamine with non-advanced AMD corroborates a recent report demonstrating an elevated glutamine level in early AMD using a different metabolomics technique. In conclusion, this study indicates that metabolomics is a suitable method for the discovery of biomarker candidates for AMD. In the future, larger metabolomics studies could add to the discovery of novel biomarkers in yet unknown AMD pathways and expand our insights in AMD pathophysiology

Measurement and Interpretation of Moments of the Combined Hadronic Mass and Energy Spectrum in Inclusive Semileptonic B-Meson Decays

This thesis presents first measurements of moments of the hadronic n{sub X}{sup 2} distribution measured in inclusive semileptonic decays of B mesons to final states containing a charm quark, B {yields} X{sub c}{ell}{nu}. The variable n{sub X}{sup 2} is a combination of the invariant mass of the charmed meson m{sub X}, its energy in the B-meson rest-frame E{sub X;BRF}, and a constant {tilde {Lambda}} = 0.65 GeV, n{sub X}{sup 2} = m{sub X}{sup 2}c{sup 4}-2{tilde {Lambda}}E{sub X,BRF} + {tilde {Lambda}}{sup 2}. The moments <n{sub X}{sup k}> with k = 2,4,6 are measured as proposed by theory to constrain assumptions made in the theoretical description of inclusive observables in semileptonic B-meson decays. This description uses Heavy Quark Expansion (HQE), an effective QCD combined with an Operator Product Expansion. The measurement is based on a sample of 231.6 million e{sup +}e{sup -} {yields} {Upsilon}(4S) {yields} B{bar B} events recorded with the BABAR experiment at the PEP-II e{sup +}e{sup -}-storage rings at SLAC. We reconstruct the semileptonic decay by identifying a charged lepton in events tagged by a fully reconstructed hadronic decay of the second B meson. Correction procedures are derived from Monte Carlo simulations to ensure an unbiased measurement of the moments of the n{sub X}{sup 2} distribution. All moments are measured requiring minimum lepton momenta between 0.8 GeV/c and 1.9 GeV/c in the rest frame of the B meson. Performing a simultaneous fit to the measured moments <n{sub X}{sup k}> up to order k = 6 combined with other measurements of moments of the lepton-energy spectrum in decays B {yields} X{sub c}{ell}{nu} and moments of the photon-energy spectrum in decays B {yields} X{sub s}{gamma}, we determine the quark-mixing parameter |V{sub cb}|, the bottom and charm quark masses, the semileptonic branching fraction {Beta}(B {yields} X{sub c}{ell}{nu}), and four non-perturbative heavy quark parameters. Using HQE calculations in the kinetic scheme up to order 1/m{sub b}{sup 3} we find |V{sub cb}| = (41.65 {+-} 0.43 {+-} 0.40 {+-} 0.58) {center_dot} 10{sup -3} and m{sub b} = (4.570 {+-} 0.033 {+-} 0.043) GeV/c{sup 2}, where the first uncertainty refers to experimental contributions, the second to uncertainties in the HQE, and the third to theoretical uncertainties in the calculations of the semileptonic decay rate {Lambda}(B {yields} X{sub c}{ell}{nu}). All obtained results are consistent with previous determinations. The inclusion of the moments <n{sub X}{sup 6}> decreases the uncertainty on the HQE parameters {mu}{sub {pi}}{sup 2} and {rho}{sub D}{sup 3}. Furthermore, the theoretical treatment of higher order corrections in the HQE used for the moments <m{sub X}{sup k}> has been verified with these new measurements

Measurement of |Vcb| and b to clnu Transitions at BaBar

Three recent preliminary results on b {yields} c{ell}{nu} transitions of the BABAR collaboration are presented, all using about 230 million B{bar B} events recorded on the {Upsilon}(4S) resonance with the BABAR detector at the SLAC e{sup +}e{sup -} storage rings PEP-II

Measurement and Interpretation of Moments of the Combined Hadronic Mass and Energy Spectrum in Inclusive Semileptonic B-Meson Decays

This thesis presents first measurements of moments of the hadronic n{sub X}{sup 2} distribution measured in inclusive semileptonic decays of B mesons to final states containing a charm quark, B {yields} X{sub c}{ell}{nu}. The variable n{sub X}{sup 2} is a combination of the invariant mass of the charmed meson m{sub X}, its energy in the B-meson rest-frame E{sub X;BRF}, and a constant {tilde {Lambda}} = 0.65 GeV, n{sub X}{sup 2} = m{sub X}{sup 2}c{sup 4}-2{tilde {Lambda}}E{sub X,BRF} + {tilde {Lambda}}{sup 2}. The moments <n{sub X}{sup k}> with k = 2,4,6 are measured as proposed by theory to constrain assumptions made in the theoretical description of inclusive observables in semileptonic B-meson decays. This description uses Heavy Quark Expansion (HQE), an effective QCD combined with an Operator Product Expansion. The measurement is based on a sample of 231.6 million e{sup +}e{sup -} {yields} {Upsilon}(4S) {yields} B{bar B} events recorded with the BABAR experiment at the PEP-II e{sup +}e{sup -}-storage rings at SLAC. We reconstruct the semileptonic decay by identifying a charged lepton in events tagged by a fully reconstructed hadronic decay of the second B meson. Correction procedures are derived from Monte Carlo simulations to ensure an unbiased measurement of the moments of the n{sub X}{sup 2} distribution. All moments are measured requiring minimum lepton momenta between 0.8 GeV/c and 1.9 GeV/c in the rest frame of the B meson. Performing a simultaneous fit to the measured moments <n{sub X}{sup k}> up to order k = 6 combined with other measurements of moments of the lepton-energy spectrum in decays B {yields} X{sub c}{ell}{nu} and moments of the photon-energy spectrum in decays B {yields} X{sub s}{gamma}, we determine the quark-mixing parameter |V{sub cb}|, the bottom and charm quark masses, the semileptonic branching fraction {Beta}(B {yields} X{sub c}{ell}{nu}), and four non-perturbative heavy quark parameters. Using HQE calculations in the kinetic scheme up to order 1/m{sub b}{sup 3} we find |V{sub cb}| = (41.65 {+-} 0.43 {+-} 0.40 {+-} 0.58) {center_dot} 10{sup -3} and m{sub b} = (4.570 {+-} 0.033 {+-} 0.043) GeV/c{sup 2}, where the first uncertainty refers to experimental contributions, the second to uncertainties in the HQE, and the third to theoretical uncertainties in the calculations of the semileptonic decay rate {Lambda}(B {yields} X{sub c}{ell}{nu}). All obtained results are consistent with previous determinations. The inclusion of the moments <n{sub X}{sup 6}> decreases the uncertainty on the HQE parameters {mu}{sub {pi}}{sup 2} and {rho}{sub D}{sup 3}. Furthermore, the theoretical treatment of higher order corrections in the HQE used for the moments <m{sub X}{sup k}> has been verified with these new measurements

Measurement and Interpretation of Moments of the Combined Hadronic Mass and Energy Spectrum in Inclusive Semileptonic B-meson Decays

This thesis presents first measurements of moments of the hadronic n_X^2 distribution measured in inclusive semileptonic decays of B mesons to final states containing a charm quark, B->Xc l nu. The variable n_X^2 is a combination of the invariant mass of the charmed meson m_X, its energy in the B-meson rest-frame E_X, and a constant \tilde{\Lambda} = 0.65 GeV, n_X^2 = m_X^2 c^4 - 2 \tilde{\Lambda} E_X + \tilde{\Lambda}^2. The moments <n_X^k> with k=2,4,6 are measured as proposed by theory to constrain assumptions made in the theoretical description of inclusive observables in semileptonic B-meson decays. This description uses Heavy Quark Expansion (HQE), an effective QCD combined with an Operator Product Expansion. The measurement is based on a sample of 231.6 million e+e- -> Y(4S) -> B\bar{B} events recorded with the BABAR experiment at the PEP-II e+e--storage rings at SLAC. We reconstruct the semileptonic decay by identifying a charged lepton in events tagged by a fully reconstructed hadronic decay of the second B meson. Correction procedures are derived from Monte Carlo simulations to ensure an unbiased measurement of the moments of the n_X^2 distribution. All moments are measured requiring minimum lepton momenta between 0.8 GeV/c and 1.9 GeV/c in the rest frame of the B meson. Performing a simultaneous fit to the measured moments <n_X^k> up to order k=6 combined with other measurements of moments of the lepton-energy spectrum in decays B->Xc l nu and moments of the photon-energy spectrum in decays B->Xs gamma, we determine the quark-mixing parameter |V_{cb}|, the bottom and charm quark masses, the semileptonic branching fraction BR(B->X l nu), and four non-perturbative heavy quark parameters. Using HQE calculations in the kinetic scheme up to order 1/m_b^3 we find |V_{cb}| = (41.65 +- 0.43 +- 0.40 +- 0.58) x 10^{-3} and m_b = (4.570 \pm 0.033 \pm 0.043)GeV/c^2, where the first uncertainty refers to experimental contributions, the second to uncertainties in the HQE, and the third to theoretical uncertainties in the calculations of the semileptonic decay rate. All obtained results are consistent with previous determinations. The inclusion of the moments <n_X^6> decreases the uncertainty on the HQE parameters mu_{pi} and rho_{D}. Furthermore, the theoretical treatment of higher order corrections in the HQE used for the moments <m_X^k> has been verified with these new measurements